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su.c
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su.c
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// vim: set ts=4 expandtab sw=4 :
/*
** Copyright 2015, Pierre-Hugues Husson <phh@phh.me>
** Copyright 2010, Adam Shanks (@ChainsDD)
** Copyright 2008, Zinx Verituse (@zinxv)
**
** 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.
*/
#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <sys/select.h>
#include <sys/time.h>
#include <unistd.h>
#include <limits.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <strings.h>
#include <stdint.h>
#include <pwd.h>
#include <sys/stat.h>
#include <stdarg.h>
#include <sys/types.h>
#include <selinux/selinux.h>
#include <arpa/inet.h>
#include <sys/auxv.h>
#include "su.h"
#include "utils.h"
#include "binds.h"
extern int is_daemon;
extern int daemon_from_uid;
extern int daemon_from_pid;
unsigned get_shell_uid() {
struct passwd* ppwd = getpwnam("shell");
if (NULL == ppwd) {
return 2000;
}
return ppwd->pw_uid;
}
unsigned get_system_uid() {
struct passwd* ppwd = getpwnam("system");
if (NULL == ppwd) {
return 1000;
}
return ppwd->pw_uid;
}
unsigned get_radio_uid() {
struct passwd* ppwd = getpwnam("radio");
if (NULL == ppwd) {
return 1001;
}
return ppwd->pw_uid;
}
int fork_zero_fucks() {
int pid = fork();
if (pid) {
int status;
waitpid(pid, &status, 0);
return pid;
}
else {
if ( (pid = fork()) != 0)
exit(0);
return 0;
}
}
void exec_log(char *priority, char* logline) {
int pid;
if ((pid = fork()) == 0) {
int null = open("/dev/null", O_WRONLY | O_CLOEXEC);
dup2(null, STDIN_FILENO);
dup2(null, STDOUT_FILENO);
dup2(null, STDERR_FILENO);
execl("/system/bin/log", "/system/bin/log", "-p", priority, "-t", LOG_TAG, logline, NULL);
_exit(0);
}
int status;
waitpid(pid, &status, 0);
}
void exec_loge(const char* fmt, ...) {
va_list args;
char logline[PATH_MAX];
va_start(args, fmt);
vsnprintf(logline, PATH_MAX, fmt, args);
va_end(args);
exec_log("e", logline);
}
void exec_logw(const char* fmt, ...) {
va_list args;
char logline[PATH_MAX];
va_start(args, fmt);
vsnprintf(logline, PATH_MAX, fmt, args);
va_end(args);
exec_log("w", logline);
}
void exec_logd(const char* fmt, ...) {
va_list args;
char logline[PATH_MAX];
va_start(args, fmt);
vsnprintf(logline, PATH_MAX, fmt, args);
va_end(args);
exec_log("d", logline);
}
static int from_init(struct su_initiator *from) {
char path[PATH_MAX], exe[PATH_MAX];
char args[4096], *argv0, *argv_rest;
int fd;
ssize_t len;
int i;
int err;
from->uid = getuid();
from->pid = getppid();
if (is_daemon) {
from->uid = daemon_from_uid;
from->pid = daemon_from_pid;
}
/* Get the command line */
snprintf(path, sizeof(path), "/proc/%u/cmdline", from->pid);
fd = open(path, O_RDONLY);
if (fd < 0) {
PLOGE("Opening command line");
return -1;
}
len = read(fd, args, sizeof(args));
err = errno;
close(fd);
if (len < 0 || len == sizeof(args)) {
PLOGEV("Reading command line", err);
return -1;
}
argv0 = args;
argv_rest = NULL;
for (i = 0; i < len; i++) {
if (args[i] == '\0') {
