This change adds DNS manager support for registrations not referencing a peer entry. It looks like there is support for DNS manager for realtime peers as well, however it is not implemented correctly. The improper usage occurs when ast_dnsmgr_lookup is called with one of the arguments being an address from the stack to be continually updated. The variable from the stack will go out of scope and dnsmgr will continue to try and update the memory there, causing possible stack corruption. This problem will be worked on next as well as adding DNS manager support for peer entries.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@110087 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 34 insertions, 17 deletions

diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 43484ea36..012f4020f 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -1303,7 +1303,6 @@ struct sip_pvt {
 	struct sip_st_dlg *stimer;		/*!< SIP Session-Timers */              
 };
 
-
 /*! Max entires in the history list for a sip_pvt */
 #define MAX_HISTORY_ENTRIES 50
 
@@ -1547,6 +1546,8 @@ struct sip_registry {
 	struct timeval regtime;		/*!< Last successful registration time */
 	int callid_valid;		/*!< 0 means we haven't chosen callid for this registry yet. */
 	unsigned int ocseq;		/*!< Sequence number we got to for REGISTERs for this registry */
+	struct ast_dnsmgr_entry *dnsmgr;	/*!<  DNS refresh manager for register */
+	struct sockaddr_in us;		/*!< Who the server thinks we are */
 	int noncecount;			/*!< Nonce-count */
 	char lastmsg[256];		/*!< Last Message sent/received */
 };
@@ -1959,7 +1960,7 @@ static int respprep(struct sip_request *resp, struct sip_pvt *p, const char *msg
 static const struct sockaddr_in *sip_real_dst(const struct sip_pvt *p);
 static void build_via(struct sip_pvt *p);
 static int create_addr_from_peer(struct sip_pvt *r, struct sip_peer *peer);
-static int create_addr(struct sip_pvt *dialog, const char *opeer);
+static int create_addr(struct sip_pvt *dialog, const char *opeer, struct in_addr *sin);
 static char *generate_random_string(char *buf, size_t size);
 static void build_callid_pvt(struct sip_pvt *pvt);
 static void build_callid_registry(struct sip_registry *reg, struct in_addr ourip, const char *fromdomain);
@@ -2528,7 +2529,7 @@ static int __sip_xmit(struct sip_pvt *p, struct ast_str *data, int len)
 	int res = 0;
 	const struct sockaddr_in *dst = sip_real_dst(p);
 
-	ast_debug(1, "Trying to put '%.10s' onto %s socket...\n", data->str, get_transport(p->socket.type));
+	ast_debug(1, "Trying to put '%.10s' onto %s socket destined for %s\n", data->str, get_transport(p->socket.type), ast_inet_ntoa(dst->sin_addr));
 
 	if (sip_prepare_socket(p) < 0)
 		return XMIT_ERROR;
@@ -4057,7 +4058,7 @@ static int create_addr_from_peer(struct sip_pvt *dialog, struct sip_peer *peer)
 /*! \brief create address structure from peer name
  *      Or, if peer not found, find it in the global DNS 
  *      returns TRUE (-1) on failure, FALSE on success */
-static int create_addr(struct sip_pvt *dialog, const char *opeer)
+static int create_addr(struct sip_pvt *dialog, const char *opeer, struct in_addr *sin)
 {
 	struct hostent *hp;
 	struct ast_hostent ahp;
@@ -4066,6 +4067,7 @@ static int create_addr(struct sip_pvt *dialog, const char *opeer)
 	int portno;
 	char host[MAXHOSTNAMELEN], *hostn;
 	char peername[256];
+	int srv_ret = 0;
 
 	ast_copy_string(peername, opeer, sizeof(peername));
 	port = strchr(peername, ':');
@@ -4097,27 +4099,32 @@ static int create_addr(struct sip_pvt *dialog, const char *opeer)
 
 	/* Let's see if we can find the host in DNS. First try DNS SRV records,
    	   then hostname lookup */
-
 	hostn = peername;
 	portno = port ? atoi(port) : (dialog->socket.type & SIP_TRANSPORT_TLS) ? STANDARD_TLS_PORT : STANDARD_SIP_PORT;
 	if (global_srvlookup) {
 		char service[MAXHOSTNAMELEN];
 		int tportno;
-		int ret;
 
