Magisk/native/jni/utils/misc.c
2018-02-11 21:55:57 +08:00

382 lines
8.1 KiB
C

/* misc.c - Store all functions that are unable to be catagorized clearly
*/
#define _GNU_SOURCE
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <fcntl.h>
#include <pwd.h>
#include <signal.h>
#include <sched.h>
#include <unistd.h>
#include <libgen.h>
#include <sys/types.h>
#include <sys/mount.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/inotify.h>
#include <sys/sysmacros.h>
#include "logging.h"
#include "utils.h"
#include "resetprop.h"
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 check_data() {
struct vector v;
vec_init(&v);
file_to_vector("/proc/mounts", &v);
char *line;
int mnt = 0;
vec_for_each(&v, line) {
if (strstr(line, " /data ")) {
if (strstr(line, "tmpfs") == NULL)
mnt = 1;
break;
}
}
vec_deep_destroy(&v);
int data = 0;
if (mnt) {
char *crypto = getprop("ro.crypto.state");
if (crypto != NULL) {
if (strcmp(crypto, "unencrypted") == 0) {
// Unencrypted, we can directly access data
data = 1;
} else {
// Encrypted, check whether vold is started
char *vold = getprop("init.svc.vold");
if (vold != NULL) {
free(vold);
data = 1;
}
}
free(crypto);
} else {
// ro.crypto.state is not set, assume it's unencrypted
data = 1;
}
}
return data;
}
/* All the string should be freed manually!! */
int file_to_vector(const char* filename, struct vector *v) {
char *line = NULL;
size_t len = 0;
ssize_t read;
FILE *fp = xfopen(filename, "r");
if (fp == NULL)
return 1;
while ((read = getline(&line, &len, fp)) != -1) {
// Remove end newline
if (line[read - 1] == '\n')
line[read - 1] = '\0';
vec_push_back(v, line);
line = NULL;
}
fclose(fp);
return 0;
}
int vector_to_file(const char *filename, struct vector *v) {
FILE *fp = xfopen(filename, "w");
if (fp == NULL)
return 1;
char *line;
vec_for_each(v, line) {
fprintf(fp, "%s\n", line);
}
fclose(fp);
return 0;
}
/* Check if the string only contains digits */
static int is_num(const char *s) {
int len = strlen(s);
for (int i = 0; i < len; ++i)
if (s[i] < '0' || s[i] > '9')
return 0;
return 1;
}
/* Read a whole line from file descriptor */
ssize_t fdgets(char *buf, const size_t size, int fd) {
ssize_t len = 0;
buf[0] = '\0';
while (len < size - 1) {
int ret = read(fd, buf + len, 1);
if (ret < 0)
return -1;
if (ret == 0)
break;
if (buf[len] == '\0' || buf[len++] == '\n') {
buf[len] = '\0';
break;
}
}
buf[size - 1] = '\0';
return len;
}
/* Call func for each process */
void ps(void (*func)(int)) {
DIR *dir;
struct dirent *entry;
if (!(dir = xopendir("/proc")))
return;
while ((entry = xreaddir(dir))) {
if (entry->d_type == DT_DIR) {
if (is_num(entry->d_name))
func(atoi(entry->d_name));
}
}
closedir(dir);
}
// Internal usage
static void (*ps_filter_cb)(int);
static const char *ps_filter_pattern;
static void proc_name_filter(int pid) {
char buf[64];
int fd;
snprintf(buf, sizeof(buf), "/proc/%d/cmdline", pid);
if (access(buf, R_OK) == -1 || (fd = xopen(buf, O_RDONLY)) == -1)
return;
if (fdgets(buf, sizeof(buf), fd) == 0) {
snprintf(buf, sizeof(buf), "/proc/%d/comm", pid);
close(fd);
if (access(buf, R_OK) == -1 || (fd = xopen(buf, O_RDONLY)) == -1)
return;
fdgets(buf, sizeof(buf), fd);
}
if (strcmp(buf, ps_filter_pattern) == 0) {
ps_filter_cb(pid);
}
close(fd);
}
/* Call func with process name filtered with pattern */
void ps_filter_proc_name(const char *pattern, void (*func)(int)) {
ps_filter_cb = func;
ps_filter_pattern = ((pattern == NULL) ? "" : pattern);
ps(proc_name_filter);
}
void unlock_blocks() {
DIR *dir;
struct dirent *entry;
int fd, dev, OFF = 0;
if ((dev = xopen("/dev/block", O_RDONLY | O_CLOEXEC)) < 0)
return;
dir = xfdopendir(dev);
while((entry = readdir(dir))) {
if (entry->d_type == DT_BLK) {
if ((fd = openat(dev, entry->d_name, O_RDONLY)) < 0)
