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freebsd/sys/kern/kern_rctl.c
Edward Tomasz Napierala a7ad07bff3 Change the way rctl interfaces with jails by introducing prison_racct 
structure, which acts as a proxy between them.  This makes jail rules
persistent, i.e. they can be added before jail gets created, and they
don't disappear when the jail gets destroyed.
2011-05-03 07:32:58 +00:00

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/*-
* Copyright (c) 2010 The FreeBSD Foundation
* All rights reserved.
*
* 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/param.h>
#include <sys/bus.h>
#include <sys/malloc.h>
#include <sys/queue.h>
#include <sys/refcount.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/loginclass.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/racct.h>
#include <sys/rctl.h>
#include <sys/resourcevar.h>
#include <sys/sx.h>
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/eventhandler.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#include <sys/sbuf.h>
#include <sys/taskqueue.h>
#include <sys/tree.h>
#include <vm/uma.h>
#ifdef RCTL
#ifndef RACCT
#error "The RCTL option requires the RACCT option"
#endif
FEATURE(rctl, "Resource Limits");
#define HRF_DEFAULT 0
#define HRF_DONT_INHERIT 1
#define HRF_DONT_ACCUMULATE 2
/* Default buffer size for rctl_get_rules(2). */
#define RCTL_DEFAULT_BUFSIZE 4096
#define RCTL_LOG_BUFSIZE 128
/*
* 'rctl_rule_link' connects a rule with every racct it's related to.
* For example, rule 'user:X:openfiles:deny=N/process' is linked
* with uidinfo for user X, and to each process of that user.
*/
struct rctl_rule_link {
LIST_ENTRY(rctl_rule_link) rrl_next;
struct rctl_rule *rrl_rule;
int rrl_exceeded;
};
struct dict {
const char *d_name;
int d_value;
};
static struct dict subjectnames[] = {
{ "process", RCTL_SUBJECT_TYPE_PROCESS },
{ "user", RCTL_SUBJECT_TYPE_USER },
{ "loginclass", RCTL_SUBJECT_TYPE_LOGINCLASS },
{ "jail", RCTL_SUBJECT_TYPE_JAIL },
{ NULL, -1 }};
static struct dict resourcenames[] = {
{ "cpu", RACCT_CPU },
{ "fsize", RACCT_FSIZE },
{ "data", RACCT_DATA },
{ "stack", RACCT_STACK },
{ "core", RACCT_CORE },
{ "rss", RACCT_RSS },
{ "memlock", RACCT_MEMLOCK },
{ "nproc", RACCT_NPROC },
{ "nofile", RACCT_NOFILE },
{ "sbsize", RACCT_SBSIZE },
{ "vmem", RACCT_VMEM },
{ "npts", RACCT_NPTS },
{ "swap", RACCT_SWAP },
{ "nthr", RACCT_NTHR },
{ "msgqqueued", RACCT_MSGQQUEUED },
{ "msgqsize", RACCT_MSGQSIZE },
{ "nmsgq", RACCT_NMSGQ },
{ "nsem", RACCT_NSEM },
{ "nsemop", RACCT_NSEMOP },
{ "nshm", RACCT_NSHM },
{ "shmsize", RACCT_SHMSIZE },
{ "wallclock", RACCT_WALLCLOCK },
{ NULL, -1 }};
static struct dict actionnames[] = {
{ "sighup", RCTL_ACTION_SIGHUP },
{ "sigint", RCTL_ACTION_SIGINT },
{ "sigquit", RCTL_ACTION_SIGQUIT },
{ "sigill", RCTL_ACTION_SIGILL },
{ "sigtrap", RCTL_ACTION_SIGTRAP },
{ "sigabrt", RCTL_ACTION_SIGABRT },
{ "sigemt", RCTL_ACTION_SIGEMT },
{ "sigfpe", RCTL_ACTION_SIGFPE },
{ "sigkill", RCTL_ACTION_SIGKILL },
{ "sigbus", RCTL_ACTION_SIGBUS },
{ "sigsegv", RCTL_ACTION_SIGSEGV },
