/mandos/trunk : revision 24.1.174

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* "browse_callback", and parts of "main".

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*

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* Everything else is

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*

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* This program is free software: you can redistribute it and/or

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* modify it under the terms of the GNU General Public License as

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* along with this program. If not, see

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* <http://www.gnu.org/licenses/>.

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*

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* Contact the authors at <mandos@recompile.se>.

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* Contact the authors at <mandos@fukt.bsnet.se>.

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*/

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/* Needed by GPGME, specifically gpgme_data_seek() */

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#ifndef _LARGEFILE_SOURCE

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#define _LARGEFILE_SOURCE

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#endif /* not _LARGEFILE_SOURCE */

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#endif

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#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

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#endif /* not _FILE_OFFSET_BITS */

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#endif

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#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

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#include <stdio.h> /* fprintf(), stderr, fwrite(),

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stdout, ferror() */

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#include <stdint.h> /* uint16_t, uint32_t, intptr_t */

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stdout, ferror(), remove() */

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#include <stdint.h> /* uint16_t, uint32_t */

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#include <stddef.h> /* NULL, size_t, ssize_t */

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#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),

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strtof(), abort() */

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sockaddr_in6, PF_INET6,

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SOCK_STREAM, uid_t, gid_t, open(),

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opendir(), DIR */

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#include <sys/stat.h> /* open(), S_ISREG */

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#include <sys/stat.h> /* open() */

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#include <sys/socket.h> /* socket(), struct sockaddr_in6,

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inet_pton(), connect(),

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getnameinfo() */

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#include <fcntl.h> /* open(), unlinkat() */

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inet_pton(), connect() */

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#include <fcntl.h> /* open() */

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#include <dirent.h> /* opendir(), struct dirent, readdir()

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*/

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#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,

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strtoimax() */

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#include <errno.h> /* perror(), errno,

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program_invocation_short_name */

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#include <assert.h> /* assert() */

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#include <errno.h> /* perror(), errno, program_invocation_short_name */

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#include <time.h> /* nanosleep(), time(), sleep() */

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#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,

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SIOCSIFFLAGS, if_indextoname(),

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*/

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#include <unistd.h> /* close(), SEEK_SET, off_t, write(),

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getuid(), getgid(), seteuid(),

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setgid(), pause(), _exit(),

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unlinkat() */

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#include <arpa/inet.h> /* inet_pton(), htons() */

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setgid(), pause() */

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#include <arpa/inet.h> /* inet_pton(), htons */

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#include <iso646.h> /* not, or, and */

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#include <argp.h> /* struct argp_option, error_t, struct

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argp_state, struct argp,

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raise() */

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#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,

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EX_NOHOST, EX_IOERR, EX_PROTOCOL */

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#include <sys/wait.h> /* waitpid(), WIFEXITED(),

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WEXITSTATUS(), WTERMSIG() */

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#include <grp.h> /* setgroups() */

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#include <argz.h> /* argz_add_sep(), argz_next(),

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

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argz_count() */

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#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,

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EAI_SYSTEM, gai_strerror() */

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#ifdef __linux__

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#include <sys/klog.h> /* klogctl() */

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init_gnutls_session(),

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GNUTLS_* */

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#include <gnutls/openpgp.h>

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/* gnutls_certificate_set_openpgp_key_file(),

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GNUTLS_OPENPGP_FMT_BASE64 */

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/* gnutls_certificate_set_openpgp_key_file(),

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GNUTLS_OPENPGP_FMT_BASE64 */

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/* GPGME */

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#include <gpgme.h> /* All GPGME types, constants and

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#define PATHDIR "/conf/conf.d/mandos"

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#define SECKEY "seckey.txt"

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#define PUBKEY "pubkey.txt"

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#define HOOKDIR "/lib/mandos/network-hooks.d"

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bool debug = false;

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static const char mandos_protocol_version[] = "1";

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const char *argp_program_version = "mandos-client " VERSION;

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const char *argp_program_bug_address = "<mandos@recompile.se>";

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const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";

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static const char sys_class_net[] = "/sys/class/net";

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char *connect_to = NULL;

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const char *hookdir = HOOKDIR;

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int hookdir_fd = -1;

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uid_t uid = 65534;

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gid_t gid = 65534;

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/* Doubly linked list that need to be circularly linked when used */

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/* Doubly linked list that need to be circular linked when ever used */

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typedef struct server{

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const char *ip;

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in_port_t port;

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uint16_t port;

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AvahiIfIndex if_index;

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int af;

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struct timespec last_seen;

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/* Used for passing in values through the Avahi callback functions */

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typedef struct {

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AvahiSimplePoll *simple_poll;

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AvahiServer *server;

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gnutls_certificate_credentials_t cred;

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unsigned int dh_bits;

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const char *priority;

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gpgme_ctx_t ctx;

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server *current_server;

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char *interfaces;

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size_t interfaces_size;

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} mandos_context;

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/* global so signal handler can reach it*/

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AvahiSimplePoll *simple_poll;

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/* global context so signal handler can reach it*/

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mandos_context mc = { .simple_poll = NULL, .server = NULL,

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.dh_bits = 1024, .priority = "SECURE256"

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":!CTYPE-X.509:+CTYPE-OPENPGP", .current_server = NULL };

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sig_atomic_t quit_now = 0;

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int signal_received = 0;

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/* Function to use when printing errors */

180

165

void perror_plus(const char *print_text){

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int e = errno;

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fprintf(stderr, "Mandos plugin %s: ",

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program_invocation_short_name);

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errno = e;

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fprintf(stderr, "Mandos plugin %s: ", program_invocation_short_name);

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perror(print_text);

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}

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__attribute__((format (gnu_printf, 2, 3), nonnull))

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int fprintf_plus(FILE *stream, const char *format, ...){

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va_list ap;

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va_start (ap, format);

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TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",

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program_invocation_short_name));

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return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));

196

}

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/*

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* Make additional room in "buffer" for at least BUFFER_SIZE more

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* bytes. "buffer_capacity" is how much is currently allocated,

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* "buffer_length" is how much is already used.

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174

*/

203

__attribute__((nonnull, warn_unused_result))

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175

size_t incbuffer(char **buffer, size_t buffer_length,

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size_t buffer_capacity){

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size_t buffer_capacity){

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if(buffer_length + BUFFER_SIZE > buffer_capacity){

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char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

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if(new_buf == NULL){

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int old_errno = errno;

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free(*buffer);

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errno = old_errno;

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*buffer = NULL;

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*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

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if(buffer == NULL){

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180

return 0;

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}

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*buffer = new_buf;

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182

buffer_capacity += BUFFER_SIZE;

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183

}

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return buffer_capacity;

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}

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/* Add server to set of servers to retry periodically */

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__attribute__((nonnull, warn_unused_result))

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bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,

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int af, server **current_server){

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int add_server(const char *ip, uint16_t port,

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AvahiIfIndex if_index,

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int af){

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190

int ret;

226

191

server *new_server = malloc(sizeof(server));

227

192

if(new_server == NULL){

228

193

perror_plus("malloc");

229

return false;

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return -1;

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195

}

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*new_server = (server){ .ip = strdup(ip),

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.port = port,

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.if_index = if_index,

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.af = af };

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.port = port,

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.if_index = if_index,

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.af = af };

235

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if(new_server->ip == NULL){

236

201

perror_plus("strdup");

237

free(new_server);

238

return false;

239

}

240

ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));

241

if(ret == -1){

242

perror_plus("clock_gettime");

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#ifdef __GNUC__

244

#pragma GCC diagnostic push

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#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

free((char *)(new_server->ip));

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#ifdef __GNUC__

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#pragma GCC diagnostic pop

250

#endif

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free(new_server);

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return false;

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}

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/* Special case of first server */

255

if(*current_server == NULL){

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return -1;

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}

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/* uniqe case of first server */

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if (mc.current_server == NULL){

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206

new_server->next = new_server;

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new_server->prev = new_server;

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*current_server = new_server;

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mc.current_server = new_server;

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/* Placing the new server last in the list */

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} else {

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/* Place the new server last in the list */

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new_server->next = *current_server;

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new_server->prev = (*current_server)->prev;

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new_server->next = mc.current_server;

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new_server->prev = mc.current_server->prev;

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new_server->prev->next = new_server;

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(*current_server)->prev = new_server;

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}

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return true;

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mc.current_server->prev = new_server;

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}

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ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);

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if(ret == -1){

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perror_plus("clock_gettime");

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return -1;

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}

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return 0;

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}

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/*

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* Initialize GPGME.

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*/

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__attribute__((nonnull, warn_unused_result))

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static bool init_gpgme(const char * const seckey,

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const char * const pubkey,

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const char * const tempdir,

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mandos_context *mc){

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static bool init_gpgme(const char *seckey,

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const char *pubkey, const char *tempdir){

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gpgme_error_t rc;

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gpgme_engine_info_t engine_info;

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/*

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* Helper function to insert pub and seckey to the engine keyring.

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*/

283

bool import_key(const char * const filename){

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bool import_key(const char *filename){

284

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int ret;

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int fd;

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gpgme_data_t pgp_data;

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rc = gpgme_data_new_from_fd(&pgp_data, fd);

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if(rc != GPG_ERR_NO_ERROR){

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fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

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fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

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return false;

299

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}

300

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rc = gpgme_op_import(mc->ctx, pgp_data);

254

rc = gpgme_op_import(mc.ctx, pgp_data);

302

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if(rc != GPG_ERR_NO_ERROR){

303

fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

256

fprintf(stderr, "bad gpgme_op_import: %s: %s\n",

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gpgme_strsource(rc), gpgme_strerror(rc));

305

258

return false;

306

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}

307

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267

}

315

268

316

269

if(debug){

317

fprintf_plus(stderr, "Initializing GPGME\n");

270

fprintf(stderr, "Initializing GPGME\n");

318

271

}

319

272

320

273

/* Init GPGME */

321

274

gpgme_check_version(NULL);

322

275

rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

323

276

if(rc != GPG_ERR_NO_ERROR){

324

fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",

325

gpgme_strsource(rc), gpgme_strerror(rc));

277

fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",

278

gpgme_strsource(rc), gpgme_strerror(rc));

326

279

return false;

327

280

}

328

281

329

/* Set GPGME home directory for the OpenPGP engine only */

282

/* Set GPGME home directory for the OpenPGP engine only */

330

283

rc = gpgme_get_engine_info(&engine_info);

331

284

if(rc != GPG_ERR_NO_ERROR){

332

fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",

333

gpgme_strsource(rc), gpgme_strerror(rc));

285

fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",

286

gpgme_strsource(rc), gpgme_strerror(rc));

334

287

return false;

335

288

}

336

289

while(engine_info != NULL){

342

295

engine_info = engine_info->next;

343

296

}

344

297

if(engine_info == NULL){

345

fprintf_plus(stderr, "Could not set GPGME home dir to %s\n",

346

tempdir);

298

fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);

347

299

return false;

348

300

}

349

301

350

302

/* Create new GPGME "context" */

351

rc = gpgme_new(&(mc->ctx));

303

rc = gpgme_new(&(mc.ctx));

352

304

if(rc != GPG_ERR_NO_ERROR){

353

fprintf_plus(stderr, "Mandos plugin mandos-client: "

354

"bad gpgme_new: %s: %s\n", gpgme_strsource(rc),

355

gpgme_strerror(rc));

305

fprintf(stderr, "bad gpgme_new: %s: %s\n",

306

gpgme_strsource(rc), gpgme_strerror(rc));

356

307

return false;

357

308

}

358

309

367

318

* Decrypt OpenPGP data.

368

319

* Returns -1 on error

369

320

*/

370

__attribute__((nonnull, warn_unused_result))

371

321

static ssize_t pgp_packet_decrypt(const char *cryptotext,

372

322

size_t crypto_size,

373

char **plaintext,

374

mandos_context *mc){

323

char **plaintext){

375

324

gpgme_data_t dh_crypto, dh_plain;

376

325

gpgme_error_t rc;

377

326

ssize_t ret;

379

328

ssize_t plaintext_length = 0;

380

329

381

330

if(debug){

382

fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");

331

fprintf(stderr, "Trying to decrypt OpenPGP data\n");

383

332

}

384

333

385

334

/* Create new GPGME data buffer from memory cryptotext */

386

335

rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,

387

336

0);

388

337

if(rc != GPG_ERR_NO_ERROR){

389

fprintf_plus(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",

390

gpgme_strsource(rc), gpgme_strerror(rc));

338

fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",

339

gpgme_strsource(rc), gpgme_strerror(rc));

391

340

return -1;

392

341

}

393

342

394

343

/* Create new empty GPGME data buffer for the plaintext */

395

344

rc = gpgme_data_new(&dh_plain);

396

345

if(rc != GPG_ERR_NO_ERROR){

397

fprintf_plus(stderr, "Mandos plugin mandos-client: "

398

"bad gpgme_data_new: %s: %s\n",

399

gpgme_strsource(rc), gpgme_strerror(rc));

346

fprintf(stderr, "bad gpgme_data_new: %s: %s\n",

347

gpgme_strsource(rc), gpgme_strerror(rc));

400

348

gpgme_data_release(dh_crypto);

401

349

return -1;

402

350

}

403

351

404

352

/* Decrypt data from the cryptotext data buffer to the plaintext

405

353

data buffer */

406

rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);

354

rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);

407

355

if(rc != GPG_ERR_NO_ERROR){

408

fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",

409

gpgme_strsource(rc), gpgme_strerror(rc));

356

fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",

357

gpgme_strsource(rc), gpgme_strerror(rc));

410

358

plaintext_length = -1;

411

359

if(debug){

412

360

gpgme_decrypt_result_t result;

