/mandos/release : revision 237.16.26

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

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*

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* Everything else is

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*

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* This file is part of Mandos.

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*

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* Mandos is free software: you can redistribute it and/or modify it

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* under the terms of the GNU General Public License as published by

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* the Free Software Foundation, either version 3 of the License, or

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* (at your option) any later version.

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*

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* Mandos is distributed in the hope that it will be useful, but

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*

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

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

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* published by the Free Software Foundation, either version 3 of the

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* License, or (at your option) any later version.

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*

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* This program is distributed in the hope that it will be useful, but

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* WITHOUT ANY WARRANTY; without even the implied warranty of

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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

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* General Public License for more details.

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*

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* You should have received a copy of the GNU General Public License

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* along with Mandos. If not, see <http://www.gnu.org/licenses/>.

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* along with this program. If not, see

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

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*

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

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*/

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

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#ifndef _LARGEFILE_SOURCE

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#define _LARGEFILE_SOURCE

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#endif /* not _LARGEFILE_SOURCE */

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#endif

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#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

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#endif /* not _FILE_OFFSET_BITS */

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#endif

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

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

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stdout, ferror() */

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

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stdout, ferror(), remove() */

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

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

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

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strtof(), abort() */

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#include <stdbool.h> /* bool, false, true */

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#include <string.h> /* strcmp(), strlen(), strerror(),

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asprintf(), strncpy(), strsignal()

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*/

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#include <string.h> /* memset(), strcmp(), strlen(),

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strerror(), asprintf(), strcpy() */

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#include <sys/ioctl.h> /* ioctl */

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#include <sys/types.h> /* socket(), inet_pton(), sockaddr,

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sockaddr_in6, PF_INET6,

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opendir(), DIR */

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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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getnameinfo() */

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

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inet_pton(), connect() */

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

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

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*/

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

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strtoimax() */

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

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

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ENOTEMPTY,

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

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*/

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

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

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

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unlinkat() */

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

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setgid(), pause(), _exit() */

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

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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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#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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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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in_port_t port;

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uint16_t port;

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AvahiIfIndex if_index;

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int af;

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struct timespec last_seen;

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

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typedef struct {

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AvahiSimplePoll *simple_poll;

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AvahiServer *server;

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gnutls_certificate_credentials_t cred;

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unsigned int dh_bits;

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const char *priority;

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gpgme_ctx_t ctx;

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server *current_server;

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char *interfaces;

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size_t interfaces_size;

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} mandos_context;

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161

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/* global so signal handler can reach it*/

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AvahiSimplePoll *simple_poll;

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

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

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.dh_bits = 1024, .priority = "SECURE256"

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":!CTYPE-X.509:+CTYPE-OPENPGP",

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.current_server = NULL };

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sig_atomic_t quit_now = 0;

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int signal_received = 0;

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/* Function to use when printing errors */

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172

void perror_plus(const char *print_text){

187

int e = errno;

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

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program_invocation_short_name);

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errno = e;

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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);

198

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199

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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));

184

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

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}

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/*

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

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* "buffer_length" is how much is already used.

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*/

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__attribute__((nonnull, warn_unused_result))

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size_t incbuffer(char **buffer, size_t buffer_length,

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size_t buffer_capacity){

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if(buffer_length + BUFFER_SIZE > buffer_capacity){

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

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if(new_buf == NULL){

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int old_errno = errno;

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free(*buffer);

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errno = old_errno;

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*buffer = NULL;

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

196

if(buffer == NULL){

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return 0;

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}

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*buffer = new_buf;

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buffer_capacity += BUFFER_SIZE;

223

200

}

224

201

return buffer_capacity;

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202

}

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

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__attribute__((nonnull, warn_unused_result))

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

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int af, server **current_server){

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int add_server(const char *ip, uint16_t port, AvahiIfIndex if_index,

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int af){

231

207

int ret;

232

208

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

233

209

if(new_server == NULL){

234

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perror_plus("malloc");

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return false;

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return -1;

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212

}

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213

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

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.port = port,

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.af = af };

241

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if(new_server->ip == NULL){

242

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perror_plus("strdup");

243

free(new_server);

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return false;

245

}

246

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

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if(ret == -1){

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perror_plus("clock_gettime");

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#ifdef __GNUC__

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#pragma GCC diagnostic push

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#pragma GCC diagnostic ignored "-Wcast-qual"

252

#endif

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

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#ifdef __GNUC__

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#pragma GCC diagnostic pop

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#endif

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free(new_server);

258

return false;

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return -1;

259

220

}

260

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/* Special case of first server */

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if(*current_server == NULL){

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if (mc.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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*current_server = new_server;

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mc.current_server = new_server;

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

265

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} else {

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

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new_server->next = *current_server;

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

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new_server->next = mc.current_server;

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

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new_server->prev->next = new_server;

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(*current_server)->prev = new_server;

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}

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return true;

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}

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

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__attribute__((warn_unused_result))

277

int raise_privileges(void){

278

int old_errno = errno;

279

int ret = 0;

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

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ret = errno;

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}

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errno = old_errno;

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return ret;

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}

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

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__attribute__((warn_unused_result))

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int raise_privileges_permanently(void){

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int old_errno = errno;

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int ret = raise_privileges();

292

if(ret != 0){

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errno = old_errno;

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return ret;

295

}

296

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

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ret = errno;

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}

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errno = old_errno;

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return ret;

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}

302

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

304

__attribute__((warn_unused_result))

305

int lower_privileges(void){

306

int old_errno = errno;

307

int ret = 0;

308

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

309

ret = errno;

310

}

311

errno = old_errno;

312

return ret;

313

}

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315

/* Lower privileges permanently */

316

__attribute__((warn_unused_result))

317

int lower_privileges_permanently(void){

318

int old_errno = errno;

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int ret = 0;

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

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ret = errno;

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}

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errno = old_errno;

324

return ret;

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mc.current_server->prev = new_server;

232

}

233

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");

236

return -1;

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}

238

return 0;

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}

326

240

327

241

/*

328

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* Initialize GPGME.

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*/

330

__attribute__((nonnull, warn_unused_result))

331

static bool init_gpgme(const char * const seckey,

332

const char * const pubkey,

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const char * const tempdir,

334

mandos_context *mc){

244

static bool init_gpgme(const char *seckey, const char *pubkey,

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const char *tempdir){

335

246

gpgme_error_t rc;

336

247

gpgme_engine_info_t engine_info;

337

248

249

338

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/*

339

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

340

252

*/

341

bool import_key(const char * const filename){

253

bool import_key(const char *filename){

342

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int ret;

343

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int fd;

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gpgme_data_t pgp_data;

349

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return false;

350

262

}

351

263

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/* Workaround for systems without a real-time clock; see also

353

Debian bug #894495: <https://bugs.debian.org/894495> */

354

do {

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{

356

time_t currtime = time(NULL);

357

if(currtime != (time_t)-1){

358

struct tm tm;

359

if(gmtime_r(&currtime, &tm) == NULL) {

360

perror_plus("gmtime_r");

361

break;

362

}

363

if(tm.tm_year != 70 or tm.tm_mon != 0){

364

break;

365

}

366

if(debug){

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fprintf_plus(stderr, "System clock is January 1970");

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}

369

} else {

370

if(debug){

371

fprintf_plus(stderr, "System clock is invalid");

372

}

373

}

374

}

375

struct stat keystat;

376

ret = fstat(fd, &keystat);

377

if(ret != 0){

378

perror_plus("fstat");

379

break;

380

}

381

ret = raise_privileges();

382

if(ret != 0){

383

errno = ret;

384

perror_plus("Failed to raise privileges");

385

break;

386

}

387

if(debug){

388

fprintf_plus(stderr,

389

"Setting system clock to key file mtime");

390

}

391

time_t keytime = keystat.st_mtim.tv_sec;

392

if(stime(&keytime) != 0){

393

perror_plus("stime");

394

}

395

ret = lower_privileges();

396

if(ret != 0){

397

errno = ret;

398

perror_plus("Failed to lower privileges");

399

}

400

} while(false);

401

402

264

rc = gpgme_data_new_from_fd(&pgp_data, fd);

403

265

if(rc != GPG_ERR_NO_ERROR){

404

266

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

406

268

return false;

407

269

}

408

270

409

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

271

rc = gpgme_op_import(mc.ctx, pgp_data);

410

272

if(rc != GPG_ERR_NO_ERROR){

411

273

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

412

274

gpgme_strsource(rc), gpgme_strerror(rc));

413

275

return false;

414

276

}

415

{

416

gpgme_import_result_t import_result

417

= gpgme_op_import_result(mc->ctx);

418

if((import_result->imported < 1

419

or import_result->not_imported > 0)

420

and import_result->unchanged == 0){

421

fprintf_plus(stderr, "bad gpgme_op_import_results:\n");

422

fprintf_plus(stderr,

423

"The total number of considered keys: %d\n",

424

import_result->considered);

425

fprintf_plus(stderr,

426

"The number of keys without user ID: %d\n",

427

import_result->no_user_id);

428

fprintf_plus(stderr,

429

"The total number of imported keys: %d\n",

430

import_result->imported);

431

fprintf_plus(stderr, "The number of imported RSA keys: %d\n",

432

import_result->imported_rsa);

433

fprintf_plus(stderr, "The number of unchanged keys: %d\n",

434

import_result->unchanged);

435

fprintf_plus(stderr, "The number of new user IDs: %d\n",

436

import_result->new_user_ids);

437

fprintf_plus(stderr, "The number of new sub keys: %d\n",

438

import_result->new_sub_keys);

439

fprintf_plus(stderr, "The number of new signatures: %d\n",

440

import_result->new_signatures);

441

fprintf_plus(stderr, "The number of new revocations: %d\n",

442

import_result->new_revocations);

443

fprintf_plus(stderr,

444

"The total number of secret keys read: %d\n",

445

import_result->secret_read);

446

fprintf_plus(stderr,

447

"The number of imported secret keys: %d\n",

448

import_result->secret_imported);

449

fprintf_plus(stderr,

450

"The number of unchanged secret keys: %d\n",

451

import_result->secret_unchanged);

452

fprintf_plus(stderr, "The number of keys not imported: %d\n",

453

import_result->not_imported);

454

for(gpgme_import_status_t import_status

455

= import_result->imports;

456

import_status != NULL;

