Convert chan_iax2 to use dnsmgr in order to deal with hostnames that can change their resolved IP (aka dynamic dns setups) (issue #6305 reported and fixed by ivanfm)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@32304 65c4cc65-6c06-0410-ace0-fbb531ad65f3
2025-11-08 02:48:29 +00:00 · 2006-06-05 15:44:37 +00:00
parent 723e900bf3
commit 2a71835d41
3 changed files with 106 additions and 51 deletions
--- a/channels/chan_iax2.c
+++ b/channels/chan_iax2.c
@@ -416,6 +416,7 @@ struct iax2_registry {
 	int callno;				/*!< Associated call number if applicable */
 	struct sockaddr_in us;			/*!< Who the server thinks we are */
 	struct iax2_registry *next;
+	struct ast_dnsmgr_entry *dnsmgr;	/*!< DNS refresh manager */
 };

 static struct iax2_registry *registrations;
@@ -1894,7 +1895,7 @@ static int iax2_prune_realtime(int fd, int argc, char *argv[])
 	} else if ((peer = find_peer(argv[3], 0))) {
 		if(ast_test_flag(peer, IAX_RTCACHEFRIENDS)) {
 			ast_set_flag(peer, IAX_RTAUTOCLEAR);
-			expire_registry(peer->name);
+			expire_registry(peer);
 			ast_cli(fd, "OK peer %s was removed from the cache.\n", argv[3]);
 		} else {
 			ast_cli(fd, "SORRY peer %s is not eligible for this operation.\n", argv[3]);
@@ -2532,7 +2533,7 @@ static struct iax2_peer *realtime_peer(const char *peername, struct sockaddr_in
 		if (ast_test_flag(peer, IAX_RTAUTOCLEAR)) {
 			if (peer->expire > -1)
 				ast_sched_del(sched, peer->expire);
-			peer->expire = ast_sched_add(sched, (global_rtautoclear) * 1000, expire_registry, (void*)peer->name);
+			peer->expire = ast_sched_add(sched, (global_rtautoclear) * 1000, expire_registry, (void*)peer);
 		}
 		AST_LIST_LOCK(&peers);
 		AST_LIST_INSERT_HEAD(&peers, peer, entry);
@@ -4304,8 +4305,8 @@ static char *regstate2str(int regstate)

 static int iax2_show_registry(int fd, int argc, char *argv[])
 {
-#define FORMAT2 "%-20.20s  %-10.10s  %-20.20s %8.8s  %s\n"
-#define FORMAT "%-20.20s  %-10.10s  %-20.20s %8d  %s\n"
+#define FORMAT2 "%-20.20s  %-6.6s  %-10.10s  %-20.20s %8.8s  %s\n"
+#define FORMAT  "%-20.20s  %-6.6s  %-10.10s  %-20.20s %8d  %s\n"
 	struct iax2_registry *reg = NULL;

 	char host[80];
@@ -4314,7 +4315,7 @@ static int iax2_show_registry(int fd, int argc, char *argv[])
 	if (argc != 3)
 		return RESULT_SHOWUSAGE;
 	AST_LIST_LOCK(&peers);
-	ast_cli(fd, FORMAT2, "Host", "Username", "Perceived", "Refresh", "State");
+	ast_cli(fd, FORMAT2, "Host", "dnsmgr", "Username", "Perceived", "Refresh", "State");
 	for (reg = registrations;reg;reg = reg->next) {
 		snprintf(host, sizeof(host), "%s:%d", ast_inet_ntoa(iabuf, sizeof(iabuf), reg->addr.sin_addr), ntohs(reg->addr.sin_port));
 		if (reg->us.sin_addr.s_addr) 
@@ -4322,6 +4323,7 @@ static int iax2_show_registry(int fd, int argc, char *argv[])
 		else
 			ast_copy_string(perceived, "<Unregistered>", sizeof(perceived));
 		ast_cli(fd, FORMAT, host, 
+					(reg->dnsmgr) ? "Y" : "N", 
 					reg->username, perceived, reg->refresh, regstate2str(reg->regstate));
 	}
 	AST_LIST_UNLOCK(&peers);
@@ -5447,7 +5449,6 @@ static int iax2_register(char *value, int lineno)
 	char *porta;
 	char *stringp=NULL;
 	
