gecko-dev/netwerk/socket/nsSOCKSIOLayer.cpp

1357 строки
40 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim:set expandtab ts=4 sw=4 sts=4 cin: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nspr.h"
#include "private/pprio.h"
#include "nsString.h"
#include "nsCRT.h"
#include "nsIServiceManager.h"
#include "nsIDNSService.h"
#include "nsIDNSRecord.h"
#include "nsISOCKSSocketInfo.h"
#include "nsISocketProvider.h"
#include "nsSOCKSIOLayer.h"
#include "nsNetCID.h"
#include "nsIDNSListener.h"
#include "nsICancelable.h"
#include "nsThreadUtils.h"
#include "mozilla/net/DNS.h"
using namespace mozilla::net;
static PRDescIdentity nsSOCKSIOLayerIdentity;
static PRIOMethods nsSOCKSIOLayerMethods;
static bool firstTime = true;
static bool ipv6Supported = true;
#if defined(PR_LOGGING)
static PRLogModuleInfo *gSOCKSLog;
#define LOGDEBUG(args) PR_LOG(gSOCKSLog, PR_LOG_DEBUG, args)
#define LOGERROR(args) PR_LOG(gSOCKSLog, PR_LOG_ERROR , args)
#else
#define LOGDEBUG(args)
#define LOGERROR(args)
#endif
class nsSOCKSSocketInfo : public nsISOCKSSocketInfo
, public nsIDNSListener
{
enum State {
SOCKS_INITIAL,
SOCKS_DNS_IN_PROGRESS,
SOCKS_DNS_COMPLETE,
SOCKS_CONNECTING_TO_PROXY,
SOCKS4_WRITE_CONNECT_REQUEST,
SOCKS4_READ_CONNECT_RESPONSE,
SOCKS5_WRITE_AUTH_REQUEST,
SOCKS5_READ_AUTH_RESPONSE,
SOCKS5_WRITE_CONNECT_REQUEST,
SOCKS5_READ_CONNECT_RESPONSE_TOP,
SOCKS5_READ_CONNECT_RESPONSE_BOTTOM,
SOCKS_CONNECTED,
SOCKS_FAILED
};
// A buffer of 265 bytes should be enough for any request and response
// in case of SOCKS4 as well as SOCKS5
static const uint32_t BUFFER_SIZE = 265;
static const uint32_t MAX_HOSTNAME_LEN = 255;
public:
nsSOCKSSocketInfo();
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSISOCKSSOCKETINFO
NS_DECL_NSIDNSLISTENER
void Init(int32_t version,
int32_t family,
const char *proxyHost,
int32_t proxyPort,
const char *destinationHost,
uint32_t flags);
void SetConnectTimeout(PRIntervalTime to);
PRStatus DoHandshake(PRFileDesc *fd, int16_t oflags = -1);
int16_t GetPollFlags() const;
bool IsConnected() const { return mState == SOCKS_CONNECTED; }
void ForgetFD() { mFD = nullptr; }
private:
virtual ~nsSOCKSSocketInfo() { HandshakeFinished(); }
void HandshakeFinished(PRErrorCode err = 0);
PRStatus StartDNS(PRFileDesc *fd);
PRStatus ConnectToProxy(PRFileDesc *fd);
void FixupAddressFamily(PRFileDesc *fd, NetAddr *proxy);
PRStatus ContinueConnectingToProxy(PRFileDesc *fd, int16_t oflags);
PRStatus WriteV4ConnectRequest();
PRStatus ReadV4ConnectResponse();
PRStatus WriteV5AuthRequest();
PRStatus ReadV5AuthResponse();
PRStatus WriteV5ConnectRequest();
PRStatus ReadV5AddrTypeAndLength(uint8_t *type, uint32_t *len);
PRStatus ReadV5ConnectResponseTop();
PRStatus ReadV5ConnectResponseBottom();
uint8_t ReadUint8();
uint16_t ReadUint16();
uint32_t ReadUint32();
void ReadNetAddr(NetAddr *addr, uint16_t fam);
void ReadNetPort(NetAddr *addr);
void WantRead(uint32_t sz);
PRStatus ReadFromSocket(PRFileDesc *fd);
PRStatus WriteToSocket(PRFileDesc *fd);
private:
State mState;
uint8_t * mData;
uint8_t * mDataIoPtr;
uint32_t mDataLength;
uint32_t mReadOffset;
uint32_t mAmountToRead;
nsCOMPtr<nsIDNSRecord> mDnsRec;
nsCOMPtr<nsICancelable> mLookup;
nsresult mLookupStatus;
PRFileDesc *mFD;
nsCString mDestinationHost;
nsCString mProxyHost;
int32_t mProxyPort;
int32_t mVersion; // SOCKS version 4 or 5
int32_t mDestinationFamily;
uint32_t mFlags;
NetAddr mInternalProxyAddr;
NetAddr mExternalProxyAddr;
NetAddr mDestinationAddr;
PRIntervalTime mTimeout;
};
nsSOCKSSocketInfo::nsSOCKSSocketInfo()
: mState(SOCKS_INITIAL)
, mDataIoPtr(nullptr)
, mDataLength(0)
, mReadOffset(0)
, mAmountToRead(0)
, mProxyPort(-1)
, mVersion(-1)
, mDestinationFamily(AF_INET)
, mFlags(0)
, mTimeout(PR_INTERVAL_NO_TIMEOUT)
{
mData = new uint8_t[BUFFER_SIZE];
mInternalProxyAddr.raw.family = AF_INET;
mInternalProxyAddr.inet.ip = htonl(INADDR_ANY);
mInternalProxyAddr.inet.port = htons(0);
mExternalProxyAddr.raw.family = AF_INET;
mExternalProxyAddr.inet.ip = htonl(INADDR_ANY);
mExternalProxyAddr.inet.port = htons(0);
mDestinationAddr.raw.family = AF_INET;
mDestinationAddr.inet.ip = htonl(INADDR_ANY);
mDestinationAddr.inet.port = htons(0);
}
/* Helper template class to statically check that writes to a fixed-size
* buffer are not going to overflow.
