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- /* implement the "debug-ports" and "track-debug-ports" device services */
- #include "sysdeps.h"
- #define TRACE_TAG TRACE_JDWP
- #include "adb.h"
- #include <errno.h>
- #include <stdio.h>
- #include <string.h>
- #include <unistd.h>
- /* here's how these things work.
- when adbd starts, it creates a unix server socket
- named @vm-debug-control (@ is a shortcut for "first byte is zero"
- to use the private namespace instead of the file system)
- when a new JDWP daemon thread starts in a new VM process, it creates
- a connection to @vm-debug-control to announce its availability.
- JDWP thread @vm-debug-control
- | |
- |-------------------------------> |
- | hello I'm in process <pid> |
- | |
- | |
- the connection is kept alive. it will be closed automatically if
- the JDWP process terminates (this allows adbd to detect dead
- processes).
- adbd thus maintains a list of "active" JDWP processes. it can send
- its content to clients through the "device:debug-ports" service,
- or even updates through the "device:track-debug-ports" service.
- when a debugger wants to connect, it simply runs the command
- equivalent to "adb forward tcp:<hostport> jdwp:<pid>"
- "jdwp:<pid>" is a new forward destination format used to target
- a given JDWP process on the device. when sutch a request arrives,
- adbd does the following:
- - first, it calls socketpair() to create a pair of equivalent
- sockets.
- - it attaches the first socket in the pair to a local socket
- which is itself attached to the transport's remote socket:
- - it sends the file descriptor of the second socket directly
- to the JDWP process with the help of sendmsg()
- JDWP thread @vm-debug-control
- | |
- | <----------------------|
- | OK, try this file descriptor |
- | |
- | |
- then, the JDWP thread uses this new socket descriptor as its
- pass-through connection to the debugger (and receives the
- JDWP-Handshake message, answers to it, etc...)
- this gives the following graphics:
- ____________________________________
- | |
- | ADB Server (host) |
- | |
- Debugger <---> LocalSocket <----> RemoteSocket |
- | ^^ |
- |___________________________||_______|
- ||
- Transport ||
- (TCP for emulator - USB for device) ||
- ||
- ___________________________||_______
- | || |
- | ADBD (device) || |
- | VV |
- JDWP <======> LocalSocket <----> RemoteSocket |
- | |
- |____________________________________|
- due to the way adb works, this doesn't need a special socket
- type or fancy handling of socket termination if either the debugger
- or the JDWP process closes the connection.
- THIS IS THE SIMPLEST IMPLEMENTATION I COULD FIND, IF YOU HAPPEN
- TO HAVE A BETTER IDEA, LET ME KNOW - Digit
- **********************************************************************/
- /** JDWP PID List Support Code
- ** for each JDWP process, we record its pid and its connected socket
- **/
- #define MAX_OUT_FDS 4
- #if !ADB_HOST
- #include <sys/socket.h>
- #include <sys/un.h>
- typedef struct JdwpProcess JdwpProcess;
- struct JdwpProcess {
- JdwpProcess* next;
- JdwpProcess* prev;
- int pid;
- int socket;
- fdevent* fde;
- char in_buff[4]; /* input character to read PID */
- int in_len; /* number from JDWP process */
- int out_fds[MAX_OUT_FDS]; /* output array of file descriptors */
- int out_count; /* to send to the JDWP process */
- };
- static JdwpProcess _jdwp_list;
- static int
- jdwp_process_list( char* buffer, int bufferlen )
