diff options
| -rw-r--r-- | toys/posix/cpio.c | 56 |
1 files changed, 47 insertions, 9 deletions
diff --git a/toys/posix/cpio.c b/toys/posix/cpio.c index 8263de3e..958931e6 100644 --- a/toys/posix/cpio.c +++ b/toys/posix/cpio.c @@ -39,14 +39,14 @@ GLOBALS( ) // Read strings, tail padded to 4 byte alignment. Argument "align" is amount -// by which start of string isn't aligned (usually 0). +// by which start of string isn't aligned (usually 0, but header is 110 bytes +// which is 2 bytes off because the first field wasn't expanded from 6 to 8). static char *strpad(int fd, unsigned len, unsigned align) { char *str; align = (align + len) & 3; if (align) len += (4-align); - xreadall(fd, str = xmalloc(len+1), len); str[len]=0; // redundant, in case archive is bad @@ -88,7 +88,7 @@ void cpio_main(void) if (toys.optflags & (FLAG_i|FLAG_t)) for (;;) { char *name, *tofree, *data; - unsigned size, mode; + unsigned size, mode, uid, gid, timestamp; int test = toys.optflags & FLAG_t, err = 0; // Read header and name. @@ -98,11 +98,13 @@ void cpio_main(void) // If you want to extract absolute paths, "cd /" and run cpio. while (*name == '/') name++; - - // Align to 4 bytes. Note header is 110 bytes which is 2 bytes over. + // TODO: remove .. entries size = x8u(toybuf+54); mode = x8u(toybuf+14); + uid = x8u(toybuf+30); + gid = x8u(toybuf+38); + timestamp = x8u(toybuf+46); // unsigned 32 bit, so year 2100 problem if (toys.optflags & (FLAG_t|FLAG_v)) puts(name); @@ -119,12 +121,13 @@ void cpio_main(void) } else if (S_ISLNK(mode)) { data = strpad(afd, size, 0); if (!test) err = symlink(data, name); + // Can't get a filehandle to a symlink, so do special chown + if (!err && !getpid()) err = lchown(name, uid, gid); } else if (S_ISREG(mode)) { - int fd; + int fd = test ? 0 : open(name, O_CREAT|O_WRONLY|O_TRUNC|O_NOFOLLOW, mode); // If write fails, we still need to read/discard data to continue with // archive. Since doing so overwrites errno, report error now - fd = test ? 0 : open(name, O_CREAT|O_WRONLY|O_TRUNC|O_NOFOLLOW, mode); if (fd < 0) { perror_msg("create %s", name); test++; @@ -141,11 +144,46 @@ void cpio_main(void) } size -= sizeof(toybuf); } - if (!test) close(fd); + + if (!test) { + // set owner, restore dropped suid bit + if (!getpid()) { + err = fchown(fd, uid, gid); + if (!err) err = fchmod(fd, mode); + } + close(fd); + } } else if (!test) err = mknod(name, mode, makedev(x8u(toybuf+62), x8u(toybuf+70))); - if (err<0) perror_msg("create '%s'", name); + // Set ownership and timestamp. + if (!test && !err) { + // Creading dir/dev doesn't give us a filehandle, we have to refer to it + // by name to chown/utime, but how do we know it's the same item? + // Check that we at least have the right type of entity open, and do + // NOT restore dropped suid bit in this case. + if (!S_ISREG(mode) && !S_ISLNK(mode) && !getpid()) { + int fd = open(name, O_WRONLY|O_NOFOLLOW); + struct stat st; + + if (fd != -1 && !fstat(fd, &st) && (st.st_mode&S_IFMT) == mode) + err = fchown(fd, uid, gid); + else err = 1; + + close(fd); + } + + // set timestamp + if (!err) { + struct timespec times[2]; + + memset(times, 0, sizeof(struct timespec)*2); + times[0].tv_sec = times[1].tv_sec = timestamp; + err = utimensat(AT_FDCWD, name, times, AT_SYMLINK_NOFOLLOW); + } + } + + if (err) perror_msg("'%s'", name); free(tofree); // Output cpio archive |