*
* Example usage:
* uint8_t real_buf[TOTAL_SIZE];
* Buffer<TOTAL_SIZE> buf(&real_buf);
* auto buf2 = buf.WriteUint16(1);
* auto buf3 = buf2.WriteUint8(2);
*
* It is possible to chain them, to limit the number of (error-prone)
* intermediate variables:
* auto buf = Buffer<TOTAL_SIZE>(&real_buf)
* .WriteUint16(1)
* .WriteUint8(2);
*
* Debug builds assert when intermediate variables are reused:
* Buffer<TOTAL_SIZE> buf(&real_buf);
* auto buf2 = buf.WriteUint16(1);
* auto buf3 = buf.WriteUint8(2); // Asserts
*
* Strings can be written, given an explicit maximum length.
* buf.WriteString<MAX_STRING_LENGTH>(str);
*
* The Written() method returns how many bytes have been written so far:
* Buffer<TOTAL_SIZE> buf(&real_buf);
* auto buf2 = buf.WriteUint16(1);
* auto buf3 = buf2.WriteUint8(2);
* buf3.Written(); // returns 3.
*/
template <size_t Size>
class Buffer
{
public:
Buffer() : mBuf(nullptr), mLength(0) {}
explicit Buffer(uint8_t* aBuf, size_t aLength=0)
: mBuf(aBuf), mLength(aLength) {}
template <size_t Size2>
Buffer(const Buffer<Size2>& aBuf) : mBuf(aBuf.mBuf), mLength(aBuf.mLength) {
static_assert(Size2 > Size, "Cannot cast buffer");
}
Buffer<Size - sizeof(uint8_t)> WriteUint8(uint8_t aValue) {
return Write(aValue);
}
Buffer<Size - sizeof(uint16_t)> WriteUint16(uint16_t aValue) {
return Write(aValue);
}
Buffer<Size - sizeof(uint32_t)> WriteUint32(uint32_t aValue) {
return Write(aValue);
}
Buffer<Size - sizeof(uint16_t)> WriteNetPort(const NetAddr* aAddr) {
return WriteUint16(aAddr->inet.port);
}
Buffer<Size - sizeof(IPv6Addr)> WriteNetAddr(const NetAddr* aAddr) {
if (aAddr->raw.family == AF_INET) {
return Write(aAddr->inet.ip);
} else if (aAddr->raw.family == AF_INET6) {
return Write(aAddr->inet6.ip.u8);
}
NS_NOTREACHED("Unknown address family");
return *this;
}
template <size_t MaxLength>
Buffer<Size - MaxLength> WriteString(const nsACString& aStr) {
if (aStr.Length() > MaxLength) {
return Buffer<Size - MaxLength>(nullptr);
}
return WritePtr<char, MaxLength>(aStr.Data(), aStr.Length());
}
size_t Written() {
MOZ_ASSERT(mBuf);
return mLength;
}
operator bool() { return !!mBuf; }
private:
template <size_t Size2>
friend class Buffer;
template <typename T>
Buffer<Size - sizeof(T)> Write(T& aValue) {
return WritePtr<T, sizeof(T)>(&aValue, sizeof(T));
}
template <typename T, size_t Length>
Buffer<Size - Length> WritePtr(const T* aValue, size_t aCopyLength) {
static_assert(Size >= Length, "Cannot write that much");
MOZ_ASSERT(aCopyLength <= Length);
MOZ_ASSERT(mBuf);
memcpy(mBuf, aValue, aCopyLength);
Buffer<Size - Length> result(mBuf + aCopyLength, mLength + aCopyLength);
mBuf = nullptr;
mLength = 0;
return result;
}
uint8_t* mBuf;
size_t mLength;
};
void
nsSOCKSSocketInfo::Init(int32_t version, int32_t family, const char *proxyHost, int32_t proxyPort, const char *host, uint32_t flags)
{
mVersion = version;
mDestinationFamily = family;
mProxyHost = proxyHost;
mProxyPort = proxyPort;
mDestinationHost = host;
mFlags = flags;
}
NS_IMPL_ISUPPORTS(nsSOCKSSocketInfo, nsISOCKSSocketInfo, nsIDNSListener)
NS_IMETHODIMP
nsSOCKSSocketInfo::GetExternalProxyAddr(NetAddr * *aExternalProxyAddr)
{
memcpy(*aExternalProxyAddr, &mExternalProxyAddr, sizeof(NetAddr));
return NS_OK;
}
NS_IMETHODIMP
nsSOCKSSocketInfo::SetExternalProxyAddr(NetAddr *aExternalProxyAddr)
{
memcpy(&mExternalProxyAddr, aExternalProxyAddr, sizeof(NetAddr));
return NS_OK;
}
NS_IMETHODIMP
nsSOCKSSocketInfo::GetDestinationAddr(NetAddr * *aDestinationAddr)
{
memcpy(*aDestinationAddr, &mDestinationAddr, sizeof(NetAddr));
return NS_OK;
}
NS_IMETHODIMP
nsSOCKSSocketInfo::SetDestinationAddr(NetAddr *aDestinationAddr)
{
memcpy(&mDestinationAddr, aDestinationAddr, sizeof(NetAddr));
return NS_OK;
}
NS_IMETHODIMP
nsSOCKSSocketInfo::GetInternalProxyAddr(NetAddr * *aInternalProxyAddr)
{
memcpy(*aInternalProxyAddr, &mInternalProxyAddr, sizeof(NetAddr));
return NS_OK;
}
NS_IMETHODIMP
nsSOCKSSocketInfo::SetInternalProxyAddr(NetAddr *aInternalProxyAddr)
{
memcpy(&mInternalProxyAddr, aInternalProxyAddr, sizeof(NetAddr));
return NS_OK;
}
// There needs to be a means of distinguishing between connection errors
// that the SOCKS server reports when it rejects a connection request, and
// connection errors that happen while attempting to connect to the SOCKS
// server. Otherwise, Firefox will report incorrectly that the proxy server
// is refusing connections when a SOCKS request is rejected by the proxy.
