Add support for AsyncUDPSocket SO_BINDTODEVICE

Summary: Add support for AsyncUDPSocket SO_BINDTODEVICE

Reviewed By: danobi

Differential Revision: D28100917

fbshipit-source-id: bcc66d943342cbd40b634ef095eccf3e599fcb65

folly/io/async/AsyncUDPServerSocket.h

@@ -116,7 +116,8 @@ class AsyncUDPServerSocket : private AsyncUDPSocket::ReadCallback,
 
   void bind(
       const folly::SocketAddress& addy,
-      const SocketOptionMap& options = emptySocketOptionMap) {
+      const SocketOptionMap& options = emptySocketOptionMap,
+      const std::string& ifName = "") {
     CHECK(!socket_);
 
     socket_ = std::make_shared<AsyncUDPSocket>(evb_);
@@ -126,7 +127,14 @@ class AsyncUDPServerSocket : private AsyncUDPSocket::ReadCallback,
         validateSocketOptions(
             options, addy.getFamily(), SocketOptionKey::ApplyPos::PRE_BIND),
         SocketOptionKey::ApplyPos::PRE_BIND);
+#ifdef FOLLY_HAVE_BIND_OPTIONS_IFNAME
+    AsyncUDPSocket::BindOptions bindOptions;
+    bindOptions.ifName = ifName;
+    socket_->bind(addy, bindOptions);
+#else
+    (void)ifName;
     socket_->bind(addy);
+#endif
     socket_->applyOptions(
         validateSocketOptions(
             options, addy.getFamily(), SocketOptionKey::ApplyPos::POST_BIND),

folly/io/async/AsyncUDPSocket.cpp

@@ -207,6 +207,23 @@ void AsyncUDPSocket::bind(
     const folly::SocketAddress& address, BindOptions bindOptions) {
   init(address.getFamily(), bindOptions);
 
+  // bind the socket to the interface
+#ifdef FOLLY_HAVE_BIND_OPTIONS_IFNAME
+  if (!bindOptions.ifName.empty() &&
+      netops::setsockopt(
+          fd_,
+          SOL_SOCKET,
+          SO_BINDTODEVICE,
+          bindOptions.ifName.c_str(),
+          bindOptions.ifName.length())) {
+    auto errnoCopy = errno;
+    throw AsyncSocketException(
+        AsyncSocketException::NOT_OPEN,
+        "failed to bind to device: " + bindOptions.ifName,
+        errnoCopy);
+  }
+#endif
+
   // bind to the address
   sockaddr_storage addrStorage;
   address.getAddress(&addrStorage);

folly/io/async/AsyncUDPSocket.h

@@ -30,6 +30,10 @@
 #include <folly/net/NetOps.h>
 #include <folly/net/NetworkSocket.h>
 
+#if defined(__linux__) && !FOLLY_MOBILE
+#define FOLLY_HAVE_BIND_OPTIONS_IFNAME
+#endif
+
 namespace folly {
 
 /**
@@ -170,9 +174,12 @@ class AsyncUDPSocket : public EventHandler {
    * Contains options to pass to bind.
    */
   struct BindOptions {
-    constexpr BindOptions() noexcept {}
+    BindOptions() noexcept {}
     // Whether IPV6_ONLY should be set on the socket.
     bool bindV6Only{true};
+#ifdef FOLLY_HAVE_BIND_OPTIONS_IFNAME
+    std::string ifName;
+#endif
   };
 
   /**