Add "exec" service: shell commands with no pty.
To facilitate device scripts that want to read/write binary data from
the host side, this change introduces a new "exec" service that
behaves like "shell" but without creating a pty, which would otherwise
mangle binary data.
After forking, it hooks up stdin/stdout of the child process to
the socket connected through to the host. The adb transport doesn't
support shutdown(), so the host can't half-close the socket and wait
for device termination. Instead, the host side now has two explicit
commands "exec-in" and "exec-out" for either sending or receiving
data.
Teach host side copy_to_file() to deal with stdin/stdout special
cases. Switch device side backup/restore services to use the new
create_subproc_raw under the hood.
Change-Id: I5993049803519d3959761f2363037b02c50920ee
diff --git a/services.c b/services.c
index e25a232..50b81ab 100644
--- a/services.c
+++ b/services.c
@@ -173,11 +173,26 @@
}
#if !ADB_HOST
-static int create_subprocess(const char *cmd, const char *arg0, const char *arg1, pid_t *pid)
+
+static void init_subproc_child()
{
+ setsid();
+
+ // Set OOM adjustment to prevent killing
+ int fd = adb_open("/proc/self/oom_adj", O_WRONLY);
+ if (fd >= 0) {
+ adb_write(fd, "0", 1);
+ adb_close(fd);
+ } else {
+ D("adb: unable to update oom_adj\n");
+ }
+}
+
+static int create_subproc_pty(const char *cmd, const char *arg0, const char *arg1, pid_t *pid)
+{
+ D("create_subproc_pty(cmd=%s, arg0=%s, arg1=%s)\n", cmd, arg0, arg1);
#ifdef HAVE_WIN32_PROC
- D("create_subprocess(cmd=%s, arg0=%s, arg1=%s)\n", cmd, arg0, arg1);
- fprintf(stderr, "error: create_subprocess not implemented on Win32 (%s %s %s)\n", cmd, arg0, arg1);
+ fprintf(stderr, "error: create_subproc_pty not implemented on Win32 (%s %s %s)\n", cmd, arg0, arg1);
return -1;
#else /* !HAVE_WIN32_PROC */
char *devname;
@@ -204,47 +219,74 @@
return -1;
}
- if(*pid == 0){
- int pts;
+ if (*pid == 0) {
+ init_subproc_child();
- setsid();
-
- pts = unix_open(devname, O_RDWR);
- if(pts < 0) {
+ int pts = unix_open(devname, O_RDWR);
+ if (pts < 0) {
fprintf(stderr, "child failed to open pseudo-term slave: %s\n", devname);
exit(-1);
}
- dup2(pts, 0);
- dup2(pts, 1);
- dup2(pts, 2);
+ dup2(pts, STDIN_FILENO);
+ dup2(pts, STDOUT_FILENO);
+ dup2(pts, STDERR_FILENO);
adb_close(pts);
adb_close(ptm);
- // set OOM adjustment to zero
- char text[64];
- snprintf(text, sizeof text, "/proc/%d/oom_adj", getpid());
- int fd = adb_open(text, O_WRONLY);
- if (fd >= 0) {
- adb_write(fd, "0", 1);
- adb_close(fd);
- } else {
- D("adb: unable to open %s\n", text);
- }
execl(cmd, cmd, arg0, arg1, NULL);
fprintf(stderr, "- exec '%s' failed: %s (%d) -\n",
cmd, strerror(errno), errno);
exit(-1);
} else {
- // Don't set child's OOM adjustment to zero.
- // Let the child do it itself, as sometimes the parent starts
- // running before the child has a /proc/pid/oom_adj.
- // """adb: unable to open /proc/644/oom_adj""" seen in some logs.
