2 meshlink.c -- Implementation of the MeshLink API.
3 Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 #define VAR_SERVER 1 /* Should be in meshlink.conf */
20 #define VAR_HOST 2 /* Can be in host config file */
21 #define VAR_MULTIPLE 4 /* Multiple statements allowed */
22 #define VAR_OBSOLETE 8 /* Should not be used anymore */
23 #define VAR_SAFE 16 /* Variable is safe when accepting invitations */
24 #define MAX_ADDRESS_LENGTH 45 /* Max length of an (IPv6) address */
25 #define MAX_PORT_LENGTH 5 /* 0-65535 */
36 #include "meshlink_internal.h"
43 #include "ed25519/sha512.h"
46 #define MSG_NOSIGNAL 0
49 __thread meshlink_errno_t meshlink_errno;
51 //TODO: this can go away completely
52 const var_t variables[] = {
53 /* Server configuration */
54 {"AddressFamily", VAR_SERVER},
55 {"AutoConnect", VAR_SERVER | VAR_SAFE},
56 {"BindToAddress", VAR_SERVER | VAR_MULTIPLE},
57 {"BindToInterface", VAR_SERVER},
58 {"Broadcast", VAR_SERVER | VAR_SAFE},
59 {"ConnectTo", VAR_SERVER | VAR_MULTIPLE | VAR_SAFE},
60 {"DecrementTTL", VAR_SERVER},
61 {"Device", VAR_SERVER},
62 {"DeviceType", VAR_SERVER},
63 {"DirectOnly", VAR_SERVER},
64 {"ECDSAPrivateKeyFile", VAR_SERVER},
65 {"ExperimentalProtocol", VAR_SERVER},
66 {"Forwarding", VAR_SERVER},
67 {"GraphDumpFile", VAR_SERVER | VAR_OBSOLETE},
68 {"Hostnames", VAR_SERVER},
69 {"IffOneQueue", VAR_SERVER},
70 {"Interface", VAR_SERVER},
71 {"KeyExpire", VAR_SERVER},
72 {"ListenAddress", VAR_SERVER | VAR_MULTIPLE},
73 {"LocalDiscovery", VAR_SERVER},
74 {"MACExpire", VAR_SERVER},
75 {"MaxConnectionBurst", VAR_SERVER},
76 {"MaxOutputBufferSize", VAR_SERVER},
77 {"MaxTimeout", VAR_SERVER},
78 {"Mode", VAR_SERVER | VAR_SAFE},
80 {"PingInterval", VAR_SERVER},
81 {"PingTimeout", VAR_SERVER},
82 {"PriorityInheritance", VAR_SERVER},
83 {"PrivateKey", VAR_SERVER | VAR_OBSOLETE},
84 {"PrivateKeyFile", VAR_SERVER},
85 {"ProcessPriority", VAR_SERVER},
86 {"Proxy", VAR_SERVER},
87 {"ReplayWindow", VAR_SERVER},
88 {"ScriptsExtension", VAR_SERVER},
89 {"ScriptsInterpreter", VAR_SERVER},
90 {"StrictSubnets", VAR_SERVER},
91 {"TunnelServer", VAR_SERVER},
92 {"VDEGroup", VAR_SERVER},
93 {"VDEPort", VAR_SERVER},
94 /* Host configuration */
95 {"Address", VAR_HOST | VAR_MULTIPLE},
96 {"Cipher", VAR_SERVER | VAR_HOST},
97 {"ClampMSS", VAR_SERVER | VAR_HOST},
98 {"Compression", VAR_SERVER | VAR_HOST},
99 {"Digest", VAR_SERVER | VAR_HOST},
100 {"ECDSAPublicKey", VAR_HOST},
101 {"ECDSAPublicKeyFile", VAR_SERVER | VAR_HOST},
102 {"IndirectData", VAR_SERVER | VAR_HOST},
103 {"MACLength", VAR_SERVER | VAR_HOST},
104 {"PMTU", VAR_SERVER | VAR_HOST},
105 {"PMTUDiscovery", VAR_SERVER | VAR_HOST},
107 {"PublicKey", VAR_HOST | VAR_OBSOLETE},
108 {"PublicKeyFile", VAR_SERVER | VAR_HOST | VAR_OBSOLETE},
109 {"Subnet", VAR_HOST | VAR_MULTIPLE | VAR_SAFE},
110 {"TCPOnly", VAR_SERVER | VAR_HOST},
111 {"Weight", VAR_HOST | VAR_SAFE},
115 static bool fcopy(FILE *out, const char *filename) {
116 FILE *in = fopen(filename, "r");
118 fprintf(stderr, "Could not open %s: %s\n", filename, strerror(errno));
124 while((len = fread(buf, 1, sizeof buf, in)))
125 fwrite(buf, len, 1, out);
130 static int rstrip(char *value) {
131 int len = strlen(value);
132 while(len && strchr("\t\r\n ", value[len - 1]))
137 static void scan_for_hostname(const char *filename, char **hostname, char **port) {
139 if(!filename || (*hostname && *port))
142 FILE *f = fopen(filename, "r");
146 while(fgets(line, sizeof line, f)) {
150 p += strcspn(p, "\t =");
153 q = p + strspn(p, "\t ");
155 q += 1 + strspn(q + 1, "\t ");
157 p = q + strcspn(q, "\t ");
160 p += strspn(p, "\t ");
161 p[strcspn(p, "\t ")] = 0;
163 if(!*port && !strcasecmp(line, "Port")) {
165 } else if(!*hostname && !strcasecmp(line, "Address")) {
166 *hostname = xstrdup(q);
173 if(*hostname && *port)
179 static char *get_my_hostname(meshlink_handle_t* mesh) {
180 char *hostname = NULL;
182 char *hostport = NULL;
183 char *name = mesh->self->name;
184 char filename[PATH_MAX] = "";
188 // Use first Address statement in own host config file
