blob: 1cd610b71521d6139ffd66d0ab21bb4e09a6d49f [file] [log] [blame]
/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* JDWP TCP socket network code.
*/
#include "jdwp/jdwp_priv.h"
#include "jdwp/jdwp_handler.h"
#include "logging.h"
#include "stringprintf.h"
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#define kBasePort 8000
#define kMaxPort 8040
#define kInputBufferSize 8192
namespace art {
namespace JDWP {
// fwd
static void netShutdown(JdwpNetState* state);
static void netFree(JdwpNetState* state);
/*
* JDWP network state.
*
* We only talk to one debugger at a time.
*/
struct JdwpNetState : public JdwpNetStateBase {
uint16_t listenPort;
int listenSock; /* listen for connection from debugger */
int wakePipe[2]; /* break out of select */
in_addr remoteAddr;
uint16_t remotePort;
bool awaitingHandshake; /* waiting for "JDWP-Handshake" */
/* pending data from the network; would be more efficient as circular buf */
unsigned char inputBuffer[kInputBufferSize];
size_t inputCount;
JdwpNetState() {
listenPort = 0;
listenSock = -1;
wakePipe[0] = -1;
wakePipe[1] = -1;
awaitingHandshake = false;
inputCount = 0;
}
};
static JdwpNetState* netStartup(uint16_t port, bool probe);
/*
* Set up some stuff for transport=dt_socket.
*/
static bool prepareSocket(JdwpState* state, const JdwpOptions* options) {
uint16_t port = options->port;
if (options->server) {
if (options->port != 0) {
/* try only the specified port */
state->netState = netStartup(port, false);
} else {
/* scan through a range of ports, binding to the first available */
for (port = kBasePort; port <= kMaxPort; port++) {
state->netState = netStartup(port, true);
if (state->netState != NULL) {
break;
}
}
}
if (state->netState == NULL) {
LOG(ERROR) << "JDWP net startup failed (req port=" << options->port << ")";
return false;
}
} else {
state->netState = netStartup(0, false);
}
if (options->suspend) {
LOG(INFO) << "JDWP will wait for debugger on port " << port;
} else {
LOG(INFO) << "JDWP will " << (options->server ? "listen" : "connect") << " on port " << port;
}
return true;
}
/*
* Are we still waiting for the handshake string?
*/
static bool awaitingHandshake(JdwpState* state) {
return state->netState->awaitingHandshake;
}
/*
* Initialize JDWP stuff.
*
* Allocates a new state structure. If "port" is non-zero, this also
* tries to bind to a listen port. If "port" is zero, we assume
* we're preparing for an outbound connection, and return without binding
* to anything.
*
* This may be called several times if we're probing for a port.
*
* Returns 0 on success.
*/
static JdwpNetState* netStartup(uint16_t port, bool probe) {
JdwpNetState* netState = new JdwpNetState;
if (port == 0) {
return netState;
}
netState->listenSock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (netState->listenSock < 0) {
PLOG(probe ? ERROR : FATAL) << "Socket create failed";
goto fail;
}
/* allow immediate re-use */
{
int one = 1;
if (setsockopt(netState->listenSock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0) {
PLOG(probe ? ERROR : FATAL) << "setsockopt(SO_REUSEADDR) failed";
goto fail;
}
}
union {
sockaddr_in addrInet;
sockaddr addrPlain;
} addr;
addr.addrInet.sin_family = AF_INET;
addr.addrInet.sin_port = htons(port);
inet_aton("127.0.0.1", &addr.addrInet.sin_addr);
if (bind(netState->listenSock, &addr.addrPlain, sizeof(addr)) != 0) {
PLOG(probe ? ERROR : FATAL) << "Attempt to bind to port " << port << " failed";
goto fail;
}
netState->listenPort = port;
if (listen(netState->listenSock, 5) != 0) {
PLOG(probe ? ERROR : FATAL) << "Listen failed";
goto fail;
}
return netState;
fail:
netShutdown(netState);
netFree(netState);
return NULL;
}
/*
* Shut down JDWP listener. Don't free state.
*
* Note that "netState" may be partially initialized if "startup" failed.
*
* This may be called from a non-JDWP thread as part of shutting the
* JDWP thread down.
