/mandos/release : revision 237.7.311

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

10

*

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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

32

/* 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

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#endif /* not _LARGEFILE_SOURCE */

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#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

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#endif

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#endif /* not _FILE_OFFSET_BITS */

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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(), remove() */

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

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stdout, ferror() */

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

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

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

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inet_pton(), connect() */

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

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

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

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program_invocation_short_name */

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

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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() */

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

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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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#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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133

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

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#define SECKEY "seckey.txt"

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135

#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_bug_address = "<mandos@recompile.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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typedef struct server{

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const char *ip;

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uint16_t port;

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in_port_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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168

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 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",

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.current_server = NULL };

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/* global so signal handler can reach it*/

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AvahiSimplePoll *simple_poll;

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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 */

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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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183

program_invocation_short_name);

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errno = e;

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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

}

197

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198

/*

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

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200

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

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201

* "buffer_length" is how much is already used.

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*/

203

__attribute__((nonnull, warn_unused_result))

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204

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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206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

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

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if(buffer == NULL){

207

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

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

183

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return 0;

184

214

}

215

*buffer = new_buf;

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buffer_capacity += BUFFER_SIZE;

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217

}

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218

return buffer_capacity;

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219

}

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

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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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__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 ret;

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

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if(new_server == NULL){

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228

perror_plus("malloc");

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return -1;

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return false;

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}

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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 };

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if(new_server->ip == NULL){

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236

perror_plus("strdup");

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return -1;

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free(new_server);

238

return false;

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}

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

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

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

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

252

return false;

207

253

}

208

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/* Special case of first server */

209

if (mc.current_server == NULL){

255

if(*current_server == NULL){

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new_server->next = new_server;

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new_server->prev = new_server;

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mc.current_server = new_server;

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

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*current_server = new_server;

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} else {

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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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/* 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->prev->next = new_server;

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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");

223

return -1;

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}

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return 0;

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(*current_server)->prev = new_server;

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}

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return true;

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}

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/*

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* Initialize GPGME.

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*/

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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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__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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gpgme_error_t rc;

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gpgme_engine_info_t engine_info;

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279

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/*

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

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282

*/

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bool import_key(const char *filename){

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bool import_key(const char * const filename){

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int ret;

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285

int fd;

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286

gpgme_data_t pgp_data;

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rc = gpgme_data_new_from_fd(&pgp_data, fd);

252

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if(rc != GPG_ERR_NO_ERROR){

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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));

296

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

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gpgme_strsource(rc), gpgme_strerror(rc));

255

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return false;

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}

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300

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rc = gpgme_op_import(mc.ctx, pgp_data);

301

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

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302

if(rc != GPG_ERR_NO_ERROR){

260

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

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gpgme_strsource(rc), gpgme_strerror(rc));

303

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

304

gpgme_strsource(rc), gpgme_strerror(rc));

262

305

return false;

263

306

}

264

307

271

314

}

272

315

273

316

if(debug){

274

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

317

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

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318

}

276

319

277

320

/* Init GPGME */

278

321

gpgme_check_version(NULL);

279

322

rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

280

323

if(rc != GPG_ERR_NO_ERROR){

281

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

282

gpgme_strsource(rc), gpgme_strerror(rc));

324

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

325

gpgme_strsource(rc), gpgme_strerror(rc));

283

326

return false;

284

327

}

285

328

286

329

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

287

330

rc = gpgme_get_engine_info(&engine_info);

288

331

if(rc != GPG_ERR_NO_ERROR){

289

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

290

gpgme_strsource(rc), gpgme_strerror(rc));

332

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

333

gpgme_strsource(rc), gpgme_strerror(rc));

291

334

return false;

292

335

}

293

336

while(engine_info != NULL){

299

342

engine_info = engine_info->next;

300

343

}

301

344

if(engine_info == NULL){

302

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

345

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

346

tempdir);

303

347

return false;

304

348

}

305

349

306

350

/* Create new GPGME "context" */

307

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

351

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

308

352

if(rc != GPG_ERR_NO_ERROR){

309

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

310

gpgme_strsource(rc), gpgme_strerror(rc));

353

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

354

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

355

gpgme_strerror(rc));

311

356

return false;

312

357

}

313

358

322

367

* Decrypt OpenPGP data.

323

368

* Returns -1 on error

324

369

*/

370

__attribute__((nonnull, warn_unused_result))

325

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

326

372

size_t crypto_size,

327

char **plaintext){

373

char **plaintext,

374

mandos_context *mc){

328

375

gpgme_data_t dh_crypto, dh_plain;

329

376

gpgme_error_t rc;

330

377

ssize_t ret;

332

379

ssize_t plaintext_length = 0;

333

380

334

381

if(debug){

335

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

382

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

336

383

}

337

384

338

385

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

339

386

rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,

340

387

0);

341

388

if(rc != GPG_ERR_NO_ERROR){

342

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

343

gpgme_strsource(rc), gpgme_strerror(rc));

389

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

390

gpgme_strsource(rc), gpgme_strerror(rc));

344

391

return -1;

345

392

}

346

393

347

394

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

348

395

rc = gpgme_data_new(&dh_plain);

349

396

if(rc != GPG_ERR_NO_ERROR){

350

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

351

gpgme_strsource(rc), gpgme_strerror(rc));

397

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

398

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

399

gpgme_strsource(rc), gpgme_strerror(rc));

352

400

gpgme_data_release(dh_crypto);

353

401

return -1;

354

402

}

355

403

356

404

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

357

405

data buffer */

358

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

406

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

359

407

if(rc != GPG_ERR_NO_ERROR){

360

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

361

gpgme_strsource(rc), gpgme_strerror(rc));

408

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

409

gpgme_strsource(rc), gpgme_strerror(rc));

