Add API to retrieve DNS server bound address to allow specifying zero…

… as port number (#3999)
pjsip · Jun 24, 2024 · 8c8675d · 8c8675d
1 parent 8293af9
commit 8c8675d
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Showing 2 changed files with 25 additions and 2 deletions.
diff --git a/pjlib-util/include/pjlib-util/dns_server.h b/pjlib-util/include/pjlib-util/dns_server.h
@@ -50,7 +50,8 @@ typedef struct pj_dns_server pj_dns_server;
  *                  registered to.
  * @param af        Address family of the server socket (valid values
  *                  are pj_AF_INET() for IPv4 and pj_AF_INET6() for IPv6).
- * @param port      The UDP port to listen.
+ * @param port      The UDP port to listen. Specify zero to bind to any
+ *                  port.
  * @param flags     Flags, currently must be zero.
  * @param p_srv     Pointer to receive the DNS server instance.
  *
@@ -65,6 +66,17 @@ PJ_DECL(pj_status_t) pj_dns_server_create(pj_pool_factory *pf,
                                           unsigned flags,
                                           pj_dns_server **p_srv);
 
+/**
+ * Get the DNS server address
+ *
+ * @param srv	    The DNS server instance.
+ * @param addr      It will be filled with the server's bound address.
+ *
+ * @return	    PJ_SUCCESS on success or the appropriate error code.
+ */
+PJ_DECL(pj_status_t) pj_dns_server_get_addr(pj_dns_server *srv,
+                                            pj_sockaddr *bound_addr);
+
 /**
  * Destroy DNS server instance.
  *

diff --git a/pjlib-util/src/pjlib-util/dns_server.c b/pjlib-util/src/pjlib-util/dns_server.c
@@ -52,6 +52,7 @@ struct pj_dns_server
     pj_pool_t           *pool;
     pj_pool_factory     *pf;
     pj_activesock_t     *asock;
+    pj_sockaddr          bound_addr;
     pj_ioqueue_op_key_t  send_key;
     struct rr            rr_list;
 };
@@ -97,7 +98,8 @@ PJ_DEF(pj_status_t) pj_dns_server_create( pj_pool_factory *pf,
     pj_activesock_cfg_default(&sock_cfg);
 
     status = pj_activesock_create_udp(pool, &sock_addr, &sock_cfg, ioqueue,
-                                      &sock_cb, srv, &srv->asock, NULL);
+                                      &sock_cb, srv, &srv->asock,
+                                      &srv->bound_addr);
     if (status != PJ_SUCCESS)
         goto on_error;
 
@@ -116,6 +118,15 @@ PJ_DEF(pj_status_t) pj_dns_server_create( pj_pool_factory *pf,
 }
 
 
+PJ_DEF(pj_status_t) pj_dns_server_get_addr(pj_dns_server *srv,
+                                           pj_sockaddr *bound_addr)
+{
+    PJ_ASSERT_RETURN(srv && bound_addr, PJ_EINVAL);
+    pj_memcpy(bound_addr, &srv->bound_addr, sizeof(*bound_addr));
+    return PJ_SUCCESS;
+}
+
+
 PJ_DEF(pj_status_t) pj_dns_server_destroy(pj_dns_server *srv)
 {
     PJ_ASSERT_RETURN(srv, PJ_EINVAL);