Magisk/jni/magiskboot/cpio.c
2017-03-10 07:52:59 +08:00

480 lines
12 KiB
C

#include "magiskboot.h"
#include "cpio.h"
static uint32_t x8u(char *hex) {
uint32_t val, inpos = 8, outpos;
char pattern[6];
while (*hex == '0') {
hex++;
if (!--inpos) return 0;
}
// Because scanf gratuitously treats %*X differently than printf does.
sprintf(pattern, "%%%dx%%n", inpos);
sscanf(hex, pattern, &val, &outpos);
if (inpos != outpos) error(1, "bad cpio header");
return val;
}
static void cpio_free(cpio_file *f) {
if (f) {
free(f->filename);
free(f->data);
free(f);
}
}
static void cpio_vec_insert(vector *v, cpio_file *n) {
cpio_file *f, *t;
int shift = 0;
// Insert in alphabet order
vec_for_each(v, f) {
if (shift) {
vec_entry(v)[_i] = t;
t = f;
continue;
}
t = f;
if (strcmp(f->filename, n->filename) == 0) {
// Replace, then all is done
cpio_free(f);
vec_entry(v)[_i] = n;
return;
} else if (strcmp(f->filename, n->filename) > 0) {
// Insert, then start shifting
vec_entry(v)[_i] = n;
t = f;
shift = 1;
}
}
if (shift)
vec_push_back(v, t);
else
vec_push_back(v, n);
}
static int cpio_compare(const void *a, const void *b) {
return strcmp((*(cpio_file **) a)->filename, (*(cpio_file **) b)->filename);
}
// Parse cpio file to a vector of cpio_file
static void parse_cpio(const char *filename, vector *v) {
printf("Loading cpio: [%s]\n\n", filename);
int fd = open(filename, O_RDONLY);
if (fd < 0)
error(1, "Cannot open %s", filename);
cpio_newc_header header;
cpio_file *f;
while(read(fd, &header, 110) == 110) {
f = calloc(sizeof(*f), 1);
// f->ino = x8u(header.ino);
f->mode = x8u(header.mode);
f->uid = x8u(header.uid);
f->gid = x8u(header.gid);
// f->nlink = x8u(header.nlink);
// f->mtime = x8u(header.mtime);
f->filesize = x8u(header.filesize);
// f->devmajor = x8u(header.devmajor);
// f->devminor = x8u(header.devminor);
// f->rdevmajor = x8u(header.rdevmajor);
// f->rdevminor = x8u(header.rdevminor);
f->namesize = x8u(header.namesize);
// f->check = x8u(header.check);
f->filename = malloc(f->namesize);
read(fd, f->filename, f->namesize);
file_align(fd, 4, 0);
if (strcmp(f->filename, "TRAILER!!!") == 0 || strcmp(f->filename, ".") == 0) {
cpio_free(f);
continue;
}
if (f->filesize) {
f->data = malloc(f->filesize);
read(fd, f->data, f->filesize);
file_align(fd, 4, 0);
}
vec_push_back(v, f);
}
close(fd);
// Sort by name
vec_sort(v, cpio_compare);
}
static void dump_cpio(const char *filename, vector *v) {
printf("\nDump cpio: [%s]\n\n", filename);
int fd = open_new(filename);
unsigned inode = 300000;
char header[111];
cpio_file *f;
vec_for_each(v, f) {
if (f->remove) continue;
sprintf(header, "070701%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x",
inode++, // f->ino
f->mode,
f->uid,
f->gid,
1, // f->nlink
0, // f->mtime
f->filesize,
0, // f->devmajor
0, // f->devminor
0, // f->rdevmajor
0, // f->rdevminor
f->namesize,
0 // f->check
);
write(fd, header, 110);
write(fd, f->filename, f->namesize);
file_align(fd, 4, 1);
if (f->filesize) {
write(fd, f->data, f->filesize);
file_align(fd, 4, 1);
}
}
// Write trailer
sprintf(header, "070701%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x", inode++, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 11, 0);
write(fd, header, 110);
write(fd, "TRAILER!!!\0", 11);
file_align(fd, 4, 1);
close(fd);
}
static void cpio_vec_destroy(vector *v) {
// Free each cpio_file
cpio_file *f;
vec_for_each(v, f) {
cpio_free(f);
}
vec_destroy(v);
}
static void cpio_rm(int recursive, const char *entry, vector *v) {
cpio_file *f;
vec_for_each(v, f) {
if ((recursive && strncmp(f->filename, entry, strlen(entry)) == 0)
|| (strcmp(f->filename, entry) == 0) ) {
if (!f->remove) {
printf("Remove [%s]\n", entry);
f->remove = 1;
}
if (!recursive) return;
}
}
}
static void cpio_mkdir(mode_t mode, const char *entry, vector *v) {
cpio_file *f = calloc(sizeof(*f), 1);
f->mode = S_IFDIR | mode;
f->namesize = strlen(entry) + 1;