 		snprintf(service, sizeof(service), "_sip._%s.%s", get_transport(dialog->socket.type), peername);
-		ret = ast_get_srv(NULL, host, sizeof(host), &tportno, service);
-		if (ret > 0) {
+		srv_ret = ast_get_srv(NULL, host, sizeof(host), &tportno, service);
+		if (srv_ret > 0) {
 			hostn = host;
 			portno = tportno;
 		}
 	}
-	hp = ast_gethostbyname(hostn, &ahp);
-	if (!hp) {
-		ast_log(LOG_WARNING, "No such host: %s\n", peername);
-		return -1;
+
+	if (sin && srv_ret <= 0) {
+		memcpy(&dialog->sa.sin_addr, sin, sizeof(dialog->sa.sin_addr));
+		ast_log(LOG_DEBUG, "IP lookup for hostname=%s, using dnsmgr resolved to %s...\n", peername, ast_inet_ntoa(*sin));
+	} else {
+		hp = ast_gethostbyname(hostn, &ahp);
+		if (!hp) {
+			ast_log(LOG_WARNING, "No such host: %s\n", peername);
+			return -1;
+		}
+		memcpy(&dialog->sa.sin_addr, hp->h_addr, sizeof(dialog->sa.sin_addr));
 	}
-	memcpy(&dialog->sa.sin_addr, hp->h_addr, sizeof(dialog->sa.sin_addr));
+
 	dialog->sa.sin_port = htons(portno);
 	dialog->recv = dialog->sa;
 	return 0;
@@ -4255,6 +4262,7 @@ static void sip_registry_destroy(struct sip_registry *reg)
 	AST_SCHED_DEL(sched, reg->timeout);
 	ast_string_field_free_memory(reg);
 	regobjs--;
+	ast_dnsmgr_release(reg->dnsmgr);
 	ast_free(reg);
 	
 }
@@ -9141,6 +9149,11 @@ static int sip_reg_timeout(const void *data)
 	if (!r)
 		return 0;
 
+	if (r->dnsmgr) {
+		/* If the registration has timed out, maybe the IP changed.  Force a refresh. */
+		ast_dnsmgr_refresh(r->dnsmgr);
+	}
+
 	ast_log(LOG_NOTICE, "   -- Registration for '%s@%s' timed out, trying again (Attempt #%d)\n", r->username, r->hostname, r->regattempts); 
 	/* If the initial tranmission failed, we may not have an existing dialog,
 	 * so it is possible that r->call == NULL.
@@ -9192,11 +9205,15 @@ static int transmit_register(struct sip_registry *r, int sipmethod, const char *
 	struct sip_pvt *p;
 
 	/* exit if we are already in process with this registrar ?*/
-	if ( r == NULL || ((auth==NULL) && (r->regstate==REG_STATE_REGSENT || r->regstate==REG_STATE_AUTHSENT))) {
+	if (r == NULL || ((auth == NULL) && (r->regstate == REG_STATE_REGSENT || r->regstate == REG_STATE_AUTHSENT))) {
 		ast_log(LOG_NOTICE, "Strange, trying to register %s@%s when registration already pending\n", r->username, r->hostname);
 		return 0;
 	}
 
+	if (r->dnsmgr == NULL) {
+		ast_dnsmgr_lookup(r->hostname, &r->us.sin_addr, &r->dnsmgr);
+	} 
+
 	if (r->call) {	/* We have a registration */
 		if (!auth) {
 			ast_log(LOG_WARNING, "Already have a REGISTER going on to %s@%s?? \n", r->username, r->hostname);
@@ -9224,7 +9241,7 @@ static int transmit_register(struct sip_registry *r, int sipmethod, const char *
 		p->outboundproxy = obproxy_get(p, NULL);
 
 		/* Find address to hostname */
-		if (create_addr(p, r->hostname)) {
+		if (create_addr(p, r->hostname, &r->us.sin_addr)) {
 			/* we have what we hope is a temporary network error,
 			 * probably DNS.  We need to reschedule a registration try */
 			sip_destroy(p);
@@ -13868,7 +13885,7 @@ static char *sip_notify(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a
 			return CLI_FAILURE;
 		}
 
-		if (create_addr(p, a->argv[i])) {
+		if (create_addr(p, a->argv[i], NULL)) {
 			/* Maybe they're not registered, etc. */
 			sip_destroy(p);
 			ast_cli(a->fd, "Could not create address for '%s'\n", a->argv[i]);
@@ -19115,7 +19132,7 @@ static struct ast_channel *sip_request_call(const char *type, int format, void *
 		ext = extension (user part of URI)
 		dnid = destination of the call (applies to the To: header)
 	*/
-	if (create_addr(p, host)) {
+	if (create_addr(p, host, NULL)) {
 		*cause = AST_CAUSE_UNREGISTERED;
 		ast_debug(3, "Cant create SIP call - target device not registred\n");
 		sip_destroy(p);