413

result = gpgme_op_decrypt_result(mc->ctx);

361

result = gpgme_op_decrypt_result(mc.ctx);

414

362

if(result == NULL){

415

fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");

363

fprintf(stderr, "gpgme_op_decrypt_result failed\n");

416

364

} else {

417

fprintf_plus(stderr, "Unsupported algorithm: %s\n",

418

result->unsupported_algorithm);

419

fprintf_plus(stderr, "Wrong key usage: %u\n",

420

result->wrong_key_usage);

365

fprintf(stderr, "Unsupported algorithm: %s\n",

366

result->unsupported_algorithm);

367

fprintf(stderr, "Wrong key usage: %u\n",

368

result->wrong_key_usage);

421

369

if(result->file_name != NULL){

422

fprintf_plus(stderr, "File name: %s\n", result->file_name);

370

fprintf(stderr, "File name: %s\n", result->file_name);

423

371

}

424

372

gpgme_recipient_t recipient;

425

373

recipient = result->recipients;

426

374

while(recipient != NULL){

427

fprintf_plus(stderr, "Public key algorithm: %s\n",

428

gpgme_pubkey_algo_name

429

(recipient->pubkey_algo));

430

fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);

431

fprintf_plus(stderr, "Secret key available: %s\n",

432

recipient->status == GPG_ERR_NO_SECKEY

433

? "No" : "Yes");

375

fprintf(stderr, "Public key algorithm: %s\n",

376

gpgme_pubkey_algo_name(recipient->pubkey_algo));

377

fprintf(stderr, "Key ID: %s\n", recipient->keyid);

378

fprintf(stderr, "Secret key available: %s\n",

379

recipient->status == GPG_ERR_NO_SECKEY

380

? "No" : "Yes");

434

381

recipient = recipient->next;

435

382

}

436

383

}

439

386

}

440

387

441

388

if(debug){

442

fprintf_plus(stderr, "Decryption of OpenPGP data succeeded\n");

389

fprintf(stderr, "Decryption of OpenPGP data succeeded\n");

443

390

}

444

391

445

392

/* Seek back to the beginning of the GPGME plaintext data buffer */

452

399

*plaintext = NULL;

453

400

while(true){

454

401

plaintext_capacity = incbuffer(plaintext,

455

(size_t)plaintext_length,

456

plaintext_capacity);

402

(size_t)plaintext_length,

403

plaintext_capacity);

457

404

if(plaintext_capacity == 0){

458

perror_plus("incbuffer");

459

plaintext_length = -1;

460

goto decrypt_end;

405

perror_plus("incbuffer");

406

plaintext_length = -1;

407

goto decrypt_end;

461

408

}

462

409

463

410

ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,

476

423

}

477

424

478

425

if(debug){

479

fprintf_plus(stderr, "Decrypted password is: ");

426

fprintf(stderr, "Decrypted password is: ");

480

427

for(ssize_t i = 0; i < plaintext_length; i++){

481

428

fprintf(stderr, "%02hhX ", (*plaintext)[i]);

482

429

}

493

440

return plaintext_length;

494

441

}

495

442

496

__attribute__((warn_unused_result, const))

497

static const char *safe_string(const char *str){

498

if(str == NULL)

499

return "(unknown)";

500

return str;

501

}

502

503

__attribute__((warn_unused_result))

504

static const char *safer_gnutls_strerror(int value){

505

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

443

static const char * safer_gnutls_strerror(int value){

444

const char *ret = gnutls_strerror(value); /* Spurious warning from

445

-Wunreachable-code */

446

if(ret == NULL)

447

ret = "(unknown)";

448

return ret;

507

449

}

508

450

509

451

/* GnuTLS log function callback */

510

__attribute__((nonnull))

511

452

static void debuggnutls(__attribute__((unused)) int level,

512

453

const char* string){

513

fprintf_plus(stderr, "GnuTLS: %s", string);

454

fprintf(stderr, "GnuTLS: %s", string);

514

455

}

515

456

516

__attribute__((nonnull, warn_unused_result))

517

457

static int init_gnutls_global(const char *pubkeyfilename,

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

mandos_context *mc){

458

const char *seckeyfilename){

521

459

int ret;

522

unsigned int uret;

523

460

524

461

if(debug){

525

fprintf_plus(stderr, "Initializing GnuTLS\n");

462

fprintf(stderr, "Initializing GnuTLS\n");

526

463

}

527

464

528

465

ret = gnutls_global_init();

529

466

if(ret != GNUTLS_E_SUCCESS){

530

fprintf_plus(stderr, "GnuTLS global_init: %s\n",

531

safer_gnutls_strerror(ret));

467

fprintf(stderr, "GnuTLS global_init: %s\n",

468

safer_gnutls_strerror(ret));

532

469

return -1;

533

470

}

534

471

541

478

}

542

479

543

480

/* OpenPGP credentials */

544

ret = gnutls_certificate_allocate_credentials(&mc->cred);

481

gnutls_certificate_allocate_credentials(&mc.cred);

545

482

if(ret != GNUTLS_E_SUCCESS){

546

fprintf_plus(stderr, "GnuTLS memory error: %s\n",

547

safer_gnutls_strerror(ret));

483

fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning

484

from

485

-Wunreachable-code

486

*/

487

safer_gnutls_strerror(ret));

548

488

gnutls_global_deinit();

549

489

return -1;

550

490

}

551

491

552

492

if(debug){

553

fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"

554

" secret key %s as GnuTLS credentials\n",

555

pubkeyfilename,

556

seckeyfilename);

493

fprintf(stderr, "Attempting to use OpenPGP public key %s and"

494

" secret key %s as GnuTLS credentials\n", pubkeyfilename,

495

seckeyfilename);

557

496

}

558

497

559

498

ret = gnutls_certificate_set_openpgp_key_file

560

(mc->cred, pubkeyfilename, seckeyfilename,

499

(mc.cred, pubkeyfilename, seckeyfilename,

561

500

GNUTLS_OPENPGP_FMT_BASE64);

562

501

if(ret != GNUTLS_E_SUCCESS){

563

fprintf_plus(stderr,

564

"Error[%d] while reading the OpenPGP key pair ('%s',"

565

" '%s')\n", ret, pubkeyfilename, seckeyfilename);

566

fprintf_plus(stderr, "The GnuTLS error is: %s\n",

567

safer_gnutls_strerror(ret));

502

fprintf(stderr,

503

"Error[%d] while reading the OpenPGP key pair ('%s',"

504

" '%s')\n", ret, pubkeyfilename, seckeyfilename);

505

fprintf(stderr, "The GnuTLS error is: %s\n",

506

safer_gnutls_strerror(ret));

568

507

goto globalfail;

569

508

}

570

509

571

510

/* GnuTLS server initialization */

572

ret = gnutls_dh_params_init(&mc->dh_params);

573

if(ret != GNUTLS_E_SUCCESS){

574

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

575

" initialization: %s\n",

576

safer_gnutls_strerror(ret));

577

goto globalfail;

578

}

579

/* If a Diffie-Hellman parameters file was given, try to use it */

580

if(dhparamsfilename != NULL){

581

gnutls_datum_t params = { .data = NULL, .size = 0 };

582

do {

583

int dhpfile = open(dhparamsfilename, O_RDONLY);

584

if(dhpfile == -1){

585

perror_plus("open");

586

dhparamsfilename = NULL;

587

break;

588

}

589

size_t params_capacity = 0;

590

while(true){

591

params_capacity = incbuffer((char **)&params.data,

592

(size_t)params.size,

593

(size_t)params_capacity);

594

if(params_capacity == 0){

595

perror_plus("incbuffer");

596

free(params.data);

597

params.data = NULL;

598

dhparamsfilename = NULL;

599

break;

600

}

601

ssize_t bytes_read = read(dhpfile,

602

params.data + params.size,

603

BUFFER_SIZE);

604

/* EOF */

605

if(bytes_read == 0){

606

break;

607

}

608

/* check bytes_read for failure */

609

if(bytes_read < 0){

610

perror_plus("read");

611

free(params.data);

612

params.data = NULL;

613

dhparamsfilename = NULL;

614

break;

615

}

616

params.size += (unsigned int)bytes_read;

617

}

618

if(params.data == NULL){

619

dhparamsfilename = NULL;

620

}

621

if(dhparamsfilename == NULL){

622

break;

623

}

624

ret = gnutls_dh_params_import_pkcs3(mc->dh_params, &params,

625

GNUTLS_X509_FMT_PEM);

626

if(ret != GNUTLS_E_SUCCESS){

627

fprintf_plus(stderr, "Failed to parse DH parameters in file"

628

" \"%s\": %s\n", dhparamsfilename,

629

safer_gnutls_strerror(ret));

630

dhparamsfilename = NULL;

631

}

632

} while(false);

633

}

634

if(dhparamsfilename == NULL){

635

if(mc->dh_bits == 0){

636

/* Find out the optimal number of DH bits */

637

/* Try to read the private key file */

638

gnutls_datum_t buffer = { .data = NULL, .size = 0 };

639

do {

640

int secfile = open(seckeyfilename, O_RDONLY);

641

if(secfile == -1){

642

perror_plus("open");

643

break;

644

}

645

size_t buffer_capacity = 0;

646

while(true){

647

buffer_capacity = incbuffer((char **)&buffer.data,

648

(size_t)buffer.size,

649

(size_t)buffer_capacity);

650

if(buffer_capacity == 0){

651

perror_plus("incbuffer");

652

free(buffer.data);

653

buffer.data = NULL;

654

break;

655

}

656

ssize_t bytes_read = read(secfile,

657

buffer.data + buffer.size,

658

BUFFER_SIZE);

659

/* EOF */

660

if(bytes_read == 0){

661

break;

662

}

663

/* check bytes_read for failure */

664

if(bytes_read < 0){

665

perror_plus("read");

666

free(buffer.data);

667

buffer.data = NULL;

668

break;

669

}

670

buffer.size += (unsigned int)bytes_read;

671

}

672

close(secfile);

673

} while(false);

674

/* If successful, use buffer to parse private key */

675

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

676

if(buffer.data != NULL){

677

{

678

gnutls_openpgp_privkey_t privkey = NULL;

679

ret = gnutls_openpgp_privkey_init(&privkey);

680

if(ret != GNUTLS_E_SUCCESS){

681

fprintf_plus(stderr, "Error initializing OpenPGP key"

682

" structure: %s",

683

safer_gnutls_strerror(ret));

684

free(buffer.data);

685

buffer.data = NULL;

686

} else {

687

ret = gnutls_openpgp_privkey_import

688

(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);

689

if(ret != GNUTLS_E_SUCCESS){

690

fprintf_plus(stderr, "Error importing OpenPGP key : %s",

691

safer_gnutls_strerror(ret));

692

privkey = NULL;

693

}

694

free(buffer.data);

695

buffer.data = NULL;

696

if(privkey != NULL){

697

/* Use private key to suggest an appropriate

698

sec_param */

699

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

700

gnutls_openpgp_privkey_deinit(privkey);

701

if(debug){

702

fprintf_plus(stderr, "This OpenPGP key implies using"

703

" a GnuTLS security parameter \"%s\".\n",

704

safe_string(gnutls_sec_param_get_name

705

(sec_param)));

706

}

707

}

708

}

709

}

710

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

711

/* Err on the side of caution */

712

sec_param = GNUTLS_SEC_PARAM_ULTRA;

713

if(debug){

714

fprintf_plus(stderr, "Falling back to security parameter"

715

" \"%s\"\n",

716

safe_string(gnutls_sec_param_get_name

717

(sec_param)));

718

}

719

}

720

}

721

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

722

if(uret != 0){

723

mc->dh_bits = uret;

724

if(debug){

725

fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"

726

" implies %u DH bits; using that.\n",

727

safe_string(gnutls_sec_param_get_name

728

(sec_param)),

729

mc->dh_bits);

730

}

731

} else {

732

fprintf_plus(stderr, "Failed to get implied number of DH"

733

" bits for security parameter \"%s\"): %s\n",

734

safe_string(gnutls_sec_param_get_name

735

(sec_param)),

736

safer_gnutls_strerror(ret));

737

goto globalfail;

738

}

739

} else if(debug){

740

fprintf_plus(stderr, "DH bits explicitly set to %u\n",

741

mc->dh_bits);

742

}

743

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

744

if(ret != GNUTLS_E_SUCCESS){

745

fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"

746

" bits): %s\n", mc->dh_bits,

747

safer_gnutls_strerror(ret));

748

goto globalfail;

749

}

750

}

751

gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);

511

ret = gnutls_dh_params_init(&mc.dh_params);

512

if(ret != GNUTLS_E_SUCCESS){

513

fprintf(stderr, "Error in GnuTLS DH parameter initialization:"

514

" %s\n", safer_gnutls_strerror(ret));

515

goto globalfail;

516

}

517

ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);

518

if(ret != GNUTLS_E_SUCCESS){

519

fprintf(stderr, "Error in GnuTLS prime generation: %s\n",

520

safer_gnutls_strerror(ret));

521

goto globalfail;

522

}

523

524

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

752

525

753

526

return 0;

754

527

755

528

globalfail:

756

529

757

gnutls_certificate_free_credentials(mc->cred);

530

gnutls_certificate_free_credentials(mc.cred);

758

531

gnutls_global_deinit();

759

gnutls_dh_params_deinit(mc->dh_params);

532

gnutls_dh_params_deinit(mc.dh_params);

760

533

return -1;

761

534

}

762

535

763

__attribute__((nonnull, warn_unused_result))

764

static int init_gnutls_session(gnutls_session_t *session,

765

mandos_context *mc){

536

static int init_gnutls_session(gnutls_session_t *session){

766

537

int ret;

