Add a function to get Wifi SSID to net_util.

net/base/net_util_linux.cc

 // Copyright (c) 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/base/net_util_linux.h"
 
 #if !defined(OS_ANDROID)
 #include <linux/ethtool.h>
 #endif  // !defined(OS_ANDROID)
 #include <linux/if.h>
@@ skipping 85 matching lines @@
   struct ifreq ifr = {};
   ifr.ifr_data = &ecmd;
   strncpy(ifr.ifr_name, ifname.c_str(), IFNAMSIZ - 1);
   if (ioctl(s.get(), SIOCETHTOOL, &ifr) != -1)
     return NetworkChangeNotifier::CONNECTION_ETHERNET;
 #endif  // !defined(OS_ANDROID)
 
   return NetworkChangeNotifier::CONNECTION_UNKNOWN;
 }
 
+std::string GetInterfaceSSID(const std::string& ifname) {
+  int ioctl_socket = socket(AF_INET, SOCK_DGRAM, 0);
+  if (ioctl_socket < 0)
+    return "";
+  struct iwreq wreq;
+  memset(&wreq, 0, sizeof(wreq));

[pauljensen, 2015/02/09 12:28:05]

Can you combine these two lines like line 87?

[meacer, 2015/02/10 04:42:50]

Done.

+  strncpy(wreq.ifr_name, ifname.c_str(), IFNAMSIZ - 1);
+
+  char ssid[IW_ESSID_MAX_SIZE + 1] = {0};
+  wreq.u.essid.pointer = ssid;
+  wreq.u.essid.length = IW_ESSID_MAX_SIZE;
+  int rv = ioctl(ioctl_socket, SIOCGIWESSID, &wreq);
+  close(ioctl_socket);

[pauljensen, 2015/02/09 12:28:05]

Can you eliminate this line using ScopedFD like line 82?  I find this to be a
little safer as someone cannot add a "return" statement without forgetting to
close().

[meacer, 2015/02/10 04:42:50]

Good point, done.

+  return (rv == 0) ? ssid : "";
+}
+
 bool GetNetworkListImpl(
     NetworkInterfaceList* networks,
     int policy,
     const base::hash_set<int>& online_links,
     const internal::AddressTrackerLinux::AddressMap& address_map,
     GetInterfaceNameFunction get_interface_name) {
   std::map<int, std::string> ifnames;
 
   for (internal::AddressTrackerLinux::AddressMap::const_iterator it =
            address_map.begin();
@@ skipping 49 matching lines @@
         GetInterfaceConnectionType(ifname);
 
     networks->push_back(
         NetworkInterface(ifname, ifname, it->second.ifa_index, type, it->first,
                          it->second.ifa_prefixlen, ip_attributes));
   }
 
   return true;
 }
 
+std::string GetWifiSSIDFromInterfaceListInternal(
+    const NetworkInterfaceList& interfaces,
+    internal::GetInterfaceSSIDFunction get_interface_ssid) {
+  std::string connected_ssid;
+  bool first = true;
+  for (size_t i = 0; i < interfaces.size(); ++i) {
+    if (interfaces[i].type != NetworkChangeNotifier::CONNECTION_WIFI)
+      return "";
+    std::string ssid = get_interface_ssid(interfaces[i].name);
+    if (first) {
+      first = false;
+      connected_ssid = ssid;
+    } else if (ssid != connected_ssid) {
+      return "";
+    }
+  }
+  return connected_ssid;
+}
+
 }  // namespace internal
 
 bool GetNetworkList(NetworkInterfaceList* networks, int policy) {
   if (networks == NULL)
     return false;
 
   internal::AddressTrackerLinux tracker;
   tracker.Init();
 
   return internal::GetNetworkListImpl(
       networks, policy, tracker.GetOnlineLinks(), tracker.GetAddressMap(),
       &internal::AddressTrackerLinux::GetInterfaceName);
 }
 
+std::string GetWifiSSID() {
+  NetworkInterfaceList networks;
+  if (GetNetworkList(&networks, net::INCLUDE_HOST_SCOPE_VIRTUAL_INTERFACES)) {
+    return internal::GetWifiSSIDFromInterfaceListInternal(
+        networks, internal::GetInterfaceSSID);
+  }
+  return "";
+}
+
 }  // namespace net