36
36
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
38
38
#include <stdio.h> /* fprintf(), stderr, fwrite(),
39
stdout, ferror(), sscanf(),
39
stdout, ferror(), remove() */
41
40
#include <stdint.h> /* uint16_t, uint32_t */
42
41
#include <stddef.h> /* NULL, size_t, ssize_t */
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#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
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#include <stdbool.h> /* bool, false, true */
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#include <string.h> /* memset(), strcmp(), strlen(),
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strerror(), asprintf(), strcpy() */
56
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#include <fcntl.h> /* open() */
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56
#include <dirent.h> /* opendir(), struct dirent, readdir()
59
#include <inttypes.h> /* PRIu16, intmax_t, SCNdMAX */
58
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
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#include <assert.h> /* assert() */
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#include <errno.h> /* perror(), errno */
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62
#include <time.h> /* nanosleep(), time() */
75
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argp_state, struct argp,
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argp_parse(), ARGP_KEY_ARG,
77
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ARGP_KEY_END, ARGP_ERR_UNKNOWN */
78
#include <signal.h> /* sigemptyset(), sigaddset(),
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sigaction(), SIGTERM, sigaction,
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#include <sys/klog.h> /* klogctl() */
84
#endif /* __linux__ */
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/* All Avahi types, constants and functions
130
134
} mandos_context;
136
/* global context so signal handler can reach it*/
137
mandos_context mc = { .simple_poll = NULL, .server = NULL,
138
.dh_bits = 1024, .priority = "SECURE256"
139
":!CTYPE-X.509:+CTYPE-OPENPGP" };
133
* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
134
* "buffer_capacity" is how much is currently allocated,
142
* Make additional room in "buffer" for at least BUFFER_SIZE more
143
* bytes. "buffer_capacity" is how much is currently allocated,
135
144
* "buffer_length" is how much is already used.
137
size_t adjustbuffer(char **buffer, size_t buffer_length,
146
size_t incbuffer(char **buffer, size_t buffer_length,
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147
size_t buffer_capacity){
139
148
if(buffer_length + BUFFER_SIZE > buffer_capacity){
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149
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
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159
* Initialize GPGME.
152
static bool init_gpgme(mandos_context *mc, const char *seckey,
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static bool init_gpgme(const char *seckey,
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162
const char *pubkey, const char *tempdir){
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gpgme_error_t rc;
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rc = gpgme_op_import(mc->ctx, pgp_data);
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rc = gpgme_op_import(mc.ctx, pgp_data);
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if(rc != GPG_ERR_NO_ERROR){
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fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
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191
gpgme_strsource(rc), gpgme_strerror(rc));
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/* Create new GPGME "context" */
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rc = gpgme_new(&(mc->ctx));
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rc = gpgme_new(&(mc.ctx));
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if(rc != GPG_ERR_NO_ERROR){
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fprintf(stderr, "bad gpgme_new: %s: %s\n",
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gpgme_strsource(rc), gpgme_strerror(rc));
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* Decrypt OpenPGP data.
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* Returns -1 on error
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static ssize_t pgp_packet_decrypt(const mandos_context *mc,
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const char *cryptotext,
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static ssize_t pgp_packet_decrypt(const char *cryptotext,
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size_t crypto_size,
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char **plaintext){
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gpgme_data_t dh_crypto, dh_plain;
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/* Decrypt data from the cryptotext data buffer to the plaintext
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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(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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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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fprintf(stderr, "gpgme_op_decrypt_result failed\n");
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*plaintext = NULL;
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plaintext_capacity = adjustbuffer(plaintext,
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plaintext_capacity = incbuffer(plaintext,
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(size_t)plaintext_length,
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plaintext_capacity);
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if(plaintext_capacity == 0){
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perror("adjustbuffer");
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plaintext_length = -1;
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goto decrypt_end;
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fprintf(stderr, "GnuTLS: %s", string);
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static int init_gnutls_global(mandos_context *mc,
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const char *pubkeyfilename,
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static int init_gnutls_global(const char *pubkeyfilename,
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const char *seckeyfilename){
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/* OpenPGP credentials */