767

538

/* GnuTLS session creation */

768

539

do {

772

543

}

773

544

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

774

545

if(ret != GNUTLS_E_SUCCESS){

775

fprintf_plus(stderr,

776

"Error in GnuTLS session initialization: %s\n",

777

safer_gnutls_strerror(ret));

546

fprintf(stderr, "Error in GnuTLS session initialization: %s\n",

547

safer_gnutls_strerror(ret));

778

548

}

779

549

780

550

{

781

551

const char *err;

782

552

do {

783

ret = gnutls_priority_set_direct(*session, mc->priority, &err);

553

ret = gnutls_priority_set_direct(*session, mc.priority, &err);

784

554

if(quit_now){

785

555

gnutls_deinit(*session);

786

556

return -1;

787

557

}

788

558

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

789

559

if(ret != GNUTLS_E_SUCCESS){

790

fprintf_plus(stderr, "Syntax error at: %s\n", err);

791

fprintf_plus(stderr, "GnuTLS error: %s\n",

792

safer_gnutls_strerror(ret));

560

fprintf(stderr, "Syntax error at: %s\n", err);

561

fprintf(stderr, "GnuTLS error: %s\n",

562

safer_gnutls_strerror(ret));

793

563

gnutls_deinit(*session);

794

564

return -1;

795

565

}

797

567

798

568

do {

799

569

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

800

mc->cred);

570

mc.cred);

801

571

if(quit_now){

802

572

gnutls_deinit(*session);

803

573

return -1;

804

574

}

805

575

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

806

576

if(ret != GNUTLS_E_SUCCESS){

807

fprintf_plus(stderr, "Error setting GnuTLS credentials: %s\n",

808

safer_gnutls_strerror(ret));

577

fprintf(stderr, "Error setting GnuTLS credentials: %s\n",

578

safer_gnutls_strerror(ret));

809

579

gnutls_deinit(*session);

810

580

return -1;

811

581

}

813

583

/* ignore client certificate if any. */

814

584

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

815

585

586

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

587

816

588

return 0;

817

589

}

818

590

820

592

static void empty_log(__attribute__((unused)) AvahiLogLevel level,

821

593

__attribute__((unused)) const char *txt){}

822

594

823

/* Set effective uid to 0, return errno */

824

__attribute__((warn_unused_result))

825

error_t raise_privileges(void){

826

error_t old_errno = errno;

827

error_t ret_errno = 0;

828

if(seteuid(0) == -1){

829

ret_errno = errno;

830

}

831

errno = old_errno;

832

return ret_errno;

833

}

834

835

/* Set effective and real user ID to 0. Return errno. */

836

__attribute__((warn_unused_result))

837

error_t raise_privileges_permanently(void){

838

error_t old_errno = errno;

839

error_t ret_errno = raise_privileges();

840

if(ret_errno != 0){

841

errno = old_errno;

842

return ret_errno;

843

}

844

if(setuid(0) == -1){

845

ret_errno = errno;

846

}

847

errno = old_errno;

848

return ret_errno;

849

}

850

851

/* Set effective user ID to unprivileged saved user ID */

852

__attribute__((warn_unused_result))

853

error_t lower_privileges(void){

854

error_t old_errno = errno;

855

error_t ret_errno = 0;

856

if(seteuid(uid) == -1){

857

ret_errno = errno;

858

}

859

errno = old_errno;

860

return ret_errno;

861

}

862

863

/* Lower privileges permanently */

864

__attribute__((warn_unused_result))

865

error_t lower_privileges_permanently(void){

866

error_t old_errno = errno;

867

error_t ret_errno = 0;

868

if(setuid(uid) == -1){

869

ret_errno = errno;

870

}

871

errno = old_errno;

872

return ret_errno;

873

}

874

875

/* Helper function to add_local_route() and delete_local_route() */

876

__attribute__((nonnull, warn_unused_result))

877

static bool add_delete_local_route(const bool add,

878

const char *address,

879

AvahiIfIndex if_index){

880

int ret;

881

char helper[] = "mandos-client-iprouteadddel";

882

char add_arg[] = "add";

883

char delete_arg[] = "delete";

884

char debug_flag[] = "--debug";

885

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

886

if(pluginhelperdir == NULL){

887

if(debug){

888

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

889

" variable not set; cannot run helper\n");

890

}

891

return false;

892

}

893

894

char interface[IF_NAMESIZE];

895

if(if_indextoname((unsigned int)if_index, interface) == NULL){

896

perror_plus("if_indextoname");

897

return false;

898

}

899

900

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

901

if(devnull == -1){

902

perror_plus("open(\"/dev/null\", O_RDONLY)");

903

return false;

904

}

905

pid_t pid = fork();

906

if(pid == 0){

907

/* Child */

908

/* Raise privileges */

909

errno = raise_privileges_permanently();

910

if(errno != 0){

911

perror_plus("Failed to raise privileges");

912

/* _exit(EX_NOPERM); */

913

} else {

914

/* Set group */

915

errno = 0;

916

ret = setgid(0);

917

if(ret == -1){

918

perror_plus("setgid");

919

_exit(EX_NOPERM);

920

}

921

/* Reset supplementary groups */

922

errno = 0;

923

ret = setgroups(0, NULL);

924

if(ret == -1){

925

perror_plus("setgroups");

926

_exit(EX_NOPERM);

927

}

928

}

929

ret = dup2(devnull, STDIN_FILENO);

930

if(ret == -1){

931

perror_plus("dup2(devnull, STDIN_FILENO)");

932

_exit(EX_OSERR);

933

}

934

ret = (int)TEMP_FAILURE_RETRY(close(devnull));

935

if(ret == -1){

936

perror_plus("close");

937

_exit(EX_OSERR);

938

}

939

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

940

if(ret == -1){

941

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

942

_exit(EX_OSERR);

943

}

944

int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,

945

O_RDONLY

946

| O_DIRECTORY

947

| O_PATH

948

| O_CLOEXEC));

949

if(helperdir_fd == -1){

950

perror_plus("open");

951

_exit(EX_UNAVAILABLE);

952

}

953

int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,

954

helper, O_RDONLY));

955

if(helper_fd == -1){

956

perror_plus("openat");

957

_exit(EX_UNAVAILABLE);

958

}

959

TEMP_FAILURE_RETRY(close(helperdir_fd));

960

#ifdef __GNUC__

961

#pragma GCC diagnostic push

962

#pragma GCC diagnostic ignored "-Wcast-qual"

963

#endif

964

if(fexecve(helper_fd, (char *const [])

965

{ helper, add ? add_arg : delete_arg, (char *)address,

966

interface, debug ? debug_flag : NULL, NULL },

967

environ) == -1){

968

#ifdef __GNUC__

969

#pragma GCC diagnostic pop

970

#endif

971

perror_plus("fexecve");

972

_exit(EXIT_FAILURE);

973

}

974

}

975

if(pid == -1){

976

perror_plus("fork");

977

return false;

978

}

979

int status;

980

pid_t pret = -1;

981

errno = 0;

982

do {

983

pret = waitpid(pid, &status, 0);

984

if(pret == -1 and errno == EINTR and quit_now){

985

int errno_raising = 0;

986

if((errno = raise_privileges()) != 0){

987

errno_raising = errno;

988

perror_plus("Failed to raise privileges in order to"

989

" kill helper program");

990

}

991

if(kill(pid, SIGTERM) == -1){

992

perror_plus("kill");

993

}

994

if((errno_raising == 0) and (errno = lower_privileges()) != 0){

995

perror_plus("Failed to lower privileges after killing"

996

" helper program");

997

}

998

return false;

999

}

1000

} while(pret == -1 and errno == EINTR);

1001

if(pret == -1){

1002

perror_plus("waitpid");

1003

return false;

1004

}

1005

if(WIFEXITED(status)){

1006

if(WEXITSTATUS(status) != 0){

1007

fprintf_plus(stderr, "Error: iprouteadddel exited"

1008

" with status %d\n", WEXITSTATUS(status));

1009

return false;

1010

}

1011

return true;

1012

}

1013

if(WIFSIGNALED(status)){

1014

fprintf_plus(stderr, "Error: iprouteadddel died by"

1015

" signal %d\n", WTERMSIG(status));

1016

return false;

1017

}

1018

fprintf_plus(stderr, "Error: iprouteadddel crashed\n");

1019

return false;

1020

}

1021

1022

__attribute__((nonnull, warn_unused_result))

1023

static bool add_local_route(const char *address,

1024

AvahiIfIndex if_index){

1025

if(debug){

1026

fprintf_plus(stderr, "Adding route to %s\n", address);

1027

}

1028

return add_delete_local_route(true, address, if_index);

1029

}

1030

1031

__attribute__((nonnull, warn_unused_result))

1032

static bool delete_local_route(const char *address,

1033

AvahiIfIndex if_index){

1034

if(debug){

1035

fprintf_plus(stderr, "Removing route to %s\n", address);

1036

}

1037

return add_delete_local_route(false, address, if_index);

1038

}

1039

1040

595

/* Called when a Mandos server is found */

1041

__attribute__((nonnull, warn_unused_result))

1042

static int start_mandos_communication(const char *ip, in_port_t port,

596

static int start_mandos_communication(const char *ip, uint16_t port,

1043

597

AvahiIfIndex if_index,

1044

int af, mandos_context *mc){

598

int af){

1045

599

int ret, tcp_sd = -1;

1046

600

ssize_t sret;

1047

struct sockaddr_storage to;

601

union {

602

struct sockaddr_in in;

603

struct sockaddr_in6 in6;

604

} to;

1048

605

char *buffer = NULL;

1049

606

char *decrypted_buffer = NULL;

1050

607

size_t buffer_length = 0;

1053

610

int retval = -1;

1054

611

gnutls_session_t session;

1055

612

int pf; /* Protocol family */

1056

bool route_added = false;

1057

613

1058

614

errno = 0;

1059

615

1070

626

pf = PF_INET;

1071

627

break;

1072

628

default:

1073

fprintf_plus(stderr, "Bad address family: %d\n", af);

629

fprintf(stderr, "Bad address family: %d\n", af);

1074

630

errno = EINVAL;

1075

631

return -1;

1076

632

}

1077

633

1078

/* If the interface is specified and we have a list of interfaces */

1079

if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){

1080

/* Check if the interface is one of the interfaces we are using */

1081

bool match = false;

1082

{

1083

char *interface = NULL;

1084

while((interface=argz_next(mc->interfaces, mc->interfaces_size,

1085

interface))){

1086

if(if_nametoindex(interface) == (unsigned int)if_index){

1087

match = true;

1088

break;

1089

}

1090

}

1091

}

1092

if(not match){

1093

/* This interface does not match any in the list, so we don't

1094

connect to the server */

1095

if(debug){

1096

char interface[IF_NAMESIZE];

1097

if(if_indextoname((unsigned int)if_index, interface) == NULL){

1098

perror_plus("if_indextoname");

1099

} else {

1100

fprintf_plus(stderr, "Skipping server on non-used interface"

1101

" \"%s\"\n",

1102

if_indextoname((unsigned int)if_index,

1103

interface));

1104

}

1105

}

1106

return -1;

1107

}

1108

}

1109

1110

ret = init_gnutls_session(&session, mc);

634

ret = init_gnutls_session(&session);

1111

635

if(ret != 0){

1112

636

return -1;

1113

637

}

1114

638

1115

639

if(debug){

1116

fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"

1117

PRIuMAX "\n", ip, (uintmax_t)port);

640

fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16

641

"\n", ip, port);

1118

642

}

1119

643

1120

tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);

644

tcp_sd = socket(pf, SOCK_STREAM, 0);

1121

645

if(tcp_sd < 0){

1122

646

int e = errno;

1123

647

perror_plus("socket");

1132

656

1133

657

memset(&to, 0, sizeof(to));

1134

658

if(af == AF_INET6){

1135

((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;

1136

ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);

659

to.in6.sin6_family = (sa_family_t)af;

660

ret = inet_pton(af, ip, &to.in6.sin6_addr);

1137

661

} else { /* IPv4 */

1138

((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;

1139

ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);

662

to.in.sin_family = (sa_family_t)af;

663

ret = inet_pton(af, ip, &to.in.sin_addr);

1140

664

}

1141

665

if(ret < 0 ){

1142

666

int e = errno;

1146

670

}

1147

671

if(ret == 0){

1148

672

int e = errno;

1149

fprintf_plus(stderr, "Bad address: %s\n", ip);

673

fprintf(stderr, "Bad address: %s\n", ip);

1150

674

errno = e;

1151

675

goto mandos_end;

1152

676

}

1153

677

if(af == AF_INET6){

1154

((struct sockaddr_in6 *)&to)->sin6_port = htons(port);

1155

if(IN6_IS_ADDR_LINKLOCAL

1156

(&((struct sockaddr_in6 *)&to)->sin6_addr)){

678

to.in6.sin6_port = htons(port); /* Spurious warnings from

679

-Wconversion and

680

-Wunreachable-code */

681

682

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

683

(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and

684

-Wunreachable-code*/

1157

685

if(if_index == AVAHI_IF_UNSPEC){

1158

fprintf_plus(stderr, "An IPv6 link-local address is"

1159

" incomplete without a network interface\n");

686

fprintf(stderr, "An IPv6 link-local address is incomplete"

687

" without a network interface\n");

1160

688

errno = EINVAL;

1161

689

goto mandos_end;

1162

690

}

1163

691

/* Set the network interface number as scope */

1164

((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;

692

to.in6.sin6_scope_id = (uint32_t)if_index;

1165

693

}

1166

694

} else {

1167

((struct sockaddr_in *)&to)->sin_port = htons(port);

