Defines SSLServerSocket and implements SSLServerSocketNSS

net/socket/ssl_server_socket_nss.cc

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.

[wtc, 2010/12/17 00:16:26]

If ssl_server_socket_nss.cc is heavily based on
ssl_client_socket_nss.cc, please use "svn cp" to add
this file, so I can see the diffs more easily.

[Alpha Left Google, 2010/12/17 08:30:43]

In fact I can't do this.. since git doesn't have an equivalent command for svn
cp.. :(

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/socket/ssl_server_socket_nss.h"
+
+#if defined(USE_SYSTEM_SSL)
+#include <dlfcn.h>
+#endif
+#if defined(OS_MACOSX)
+#include <Security/Security.h>
+#endif
+#include <certdb.h>
+#include <cryptohi.h>
+#include <hasht.h>
+#include <keyhi.h>
+#include <nspr.h>
+#include <nss.h>
+#include <pk11pub.h>
+#include <secerr.h>
+#include <sechash.h>
+#include <ssl.h>
+#include <sslerr.h>
+#include <sslproto.h>
+
+#include <limits>
+
+#include "base/crypto/rsa_private_key.h"
+#include "base/ref_counted.h"
+#include "net/base/io_buffer.h"
+#include "net/base/net_errors.h"
+#include "net/base/net_log.h"
+#include "net/ocsp/nss_ocsp.h"
+#include "net/socket/nss_common.h"
+#include "net/socket/ssl_error_params.h"
+
+static const int kRecvBufferSize = 4096;
+
+#define GotoState(s) next_handshake_state_ = s
+
+namespace net {
+
+SSLServerSocket* CreateSSLServerSocket(
+    Socket* socket, scoped_refptr<X509Certificate> cert,
+    base::RSAPrivateKey* key) {
+  return new SSLServerSocketNSS(socket, cert, key);
+}
+
+SSLServerSocketNSS::SSLServerSocketNSS(
+    Socket* socket, scoped_refptr<X509Certificate> cert,
+    base::RSAPrivateKey* key)
+    : ALLOW_THIS_IN_INITIALIZER_LIST(buffer_send_callback_(
+          this, &SSLServerSocketNSS::BufferSendComplete)),
+      ALLOW_THIS_IN_INITIALIZER_LIST(buffer_recv_callback_(
+          this, &SSLServerSocketNSS::BufferRecvComplete)),
+      transport_send_busy_(false),
+      transport_recv_busy_(false),
+      user_accept_callback_(NULL),
+      user_read_callback_(NULL),
+      user_write_callback_(NULL),
+      nss_fd_(NULL),
+      nss_bufs_(NULL),
+      socket_(socket),
+      cert_(cert),
+      next_handshake_state_(STATE_NONE),
+      completed_handshake_(false) {
+  ssl_config_.false_start_enabled = false;
+  ssl_config_.ssl3_enabled = true;
+  ssl_config_.tls1_enabled = true;
+
+  // TODO(hclam): Need a better way to clone a key.
+  std::vector<uint8> key_bytes;
+  CHECK(key->ExportPrivateKey(&key_bytes));
+  key_.reset(base::RSAPrivateKey::CreateFromPrivateKeyInfo(key_bytes));
+  CHECK(key_.get());
+}
+
+int SSLServerSocketNSS::Init() {
+  // Initialize the NSS SSL library in a threadsafe way.  This also
+  // initializes the NSS base library.
+  EnsureNSSSSLInit();
+  if (!NSS_IsInitialized())
+    return ERR_UNEXPECTED;
+#if !defined(OS_MACOSX) && !defined(OS_WIN)
+  // We must call EnsureOCSPInit() here, on the IO thread, to get the IO loop
+  // by MessageLoopForIO::current().
+  // X509Certificate::Verify() runs on a worker thread of CertVerifier.
+  EnsureOCSPInit();
+#endif
+
+  return OK;
+}
+
+int SSLServerSocketNSS::Accept(CompletionCallback* callback) {
