/mandos/trunk : revision 678

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

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*

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* Everything else is

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*

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

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

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

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stdout, ferror(), remove() */

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

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

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

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

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strtof(), abort() */

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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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inet_pton(), connect(),

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getnameinfo() */

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

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

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

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

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argp_state, struct argp,

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#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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bool debug = false;

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static const char mandos_protocol_version[] = "1";

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

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

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

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

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

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char *connect_to = NULL;

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const char *hookdir = HOOKDIR;

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uid_t uid = 65534;

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gid_t gid = 65534;

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

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typedef struct server{

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const char *ip;

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uint16_t port;

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in_port_t port;

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AvahiIfIndex if_index;

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int af;

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struct timespec last_seen;

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

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typedef struct {

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AvahiSimplePoll *simple_poll;

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AvahiServer *server;

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gnutls_certificate_credentials_t cred;

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unsigned int dh_bits;

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const char *priority;

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gpgme_ctx_t ctx;

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server *current_server;

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char *interfaces;

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size_t interfaces_size;

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} mandos_context;

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

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

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.dh_bits = 1024, .priority = "SECURE256"

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

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.current_server = NULL };

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/* global so signal handler can reach it*/

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AvahiSimplePoll *simple_poll;

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sig_atomic_t quit_now = 0;

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int signal_received = 0;

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/* Function to use when printing errors */

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void perror_plus(const char *print_text){

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int e = errno;

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

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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)))

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

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

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va_list ap;

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va_start (ap, format);

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

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program_invocation_short_name));

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

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

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if(buffer == NULL){

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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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return 0;

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}

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*buffer = new_buf;

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buffer_capacity += BUFFER_SIZE;

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}

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return buffer_capacity;

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}

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

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

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int af){

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__attribute__((nonnull, warn_unused_result))

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

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int af, server **current_server){

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int ret;

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

210

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if(new_server == NULL){

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perror_plus("strdup");

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return false;

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}

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

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if(ret == -1){

239

perror_plus("clock_gettime");

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return false;

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}

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/* Special case of first server */

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if (mc.current_server == NULL){

243

if(*current_server == NULL){

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new_server->next = new_server;

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new_server->prev = new_server;

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mc.current_server = new_server;

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

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*current_server = new_server;

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} else {

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new_server->next = mc.current_server;

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

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

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new_server->next = *current_server;

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

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new_server->prev->next = new_server;

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mc.current_server->prev = new_server;

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}

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

235

if(ret == -1){

236

perror_plus("clock_gettime");

237

return false;

252

(*current_server)->prev = new_server;

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253

}

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return true;

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}

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/*

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* Initialize GPGME.

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*/

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

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const char *tempdir){

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__attribute__((nonnull, warn_unused_result))

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static bool init_gpgme(const char * const seckey,

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const char * const pubkey,

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const char * const tempdir,

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mandos_context *mc){

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gpgme_error_t rc;

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gpgme_engine_info_t engine_info;

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/*

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

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270

*/

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bool import_key(const char *filename){

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bool import_key(const char * const filename){

255

272

int ret;

256

273

int fd;

257

274

gpgme_data_t pgp_data;

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286

return false;

270

287

}

271

288

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rc = gpgme_op_import(mc.ctx, pgp_data);

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

273

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if(rc != GPG_ERR_NO_ERROR){

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

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gpgme_strsource(rc), gpgme_strerror(rc));

319

336

}

320

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/* Create new GPGME "context" */

322

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

339

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

323

340

if(rc != GPG_ERR_NO_ERROR){

324

341

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

325

342

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

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355

* Decrypt OpenPGP data.

339

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* Returns -1 on error

340

357

*/

358

__attribute__((nonnull, warn_unused_result))

341

359

static ssize_t pgp_packet_decrypt(const char *cryptotext,

342

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size_t crypto_size,

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char **plaintext){

361

char **plaintext,

362

mandos_context *mc){

344

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gpgme_data_t dh_crypto, dh_plain;

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gpgme_error_t rc;

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ssize_t ret;

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

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data buffer */

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

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

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if(rc != GPG_ERR_NO_ERROR){

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

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gpgme_strsource(rc), gpgme_strerror(rc));

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plaintext_length = -1;

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if(debug){

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gpgme_decrypt_result_t result;

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result = gpgme_op_decrypt_result(mc.ctx);

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result = gpgme_op_decrypt_result(mc->ctx);

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if(result == NULL){

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403

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

385

404

} else {

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return plaintext_length;

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}

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static const char * safer_gnutls_strerror(int value){

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

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-Wunreachable-code */

484

__attribute__((warn_unused_result))

485

static const char *safer_gnutls_strerror(int value){

486

const char *ret = gnutls_strerror(value);

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if(ret == NULL)

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ret = "(unknown)";

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return ret;

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}

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/* GnuTLS log function callback */

493

__attribute__((nonnull))

474

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

475

495

const char* string){

476

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

477

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}

478

498

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__attribute__((nonnull, warn_unused_result))

479

500

static int init_gnutls_global(const char *pubkeyfilename,

480

const char *seckeyfilename){

501

const char *seckeyfilename,

502

mandos_context *mc){

481

503

int ret;

482

504

483

505

if(debug){

500

522

}

501

523

502

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/* OpenPGP credentials */

503

ret = gnutls_certificate_allocate_credentials(&mc.cred);

525

ret = gnutls_certificate_allocate_credentials(&mc->cred);

504

526

if(ret != GNUTLS_E_SUCCESS){

505

527

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

506

528

safer_gnutls_strerror(ret));

516

538

}

517

539

518

540

ret = gnutls_certificate_set_openpgp_key_file

519

(mc.cred, pubkeyfilename, seckeyfilename,

541

(mc->cred, pubkeyfilename, seckeyfilename,

520

542

GNUTLS_OPENPGP_FMT_BASE64);

521

543

if(ret != GNUTLS_E_SUCCESS){

522

544

fprintf_plus(stderr,

528

550

}

529

551

530

552

/* GnuTLS server initialization */

531

ret = gnutls_dh_params_init(&mc.dh_params);

553

ret = gnutls_dh_params_init(&mc->dh_params);

532

554

if(ret != GNUTLS_E_SUCCESS){

533

555

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

534

556

" initialization: %s\n",

535

557

safer_gnutls_strerror(ret));