457

import_status = import_status->next){

458

fprintf_plus(stderr, "Import status for key: %s\n",

459

import_status->fpr);

460

if(import_status->result != GPG_ERR_NO_ERROR){

461

fprintf_plus(stderr, "Import result: %s: %s\n",

462

gpgme_strsource(import_status->result),

463

gpgme_strerror(import_status->result));

464

}

465

fprintf_plus(stderr, "Key status:\n");

466

fprintf_plus(stderr,

467

import_status->status & GPGME_IMPORT_NEW

468

? "The key was new.\n"

469

: "The key was not new.\n");

470

fprintf_plus(stderr,

471

import_status->status & GPGME_IMPORT_UID

472

? "The key contained new user IDs.\n"

473

: "The key did not contain new user IDs.\n");

474

fprintf_plus(stderr,

475

import_status->status & GPGME_IMPORT_SIG

476

? "The key contained new signatures.\n"

477

: "The key did not contain new signatures.\n");

478

fprintf_plus(stderr,

479

import_status->status & GPGME_IMPORT_SUBKEY

480

? "The key contained new sub keys.\n"

481

: "The key did not contain new sub keys.\n");

482

fprintf_plus(stderr,

483

import_status->status & GPGME_IMPORT_SECRET

484

? "The key contained a secret key.\n"

485

: "The key did not contain a secret key.\n");

486

}

487

return false;

488

}

489

}

490

277

491

ret = close(fd);

278

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

492

279

if(ret == -1){

493

280

perror_plus("close");

494

281

}

531

318

}

532

319

533

320

/* Create new GPGME "context" */

534

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

321

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

535

322

if(rc != GPG_ERR_NO_ERROR){

536

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

537

gpgme_strsource(rc), gpgme_strerror(rc));

323

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

324

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

325

gpgme_strerror(rc));

538

326

return false;

539

327

}

540

328

549

337

* Decrypt OpenPGP data.

550

338

* Returns -1 on error

551

339

*/

552

__attribute__((nonnull, warn_unused_result))

553

340

static ssize_t pgp_packet_decrypt(const char *cryptotext,

554

341

size_t crypto_size,

555

char **plaintext,

556

mandos_context *mc){

342

char **plaintext){

557

343

gpgme_data_t dh_crypto, dh_plain;

558

344

gpgme_error_t rc;

559

345

ssize_t ret;

576

362

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

577

363

rc = gpgme_data_new(&dh_plain);

578

364

if(rc != GPG_ERR_NO_ERROR){

579

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

365

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

366

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

580

367

gpgme_strsource(rc), gpgme_strerror(rc));

581

368

gpgme_data_release(dh_crypto);

582

369

return -1;

584

371

585

372

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

586

373

data buffer */

587

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

374

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

588

375

if(rc != GPG_ERR_NO_ERROR){

589

376

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

590

377

gpgme_strsource(rc), gpgme_strerror(rc));

591

378

plaintext_length = -1;

592

379

if(debug){

593

380

gpgme_decrypt_result_t result;

594

result = gpgme_op_decrypt_result(mc->ctx);

381

result = gpgme_op_decrypt_result(mc.ctx);

595

382

if(result == NULL){

596

383

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

597

384

} else {

598

if(result->unsupported_algorithm != NULL) {

599

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

600

result->unsupported_algorithm);

601

}

602

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

603

result->wrong_key_usage ? "Yes" : "No");

385

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

386

result->unsupported_algorithm);

387

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

388

result->wrong_key_usage);

604

389

if(result->file_name != NULL){

605

390

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

606

391

}

607

608

for(gpgme_recipient_t r = result->recipients; r != NULL;

609

r = r->next){

392

gpgme_recipient_t recipient;

393

recipient = result->recipients;

394

while(recipient != NULL){

610

395

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

611

gpgme_pubkey_algo_name(r->pubkey_algo));

612

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

396

gpgme_pubkey_algo_name

397

(recipient->pubkey_algo));

398

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

613

399

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

614

r->status == GPG_ERR_NO_SECKEY ? "No" : "Yes");

400

recipient->status == GPG_ERR_NO_SECKEY

401

? "No" : "Yes");

402

recipient = recipient->next;

615

403

}

616

404

}

617

405

}

673

461

return plaintext_length;

674

462

}

675

463

676

__attribute__((warn_unused_result, const))

677

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

678

if(str == NULL)

679

return "(unknown)";

680

return str;

681

}

682

683

__attribute__((warn_unused_result))

684

static const char *safer_gnutls_strerror(int value){

685

const char *ret = gnutls_strerror(value);

686

return safe_string(ret);

464

static const char * safer_gnutls_strerror(int value){

465

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

466

-Wunreachable-code */

467

if(ret == NULL)

468

ret = "(unknown)";

469

return ret;

687

470

}

688

471

689

472

/* GnuTLS log function callback */

690

__attribute__((nonnull))

691

473

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

692

474

const char* string){

693

475

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

694

476

}

695

477

696

__attribute__((nonnull(1, 2, 4), warn_unused_result))

697

478

static int init_gnutls_global(const char *pubkeyfilename,

698

const char *seckeyfilename,

699

const char *dhparamsfilename,

700

mandos_context *mc){

479

const char *seckeyfilename){

701

480

int ret;

702

unsigned int uret;

703

481

704

482

if(debug){

705

483

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

706

484

}

707

485

486

ret = gnutls_global_init();

487

if(ret != GNUTLS_E_SUCCESS){

488

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

489

safer_gnutls_strerror(ret));

490

return -1;

491

}

492

708

493

if(debug){

709

494

/* "Use a log level over 10 to enable all debugging options."

710

495

* - GnuTLS manual

714

499

}

715

500

716

501

/* OpenPGP credentials */

717

ret = gnutls_certificate_allocate_credentials(&mc->cred);

502

ret = gnutls_certificate_allocate_credentials(&mc.cred);

718

503

if(ret != GNUTLS_E_SUCCESS){

719

504

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

720

505

safer_gnutls_strerror(ret));

506

gnutls_global_deinit();

721

507

return -1;

722

508

}

723

509

729

515

}

730

516

731

517

ret = gnutls_certificate_set_openpgp_key_file

732

(mc->cred, pubkeyfilename, seckeyfilename,

518

(mc.cred, pubkeyfilename, seckeyfilename,

733

519

GNUTLS_OPENPGP_FMT_BASE64);

734

520

if(ret != GNUTLS_E_SUCCESS){

735

521

fprintf_plus(stderr,

741

527

}

742

528

743

529

/* GnuTLS server initialization */

744

ret = gnutls_dh_params_init(&mc->dh_params);

530

ret = gnutls_dh_params_init(&mc.dh_params);

745

531

if(ret != GNUTLS_E_SUCCESS){

746

532

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

747

533

" initialization: %s\n",

748

534

safer_gnutls_strerror(ret));

749

535

goto globalfail;

750

536

}

751

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

752

if(dhparamsfilename != NULL){

753

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

754

do {

755

int dhpfile = open(dhparamsfilename, O_RDONLY);

756

if(dhpfile == -1){

757

perror_plus("open");

758

dhparamsfilename = NULL;

759

break;

760

}

761

size_t params_capacity = 0;

762

while(true){

763

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

764

(size_t)params.size,

765

(size_t)params_capacity);

766

if(params_capacity == 0){

767

perror_plus("incbuffer");

768

free(params.data);

769

params.data = NULL;

770

dhparamsfilename = NULL;

771

break;

772

}

773

ssize_t bytes_read = read(dhpfile,

774

params.data + params.size,

775

BUFFER_SIZE);

776

/* EOF */

777

if(bytes_read == 0){

778

break;

779

}

780

/* check bytes_read for failure */

781

if(bytes_read < 0){

782

perror_plus("read");

783

free(params.data);

784

params.data = NULL;

785

dhparamsfilename = NULL;

786

break;

787

}

788

params.size += (unsigned int)bytes_read;

789

}

790

ret = close(dhpfile);

791

if(ret == -1){

792

perror_plus("close");

793

}

794

if(params.data == NULL){

795

dhparamsfilename = NULL;

796

}

797

if(dhparamsfilename == NULL){

798

break;

799

}

800

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

801

GNUTLS_X509_FMT_PEM);

802

if(ret != GNUTLS_E_SUCCESS){

803

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

804

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

805

safer_gnutls_strerror(ret));

806

dhparamsfilename = NULL;

807

}

808

free(params.data);

809

} while(false);

810

}

811

if(dhparamsfilename == NULL){

812

if(mc->dh_bits == 0){

813

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

814

/* Try to read the private key file */

815

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

816

do {

817

int secfile = open(seckeyfilename, O_RDONLY);

818

if(secfile == -1){

819

perror_plus("open");

820

break;

821

}

822

size_t buffer_capacity = 0;

823

while(true){

824

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

825

(size_t)buffer.size,

826

(size_t)buffer_capacity);

827

if(buffer_capacity == 0){

828

perror_plus("incbuffer");

829

free(buffer.data);

830

buffer.data = NULL;

831

break;

832

}

833

ssize_t bytes_read = read(secfile,

834

buffer.data + buffer.size,

835

BUFFER_SIZE);

836

/* EOF */

837

if(bytes_read == 0){

838

break;

839

}

840

/* check bytes_read for failure */

841

if(bytes_read < 0){

842

perror_plus("read");

843

free(buffer.data);

844

buffer.data = NULL;

845

break;

846

}

847

buffer.size += (unsigned int)bytes_read;

848

}

849

close(secfile);

850

} while(false);

851

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

852

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

853

if(buffer.data != NULL){

854

{

855

gnutls_openpgp_privkey_t privkey = NULL;

856

ret = gnutls_openpgp_privkey_init(&privkey);

857

if(ret != GNUTLS_E_SUCCESS){

858

fprintf_plus(stderr, "Error initializing OpenPGP key"

859

" structure: %s",

860

safer_gnutls_strerror(ret));

861

free(buffer.data);

862

buffer.data = NULL;

863

} else {

864

ret = gnutls_openpgp_privkey_import

865

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

866

if(ret != GNUTLS_E_SUCCESS){

867

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

868

safer_gnutls_strerror(ret));

869

privkey = NULL;

870

}

871

free(buffer.data);

872

buffer.data = NULL;

873

if(privkey != NULL){

874

/* Use private key to suggest an appropriate

875

sec_param */

876

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

877

gnutls_openpgp_privkey_deinit(privkey);

