+ if (uid <= SYSTEM_UID_MAX)
+ return 0;
+
+ /* Make sure normal users can read (but not write or delete)
+ * their own coredumps */
+
+ acl = acl_get_fd(fd);
+ if (!acl) {
+ log_error("Failed to get ACL: %m");
+ return -errno;
+ }
+
+ if (acl_create_entry(&acl, &entry) < 0 ||
+ acl_set_tag_type(entry, ACL_USER) < 0 ||
+ acl_set_qualifier(entry, &uid) < 0) {
+ log_error("Failed to patch ACL: %m");
+ return -errno;
+ }
+
+ if (acl_get_permset(entry, &permset) < 0 ||
+ acl_add_perm(permset, ACL_READ) < 0 ||
+ calc_acl_mask_if_needed(&acl) < 0) {
+ log_warning("Failed to patch ACL: %m");
+ return -errno;
+ }
+
+ if (acl_set_fd(fd, acl) < 0) {
+ log_error("Failed to apply ACL: %m");
+ return -errno;
+ }
+#endif
+
+ return 0;
+}
+
+static int fix_xattr(int fd, const char *info[_INFO_LEN]) {
+
+ static const char * const xattrs[_INFO_LEN] = {
+ [INFO_PID] = "user.coredump.pid",
+ [INFO_UID] = "user.coredump.uid",
+ [INFO_GID] = "user.coredump.gid",
+ [INFO_SIGNAL] = "user.coredump.signal",
+ [INFO_TIMESTAMP] = "user.coredump.timestamp",
+ [INFO_COMM] = "user.coredump.comm",
+ [INFO_EXE] = "user.coredump.exe",
+ };
+
+ int r = 0;
+ unsigned i;
+
+ assert(fd >= 0);
+
+ /* Attach some metadata to coredumps via extended
+ * attributes. Just because we can. */
+
+ for (i = 0; i < _INFO_LEN; i++) {
+ int k;
+
+ if (isempty(info[i]) || !xattrs[i])
+ continue;
+
+ k = fsetxattr(fd, xattrs[i], info[i], strlen(info[i]), XATTR_CREATE);
+ if (k < 0 && r == 0)
+ r = -errno;
+ }
+
+ return r;
+}
+
+#define filename_escape(s) xescape((s), "./ ")
+
+static int fix_permissions(
+ int fd,
+ const char *filename,
+ const char *target,
+ const char *info[_INFO_LEN],
+ uid_t uid) {
+
+ assert(fd >= 0);
+ assert(filename);
+ assert(target);
+ assert(info);
+
+ /* Ignore errors on these */
+ fchmod(fd, 0640);
+ fix_acl(fd, uid);
+ fix_xattr(fd, info);
+
+ if (fsync(fd) < 0) {
+ log_error("Failed to sync coredump %s: %m", filename);
+ return -errno;
+ }
+
+ if (rename(filename, target) < 0) {
+ log_error("Failed to rename coredump %s -> %s: %m", filename, target);
+ return -errno;
+ }
+
+ return 0;
+}
+
+static int maybe_remove_external_coredump(const char *filename, off_t size) {
+
+ /* Returns 1 if might remove, 0 if will not remove, < 0 on error. */
+
+ if (IN_SET(arg_storage, COREDUMP_STORAGE_EXTERNAL, COREDUMP_STORAGE_BOTH) &&
+ size <= arg_external_size_max)
+ return 0;
+
+ if (!filename)
+ return 1;
+
+ if (unlink(filename) < 0 && errno != ENOENT) {
+ log_error("Failed to unlink %s: %m", filename);
+ return -errno;
+ }
+
+ return 1;
+}
+
+static int make_filename(const char *info[_INFO_LEN], char **ret) {
+ _cleanup_free_ char *c = NULL, *u = NULL, *p = NULL, *t = NULL;
+ sd_id128_t boot;
+ int r;
+
+ assert(info);
+
+ c = filename_escape(info[INFO_COMM]);
+ if (!c)
+ return -ENOMEM;
+
+ u = filename_escape(info[INFO_UID]);
+ if (!u)
+ return -ENOMEM;
+
+ r = sd_id128_get_boot(&boot);
+ if (r < 0)
+ return r;
+
+ p = filename_escape(info[INFO_PID]);
+ if (!p)
+ return -ENOMEM;
+
+ t = filename_escape(info[INFO_TIMESTAMP]);
+ if (!t)
+ return -ENOMEM;
+
+ if (asprintf(ret,
+ "/var/lib/systemd/coredump/core.%s.%s." SD_ID128_FORMAT_STR ".%s.%s000000",
+ c,
+ u,
+ SD_ID128_FORMAT_VAL(boot),
+ p,
+ t) < 0)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static int save_external_coredump(
+ const char *info[_INFO_LEN],
+ uid_t uid,
+ char **ret_filename,
+ int *ret_fd,
+ off_t *ret_size) {
+
+ _cleanup_free_ char *fn = NULL, *tmp = NULL;
+ _cleanup_close_ int fd = -1;
+ struct stat st;
+ int r;
+
+ assert(info);
+ assert(ret_filename);
+ assert(ret_fd);
+ assert(ret_size);
+
+ r = make_filename(info, &fn);
+ if (r < 0) {
+ log_error("Failed to determine coredump file name: %s", strerror(-r));
+ return r;
+ }
+
+ tmp = tempfn_random(fn);
+ if (!tmp)
+ return log_oom();