return meshlink_get_external_address_for_family(handle, family);
}
+ /** This function performs tries to discover the address of the local interface used for outgoing connection.
+ *
+ * Please note that this is function only returns a single address,
+ * even if the local node might have more than one external address.
+ * In that case, there is no control over which address will be selected.
+ * Also note that if you have a dynamic IP address, or are behind carrier-grade NAT,
+ * there is no guarantee that the external address will be valid for an extended period of time.
+ *
+ * This function will fail if it couldn't find a local address for the given address family.
+ * If hostname resolving is requested, this function may block for a few seconds.
+ *
+ * @param family The address family to check, for example AF_INET or AF_INET6. If AF_UNSPEC is given,
+ * this might return the external address for any working address family.
+ *
+ * @return This function returns a pointer to a C string containing the discovered external address,
+ * or NULL if there was an error looking up the address.
+ * After get_external_address() returns, the application is free to overwrite or free this string.
+ */
+ bool get_local_address(int family = AF_UNSPEC) {
+ return meshlink_get_local_address_for_family(handle, family);
+ }
+
/// Try to discover the external address for the local node, and add it to its list of addresses.
/** This function is equivalent to:
*
* The URL can only be used once, after the user has joined the mesh the URL is no longer valid.
*
* @param name The name that the invitee will use in the mesh.
+ * @param flags A bitwise-or'd combination of flags that controls how the URL is generated.
*
* @return This function returns a string that contains the invitation URL.
* The application should call free() after it has finished using the URL.
*/
- char *invite(const char *name) {
- return meshlink_invite(handle, name);
+ char *invite(const char *name, uint32_t flags = 0) {
+ return meshlink_invite_ex(handle, name, flags);
}
/// Use an invitation to join a mesh.
return len;
}
-static void scan_for_hostname(const char *filename, char **hostname, char **port) {
+static void scan_for_canonical_address(const char *filename, char **hostname, char **port) {
char line[4096];
- bool canonical = false;
if(!filename || (*hostname && *port)) {
return;
if(!*port && !strcasecmp(line, "Port")) {
*port = xstrdup(q);
- } else if(!canonical && !*hostname && !strcasecmp(line, "Address")) {
- // Check that the hostname is a symbolic name (it's not a numeric IPv4 or IPv6 address)
- if(!q[strspn(q, "0123456789.")] || strchr(q, ':')) {
- continue;
- }
-
- *hostname = xstrdup(q);
-
- if(*p) {
- free(*port);
- *port = xstrdup(p);
- }
} else if(!strcasecmp(line, "CanonicalAddress")) {
*hostname = xstrdup(q);
- canonical = true;
if(*p) {
free(*port);
}
}
- if(canonical && *hostname && *port) {
+ if(*hostname && *port) {
break;
}
}
hostname = NULL;
}
- // If there is no hostname, determine the address used for an outgoing connection.
if(!hostname) {
- char localaddr[NI_MAXHOST];
- bool success = false;
+ meshlink_errno = MESHLINK_ERESOLV;
+ }
- if(family == AF_INET) {
- success = getlocaladdrname("93.184.216.34", localaddr, sizeof(localaddr));
- } else if(family == AF_INET6) {
- success = getlocaladdrname("2606:2800:220:1:248:1893:25c8:1946", localaddr, sizeof(localaddr));
- }
+ return hostname;
+}
- if(success) {
- hostname = xstrdup(localaddr);
- }
+char *meshlink_get_local_address_for_family(meshlink_handle_t *mesh, int family) {
+ (void)mesh;
+
+ // Determine address of the local interface used for outgoing connections.