362

410

plaintext_length = -1;

363

411

if(debug){

364

412

gpgme_decrypt_result_t result;

365

result = gpgme_op_decrypt_result(mc.ctx);

413

result = gpgme_op_decrypt_result(mc->ctx);

366

414

if(result == NULL){

367

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

415

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

368

416

} else {

369

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

370

result->unsupported_algorithm);

371

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

372

result->wrong_key_usage);

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);

373

421

if(result->file_name != NULL){

374

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

422

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

375

423

}

376

424

gpgme_recipient_t recipient;

377

425

recipient = result->recipients;

378

426

while(recipient != NULL){

379

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

380

gpgme_pubkey_algo_name(recipient->pubkey_algo));

381

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

382

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

383

recipient->status == GPG_ERR_NO_SECKEY

384

? "No" : "Yes");

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");

385

434

recipient = recipient->next;

386

435

}

387

436

}

390

439

}

391

440

392

441

if(debug){

393

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

442

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

394

443

}

395

444

396

445

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

403

452

*plaintext = NULL;

404

453

while(true){

405

454

plaintext_capacity = incbuffer(plaintext,

406

(size_t)plaintext_length,

407

plaintext_capacity);

455

(size_t)plaintext_length,

456

plaintext_capacity);

408

457

if(plaintext_capacity == 0){

409

perror_plus("incbuffer");

410

plaintext_length = -1;

411

goto decrypt_end;

458

perror_plus("incbuffer");

459

plaintext_length = -1;

460

goto decrypt_end;

412

461

}

413

462

414

463

ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,

427

476

}

428

477

429

478

if(debug){

430

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

479

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

431

480

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

432

481

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

433

482

}

444

493

return plaintext_length;

445

494

}

446

495

447

static const char * safer_gnutls_strerror(int value){

448

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

449

-Wunreachable-code */

450

if(ret == NULL)

451

ret = "(unknown)";

452

return ret;

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);

453

507

}

454

508

455

509

/* GnuTLS log function callback */

510

__attribute__((nonnull))

456

511

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

457

512

const char* string){

458

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

513

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

459

514

}

460

515

516

__attribute__((nonnull, warn_unused_result))

461

517

static int init_gnutls_global(const char *pubkeyfilename,

462

const char *seckeyfilename){

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

mandos_context *mc){

463

521

int ret;

522

unsigned int uret;

464

523

465

524

if(debug){

466

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

525

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

467

526

}

468

527

469

528

ret = gnutls_global_init();

470

529

if(ret != GNUTLS_E_SUCCESS){

471

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

472

safer_gnutls_strerror(ret));

530

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

531

safer_gnutls_strerror(ret));

473

532

return -1;

474

533

}

475

534

482

541

}

483

542

484

543

/* OpenPGP credentials */

485

ret = gnutls_certificate_allocate_credentials(&mc.cred);

544

ret = gnutls_certificate_allocate_credentials(&mc->cred);

486

545

if(ret != GNUTLS_E_SUCCESS){

487

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

488

safer_gnutls_strerror(ret));

546

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

547

safer_gnutls_strerror(ret));

489

548

gnutls_global_deinit();

490

549

return -1;

491

550

}

492

551

493

552

if(debug){

494

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

495

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

496

seckeyfilename);

553

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

554

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

555

pubkeyfilename,

556

seckeyfilename);

497

557

}

498

558

499

559

ret = gnutls_certificate_set_openpgp_key_file

500

(mc.cred, pubkeyfilename, seckeyfilename,

560

(mc->cred, pubkeyfilename, seckeyfilename,

501

561

GNUTLS_OPENPGP_FMT_BASE64);

502

562

if(ret != GNUTLS_E_SUCCESS){

503

fprintf(stderr,

504

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

505

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

506

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

507

safer_gnutls_strerror(ret));

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));

508

568

goto globalfail;

509

569

}

510

570

511

571

/* GnuTLS server initialization */

512

ret = gnutls_dh_params_init(&mc.dh_params);

513

if(ret != GNUTLS_E_SUCCESS){

514

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

515

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

516

goto globalfail;

517

}

518

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

519

if(ret != GNUTLS_E_SUCCESS){

520

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

521

safer_gnutls_strerror(ret));

522

goto globalfail;

523

}

524

525

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

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);

526

752

527

753

return 0;

528

754

529

755

globalfail:

530

756

531

gnutls_certificate_free_credentials(mc.cred);

757

gnutls_certificate_free_credentials(mc->cred);

532

758

gnutls_global_deinit();

533

gnutls_dh_params_deinit(mc.dh_params);

759

gnutls_dh_params_deinit(mc->dh_params);

534

760

return -1;

535

761

}

536

762

537

static int init_gnutls_session(gnutls_session_t *session){

763

__attribute__((nonnull, warn_unused_result))

764

static int init_gnutls_session(gnutls_session_t *session,

765

mandos_context *mc){

538

766

int ret;

539

767

/* GnuTLS session creation */

540

768

do {

544

772

}

545

773

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

546

774

if(ret != GNUTLS_E_SUCCESS){

547

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

548

safer_gnutls_strerror(ret));

775

fprintf_plus(stderr,

776

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

777

safer_gnutls_strerror(ret));

549

778

}

550

779

551

780

{

552

781

const char *err;

553

782

do {

554

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

783

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

555

784

if(quit_now){

556

785

gnutls_deinit(*session);

557

786

return -1;

558

787

}

559

788

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

560

789

if(ret != GNUTLS_E_SUCCESS){

561

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

562

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

563

safer_gnutls_strerror(ret));

790

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

791

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

792

safer_gnutls_strerror(ret));

564

793

gnutls_deinit(*session);

565

794

return -1;

566

795

}

568

797

569

798

do {

570

799

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

571

mc.cred);

