Refactor ramdisk pattern patches

This commit is contained in:
topjohnwu 2017-09-15 01:45:39 +08:00
parent 8b2ec23a89
commit 9f6205f47f
5 changed files with 69 additions and 103 deletions

View File

@ -82,8 +82,7 @@ LOCAL_SRC_FILES := \
magiskboot/sha1.c \
magiskboot/types.c \
utils/xwrap.c \
utils/vector.c \
utils/list.c
utils/vector.c
LOCAL_CFLAGS := -DZLIB_CONST
include $(BUILD_EXECUTABLE)

View File

@ -50,3 +50,53 @@ void file_align(int fd, size_t align, int out) {
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] != ' ' && s[pos] != '\n' && s[pos] != ',') ++pos;
}
return pos;
}
int check_encryption_pattern(const char *s) {
const char *encrypt_list[] = { "forceencrypt", "forcefdeorfbe", "fileencryptioninline", "fileencryption", 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;
}

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@ -204,98 +204,24 @@ static void cpio_test(struct vector *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 struct list_head *block_to_list(char *data) {
struct list_head *head = xmalloc(sizeof(*head));
line_list *line;
init_list_head(head);
char *tok;
tok = strsep(&data, "\n");
while (tok) {
line = xcalloc(sizeof(*line), 1);
line->line = tok;
list_insert_end(head, &line->pos);
tok = strsep(&data, "\n");
}
return head;
}
static char *list_to_block(struct list_head *head, uint32_t filesize) {
line_list *line;
char *data = xmalloc(filesize);
uint32_t off = 0;
list_for_each(line, head, line_list, pos) {
strcpy(data + off, line->line);
off += strlen(line->line);
data[off++] = '\n';
}
return data;
}
static void free_newline(line_list *line) {
if (line->isNew)
free(line->line);
}
static void cpio_patch(struct vector *v, int keepverity, int keepforceencrypt) {
struct list_head *head;
line_list *line;
cpio_entry *f;
int skip, injected = 0;
size_t read, write;
const char *ENCRYPT_LIST[] = { "forceencrypt", "forcefdeorfbe", "fileencryptioninline", NULL };
int skip;
vec_for_each(v, f) {
if (strcmp(f->filename, "init.rc") == 0) {
head = block_to_list(f->data);
list_for_each(line, head, line_list, pos) {
if (strstr(line->line, "import")) {
if (strstr(line->line, "init.magisk.rc"))
injected = 1;
if (injected)
continue;
// Inject magisk script as import
fprintf(stderr, "Inject new line [import /init.magisk.rc] in [init.rc]\n");
line = xcalloc(sizeof(*line), 1);
line->line = strdup("import /init.magisk.rc");
line->isNew = 1;
f->filesize += 23;
list_insert(__->prev, &line->pos);
injected = 1;
} else if (strstr(line->line, "selinux.reload_policy")) {
// Remove this line
fprintf(stderr, "Remove line [%s] in [init.rc]\n", line->line);
f->filesize -= strlen(line->line) + 1;
__ = list_pop(&line->pos);
free(line);
}
}
char *temp = list_to_block(head, f->filesize);
void *new_data = patch_init_rc(f->data, &f->filesize);
free(f->data);
f->data = temp;
list_destory(head, list_head, pos, free_newline);
free(head);
f->data = new_data;
} else {
if (!keepverity) {
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) {
fprintf(stderr, "Remove pattern [%.*s] in [%s]\n", skip, f->data + read, f->filename);
read += skip;
for (int i = 0; i < f->filesize; ++i) {
if ((skip = check_verity_pattern(f->data + i)) > 0) {
fprintf(stderr, "Remove pattern [%.*s] in [%s]\n", skip, f->data + i, f->filename);
memcpy(f->data + i, f->data + i + skip, f->filesize - i - skip);
f->filesize -= skip;
}
f->data[write] = f->data[read];
}
f->filesize = write;
} else if (strcmp(f->filename, "verity_key") == 0) {
fprintf(stderr, "Remove [verity_key]\n");
f->remove = 1;
@ -303,19 +229,15 @@ static void cpio_patch(struct vector *v, int keepverity, int keepforceencrypt) {
}
if (!keepforceencrypt) {
if (strstr(f->filename, "fstab") != NULL && S_ISREG(f->mode)) {
for (read = 0, write = 0; read < f->filesize; ++read, ++write) {
for (int i = 0 ; ENCRYPT_LIST[i]; ++i) {
if (strncmp(f->data + read, ENCRYPT_LIST[i], strlen(ENCRYPT_LIST[i])) == 0) {
memcpy(f->data + write, "encryptable", 11);
fprintf(stderr, "Replace [%s] with [%s] in [%s]\n", ENCRYPT_LIST[i], "encryptable", f->filename);
write += 11;
read += strlen(ENCRYPT_LIST[i]);
break;
}
for (int i = 0; i < f->filesize; ++i) {
if ((skip = check_encryption_pattern(f->data + i)) > 0) {
fprintf(stderr, "Replace pattern [%.*s] with [encryptable] in [%s]\n", skip, f->data + i, f->filename);
memcpy(f->data + i, "encryptable", 11);
// assert(skip > 11)!
memcpy(f->data + i + 11, f->data + i + skip, f->filesize - i - skip);
f->filesize = f->filesize - skip + 11;
}
f->data[write] = f->data[read];
}
f->filesize = write;
}
}
}

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@ -3,8 +3,6 @@
#include <stdint.h>
#include "list.h"
typedef struct cpio_entry {
// uint32_t ino;
uint32_t mode;
@ -24,12 +22,6 @@ typedef struct cpio_entry {
int remove;
} cpio_entry;
typedef struct line_list {
char *line;
int isNew;
struct list_head pos;
} line_list;
typedef struct cpio_newc_header {
char magic[6];
char ino[8];

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@ -39,5 +39,8 @@ extern void write_zero(int fd, size_t size);
extern void mem_align(size_t *pos, size_t align);
extern void file_align(int fd, size_t align, int out);
extern int open_new(const char *filename);
extern void *patch_init_rc(char *data, uint32_t *size);
extern int check_verity_pattern(const char *s);
extern int check_encryption_pattern(const char *s);
#endif