*
* (This is currently called several times during startup as we probe
* for an open port.)
*/
static void netShutdown(JdwpNetState* netState) {
if (netState == NULL) {
return;
}
int listenSock = netState->listenSock;
int clientSock = netState->clientSock;
/* clear these out so it doesn't wake up and try to reuse them */
netState->listenSock = netState->clientSock = -1;
/* "shutdown" dislodges blocking read() and accept() calls */
if (listenSock >= 0) {
shutdown(listenSock, SHUT_RDWR);
close(listenSock);
}
if (clientSock >= 0) {
shutdown(clientSock, SHUT_RDWR);
close(clientSock);
}
/* if we might be sitting in select, kick us loose */
if (netState->wakePipe[1] >= 0) {
VLOG(jdwp) << "+++ writing to wakePipe";
(void) write(netState->wakePipe[1], "", 1);
}
}
static void netShutdownExtern(JdwpState* state) {
netShutdown(state->netState);
}
/*
* Free JDWP state.
*
* Call this after shutting the network down with netShutdown().
*/
static void netFree(JdwpNetState* netState) {
if (netState == NULL) {
return;
}
CHECK_EQ(netState->listenSock, -1);
CHECK_EQ(netState->clientSock, -1);
if (netState->wakePipe[0] >= 0) {
close(netState->wakePipe[0]);
netState->wakePipe[0] = -1;
}
if (netState->wakePipe[1] >= 0) {
close(netState->wakePipe[1]);
netState->wakePipe[1] = -1;
}
delete netState;
}
static void netFreeExtern(JdwpState* state) {
netFree(state->netState);
}
/*
* Returns "true" if we're connected to a debugger.
*/
static bool isConnected(JdwpState* state) {
return (state->netState != NULL && state->netState->clientSock >= 0);
}
/*
* Disable the TCP Nagle algorithm, which delays transmission of outbound
* packets until the previous transmissions have been acked. JDWP does a
* lot of back-and-forth with small packets, so this may help.
*/
static int setNoDelay(int fd) {
int on = 1;
int cc = setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on));
CHECK_EQ(cc, 0);
return cc;
}
/*
* Accept a connection. This will block waiting for somebody to show up.
* If that's not desirable, use checkConnection() to make sure something
* is pending.
*/
static bool acceptConnection(JdwpState* state) {
JdwpNetState* netState = state->netState;
union {
sockaddr_in addrInet;
sockaddr addrPlain;
} addr;
socklen_t addrlen;
int sock;
if (netState->listenSock < 0) {
return false; /* you're not listening! */
}
CHECK_LT(netState->clientSock, 0); /* must not already be talking */
addrlen = sizeof(addr);
do {
sock = accept(netState->listenSock, &addr.addrPlain, &addrlen);
if (sock < 0 && errno != EINTR) {
// When we call shutdown() on the socket, accept() returns with
// EINVAL. Don't gripe about it.
if (errno == EINVAL) {
if (VLOG_IS_ON(jdwp)) {
PLOG(ERROR) << "accept failed";
}
} else {
PLOG(ERROR) << "accept failed";
return false;
}
}
} while (sock < 0);
netState->remoteAddr = addr.addrInet.sin_addr;
netState->remotePort = ntohs(addr.addrInet.sin_port);
VLOG(jdwp) << "+++ accepted connection from " << inet_ntoa(netState->remoteAddr) << ":" << netState->remotePort;
netState->clientSock = sock;
netState->awaitingHandshake = true;
netState->inputCount = 0;
VLOG(jdwp) << "Setting TCP_NODELAY on accepted socket";
setNoDelay(netState->clientSock);
if (pipe(netState->wakePipe) < 0) {
PLOG(ERROR) << "pipe failed";
return false;
}
return true;
}
/*
* Create a connection to a waiting debugger.
*/
static bool establishConnection(JdwpState* state, const JdwpOptions* options) {
union {
sockaddr_in addrInet;
sockaddr addrPlain;
} addr;
hostent* pEntry;
CHECK(state != NULL && state->netState != NULL);
CHECK(!options->server);
CHECK(!options->host.empty());
CHECK_NE(options->port, 0);
/*
* Start by resolving the host name.