f->filename = malloc(f->namesize);
memcpy(f->filename, entry, f->namesize);
cpio_vec_insert(v, f);
printf("Create directory [%s] (%04o)\n",entry, mode);
}
static void cpio_add(mode_t mode, const char *entry, const char *filename, vector *v) {
int fd = open(filename, O_RDONLY);
if (fd < 0)
error(1, "Cannot open %s", filename);
cpio_file *f = calloc(sizeof(*f), 1);
f->mode = S_IFREG | mode;
f->namesize = strlen(entry) + 1;
f->filename = malloc(f->namesize);
memcpy(f->filename, entry, f->namesize);
f->filesize = lseek(fd, 0, SEEK_END);
lseek(fd, 0, SEEK_SET);
f->data = malloc(f->filesize);
read(fd, f->data, f->filesize);
close(fd);
cpio_vec_insert(v, f);
printf("Add entry [%s] (%04o)\n", entry, mode);
}
static void cpio_test(vector *v) {
int ret = 0;
cpio_file *f;
vec_for_each(v, f) {
if (strcmp(f->filename, "sbin/launch_daemonsu.sh") == 0) {
if (!ret) ret = 2;
} else if (strcmp(f->filename, "magisk") == 0) {
ret = 1;
break;
}
}
cpio_vec_destroy(v);
exit(ret);
}
static 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] != ' ' && s[pos] != '\n' && s[pos] != ',') ++pos;
}
return pos;
}
static void cpio_dmverity(vector *v) {
cpio_file *f;
size_t read, write;
int skip;
vec_for_each(v, f) {
if (strstr(f->filename, "fstab") != NULL && S_ISREG(f->mode)) {
for (read = 0, write = 0; read < f->filesize; ++read, ++write) {
skip = check_verity_pattern(f->data + read);
if (skip > 0) {
printf("Remove pattern [%.*s] in [%s]\n", (int) skip, f->data + read, f->filename);
read += skip;
}
f->data[write] = f->data[read];
}
f->filesize = write;
} else if (strcmp(f->filename, "verity_key") == 0) {
f->remove = 1;
break;
}
}
}
static void cpio_forceencrypt(vector *v) {
cpio_file *f;
size_t read, write;
#define ENCRYPT_LIST_SIZE 2
const char *ENCRYPT_LIST[ENCRYPT_LIST_SIZE] = { "forceencrypt", "forcefdeorfbe" };
vec_for_each(v, f) {
if (strstr(f->filename, "fstab") != NULL && S_ISREG(f->mode)) {
for (read = 0, write = 0; read < f->filesize; ++read, ++write) {
for (int i = 0 ; i < ENCRYPT_LIST_SIZE; ++i) {
if (strncmp(f->data + read, ENCRYPT_LIST[i], strlen(ENCRYPT_LIST[i])) == 0) {
memcpy(f->data + write, "encryptable", 11);
printf("Replace [%s] with [%s] in [%s]\n", ENCRYPT_LIST[i], "encryptable", f->filename);
write += 11;
read += strlen(ENCRYPT_LIST[i]);
break;
}
}
f->data[write] = f->data[read];
}
f->filesize = write;
}
}
}
static void cpio_extract(const char *entry, const char *filename, vector *v) {
cpio_file *f;
vec_for_each(v, f) {
if (strcmp(f->filename, entry) == 0 && S_ISREG(f->mode)) {
printf("Extracting [%s] to [%s]\n", entry, filename);
int fd = open_new(filename);
write(fd, f->data, f->filesize);
fchmod(fd, f->mode);
fchown(fd, f->uid, f->gid);
close(fd);
return;
}
}
error(1, "Cannot find the file entry [%s]", entry);
}
static void cpio_backup(const char *orig, vector *v) {
vector o_body, *o = &o_body, bak;
cpio_file *m, *n, *dir, *rem;
char chk1[21], chk2[21], buf[PATH_MAX];
int res, doBak;
dir = calloc(sizeof(*dir), 1);
rem = calloc(sizeof(*rem), 1);
vec_init(o);
vec_init(&bak);
// First push back the directory and the rmlist
vec_push_back(&bak, dir);
vec_push_back(&bak, rem);
parse_cpio(orig, o);
// Remove possible backups in original ramdisk
cpio_rm(1, ".backup", o);
cpio_rm(1, ".backup", v);
// Init the directory and rmlist
dir->filename = strdup(".backup");
dir->namesize = strlen(dir->filename) + 1;
dir->mode = S_IFDIR;
rem->filename = strdup(".backup/.rmlist");
rem->namesize = strlen(rem->filename) + 1;
rem->mode = S_IFREG;
// Start comparing
size_t i = 0, j = 0;
while(i != vec_size(o) || j != vec_size(v)) {
doBak = 0;
if (i != vec_size(o) && j != vec_size(v)) {
m = vec_entry(o)[i];
n = vec_entry(v)[j];
res = strcmp(m->filename, n->filename);
} else if (i == vec_size(o)) {
n = vec_entry(v)[j];
res = 1;
} else if (j == vec_size(v)) {
m = vec_entry(o)[i];
res = -1;
}
if (res < 0) {
// Something is missing in new ramdisk, backup!