536

558

goto globalfail;

537

559

}

538

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

560

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

539

561

if(ret != GNUTLS_E_SUCCESS){

540

562

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

541

563

safer_gnutls_strerror(ret));

542

564

goto globalfail;

543

565

}

544

566

545

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

567

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

546

568

547

569

return 0;

548

570

549

571

globalfail:

550

572

551

gnutls_certificate_free_credentials(mc.cred);

573

gnutls_certificate_free_credentials(mc->cred);

552

574

gnutls_global_deinit();

553

gnutls_dh_params_deinit(mc.dh_params);

575

gnutls_dh_params_deinit(mc->dh_params);

554

576

return -1;

555

577

}

556

578

557

static int init_gnutls_session(gnutls_session_t *session){

579

__attribute__((nonnull, warn_unused_result))

580

static int init_gnutls_session(gnutls_session_t *session,

581

mandos_context *mc){

558

582

int ret;

559

583

/* GnuTLS session creation */

560

584

do {

572

596

{

573

597

const char *err;

574

598

do {

575

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

599

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

576

600

if(quit_now){

577

601

gnutls_deinit(*session);

578

602

return -1;

589

613

590

614

do {

591

615

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

592

mc.cred);

616

mc->cred);

593

617

if(quit_now){

594

618

gnutls_deinit(*session);

595

619

return -1;

605

629

/* ignore client certificate if any. */

606

630

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

607

631

608

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

632

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

609

633

610

634

return 0;

611

635

}

615

639

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

616

640

617

641

/* Called when a Mandos server is found */

618

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

642

__attribute__((nonnull, warn_unused_result))

643

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

619

644

AvahiIfIndex if_index,

620

int af){

645

int af, mandos_context *mc){

621

646

int ret, tcp_sd = -1;

622

647

ssize_t sret;

623

union {

624

struct sockaddr_in in;

625

struct sockaddr_in6 in6;

626

} to;

648

struct sockaddr_storage to;

627

649

char *buffer = NULL;

628

650

char *decrypted_buffer = NULL;

629

651

size_t buffer_length = 0;

653

675

return -1;

654

676

}

655

677

656

ret = init_gnutls_session(&session);

678

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

679

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

680

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

681

bool match = false;

682

{

683

char *interface = NULL;

684

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

685

interface))){

686

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

687

match = true;

688

break;

689

}

690

}

691

}

692

if(not match){

693

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

694

connect to the server */

695

if(debug){

696

char interface[IF_NAMESIZE];

697

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

698

perror_plus("if_indextoname");

699

} else {

700

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

701

" \"%s\"\n",

702

if_indextoname((unsigned int)if_index,

703

interface));

704

}

705

}

706

return -1;

707

}

708

}

709

710

ret = init_gnutls_session(&session, mc);

657

711

if(ret != 0){

658

712

return -1;

659

713

}

660

714

661

715

if(debug){

662

716

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

663

PRIu16 "\n", ip, port);

717

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

664

718

}

665

719

666

720

tcp_sd = socket(pf, SOCK_STREAM, 0);

678

732

679

733

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

680

734

if(af == AF_INET6){

681

to.in6.sin6_family = (sa_family_t)af;

682

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

735

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

736

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

683

737

} else { /* IPv4 */

684

to.in.sin_family = (sa_family_t)af;

685

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

738

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

739

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

686

740

}

687

741

if(ret < 0 ){

688

742

int e = errno;

697

751

goto mandos_end;

698

752

}

699

753

if(af == AF_INET6){

700

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

701

-Wconversion and

702

-Wunreachable-code */

703

704

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

705

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

706

-Wunreachable-code*/

754

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

755

if(IN6_IS_ADDR_LINKLOCAL

756

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

707

757

if(if_index == AVAHI_IF_UNSPEC){

708

758

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

709

759

" incomplete without a network interface\n");

711

761

goto mandos_end;

712

762

}

713

763

/* Set the network interface number as scope */

714

to.in6.sin6_scope_id = (uint32_t)if_index;

764

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

715

765

}

716

766

} else {

717

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

718

-Wconversion and

719

-Wunreachable-code */

767

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

720

768

}

721

769

722

770

if(quit_now){

730

778

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

731

779

perror_plus("if_indextoname");

732

780

} else {

733

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

734

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

781

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

782

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

735

783

}

736

784

} else {

737

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

738

ip, port);

785

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

786

ip, (uintmax_t)port);

739

787

}

740

788

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

741

789

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

742

const char *pcret;

743

790

if(af == AF_INET6){

744

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

745

sizeof(addrstr));

791

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

792

sizeof(struct sockaddr_in6),

793

addrstr, sizeof(addrstr), NULL, 0,

794

NI_NUMERICHOST);

746

795

} else {

747

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

748

sizeof(addrstr));

796

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

797

sizeof(struct sockaddr_in),

798

addrstr, sizeof(addrstr), NULL, 0,

799

NI_NUMERICHOST);

749

800

}

750

if(pcret == NULL){

751

perror_plus("inet_ntop");

752

} else {

753

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

754

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

755

}

801

if(ret == EAI_SYSTEM){

802

perror_plus("getnameinfo");

803

} else if(ret != 0) {

804

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

805

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

806

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

756

807

}

757

808

}

758

809

762

813

}

763

814

764

815

if(af == AF_INET6){

765

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

816

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

817

sizeof(struct sockaddr_in6));

766

818

} else {

767

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

819

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

820

sizeof(struct sockaddr_in));

768

821

}

769

822

if(ret < 0){

770

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

823

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

771

824

int e = errno;

772

825

perror_plus("connect");

773

826

errno = e;

819

872

goto mandos_end;

820

873

}

821

874

822

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

823

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

875

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

876

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

877

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

878

gnutls_transport_set_ptr(session,

879

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

824

880

825

881

if(quit_now){

826

882

errno = EINTR;

931

987

if(buffer_length > 0){

932

988

ssize_t decrypted_buffer_size;

933

989

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

934

&decrypted_buffer);

990

&decrypted_buffer, mc);

935

991

if(decrypted_buffer_size >= 0){

936

992

937

993

written = 0;

985

1041

return retval;

