freebsd-nq/usr.bin/rctl/rctl.c
Edward Tomasz Napierala bce7ee9d41 Drop "All rights reserved" from all my stuff. This includes
Foundation copyrights, approved by emaste@.  It does not include
files which carry other people's copyrights; if you're one
of those people, feel free to make similar change.

Reviewed by:	emaste, imp, gbe (manpages)
Differential Revision:	https://reviews.freebsd.org/D26980
2020-10-28 13:46:11 +00:00

689 lines
14 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2010 The FreeBSD Foundation
*
* This software was developed by Edward Tomasz Napierala under sponsorship
* from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/rctl.h>
#include <sys/sysctl.h>
#include <assert.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <getopt.h>
#include <grp.h>
#include <libutil.h>
#include <pwd.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define RCTL_DEFAULT_BUFSIZE 128 * 1024
static int
parse_user(const char *s, id_t *uidp, const char *unexpanded_rule)
{
char *end;
struct passwd *pwd;
pwd = getpwnam(s);
if (pwd != NULL) {
*uidp = pwd->pw_uid;
return (0);
}
if (!isnumber(s[0])) {
warnx("malformed rule '%s': unknown user '%s'",
unexpanded_rule, s);
return (1);
}
*uidp = strtod(s, &end);
if ((size_t)(end - s) != strlen(s)) {
warnx("malformed rule '%s': trailing characters "
"after numerical id", unexpanded_rule);
return (1);
}
return (0);
}
static int
parse_group(const char *s, id_t *gidp, const char *unexpanded_rule)
{
char *end;
struct group *grp;
grp = getgrnam(s);
if (grp != NULL) {
*gidp = grp->gr_gid;
return (0);
}
if (!isnumber(s[0])) {
warnx("malformed rule '%s': unknown group '%s'",
unexpanded_rule, s);
return (1);
}
*gidp = strtod(s, &end);
if ((size_t)(end - s) != strlen(s)) {
warnx("malformed rule '%s': trailing characters "
"after numerical id", unexpanded_rule);
return (1);
}
return (0);
}
/*
* Replace human-readable number with its expanded form.
*/
static char *
expand_amount(const char *rule, const char *unexpanded_rule)
{
uint64_t num;
const char *subject, *subject_id, *resource, *action, *amount, *per;
char *copy, *expanded, *tofree;
int ret;
tofree = copy = strdup(rule);
if (copy == NULL) {
warn("strdup");
return (NULL);
}
subject = strsep(&copy, ":");
subject_id = strsep(&copy, ":");
resource = strsep(&copy, ":");
action = strsep(&copy, "=/");
amount = strsep(&copy, "/");
per = copy;
if (amount == NULL || strlen(amount) == 0) {
/*
* The "copy" has already been tinkered with by strsep().