878

if(debug){

879

fprintf_plus(stderr, "This OpenPGP key implies using"

880

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

881

safe_string(gnutls_sec_param_get_name

882

(sec_param)));

883

}

884

}

885

}

886

}

887

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

888

/* Err on the side of caution */

889

sec_param = GNUTLS_SEC_PARAM_ULTRA;

890

if(debug){

891

fprintf_plus(stderr, "Falling back to security parameter"

892

" \"%s\"\n",

893

safe_string(gnutls_sec_param_get_name

894

(sec_param)));

895

}

896

}

897

}

898

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

899

if(uret != 0){

900

mc->dh_bits = uret;

901

if(debug){

902

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

903

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

904

safe_string(gnutls_sec_param_get_name

905

(sec_param)),

906

mc->dh_bits);

907

}

908

} else {

909

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

910

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

911

safe_string(gnutls_sec_param_get_name

912

(sec_param)),

913

safer_gnutls_strerror(ret));

914

goto globalfail;

915

}

916

} else if(debug){

917

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

918

mc->dh_bits);

919

}

920

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

921

if(ret != GNUTLS_E_SUCCESS){

922

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

923

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

924

safer_gnutls_strerror(ret));

925

goto globalfail;

926

}

927

}

928

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

537

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

538

if(ret != GNUTLS_E_SUCCESS){

539

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

540

safer_gnutls_strerror(ret));

541

goto globalfail;

542

}

543

544

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

929

545

930

546

return 0;

931

547

932

548

globalfail:

933

549

934

gnutls_certificate_free_credentials(mc->cred);

935

gnutls_dh_params_deinit(mc->dh_params);

550

gnutls_certificate_free_credentials(mc.cred);

551

gnutls_global_deinit();

552

gnutls_dh_params_deinit(mc.dh_params);

936

553

return -1;

937

554

}

938

555

939

__attribute__((nonnull, warn_unused_result))

940

static int init_gnutls_session(gnutls_session_t *session,

941

mandos_context *mc){

556

static int init_gnutls_session(gnutls_session_t *session){

942

557

int ret;

943

558

/* GnuTLS session creation */

944

559

do {

956

571

{

957

572

const char *err;

958

573

do {

959

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

574

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

960

575

if(quit_now){

961

576

gnutls_deinit(*session);

962

577

return -1;

973

588

974

589

do {

975

590

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

976

mc->cred);

591

mc.cred);

977

592

if(quit_now){

978

593

gnutls_deinit(*session);

979

594

return -1;

989

604

/* ignore client certificate if any. */

990

605

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

991

606

607

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

608

992

609

return 0;

993

610

}

994

611

996

613

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

997

614

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

998

615

999

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

1000

__attribute__((nonnull, warn_unused_result))

1001

static bool add_delete_local_route(const bool add,

1002

const char *address,

1003

AvahiIfIndex if_index){

1004

int ret;

1005

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

1006

char add_arg[] = "add";

1007

char delete_arg[] = "delete";

1008

char debug_flag[] = "--debug";

1009

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

1010

if(pluginhelperdir == NULL){

1011

if(debug){

1012

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

1013

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

1014

}

1015

return false;

1016

}

1017

1018

char interface[IF_NAMESIZE];

1019

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

1020

perror_plus("if_indextoname");

1021

return false;

1022

}

1023

1024

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

1025

if(devnull == -1){

1026

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

1027

return false;

1028

}

1029

pid_t pid = fork();

1030

if(pid == 0){

1031

/* Child */

1032

/* Raise privileges */

1033

errno = raise_privileges_permanently();

1034

if(errno != 0){

1035

perror_plus("Failed to raise privileges");

1036

/* _exit(EX_NOPERM); */

1037

} else {

1038

/* Set group */

1039

errno = 0;

1040

ret = setgid(0);

1041

if(ret == -1){

1042

perror_plus("setgid");

1043

_exit(EX_NOPERM);

1044

}

1045

/* Reset supplementary groups */

1046

errno = 0;

1047

ret = setgroups(0, NULL);

1048

if(ret == -1){

1049

perror_plus("setgroups");

1050

_exit(EX_NOPERM);

1051

}

1052

}

1053

ret = dup2(devnull, STDIN_FILENO);

1054

if(ret == -1){

1055

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

1056

_exit(EX_OSERR);

1057

}

1058

ret = close(devnull);

1059

if(ret == -1){

1060

perror_plus("close");

1061

_exit(EX_OSERR);

1062

}

1063

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1064

if(ret == -1){

1065

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

1066

_exit(EX_OSERR);

1067

}

1068

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

1069

O_RDONLY

1070

| O_DIRECTORY

1071

| O_PATH

1072

| O_CLOEXEC));

1073

if(helperdir_fd == -1){

1074

perror_plus("open");

1075

_exit(EX_UNAVAILABLE);

1076

}

1077

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

1078

helper, O_RDONLY));

1079

if(helper_fd == -1){

1080

perror_plus("openat");

1081

close(helperdir_fd);

1082

_exit(EX_UNAVAILABLE);

1083

}

1084

close(helperdir_fd);

1085

#ifdef __GNUC__

1086

#pragma GCC diagnostic push

1087

#pragma GCC diagnostic ignored "-Wcast-qual"

1088

#endif

1089

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

1090

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

1091

interface, debug ? debug_flag : NULL, NULL },

1092

environ) == -1){

1093

#ifdef __GNUC__

1094

#pragma GCC diagnostic pop

1095

#endif

1096

perror_plus("fexecve");

1097

_exit(EXIT_FAILURE);

1098

}

1099

}

1100

if(pid == -1){

1101

perror_plus("fork");

1102

return false;

1103

}

1104

int status;

1105

pid_t pret = -1;

1106

errno = 0;

1107

do {

1108

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

1109

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

1110

int errno_raising = 0;

1111

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

1112

errno_raising = errno;

1113

perror_plus("Failed to raise privileges in order to"

1114

" kill helper program");

1115

}

1116

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

1117

perror_plus("kill");

1118

}

1119

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

1120

perror_plus("Failed to lower privileges after killing"

1121

" helper program");

1122

}

1123

return false;

1124

}

1125

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

1126

if(pret == -1){

1127

perror_plus("waitpid");

1128

return false;

1129

}

1130

if(WIFEXITED(status)){

1131

if(WEXITSTATUS(status) != 0){

1132

fprintf_plus(stderr, "Error: iprouteadddel exited"

1133

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

1134

return false;

1135

}

1136

return true;

1137

}

1138

if(WIFSIGNALED(status)){

1139

fprintf_plus(stderr, "Error: iprouteadddel died by"

1140

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

1141

return false;

1142

}

1143

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

1144

return false;

1145

}

1146

1147

__attribute__((nonnull, warn_unused_result))

1148

static bool add_local_route(const char *address,

1149

AvahiIfIndex if_index){

1150

if(debug){

1151

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

1152

}

1153

return add_delete_local_route(true, address, if_index);

1154

}

1155

1156

__attribute__((nonnull, warn_unused_result))

1157

static bool delete_local_route(const char *address,

1158

AvahiIfIndex if_index){

1159

if(debug){

1160

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

1161

}

1162

return add_delete_local_route(false, address, if_index);

1163

}

1164

1165

616

/* Called when a Mandos server is found */

1166

__attribute__((nonnull, warn_unused_result))

1167

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

617

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

1168

618

AvahiIfIndex if_index,

1169

int af, mandos_context *mc){

619

int af){

1170

620

int ret, tcp_sd = -1;

1171

621

ssize_t sret;

1172

struct sockaddr_storage to;

622

union {

623

struct sockaddr_in in;

624

struct sockaddr_in6 in6;

625

} to;

1173

626

char *buffer = NULL;

1174

627

char *decrypted_buffer = NULL;

1175

628

size_t buffer_length = 0;

1178

631

int retval = -1;

1179

632

gnutls_session_t session;

1180

633

int pf; /* Protocol family */

1181

bool route_added = false;

1182

634

1183

635

errno = 0;

1184

636

1200

652

return -1;

1201

653

}

1202

654

1203

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

1204

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

1205

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

1206

bool match = false;

1207

{

1208

char *interface = NULL;

1209

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

1210

mc->interfaces_size,

1211

interface))){

1212

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

1213

match = true;

1214

break;

1215

}

1216

}

1217

}

1218

if(not match){

1219

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

1220

connect to the server */

1221

if(debug){

1222

char interface[IF_NAMESIZE];

1223

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

1224

perror_plus("if_indextoname");

1225

} else {

1226

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

1227

" \"%s\"\n",

1228

if_indextoname((unsigned int)if_index,

1229

interface));

1230

}

1231

}

1232

return -1;

1233

}

1234

}

1235

1236

ret = init_gnutls_session(&session, mc);

655

ret = init_gnutls_session(&session);

1237

656

if(ret != 0){

1238

657

return -1;

1239

658

}

1240

659

1241

660

if(debug){

1242

661

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

1243

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

662

PRIu16 "\n", ip, port);

1244

663

}

1245

664

1246

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

665

tcp_sd = socket(pf, SOCK_STREAM, 0);

1247

666

if(tcp_sd < 0){

1248

667

int e = errno;

1249

668

perror_plus("socket");

1256

675

goto mandos_end;

1257

676

}

1258

677

678

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

1259

679

if(af == AF_INET6){

1260

struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;

1261

*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };

1262

ret = inet_pton(af, ip, &to6->sin6_addr);

680

to.in6.sin6_family = (sa_family_t)af;

681

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

1263

682

} else { /* IPv4 */

1264

struct sockaddr_in *to4 = (struct sockaddr_in *)&to;

1265

*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };

1266

ret = inet_pton(af, ip, &to4->sin_addr);

683

to.in.sin_family = (sa_family_t)af;

684

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

1267

685

}

1268

686

if(ret < 0 ){

1269

687

int e = errno;

1278

696

goto mandos_end;

1279

697

}

1280

698

if(af == AF_INET6){

1281

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

1282

if(IN6_IS_ADDR_LINKLOCAL

1283

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

699

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

700

-Wconversion and

701

-Wunreachable-code */

702

703

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

704

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

705

-Wunreachable-code*/

1284

706

if(if_index == AVAHI_IF_UNSPEC){

1285

707

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

1286

708

" incomplete without a network interface\n");

1288

710

goto mandos_end;