if (!argv_rest) {
argv_rest = &args[i+1];
} else {
args[i] = ' ';
}
}
}
args[len] = '\0';
if (argv_rest) {
strncpy(from->args, argv_rest, sizeof(from->args));
from->args[sizeof(from->args)-1] = '\0';
} else {
from->args[0] = '\0';
}
/* If this isn't app_process, use the real path instead of argv[0] */
snprintf(path, sizeof(path), "/proc/%u/exe", from->pid);
len = readlink(path, exe, sizeof(exe));
if (len < 0) {
PLOGE("Getting exe path");
return -1;
}
exe[len] = '\0';
if (strcmp(exe, "/system/bin/app_process")) {
argv0 = exe;
}
strncpy(from->bin, argv0, sizeof(from->bin));
from->bin[sizeof(from->bin)-1] = '\0';
struct passwd *pw;
pw = getpwuid(from->uid);
if (pw && pw->pw_name) {
strncpy(from->name, pw->pw_name, sizeof(from->name));
}
return 0;
}
static int get_multiuser_mode() {
char *data;
char sdk_ver[PROPERTY_VALUE_MAX];
data = read_file("/system/build.prop");
get_property(data, sdk_ver, "ro.build.version.sdk", "0");
free(data);
int sdk = atoi(sdk_ver);
if (sdk < 17)
return MULTIUSER_MODE_NONE;
int ret = MULTIUSER_MODE_OWNER_ONLY;
char mode[12];
FILE *fp;
if ((fp = fopen(REQUESTOR_MULTIUSER_MODE, "r"))) {
fgets(mode, sizeof(mode), fp);
int last = strlen(mode) - 1;
if (mode[last] == '\n')
mode[last] = '\0';
if (strcmp(mode, MULTIUSER_VALUE_USER) == 0) {
ret = MULTIUSER_MODE_USER;
} else if (strcmp(mode, MULTIUSER_VALUE_OWNER_MANAGED) == 0) {
ret = MULTIUSER_MODE_OWNER_MANAGED;
}
else {
ret = MULTIUSER_MODE_OWNER_ONLY;
}
fclose(fp);
}
return ret;
}
static void read_options(struct su_context *ctx) {
ctx->user.multiuser_mode = get_multiuser_mode();
}
static void user_init(struct su_context *ctx) {
if (ctx->from.uid > 99999) {
ctx->user.android_user_id = ctx->from.uid / 100000;
if (ctx->user.multiuser_mode == MULTIUSER_MODE_USER) {
snprintf(ctx->user.database_path, PATH_MAX, "%s/%d/%s", REQUESTOR_USER_PATH, ctx->user.android_user_id, REQUESTOR_DATABASE_PATH);
snprintf(ctx->user.base_path, PATH_MAX, "%s/%d/%s", REQUESTOR_USER_PATH, ctx->user.android_user_id, REQUESTOR);
}
}
}
static void populate_environment(const struct su_context *ctx) {
struct passwd *pw;
if (ctx->to.keepenv)
return;
pw = getpwuid(ctx->to.uid);
if (pw) {
setenv("HOME", pw->pw_dir, 1);
if (ctx->to.shell)
setenv("SHELL", ctx->to.shell, 1);
else
setenv("SHELL", DEFAULT_SHELL, 1);
if (ctx->to.login || ctx->to.uid) {
setenv("USER", pw->pw_name, 1);
setenv("LOGNAME", pw->pw_name, 1);
}
}
}
void set_identity(unsigned int uid) {
/*
* Set effective uid back to root, otherwise setres[ug]id will fail
* if uid isn't root.
*/
if (seteuid(0)) {
PLOGE("seteuid (root)");
exit(EXIT_FAILURE);
}
if (setresgid(uid, uid, uid)) {
PLOGE("setresgid (%u)", uid);
exit(EXIT_FAILURE);
}
if (setresuid(uid, uid, uid)) {
PLOGE("setresuid (%u)", uid);
exit(EXIT_FAILURE);
}
}
static void socket_cleanup(struct su_context *ctx) {
if (ctx && ctx->sock_path[0]) {
if (unlink(ctx->sock_path))
PLOGE("unlink (%s)", ctx->sock_path);
ctx->sock_path[0] = 0;
}
}
/*
* For use in signal handlers/atexit-function
* NOTE: su_ctx points to main's local variable.