{ "sigsys", RCTL_ACTION_SIGSYS },
{ "sigpipe", RCTL_ACTION_SIGPIPE },
{ "sigalrm", RCTL_ACTION_SIGALRM },
{ "sigterm", RCTL_ACTION_SIGTERM },
{ "sigurg", RCTL_ACTION_SIGURG },
{ "sigstop", RCTL_ACTION_SIGSTOP },
{ "sigtstp", RCTL_ACTION_SIGTSTP },
{ "sigchld", RCTL_ACTION_SIGCHLD },
{ "sigttin", RCTL_ACTION_SIGTTIN },
{ "sigttou", RCTL_ACTION_SIGTTOU },
{ "sigio", RCTL_ACTION_SIGIO },
{ "sigxcpu", RCTL_ACTION_SIGXCPU },
{ "sigxfsz", RCTL_ACTION_SIGXFSZ },
{ "sigvtalrm", RCTL_ACTION_SIGVTALRM },
{ "sigprof", RCTL_ACTION_SIGPROF },
{ "sigwinch", RCTL_ACTION_SIGWINCH },
{ "siginfo", RCTL_ACTION_SIGINFO },
{ "sigusr1", RCTL_ACTION_SIGUSR1 },
{ "sigusr2", RCTL_ACTION_SIGUSR2 },
{ "sigthr", RCTL_ACTION_SIGTHR },
{ "deny", RCTL_ACTION_DENY },
{ "log", RCTL_ACTION_LOG },
{ "devctl", RCTL_ACTION_DEVCTL },
{ NULL, -1 }};
static void rctl_init(void);
SYSINIT(rctl, SI_SUB_RACCT, SI_ORDER_FIRST, rctl_init, NULL);
static uma_zone_t rctl_rule_link_zone;
static uma_zone_t rctl_rule_zone;
static struct rwlock rctl_lock;
RW_SYSINIT(rctl_lock, &rctl_lock, "RCTL lock");
static int rctl_rule_fully_specified(const struct rctl_rule *rule);
static void rctl_rule_to_sbuf(struct sbuf *sb, const struct rctl_rule *rule);
MALLOC_DEFINE(M_RCTL, "rctl", "Resource Limits");
static const char *
rctl_subject_type_name(int subject)
{
int i;
for (i = 0; subjectnames[i].d_name != NULL; i++) {
if (subjectnames[i].d_value == subject)
return (subjectnames[i].d_name);
}
panic("rctl_subject_type_name: unknown subject type %d", subject);
}
static const char *
rctl_action_name(int action)
{
int i;
for (i = 0; actionnames[i].d_name != NULL; i++) {
if (actionnames[i].d_value == action)
return (actionnames[i].d_name);
}
panic("rctl_action_name: unknown action %d", action);
}
const char *
rctl_resource_name(int resource)
{
int i;
for (i = 0; resourcenames[i].d_name != NULL; i++) {
if (resourcenames[i].d_value == resource)
return (resourcenames[i].d_name);
}
panic("rctl_resource_name: unknown resource %d", resource);
}
/*
* Return the amount of resource that can be allocated by 'p' before
* hitting 'rule'.
*/
static int64_t
rctl_available_resource(const struct proc *p, const struct rctl_rule *rule)
{
int resource;
int64_t available = INT64_MAX;
struct ucred *cred = p->p_ucred;
rw_assert(&rctl_lock, RA_LOCKED);
resource = rule->rr_resource;
switch (rule->rr_per) {
case RCTL_SUBJECT_TYPE_PROCESS:
available = rule->rr_amount -
p->p_racct->r_resources[resource];
break;
case RCTL_SUBJECT_TYPE_USER:
available = rule->rr_amount -
cred->cr_ruidinfo->ui_racct->r_resources[resource];
break;
case RCTL_SUBJECT_TYPE_LOGINCLASS:
available = rule->rr_amount -
cred->cr_loginclass->lc_racct->r_resources[resource];
break;
case RCTL_SUBJECT_TYPE_JAIL:
available = rule->rr_amount -
cred->cr_prison->pr_prison_racct->prr_racct->
r_resources[resource];
break;
default:
panic("rctl_compute_available: unknown per %d",
rule->rr_per);
}
return (available);
}
/*
* Return non-zero if allocating 'amount' by proc 'p' would exceed
* resource limit specified by 'rule'.