- {
- char* end = buffer + bufferlen;
- char* p = buffer;
- JdwpProcess* proc = _jdwp_list.next;
- for ( ; proc != &_jdwp_list; proc = proc->next ) {
- int len;
- /* skip transient connections */
- if (proc->pid < 0)
- continue;
- len = snprintf(p, end-p, "%d\n", proc->pid);
- if (p + len >= end)
- break;
- p += len;
- }
- p[0] = 0;
- return (p - buffer);
- }
- static int
- jdwp_process_list_msg( char* buffer, int bufferlen )
- {
- char head[5];
- int len = jdwp_process_list( buffer+4, bufferlen-4 );
- snprintf(head, sizeof head, "%04x", len);
- memcpy(buffer, head, 4);
- return len + 4;
- }
- static void jdwp_process_list_updated(void);
- static void
- jdwp_process_free( JdwpProcess* proc )
- {
- if (proc) {
- int n;
- proc->prev->next = proc->next;
- proc->next->prev = proc->prev;
- if (proc->socket >= 0) {
- adb_shutdown(proc->socket);
- adb_close(proc->socket);
- proc->socket = -1;
- }
- if (proc->fde != NULL) {
- fdevent_destroy(proc->fde);
- proc->fde = NULL;
- }
- proc->pid = -1;
- for (n = 0; n < proc->out_count; n++) {
- adb_close(proc->out_fds[n]);
- }
- proc->out_count = 0;
- free(proc);
- jdwp_process_list_updated();
- }
- }
- static void jdwp_process_event(int, unsigned, void*); /* forward */
- static JdwpProcess*
- jdwp_process_alloc( int socket )
- {
- JdwpProcess* proc = calloc(1,sizeof(*proc));
- if (proc == NULL) {
- D("not enough memory to create new JDWP process\n");
- return NULL;
- }
- proc->socket = socket;
- proc->pid = -1;
- proc->next = proc;
- proc->prev = proc;
- proc->fde = fdevent_create( socket, jdwp_process_event, proc );
- if (proc->fde == NULL) {
- D("could not create fdevent for new JDWP process\n" );
- free(proc);
- return NULL;
- }
- proc->fde->state |= FDE_DONT_CLOSE;
- proc->in_len = 0;
- proc->out_count = 0;
- /* append to list */
- proc->next = &_jdwp_list;
- proc->prev = proc->next->prev;
- proc->prev->next = proc;
- proc->next->prev = proc;
- /* start by waiting for the PID */
- fdevent_add(proc->fde, FDE_READ);
- return proc;
- }
- static void
- jdwp_process_event( int socket, unsigned events, void* _proc )
- {
- JdwpProcess* proc = _proc;
- if (events & FDE_READ) {
- if (proc->pid < 0) {
- /* read the PID as a 4-hexchar string */
- char* p = proc->in_buff + proc->in_len;
- int size = 4 - proc->in_len;
- char temp[5];
- while (size > 0) {
- int len = recv( socket, p, size, 0 );
- if (len < 0) {
- if (errno == EINTR)
- continue;
- if (errno == EAGAIN)
- return;
- /* this can fail here if the JDWP process crashes very fast */
- D("weird unknown JDWP process failure: %s\n",
- strerror(errno));
- goto CloseProcess;
- }
- if (len == 0) { /* end of stream ? */
- D("weird end-of-stream from unknown JDWP process\n");
- goto CloseProcess;
- }
- p += len;
- proc->in_len += len;
- size -= len;
- }
- /* we have read 4 characters, now decode the pid */
- memcpy(temp, proc->in_buff, 4);
- temp[4] = 0;
- if (sscanf( temp, "%04x", &proc->pid ) != 1) {
- D("could not decode JDWP %p PID number: '%s'\n", proc, temp);
- goto CloseProcess;
- }
- /* all is well, keep reading to detect connection closure */
- D("Adding pid %d to jdwp process list\n", proc->pid);
- jdwp_process_list_updated();
- }
- else
- {
- /* the pid was read, if we get there it's probably because the connection
- * was closed (e.g. the JDWP process exited or crashed) */
- char buf[32];
- for (;;) {
- int len = recv(socket, buf, sizeof(buf), 0);
- if (len <= 0) {