+  net_log_.BeginEvent(NetLog::TYPE_SSL_ACCEPT, NULL);
+
+  int rv = Init();
+  if (rv != OK) {
+    LOG(ERROR) << "Failed to initialize NSS";
+    net_log_.EndEvent(NetLog::TYPE_SSL_ACCEPT, NULL);
+    return rv;
+  }
+
+  rv = InitializeSSLOptions();
+  if (rv != OK) {
+    LOG(ERROR) << "Failed to initialize SSL options";
+    net_log_.EndEvent(NetLog::TYPE_SSL_ACCEPT, NULL);
+    return rv;
+  }
+
+  // Set peer address. TODO(hclam): This should be in a separate method.
+  PRNetAddr peername;
+  memset(&peername, 0, sizeof(peername));
+  peername.raw.family = AF_INET;
+  memio_SetPeerName(nss_fd_, &peername);
+
+  GotoState(STATE_HANDSHAKE);
+  rv = DoHandshakeLoop(net::OK);
+  if (rv == ERR_IO_PENDING) {
+    user_accept_callback_ = callback;
+  } else {
+    net_log_.EndEvent(NetLog::TYPE_SSL_ACCEPT, NULL);
+  }
+
+  return rv > OK ? OK : rv;
+}
+
+int SSLServerSocketNSS::Read(IOBuffer* buf, int buf_len,
+                             CompletionCallback* callback) {
+  DCHECK(!user_read_callback_);
+  DCHECK(!user_accept_callback_);
+  DCHECK(!user_read_buf_);
+  DCHECK(nss_bufs_);
+
+  user_read_buf_ = buf;
+  user_read_buf_len_ = buf_len;
+
+  DCHECK(completed_handshake_);
+
+  int rv = DoReadLoop(OK);
+
+  if (rv == ERR_IO_PENDING) {
+    user_read_callback_ = callback;
+  } else {
+    user_read_buf_ = NULL;
+    user_read_buf_len_ = 0;
+  }
+  return rv;
+}
+
+int SSLServerSocketNSS::Write(IOBuffer* buf, int buf_len,
+                              CompletionCallback* callback) {
+  DCHECK(!user_write_callback_);
+  DCHECK(!user_write_buf_);
+  DCHECK(nss_bufs_);
+
+  user_write_buf_ = buf;
+  user_write_buf_len_ = buf_len;
+
+  int rv = DoWriteLoop(OK);
+
+  if (rv == ERR_IO_PENDING) {
+    user_write_callback_ = callback;
+  } else {
+    user_write_buf_ = NULL;
+    user_write_buf_len_ = 0;
+  }
+  return rv;
+}
+
+// static
+// NSS calls this if an incoming certificate needs to be verified.
+// Do nothing but return SECSuccess.
+// This is called only in full handshake mode.
+// Peer certificate is retrieved in HandshakeCallback() later, which is called
+// in full handshake mode or in resumption handshake mode.
+SECStatus SSLServerSocketNSS::OwnAuthCertHandler(void* arg,
+                                                 PRFileDesc* socket,
+                                                 PRBool checksig,
+                                                 PRBool is_server) {
+  // TODO(hclam): Implement.
+  // Tell NSS to not verify the certificate.
+  return SECSuccess;
+}
+
+// static
+// NSS calls this when handshake is completed.
+// After the SSL handshake is finished we need to verify the certificate.
+void SSLServerSocketNSS::HandshakeCallback(PRFileDesc* socket,
+                                           void* arg) {
+  // TODO(hclam): Implement.
+}
+
+int SSLServerSocketNSS::InitializeSSLOptions() {
+  // Transport connected, now hook it up to nss
+  // TODO(port): specify rx and tx buffer sizes separately
+  nss_fd_ = memio_CreateIOLayer(kRecvBufferSize);
+  if (nss_fd_ == NULL) {
+    return ERR_OUT_OF_MEMORY;  // TODO(port): map NSPR error code.
+  }
+