1289

711

}

1290

712

/* Set the network interface number as scope */

1291

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

713

to.in6.sin6_scope_id = (uint32_t)if_index;

1292

714

}

1293

715

} else {

1294

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

716

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

717

-Wconversion and

718

-Wunreachable-code */

1295

719

}

1296

720

1297

721

if(quit_now){

1305

729

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

1306

730

perror_plus("if_indextoname");

1307

731

} else {

1308

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

1309

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

732

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIu16

733

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

1310

734

}

1311

735

} else {

1312

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

1313

ip, (uintmax_t)port);

736

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

737

ip, port);

1314

738

}

1315

739

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1316

740

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1317

if(af == AF_INET6){

1318

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

1319

sizeof(struct sockaddr_in6),

1320

addrstr, sizeof(addrstr), NULL, 0,

1321

NI_NUMERICHOST);

1322

} else {

1323

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

1324

sizeof(struct sockaddr_in),

1325

addrstr, sizeof(addrstr), NULL, 0,

1326

NI_NUMERICHOST);

1327

}

1328

if(ret == EAI_SYSTEM){

1329

perror_plus("getnameinfo");

1330

} else if(ret != 0) {

1331

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

1332

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

1333

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

1334

}

1335

}

1336

1337

if(quit_now){

1338

errno = EINTR;

1339

goto mandos_end;

1340

}

1341

1342

while(true){

1343

if(af == AF_INET6){

1344

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

1345

sizeof(struct sockaddr_in6));

1346

} else {

1347

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

1348

sizeof(struct sockaddr_in));

1349

}

1350

if(ret < 0){

1351

if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))

1352

and if_index != AVAHI_IF_UNSPEC

1353

and connect_to == NULL

1354

and not route_added and

1355

((af == AF_INET6 and not

1356

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1357

&to)->sin6_addr)))

1358

or (af == AF_INET and

1359

/* Not a a IPv4LL address */

1360

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

1361

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

1362

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

1363

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

1364

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

1365

connect to a Mandos server announced by Avahi on a server

1366

host with a global address. Work around this by retrying

1367

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

1368

1369

Avahi bug reference:

1370

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

1371

https://bugs.debian.org/587961

1372

*/

1373

if(debug){

1374

fprintf_plus(stderr, "Mandos server unreachable, trying"

1375

" direct route\n");

1376

}

1377

int e = errno;

1378

route_added = add_local_route(ip, if_index);

1379

if(route_added){

1380

continue;

1381

}

1382

errno = e;

1383

}

1384

if(errno != ECONNREFUSED or debug){

1385

int e = errno;

1386

perror_plus("connect");

1387

errno = e;

1388

}

1389

goto mandos_end;

1390

}

1391

1392

if(quit_now){

1393

errno = EINTR;

1394

goto mandos_end;

1395

}

1396

break;

741

const char *pcret;

742

if(af == AF_INET6){

743

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

744

sizeof(addrstr));

745

} else {

746

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

747

sizeof(addrstr));

748

}

749

if(pcret == NULL){

750

perror_plus("inet_ntop");

751

} else {

752

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

753

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

754

}

755

}

756

}

757

758

if(quit_now){

759

errno = EINTR;

760

goto mandos_end;

761

}

762

763

if(af == AF_INET6){

764

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

765

} else {

766

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

767

}

768

if(ret < 0){

769

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

770

int e = errno;

771

perror_plus("connect");

772

errno = e;

773

}

774

goto mandos_end;

775

}

776

777

if(quit_now){

778

errno = EINTR;

779

goto mandos_end;

1397

780

}

1398

781

1399

782

const char *out = mandos_protocol_version;

1435

818

goto mandos_end;

1436

819

}

1437

820

1438

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

1439

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

1440

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

1441

gnutls_transport_set_ptr(session,

1442

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

821

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

822

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1443

823

1444

824

if(quit_now){

1445

825

errno = EINTR;

1550

930

if(buffer_length > 0){

1551

931

ssize_t decrypted_buffer_size;

1552

932

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1553

&decrypted_buffer, mc);

933

&decrypted_buffer);

1554

934

if(decrypted_buffer_size >= 0){

1555

935

1556

clearerr(stdout);

1557

936

written = 0;

1558

937

while(written < (size_t) decrypted_buffer_size){

1559

938

if(quit_now){

1575

954

}

1576

955

written += (size_t)ret;

1577

956

}

1578

ret = fflush(stdout);

1579

if(ret != 0){

1580

int e = errno;

1581

if(debug){

1582

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

1583

strerror(errno));

1584

}

1585

errno = e;

1586

goto mandos_end;

1587

}

1588

957

retval = 0;

1589

958

}

1590

959

}

1593

962

1594

963

mandos_end:

1595

964

{

1596

if(route_added){

1597

if(not delete_local_route(ip, if_index)){

1598

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

1599

" interface %d", ip, if_index);

1600

}

1601

}

1602

965

int e = errno;

1603

966

free(decrypted_buffer);

1604

967

free(buffer);

1605

968

if(tcp_sd >= 0){

1606

ret = close(tcp_sd);

969

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

1607

970

}

1608

971

if(ret == -1){

1609

972

if(e == 0){

1634

997

AVAHI_GCC_UNUSED AvahiStringList *txt,

1635

998

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1636

999

flags,

1637

void *mc){

1638

if(r == NULL){

1639

return;

1640

}

1000

AVAHI_GCC_UNUSED void* userdata){

1001

assert(r);

1641

1002

1642

1003

/* Called whenever a service has been resolved successfully or

1643

1004

timed out */

1644

1005

1645

1006

if(quit_now){

1646

avahi_s_service_resolver_free(r);

1647

1007

return;

1648

1008

}

1649

1009

1653

1013

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

1654

1014

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

1655

1015

domain,

1656

avahi_strerror(avahi_server_errno

1657

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

1016

avahi_strerror(avahi_server_errno(mc.server)));

1658

1017

break;

1659

1018

1660

1019

case AVAHI_RESOLVER_FOUND:

1666

1025

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

1667

1026

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

1668

1027

}

1669

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

1670

interface,

1671

avahi_proto_to_af(proto),

1672

mc);

1028

int ret = start_mandos_communication(ip, port, interface,

1029

avahi_proto_to_af(proto));

1673

1030

if(ret == 0){

1674

avahi_simple_poll_quit(simple_poll);

1031

avahi_simple_poll_quit(mc.simple_poll);

1675

1032

} else {

1676

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

1677

avahi_proto_to_af(proto),

1678

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

1679

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

1680

" list\n", name);

1681

}

1033

ret = add_server(ip, port, interface,

1034

avahi_proto_to_af(proto));

1682

1035

}

1683

1036

}

1684

1037

}

1694

1047

const char *domain,

1695

1048

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1696

1049

flags,

1697

void *mc){

1698

if(b == NULL){

1699

return;

1700

}

1050

AVAHI_GCC_UNUSED void* userdata){

1051

assert(b);

1701

1052

1702

1053

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

1703

1054

is removed from the LAN */

1711

1062

case AVAHI_BROWSER_FAILURE:

1712

1063

1713

1064

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

1714

avahi_strerror(avahi_server_errno

1715

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

1716

avahi_simple_poll_quit(simple_poll);

1065

avahi_strerror(avahi_server_errno(mc.server)));

1066

avahi_simple_poll_quit(mc.simple_poll);

1717

1067

return;

1718

1068

1719

1069

case AVAHI_BROWSER_NEW:

1722

1072

the callback function is called the Avahi server will free the

1723

1073

resolver for us. */

1724

1074

1725

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

1726

interface, protocol, name, type,

1727

domain, protocol, 0,

1728

resolve_callback, mc) == NULL)

1075

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

1076

name, type, domain, protocol, 0,

1077

resolve_callback, NULL) == NULL)

1729

1078

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

1730

1079

" %s\n", name,

1731

avahi_strerror(avahi_server_errno

1732

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

1080

avahi_strerror(avahi_server_errno(mc.server)));

1733

1081

break;

1734

1082

1735

1083

case AVAHI_BROWSER_REMOVE:

1754

1102

signal_received = sig;

1755

1103

int old_errno = errno;

1756

1104

/* set main loop to exit */

1757

if(simple_poll != NULL){

1758

avahi_simple_poll_quit(simple_poll);

1105

if(mc.simple_poll != NULL){

1106

avahi_simple_poll_quit(mc.simple_poll);

1759

1107

}

1760

1108

errno = old_errno;

1761

1109

}

1762

1110

1763

__attribute__((nonnull, warn_unused_result))

1764

1111

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

1765

1112

int ret;

1766

int old_errno;

1767

1113

1768

1114

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

1769

1115

if(s < 0){

1770

old_errno = errno;

1771

1116

perror_plus("socket");

1772

errno = old_errno;

1773

1117

return false;

1774

1118

}

1775

strncpy(ifr->ifr_name, ifname, IF_NAMESIZE);

1776

ifr->ifr_name[IF_NAMESIZE-1] = '\0'; /* NUL terminate */

1119

strcpy(ifr->ifr_name, ifname);

1777

1120

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1778

1121

if(ret == -1){

1779

1122

if(debug){

1780

old_errno = errno;

1781

1123

perror_plus("ioctl SIOCGIFFLAGS");

1782

errno = old_errno;

1783

}

1784

if((close(s) == -1) and debug){

1785

old_errno = errno;

1786

perror_plus("close");

1787

errno = old_errno;

1788

1124

}

1789

1125

return false;

1790

1126

}

1791

if((close(s) == -1) and debug){

1792

old_errno = errno;

1793

perror_plus("close");

1794

errno = old_errno;

1795

}

1796

1127

return true;

1797

1128

}

1798

1129

1799

__attribute__((nonnull, warn_unused_result))

1800

1130

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

1801

1131

1802

1132

/* Reject the loopback device */

1844

1174

* corresponds to an acceptable network device.

1845

1175

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

1846

1176

*/

1847

__attribute__((nonnull, warn_unused_result))

1848

1177

int good_interface(const struct dirent *if_entry){

1849

1178

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

1850

1179

return 0;

1866

1195

}

1867

1196

1868

1197

/*

1869

* This function determines if a network interface is up.

