Tests for socks4/4a implementation.

net/socket/socks_client_socket.cc

Index: net/socket/socks_client_socket.cc
===================================================================
--- net/socket/socks_client_socket.cc	(revision 19473)
+++ net/socket/socks_client_socket.cc	(working copy)
@@ -28,10 +28,10 @@
 
 // For SOCKS4, the client sends 8 bytes  plus the size of the user-id.
 // For SOCKS4A, this increases to accomodate the unresolved hostname.
-static const int kWriteHeaderSize = 8;
+static const unsigned int kWriteHeaderSize = 8;
 
 // For SOCKS4 and SOCKS4a, the server sends 8 bytes for acknowledgement.
-static const int kReadHeaderSize = 8;
+static const unsigned int kReadHeaderSize = 8;
 
 // Server Response codes for SOCKS.
 static const uint8 kServerResponseOk  = 0x5A;
@@ -72,13 +72,10 @@
       next_state_(STATE_NONE),
       socks_version_(kSOCKS4Unresolved),
       user_callback_(NULL),
-      handshake_buf_len_(0),
-      buffer_(NULL),
-      buffer_len_(0),
       completed_handshake_(false),
       bytes_sent_(0),
       bytes_received_(0),
-      resolver_(host_resolver),
+      host_resolver_(host_resolver),
       host_request_info_(req_info) {
 }
 
@@ -199,7 +196,7 @@
   DCHECK_EQ(kSOCKS4Unresolved, socks_version_);
 
   next_state_ = STATE_RESOLVE_HOST_COMPLETE;
-  return resolver_.Resolve(host_request_info_, &addresses_, &io_callback_);
+  return host_resolver_.Resolve(host_request_info_, &addresses_, &io_callback_);
 }
 
 int SOCKSClientSocket::DoResolveHostComplete(int result) {
@@ -233,65 +230,60 @@
 // Builds the buffer that is to be sent to the server.
 // We check whether the SOCKS proxy is 4 or 4A.
 // In case it is 4A, the record size increases by size of the hostname.
-void SOCKSClientSocket::BuildHandshakeWriteBuffer() {
+const std::string SOCKSClientSocket::BuildHandshakeWriteBuffer() const {
   DCHECK_NE(kSOCKS4Unresolved, socks_version_);
 
-  int record_size = kWriteHeaderSize + arraysize(kEmptyUserId);
-  if (socks_version_ == kSOCKS4a) {
-    record_size += host_request_info_.hostname().size() + 1;
-  }
+  SOCKS4ServerRequest request;
+  request.version = kSOCKSVersion4;
+  request.command = kSOCKSStreamRequest;
+  request.nw_port = htons(host_request_info_.port());
 
-  buffer_len_ = record_size;
-  buffer_.reset(new char[buffer_len_]);
-
-  SOCKS4ServerRequest* request =
-      reinterpret_cast<SOCKS4ServerRequest*>(buffer_.get());
-
-  request->version = kSOCKSVersion4;
-  request->command = kSOCKSStreamRequest;
-  request->nw_port = htons(host_request_info_.port());
-
   if (socks_version_ == kSOCKS4) {
     const struct addrinfo* ai = addresses_.head();
     DCHECK(ai);
     // If the sockaddr is IPv6, we have already marked the version to socks4a
     // and so this step does not get hit.
-    struct sockaddr_in *ipv4_host =
+    struct sockaddr_in* ipv4_host =
         reinterpret_cast<struct sockaddr_in*>(ai->ai_addr);
-    memcpy(&request->ip, &(ipv4_host->sin_addr), sizeof(ipv4_host->sin_addr));
+    memcpy(&request.ip, &(ipv4_host->sin_addr), sizeof(ipv4_host->sin_addr));
 
     DLOG(INFO) << "Resolved Host is : " << NetAddressToString(ai);
   } else if (socks_version_ == kSOCKS4a) {
     // invalid IP of the form 0.0.0.127
-    memcpy(&request->ip, kInvalidIp, arraysize(kInvalidIp));
+    memcpy(&request.ip, kInvalidIp, arraysize(kInvalidIp));
   } else {
     NOTREACHED();
   }
 
-  memcpy(&buffer_[kWriteHeaderSize], kEmptyUserId, arraysize(kEmptyUserId));
+  std::string handshake_data(reinterpret_cast<char*>(&request),
+                             sizeof(request));
+  handshake_data.append(kEmptyUserId, arraysize(kEmptyUserId));
 