* It's OK due to the program uses exit(3), not return from main()
*/
static struct su_context *su_ctx = NULL;
static void cleanup(void) {
socket_cleanup(su_ctx);
}
static void cleanup_signal(int sig) {
socket_cleanup(su_ctx);
exit(128 + sig);
}
static int socket_create_temp(char *path, size_t len) {
int fd;
struct sockaddr_un sun;
fd = socket(AF_LOCAL, SOCK_STREAM, 0);
if (fd < 0) {
PLOGE("socket");
return -1;
}
if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
PLOGE("fcntl FD_CLOEXEC");
goto err;
}
memset(&sun, 0, sizeof(sun));
sun.sun_family = AF_LOCAL;
snprintf(path, len, "%s/.socket%d", REQUESTOR_CACHE_PATH, getpid());
memset(sun.sun_path, 0, sizeof(sun.sun_path));
snprintf(sun.sun_path, sizeof(sun.sun_path), "%s", path);
/*
* Delete the socket to protect from situations when
* something bad occured previously and the kernel reused pid from that process.
* Small probability, isn't it.
*/
unlink(sun.sun_path);
if (bind(fd, (struct sockaddr*)&sun, sizeof(sun)) < 0) {
PLOGE("bind");
goto err;
}
if (listen(fd, 1) < 0) {
PLOGE("listen");
goto err;
}
return fd;
err:
close(fd);
return -1;
}
static int socket_accept(int serv_fd) {
struct timeval tv;
fd_set fds;
int fd, rc;
/* Wait 20 seconds for a connection, then give up. */
tv.tv_sec = 20;
tv.tv_usec = 0;
FD_ZERO(&fds);
FD_SET(serv_fd, &fds);
do {
rc = select(serv_fd + 1, &fds, NULL, NULL, &tv);
} while (rc < 0 && errno == EINTR);
if (rc < 1) {
PLOGE("select");
return -1;
}
fd = accept(serv_fd, NULL, NULL);
if (fd < 0) {
PLOGE("accept");
return -1;
}
return fd;
}
#define write_data(fd, data, data_len) \
do { \
uint32_t __len = htonl(data_len); \
__len = write((fd), &__len, sizeof(__len)); \
if (__len != sizeof(__len)) { \
PLOGE("write(" #data ")"); \
return -1; \
} \
__len = write((fd), data, data_len); \
if (__len != data_len) { \
PLOGE("write(" #data ")"); \
return -1; \
} \
} while (0)
#define write_string_data(fd, name, data) \
do { \
write_data(fd, name, strlen(name)); \
write_data(fd, data, strlen(data)); \
} while (0)
// stringify everything.
#define write_token(fd, name, data) \
do { \
char buf[16]; \
snprintf(buf, sizeof(buf), "%d", data); \
write_string_data(fd, name, buf); \
} while (0)
static int socket_send_request(int fd, const struct su_context *ctx) {
write_token(fd, "version", PROTO_VERSION);
write_token(fd, "binary.version", VERSION_CODE);
write_token(fd, "pid", ctx->from.pid);
write_string_data(fd, "from.name", ctx->from.name);
write_string_data(fd, "to.name", ctx->to.name);
write_token(fd, "from.uid", ctx->from.uid);
write_token(fd, "to.uid", ctx->to.uid);
write_string_data(fd, "from.bin", ctx->from.bin);
write_string_data(fd, "bind.from", ctx->bind.from);
write_string_data(fd, "bind.to", ctx->bind.to);
write_string_data(fd, "init", ctx->init);
// TODO: Fix issue where not using -c does not result a in a command
write_string_data(fd, "command", get_command(&ctx->to));
write_token(fd, "eof", PROTO_VERSION);
return 0;
}
static int socket_receive_result(int fd, char *result, ssize_t result_len) {
ssize_t len;
LOGD("waiting for user");
len = read(fd, result, result_len-1);