1870

*/

1871

__attribute__((nonnull, warn_unused_result))

1872

bool interface_is_up(const char *interface){

1873

struct ifreq ifr;

1874

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

1875

if(debug){

1876

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

1877

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

1878

}

1879

return false;

1880

}

1881

1882

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

1883

}

1884

1885

/*

1886

* This function determines if a network interface is running

1887

*/

1888

__attribute__((nonnull, warn_unused_result))

1889

bool interface_is_running(const char *interface){

1890

struct ifreq ifr;

1891

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

1892

if(debug){

1893

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

1894

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

1895

}

1896

return false;

1897

}

1898

1899

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

1900

}

1901

1902

__attribute__((nonnull, pure, warn_unused_result))

1198

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

1199

* corresponds to an acceptable network device which is up.

1200

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

1201

*/

1202

int up_interface(const struct dirent *if_entry){

1203

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

1204

return 0;

1205

}

1206

1207

struct ifreq ifr;

1208

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

1209

if(debug){

1210

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

1211

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

1212

}

1213

return 0;

1214

}

1215

1216

/* Reject down interfaces */

1217

if(not (ifr.ifr_flags & IFF_UP)){

1218

if(debug){

1219

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

1220

if_entry->d_name);

1221

}

1222

return 0;

1223

}

1224

1225

/* Reject non-running interfaces */

1226

if(not (ifr.ifr_flags & IFF_RUNNING)){

1227

if(debug){

1228

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

1229

if_entry->d_name);

1230

}

1231

return 0;

1232

}

1233

1234

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

1235

return 0;

1236

}

1237

return 1;

1238

}

1239

1903

1240

int notdotentries(const struct dirent *direntry){

1904

1241

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

1905

1242

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

1912

1249

}

1913

1250

1914

1251

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

1915

__attribute__((nonnull, warn_unused_result))

1916

1252

int runnable_hook(const struct dirent *direntry){

1917

1253

int ret;

1918

1254

size_t sret;

1926

1262

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

1927

1263

"abcdefghijklmnopqrstuvwxyz"

1928

1264

"0123456789"

1929

"_.-");

1265

"_-");

1930

1266

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

1931

1267

/* Contains non-allowed characters */

1932

1268

if(debug){

1936

1272

return 0;

1937

1273

}

1938

1274

1939

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

1275

char *fullname = NULL;

1276

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1277

if(ret < 0){

1278

perror_plus("asprintf");

1279

return 0;

1280

}

1281

1282

ret = stat(fullname, &st);

1940

1283

if(ret == -1){

1941

1284

if(debug){

1942

1285

perror_plus("Could not stat hook");

1966

1309

return 1;

1967

1310

}

1968

1311

1969

__attribute__((nonnull, warn_unused_result))

1970

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1971

mandos_context *mc){

1312

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1972

1313

int ret;

1973

1314

struct timespec now;

1974

1315

struct timespec waited_time;

1975

1316

intmax_t block_time;

1976

1317

1977

1318

while(true){

1978

if(mc->current_server == NULL){

1979

if(debug){

1319

if(mc.current_server == NULL){

1320

if (debug){

1980

1321

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

1981

1322

" No timeout!\n");

1982

1323

}

1983

1324

ret = avahi_simple_poll_iterate(s, -1);

1984

1325

} else {

1985

if(debug){

1326

if (debug){

1986

1327

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

1987

1328

" it, or wait\n");

1988

1329

}

1995

1336

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

1996

1337

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

1997

1338

waited_time.tv_sec = (now.tv_sec

1998

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

1339

- mc.current_server->last_seen.tv_sec);

1999

1340

waited_time.tv_nsec = (now.tv_nsec

2000

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

1341

- mc.current_server->last_seen.tv_nsec);

2001

1342

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

2002

1343

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

2003

1344

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

2005

1346

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

2006

1347

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

2007

1348

2008

if(debug){

1349

if (debug){

2009

1350

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

2010

1351

block_time);

2011

1352

}

2012

1353

2013

1354

if(block_time <= 0){

2014

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

2015

mc->current_server->port,

2016

mc->current_server->if_index,

2017

mc->current_server->af, mc);

1355

ret = start_mandos_communication(mc.current_server->ip,

1356

mc.current_server->port,

1357

mc.current_server->if_index,

1358

mc.current_server->af);

2018

1359

if(ret == 0){

2019

avahi_simple_poll_quit(s);

1360

avahi_simple_poll_quit(mc.simple_poll);

2020

1361

return 0;

2021

1362

}

2022

1363

ret = clock_gettime(CLOCK_MONOTONIC,

2023

&mc->current_server->last_seen);

1364

&mc.current_server->last_seen);

2024

1365

if(ret == -1){

2025

1366

perror_plus("clock_gettime");

2026

1367

return -1;

2027

1368

}

2028

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

1369

mc.current_server = mc.current_server->next;

2029

1370

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

2030

1371

servers, but don't block */

2031

1372

}

2033

1374

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

2034

1375

}

2035

1376

if(ret != 0){

2036

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

1377

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

2037

1378

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

2038

1379

}

2039

1380

}

2040

1381

}

2041

1382

}

2042

1383

2043

__attribute__((nonnull))

2044

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

1384

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

2045

1385

const float delay){

2046

struct dirent **direntries = NULL;

2047

if(hookdir_fd == -1){

2048

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

2049

| O_CLOEXEC);

2050

if(hookdir_fd == -1){

2051

if(errno == ENOENT){

2052

if(debug){

2053

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

2054

" found\n", hookdir);

2055

}

2056

} else {

2057

perror_plus("open");

2058

}

2059

return;

2060

}

2061

}

2062

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

2063

if(devnull == -1){

2064

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

2065

return;

2066

}

2067

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

2068

runnable_hook, alphasort);

1386

struct dirent **direntries;

1387

struct dirent *direntry;

1388

int ret;

1389

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

1390

alphasort);

2069

1391

if(numhooks == -1){

2070

1392

perror_plus("scandir");

2071

close(devnull);

2072

return;

2073

}

2074

struct dirent *direntry;

2075

int ret;

2076

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

2077

direntry = direntries[i];

2078

if(debug){

2079

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

2080

direntry->d_name);

2081

}

2082

pid_t hook_pid = fork();

2083

if(hook_pid == 0){

2084

/* Child */

2085

/* Raise privileges */

2086

errno = raise_privileges_permanently();

2087

if(errno != 0){

2088

perror_plus("Failed to raise privileges");

2089

_exit(EX_NOPERM);

2090

}

2091

/* Set group */

2092

errno = 0;

2093

ret = setgid(0);

2094

if(ret == -1){

2095

perror_plus("setgid");

2096

_exit(EX_NOPERM);

2097

}

2098

/* Reset supplementary groups */

2099

errno = 0;

2100

ret = setgroups(0, NULL);

2101

if(ret == -1){

2102

perror_plus("setgroups");

2103

_exit(EX_NOPERM);

2104

}

2105

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

2106

if(ret == -1){

2107

perror_plus("setenv");

2108

_exit(EX_OSERR);

2109

}

2110

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

2111

if(ret == -1){

2112

perror_plus("setenv");

2113

_exit(EX_OSERR);

2114

}

2115

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

2116

if(ret == -1){

2117

perror_plus("setenv");

2118

_exit(EX_OSERR);

2119

}

2120

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

2121

if(ret == -1){

2122

perror_plus("setenv");

2123

_exit(EX_OSERR);

2124

}

2125

char *delaystring;

2126

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

2127

if(ret == -1){

1393

} else {

1394

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

1395

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

1396

direntry = direntries[i];

1397

char *fullname = NULL;

1398

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1399

if(ret < 0){

2128

1400

perror_plus("asprintf");

2129

_exit(EX_OSERR);

2130

}

2131

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

2132

if(ret == -1){

1401

continue;

1402

}

1403

if(debug){

1404

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

1405

direntry->d_name);

1406

}

1407

pid_t hook_pid = fork();

1408

if(hook_pid == 0){

1409

/* Child */

1410

/* Raise privileges */

1411

errno = 0;

1412

ret = seteuid(0);

1413

if(ret == -1){

1414

perror_plus("seteuid");

1415

}

1416

/* Raise privileges even more */

1417

errno = 0;

1418

ret = setuid(0);

1419

if(ret == -1){

1420

perror_plus("setuid");

1421

}

1422

/* Set group */

1423

errno = 0;

1424

ret = setgid(0);

1425

if(ret == -1){

1426

perror_plus("setgid");

1427

}

1428

/* Reset supplementary groups */

1429

errno = 0;

1430

ret = setgroups(0, NULL);

1431

if(ret == -1){

1432

perror_plus("setgroups");

1433

}

1434

dup2(devnull, STDIN_FILENO);

1435

close(devnull);

1436

dup2(STDERR_FILENO, STDOUT_FILENO);

1437

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

1438

if(ret == -1){

1439

perror_plus("setenv");

1440

_exit(EX_OSERR);

1441

}

1442

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

1443

if(ret == -1){

1444

perror_plus("setenv");

1445

_exit(EX_OSERR);

1446

}

1447

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

1448

if(ret == -1){

1449

perror_plus("setenv");

1450

_exit(EX_OSERR);

1451

}

1452

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

1453

if(ret == -1){

1454

perror_plus("setenv");

1455

_exit(EX_OSERR);

1456

}

1457

char *delaystring;

1458

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

1459

if(ret == -1){

1460

perror_plus("asprintf");

1461

_exit(EX_OSERR);

1462

}

1463

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

1464

if(ret == -1){

1465

free(delaystring);

1466

perror_plus("setenv");

1467

_exit(EX_OSERR);

1468

}

2133

1469

free(delaystring);

2134

perror_plus("setenv");

2135

_exit(EX_OSERR);

2136

}

2137

free(delaystring);

2138

if(connect_to != NULL){

2139

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

2140

if(ret == -1){

2141

perror_plus("setenv");

2142

_exit(EX_OSERR);

2143

}

2144

}

2145

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

2146

direntry->d_name,

2147

O_RDONLY));

2148

if(hook_fd == -1){

2149

perror_plus("openat");

2150

_exit(EXIT_FAILURE);

2151

}

2152

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

2153

perror_plus("close");

2154

_exit(EXIT_FAILURE);

2155

}

2156

ret = dup2(devnull, STDIN_FILENO);

2157

if(ret == -1){

2158

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

2159

_exit(EX_OSERR);

2160

}

2161

ret = close(devnull);

2162

if(ret == -1){

2163

perror_plus("close");

2164

_exit(EX_OSERR);

2165

}

2166

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2167

if(ret == -1){

2168

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

2169

_exit(EX_OSERR);