+  // In case we are passing the domain also, pass the hostname
+  // terminated with a null character.
   if (socks_version_ == kSOCKS4a) {
-    memcpy(&buffer_[kWriteHeaderSize + arraysize(kEmptyUserId)],
-           host_request_info_.hostname().c_str(),
-           host_request_info_.hostname().size() + 1);
+    handshake_data.append(host_request_info_.hostname());
+    handshake_data.push_back('\0');
   }
+
+  return handshake_data;
 }
 
 // Writes the SOCKS handshake data to the underlying socket connection.
 int SOCKSClientSocket::DoHandshakeWrite() {
   next_state_ = STATE_HANDSHAKE_WRITE_COMPLETE;
 
-  if (!buffer_.get()) {
-    BuildHandshakeWriteBuffer();
+  if (buffer_.empty()) {
+    buffer_ = BuildHandshakeWriteBuffer();
     bytes_sent_ = 0;
   }
 
-  handshake_buf_len_ = buffer_len_ - bytes_sent_;
-  DCHECK_GT(handshake_buf_len_, 0);
-  handshake_buf_ = new IOBuffer(handshake_buf_len_);
-  memcpy(handshake_buf_.get()->data(), &buffer_[bytes_sent_],
-         handshake_buf_len_);
-  return transport_->Write(handshake_buf_, handshake_buf_len_, &io_callback_);
+  int handshake_buf_len = buffer_.size() - bytes_sent_;
+  DCHECK_GT(handshake_buf_len, 0);
+  handshake_buf_ = new IOBuffer(handshake_buf_len);
+  memcpy(handshake_buf_->data(), &buffer_[bytes_sent_],
+         handshake_buf_len);
+  return transport_->Write(handshake_buf_, handshake_buf_len, &io_callback_);
 }
 
 int SOCKSClientSocket::DoHandshakeWriteComplete(int result) {
@@ -300,11 +292,14 @@
   if (result < 0)
     return result;
 
+  // We ignore the case when result is 0, since the underlying Write
+  // may return spurious writes while waiting on the socket.
+
   bytes_sent_ += result;
-  if (bytes_sent_ == buffer_len_) {
+  if (bytes_sent_ == buffer_.size()) {
     next_state_ = STATE_HANDSHAKE_READ;
-    buffer_.reset(NULL);
-  } else if (bytes_sent_ < buffer_len_) {
+    buffer_.clear();
+  } else if (bytes_sent_ < buffer_.size()) {
     next_state_ = STATE_HANDSHAKE_WRITE;
   } else {
     return ERR_UNEXPECTED;
@@ -318,15 +313,13 @@
 
   next_state_ = STATE_HANDSHAKE_READ_COMPLETE;
 
-  if (!buffer_.get()) {
-    buffer_.reset(new char[kReadHeaderSize]);
-    buffer_len_ = kReadHeaderSize;
+  if (buffer_.empty()) {
     bytes_received_ = 0;
   }
 
-  handshake_buf_len_ = buffer_len_ - bytes_received_;
-  handshake_buf_ = new IOBuffer(handshake_buf_len_);
-  return transport_->Read(handshake_buf_, handshake_buf_len_, &io_callback_);
+  int handshake_buf_len = kReadHeaderSize - bytes_received_;
+  handshake_buf_ = new IOBuffer(handshake_buf_len);
+  return transport_->Read(handshake_buf_, handshake_buf_len, &io_callback_);
 }
 
 int SOCKSClientSocket::DoHandshakeReadComplete(int result) {
@@ -334,18 +327,23 @@
 
   if (result < 0)
     return result;
-  if (bytes_received_ + result > buffer_len_)
+
+  // The underlying socket closed unexpectedly.
+  if (result == 0)
+    return ERR_CONNECTION_CLOSED;
+
+  if (bytes_received_ + result > kReadHeaderSize)
     return ERR_INVALID_RESPONSE;
 
-  memcpy(buffer_.get() + bytes_received_, handshake_buf_->data(), result);
+  buffer_.append(handshake_buf_->data(), result);
   bytes_received_ += result;
-  if (bytes_received_ < buffer_len_) {
+  if (bytes_received_ < kReadHeaderSize) {
     next_state_ = STATE_HANDSHAKE_READ;
     return OK;
   }
 
-  SOCKS4ServerResponse* response =
-      reinterpret_cast<SOCKS4ServerResponse*>(buffer_.get());
+  const SOCKS4ServerResponse* response =
+      reinterpret_cast<const SOCKS4ServerResponse*>(buffer_.data());
 
   if (response->reserved_null != 0x00) {
     LOG(ERROR) << "Unknown response from SOCKS server.";