// When a SOCKS handshake failure occurs, the PR error is set to
// PR_UNKNOWN_ERROR, and the real error code is returned via the OS error.
void
nsSOCKSSocketInfo::HandshakeFinished(PRErrorCode err)
{
if (err == 0) {
mState = SOCKS_CONNECTED;
} else {
mState = SOCKS_FAILED;
PR_SetError(PR_UNKNOWN_ERROR, err);
}
// We don't need the buffer any longer, so free it.
delete [] mData;
mData = nullptr;
mDataIoPtr = nullptr;
mDataLength = 0;
mReadOffset = 0;
mAmountToRead = 0;
if (mLookup) {
mLookup->Cancel(NS_ERROR_FAILURE);
mLookup = nullptr;
}
}
PRStatus
nsSOCKSSocketInfo::StartDNS(PRFileDesc *fd)
{
NS_ABORT_IF_FALSE(!mDnsRec && mState == SOCKS_INITIAL,
"Must be in initial state to make DNS Lookup");
nsCOMPtr<nsIDNSService> dns = do_GetService(NS_DNSSERVICE_CONTRACTID);
if (!dns)
return PR_FAILURE;
mFD = fd;
nsresult rv = dns->AsyncResolve(mProxyHost, 0, this,
NS_GetCurrentThread(),
getter_AddRefs(mLookup));
if (NS_FAILED(rv)) {
LOGERROR(("socks: DNS lookup for SOCKS proxy %s failed",
mProxyHost.get()));
return PR_FAILURE;
}
mState = SOCKS_DNS_IN_PROGRESS;
PR_SetError(PR_IN_PROGRESS_ERROR, 0);
return PR_FAILURE;
}
NS_IMETHODIMP
nsSOCKSSocketInfo::OnLookupComplete(nsICancelable *aRequest,
nsIDNSRecord *aRecord,
nsresult aStatus)
{
NS_ABORT_IF_FALSE(aRequest == mLookup, "wrong DNS query");
mLookup = nullptr;
mLookupStatus = aStatus;
mDnsRec = aRecord;
mState = SOCKS_DNS_COMPLETE;
if (mFD) {
ConnectToProxy(mFD);
ForgetFD();
}
return NS_OK;
}
PRStatus
nsSOCKSSocketInfo::ConnectToProxy(PRFileDesc *fd)
{
PRStatus status;
nsresult rv;
NS_ABORT_IF_FALSE(mState == SOCKS_DNS_COMPLETE,
"Must have DNS to make connection!");
if (NS_FAILED(mLookupStatus)) {
PR_SetError(PR_BAD_ADDRESS_ERROR, 0);
return PR_FAILURE;
}
// Try socks5 if the destination addrress is IPv6
if (mVersion == 4 &&
mDestinationAddr.raw.family == AF_INET6) {
mVersion = 5;
}
int32_t addresses = 0;
do {
if (addresses++)
mDnsRec->ReportUnusable(mProxyPort);
rv = mDnsRec->GetNextAddr(mProxyPort, &mInternalProxyAddr);
// No more addresses to try? If so, we'll need to bail
if (NS_FAILED(rv)) {
LOGERROR(("socks: unable to connect to SOCKS proxy, %s",
mProxyHost.get()));
return PR_FAILURE;
}
#if defined(PR_LOGGING)
char buf[kIPv6CStrBufSize];
NetAddrToString(&mInternalProxyAddr, buf, sizeof(buf));
LOGDEBUG(("socks: trying proxy server, %s:%hu",
buf, ntohs(mInternalProxyAddr.inet.port)));
#endif
NetAddr proxy = mInternalProxyAddr;
FixupAddressFamily(fd, &proxy);
PRNetAddr prProxy;
NetAddrToPRNetAddr(&proxy, &prProxy);
status = fd->lower->methods->connect(fd->lower, &prProxy, mTimeout);
if (status != PR_SUCCESS) {
PRErrorCode c = PR_GetError();
// If EINPROGRESS, return now and check back later after polling
if (c == PR_WOULD_BLOCK_ERROR || c == PR_IN_PROGRESS_ERROR) {
mState = SOCKS_CONNECTING_TO_PROXY;
return status;
}
}
} while (status != PR_SUCCESS);
// Connected now, start SOCKS
if (mVersion == 4)
return WriteV4ConnectRequest();
return WriteV5AuthRequest();
}
void
nsSOCKSSocketInfo::FixupAddressFamily(PRFileDesc *fd, NetAddr *proxy)
{
int32_t proxyFamily = mInternalProxyAddr.raw.family;
// Do nothing if the address family is already matched
if (proxyFamily == mDestinationFamily) {
return;
}
// If the system does not support IPv6 and the proxy address is IPv6,
// We can do nothing here.