986

1042

}

987

1043

1044

__attribute__((nonnull))

988

1045

static void resolve_callback(AvahiSServiceResolver *r,

989

1046

AvahiIfIndex interface,

990

1047

AvahiProtocol proto,

998

1055

AVAHI_GCC_UNUSED AvahiStringList *txt,

999

1056

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1000

1057

flags,

1001

AVAHI_GCC_UNUSED void* userdata){

1002

assert(r);

1058

void *mc){

1059

if(r == NULL){

1060

return;

1061

}

1003

1062

1004

1063

/* Called whenever a service has been resolved successfully or

1005

1064

timed out */

1014

1073

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

1015

1074

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

1016

1075

domain,

1017

avahi_strerror(avahi_server_errno(mc.server)));

1076

avahi_strerror(avahi_server_errno

1077

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

1018

1078

break;

1019

1079

1020

1080

case AVAHI_RESOLVER_FOUND:

1026

1086

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

1027

1087

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

1028

1088

}

1029

int ret = start_mandos_communication(ip, port, interface,

1030

avahi_proto_to_af(proto));

1089

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

1090

interface,

1091

avahi_proto_to_af(proto),

1092

mc);

1031

1093

if(ret == 0){

1032

avahi_simple_poll_quit(mc.simple_poll);

1094

avahi_simple_poll_quit(simple_poll);

1033

1095

} else {

1034

if(not add_server(ip, port, interface,

1035

avahi_proto_to_af(proto))){

1096

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

1097

avahi_proto_to_af(proto),

1098

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

1036

1099

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

1037

1100

" list\n", name);

1038

1101

}

1051

1114

const char *domain,

1052

1115

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1053

1116

flags,

1054

AVAHI_GCC_UNUSED void* userdata){

1055

assert(b);

1117

void *mc){

1118

if(b == NULL){

1119

return;

1120

}

1056

1121

1057

1122

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

1058

1123

is removed from the LAN */

1066

1131

case AVAHI_BROWSER_FAILURE:

1067

1132

1068

1133

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

1069

avahi_strerror(avahi_server_errno(mc.server)));

1070

avahi_simple_poll_quit(mc.simple_poll);

1134

avahi_strerror(avahi_server_errno

1135

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

1136

avahi_simple_poll_quit(simple_poll);

1071

1137

return;

1072

1138

1073

1139

case AVAHI_BROWSER_NEW:

1076

1142

the callback function is called the Avahi server will free the

1077

1143

resolver for us. */

1078

1144

1079

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

1080

name, type, domain, protocol, 0,

1081

resolve_callback, NULL) == NULL)

1145

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

1146

interface, protocol, name, type,

1147

domain, protocol, 0,

1148

resolve_callback, mc) == NULL)

1082

1149

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

1083

1150

" %s\n", name,

1084

avahi_strerror(avahi_server_errno(mc.server)));

1151

avahi_strerror(avahi_server_errno

1152

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

1085

1153

break;

1086

1154

1087

1155

case AVAHI_BROWSER_REMOVE:

1106

1174

signal_received = sig;

1107

1175

int old_errno = errno;

1108

1176

/* set main loop to exit */

1109

if(mc.simple_poll != NULL){

1110

avahi_simple_poll_quit(mc.simple_poll);

1177

if(simple_poll != NULL){

1178

avahi_simple_poll_quit(simple_poll);

1111

1179

}

1112

1180

errno = old_errno;

1113

1181

}

1114

1182

1183

__attribute__((nonnull, warn_unused_result))

1115

1184

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

1116

1185

int ret;

1186

error_t ret_errno;

1117

1187

1118

1188

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

1119

1189

if(s < 0){

1190

ret_errno = errno;

1120

1191

perror_plus("socket");

1192

errno = ret_errno;

1121

1193

return false;

1122

1194

}

1123

1195

strcpy(ifr->ifr_name, ifname);

1124

1196

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1125

1197

if(ret == -1){

1126

1198

if(debug){

1199

ret_errno = errno;

1127

1200

perror_plus("ioctl SIOCGIFFLAGS");

1201

errno = ret_errno;

1128

1202

}

1129

1203

return false;

1130

1204

}

1131

1205

return true;

1132

1206

}

1133

1207

1208

__attribute__((nonnull, warn_unused_result))

1134

1209

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

1135

1210

1136

1211

/* Reject the loopback device */

1178

1253

* corresponds to an acceptable network device.

1179

1254

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

1180

1255

*/

1256

__attribute__((nonnull, warn_unused_result))

1181

1257

int good_interface(const struct dirent *if_entry){

1182

1258

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

1183

1259

return 0;

1199

1275

}

1200

1276

1201

1277

/*

1202

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

1203

* corresponds to an acceptable network device which is up.

1204

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

1205

*/

1206

int up_interface(const struct dirent *if_entry){

1207

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

1208

return 0;

1209

}

1210

1211

struct ifreq ifr;

1212

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

1213

if(debug){

1214

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

1215

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

1216

}

1217

return 0;

1218

}

1219

1220

/* Reject down interfaces */

1221

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

1222

if(debug){

1223

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

1224

if_entry->d_name);

1225

}

1226

return 0;

1227

}

1228

1229

/* Reject non-running interfaces */

1230

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

1231

if(debug){

1232

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

1233

if_entry->d_name);

1234

}

1235

return 0;

1236

}

1237

1238

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

1239

return 0;

1240

}

1241

return 1;

1242

}

1243

1278

* This function determines if a network interface is up.