189 snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, name);
190 scan_for_hostname(filename, &hostname, &port);
195 // If that doesn't work, guess externally visible hostname
196 fprintf(stderr, "Trying to discover externally visible hostname...\n");
197 struct addrinfo *ai = str2addrinfo("meshlink.io", "80", SOCK_STREAM);
198 struct addrinfo *aip = ai;
199 static const char request[] = "GET http://www.meshlink.io/host.cgi HTTP/1.0\r\n\r\n";
202 int s = socket(aip->ai_family, aip->ai_socktype, aip->ai_protocol);
204 if(connect(s, aip->ai_addr, aip->ai_addrlen)) {
210 send(s, request, sizeof request - 1, 0);
211 int len = recv(s, line, sizeof line - 1, MSG_WAITALL);
214 if(line[len - 1] == '\n')
216 char *p = strrchr(line, '\n');
218 hostname = xstrdup(p + 1);
231 // Check that the hostname is reasonable
233 for(char *p = hostname; *p; p++) {
234 if(isalnum(*p) || *p == '-' || *p == '.' || *p == ':')
236 // If not, forget it.
246 f = fopen(filename, "a");
248 fprintf(f, "\nAddress = %s\n", hostname);
251 fprintf(stderr, "Could not append Address to %s: %s\n", filename, strerror(errno));
256 if(strchr(hostname, ':'))
257 xasprintf(&hostport, "[%s]:%s", hostname, port);
259 xasprintf(&hostport, "%s:%s", hostname, port);
261 if(strchr(hostname, ':'))
262 xasprintf(&hostport, "[%s]", hostname);
264 hostport = xstrdup(hostname);
272 static char *get_line(const char **data) {
281 static char line[1024];
282 const char *end = strchr(*data, '\n');
283 size_t len = end ? end - *data : strlen(*data);
284 if(len >= sizeof line) {
285 fprintf(stderr, "Maximum line length exceeded!\n");
288 if(len && !isprint(**data))
291 memcpy(line, *data, len);
302 static char *get_value(const char *data, const char *var) {
303 char *line = get_line(&data);
307 char *sep = line + strcspn(line, " \t=");
308 char *val = sep + strspn(sep, " \t");
310 val += 1 + strspn(val + 1, " \t");
312 if(strcasecmp(line, var))
317 static bool try_bind(int port) {
318 struct addrinfo *ai = NULL;
319 struct addrinfo hint = {
320 .ai_flags = AI_PASSIVE,
321 .ai_family = AF_UNSPEC,
322 .ai_socktype = SOCK_STREAM,
323 .ai_protocol = IPPROTO_TCP,
327 snprintf(portstr, sizeof portstr, "%d", port);
329 if(getaddrinfo(NULL, portstr, &hint, &ai) || !ai)
333 int fd = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
338 int result = bind(fd, ai->ai_addr, ai->ai_addrlen);
351 static int check_port(meshlink_handle_t *mesh) {
355 fprintf(stderr, "Warning: could not bind to port 655.\n");
357 for(int i = 0; i < 100; i++) {
358 int port = 0x1000 + (rand() & 0x7fff);
360 char filename[PATH_MAX];
361 snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, mesh->name);
362 FILE *f = fopen(filename, "a");
364 fprintf(stderr, "Please change MeshLink's Port manually.\n");
368 fprintf(f, "Port = %d\n", port);
370 fprintf(stderr, "MeshLink will instead listen on port %d.\n", port);
375 fprintf(stderr, "Please change MeshLink's Port manually.\n");
379 static bool finalize_join(meshlink_handle_t *mesh) {
380 char *name = xstrdup(get_value(mesh->data, "Name"));
382 fprintf(stderr, "No Name found in invitation!\n");
386 if(!check_id(name)) {
387 fprintf(stderr, "Invalid Name found in invitation: %s!\n", name);
391 char filename[PATH_MAX];
392 snprintf(filename, sizeof filename, "%s" SLASH "meshlink.conf", mesh->confbase);
394 FILE *f = fopen(filename, "w");
396 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
400 fprintf(f, "Name = %s\n", name);
402 snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, name);
403 FILE *fh = fopen(filename, "w");
405 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
410 // Filter first chunk on approved keywords, split between meshlink.conf and hosts/Name
411 // Other chunks go unfiltered to their respective host config files
412 const char *p = mesh->data;
415 while((l = get_line(&p))) {
420 // Split line into variable and value
421 int len = strcspn(l, "\t =");
423 value += strspn(value, "\t ");
426 value += strspn(value, "\t ");
