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-rw-r--r--src/basic/rlimit-util.c428
1 files changed, 428 insertions, 0 deletions
diff --git a/src/basic/rlimit-util.c b/src/basic/rlimit-util.c
new file mode 100644
index 0000000..c1f0b2b
--- /dev/null
+++ b/src/basic/rlimit-util.c
@@ -0,0 +1,428 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+
+#include "alloc-util.h"
+#include "errno-util.h"
+#include "extract-word.h"
+#include "fd-util.h"
+#include "format-util.h"
+#include "macro.h"
+#include "missing_resource.h"
+#include "rlimit-util.h"
+#include "string-table.h"
+#include "time-util.h"
+
+int setrlimit_closest(int resource, const struct rlimit *rlim) {
+ struct rlimit highest, fixed;
+
+ assert(rlim);
+
+ if (setrlimit(resource, rlim) >= 0)
+ return 0;
+
+ if (errno != EPERM)
+ return -errno;
+
+ /* So we failed to set the desired setrlimit, then let's try
+ * to get as close as we can */
+ if (getrlimit(resource, &highest) < 0)
+ return -errno;
+
+ /* If the hard limit is unbounded anyway, then the EPERM had other reasons, let's propagate the original EPERM
+ * then */
+ if (highest.rlim_max == RLIM_INFINITY)
+ return -EPERM;
+
+ fixed = (struct rlimit) {
+ .rlim_cur = MIN(rlim->rlim_cur, highest.rlim_max),
+ .rlim_max = MIN(rlim->rlim_max, highest.rlim_max),
+ };
+
+ /* Shortcut things if we wouldn't change anything. */
+ if (fixed.rlim_cur == highest.rlim_cur &&
+ fixed.rlim_max == highest.rlim_max)
+ return 0;
+
+ log_debug("Failed at setting rlimit " RLIM_FMT " for resource RLIMIT_%s. Will attempt setting value " RLIM_FMT " instead.", rlim->rlim_max, rlimit_to_string(resource), fixed.rlim_max);
+
+ return RET_NERRNO(setrlimit(resource, &fixed));
+}
+
+int setrlimit_closest_all(const struct rlimit *const *rlim, int *which_failed) {
+ int r;
+
+ assert(rlim);
+
+ /* On failure returns the limit's index that failed in *which_failed, but only if non-NULL */
+
+ for (int i = 0; i < _RLIMIT_MAX; i++) {
+ if (!rlim[i])
+ continue;
+
+ r = setrlimit_closest(i, rlim[i]);
+ if (r < 0) {
+ if (which_failed)
+ *which_failed = i;
+
+ return r;
+ }
+ }
+
+ if (which_failed)
+ *which_failed = -1;
+
+ return 0;
+}
+
+static int rlimit_parse_u64(const char *val, rlim_t *ret) {
+ uint64_t u;
+ int r;
+
+ assert(val);
+ assert(ret);
+
+ if (streq(val, "infinity")) {
+ *ret = RLIM_INFINITY;
+ return 0;
+ }
+
+ /* setrlimit(2) suggests rlim_t is always 64-bit on Linux. */
+ assert_cc(sizeof(rlim_t) == sizeof(uint64_t));
+
+ r = safe_atou64(val, &u);
+ if (r < 0)
+ return r;
+ if (u >= (uint64_t) RLIM_INFINITY)
+ return -ERANGE;
+
+ *ret = (rlim_t) u;
+ return 0;
+}
+
+static int rlimit_parse_size(const char *val, rlim_t *ret) {
+ uint64_t u;
+ int r;
+
+ assert(val);
+ assert(ret);
+
+ if (streq(val, "infinity")) {
+ *ret = RLIM_INFINITY;
+ return 0;
+ }
+
+ r = parse_size(val, 1024, &u);
+ if (r < 0)
+ return r;
+ if (u >= (uint64_t) RLIM_INFINITY)
+ return -ERANGE;
+
+ *ret = (rlim_t) u;
+ return 0;
+}
+
+static int rlimit_parse_sec(const char *val, rlim_t *ret) {
+ uint64_t u;
+ usec_t t;
+ int r;
+
+ assert(val);
+ assert(ret);
+
+ if (streq(val, "infinity")) {
+ *ret = RLIM_INFINITY;
+ return 0;
+ }
+
+ r = parse_sec(val, &t);
+ if (r < 0)
+ return r;
+ if (t == USEC_INFINITY) {
+ *ret = RLIM_INFINITY;
+ return 0;
+ }
+
+ u = (uint64_t) DIV_ROUND_UP(t, USEC_PER_SEC);
+ if (u >= (uint64_t) RLIM_INFINITY)
+ return -ERANGE;
+
+ *ret = (rlim_t) u;
+ return 0;
+}
+
+static int rlimit_parse_usec(const char *val, rlim_t *ret) {
+ usec_t t;
+ int r;
+
+ assert(val);
+ assert(ret);
+
+ if (streq(val, "infinity")) {
+ *ret = RLIM_INFINITY;
+ return 0;
+ }
+
+ r = parse_time(val, &t, 1);
+ if (r < 0)
+ return r;
+ if (t == USEC_INFINITY) {
+ *ret = RLIM_INFINITY;
+ return 0;
+ }
+
+ *ret = (rlim_t) t;
+ return 0;
+}
+
+static int rlimit_parse_nice(const char *val, rlim_t *ret) {
+ uint64_t rl;
+ int r;
+
+ /* So, Linux is weird. The range for RLIMIT_NICE is 40..1, mapping to the nice levels -20..19. However, the
+ * RLIMIT_NICE limit defaults to 0 by the kernel, i.e. a value that maps to nice level 20, which of course is
+ * bogus and does not exist. In order to permit parsing the RLIMIT_NICE of 0 here we hence implement a slight
+ * asymmetry: when parsing as positive nice level we permit 0..19. When parsing as negative nice level, we
+ * permit -20..0. But when parsing as raw resource limit value then we also allow the special value 0.
