busybox/archival/libunarchive/data_extract_to_command.c

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/* vi: set sw=4 ts=4: */
/*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include "unarchive.h"
enum {
//TAR_FILETYPE,
TAR_MODE,
TAR_FILENAME,
TAR_REALNAME,
#if ENABLE_FEATURE_TAR_UNAME_GNAME
TAR_UNAME,
TAR_GNAME,
#endif
TAR_SIZE,
TAR_UID,
TAR_GID,
TAR_MAX,
};
static const char *const tar_var[] = {
// "FILETYPE",
"MODE",
"FILENAME",
"REALNAME",
#if ENABLE_FEATURE_TAR_UNAME_GNAME
"UNAME",
"GNAME",
#endif
"SIZE",
"UID",
"GID",
};
static void xputenv(char *str)
{
if (putenv(str))
bb_error_msg_and_die(bb_msg_memory_exhausted);
}
static void str2env(char *env[], int idx, const char *str)
{
env[idx] = xasprintf("TAR_%s=%s", tar_var[idx], str);
xputenv(env[idx]);
}
static void dec2env(char *env[], int idx, unsigned long long val)
{
env[idx] = xasprintf("TAR_%s=%llu", tar_var[idx], val);
xputenv(env[idx]);
}
static void oct2env(char *env[], int idx, unsigned long val)
{
env[idx] = xasprintf("TAR_%s=%lo", tar_var[idx], val);
xputenv(env[idx]);
}
void FAST_FUNC data_extract_to_command(archive_handle_t *archive_handle)
{
file_header_t *file_header = archive_handle->file_header;
#if 0 /* do we need this? ENABLE_FEATURE_TAR_SELINUX */
char *sctx = archive_handle->tar__next_file_sctx;
if (!sctx)
sctx = archive_handle->tar__global_sctx;
if (sctx) { /* setfscreatecon is 4 syscalls, avoid if possible */
setfscreatecon(sctx);
free(archive_handle->tar__next_file_sctx);
archive_handle->tar__next_file_sctx = NULL;
}
#endif
if ((file_header->mode & S_IFMT) == S_IFREG) {
pid_t pid;
int p[2], status;
char *tar_env[TAR_MAX];
memset(tar_env, 0, sizeof(tar_env));
xpipe(p);
pid = BB_MMU ? xfork() : xvfork();
if (pid == 0) {
/* Child */
/* str2env(tar_env, TAR_FILETYPE, "f"); - parent should do it once */
oct2env(tar_env, TAR_MODE, file_header->mode);
str2env(tar_env, TAR_FILENAME, file_header->name);
str2env(tar_env, TAR_REALNAME, file_header->name);
#if ENABLE_FEATURE_TAR_UNAME_GNAME
str2env(tar_env, TAR_UNAME, file_header->tar__uname);
str2env(tar_env, TAR_GNAME, file_header->tar__gname);
#endif
dec2env(tar_env, TAR_SIZE, file_header->size);
dec2env(tar_env, TAR_UID, file_header->uid);
dec2env(tar_env, TAR_GID, file_header->gid);
close(p[1]);
xdup2(p[0], STDIN_FILENO);
signal(SIGPIPE, SIG_DFL);
execl(DEFAULT_SHELL, DEFAULT_SHELL_SHORT_NAME, "-c", archive_handle->tar__to_command, NULL);
bb_perror_msg_and_die("can't execute '%s'", DEFAULT_SHELL);
}
close(p[0]);
/* Our caller is expected to do signal(SIGPIPE, SIG_IGN)
* so that we don't die if child don't read all the input: */
bb_copyfd_exact_size(archive_handle->src_fd, p[1], -file_header->size);
close(p[1]);
if (safe_waitpid(pid, &status, 0) == -1)
bb_perror_msg_and_die("waitpid");
if (WIFEXITED(status) && WEXITSTATUS(status))
bb_error_msg_and_die("'%s' returned status %d",
archive_handle->tar__to_command, WEXITSTATUS(status));
if (WIFSIGNALED(status))
bb_error_msg_and_die("'%s' terminated on signal %d",
archive_handle->tar__to_command, WTERMSIG(status));
if (!BB_MMU) {
int i;
for (i = 0; i < TAR_MAX; i++) {
if (tar_env[i])
bb_unsetenv_and_free(tar_env[i]);
}
}
}
#if 0 /* ENABLE_FEATURE_TAR_SELINUX */
if (sctx)
/* reset the context after creating an entry */
setfscreatecon(NULL);
#endif
}