800

mc->cred);

572

801

if(quit_now){

573

802

gnutls_deinit(*session);

574

803

return -1;

575

804

}

576

805

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

577

806

if(ret != GNUTLS_E_SUCCESS){

578

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

579

safer_gnutls_strerror(ret));

807

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

808

safer_gnutls_strerror(ret));

580

809

gnutls_deinit(*session);

581

810

return -1;

582

811

}

584

813

/* ignore client certificate if any. */

585

814

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

586

815

587

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

588

589

816

return 0;

590

817

}

591

818

593

820

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

594

821

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

595

822

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

596

1040

/* Called when a Mandos server is found */

597

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

1041

__attribute__((nonnull, warn_unused_result))

1042

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

598

1043

AvahiIfIndex if_index,

599

int af){

1044

int af, mandos_context *mc){

600

1045

int ret, tcp_sd = -1;

601

1046

ssize_t sret;

602

union {

603

struct sockaddr_in in;

604

struct sockaddr_in6 in6;

605

} to;

1047

struct sockaddr_storage to;

606

1048

char *buffer = NULL;

607

1049

char *decrypted_buffer = NULL;

608

1050

size_t buffer_length = 0;

611

1053

int retval = -1;

612

1054

gnutls_session_t session;

613

1055

int pf; /* Protocol family */

1056

bool route_added = false;

614

1057

615

1058

errno = 0;

616

1059

627

1070

pf = PF_INET;

628

1071

break;

629

1072

default:

630

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

1073

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

631

1074

errno = EINVAL;

632

1075

return -1;

633

1076

}

634

1077

635

ret = init_gnutls_session(&session);

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);

636

1111

if(ret != 0){

637

1112

return -1;

638

1113

}

639

1114

640

1115

if(debug){

641

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

642

"\n", ip, port);

1116

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

1117

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

643

1118

}

644

1119

645

tcp_sd = socket(pf, SOCK_STREAM, 0);

1120

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

646

1121

if(tcp_sd < 0){

647

1122

int e = errno;

648

1123

perror_plus("socket");

657

1132

658

1133

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

659

1134

if(af == AF_INET6){

660

to.in6.sin6_family = (sa_family_t)af;

661

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

1135

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

1136

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

662

1137

} else { /* IPv4 */

663

to.in.sin_family = (sa_family_t)af;

664

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

1138

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

1139

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

665

1140

}

666

1141

if(ret < 0 ){

667

1142

int e = errno;

671

1146

}

672

1147

if(ret == 0){

673

1148

int e = errno;

674

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

1149

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

675

1150

errno = e;

676

1151

goto mandos_end;

677

1152

}

678

1153

if(af == AF_INET6){

679

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

680

-Wconversion and

681

-Wunreachable-code */

682

683

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

684

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

685

-Wunreachable-code*/

1154

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

1155

if(IN6_IS_ADDR_LINKLOCAL

1156

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

686

1157

if(if_index == AVAHI_IF_UNSPEC){

687

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

688

" without a network interface\n");

1158

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

1159

" incomplete without a network interface\n");

689

1160

errno = EINVAL;

690

1161

goto mandos_end;

691

1162

}

692

1163

/* Set the network interface number as scope */

693

to.in6.sin6_scope_id = (uint32_t)if_index;

1164

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

694

1165

}

695

1166

} else {

696

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

697

-Wconversion and

698

-Wunreachable-code */

1167

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

699

1168

}

700

1169

701

1170

if(quit_now){

709

1178

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

710

1179

perror_plus("if_indextoname");

711

1180

} else {

712

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

713

ip, interface, port);

1181

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

1182

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

714

1183

}

715

1184

} else {

716

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

717

port);

1185

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

1186

ip, (uintmax_t)port);

718

1187

}

719

1188

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

720

1189

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

721

const char *pcret;

722

if(af == AF_INET6){

723

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

724

sizeof(addrstr));

725

} else {

726

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

727

sizeof(addrstr));

728

}

729

if(pcret == NULL){

730

perror_plus("inet_ntop");

731

} else {

732

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

733

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

734

}

735

}

736

}

737

738

if(quit_now){

739

errno = EINTR;

740

goto mandos_end;

741

}

742

743

if(af == AF_INET6){

744

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

745

} else {

746

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

747

}

748

if(ret < 0){

749

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

750

int e = errno;

751

perror_plus("connect");

752

errno = e;

753

}

754

goto mandos_end;

755

}

756

757

if(quit_now){

758

errno = EINTR;

759

goto mandos_end;

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;

760

1270

}

761

1271

762

1272

const char *out = mandos_protocol_version;

764

1274

while(true){

765

1275

size_t out_size = strlen(out);

766

1276

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

767

out_size - written));

1277

out_size - written));

768

1278

if(ret == -1){

769

1279

int e = errno;

770

1280

perror_plus("write");

790

1300

}

791

1301

792

1302

if(debug){

793

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

1303

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

794

1304

}

795

1305

796

1306

if(quit_now){

798

1308

goto mandos_end;

799

1309

}

800

1310

801

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

802

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

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);

803

1316

804

1317

if(quit_now){

805

1318

errno = EINTR;

816

1329

817

1330

if(ret != GNUTLS_E_SUCCESS){

818

1331

if(debug){

819

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

1332

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

820

1333

gnutls_perror(ret);

821

1334

}

822

1335

errno = EPROTO;

826

1339

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

827

1340

828

1341

if(debug){

829

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

830

ip);

1342

fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"

1343

" %s\n", ip);

831

1344

}

832

1345

833

1346

while(true){

838

1351

}

839

1352

840

1353

buffer_capacity = incbuffer(&buffer, buffer_length,

841

buffer_capacity);

1354

buffer_capacity);

842

1355

if(buffer_capacity == 0){

843

1356

int e = errno;

