Magisk/native/jni/magiskboot/cpio.cpp

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2018-10-25 03:08:06 +02:00
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <stdlib.h>
#include "cpio.h"
#include "utils.h"
#include "logging.h"
#define parse_align() lseek(fd, align(lseek(fd, 0, SEEK_CUR), 4), SEEK_SET)
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)
LOGE("bad cpio header\n");
return val;
}
cpio_entry::cpio_entry(int fd, cpio_newc_header &header) {
// ino = x8u(header.ino);
mode = x8u(header.mode);
uid = x8u(header.uid);
gid = x8u(header.gid);
// nlink = x8u(header.nlink);
// mtime = x8u(header.mtime);
filesize = x8u(header.filesize);
// devmajor = x8u(header.devmajor);
// devminor = x8u(header.devminor);
// rdevmajor = x8u(header.rdevmajor);
// rdevminor = x8u(header.rdevminor);
uint32_t namesize = x8u(header.namesize);
// check = x8u(header.check);
filename = (char *) xmalloc(namesize);
xxread(fd, filename, namesize);
parse_align();
if (filesize) {
data = xmalloc(filesize);
xxread(fd, data, filesize);
parse_align();
}
}
cpio_entry::~cpio_entry() {
free(filename);
free(data);
}
// Define the way to sort cpio_entry
template<>
int(*Array<cpio_entry*>::_cmp)(cpio_entry*&, cpio_entry*&) = [](auto a, auto b) -> int {
if (a == b) return 0;
if (a == nullptr) return 1;
if (b == nullptr) return -1;
return strcmp(a->filename, b->filename);
};
cpio::cpio(const char *filename) {
int fd = open(filename, O_RDONLY);
if (fd < 0) return;
fprintf(stderr, "Loading cpio: [%s]\n", filename);
cpio_newc_header header;
cpio_entry *entry;
while(xxread(fd, &header, sizeof(cpio_newc_header)) != -1) {
entry = new cpio_entry(fd, header);
if (strcmp(entry->filename, ".") == 0 || strcmp(entry->filename, "..") == 0 ||
strcmp(entry->filename, "TRAILER!!!") == 0) {
delete entry;
if (entry->filename[0] == 'T')
break;
continue;
}
arr.push_back(entry);
}
close(fd);
}
cpio::~cpio() {
for (auto &e : arr)
if (e) delete e;
}
#define dump_align() write_zero(fd, align_off(lseek(fd, 0, SEEK_CUR), 4))
void cpio::dump(const char *file) {
fprintf(stderr, "Dump cpio: [%s]\n", file);
unsigned inode = 300000;
char header[111];
sort();
int fd = creat(file, 0644);
for (auto &e : arr) {
sprintf(header, "070701%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x%08x",
inode++, // e->ino
e->mode,
e->uid,
e->gid,
1, // e->nlink
0, // e->mtime
e->filesize,
0, // e->devmajor
0, // e->devminor
0, // e->rdevmajor
0, // e->rdevminor
(uint32_t) strlen(e->filename) + 1,
0 // e->check
);
xwrite(fd, header, 110);
xwrite(fd, e->filename, strlen(e->filename) + 1);
dump_align();
if (e->filesize) {
xwrite(fd, e->data, e->filesize);
dump_align();
}
}
// 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);
xwrite(fd, header, 110);
xwrite(fd, "TRAILER!!!\0", 11);
dump_align();
close(fd);
}
int cpio::find(const char *name) {
for (int i = 0; i < arr.size(); ++i) {
if (!arr[i])
continue;
if (strcmp(arr[i]->filename, name) == 0)
return i;
}
return -1;
}
void cpio::insert(cpio_entry *e) {
int i = find(e->filename);
if (i >= 0) {
// Replace, then all is done
delete arr[i];
arr[i] = e;
return;
}
arr.push_back(e);
}
void cpio::insert(Array<cpio_entry *> &arr) {
for (auto &e : arr)
insert(e);
}
void cpio::rm(int recur, const char *name) {
size_t len = strlen(name);
for (auto &e : arr) {
if (!e)
continue;
if (strncmp(e->filename, name, len) == 0 &&
((recur && e->filename[len] == '/') || e->filename[len] == '\0')) {
fprintf(stderr, "Remove [%s]\n", e->filename);
delete e;
e = nullptr;
if (!recur)
return;
}
}
}
void cpio::makedir(mode_t mode, const char *name) {
auto e = new cpio_entry();
e->mode = S_IFDIR | mode;
e->filename = strdup(name);
insert(e);
fprintf(stderr, "Create directory [%s] (%04o)\n", name, mode);
}
void cpio::ln(const char *target, const char *name) {
auto e = new cpio_entry();
e->mode = S_IFLNK;
e->filename = strdup(name);
e->filesize = strlen(target);
e->data = strdup(target);
insert(e);
fprintf(stderr, "Create symlink [%s] -> [%s]\n", name, target);
}
void cpio::add(mode_t mode, const char *name, const char *file) {
int fd = xopen(file, O_RDONLY);
auto e = new cpio_entry();
e->mode = S_IFREG | mode;
e->filename = strdup(name);
e->filesize = lseek(fd, 0, SEEK_END);
lseek(fd, 0, SEEK_SET);
e->data = xmalloc(e->filesize);
xxread(fd, e->data, e->filesize);
close(fd);
insert(e);
fprintf(stderr, "Add entry [%s] (%04o)\n", name, mode);
}
bool cpio::mv(const char *from, const char *to) {
int f = find(from), t = find(to);
if (f >= 0) {
if (t > 0) {
delete arr[t];
arr[t] = nullptr;
}
fprintf(stderr, "Move [%s] -> [%s]\n", from, to);
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char * tmp = strdup(to);
free(arr[f]->filename);
arr[f]->filename = tmp;
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return true;
}
fprintf(stderr, "Cannot find entry %s\n", from);
return false;
}
void cpio::extract() {
for (auto &e : arr) {
if (!e)
continue;
fprintf(stderr, "Extract [%s]\n", e->filename);
unlink(e->filename);
rmdir(e->filename);
if (S_ISDIR(e->mode)) {
mkdir(e->filename, e->mode & 0777);
} else if (S_ISREG(e->mode)) {
int fd = creat(e->filename, e->mode & 0777);
xwrite(fd, e->data, e->filesize);
fchown(fd, e->uid, e->gid);
close(fd);
} else if (S_ISLNK(e->mode)) {
char *target = new char[e->filesize + 1];
memcpy(target, e->data, e->filesize);
symlink(target, e->filename);
delete[] target;
}
}
}
bool cpio::extract(const char *name, const char *file) {
int i = find(name);
if (i > 0) {
auto e = arr[i];
fprintf(stderr, "Extract [%s] to [%s]\n", name, file);
if (S_ISREG(e->mode)) {
int fd = creat(file, e->mode & 0777);
xwrite(fd, e->data, e->filesize);
fchown(fd, e->uid, e->gid);
close(fd);
} else if (S_ISLNK(e->mode)) {
char *target = new char[e->filesize + 1];
memcpy(target, e->data, e->filesize);
symlink(target, e->filename);
delete[] target;
}
return true;
}
fprintf(stderr, "Cannot find the file entry [%s]\n", name);
return false;
}
void cpio::sort() {
arr.sort();
while (arr.back() == nullptr)
arr.pop_back();
}