*/
static int
rctl_would_exceed(const struct proc *p, const struct rctl_rule *rule,
int64_t amount)
{
int64_t available;
rw_assert(&rctl_lock, RA_LOCKED);
available = rctl_available_resource(p, rule);
if (available >= amount)
return (0);
return (1);
}
/*
* Check whether the proc 'p' can allocate 'amount' of 'resource' in addition
* to what it keeps allocated now. Returns non-zero if the allocation should
* be denied, 0 otherwise.
*/
int
rctl_enforce(struct proc *p, int resource, uint64_t amount)
{
struct rctl_rule *rule;
struct rctl_rule_link *link;
struct sbuf sb;
int should_deny = 0;
char *buf;
static int curtime = 0;
static struct timeval lasttime;
rw_rlock(&rctl_lock);
/*
* There may be more than one matching rule; go through all of them.
* Denial should be done last, after logging and sending signals.
*/
LIST_FOREACH(link, &p->p_racct->r_rule_links, rrl_next) {
rule = link->rrl_rule;
if (rule->rr_resource != resource)
continue;
if (!rctl_would_exceed(p, rule, amount)) {
link->rrl_exceeded = 0;
continue;
}
switch (rule->rr_action) {
case RCTL_ACTION_DENY:
should_deny = 1;
continue;
case RCTL_ACTION_LOG:
/*
* If rrl_exceeded != 0, it means we've already
* logged a warning for this process.
*/
if (link->rrl_exceeded != 0)
continue;
if (!ppsratecheck(&lasttime, &curtime, 10))
continue;
buf = malloc(RCTL_LOG_BUFSIZE, M_RCTL, M_NOWAIT);
if (buf == NULL) {
printf("rctl_enforce: out of memory\n");
continue;
}
sbuf_new(&sb, buf, RCTL_LOG_BUFSIZE, SBUF_FIXEDLEN);
rctl_rule_to_sbuf(&sb, rule);
sbuf_finish(&sb);
printf("rctl: rule \"%s\" matched by pid %d "
"(%s), uid %d, jail %s\n", sbuf_data(&sb),
p->p_pid, p->p_comm, p->p_ucred->cr_uid,
p->p_ucred->cr_prison->pr_prison_racct->prr_name);
sbuf_delete(&sb);
free(buf, M_RCTL);
link->rrl_exceeded = 1;
continue;
case RCTL_ACTION_DEVCTL:
if (link->rrl_exceeded != 0)
continue;
buf = malloc(RCTL_LOG_BUFSIZE, M_RCTL, M_NOWAIT);
if (buf == NULL) {
printf("rctl_enforce: out of memory\n");
continue;
}
sbuf_new(&sb, buf, RCTL_LOG_BUFSIZE, SBUF_FIXEDLEN);
sbuf_printf(&sb, "rule=");
rctl_rule_to_sbuf(&sb, rule);
sbuf_printf(&sb, " pid=%d ruid=%d jail=%s",
p->p_pid, p->p_ucred->cr_ruid,
p->p_ucred->cr_prison->pr_prison_racct->prr_name);
sbuf_finish(&sb);
devctl_notify_f("RCTL", "rule", "matched",
sbuf_data(&sb), M_NOWAIT);
sbuf_delete(&sb);
free(buf, M_RCTL);
link->rrl_exceeded = 1;
continue;
default:
if (link->rrl_exceeded != 0)
continue;
KASSERT(rule->rr_action > 0 &&
rule->rr_action <= RCTL_ACTION_SIGNAL_MAX,
("rctl_enforce: unknown action %d",
rule->rr_action));
/*
* We're using the fact that RCTL_ACTION_SIG* values
* are equal to their counterparts from sys/signal.h.
*/
psignal(p, rule->rr_action);
link->rrl_exceeded = 1;
continue;
}
}
rw_runlock(&rctl_lock);
if (should_deny) {
/*
* Return fake error code; the caller should change it
* into one proper for the situation - EFSIZ, ENOMEM etc.