1279

*/

1280

__attribute__((nonnull, warn_unused_result))

1281

bool interface_is_up(const char *interface){

1282

struct ifreq ifr;

1283

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

1284

if(debug){

1285

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

1286

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

1287

}

1288

return false;

1289

}

1290

1291

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

1292

}

1293

1294

/*

1295

* This function determines if a network interface is running

1296

*/

1297

__attribute__((nonnull, warn_unused_result))

1298

bool interface_is_running(const char *interface){

1299

struct ifreq ifr;

1300

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

1301

if(debug){

1302

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

1303

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

1304

}

1305

return false;

1306

}

1307

1308

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

1309

}

1310

1311

__attribute__((nonnull, pure, warn_unused_result))

1244

1312

int notdotentries(const struct dirent *direntry){

1245

1313

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

1246

1314

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

1253

1321

}

1254

1322

1255

1323

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

1324

__attribute__((nonnull, warn_unused_result))

1256

1325

int runnable_hook(const struct dirent *direntry){

1257

1326

int ret;

1258

1327

size_t sret;

1313

1382

return 1;

1314

1383

}

1315

1384

1316

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1385

__attribute__((nonnull, warn_unused_result))

1386

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1387

mandos_context *mc){

1317

1388

int ret;

1318

1389

struct timespec now;

1319

1390

struct timespec waited_time;

1320

1391

intmax_t block_time;

1321

1392

1322

1393

while(true){

1323

if(mc.current_server == NULL){

1324

if (debug){

1394

if(mc->current_server == NULL){

1395

if(debug){

1325

1396

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

1326

1397

" No timeout!\n");

1327

1398

}

1328

1399

ret = avahi_simple_poll_iterate(s, -1);

1329

1400

} else {

1330

if (debug){

1401

if(debug){

1331

1402

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

1332

1403

" it, or wait\n");

1333

1404

}

1340

1411

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

1341

1412

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

1342

1413

waited_time.tv_sec = (now.tv_sec

1343

- mc.current_server->last_seen.tv_sec);

1414

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

1344

1415

waited_time.tv_nsec = (now.tv_nsec

1345

- mc.current_server->last_seen.tv_nsec);

1416

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

1346

1417

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

1347

1418

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

1348

1419

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

1350

1421

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

1351

1422

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

1352

1423

1353

if (debug){

1424

if(debug){

1354

1425

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

1355

1426

block_time);

1356

1427

}

1357

1428

1358

1429

if(block_time <= 0){

1359

ret = start_mandos_communication(mc.current_server->ip,

1360

mc.current_server->port,

1361

mc.current_server->if_index,

1362

mc.current_server->af);

1430

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

1431

mc->current_server->port,

1432

mc->current_server->if_index,

1433

mc->current_server->af, mc);

1363

1434

if(ret == 0){

1364

avahi_simple_poll_quit(mc.simple_poll);

1435

avahi_simple_poll_quit(s);

1365

1436

return 0;

1366

1437

}

1367

1438

ret = clock_gettime(CLOCK_MONOTONIC,

1368

&mc.current_server->last_seen);

1439

&mc->current_server->last_seen);

1369

1440

if(ret == -1){

1370

1441

perror_plus("clock_gettime");

1371

1442

return -1;

1372

1443

}

1373

mc.current_server = mc.current_server->next;

1444

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

1374

1445

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

1375

1446

servers, but don't block */

1376

1447

}

1378

1449

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

1379

1450

}

1380

1451

if(ret != 0){

1381

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

1452

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

1382

1453

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

1383

1454

}

1384

1455

}

1385

1456

}

1386

1457

}

1387

1458

1388

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

1459

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

1460

__attribute__((warn_unused_result))

1461

error_t raise_privileges(void){

1462

error_t old_errno = errno;

1463

error_t ret_errno = 0;

1464

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

1465

ret_errno = errno;

1466

perror_plus("seteuid");

1467

}

1468

errno = old_errno;

1469

return ret_errno;

1470

}

1471

1472

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

1473

__attribute__((warn_unused_result))

1474

error_t raise_privileges_permanently(void){

1475

error_t old_errno = errno;

1476

error_t ret_errno = raise_privileges();

1477

if(ret_errno != 0){

1478

errno = old_errno;

1479

return ret_errno;

1480

}

1481

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

1482

ret_errno = errno;

1483

perror_plus("seteuid");

1484

}

1485

errno = old_errno;

1486

return ret_errno;

1487

}

1488

1489

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

1490

__attribute__((warn_unused_result))

1491

error_t lower_privileges(void){

1492

error_t old_errno = errno;

1493

error_t ret_errno = 0;

1494

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

1495

ret_errno = errno;

1496

perror_plus("seteuid");

1497

}

1498

errno = old_errno;

1499

return ret_errno;

1500

}

1501

1502

/* Lower privileges permanently */

1503

__attribute__((warn_unused_result))

1504

error_t lower_privileges_permanently(void){

1505

error_t old_errno = errno;

1506

error_t ret_errno = 0;

1507

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

1508

ret_errno = errno;

1509

perror_plus("setuid");

1510

}

1511

errno = old_errno;

1512

return ret_errno;

1513

}

1514

1515

__attribute__((nonnull))

1516

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

1389

1517

const float delay){

1390

1518

struct dirent **direntries;

1391

struct dirent *direntry;

1392

int ret;

1393

1519

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

1394

1520

alphasort);

1395

1521

if(numhooks == -1){

1396

perror_plus("scandir");

1522

if(errno == ENOENT){

1523

if(debug){

1524

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

1525

" found\n", hookdir);

1526

}

1527

} else {

1528

perror_plus("scandir");

1529

}

1397

1530

} else {

1531

struct dirent *direntry;

1532

int ret;

1398

1533

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

1399

1534

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

1400

1535

direntry = direntries[i];

1412

1547

if(hook_pid == 0){

1413

1548

/* Child */

1414

1549

/* Raise privileges */

1415

errno = 0;

1416

ret = seteuid(0);

1417

if(ret == -1){

1418

perror_plus("seteuid");

1419

}

1420

/* Raise privileges even more */

1421

errno = 0;

1422

ret = setuid(0);

1423

if(ret == -1){

1424

perror_plus("setuid");

1550

if(raise_privileges_permanently() != 0){

1551

perror_plus("Failed to raise privileges");

1552

_exit(EX_NOPERM);

1425

1553

}

1426

1554

/* Set group */

1427

1555

errno = 0;

1428

1556

ret = setgid(0);

1429

1557

if(ret == -1){

1430

1558

perror_plus("setgid");

1559

_exit(EX_NOPERM);

1431

1560

}

1432

1561

/* Reset supplementary groups */

1433

1562

errno = 0;

1434

1563

ret = setgroups(0, NULL);

1435

1564

if(ret == -1){

1436

1565

perror_plus("setgroups");

1437

}

1438

dup2(devnull, STDIN_FILENO);

1439

close(devnull);

1440

dup2(STDERR_FILENO, STDOUT_FILENO);

1566

_exit(EX_NOPERM);