- if (len < 0 && errno == EINTR)
- continue;
- if (len < 0 && errno == EAGAIN)
- return;
- else {
- D("terminating JDWP %d connection: %s\n", proc->pid,
- strerror(errno));
- break;
- }
- }
- else {
- D( "ignoring unexpected JDWP %d control socket activity (%d bytes)\n",
- proc->pid, len );
- }
- }
- CloseProcess:
- if (proc->pid >= 0)
- D( "remove pid %d to jdwp process list\n", proc->pid );
- jdwp_process_free(proc);
- return;
- }
- }
- if (events & FDE_WRITE) {
- D("trying to write to JDWP pid controli (count=%d first=%d) %d\n",
- proc->pid, proc->out_count, proc->out_fds[0]);
- if (proc->out_count > 0) {
- int fd = proc->out_fds[0];
- int n, ret;
- struct cmsghdr* cmsg;
- struct msghdr msg;
- struct iovec iov;
- char dummy = '!';
- char buffer[sizeof(struct cmsghdr) + sizeof(int)];
- int flags;
- iov.iov_base = &dummy;
- iov.iov_len = 1;
- msg.msg_name = NULL;
- msg.msg_namelen = 0;
- msg.msg_iov = &iov;
- msg.msg_iovlen = 1;
- msg.msg_flags = 0;
- msg.msg_control = buffer;
- msg.msg_controllen = sizeof(buffer);
- cmsg = CMSG_FIRSTHDR(&msg);
- cmsg->cmsg_len = msg.msg_controllen;
- cmsg->cmsg_level = SOL_SOCKET;
- cmsg->cmsg_type = SCM_RIGHTS;
- ((int*)CMSG_DATA(cmsg))[0] = fd;
- flags = fcntl(proc->socket,F_GETFL,0);
- if (flags == -1) {
- D("failed to get cntl flags for socket %d: %s\n",
- proc->pid, strerror(errno));
- goto CloseProcess;
- }
- if (fcntl(proc->socket, F_SETFL, flags & ~O_NONBLOCK) == -1) {
- D("failed to remove O_NONBLOCK flag for socket %d: %s\n",
- proc->pid, strerror(errno));
- goto CloseProcess;
- }
- for (;;) {
- ret = sendmsg(proc->socket, &msg, 0);
- if (ret >= 0) {
- adb_close(fd);
- break;
- }
- if (errno == EINTR)
- continue;
- D("sending new file descriptor to JDWP %d failed: %s\n",
- proc->pid, strerror(errno));
- goto CloseProcess;
- }
- D("sent file descriptor %d to JDWP process %d\n",
- fd, proc->pid);
- for (n = 1; n < proc->out_count; n++)
- proc->out_fds[n-1] = proc->out_fds[n];
- if (fcntl(proc->socket, F_SETFL, flags) == -1) {
- D("failed to set O_NONBLOCK flag for socket %d: %s\n",
- proc->pid, strerror(errno));
- goto CloseProcess;
- }
- if (--proc->out_count == 0)
- fdevent_del( proc->fde, FDE_WRITE );
- }
- }
- }
- int
- create_jdwp_connection_fd(int pid)
- {
- JdwpProcess* proc = _jdwp_list.next;
- D("looking for pid %d in JDWP process list\n", pid);
- for ( ; proc != &_jdwp_list; proc = proc->next ) {
- if (proc->pid == pid) {
- goto FoundIt;
- }
- }
- D("search failed !!\n");
- return -1;
- FoundIt:
- {
- int fds[2];
- if (proc->out_count >= MAX_OUT_FDS) {
- D("%s: too many pending JDWP connection for pid %d\n",
- __FUNCTION__, pid);
- return -1;
- }
- if (adb_socketpair(fds) < 0) {
- D("%s: socket pair creation failed: %s\n",
- __FUNCTION__, strerror(errno));
- return -1;
- }
- proc->out_fds[ proc->out_count ] = fds[1];
- if (++proc->out_count == 1)
- fdevent_add( proc->fde, FDE_WRITE );
- return fds[0];
- }
- }
- /** VM DEBUG CONTROL SOCKET
- **
- ** we do implement a custom asocket to receive the data
- **/
- /* name of the debug control Unix socket */
- #define JDWP_CONTROL_NAME "\0jdwp-control"
- #define JDWP_CONTROL_NAME_LEN (sizeof(JDWP_CONTROL_NAME)-1)
- typedef struct {
- int listen_socket;
- fdevent* fde;
- } JdwpControl;
- static void
- jdwp_control_event(int s, unsigned events, void* user);
- static int
- jdwp_control_init( JdwpControl* control,
- const char* sockname,
- int socknamelen )
- {
- struct sockaddr_un addr;
- socklen_t addrlen;