695

to.in.sin_port = htons(port); /* Spurious warnings from

696

-Wconversion and

697

-Wunreachable-code */

1168

698

}

1169

699

1170

700

if(quit_now){

1178

708

if(if_indextoname((unsigned int)if_index, interface) == NULL){

1179

709

perror_plus("if_indextoname");

1180

710

} else {

1181

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX

1182

"\n", ip, interface, (uintmax_t)port);

711

fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",

712

ip, interface, port);

1183

713

}

1184

714

} else {

1185

fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",

1186

ip, (uintmax_t)port);

715

fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,

716

port);

1187

717

}

1188

718

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1189

719

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1190

if(af == AF_INET6){

1191

ret = getnameinfo((struct sockaddr *)&to,

1192

sizeof(struct sockaddr_in6),

1193

addrstr, sizeof(addrstr), NULL, 0,

1194

NI_NUMERICHOST);

1195

} else {

1196

ret = getnameinfo((struct sockaddr *)&to,

1197

sizeof(struct sockaddr_in),

1198

addrstr, sizeof(addrstr), NULL, 0,

1199

NI_NUMERICHOST);

1200

}

1201

if(ret == EAI_SYSTEM){

1202

perror_plus("getnameinfo");

1203

} else if(ret != 0) {

1204

fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));

1205

} else if(strcmp(addrstr, ip) != 0){

1206

fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);

1207

}

1208

}

1209

1210

if(quit_now){

1211

errno = EINTR;

1212

goto mandos_end;

1213

}

1214

1215

while(true){

1216

if(af == AF_INET6){

1217

ret = connect(tcp_sd, (struct sockaddr *)&to,

1218

sizeof(struct sockaddr_in6));

1219

} else {

1220

ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */

1221

sizeof(struct sockaddr_in));

1222

}

1223

if(ret < 0){

1224

if(errno == ENETUNREACH

1225

and if_index != AVAHI_IF_UNSPEC

1226

and connect_to == NULL

1227

and not route_added and

1228

((af == AF_INET6 and not

1229

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1230

&to)->sin6_addr)))

1231

or (af == AF_INET and

1232

/* Not a a IPv4LL address */

1233

(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)

1234

& 0xFFFF0000L) != 0xA9FE0000L))){

1235

/* Work around Avahi bug - Avahi does not announce link-local

1236

addresses if it has a global address, so local hosts with

1237

*only* a link-local address (e.g. Mandos clients) cannot

1238

connect to a Mandos server announced by Avahi on a server

1239

host with a global address. Work around this by retrying

1240

with an explicit route added with the server's address.

1241

1242

Avahi bug reference:

1243

http://lists.freedesktop.org/archives/avahi/2010-February/001833.html

1244

https://bugs.debian.org/587961

1245

*/

1246

if(debug){

1247

fprintf_plus(stderr, "Mandos server unreachable, trying"

1248

" direct route\n");

1249

}

1250

int e = errno;

1251

route_added = add_local_route(ip, if_index);

1252

if(route_added){

1253

continue;

1254

}

1255

errno = e;

1256

}

1257

if(errno != ECONNREFUSED or debug){

1258

int e = errno;

1259

perror_plus("connect");

1260

errno = e;

1261

}

1262

goto mandos_end;

1263

}

1264

1265

if(quit_now){

1266

errno = EINTR;

1267

goto mandos_end;

1268

}

1269

break;

720

const char *pcret;

721

if(af == AF_INET6){

722

pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,

723

sizeof(addrstr));

724

} else {

725

pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,

726

sizeof(addrstr));

727

}

728

if(pcret == NULL){

729

perror_plus("inet_ntop");

730

} else {

731

if(strcmp(addrstr, ip) != 0){

732

fprintf(stderr, "Canonical address form: %s\n", addrstr);

733

}

734

}

735

}

736

737

if(quit_now){

738

errno = EINTR;

739

goto mandos_end;

740

}

741

742

if(af == AF_INET6){

743

ret = connect(tcp_sd, &to.in6, sizeof(to));

744

} else {

745

ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */

746

}

747

if(ret < 0){

748

if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){

749

int e = errno;

750

perror_plus("connect");

751

errno = e;

752

}

753

goto mandos_end;

754

}

755

756

if(quit_now){

757

errno = EINTR;

758

goto mandos_end;

1270

759

}

1271

760

1272

761

const char *out = mandos_protocol_version;

1274

763

while(true){

1275

764

size_t out_size = strlen(out);

1276

765

ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,

1277

out_size - written));

766

out_size - written));

1278

767

if(ret == -1){

1279

768

int e = errno;

1280

769

perror_plus("write");

1300

789

}

1301

790

1302

791

if(debug){

1303

fprintf_plus(stderr, "Establishing TLS session with %s\n", ip);

792

fprintf(stderr, "Establishing TLS session with %s\n", ip);

1304

793

}

1305

794

1306

795

if(quit_now){

1307

796

errno = EINTR;

1308

797

goto mandos_end;

1309

798

}

1310

1311

/* This casting via intptr_t is to eliminate warning about casting

1312

an int to a pointer type. This is exactly how the GnuTLS Guile

1313

function "set-session-transport-fd!" does it. */

1314

gnutls_transport_set_ptr(session,

1315

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

799

800

/* Spurious warnings from -Wint-to-pointer-cast */

801

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1316

802

1317

803

if(quit_now){

1318

804

errno = EINTR;

1329

815

1330

816

if(ret != GNUTLS_E_SUCCESS){

1331

817

if(debug){

1332

fprintf_plus(stderr, "*** GnuTLS Handshake failed ***\n");

818

fprintf(stderr, "*** GnuTLS Handshake failed ***\n");

1333

819

gnutls_perror(ret);

1334

820

}

1335

821

errno = EPROTO;

1339

825

/* Read OpenPGP packet that contains the wanted password */

1340

826

1341

827

if(debug){

1342

fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"

1343

" %s\n", ip);

828

fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",

829

ip);

1344

830

}

1345

831

1346

832

while(true){

1351

837

}

1352

838

1353

839

buffer_capacity = incbuffer(&buffer, buffer_length,

1354

buffer_capacity);

840

buffer_capacity);

1355

841

if(buffer_capacity == 0){

1356

842

int e = errno;

1357

843

perror_plus("incbuffer");

1384

870

}

1385

871

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

1386

872

if(ret < 0){

1387

fprintf_plus(stderr, "*** GnuTLS Re-handshake failed "

1388

"***\n");

873

fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");

1389

874

gnutls_perror(ret);

1390

875

errno = EPROTO;

1391

876

goto mandos_end;

1392

877

}

1393

878

break;

1394

879

default:

1395

fprintf_plus(stderr, "Unknown error while reading data from"

1396

" encrypted session with Mandos server\n");

880

fprintf(stderr, "Unknown error while reading data from"

881

" encrypted session with Mandos server\n");

1397

882

gnutls_bye(session, GNUTLS_SHUT_RDWR);

1398

883

errno = EIO;

1399

884

goto mandos_end;

1404

889

}

1405

890

1406

891

if(debug){

1407

fprintf_plus(stderr, "Closing TLS session\n");

892

fprintf(stderr, "Closing TLS session\n");

1408

893

}

1409

894

1410

895

if(quit_now){

1422

907

1423

908

if(buffer_length > 0){

1424

909

ssize_t decrypted_buffer_size;

1425

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1426

&decrypted_buffer, mc);

910

decrypted_buffer_size = pgp_packet_decrypt(buffer,

911

buffer_length,

912

&decrypted_buffer);

1427

913

if(decrypted_buffer_size >= 0){

1428

914

1429

915

written = 0;

1439

925

if(ret == 0 and ferror(stdout)){

1440

926

int e = errno;

1441

927

if(debug){

1442

fprintf_plus(stderr, "Error writing encrypted data: %s\n",

1443

strerror(errno));

928

fprintf(stderr, "Error writing encrypted data: %s\n",

929

strerror(errno));

1444

930

}

1445

931

errno = e;

1446

932

goto mandos_end;

1455

941

1456

942

mandos_end:

1457

943

{

1458

if(route_added){

1459

if(not delete_local_route(ip, if_index)){

1460

fprintf_plus(stderr, "Failed to delete local route to %s on"

1461

" interface %d", ip, if_index);

1462

}

1463

}

1464

944

int e = errno;

1465

945

free(decrypted_buffer);

1466

946

free(buffer);

1483

963

return retval;

1484

964

}

1485

965

1486

__attribute__((nonnull))

1487

966

static void resolve_callback(AvahiSServiceResolver *r,

1488

967

AvahiIfIndex interface,

1489

968

AvahiProtocol proto,

1497

976

AVAHI_GCC_UNUSED AvahiStringList *txt,

1498

977

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1499

978

flags,

1500

void *mc){

1501

if(r == NULL){

1502

return;

1503

}

979

AVAHI_GCC_UNUSED void* userdata){

980

assert(r);

1504

981

1505

982

/* Called whenever a service has been resolved successfully or

1506

983

timed out */

1507

984

1508

985

if(quit_now){

1509

avahi_s_service_resolver_free(r);

1510

986

return;

1511

987

}

1512

988

1513

989

switch(event){

1514

990

default:

1515

991

case AVAHI_RESOLVER_FAILURE:

1516

fprintf_plus(stderr, "(Avahi Resolver) Failed to resolve service "

1517

"'%s' of type '%s' in domain '%s': %s\n", name, type,

1518

domain,

1519

avahi_strerror(avahi_server_errno

1520

(((mandos_context*)mc)->server)));

992

fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"

993

" of type '%s' in domain '%s': %s\n", name, type, domain,

994

avahi_strerror(avahi_server_errno(mc.server)));

1521

995

break;

1522

996

1523

997

case AVAHI_RESOLVER_FOUND:

1525

999

char ip[AVAHI_ADDRESS_STR_MAX];

1526

1000

avahi_address_snprint(ip, sizeof(ip), address);

1527

1001

if(debug){

1528

fprintf_plus(stderr, "Mandos server \"%s\" found on %s (%s, %"

1529

PRIdMAX ") on port %" PRIu16 "\n", name,

1530

host_name, ip, (intmax_t)interface, port);

1002

fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"

1003

PRIdMAX ") on port %" PRIu16 "\n", name, host_name,

1004

ip, (intmax_t)interface, port);

1531

1005

}

1532

int ret = start_mandos_communication(ip, (in_port_t)port,

1533

interface,

1534

avahi_proto_to_af(proto),

1535

mc);

1006

int ret = start_mandos_communication(ip, port, interface,

1007

avahi_proto_to_af(proto));

1536

1008

if(ret == 0){

1537

avahi_simple_poll_quit(simple_poll);

1009

avahi_simple_poll_quit(mc.simple_poll);

1538

1010

} else {

1539

if(not add_server(ip, (in_port_t)port, interface,

1540

avahi_proto_to_af(proto),

1541

&((mandos_context*)mc)->current_server)){

1542

fprintf_plus(stderr, "Failed to add server \"%s\" to server"

1543

" list\n", name);

1544

}

1011

ret = add_server(ip, port, interface,

1012

avahi_proto_to_af(proto));

1545

1013

}

1546

1014

}

1547

1015

}

1557

1025

const char *domain,

1558

1026

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1559

1027

flags,

1560

void *mc){

1561

if(b == NULL){

1562

return;

1563

}

1028

AVAHI_GCC_UNUSED void* userdata){

1029

assert(b);

1564

1030

1565

1031

/* Called whenever a new services becomes available on the LAN or

1566

1032

is removed from the LAN */

1573

1039

default:

1574

1040

case AVAHI_BROWSER_FAILURE:

1575

1041

1576

fprintf_plus(stderr, "(Avahi browser) %s\n",

1577

avahi_strerror(avahi_server_errno

1578

(((mandos_context*)mc)->server)));

1579

avahi_simple_poll_quit(simple_poll);

1042

fprintf(stderr, "(Avahi browser) %s\n",

1043

avahi_strerror(avahi_server_errno(mc.server)));

1044

avahi_simple_poll_quit(mc.simple_poll);

1580

1045

return;

1581

1046

1582

1047

case AVAHI_BROWSER_NEW:

1585

1050

the callback function is called the Avahi server will free the

1586

1051

resolver for us. */

1587

1052

1588

if(avahi_s_service_resolver_new(((mandos_context*)mc)->server,

1589

interface, protocol, name, type,

1590

domain, protocol, 0,

1591

resolve_callback, mc) == NULL)

1592

fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"

1593

" %s\n", name,

1594

avahi_strerror(avahi_server_errno

1595

(((mandos_context*)mc)->server)));

1053

if(avahi_s_service_resolver_new(mc.server, interface, protocol,

1054

name, type, domain, protocol, 0,

1055

resolve_callback, NULL) == NULL)

1056

fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",

1057

name, avahi_strerror(avahi_server_errno(mc.server)));

1596

1058

break;

1597

1059

1598

1060

case AVAHI_BROWSER_REMOVE:

1601

1063

case AVAHI_BROWSER_ALL_FOR_NOW:

1602

1064

case AVAHI_BROWSER_CACHE_EXHAUSTED:

1603

1065

if(debug){

1604

fprintf_plus(stderr, "No Mandos server found, still"

1605

" searching...\n");

1066

fprintf(stderr, "No Mandos server found, still searching...\n");

1606

1067

}

1607

1068

break;

1608

1069

}

1609

1070

}

1610

1071

1611

/* Signal handler that stops main loop after SIGTERM */

1072

/* Signal handler that stops main loop after sigterm has been called */

1612

1073

static void handle_sigterm(int sig){

1613

1074

if(quit_now){

1614

1075

return;

1617

1078

signal_received = sig;

1618

1079

int old_errno = errno;

1619

1080

/* set main loop to exit */

1620

if(simple_poll != NULL){

1621

avahi_simple_poll_quit(simple_poll);

1081

if(mc.simple_poll != NULL){

1082

avahi_simple_poll_quit(mc.simple_poll);

1622

1083

}

1623

1084

errno = old_errno;

1624

1085

}

1625

1086

1626

__attribute__((nonnull, warn_unused_result))

1627

bool get_flags(const char *ifname, struct ifreq *ifr){

1628

int ret;

1629

error_t ret_errno;

1630

1631

int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1632

if(s < 0){

1633

ret_errno = errno;

1634

perror_plus("socket");

1635

errno = ret_errno;

1636

return false;

1637

}

1638

strcpy(ifr->ifr_name, ifname);

1639

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1640

if(ret == -1){

1087

/*

1088

* This function determines if a directory entry in /sys/class/net

1089

* corresponds to an acceptable network device.

