Support variable length socket options.

Summary: Add a feature to apply and read variable length socket options.

Differential Revision: D33410246

fbshipit-source-id: 3407a926c2ba9323a2318f3d34f8e1f1173bde59

folly/io/SocketOptionMap.cpp

@@ -23,11 +23,17 @@
 namespace folly {
 
 const SocketOptionMap emptySocketOptionMap;
+const SocketNontrivialOptionMap emptySocketNontrivialOptionMap;
 
 int SocketOptionKey::apply(NetworkSocket fd, int val) const {
   return netops::setsockopt(fd, level, optname, &val, sizeof(val));
 }
 
+int SocketOptionKey::apply(
+    NetworkSocket fd, const void* val, socklen_t len) const {
+  return netops::setsockopt(fd, level, optname, val, len);
+}
+
 int applySocketOptions(
     NetworkSocket fd,
     const SocketOptionMap& options,
@@ -43,6 +49,22 @@ int applySocketOptions(
   return 0;
 }
 
+int applySocketOptions(
+    NetworkSocket fd,
+    const SocketNontrivialOptionMap& options,
+    SocketOptionKey::ApplyPos pos) {
+  for (const auto& opt : options) {
+    if (opt.first.applyPos_ == pos) {
+      auto rv =
+          opt.first.apply(fd, (void*)opt.second.data(), opt.second.size());
+      if (rv) {
+        return errno;
+      }
+    }
+  }
+  return 0;
+}
+
 SocketOptionMap validateSocketOptions(
     const SocketOptionMap& options,
     sa_family_t family,
@@ -62,4 +84,23 @@ SocketOptionMap validateSocketOptions(
   return validOptions;
 }
 
+SocketNontrivialOptionMap validateSocketOptions(
+    const SocketNontrivialOptionMap& options,
+    sa_family_t family,
+    SocketOptionKey::ApplyPos pos) {
+  SocketNontrivialOptionMap validOptions;
+  for (const auto& option : options) {
+    if (pos != option.first.applyPos_) {
+      continue;
+    }
+    if ((family == AF_INET && option.first.level == IPPROTO_IP) ||
+        (family == AF_INET6 && option.first.level == IPPROTO_IPV6) ||
+        option.first.level == IPPROTO_UDP || option.first.level == SOL_SOCKET ||
+        option.first.level == SOL_UDP) {
+      validOptions.insert(option);
+    }
+  }
+  return validOptions;
+}
+
 } // namespace folly

folly/io/SocketOptionMap.h

@@ -46,6 +46,7 @@ class SocketOptionKey {
   }
 
   int apply(NetworkSocket fd, int val) const;
+  int apply(NetworkSocket fd, const void* val, socklen_t len) const;
 
   int level;
   int optname;
@@ -54,17 +55,29 @@ class SocketOptionKey {
 
 // Maps from a socket option key to its value
 using SocketOptionMap = std::map<SocketOptionKey, int>;
+using SocketNontrivialOptionMap = std::map<SocketOptionKey, std::string>;
 
 extern const SocketOptionMap emptySocketOptionMap;
+extern const SocketNontrivialOptionMap emptySocketNontrivialOptionMap;
 
 int applySocketOptions(
     NetworkSocket fd,
     const SocketOptionMap& options,
     SocketOptionKey::ApplyPos pos);
 
+int applySocketOptions(
+    NetworkSocket fd,
+    const SocketNontrivialOptionMap& options,
+    SocketOptionKey::ApplyPos pos);
+
 SocketOptionMap validateSocketOptions(
     const SocketOptionMap& options,
     sa_family_t family,
     SocketOptionKey::ApplyPos pos);
 
+SocketNontrivialOptionMap validateSocketOptions(
+    const SocketNontrivialOptionMap& options,
+    sa_family_t family,
+    SocketOptionKey::ApplyPos pos);
+
 } // namespace folly

folly/io/async/AsyncUDPSocket.cpp

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <folly/io/SocketOptionMap.h>
 #include <folly/io/async/AsyncUDPSocket.h>
 
 #include <cerrno>
@@ -1371,6 +1372,17 @@ void AsyncUDPSocket::applyOptions(
   }
 }
 
+void AsyncUDPSocket::applyNontrivialOptions(
+    const SocketNontrivialOptionMap& options, SocketOptionKey::ApplyPos pos) {
+  auto result = applySocketOptions(fd_, options, pos);
+  if (result) {
+    throw AsyncSocketException(
+        AsyncSocketException::INTERNAL_ERROR,
+        "failed to set nontrivial socket option",
+        result);
+  }
+}
+
 void AsyncUDPSocket::detachEventBase() {
   DCHECK(eventBase_ && eventBase_->isInEventBaseThread());
   registerHandler(uint16_t(NONE));

folly/io/async/AsyncUDPSocket.h

@@ -17,6 +17,7 @@
 #pragma once
 
 #include <memory>
+#include <folly/io/SocketOptionMap.h>
 
 #include <folly/Function.h>
 #include <folly/ScopeGuard.h>
@@ -461,6 +462,9 @@ class AsyncUDPSocket : public EventHandler {
   virtual void applyOptions(
       const SocketOptionMap& options, SocketOptionKey::ApplyPos pos);
 
+  virtual void applyNontrivialOptions(
+      const SocketNontrivialOptionMap& options, SocketOptionKey::ApplyPos pos);
+
   /**
    * Override netops::Dispatcher to be used for netops:: calls.
    *

folly/io/async/test/AsyncUDPSocketTest.cpp

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <folly/io/SocketOptionMap.h>
 #include <folly/io/async/AsyncUDPSocket.h>
 
 #include <thread>
@@ -1097,3 +1098,29 @@ TEST_F(AsyncUDPSocketTest, TestWritemCmsg) {
 #endif // FOLLY_HAVE_MSG_ERRQUEUE
   socket_->close();
 }
+
+TEST_F(AsyncUDPSocketTest, TestApplyNontrivialOptionsPostBind) {
+  EventBase evb;
+  AsyncUDPSocket socket(&evb);
+  ASSERT_FALSE(socket.isBound());
+  folly::SocketAddress address("127.0.0.1", 443);
+  socket.connect(address);
+  ASSERT_TRUE(socket.isBound());
+
+  const auto& localAddr = socket.address();
+  ASSERT_TRUE(localAddr.isInitialized());
+  ASSERT_GT(localAddr.getPort(), 0);
+
+  folly::SocketNontrivialOptionMap options =
+      folly::emptySocketNontrivialOptionMap;
+  struct linger sl {
+    .l_onoff = 1, .l_linger = 123,
+  };
+
+  options.insert(
+      {folly::SocketOptionKey{SOL_SOCKET, SO_LINGER},
+       std::string((char*)&sl, sizeof(sl))});
+
+  socket.applyNontrivialOptions(
+      options, folly::SocketOptionKey::ApplyPos::POST_BIND);
+}