*/
return (EDOOFUS);
}
return (0);
}
uint64_t
rctl_get_limit(struct proc *p, int resource)
{
struct rctl_rule *rule;
struct rctl_rule_link *link;
uint64_t amount = UINT64_MAX;
rw_rlock(&rctl_lock);
/*
* There may be more than one matching rule; go through all of them.
* Denial should be done last, after logging and sending signals.
*/
LIST_FOREACH(link, &p->p_racct->r_rule_links, rrl_next) {
rule = link->rrl_rule;
if (rule->rr_resource != resource)
continue;
if (rule->rr_action != RCTL_ACTION_DENY)
continue;
if (rule->rr_amount < amount)
amount = rule->rr_amount;
}
rw_runlock(&rctl_lock);
return (amount);
}
uint64_t
rctl_get_available(struct proc *p, int resource)
{
struct rctl_rule *rule;
struct rctl_rule_link *link;
int64_t available, minavailable, allocated;
minavailable = INT64_MAX;
rw_rlock(&rctl_lock);
/*
* There may be more than one matching rule; go through all of them.
* Denial should be done last, after logging and sending signals.
*/
LIST_FOREACH(link, &p->p_racct->r_rule_links, rrl_next) {
rule = link->rrl_rule;
if (rule->rr_resource != resource)
continue;
if (rule->rr_action != RCTL_ACTION_DENY)
continue;
available = rctl_available_resource(p, rule);
if (available < minavailable)
minavailable = available;
}
rw_runlock(&rctl_lock);
/*
* XXX: Think about this _hard_.
*/
allocated = p->p_racct->r_resources[resource];
if (minavailable < INT64_MAX - allocated)
minavailable += allocated;
if (minavailable < 0)
minavailable = 0;
return (minavailable);
}
static int
rctl_rule_matches(const struct rctl_rule *rule, const struct rctl_rule *filter)
{
if (filter->rr_subject_type != RCTL_SUBJECT_TYPE_UNDEFINED) {
if (rule->rr_subject_type != filter->rr_subject_type)
return (0);
switch (filter->rr_subject_type) {
case RCTL_SUBJECT_TYPE_PROCESS:
if (filter->rr_subject.rs_proc != NULL &&
rule->rr_subject.rs_proc !=
filter->rr_subject.rs_proc)
return (0);
break;
case RCTL_SUBJECT_TYPE_USER:
if (filter->rr_subject.rs_uip != NULL &&
rule->rr_subject.rs_uip !=
filter->rr_subject.rs_uip)
return (0);
break;
case RCTL_SUBJECT_TYPE_LOGINCLASS:
if (filter->rr_subject.rs_loginclass != NULL &&
rule->rr_subject.rs_loginclass !=
filter->rr_subject.rs_loginclass)
return (0);
break;
case RCTL_SUBJECT_TYPE_JAIL:
if (filter->rr_subject.rs_prison_racct != NULL &&
rule->rr_subject.rs_prison_racct !=
filter->rr_subject.rs_prison_racct)
return (0);
break;
default:
panic("rctl_rule_matches: unknown subject type %d",
filter->rr_subject_type);
}
}
if (filter->rr_resource != RACCT_UNDEFINED) {
if (rule->rr_resource != filter->rr_resource)
return (0);
}
if (filter->rr_action != RCTL_ACTION_UNDEFINED) {
if (rule->rr_action != filter->rr_action)
return (0);
}
if (filter->rr_amount != RCTL_AMOUNT_UNDEFINED) {
if (rule->rr_amount != filter->rr_amount)
return (0);
}
if (filter->rr_per != RCTL_SUBJECT_TYPE_UNDEFINED) {
if (rule->rr_per != filter->rr_per)
return (0);
}
return (1);
}
static int
str2value(const char *str, int *value, struct dict *table)
{
int i;
if (value == NULL)
return (EINVAL);
for (i = 0; table[i].d_name != NULL; i++) {
if (strcasecmp(table[i].d_name, str) == 0) {
*value = table[i].d_value;
return (0);
}
}
return (EINVAL);
}
static int
str2id(const char *str, id_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 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);
}
/*
* Connect the rule to the racct, increasing refcount for the rule.