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gnutls_certificate_allocate_credentials(&mc->cred);
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gnutls_certificate_allocate_credentials(&mc.cred);
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if(ret != GNUTLS_E_SUCCESS){
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fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
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ret = gnutls_certificate_set_openpgp_key_file
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(mc->cred, pubkeyfilename, seckeyfilename,
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(mc.cred, pubkeyfilename, seckeyfilename,
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GNUTLS_OPENPGP_FMT_BASE64);
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if(ret != GNUTLS_E_SUCCESS){
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/* GnuTLS server initialization */
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ret = gnutls_dh_params_init(&mc->dh_params);
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ret = gnutls_dh_params_init(&mc.dh_params);
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if(ret != GNUTLS_E_SUCCESS){
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fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
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" %s\n", safer_gnutls_strerror(ret));
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ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
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ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
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if(ret != GNUTLS_E_SUCCESS){
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fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
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safer_gnutls_strerror(ret));
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gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
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gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
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gnutls_certificate_free_credentials(mc->cred);
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gnutls_certificate_free_credentials(mc.cred);
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gnutls_global_deinit();
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gnutls_dh_params_deinit(mc->dh_params);
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gnutls_dh_params_deinit(mc.dh_params);
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static int init_gnutls_session(mandos_context *mc,
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gnutls_session_t *session){
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static int init_gnutls_session(gnutls_session_t *session){
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/* GnuTLS session creation */
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ret = gnutls_init(session, GNUTLS_SERVER);
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ret = gnutls_priority_set_direct(*session, mc->priority, &err);
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ret = gnutls_priority_set_direct(*session, mc.priority, &err);
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if(ret != GNUTLS_E_SUCCESS){
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fprintf(stderr, "Syntax error at: %s\n", err);
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fprintf(stderr, "GnuTLS error: %s\n",
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ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
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if(ret != GNUTLS_E_SUCCESS){
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fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
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safer_gnutls_strerror(ret));
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gnutls_certificate_server_set_request(*session,
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GNUTLS_CERT_IGNORE);
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gnutls_dh_set_prime_bits(*session, mc->dh_bits);
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gnutls_dh_set_prime_bits(*session, mc.dh_bits);
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/* Called when a Mandos server is found */
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static int start_mandos_communication(const char *ip, uint16_t port,
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AvahiIfIndex if_index,
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mandos_context *mc, int af){
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buffer_capacity = adjustbuffer(&buffer, buffer_length,
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buffer_capacity = incbuffer(&buffer, buffer_length,
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buffer_capacity);
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if(buffer_capacity == 0){
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perror("adjustbuffer");
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gnutls_bye(session, GNUTLS_SHUT_RDWR);
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if(buffer_length > 0){
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decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,
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decrypted_buffer_size = pgp_packet_decrypt(buffer,
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&decrypted_buffer);
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if(decrypted_buffer_size >= 0){
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AVAHI_GCC_UNUSED AvahiStringList *txt,
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AVAHI_GCC_UNUSED AvahiLookupResultFlags
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mandos_context *mc = userdata;
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AVAHI_GCC_UNUSED void* userdata){
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/* Called whenever a service has been resolved successfully or
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802
case AVAHI_RESOLVER_FAILURE:
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fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"
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" of type '%s' in domain '%s': %s\n", name, type, domain,
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avahi_strerror(avahi_server_errno(mc->server)));
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avahi_strerror(avahi_server_errno(mc.server)));
