2 libmeshlink.h -- Tincd Library
3 Copyright (C) 2014 Guus Sliepen <guus@tinc-vpn.org> Saverio Proto <zioproto@gmail.com>
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.
20 #include "libmeshlink.h"
23 char *hosts_dir = NULL;
24 static char *name = NULL;
25 char *tinc_conf = NULL;
29 Generate a public/private ECDSA keypair, and ask for a file to store
32 bool ecdsa_keygen(bool ask) {
35 char *pubname, *privname;
37 fprintf(stderr, "Generating ECDSA keypair:\n");
39 if(!(key = ecdsa_generate())) {
40 fprintf(stderr, "Error during key generation!\n");
43 fprintf(stderr, "Done.\n");
45 xasprintf(&privname, "%s" SLASH "ecdsa_key.priv", confbase);
46 //f = ask_and_open(privname, "private ECDSA key", "a", ask, 0600); //this function is not ported to lib because makes no sense
52 if(!ecdsa_write_pem_private_key(key, f)) {
53 fprintf(stderr, "Error writing private key!\n");
62 xasprintf(&pubname, "%s" SLASH "hosts" SLASH "%s", confbase, name);
64 xasprintf(&pubname, "%s" SLASH "ecdsa_key.pub", confbase);
66 //f = ask_and_open(pubname, "public ECDSA key", "a", ask, 0666);
72 char *pubkey = ecdsa_get_base64_public_key(key);
73 fprintf(f, "ECDSAPublicKey = %s\n", pubkey);
83 Generate a public/private RSA keypair, and ask for a file to store
86 bool rsa_keygen(int bits, bool ask) {
89 char *pubname, *privname;
91 fprintf(stderr, "Generating %d bits keys:\n", bits);
93 if(!(key = rsa_generate(bits, 0x10001))) {
94 fprintf(stderr, "Error during key generation!\n");
97 fprintf(stderr, "Done.\n");
99 xasprintf(&privname, "%s" SLASH "rsa_key.priv", confbase);
100 //f = ask_and_open(privname, "private RSA key", "a", ask, 0600);
106 if(!rsa_write_pem_private_key(key, f)) {
107 fprintf(stderr, "Error writing private key!\n");
116 xasprintf(&pubname, "%s" SLASH "hosts" SLASH "%s", confbase, name);
118 xasprintf(&pubname, "%s" SLASH "rsa_key.pub", confbase);
120 //f = ask_and_open(pubname, "public RSA key", "a", ask, 0666);
126 if(!rsa_write_pem_public_key(key, f)) {
127 fprintf(stderr, "Error writing public key!\n");
139 static bool try_bind(int port) {
140 struct addrinfo *ai = NULL;
141 struct addrinfo hint = {
142 .ai_flags = AI_PASSIVE,
143 .ai_family = AF_UNSPEC,
144 .ai_socktype = SOCK_STREAM,
145 .ai_protocol = IPPROTO_TCP,
149 snprintf(portstr, sizeof portstr, "%d", port);
151 if(getaddrinfo(NULL, portstr, &hint, &ai) || !ai)
155 int fd = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
158 int result = bind(fd, ai->ai_addr, ai->ai_addrlen);
168 int check_port(char *name) {
172 fprintf(stderr, "Warning: could not bind to port 655. ");
174 for(int i = 0; i < 100; i++) {
175 int port = 0x1000 + (rand() & 0x7fff);
178 xasprintf(&filename, "%s" SLASH "hosts" SLASH "%s", confbase, name);
179 FILE *f = fopen(filename, "a");
182 fprintf(stderr, "Please change tinc's Port manually.\n");
186 fprintf(f, "Port = %d\n", port);
188 fprintf(stderr, "Tinc will instead listen on port %d.\n", port);
193 fprintf(stderr, "Please change tinc's Port manually.\n");
196 //tinc_setup() should basically do what cmd_init() from src/tincctl.c does, except it doesn't have to generate a tinc-up script.
197 bool tinc_setup(const char* confbase, const char* name) {
199 xasprintf(&tinc_conf, "%s" SLASH "tinc.conf", confbase);
200 xasprintf(&hosts_dir, "%s" SLASH "hosts", confbase);
201 if(!access(tinc_conf, F_OK)) {
202 fprintf(stderr, "Configuration file %s already exists!\n", tinc_conf);
206 if(!check_id(name)) {
207 fprintf(stderr, "Invalid Name! Only a-z, A-Z, 0-9 and _ are allowed characters.\n");
211 if(!confbase_given && mkdir(confdir, 0755) && errno != EEXIST) {
212 fprintf(stderr, "Could not create directory %s: %s\n", confdir, strerror(errno));
216 if(mkdir(confbase, 0777) && errno != EEXIST) {
217 fprintf(stderr, "Could not create directory %s: %s\n", confbase, strerror(errno));
221 if(mkdir(hosts_dir, 0777) && errno != EEXIST) {
222 fprintf(stderr, "Could not create directory %s: %s\n", hosts_dir, strerror(errno));
226 FILE *f = fopen(tinc_conf, "w");
228 fprintf(stderr, "Could not create file %s: %s\n", tinc_conf, strerror(errno));
232 fprintf(f, "Name = %s\n", name);
235 if(!rsa_keygen(2048, false) || !ecdsa_keygen(false))
245 bool tinc_start(const char* path);
249 // can be called from any thread
250 bool tinc_send_packet(node_t *receiver, const char* buf, unsigned int len);
252 // handler runs in tinc thread and should return immediately
253 bool tinc_set_packet_receive_handler(void (*handler)(const char* sender, const char* buf, unsigned int len));
256 //It might also be a good idea to add the option of looking up hosts by public
257 //key (fingerprints) instead of names.
259 node_t *tinc_get_host(const char *name);
261 bool tinc_get_hosts(node_t** hosts);
263 bool tinc_sign(const char* payload, unsigned int len, const char** signature);
265 int tinc_verify(const char* sender, const char* payload, unsigned int plen, const char* signature, unsigned int slen);
268 TODO: It would be good to add a void pointer here that will be passed on to the
269 handler function whenever it is called, or have a void pointer in node_t
270 that can be filled in by the application. That way, you can easily link an
271 application-specific data structure to a node_t.
273 void channel_set_packet_send_handler(int (*handler)(const char* receiver, const char* buf, unsigned int len));
274 void channel_packet_receive_handler(const char* sender, const char* buf, unsigned int len);
276 bool channel_open(const char* partner, void(*read)(int id, const char* buf, unsigned int len), void(*result)(int result, int id));
277 void channel_close(int id);
278 bool channel_write(int id, const char* buf, unsigned int len, void(*result)(int result, int id, unsigned int written));
281 //We do need some more functions. First of all, we need to be able to add nodes
282 //to a VPN. To do that, either an invitation protocol should be used:
284 bool tinc_join_network(const char *invitation);
285 const char *tinc_generate_invitation(const char *name);
288 Or two nodes should exchange some information (their name, address, public
289 key). If the application provides a way to exchange some data with another
293 bool tinc_export(char *buf, size_t *len);
294 node_t *tinc_import(const char *buf, size_t len);
296 Last but not least, some way to get rid of unwanted nodes. Simplest is a
297 function that just blacklists a node.
298 Which should immediately cause the local tincd to ignore any data from that
299 host from that point on. Of course, a somewhat centrally managed,
300 automatically distributed blacklist or whitelist would be the next step.
302 bool tinc_blacklist(node_t *host);