2170

}

2171

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

2172

environ) == -1){

2173

perror_plus("fexecve");

2174

_exit(EXIT_FAILURE);

2175

}

2176

} else {

2177

if(hook_pid == -1){

2178

perror_plus("fork");

2179

free(direntry);

2180

continue;

2181

}

2182

int status;

2183

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

2184

perror_plus("waitpid");

2185

free(direntry);

2186

continue;

2187

}

2188

if(WIFEXITED(status)){

2189

if(WEXITSTATUS(status) != 0){

2190

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

2191

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

2192

WEXITSTATUS(status));

2193

free(direntry);

2194

continue;

2195

}

2196

} else if(WIFSIGNALED(status)){

2197

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

2198

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

2199

WTERMSIG(status));

2200

free(direntry);

2201

continue;

2202

} else {

2203

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

2204

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

2205

free(direntry);

2206

continue;

2207

}

2208

}

2209

if(debug){

2210

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

2211

direntry->d_name);

2212

}

2213

free(direntry);

2214

}

2215

free(direntries);

2216

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

2217

perror_plus("close");

2218

} else {

2219

hookdir_fd = -1;

2220

}

2221

close(devnull);

2222

}

2223

2224

__attribute__((nonnull, warn_unused_result))

2225

int bring_up_interface(const char *const interface,

2226

const float delay){

2227

int old_errno = errno;

2228

int ret;

2229

struct ifreq network;

2230

unsigned int if_index = if_nametoindex(interface);

2231

if(if_index == 0){

2232

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

2233

errno = old_errno;

2234

return ENXIO;

2235

}

2236

2237

if(quit_now){

2238

errno = old_errno;

2239

return EINTR;

2240

}

2241

2242

if(not interface_is_up(interface)){

2243

int ret_errno = 0;

2244

int ioctl_errno = 0;

2245

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

2246

ret_errno = errno;

2247

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

2248

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

2249

errno = old_errno;

2250

return ret_errno;

2251

}

2252

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

2253

2254

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

2255

if(sd == -1){

2256

ret_errno = errno;

2257

perror_plus("socket");

2258

errno = old_errno;

2259

return ret_errno;

2260

}

2261

2262

if(quit_now){

2263

ret = close(sd);

2264

if(ret == -1){

2265

perror_plus("close");

2266

}

2267

errno = old_errno;

2268

return EINTR;

2269

}

2270

2271

if(debug){

2272

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

2273

interface);

2274

}

2275

2276

/* Raise privileges */

2277

ret_errno = raise_privileges();

2278

if(ret_errno != 0){

2279

errno = ret_errno;

2280

perror_plus("Failed to raise privileges");

2281

}

2282

2283

#ifdef __linux__

2284

int ret_linux;

2285

bool restore_loglevel = false;

2286

if(ret_errno == 0){

2287

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2288

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

2289

ret_linux = klogctl(8, NULL, 5);

2290

if(ret_linux == -1){

2291

perror_plus("klogctl");

2292

} else {

2293

restore_loglevel = true;

2294

}

2295

}

2296

#endif /* __linux__ */

2297

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

2298

ioctl_errno = errno;

2299

#ifdef __linux__

2300

if(restore_loglevel){

2301

ret_linux = klogctl(7, NULL, 0);

2302

if(ret_linux == -1){

2303

perror_plus("klogctl");

2304

}

2305

}

2306

#endif /* __linux__ */

2307

2308

/* If raise_privileges() succeeded above */

2309

if(ret_errno == 0){

2310

/* Lower privileges */

2311

ret_errno = lower_privileges();

2312

if(ret_errno != 0){

2313

errno = ret_errno;

2314

perror_plus("Failed to lower privileges");

2315

}

2316

}

2317

2318

/* Close the socket */

2319

ret = close(sd);

2320

if(ret == -1){

2321

perror_plus("close");

2322

}

2323

2324

if(ret_setflags == -1){

2325

errno = ioctl_errno;

2326

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2327

errno = old_errno;

2328

return ioctl_errno;

2329

}

2330

} else if(debug){

2331

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

2332

interface);

2333

}

2334

2335

/* Sleep checking until interface is running.

2336

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

2337

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

2338

if(interface_is_running(interface)){

2339

break;

2340

}

2341

struct timespec sleeptime = { .tv_nsec = 250000000 };

2342

ret = nanosleep(&sleeptime, NULL);

2343

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

2344

perror_plus("nanosleep");

2345

}

2346

}

2347

2348

errno = old_errno;

2349

return 0;

2350

}

2351

2352

__attribute__((nonnull, warn_unused_result))

2353

int take_down_interface(const char *const interface){

2354

int old_errno = errno;

2355

struct ifreq network;

2356

unsigned int if_index = if_nametoindex(interface);

2357

if(if_index == 0){

2358

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

2359

errno = old_errno;

2360

return ENXIO;

2361

}

2362

if(interface_is_up(interface)){

2363

int ret_errno = 0;

2364

int ioctl_errno = 0;

2365

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

2366

ret_errno = errno;

2367

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

2368

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

2369

errno = old_errno;

2370

return ret_errno;

2371

}

2372

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

2373

2374

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

2375

if(sd == -1){

2376

ret_errno = errno;

2377

perror_plus("socket");

2378

errno = old_errno;

2379

return ret_errno;

2380

}

2381

2382

if(debug){

2383

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

2384

interface);

2385

}

2386

2387

/* Raise privileges */

2388

ret_errno = raise_privileges();

2389

if(ret_errno != 0){

2390

errno = ret_errno;

2391

perror_plus("Failed to raise privileges");

2392

}

2393

2394

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

2395

ioctl_errno = errno;

2396

2397

/* If raise_privileges() succeeded above */

2398

if(ret_errno == 0){

2399

/* Lower privileges */

2400

ret_errno = lower_privileges();

2401

if(ret_errno != 0){

2402

errno = ret_errno;

2403

perror_plus("Failed to lower privileges");

2404

}

2405

}

2406

2407

/* Close the socket */

2408

int ret = close(sd);

2409

if(ret == -1){

2410

perror_plus("close");

2411

}

2412

2413

if(ret_setflags == -1){

2414

errno = ioctl_errno;

2415

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2416

errno = old_errno;

2417

return ioctl_errno;

2418

}

2419

} else if(debug){

2420

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

2421

interface);

2422

}

2423

2424

errno = old_errno;

2425

return 0;

1470

ret = execl(fullname, direntry->d_name, mode, NULL);

1471

perror_plus("execl");

1472

} else {

1473

int status;

1474

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

1475

perror_plus("waitpid");

1476

free(fullname);

1477

continue;

1478

}

1479

if(WIFEXITED(status)){

1480

if(WEXITSTATUS(status) != 0){

1481

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

1482

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

1483

WEXITSTATUS(status));

1484

free(fullname);

1485

continue;

1486

}

1487

} else if(WIFSIGNALED(status)){

1488

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

1489

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

1490

WTERMSIG(status));

1491

free(fullname);

1492

continue;

1493

} else {

1494

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

1495

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

1496

free(fullname);

1497

continue;

1498

}

1499

}

1500

free(fullname);

1501

if(debug){

1502

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

1503

direntry->d_name);

1504

}

1505

}

1506

close(devnull);

1507

}

1508

return true;

2426

1509

}

2427

1510

2428

1511

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

2429

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

2430

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

2431

":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",

2432

.current_server = NULL, .interfaces = NULL,

2433

.interfaces_size = 0 };

2434

1512

AvahiSServiceBrowser *sb = NULL;

2435

error_t ret_errno;

1513

int error;

2436

1514

int ret;

2437

1515

intmax_t tmpmax;

2438

1516

char *tmp;

2439

1517

int exitcode = EXIT_SUCCESS;

2440

char *interfaces_to_take_down = NULL;

2441

size_t interfaces_to_take_down_size = 0;

2442

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

2443

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

2444

char *tempdir = NULL;

1518

const char *interface = "";

1519

struct ifreq network;

1520

int sd = -1;

1521

bool take_down_interface = false;

1522

uid_t uid;

1523

gid_t gid;

1524

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

1525

bool tempdir_created = false;

2445

1526

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2446

1527

const char *seckey = PATHDIR "/" SECKEY;

2447

1528

const char *pubkey = PATHDIR "/" PUBKEY;

2448

const char *dh_params_file = NULL;

2449

char *interfaces_hooks = NULL;

2450

1529

2451

1530

bool gnutls_initialized = false;

2452

1531

bool gpgme_initialized = false;

2504

1583

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

2505

1584

" Diffie-Hellman key exchange",

2506

1585

.group = 2 },

2507

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

2508

.arg = "FILE",

2509

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

2510

" for the Diffie-Hellman key exchange",

2511

.group = 2 },

2512

1586

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

2513

1587

.arg = "STRING",

2514

1588

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

2519

1593

.group = 2 },

2520

1594

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

2521

1595

.arg = "SECONDS",

2522

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

1596

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

2523

1597

.group = 2 },

2524

1598

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

2525

1599

.arg = "DIR",

2548

1622

connect_to = arg;

2549

1623

break;

2550

1624

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

2551

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

2552

arg, (int)',');

2553

if(ret_errno != 0){

2554

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

2555

}

1625

interface = arg;

2556

1626

break;

2557

1627

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

2558

1628

seckey = arg;

2569

1639

}

2570

1640

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

2571

1641

break;

2572

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

2573

dh_params_file = arg;

2574

break;

2575

1642

case 130: /* --priority */

2576

1643

mc.priority = arg;

2577

1644

break;

2604

1671

argp_state_help(state, state->out_stream,

2605

1672

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

2606

1673

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

1674

fprintf_plus(state->out_stream,

1675

"Mandos plugin mandos-client: ");

2607

1676

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

2608

1677

exit(argp_err_exit_status);

2609

1678

break;

2617

1686

.args_doc = "",

2618

1687

.doc = "Mandos client -- Get and decrypt"

2619

1688

" passwords from a Mandos server" };

2620

ret_errno = argp_parse(&argp, argc, argv,

2621

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2622

switch(ret_errno){

1689

ret = argp_parse(&argp, argc, argv,

1690

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1691

switch(ret){

2623

1692

case 0:

2624

1693

break;

2625

1694

case ENOMEM:

2626

1695

default:

2627

errno = ret_errno;

1696

errno = ret;

2628

1697

perror_plus("argp_parse");