+ *
+ * Yeah, Linux is quality engineering sometimes... */
+
+ if (val[0] == '+') {
+
+ /* Prefixed with "+": Parse as positive user-friendly nice value */
+ r = safe_atou64(val + 1, &rl);
+ if (r < 0)
+ return r;
+
+ if (rl >= PRIO_MAX)
+ return -ERANGE;
+
+ rl = 20 - rl;
+
+ } else if (val[0] == '-') {
+
+ /* Prefixed with "-": Parse as negative user-friendly nice value */
+ r = safe_atou64(val + 1, &rl);
+ if (r < 0)
+ return r;
+
+ if (rl > (uint64_t) (-PRIO_MIN))
+ return -ERANGE;
+
+ rl = 20 + rl;
+ } else {
+
+ /* Not prefixed: parse as raw resource limit value */
+ r = safe_atou64(val, &rl);
+ if (r < 0)
+ return r;
+
+ if (rl > (uint64_t) (20 - PRIO_MIN))
+ return -ERANGE;
+ }
+
+ *ret = (rlim_t) rl;
+ return 0;
+}
+
+static int (*const rlimit_parse_table[_RLIMIT_MAX])(const char *val, rlim_t *ret) = {
+ [RLIMIT_CPU] = rlimit_parse_sec,
+ [RLIMIT_FSIZE] = rlimit_parse_size,
+ [RLIMIT_DATA] = rlimit_parse_size,
+ [RLIMIT_STACK] = rlimit_parse_size,
+ [RLIMIT_CORE] = rlimit_parse_size,
+ [RLIMIT_RSS] = rlimit_parse_size,
+ [RLIMIT_NOFILE] = rlimit_parse_u64,
+ [RLIMIT_AS] = rlimit_parse_size,
+ [RLIMIT_NPROC] = rlimit_parse_u64,
+ [RLIMIT_MEMLOCK] = rlimit_parse_size,
+ [RLIMIT_LOCKS] = rlimit_parse_u64,
+ [RLIMIT_SIGPENDING] = rlimit_parse_u64,
+ [RLIMIT_MSGQUEUE] = rlimit_parse_size,
+ [RLIMIT_NICE] = rlimit_parse_nice,
+ [RLIMIT_RTPRIO] = rlimit_parse_u64,
+ [RLIMIT_RTTIME] = rlimit_parse_usec,
+};
+
+int rlimit_parse_one(int resource, const char *val, rlim_t *ret) {
+ assert(val);
+ assert(ret);
+
+ if (resource < 0)
+ return -EINVAL;
+ if (resource >= _RLIMIT_MAX)
+ return -EINVAL;
+
+ return rlimit_parse_table[resource](val, ret);
+}
+
+int rlimit_parse(int resource, const char *val, struct rlimit *ret) {
+ _cleanup_free_ char *hard = NULL, *soft = NULL;
+ rlim_t hl, sl;
+ int r;
+
+ assert(val);
+ assert(ret);
+
+ r = extract_first_word(&val, &soft, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return -EINVAL;
+
+ r = rlimit_parse_one(resource, soft, &sl);
+ if (r < 0)
+ return r;
+
+ r = extract_first_word(&val, &hard, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
+ if (r < 0)
+ return r;
+ if (!isempty(val))
+ return -EINVAL;
+ if (r == 0)
+ hl = sl;
+ else {
+ r = rlimit_parse_one(resource, hard, &hl);
+ if (r < 0)
+ return r;
+ if (sl > hl)
+ return -EILSEQ;
+ }
+
+ *ret = (struct rlimit) {
+ .rlim_cur = sl,
+ .rlim_max = hl,
+ };
+
+ return 0;
+}
+
+int rlimit_format(const struct rlimit *rl, char **ret) {
+ _cleanup_free_ char *s = NULL;
+ int r;
+
+ assert(rl);
+ assert(ret);
+
+ if (rl->rlim_cur >= RLIM_INFINITY && rl->rlim_max >= RLIM_INFINITY)
+ r = free_and_strdup(&s, "infinity");
+ else if (rl->rlim_cur >= RLIM_INFINITY)
+ r = asprintf(&s, "infinity:" RLIM_FMT, rl->rlim_max);
+ else if (rl->rlim_max >= RLIM_INFINITY)
+ r = asprintf(&s, RLIM_FMT ":infinity", rl->rlim_cur);
+ else if (rl->rlim_cur == rl->rlim_max)
+ r = asprintf(&s, RLIM_FMT, rl->rlim_cur);
+ else
+ r = asprintf(&s, RLIM_FMT ":" RLIM_FMT, rl->rlim_cur, rl->rlim_max);
+ if (r < 0)
+ return -ENOMEM;
+
+ *ret = TAKE_PTR(s);
+ return 0;
+}
+
