]> git.meshlink.io Git - meshlink/blobdiff - src/meshlink.c
Have try_bind() reuse the setup_*_listen_socket() functions.
[meshlink] / src / meshlink.c
index 0354c86dc096d5036d6a2298c28dfd5cfbb4fd9e..9f3b6ecd2094a89c92e68c0e9e62537b55a04518 100644 (file)
@@ -221,12 +221,42 @@ char *meshlink_get_external_address(meshlink_handle_t *mesh) {
 }
 
 char *meshlink_get_external_address_for_family(meshlink_handle_t *mesh, int family) {
-       char *hostname = NULL;
+       const char *url = mesh->external_address_url;
+
+       if(!url) {
+               url = "http://meshlink.io/host.cgi";
+       }
+
+       /* Find the hostname part between the slashes */
+       if(strncmp(url, "http://", 7)) {
+               abort();
+               meshlink_errno = MESHLINK_EINTERNAL;
+               return NULL;
+       }
+
+       const char *begin = url + 7;
+
+       const char *end = strchr(begin, '/');
+
+       if(!end) {
+               end = begin + strlen(begin);
+       }
+
+       /* Make a copy */
+       char host[end - begin + 1];
+       strncpy(host, begin, end - begin);
+       host[end - begin] = 0;
+
+       char *port = strchr(host, ':');
+
+       if(port) {
+               *port++ = 0;
+       }
 
        logger(mesh, MESHLINK_DEBUG, "Trying to discover externally visible hostname...\n");
-       struct addrinfo *ai = str2addrinfo("meshlink.io", "80", SOCK_STREAM);
-       static const char request[] = "GET http://www.meshlink.io/host.cgi HTTP/1.0\r\n\r\n";
+       struct addrinfo *ai = str2addrinfo(host, port ? port : "80", SOCK_STREAM);
        char line[256];
+       char *hostname = NULL;
 
        for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
                if(family != AF_UNSPEC && aip->ai_family != family) {
@@ -245,7 +275,9 @@ char *meshlink_get_external_address_for_family(meshlink_handle_t *mesh, int fami
                }
 
                if(s >= 0) {
-                       send(s, request, sizeof(request) - 1, 0);
+                       send(s, "GET ", 4, 0);
+                       send(s, url, strlen(url), 0);
+                       send(s, " HTTP/1.0\r\n\r\n", 13, 0);
                        int len = recv(s, line, sizeof(line) - 1, MSG_WAITALL);
 
                        if(len > 0) {
@@ -389,10 +421,15 @@ void remove_duplicate_hostnames(char *host[], char *port[], int n) {
 
 // This gets the hostname part for use in invitation URLs
 static char *get_my_hostname(meshlink_handle_t *mesh, uint32_t flags) {
-       char *hostname[4] = {NULL};
-       char *port[4] = {NULL};
+       int count = 4 + (mesh->invitation_addresses ? mesh->invitation_addresses->count : 0);
+       int n = 0;
+       char *hostname[count];
+       char *port[count];
        char *hostport = NULL;
 
+       memset(hostname, 0, sizeof(hostname));
+       memset(port, 0, sizeof(port));
+
        if(!(flags & (MESHLINK_INVITE_LOCAL | MESHLINK_INVITE_PUBLIC))) {
                flags |= MESHLINK_INVITE_LOCAL | MESHLINK_INVITE_PUBLIC;
        }
@@ -401,44 +438,61 @@ static char *get_my_hostname(meshlink_handle_t *mesh, uint32_t flags) {
                flags |= MESHLINK_INVITE_IPV4 | MESHLINK_INVITE_IPV6;
        }
 
+       // Add all explicitly set invitation addresses
+       if(mesh->invitation_addresses) {
+               for list_each(char, combo, mesh->invitation_addresses) {
+                       hostname[n] = xstrdup(combo);
+                       char *slash = strrchr(hostname[n], '/');
+
+                       if(slash) {
+                               *slash = 0;
+                               port[n] = xstrdup(slash + 1);
+                       }
+
+                       n++;
+               }
+       }
+
        // Add local addresses if requested
        if(flags & MESHLINK_INVITE_LOCAL) {
                if(flags & MESHLINK_INVITE_IPV4) {
-                       hostname[0] = meshlink_get_local_address_for_family(mesh, AF_INET);
+                       hostname[n++] = meshlink_get_local_address_for_family(mesh, AF_INET);
                }
 
                if(flags & MESHLINK_INVITE_IPV6) {
-                       hostname[1] = meshlink_get_local_address_for_family(mesh, AF_INET6);
+                       hostname[n++] = meshlink_get_local_address_for_family(mesh, AF_INET6);
                }
        }
 
        // Add public/canonical addresses if requested
        if(flags & MESHLINK_INVITE_PUBLIC) {
                // Try the CanonicalAddress first
-               get_canonical_address(mesh->self, &hostname[2], &port[2]);
+               get_canonical_address(mesh->self, &hostname[n], &port[n]);
 