431 if(!strcasecmp(l, "Name"))
432 if(strcmp(value, name))
436 else if(!strcasecmp(l, "NetName"))
439 // Check the list of known variables //TODO: most variables will not be available in meshlink, only name and key will be absolutely necessary
442 for(i = 0; variables[i].name; i++) {
443 if(strcasecmp(l, variables[i].name))
449 // Ignore unknown and unsafe variables
451 fprintf(stderr, "Ignoring unknown variable '%s' in invitation.\n", l);
453 } else if(!(variables[i].type & VAR_SAFE)) {
454 fprintf(stderr, "Ignoring unsafe variable '%s' in invitation.\n", l);
458 // Copy the safe variable to the right config file
459 fprintf(variables[i].type & VAR_HOST ? fh : f, "%s = %s\n", l, value);
464 while(l && !strcasecmp(l, "Name")) {
465 if(!check_id(value)) {
466 fprintf(stderr, "Invalid Name found in invitation.\n");
470 if(!strcmp(value, name)) {
471 fprintf(stderr, "Secondary chunk would overwrite our own host config file.\n");
475 snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, value);
476 f = fopen(filename, "w");
479 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
483 while((l = get_line(&p))) {
484 if(!strcmp(l, "#---------------------------------------------------------------#"))
486 int len = strcspn(l, "\t =");
487 if(len == 4 && !strncasecmp(l, "Name", 4)) {
489 value += strspn(value, "\t ");
492 value += strspn(value, "\t ");
505 char *b64key = ecdsa_get_base64_public_key(mesh->self->connection->ecdsa);
509 fprintf(fh, "ECDSAPublicKey = %s\n", b64key);
510 fprintf(fh, "Port = %s\n", mesh->myport);
514 sptps_send_record(&(mesh->sptps), 1, b64key, strlen(b64key));
517 free(mesh->self->name);
518 free(mesh->self->connection->name);
519 mesh->self->name = xstrdup(name);
520 mesh->self->connection->name = name;
522 fprintf(stderr, "Configuration stored in: %s\n", mesh->confbase);
524 load_all_nodes(mesh);
529 static bool invitation_send(void *handle, uint8_t type, const void *data, size_t len) {
530 meshlink_handle_t* mesh = handle;
532 int result = send(mesh->sock, data, len, 0);
533 if(result == -1 && errno == EINTR)
543 static bool invitation_receive(void *handle, uint8_t type, const void *msg, uint16_t len) {
544 meshlink_handle_t* mesh = handle;
546 case SPTPS_HANDSHAKE:
547 return sptps_send_record(&(mesh->sptps), 0, mesh->cookie, sizeof mesh->cookie);
550 mesh->data = xrealloc(mesh->data, mesh->thedatalen + len + 1);
551 memcpy(mesh->data + mesh->thedatalen, msg, len);
552 mesh->thedatalen += len;
553 mesh->data[mesh->thedatalen] = 0;
557 return finalize_join(mesh);
560 fprintf(stderr, "Invitation succesfully accepted.\n");
561 shutdown(mesh->sock, SHUT_RDWR);
562 mesh->success = true;
572 static bool recvline(meshlink_handle_t* mesh, size_t len) {
573 char *newline = NULL;
578 while(!(newline = memchr(mesh->buffer, '\n', mesh->blen))) {
579 int result = recv(mesh->sock, mesh->buffer + mesh->blen, sizeof mesh->buffer - mesh->blen, 0);
580 if(result == -1 && errno == EINTR)
584 mesh->blen += result;
587 if(newline - mesh->buffer >= len)
590 len = newline - mesh->buffer;
592 memcpy(mesh->line, mesh->buffer, len);
594 memmove(mesh->buffer, newline + 1, mesh->blen - len - 1);
595 mesh->blen -= len + 1;
599 static bool sendline(int fd, char *format, ...) {
600 static char buffer[4096];
605 va_start(ap, format);
606 blen = vsnprintf(buffer, sizeof buffer, format, ap);
609 if(blen < 1 || blen >= sizeof buffer)
616 int result = send(fd, p, blen, MSG_NOSIGNAL);
617 if(result == -1 && errno == EINTR)
628 static const char *errstr[] = {
629 [MESHLINK_OK] = "No error",
630 [MESHLINK_ENOMEM] = "Out of memory",
631 [MESHLINK_ENOENT] = "No such node",
634 const char *meshlink_strerror(meshlink_errno_t err) {
635 if(err < 0 || err >= sizeof errstr / sizeof *errstr)
636 return "Invalid error code";
640 static bool ecdsa_keygen(meshlink_handle_t *mesh) {
643 char pubname[PATH_MAX], privname[PATH_MAX];
645 fprintf(stderr, "Generating ECDSA keypair:\n");
647 if(!(key = ecdsa_generate())) {
648 fprintf(stderr, "Error during key generation!\n");