1567

}

1568

ret = dup2(devnull, STDIN_FILENO);

1569

if(ret == -1){

1570

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

1571

_exit(EX_OSERR);

1572

}

1573

ret = close(devnull);

1574

if(ret == -1){

1575

perror_plus("close");

1576

_exit(EX_OSERR);

1577

}

1578

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1579

if(ret == -1){

1580

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

1581

_exit(EX_OSERR);

1582

}

1441

1583

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

1442

1584

if(ret == -1){

1443

1585

perror_plus("setenv");

1448

1590

perror_plus("setenv");

1449

1591

_exit(EX_OSERR);

1450

1592

}

1451

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

1593

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

1452

1594

if(ret == -1){

1453

1595

perror_plus("setenv");

1454

1596

_exit(EX_OSERR);

1459

1601

_exit(EX_OSERR);

1460

1602

}

1461

1603

char *delaystring;

1462

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

1604

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

1463

1605

if(ret == -1){

1464

1606

perror_plus("asprintf");

1465

1607

_exit(EX_OSERR);

1471

1613

_exit(EX_OSERR);

1472

1614

}

1473

1615

free(delaystring);

1616

if(connect_to != NULL){

1617

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

1618

if(ret == -1){

1619

perror_plus("setenv");

1620

_exit(EX_OSERR);

1621

}

1622

}

1474

1623

if(execl(fullname, direntry->d_name, mode, NULL) == -1){

1475

1624

perror_plus("execl");

1476

1625

_exit(EXIT_FAILURE);

1511

1660

}

1512

1661

close(devnull);

1513

1662

}

1514

return true;

1663

}

1664

1665

__attribute__((nonnull, warn_unused_result))

1666

error_t bring_up_interface(const char *const interface,

1667

const float delay){

1668

error_t old_errno = errno;

1669

int ret;

1670

struct ifreq network;

1671

unsigned int if_index = if_nametoindex(interface);

1672

if(if_index == 0){

1673

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

1674

errno = old_errno;

1675

return ENXIO;

1676

}

1677

1678

if(quit_now){

1679

errno = old_errno;

1680

return EINTR;

1681

}

1682

1683

if(not interface_is_up(interface)){

1684

error_t ret_errno = 0, ioctl_errno = 0;

1685

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

1686

ret_errno = errno;

1687

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

1688

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

1689

errno = old_errno;

1690

return ret_errno;

1691

}

1692

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

1693

1694

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

1695

if(sd == -1){

1696

ret_errno = errno;

1697

perror_plus("socket");

1698

errno = old_errno;

1699

return ret_errno;

1700

}

1701

1702

if(quit_now){

1703

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

1704

if(ret == -1){

1705

perror_plus("close");

1706

}

1707

errno = old_errno;

1708

return EINTR;

1709

}

1710

1711

if(debug){

1712

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

1713

interface);

1714

}

1715

1716

/* Raise privileges */

1717

ret_errno = raise_privileges();

1718

bool restore_loglevel = false;

1719

if(ret_errno != 0){

1720

perror_plus("Failed to raise privileges");

1721

}

1722

#ifdef __linux__

1723

int ret_linux;

1724

if(ret_errno == 0){

1725

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1726

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

1727

ret_linux = klogctl(8, NULL, 5);

1728

if(ret_linux == -1){

1729

perror_plus("klogctl");

1730

} else {

1731

restore_loglevel = true;

1732

}

1733

}

1734

#endif /* __linux__ */

1735

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

1736

ioctl_errno = errno;

1737

#ifdef __linux__

1738

if(restore_loglevel){

1739

ret_linux = klogctl(7, NULL, 0);

1740

if(ret_linux == -1){

1741

perror_plus("klogctl");

1742

}

1743

}

1744

#endif /* __linux__ */

1745

1746

/* If raise_privileges() succeeded above */

1747

if(ret_errno == 0){

1748

/* Lower privileges */

1749

ret_errno = lower_privileges();

1750

if(ret_errno != 0){

1751

errno = ret_errno;

1752

perror_plus("Failed to lower privileges");

1753

}

1754

}

1755

1756

/* Close the socket */

1757

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

1758

if(ret == -1){

1759

perror_plus("close");

1760

}

1761

1762

if(ret_setflags == -1){

1763

errno = ioctl_errno;

1764

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1765

errno = old_errno;

1766

return ioctl_errno;

1767

}

1768

} else if(debug){

1769

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

1770

interface);

1771

}

1772

1773

/* Sleep checking until interface is running.

1774

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

1775

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

1776

if(interface_is_running(interface)){

1777

break;

1778

}

1779

struct timespec sleeptime = { .tv_nsec = 250000000 };

1780

ret = nanosleep(&sleeptime, NULL);

1781

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

1782

perror_plus("nanosleep");

1783

}

1784

}

1785

1786

errno = old_errno;

1787

return 0;

1788

}

1789

1790

__attribute__((nonnull, warn_unused_result))

1791

error_t take_down_interface(const char *const interface){

1792

error_t old_errno = errno;

1793

struct ifreq network;

1794

unsigned int if_index = if_nametoindex(interface);

1795

if(if_index == 0){

1796

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

1797

errno = old_errno;

1798

return ENXIO;

1799

}

1800

if(interface_is_up(interface)){

1801

error_t ret_errno = 0, ioctl_errno = 0;

1802

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

1803

ret_errno = errno;

1804

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

1805

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

1806

errno = old_errno;

1807

return ret_errno;

1808

}

1809

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

1810

1811

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

1812

if(sd == -1){

1813

ret_errno = errno;

1814

perror_plus("socket");

1815

errno = old_errno;

1816

return ret_errno;

1817

}

1818

1819

if(debug){

1820

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

1821

interface);

1822

}

1823

1824

/* Raise privileges */

1825

ret_errno = raise_privileges();

1826

if(ret_errno != 0){

1827

perror_plus("Failed to raise privileges");

1828

}

1829

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

1830

ioctl_errno = errno;

1831

1832

/* If raise_privileges() succeeded above */

1833

if(ret_errno == 0){

1834

/* Lower privileges */

1835

ret_errno = lower_privileges();

1836

if(ret_errno != 0){

1837

errno = ret_errno;

1838

perror_plus("Failed to lower privileges");