-               if(!hostname[2]) {
+               if(!hostname[n] && count == 4) {
                        if(flags & MESHLINK_INVITE_IPV4) {
-                               hostname[2] = meshlink_get_external_address_for_family(mesh, AF_INET);
+                               hostname[n++] = meshlink_get_external_address_for_family(mesh, AF_INET);
                        }
 
                        if(flags & MESHLINK_INVITE_IPV6) {
-                               hostname[3] = meshlink_get_external_address_for_family(mesh, AF_INET6);
+                               hostname[n++] = meshlink_get_external_address_for_family(mesh, AF_INET6);
                        }
+               } else {
+                       n++;
                }
        }
 
-       for(int i = 0; i < 4; i++) {
+       for(int i = 0; i < n; i++) {
                // Ensure we always have a port number
                if(hostname[i] && !port[i]) {
                        port[i] = xstrdup(mesh->myport);
                }
        }
 
-       remove_duplicate_hostnames(hostname, port, 4);
+       remove_duplicate_hostnames(hostname, port, n);
 
        // Resolve the hostnames
-       for(int i = 0; i < 4; i++) {
+       for(int i = 0; i < n; i++) {
                if(!hostname[i]) {
                        continue;
                }
@@ -456,8 +510,10 @@ static char *get_my_hostname(meshlink_handle_t *mesh, uint32_t flags) {
                        continue;
                }
 
-               // Remember the address
-               node_add_recent_address(mesh, mesh->self, (sockaddr_t *)ai_in->ai_addr);
+               // Remember the address(es)
+               for(struct addrinfo *aip = ai_in; aip; aip = aip->ai_next) {
+                       node_add_recent_address(mesh, mesh->self, (sockaddr_t *)aip->ai_addr);
+               }
 
                if(flags & MESHLINK_INVITE_NUMERIC) {
                        // We don't need to do any further conversion
@@ -500,10 +556,10 @@ static char *get_my_hostname(meshlink_handle_t *mesh, uint32_t flags) {
        }
 
        // Remove duplicates again, since IPv4 and IPv6 addresses might map to the same hostname
-       remove_duplicate_hostnames(hostname, port, 4);
+       remove_duplicate_hostnames(hostname, port, n);
 
        // Concatenate all unique address to the hostport string
-       for(int i = 0; i < 4; i++) {
+       for(int i = 0; i < n; i++) {
                if(!hostname[i]) {
                        continue;
                }
@@ -521,7 +577,7 @@ static char *get_my_hostname(meshlink_handle_t *mesh, uint32_t flags) {
        return hostport;
 }
 
-static bool try_bind(int port) {
+static bool try_bind(meshlink_handle_t *mesh, int port) {
        struct addrinfo *ai = NULL;
        struct addrinfo hint = {
                .ai_flags = AI_PASSIVE,
@@ -537,33 +593,47 @@ static bool try_bind(int port) {
                return false;
        }
 
-       //while(ai) {
+       bool success = false;
+
        for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
-               int fd = socket(aip->ai_family, SOCK_STREAM, IPPROTO_TCP);
+               /* Try to bind to TCP. */
 
-               if(!fd) {
-                       freeaddrinfo(ai);
-                       return false;
+               int tcp_fd = setup_tcp_listen_socket(mesh, aip);
+
+               if(tcp_fd == -1) {
+                       if(errno == EADDRINUSE) {
+                               /* If this port is in use for any address family, avoid it. */
+                               success = false;
+                               break;
+                       } else {
+                               continue;
+                       }
                }
 
-               int result = bind(fd, aip->ai_addr, aip->ai_addrlen);
-               closesocket(fd);
+               /* If TCP worked, then we require that UDP works as well. */
 
-               if(result) {
-                       freeaddrinfo(ai);
-                       return false;
+               int udp_fd = setup_udp_listen_socket(mesh, aip);
+
+               if(udp_fd == -1) {
+                       closesocket(tcp_fd);
+                       success = false;
+                       break;
                }
+
+               closesocket(tcp_fd);
+               closesocket(udp_fd);
+               success = true;
        }
 
        freeaddrinfo(ai);
-       return true;
+       return success;
 }
 
-static int check_port(meshlink_handle_t *mesh) {
+int check_port(meshlink_handle_t *mesh) {
        for(int i = 0; i < 1000; i++) {
                int port = 0x1000 + prng(mesh, 0x8000);
 
-               if(try_bind(port)) {
+               if(try_bind(mesh, port)) {
                        free(mesh->myport);
                        xasprintf(&mesh->myport, "%d", port);
                        return port;
@@ -1558,9 +1628,6 @@ static void *meshlink_main_loop(void *arg) {
 }
 
 bool meshlink_start(meshlink_handle_t *mesh) {
-       assert(mesh->self);
-       assert(mesh->private_key);
-
        if(!mesh) {
                meshlink_errno = MESHLINK_EINVAL;
                return false;
@@ -1570,6 +1637,8 @@ bool meshlink_start(meshlink_handle_t *mesh) {
 
        pthread_mutex_lock(&mesh->mutex);
 