++i;
doBak = 1;
printf("Entry [%s] is missing\n", m->filename);
} else if (res == 0) {
// Do SHA1 checksum to check if file is identical
++i; ++j;
SHA1(chk1, m->data, m->filesize);
SHA1(chk2, n->data, n->filesize);
if (strcmp(chk1, chk2) != 0) {
// Not the same!
doBak = 1;
printf("Entry [%s] checksum missmatch\n", m->filename);
}
} else {
// Someting new in ramdisk, record in rem
++j;
if (n->remove) continue;
rem->data = realloc(rem->data, rem->filesize + n->namesize);
memcpy(rem->data + rem->filesize, n->filename, n->namesize);
rem->filesize += n->namesize;
printf("Entry [%s] is new\n", n->filename);
}
if (doBak) {
m->namesize += 8;
m->filename = realloc(m->filename, m->namesize);
strcpy(buf, m->filename);
sprintf(m->filename, ".backup/%s", buf);
vec_push_back(&bak, m);
// NULL the original entry, so it won't be freed
vec_entry(o)[i - 1] = NULL;
}
}
// Add the backup files to the original ramdisk
vec_for_each(&bak, m) {
vec_push_back(v, m);
}
// Don't include if empty
if (rem->filesize == 0) {
rem->remove = 1;
if (bak.size == 2)
dir->remove = 1;
}
// Sort
vec_sort(v, cpio_compare);
// Cleanup
cpio_vec_destroy(o);
}
static void cpio_restore(vector *v) {
cpio_file *f, *n;
vec_for_each(v, f) {
if (strstr(f->filename, ".backup") != NULL) {
f->remove = 1;
if (strcmp(f->filename, ".backup") == 0) continue;
if (strcmp(f->filename, ".backup/.rmlist") == 0) {
int pos = 0;
while(pos < f->filesize) {
cpio_rm(0, f->data + pos, v);
pos += strlen(f->data + pos) + 1;
}
continue;
}
n = calloc(sizeof(*n), 1);
memcpy(n, f, sizeof(*f));
n->namesize -= 8;
n->filename = malloc(n->namesize);
memcpy(n->filename, f->filename + 8, n->namesize);
n->data = malloc(n->filesize);
memcpy(n->data, f->data, n->filesize);
n->remove = 0;
printf("Restoring [%s] -> [%s]\n", f->filename, n->filename);
cpio_vec_insert(v, n);
}
}
// Some known stuff we can remove
cpio_rm(0, "sbin/magic_mask.sh", v);
cpio_rm(0, "init.magisk.rc", v);
cpio_rm(0, "magisk", v);
}
int cpio_commands(const char *command, int argc, char *argv[]) {
int recursive = 0;
command_t cmd;
char *incpio = argv[0];
++argv;
--argc;
if (strcmp(command, "test") == 0) {
cmd = TEST;
} else if (strcmp(command, "patch-dmverity") == 0) {
cmd = DMVERITY;
} else if (strcmp(command, "patch-forceencrypt") == 0) {
cmd = FORCEENCRYPT;
} else if (strcmp(command, "restore") == 0) {
cmd = RESTORE;
} else if (argc == 1 && strcmp(command, "backup") == 0) {
cmd = BACKUP;
} else if (argc > 0 && strcmp(command, "rm") == 0) {
cmd = RM;
if (argc == 2 && strcmp(argv[0], "-r") == 0) {
recursive = 1;
++argv;
--argc;
}
} else if (argc == 2 && strcmp(command, "extract") == 0) {
cmd = EXTRACT;
} else if (argc == 2 && strcmp(command, "mkdir") == 0) {
cmd = MKDIR;
} else if (argc == 3 && strcmp(command, "add") == 0) {
cmd = ADD;
} else {
cmd = NONE;
return 1;
}
vector v;
vec_init(&v);
parse_cpio(incpio, &v);
switch(cmd) {
case TEST:
cpio_test(&v);
break;
case DMVERITY:
cpio_dmverity(&v);
break;
case FORCEENCRYPT:
cpio_forceencrypt(&v);
break;
case RESTORE:
cpio_restore(&v);
break;
case BACKUP:
cpio_backup(argv[0], &v);
case RM:
cpio_rm(recursive, argv[0], &v);
break;
case EXTRACT:
cpio_extract(argv[0], argv[1], &v);
break;
case MKDIR:
cpio_mkdir(strtoul(argv[0], NULL, 8), argv[1], &v);
break;
case ADD:
cpio_add(strtoul(argv[0], NULL, 8), argv[1], argv[2], &v);
break;
default:
// Never happen
break;
}
dump_cpio(incpio, &v);
cpio_vec_destroy(&v);
return 0;
}