/*-
* Copyright (c) 2007 Joerg Sonnenberger
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "archive_platform.h"
__FBSDID("$FreeBSD: src/lib/libarchive/archive_read_support_compression_program.c,v 1.6 2008/12/06 06:45:15 kientzle Exp $");
#ifdef HAVE_SYS_WAIT_H
# include <sys/wait.h>
#endif
#ifdef HAVE_ERRNO_H
# include <errno.h>
#endif
#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#endif
#ifdef HAVE_LIMITS_H
# include <limits.h>
#endif
#ifdef HAVE_SIGNAL_H
# include <signal.h>
#endif
#ifdef HAVE_STDLIB_H
# include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
# include <string.h>
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#include "archive.h"
#include "archive_private.h"
#include "archive_read_private.h"
int
archive_read_support_compression_program(struct archive *a, const char *cmd)
{
return (archive_read_support_compression_program_signature(a, cmd, NULL, 0));
}
/* This capability is only available on POSIX systems. */
#if (!defined(HAVE_PIPE) || !defined(HAVE_FCNTL) || \
!(defined(HAVE_FORK) || defined(HAVE_VFORK))) && (!defined(_WIN32) || defined(__CYGWIN__))
/*
* On non-Posix systems, allow the program to build, but choke if
* this function is actually invoked.
*/
int
archive_read_support_compression_program_signature(struct archive *_a,
const char *cmd, const void *signature, size_t signature_len)
{
(void)_a; /* UNUSED */
(void)cmd; /* UNUSED */
(void)signature; /* UNUSED */
(void)signature_len; /* UNUSED */
archive_set_error(_a, -1,
"External compression programs not supported on this platform");
return (ARCHIVE_FATAL);
}
int
__archive_read_program(struct archive_read_filter *self, const char *cmd)
{
(void)self; /* UNUSED */
(void)cmd; /* UNUSED */
archive_set_error(&self->archive->archive, -1,
"External compression programs not supported on this platform");
return (ARCHIVE_FATAL);
}
#else
#include "filter_fork.h"
/*
* The bidder object stores the command and the signature to watch for.
* The 'inhibit' entry here is used to ensure that unchecked filters never
* bid twice in the same pipeline.
*/
struct program_bidder {
char *cmd;
void *signature;
size_t signature_len;
int inhibit;
};
static int program_bidder_bid(struct archive_read_filter_bidder *,
struct archive_read_filter *upstream);
static int program_bidder_init(struct archive_read_filter *);
static int program_bidder_free(struct archive_read_filter_bidder *);
/*
* The actual filter needs to track input and output data.
*/
struct program_filter {
char *description;
pid_t child;
int exit_status;
int waitpid_return;
int child_stdin, child_stdout;
char *out_buf;
size_t out_buf_len;
};
static ssize_t program_filter_read(struct archive_read_filter *,
const void **);
static int program_filter_close(struct archive_read_filter *);
int
archive_read_support_compression_program_signature(struct archive *_a,
const char *cmd, const void *signature, size_t signature_len)
{
struct archive_read *a = (struct archive_read *)_a;
struct archive_read_filter_bidder *bidder;
struct program_bidder *state;
/*
* Get a bidder object from the read core.
*/
bidder = __archive_read_get_bidder(a);
if (bidder == NULL)
return (ARCHIVE_FATAL);
/*
* Allocate our private state.
*/
state = (struct program_bidder *)calloc(sizeof (*state), 1);
if (state == NULL)
return (ARCHIVE_FATAL);
state->cmd = strdup(cmd);
if (signature != NULL && signature_len > 0) {
state->signature_len = signature_len;
state->signature = malloc(signature_len);
memcpy(state->signature, signature, signature_len);
}
/*
* Fill in the bidder object.