+       assert(mesh->self);
+       assert(mesh->private_key);
        assert(mesh->self->ecdsa);
        assert(!memcmp((uint8_t *)mesh->self->ecdsa + 64, (uint8_t *)mesh->private_key + 64, 32));
 
@@ -1729,8 +1798,13 @@ void meshlink_close(meshlink_handle_t *mesh) {
        free(mesh->appname);
        free(mesh->confbase);
        free(mesh->config_key);
+       free(mesh->external_address_url);
        ecdsa_free(mesh->private_key);
 
+       if(mesh->invitation_addresses) {
+               list_delete_list(mesh->invitation_addresses);
+       }
+
        main_config_unlock(mesh);
 
        pthread_mutex_unlock(&mesh->mutex);
@@ -2362,6 +2436,60 @@ bool meshlink_set_canonical_address(meshlink_handle_t *mesh, meshlink_node_t *no
        return config_sync(mesh, "current");
 }
 
+bool meshlink_add_invitation_address(struct meshlink_handle *mesh, const char *address, const char *port) {
+       if(!mesh || !address) {
+               meshlink_errno = MESHLINK_EINVAL;
+               return false;
+       }
+
+       if(!is_valid_hostname(address)) {
+               logger(mesh, MESHLINK_DEBUG, "Invalid character in address: %s\n", address);
+               meshlink_errno = MESHLINK_EINVAL;
+               return false;
+       }
+
+       if(port && !is_valid_port(port)) {
+               logger(mesh, MESHLINK_DEBUG, "Invalid character in port: %s\n", address);
+               meshlink_errno = MESHLINK_EINVAL;
+               return false;
+       }
+
+       char *combo;
+
+       if(port) {
+               xasprintf(&combo, "%s/%s", address, port);
+       } else {
+               combo = xstrdup(address);
+       }
+
+       pthread_mutex_lock(&mesh->mutex);
+
+       if(!mesh->invitation_addresses) {
+               mesh->invitation_addresses = list_alloc((list_action_t)free);
+       }
+
+       list_insert_tail(mesh->invitation_addresses, combo);
+       pthread_mutex_unlock(&mesh->mutex);
+
+       return true;
+}
+
+void meshlink_clear_invitation_addresses(struct meshlink_handle *mesh) {
+       if(!mesh) {
+               meshlink_errno = MESHLINK_EINVAL;
+               return;
+       }
+
+       pthread_mutex_lock(&mesh->mutex);
+
+       if(mesh->invitation_addresses) {
+               list_delete_list(mesh->invitation_addresses);
+               mesh->invitation_addresses = NULL;
+       }
+
+       pthread_mutex_unlock(&mesh->mutex);
+}
+
 bool meshlink_add_address(meshlink_handle_t *mesh, const char *address) {
        return meshlink_set_canonical_address(mesh, (meshlink_node_t *)mesh->self, address, NULL);
 }
@@ -2378,7 +2506,7 @@ bool meshlink_add_external_address(meshlink_handle_t *mesh) {
                return false;
        }
 
-       bool rval = meshlink_add_address(mesh, address);
+       bool rval = meshlink_set_canonical_address(mesh, (meshlink_node_t *)mesh->self, address, NULL);
        free(address);
 
        return rval;
@@ -2414,7 +2542,7 @@ bool meshlink_set_port(meshlink_handle_t *mesh, int port) {
                return true;
        }
 
-       if(!try_bind(port)) {
+       if(!try_bind(mesh, port)) {
                meshlink_errno = MESHLINK_ENETWORK;
                return false;
        }
@@ -2744,6 +2872,8 @@ bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
                                        state.sock = -1;
                                        continue;
                                }
+
+                               break;
                        }
 
                        freeaddrinfo(ai);
@@ -3959,6 +4089,23 @@ extern void meshlink_set_inviter_commits_first(struct meshlink_handle *mesh, boo
        pthread_mutex_unlock(&mesh->mutex);
 }
 
+void meshlink_set_external_address_discovery_url(struct meshlink_handle *mesh, const char *url) {
+       if(!mesh) {
+               meshlink_errno = EINVAL;
+               return;
+       }
+
+       if(url && (strncmp(url, "http://", 7) || strchr(url, ' '))) {
+               meshlink_errno = EINVAL;
+               return;
+       }
+
+       pthread_mutex_lock(&mesh->mutex);
+       free(mesh->external_address_url);
+       mesh->external_address_url = url ? xstrdup(url) : NULL;
+       pthread_mutex_unlock(&mesh->mutex);
+}
+
 void handle_network_change(meshlink_handle_t *mesh, bool online) {
        (void)online;