651 fprintf(stderr, "Done.\n");
653 snprintf(privname, sizeof privname, "%s" SLASH "ecdsa_key.priv", mesh->confbase);
654 f = fopen(privname, "w");
660 fchmod(fileno(f), 0600);
663 if(!ecdsa_write_pem_private_key(key, f)) {
664 fprintf(stderr, "Error writing private key!\n");
673 snprintf(pubname, sizeof pubname, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, mesh->name);
674 f = fopen(pubname, "a");
679 char *pubkey = ecdsa_get_base64_public_key(key);
680 fprintf(f, "ECDSAPublicKey = %s\n", pubkey);
689 static bool meshlink_setup(meshlink_handle_t *mesh) {
690 if(mkdir(mesh->confbase, 0777) && errno != EEXIST) {
691 fprintf(stderr, "Could not create directory %s: %s\n", mesh->confbase, strerror(errno));
695 char filename[PATH_MAX];
696 snprintf(filename, sizeof filename, "%s" SLASH "hosts", mesh->confbase);
698 if(mkdir(filename, 0777) && errno != EEXIST) {
699 fprintf(stderr, "Could not create directory %s: %s\n", filename, strerror(errno));
703 snprintf(filename, sizeof filename, "%s" SLASH "meshlink.conf", mesh->confbase);
705 if(!access(filename, F_OK)) {
706 fprintf(stderr, "Configuration file %s already exists!\n", filename);
710 FILE *f = fopen(filename, "w");
712 fprintf(stderr, "Could not create file %s: %s\n", filename, strerror(errno));
716 fprintf(f, "Name = %s\n", mesh->name);
719 if(!ecdsa_keygen(mesh))
727 meshlink_handle_t *meshlink_open(const char *confbase, const char *name) {
728 // Validate arguments provided by the application
729 bool usingname = false;
731 if(!confbase || !*confbase) {
732 fprintf(stderr, "No confbase given!\n");
736 if(!name || !*name) {
737 fprintf(stderr, "No name given!\n");
740 else { //check name only if there is a name != NULL
742 if(!check_id(name)) {
743 fprintf(stderr, "Invalid name given!\n");
745 } else { usingname = true;}
748 meshlink_handle_t *mesh = xzalloc(sizeof *mesh);
749 mesh->confbase = xstrdup(confbase);
750 if (usingname) mesh->name = xstrdup(name);
751 pthread_mutex_init ( &(mesh->outpacketqueue_mutex), NULL);
752 pthread_mutex_init ( &(mesh->nodes_mutex), NULL);
753 mesh->threadstarted = false;
754 event_loop_init(&mesh->loop);
755 mesh->loop.data = mesh;
757 // TODO: should be set by a function.
758 mesh->debug_level = 5;
760 // Check whether meshlink.conf already exists
762 char filename[PATH_MAX];
763 snprintf(filename, sizeof filename, "%s" SLASH "meshlink.conf", confbase);
765 if(access(filename, R_OK)) {
766 if(errno == ENOENT) {
768 meshlink_setup(mesh);
770 fprintf(stderr, "Cannot not read from %s: %s\n", filename, strerror(errno));
771 return meshlink_close(mesh), NULL;
775 // Read the configuration
777 init_configuration(&mesh->config);
779 if(!read_server_config(mesh))
780 return meshlink_close(mesh), NULL;
783 struct WSAData wsa_state;
784 WSAStartup(MAKEWORD(2, 2), &wsa_state);
787 // Setup up everything
788 // TODO: we should not open listening sockets yet
790 if(!setup_network(mesh))
791 return meshlink_close(mesh), NULL;
796 static void *meshlink_main_loop(void *arg) {
797 meshlink_handle_t *mesh = arg;
799 try_outgoing_connections(mesh);
806 bool meshlink_start(meshlink_handle_t *mesh) {
810 // TODO: open listening sockets first
812 //Check that a valid name is set
814 fprintf(stderr, "No name given!\n");
818 // Start the main thread
820 if(pthread_create(&mesh->thread, NULL, meshlink_main_loop, mesh) != 0) {
821 fprintf(stderr, "Could not start thread: %s\n", strerror(errno));
822 memset(&mesh->thread, 0, sizeof mesh->thread);
826 mesh->threadstarted=true;
831 void meshlink_stop(meshlink_handle_t *mesh) {
835 // Shut down the listening sockets to signal the main thread to shut down
837 for(int i = 0; i < mesh->listen_sockets; i++) {
838 shutdown(mesh->listen_socket[i].tcp.fd, SHUT_RDWR);
839 shutdown(mesh->listen_socket[i].udp.fd, SHUT_RDWR);
842 // Wait for the main thread to finish
844 pthread_join(mesh->thread, NULL);
847 void meshlink_close(meshlink_handle_t *mesh) {
848 if(!mesh || !mesh->confbase)
851 // Close and free all resources used.
