1 files changed, 361 insertions, 0 deletions
diff --git a/modules/avahi/avahi.c b/modules/avahi/avahi.c
new file mode 100644
index 0000000..9bf4a8c
--- /dev/null
+++ b/modules/avahi/avahi.c
@@ -0,0 +1,361 @@
+/**
+ * @file avahi.c Avahi Zeroconf Module
+ *
+ * Copyright (C) 2010 Creytiv.com
+ * Copyright (C) 2017 Jonathan Sieber
+ */
+
+/**
+ * @defgroup avahi avahi
+ *
+ * This module implements DNS Service Discovery via Avahi Client API
+ * It does 2 things:
+ * 1) Announce _sipuri._udp resource for the main UA (under the local IP)
+ * 2) Fills contact list with discovered hosts
+ *
+ * NOTE: This module is experimental.
+ *
+ */
+
+#include <re.h>
+#include <baresip.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <avahi-common/simple-watch.h>
+#include <avahi-client/lookup.h>
+#include <avahi-client/publish.h>
+#include <avahi-common/error.h>
+
+/* for if_nametoindex */
+#include <net/if.h>
+
+/* gethostname, getaddrinfo */
+#define __USE_XOPEN2K
+#include <unistd.h>
+#include <netdb.h>
+
+
+struct avahi_st {
+	AvahiSimplePoll* poll;
+	AvahiClient* client;
+	AvahiEntryGroup* group;
+	AvahiServiceBrowser* browser;
+	struct ua* local_ua;
+	struct tmr poll_timer;
+};
+
+static struct avahi_st* avahi = NULL;
+
+static void group_callback(AvahiEntryGroup* group,
+	AvahiEntryGroupState state, void* userdata)
+{
+	switch (state) {
+	case AVAHI_ENTRY_GROUP_ESTABLISHED:
+		info ("avahi: Service Registration completed\n");
+		break;
+	case AVAHI_ENTRY_GROUP_FAILURE:
+	case AVAHI_ENTRY_GROUP_COLLISION:
+		warning("avahi: Service Registration failed\n");
+		/* TODO: Think of smart way to handle collision? */
+		break;
+	case AVAHI_ENTRY_GROUP_UNCOMMITED:
+	case AVAHI_ENTRY_GROUP_REGISTERING:
+		/* Do nothing */
+		break;
+	}
+}
+
+static void create_services(AvahiClient* client)
+{
+	int err;
+	char buf[128] = "";
+	char hostname[128] = "";
+
+	int if_idx = AVAHI_IF_UNSPEC;
+	int af = AVAHI_PROTO_INET;
+
+	struct sa laddr;
+
+	/* Build announced sipuri as username@hostname */
+	strncpy(hostname, avahi_client_get_host_name_fqdn(client),
+		sizeof (hostname));
+	re_snprintf(buf, sizeof(buf), "<sip:%s@%s>;regint=0",
+				sys_username(),
+				hostname);
+
+	info("avahi: Creating local UA %s\n", buf);
+	err = ua_alloc(&avahi->local_ua, buf);
+
+	if (err) {
+		warning("avahi: Could not create UA %s: %m\n", buf, err);
+		return;
+	}
+
+	re_snprintf(buf, sizeof(buf), "sip:%s@%s",
+				sys_username(),
+				hostname);
+
+	debug("avahi: Announcing URI: %s\n", buf);
+
+	/* Get interface number of baresip interface */
+	if (str_isset(conf_config()->net.ifname)) {
+		if_idx = if_nametoindex(conf_config()->net.ifname);
+	}
+
+	if (net_af(baresip_network()) == AF_INET6) {
+		af = AVAHI_PROTO_INET6;
+	}
+
+	err |= sip_transp_laddr(uag_sip(), &laddr, SIP_TRANSP_UDP, 0);
+	if (err) {
+		warning("avahi: Can not find local SIP address\n");
+	}
+
+	/* TODO: Query enabled transports and register these */
+	avahi->group = avahi_entry_group_new(client, group_callback, NULL);
+	err = avahi_entry_group_add_service(avahi->group,
+		if_idx, af, 0,
+		buf, "_sipuri._udp",
+		NULL, NULL,
+		ntohs(laddr.u.in.sin_port), NULL);
+	err |= avahi_entry_group_commit(avahi->group);
+
+	if (err) {
+		warning("avahi: Error in registering service");
+	}
+}
+
+static void client_callback(AvahiClient *c, AvahiClientState state,
+	AVAHI_GCC_UNUSED void * userdata)
+{
+	switch (state) {
+	case AVAHI_CLIENT_S_RUNNING:
+		info("avahi: Avahi Daemon running\n", state);
+		break;
+	default:
+		warning("avahi: unknown client_callback: %d\n", state);
+		break;
+	}
+}
+
+static void add_contact(const char* uri,
+	const AvahiAddress *address, uint16_t port)
+{
+	int err;
+	struct pl addr;
+	char buf[128];
+	struct contact *c;
+	struct sa sa;
+	struct sip_addr sipaddr;
+
+	/* Parse SIPURI to get username and stuff... */
+	pl_set_str(&addr, uri);
+	if (sip_addr_decode(&sipaddr, &addr)) {
+		warning("avahi: could not decode sipuri %s\n", uri);
+		return;
+	}
+
+	if (address->proto == AVAHI_PROTO_INET6) {;
+		sa_set_in6(&sa, address->data.ipv6.address, port);
+	}
+	else {
+		sa_set_in(&sa, htonl(address->data.ipv4.address), port);
+	}
+
+	re_snprintf(buf, sizeof(buf),
+		"\"%r@%r\" <sip:%r@%J>;presence=p2p",
+		&sipaddr.uri.user, &sipaddr.uri.host,
+		&sipaddr.uri.user, &sa);