return ptm;
}
#endif /* !HAVE_WIN32_PROC */
}
+
+static int create_subproc_raw(const char *cmd, const char *arg0, const char *arg1, pid_t *pid)
+{
+ D("create_subproc_raw(cmd=%s, arg0=%s, arg1=%s)\n", cmd, arg0, arg1);
+#ifdef HAVE_WIN32_PROC
+ fprintf(stderr, "error: create_subproc_raw not implemented on Win32 (%s %s %s)\n", cmd, arg0, arg1);
+ return -1;
+#else /* !HAVE_WIN32_PROC */
+
+ // 0 is parent socket, 1 is child socket
+ int sv[2];
+ if (unix_socketpair(AF_UNIX, SOCK_STREAM, 0, sv) < 0) {
+ printf("[ cannot create socket pair - %s ]\n", strerror(errno));
+ return -1;
+ }
+
+ *pid = fork();
+ if (*pid < 0) {
+ printf("- fork failed: %s -\n", strerror(errno));
+ adb_close(sv[0]);
+ adb_close(sv[1]);
+ return -1;
+ }
+
+ if (*pid == 0) {
+ adb_close(sv[0]);
+ init_subproc_child();
+
+ // Only hook up stdin/stdout; drop stderr
+ dup2(sv[1], STDIN_FILENO);
+ dup2(sv[1], STDOUT_FILENO);
+ adb_close(sv[1]);
+
+ execl(cmd, cmd, arg0, arg1, NULL);
+ fprintf(stderr, "- exec '%s' failed: %s (%d) -\n",
+ cmd, strerror(errno), errno);
+ exit(-1);
+ } else {
+ adb_close(sv[1]);
+ return sv[0];
+ }
+#endif /* !HAVE_WIN32_PROC */
+}
#endif /* !ABD_HOST */
#if ADB_HOST
@@ -285,18 +327,32 @@
}
}
-static int create_subproc_thread(const char *name)
+static int create_subproc_thread(const char *name, const subproc_mode mode)
{
stinfo *sti;
adb_thread_t t;
int ret_fd;
- pid_t pid;
- if(name) {
- ret_fd = create_subprocess(SHELL_COMMAND, "-c", name, &pid);
+ pid_t pid = -1;
+
+ const char *arg0, *arg1;
+ if (name == 0 || *name == 0) {
+ arg0 = "-"; arg1 = 0;
} else {
- ret_fd = create_subprocess(SHELL_COMMAND, "-", 0, &pid);
+ arg0 = "-c"; arg1 = name;
}
- D("create_subprocess() ret_fd=%d pid=%d\n", ret_fd, pid);
+
+ switch (mode) {
+ case SUBPROC_PTY:
+ ret_fd = create_subproc_pty(SHELL_COMMAND, arg0, arg1, &pid);
+ break;
+ case SUBPROC_RAW:
+ ret_fd = create_subproc_raw(SHELL_COMMAND, arg0, arg1, &pid);
+ break;
+ default:
+ fprintf(stderr, "invalid subproc_mode %d\n", mode);
+ return -1;
+ }
+ D("create_subproc ret_fd=%d pid=%d\n", ret_fd, pid);
sti = malloc(sizeof(stinfo));
if(sti == 0) fatal("cannot allocate stinfo");
@@ -304,14 +360,14 @@
sti->cookie = (void*) (uintptr_t) pid;
sti->fd = ret_fd;
- if(adb_thread_create( &t, service_bootstrap_func, sti)){
+ if (adb_thread_create(&t, service_bootstrap_func, sti)) {
free(sti);
adb_close(ret_fd);
- printf("cannot create service thread\n");
+ fprintf(stderr, "cannot create service thread\n");
return -1;
}
- D("service thread started, fd=%d pid=%d\n",ret_fd, pid);
+ D("service thread started, fd=%d pid=%d\n", ret_fd, pid);
return ret_fd;
}
#endif
@@ -356,27 +412,35 @@
} else if (!strncmp(name, "jdwp:", 5)) {
ret = create_jdwp_connection_fd(atoi(name+5));
} else if(!HOST && !strncmp(name, "shell:", 6)) {
- if(name[6]) {
- ret = create_subproc_thread(name + 6);
- } else {
- ret = create_subproc_thread(0);
- }
+ ret = create_subproc_thread(name + 6, SUBPROC_PTY);
+ } else if(!HOST && !strncmp(name, "exec:", 5)) {
+ ret = create_subproc_thread(name + 5, SUBPROC_RAW);
} else if(!strncmp(name, "sync:", 5)) {
ret = create_service_thread(file_sync_service, NULL);
} else if(!strncmp(name, "remount:", 8)) {
ret = create_service_thread(remount_service, NULL);
} else if(!strncmp(name, "reboot:", 7)) {
void* arg = strdup(name + 7);
- if(arg == 0) return -1;
+ if (arg == NULL) return -1;
ret = create_service_thread(reboot_service, arg);
} else if(!strncmp(name, "root:", 5)) {
ret = create_service_thread(restart_root_service, NULL);
} else if(!strncmp(name, "backup:", 7)) {
- char* arg = strdup(name+7);
+ char* arg = strdup(name + 7);
if (arg == NULL) return -1;
- ret = backup_service(BACKUP, arg);
+ char* c = arg;
+ for (; *c != '\0'; c++) {
+ if (*c == ':')
+ *c = ' ';
+ }
+ char* cmd;
+ if (asprintf(&cmd, "/system/bin/bu backup %s", arg) != -1) {
+ ret = create_subproc_thread(cmd, SUBPROC_RAW);
+ free(cmd);
+ }
+ free(arg);
} else if(!strncmp(name, "restore:", 8)) {
- ret = backup_service(RESTORE, NULL);
+ ret = create_subproc_thread("/system/bin/bu restore", SUBPROC_RAW);
} else if(!strncmp(name, "tcpip:", 6)) {
int port;
if (sscanf(name + 6, "%d", &port) == 0) {