853 close_network_connections(mesh);
855 logger(DEBUG_ALWAYS, LOG_NOTICE, "Terminating");
857 exit_configuration(&mesh->config);
858 event_loop_exit(&mesh->loop);
865 ecdsa_free(mesh->invitation_key);
868 free(mesh->confbase);
870 memset(mesh, 0, sizeof *mesh);
875 void meshlink_set_receive_cb(meshlink_handle_t *mesh, meshlink_receive_cb_t cb) {
878 mesh->receive_cb = cb;
881 void meshlink_set_node_status_cb(meshlink_handle_t *mesh, meshlink_node_status_cb_t cb) {
884 mesh->node_status_cb = cb;
887 void meshlink_set_log_cb(meshlink_handle_t *mesh, meshlink_log_level_t level, meshlink_log_cb_t cb) {
891 mesh->log_level = level;
894 bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, const void *data, size_t len) {
895 if(!mesh || !destination)
902 /* If there is no outgoing list yet, create one. */
904 if(!mesh->outpacketqueue)
905 mesh->outpacketqueue = list_alloc(NULL);
907 //add packet to the queue
908 outpacketqueue_t *packet_in_queue = xzalloc(sizeof *packet_in_queue);
909 packet_in_queue->destination=destination;
910 packet_in_queue->data=data;
911 packet_in_queue->len=len;
912 pthread_mutex_lock(&(mesh->outpacketqueue_mutex));
913 list_insert_head(mesh->outpacketqueue,packet_in_queue);
914 pthread_mutex_unlock(&(mesh->outpacketqueue_mutex));
917 signal_trigger(&(mesh->loop),&(mesh->datafromapp));
921 void meshlink_send_from_queue(event_loop_t* el,meshlink_handle_t *mesh) {
923 meshlink_packethdr_t *hdr = (meshlink_packethdr_t *)packet.data;
925 outpacketqueue_t* p = list_get_tail(mesh->outpacketqueue);
927 list_delete_tail(mesh->outpacketqueue);
930 if (sizeof(meshlink_packethdr_t) + p->len > MAXSIZE) {
935 packet.probe = false;
936 memset(hdr, 0, sizeof *hdr);
937 memcpy(hdr->destination, p->destination->name, sizeof hdr->destination);
938 memcpy(hdr->source, mesh->self->name, sizeof hdr->source);
940 packet.len = sizeof *hdr + p->len;
941 memcpy(packet.data + sizeof *hdr, p->data, p->len);
943 mesh->self->in_packets++;
944 mesh->self->in_bytes += packet.len;
945 route(mesh, mesh->self, &packet);
949 ssize_t meshlink_get_pmtu(meshlink_handle_t *mesh, meshlink_node_t *destination) {
950 if(!mesh || !destination)
953 node_t *n = (node_t *)destination;
954 if(!n->status.reachable)
956 else if(n->mtuprobes > 30 && n->minmtu)
962 meshlink_node_t *meshlink_get_node(meshlink_handle_t *mesh, const char *name) {
965 return (meshlink_node_t *)lookup_node(mesh, (char *)name); // TODO: make lookup_node() use const
968 meshlink_node_t **meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_t **nodes, size_t *nmemb) {
969 if(!mesh || (nmemb && !nodes))
972 meshlink_node_t **result, **p;
975 pthread_mutex_lock(&(mesh->nodes_mutex));
977 *nmemb = mesh->nodes->count;
978 result = realloc(nodes, *nmemb * sizeof *nodes);
981 for splay_each(node_t, n, mesh->nodes)
982 *p++ = (meshlink_node_t *)n;
986 meshlink_errno = MESHLINK_ENOMEM;
989 pthread_mutex_unlock(&(mesh->nodes_mutex));
994 bool meshlink_sign(meshlink_handle_t *mesh, const void *data, size_t len, void *signature, size_t *siglen) {
995 if(!mesh || !data || !len || !signature || !siglen)
997 if(*siglen < MESHLINK_SIGLEN)
999 if(!ecdsa_sign(mesh->self->connection->ecdsa, data, len, signature))
1001 *siglen = MESHLINK_SIGLEN;
1005 bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const void *data, size_t len, const void *signature, size_t siglen) {
1006 if(!mesh || !data || !len || !signature)
1008 if(siglen != MESHLINK_SIGLEN)
1010 struct node_t *n = (struct node_t *)source;
1011 node_read_ecdsa_public_key(mesh, n);
1014 return ecdsa_verify(((struct node_t *)source)->ecdsa, data, len, signature);
1017 static bool refresh_invitation_key(meshlink_handle_t *mesh) {
1018 char filename[PATH_MAX];
