Improved warnings on failure to connect

Adding a warning (with the error message) when can't connect to a host.
And adding the host name into the error message when failed.

Closes #91

Author: Jérôme Lebel

build/autotools/versions.ldscript

@@ -234,6 +234,7 @@ LIBMONGOC_1.1 {
         mongoc_rand_add;
         mongoc_rand_seed;
         mongoc_rand_status;
+        mongoc_socket_inet_ntop
         mongoc_uri_get_credentials;
         mongoc_uri_get_mechanism_properties;
 } LIBMONGOC_1.0;

build/cmake/libmongoc-ssl.def

@@ -170,6 +170,7 @@ mongoc_socket_destroy
 mongoc_socket_errno
 mongoc_socket_getnameinfo
 mongoc_socket_getsockname
+mongoc_socket_inet_ntop
 mongoc_socket_listen
 mongoc_socket_new
 mongoc_socket_recv

build/cmake/libmongoc.def

@@ -168,6 +168,7 @@ mongoc_socket_destroy
 mongoc_socket_errno
 mongoc_socket_getnameinfo
 mongoc_socket_getsockname
+mongoc_socket_inet_ntop
 mongoc_socket_listen
 mongoc_socket_new
 mongoc_socket_recv

src/libmongoc.symbols

@@ -169,6 +169,7 @@ mongoc_socket_destroy
 mongoc_socket_errno
 mongoc_socket_getnameinfo
 mongoc_socket_getsockname
+mongoc_socket_inet_ntop
 mongoc_socket_listen
 mongoc_socket_new
 mongoc_socket_recv

src/mongoc/mongoc-client.c

@@ -142,11 +142,16 @@ mongoc_client_connect_tcp (const mongoc_uri_t       *uri,
                                       rp->ai_addr,
                                       (socklen_t)rp->ai_addrlen,
                                       expire_at)) {
+         char *errmsg;
          char errmsg_buf[32];
-         const char * errmsg;
-
-         errmsg = bson_strerror_r (mongoc_socket_errno (sock), errmsg_buf, sizeof errmsg_buf);
-         MONGOC_WARNING ("Failed to connect, error: %d, %s\n",
+         char ip[255];
+
+         mongoc_socket_inet_ntop (rp, ip, sizeof ip);
+         errmsg = bson_strerror_r (
+            mongoc_socket_errno (sock), errmsg_buf, sizeof errmsg_buf);
+         MONGOC_WARNING ("Failed to connect to: %s:%d, error: %d, %s\n",
+                         ip,
+                         host->port,
                          mongoc_socket_errno(sock),
                          errmsg);
          mongoc_socket_destroy (sock);

src/mongoc/mongoc-socket.c

@@ -1094,3 +1094,46 @@ mongoc_socket_check_closed (mongoc_socket_t *sock) /* IN */
 
    return closed;
 }
+
+/*
+ *
+ *--------------------------------------------------------------------------
+ *
+ * mongoc_socket_inet_ntop --
+ *
+ *       Convert the ip from addrinfo into a c string.
+ *
+ * Returns:
+ *       The value is returned into 'buffer'. The memory has to be allocated
+ *       by the caller
+ *
+ * Side effects:
+ *       None.
+ *
+ *--------------------------------------------------------------------------
+ */
+
+void
+mongoc_socket_inet_ntop (struct addrinfo *rp,        /* IN */
+                         char            *buf,       /* INOUT */
+                         size_t           buflen)    /* IN */
+{
+   void *ptr;
+   char tmp[256];
+
+   switch (rp->ai_family) {
+   case AF_INET:
+      ptr = &((struct sockaddr_in *)rp->ai_addr)->sin_addr;
+      inet_ntop (rp->ai_family, ptr, tmp, sizeof (tmp));
+      bson_snprintf (buf, buflen, "ipv4 %s", tmp);
+      break;
+   case AF_INET6:
+      ptr = &((struct sockaddr_in6 *)rp->ai_addr)->sin6_addr;
+      inet_ntop (rp->ai_family, ptr, tmp, sizeof (tmp));
+      bson_snprintf (buf, buflen, "ipv6 %s", tmp);
+      break;
+   default:
+      bson_snprintf (buf, buflen, "unknown ip %d", rp->ai_family);
+      break;
+   }
+}

src/mongoc/mongoc-socket.h

@@ -87,6 +87,9 @@ ssize_t          mongoc_socket_sendv      (mongoc_socket_t       *sock,
                                            size_t                 iovcnt,
                                            int64_t                expire_at);
 bool             mongoc_socket_check_closed (mongoc_socket_t       *sock);
+void             mongoc_socket_inet_ntop  (struct addrinfo         *rp,
+                                           char                    *buf,
+                                           size_t                   buflen);
 
 
 BSON_END_DECLS