Magisk/jni/utils/misc.c
2017-08-01 15:34:16 +08:00

420 lines
8.8 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 <dirent.h>
#include <unistd.h>
#include <fcntl.h>
#include <pwd.h>
#include <signal.h>
#include <errno.h>
#include <sched.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <selinux/selinux.h>
#include "magisk.h"
#include "utils.h"
int quit_signals[] = { SIGALRM, SIGABRT, SIGHUP, SIGPIPE, SIGQUIT, SIGTERM, SIGINT, 0 };
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() {
int ret = 0;
char buffer[4096];
FILE *fp = xfopen("/proc/mounts", "r");
while (fgets(buffer, sizeof(buffer), fp)) {
if (strstr(buffer, " /data ")) {
if (strstr(buffer, "tmpfs") == NULL)
ret = 1;
break;
}
}
fclose(fp);
return ret;
}
/* 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 = fopen(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 */
int isNum(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 (read(fd, buf + len, 1) >= 0 && len < size - 1) {
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 (isNum(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 ((fd = open(buf, O_RDONLY)) == -1)
return;
if (fdgets(buf, sizeof(buf), fd) == 0) {
snprintf(buf, sizeof(buf), "/proc/%d/comm", pid);
close(fd);
if ((fd = open(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);
}
int create_links(const char *bin, const char *path) {
char self[PATH_MAX], linkpath[PATH_MAX];
if (bin == NULL) {
xreadlink("/proc/self/exe", self, sizeof(self));
bin = self;
}
int ret = 0;
for (int i = 0; applet[i]; ++i) {
snprintf(linkpath, sizeof(linkpath), "%s/%s", path, applet[i]);
unlink(linkpath);
ret |= symlink(bin, linkpath);
}
return ret;
}
#define DEV_BLOCK "/dev/block"
void unlock_blocks() {
char path[PATH_MAX];
DIR *dir;
struct dirent *entry;
int fd, OFF = 0;
if (!(dir = xopendir(DEV_BLOCK)))
return;
while((entry = readdir(dir))) {
if (entry->d_type == DT_BLK &&
strstr(entry->d_name, "ram") == NULL &&
strstr(entry->d_name, "loop") == NULL &&
strstr(entry->d_name, "dm-0") == NULL) {
snprintf(path, sizeof(path), "%s/%s", DEV_BLOCK, entry->d_name);
if ((fd = xopen(path, O_RDONLY)) < 0)
continue;
if (ioctl(fd, BLKROSET, &OFF) == -1)
PLOGE("unlock %s", path);
close(fd);
}
}
closedir(dir);
}
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
*/
int run_command(int err, int *fd, void (*cb)(void), const char *path, char *const 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;
}
}
int pid = fork();
if (pid != 0) {
if (fd && *fd < 0) {
// Give the read end and close write end
*fd = pipefd[0];
close(pipefd[1]);
}
return pid;
}
if (cb) cb();
if (fd) {
xdup2(writeEnd, STDOUT_FILENO);
if (err) xdup2(writeEnd, STDERR_FILENO);
}
execv(path, argv);
PLOGE("execv");
return -1;
}
int mkdir_p(const char *pathname, mode_t mode) {
char *path = strdup(pathname), *p;
errno = 0;
for (p = path + 1; *p; ++p) {
if (*p == '/') {
*p = '\0';
if (mkdir(path, mode) == -1) {
if (errno != EEXIST)
return -1;
}
*p = '/';
}
}
if (mkdir(path, mode) == -1) {
if (errno != EEXIST)
return -1;
}
free(path);
return 0;
}
int bind_mount(const char *from, const char *to) {
int ret = xmount(from, to, NULL, MS_BIND, NULL);
#ifdef MAGISK_DEBUG
LOGD("bind_mount: %s -> %s\n", from, to);
#else
LOGI("bind_mount: %s\n", to);
#endif
return ret;
}
int open_new(const char *filename) {
return xopen(filename, O_WRONLY | O_CREAT | O_TRUNC, 0644);
}
// file/link -> file/link only!!
int cp_afc(const char *source, const char *target) {
struct stat buf;
xlstat(source, &buf);
unlink(target);
char *con;
if (S_ISREG(buf.st_mode)) {
int sfd, tfd;
sfd = xopen(source, O_RDONLY);
tfd = xopen(target, O_WRONLY | O_CREAT | O_TRUNC);
xsendfile(tfd, sfd, NULL, buf.st_size);
fclone_attr(sfd, tfd);
close(sfd);
close(tfd);
} else if (S_ISLNK(buf.st_mode)) {
char buffer[PATH_MAX];
xreadlink(source, buffer, sizeof(buffer));
xsymlink(buffer, target);
lchown(target, buf.st_uid, buf.st_gid);
lgetfilecon(source, &con);
lsetfilecon(target, con);
free(con);
} else {
return 1;
}
return 0;
}
int clone_dir(const char *source, const char *target) {
DIR *dir;
struct dirent *entry;
char *s_path, *t_path;
if (!(dir = xopendir(source)))
return 1;
s_path = xmalloc(PATH_MAX);
t_path = xmalloc(PATH_MAX);
mkdir_p(target, 0755);
clone_attr(source, target);
while ((entry = xreaddir(dir))) {
if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
continue;
snprintf(s_path, PATH_MAX, "%s/%s", source, entry->d_name);
snprintf(t_path, PATH_MAX, "%s/%s", target, entry->d_name);
switch (entry->d_type) {
case DT_DIR:
clone_dir(s_path, t_path);
break;
case DT_REG:
case DT_LNK:
cp_afc(s_path, t_path);
break;
}
}
free(s_path);
free(t_path);
closedir(dir);
return 0;
}
int rm_rf(const char *target) {
if (access(target, F_OK) == -1)
return 0;
// Use external rm command, saves a lot of headache and issues
char command[PATH_MAX];
snprintf(command, sizeof(command), "rm -rf %s", target);
return system(command);
}
void clone_attr(const char *source, const char *target) {
struct stat buf;
xstat(source, &buf);
chmod(target, buf.st_mode & 0777);
chown(target, buf.st_uid, buf.st_gid);
char *con;
lgetfilecon(source, &con);
lsetfilecon(target, con);
free(con);
}
void fclone_attr(const int sourcefd, const int targetfd) {
struct stat buf;
fstat(sourcefd, &buf);
fchmod(targetfd, buf.st_mode & 0777);
fchown(targetfd, buf.st_uid, buf.st_gid);
char *con;
fgetfilecon(sourcefd, &con);
fsetfilecon(sourcefd, con);
free(con);
}
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 = setns(fd, 0);
close(fd);
return ret;
}
void link_busybox() {
mkdir_p(BBPATH, 0755);
char *const command[] = { "busybox", "--install", "-s", BBPATH, NULL};
int pid = run_command(0, NULL, NULL, BBBIN, command);
if (pid != -1)
waitpid(pid, NULL, 0);
}