1020 snprintf(filename, sizeof filename, "%s" SLASH "invitations", mesh->confbase);
1021 if(mkdir(filename, 0700) && errno != EEXIST) {
1022 fprintf(stderr, "Could not create directory %s: %s\n", filename, strerror(errno));
1026 // Count the number of valid invitations, clean up old ones
1027 DIR *dir = opendir(filename);
1029 fprintf(stderr, "Could not read directory %s: %s\n", filename, strerror(errno));
1036 time_t deadline = time(NULL) - 604800; // 1 week in the past
1038 while((ent = readdir(dir))) {
1039 if(strlen(ent->d_name) != 24)
1041 char invname[PATH_MAX];
1043 snprintf(invname, sizeof invname, "%s" SLASH "%s", filename, ent->d_name);
1044 if(!stat(invname, &st)) {
1045 if(mesh->invitation_key && deadline < st.st_mtime)
1050 fprintf(stderr, "Could not stat %s: %s\n", invname, strerror(errno));
1056 fprintf(stderr, "Error while reading directory %s: %s\n", filename, strerror(errno));
1063 snprintf(filename, sizeof filename, "%s" SLASH "invitations" SLASH "ecdsa_key.priv", mesh->confbase);
1065 // Remove the key if there are no outstanding invitations.
1068 if(mesh->invitation_key) {
1069 ecdsa_free(mesh->invitation_key);
1070 mesh->invitation_key = NULL;
1074 if(mesh->invitation_key)
1077 // Create a new key if necessary.
1078 FILE *f = fopen(filename, "r");
1080 if(errno != ENOENT) {
1081 fprintf(stderr, "Could not read %s: %s\n", filename, strerror(errno));
1085 mesh->invitation_key = ecdsa_generate();
1086 if(!mesh->invitation_key) {
1087 fprintf(stderr, "Could not generate a new key!\n");
1090 f = fopen(filename, "w");
1092 fprintf(stderr, "Could not write %s: %s\n", filename, strerror(errno));
1095 chmod(filename, 0600);
1096 ecdsa_write_pem_private_key(mesh->invitation_key, f);
1099 mesh->invitation_key = ecdsa_read_pem_private_key(f);
1101 if(!mesh->invitation_key)
1102 fprintf(stderr, "Could not read private key from %s\n", filename);
1105 return mesh->invitation_key;
1108 bool meshlink_add_address(meshlink_handle_t *mesh, const char *address) {
1109 if(!mesh || !address)
1112 for(const char *p = address; *p; p++) {
1113 if(isalnum(*p) || *p == '-' || *p == '.' || *p == ':')
1115 fprintf(stderr, "Invalid character in address: %s\n", address);
1119 return append_config_file(mesh, mesh->self->name, "Address", address);
1122 char *meshlink_invite(meshlink_handle_t *mesh, const char *name) {
1126 // Check validity of the new node's name
1127 if(!check_id(name)) {
1128 fprintf(stderr, "Invalid name for node.\n");
1132 // Ensure no host configuration file with that name exists
1133 char filename[PATH_MAX];
1134 snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, name);
1135 if(!access(filename, F_OK)) {
1136 fprintf(stderr, "A host config file for %s already exists!\n", name);
1140 // Ensure no other nodes know about this name
1141 if(meshlink_get_node(mesh, name)) {
1142 fprintf(stderr, "A node with name %s is already known!\n", name);
1146 // Get the local address
1147 char *address = get_my_hostname(mesh);
1149 fprintf(stderr, "No Address known for ourselves!\n");
1153 if(!refresh_invitation_key(mesh))
1158 // Create a hash of the key.
1159 char *fingerprint = ecdsa_get_base64_public_key(mesh->invitation_key);
1160 sha512(fingerprint, strlen(fingerprint), hash);
1161 b64encode_urlsafe(hash, hash, 18);
1163 // Create a random cookie for this invitation.
1165 randomize(cookie, 18);
1167 // Create a filename that doesn't reveal the cookie itself
1168 char buf[18 + strlen(fingerprint)];
1169 char cookiehash[64];
1170 memcpy(buf, cookie, 18);
1171 memcpy(buf + 18, fingerprint, sizeof buf - 18);
1172 sha512(buf, sizeof buf, cookiehash);
1173 b64encode_urlsafe(cookiehash, cookiehash, 18);
1175 b64encode_urlsafe(cookie, cookie, 18);
1179 // Create a file containing the details of the invitation.