*/
free(tofree);
copy = strdup(rule);
if (copy == NULL) {
warn("strdup");
return (NULL);
}
return (copy);
}
assert(subject != NULL);
assert(subject_id != NULL);
assert(resource != NULL);
assert(action != NULL);
if (expand_number(amount, &num)) {
warnx("malformed rule '%s': invalid numeric value '%s'",
unexpanded_rule, amount);
free(tofree);
return (NULL);
}
if (per == NULL) {
ret = asprintf(&expanded, "%s:%s:%s:%s=%ju",
subject, subject_id, resource, action, (uintmax_t)num);
} else {
ret = asprintf(&expanded, "%s:%s:%s:%s=%ju/%s",
subject, subject_id, resource, action, (uintmax_t)num, per);
}
if (ret <= 0) {
warn("asprintf");
free(tofree);
return (NULL);
}
free(tofree);
return (expanded);
}
static char *
expand_rule(const char *rule, bool resolve_ids)
{
id_t id;
const char *subject, *textid, *rest;
char *copy, *expanded, *resolved, *tofree;
int error, ret;
tofree = copy = strdup(rule);
if (copy == NULL) {
warn("strdup");
return (NULL);
}
subject = strsep(&copy, ":");
textid = strsep(&copy, ":");
if (textid == NULL) {
warnx("malformed rule '%s': missing subject", rule);
return (NULL);
}
if (copy != NULL)
rest = copy;
else
rest = "";
if (strcasecmp(subject, "u") == 0)
subject = "user";
else if (strcasecmp(subject, "g") == 0)
subject = "group";
else if (strcasecmp(subject, "p") == 0)
subject = "process";
else if (strcasecmp(subject, "l") == 0 ||
strcasecmp(subject, "c") == 0 ||
strcasecmp(subject, "class") == 0)
subject = "loginclass";
else if (strcasecmp(subject, "j") == 0)
subject = "jail";
if (resolve_ids &&
strcasecmp(subject, "user") == 0 && strlen(textid) > 0) {
error = parse_user(textid, &id, rule);
if (error != 0) {
free(tofree);
return (NULL);
}
ret = asprintf(&resolved, "%s:%d:%s", subject, (int)id, rest);
} else if (resolve_ids &&
strcasecmp(subject, "group") == 0 && strlen(textid) > 0) {
error = parse_group(textid, &id, rule);
if (error != 0) {
free(tofree);
return (NULL);
}
ret = asprintf(&resolved, "%s:%d:%s", subject, (int)id, rest);
} else {
ret = asprintf(&resolved, "%s:%s:%s", subject, textid, rest);
}
if (ret <= 0) {
warn("asprintf");
free(tofree);
return (NULL);
}
free(tofree);
expanded = expand_amount(resolved, rule);
free(resolved);
return (expanded);
}
static char *
humanize_ids(char *rule)
{
id_t id;
struct passwd *pwd;
struct group *grp;
const char *subject, *textid, *rest;
char *end, *humanized;
int ret;
subject = strsep(&rule, ":");
textid = strsep(&rule, ":");
if (textid == NULL)
errx(1, "rule passed from the kernel didn't contain subject");
if (rule != NULL)
rest = rule;
else
rest = "";
/* Replace numerical user and group ids with names. */
if (strcasecmp(subject, "user") == 0) {
id = strtod(textid, &end);
if ((size_t)(end - textid) != strlen(textid))
errx(1, "malformed uid '%s'", textid);
pwd = getpwuid(id);
if (pwd != NULL)
textid = pwd->pw_name;
} else if (strcasecmp(subject, "group") == 0) {
id = strtod(textid, &end);
if ((size_t)(end - textid) != strlen(textid))
errx(1, "malformed gid '%s'", textid);
grp = getgrgid(id);
if (grp != NULL)
textid = grp->gr_name;
}
ret = asprintf(&humanized, "%s:%s:%s", subject, textid, rest);
if (ret <= 0)
err(1, "asprintf");
return (humanized);
}
static int
str2int64(const char *str, int64_t *value)
{
char *end;
if (str == NULL)
return (EINVAL);
*value = strtoul(str, &end, 10);
if ((size_t)(end - str) != strlen(str))
return (EINVAL);
return (0);
}
static char *
humanize_amount(char *rule)
{
int64_t num;
const char *subject, *subject_id, *resource, *action, *amount, *per;
char *copy, *humanized, buf[6], *tofree;
int ret;
tofree = copy = strdup(rule);
if (copy == NULL)
err(1, "strdup");
subject = strsep(&copy, ":");
subject_id = strsep(&copy, ":");
resource = strsep(&copy, ":");
action = strsep(&copy, "=/");
amount = strsep(&copy, "/");
per = copy;
if (amount == NULL || strlen(amount) == 0 ||
str2int64(amount, &num) != 0) {
free(tofree);
return (rule);
}
assert(subject != NULL);
assert(subject_id != NULL);
assert(resource != NULL);
assert(action != NULL);
if (humanize_number(buf, sizeof(buf), num, "", HN_AUTOSCALE,
HN_DECIMAL | HN_NOSPACE) == -1)
err(1, "humanize_number");
if (per == NULL) {
ret = asprintf(&humanized, "%s:%s:%s:%s=%s",
subject, subject_id, resource, action, buf);
} else {
ret = asprintf(&humanized, "%s:%s:%s:%s=%s/%s",
subject, subject_id, resource, action, buf, per);
}
if (ret <= 0)
err(1, "asprintf");
free(tofree);
return (humanized);
}
/*
* Print rules, one per line.