844

1357

perror_plus("incbuffer");

871

1384

}

872

1385

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

873

1386

if(ret < 0){

874

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

1387

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

1388

"***\n");

875

1389

gnutls_perror(ret);

876

1390

errno = EPROTO;

877

1391

goto mandos_end;

878

1392

}

879

1393

break;

880

1394

default:

881

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

882

" encrypted session with Mandos server\n");

1395

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

1396

" encrypted session with Mandos server\n");

883

1397

gnutls_bye(session, GNUTLS_SHUT_RDWR);

884

1398

errno = EIO;

885

1399

goto mandos_end;

890

1404

}

891

1405

892

1406

if(debug){

893

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

1407

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

894

1408

}

895

1409

896

1410

if(quit_now){

908

1422

909

1423

if(buffer_length > 0){

910

1424

ssize_t decrypted_buffer_size;

911

decrypted_buffer_size = pgp_packet_decrypt(buffer,

912

buffer_length,

913

&decrypted_buffer);

1425

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1426

&decrypted_buffer, mc);

914

1427

if(decrypted_buffer_size >= 0){

915

1428

916

1429

written = 0;

926

1439

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

927

1440

int e = errno;

928

1441

if(debug){

929

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

930

strerror(errno));

1442

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

1443

strerror(errno));

931

1444

}

932

1445

errno = e;

933

1446

goto mandos_end;

942

1455

943

1456

mandos_end:

944

1457

{

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

}

945

1464

int e = errno;

946

1465

free(decrypted_buffer);

947

1466

free(buffer);

964

1483

return retval;

965

1484

}

966

1485

1486

__attribute__((nonnull))

967

1487

static void resolve_callback(AvahiSServiceResolver *r,

968

1488

AvahiIfIndex interface,

969

1489

AvahiProtocol proto,

977

1497

AVAHI_GCC_UNUSED AvahiStringList *txt,

978

1498

AVAHI_GCC_UNUSED AvahiLookupResultFlags

979

1499

flags,

980

AVAHI_GCC_UNUSED void* userdata){

981

assert(r);

1500

void *mc){

1501

if(r == NULL){

1502

return;

1503

}

982

1504

983

1505

/* Called whenever a service has been resolved successfully or

984

1506

timed out */

985

1507

986

1508

if(quit_now){

1509

avahi_s_service_resolver_free(r);

987

1510

return;

988

1511

}

989

1512

990

1513

switch(event){

991

1514

default:

992

1515

case AVAHI_RESOLVER_FAILURE:

993

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

994

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

995

avahi_strerror(avahi_server_errno(mc.server)));

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)));

996

1521

break;

997

1522

998

1523

case AVAHI_RESOLVER_FOUND:

1000

1525

char ip[AVAHI_ADDRESS_STR_MAX];

1001

1526

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

1002

1527

if(debug){

1003

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

1004

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

1005

ip, (intmax_t)interface, port);

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);

1006

1531

}

1007

int ret = start_mandos_communication(ip, port, interface,

1008

avahi_proto_to_af(proto));

1532

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

1533

interface,

1534

avahi_proto_to_af(proto),

1535

mc);

1009

1536

if(ret == 0){

1010

avahi_simple_poll_quit(mc.simple_poll);

1537

avahi_simple_poll_quit(simple_poll);

1011

1538

} else {

1012

ret = add_server(ip, port, interface,

1013

avahi_proto_to_af(proto));

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

}

1014

1545

}

1015

1546

}

1016

1547

}

1026

1557

const char *domain,

1027

1558

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1028

1559

flags,

1029

AVAHI_GCC_UNUSED void* userdata){

1030

assert(b);

1560

void *mc){

1561

if(b == NULL){

1562

return;

1563

}

1031

1564

1032

1565

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

1033

1566

is removed from the LAN */

1040

1573

default:

1041

1574

case AVAHI_BROWSER_FAILURE:

1042

1575

1043

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

1044

avahi_strerror(avahi_server_errno(mc.server)));

1045

avahi_simple_poll_quit(mc.simple_poll);

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);

1046

1580

return;

1047

1581

1048

1582

case AVAHI_BROWSER_NEW:

1051

1585

the callback function is called the Avahi server will free the

1052

1586

resolver for us. */

1053

1587

1054

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

1055

name, type, domain, protocol, 0,

1056

resolve_callback, NULL) == NULL)

1057

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

1058

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

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)));

1059

1596

break;

1060

1597

1061

1598

case AVAHI_BROWSER_REMOVE:

1064

1601

case AVAHI_BROWSER_ALL_FOR_NOW:

1065

1602

case AVAHI_BROWSER_CACHE_EXHAUSTED:

1066

1603

if(debug){

1067

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

1604

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

1605

" searching...\n");

1068

1606

}

1069

1607

break;

1070

1608

}

1079

1617

signal_received = sig;

1080

1618

int old_errno = errno;

1081

1619

/* set main loop to exit */

1082

if(mc.simple_poll != NULL){

1083

avahi_simple_poll_quit(mc.simple_poll);

1620

if(simple_poll != NULL){

1621

avahi_simple_poll_quit(simple_poll);

1084

1622

}

1085

1623

errno = old_errno;

1086

1624

}

1087

1625

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){

1641

if(debug){

1642

ret_errno = errno;

1643

perror_plus("ioctl SIOCGIFFLAGS");

1644

errno = ret_errno;

1645

}

1646

return false;

1647

}

1648

return true;

1649

}

1650

1651

__attribute__((nonnull, warn_unused_result))

1652

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

1653

1654

/* Reject the loopback device */

1655

if(ifr->ifr_flags & IFF_LOOPBACK){

1656

if(debug){

1657

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

1658

ifname);

1659

}

1660

return false;

1661

}

1662

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

1663

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

1664

if(debug){

1665

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

1666

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

1667

}

1668

return true;

1669

}

1670

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

1671

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

1672

if(debug){

1673

fprintf_plus(stderr, "Rejecting non-broadcast interface"

1674

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

1675

}

1676

return false;

1677

}

1678

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

1679

if(ifr->ifr_flags & IFF_NOARP){

1680

if(debug){

1681

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

1682

ifname);

1683

}

1684

return false;

1685

}

1686

1687

/* Accept this device */

1688

if(debug){

1689

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

1690

}

1691

return true;

1692

}

1693

1088

1694

/*

1089

1695

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

1090

1696

* corresponds to an acceptable network device.

