[Fuchsia] Implements NetworkInterface.list()

runtime/bin/socket_base_fuchsia.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #if !defined(DART_IO_DISABLED)
 
 #include "platform/globals.h"
 #if defined(HOST_OS_FUCHSIA)
 
 #include "bin/socket_base.h"
 
+// TODO(MG-766): If/when Fuchsia adds getifaddrs(), use that instead of the
+// ioctl in netconfig.h.
+#include <apps/netstack/apps/include/netconfig.h>
 #include <errno.h>        // NOLINT
 #include <fcntl.h>        // NOLINT
 #include <ifaddrs.h>      // NOLINT
 #include <net/if.h>       // NOLINT
 #include <netinet/tcp.h>  // NOLINT
 #include <stdio.h>        // NOLINT
 #include <stdlib.h>       // NOLINT
 #include <string.h>       // NOLINT
 #include <sys/ioctl.h>    // NOLINT
 #include <sys/stat.h>     // NOLINT
@@ skipping 253 matching lines @@
     result = NO_RETRY_EXPECTED(inet_pton(AF_INET, address, &addr->in.sin_addr));
   } else {
     ASSERT(type == SocketAddress::TYPE_IPV6);
     result =
         NO_RETRY_EXPECTED(inet_pton(AF_INET6, address, &addr->in6.sin6_addr));
   }
   return (result == 1);
 }
 
 
+static bool ShouldIncludeIfaAddrs(netc_if_info_t* if_info, int lookup_family) {
+  const int family = if_info->addr.ss_family;
+  return ((lookup_family == family) ||
+          (((lookup_family == AF_UNSPEC) &&
+            ((family == AF_INET) || (family == AF_INET6)))));
+}
+
+
 bool SocketBase::ListInterfacesSupported() {
-  return false;
+  return true;
 }
 
 
 AddressList<InterfaceSocketAddress>* SocketBase::ListInterfaces(
     int type,
     OSError** os_error) {
-  UNIMPLEMENTED();
-  return NULL;
+  // We need a dummy socket.
+  const int fd = socket(AF_INET6, SOCK_STREAM, 0);
+  if (fd < 0) {
+    LOG_ERR("ListInterfaces: socket(AF_INET, SOCK_DGRAM, 0) failed\n");
+    return NULL;
+  }
+
+  // Call the ioctl.
+  netc_get_if_info_t get_if_info;
+  const ssize_t size = ioctl_netc_get_if_info(fd, &get_if_info);
+  if (size < 0) {
+    LOG_ERR("ListInterfaces: ioctl_netc_get_if_info() failed");
+    return NULL;
+  }
+  if (get_if_info.n_info == 0) {

[tkilbourn, 2017/06/30 17:38:47]

this seems like a valid return value; should this just return an empty list in
that case, rather than treating it like an error?

[zra, 2017/06/30 17:42:42]

Done.

+    LOG_ERR("ListInterfaces: ioctl_netc_get_if_info() returned no interfaces");
+    return NULL;
+  }
+
+  // Process the results.
+  const int lookup_family = SocketAddress::FromType(type);
+  intptr_t count = 0;
+  for (intptr_t i = 0; i < get_if_info.n_info; i++) {
+    if (ShouldIncludeIfaAddrs(&get_if_info.info[i], lookup_family)) {
+      count++;
+    }
+  }
+
+  AddressList<InterfaceSocketAddress>* addresses =
+      new AddressList<InterfaceSocketAddress>(count);
+  int addresses_idx = 0;
+  for (intptr_t i = 0; i < get_if_info.n_info; i++) {
+    if (ShouldIncludeIfaAddrs(&get_if_info.info[i], lookup_family)) {
+      char* ifa_name = DartUtils::ScopedCopyCString(get_if_info.info[i].name);
+      InterfaceSocketAddress* isa = new InterfaceSocketAddress(
+          reinterpret_cast<struct sockaddr*>(&get_if_info.info[i].addr),
+          ifa_name,
+          if_nametoindex(get_if_info.info[i].name));
+      addresses->SetAt(addresses_idx, isa);
+      addresses_idx++;
+    }
+  }
+  return addresses;
 }
 
 
 void SocketBase::Close(intptr_t fd) {
   IOHandle* handle = reinterpret_cast<IOHandle*>(fd);
   ASSERT(handle->fd() >= 0);
   NO_RETRY_EXPECTED(close(handle->fd()));
 }
 
 
@@ skipping 77 matching lines @@
   UNIMPLEMENTED();
   return false;
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(HOST_OS_FUCHSIA)
 
 #endif  // !defined(DART_IO_DISABLED)