2629

1698

exitcode = EX_OSERR;

2630

1699

goto end;

2633

1702

goto end;

2634

1703

}

2635

1704

}

2636

1705

2637

1706

{

2638

1707

/* Work around Debian bug #633582:

2639

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

1708

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

2640

1709

2641

/* Re-raise privileges */

2642

ret = raise_privileges();

2643

if(ret != 0){

2644

errno = ret;

2645

perror_plus("Failed to raise privileges");

1710

/* Re-raise priviliges */

1711

errno = 0;

1712

ret = seteuid(0);

1713

if(ret == -1){

1714

perror_plus("seteuid");

2646

1715

} else {

2647

1716

struct stat st;

2648

1717

2663

1732

}

2664

1733

}

2665

1734

}

2666

close(seckey_fd);

1735

TEMP_FAILURE_RETRY(close(seckey_fd));

2667

1736

}

2668

1737

}

2669

1738

2670

1739

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

2671

1740

int pubkey_fd = open(pubkey, O_RDONLY);

2672

1741

if(pubkey_fd == -1){

2684

1753

}

2685

1754

}

2686

1755

}

2687

close(pubkey_fd);

2688

}

2689

}

2690

2691

if(dh_params_file != NULL

2692

and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){

2693

int dhparams_fd = open(dh_params_file, O_RDONLY);

2694

if(dhparams_fd == -1){

2695

perror_plus("open");

2696

} else {

2697

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

2698

if(ret == -1){

2699

perror_plus("fstat");

2700

} else {

2701

if(S_ISREG(st.st_mode)

2702

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

2703

ret = fchown(dhparams_fd, uid, gid);

2704

if(ret == -1){

2705

perror_plus("fchown");

2706

}

2707

}

2708

}

2709

close(dhparams_fd);

2710

}

2711

}

2712

1756

TEMP_FAILURE_RETRY(close(pubkey_fd));

1757

}

1758

}

1759

2713

1760

/* Lower privileges */

2714

ret = lower_privileges();

2715

if(ret != 0){

2716

errno = ret;

2717

perror_plus("Failed to lower privileges");

2718

}

2719

}

2720

}

2721

2722

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

2723

{

2724

char *interface = NULL;

2725

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

2726

interface))){

2727

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

2728

and if_nametoindex(interface) == 0){

2729

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

2730

fprintf_plus(stderr, "Not using nonexisting interface"

2731

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

2732

}

2733

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

2734

interface = NULL;

1761

errno = 0;

1762

ret = seteuid(uid);

1763

if(ret == -1){

1764

perror_plus("seteuid");

2735

1765

}

2736

1766

}

2737

1767

}

2738

1768

2739

1769

/* Run network hooks */

2740

{

2741

if(mc.interfaces != NULL){

2742

interfaces_hooks = malloc(mc.interfaces_size);

2743

if(interfaces_hooks == NULL){

2744

perror_plus("malloc");

2745

goto end;

2746

}

2747

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

2748

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

2749

}

2750

run_network_hooks("start", interfaces_hooks != NULL ?

2751

interfaces_hooks : "", delay);

1770

if(not run_network_hooks("start", interface, delay)){

1771

goto end;

2752

1772

}

2753

1773

2754

1774

if(not debug){

2755

1775

avahi_set_log_function(empty_log);

2756

1776

}

2757

1777

1778

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

1779

struct dirent **direntries;

1780

/* First look for interfaces that are up */

1781

ret = scandir(sys_class_net, &direntries, up_interface,

1782

alphasort);

1783

if(ret == 0){

1784

/* No up interfaces, look for any good interfaces */

1785

free(direntries);

1786

ret = scandir(sys_class_net, &direntries, good_interface,

1787

alphasort);

1788

}

1789

if(ret >= 1){

1790

/* Pick the first interface returned */

1791

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

1792

if(debug){

1793

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

1794

}

1795

if(interface == NULL){

1796

perror_plus("malloc");

1797

free(direntries);

1798

exitcode = EXIT_FAILURE;

1799

goto end;

1800

}

1801

free(direntries);

1802

} else {

1803

free(direntries);

1804

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

1805

exitcode = EXIT_FAILURE;

1806

goto end;

1807

}

1808

}

1809

2758

1810

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

2759

1811

from the signal handler */

2760

1812

/* Initialize the pseudo-RNG for Avahi */

2761

1813

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

2762

simple_poll = avahi_simple_poll_new();

2763

if(simple_poll == NULL){

1814

mc.simple_poll = avahi_simple_poll_new();

1815

if(mc.simple_poll == NULL){

2764

1816

fprintf_plus(stderr,

2765

1817

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

2766

1818

exitcode = EX_UNAVAILABLE;

2830

1882

}

2831

1883

}

2832

1884

2833

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

2834

if(mc.interfaces == NULL){

2835

struct dirent **direntries = NULL;

2836

/* Look for any good interfaces */

2837

ret = scandir(sys_class_net, &direntries, good_interface,

2838

alphasort);

2839

if(ret >= 1){

2840

/* Add all found interfaces to interfaces list */

2841

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

2842

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

2843

direntries[i]->d_name);

2844

if(ret_errno != 0){

2845

errno = ret_errno;

2846

perror_plus("argz_add");

2847

free(direntries[i]);

2848

continue;

2849

}

2850

if(debug){

2851

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

2852

direntries[i]->d_name);

2853

}

2854

free(direntries[i]);

2855

}

2856

free(direntries);

2857

} else {

2858

if(ret == 0){

2859

free(direntries);

2860

}

2861

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

2862

exitcode = EXIT_FAILURE;

2863

goto end;

2864

}

2865

}

2866

2867

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

2868

{

2869

char *interface = NULL;

2870

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

2871

interface))){

2872

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

2873

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

2874

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

2875

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

2876

interface);

2877

interface = NULL;

2878

while((interface = argz_next(mc.interfaces,

2879

mc.interfaces_size, interface))){

2880

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

2881

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

2882

interface);

2883

interface = NULL;

1885

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

1886

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

1887

if_index = (AvahiIfIndex) if_nametoindex(interface);

1888

if(if_index == 0){

1889

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

1890

exitcode = EX_UNAVAILABLE;

1891

goto end;

1892

}

1893

1894

if(quit_now){

1895

goto end;

1896

}

1897

1898

/* Re-raise priviliges */

1899

errno = 0;

1900

ret = seteuid(0);

1901

if(ret == -1){

1902

perror_plus("seteuid");

1903

}

1904

1905

#ifdef __linux__

1906

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1907

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

1908

ret = klogctl(8, NULL, 5);

1909

bool restore_loglevel = true;

1910

if(ret == -1){

1911

restore_loglevel = false;

1912

perror_plus("klogctl");

1913

}

1914

#endif /* __linux__ */

1915

1916

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1917

if(sd < 0){

1918

perror_plus("socket");

1919

exitcode = EX_OSERR;

1920

#ifdef __linux__

1921

if(restore_loglevel){

1922

ret = klogctl(7, NULL, 0);

1923

if(ret == -1){

1924

perror_plus("klogctl");

1925

}

1926

}

1927

#endif /* __linux__ */

1928

/* Lower privileges */

1929

errno = 0;

1930

ret = seteuid(uid);

1931

if(ret == -1){

1932

perror_plus("seteuid");

1933

}

1934

goto end;

1935

}

1936

strcpy(network.ifr_name, interface);

1937

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

1938

if(ret == -1){

1939

perror_plus("ioctl SIOCGIFFLAGS");

1940

#ifdef __linux__

1941

if(restore_loglevel){

1942

ret = klogctl(7, NULL, 0);

1943

if(ret == -1){

1944

perror_plus("klogctl");

1945

}

1946

}

1947

#endif /* __linux__ */

1948

exitcode = EX_OSERR;

1949

/* Lower privileges */

1950

errno = 0;

1951

ret = seteuid(uid);

1952

if(ret == -1){

1953

perror_plus("seteuid");

1954

}

1955

goto end;

1956

}

1957

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

1958

network.ifr_flags |= IFF_UP;

1959

take_down_interface = true;

1960

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

1961

if(ret == -1){

1962

take_down_interface = false;

1963

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1964

exitcode = EX_OSERR;

1965

#ifdef __linux__

1966

if(restore_loglevel){

1967

ret = klogctl(7, NULL, 0);

1968

if(ret == -1){

1969

perror_plus("klogctl");

2884

1970

}

2885

1971

}

1972

#endif /* __linux__ */

1973

/* Lower privileges */

1974

errno = 0;

1975

ret = seteuid(uid);

1976

if(ret == -1){

1977

perror_plus("seteuid");

1978

}

1979

goto end;

1980

}

1981

}

1982

/* Sleep checking until interface is running.

1983

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

1984

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

1985

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

1986

if(ret == -1){

1987

perror_plus("ioctl SIOCGIFFLAGS");

1988

} else if(network.ifr_flags & IFF_RUNNING){

2886

1989

break;

2887

1990

}

2888

bool interface_was_up = interface_is_up(interface);

2889

errno = bring_up_interface(interface, delay);

2890

if(not interface_was_up){

2891

if(errno != 0){

2892

fprintf_plus(stderr, "Failed to bring up interface \"%s\":"

2893

" %s\n", interface, strerror(errno));

2894

} else {

2895

errno = argz_add(&interfaces_to_take_down,

2896

&interfaces_to_take_down_size,

2897

interface);

2898

if(errno != 0){

2899

perror_plus("argz_add");

2900

}

2901

}

2902

}

2903

}

2904

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

2905

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

2906

}

2907

}

2908

2909

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

2910

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

2911

if(debug){

2912

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

2913

mc.interfaces);

2914

}

2915

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

1991

struct timespec sleeptime = { .tv_nsec = 250000000 };

1992

ret = nanosleep(&sleeptime, NULL);

1993

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

1994

perror_plus("nanosleep");

1995

}

1996

}

1997

if(not take_down_interface){

1998

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

1999

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

2000

if(ret == -1){

2001

perror_plus("close");

2002

}

2003

}

2004

#ifdef __linux__

2005

if(restore_loglevel){

2006

/* Restores kernel loglevel to default */

2007

ret = klogctl(7, NULL, 0);

2008

if(ret == -1){

2009

perror_plus("klogctl");

2010

}

2011

}

2012

#endif /* __linux__ */

2013

/* Lower privileges */

2014

errno = 0;