*/
bidder->data = state;
bidder->bid = program_bidder_bid;
bidder->init = program_bidder_init;
bidder->options = NULL;
bidder->free = program_bidder_free;
return (ARCHIVE_OK);
}
static int
program_bidder_free(struct archive_read_filter_bidder *self)
{
struct program_bidder *state = (struct program_bidder *)self->data;
free(state->cmd);
free(state->signature);
free(self->data);
return (ARCHIVE_OK);
}
/*
* If we do have a signature, bid only if that matches.
*
* If there's no signature, we bid INT_MAX the first time
* we're called, then never bid again.
*/
static int
program_bidder_bid(struct archive_read_filter_bidder *self,
struct archive_read_filter *upstream)
{
struct program_bidder *state = self->data;
const char *p;
/* If we have a signature, use that to match. */
if (state->signature_len > 0) {
p = __archive_read_filter_ahead(upstream,
state->signature_len, NULL);
if (p == NULL)
return (0);
/* No match, so don't bid. */
if (memcmp(p, state->signature, state->signature_len) != 0)
return (0);
return (state->signature_len * 8);
}
/* Otherwise, bid once and then never bid again. */
if (state->inhibit)
return (0);
state->inhibit = 1;
return (INT_MAX);
}
/*
* Shut down the child, return ARCHIVE_OK if it exited normally.
*
* Note that the return value is sticky; if we're called again,
* we won't reap the child again, but we will return the same status
* (including error message if the child came to a bad end).
*/
static int
child_stop(struct archive_read_filter *self, struct program_filter *state)
{
/* Close our side of the I/O with the child. */
if (state->child_stdin != -1) {
close(state->child_stdin);
state->child_stdin = -1;
}
if (state->child_stdout != -1) {
close(state->child_stdout);
state->child_stdout = -1;
}
if (state->child != 0) {
/* Reap the child. */
do {
state->waitpid_return
= waitpid(state->child, &state->exit_status, 0);
} while (state->waitpid_return == -1 && errno == EINTR);
state->child = 0;
}
if (state->waitpid_return < 0) {
/* waitpid() failed? This is ugly. */
archive_set_error(&self->archive->archive, ARCHIVE_ERRNO_MISC,
"Child process exited badly");
return (ARCHIVE_WARN);
}
if (WIFSIGNALED(state->exit_status)) {
#ifdef SIGPIPE
/* If the child died because we stopped reading before
* it was done, that's okay. Some archive formats
* have padding at the end that we routinely ignore. */
/* The alternative to this would be to add a step
* before close(child_stdout) above to read from the
* child until the child has no more to write. */
if (WTERMSIG(state->exit_status) == SIGPIPE)
return (ARCHIVE_OK);
#endif
archive_set_error(&self->archive->archive, ARCHIVE_ERRNO_MISC,
"Child process exited with signal %d",
WTERMSIG(state->exit_status));
return (ARCHIVE_WARN);
}
if (WIFEXITED(state->exit_status)) {
if (WEXITSTATUS(state->exit_status) == 0)
return (ARCHIVE_OK);
archive_set_error(&self->archive->archive,
ARCHIVE_ERRNO_MISC,
"Child process exited with status %d",
WEXITSTATUS(state->exit_status));
return (ARCHIVE_WARN);
}
return (ARCHIVE_WARN);
}
/*
* Use select() to decide whether the child is ready for read or write.