+  // Grab pointer to buffers
+  nss_bufs_ = memio_GetSecret(nss_fd_);
+
+  /* Create SSL state machine */
+  /* Push SSL onto our fake I/O socket */
+  nss_fd_ = SSL_ImportFD(NULL, nss_fd_);
+  if (nss_fd_ == NULL) {
+    LogFailedNSSFunction(net_log_, "SSL_ImportFD", "");
+    return ERR_OUT_OF_MEMORY;  // TODO(port): map NSPR/NSS error code.
+  }
+  // TODO(port): set more ssl options!  Check errors!
+
+  int rv;
+
+  rv = SSL_OptionSet(nss_fd_, SSL_SECURITY, PR_TRUE);
+  if (rv != SECSuccess) {
+    LogFailedNSSFunction(net_log_, "SSL_OptionSet", "SSL_SECURITY");
+    return ERR_UNEXPECTED;
+  }
+
+  rv = SSL_OptionSet(nss_fd_, SSL_ENABLE_SSL2, PR_FALSE);
+  if (rv != SECSuccess) {
+    LogFailedNSSFunction(net_log_, "SSL_OptionSet", "SSL_ENABLE_SSL2");
+    return ERR_UNEXPECTED;
+  }
+
+  rv = SSL_OptionSet(nss_fd_, SSL_ENABLE_SSL3, PR_TRUE);
+  if (rv != SECSuccess) {
+    LogFailedNSSFunction(net_log_, "SSL_OptionSet", "SSL_ENABLE_SSL3");
+    return ERR_UNEXPECTED;
+  }
+
+  rv = SSL_OptionSet(nss_fd_, SSL_ENABLE_TLS, ssl_config_.tls1_enabled);
+  if (rv != SECSuccess) {
+    LogFailedNSSFunction(net_log_, "SSL_OptionSet", "SSL_ENABLE_TLS");
+    return ERR_UNEXPECTED;
+  }
+
+  for (std::vector<uint16>::const_iterator it =
+           ssl_config_.disabled_cipher_suites.begin();
+       it != ssl_config_.disabled_cipher_suites.end(); ++it) {
+    // This will fail if the specified cipher is not implemented by NSS, but
+    // the failure is harmless.
+    SSL_CipherPrefSet(nss_fd_, *it, PR_FALSE);
+  }
+
+  // Server socket doesn't need session tickets.
+  rv = SSL_OptionSet(nss_fd_, SSL_ENABLE_SESSION_TICKETS, PR_FALSE);
+  if (rv != SECSuccess) {
+    LogFailedNSSFunction(
+        net_log_, "SSL_OptionSet", "SSL_ENABLE_SESSION_TICKETS");
+  }
+
+  // Doing this will force PR_Accept perform handshake as server.
+  rv = SSL_OptionSet(nss_fd_, SSL_HANDSHAKE_AS_CLIENT, PR_FALSE);
+  if (rv != SECSuccess) {
+    LogFailedNSSFunction(net_log_, "SSL_OptionSet", "SSL_HANDSHAKE_AS_CLIENT");
+    return ERR_UNEXPECTED;
+  }
+
+  rv = SSL_OptionSet(nss_fd_, SSL_HANDSHAKE_AS_SERVER, PR_TRUE);
+  if (rv != SECSuccess) {
+    LogFailedNSSFunction(net_log_, "SSL_OptionSet", "SSL_HANDSHAKE_AS_SERVER");
+    return ERR_UNEXPECTED;
+  }
+
+  rv = SSL_OptionSet(nss_fd_, SSL_REQUEST_CERTIFICATE, PR_FALSE);
+  if (rv != SECSuccess) {
+    LogFailedNSSFunction(net_log_, "SSL_OptionSet", "SSL_REQUEST_CERTIFICATE");
+    return ERR_UNEXPECTED;
+  }
+
+  rv = SSL_OptionSet(nss_fd_, SSL_REQUIRE_CERTIFICATE, PR_FALSE);
+  if (rv != SECSuccess) {
+    LogFailedNSSFunction(net_log_, "SSL_OptionSet", "SSL_REQUIRE_CERTIFICATE");
+    return ERR_UNEXPECTED;
+  }
+
+  rv = SSL_OptionSet(nss_fd_, SSL_NO_CACHE, PR_TRUE);
+  if (rv != SECSuccess) {
+    LogFailedNSSFunction(net_log_, "SSL_OptionSet", "SSL_NO_CACHE");
+    return ERR_UNEXPECTED;
+  }
+
+  rv = SSL_AuthCertificateHook(nss_fd_, OwnAuthCertHandler, this);
+  if (rv != SECSuccess) {
+    LogFailedNSSFunction(net_log_, "SSL_AuthCertificateHook", "");
+    return ERR_UNEXPECTED;
+  }
+
+  rv = SSL_HandshakeCallback(nss_fd_, HandshakeCallback, this);
+  if (rv != SECSuccess) {