2015

/* Lower privileges */

2016

ret = seteuid(uid);

2017

if(ret == -1){

2018

perror_plus("seteuid");

2019

}

2916

2020

}

2917

2021

2918

2022

if(quit_now){

2919

2023

goto end;

2920

2024

}

2921

2025

2922

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

2026

ret = init_gnutls_global(pubkey, seckey);

2923

2027

if(ret == -1){

2924

2028

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

2925

2029

exitcode = EX_UNAVAILABLE;

2932

2036

goto end;

2933

2037

}

2934

2038

2935

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

2936

tempdir = mkdtemp(run_tempdir);

2937

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

2938

if(debug){

2939

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

2940

run_tempdir, old_tempdir);

2941

}

2942

tempdir = mkdtemp(old_tempdir);

2943

}

2944

if(tempdir == NULL){

2039

if(mkdtemp(tempdir) == NULL){

2945

2040

perror_plus("mkdtemp");

2946

2041

goto end;

2947

2042

}

2043

tempdir_created = true;

2948

2044

2949

2045

if(quit_now){

2950

2046

goto end;

2951

2047

}

2952

2048

2953

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

2049

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

2954

2050

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

2955

2051

exitcode = EX_UNAVAILABLE;

2956

2052

goto end;

2966

2062

/* Connect directly, do not use Zeroconf */

2967

2063

/* (Mainly meant for debugging) */

2968

2064

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

2969

2970

2065

if(address == NULL){

2971

2066

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

2972

2067

exitcode = EX_USAGE;

2977

2072

goto end;

2978

2073

}

2979

2074

2980

in_port_t port;

2075

uint16_t port;

2981

2076

errno = 0;

2982

2077

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

2983

2078

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

2984

or tmpmax != (in_port_t)tmpmax){

2079

or tmpmax != (uint16_t)tmpmax){

2985

2080

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

2986

2081

exitcode = EX_USAGE;

2987

2082

goto end;

2988

2083

}

2989

2084

2990

2085

if(quit_now){

2991

2086

goto end;

2992

2087

}

2993

2088

2994

port = (in_port_t)tmpmax;

2089

port = (uint16_t)tmpmax;

2995

2090

*address = '\0';

2996

2091

/* Colon in address indicates IPv6 */

2997

2092

int af;

3013

2108

}

3014

2109

3015

2110

while(not quit_now){

3016

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

3017

&mc);

2111

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

3018

2112

if(quit_now or ret == 0){

3019

2113

break;

3020

2114

}

3022

2116

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

3023

2117

(int)retry_interval);

3024

2118

}

3025

sleep((unsigned int)retry_interval);

2119

sleep((int)retry_interval);

3026

2120

}

3027

2121

3028

if(not quit_now){

2122

if (not quit_now){

3029

2123

exitcode = EXIT_SUCCESS;

3030

2124

}

3031

2125

3046

2140

config.publish_domain = 0;

3047

2141

3048

2142

/* Allocate a new server */

3049

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

3050

&config, NULL, NULL, &ret);

2143

mc.server = avahi_server_new(avahi_simple_poll_get

2144

(mc.simple_poll), &config, NULL,

2145

NULL, &error);

3051

2146

3052

2147

/* Free the Avahi configuration data */

3053

2148

avahi_server_config_free(&config);

3056

2151

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

3057

2152

if(mc.server == NULL){

3058

2153

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

3059

avahi_strerror(ret));

2154

avahi_strerror(error));

3060

2155

exitcode = EX_UNAVAILABLE;

3061

2156

goto end;

3062

2157

}

3068

2163

/* Create the Avahi service browser */

3069

2164

sb = avahi_s_service_browser_new(mc.server, if_index,

3070

2165

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

3071

NULL, 0, browse_callback,

3072

(void *)&mc);

2166

NULL, 0, browse_callback, NULL);

3073

2167

if(sb == NULL){

3074

2168

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

3075

2169

avahi_strerror(avahi_server_errno(mc.server)));

3086

2180

if(debug){

3087

2181

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

3088

2182

}

3089

3090

ret = avahi_loop_with_timeout(simple_poll,

3091

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

2183

2184

ret = avahi_loop_with_timeout(mc.simple_poll,

2185

(int)(retry_interval * 1000));

3092

2186

if(debug){

3093

2187

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

3094

2188

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

3097

2191

end:

3098

2192

3099

2193

if(debug){

3100

if(signal_received){

3101

fprintf_plus(stderr, "%s exiting due to signal %d: %s\n",

3102

argv[0], signal_received,

3103

strsignal(signal_received));

3104

} else {

3105

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

3106

}

2194

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

3107

2195

}

3108

2196

3109

2197

/* Cleanup things */

3110

free(mc.interfaces);

3111

3112

2198

if(sb != NULL)

3113

2199

avahi_s_service_browser_free(sb);

3114

2200

3115

2201

if(mc.server != NULL)

3116

2202

avahi_server_free(mc.server);

3117

2203

3118

if(simple_poll != NULL)

3119

avahi_simple_poll_free(simple_poll);

2204

if(mc.simple_poll != NULL)

2205

avahi_simple_poll_free(mc.simple_poll);

3120

2206

3121

2207

if(gnutls_initialized){

3122

2208

gnutls_certificate_free_credentials(mc.cred);

2209

gnutls_global_deinit();

3123

2210

gnutls_dh_params_deinit(mc.dh_params);

3124

2211

}

3125

2212

3133

2220

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

3134

2221

while(mc.current_server != NULL){

3135

2222

server *next = mc.current_server->next;

3136

#ifdef __GNUC__

3137

#pragma GCC diagnostic push

3138

#pragma GCC diagnostic ignored "-Wcast-qual"

3139

#endif

3140

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

3141

#ifdef __GNUC__

3142

#pragma GCC diagnostic pop

3143

#endif

3144

2223

free(mc.current_server);

3145

2224

mc.current_server = next;

3146

2225

}

3147

2226

}

3148

2227

3149

/* Re-raise privileges */

2228

/* Run network hooks */

2229

run_network_hooks("stop", interface, delay);

2230

2231

/* Re-raise priviliges */

3150

2232

{

3151

ret = raise_privileges();

3152

if(ret != 0){

3153

errno = ret;

3154

perror_plus("Failed to raise privileges");

3155

} else {

3156

3157

/* Run network hooks */

3158

run_network_hooks("stop", interfaces_hooks != NULL ?

3159

interfaces_hooks : "", delay);

3160

3161

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

3162

{

3163

char *interface = NULL;

3164

while((interface = argz_next(interfaces_to_take_down,

3165

interfaces_to_take_down_size,

3166

interface))){

3167

ret = take_down_interface(interface);

3168

if(ret != 0){

3169

errno = ret;

3170

perror_plus("Failed to take down interface");

3171

}

3172

}

3173

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

3174

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

3175

" down\n");

3176

}

3177

}

2233

errno = 0;

2234

ret = seteuid(0);

2235

if(ret == -1){

2236

perror_plus("seteuid");

3178

2237

}

3179

2238

3180

ret = lower_privileges_permanently();

3181

if(ret != 0){

3182

errno = ret;

3183

perror_plus("Failed to lower privileges permanently");

2239

/* Take down the network interface */

2240

if(take_down_interface and geteuid() == 0){

2241

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

2242

if(ret == -1){

2243

perror_plus("ioctl SIOCGIFFLAGS");

2244

} else if(network.ifr_flags & IFF_UP){

2245

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

2246

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

2247

if(ret == -1){

2248

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2249

}

2250

}

2251

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

2252

if(ret == -1){

2253

perror_plus("close");

2254

}

3184

2255

}

3185

2256

}

3186

3187

free(interfaces_to_take_down);

3188

free(interfaces_hooks);

3189

3190

void clean_dir_at(int base, const char * const dirname,

3191

uintmax_t level){

2257

/* Lower privileges permanently */

2258

errno = 0;

2259

ret = setuid(uid);

2260

if(ret == -1){

2261

perror_plus("setuid");

2262

}

2263

2264

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

2265

if(tempdir_created){

3192

2266

struct dirent **direntries = NULL;

3193

int dret;

3194

int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,

3195

O_RDONLY

3196

| O_NOFOLLOW

3197

| O_DIRECTORY

3198

| O_PATH));

3199

if(dir_fd == -1){

3200

perror_plus("open");

3201

return;

3202

}

3203

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

3204

notdotentries, alphasort);

3205

if(numentries >= 0){

2267

struct dirent *direntry = NULL;

2268

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

2269

alphasort);

2270

if (numentries > 0){

3206

2271

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

3207

if(debug){

3208

fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",

3209

dirname, direntries[i]->d_name);

3210

}

3211

dret = unlinkat(dir_fd, direntries[i]->d_name, 0);

3212

if(dret == -1){

3213

if(errno == EISDIR){

3214

dret = unlinkat(dir_fd, direntries[i]->d_name,

3215

AT_REMOVEDIR);

3216

}

3217

if((dret == -1) and (errno == ENOTEMPTY)

3218

and (strcmp(direntries[i]->d_name, "private-keys-v1.d")

3219

== 0) and (level == 0)){

3220

/* Recurse only in this special case */

3221

clean_dir_at(dir_fd, direntries[i]->d_name, level+1);

3222

dret = 0;

3223

}

3224

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

3225

fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,

3226

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

3227

}

3228

}

3229

free(direntries[i]);

3230

}

3231

3232

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

3233

free(direntries);

3234

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3235

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

3236

perror_plus("rmdir");

3237

}

3238

} else {

3239

perror_plus("scandirat");

3240

}

3241

close(dir_fd);

3242

}

3243

3244

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

3245

if(tempdir != NULL){

3246

clean_dir_at(-1, tempdir, 0);

2272

direntry = direntries[i];

2273

char *fullname = NULL;

2274

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

2275

direntry->d_name);

2276

if(ret < 0){

2277

perror_plus("asprintf");

2278

continue;

2279

}

2280

ret = remove(fullname);

2281

if(ret == -1){

2282

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

2283

strerror(errno));

2284

}

2285

free(fullname);

2286

}

2287

}

2288

2289

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

2290

free(direntries);

2291

if (numentries == -1){

2292

perror_plus("scandir");

2293

}

2294

ret = rmdir(tempdir);

2295

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

2296

perror_plus("rmdir");

2297

}

3247

2298

}

3248

2299

3249

2300

if(quit_now){