1090

* (This function is passed to scandir(3) as a filter function.)

1091

*/

1092

int good_interface(const struct dirent *if_entry){

1093

ssize_t ssret;

1094

char *flagname = NULL;

1095

if(if_entry->d_name[0] == '.'){

1096

return 0;

1097

}

1098

int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,

1099

if_entry->d_name);

1100

if(ret < 0){

1101

perror_plus("asprintf");

1102

return 0;

1103

}

1104

int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));

1105

if(flags_fd == -1){

1106

perror_plus("open");

1107

free(flagname);

1108

return 0;

1109

}

1110

free(flagname);

1111

typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */

1112

/* read line from flags_fd */

1113

ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */

1114

char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */

1115

flagstring[(size_t)to_read] = '\0';

1116

if(flagstring == NULL){

1117

perror_plus("malloc");

1118

close(flags_fd);

1119

return 0;

1120

}

1121

while(to_read > 0){

1122

ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,

1123

(size_t)to_read));

1124

if(ssret == -1){

1125

perror_plus("read");

1126

free(flagstring);

1127

close(flags_fd);

1128

return 0;

1129

}

1130

to_read -= ssret;

1131

if(ssret == 0){

1132

break;

1133

}

1134

}

1135

close(flags_fd);

1136

intmax_t tmpmax;

1137

char *tmp;

1138

errno = 0;

1139

tmpmax = strtoimax(flagstring, &tmp, 0);

1140

if(errno != 0 or tmp == flagstring or (*tmp != '\0'

1141

and not (isspace(*tmp)))

1142

or tmpmax != (ifreq_flags)tmpmax){

1641

1143

if(debug){

1642

ret_errno = errno;

1643

perror_plus("ioctl SIOCGIFFLAGS");

1644

errno = ret_errno;

1144

fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",

1145

flagstring, if_entry->d_name);

1645

1146

}

1646

return false;

1147

free(flagstring);

1148

return 0;

1647

1149

}

1648

return true;

1649

}

1650

1651

__attribute__((nonnull, warn_unused_result))

1652

bool good_flags(const char *ifname, const struct ifreq *ifr){

1653

1150

free(flagstring);

1151

ifreq_flags flags = (ifreq_flags)tmpmax;

1654

1152

/* Reject the loopback device */

1655

if(ifr->ifr_flags & IFF_LOOPBACK){

1153

if(flags & IFF_LOOPBACK){

1656

1154

if(debug){

1657

fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",

1658

ifname);

1155

fprintf(stderr, "Rejecting loopback interface \"%s\"\n",

1156

if_entry->d_name);

1659

1157

}

1660

return false;

1158

return 0;

1661

1159

}

1662

1160

/* Accept point-to-point devices only if connect_to is specified */

1663

if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){

1161

if(connect_to != NULL and (flags & IFF_POINTOPOINT)){

1664

1162

if(debug){

1665

fprintf_plus(stderr, "Accepting point-to-point interface"

1666

" \"%s\"\n", ifname);

1163

fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",

1164

if_entry->d_name);

1667

1165

}

1668

return true;

1166

return 1;

1669

1167

}

1670

1168

/* Otherwise, reject non-broadcast-capable devices */

1671

if(not (ifr->ifr_flags & IFF_BROADCAST)){

1169

if(not (flags & IFF_BROADCAST)){

1672

1170

if(debug){

1673

fprintf_plus(stderr, "Rejecting non-broadcast interface"

1674

" \"%s\"\n", ifname);

1171

fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",

1172

if_entry->d_name);

1675

1173

}

1676

return false;

1174

return 0;

1677

1175

}

1678

1176

/* Reject non-ARP interfaces (including dummy interfaces) */

1679

if(ifr->ifr_flags & IFF_NOARP){

1177

if(flags & IFF_NOARP){

1680

1178

if(debug){

1681

fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",

1682

ifname);

1179

fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",

1180

if_entry->d_name);

1683

1181

}

1684

return false;

1182

return 0;

1685

1183

}

1686

1687

1184

/* Accept this device */

1688

1185

if(debug){

1689

fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);

1690

}

1691

return true;

1692

}

1693

1694

/*

1695

* This function determines if a directory entry in /sys/class/net

1696

* corresponds to an acceptable network device.

1697

* (This function is passed to scandir(3) as a filter function.)

1698

*/

1699

__attribute__((nonnull, warn_unused_result))

1700

int good_interface(const struct dirent *if_entry){

1701

if(if_entry->d_name[0] == '.'){

1702

return 0;

1703

}

1704

1705

struct ifreq ifr;

1706

if(not get_flags(if_entry->d_name, &ifr)){

1707

if(debug){

1708

fprintf_plus(stderr, "Failed to get flags for interface "

1709

"\"%s\"\n", if_entry->d_name);

1710

}

1711

return 0;

1712

}

1713

1714

if(not good_flags(if_entry->d_name, &ifr)){

1715

return 0;

1186

fprintf(stderr, "Interface \"%s\" is acceptable\n",

1187

if_entry->d_name);

1716

1188

}

1717

1189

return 1;

1718

1190

}

1719

1191

1720

/*

1721

* This function determines if a network interface is up.

1722

*/

1723

__attribute__((nonnull, warn_unused_result))

1724

bool interface_is_up(const char *interface){

1725

struct ifreq ifr;

1726

if(not get_flags(interface, &ifr)){

1727

if(debug){

1728

fprintf_plus(stderr, "Failed to get flags for interface "

1729

"\"%s\"\n", interface);

1730

}

1731

return false;

1732

}

1733

1734

return (bool)(ifr.ifr_flags & IFF_UP);

1735

}

1736

1737

/*

1738

* This function determines if a network interface is running

1739

*/

1740

__attribute__((nonnull, warn_unused_result))

1741

bool interface_is_running(const char *interface){

1742

struct ifreq ifr;

1743

if(not get_flags(interface, &ifr)){

1744

if(debug){

1745

fprintf_plus(stderr, "Failed to get flags for interface "

1746

"\"%s\"\n", interface);

1747

}

1748

return false;

1749

}

1750

1751

return (bool)(ifr.ifr_flags & IFF_RUNNING);

1752

}

1753

1754

__attribute__((nonnull, pure, warn_unused_result))

1755

1192

int notdotentries(const struct dirent *direntry){

1756

1193

/* Skip "." and ".." */

1757

1194

if(direntry->d_name[0] == '.'

1763

1200

return 1;

1764

1201

}

1765

1202

1766

/* Is this directory entry a runnable program? */

1767

__attribute__((nonnull, warn_unused_result))

1768

int runnable_hook(const struct dirent *direntry){

1769

int ret;

1770

size_t sret;

1771

struct stat st;

1772

1773

if((direntry->d_name)[0] == '\0'){

1774

/* Empty name? */

1775

return 0;

1776

}

1777

1778

sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

1779

"abcdefghijklmnopqrstuvwxyz"

1780

"0123456789"

1781

"_.-");

1782

if((direntry->d_name)[sret] != '\0'){

1783

/* Contains non-allowed characters */

1784

if(debug){

1785

fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",

1786

direntry->d_name);

1787

}

1788

return 0;

1789

}

1790

1791

ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);

1792

if(ret == -1){

1793

if(debug){

1794

perror_plus("Could not stat hook");

1795

}

1796

return 0;

1797

}

1798

if(not (S_ISREG(st.st_mode))){

1799

/* Not a regular file */

1800

if(debug){

1801

fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",

1802

direntry->d_name);

1803

}

1804

return 0;

1805

}

1806

if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){

1807

/* Not executable */

1808

if(debug){

1809

fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",

1810

direntry->d_name);

1811

}

1812

return 0;

1813

}

1814

if(debug){

1815

fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",

1816

direntry->d_name);

1817

}

1818

return 1;

1819

}

1820

1821

__attribute__((nonnull, warn_unused_result))

1822

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1823

mandos_context *mc){

1203

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1824

1204

int ret;

1825

1205

struct timespec now;

1826

1206

struct timespec waited_time;

1827

1207

intmax_t block_time;

1828

1208

1829

1209

while(true){

1830

if(mc->current_server == NULL){

1831

if(debug){

1832

fprintf_plus(stderr, "Wait until first server is found."

1833

" No timeout!\n");

1210

if(mc.current_server == NULL){

1211

if (debug){

1212

fprintf(stderr, "Wait until first server is found. No timeout!\n");

1834

1213

}

1835

1214

ret = avahi_simple_poll_iterate(s, -1);

1836

1215

} else {

1837

if(debug){

1838

fprintf_plus(stderr, "Check current_server if we should run"

1839

" it, or wait\n");

1216

if (debug){

1217

fprintf(stderr, "Check current_server if we should run it, or wait\n");

1840

1218

}

1841

1219

/* the current time */

1842

1220

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1846

1224

}

1847

1225

/* Calculating in ms how long time between now and server

1848

1226

who we visted longest time ago. Now - last seen. */

1849

waited_time.tv_sec = (now.tv_sec

1850

- mc->current_server->last_seen.tv_sec);

1851

waited_time.tv_nsec = (now.tv_nsec

1852

- mc->current_server->last_seen.tv_nsec);

1853

/* total time is 10s/10,000ms.

1854

Converting to s from ms by dividing by 1,000,

1855

and ns to ms by dividing by 1,000,000. */

1856

block_time = ((retry_interval

1857

- ((intmax_t)waited_time.tv_sec * 1000))

1858

- ((intmax_t)waited_time.tv_nsec / 1000000));

1859

1860

if(debug){

1861

fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",

1862

block_time);

1227

waited_time.tv_sec = now.tv_sec - mc.current_server->last_seen.tv_sec;

1228

waited_time.tv_nsec = now.tv_nsec - mc.current_server->last_seen.tv_nsec;

1229

/* total time is 10s/10000ms. Converting to s to ms by 1000/s, and ns to ms by divind by 1000000. */

1230

block_time = (retry_interval - ((intmax_t)waited_time.tv_sec * 1000)) - ((intmax_t)waited_time.tv_nsec / 1000000);

1231

1232

if (debug){

1233

fprintf(stderr, "Blocking for %ld ms\n", block_time);

1863

1234

}

1864

1235

1865

1236

if(block_time <= 0){

1866

ret = start_mandos_communication(mc->current_server->ip,

1867

mc->current_server->port,

1868

mc->current_server->if_index,

1869

mc->current_server->af, mc);

1237

ret = start_mandos_communication(mc.current_server->ip,

1238

mc.current_server->port,

1239

mc.current_server->if_index,

1240

mc.current_server->af);

1870

1241

if(ret == 0){

1871

avahi_simple_poll_quit(s);

1242

avahi_simple_poll_quit(mc.simple_poll);

1872

1243

return 0;

1873

1244

}

1874

ret = clock_gettime(CLOCK_MONOTONIC,

1875

&mc->current_server->last_seen);

1245

ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);

1876

1246

if(ret == -1){

1877

1247

perror_plus("clock_gettime");

1878

1248

return -1;

1879

1249

}

1880

mc->current_server = mc->current_server->next;

1881

block_time = 0; /* Call avahi to find new Mandos

1882

servers, but don't block */

1250

mc.current_server = mc.current_server->next;

1251

block_time = 0; /* call avahi to find new mandos servers, but dont block */

1883

1252

}

1884

1253

1885

1254

ret = avahi_simple_poll_iterate(s, (int)block_time);

1886

1255

}

1887

1256

if(ret != 0){

1888

if(ret > 0 or errno != EINTR){

1257

if (ret > 0 or errno != EINTR) {

1889

1258

return (ret != 1) ? ret : 0;

1890

1259

}

1891

1260

}

1892

1261

}

1893

1262

}

1894

1263

1895

__attribute__((nonnull))

1896

void run_network_hooks(const char *mode, const char *interface,

1897

const float delay){

1898

struct dirent **direntries = NULL;

1899

if(hookdir_fd == -1){

1900

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1901

| O_CLOEXEC);

1902

if(hookdir_fd == -1){

1903

if(errno == ENOENT){

1904

if(debug){

1905

fprintf_plus(stderr, "Network hook directory \"%s\" not"

1906

" found\n", hookdir);

1907

}

1908

} else {

1909

perror_plus("open");

1910

}

1911

return;

1912

}

1913

}

1914

#ifdef __GLIBC__

1915

#if __GLIBC_PREREQ(2, 15)

1916

int numhooks = scandirat(hookdir_fd, ".", &direntries,

1917

runnable_hook, alphasort);

1918

#else /* not __GLIBC_PREREQ(2, 15) */

1919

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1920

alphasort);

1921

#endif /* not __GLIBC_PREREQ(2, 15) */

1922

#else /* not __GLIBC__ */

1923

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1924

alphasort);

1925

#endif /* not __GLIBC__ */

1926

if(numhooks == -1){

1927

perror_plus("scandir");

