- some experimental mdns bits

1 files changed, 187 insertions, 0 deletions

diff --git a/mdns.c b/mdns.c
new file mode 100644
index 0000000..19e44ca
--- /dev/null
+++ b/mdns.c
@@ -0,0 +1,187 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+#include <glib.h>
+
+#include <avahi-client/client.h>
+#include <avahi-client/lookup.h>
+#include <avahi-common/error.h>
+#include <avahi-common/timeval.h>
+#include <avahi-glib/glib-watch.h>
+#include <avahi-glib/glib-malloc.h>
+
+#include "list.h"
+#include "mdns.h"
+
+/* ---------------------------------------------------------------------- */
+
+static const char *revents[] = {
+    [ AVAHI_RESOLVER_FOUND ]          = "FOUND",
+    [ AVAHI_RESOLVER_FAILURE ]        = "FAILURE",
+};
+static const char *bevents[] = {
+    [ AVAHI_BROWSER_NEW ]             = "NEW",
+    [ AVAHI_BROWSER_REMOVE ]          = "REMOVE",
+    [ AVAHI_BROWSER_CACHE_EXHAUSTED ] = "CACHE_EXHAUSTED",
+    [ AVAHI_BROWSER_ALL_FOR_NOW ]     = "ALL_FOR_NOW",
+    [ AVAHI_BROWSER_FAILURE ]         = "FAILURE",
+};
+
+static const AvahiPoll *poll_api;
+static AvahiGLibPoll *glib_poll;
+static AvahiClient *client;
+
+struct mdns_entry {
+    const char         *name;
+    const char         *type;
+    const char         *domain;
+    AvahiIfIndex       interface;
+    AvahiProtocol      protocol;
+
+    const char         *address;
+    const char         *hostname;
+    uint16_t           port;
+	
+    struct list_head   next;
+};
+static LIST_HEAD(mdns_entries);
+
+/* ---------------------------------------------------------------------- */
+
+static void resolve_callback(AvahiServiceResolver *r,
+			     AvahiIfIndex interface,
+			     AvahiProtocol protocol,
+			     AvahiResolverEvent event,
+			     const char *name,
+			     const char *type,
+			     const char *domain,
+			     const char *host_name,
+			     const AvahiAddress *address,
+			     uint16_t port,
+			     AvahiStringList *txt,
+			     AvahiLookupResultFlags flags,
+			     void* userdata)
+{
+    struct mdns_entry *e = userdata;
+    char a[AVAHI_ADDRESS_STR_MAX];
+
+    switch (event) {
+    case AVAHI_RESOLVER_FOUND:
+	avahi_address_snprint(a, sizeof(a), address);
+	e->address  = strdup(a);
+	e->hostname = strdup(host_name);
+	e->port     = port;
+	fprintf(stderr, "%s @ %s: %s | %s if #%d | %s:%d (%s)\n",
+		e->type, e->domain, e->name,
+		avahi_proto_to_string(e->protocol), e->interface, 
+		e->address, e->port, e->hostname);
+	break;
+    default:
+	fprintf(stderr, "%s: %s (#%d)\n", __FUNCTION__,
+		revents[event], event);
+	break;
+    }
+    avahi_service_resolver_free(r);
+}
+
+static void browse_callback(AvahiServiceBrowser *b,
+			    AvahiIfIndex interface,
+			    AvahiProtocol protocol,
+			    AvahiBrowserEvent event,
+			    const char *name,
+			    const char *type,
+			    const char *domain,
+			    AvahiLookupResultFlags flags,
+			    void* userdata)
+{
+    AvahiClient *c = userdata;
+    struct mdns_entry *e;
+
+    switch (event) {
+    case AVAHI_BROWSER_NEW:
+	e = malloc(sizeof(*e));
+	memset(e,0,sizeof(*e));
+	e->name      = strdup(name);
+	e->type      = strdup(type);
+	e->domain    = strdup(domain);
+	e->interface = interface;
+	e->protocol  = protocol;
+	list_add_tail(&e->next, &mdns_entries);
+	avahi_service_resolver_new(c, interface, protocol, name, type, domain,
+				   AVAHI_PROTO_UNSPEC, 0, resolve_callback, e);
+	break;
+    case AVAHI_BROWSER_REMOVE:
+	fprintf(stderr, "%s: DEL: service '%s' of type '%s' in domain '%s'\n",
+		__FUNCTION__, name, type, domain);
+	break;
+    default:
+	fprintf(stderr, "%s: %s (#%d)\n", __FUNCTION__,
+		bevents[event], event);
+	break;
+    }
+}
+
+static void
+client_callback(AvahiClient *client, AvahiClientState state, void *userdata)
+{
+    switch (state) {
+    case AVAHI_CLIENT_FAILURE:
+	fprintf(stderr, "%s: error: connection lost\n", __FUNCTION__);
+	break;
+    default:
+	fprintf(stderr, "%s: state %d\n", __FUNCTION__, state);
+	break;
+    }
+}
+
+/* ---------------------------------------------------------------------- */
+
+void mdns_fini(void)
+{
+    if (client) {
+	avahi_client_free(client);
+	client = NULL;
+    }
+    if (glib_poll) {
+	avahi_glib_poll_free(glib_poll);
+	glib_poll = NULL;
+    }
+}
+
+int mdns_init(void)
+{
+    int error;
+
+    /* Create the GLIB Adaptor */
+    avahi_set_allocator(avahi_glib_allocator());
+    glib_poll = avahi_glib_poll_new(NULL, G_PRIORITY_DEFAULT);
+    poll_api = avahi_glib_poll_get(glib_poll);
+    client = avahi_client_new(poll_api, AVAHI_CLIENT_NO_FAIL,
+			      client_callback, NULL /* user data */,
+			      &error);
+    if (client == NULL)
+        goto fail;
+    return 0;
+
+fail:
+    mdns_fini();
+    return -1;
+}
+
+int mdns_browse(const char *service, const char *domain)
+{
+    AvahiServiceBrowser *sb = NULL;
+
+    if (NULL == domain)
+	domain = avahi_client_get_domain_name(client);
+    sb = avahi_service_browser_new(client, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC,
+				   service, domain, 0, browse_callback, client);
+    if (NULL == sb) {
+	fprintf(stderr, "%s: failed to create service browser: %s\n",
+		__FUNCTION__, avahi_strerror(avahi_client_errno(client)));
+	return -1;
+    }
+    return 0;
+}