*/
static void
print_rules(char *rules, int hflag, int nflag)
{
char *rule;
while ((rule = strsep(&rules, ",")) != NULL) {
if (rule[0] == '\0')
break; /* XXX */
if (nflag == 0)
rule = humanize_ids(rule);
if (hflag)
rule = humanize_amount(rule);
printf("%s\n", rule);
}
}
static void
enosys(void)
{
size_t racct_enable_len;
int error;
bool racct_enable;
racct_enable_len = sizeof(racct_enable);
error = sysctlbyname("kern.racct.enable",
&racct_enable, &racct_enable_len, NULL, 0);
if (error != 0) {
if (errno == ENOENT)
errx(1, "RACCT/RCTL support not present in kernel; see rctl(8) for details");
err(1, "sysctlbyname");
}
if (!racct_enable)
errx(1, "RACCT/RCTL present, but disabled; enable using kern.racct.enable=1 tunable");
}
static int
add_rule(const char *rule, const char *unexpanded_rule)
{
int error;
error = rctl_add_rule(rule, strlen(rule) + 1, NULL, 0);
if (error != 0) {
if (errno == ENOSYS)
enosys();
warn("failed to add rule '%s'", unexpanded_rule);
}
return (error);
}
static int
show_limits(const char *filter, const char *unexpanded_rule,
int hflag, int nflag)
{
int error;
char *outbuf = NULL;
size_t outbuflen = RCTL_DEFAULT_BUFSIZE / 4;
for (;;) {
outbuflen *= 4;
outbuf = realloc(outbuf, outbuflen);
if (outbuf == NULL)
err(1, "realloc");
error = rctl_get_limits(filter, strlen(filter) + 1,
outbuf, outbuflen);
if (error == 0)
break;
if (errno == ERANGE)
continue;
if (errno == ENOSYS)
enosys();
warn("failed to get limits for '%s'", unexpanded_rule);
free(outbuf);
return (error);
}
print_rules(outbuf, hflag, nflag);
free(outbuf);
return (error);
}
static int
remove_rule(const char *filter, const char *unexpanded_rule)
{
int error;
error = rctl_remove_rule(filter, strlen(filter) + 1, NULL, 0);
if (error != 0) {
if (errno == ENOSYS)
enosys();
warn("failed to remove rule '%s'", unexpanded_rule);
}
return (error);
}
static char *
humanize_usage_amount(char *usage)
{
int64_t num;
const char *resource, *amount;
char *copy, *humanized, buf[6], *tofree;
int ret;
tofree = copy = strdup(usage);
if (copy == NULL)
err(1, "strdup");
resource = strsep(&copy, "=");
amount = copy;
assert(resource != NULL);
assert(amount != NULL);
if (str2int64(amount, &num) != 0 ||
humanize_number(buf, sizeof(buf), num, "", HN_AUTOSCALE,
HN_DECIMAL | HN_NOSPACE) == -1) {
free(tofree);
return (usage);
}
ret = asprintf(&humanized, "%s=%s", resource, buf);
if (ret <= 0)
err(1, "asprintf");
free(tofree);
return (humanized);
}
/*
* Query the kernel about a resource usage and print it out.
