libweave: Add diagnostic messages when conneting to XMPP server

Added logging for socket connection attempts when estabilishing
connection to the XMPP server.

BUG=None
TEST=`FEATURES=test emerge-link buffet`

Change-Id: I2b60e96909baffd4fddcb6f5facb37c5e1679620
Reviewed-on: https://chromium-review.googlesource.com/284638
Trybot-Ready: Alex Vakulenko <avakulenko@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
Reviewed-by: Vitaly Buka <vitalybuka@chromium.org>
Commit-Queue: Vitaly Buka <vitalybuka@chromium.org>

libweave/src/utils.cc

diff --git a/libweave/src/utils.cc b/libweave/src/utils.cc
index 71ea0d4..a8cd587 100644
--- a/libweave/src/utils.cc
+++ b/libweave/src/utils.cc
@@ -4,6 +4,7 @@
 
 #include "libweave/src/utils.h"
 
+#include <arpa/inet.h>
 #include <map>
 #include <netdb.h>
 #include <string>
@@ -86,8 +87,10 @@
   std::string service = std::to_string(port);
   addrinfo hints = {0, AF_UNSPEC, SOCK_STREAM};
   addrinfo* result = nullptr;
-  if (getaddrinfo(host.c_str(), service.c_str(), &hints, &result))
+  if (getaddrinfo(host.c_str(), service.c_str(), &hints, &result)) {
+    PLOG(WARNING) << "Failed to resolve host name: " << host;
     return -1;
+  }
 
   int socket_fd = -1;
   for (const addrinfo* info = result; info != nullptr; info = info->ai_next) {
@@ -95,9 +98,13 @@
     if (socket_fd < 0)
       continue;
 
+    char str[INET6_ADDRSTRLEN] = {};
+    inet_ntop(info->ai_family, info->ai_addr, str, info->ai_addrlen);
+    LOG(INFO) << "Connecting to address: " << str;
     if (connect(socket_fd, info->ai_addr, info->ai_addrlen) == 0)
       break;  // Success.
 
+    PLOG(WARNING) << "Failed to connect to address: " << str;
     close(socket_fd);
     socket_fd = -1;
   }