*/
//#undef HAVE_GETHOSTBYNAME_R
//#warning "forcing non-R"
#ifdef HAVE_GETHOSTBYNAME_R
hostent he;
char auxBuf[128];
int error;
int cc = gethostbyname_r(options->host.c_str(), &he, auxBuf, sizeof(auxBuf), &pEntry, &error);
if (cc != 0) {
LOG(WARNING) << "gethostbyname_r('" << options->host << "') failed: " << hstrerror(error);
return false;
}
#else
h_errno = 0;
pEntry = gethostbyname(options->host.c_str());
if (pEntry == NULL) {
PLOG(WARNING) << "gethostbyname('" << options->host << "') failed";
return false;
}
#endif
/* copy it out ASAP to minimize risk of multithreaded annoyances */
memcpy(&addr.addrInet.sin_addr, pEntry->h_addr, pEntry->h_length);
addr.addrInet.sin_family = pEntry->h_addrtype;
addr.addrInet.sin_port = htons(options->port);
LOG(INFO) << "Connecting out to " << inet_ntoa(addr.addrInet.sin_addr) << ":" << ntohs(addr.addrInet.sin_port);
/*
* Create a socket.
*/
JdwpNetState* netState;
netState = state->netState;
netState->clientSock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (netState->clientSock < 0) {
PLOG(ERROR) << "Unable to create socket";
return false;
}
/*
* Try to connect.
*/
if (connect(netState->clientSock, &addr.addrPlain, sizeof(addr)) != 0) {
PLOG(ERROR) << "Unable to connect to " << inet_ntoa(addr.addrInet.sin_addr) << ":" << ntohs(addr.addrInet.sin_port);
close(netState->clientSock);
netState->clientSock = -1;
return false;
}
LOG(INFO) << "Connection established to " << options->host << " (" << inet_ntoa(addr.addrInet.sin_addr) << ":" << ntohs(addr.addrInet.sin_port) << ")";
netState->awaitingHandshake = true;
netState->inputCount = 0;
setNoDelay(netState->clientSock);
if (pipe(netState->wakePipe) < 0) {
PLOG(ERROR) << "pipe failed";
return false;
}
return true;
}
/*
* Close the connection to the debugger.
*
* Reset the state so we're ready to receive a new connection.
*/
static void closeConnection(JdwpState* state) {
JdwpNetState* netState;
CHECK(state != NULL && state->netState != NULL);
netState = state->netState;
if (netState->clientSock < 0) {
return;
}
VLOG(jdwp) << "+++ closed connection to " << inet_ntoa(netState->remoteAddr) << ":" << netState->remotePort;
close(netState->clientSock);
netState->clientSock = -1;
}
/*
* Figure out if we have a full packet in the buffer.
*/
static bool haveFullPacket(JdwpNetState* netState) {
if (netState->awaitingHandshake) {
return (netState->inputCount >= kMagicHandshakeLen);
}
if (netState->inputCount < 4) {
return false;
}
uint32_t length = Get4BE(netState->inputBuffer);
return (netState->inputCount >= length);
}
/*
* Consume bytes from the buffer.
*
* This would be more efficient with a circular buffer. However, we're
* usually only going to find one packet, which is trivial to handle.
*/
static void consumeBytes(JdwpNetState* netState, size_t count) {
CHECK_GT(count, 0U);
CHECK_LE(count, netState->inputCount);
if (count == netState->inputCount) {
netState->inputCount = 0;
return;
}
memmove(netState->inputBuffer, netState->inputBuffer + count, netState->inputCount - count);
netState->inputCount -= count;
}
/*
* Handle a packet. Returns "false" if we encounter a connection-fatal error.