+    LogFailedNSSFunction(net_log_, "SSL_HandshakeCallback", "");
+    return ERR_UNEXPECTED;
+  }
+
+  // Assign server certificate and private key.
+  SSLKEAType cert_kea = NSS_FindCertKEAType(cert_->os_cert_handle());
+  rv = SSL_ConfigSecureServer(nss_fd_, cert_->os_cert_handle(),
+                              key_->key(), cert_kea);
+  if (rv != SECSuccess) {
+    PRErrorCode prerr = PR_GetError();
+    LOG(ERROR) << "Failed to config SSL server: " << prerr;
+    LogFailedNSSFunction(net_log_, "SSL_ConfigureSecureServer", "");
+    return ERR_UNEXPECTED;
+  }
+
+  // Tell SSL we're a server; needed if not letting NSPR do socket I/O
+  rv = SSL_ResetHandshake(nss_fd_, PR_TRUE);
+  if (rv != SECSuccess) {
+    LogFailedNSSFunction(net_log_, "SSL_ResetHandshake", "");
+    return ERR_UNEXPECTED;
+  }
+
+  return OK;
+}
+
+// Return 0 for EOF,
+// > 0 for bytes transferred immediately,
+// < 0 for error (or the non-error ERR_IO_PENDING).
+int SSLServerSocketNSS::BufferSend(void) {
+  if (transport_send_busy_)
+    return ERR_IO_PENDING;
+
+  const char* buf1;
+  const char* buf2;
+  unsigned int len1, len2;
+  memio_GetWriteParams(nss_bufs_, &buf1, &len1, &buf2, &len2);
+  const unsigned int len = len1 + len2;
+
+  int rv = 0;
+  if (len) {
+    scoped_refptr<IOBuffer> send_buffer(new IOBuffer(len));
+    memcpy(send_buffer->data(), buf1, len1);
+    memcpy(send_buffer->data() + len1, buf2, len2);
+    rv = socket_->Write(send_buffer, len,
+                        &buffer_send_callback_);
+    if (rv == ERR_IO_PENDING) {
+      transport_send_busy_ = true;
+    } else {
+      memio_PutWriteResult(nss_bufs_, MapErrorToNSS(rv));
+    }
+  }
+
+  return rv;
+}
+
+void SSLServerSocketNSS::BufferSendComplete(int result) {
+  memio_PutWriteResult(nss_bufs_, MapErrorToNSS(result));
+  transport_send_busy_ = false;
+  OnSendComplete(result);
+}
+
+int SSLServerSocketNSS::BufferRecv(void) {
+  if (transport_recv_busy_) return ERR_IO_PENDING;
+
+  char *buf;
+  int nb = memio_GetReadParams(nss_bufs_, &buf);
+  int rv;
+  if (!nb) {
+    // buffer too full to read into, so no I/O possible at moment
+    rv = ERR_IO_PENDING;
+  } else {
+    recv_buffer_ = new IOBuffer(nb);
+    rv = socket_->Read(recv_buffer_, nb, &buffer_recv_callback_);
+    if (rv == ERR_IO_PENDING) {
+      transport_recv_busy_ = true;
+    } else {
+      if (rv > 0)
+        memcpy(buf, recv_buffer_->data(), rv);
+      memio_PutReadResult(nss_bufs_, MapErrorToNSS(rv));
+      recv_buffer_ = NULL;
+    }
+  }
+  return rv;
+}
+
+void SSLServerSocketNSS::BufferRecvComplete(int result) {
+  if (result > 0) {
+    char *buf;
+    memio_GetReadParams(nss_bufs_, &buf);
+    memcpy(buf, recv_buffer_->data(), result);
+  }
+  recv_buffer_ = NULL;
+  memio_PutReadResult(nss_bufs_, MapErrorToNSS(result));
+  transport_recv_busy_ = false;
+  OnRecvComplete(result);
+}
+
+void SSLServerSocketNSS::OnSendComplete(int result) {
+  if (next_handshake_state_ == STATE_HANDSHAKE) {
+    // In handshake phase.
+    OnHandshakeIOComplete(result);
+    return;
+  }
+
+  // OnSendComplete may need to call DoPayloadRead while the renegotiation