-	struct ast_hostent ahp; struct hostent *hp;
 	if (!value)
 		return -1;
 	ast_copy_string(copy, value, sizeof(copy));
@@ -5469,20 +5470,18 @@ static int iax2_register(char *value, int lineno)
 		ast_log(LOG_WARNING, "%s is not a valid port number at line %d\n", porta, lineno);
 		return -1;
 	}
-	hp = ast_gethostbyname(hostname, &ahp);
-	if (!hp) {
-		ast_log(LOG_WARNING, "Host '%s' not found at line %d\n", hostname, lineno);
-		return -1;
-	}
 	if (!(reg = ast_calloc(1, sizeof(*reg))))
 		return -1;
+	if (ast_dnsmgr_lookup(hostname, &reg->addr.sin_addr, &reg->dnsmgr) < 0) {
+		free(reg);
+		return -1;
+	}
 	ast_copy_string(reg->username, username, sizeof(reg->username));
 	if (secret)
 		ast_copy_string(reg->secret, secret, sizeof(reg->secret));
 	reg->expire = -1;
 	reg->refresh = IAX_DEFAULT_REG_EXPIRE;
 	reg->addr.sin_family = AF_INET;
-	memcpy(&reg->addr.sin_addr, hp->h_addr, sizeof(&reg->addr.sin_addr));
 	reg->addr.sin_port = porta ? htons(atoi(porta)) : htons(IAX_DEFAULT_PORTNO);
 	reg->next = registrations;
 	reg->callno = 0;
@@ -5512,26 +5511,7 @@ static void prune_peers(void);

 static void __expire_registry(void *data)
 {
-	char *name = data;
-	struct iax2_peer *p = NULL;
-
-	/* Go through and grab this peer... and if it needs to be removed... then do it */
-	AST_LIST_LOCK(&peers);
-	AST_LIST_TRAVERSE_SAFE_BEGIN(&peers, p, entry) {
-		if (!strcasecmp(p->name, name)) {
-			/* If we are set to auto clear then remove ourselves */
-			if (ast_test_flag(p, IAX_RTAUTOCLEAR))
-				AST_LIST_REMOVE_CURRENT(&peers, entry);
-			p->expire = -1;
-			break;
-		}
-	}
-	AST_LIST_TRAVERSE_SAFE_END
-	AST_LIST_UNLOCK(&peers);
-
-	/* Peer is already gone for whatever reason */
-	if (!p)
-		return;
+	struct iax2_peer *p = data;

 	ast_log(LOG_DEBUG, "Expiring registration for peer '%s'\n", p->name);
 	manager_event(EVENT_FLAG_SYSTEM, "PeerStatus", "Peer: IAX2/%s\r\nPeerStatus: Unregistered\r\nCause: Expired\r\n", p->name);
@@ -5548,16 +5528,18 @@ static void __expire_registry(void *data)

 	if (ast_test_flag(p, IAX_RTAUTOCLEAR)) {
 		/* We are already gone from the list, so we can just destroy ourselves */
+		AST_LIST_LOCK(&peers);
+		AST_LIST_REMOVE(&peers, p, entry);
+		AST_LIST_UNLOCK(&peers);
 		destroy_peer(p);
 	}
 }

 static int expire_registry(void *data)
 {
-#ifdef SCHED_MULTITHREADED
-	if (schedule_action(__expire_registry, data))
-#endif		
-		__expire_registry(data);
+	struct iax2_peer *p = data;
+	p->expire = -1;
+	__expire_registry(p);
 	return 0;
 }