if (len < 0) {
PLOGE("read(result)");
return -1;
}
result[len] = '\0';
return 0;
}
static void usage(int status) {
FILE *stream = (status == EXIT_SUCCESS) ? stdout : stderr;
fprintf(stream,
"Usage: su [options] [--] [-] [LOGIN] [--] [args...]\n\n"
"Options:\n"
" --daemon start the su daemon agent\n"
" -c, --command COMMAND pass COMMAND to the invoked shell\n"
" --context context Change SELinux context\n"
" -h, --help display this help message and exit\n"
" -, -l, --login pretend the shell to be a login shell\n"
" -m, -p,\n"
" --preserve-environment do not change environment variables\n"
" -s, --shell SHELL use SHELL instead of the default " DEFAULT_SHELL "\n"
" -u display the multiuser mode and exit\n"
" -v, --version display version number and exit\n"
" -V display version code and exit,\n"
" this is used almost exclusively by Superuser.apk\n");
exit(status);
}
static __attribute__ ((noreturn)) void allow_bind(struct su_context *ctx) {
if(ctx->from.uid == 0)
exit(1);
if(ctx->bind.from[0] == '!') {
int ret = bind_remove(ctx->bind.to, ctx->from.uid);
if(!ret) {
fprintf(stderr, "The mentioned bind destination path didn't exist\n");
exit(1);
}
exit(0);
}
if(strcmp("--ls", ctx->bind.from)==0) {
bind_ls(ctx->from.uid);
exit(0);
}
if(!bind_uniq_dst(ctx->bind.to)) {
fprintf(stderr, "BIND: Distant file NOT unique. I refuse.\n");
exit(1);
}
int fd = open(BINDS_PATH, O_WRONLY|O_APPEND|O_CREAT, 0600);
if(fd<0) {
fprintf(stderr, "Failed to open binds file\n");
exit(1);
}
char *str = NULL;
int len = asprintf(&str, "%d:%s:%s", ctx->from.uid, ctx->bind.from, ctx->bind.to);
write(fd, str, len+1); //len doesn't include final \0 and we want to write it
free(str);
close(fd);
exit(0);
}
static __attribute__ ((noreturn)) void allow_init(struct su_context *ctx) {
if(ctx->init[0]=='!') {
int ret = init_remove(ctx->init+1, ctx->from.uid);
if(!ret) {
fprintf(stderr, "The mentioned init path didn't exist\n");
exit(1);
}
exit(0);
}
if(strcmp("--ls", ctx->init) == 0) {
init_ls(ctx->from.uid);
exit(0);
}
if(!init_uniq(ctx->init))
//This script is already in init list
exit(1);
int fd = open("/data/su/init", O_WRONLY|O_APPEND|O_CREAT, 0600);
if(fd<0) {
fprintf(stderr, "Failed to open init file\n");
exit(1);
}
char *str = NULL;
int len = asprintf(&str, "%d:%s", ctx->from.uid, ctx->init);
write(fd, str, len+1); //len doesn't include final \0 and we want to write it
free(str);
close(fd);
exit(0);
}
static __attribute__ ((noreturn)) void deny(struct su_context *ctx) {
char *cmd = get_command(&ctx->to);
int send_to_app = 1;
// no need to log if called by root
if (ctx->from.uid == AID_ROOT)
send_to_app = 0;
// dumpstate (which logs to logcat/shell) will spam the crap out of the system with su calls
if (strcmp("/system/bin/dumpstate", ctx->from.bin) == 0)
send_to_app = 0;
if (send_to_app)
send_result(ctx, DENY);
LOGW("request rejected (%u->%u %s)", ctx->from.uid, ctx->to.uid, cmd);
fprintf(stderr, "%s\n", strerror(EACCES));
exit(EXIT_FAILURE);
}
static __attribute__ ((noreturn)) void allow(struct su_context *ctx) {
char *arg0;
int argc, err;
hacks_update_context(ctx);