1928

return;

1929

}

1930

struct dirent *direntry;

1931

int ret;

1932

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

1933

if(devnull == -1){

1934

perror_plus("open(\"/dev/null\", O_RDONLY)");

1935

return;

1936

}

1937

for(int i = 0; i < numhooks; i++){

1938

direntry = direntries[i];

1939

if(debug){

1940

fprintf_plus(stderr, "Running network hook \"%s\"\n",

1941

direntry->d_name);

1942

}

1943

pid_t hook_pid = fork();

1944

if(hook_pid == 0){

1945

/* Child */

1946

/* Raise privileges */

1947

errno = raise_privileges_permanently();

1948

if(errno != 0){

1949

perror_plus("Failed to raise privileges");

1950

_exit(EX_NOPERM);

1951

}

1952

/* Set group */

1953

errno = 0;

1954

ret = setgid(0);

1955

if(ret == -1){

1956

perror_plus("setgid");

1957

_exit(EX_NOPERM);

1958

}

1959

/* Reset supplementary groups */

1960

errno = 0;

1961

ret = setgroups(0, NULL);

1962

if(ret == -1){

1963

perror_plus("setgroups");

1964

_exit(EX_NOPERM);

1965

}

1966

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

1967

if(ret == -1){

1968

perror_plus("setenv");

1969

_exit(EX_OSERR);

1970

}

1971

ret = setenv("DEVICE", interface, 1);

1972

if(ret == -1){

1973

perror_plus("setenv");

1974

_exit(EX_OSERR);

1975

}

1976

ret = setenv("VERBOSITY", debug ? "1" : "0", 1);

1977

if(ret == -1){

1978

perror_plus("setenv");

1979

_exit(EX_OSERR);

1980

}

1981

ret = setenv("MODE", mode, 1);

1982

if(ret == -1){

1983

perror_plus("setenv");

1984

_exit(EX_OSERR);

1985

}

1986

char *delaystring;

1987

ret = asprintf(&delaystring, "%f", (double)delay);

1988

if(ret == -1){

1989

perror_plus("asprintf");

1990

_exit(EX_OSERR);

1991

}

1992

ret = setenv("DELAY", delaystring, 1);

1993

if(ret == -1){

1994

free(delaystring);

1995

perror_plus("setenv");

1996

_exit(EX_OSERR);

1997

}

1998

free(delaystring);

1999

if(connect_to != NULL){

2000

ret = setenv("CONNECT", connect_to, 1);

2001

if(ret == -1){

2002

perror_plus("setenv");

2003

_exit(EX_OSERR);

2004

}

2005

}

2006

int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,

2007

direntry->d_name,

2008

O_RDONLY));

2009

if(hook_fd == -1){

2010

perror_plus("openat");

2011

_exit(EXIT_FAILURE);

2012

}

2013

if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){

2014

perror_plus("close");

2015

_exit(EXIT_FAILURE);

2016

}

2017

ret = dup2(devnull, STDIN_FILENO);

2018

if(ret == -1){

2019

perror_plus("dup2(devnull, STDIN_FILENO)");

2020

_exit(EX_OSERR);

2021

}

2022

ret = (int)TEMP_FAILURE_RETRY(close(devnull));

2023

if(ret == -1){

2024

perror_plus("close");

2025

_exit(EX_OSERR);

2026

}

2027

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2028

if(ret == -1){

2029

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

2030

_exit(EX_OSERR);

2031

}

2032

if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },

2033

environ) == -1){

2034

perror_plus("fexecve");

2035

_exit(EXIT_FAILURE);

2036

}

2037

} else {

2038

if(hook_pid == -1){

2039

perror_plus("fork");

2040

free(direntry);

2041

continue;

2042

}

2043

int status;

2044

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

2045

perror_plus("waitpid");

2046

free(direntry);

2047

continue;

2048

}

2049

if(WIFEXITED(status)){

2050

if(WEXITSTATUS(status) != 0){

2051

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

2052

" with status %d\n", direntry->d_name,

2053

WEXITSTATUS(status));

2054

free(direntry);

2055

continue;

2056

}

2057

} else if(WIFSIGNALED(status)){

2058

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

2059

" signal %d\n", direntry->d_name,

2060

WTERMSIG(status));

2061

free(direntry);

2062

continue;

2063

} else {

2064

fprintf_plus(stderr, "Warning: network hook \"%s\""

2065

" crashed\n", direntry->d_name);

2066

free(direntry);

2067

continue;

2068

}

2069

}

2070

if(debug){

2071

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

2072

direntry->d_name);

2073

}

2074

free(direntry);

2075

}

2076

free(direntries);

2077

if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){

2078

perror_plus("close");

2079

} else {

2080

hookdir_fd = -1;

2081

}

2082

close(devnull);

2083

}

2084

2085

__attribute__((nonnull, warn_unused_result))

2086

error_t bring_up_interface(const char *const interface,

2087

const float delay){

2088

error_t old_errno = errno;

2089

int ret;

2090

struct ifreq network;

2091

unsigned int if_index = if_nametoindex(interface);

2092

if(if_index == 0){

2093

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

2094

errno = old_errno;

2095

return ENXIO;

2096

}

2097

2098

if(quit_now){

2099

errno = old_errno;

2100

return EINTR;

2101

}

2102

2103

if(not interface_is_up(interface)){

2104

error_t ret_errno = 0, ioctl_errno = 0;

2105

if(not get_flags(interface, &network)){

2106

ret_errno = errno;

2107

fprintf_plus(stderr, "Failed to get flags for interface "

2108

"\"%s\"\n", interface);

2109

errno = old_errno;

2110

return ret_errno;

2111

}

2112

network.ifr_flags |= IFF_UP; /* set flag */

2113

2114

int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

2115

if(sd == -1){

2116

ret_errno = errno;

2117

perror_plus("socket");

2118

errno = old_errno;

2119

return ret_errno;

2120

}

2121

2122

if(quit_now){

2123

ret = (int)TEMP_FAILURE_RETRY(close(sd));

2124

if(ret == -1){

2125

perror_plus("close");

2126

}

2127

errno = old_errno;

2128

return EINTR;

2129

}

2130

2131

if(debug){

2132

fprintf_plus(stderr, "Bringing up interface \"%s\"\n",

2133

interface);

2134

}

2135

2136

/* Raise privileges */

2137

ret_errno = raise_privileges();

2138

if(ret_errno != 0){

2139

errno = ret_errno;

2140

perror_plus("Failed to raise privileges");

2141

}

2142

2143

#ifdef __linux__

2144

int ret_linux;

2145

bool restore_loglevel = false;

2146

if(ret_errno == 0){

2147

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2148

messages about the network interface to mess up the prompt */

2149

ret_linux = klogctl(8, NULL, 5);

2150

if(ret_linux == -1){

2151

perror_plus("klogctl");

2152

} else {

2153

restore_loglevel = true;

2154

}

2155

}

2156

#endif /* __linux__ */

2157

int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);

2158

ioctl_errno = errno;

2159

#ifdef __linux__

2160

if(restore_loglevel){

2161

ret_linux = klogctl(7, NULL, 0);

2162

if(ret_linux == -1){

2163

perror_plus("klogctl");

2164

}

2165

}

2166

#endif /* __linux__ */

2167

2168

/* If raise_privileges() succeeded above */

2169

if(ret_errno == 0){

2170

/* Lower privileges */

2171

ret_errno = lower_privileges();

2172

if(ret_errno != 0){

2173

errno = ret_errno;

2174

perror_plus("Failed to lower privileges");

2175

}

2176

}

2177

2178

/* Close the socket */

2179

ret = (int)TEMP_FAILURE_RETRY(close(sd));

2180

if(ret == -1){

2181

perror_plus("close");

2182

}

2183

2184

if(ret_setflags == -1){

2185

errno = ioctl_errno;

2186

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2187

errno = old_errno;

2188

return ioctl_errno;

2189

}

2190

} else if(debug){

2191

fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",

2192

interface);

2193

}

2194

2195

/* Sleep checking until interface is running.

2196

Check every 0.25s, up to total time of delay */

2197

for(int i=0; i < delay * 4; i++){

2198

if(interface_is_running(interface)){

2199

break;

2200

}

2201

struct timespec sleeptime = { .tv_nsec = 250000000 };

2202

ret = nanosleep(&sleeptime, NULL);

2203

if(ret == -1 and errno != EINTR){

2204

perror_plus("nanosleep");

2205

}

2206

}

2207

2208

errno = old_errno;

2209

return 0;

2210

}

2211

2212

__attribute__((nonnull, warn_unused_result))

2213

error_t take_down_interface(const char *const interface){

2214

error_t old_errno = errno;

2215

struct ifreq network;

2216

unsigned int if_index = if_nametoindex(interface);

2217

if(if_index == 0){

2218

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

2219

errno = old_errno;

2220

return ENXIO;

2221

}

2222

if(interface_is_up(interface)){

2223

error_t ret_errno = 0, ioctl_errno = 0;

2224

if(not get_flags(interface, &network) and debug){

2225

ret_errno = errno;

2226

fprintf_plus(stderr, "Failed to get flags for interface "

2227

"\"%s\"\n", interface);

2228

errno = old_errno;

2229

return ret_errno;

2230

}

2231

network.ifr_flags &= ~(short)IFF_UP; /* clear flag */

2232

2233

int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

2234

if(sd == -1){

2235

ret_errno = errno;

2236

perror_plus("socket");

2237

errno = old_errno;

2238

return ret_errno;

2239

}

2240

2241

if(debug){

2242

fprintf_plus(stderr, "Taking down interface \"%s\"\n",

2243

interface);

2244

}

2245

2246

/* Raise privileges */

2247

ret_errno = raise_privileges();

2248

if(ret_errno != 0){

2249

errno = ret_errno;

2250

perror_plus("Failed to raise privileges");

2251

}

2252

2253

int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);

2254

ioctl_errno = errno;

2255

2256

/* If raise_privileges() succeeded above */

2257

if(ret_errno == 0){

2258

/* Lower privileges */

2259

ret_errno = lower_privileges();

2260

if(ret_errno != 0){

2261

errno = ret_errno;

2262

perror_plus("Failed to lower privileges");

2263

}

2264

}

2265

2266

/* Close the socket */

2267

int ret = (int)TEMP_FAILURE_RETRY(close(sd));

2268

if(ret == -1){

2269

perror_plus("close");

2270

}

2271

2272

if(ret_setflags == -1){

2273

errno = ioctl_errno;

2274

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2275

errno = old_errno;

2276

return ioctl_errno;

2277

}

2278

} else if(debug){

2279

fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",

2280

interface);

2281

}

2282

2283

errno = old_errno;

2284

return 0;

2285

}

2286

2287

1264

int main(int argc, char *argv[]){

2288

mandos_context mc = { .server = NULL, .dh_bits = 0,

2289

.priority = "SECURE256:!CTYPE-X.509:"

2290

"+CTYPE-OPENPGP:!RSA", .current_server = NULL,

2291

.interfaces = NULL, .interfaces_size = 0 };

2292

1265

AvahiSServiceBrowser *sb = NULL;

2293

error_t ret_errno;

1266

int error;

2294

1267

int ret;

2295

1268

intmax_t tmpmax;

2296

1269

char *tmp;

2297

1270

int exitcode = EXIT_SUCCESS;

2298

char *interfaces_to_take_down = NULL;

2299

size_t interfaces_to_take_down_size = 0;

2300

char run_tempdir[] = "/run/tmp/mandosXXXXXX";

2301

char old_tempdir[] = "/tmp/mandosXXXXXX";

2302

char *tempdir = NULL;

1271

const char *interface = "";

1272

struct ifreq network;

1273

int sd = -1;

1274

bool take_down_interface = false;

1275

uid_t uid;

1276

gid_t gid;

1277

char tempdir[] = "/tmp/mandosXXXXXX";

1278

bool tempdir_created = false;

2303

1279

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2304

1280

const char *seckey = PATHDIR "/" SECKEY;

2305

1281

const char *pubkey = PATHDIR "/" PUBKEY;

2306

const char *dh_params_file = NULL;

2307

char *interfaces_hooks = NULL;

2308

1282

2309

1283

bool gnutls_initialized = false;

2310

1284

bool gpgme_initialized = false;

2311

1285

float delay = 2.5f;

2312

double retry_interval = 10; /* 10s between trying a server and

2313

retrying the same server again */

1286

double retry_interval = 10; /* 10s between retrying a server and checking again*/

2314

1287

2315

1288

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

2316

1289

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

2362

1335

.doc = "Bit length of the prime number used in the"

2363

1336

" Diffie-Hellman key exchange",

2364

1337

.group = 2 },

2365

{ .name = "dh-params", .key = 134,

2366

.arg = "FILE",

2367

.doc = "PEM-encoded PKCS#3 file with pre-generated parameters"

2368

" for the Diffie-Hellman key exchange",

2369

.group = 2 },

2370

1338

{ .name = "priority", .key = 130,

2371

1339

.arg = "STRING",

2372

1340

.doc = "GnuTLS priority string for the TLS handshake",

2377

1345

.group = 2 },

2378

1346

{ .name = "retry", .key = 132,

2379

1347

.arg = "SECONDS",

2380

.doc = "Retry interval used when denied by the Mandos server",

2381

.group = 2 },

2382

{ .name = "network-hook-dir", .key = 133,

2383

.arg = "DIR",

2384

.doc = "Directory where network hooks are located",

1348

.doc = "Retry interval used when denied by the mandos server",

2385

1349

.group = 2 },

2386

1350

/*

2387

1351

* These reproduce what we would get without ARGP_NO_HELP

2406

1370

connect_to = arg;

2407

1371

break;