+ char localaddr[NI_MAXHOST];
+ bool success = false;
+
+ if(family == AF_INET) {
+ success = getlocaladdrname("93.184.216.34", localaddr, sizeof(localaddr));
+ } else if(family == AF_INET6) {
+ success = getlocaladdrname("2606:2800:220:1:248:1893:25c8:1946", localaddr, sizeof(localaddr));
}
- if(!hostname) {
- meshlink_errno = MESHLINK_ERESOLV;
+ if(!success) {
+ meshlink_errno = MESHLINK_ENETWORK;
+ return NULL;
}
- return hostname;
+ return xstrdup(localaddr);
}
-// String comparison which handles NULL arguments
-static bool safe_streq(const char *a, const char *b) {
- if(!a || !b) {
- return a == b;
- } else {
- return !strcmp(a, b);
+void remove_duplicate_hostnames(char *host[], char *port[], int n) {
+ for(int i = 0; i < n; i++) {
+ if(!host[i]) {
+ continue;
+ }
+
+ // Ignore duplicate hostnames
+ bool found = false;
+
+ for(int j = 0; j < i; j++) {
+ if(!host[j]) {
+ continue;
+ }
+
+ if(strcmp(host[i], host[j])) {
+ continue;
+ }
+
+ if(strcmp(port[i], port[j])) {
+ continue;
+ }
+
+ found = true;
+ break;
+ }
+
+ if(found) {
+ free(host[i]);
+ free(port[i]);
+ host[i] = NULL;
+ port[i] = NULL;
+ continue;
+ }
}
}
// This gets the hostname part for use in invitation URLs
-static char *get_my_hostname(meshlink_handle_t *mesh) {
- char *hostname[3] = {NULL};
- char *port[3] = {NULL};
+static char *get_my_hostname(meshlink_handle_t *mesh, uint32_t flags) {
+ char *hostname[4] = {NULL};
+ char *port[4] = {NULL};
char *hostport = NULL;
- // Use the best Address statement in our own host config file
- char filename[PATH_MAX] = "";
- snprintf(filename, sizeof(filename), "%s" SLASH "hosts" SLASH "%s", mesh->confbase, mesh->self->name);
- scan_for_hostname(filename, &hostname[0], &port[0]);
+ if(!(flags & (MESHLINK_INVITE_LOCAL | MESHLINK_INVITE_PUBLIC))) {
+ flags |= MESHLINK_INVITE_LOCAL | MESHLINK_INVITE_PUBLIC;
+ }
- hostname[1] = meshlink_get_external_address_for_family(mesh, AF_INET);
- hostname[2] = meshlink_get_external_address_for_family(mesh, AF_INET6);
+ if(!(flags & (MESHLINK_INVITE_IPV4 | MESHLINK_INVITE_IPV6))) {
+ flags |= MESHLINK_INVITE_IPV4 | MESHLINK_INVITE_IPV6;
+ }
- // Concatenate all unique address to the hostport string
- for(int i = 0; i < 3; i++) {
- if(!hostname[i]) {
- continue;
+ fprintf(stderr, "flags = %u\n", flags);
+
+ // 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);
}
- // Ignore duplicate hostnames
- bool found = false;
+ if(flags & MESHLINK_INVITE_IPV6) {
+ hostname[1] = meshlink_get_local_address_for_family(mesh, AF_INET6);
+ }
+ }
- for(int j = 0; i < j; j++) {
- if(safe_streq(hostname[i], hostname[j]) && safe_streq(port[i], port[j])) {
- found = true;
- break;
+ // Add public/canonical addresses if requested
+ if(flags & MESHLINK_INVITE_PUBLIC) {
+ // Try the CanonicalAddress first
+ char filename[PATH_MAX] = "";
+ snprintf(filename, sizeof(filename), "%s" SLASH "hosts" SLASH "%s", mesh->confbase, mesh->self->name);
+ scan_for_canonical_address(filename, &hostname[2], &port[2]);
+
+ if(!hostname[2]) {
+ if(flags & MESHLINK_INVITE_IPV4) {
+ hostname[2] = 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);
}
}
+ }
- if(found) {
+ for(int i = 0; i < 4; i++) {
+ // Ensure we always have a port number
+ if(hostname[i] && !port[i]) {
+ port[i] = xstrdup(mesh->myport);
+ }
+ }
+
+ remove_duplicate_hostnames(hostname, port, 4);
+
+ if(!(flags & MESHLINK_INVITE_NUMERIC)) {
+ for(int i = 0; i < 4; i++) {
+ if(!hostname[i]) {
+ continue;
+ }
+
+ // Convert what we have to a sockaddr
+ struct addrinfo *ai_in, *ai_out;
+ struct addrinfo hint = {
+ .ai_family = AF_UNSPEC,