1091

1697

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

1092

1698

*/

1699

__attribute__((nonnull, warn_unused_result))

1093

1700

int good_interface(const struct dirent *if_entry){

1094

ssize_t ssret;

1095

char *flagname = NULL;

1096

1701

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

1097

1702

return 0;

1098

1703

}

1099

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

1100

if_entry->d_name);

1101

if(ret < 0){

1102

perror_plus("asprintf");

1103

return 0;

1104

}

1105

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

1106

if(flags_fd == -1){

1107

perror_plus("open");

1108

free(flagname);

1109

return 0;

1110

}

1111

free(flagname);

1112

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

1113

/* read line from flags_fd */

1114

ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */

1115

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

1116

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

1117

if(flagstring == NULL){

1118

perror_plus("malloc");

1119

close(flags_fd);

1120

return 0;

1121

}

1122

while(to_read > 0){

1123

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

1124

(size_t)to_read));

1125

if(ssret == -1){

1126

perror_plus("read");

1127

free(flagstring);

1128

close(flags_fd);

1129

return 0;

1130

}

1131

to_read -= ssret;

1132

if(ssret == 0){

1133

break;

1134

}

1135

}

1136

close(flags_fd);

1137

intmax_t tmpmax;

1138

char *tmp;

1139

errno = 0;

1140

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

1141

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

1142

and not (isspace(*tmp)))

1143

or tmpmax != (ifreq_flags)tmpmax){

1144

if(debug){

1145

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

1146

flagstring, if_entry->d_name);

1147

}

1148

free(flagstring);

1149

return 0;

1150

}

1151

free(flagstring);

1152

ifreq_flags flags = (ifreq_flags)tmpmax;

1153

/* Reject the loopback device */

1154

if(flags & IFF_LOOPBACK){

1155

if(debug){

1156

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

1157

if_entry->d_name);

1158

}

1159

return 0;

1160

}

1161

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

1162

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

1163

if(debug){

1164

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

1165

if_entry->d_name);

1166

}

1167

return 1;

1168

}

1169

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

1170

if(not (flags & IFF_BROADCAST)){

1171

if(debug){

1172

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

1173

if_entry->d_name);

1174

}

1175

return 0;

1176

}

1177

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

1178

if(flags & IFF_NOARP){

1179

if(debug){

1180

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

1181

if_entry->d_name);

1182

}

1183

return 0;

1184

}

1185

/* Accept this device */

1186

if(debug){

1187

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

1188

if_entry->d_name);

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;

1189

1716

}

1190

1717

return 1;

1191

1718

}

1192

1719

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))

1193

1755

int notdotentries(const struct dirent *direntry){

1194

1756

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

1195

1757

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

1201

1763

return 1;

1202

1764

}

1203

1765

1204

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

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){

1205

1824

int ret;

1206

1825

struct timespec now;

1207

1826

struct timespec waited_time;

1208

1827

intmax_t block_time;

1209

1828

1210

1829

while(true){

1211

if(mc.current_server == NULL){

1212

if (debug){

1213

fprintf(stderr,

1214

"Wait until first server is found. No timeout!\n");

1830

if(mc->current_server == NULL){

1831

if(debug){

1832

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

1833

" No timeout!\n");

1215

1834

}

1216

1835

ret = avahi_simple_poll_iterate(s, -1);

1217

1836

} else {

1218

if (debug){

1219

fprintf(stderr, "Check current_server if we should run it,"

1220

" or wait\n");

1837

if(debug){

1838

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

1839

" it, or wait\n");

1221

1840

}

1222

1841

/* the current time */

1223

1842

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1228

1847

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

1229

1848

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

1230

1849

waited_time.tv_sec = (now.tv_sec

1231

- mc.current_server->last_seen.tv_sec);

1850

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

1232

1851

waited_time.tv_nsec = (now.tv_nsec

1233

- mc.current_server->last_seen.tv_nsec);

1852

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

1234

1853

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

1235

1854

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

1236

1855

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

1238

1857

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

1239

1858

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

1240

1859

1241

if (debug){

1242

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

1860

if(debug){

1861

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

1862

block_time);

1243

1863

}

1244

1864

1245

1865

if(block_time <= 0){

1246

ret = start_mandos_communication(mc.current_server->ip,

1247

mc.current_server->port,

1248

mc.current_server->if_index,

1249

mc.current_server->af);

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);

1250

1870

if(ret == 0){

1251

avahi_simple_poll_quit(mc.simple_poll);

1871

avahi_simple_poll_quit(s);

1252

1872

return 0;

1253

1873

}

1254

1874

ret = clock_gettime(CLOCK_MONOTONIC,

1255

&mc.current_server->last_seen);

1875

&mc->current_server->last_seen);

1256

1876

if(ret == -1){

1257

1877

perror_plus("clock_gettime");

1258

1878

return -1;

1259

1879

}

1260

mc.current_server = mc.current_server->next;

1880

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

1261

1881

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

1262

1882

servers, but don't block */

1263

1883

}

1265

1885

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

1266

1886

}

1267

1887

if(ret != 0){

1268

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

1888

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

1269

1889

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

1270

1890

}

1271

1891

}

1272

1892

}

1273

1893

}

1274

1894

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

1275

2287

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 };

