--- /dev/null
+/* 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;
+ }
+}
+
+
+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 */
+
OSDN Git Service
