Magisk/jni/magiskboot/boot_utils.c
2017-10-07 22:08:10 +08:00

103 lines
2.4 KiB
C

#include <unistd.h>
#include <stdio.h>
#include <sys/mman.h>
#include "utils.h"
void mmap_ro(const char *filename, void **buf, size_t *size) {
int fd = xopen(filename, O_RDONLY);
*size = lseek(fd, 0, SEEK_END);
lseek(fd, 0, SEEK_SET);
*buf = *size > 0 ? xmmap(NULL, *size, PROT_READ, MAP_SHARED, fd, 0) : NULL;
close(fd);
}
void mmap_rw(const char *filename, void **buf, size_t *size) {
int fd = xopen(filename, O_RDWR);
*size = lseek(fd, 0, SEEK_END);
lseek(fd, 0, SEEK_SET);
*buf = *size > 0 ? xmmap(NULL, *size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0) : NULL;
close(fd);
}
void write_zero(int fd, size_t size) {
size_t pos = lseek(fd, 0, SEEK_CUR);
ftruncate(fd, pos + size);
lseek(fd, pos + size, SEEK_SET);
}
void mem_align(size_t *pos, size_t align) {
size_t mask = align - 1;
if (*pos & mask) {
*pos += align - (*pos & mask);
}
}
void file_align(int fd, size_t align, int out) {
size_t pos = lseek(fd, 0, SEEK_CUR);
size_t mask = align - 1;
size_t off;
if (pos & mask) {
off = align - (pos & mask);
if (out) {
write_zero(fd, off);
} else {
lseek(fd, pos + off, SEEK_SET);
}
}
}
int open_new(const char *filename) {
return xopen(filename, O_WRONLY | O_CREAT | O_TRUNC, 0644);
}
void *patch_init_rc(char *data, uint32_t *size) {
int injected = 0;
char *new_data = xmalloc(*size + 23);
char *old_data = data;
uint32_t pos = 0;
for (char *tok = strsep(&old_data, "\n"); tok; tok = strsep(&old_data, "\n")) {
if (!injected && strncmp(tok, "import", 6) == 0) {
if (strstr(tok, "init.magisk.rc")) {
injected = 1;
} else {
fprintf(stderr, "Inject [import /init.magisk.rc] to [init.rc]\n");
strcpy(new_data + pos, "import /init.magisk.rc\n");
pos += 23;
injected = 1;
}
} else if (strstr(tok, "selinux.reload_policy")) {
continue;
}
// Copy the line
strcpy(new_data + pos, tok);
pos += strlen(tok);
new_data[pos++] = '\n';
}
*size = pos;
return new_data;
}
int check_verity_pattern(const char *s) {
int pos = 0;
if (s[0] == ',') ++pos;
if (strncmp(s + pos, "verify", 6) != 0) return -1;
pos += 6;
if (s[pos] == '=') {
while (s[pos] != '\0' && s[pos] != ' ' && s[pos] != '\n' && s[pos] != ',') ++pos;
}
return pos;
}
int check_encryption_pattern(const char *s) {
const char *encrypt_list[] = { "forceencrypt", "forcefdeorfbe", NULL };
for (int i = 0 ; encrypt_list[i]; ++i) {
int len = strlen(encrypt_list[i]);
if (strncmp(s, encrypt_list[i], len) == 0)
return len;
}
return -1;
}