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/* vi: set sw=4 ts=4: */
/*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
#include "bb_archive.h"
void FAST_FUNC init_transformer_aux_data(transformer_aux_data_t *aux)
{
memset(aux, 0, sizeof(*aux));
}
int FAST_FUNC check_signature16(transformer_aux_data_t *aux, int src_fd, unsigned magic16)
{
if (aux && aux->check_signature) {
uint16_t magic2;
if (full_read(src_fd, &magic2, 2) != 2 || magic2 != magic16) {
bb_error_msg("invalid magic");
#if 0 /* possible future extension */
if (aux->check_signature > 1)
xfunc_die();
#endif
return -1;
}
}
return 0;
}
void check_errors_in_children(int signo)
{
int status;
if (!signo) {
/* block waiting for any child */
if (wait(&status) < 0)
//FIXME: check EINTR?
return; /* probably there are no children */
goto check_status;
}
/* Wait for any child without blocking */
for (;;) {
if (wait_any_nohang(&status) < 0)
//FIXME: check EINTR?
/* wait failed?! I'm confused... */
return;
check_status:
/*if (WIFEXITED(status) && WEXITSTATUS(status) == 0)*/
/* On Linux, the above can be checked simply as: */
if (status == 0)
/* this child exited with 0 */
continue;
/* Cannot happen:
if (!WIFSIGNALED(status) && !WIFEXITED(status)) ???;
*/
bb_got_signal = 1;
}
}
/* transformer(), more than meets the eye */
#if BB_MMU
void FAST_FUNC open_transformer(int fd,
int check_signature,
IF_DESKTOP(long long) int FAST_FUNC (*transformer)(transformer_aux_data_t *aux, int src_fd, int dst_fd)
)
#else
void FAST_FUNC open_transformer(int fd, const char *transform_prog)
#endif
{
struct fd_pair fd_pipe;
int pid;
xpiped_pair(fd_pipe);
pid = BB_MMU ? xfork() : xvfork();
if (pid == 0) {
/* Child */
close(fd_pipe.rd); /* we don't want to read from the parent */
// FIXME: error check?
#if BB_MMU
{
IF_DESKTOP(long long) int r;
transformer_aux_data_t aux;
init_transformer_aux_data(&aux);
aux.check_signature = check_signature;
r = transformer(&aux, fd, fd_pipe.wr);
if (ENABLE_FEATURE_CLEAN_UP) {
close(fd_pipe.wr); /* send EOF */
close(fd);
}
/* must be _exit! bug was actually seen here */
_exit(/*error if:*/ r < 0);
}
#else
{
char *argv[4];
xmove_fd(fd, 0);
xmove_fd(fd_pipe.wr, 1);
argv[0] = (char*)transform_prog;
argv[1] = (char*)"-cf";
argv[2] = (char*)"-";
argv[3] = NULL;
BB_EXECVP(transform_prog, argv);
bb_perror_msg_and_die("can't execute '%s'", transform_prog);
}
#endif
/* notreached */
}
/* parent process */
close(fd_pipe.wr); /* don't want to write to the child */
xmove_fd(fd_pipe.rd, fd);
}
#if SEAMLESS_COMPRESSION
/* Used by e.g. rpm which gives us a fd without filename,
* thus we can't guess the format from filename's extension.
*/
int FAST_FUNC setup_unzip_on_fd(int fd, int fail_if_not_detected)
{
union {
uint8_t b[4];
uint16_t b16[2];
uint32_t b32[1];
} magic;
int offset = -2;
USE_FOR_MMU(IF_DESKTOP(long long) int FAST_FUNC (*xformer)(transformer_aux_data_t *aux, int src_fd, int dst_fd);)
USE_FOR_NOMMU(const char *xformer_prog;)
/* .gz and .bz2 both have 2-byte signature, and their
* unpack_XXX_stream wants this header skipped. */
xread(fd, magic.b16, sizeof(magic.b16[0]));
if (ENABLE_FEATURE_SEAMLESS_GZ
&& magic.b16[0] == GZIP_MAGIC
) {
USE_FOR_MMU(xformer = unpack_gz_stream;)
USE_FOR_NOMMU(xformer_prog = "gunzip";)
goto found_magic;
}
if (ENABLE_FEATURE_SEAMLESS_BZ2
&& magic.b16[0] == BZIP2_MAGIC
) {
USE_FOR_MMU(xformer = unpack_bz2_stream;)
USE_FOR_NOMMU(xformer_prog = "bunzip2";)
goto found_magic;
}
if (ENABLE_FEATURE_SEAMLESS_XZ
&& magic.b16[0] == XZ_MAGIC1
) {
offset = -6;
xread(fd, magic.b32, sizeof(magic.b32[0]));
if (magic.b32[0] == XZ_MAGIC2) {
USE_FOR_MMU(xformer = unpack_xz_stream;)
USE_FOR_NOMMU(xformer_prog = "unxz";)
goto found_magic;
}
}
/* No known magic seen */
if (fail_if_not_detected)
bb_error_msg_and_die("no gzip"
IF_FEATURE_SEAMLESS_BZ2("/bzip2")
IF_FEATURE_SEAMLESS_XZ("/xz")
" magic");
xlseek(fd, offset, SEEK_CUR);
return 1;
found_magic:
# if BB_MMU
open_transformer_with_no_sig(fd, xformer);
# else
/* NOMMU version of open_transformer execs
* an external unzipper that wants
* file position at the start of the file */
xlseek(fd, offset, SEEK_CUR);
open_transformer_with_sig(fd, xformer, xformer_prog);
# endif
return 0;
}
int FAST_FUNC open_zipped(const char *fname)
{
int fd;
fd = open(fname, O_RDONLY);
if (fd < 0)
return fd;
if (ENABLE_FEATURE_SEAMLESS_LZMA) {
/* .lzma has no header/signature, can only detect it by extension */
char *sfx = strrchr(fname, '.');
if (sfx && strcmp(sfx+1, "lzma") == 0) {
open_transformer_with_sig(fd, unpack_lzma_stream, "unlzma");
return fd;
}
}
if ((ENABLE_FEATURE_SEAMLESS_GZ)
|| (ENABLE_FEATURE_SEAMLESS_BZ2)
|| (ENABLE_FEATURE_SEAMLESS_XZ)
) {
setup_unzip_on_fd(fd, /*fail_if_not_detected:*/ 1);
}
return fd;
}
#endif /* SEAMLESS_COMPRESSION */
void* FAST_FUNC xmalloc_open_zipped_read_close(const char *fname, size_t *maxsz_p)
{
int fd;
char *image;
fd = open_zipped(fname);
if (fd < 0)
return NULL;
image = xmalloc_read(fd, maxsz_p);
if (!image)
bb_perror_msg("read error from '%s'", fname);
close(fd);
return image;
}
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