*/
static ssize_t
child_read(struct archive_read_filter *self, char *buf, size_t buf_len)
{
struct program_filter *state = self->data;
ssize_t ret, requested, avail;
const char *p;
requested = buf_len > SSIZE_MAX ? SSIZE_MAX : buf_len;
for (;;) {
do {
ret = read(state->child_stdout, buf, requested);
} while (ret == -1 && errno == EINTR);
if (ret > 0)
return (ret);
if (ret == 0 || (ret == -1 && errno == EPIPE))
/* Child has closed its output; reap the child
* and return the status. */
return (child_stop(self, state));
if (ret == -1 && errno != EAGAIN)
return (-1);
if (state->child_stdin == -1) {
/* Block until child has some I/O ready. */
__archive_check_child(state->child_stdin,
state->child_stdout);
continue;
}
/* Get some more data from upstream. */
p = __archive_read_filter_ahead(self->upstream, 1, &avail);
if (p == NULL) {
close(state->child_stdin);
state->child_stdin = -1;
fcntl(state->child_stdout, F_SETFL, 0);
if (avail < 0)
return (avail);
continue;
}
do {
ret = write(state->child_stdin, p, avail);
} while (ret == -1 && errno == EINTR);
if (ret > 0) {
/* Consume whatever we managed to write. */
__archive_read_filter_consume(self->upstream, ret);
} else if (ret == -1 && errno == EAGAIN) {
/* Block until child has some I/O ready. */
__archive_check_child(state->child_stdin,
state->child_stdout);
} else {
/* Write failed. */
close(state->child_stdin);
state->child_stdin = -1;
fcntl(state->child_stdout, F_SETFL, 0);
/* If it was a bad error, we're done; otherwise
* it was EPIPE or EOF, and we can still read
* from the child. */
if (ret == -1 && errno != EPIPE)
return (-1);
}
}
}
int
__archive_read_program(struct archive_read_filter *self, const char *cmd)
{
struct program_filter *state;
static const size_t out_buf_len = 65536;
char *out_buf;
char *description;
const char *prefix = "Program: ";
state = (struct program_filter *)calloc(1, sizeof(*state));
out_buf = (char *)malloc(out_buf_len);
description = (char *)malloc(strlen(prefix) + strlen(cmd) + 1);
if (state == NULL || out_buf == NULL || description == NULL) {
archive_set_error(&self->archive->archive, ENOMEM,
"Can't allocate input data");
free(state);
free(out_buf);
free(description);
return (ARCHIVE_FATAL);
}
self->code = ARCHIVE_COMPRESSION_PROGRAM;
state->description = description;
strcpy(state->description, prefix);
strcat(state->description, cmd);
self->name = state->description;
state->out_buf = out_buf;
state->out_buf_len = out_buf_len;
if ((state->child = __archive_create_child(cmd,
&state->child_stdin, &state->child_stdout)) == -1) {
free(state->out_buf);
free(state);
archive_set_error(&self->archive->archive, EINVAL,
"Can't initialise filter");
return (ARCHIVE_FATAL);
}
self->data = state;
self->read = program_filter_read;
self->skip = NULL;
self->close = program_filter_close;
/* XXX Check that we can read at least one byte? */
return (ARCHIVE_OK);
}
static int
program_bidder_init(struct archive_read_filter *self)
{
struct program_bidder *bidder_state;
bidder_state = (struct program_bidder *)self->bidder->data;
return (__archive_read_program(self, bidder_state->cmd));
}
static ssize_t
program_filter_read(struct archive_read_filter *self, const void **buff)
{
struct program_filter *state;
ssize_t bytes;
size_t total;
char *p;
state = (struct program_filter *)self->data;
total = 0;
p = state->out_buf;
while (state->child_stdout != -1 && total < state->out_buf_len) {
bytes = child_read(self, p, state->out_buf_len - total);
if (bytes < 0)
/* No recovery is possible if we can no longer
* read from the child. */
return (ARCHIVE_FATAL);
if (bytes == 0)
/* We got EOF from the child. */
break;
total += bytes;
p += bytes;
}
*buff = state->out_buf;
return (total);
}
static int
program_filter_close(struct archive_read_filter *self)
{
struct program_filter *state;
int e;
state = (struct program_filter *)self->data;
e = child_stop(self, state);
/* Release our private data. */
free(state->out_buf);
free(state->description);
free(state);
return (e);
}
#endif /* !defined(HAVE_PIPE) || !defined(HAVE_VFORK) || !defined(HAVE_FCNTL) */