systemd/0655-random-seed-use-getopt...

208 lines
7.1 KiB
Diff

From f6b55583600b4f8bfa2e7883d60685e2fb6c6b9d Mon Sep 17 00:00:00 2001
From: Franck Bui <fbui@suse.com>
Date: Wed, 19 Oct 2022 15:49:24 +0200
Subject: [PATCH] random-seed: use getopt()
It's not really necessary since systemd-random-seed is an internal tool for the
moment but this might change in future (to allow system installers to
initialize a random seed file for example).
Also introducing new options will be easier.
(cherry picked from commit 0d0c6639d4d61ff6cee43bc059c56a5170a0d280)
Related: RHEL-16952
---
src/random-seed/random-seed.c | 116 ++++++++++++++++++++++++++++++----
1 file changed, 103 insertions(+), 13 deletions(-)
diff --git a/src/random-seed/random-seed.c b/src/random-seed/random-seed.c
index d94005bdde..2ca2181ddb 100644
--- a/src/random-seed/random-seed.c
+++ b/src/random-seed/random-seed.c
@@ -2,6 +2,7 @@
#include <errno.h>
#include <fcntl.h>
+#include <getopt.h>
#include <linux/random.h>
#include <sys/ioctl.h>
#if USE_SYS_RANDOM_H
@@ -22,20 +23,34 @@
#include "missing_random.h"
#include "missing_syscall.h"
#include "mkdir.h"
+#include "parse-argument.h"
#include "parse-util.h"
+#include "pretty-print.h"
#include "random-util.h"
+#include "string-table.h"
#include "string-util.h"
+#include "strv.h"
#include "sync-util.h"
#include "sha256.h"
+#include "terminal-util.h"
#include "util.h"
#include "xattr-util.h"
+typedef enum SeedAction {
+ ACTION_LOAD,
+ ACTION_SAVE,
+ _ACTION_MAX,
+ _ACTION_INVALID = -EINVAL,
+} SeedAction;
+
typedef enum CreditEntropy {
CREDIT_ENTROPY_NO_WAY,
CREDIT_ENTROPY_YES_PLEASE,
CREDIT_ENTROPY_YES_FORCED,
} CreditEntropy;
+static SeedAction arg_action = _ACTION_INVALID;
+
static CreditEntropy may_credit(int seed_fd) {
_cleanup_free_ char *creditable = NULL;
const char *e;
@@ -100,6 +115,78 @@ static CreditEntropy may_credit(int seed_fd) {
return CREDIT_ENTROPY_NO_WAY;
}
+static int help(int argc, char *argv[], void *userdata) {
+ _cleanup_free_ char *link = NULL;
+ int r;
+
+ r = terminal_urlify_man("systemd-random-seed", "8", &link);
+ if (r < 0)
+ return log_oom();
+
+ printf("%1$s [OPTIONS...] COMMAND\n"
+ "\n%5$sLoad and save the system random seed at boot and shutdown.%6$s\n"
+ "\n%3$sCommands:%4$s\n"
+ " load Load a random seed saved on disk into the kernel entropy pool\n"
+ " save Save a new random seed on disk\n"
+ "\n%3$sOptions:%4$s\n"
+ " -h --help Show this help\n"
+ " --version Show package version\n"
+ "\nSee the %2$s for details.\n",
+ program_invocation_short_name,
+ link,
+ ansi_underline(),
+ ansi_normal(),
+ ansi_highlight(),
+ ansi_normal());
+
+ return 0;
+}
+
+static const char* const seed_action_table[_ACTION_MAX] = {
+ [ACTION_LOAD] = "load",
+ [ACTION_SAVE] = "save",
+};
+
+DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING(seed_action, SeedAction);
+
+static int parse_argv(int argc, char *argv[]) {
+ enum {
+ ARG_VERSION = 0x100,
+ };
+
+ static const struct option options[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "version", no_argument, NULL, ARG_VERSION },
+ };
+
+ int c;
+
+ assert(argc >= 0);
+ assert(argv);
+
+ while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
+ switch (c) {
+ case 'h':
+ return help(0, NULL, NULL);
+ case ARG_VERSION:
+ return version();
+ case '?':
+ return -EINVAL;
+
+ default:
+ assert_not_reached();
+ }
+
+ if (optind + 1 != argc)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program requires one argument.");
+
+ arg_action = seed_action_from_string(argv[optind]);
+ if (arg_action < 0)
+ return log_error_errno(arg_action, "Unknown action '%s'", argv[optind]);
+
+ return 1;
+}
+
static int run(int argc, char *argv[]) {
bool read_seed_file, write_seed_file, synchronous, hashed_old_seed = false;
_cleanup_close_ int seed_fd = -1, random_fd = -1;
@@ -112,9 +199,9 @@ static int run(int argc, char *argv[]) {
log_setup();
- if (argc != 2)
- return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
- "This program requires one argument.");
+ r = parse_argv(argc, argv);
+ if (r <= 0)
+ return r;
umask(0022);
@@ -124,11 +211,11 @@ static int run(int argc, char *argv[]) {
if (r < 0)
return log_error_errno(r, "Failed to create directory " RANDOM_SEED_DIR ": %m");
- /* When we load the seed we read it and write it to the device and then immediately update the saved seed with
- * new data, to make sure the next boot gets seeded differently. */
-
- if (streq(argv[1], "load")) {
+ /* When we load the seed we read it and write it to the device and then immediately update the saved
+ * seed with new data, to make sure the next boot gets seeded differently. */
+ switch (arg_action) {
+ case ACTION_LOAD:
seed_fd = open(RANDOM_SEED, O_RDWR|O_CLOEXEC|O_NOCTTY|O_CREAT, 0600);
if (seed_fd < 0) {
int open_rw_error = -errno;
@@ -154,9 +241,9 @@ static int run(int argc, char *argv[]) {
read_seed_file = true;
synchronous = true; /* make this invocation a synchronous barrier for random pool initialization */
+ break;
- } else if (streq(argv[1], "save")) {
-
+ case ACTION_SAVE:
random_fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (random_fd < 0)
return log_error_errno(errno, "Failed to open /dev/urandom: %m");
@@ -168,14 +255,17 @@ static int run(int argc, char *argv[]) {
read_seed_file = false;
write_seed_file = true;
synchronous = false;
- } else
- return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
- "Unknown verb '%s'.", argv[1]);
+ break;
+
+ default:
+ assert_not_reached();
+ }
if (fstat(seed_fd, &st) < 0)
return log_error_errno(errno, "Failed to stat() seed file " RANDOM_SEED ": %m");
- /* If the seed file is larger than what we expect, then honour the existing size and save/restore as much as it says */
+ /* If the seed file is larger than what we expect, then honour the existing size and save/restore as
+ * much as it says */
if ((uint64_t) st.st_size > buf_size)
buf_size = MIN(st.st_size, RANDOM_POOL_SIZE_MAX);