+static const char* const rlimit_table[_RLIMIT_MAX] = {
+ [RLIMIT_AS] = "AS",
+ [RLIMIT_CORE] = "CORE",
+ [RLIMIT_CPU] = "CPU",
+ [RLIMIT_DATA] = "DATA",
+ [RLIMIT_FSIZE] = "FSIZE",
+ [RLIMIT_LOCKS] = "LOCKS",
+ [RLIMIT_MEMLOCK] = "MEMLOCK",
+ [RLIMIT_MSGQUEUE] = "MSGQUEUE",
+ [RLIMIT_NICE] = "NICE",
+ [RLIMIT_NOFILE] = "NOFILE",
+ [RLIMIT_NPROC] = "NPROC",
+ [RLIMIT_RSS] = "RSS",
+ [RLIMIT_RTPRIO] = "RTPRIO",
+ [RLIMIT_RTTIME] = "RTTIME",
+ [RLIMIT_SIGPENDING] = "SIGPENDING",
+ [RLIMIT_STACK] = "STACK",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(rlimit, int);
+
+int rlimit_from_string_harder(const char *s) {
+ const char *suffix;
+
+ /* The official prefix */
+ suffix = startswith(s, "RLIMIT_");
+ if (suffix)
+ return rlimit_from_string(suffix);
+
+ /* Our own unit file setting prefix */
+ suffix = startswith(s, "Limit");
+ if (suffix)
+ return rlimit_from_string(suffix);
+
+ return rlimit_from_string(s);
+}
+
+void rlimit_free_all(struct rlimit **rl) {
+ free_many((void**) rl, _RLIMIT_MAX);
+}
+
+int rlimit_copy_all(struct rlimit* target[static _RLIMIT_MAX], struct rlimit* const source[static _RLIMIT_MAX]) {
+ struct rlimit* copy[_RLIMIT_MAX] = {};
+
+ assert(target);
+ assert(source);
+
+ for (int i = 0; i < _RLIMIT_MAX; i++) {
+ if (!source[i])
+ continue;
+
+ copy[i] = newdup(struct rlimit, source[i], 1);
+ if (!copy[i]) {
+ rlimit_free_all(copy);
+ return -ENOMEM;
+ }
+ }
+
+ memcpy(target, copy, sizeof(struct rlimit*) * _RLIMIT_MAX);
+ return 0;
+}
+
+int rlimit_nofile_bump(int limit) {
+ int r;
+
+ /* Bumps the (soft) RLIMIT_NOFILE resource limit as close as possible to the specified limit. If a negative
+ * limit is specified, bumps it to the maximum the kernel and the hard resource limit allows. This call should
+ * be used by all our programs that might need a lot of fds, and that know how to deal with high fd numbers
+ * (i.e. do not use select() — which chokes on fds >= 1024) */
+
+ if (limit < 0)
+ limit = read_nr_open();
+
+ if (limit < 3)
+ limit = 3;
+
+ r = setrlimit_closest(RLIMIT_NOFILE, &RLIMIT_MAKE_CONST(limit));
+ if (r < 0)
+ return log_debug_errno(r, "Failed to set RLIMIT_NOFILE: %m");
+
+ return 0;
+}
+
+int rlimit_nofile_safe(void) {
+ struct rlimit rl;
+
+ /* Resets RLIMIT_NOFILE's soft limit FD_SETSIZE (i.e. 1024), for compatibility with software still using
+ * select() */
+
+ if (getrlimit(RLIMIT_NOFILE, &rl) < 0)
+ return log_debug_errno(errno, "Failed to query RLIMIT_NOFILE: %m");
+
+ if (rl.rlim_cur <= FD_SETSIZE)
+ return 0;
+
+ /* So we might have inherited a hard limit that's larger than the kernel's maximum limit as stored in
+ * /proc/sys/fs/nr_open. If we pass this hard limit unmodified to setrlimit(), we'll get EPERM. To
+ * make sure that doesn't happen, let's limit our hard limit to the value from nr_open. */
+ rl.rlim_max = MIN(rl.rlim_max, (rlim_t) read_nr_open());
+ rl.rlim_cur = MIN((rlim_t) FD_SETSIZE, rl.rlim_max);
+ if (setrlimit(RLIMIT_NOFILE, &rl) < 0)
+ return log_debug_errno(errno, "Failed to lower RLIMIT_NOFILE's soft limit to " RLIM_FMT ": %m", rl.rlim_cur);
+
+ return 1;
+}