1180 snprintf(filename, sizeof filename, "%s" SLASH "invitations" SLASH "%s", mesh->confbase, cookiehash);
1181 int ifd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600);
1183 fprintf(stderr, "Could not create invitation file %s: %s\n", filename, strerror(errno));
1186 FILE *f = fdopen(ifd, "w");
1190 // Fill in the details.
1191 fprintf(f, "Name = %s\n", name);
1193 // fprintf(f, "NetName = %s\n", netname);
1194 fprintf(f, "ConnectTo = %s\n", mesh->self->name);
1196 // Copy Broadcast and Mode
1197 snprintf(filename, sizeof filename, "%s" SLASH "meshlink.conf", mesh->confbase);
1198 FILE *tc = fopen(filename, "r");
1201 while(fgets(buf, sizeof buf, tc)) {
1202 if((!strncasecmp(buf, "Mode", 4) && strchr(" \t=", buf[4]))
1203 || (!strncasecmp(buf, "Broadcast", 9) && strchr(" \t=", buf[9]))) {
1205 // Make sure there is a newline character.
1206 if(!strchr(buf, '\n'))
1212 fprintf(stderr, "Could not create %s: %s\n", filename, strerror(errno));
1216 fprintf(f, "#---------------------------------------------------------------#\n");
1217 fprintf(f, "Name = %s\n", mesh->self->name);
1219 snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, mesh->self->name);
1223 // Create an URL from the local address, key hash and cookie
1225 xasprintf(&url, "%s/%s%s", address, hash, cookie);
1231 bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
1232 if(!mesh || !invitation)
1235 //TODO: think of a better name for this variable, or of a different way to tokenize the invitation URL.
1236 char copy[strlen(invitation) + 1];
1237 strcpy(copy, invitation);
1239 // Split the invitation URL into hostname, port, key hash and cookie.
1241 char *slash = strchr(copy, '/');
1247 if(strlen(slash) != 48)
1250 char *address = copy;
1252 if(*address == '[') {
1254 char *bracket = strchr(address, ']');
1258 if(bracket[1] == ':')
1261 port = strchr(address, ':');
1269 if(!b64decode(slash, mesh->hash, 18) || !b64decode(slash + 24, mesh->cookie, 18))
1272 // Generate a throw-away key for the invitation.
1273 ecdsa_t *key = ecdsa_generate();
1277 char *b64key = ecdsa_get_base64_public_key(key);
1279 //Before doing meshlink_join make sure we are not connected to another mesh
1280 if ( mesh->threadstarted ){
1284 // Connect to the meshlink daemon mentioned in the URL.
1285 struct addrinfo *ai = str2addrinfo(address, port, SOCK_STREAM);
1289 mesh->sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1290 if(mesh->sock <= 0) {
1291 fprintf(stderr, "Could not open socket: %s\n", strerror(errno));
1296 if(connect(mesh->sock, ai->ai_addr, ai->ai_addrlen)) {
1297 fprintf(stderr, "Could not connect to %s port %s: %s\n", address, port, strerror(errno));
1298 closesocket(mesh->sock);
1305 fprintf(stderr, "Connected to %s port %s...\n", address, port);
1307 // Tell him we have an invitation, and give him our throw-away key.
1311 if(!sendline(mesh->sock, "0 ?%s %d.%d", b64key, PROT_MAJOR, 1)) {
1312 fprintf(stderr, "Error sending request to %s port %s: %s\n", address, port, strerror(errno));
1313 closesocket(mesh->sock);
1319 char hisname[4096] = "";
1320 int code, hismajor, hisminor = 0;
1322 if(!recvline(mesh, sizeof mesh->line) || sscanf(mesh->line, "%d %s %d.%d", &code, hisname, &hismajor, &hisminor) < 3 || code != 0 || hismajor != PROT_MAJOR || !check_id(hisname) || !recvline(mesh, sizeof mesh->line) || !rstrip(mesh->line) || sscanf(mesh->line, "%d ", &code) != 1 || code != ACK || strlen(mesh->line) < 3) {
1323 fprintf(stderr, "Cannot read greeting from peer\n");
1324 closesocket(mesh->sock);
1328 // Check if the hash of the key he gave us matches the hash in the URL.
