From 516fc73142e803a7a6cbd126c338e1c3c73d6843 Mon Sep 17 00:00:00 2001
From: Jan Macku <jamacku@redhat.com>
Date: Fri, 21 Jan 2022 12:10:45 +0100
Subject: [PATCH] sysctl: if options are prefixed with "-" ignore write errors
(cherry picked from commit dec02d6e1993d420a0a94c7fec294605df55e88e)
Resolves: #2037807
---
src/sysctl/sysctl.c | 115 ++++++++++++++++++++++++++++++--------------
1 file changed, 80 insertions(+), 35 deletions(-)
diff --git a/src/sysctl/sysctl.c b/src/sysctl/sysctl.c
index 0151f7dabe..7b0528877c 100644
--- a/src/sysctl/sysctl.c
+++ b/src/sysctl/sysctl.c
@@ -26,25 +26,71 @@ static char **arg_prefixes = NULL;
static bool arg_cat_config = false;
static bool arg_no_pager = false;
+typedef struct Option {
+ char *key;
+ char *value;
+ bool ignore_failure;
+} Option;
+
+static Option *option_free(Option *o) {
+ if (!o)
+ return NULL;
+
+ free(o->key);
+ free(o->value);
+
+ return mfree(o);
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(Option*, option_free);
+DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(option_hash_ops, char, string_hash_func, string_compare_func, Option, option_free);
+
+static Option *option_new(
+ const char *key,
+ const char *value,
+ bool ignore_failure) {
+
+ _cleanup_(option_freep) Option *o = NULL;
+
+ assert(key);
+ assert(value);
+
+ o = new(Option, 1);
+ if (!o)
+ return NULL;
+
+ *o = (Option) {
+ .key = strdup(key),
+ .value = strdup(value),
+ .ignore_failure = ignore_failure,
+ };
+
+ if (!o->key || !o->value)
+ return NULL;
+
+ return TAKE_PTR(o);
+}
+
static int apply_all(OrderedHashmap *sysctl_options) {
- char *property, *value;
+ Option *option;
Iterator i;
int r = 0;
- ORDERED_HASHMAP_FOREACH_KEY(value, property, sysctl_options, i) {
+ ORDERED_HASHMAP_FOREACH(option, sysctl_options, i) {
int k;
- k = sysctl_write(property, value);
+ k = sysctl_write(option->key, option->value);
if (k < 0) {
- /* If the sysctl is not available in the kernel or we are running with reduced privileges and
- * cannot write it, then log about the issue at LOG_NOTICE level, and proceed without
- * failing. (EROFS is treated as a permission problem here, since that's how container managers
- * usually protected their sysctls.) In all other cases log an error and make the tool fail. */
-
- if (IN_SET(k, -EPERM, -EACCES, -EROFS, -ENOENT))
- log_notice_errno(k, "Couldn't write '%s' to '%s', ignoring: %m", value, property);
+ /* If the sysctl is not available in the kernel or we are running with reduced
+ * privileges and cannot write it, then log about the issue at LOG_NOTICE level, and
+ * proceed without failing. (EROFS is treated as a permission problem here, since
+ * that's how container managers usually protected their sysctls.) In all other cases
+ * log an error and make the tool fail. */
+
+ if (IN_SET(k, -EPERM, -EACCES, -EROFS, -ENOENT) || option->ignore_failure)
+ log_notice_errno(k, "Couldn't write '%s' to '%s', ignoring: %m", option->value, option->key);
else {
- log_error_errno(k, "Couldn't write '%s' to '%s': %m", value, property);
+ log_error_errno(k, "Couldn't write '%s' to '%s': %m", option->value, option->key);
if (r == 0)
r = k;
}
@@ -90,9 +136,11 @@ static int parse_file(OrderedHashmap *sysctl_options, const char *path, bool ign
log_debug("Parsing %s", path);
for (;;) {
- char *p, *value, *new_value, *property, *existing;
+ _cleanup_(option_freep) Option *new_option = NULL;
_cleanup_free_ char *l = NULL;
- void *v;
+ bool ignore_failure;
+ Option *existing;
+ char *p, *value;
int k;
k = read_line(f, LONG_LINE_MAX, &l);
@@ -122,39 +170,37 @@ static int parse_file(OrderedHashmap *sysctl_options, const char *path, bool ign
*value = 0;
value++;
- p = sysctl_normalize(strstrip(p));
+ p = strstrip(p);
+ ignore_failure = p[0] == '-';
+ if (ignore_failure)
+ p++;
+
+ p = sysctl_normalize(p);
value = strstrip(value);
if (!test_prefix(p))
continue;
- existing = ordered_hashmap_get2(sysctl_options, p, &v);
+ existing = ordered_hashmap_get(sysctl_options, p);
if (existing) {
- if (streq(value, existing))
+ if (streq(value, existing->value)) {
+ existing->ignore_failure = existing->ignore_failure || ignore_failure;
continue;
+ }
log_debug("Overwriting earlier assignment of %s at '%s:%u'.", p, path, c);
- free(ordered_hashmap_remove(sysctl_options, p));
- free(v);
+ option_free(ordered_hashmap_remove(sysctl_options, p));
}
- property = strdup(p);
- if (!property)
+ new_option = option_new(p, value, ignore_failure);
+ if (!new_option)
return log_oom();
- new_value = strdup(value);
- if (!new_value) {
- free(property);
- return log_oom();
- }
+ k = ordered_hashmap_put(sysctl_options, new_option->key, new_option);
+ if (k < 0)
+ return log_error_errno(k, "Failed to add sysctl variable %s to hashmap: %m", p);
- k = ordered_hashmap_put(sysctl_options, property, new_value);
- if (k < 0) {
- log_error_errno(k, "Failed to add sysctl variable %s to hashmap: %m", property);
- free(property);
- free(new_value);
- return k;
- }
+ TAKE_PTR(new_option);
}
return r;
@@ -251,7 +297,7 @@ static int parse_argv(int argc, char *argv[]) {
}
int main(int argc, char *argv[]) {
- OrderedHashmap *sysctl_options = NULL;
+ _cleanup_(ordered_hashmap_freep) OrderedHashmap *sysctl_options = NULL;
int r = 0, k;
r = parse_argv(argc, argv);
@@ -264,7 +310,7 @@ int main(int argc, char *argv[]) {
umask(0022);
- sysctl_options = ordered_hashmap_new(&path_hash_ops);
+ sysctl_options = ordered_hashmap_new(&option_hash_ops);
if (!sysctl_options) {
r = log_oom();
goto finish;
@@ -311,7 +357,6 @@ int main(int argc, char *argv[]) {
finish:
pager_close();
- ordered_hashmap_free_free_free(sysctl_options);
strv_free(arg_prefixes);
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;