1839

}

1840

}

1841

1842

/* Close the socket */

1843

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

1844

if(ret == -1){

1845

perror_plus("close");

1846

}

1847

1848

if(ret_setflags == -1){

1849

errno = ioctl_errno;

1850

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1851

errno = old_errno;

1852

return ioctl_errno;

1853

}

1854

} else if(debug){

1855

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

1856

interface);

1857

}

1858

1859

errno = old_errno;

1860

return 0;

1515

1861

}

1516

1862

1517

1863

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

1864

mandos_context mc = { .server = NULL, .dh_bits = 1024,

1865

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

1866

"+CTYPE-OPENPGP", .current_server = NULL,

1867

.interfaces = NULL, .interfaces_size = 0 };

1518

1868

AvahiSServiceBrowser *sb = NULL;

1519

int error;

1869

error_t ret_errno;

1520

1870

int ret;

1521

1871

intmax_t tmpmax;

1522

1872

char *tmp;

1523

1873

int exitcode = EXIT_SUCCESS;

1524

const char *interface = "";

1525

struct ifreq network;

1526

int sd = -1;

1527

bool take_down_interface = false;

1528

uid_t uid;

1529

gid_t gid;

1530

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

1531

bool tempdir_created = false;

1874

char *interfaces_to_take_down = NULL;

1875

size_t interfaces_to_take_down_size = 0;

1876

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

1877

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

1878

char *tempdir = NULL;

1532

1879

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1533

1880

const char *seckey = PATHDIR "/" SECKEY;

1534

1881

const char *pubkey = PATHDIR "/" PUBKEY;

1882

char *interfaces_hooks = NULL;

1535

1883

1536

1884

bool gnutls_initialized = false;

1537

1885

bool gpgme_initialized = false;

1599

1947

.group = 2 },

1600

1948

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

1601

1949

.arg = "SECONDS",

1602

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

1950

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

1603

1951

.group = 2 },

1604

1952

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

1605

1953

.arg = "DIR",

1628

1976

connect_to = arg;

1629

1977

break;

1630

1978

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

1631

interface = arg;

1979

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

1980

arg, (int)',');

1981

if(ret_errno != 0){

1982

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

1983

}

1632

1984

break;

1633

1985

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

1634

1986

seckey = arg;

1711

2063

/* Work around Debian bug #633582:

1712

2064

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

1713

2065

1714

/* Re-raise priviliges */

1715

errno = 0;

1716

ret = seteuid(0);

1717

if(ret == -1){

1718

perror_plus("seteuid");

2066

/* Re-raise privileges */

2067

ret_errno = raise_privileges();

2068

if(ret_errno != 0){

2069

errno = ret_errno;

2070

perror_plus("Failed to raise privileges");

1719

2071

} else {

1720

2072

struct stat st;

1721

2073

1762

2114

}

1763

2115

1764

2116

/* Lower privileges */

1765

errno = 0;

1766

ret = seteuid(uid);

1767

if(ret == -1){

1768

perror_plus("seteuid");

2117

ret_errno = lower_privileges();

2118

if(ret_errno != 0){

2119

errno = ret_errno;

2120

perror_plus("Failed to lower privileges");

2121

}

2122

}

2123

}

2124

2125

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

2126

{

2127

char *interface = NULL;

2128

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

2129

interface))){

2130

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

2131

and if_nametoindex(interface) == 0){

2132

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

2133

fprintf_plus(stderr, "Not using nonexisting interface"

2134

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

2135

}

2136

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

2137

interface = NULL;

1769

2138

}

1770

2139

}

1771

2140

}

1772

2141

1773

2142

/* Run network hooks */

1774

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

1775

goto end;

2143

{

2144

if(mc.interfaces != NULL){

2145

interfaces_hooks = malloc(mc.interfaces_size);

2146

if(interfaces_hooks == NULL){

2147

perror_plus("malloc");

2148

goto end;

2149

}

2150

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

2151

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

2152

}

2153

run_network_hooks("start", interfaces_hooks != NULL ?

2154

interfaces_hooks : "", delay);

1776

2155

}

1777

2156

1778

2157

if(not debug){

1779

2158

avahi_set_log_function(empty_log);

1780

2159

}

1781

2160

1782

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

1783

struct dirent **direntries;

1784

/* First look for interfaces that are up */

1785

ret = scandir(sys_class_net, &direntries, up_interface,

1786

alphasort);

1787

if(ret == 0){

1788

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

1789

free(direntries);

1790

ret = scandir(sys_class_net, &direntries, good_interface,

1791

alphasort);

1792

}

1793

if(ret >= 1){

1794

/* Pick the first interface returned */

1795

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

1796

if(debug){

1797

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

1798

}

1799

if(interface == NULL){

1800

perror_plus("malloc");

1801

free(direntries);

1802

exitcode = EXIT_FAILURE;

1803

goto end;

1804

}

1805

free(direntries);

1806

} else {

1807

free(direntries);

1808

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

1809

exitcode = EXIT_FAILURE;

1810

goto end;

1811

}

1812

}

1813

1814

2161

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

1815

2162

from the signal handler */

1816

2163

/* Initialize the pseudo-RNG for Avahi */

1817

2164

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

1818

mc.simple_poll = avahi_simple_poll_new();

1819

if(mc.simple_poll == NULL){

2165

simple_poll = avahi_simple_poll_new();

2166

if(simple_poll == NULL){

1820

2167

fprintf_plus(stderr,

1821

2168

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

1822

2169

exitcode = EX_UNAVAILABLE;

1886

2233

}

1887

2234

}

1888

2235

1889

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

1890

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

1891

if_index = (AvahiIfIndex) if_nametoindex(interface);

1892

if(if_index == 0){

1893

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

1894

exitcode = EX_UNAVAILABLE;

1895

goto end;

1896

}

1897

1898

if(quit_now){

1899

goto end;

1900

}

1901

1902

/* Re-raise priviliges */

1903

errno = 0;

1904

ret = seteuid(0);

1905

if(ret == -1){

1906

perror_plus("seteuid");

1907

}

1908

1909

#ifdef __linux__

1910

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1911

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

1912

ret = klogctl(8, NULL, 5);

1913

bool restore_loglevel = true;

1914

if(ret == -1){

1915

restore_loglevel = false;