1329 char *fingerprint = mesh->line + 2;
1331 if(sha512(fingerprint, strlen(fingerprint), hishash)) {
1332 fprintf(stderr, "Could not create hash\n%s\n", mesh->line + 2);
1335 if(memcmp(hishash, mesh->hash, 18)) {
1336 fprintf(stderr, "Peer has an invalid key!\n%s\n", mesh->line + 2);
1341 ecdsa_t *hiskey = ecdsa_set_base64_public_key(fingerprint);
1345 // Start an SPTPS session
1346 if(!sptps_start(&mesh->sptps, mesh, true, false, key, hiskey, "meshlink invitation", 15, invitation_send, invitation_receive))
1349 // Feed rest of input buffer to SPTPS
1350 if(!sptps_receive_data(&mesh->sptps, mesh->buffer, mesh->blen))
1355 while((len = recv(mesh->sock, mesh->line, sizeof mesh->line, 0))) {
1359 fprintf(stderr, "Error reading data from %s port %s: %s\n", address, port, strerror(errno));
1363 if(!sptps_receive_data(&mesh->sptps, mesh->line, len))
1367 sptps_stop(&mesh->sptps);
1370 closesocket(mesh->sock);
1372 if(!mesh->success) {
1373 fprintf(stderr, "Connection closed by peer, invitation cancelled.\n");
1380 fprintf(stderr, "Invalid invitation URL or you are already connected to a Mesh ?\n");
1384 char *meshlink_export(meshlink_handle_t *mesh) {
1388 char filename[PATH_MAX];
1389 snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, mesh->self->name);
1390 FILE *f = fopen(filename, "r");
1392 fprintf(stderr, "Could not open %s: %s\n", filename, strerror(errno));
1396 fseek(f, 0, SEEK_END);
1397 int fsize = ftell(f);
1400 size_t len = fsize + 9 + strlen(mesh->self->name);
1401 char *buf = xmalloc(len);
1402 snprintf(buf, len, "Name = %s\n", mesh->self->name);
1403 if(fread(buf + len - fsize - 1, fsize, 1, f) != 1) {
1404 fprintf(stderr, "Error reading from %s: %s\n", filename, strerror(errno));
1414 bool meshlink_import(meshlink_handle_t *mesh, const char *data) {
1418 if(strncmp(data, "Name = ", 7)) {
1419 fprintf(stderr, "Invalid data\n");
1423 char *end = strchr(data + 7, '\n');
1425 fprintf(stderr, "Invalid data\n");
1429 int len = end - (data + 7);
1431 memcpy(name, data + 7, len);
1433 if(!check_id(name)) {
1434 fprintf(stderr, "Invalid Name\n");
1438 char filename[PATH_MAX];
1439 snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", mesh->confbase, name);
1440 if(!access(filename, F_OK)) {
1441 fprintf(stderr, "File %s already exists, not importing\n", filename);
1445 if(errno != ENOENT) {
1446 fprintf(stderr, "Error accessing %s: %s\n", filename, strerror(errno));
1450 FILE *f = fopen(filename, "w");
1452 fprintf(stderr, "Could not create %s: %s\n", filename, strerror(errno));
1456 fwrite(end + 1, strlen(end + 1), 1, f);
1459 load_all_nodes(mesh);
1464 void meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node) {
1470 n->status.blacklisted=true;
1471 fprintf(stderr, "Blacklisted %s.\n",node->name);
1473 //Make blacklisting persistent in the config file
1474 append_config_file(mesh, n->name, "blacklisted", "yes");
1479 void meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node) {
1483 node_t *n = (node_t *)node;
1484 n->status.blacklisted = false;
1486 //TODO: remove blacklisted = yes from the config file
1491 /* Hint that a hostname may be found at an address
1492 * See header file for detailed comment.
1494 extern void meshlink_hint_address(meshlink_handle_t *mesh, char *hostname, struct sockaddr *addr) {
1495 if(!mesh || !hostname || !addr)
1499 char *addr_str = malloc(MAX_ADDRESS_LENGTH*sizeof(char));
1500 memset(addr_str, 0, MAX_ADDRESS_LENGTH*sizeof(char));
1502 char *port_str = malloc(MAX_PORT_LENGTH*sizeof(char));
1503 memset(port_str, 0, MAX_PORT_LENGTH*sizeof(char));
1505 // extra byte for a space, and one to make sure string is null-terminated
1506 int full_addr_len = MAX_ADDRESS_LENGTH + MAX_PORT_LENGTH + 2;
1508 char *full_addr_str = malloc(full_addr_len*sizeof(char));
1509 memset(full_addr_str, 0, full_addr_len*sizeof(char));
1511 // check that hostname matches an existing node
1512 n = lookup_node(mesh, hostname);
1516 // get address and port number
1517 if(!get_ip_str(addr, addr_str, MAX_ADDRESS_LENGTH))
1519 if(!get_port_str(addr, port_str, MAX_ADDRESS_LENGTH))
1522 // append_config_file expects an address, a space, and then a port number
1523 strcat(full_addr_str, addr_str);
1524 strcat(full_addr_str, " ");
1525 strcat(full_addr_str, port_str);
1527 append_config_file(mesh, n->name, "Address", full_addr_str);
1531 free(full_addr_str);
1533 // TODO do we want to fire off a connection attempt right away?
1536 static void __attribute__((constructor)) meshlink_init(void) {
1540 static void __attribute__((destructor)) meshlink_exit(void) {