*/
static int
show_usage(const char *filter, const char *unexpanded_rule, int hflag)
{
int error;
char *copy, *outbuf = NULL, *tmp;
size_t outbuflen = RCTL_DEFAULT_BUFSIZE / 4;
for (;;) {
outbuflen *= 4;
outbuf = realloc(outbuf, outbuflen);
if (outbuf == NULL)
err(1, "realloc");
error = rctl_get_racct(filter, strlen(filter) + 1,
outbuf, outbuflen);
if (error == 0)
break;
if (errno == ERANGE)
continue;
if (errno == ENOSYS)
enosys();
warn("failed to show resource consumption for '%s'",
unexpanded_rule);
free(outbuf);
return (error);
}
copy = outbuf;
while ((tmp = strsep(&copy, ",")) != NULL) {
if (tmp[0] == '\0')
break; /* XXX */
if (hflag)
tmp = humanize_usage_amount(tmp);
printf("%s\n", tmp);
}
free(outbuf);
return (error);
}
/*
* Query the kernel about resource limit rules and print them out.
*/
static int
show_rules(const char *filter, const char *unexpanded_rule,
int hflag, int nflag)
{
int error;
char *outbuf = NULL;
size_t filterlen, outbuflen = RCTL_DEFAULT_BUFSIZE / 4;
if (filter != NULL)
filterlen = strlen(filter) + 1;
else
filterlen = 0;
for (;;) {
outbuflen *= 4;
outbuf = realloc(outbuf, outbuflen);
if (outbuf == NULL)
err(1, "realloc");
error = rctl_get_rules(filter, filterlen, outbuf, outbuflen);
if (error == 0)
break;
if (errno == ERANGE)
continue;
if (errno == ENOSYS)
enosys();
warn("failed to show rules for '%s'", unexpanded_rule);
free(outbuf);
return (error);
}
print_rules(outbuf, hflag, nflag);
free(outbuf);
return (error);
}
static void
usage(void)
{
fprintf(stderr, "usage: rctl [ -h ] [-a rule | -l filter | -r filter "
"| -u filter | filter]\n");
exit(1);
}
int
main(int argc, char **argv)
{
int ch, aflag = 0, hflag = 0, nflag = 0, lflag = 0, rflag = 0,
uflag = 0;
char *rule = NULL, *unexpanded_rule;
int i, cumulated_error, error;
while ((ch = getopt(argc, argv, "ahlnru")) != -1) {
switch (ch) {
case 'a':
aflag = 1;
break;
case 'h':
hflag = 1;
break;
case 'l':
lflag = 1;
break;
case 'n':
nflag = 1;
break;
case 'r':
rflag = 1;
break;
case 'u':
uflag = 1;
break;
case '?':
default:
usage();
}
}
argc -= optind;
argv += optind;
if (aflag + lflag + rflag + uflag > 1)
errx(1, "at most one of -a, -l, -r, or -u may be specified");
if (argc == 0) {
if (aflag + lflag + rflag + uflag == 0) {
rule = strdup("::");
show_rules(rule, rule, hflag, nflag);
return (0);
}
usage();
}
cumulated_error = 0;
for (i = 0; i < argc; i++) {
unexpanded_rule = argv[i];
/*
* Skip resolving if passed -n _and_ -a. Ignore -n otherwise,
* so we can still do "rctl -n u:root" and see the rules without
* resolving the UID.
*/
if (aflag != 0 && nflag != 0)
rule = expand_rule(unexpanded_rule, false);
else
rule = expand_rule(unexpanded_rule, true);
if (rule == NULL) {
cumulated_error++;
continue;
}
/*
* The reason for passing the unexpanded_rule is to make
* it easier for the user to search for the problematic
* rule in the passed input.
*/
if (aflag) {
error = add_rule(rule, unexpanded_rule);
} else if (lflag) {
error = show_limits(rule, unexpanded_rule,
hflag, nflag);
} else if (rflag) {
error = remove_rule(rule, unexpanded_rule);
} else if (uflag) {
error = show_usage(rule, unexpanded_rule, hflag);
} else {
error = show_rules(rule, unexpanded_rule,
hflag, nflag);
}
if (error != 0)
cumulated_error++;
free(rule);
}
return (cumulated_error);
}