@@ -5591,7 +5573,7 @@ static void reg_source_db(struct iax2_peer *p)
 					if (p->expire > -1)
 						ast_sched_del(sched, p->expire);
 					ast_device_state_changed("IAX2/%s", p->name); /* Activate notification */
-					p->expire = ast_sched_add(sched, (p->expiry + 10) * 1000, expire_registry, (void *)p->name);
+					p->expire = ast_sched_add(sched, (p->expiry + 10) * 1000, expire_registry, (void *)p);
 					if (iax2_regfunk)
 						iax2_regfunk(p->name, 1);
 					register_peer_exten(p, 1);
@@ -5669,7 +5651,7 @@ static int update_registry(char *name, struct sockaddr_in *sin, int callno, char
 		p->expiry = refresh;
 	}
 	if (p->expiry && sin->sin_addr.s_addr)
-		p->expire = ast_sched_add(sched, (p->expiry + 10) * 1000, expire_registry, (void *)p->name);
+		p->expire = ast_sched_add(sched, (p->expiry + 10) * 1000, expire_registry, (void *)p);
 	iax_ie_append_str(&ied, IAX_IE_USERNAME, p->name);
 	iax_ie_append_int(&ied, IAX_IE_DATETIME, iax2_datetime(p->zonetag));
 	if (sin->sin_addr.s_addr) {
@@ -7741,6 +7723,31 @@ static int iax2_do_register(struct iax2_registry *reg)
 	struct iax_ie_data ied;
 	if (option_debug && iaxdebug)
 		ast_log(LOG_DEBUG, "Sending registration request for '%s'\n", reg->username);
+
+	if (reg->dnsmgr && 
+	    ((reg->regstate == REG_STATE_TIMEOUT) || !reg->addr.sin_addr.s_addr)) {
+		/* Maybe the IP has changed, force DNS refresh */
+		ast_dnsmgr_refresh(reg->dnsmgr, 1);
+	}
+	
+	/*
+	 * if IP has Changed, free allocated call to create a new one with new IP
+	 * call has the pointer to IP and must be updated to the new one
+	 */
+	if (reg->dnsmgr && ast_dnsmgr_changed(reg->dnsmgr) && (reg->callno > 0)) {
+		iax2_destroy(reg->callno);
+		reg->callno = 0;
+	}
+	if (!reg->addr.sin_addr.s_addr) {
+		if (option_debug && iaxdebug)
+			ast_log(LOG_DEBUG, "Unable to send registration request for '%s' without IP address\n", reg->username);
+		/* Setup the next registration attempt */
+		if (reg->expire > -1)
+			ast_sched_del(sched, reg->expire);
+		reg->expire  = ast_sched_add(sched, (5 * reg->refresh / 6) * 1000, iax2_do_register_s, reg);
+		return -1;
+	}
+
 	if (!reg->callno) {
 		if (option_debug)
 			ast_log(LOG_DEBUG, "Allocate call number\n");
@@ -8633,6 +8640,8 @@ static void delete_users(void)
 			}
 			ast_mutex_unlock(&iaxsl[regl->callno]);
 		}
+		if (regl->dnsmgr)
+			ast_dnsmgr_release(regl->dnsmgr);
 		free(regl);
 	}
 	registrations = NULL;
--- a/dnsmgr.c
+++ b/dnsmgr.c
@@ -53,9 +53,11 @@ static int refresh_sched = -1;
 static pthread_t refresh_thread = AST_PTHREADT_NULL;

 struct ast_dnsmgr_entry {
-	struct in_addr *result;
+	struct in_addr *result; 	/* where we will store the resulting address */
+	struct in_addr last; 		/* the last result, used to check if address has changed */
+	int changed;
 	AST_LIST_ENTRY(ast_dnsmgr_entry) list;
-	char name[1];
+	char name[1];			/* just 1 here, but we use calloc to allocate the correct size */
 };

 static AST_LIST_HEAD_STATIC(entry_list, ast_dnsmgr_entry);
@@ -104,6 +106,8 @@ void ast_dnsmgr_release(struct ast_dnsmgr_entry *entry)
 	AST_LIST_LOCK(&entry_list);
 	AST_LIST_REMOVE(&entry_list, entry, list);
 	AST_LIST_UNLOCK(&entry_list);
+	if (option_verbose > 4)
+		ast_verbose(VERBOSE_PREFIX_4 "removing dns manager for '%s'\n", entry->name);
 	free(entry);
 }

@@ -116,7 +120,7 @@ int ast_dnsmgr_lookup(const char *name, struct in_addr *result, struct ast_dnsmg
 		return 0;

 	if (option_verbose > 3)
-		ast_verbose(VERBOSE_PREFIX_3 "doing lookup for '%s'\n", name);
+		ast_verbose(VERBOSE_PREFIX_3 "doing dnsmgr_lookup for '%s'\n", name);