*/
static bool handlePacket(JdwpState* state) {
JdwpNetState* netState = state->netState;
const unsigned char* buf = netState->inputBuffer;
uint8_t cmdSet, cmd;
bool reply;
cmd = cmdSet = 0; // shut up gcc
uint32_t length = Read4BE(&buf);
uint32_t id = Read4BE(&buf);
int8_t flags = Read1(&buf);
if ((flags & kJDWPFlagReply) != 0) {
reply = true;
Read2BE(&buf); // error
} else {
reply = false;
cmdSet = Read1(&buf);
cmd = Read1(&buf);
}
CHECK_LE(length, netState->inputCount);
int dataLen = length - (buf - netState->inputBuffer);
if (!reply) {
ExpandBuf* pReply = expandBufAlloc();
JdwpReqHeader hdr;
hdr.length = length;
hdr.id = id;
hdr.cmdSet = cmdSet;
hdr.cmd = cmd;
state->ProcessRequest(&hdr, buf, dataLen, pReply);
if (expandBufGetLength(pReply) > 0) {
ssize_t cc = netState->writePacket(pReply);
if (cc != (ssize_t) expandBufGetLength(pReply)) {
PLOG(ERROR) << "Failed sending reply to debugger";
expandBufFree(pReply);
return false;
}
} else {
LOG(WARNING) << "No reply created for set=" << cmdSet << " cmd=" << cmd;
}
expandBufFree(pReply);
} else {
LOG(ERROR) << "reply?!";
DCHECK(false);
}
VLOG(jdwp) << "----------";
consumeBytes(netState, length);
return true;
}
/*
* Process incoming data. If no data is available, this will block until
* some arrives.
*
* If we get a full packet, handle it.
*
* To take some of the mystery out of life, we want to reject incoming
* connections if we already have a debugger attached. If we don't, the
* debugger will just mysteriously hang until it times out. We could just
* close the listen socket, but there's a good chance we won't be able to
* bind to the same port again, which would confuse utilities.
*
* Returns "false" on error (indicating that the connection has been severed),
* "true" if things are still okay.
*/
static bool processIncoming(JdwpState* state) {
JdwpNetState* netState = state->netState;
int readCount;
CHECK_GE(netState->clientSock, 0);
if (!haveFullPacket(netState)) {
/* read some more, looping until we have data */
errno = 0;
while (1) {
int selCount;
fd_set readfds;
int maxfd;
int fd;
maxfd = netState->listenSock;
if (netState->clientSock > maxfd) {
maxfd = netState->clientSock;
}
if (netState->wakePipe[0] > maxfd) {
maxfd = netState->wakePipe[0];
}
if (maxfd < 0) {
VLOG(jdwp) << "+++ all fds are closed";
return false;
}
FD_ZERO(&readfds);
/* configure fds; note these may get zapped by another thread */
fd = netState->listenSock;
if (fd >= 0) {
FD_SET(fd, &readfds);
}
fd = netState->clientSock;
if (fd >= 0) {
FD_SET(fd, &readfds);
}
fd = netState->wakePipe[0];
if (fd >= 0) {
FD_SET(fd, &readfds);
} else {
LOG(INFO) << "NOTE: entering select w/o wakepipe";
}
/*
* Select blocks until it sees activity on the file descriptors.
* Closing the local file descriptor does not count as activity,
* so we can't rely on that to wake us up (it works for read()
* and accept(), but not select()).
*
* We can do one of three things: (1) send a signal and catch
* EINTR, (2) open an additional fd ("wakePipe") and write to
* it when it's time to exit, or (3) time out periodically and
* re-issue the select. We're currently using #2, as it's more
* reliable than #1 and generally better than #3. Wastes two fds.