if (proxyFamily == AF_INET6 && !ipv6Supported) {
return;
}
// If the system does not support IPv6 and the destination address is
// IPv6, convert IPv4 address to IPv4-mapped IPv6 address to satisfy
// the emulation layer
if (mDestinationFamily == AF_INET6 && !ipv6Supported) {
proxy->inet6.family = AF_INET6;
proxy->inet6.port = mInternalProxyAddr.inet.port;
uint8_t *proxyp = proxy->inet6.ip.u8;
memset(proxyp, 0, 10);
memset(proxyp + 10, 0xff, 2);
memcpy(proxyp + 12,(char *) &mInternalProxyAddr.inet.ip, 4);
// mDestinationFamily should not be updated
return;
}
// Get an OS native handle from a specified FileDesc
PROsfd osfd = PR_FileDesc2NativeHandle(fd);
if (osfd == -1) {
return;
}
// Create a new FileDesc with a specified family
PRFileDesc *tmpfd = PR_OpenTCPSocket(proxyFamily);
if (!tmpfd) {
return;
}
PROsfd newsd = PR_FileDesc2NativeHandle(tmpfd);
if (newsd == -1) {
PR_Close(tmpfd);
return;
}
// Must succeed because PR_FileDesc2NativeHandle succeeded
fd = PR_GetIdentitiesLayer(fd, PR_NSPR_IO_LAYER);
MOZ_ASSERT(fd);
// Swap OS native handles
PR_ChangeFileDescNativeHandle(fd, newsd);
PR_ChangeFileDescNativeHandle(tmpfd, osfd);
// Close temporary FileDesc which is now associated with
// old OS native handle
PR_Close(tmpfd);
mDestinationFamily = proxyFamily;
}
PRStatus
nsSOCKSSocketInfo::ContinueConnectingToProxy(PRFileDesc *fd, int16_t oflags)
{
PRStatus status;
NS_ABORT_IF_FALSE(mState == SOCKS_CONNECTING_TO_PROXY,
"Continuing connection in wrong state!");
LOGDEBUG(("socks: continuing connection to proxy"));
status = fd->lower->methods->connectcontinue(fd->lower, oflags);
if (status != PR_SUCCESS) {
PRErrorCode c = PR_GetError();
if (c != PR_WOULD_BLOCK_ERROR && c != PR_IN_PROGRESS_ERROR) {
// A connection failure occured, try another address
mState = SOCKS_DNS_COMPLETE;
return ConnectToProxy(fd);
}
// We're still connecting
return PR_FAILURE;
}
// Connected now, start SOCKS
if (mVersion == 4)
return WriteV4ConnectRequest();
return WriteV5AuthRequest();
}
PRStatus
nsSOCKSSocketInfo::WriteV4ConnectRequest()
{
NetAddr *addr = &mDestinationAddr;
int32_t proxy_resolve;
NS_ABORT_IF_FALSE(mState == SOCKS_CONNECTING_TO_PROXY,
"Invalid state!");
proxy_resolve = mFlags & nsISocketProvider::PROXY_RESOLVES_HOST;
mDataLength = 0;
mState = SOCKS4_WRITE_CONNECT_REQUEST;
LOGDEBUG(("socks4: sending connection request (socks4a resolve? %s)",
proxy_resolve? "yes" : "no"));
// Send a SOCKS 4 connect request.
auto buf = Buffer<BUFFER_SIZE>(mData)
.WriteUint8(0x04) // version -- 4
.WriteUint8(0x01) // command -- connect
.WriteNetPort(addr);
// We don't have anything more to write after the if, so we can
// use a buffer with no further writes allowed.
Buffer<0> buf3;
if (proxy_resolve) {
// Add the full name, null-terminated, to the request
// according to SOCKS 4a. A fake IP address, with the first
// four bytes set to 0 and the last byte set to something other
// than 0, is used to notify the proxy that this is a SOCKS 4a
// request. This request type works for Tor and perhaps others.
auto buf2 = buf.WriteUint32(htonl(0x00000001)) // Fake IP
.WriteUint8(0x00) // Send an emtpy username
.WriteString<MAX_HOSTNAME_LEN>(mDestinationHost); // Hostname
if (!buf2) {
LOGERROR(("socks4: destination host name is too long!"));
HandshakeFinished(PR_BAD_ADDRESS_ERROR);
return PR_FAILURE;
}
buf3 = buf2.WriteUint8(0x00);
} else if (addr->raw.family == AF_INET) {
buf3 = buf.WriteNetAddr(addr) // Add the IPv4 address
.WriteUint8(0x00); // Send an emtpy username
} else {
LOGERROR(("socks: SOCKS 4 can only handle IPv4 addresses!"));
HandshakeFinished(PR_BAD_ADDRESS_ERROR);
return PR_FAILURE;
}
mDataLength = buf3.Written();
return PR_SUCCESS;
}
PRStatus
nsSOCKSSocketInfo::ReadV4ConnectResponse()
{
NS_ABORT_IF_FALSE(mState == SOCKS4_READ_CONNECT_RESPONSE,
"Handling SOCKS 4 connection reply in wrong state!");
NS_ABORT_IF_FALSE(mDataLength == 8,
"SOCKS 4 connection reply must be 8 bytes!");
LOGDEBUG(("socks4: checking connection reply"));
if (ReadUint8() != 0x00) {
LOGERROR(("socks4: wrong connection reply"));
HandshakeFinished(PR_CONNECT_REFUSED_ERROR);
return PR_FAILURE;
}
// See if our connection request was granted
if (ReadUint8() == 90) {
LOGDEBUG(("socks4: connection successful!"));
HandshakeFinished();
return PR_SUCCESS;
}
LOGERROR(("socks4: unable to connect"));
HandshakeFinished(PR_CONNECT_REFUSED_ERROR);
return PR_FAILURE;
}
PRStatus
nsSOCKSSocketInfo::WriteV5AuthRequest()
{
NS_ABORT_IF_FALSE(mVersion == 5, "SOCKS version must be 5!");
mState = SOCKS5_WRITE_AUTH_REQUEST;
// Send an initial SOCKS 5 greeting
LOGDEBUG(("socks5: sending auth methods"));
mDataLength = Buffer<BUFFER_SIZE>(mData)
.WriteUint8(0x05) // version -- 5
.WriteUint8(0x01) // # auth methods -- 1
.WriteUint8(0x00) // we don't support authentication
.Written();
return PR_SUCCESS;
}
PRStatus
nsSOCKSSocketInfo::ReadV5AuthResponse()
{
NS_ABORT_IF_FALSE(mState == SOCKS5_READ_AUTH_RESPONSE,
"Handling SOCKS 5 auth method reply in wrong state!");
NS_ABORT_IF_FALSE(mDataLength == 2,
"SOCKS 5 auth method reply must be 2 bytes!");
LOGDEBUG(("socks5: checking auth method reply"));
// Check version number
if (ReadUint8() != 0x05) {
LOGERROR(("socks5: unexpected version in the reply"));
HandshakeFinished(PR_CONNECT_REFUSED_ERROR);
return PR_FAILURE;
}
// Make sure our authentication choice was accepted
if (ReadUint8() != 0x00) {
LOGERROR(("socks5: server did not accept our authentication method"));
HandshakeFinished(PR_CONNECT_REFUSED_ERROR);
return PR_FAILURE;
}
return WriteV5ConnectRequest();
}
PRStatus
nsSOCKSSocketInfo::WriteV5ConnectRequest()
{
// Send SOCKS 5 connect request
NetAddr *addr = &mDestinationAddr;
int32_t proxy_resolve;
proxy_resolve = mFlags & nsISocketProvider::PROXY_RESOLVES_HOST;
LOGDEBUG(("socks5: sending connection request (socks5 resolve? %s)",
proxy_resolve? "yes" : "no"));
mDataLength = 0;
mState = SOCKS5_WRITE_CONNECT_REQUEST;
auto buf = Buffer<BUFFER_SIZE>(mData)
.WriteUint8(0x05) // version -- 5
.WriteUint8(0x01) // command -- connect
.WriteUint8(0x00); // reserved
// We're writing a net port after the if, so we need a buffer allowing
// to write that much.