- int s;
- int maxpath = sizeof(addr.sun_path);
- int pathlen = socknamelen;
- if (pathlen >= maxpath) {
- D( "vm debug control socket name too long (%d extra chars)\n",
- pathlen+1-maxpath );
- return -1;
- }
- memset(&addr, 0, sizeof(addr));
- addr.sun_family = AF_UNIX;
- memcpy(addr.sun_path, sockname, socknamelen);
- s = socket( AF_UNIX, SOCK_STREAM, 0 );
- if (s < 0) {
- D( "could not create vm debug control socket. %d: %s\n",
- errno, strerror(errno));
- return -1;
- }
- addrlen = (pathlen + sizeof(addr.sun_family));
- if (bind(s, (struct sockaddr*)&addr, addrlen) < 0) {
- D( "could not bind vm debug control socket: %d: %s\n",
- errno, strerror(errno) );
- adb_close(s);
- return -1;
- }
- if ( listen(s, 4) < 0 ) {
- D("listen failed in jdwp control socket: %d: %s\n",
- errno, strerror(errno));
- adb_close(s);
- return -1;
- }
- control->listen_socket = s;
- control->fde = fdevent_create(s, jdwp_control_event, control);
- if (control->fde == NULL) {
- D( "could not create fdevent for jdwp control socket\n" );
- adb_close(s);
- return -1;
- }
- /* only wait for incoming connections */
- fdevent_add(control->fde, FDE_READ);
- close_on_exec(s);
- D("jdwp control socket started (%d)\n", control->listen_socket);
- return 0;
- }
- static void
- jdwp_control_event( int s, unsigned events, void* _control )
- {
- JdwpControl* control = (JdwpControl*) _control;
- if (events & FDE_READ) {
- struct sockaddr addr;
- socklen_t addrlen = sizeof(addr);
- int s = -1;
- JdwpProcess* proc;
- do {
- s = adb_socket_accept( control->listen_socket, &addr, &addrlen );
- if (s < 0) {
- if (errno == EINTR)
- continue;
- if (errno == ECONNABORTED) {
- /* oops, the JDWP process died really quick */
- D("oops, the JDWP process died really quick\n");
- return;
- }
- /* the socket is probably closed ? */
- D( "weird accept() failed on jdwp control socket: %s\n",
- strerror(errno) );
- return;
- }
- }
- while (s < 0);
- proc = jdwp_process_alloc( s );
- if (proc == NULL)
- return;
- free(proc);
- }
- }
- static JdwpControl _jdwp_control;
- /** "jdwp" local service implementation
- ** this simply returns the list of known JDWP process pids
- **/
- typedef struct {
- asocket socket;
- int pass;
- } JdwpSocket;
- static void
- jdwp_socket_close( asocket* s )
- {
- asocket* peer = s->peer;
- remove_socket(s);
- if (peer) {
- peer->peer = NULL;
- peer->close(peer);
- }
- free(s);
- }
- static int
- jdwp_socket_enqueue( asocket* s, apacket* p )
- {
- /* you can't write to this asocket */
- put_apacket(p);
- s->peer->close(s->peer);
- return -1;
- }
- static void
- jdwp_socket_ready( asocket* s )
- {
- JdwpSocket* jdwp = (JdwpSocket*)s;
- asocket* peer = jdwp->socket.peer;
- /* on the first call, send the list of pids,
- * on the second one, close the connection
- */
- if (jdwp->pass == 0) {
- apacket* p = get_apacket();
- p->len = jdwp_process_list((char*)p->data, MAX_PAYLOAD);
- peer->enqueue(peer, p);
- jdwp->pass = 1;
- }
- else {
- peer->close(peer);
- }
- }
- asocket*
- create_jdwp_service_socket( void )
- {
- JdwpSocket* s = calloc(sizeof(*s),1);
- if (s == NULL)
- return NULL;
- install_local_socket(&s->socket);
- s->socket.ready = jdwp_socket_ready;
- s->socket.enqueue = jdwp_socket_enqueue;
- s->socket.close = jdwp_socket_close;
- s->pass = 0;
- return &s->socket;
- }
- /** "track-jdwp" local service implementation
- ** this periodically sends the list of known JDWP process pids
- ** to the client...