+ .ai_flags = AI_NUMERICSERV,
+ .ai_socktype = SOCK_STREAM,
+ };
+ int err = getaddrinfo(hostname[i], port[i], &hint, &ai_in);
+
+ if(err || !ai_in) {
+ continue;
+ }
+
+ // Convert it to a hostname
+ char resolved_host[NI_MAXHOST];
+ char resolved_port[NI_MAXSERV];
+ err = getnameinfo(ai_in->ai_addr, ai_in->ai_addrlen, resolved_host, sizeof resolved_host, resolved_port, sizeof resolved_port, NI_NUMERICSERV);
+
+ if(err) {
+ freeaddrinfo(ai_in);
+ continue;
+ }
+
+ // Convert the hostname back to a sockaddr
+ hint.ai_family = ai_in->ai_family;
+ err = getaddrinfo(resolved_host, resolved_port, &hint, &ai_out);
+
+ if(err || !ai_out) {
+ freeaddrinfo(ai_in);
+ continue;
+ }
+
+ // Check if it's still the same sockaddr
+ if(ai_in->ai_addrlen != ai_out->ai_addrlen || memcmp(ai_in->ai_addr, ai_out->ai_addr, ai_in->ai_addrlen)) {
+ freeaddrinfo(ai_in);
+ freeaddrinfo(ai_out);
+ continue;
+ }
+
+ // Yes: replace the hostname with the resolved one
free(hostname[i]);
- free(port[i]);
- hostname[i] = NULL;
- port[i] = NULL;
+ hostname[i] = xstrdup(resolved_host);
+
+ freeaddrinfo(ai_in);
+ freeaddrinfo(ai_out);
+ }
+ }
+
+ // Remove duplicates again, since IPv4 and IPv6 addresses might map to the same hostname
+ remove_duplicate_hostnames(hostname, port, 4);
+
+ // Concatenate all unique address to the hostport string
+ for(int i = 0; i < 4; i++) {
+ if(!hostname[i]) {
continue;
}
// Ensure we have the same addresses in our own host config file.
char *tmphostport;
- xasprintf(&tmphostport, "%s %s", hostname[i], port[i] ? port[i] : mesh->myport);
+ xasprintf(&tmphostport, "%s %s", hostname[i], port[i]);
append_config_file(mesh, mesh->self->name, "Address", tmphostport);
free(tmphostport);
// Append the address to the hostport string
char *newhostport;
- xasprintf(&newhostport, (strchr(hostname[i], ':') ? "%s%s[%s]:%s" : "%s%s%s:%s"), hostport ? hostport : "", hostport ? "," : "", hostname[i], port[i] ? port[i] : mesh->myport);
- free(hostname[i]);
- free(port[i]);
+ xasprintf(&newhostport, (strchr(hostname[i], ':') ? "%s%s[%s]:%s" : "%s%s%s:%s"), hostport ? hostport : "", hostport ? "," : "", hostname[i], port[i]);
free(hostport);
hostport = newhostport;
+
+ free(hostname[i]);
+ free(port[i]);
}
return hostport;
mesh->invitation_timeout = timeout;
}
-char *meshlink_invite(meshlink_handle_t *mesh, const char *name) {
+char *meshlink_invite_ex(meshlink_handle_t *mesh, const char *name, uint32_t flags) {
if(!mesh) {
meshlink_errno = MESHLINK_EINVAL;
return NULL;
}
// Get the local address
- char *address = get_my_hostname(mesh);
+ char *address = get_my_hostname(mesh, flags);
if(!address) {
logger(mesh, MESHLINK_DEBUG, "No Address known for ourselves!\n");
return url;
}
+char *meshlink_invite(meshlink_handle_t *mesh, const char *name) {
+ return meshlink_invite_ex(mesh, name, 0);
+}
+
bool meshlink_join(meshlink_handle_t *mesh, const char *invitation) {
if(!mesh || !invitation) {
meshlink_errno = MESHLINK_EINVAL;
_DEV_CLASS_MAX = 3
} dev_class_t;
+/// Invitation flags
+static const uint32_t MESHLINK_INVITE_LOCAL = 1; // Only use local addresses in the URL
+static const uint32_t MESHLINK_INVITE_PUBLIC = 2; // Only use public or canonical addresses in the URL
+static const uint32_t MESHLINK_INVITE_IPV4 = 4; // Only use IPv4 addresses in the URL
+static const uint32_t MESHLINK_INVITE_IPV6 = 8; // Only use IPv6 addresses in the URL
+static const uint32_t MESHLINK_INVITE_NUMERIC = 16; // Don't look up hostnames
+
/// Channel flags
static const uint32_t MESHLINK_CHANNEL_RELIABLE = 1; // Data is retransmitted when packets are lost.