umask(ctx->umask);
int send_to_app = 1;
// no need to log if called by root
if (ctx->from.uid == AID_ROOT)
send_to_app = 0;
// dumpstate (which logs to logcat/shell) will spam the crap out of the system with su calls
if (strcmp("/system/bin/dumpstate", ctx->from.bin) == 0)
send_to_app = 0;
if (send_to_app)
send_result(ctx, ALLOW);
if(ctx->bind.from[0] && ctx->bind.to[0])
allow_bind(ctx);
if(ctx->init[0])
allow_init(ctx);
char *binary;
argc = ctx->to.optind;
if (ctx->to.command) {
binary = ctx->to.shell;
ctx->to.argv[--argc] = ctx->to.command;
ctx->to.argv[--argc] = "-c";
}
else if (ctx->to.shell) {
binary = ctx->to.shell;
}
else {
if (ctx->to.argv[argc]) {
binary = ctx->to.argv[argc++];
}
else {
binary = DEFAULT_SHELL;
}
}
arg0 = strrchr (binary, '/');
arg0 = (arg0) ? arg0 + 1 : binary;
if (ctx->to.login) {
int s = strlen(arg0) + 2;
char *p = malloc(s);
if (!p)
exit(EXIT_FAILURE);
*p = '-';
strcpy(p + 1, arg0);
arg0 = p;
}
populate_environment(ctx);
set_identity(ctx->to.uid);
#define PARG(arg) \
(argc + (arg) < ctx->to.argc) ? " " : "", \
(argc + (arg) < ctx->to.argc) ? ctx->to.argv[argc + (arg)] : ""
LOGD("%u %s executing %u %s using binary %s : %s%s%s%s%s%s%s%s%s%s%s%s%s%s",
ctx->from.uid, ctx->from.bin,
ctx->to.uid, get_command(&ctx->to), binary,
arg0, PARG(0), PARG(1), PARG(2), PARG(3), PARG(4), PARG(5),
(ctx->to.optind + 6 < ctx->to.argc) ? " ..." : "");
if(ctx->to.context && strcmp(ctx->to.context, "u:r:su_light:s0") == 0) {
setexeccon(ctx->to.context);
} else {
setexeccon("u:r:su:s0");
}
ctx->to.argv[--argc] = arg0;
execvp(binary, ctx->to.argv + argc);
err = errno;
PLOGE("exec");
fprintf(stderr, "Cannot execute %s: %s\n", binary, strerror(err));
exit(EXIT_FAILURE);
}
static int get_api_version() {
char sdk_ver[PROPERTY_VALUE_MAX];
char *data = read_file("/system/build.prop");
get_property(data, sdk_ver, "ro.build.version.sdk", "0");
int ver = atoi(sdk_ver);
free(data);
return ver;
}
static void fork_for_samsung(void)
{
// Samsung CONFIG_SEC_RESTRICT_SETUID wants the parent process to have
// EUID 0, or else our setresuid() calls will be denied. So make sure
// all such syscalls are executed by a child process.
int rv;
switch (fork()) {
case 0:
return;
case -1:
PLOGE("fork");
exit(1);
default:
if (wait(&rv) < 0) {
exit(1);
} else {
exit(WEXITSTATUS(rv));
}
}
}
int main(int argc, char *argv[]) {
if (argc == 2 && strcmp(argv[1], "--daemon") == 0) {
//Everything we'll exec will be in su, not su_daemon
setexeccon("u:r:su:s0");
return run_daemon();
}
return su_main(argc, argv);
}
int su_main(int argc, char *argv[]) {
int ppid = getppid();
if ((geteuid() != AID_ROOT && getuid() != AID_ROOT) ||
(get_api_version() >= 18 && getuid() == AID_SHELL) ||
get_api_version() >= 19) {
// attempt to connect to daemon...
LOGD("starting daemon client %d %d", getuid(), geteuid());
return connect_daemon(argc, argv, ppid);
} else {
return su_main_nodaemon(argc, argv);
}
}
int su_main_nodaemon(int argc, char **argv) {
int ppid = getppid();
fork_for_samsung();
// Sanitize all secure environment variables (from linker_environ.c in AOSP linker).