 	/* if it's actually an IP address and not a name,
 	   there's no need for a managed lookup */
@@ -134,12 +138,58 @@ int ast_dnsmgr_lookup(const char *name, struct in_addr *result, struct ast_dnsmg
 		return 0;
 	} else {
 		if (option_verbose > 2)
-			ast_verbose(VERBOSE_PREFIX_2 "adding manager for '%s'\n", name);
+			ast_verbose(VERBOSE_PREFIX_2 "adding dns manager for '%s'\n", name);
 		*dnsmgr = ast_dnsmgr_get(name, result);
 		return !*dnsmgr;
 	}
 }

+/*
+ * Refresh a dnsmgr entry
+ *
+ * XXX maybe we must lock the entry to make safer
+ */
+int ast_dnsmgr_refresh(struct ast_dnsmgr_entry *entry, int verbose)
+{
+	struct ast_hostent ahp;
+	struct hostent *hp;
+        char iabuf[INET_ADDRSTRLEN];
+        char iabuf2[INET_ADDRSTRLEN];
+        struct in_addr tmp;
+        
+	if (verbose && (option_verbose > 2))
+		ast_verbose(VERBOSE_PREFIX_2 "refreshing '%s'\n", entry->name);
+
+	if ((hp = ast_gethostbyname(entry->name, &ahp))) {
+		/* check to see if it has changed, do callback if requested (where de callback is defined ????) */
+		memcpy(&tmp, hp->h_addr, sizeof(tmp));
+		if (tmp.s_addr != entry->last.s_addr) {
+			ast_log(LOG_NOTICE, "host '%s' changed from %s to %s\n", 
+				entry->name,
+				ast_inet_ntoa(iabuf, sizeof(iabuf), entry->last),
+				ast_inet_ntoa(iabuf2, sizeof(iabuf2), tmp));
+
+			memcpy(entry->result, hp->h_addr, sizeof(entry->result));
+			memcpy(&entry->last, hp->h_addr, sizeof(entry->last));
+			entry->changed = 1;
+			return 1;
+		} 
+		
+	}
+	return 0;
+}
+
+/*
+ * Check if dnsmgr entry has changed from since last call to this function
+ */
+int ast_dnsmgr_changed(struct ast_dnsmgr_entry *entry) 
+{
+	int ret = entry->changed;
+	entry->changed = 0;
+	
+	return ret;
+}
+
 static void *do_refresh(void *data)
 {
 	for (;;) {
@@ -155,8 +205,6 @@ static int refresh_list(void *data)
 {
 	struct refresh_info *info = data;
 	struct ast_dnsmgr_entry *entry;
-	struct ast_hostent ahp;
-	struct hostent *hp;

 	/* if a refresh or reload is already in progress, exit now */
 	if (ast_mutex_trylock(&refresh_lock)) {
@@ -172,13 +220,7 @@ static int refresh_list(void *data)
 		if (info->regex_present && regexec(&info->filter, entry->name, 0, NULL, 0))
 		    continue;

-		if (info->verbose && (option_verbose > 2))
-			ast_verbose(VERBOSE_PREFIX_2 "refreshing '%s'\n", entry->name);
-
-		if ((hp = ast_gethostbyname(entry->name, &ahp))) {
-			/* check to see if it has changed, do callback if requested */
-			memcpy(entry->result, hp->h_addr, sizeof(entry->result));
-		}
+		ast_dnsmgr_refresh(entry, info->verbose);
 	}
 	AST_LIST_UNLOCK(info->entries);

--- a/include/asterisk/dnsmgr.h
+++ b/include/asterisk/dnsmgr.h
@@ -37,6 +37,10 @@ void ast_dnsmgr_release(struct ast_dnsmgr_entry *entry);

 int ast_dnsmgr_lookup(const char *name, struct in_addr *result, struct ast_dnsmgr_entry **dnsmgr);

+int ast_dnsmgr_refresh(struct ast_dnsmgr_entry *entry, int verbose);
+
+int ast_dnsmgr_changed(struct ast_dnsmgr_entry *entry);
+
 #if defined(__cplusplus) || defined(c_plusplus)
 }
 #endif /* c_plusplus */