import: always prefer GNU tar, to avoid cmdline incompatibilities

Fixes: #16506
This commit is contained in:
Lennart Poettering
2020-07-21 14:16:02 +02:00
parent 2e3e2750bb
commit c400d040ce
+34 -4
View File
@@ -79,6 +79,17 @@ int import_fork_tar_x(const char *path, pid_t *ret) {
if (r < 0)
return r;
if (r == 0) {
const char *cmdline[] = {
"tar",
"--numeric-owner",
"-C", path,
"-px",
"--xattrs",
"--xattrs-include=*",
use_selinux ? "--selinux" : "--no-selinux",
NULL
};
uint64_t retain =
(1ULL << CAP_CHOWN) |
(1ULL << CAP_FOWNER) |
@@ -104,8 +115,15 @@ int import_fork_tar_x(const char *path, pid_t *ret) {
if (r < 0)
log_error_errno(r, "Failed to drop capabilities, ignoring: %m");
execlp("tar", "tar", "--numeric-owner", "-C", path, "-px", "--xattrs", "--xattrs-include=*",
use_selinux ? "--selinux" : "--no-selinux", NULL);
/* Try "gtar" before "tar". We only test things upstream with GNU tar. Some distros appear to
* install a different implementation as "tar" (in particular some that do not support the
* same command line switches), but then provide "gtar" as alias for the real thing, hence
* let's prefer that. (Yes, it's a bad idea they do that, given they don't provide equivalent
* command line support, but we are not here to argue, let's just expose the same
* behaviour/implementation everywhere.) */
execvp("gtar", (char* const*) cmdline);
execvp("tar", (char* const*) cmdline);
log_error_errno(errno, "Failed to execute tar: %m");
_exit(EXIT_FAILURE);
}
@@ -133,6 +151,17 @@ int import_fork_tar_c(const char *path, pid_t *ret) {
if (r < 0)
return r;
if (r == 0) {
const char *cmdline[] = {
"tar",
"-C", path,
"-c",
"--xattrs",
"--xattrs-include=*",
use_selinux ? "--selinux" : "--no-selinux",
".",
NULL
};
uint64_t retain = (1ULL << CAP_DAC_OVERRIDE);
/* Child */
@@ -152,8 +181,9 @@ int import_fork_tar_c(const char *path, pid_t *ret) {
if (r < 0)
log_error_errno(r, "Failed to drop capabilities, ignoring: %m");
execlp("tar", "tar", "-C", path, "-c", "--xattrs", "--xattrs-include=*",
use_selinux ? "--selinux" : "--no-selinux", ".", NULL);
execvp("gtar", (char* const*) cmdline);
execvp("tar", (char* const*) cmdline);
log_error_errno(errno, "Failed to execute tar: %m");
_exit(EXIT_FAILURE);
}