+	pl_set_str(&addr, buf);
+
+	err = contact_add(baresip_contacts(), &c, &addr);
+	if (err) {
+		warning("Could not add contact %s: %m\n", buf, err);
+	}
+}
+
+static void remove_contact_by_dname(const char* dname)
+{
+	const struct list *lst;
+	struct le *le;
+
+	/* remove sip: scheme for comparison */
+	if (0 != re_regex(dname, str_len(dname), "^sip:")) {
+		dname += 4;
+	}
+
+	lst = contact_list(baresip_contacts());
+
+	for (le = list_head(lst); le; le = le->next) {
+		struct contact *c = le->data;
+		const struct sip_addr* addr = contact_addr(c);
+
+		if (pl_strcmp(&addr->dname, dname) == 0) {
+			contact_remove(baresip_contacts(), c);
+			return;
+		}
+	}
+
+	warning("avahi: Could not remove contact %s\n", dname);
+}
+
+static void resolve_callback(
+	AvahiServiceResolver *r,
+	AvahiIfIndex interface,
+	AvahiProtocol protocol,
+	AvahiResolverEvent event,
+	const char *name,
+	const char *type,
+	const char *domain,
+	const char *hostname,
+	const AvahiAddress *address,
+	uint16_t port,
+	AvahiStringList *txt,
+	AvahiLookupResultFlags flags,
+	void *userdata)
+{
+	info("avahi: resolve %s %s %s %s\n", name, type, domain, hostname);
+
+	if (event == AVAHI_RESOLVER_FOUND) {
+		if (protocol != address->proto) {
+			warning("avahi: Resolved address type ambiguous\n");
+		}
+
+		/* TODO: Process TXT field */
+		if (!(flags & AVAHI_LOOKUP_RESULT_OUR_OWN)) {
+			add_contact(name, address, port);
+		}
+	}
+	else {
+		warning("avahi: Resolver Error on %s: %s\n", name,
+			avahi_strerror(avahi_client_errno(avahi->client)));
+	}
+}
+
+
+static void browse_callback(
+	AvahiServiceBrowser *b,
+	AvahiIfIndex interface,
+	AvahiProtocol protocol,
+	AvahiBrowserEvent event,
+	const char *name,
+	const char *type,
+	const char *domain,
+	AVAHI_GCC_UNUSED AvahiLookupResultFlags flags,
+	void* userdata)
+{
+
+	int proto = AVAHI_PROTO_INET;
+
+	switch (event) {
+	case AVAHI_BROWSER_NEW:
+		debug("avahi: browse_callback if=%d proto=%d %s\n",
+			interface, protocol, name);
+		if (net_af(baresip_network()) == AF_INET6) {
+			proto = AVAHI_PROTO_INET6;
+		}
+
+		if (!(avahi_service_resolver_new(avahi->client,
+				interface, protocol,
+				name, type, domain,
+				proto, 0, resolve_callback,
+				avahi->client))) {
+			warning("avahi: Error resolving %s\n", name);
+		}
+	break;
+
+	case AVAHI_BROWSER_REMOVE:
+		remove_contact_by_dname(name);
+		break;
+	case AVAHI_BROWSER_ALL_FOR_NOW:
+	case AVAHI_BROWSER_CACHE_EXHAUSTED:
+		debug("avahi: (Browser) %s\n",
+			event == AVAHI_BROWSER_CACHE_EXHAUSTED ?
+			"CACHE_EXHAUSTED" : "ALL_FOR_NOW");
+		break;
+	default:
+		warning("avahi: browse_callback %d %s\n", event, name);
+		break;
+	}
+}
+
+static void avahi_update(void* arg)
+{
+	avahi_simple_poll_iterate(avahi->poll, 0);
+	tmr_start(&avahi->poll_timer, 250, avahi_update, 0);
+}
+
+static void destructor(void* arg)
+{
+	struct avahi_st* a = arg;
+
+	tmr_cancel(&a->poll_timer);
+
+	mem_deref(a->local_ua);
+
+	/* Calling these destructor commands would be correct, but they
+	 * spew out a lot of ugly D-Bus warning */
+	if (a->browser) {
+		avahi_service_browser_free(avahi->browser);
+	}
+
+	if (a->group) {
+		avahi_entry_group_free(avahi->group);
+	}
+
+	if (a->client) {
+		avahi_client_free(avahi->client);
+	}
+}
+
+static int module_init(void)
+{
+	int err;
+	avahi = mem_zalloc(sizeof(struct avahi_st), destructor);
+	if (!avahi) {
+		return ENOMEM;
+	}
+
+	avahi->poll = avahi_simple_poll_new();
+	avahi->client = avahi_client_new(
+		avahi_simple_poll_get(avahi->poll),
+		0, client_callback, NULL, &err);
+
+	/* Check wether creating the client object succeeded */
+	if (!avahi->client) {
+		warning("Failed to create client: %s\n", avahi_strerror(err));
+		return err;
+	}
+
+	avahi->browser = avahi_service_browser_new(avahi->client,
+		AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, "_sipuri._udp", NULL,
+		0, browse_callback, 0);
+
+	tmr_init(&avahi->poll_timer);
+	avahi_update(0);
+
+	/* Register services when UA is ready */
+	if (!avahi->group) {
+		create_services(avahi->client);
+	}
+
+	return 0;
+}
+
+static int module_close(void)
+{
+	debug("avahi: module_close\n");
+
+	avahi = mem_deref(avahi);
+
+	return 0;
+}
+
+const struct mod_export DECL_EXPORTS(avahi) = {
+	"avahi",
+	"application",
+	module_init,
+	module_close
+};