1916

perror_plus("klogctl");

1917

}

1918

#endif /* __linux__ */

1919

1920

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1921

if(sd < 0){

1922

perror_plus("socket");

1923

exitcode = EX_OSERR;

1924

#ifdef __linux__

1925

if(restore_loglevel){

1926

ret = klogctl(7, NULL, 0);

1927

if(ret == -1){

1928

perror_plus("klogctl");

1929

}

1930

}

1931

#endif /* __linux__ */

1932

/* Lower privileges */

1933

errno = 0;

1934

ret = seteuid(uid);

1935

if(ret == -1){

1936

perror_plus("seteuid");

1937

}

1938

goto end;

1939

}

1940

strcpy(network.ifr_name, interface);

1941

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

1942

if(ret == -1){

1943

perror_plus("ioctl SIOCGIFFLAGS");

1944

#ifdef __linux__

1945

if(restore_loglevel){

1946

ret = klogctl(7, NULL, 0);

1947

if(ret == -1){

1948

perror_plus("klogctl");

1949

}

1950

}

1951

#endif /* __linux__ */

1952

exitcode = EX_OSERR;

1953

/* Lower privileges */

1954

errno = 0;

1955

ret = seteuid(uid);

1956

if(ret == -1){

1957

perror_plus("seteuid");

1958

}

1959

goto end;

1960

}

1961

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

1962

network.ifr_flags |= IFF_UP;

1963

take_down_interface = true;

1964

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

1965

if(ret == -1){

1966

take_down_interface = false;

1967

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1968

exitcode = EX_OSERR;

1969

#ifdef __linux__

1970

if(restore_loglevel){

1971

ret = klogctl(7, NULL, 0);

1972

if(ret == -1){

1973

perror_plus("klogctl");

2236

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

2237

if(mc.interfaces == NULL){

2238

struct dirent **direntries;

2239

/* Look for any good interfaces */

2240

ret = scandir(sys_class_net, &direntries, good_interface,

2241

alphasort);

2242

if(ret >= 1){

2243

/* Add all found interfaces to interfaces list */

2244

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

2245

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

2246

direntries[i]->d_name);

2247

if(ret_errno != 0){

2248

errno = ret_errno;

2249

perror_plus("argz_add");

2250

continue;

2251

}

2252

if(debug){

2253

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

2254

direntries[i]->d_name);

2255

}

2256

}

2257

free(direntries);

2258

} else {

2259

free(direntries);

2260

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

2261

exitcode = EXIT_FAILURE;

2262

goto end;

2263

}

2264

}

2265

2266

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

2267

{

2268

char *interface = NULL;

2269

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

2270

interface))){

2271

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

2272

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

2273

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

2274

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

2275

interface);

2276

interface = NULL;

2277

while((interface = argz_next(mc.interfaces,

2278

mc.interfaces_size, interface))){

2279

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

2280

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

2281

interface);

2282

interface = NULL;

1974

2283

}

1975

2284

}

1976

#endif /* __linux__ */

1977

/* Lower privileges */

1978

errno = 0;

1979

ret = seteuid(uid);

1980

if(ret == -1){

1981

perror_plus("seteuid");

1982

}

1983

goto end;

1984

}

1985

}

1986

/* Sleep checking until interface is running.

1987

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

1988

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

1989

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

1990

if(ret == -1){

1991

perror_plus("ioctl SIOCGIFFLAGS");

1992

} else if(network.ifr_flags & IFF_RUNNING){

1993

2285

break;

1994

2286

}

1995

struct timespec sleeptime = { .tv_nsec = 250000000 };

1996

ret = nanosleep(&sleeptime, NULL);

1997

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

1998

perror_plus("nanosleep");

1999

}

2000

}

2001

if(not take_down_interface){

2002

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

2003

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

2004

if(ret == -1){

2005

perror_plus("close");

2006

}

2007

}

2008

#ifdef __linux__

2009

if(restore_loglevel){

2010

/* Restores kernel loglevel to default */

2011

ret = klogctl(7, NULL, 0);

2012

if(ret == -1){

2013

perror_plus("klogctl");

2014

}

2015

}

2016

#endif /* __linux__ */

2017

/* Lower privileges */

2018

errno = 0;

2019

/* Lower privileges */

2020

ret = seteuid(uid);

2021

if(ret == -1){

2022

perror_plus("seteuid");

2023

}

2287

bool interface_was_up = interface_is_up(interface);

2288

errno = bring_up_interface(interface, delay);

2289

if(not interface_was_up){

2290

if(errno != 0){

2291

perror_plus("Failed to bring up interface");

2292

} else {

2293

errno = argz_add(&interfaces_to_take_down,

2294

&interfaces_to_take_down_size,

2295

interface);

2296

if(errno != 0){

2297

perror_plus("argz_add");

2298

}

2299

}

2300

}

2301

}

2302

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

2303

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

2304

}

2305

}

2306

2307

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

2308

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

2309

if(debug){

2310

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

2311

mc.interfaces);

2312

}

2313

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

2024

2314

}

2025

2315

2026

2316

if(quit_now){

2027

2317

goto end;

2028

2318

}

2029

2319

2030

ret = init_gnutls_global(pubkey, seckey);

2320

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

2031

2321

if(ret == -1){

2032

2322

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

2033

2323

exitcode = EX_UNAVAILABLE;

2040

2330

goto end;

2041

2331

}

2042

2332

2043

if(mkdtemp(tempdir) == NULL){

2333

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

2334

tempdir = mkdtemp(run_tempdir);

2335

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

2336

if(debug){

2337

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

2338

run_tempdir, old_tempdir);

2339

}

2340

tempdir = mkdtemp(old_tempdir);

2341

}

2342

if(tempdir == NULL){

2044

2343

perror_plus("mkdtemp");

2045

2344

goto end;

2046

2345

}

2047

tempdir_created = true;

2048

2346

2049

2347

if(quit_now){

2050

2348

goto end;

2051

2349

}

2052

2350

2053

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

2351

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

2054

2352

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

2055

2353

exitcode = EX_UNAVAILABLE;

2056

2354

goto end;

2066

2364

/* Connect directly, do not use Zeroconf */

2067

2365

/* (Mainly meant for debugging) */

2068

2366

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

2367

2069

2368

if(address == NULL){

2070

2369

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

2071

2370

exitcode = EX_USAGE;