Buffer<sizeof(uint16_t)> buf2;
// Add the address to the SOCKS 5 request. SOCKS 5 supports several
// address types, so we pick the one that works best for us.
if (proxy_resolve) {
// Add the host name. Only a single byte is used to store the length,
// so we must prevent long names from being used.
buf2 = buf.WriteUint8(0x03) // addr type -- domainname
.WriteUint8(mDestinationHost.Length()) // name length
.WriteString<MAX_HOSTNAME_LEN>(mDestinationHost); // Hostname
if (!buf2) {
LOGERROR(("socks5: destination host name is too long!"));
HandshakeFinished(PR_BAD_ADDRESS_ERROR);
return PR_FAILURE;
}
} else if (addr->raw.family == AF_INET) {
buf2 = buf.WriteUint8(0x01) // addr type -- IPv4
.WriteNetAddr(addr);
} else if (addr->raw.family == AF_INET6) {
buf2 = buf.WriteUint8(0x04) // addr type -- IPv6
.WriteNetAddr(addr);
} else {
LOGERROR(("socks5: destination address of unknown type!"));
HandshakeFinished(PR_BAD_ADDRESS_ERROR);
return PR_FAILURE;
}
auto buf3 = buf2.WriteNetPort(addr); // port
mDataLength = buf3.Written();
return PR_SUCCESS;
}
PRStatus
nsSOCKSSocketInfo::ReadV5AddrTypeAndLength(uint8_t *type, uint32_t *len)
{
NS_ABORT_IF_FALSE(mState == SOCKS5_READ_CONNECT_RESPONSE_TOP ||
mState == SOCKS5_READ_CONNECT_RESPONSE_BOTTOM,
"Invalid state!");
NS_ABORT_IF_FALSE(mDataLength >= 5,
"SOCKS 5 connection reply must be at least 5 bytes!");
// Seek to the address location
mReadOffset = 3;
*type = ReadUint8();
switch (*type) {
case 0x01: // ipv4
*len = 4 - 1;
break;
case 0x04: // ipv6
*len = 16 - 1;
break;
case 0x03: // fqdn
*len = ReadUint8();
break;
default: // wrong address type
LOGERROR(("socks5: wrong address type in connection reply!"));
return PR_FAILURE;
}
return PR_SUCCESS;
}
PRStatus
nsSOCKSSocketInfo::ReadV5ConnectResponseTop()
{
uint8_t res;
uint32_t len;
NS_ABORT_IF_FALSE(mState == SOCKS5_READ_CONNECT_RESPONSE_TOP,
"Invalid state!");
NS_ABORT_IF_FALSE(mDataLength == 5,
"SOCKS 5 connection reply must be exactly 5 bytes!");
LOGDEBUG(("socks5: checking connection reply"));
// Check version number
if (ReadUint8() != 0x05) {
LOGERROR(("socks5: unexpected version in the reply"));
HandshakeFinished(PR_CONNECT_REFUSED_ERROR);
return PR_FAILURE;
}
// Check response
res = ReadUint8();
if (res != 0x00) {
PRErrorCode c = PR_CONNECT_REFUSED_ERROR;
switch (res) {
case 0x01:
LOGERROR(("socks5: connect failed: "
"01, General SOCKS server failure."));
break;
case 0x02:
LOGERROR(("socks5: connect failed: "
"02, Connection not allowed by ruleset."));
break;
case 0x03:
LOGERROR(("socks5: connect failed: 03, Network unreachable."));
c = PR_NETWORK_UNREACHABLE_ERROR;
break;
case 0x04:
LOGERROR(("socks5: connect failed: 04, Host unreachable."));
break;
case 0x05:
LOGERROR(("socks5: connect failed: 05, Connection refused."));
break;
case 0x06:
LOGERROR(("socks5: connect failed: 06, TTL expired."));
c = PR_CONNECT_TIMEOUT_ERROR;
break;
case 0x07:
LOGERROR(("socks5: connect failed: "
"07, Command not supported."));
break;
case 0x08:
LOGERROR(("socks5: connect failed: "
"08, Address type not supported."));
c = PR_BAD_ADDRESS_ERROR;
break;
default:
LOGERROR(("socks5: connect failed."));
break;
}
HandshakeFinished(c);
return PR_FAILURE;
}
if (ReadV5AddrTypeAndLength(&res, &len) != PR_SUCCESS) {
HandshakeFinished(PR_BAD_ADDRESS_ERROR);
return PR_FAILURE;
}
mState = SOCKS5_READ_CONNECT_RESPONSE_BOTTOM;
WantRead(len + 2);
return PR_SUCCESS;
}
PRStatus
nsSOCKSSocketInfo::ReadV5ConnectResponseBottom()
{
uint8_t type;
uint32_t len;
NS_ABORT_IF_FALSE(mState == SOCKS5_READ_CONNECT_RESPONSE_BOTTOM,
"Invalid state!");
if (ReadV5AddrTypeAndLength(&type, &len) != PR_SUCCESS) {
HandshakeFinished(PR_BAD_ADDRESS_ERROR);
return PR_FAILURE;
}
NS_ABORT_IF_FALSE(mDataLength == 7+len,
"SOCKS 5 unexpected length of connection reply!");
LOGDEBUG(("socks5: loading source addr and port"));
// Read what the proxy says is our source address
switch (type) {