[wtc, 2010/12/17 00:16:26]

You should omit the renegotiation-related code, which is
client-side specific.

[Alpha Left Google, 2010/12/17 08:30:43]

Done.

+  // handshake is in progress.
+  int rv_read = ERR_IO_PENDING;
+  int rv_write = ERR_IO_PENDING;
+  bool network_moved;
+  do {
+      if (user_read_buf_)
+          rv_read = DoPayloadRead();
+      if (user_write_buf_)
+          rv_write = DoPayloadWrite();
+      network_moved = DoTransportIO();
+  } while (rv_read == ERR_IO_PENDING &&
+           rv_write == ERR_IO_PENDING &&
+           network_moved);
+
+  if (user_read_buf_ && rv_read != ERR_IO_PENDING)
+      DoReadCallback(rv_read);
+  if (user_write_buf_ && rv_write != ERR_IO_PENDING)
+      DoWriteCallback(rv_write);
+}
+
+void SSLServerSocketNSS::OnRecvComplete(int result) {
+  if (next_handshake_state_ == STATE_HANDSHAKE) {
+    // In handshake phase.
+    OnHandshakeIOComplete(result);
+    return;
+  }
+
+  // Network layer received some data, check if client requested to read
+  // decrypted data.
+  if (!user_read_buf_ || !completed_handshake_) {
+    return;
+  }
+
+  int rv = DoReadLoop(result);
+  if (rv != ERR_IO_PENDING)
+    DoReadCallback(rv);
+}
+
+void SSLServerSocketNSS::OnHandshakeIOComplete(int result) {
+  int rv = DoHandshakeLoop(result);
+  if (rv != ERR_IO_PENDING) {
+    net_log_.EndEvent(net::NetLog::TYPE_SSL_ACCEPT, NULL);
+    if (user_accept_callback_)
+      DoAcceptCallback(rv);
+  }
+}
+
+void SSLServerSocketNSS::DoAcceptCallback(int rv) {
+  DCHECK_NE(rv, ERR_IO_PENDING);
+
+  CompletionCallback* c = user_accept_callback_;
+  user_accept_callback_ = NULL;
+  c->Run(rv > OK ? OK : rv);
+}
+
+void SSLServerSocketNSS::DoReadCallback(int rv) {
+  DCHECK(rv != ERR_IO_PENDING);
+  DCHECK(user_read_callback_);
+
+  // Since Run may result in Read being called, clear |user_read_callback_|
+  // up front.
+  CompletionCallback* c = user_read_callback_;
+  user_read_callback_ = NULL;
+  user_read_buf_ = NULL;
+  user_read_buf_len_ = 0;
+  c->Run(rv);
+}
+
+void SSLServerSocketNSS::DoWriteCallback(int rv) {
+  DCHECK(rv != ERR_IO_PENDING);
+  DCHECK(user_write_callback_);
+
+  // Since Run may result in Write being called, clear |user_write_callback_|
+  // up front.
+  CompletionCallback* c = user_write_callback_;
+  user_write_callback_ = NULL;
+  user_write_buf_ = NULL;
+  user_write_buf_len_ = 0;
+  c->Run(rv);
+}
+
+// Do network I/O between the given buffer and the given socket.
+// Return true if some I/O performed, false otherwise (error or ERR_IO_PENDING)
+bool SSLServerSocketNSS::DoTransportIO() {
+  bool network_moved = false;
+  if (nss_bufs_ != NULL) {
+    int nsent = BufferSend();
+    int nreceived = BufferRecv();
+    network_moved = (nsent > 0 || nreceived >= 0);
+  }
+  return network_moved;
+}
+
+int SSLServerSocketNSS::DoPayloadRead() {
+  DCHECK(user_read_buf_);
+  DCHECK_GT(user_read_buf_len_, 0);
+  int rv = PR_Read(nss_fd_, user_read_buf_->data(), user_read_buf_len_);
+  if (rv >= 0)
+    return rv;
+  PRErrorCode prerr = PR_GetError();
+  if (prerr == PR_WOULD_BLOCK_ERROR) {
+    return ERR_IO_PENDING;
+  }
+  rv = MapNSPRError(prerr);
+  net_log_.AddEvent(NetLog::TYPE_SSL_READ_ERROR,
+                    make_scoped_refptr(new SSLErrorParams(rv, prerr)));
+  return rv;
+}
+
