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author | Dan Albert <danalbert@google.com> | 2015-02-25 17:51:28 -0800 |
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committer | Dan Albert <danalbert@google.com> | 2015-03-09 14:06:11 -0700 |
commit | bac3474a8256cb32a29e8d46f78cad95a5502692 (patch) | |
tree | 9763c3cb2f5e640c7061cffb47d61274a37baab8 /adb/jdwp_service.cpp | |
parent | 9b1fd969a7b7f1c6f1ed19719f21d57001d3c461 (diff) | |
download | system_core-bac3474a8256cb32a29e8d46f78cad95a5502692.zip system_core-bac3474a8256cb32a29e8d46f78cad95a5502692.tar.gz system_core-bac3474a8256cb32a29e8d46f78cad95a5502692.tar.bz2 |
Move adb to C++.
I keep trying to clean things up and needing std::strings. Might as
well just do this now.
usb_linux_client.c is going to stay as C because GCC isn't smart
enough to deal with the designated initializers it uses (though for
some reason it is in C mode).
The Darwin files are staying as C because I don't have a way to test
that they build.
The Windows files are staying as C because while I can actually build
for them, it's slow and painful.
Change-Id: I75367d29205a9049d34460032b3bb36384f43941
Diffstat (limited to 'adb/jdwp_service.cpp')
-rw-r--r-- | adb/jdwp_service.cpp | 737 |
1 files changed, 737 insertions, 0 deletions
diff --git a/adb/jdwp_service.cpp b/adb/jdwp_service.cpp new file mode 100644 index 0000000..f0b4ba7 --- /dev/null +++ b/adb/jdwp_service.cpp @@ -0,0 +1,737 @@ +/* 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 = reinterpret_cast<JdwpProcess*>( + 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 = reinterpret_cast<JdwpProcess*>(_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; + } + D("socketpair: (%d,%d)", fds[0], fds[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 = reinterpret_cast<JdwpSocket*>(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 = reinterpret_cast<JdwpTracker*>(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 */ + |