1276

2292

AvahiSServiceBrowser *sb = NULL;

1277

int error;

2293

error_t ret_errno;

1278

2294

int ret;

1279

2295

intmax_t tmpmax;

1280

2296

char *tmp;

1281

2297

int exitcode = EXIT_SUCCESS;

1282

const char *interface = "";

1283

struct ifreq network;

1284

int sd = -1;

1285

bool take_down_interface = false;

1286

uid_t uid;

1287

gid_t gid;

1288

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

1289

bool tempdir_created = false;

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;

1290

2303

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1291

2304

const char *seckey = PATHDIR "/" SECKEY;

1292

2305

const char *pubkey = PATHDIR "/" PUBKEY;

2306

const char *dh_params_file = NULL;

2307

char *interfaces_hooks = NULL;

1293

2308

1294

2309

bool gnutls_initialized = false;

1295

2310

bool gpgme_initialized = false;

1347

2362

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

1348

2363

" Diffie-Hellman key exchange",

1349

2364

.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 },

1350

2370

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

1351

2371

.arg = "STRING",

1352

2372

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

1357

2377

.group = 2 },

1358

2378

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

1359

2379

.arg = "SECONDS",

1360

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

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",

1361

2385

.group = 2 },

1362

2386

/*

1363

2387

* These reproduce what we would get without ARGP_NO_HELP

1382

2406

connect_to = arg;

1383

2407

break;

1384

2408

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

1385

interface = arg;

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

}

1386

2414

break;

1387

2415

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

1388

2416

seckey = arg;

1399

2427

}

1400

2428

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

1401

2429

break;

2430

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

2431

dh_params_file = arg;

2432

break;

1402

2433

case 130: /* --priority */

1403

2434

mc.priority = arg;

1404

2435

break;

1417

2448

argp_error(state, "Bad retry interval");

1418

2449

}

1419

2450

break;

2451

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

2452

hookdir = arg;

2453

break;

1420

2454

/*

1421

2455

* These reproduce what we would get without ARGP_NO_HELP

1422

2456

*/

1428

2462

argp_state_help(state, state->out_stream,

1429

2463

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1430

2464

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

1431

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

2465

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

1432

2466

exit(argp_err_exit_status);

1433

2467

break;

1434

2468

default:

1457

2491

goto end;

1458

2492

}

1459

2493

}

1460

2494

1461

2495

{

1462

2496

/* Work around Debian bug #633582:

1463

2497

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

1464

struct stat st;

1465

1466

/* Re-raise priviliges */

1467

errno = 0;

1468

ret = seteuid(0);

1469

if(ret == -1){

1470

perror_plus("seteuid");

1471

}

1472

1473

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

1474

int seckey_fd = open(seckey, O_RDONLY);

1475

if(seckey_fd == -1){

1476

perror_plus("open");

1477

} else {

1478

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

1479

if(ret == -1){

1480

perror_plus("fstat");

1481

} else {

1482

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1483

ret = fchown(seckey_fd, uid, gid);

1484

if(ret == -1){

1485

perror_plus("fchown");

1486

}

1487

}

1488

}

1489

TEMP_FAILURE_RETRY(close(seckey_fd));

1490

}

1491

}

1492

1493

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

1494

int pubkey_fd = open(pubkey, O_RDONLY);

1495

if(pubkey_fd == -1){

1496

perror_plus("open");

1497

} else {

1498

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

1499

if(ret == -1){

1500

perror_plus("fstat");

1501

} else {

1502

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1503

ret = fchown(pubkey_fd, uid, gid);

1504

if(ret == -1){

1505

perror_plus("fchown");

1506

}

1507

}

1508

}

1509

TEMP_FAILURE_RETRY(close(pubkey_fd));

1510

}

1511

}

1512

1513

/* Lower privileges */

1514

errno = 0;

1515

ret = seteuid(uid);

1516

if(ret == -1){

1517

perror_plus("seteuid");

1518

}

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);

1519

2588

}

1520

2589

1521

2590

if(not debug){

1522

2591

avahi_set_log_function(empty_log);

1523

2592

}

1524

1525

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

1526

struct dirent **direntries;

1527

ret = scandir(sys_class_net, &direntries, good_interface,

1528

alphasort);

1529

if(ret >= 1){

1530

/* Pick the first good interface */

1531

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

1532

if(debug){

1533

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

1534

}

1535

if(interface == NULL){

1536

perror_plus("malloc");

1537

free(direntries);

1538

exitcode = EXIT_FAILURE;

1539

goto end;

1540

}

1541

free(direntries);

1542

} else {

1543

free(direntries);

1544

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

1545

exitcode = EXIT_FAILURE;

1546

goto end;

1547

}

1548

}

1549

2593

1550

2594

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

1551

2595

from the signal handler */

1552

2596

/* Initialize the pseudo-RNG for Avahi */

1553

2597

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

1554

mc.simple_poll = avahi_simple_poll_new();

1555

if(mc.simple_poll == NULL){

1556

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

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");

1557

2602

exitcode = EX_UNAVAILABLE;

1558

2603

goto end;

1559

2604

}

1621

2666

}

1622

2667

}

1623

2668

1624

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

1625

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

1626

if_index = (AvahiIfIndex) if_nametoindex(interface);

1627

if(if_index == 0){

1628

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

1629

exitcode = EX_UNAVAILABLE;

1630

goto end;

1631

}

1632

1633

if(quit_now){

1634

goto end;

1635

}

1636

1637

/* Re-raise priviliges */

1638

errno = 0;

1639

ret = seteuid(0);

1640

if(ret == -1){

1641

perror_plus("seteuid");