+int SSLServerSocketNSS::DoPayloadWrite() {
+  DCHECK(user_write_buf_);
+  int rv = PR_Write(nss_fd_, user_write_buf_->data(), user_write_buf_len_);
+  if (rv >= 0)
+    return rv;
+  PRErrorCode prerr = PR_GetError();
+  if (prerr == PR_WOULD_BLOCK_ERROR) {
+    return ERR_IO_PENDING;
+  }
+  rv = MapNSPRError(prerr);
+  net_log_.AddEvent(NetLog::TYPE_SSL_WRITE_ERROR,
+                    make_scoped_refptr(new SSLErrorParams(rv, prerr)));
+  return rv;
+}
+
+int SSLServerSocketNSS::DoHandshakeLoop(int last_io_result) {
+  bool network_moved;
+  int rv = last_io_result;
+  do {
+    // Default to STATE_NONE for next state.
+    // (This is a quirk carried over from the windows
+    // implementation.  It makes reading the logs a bit harder.)
+    // State handlers can and often do call GotoState just
+    // to stay in the current state.
+    State state = next_handshake_state_;
+    GotoState(STATE_NONE);
+    switch (state) {
+      case STATE_NONE:
+        // we're just pumping data between the buffer and the network
+        break;
+      case STATE_HANDSHAKE:
+        rv = DoHandshake();
+        break;
+      default:
+        rv = ERR_UNEXPECTED;
+        LOG(DFATAL) << "unexpected state " << state;
+        break;
+    }
+
+    // Do the actual network I/O
+    network_moved = DoTransportIO();
+  } while ((rv != ERR_IO_PENDING || network_moved) &&
+           next_handshake_state_ != STATE_NONE);
+  return rv;
+}
+
+int SSLServerSocketNSS::DoReadLoop(int result) {
+  DCHECK(completed_handshake_);
+  DCHECK(next_handshake_state_ == STATE_NONE);
+
+  if (result < 0)
+    return result;
+
+  if (!nss_bufs_) {
+    LOG(DFATAL) << "!nss_bufs_";
+    int rv = ERR_UNEXPECTED;
+    net_log_.AddEvent(NetLog::TYPE_SSL_READ_ERROR,
+                      make_scoped_refptr(new SSLErrorParams(rv, 0)));
+    return rv;
+  }
+
+  bool network_moved;
+  int rv;
+  do {
+    rv = DoPayloadRead();
+    network_moved = DoTransportIO();
+  } while (rv == ERR_IO_PENDING && network_moved);
+  return rv;
+}
+
+int SSLServerSocketNSS::DoWriteLoop(int result) {
+  DCHECK(completed_handshake_);
+  DCHECK(next_handshake_state_ == STATE_NONE);
+
+  if (result < 0)
+    return result;
+
+  if (!nss_bufs_) {
+    LOG(DFATAL) << "!nss_bufs_";
+    int rv = ERR_UNEXPECTED;
+    net_log_.AddEvent(NetLog::TYPE_SSL_WRITE_ERROR,
+                      make_scoped_refptr(new SSLErrorParams(rv, 0)));
+    return rv;
+  }
+
+  bool network_moved;
+  int rv;
+  do {
+    rv = DoPayloadWrite();
+    network_moved = DoTransportIO();
+  } while (rv == ERR_IO_PENDING && network_moved);
+  return rv;
+}
+
+int SSLServerSocketNSS::DoHandshake() {
+  int net_error = net::OK;
+  SECStatus rv = SSL_ForceHandshake(nss_fd_);
+
+  if (rv == SECSuccess) {
+    completed_handshake_ = true;
+  } else {
+    PRErrorCode prerr = PR_GetError();
+    net_error = MapHandshakeError(prerr);
+
+    // If not done, stay in this state
+    if (net_error == ERR_IO_PENDING) {
+      GotoState(STATE_HANDSHAKE);
+    } else {
+      LOG(ERROR) << "handshake failed; NSS error code " << prerr
+                 << ", net_error " << net_error;
+      net_log_.AddEvent(
+          NetLog::TYPE_SSL_HANDSHAKE_ERROR,
+          make_scoped_refptr(new SSLErrorParams(net_error, prerr)));
+    }
+  }
+  return net_error;
+}
+
+}  // namespace net