case 0x01: // ipv4
ReadNetAddr(&mExternalProxyAddr, AF_INET);
break;
case 0x04: // ipv6
ReadNetAddr(&mExternalProxyAddr, AF_INET6);
break;
case 0x03: // fqdn (skip)
mReadOffset += len;
mExternalProxyAddr.raw.family = AF_INET;
break;
}
ReadNetPort(&mExternalProxyAddr);
LOGDEBUG(("socks5: connected!"));
HandshakeFinished();
return PR_SUCCESS;
}
void
nsSOCKSSocketInfo::SetConnectTimeout(PRIntervalTime to)
{
mTimeout = to;
}
PRStatus
nsSOCKSSocketInfo::DoHandshake(PRFileDesc *fd, int16_t oflags)
{
LOGDEBUG(("socks: DoHandshake(), state = %d", mState));
switch (mState) {
case SOCKS_INITIAL:
return StartDNS(fd);
case SOCKS_DNS_IN_PROGRESS:
PR_SetError(PR_IN_PROGRESS_ERROR, 0);
return PR_FAILURE;
case SOCKS_DNS_COMPLETE:
return ConnectToProxy(fd);
case SOCKS_CONNECTING_TO_PROXY:
return ContinueConnectingToProxy(fd, oflags);
case SOCKS4_WRITE_CONNECT_REQUEST:
if (WriteToSocket(fd) != PR_SUCCESS)
return PR_FAILURE;
WantRead(8);
mState = SOCKS4_READ_CONNECT_RESPONSE;
return PR_SUCCESS;
case SOCKS4_READ_CONNECT_RESPONSE:
if (ReadFromSocket(fd) != PR_SUCCESS)
return PR_FAILURE;
return ReadV4ConnectResponse();
case SOCKS5_WRITE_AUTH_REQUEST:
if (WriteToSocket(fd) != PR_SUCCESS)
return PR_FAILURE;
WantRead(2);
mState = SOCKS5_READ_AUTH_RESPONSE;
return PR_SUCCESS;
case SOCKS5_READ_AUTH_RESPONSE:
if (ReadFromSocket(fd) != PR_SUCCESS)
return PR_FAILURE;
return ReadV5AuthResponse();
case SOCKS5_WRITE_CONNECT_REQUEST:
if (WriteToSocket(fd) != PR_SUCCESS)
return PR_FAILURE;
// The SOCKS 5 response to the connection request is variable
// length. First, we'll read enough to tell how long the response
// is, and will read the rest later.
WantRead(5);
mState = SOCKS5_READ_CONNECT_RESPONSE_TOP;
return PR_SUCCESS;
case SOCKS5_READ_CONNECT_RESPONSE_TOP:
if (ReadFromSocket(fd) != PR_SUCCESS)
return PR_FAILURE;
return ReadV5ConnectResponseTop();
case SOCKS5_READ_CONNECT_RESPONSE_BOTTOM:
if (ReadFromSocket(fd) != PR_SUCCESS)
return PR_FAILURE;
return ReadV5ConnectResponseBottom();
case SOCKS_CONNECTED:
LOGERROR(("socks: already connected"));
HandshakeFinished(PR_IS_CONNECTED_ERROR);
return PR_FAILURE;
case SOCKS_FAILED:
LOGERROR(("socks: already failed"));
return PR_FAILURE;
}
LOGERROR(("socks: executing handshake in invalid state, %d", mState));
HandshakeFinished(PR_INVALID_STATE_ERROR);
return PR_FAILURE;
}
int16_t
nsSOCKSSocketInfo::GetPollFlags() const
{
switch (mState) {
case SOCKS_DNS_IN_PROGRESS:
case SOCKS_DNS_COMPLETE:
case SOCKS_CONNECTING_TO_PROXY:
return PR_POLL_EXCEPT | PR_POLL_WRITE;
case SOCKS4_WRITE_CONNECT_REQUEST:
case SOCKS5_WRITE_AUTH_REQUEST:
case SOCKS5_WRITE_CONNECT_REQUEST:
return PR_POLL_WRITE;
case SOCKS4_READ_CONNECT_RESPONSE:
case SOCKS5_READ_AUTH_RESPONSE:
case SOCKS5_READ_CONNECT_RESPONSE_TOP:
case SOCKS5_READ_CONNECT_RESPONSE_BOTTOM:
return PR_POLL_READ;
default:
break;
}
return 0;
}
inline uint8_t
nsSOCKSSocketInfo::ReadUint8()
{
uint8_t rv;
NS_ABORT_IF_FALSE(mReadOffset + sizeof(rv) <= mDataLength,
"Not enough space to pop a uint8_t!");
rv = mData[mReadOffset];
mReadOffset += sizeof(rv);
return rv;
}
inline uint16_t
nsSOCKSSocketInfo::ReadUint16()
{
uint16_t rv;
NS_ABORT_IF_FALSE(mReadOffset + sizeof(rv) <= mDataLength,
"Not enough space to pop a uint16_t!");
memcpy(&rv, mData + mReadOffset, sizeof(rv));
mReadOffset += sizeof(rv);
return rv;
}
inline uint32_t
nsSOCKSSocketInfo::ReadUint32()
{
uint32_t rv;
NS_ABORT_IF_FALSE(mReadOffset + sizeof(rv) <= mDataLength,
"Not enough space to pop a uint32_t!");
memcpy(&rv, mData + mReadOffset, sizeof(rv));
mReadOffset += sizeof(rv);
return rv;
}
void
nsSOCKSSocketInfo::ReadNetAddr(NetAddr *addr, uint16_t fam)
{
uint32_t amt = 0;
const uint8_t *ip = mData + mReadOffset;
addr->raw.family = fam;
if (fam == AF_INET) {
amt = sizeof(addr->inet.ip);
NS_ABORT_IF_FALSE(mReadOffset + amt <= mDataLength,
"Not enough space to pop an ipv4 addr!");
memcpy(&addr->inet.ip, ip, amt);
} else if (fam == AF_INET6) {