- **/
- typedef struct JdwpTracker JdwpTracker;
- struct JdwpTracker {
- asocket socket;
- JdwpTracker* next;
- JdwpTracker* prev;
- int need_update;
- };
- static JdwpTracker _jdwp_trackers_list;
- static void
- jdwp_process_list_updated(void)
- {
- char buffer[1024];
- int len;
- JdwpTracker* t = _jdwp_trackers_list.next;
- len = jdwp_process_list_msg(buffer, sizeof(buffer));
- for ( ; t != &_jdwp_trackers_list; t = t->next ) {
- apacket* p = get_apacket();
- asocket* peer = t->socket.peer;
- memcpy(p->data, buffer, len);
- p->len = len;
- peer->enqueue( peer, p );
- }
- }
- static void
- jdwp_tracker_close( asocket* s )
- {
- JdwpTracker* tracker = (JdwpTracker*) s;
- asocket* peer = s->peer;
- if (peer) {
- peer->peer = NULL;
- peer->close(peer);
- }
- remove_socket(s);
- tracker->prev->next = tracker->next;
- tracker->next->prev = tracker->prev;
- free(s);
- }
- static void
- jdwp_tracker_ready( asocket* s )
- {
- JdwpTracker* t = (JdwpTracker*) s;
- if (t->need_update) {
- apacket* p = get_apacket();
- t->need_update = 0;
- p->len = jdwp_process_list_msg((char*)p->data, sizeof(p->data));
- s->peer->enqueue(s->peer, p);
- }
- }
- static int
- jdwp_tracker_enqueue( asocket* s, apacket* p )
- {
- /* you can't write to this socket */
- put_apacket(p);
- s->peer->close(s->peer);
- return -1;
- }
- asocket*
- create_jdwp_tracker_service_socket( void )
- {
- JdwpTracker* t = calloc(sizeof(*t),1);
- if (t == NULL)
- return NULL;
- t->next = &_jdwp_trackers_list;
- t->prev = t->next->prev;
- t->next->prev = t;
- t->prev->next = t;
- install_local_socket(&t->socket);
- t->socket.ready = jdwp_tracker_ready;
- t->socket.enqueue = jdwp_tracker_enqueue;
- t->socket.close = jdwp_tracker_close;
- t->need_update = 1;
- return &t->socket;
- }
- int
- init_jdwp(void)
- {
- _jdwp_list.next = &_jdwp_list;
- _jdwp_list.prev = &_jdwp_list;
- _jdwp_trackers_list.next = &_jdwp_trackers_list;
- _jdwp_trackers_list.prev = &_jdwp_trackers_list;
- return jdwp_control_init( &_jdwp_control,
- JDWP_CONTROL_NAME,
- JDWP_CONTROL_NAME_LEN );
- }
- #endif /* !ADB_HOST */
|