continue;
if (ioctl(fd, BLKROSET, &OFF) == -1)
PLOGE("unlock %s", entry->d_name);
close(fd);
}
}
close(dev);
}
void setup_sighandlers(void (*handler)(int)) {
struct sigaction act;
memset(&act, 0, sizeof(act));
act.sa_handler = handler;
for (int i = 0; quit_signals[i]; ++i) {
sigaction(quit_signals[i], &act, NULL);
}
}
/*
fd == NULL -> Ignore output
*fd < 0 -> Open pipe and set *fd to the read end
*fd >= 0 -> STDOUT (or STDERR) will be redirected to *fd
*cb -> A callback function which runs after fork
*/
static int v_exec_command(int err, int *fd, void (*setupenv)(struct vector*), const char *argv0, va_list argv) {
int pipefd[2], writeEnd = -1;
if (fd) {
if (*fd < 0) {
if (xpipe2(pipefd, O_CLOEXEC) == -1)
return -1;
writeEnd = pipefd[1];
} else {
writeEnd = *fd;
}
}
// Collect va_list into vector
struct vector args;
vec_init(&args);
vec_push_back(&args, strdup(argv0));
for (void *arg = va_arg(argv, void*); arg; arg = va_arg(argv, void*))
vec_push_back(&args, strdup(arg));
vec_push_back(&args, NULL);
// Setup environment
char *const *envp;
struct vector env;
vec_init(&env);
if (setupenv) {
setupenv(&env);
envp = (char **) vec_entry(&env);
} else {
extern char **environ;
envp = environ;
}
int pid = xfork();
if (pid != 0) {
if (fd && *fd < 0) {
// Give the read end and close write end
*fd = pipefd[0];
close(pipefd[1]);
}
vec_deep_destroy(&args);
vec_deep_destroy(&env);
return pid;
}
if (fd) {
xdup2(writeEnd, STDOUT_FILENO);
if (err) xdup2(writeEnd, STDERR_FILENO);
}
execvpe(argv0, (char **) vec_entry(&args), envp);
PLOGE("execvpe");
return -1;
}
int exec_command_sync(char *const argv0, ...) {
va_list argv;
va_start(argv, argv0);
int pid, status;
pid = v_exec_command(0, NULL, NULL, argv0, argv);
va_end(argv);
if (pid < 0)
return pid;
waitpid(pid, &status, 0);
return WEXITSTATUS(status);
}
int exec_command(int err, int *fd, void (*setupenv)(struct vector*), const char *argv0, ...) {
va_list argv;
va_start(argv, argv0);
int pid = v_exec_command(err, fd, setupenv, argv0, argv);
va_end(argv);
return pid;
}
int bind_mount(const char *from, const char *to) {
int ret = xmount(from, to, NULL, MS_BIND, NULL);
#ifdef MAGISK_DEBUG
LOGI("bind_mount: %s <- %s\n", to, from);
#else
LOGI("bind_mount: %s\n", to);
#endif
return ret;
}
void get_client_cred(int fd, struct ucred *cred) {
socklen_t ucred_length = sizeof(*cred);
if(getsockopt(fd, SOL_SOCKET, SO_PEERCRED, cred, &ucred_length))
PLOGE("getsockopt");
}
int switch_mnt_ns(int pid) {
char mnt[32];
snprintf(mnt, sizeof(mnt), "/proc/%d/ns/mnt", pid);
if(access(mnt, R_OK) == -1) return 1; // Maybe process died..
int fd, ret;
fd = xopen(mnt, O_RDONLY);
if (fd < 0) return 1;
// Switch to its namespace
ret = xsetns(fd, 0);
close(fd);
return ret;
}
int fork_dont_care() {
int pid = xfork();
if (pid) {
waitpid(pid, NULL, 0);
return pid;
} else if ((pid = xfork())) {
exit(0);
}
return 0;
}
void wait_till_exists(const char *target) {
if (access(target, F_OK) == 0)
return;
int fd = inotify_init();
char *dir = dirname(target);
char crap[PATH_MAX];
inotify_add_watch(fd, dir, IN_CREATE);
while (1) {
struct inotify_event event;
read(fd, &event, sizeof(event));
read(fd, crap, event.len);
if (access(target, F_OK) == 0)
break;
}
close(fd);
}
void gen_rand_str(char *buf, int len) {
const char base[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_.";
int urandom;
if (access("/dev/urandom", R_OK) == 0) {
urandom = xopen("/dev/urandom", O_RDONLY | O_CLOEXEC);
} else {
mknod("/urandom", S_IFCHR | 0666, makedev(1, 9));
urandom = xopen("/urandom", O_RDONLY | O_CLOEXEC);
unlink("/urandom");
}
xxread(urandom, buf, len - 1);
close(urandom);
for (int i = 0; i < len - 1; ++i) {
buf[i] = base[buf[i] % (sizeof(base) - 1)];
}
buf[len - 1] = '\0';
}