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case AVAHI_RESOLVER_FOUND:
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PRIdMAX ") on port %" PRIu16 "\n", name, host_name,
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815
ip, (intmax_t)interface, port);
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int ret = start_mandos_communication(ip, port, interface, mc,
817
int ret = start_mandos_communication(ip, port, interface,
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818
avahi_proto_to_af(proto));
815
avahi_simple_poll_quit(mc->simple_poll);
820
avahi_simple_poll_quit(mc.simple_poll);
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844
case AVAHI_BROWSER_FAILURE:
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fprintf(stderr, "(Avahi browser) %s\n",
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avahi_strerror(avahi_server_errno(mc->server)));
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avahi_simple_poll_quit(mc->simple_poll);
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avahi_strerror(avahi_server_errno(mc.server)));
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avahi_simple_poll_quit(mc.simple_poll);
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851
case AVAHI_BROWSER_NEW:
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854
the callback function is called the Avahi server will free the
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855
resolver for us. */
853
if(!(avahi_s_service_resolver_new(mc->server, interface,
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protocol, name, type, domain,
855
AVAHI_PROTO_INET6, 0,
856
resolve_callback, mc)))
857
if(avahi_s_service_resolver_new(mc.server, interface, protocol,
858
name, type, domain, protocol, 0,
859
resolve_callback, NULL) == NULL)
857
860
fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",
858
name, avahi_strerror(avahi_server_errno(mc->server)));
861
name, avahi_strerror(avahi_server_errno(mc.server)));
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864
case AVAHI_BROWSER_REMOVE:
876
sig_atomic_t quit_now = 0;
878
/* stop main loop after sigterm has been called */
879
static void handle_sigterm(__attribute__((unused)) int sig){
884
int old_errno = errno;
885
if(mc.simple_poll != NULL){
886
avahi_simple_poll_quit(mc.simple_poll);
873
891
int main(int argc, char *argv[]){
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892
AvahiSServiceBrowser *sb = NULL;
879
897
int exitcode = EXIT_SUCCESS;
880
898
const char *interface = "eth0";
881
899
struct ifreq network;
889
907
const char *seckey = PATHDIR "/" SECKEY;
890
908
const char *pubkey = PATHDIR "/" PUBKEY;
892
mandos_context mc = { .simple_poll = NULL, .server = NULL,
893
.dh_bits = 1024, .priority = "SECURE256"
894
":!CTYPE-X.509:+CTYPE-OPENPGP" };
895
910
bool gnutls_initialized = false;
896
911
bool gpgme_initialized = false;
914
struct sigaction old_sigterm_action;
915
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
900
918
struct argp_option options[] = {
954
972
case 129: /* --dh-bits */
955
ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
956
if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax
957
or arg[numchars] != '\0'){
974
tmpmax = strtoimax(arg, &tmp, 10);
975
if(errno != 0 or tmp == arg or *tmp != '\0'
976
or tmpmax != (typeof(mc.dh_bits))tmpmax){
958
977
fprintf(stderr, "Bad number of DH bits\n");
959
978
exit(EXIT_FAILURE);
964
983
mc.priority = arg;
966
985
case 131: /* --delay */
967
ret = sscanf(arg, "%lf%n", &delay, &numchars);
968
if(ret < 1 or arg[numchars] != '\0'){
987
delay = strtof(arg, &tmp);
988
if(errno != 0 or tmp == arg or *tmp != '\0'){
969
989
fprintf(stderr, "Bad delay\n");
970
990
exit(EXIT_FAILURE);
1016
avahi_set_log_function(empty_log);
1019
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1020
from the signal handler */
1021
/* Initialize the pseudo-RNG for Avahi */
1022
srand((unsigned int) time(NULL));
1023
mc.simple_poll = avahi_simple_poll_new();
1024
if(mc.simple_poll == NULL){
1025
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1026
exitcode = EXIT_FAILURE;
1030
sigemptyset(&sigterm_action.sa_mask);
1031
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1033
perror("sigaddset");
1034
exitcode = EXIT_FAILURE;
1037
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1039
perror("sigaddset");
1040
exitcode = EXIT_FAILURE;
1043
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1045
perror("sigaddset");
1046
exitcode = EXIT_FAILURE;
1049
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1051
perror("sigaction");
1052
exitcode = EXIT_FAILURE;
995
1056
/* If the interface is down, bring it up */
996
1057
if(interface[0] != '\0'){
997
1058
#ifdef __linux__
1094
1155
perror("setuid");
1097
ret = init_gnutls_global(&mc, pubkey, seckey);
1158
ret = init_gnutls_global(pubkey, seckey);
1099
1160
fprintf(stderr, "init_gnutls_global failed\n");
1100
1161
exitcode = EXIT_FAILURE;
1110
1171
tempdir_created = true;
1112
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1173
if(not init_gpgme(pubkey, seckey, tempdir)){
1113
1174
fprintf(stderr, "init_gpgme failed\n");
1114
1175
exitcode = EXIT_FAILURE;
1139
ret = sscanf(address+1, "%" SCNdMAX "%n", &tmpmax, &numchars);
1140
if(ret < 1 or tmpmax != (uint16_t)tmpmax
1141
or address[numchars+1] != '\0'){
1201
tmpmax = strtoimax(address+1, &tmp, 10);
1202
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1203
or tmpmax != (uint16_t)tmpmax){
1142
1204
fprintf(stderr, "Bad port number\n");
1143
1205
exitcode = EXIT_FAILURE;
1156
ret = start_mandos_communication(address, port, if_index, &mc,
1218
ret = start_mandos_communication(address, port, if_index, af);
1159
1220
exitcode = EXIT_FAILURE;
1167
avahi_set_log_function(empty_log);
1170
/* Initialize the pseudo-RNG for Avahi */
1171
srand((unsigned int) time(NULL));
1173
/* Allocate main Avahi loop object */
1174
mc.simple_poll = avahi_simple_poll_new();
1175
if(mc.simple_poll == NULL){
1176
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1177
exitcode = EXIT_FAILURE;
1182
1228
AvahiServerConfig config;
1183
1229
/* Do not publish any local Zeroconf records */
1207
1253
/* Create the Avahi service browser */
1208
1254
sb = avahi_s_service_browser_new(mc.server, if_index,
1209
AVAHI_PROTO_INET6, "_mandos._tcp",
1210
NULL, 0, browse_callback, &mc);
1255
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
1256
NULL, 0, browse_callback, NULL);
1211
1257
if(sb == NULL){
1212
1258
fprintf(stderr, "Failed to create service browser: %s\n",
1213
1259
avahi_strerror(avahi_server_errno(mc.server)));