static const uint32_t MESHLINK_CHANNEL_ORDERED = 2; // Data is delivered in-order to the application.
*
* @return This function returns a pointer to a C string containing the discovered external address,
* or NULL if there was an error looking up the address.
- * After meshlink_get_external_address() returns, the application is free to overwrite or free this string.
+ * After meshlink_get_external_address_for_family() returns, the application is free to overwrite or free this string.
*/
extern char *meshlink_get_external_address_for_family(meshlink_handle_t *mesh, int address_family);
+/// Try to discover the local address for the local node.
+/** This function performs tries to discover the address of the local interface used for outgoing connection.
+ *
+ * Please note that this is function only returns a single address,
+ * even if the interface might have more than one address.
+ * In that case, there is no control over which address will be selected.
+ * Also note that if you have a dynamic IP address,
+ * there is no guarantee that the local address will be valid for an extended period of time.
+ *
+ * This function will fail if it couldn't find a local address for the given address family.
+ * If hostname resolving is requested, this function may block for a few seconds.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param family The address family to check, for example AF_INET or AF_INET6. If AF_UNSPEC is given,
+ * this might return the local address for any working address family.
+ *
+ * @return This function returns a pointer to a C string containing the discovered local address,
+ * or NULL if there was an error looking up the address.
+ * After meshlink_get_local_address_for_family() returns, the application is free to overwrite or free this string.
+ */
+extern char *meshlink_get_local_address_for_family(meshlink_handle_t *mesh, int address_family);
+
/// Try to discover the external address for the local node, and add it to its list of addresses.
/** This function is equivalent to:
*
* @param mesh A handle which represents an instance of MeshLink.
* @param name A nul-terminated C string containing the name that the invitee will be allowed to use in the mesh.
* After this function returns, the application is free to overwrite or free @a name @a.
+ * @param flags A bitwise-or'd combination of flags that controls how the URL is generated.
+ *
+ * @return This function returns a nul-terminated C string that contains the invitation URL, or NULL in case of an error.
+ * The application should call free() after it has finished using the URL.
+ */
+extern char *meshlink_invite_ex(meshlink_handle_t *mesh, const char *name, uint32_t flags);
+
+/// Invite another node into the mesh.
+/** This function generates an invitation that can be used by another node to join the same mesh as the local node.
+ * The generated invitation is a string containing a URL.
+ * This URL should be passed by the application to the invitee in a way that no eavesdroppers can see the URL.
+ * The URL can only be used once, after the user has joined the mesh the URL is no longer valid.
+ *
+ * Calling this function is equal to callen meshlink_invite_ex() with flags set to 0.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param name A nul-terminated C string containing the name that the invitee will be allowed to use in the mesh.
+ * After this function returns, the application is free to overwrite or free @a name @a.
*
* @return This function returns a nul-terminated C string that contains the invitation URL, or NULL in case of an error.
* The application should call free() after it has finished using the URL.
* When the application does no longer need to use this channel, it must call meshlink_close()
* to free its resources.
*
+ * Calling this function is equivalent to calling meshlink_channel_open_ex()
+ * with the flags set to MESHLINK_CHANNEL_TCP.
+ *
* @param mesh A handle which represents an instance of MeshLink.
* @param node The node to which this channel is being initiated.
* @param port The port number the peer wishes to connect to.
projects / meshlink / commitdiff