/* The same list than GLibc at this point */
static const char* const unsec_vars[] = {
"GCONV_PATH",
"GETCONF_DIR",
"HOSTALIASES",
"LD_AUDIT",
"LD_DEBUG",
"LD_DEBUG_OUTPUT",
"LD_DYNAMIC_WEAK",
"LD_LIBRARY_PATH",
"LD_ORIGIN_PATH",
"LD_PRELOAD",
"LD_PROFILE",
"LD_SHOW_AUXV",
"LD_USE_LOAD_BIAS",
"LOCALDOMAIN",
"LOCPATH",
"MALLOC_TRACE",
"MALLOC_CHECK_",
"NIS_PATH",
"NLSPATH",
"RESOLV_HOST_CONF",
"RES_OPTIONS",
"TMPDIR",
"TZDIR",
"LD_AOUT_LIBRARY_PATH",
"LD_AOUT_PRELOAD",
// not listed in linker, used due to system() call
"IFS",
};
if(getauxval(AT_SECURE)) {
const char* const* cp = unsec_vars;
const char* const* endp = cp + sizeof(unsec_vars)/sizeof(unsec_vars[0]);
while (cp < endp) {
unsetenv(*cp);
cp++;
}
}
LOGD("su invoked.");
//Chainfire compatibility
if(argc >= 3 && (
strcmp(argv[1], "-cn") == 0 ||
strcmp(argv[1], "--context") == 0
)) {
argc-=2;
argv+=2;
}
struct su_context ctx = {
.from = {
.pid = -1,
.uid = 0,
.bin = "",
.args = "",
.name = "",
},
.to = {
.uid = AID_ROOT,
.login = 0,
.keepenv = 0,
.shell = NULL,
.command = NULL,
.context = NULL,
.argv = argv,
.argc = argc,
.optind = 0,
.name = "",
},
.user = {
.android_user_id = 0,
.multiuser_mode = MULTIUSER_MODE_OWNER_ONLY,
.database_path = REQUESTOR_DATA_PATH REQUESTOR_DATABASE_PATH,
.base_path = REQUESTOR_DATA_PATH REQUESTOR
},
.bind = {
.from = "",
.to = "",
},
.init = "",
};
struct stat st;
int c, socket_serv_fd, fd;
char buf[64], *result;
policy_t dballow;
struct option long_opts[] = {
{ "bind", required_argument, NULL, 'b' },
{ "command", required_argument, NULL, 'c' },
{ "help", no_argument, NULL, 'h' },
{ "init", required_argument, NULL, 'i' },
{ "login", no_argument, NULL, 'l' },
{ "preserve-environment", no_argument, NULL, 'p' },
{ "shell", required_argument, NULL, 's' },
{ "version", no_argument, NULL, 'v' },
{ "context", required_argument, NULL, 'z' },
{ NULL, 0, NULL, 0 },
};
while ((c = getopt_long(argc, argv, "+b:c:hlmps:Vvuz:", long_opts, NULL)) != -1) {
switch(c) {
case 'b': {
char *s = strdup(optarg);
char *pos = strchr(s, ':');
if(pos) {
pos[0] = 0;
ctx.bind.to = pos + 1;
ctx.bind.from = s;
} else {
ctx.bind.from = "--ls";
ctx.bind.to = "--ls";
}
}
break;
case 'c':
ctx.to.shell = DEFAULT_SHELL;
ctx.to.command = optarg;
break;
case 'h':
usage(EXIT_SUCCESS);
break;
case 'i':
ctx.init = optarg;
break;
case 'l':
ctx.to.login = 1;
break;
case 'm':
case 'p':
ctx.to.keepenv = 1;
break;
case 's':
ctx.to.shell = optarg;
break;
case 'V':
printf("%d\n", VERSION_CODE);
exit(EXIT_SUCCESS);
case 'v':
printf("%s cm-su subind suinit\n", VERSION);
exit(EXIT_SUCCESS);
case 'u':
switch (get_multiuser_mode()) {
case MULTIUSER_MODE_USER:
printf("%s\n", MULTIUSER_VALUE_USER);
break;
case MULTIUSER_MODE_OWNER_MANAGED:
printf("%s\n", MULTIUSER_VALUE_OWNER_MANAGED);
break;
case MULTIUSER_MODE_OWNER_ONLY:
printf("%s\n", MULTIUSER_VALUE_OWNER_ONLY);
break;
case MULTIUSER_MODE_NONE:
printf("%s\n", MULTIUSER_VALUE_NONE);
break;
}
exit(EXIT_SUCCESS);
case 'z':
ctx.to.context = optarg;
break;
default:
/* Bionic getopt_long doesn't terminate its error output by newline */