2076

2375

goto end;

2077

2376

}

2078

2377

2079

uint16_t port;

2378

in_port_t port;

2080

2379

errno = 0;

2081

2380

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

2082

2381

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

2083

or tmpmax != (uint16_t)tmpmax){

2382

or tmpmax != (in_port_t)tmpmax){

2084

2383

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

2085

2384

exitcode = EX_USAGE;

2086

2385

goto end;

2087

2386

}

2088

2387

2089

2388

if(quit_now){

2090

2389

goto end;

2091

2390

}

2092

2391

2093

port = (uint16_t)tmpmax;

2392

port = (in_port_t)tmpmax;

2094

2393

*address = '\0';

2095

2394

/* Colon in address indicates IPv6 */

2096

2395

int af;

2112

2411

}

2113

2412

2114

2413

while(not quit_now){

2115

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

2414

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

2415

&mc);

2116

2416

if(quit_now or ret == 0){

2117

2417

break;

2118

2418

}

2120

2420

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

2121

2421

(int)retry_interval);

2122

2422

}

2123

sleep((int)retry_interval);

2423

sleep((unsigned int)retry_interval);

2124

2424

}

2125

2425

2126

if (not quit_now){

2426

if(not quit_now){

2127

2427

exitcode = EXIT_SUCCESS;

2128

2428

}

2129

2429

2144

2444

config.publish_domain = 0;

2145

2445

2146

2446

/* Allocate a new server */

2147

mc.server = avahi_server_new(avahi_simple_poll_get

2148

(mc.simple_poll), &config, NULL,

2149

NULL, &error);

2447

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2448

&config, NULL, NULL, &ret_errno);

2150

2449

2151

2450

/* Free the Avahi configuration data */

2152

2451

avahi_server_config_free(&config);

2155

2454

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

2156

2455

if(mc.server == NULL){

2157

2456

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

2158

avahi_strerror(error));

2457

avahi_strerror(ret_errno));

2159

2458

exitcode = EX_UNAVAILABLE;

2160

2459

goto end;

2161

2460

}

2167

2466

/* Create the Avahi service browser */

2168

2467

sb = avahi_s_service_browser_new(mc.server, if_index,

2169

2468

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2170

NULL, 0, browse_callback, NULL);

2469

NULL, 0, browse_callback,

2470

(void *)&mc);

2171

2471

if(sb == NULL){

2172

2472

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

2173

2473

avahi_strerror(avahi_server_errno(mc.server)));

2185

2485

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

2186

2486

}

2187

2487

2188

ret = avahi_loop_with_timeout(mc.simple_poll,

2189

(int)(retry_interval * 1000));

2488

ret = avahi_loop_with_timeout(simple_poll,

2489

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

2190

2490

if(debug){

2191

2491

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

2192

2492

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

2199

2499

}

2200

2500

2201

2501

/* Cleanup things */

2502

free(mc.interfaces);

2503

2202

2504

if(sb != NULL)

2203

2505

avahi_s_service_browser_free(sb);

2204

2506

2205

2507

if(mc.server != NULL)

2206

2508

avahi_server_free(mc.server);

2207

2509

2208

if(mc.simple_poll != NULL)

2209

avahi_simple_poll_free(mc.simple_poll);

2510

if(simple_poll != NULL)

2511

avahi_simple_poll_free(simple_poll);

2210

2512

2211

2513

if(gnutls_initialized){

2212

2514

gnutls_certificate_free_credentials(mc.cred);

2229

2531

}

2230

2532

}

2231

2533

2232

/* Run network hooks */

2233

run_network_hooks("stop", interface, delay);

2234

2235

/* Re-raise priviliges */

2534

/* Re-raise privileges */

2236

2535

{

2237

errno = 0;

2238

ret = seteuid(0);

2239

if(ret == -1){

2240

perror_plus("seteuid");

2241

}

2242

2243

/* Take down the network interface */

2244

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

2245

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

2246

if(ret == -1){

2247

perror_plus("ioctl SIOCGIFFLAGS");

2248

} else if(network.ifr_flags & IFF_UP){

2249

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

2250

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

2251

if(ret == -1){

2252

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2253

}

2254

}

2255

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

2256

if(ret == -1){

2257

perror_plus("close");

2258

}

2259

}

2260

}

2261

/* Lower privileges permanently */

2262

errno = 0;

2263

ret = setuid(uid);

2264

if(ret == -1){

2265

perror_plus("setuid");

2266

}

2536

ret_errno = raise_privileges();

2537

if(ret_errno != 0){

2538

perror_plus("Failed to raise privileges");

2539

} else {

2540

2541

/* Run network hooks */

2542

run_network_hooks("stop", interfaces_hooks != NULL ?

2543

interfaces_hooks : "", delay);

2544

2545

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

2546

{

2547

char *interface = NULL;

2548

while((interface=argz_next(interfaces_to_take_down,

2549

interfaces_to_take_down_size,

2550

interface))){

2551

ret_errno = take_down_interface(interface);

2552

if(ret_errno != 0){

2553

errno = ret_errno;

2554

perror_plus("Failed to take down interface");

2555

}

2556

}

2557

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

2558

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

2559

" down\n");

2560

}

2561

}

2562

}

2563

ret_errno = lower_privileges_permanently();

2564

if(ret_errno != 0){

2565

perror_plus("Failed to lower privileges permanently");

2566

}

2567

}

2568

2569

free(interfaces_to_take_down);

2570

free(interfaces_hooks);

2267

2571

2268

2572

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

2269

if(tempdir_created){

2573

if(tempdir != NULL){

2270

2574

struct dirent **direntries = NULL;

2271

2575

struct dirent *direntry = NULL;

2272

2576

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

2273

2577

alphasort);

2274

if (numentries > 0){

2578

if(numentries > 0){

2275

2579

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

2276

2580

direntry = direntries[i];

2277

2581

char *fullname = NULL;

2292

2596

2293

2597

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

2294

2598

free(direntries);

2295

if (numentries == -1){

2599

if(numentries == -1){

2296

2600

perror_plus("scandir");

2297

2601

}

2298

2602

ret = rmdir(tempdir);