1642

}

1643

1644

#ifdef __linux__

1645

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1646

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

1647

ret = klogctl(8, NULL, 5);

1648

bool restore_loglevel = true;

1649

if(ret == -1){

1650

restore_loglevel = false;

1651

perror_plus("klogctl");

1652

}

1653

#endif /* __linux__ */

1654

1655

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1656

if(sd < 0){

1657

perror_plus("socket");

1658

exitcode = EX_OSERR;

1659

#ifdef __linux__

1660

if(restore_loglevel){

1661

ret = klogctl(7, NULL, 0);

1662

if(ret == -1){

1663

perror_plus("klogctl");

1664

}

1665

}

1666

#endif /* __linux__ */

1667

/* Lower privileges */

1668

errno = 0;

1669

ret = seteuid(uid);

1670

if(ret == -1){

1671

perror_plus("seteuid");

1672

}

1673

goto end;

1674

}

1675

strcpy(network.ifr_name, interface);

1676

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

1677

if(ret == -1){

1678

perror_plus("ioctl SIOCGIFFLAGS");

1679

#ifdef __linux__

1680

if(restore_loglevel){

1681

ret = klogctl(7, NULL, 0);

1682

if(ret == -1){

1683

perror_plus("klogctl");

1684

}

1685

}

1686

#endif /* __linux__ */

1687

exitcode = EX_OSERR;

1688

/* Lower privileges */

1689

errno = 0;

1690

ret = seteuid(uid);

1691

if(ret == -1){

1692

perror_plus("seteuid");

1693

}

1694

goto end;

1695

}

1696

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

1697

network.ifr_flags |= IFF_UP;

1698

take_down_interface = true;

1699

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

1700

if(ret == -1){

1701

take_down_interface = false;

1702

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1703

exitcode = EX_OSERR;

1704

#ifdef __linux__

1705

if(restore_loglevel){

1706

ret = klogctl(7, NULL, 0);

1707

if(ret == -1){

1708

perror_plus("klogctl");

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);

2693

} 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;

1709

2720

}

1710

2721

}

1711

#endif /* __linux__ */

1712

/* Lower privileges */

1713

errno = 0;

1714

ret = seteuid(uid);

1715

if(ret == -1){

1716

perror_plus("seteuid");

1717

}

1718

goto end;

1719

}

1720

}

1721

/* Sleep checking until interface is running.

1722

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

1723

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

1724

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

1725

if(ret == -1){

1726

perror_plus("ioctl SIOCGIFFLAGS");

1727

} else if(network.ifr_flags & IFF_RUNNING){

1728

2722

break;

1729

2723

}

1730

struct timespec sleeptime = { .tv_nsec = 250000000 };

1731

ret = nanosleep(&sleeptime, NULL);

1732

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

1733

perror_plus("nanosleep");

1734

}

1735

}

1736

if(not take_down_interface){

1737

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

1738

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

1739

if(ret == -1){

1740

perror_plus("close");

1741

}

1742

}

1743

#ifdef __linux__

1744

if(restore_loglevel){

1745

/* Restores kernel loglevel to default */

1746

ret = klogctl(7, NULL, 0);

1747

if(ret == -1){

1748

perror_plus("klogctl");

1749

}

1750

}

1751

#endif /* __linux__ */

1752

/* Lower privileges */

1753

errno = 0;

1754

if(take_down_interface){

1755

/* Lower privileges */

1756

ret = seteuid(uid);

1757

if(ret == -1){

1758

perror_plus("seteuid");

1759

}

1760

} else {

1761

/* Lower privileges permanently */

1762

ret = setuid(uid);

1763

if(ret == -1){

1764

perror_plus("setuid");

1765

}

1766

}

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);

1767

2751

}

1768

2752

1769

2753

if(quit_now){

1770

2754

goto end;

1771

2755

}

1772

2756

1773

ret = init_gnutls_global(pubkey, seckey);

2757

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

1774

2758

if(ret == -1){

1775

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

2759

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

1776

2760

exitcode = EX_UNAVAILABLE;

1777

2761

goto end;

1778

2762

} else {

1783

2767

goto end;

1784

2768

}

1785

2769

1786

if(mkdtemp(tempdir) == NULL){

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){

1787

2780

perror_plus("mkdtemp");

1788

2781

goto end;

1789

2782

}

1790

tempdir_created = true;

1791

2783

1792

2784

if(quit_now){

1793

2785

goto end;

1794

2786

}

1795

2787

1796

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

1797

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

2788

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

2789

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

1798

2790

exitcode = EX_UNAVAILABLE;

1799

2791

goto end;

1800

2792

} else {

1809

2801

/* Connect directly, do not use Zeroconf */

1810

2802

/* (Mainly meant for debugging) */

1811

2803

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

2804

1812

2805

if(address == NULL){

1813

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

2806

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

1814

2807

exitcode = EX_USAGE;

1815

2808

goto end;

1816

2809

}

1819

2812

goto end;

1820

2813

}

1821

2814

1822

uint16_t port;

2815

in_port_t port;

1823

2816

errno = 0;

1824

2817

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

1825

2818

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

1826

or tmpmax != (uint16_t)tmpmax){

1827

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

2819

or tmpmax != (in_port_t)tmpmax){

2820

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

1828

2821

exitcode = EX_USAGE;

1829

2822

goto end;

1830

2823

}

1831

2824

1832

2825

if(quit_now){

1833

2826

goto end;

1834

2827

}

1835

2828

1836

port = (uint16_t)tmpmax;

2829

port = (in_port_t)tmpmax;

1837

2830

*address = '\0';

1838

2831

/* Colon in address indicates IPv6 */

1839

2832

int af;

1855

2848

}

1856

2849

1857

2850

while(not quit_now){

1858

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

2851

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

2852

&mc);