amt = sizeof(addr->inet6.ip.u8);
NS_ABORT_IF_FALSE(mReadOffset + amt <= mDataLength,
"Not enough space to pop an ipv6 addr!");
memcpy(addr->inet6.ip.u8, ip, amt);
}
mReadOffset += amt;
}
void
nsSOCKSSocketInfo::ReadNetPort(NetAddr *addr)
{
addr->inet.port = ReadUint16();
}
void
nsSOCKSSocketInfo::WantRead(uint32_t sz)
{
NS_ABORT_IF_FALSE(mDataIoPtr == nullptr,
"WantRead() called while I/O already in progress!");
NS_ABORT_IF_FALSE(mDataLength + sz <= BUFFER_SIZE,
"Can't read that much data!");
mAmountToRead = sz;
}
PRStatus
nsSOCKSSocketInfo::ReadFromSocket(PRFileDesc *fd)
{
int32_t rc;
const uint8_t *end;
if (!mAmountToRead) {
LOGDEBUG(("socks: ReadFromSocket(), nothing to do"));
return PR_SUCCESS;
}
if (!mDataIoPtr) {
mDataIoPtr = mData + mDataLength;
mDataLength += mAmountToRead;
}
end = mData + mDataLength;
while (mDataIoPtr < end) {
rc = PR_Read(fd, mDataIoPtr, end - mDataIoPtr);
if (rc <= 0) {
if (rc == 0) {
LOGERROR(("socks: proxy server closed connection"));
HandshakeFinished(PR_CONNECT_REFUSED_ERROR);
return PR_FAILURE;
} else if (PR_GetError() == PR_WOULD_BLOCK_ERROR) {
LOGDEBUG(("socks: ReadFromSocket(), want read"));
}
break;
}
mDataIoPtr += rc;
}
LOGDEBUG(("socks: ReadFromSocket(), have %u bytes total",
unsigned(mDataIoPtr - mData)));
if (mDataIoPtr == end) {
mDataIoPtr = nullptr;
mAmountToRead = 0;
mReadOffset = 0;
return PR_SUCCESS;
}
return PR_FAILURE;
}
PRStatus
nsSOCKSSocketInfo::WriteToSocket(PRFileDesc *fd)
{
int32_t rc;
const uint8_t *end;
if (!mDataLength) {
LOGDEBUG(("socks: WriteToSocket(), nothing to do"));
return PR_SUCCESS;
}
if (!mDataIoPtr)
mDataIoPtr = mData;
end = mData + mDataLength;
while (mDataIoPtr < end) {
rc = PR_Write(fd, mDataIoPtr, end - mDataIoPtr);
if (rc < 0) {
if (PR_GetError() == PR_WOULD_BLOCK_ERROR) {
LOGDEBUG(("socks: WriteToSocket(), want write"));
}
break;
}
mDataIoPtr += rc;
}
if (mDataIoPtr == end) {
mDataIoPtr = nullptr;
mDataLength = 0;
mReadOffset = 0;
return PR_SUCCESS;
}
return PR_FAILURE;
}
static PRStatus
nsSOCKSIOLayerConnect(PRFileDesc *fd, const PRNetAddr *addr, PRIntervalTime to)
{
PRStatus status;
NetAddr dst;
nsSOCKSSocketInfo * info = (nsSOCKSSocketInfo*) fd->secret;
if (info == nullptr) return PR_FAILURE;
if (addr->raw.family == PR_AF_INET6 &&
PR_IsNetAddrType(addr, PR_IpAddrV4Mapped)) {
const uint8_t *srcp;
LOGDEBUG(("socks: converting ipv4-mapped ipv6 address to ipv4"));
// copied from _PR_ConvertToIpv4NetAddr()
dst.raw.family = AF_INET;
dst.inet.ip = htonl(INADDR_ANY);
dst.inet.port = htons(0);
srcp = addr->ipv6.ip.pr_s6_addr;
memcpy(&dst.inet.ip, srcp + 12, 4);
dst.inet.family = AF_INET;
dst.inet.port = addr->ipv6.port;
} else {
memcpy(&dst, addr, sizeof(dst));
}
info->SetDestinationAddr(&dst);
info->SetConnectTimeout(to);
do {
status = info->DoHandshake(fd, -1);
} while (status == PR_SUCCESS && !info->IsConnected());
return status;
}
static PRStatus
nsSOCKSIOLayerConnectContinue(PRFileDesc *fd, int16_t oflags)
{
PRStatus status;
nsSOCKSSocketInfo * info = (nsSOCKSSocketInfo*) fd->secret;
if (info == nullptr) return PR_FAILURE;
do {
status = info->DoHandshake(fd, oflags);
} while (status == PR_SUCCESS && !info->IsConnected());
return status;
}
static int16_t
nsSOCKSIOLayerPoll(PRFileDesc *fd, int16_t in_flags, int16_t *out_flags)
{
nsSOCKSSocketInfo * info = (nsSOCKSSocketInfo*) fd->secret;
if (info == nullptr) return PR_FAILURE;
if (!info->IsConnected()) {
*out_flags = 0;
return info->GetPollFlags();
}
return fd->lower->methods->poll(fd->lower, in_flags, out_flags);
}
static PRStatus
nsSOCKSIOLayerClose(PRFileDesc *fd)
{
nsSOCKSSocketInfo * info = (nsSOCKSSocketInfo*) fd->secret;
PRDescIdentity id = PR_GetLayersIdentity(fd);
if (info && id == nsSOCKSIOLayerIdentity)
{
info->ForgetFD();
NS_RELEASE(info);
fd->identity = PR_INVALID_IO_LAYER;
}
return fd->lower->methods->close(fd->lower);
}
static PRFileDesc*