2408

1372

case 'i': /* --interface */

2409

ret_errno = argz_add_sep(&mc.interfaces, &mc.interfaces_size,

2410

arg, (int)',');

2411

if(ret_errno != 0){

2412

argp_error(state, "%s", strerror(ret_errno));

2413

}

1373

interface = arg;

2414

1374

break;

2415

1375

case 's': /* --seckey */

2416

1376

seckey = arg;

2427

1387

}

2428

1388

mc.dh_bits = (typeof(mc.dh_bits))tmpmax;

2429

1389

break;

2430

case 134: /* --dh-params */

2431

dh_params_file = arg;

2432

break;

2433

1390

case 130: /* --priority */

2434

1391

mc.priority = arg;

2435

1392

break;

2443

1400

errno = 0;

2444

1401

retry_interval = strtod(arg, &tmp);

2445

1402

if(errno != 0 or tmp == arg or *tmp != '\0'

2446

or (retry_interval * 1000) > INT_MAX

2447

or retry_interval < 0){

1403

or (retry_interval * 1000) > INT_MAX){

2448

1404

argp_error(state, "Bad retry interval");

2449

1405

}

2450

1406

break;

2451

case 133: /* --network-hook-dir */

2452

hookdir = arg;

2453

break;

2454

1407

/*

2455

1408

* These reproduce what we would get without ARGP_NO_HELP

2456

1409

*/

2462

1415

argp_state_help(state, state->out_stream,

2463

1416

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

2464

1417

case 'V': /* --version */

2465

fprintf_plus(state->out_stream, "%s\n", argp_program_version);

1418

fprintf(state->out_stream, "%s\n", argp_program_version);

2466

1419

exit(argp_err_exit_status);

2467

1420

break;

2468

1421

default:

2492

1445

}

2493

1446

}

2494

1447

2495

{

2496

/* Work around Debian bug #633582:

2497

<http://bugs.debian.org/633582> */

2498

2499

/* Re-raise privileges */

2500

ret_errno = raise_privileges();

2501

if(ret_errno != 0){

2502

errno = ret_errno;

2503

perror_plus("Failed to raise privileges");

2504

} else {

2505

struct stat st;

2506

2507

if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){

2508

int seckey_fd = open(seckey, O_RDONLY);

2509

if(seckey_fd == -1){

2510

perror_plus("open");

2511

} else {

2512

ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));

2513

if(ret == -1){

2514

perror_plus("fstat");

2515

} else {

2516

if(S_ISREG(st.st_mode)

2517

and st.st_uid == 0 and st.st_gid == 0){

2518

ret = fchown(seckey_fd, uid, gid);

2519

if(ret == -1){

2520

perror_plus("fchown");

2521

}

2522

}

2523

}

2524

TEMP_FAILURE_RETRY(close(seckey_fd));

2525

}

2526

}

2527

2528

if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){

2529

int pubkey_fd = open(pubkey, O_RDONLY);

2530

if(pubkey_fd == -1){

2531

perror_plus("open");

2532

} else {

2533

ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));

2534

if(ret == -1){

2535

perror_plus("fstat");

2536

} else {

2537

if(S_ISREG(st.st_mode)

2538

and st.st_uid == 0 and st.st_gid == 0){

2539

ret = fchown(pubkey_fd, uid, gid);

2540

if(ret == -1){

2541

perror_plus("fchown");

2542

}

2543

}

2544

}

2545

TEMP_FAILURE_RETRY(close(pubkey_fd));

2546

}

2547

}

2548

2549

/* Lower privileges */

2550

ret_errno = lower_privileges();

2551

if(ret_errno != 0){

2552

errno = ret_errno;

2553

perror_plus("Failed to lower privileges");

2554

}

2555

}

2556

}

2557

2558

/* Remove invalid interface names (except "none") */

2559

{

2560

char *interface = NULL;

2561

while((interface = argz_next(mc.interfaces, mc.interfaces_size,

2562

interface))){

2563

if(strcmp(interface, "none") != 0

2564

and if_nametoindex(interface) == 0){

2565

if(interface[0] != '\0'){

2566

fprintf_plus(stderr, "Not using nonexisting interface"

2567

" \"%s\"\n", interface);

2568

}

2569

argz_delete(&mc.interfaces, &mc.interfaces_size, interface);

2570

interface = NULL;

2571

}

2572

}

2573

}

2574

2575

/* Run network hooks */

2576

{

2577

if(mc.interfaces != NULL){

2578

interfaces_hooks = malloc(mc.interfaces_size);

2579

if(interfaces_hooks == NULL){

2580

perror_plus("malloc");

2581

goto end;

2582

}

2583

memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);

2584

argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');

2585

}

2586

run_network_hooks("start", interfaces_hooks != NULL ?

2587

interfaces_hooks : "", delay);

2588

}

2589

2590

1448

if(not debug){

2591

1449

avahi_set_log_function(empty_log);

2592

1450

}

1451

1452

if(interface[0] == '\0'){

1453

struct dirent **direntries;

1454

ret = scandir(sys_class_net, &direntries, good_interface,

1455

alphasort);

1456

if(ret >= 1){

1457

/* Pick the first good interface */

1458

interface = strdup(direntries[0]->d_name);

1459

if(debug){

1460

fprintf(stderr, "Using interface \"%s\"\n", interface);

1461

}

1462

if(interface == NULL){

1463

perror_plus("malloc");

1464

free(direntries);

1465

exitcode = EXIT_FAILURE;

1466

goto end;

1467

}

1468

free(direntries);

1469

} else {

1470

free(direntries);

1471

fprintf(stderr, "Could not find a network interface\n");

1472

exitcode = EXIT_FAILURE;

1473

goto end;

1474

}

1475

}

2593

1476

2594

1477

/* Initialize Avahi early so avahi_simple_poll_quit() can be called

2595

1478

from the signal handler */

2596

1479

/* Initialize the pseudo-RNG for Avahi */

2597

1480

srand((unsigned int) time(NULL));

2598

simple_poll = avahi_simple_poll_new();

2599

if(simple_poll == NULL){

2600

fprintf_plus(stderr,

2601

"Avahi: Failed to create simple poll object.\n");

1481

mc.simple_poll = avahi_simple_poll_new();

1482

if(mc.simple_poll == NULL){

1483

fprintf(stderr, "Avahi: Failed to create simple poll object.\n");

2602

1484

exitcode = EX_UNAVAILABLE;

2603

1485

goto end;

2604

1486

}

2666

1548

}

2667

1549

}

2668

1550

2669

/* If no interfaces were specified, make a list */

2670

if(mc.interfaces == NULL){

2671

struct dirent **direntries = NULL;

2672

/* Look for any good interfaces */

2673

ret = scandir(sys_class_net, &direntries, good_interface,

2674

alphasort);

2675

if(ret >= 1){

2676

/* Add all found interfaces to interfaces list */

2677

for(int i = 0; i < ret; ++i){

2678

ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,

2679

direntries[i]->d_name);

2680

if(ret_errno != 0){

2681

errno = ret_errno;

2682

perror_plus("argz_add");

2683

free(direntries[i]);

2684

continue;

2685

}

2686

if(debug){

2687

fprintf_plus(stderr, "Will use interface \"%s\"\n",

2688

direntries[i]->d_name);

2689

}

2690

free(direntries[i]);

2691

}

2692

free(direntries);

1551

/* If the interface is down, bring it up */

1552

if(strcmp(interface, "none") != 0){

1553

if_index = (AvahiIfIndex) if_nametoindex(interface);

1554

if(if_index == 0){

1555

fprintf(stderr, "No such interface: \"%s\"\n", interface);

1556

exitcode = EX_UNAVAILABLE;

1557

goto end;

1558

}

1559

1560

if(quit_now){

1561

goto end;

1562

}

1563

1564

/* Re-raise priviliges */

1565

errno = 0;

1566

ret = seteuid(0);

1567

if(ret == -1){

1568

perror_plus("seteuid");

1569

}

1570

1571

#ifdef __linux__

1572

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1573

messages about the network interface to mess up the prompt */

1574

ret = klogctl(8, NULL, 5);

1575

bool restore_loglevel = true;

1576

if(ret == -1){

1577

restore_loglevel = false;

1578

perror_plus("klogctl");

1579

}

1580

#endif /* __linux__ */

1581

1582

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1583

if(sd < 0){

1584

perror_plus("socket");

1585

exitcode = EX_OSERR;

1586

#ifdef __linux__

1587

if(restore_loglevel){

1588

ret = klogctl(7, NULL, 0);

1589

if(ret == -1){

1590

perror_plus("klogctl");

1591

}

1592

}

1593

#endif /* __linux__ */

1594

/* Lower privileges */

1595

errno = 0;

1596

ret = seteuid(uid);

1597

if(ret == -1){

1598

perror_plus("seteuid");

1599

}

1600

goto end;

1601

}

1602

strcpy(network.ifr_name, interface);

1603

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1604

if(ret == -1){

1605

perror_plus("ioctl SIOCGIFFLAGS");

1606

#ifdef __linux__

1607

if(restore_loglevel){

1608

ret = klogctl(7, NULL, 0);

1609

if(ret == -1){

1610

perror_plus("klogctl");

1611

}

1612

}

1613

#endif /* __linux__ */

1614

exitcode = EX_OSERR;

1615

/* Lower privileges */

1616

errno = 0;

1617

ret = seteuid(uid);

1618

if(ret == -1){

1619

perror_plus("seteuid");

1620

}

1621

goto end;

1622

}

1623

if((network.ifr_flags & IFF_UP) == 0){

1624

network.ifr_flags |= IFF_UP;

1625

take_down_interface = true;

1626

ret = ioctl(sd, SIOCSIFFLAGS, &network);

1627

if(ret == -1){

1628

take_down_interface = false;

1629

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1630

exitcode = EX_OSERR;

1631

#ifdef __linux__

1632

if(restore_loglevel){

1633

ret = klogctl(7, NULL, 0);

1634

if(ret == -1){

1635

perror_plus("klogctl");

1636

}

1637

}

1638

#endif /* __linux__ */

1639

/* Lower privileges */

1640

errno = 0;

1641

ret = seteuid(uid);

1642

if(ret == -1){

1643

perror_plus("seteuid");

1644

}

1645

goto end;

1646

}

1647

}

1648

/* sleep checking until interface is running. Check every 0.25s, up to total time of delay */

1649

for(int i=0; i < delay * 4; i++){

1650

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1651

if(ret == -1){

1652

perror_plus("ioctl SIOCGIFFLAGS");

1653

} else if(network.ifr_flags & IFF_RUNNING){

1654

break;

1655

}

1656

struct timespec sleeptime = { .tv_nsec = 250000000 };

1657

ret = nanosleep(&sleeptime, NULL);

1658

if(ret == -1 and errno != EINTR){

1659

perror_plus("nanosleep");

1660

}

1661

}

1662

if(not take_down_interface){

1663

/* We won't need the socket anymore */

1664

ret = (int)TEMP_FAILURE_RETRY(close(sd));

1665

if(ret == -1){

1666

perror_plus("close");

1667

}

1668

}

1669

#ifdef __linux__

1670

if(restore_loglevel){

1671

/* Restores kernel loglevel to default */

1672

ret = klogctl(7, NULL, 0);

1673

if(ret == -1){

1674

perror_plus("klogctl");

1675

}

1676

}

1677

#endif /* __linux__ */

1678

/* Lower privileges */

1679

errno = 0;

1680

if(take_down_interface){

1681

/* Lower privileges */

1682

ret = seteuid(uid);

1683

if(ret == -1){

1684

perror_plus("seteuid");

1685

}

2693

1686

} else {

2694

if(ret == 0){

2695

free(direntries);

2696

}

2697

fprintf_plus(stderr, "Could not find a network interface\n");

2698

exitcode = EXIT_FAILURE;

2699

goto end;

2700

}

2701

}

2702

2703

/* Bring up interfaces which are down, and remove any "none"s */

2704

{

2705

char *interface = NULL;

2706

while((interface = argz_next(mc.interfaces, mc.interfaces_size,

2707

interface))){

2708

/* If interface name is "none", stop bringing up interfaces.