*/
static void
rctl_racct_add_rule(struct racct *racct, struct rctl_rule *rule)
{
struct rctl_rule_link *link;
KASSERT(rctl_rule_fully_specified(rule), ("rule not fully specified"));
rctl_rule_acquire(rule);
link = uma_zalloc(rctl_rule_link_zone, M_WAITOK);
link->rrl_rule = rule;
link->rrl_exceeded = 0;
rw_wlock(&rctl_lock);
LIST_INSERT_HEAD(&racct->r_rule_links, link, rrl_next);
rw_wunlock(&rctl_lock);
}
static int
rctl_racct_add_rule_locked(struct racct *racct, struct rctl_rule *rule)
{
struct rctl_rule_link *link;
KASSERT(rctl_rule_fully_specified(rule), ("rule not fully specified"));
rw_assert(&rctl_lock, RA_WLOCKED);
link = uma_zalloc(rctl_rule_link_zone, M_NOWAIT);
if (link == NULL)
return (ENOMEM);
rctl_rule_acquire(rule);
link->rrl_rule = rule;
link->rrl_exceeded = 0;
LIST_INSERT_HEAD(&racct->r_rule_links, link, rrl_next);
return (0);
}
/*
* Remove limits for a rules matching the filter and release
* the refcounts for the rules, possibly freeing them. Returns
* the number of limit structures removed.
*/
static int
rctl_racct_remove_rules(struct racct *racct,
const struct rctl_rule *filter)
{
int removed = 0;
struct rctl_rule_link *link, *linktmp;
rw_assert(&rctl_lock, RA_WLOCKED);
LIST_FOREACH_SAFE(link, &racct->r_rule_links, rrl_next, linktmp) {
if (!rctl_rule_matches(link->rrl_rule, filter))
continue;
LIST_REMOVE(link, rrl_next);
rctl_rule_release(link->rrl_rule);
uma_zfree(rctl_rule_link_zone, link);
removed++;
}
return (removed);
}
static void
rctl_rule_acquire_subject(struct rctl_rule *rule)
{
switch (rule->rr_subject_type) {
case RCTL_SUBJECT_TYPE_UNDEFINED:
case RCTL_SUBJECT_TYPE_PROCESS:
break;
case RCTL_SUBJECT_TYPE_JAIL:
if (rule->rr_subject.rs_prison_racct != NULL)
prison_racct_hold(rule->rr_subject.rs_prison_racct);
break;
case RCTL_SUBJECT_TYPE_USER:
if (rule->rr_subject.rs_uip != NULL)
uihold(rule->rr_subject.rs_uip);
break;
case RCTL_SUBJECT_TYPE_LOGINCLASS:
if (rule->rr_subject.rs_loginclass != NULL)
loginclass_hold(rule->rr_subject.rs_loginclass);
break;
default:
panic("rctl_rule_acquire_subject: unknown subject type %d",
rule->rr_subject_type);
}
}
static void
rctl_rule_release_subject(struct rctl_rule *rule)
{
switch (rule->rr_subject_type) {
case RCTL_SUBJECT_TYPE_UNDEFINED:
case RCTL_SUBJECT_TYPE_PROCESS:
break;
case RCTL_SUBJECT_TYPE_JAIL:
if (rule->rr_subject.rs_prison_racct != NULL)
prison_racct_free(rule->rr_subject.rs_prison_racct);
break;
case RCTL_SUBJECT_TYPE_USER:
if (rule->rr_subject.rs_uip != NULL)
uifree(rule->rr_subject.rs_uip);
break;
case RCTL_SUBJECT_TYPE_LOGINCLASS:
if (rule->rr_subject.rs_loginclass != NULL)
loginclass_free(rule->rr_subject.rs_loginclass);
break;
default:
panic("rctl_rule_release_subject: unknown subject type %d",
rule->rr_subject_type);
}
}
struct rctl_rule *
rctl_rule_alloc(int flags)
{
struct rctl_rule *rule;
rule = uma_zalloc(rctl_rule_zone, flags);
if (rule == NULL)
return (NULL);
rule->rr_subject_type = RCTL_SUBJECT_TYPE_UNDEFINED;
rule->rr_subject.rs_proc = NULL;
rule->rr_subject.rs_uip = NULL;
rule->rr_subject.rs_loginclass = NULL;
rule->rr_subject.rs_prison_racct = NULL;
rule->rr_per = RCTL_SUBJECT_TYPE_UNDEFINED;
rule->rr_resource = RACCT_UNDEFINED;
rule->rr_action = RCTL_ACTION_UNDEFINED;
rule->rr_amount = RCTL_AMOUNT_UNDEFINED;
refcount_init(&rule->rr_refcount, 1);
return (rule);
}
struct rctl_rule *
rctl_rule_duplicate(const struct rctl_rule *rule, int flags)
{
struct rctl_rule *copy;
copy = uma_zalloc(rctl_rule_zone, flags);
if (copy == NULL)
return (NULL);
copy->rr_subject_type = rule->rr_subject_type;
copy->rr_subject.rs_proc = rule->rr_subject.rs_proc;
copy->rr_subject.rs_uip = rule->rr_subject.rs_uip;
copy->rr_subject.rs_loginclass = rule->rr_subject.rs_loginclass;
copy->rr_subject.rs_prison_racct = rule->rr_subject.rs_prison_racct;
copy->rr_per = rule->rr_per;
copy->rr_resource = rule->rr_resource;
copy->rr_action = rule->rr_action;
copy->rr_amount = rule->rr_amount;
refcount_init(&copy->rr_refcount, 1);
rctl_rule_acquire_subject(copy);
return (copy);
}
void
rctl_rule_acquire(struct rctl_rule *rule)
{
KASSERT(rule->rr_refcount > 0, ("rule->rr_refcount <= 0"));
refcount_acquire(&rule->rr_refcount);
}
static void
rctl_rule_free(void *context, int pending)
{
struct rctl_rule *rule;
rule = (struct rctl_rule *)context;
KASSERT(rule->rr_refcount == 0, ("rule->rr_refcount != 0"));
/*
* We don't need locking here; rule is guaranteed to be inaccessible.
*/
rctl_rule_release_subject(rule);
uma_zfree(rctl_rule_zone, rule);
}
void
rctl_rule_release(struct rctl_rule *rule)
{
KASSERT(rule->rr_refcount > 0, ("rule->rr_refcount <= 0"));
if (refcount_release(&rule->rr_refcount)) {
/*
* rctl_rule_release() is often called when iterating
* over all the uidinfo structures in the system,
* holding uihashtbl_lock. Since rctl_rule_free()
* might end up calling uifree(), this would lead
* to lock recursion. Use taskqueue to avoid this.