fprintf(stderr, "\n");
usage(2);
}
}
hacks_init();
if (optind < argc && !strcmp(argv[optind], "-")) {
ctx.to.login = 1;
optind++;
}
/* username or uid */
if (optind < argc && strcmp(argv[optind], "--")) {
struct passwd *pw;
pw = getpwnam(argv[optind]);
if (!pw) {
char *endptr;
/* It seems we shouldn't do this at all */
errno = 0;
ctx.to.uid = strtoul(argv[optind], &endptr, 10);
if (errno || *endptr) {
LOGE("Unknown id: %s\n", argv[optind]);
fprintf(stderr, "Unknown id: %s\n", argv[optind]);
exit(EXIT_FAILURE);
}
} else {
ctx.to.uid = pw->pw_uid;
if (pw->pw_name)
strncpy(ctx.to.name, pw->pw_name, sizeof(ctx.to.name));
}
optind++;
}
if (optind < argc && !strcmp(argv[optind], "--")) {
optind++;
}
ctx.to.optind = optind;
su_ctx = &ctx;
if (from_init(&ctx.from) < 0) {
deny(&ctx);
}
read_options(&ctx);
user_init(&ctx);
// the latter two are necessary for stock ROMs like note 2 which do dumb things with su, or crash otherwise
if (ctx.from.uid == AID_ROOT) {
LOGD("Allowing root/system/radio.");
allow(&ctx);
}
// verify superuser is installed
if (stat(ctx.user.base_path, &st) < 0) {
// send to market (disabled, because people are and think this is hijacking their su)
// if (0 == strcmp(JAVA_PACKAGE_NAME, REQUESTOR))
// silent_run("am start -d http://www.clockworkmod.com/superuser/install.html -a android.intent.action.VIEW");
PLOGE("stat %s", ctx.user.base_path);
deny(&ctx);
}
// odd perms on superuser data dir
if (st.st_gid != st.st_uid) {
LOGE("Bad uid/gid %d/%d for Superuser Requestor application",
(int)st.st_uid, (int)st.st_gid);
deny(&ctx);
}
// always allow if this is the superuser uid
// superuser needs to be able to reenable itself when disabled...
if (ctx.from.uid == st.st_uid) {
allow(&ctx);
}
// autogrant shell at this point
if (ctx.from.uid == AID_SHELL) {
LOGD("Allowing shell.");
allow(&ctx);
}
// deny if this is a non owner request and owner mode only
if (ctx.user.multiuser_mode == MULTIUSER_MODE_OWNER_ONLY && ctx.user.android_user_id != 0) {
deny(&ctx);
}
ctx.umask = umask(027);
mkdir(REQUESTOR_CACHE_PATH, 0770);
if (chown(REQUESTOR_CACHE_PATH, st.st_uid, st.st_gid)) {
PLOGE("chown (%s, %ld, %ld)", REQUESTOR_CACHE_PATH, st.st_uid, st.st_gid);
deny(&ctx);
}
if (setgroups(0, NULL)) {
PLOGE("setgroups");
deny(&ctx);
}
if (setegid(st.st_gid)) {
PLOGE("setegid (%lu)", st.st_gid);
deny(&ctx);
}
if (seteuid(st.st_uid)) {
PLOGE("seteuid (%lu)", st.st_uid);
deny(&ctx);
}
//TODO: Ignore database check for init and bind?
dballow = database_check(&ctx);
switch (dballow) {
case INTERACTIVE:
break;
case ALLOW:
LOGD("db allowed");
allow(&ctx); /* never returns */
case DENY:
default:
LOGD("db denied");
deny(&ctx); /* never returns too */
}
socket_serv_fd = socket_create_temp(ctx.sock_path, sizeof(ctx.sock_path));
LOGD(ctx.sock_path);
if (socket_serv_fd < 0) {
deny(&ctx);
}
signal(SIGHUP, cleanup_signal);
signal(SIGPIPE, cleanup_signal);
signal(SIGTERM, cleanup_signal);
signal(SIGQUIT, cleanup_signal);
signal(SIGINT, cleanup_signal);
signal(SIGABRT, cleanup_signal);
if (send_request(&ctx) < 0) {
deny(&ctx);
}