2709

Also remove all instances of "none" from the list */

2710

if(strcmp(interface, "none") == 0){

2711

argz_delete(&mc.interfaces, &mc.interfaces_size,

2712

interface);

2713

interface = NULL;

2714

while((interface = argz_next(mc.interfaces,

2715

mc.interfaces_size, interface))){

2716

if(strcmp(interface, "none") == 0){

2717

argz_delete(&mc.interfaces, &mc.interfaces_size,

2718

interface);

2719

interface = NULL;

2720

}

2721

}

2722

break;

2723

}

2724

bool interface_was_up = interface_is_up(interface);

2725

errno = bring_up_interface(interface, delay);

2726

if(not interface_was_up){

2727

if(errno != 0){

2728

perror_plus("Failed to bring up interface");

2729

} else {

2730

errno = argz_add(&interfaces_to_take_down,

2731

&interfaces_to_take_down_size,

2732

interface);

2733

if(errno != 0){

2734

perror_plus("argz_add");

2735

}

2736

}

2737

}

2738

}

2739

if(debug and (interfaces_to_take_down == NULL)){

2740

fprintf_plus(stderr, "No interfaces were brought up\n");

2741

}

2742

}

2743

2744

/* If we only got one interface, explicitly use only that one */

2745

if(argz_count(mc.interfaces, mc.interfaces_size) == 1){

2746

if(debug){

2747

fprintf_plus(stderr, "Using only interface \"%s\"\n",

2748

mc.interfaces);

2749

}

2750

if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);

1687

/* Lower privileges permanently */

1688

ret = setuid(uid);

1689

if(ret == -1){

1690

perror_plus("setuid");

1691

}

1692

}

2751

1693

}

2752

1694

2753

1695

if(quit_now){

2754

1696

goto end;

2755

1697

}

2756

1698

2757

ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);

1699

ret = init_gnutls_global(pubkey, seckey);

2758

1700

if(ret == -1){

2759

fprintf_plus(stderr, "init_gnutls_global failed\n");

1701

fprintf(stderr, "init_gnutls_global failed\n");

2760

1702

exitcode = EX_UNAVAILABLE;

2761

1703

goto end;

2762

1704

} else {

2767

1709

goto end;

2768

1710

}

2769

1711

2770

/* Try /run/tmp before /tmp */

2771

tempdir = mkdtemp(run_tempdir);

2772

if(tempdir == NULL and errno == ENOENT){

2773

if(debug){

2774

fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",

2775

run_tempdir, old_tempdir);

2776

}

2777

tempdir = mkdtemp(old_tempdir);

2778

}

2779

if(tempdir == NULL){

1712

if(mkdtemp(tempdir) == NULL){

2780

1713

perror_plus("mkdtemp");

2781

1714

goto end;

2782

1715

}

1716

tempdir_created = true;

2783

1717

2784

1718

if(quit_now){

2785

1719

goto end;

2786

1720

}

2787

1721

2788

if(not init_gpgme(pubkey, seckey, tempdir, &mc)){

2789

fprintf_plus(stderr, "init_gpgme failed\n");

1722

if(not init_gpgme(pubkey, seckey, tempdir)){

1723

fprintf(stderr, "init_gpgme failed\n");

2790

1724

exitcode = EX_UNAVAILABLE;

2791

1725

goto end;

2792

1726

} else {

2801

1735

/* Connect directly, do not use Zeroconf */

2802

1736

/* (Mainly meant for debugging) */

2803

1737

char *address = strrchr(connect_to, ':');

2804

2805

1738

if(address == NULL){

2806

fprintf_plus(stderr, "No colon in address\n");

1739

fprintf(stderr, "No colon in address\n");

2807

1740

exitcode = EX_USAGE;

2808

1741

goto end;

2809

1742

}

2812

1745

goto end;

2813

1746

}

2814

1747

2815

in_port_t port;

1748

uint16_t port;

2816

1749

errno = 0;

2817

1750

tmpmax = strtoimax(address+1, &tmp, 10);

2818

1751

if(errno != 0 or tmp == address+1 or *tmp != '\0'

2819

or tmpmax != (in_port_t)tmpmax){

2820

fprintf_plus(stderr, "Bad port number\n");

1752

or tmpmax != (uint16_t)tmpmax){

1753

fprintf(stderr, "Bad port number\n");

2821

1754

exitcode = EX_USAGE;

2822

1755

goto end;

2823

1756

}

2824

1757

2825

1758

if(quit_now){

2826

1759

goto end;

2827

1760

}

2828

1761

2829

port = (in_port_t)tmpmax;

1762

port = (uint16_t)tmpmax;

2830

1763

*address = '\0';

1764

address = connect_to;

2831

1765

/* Colon in address indicates IPv6 */

2832

1766

int af;

2833

if(strchr(connect_to, ':') != NULL){

1767

if(strchr(address, ':') != NULL){

2834

1768

af = AF_INET6;

2835

/* Accept [] around IPv6 address - see RFC 5952 */

2836

if(connect_to[0] == '[' and address[-1] == ']')

2837

{

2838

connect_to++;

2839

address[-1] = '\0';

2840

}

2841

1769

} else {

2842

1770

af = AF_INET;

2843

1771

}

2844

address = connect_to;

2845

1772

2846

1773

if(quit_now){

2847

1774

goto end;

2848

1775

}

2849

1776

2850

1777

while(not quit_now){

2851

ret = start_mandos_communication(address, port, if_index, af,

2852

&mc);

1778

ret = start_mandos_communication(address, port, if_index, af);

2853

1779

if(quit_now or ret == 0){

2854

1780

break;

2855

1781

}

2856

if(debug){

2857

fprintf_plus(stderr, "Retrying in %d seconds\n",

2858

(int)retry_interval);

2859

}

2860

sleep((unsigned int)retry_interval);

2861

}

2862

2863

if(not quit_now){

1782

sleep((int)retry_interval or 1);

1783

};

1784

1785

if (not quit_now){

2864

1786

exitcode = EXIT_SUCCESS;

2865

1787

}

2866

1788

2867

1789

goto end;

2868

1790

}

2869

1791

2881

1803

config.publish_domain = 0;

2882

1804

2883

1805

/* Allocate a new server */

2884

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2885

&config, NULL, NULL, &ret_errno);

1806

mc.server = avahi_server_new(avahi_simple_poll_get

1807

(mc.simple_poll), &config, NULL,

1808

NULL, &error);

2886

1809

2887

1810

/* Free the Avahi configuration data */

2888

1811

avahi_server_config_free(&config);

2890

1813

2891

1814

/* Check if creating the Avahi server object succeeded */

2892

1815

if(mc.server == NULL){

2893

fprintf_plus(stderr, "Failed to create Avahi server: %s\n",

2894

avahi_strerror(ret_errno));

1816

fprintf(stderr, "Failed to create Avahi server: %s\n",

1817

avahi_strerror(error));

2895

1818

exitcode = EX_UNAVAILABLE;

2896

1819

goto end;

2897

1820

}

2903

1826

/* Create the Avahi service browser */

2904

1827

sb = avahi_s_service_browser_new(mc.server, if_index,

2905

1828

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2906

NULL, 0, browse_callback,

2907

(void *)&mc);

1829

NULL, 0, browse_callback, NULL);

2908

1830

if(sb == NULL){

2909

fprintf_plus(stderr, "Failed to create service browser: %s\n",

2910

avahi_strerror(avahi_server_errno(mc.server)));

1831

fprintf(stderr, "Failed to create service browser: %s\n",

1832

avahi_strerror(avahi_server_errno(mc.server)));

2911

1833

exitcode = EX_UNAVAILABLE;

2912

1834

goto end;

2913

1835

}

2919

1841

/* Run the main loop */

2920

1842

2921

1843

if(debug){

2922

fprintf_plus(stderr, "Starting Avahi loop search\n");

1844

fprintf(stderr, "Starting Avahi loop search\n");

2923

1845

}

2924

2925

ret = avahi_loop_with_timeout(simple_poll,

2926

(int)(retry_interval * 1000), &mc);

1846

1847

ret = avahi_loop_with_timeout(mc.simple_poll, (int)(retry_interval * 1000));

2927

1848

if(debug){

2928

fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",

2929

(ret == 0) ? "successfully" : "with error");

1849

fprintf(stderr, "avahi_loop_with_timeout exited %s\n",

1850

(ret == 0) ? "successfully" : "with error");

2930

1851

}

2931

1852

2932

1853

end:

2933

1854

2934

1855

if(debug){

2935

fprintf_plus(stderr, "%s exiting\n", argv[0]);

1856

fprintf(stderr, "%s exiting\n", argv[0]);

2936

1857

}

2937

1858

2938

1859

/* Cleanup things */

2939

free(mc.interfaces);

2940

2941

1860

if(sb != NULL)

2942

1861

avahi_s_service_browser_free(sb);

2943

1862

2944

1863

if(mc.server != NULL)

2945

1864

avahi_server_free(mc.server);

2946

1865

2947

if(simple_poll != NULL)

2948

avahi_simple_poll_free(simple_poll);

1866

if(mc.simple_poll != NULL)

1867

avahi_simple_poll_free(mc.simple_poll);

2949

1868

2950

1869

if(gnutls_initialized){

2951

1870

gnutls_certificate_free_credentials(mc.cred);

2956

1875

if(gpgme_initialized){

2957

1876

gpgme_release(mc.ctx);

2958

1877

}

2959

2960

/* Cleans up the circular linked list of Mandos servers the client

2961

has seen */

1878

1879

/* cleans up the circular linked list of mandos servers the client has seen */

2962

1880

if(mc.current_server != NULL){

2963

1881

mc.current_server->prev->next = NULL;

2964

1882

while(mc.current_server != NULL){

2965

1883

server *next = mc.current_server->next;

2966

#ifdef __GNUC__

2967

#pragma GCC diagnostic push

2968

#pragma GCC diagnostic ignored "-Wcast-qual"

2969

#endif

2970

free((char *)(mc.current_server->ip));

2971

#ifdef __GNUC__

2972

#pragma GCC diagnostic pop

2973

#endif

2974

1884

free(mc.current_server);

2975

1885

mc.current_server = next;

2976

1886

}

2977

1887

}

2978

1888

2979

/* Re-raise privileges */

2980

{

2981

ret_errno = raise_privileges();

2982

if(ret_errno != 0){

2983

errno = ret_errno;

2984

perror_plus("Failed to raise privileges");

2985

} else {

2986

2987

/* Run network hooks */

2988

run_network_hooks("stop", interfaces_hooks != NULL ?

2989

interfaces_hooks : "", delay);

2990

2991

/* Take down the network interfaces which were brought up */

2992

{

2993

char *interface = NULL;

2994

while((interface=argz_next(interfaces_to_take_down,

2995

interfaces_to_take_down_size,

2996

interface))){

2997

ret_errno = take_down_interface(interface);

2998

if(ret_errno != 0){

2999

errno = ret_errno;

3000

perror_plus("Failed to take down interface");

3001

}

3002

}

3003

if(debug and (interfaces_to_take_down == NULL)){

3004

fprintf_plus(stderr, "No interfaces needed to be taken"

3005

" down\n");

3006

}

3007

}

1889

/* Take down the network interface */

1890

if(take_down_interface){

1891

/* Re-raise priviliges */

1892

errno = 0;

1893

ret = seteuid(0);

1894

if(ret == -1){

1895

perror_plus("seteuid");

3008

1896

}

3009

3010

ret_errno = lower_privileges_permanently();

3011

if(ret_errno != 0){

3012

errno = ret_errno;

3013

perror_plus("Failed to lower privileges permanently");

1897

if(geteuid() == 0){

1898

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1899

if(ret == -1){

1900

perror_plus("ioctl SIOCGIFFLAGS");

1901

} else if(network.ifr_flags & IFF_UP) {

1902

network.ifr_flags &= ~(short)IFF_UP; /* clear flag */

1903

ret = ioctl(sd, SIOCSIFFLAGS, &network);

1904

if(ret == -1){

1905

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1906

}

1907

}

1908

ret = (int)TEMP_FAILURE_RETRY(close(sd));

1909

if(ret == -1){

1910

perror_plus("close");

1911

}

1912

/* Lower privileges permanently */

1913

errno = 0;

1914

ret = setuid(uid);

1915

if(ret == -1){

1916

perror_plus("setuid");

1917

}

3014

1918

}

3015

1919

}

3016

1920

3017

free(interfaces_to_take_down);

3018

free(interfaces_hooks);

3019

3020

1921

/* Removes the GPGME temp directory and all files inside */

3021

if(tempdir != NULL){

1922

if(tempdir_created){

3022

1923

struct dirent **direntries = NULL;

3023

int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY

3024

| O_NOFOLLOW

3025

| O_DIRECTORY

3026

| O_PATH));

3027

if(tempdir_fd == -1){

3028

perror_plus("open");

3029

} else {

3030

#ifdef __GLIBC__

3031

#if __GLIBC_PREREQ(2, 15)

3032

int numentries = scandirat(tempdir_fd, ".", &direntries,

3033

notdotentries, alphasort);

3034

#else /* not __GLIBC_PREREQ(2, 15) */

3035

int numentries = scandir(tempdir, &direntries, notdotentries,

3036

alphasort);

3037

#endif /* not __GLIBC_PREREQ(2, 15) */

3038

#else /* not __GLIBC__ */

3039

int numentries = scandir(tempdir, &direntries, notdotentries,

3040

alphasort);

3041

#endif /* not __GLIBC__ */

3042

if(numentries >= 0){

3043

for(int i = 0; i < numentries; i++){

3044

ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);

3045

if(ret == -1){

3046

fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"

3047

" \"%s\", 0): %s\n", tempdir,

3048

direntries[i]->d_name, strerror(errno));

3049

}

3050

free(direntries[i]);

3051

}

3052

3053

/* need to clean even if 0 because man page doesn't specify */

3054

free(direntries);

3055

if(numentries == -1){

3056

perror_plus("scandir");

3057

}

3058

ret = rmdir(tempdir);

3059

if(ret == -1 and errno != ENOENT){

3060

perror_plus("rmdir");

3061

}

1924

struct dirent *direntry = NULL;

1925

ret = scandir(tempdir, &direntries, notdotentries, alphasort);

1926

if (ret > 0){

1927

for(int i = 0; i < ret; i++){

1928

direntry = direntries[i];

1929

char *fullname = NULL;

1930

ret = asprintf(&fullname, "%s/%s", tempdir,

1931

direntry->d_name);

1932

if(ret < 0){

1933

perror_plus("asprintf");

1934

continue;

1935

}

1936

ret = remove(fullname);

1937

if(ret == -1){

1938

fprintf(stderr, "remove(\"%s\"): %s\n", fullname,

1939

strerror(errno));

1940

}

1941

free(fullname);

3062

1942

}

3063

TEMP_FAILURE_RETRY(close(tempdir_fd));

1943

}

1944

1945

/* need to be cleaned even if ret == 0 because man page dont specify */

1946

free(direntries);

1947

if (ret == -1){

1948

perror_plus("scandir");

1949

}

1950

ret = rmdir(tempdir);

1951

if(ret == -1 and errno != ENOENT){

1952

perror_plus("rmdir");

3064

1953

}

3065

1954

}

3066

1955