*/
selCount = select(maxfd+1, &readfds, NULL, NULL, NULL);
if (selCount < 0) {
if (errno == EINTR) {
continue;
}
PLOG(ERROR) << "select failed";
goto fail;
}
if (netState->wakePipe[0] >= 0 && FD_ISSET(netState->wakePipe[0], &readfds)) {
if (netState->listenSock >= 0) {
LOG(ERROR) << "Exit wake set, but not exiting?";
} else {
LOG(DEBUG) << "Got wake-up signal, bailing out of select";
}
goto fail;
}
if (netState->listenSock >= 0 && FD_ISSET(netState->listenSock, &readfds)) {
LOG(INFO) << "Ignoring second debugger -- accepting and dropping";
union {
sockaddr_in addrInet;
sockaddr addrPlain;
} addr;
socklen_t addrlen;
int tmpSock;
tmpSock = accept(netState->listenSock, &addr.addrPlain, &addrlen);
if (tmpSock < 0) {
LOG(INFO) << "Weird -- accept failed";
} else {
close(tmpSock);
}
}
if (netState->clientSock >= 0 && FD_ISSET(netState->clientSock, &readfds)) {
readCount = read(netState->clientSock, netState->inputBuffer + netState->inputCount, sizeof(netState->inputBuffer) - netState->inputCount);
if (readCount < 0) {
/* read failed */
if (errno != EINTR) {
goto fail;
}
LOG(DEBUG) << "+++ EINTR hit";
return true;
} else if (readCount == 0) {
/* EOF hit -- far end went away */
LOG(DEBUG) << "+++ peer disconnected";
goto fail;
} else {
break;
}
}
}
netState->inputCount += readCount;
if (!haveFullPacket(netState)) {
return true; /* still not there yet */
}
}
/*
* Special-case the initial handshake. For some bizarre reason we're
* expected to emulate bad tty settings by echoing the request back
* exactly as it was sent. Note the handshake is always initiated by
* the debugger, no matter who connects to whom.
*
* Other than this one case, the protocol [claims to be] stateless.
*/
if (netState->awaitingHandshake) {
int cc;
if (memcmp(netState->inputBuffer, kMagicHandshake, kMagicHandshakeLen) != 0) {
LOG(ERROR) << StringPrintf("ERROR: bad handshake '%.14s'", netState->inputBuffer);
goto fail;
}
errno = 0;
cc = write(netState->clientSock, netState->inputBuffer, kMagicHandshakeLen);
if (cc != kMagicHandshakeLen) {
PLOG(ERROR) << "Failed writing handshake bytes (" << cc << " of " << kMagicHandshakeLen << ")";
goto fail;
}
consumeBytes(netState, kMagicHandshakeLen);
netState->awaitingHandshake = false;
VLOG(jdwp) << "+++ handshake complete";
return true;
}
/*
* Handle this packet.
*/
return handlePacket(state);
fail:
closeConnection(state);
return false;
}
/*
* Send a request.
*
* The entire packet must be sent with a single write() call to avoid
* threading issues.
*
* Returns "true" if it was sent successfully.
*/
static bool sendRequest(JdwpState* state, ExpandBuf* pReq) {
JdwpNetState* netState = state->netState;
/*dumpPacket(expandBufGetBuffer(pReq));*/
if (netState->clientSock < 0) {
/* can happen with some DDMS events */
VLOG(jdwp) << "NOT sending request -- no debugger is attached";
return false;
}
errno = 0;
ssize_t cc = netState->writePacket(pReq);
if (cc != (ssize_t) expandBufGetLength(pReq)) {
PLOG(ERROR) << "Failed sending req to debugger (" << cc << " of " << expandBufGetLength(pReq) << ")";
return false;
}
return true;
}
/*
* Send a request that was split into multiple buffers.
*
* The entire packet must be sent with a single writev() call to avoid
* threading issues.
*
* Returns "true" if it was sent successfully.
*/
static bool sendBufferedRequest(JdwpState* state, const iovec* iov, int iov_count) {
JdwpNetState* netState = state->netState;
if (netState->clientSock < 0) {
/* can happen with some DDMS events */
VLOG(jdwp) << "NOT sending request -- no debugger is attached";
return false;
}
size_t expected = 0;
for (int i = 0; i < iov_count; i++) {
expected += iov[i].iov_len;
}
ssize_t actual = netState->writeBufferedPacket(iov, iov_count);
if ((size_t)actual != expected) {
PLOG(ERROR) << "Failed sending b-req to debugger (" << actual << " of " << expected << ")";
return false;
}
return true;
}
/*
* Our functions.
*
* We can't generally share the implementations with other transports,
* even if they're also socket-based, because our JdwpNetState will be
* different from theirs.
*/
static const JdwpTransport socketTransport = {
prepareSocket,
acceptConnection,
establishConnection,
closeConnection,
netShutdownExtern,
netFreeExtern,
isConnected,
awaitingHandshake,
processIncoming,
sendRequest,
sendBufferedRequest,
};
/*
* Return our set.
*/
const JdwpTransport* SocketTransport() {
return &socketTransport;
}
} // namespace JDWP
} // namespace art