nsSOCKSIOLayerAccept(PRFileDesc *fd, PRNetAddr *addr, PRIntervalTime timeout)
{
// TODO: implement SOCKS support for accept
return fd->lower->methods->accept(fd->lower, addr, timeout);
}
static int32_t
nsSOCKSIOLayerAcceptRead(PRFileDesc *sd, PRFileDesc **nd, PRNetAddr **raddr, void *buf, int32_t amount, PRIntervalTime timeout)
{
// TODO: implement SOCKS support for accept, then read from it
return sd->lower->methods->acceptread(sd->lower, nd, raddr, buf, amount, timeout);
}
static PRStatus
nsSOCKSIOLayerBind(PRFileDesc *fd, const PRNetAddr *addr)
{
// TODO: implement SOCKS support for bind (very similar to connect)
return fd->lower->methods->bind(fd->lower, addr);
}
static PRStatus
nsSOCKSIOLayerGetName(PRFileDesc *fd, PRNetAddr *addr)
{
nsSOCKSSocketInfo * info = (nsSOCKSSocketInfo*) fd->secret;
if (info != nullptr && addr != nullptr) {
NetAddr temp;
NetAddr *tempPtr = &temp;
if (info->GetExternalProxyAddr(&tempPtr) == NS_OK) {
NetAddrToPRNetAddr(tempPtr, addr);
return PR_SUCCESS;
}
}
return PR_FAILURE;
}
static PRStatus
nsSOCKSIOLayerGetPeerName(PRFileDesc *fd, PRNetAddr *addr)
{
nsSOCKSSocketInfo * info = (nsSOCKSSocketInfo*) fd->secret;
if (info != nullptr && addr != nullptr) {
NetAddr temp;
NetAddr *tempPtr = &temp;
if (info->GetDestinationAddr(&tempPtr) == NS_OK) {
NetAddrToPRNetAddr(tempPtr, addr);
return PR_SUCCESS;
}
}
return PR_FAILURE;
}
static PRStatus
nsSOCKSIOLayerListen(PRFileDesc *fd, int backlog)
{
// TODO: implement SOCKS support for listen
return fd->lower->methods->listen(fd->lower, backlog);
}
// add SOCKS IO layer to an existing socket
nsresult
nsSOCKSIOLayerAddToSocket(int32_t family,
const char *host,
int32_t port,
const char *proxyHost,
int32_t proxyPort,
int32_t socksVersion,
uint32_t flags,
PRFileDesc *fd,
nsISupports** info)
{
NS_ENSURE_TRUE((socksVersion == 4) || (socksVersion == 5), NS_ERROR_NOT_INITIALIZED);
if (firstTime)
{
//XXX hack until NSPR provides an official way to detect system IPv6
// support (bug 388519)
PRFileDesc *tmpfd = PR_OpenTCPSocket(PR_AF_INET6);
if (!tmpfd) {
ipv6Supported = false;
} else {
// If the system does not support IPv6, NSPR will push
// IPv6-to-IPv4 emulation layer onto the native layer
ipv6Supported = PR_GetIdentitiesLayer(tmpfd, PR_NSPR_IO_LAYER) == tmpfd;
PR_Close(tmpfd);
}
nsSOCKSIOLayerIdentity = PR_GetUniqueIdentity("SOCKS layer");
nsSOCKSIOLayerMethods = *PR_GetDefaultIOMethods();
nsSOCKSIOLayerMethods.connect = nsSOCKSIOLayerConnect;
nsSOCKSIOLayerMethods.connectcontinue = nsSOCKSIOLayerConnectContinue;
nsSOCKSIOLayerMethods.poll = nsSOCKSIOLayerPoll;
nsSOCKSIOLayerMethods.bind = nsSOCKSIOLayerBind;
nsSOCKSIOLayerMethods.acceptread = nsSOCKSIOLayerAcceptRead;
nsSOCKSIOLayerMethods.getsockname = nsSOCKSIOLayerGetName;
nsSOCKSIOLayerMethods.getpeername = nsSOCKSIOLayerGetPeerName;
nsSOCKSIOLayerMethods.accept = nsSOCKSIOLayerAccept;
nsSOCKSIOLayerMethods.listen = nsSOCKSIOLayerListen;
nsSOCKSIOLayerMethods.close = nsSOCKSIOLayerClose;
firstTime = false;
#if defined(PR_LOGGING)
gSOCKSLog = PR_NewLogModule("SOCKS");
#endif
}
LOGDEBUG(("Entering nsSOCKSIOLayerAddToSocket()."));
PRFileDesc *layer;
PRStatus rv;
layer = PR_CreateIOLayerStub(nsSOCKSIOLayerIdentity, &nsSOCKSIOLayerMethods);
if (! layer)
{
LOGERROR(("PR_CreateIOLayerStub() failed."));
return NS_ERROR_FAILURE;
}
nsSOCKSSocketInfo * infoObject = new nsSOCKSSocketInfo();
if (!infoObject)
{
// clean up IOLayerStub
LOGERROR(("Failed to create nsSOCKSSocketInfo()."));
PR_DELETE(layer);
return NS_ERROR_FAILURE;
}
NS_ADDREF(infoObject);
infoObject->Init(socksVersion, family, proxyHost, proxyPort, host, flags);
layer->secret = (PRFilePrivate*) infoObject;
rv = PR_PushIOLayer(fd, PR_GetLayersIdentity(fd), layer);
if (rv == PR_FAILURE) {
LOGERROR(("PR_PushIOLayer() failed. rv = %x.", rv));
NS_RELEASE(infoObject);
PR_DELETE(layer);
return NS_ERROR_FAILURE;
}
*info = static_cast<nsISOCKSSocketInfo*>(infoObject);
NS_ADDREF(*info);
return NS_OK;
}