1859

2853

if(quit_now or ret == 0){

1860

2854

break;

1861

2855

}

1862

2856

if(debug){

1863

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

1864

(int)retry_interval);

2857

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

2858

(int)retry_interval);

1865

2859

}

1866

sleep((int)retry_interval);

2860

sleep((unsigned int)retry_interval);

1867

2861

}

1868

2862

1869

if (not quit_now){

2863

if(not quit_now){

1870

2864

exitcode = EXIT_SUCCESS;

1871

2865

}

1872

2866

1873

2867

goto end;

1874

2868

}

1875

2869

1887

2881

config.publish_domain = 0;

1888

2882

1889

2883

/* Allocate a new server */

1890

mc.server = avahi_server_new(avahi_simple_poll_get

1891

(mc.simple_poll), &config, NULL,

1892

NULL, &error);

2884

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2885

&config, NULL, NULL, &ret_errno);

1893

2886

1894

2887

/* Free the Avahi configuration data */

1895

2888

avahi_server_config_free(&config);

1897

2890

1898

2891

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

1899

2892

if(mc.server == NULL){

1900

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

1901

avahi_strerror(error));

2893

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

2894

avahi_strerror(ret_errno));

1902

2895

exitcode = EX_UNAVAILABLE;

1903

2896

goto end;

1904

2897

}

1910

2903

/* Create the Avahi service browser */

1911

2904

sb = avahi_s_service_browser_new(mc.server, if_index,

1912

2905

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1913

NULL, 0, browse_callback, NULL);

2906

NULL, 0, browse_callback,

2907

(void *)&mc);

1914

2908

if(sb == NULL){

1915

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

1916

avahi_strerror(avahi_server_errno(mc.server)));

2909

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

2910

avahi_strerror(avahi_server_errno(mc.server)));

1917

2911

exitcode = EX_UNAVAILABLE;

1918

2912

goto end;

1919

2913

}

1925

2919

/* Run the main loop */

1926

2920

1927

2921

if(debug){

1928

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

2922

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

1929

2923

}

1930

1931

ret = avahi_loop_with_timeout(mc.simple_poll,

1932

(int)(retry_interval * 1000));

2924

2925

ret = avahi_loop_with_timeout(simple_poll,

2926

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

1933

2927

if(debug){

1934

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

1935

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

2928

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

2929

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

1936

2930

}

1937

2931

1938

2932

end:

1939

2933

1940

2934

if(debug){

1941

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

2935

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

1942

2936

}

1943

2937

1944

2938

/* Cleanup things */

2939

free(mc.interfaces);

2940

1945

2941

if(sb != NULL)

1946

2942

avahi_s_service_browser_free(sb);

1947

2943

1948

2944

if(mc.server != NULL)

1949

2945

avahi_server_free(mc.server);

1950

2946

1951

if(mc.simple_poll != NULL)

1952

avahi_simple_poll_free(mc.simple_poll);

2947

if(simple_poll != NULL)

2948

avahi_simple_poll_free(simple_poll);

1953

2949

1954

2950

if(gnutls_initialized){

1955

2951

gnutls_certificate_free_credentials(mc.cred);

1960

2956

if(gpgme_initialized){

1961

2957

gpgme_release(mc.ctx);

1962

2958

}

1963

2959

1964

2960

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

1965

2961

has seen */

1966

2962

if(mc.current_server != NULL){

1967

2963

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

1968

2964

while(mc.current_server != NULL){

1969

2965

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

1970

2974

free(mc.current_server);

1971

2975

mc.current_server = next;

1972

2976

}

1973

2977

}

1974

2978

1975

/* Take down the network interface */

1976

if(take_down_interface){

1977

/* Re-raise priviliges */

1978

errno = 0;

1979

ret = seteuid(0);

1980

if(ret == -1){

1981

perror_plus("seteuid");

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

}

1982

3008

}

1983

if(geteuid() == 0){

1984

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

1985

if(ret == -1){

1986

perror_plus("ioctl SIOCGIFFLAGS");

1987

} else if(network.ifr_flags & IFF_UP) {

1988

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

1989

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

1990

if(ret == -1){

1991

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1992

}

1993

}

1994

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

1995

if(ret == -1){

1996

perror_plus("close");

1997

}

1998

/* Lower privileges permanently */

1999

errno = 0;

2000

ret = setuid(uid);

2001

if(ret == -1){

2002

perror_plus("setuid");

2003

}

3009

3010

ret_errno = lower_privileges_permanently();

3011

if(ret_errno != 0){

3012

errno = ret_errno;

3013

perror_plus("Failed to lower privileges permanently");

2004

3014

}

2005

3015

}

2006

3016

3017

free(interfaces_to_take_down);

3018

free(interfaces_hooks);

3019

2007

3020

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

2008

if(tempdir_created){

3021

if(tempdir != NULL){

2009

3022

struct dirent **direntries = NULL;

2010

struct dirent *direntry = NULL;

2011

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

2012

alphasort);

2013

if (numentries > 0){

2014

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

2015

direntry = direntries[i];

2016

char *fullname = NULL;

2017

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

2018

direntry->d_name);

2019

if(ret < 0){

2020

perror_plus("asprintf");

2021

continue;

2022

}

2023

ret = remove(fullname);

2024

if(ret == -1){

2025

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

2026

strerror(errno));

2027

}

2028

free(fullname);

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

}

2029

3062

}

2030

}

2031

2032

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

2033

free(direntries);

2034

if (numentries == -1){

2035

perror_plus("scandir");

2036

}

2037

ret = rmdir(tempdir);

2038

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

2039

perror_plus("rmdir");

3063

TEMP_FAILURE_RETRY(close(tempdir_fd));

2040

3064

}

2041

3065

}

2042

3066