*/
TASK_INIT(&rule->rr_task, 0, rctl_rule_free, rule);
taskqueue_enqueue(taskqueue_thread, &rule->rr_task);
}
}
static int
rctl_rule_fully_specified(const struct rctl_rule *rule)
{
switch (rule->rr_subject_type) {
case RCTL_SUBJECT_TYPE_UNDEFINED:
return (0);
case RCTL_SUBJECT_TYPE_PROCESS:
if (rule->rr_subject.rs_proc == NULL)
return (0);
break;
case RCTL_SUBJECT_TYPE_USER:
if (rule->rr_subject.rs_uip == NULL)
return (0);
break;
case RCTL_SUBJECT_TYPE_LOGINCLASS:
if (rule->rr_subject.rs_loginclass == NULL)
return (0);
break;
case RCTL_SUBJECT_TYPE_JAIL:
if (rule->rr_subject.rs_prison_racct == NULL)
return (0);
break;
default:
panic("rctl_rule_fully_specified: unknown subject type %d",
rule->rr_subject_type);
}
if (rule->rr_resource == RACCT_UNDEFINED)
return (0);
if (rule->rr_action == RCTL_ACTION_UNDEFINED)
return (0);
if (rule->rr_amount == RCTL_AMOUNT_UNDEFINED)
return (0);
if (rule->rr_per == RCTL_SUBJECT_TYPE_UNDEFINED)
return (0);
return (1);
}
static int
rctl_string_to_rule(char *rulestr, struct rctl_rule **rulep)
{
int error = 0;
char *subjectstr, *subject_idstr, *resourcestr, *actionstr,
*amountstr, *perstr;
struct rctl_rule *rule;
id_t id;
rule = rctl_rule_alloc(M_WAITOK);
subjectstr = strsep(&rulestr, ":");
subject_idstr = strsep(&rulestr, ":");
resourcestr = strsep(&rulestr, ":");
actionstr = strsep(&rulestr, "=/");
amountstr = strsep(&rulestr, "/");
perstr = rulestr;
if (subjectstr == NULL || subjectstr[0] == '\0')
rule->rr_subject_type = RCTL_SUBJECT_TYPE_UNDEFINED;
else {
error = str2value(subjectstr, &rule->rr_subject_type, subjectnames);
if (error != 0)
goto out;
}
if (subject_idstr == NULL || subject_idstr[0] == '\0') {
rule->rr_subject.rs_proc = NULL;
rule->rr_subject.rs_uip = NULL;
rule->rr_subject.rs_loginclass = NULL;
rule->rr_subject.rs_prison_racct = NULL;
} else {
switch (rule->rr_subject_type) {
case RCTL_SUBJECT_TYPE_UNDEFINED:
error = EINVAL;
goto out;
case RCTL_SUBJECT_TYPE_PROCESS:
error = str2id(subject_idstr, &id);
if (error != 0)
goto out;
sx_assert(&allproc_lock, SA_LOCKED);
rule->rr_subject.rs_proc = pfind(id);
if (rule->rr_subject.rs_proc == NULL) {
error = ESRCH;
goto out;
}
PROC_UNLOCK(rule->rr_subject.rs_proc);
break;
case RCTL_SUBJECT_TYPE_USER:
error = str2id(subject_idstr, &id);
if (error != 0)
goto out;
rule->rr_subject.rs_uip = uifind(id);
break;
case RCTL_SUBJECT_TYPE_LOGINCLASS:
rule->rr_subject.rs_loginclass =
loginclass_find(subject_idstr);
if (rule->rr_subject.rs_loginclass == NULL) {
error = ENAMETOOLONG;
goto out;
}
break;
case RCTL_SUBJECT_TYPE_JAIL:
rule->rr_subject.rs_prison_racct =
prison_racct_find(subject_idstr);
if (rule->rr_subject.rs_prison_racct == NULL) {
error = ENAMETOOLONG;
goto out;
}
break;
default:
panic("rctl_string_to_rule: unknown subject type %d",
rule->rr_subject_type);
}
}
if (resourcestr == NULL || resourcestr[0] == '\0')
rule->rr_resource = RACCT_UNDEFINED;
else {
error = str2value(resourcestr, &rule->rr_resource,
resourcenames);
if (error != 0)
goto out;
}
if (actionstr == NULL || actionstr[0] == '\0')
rule->rr_action = RCTL_ACTION_UNDEFINED;
else {
error = str2value(actionstr, &rule->rr_action, actionnames);
if (error != 0)
goto out;
}
if (amountstr == NULL || amountstr[0] == '\0')
rule->rr_amount = RCTL_AMOUNT_UNDEFINED;
else {
error = str2int64(amountstr, &rule->rr_amount);
if (error != 0)
goto out;
if (racct_is_in_thousands(rule->rr_resource))
rule->rr_amount *= 1000;
}
if (perstr == NULL || perstr[0] == '\0')
rule->rr_per = RCTL_SUBJECT_TYPE_UNDEFINED;
else {
error = str2value(perstr, &rule->rr_per, subjectnames);
if (error != 0)
goto out;
}
out:
if (error == 0)
*rulep = rule;
else
rctl_rule_release(rule);
return (error);
}
/*
* Link a rule with all the subjects it applies to.
*/
int
rctl_rule_add(struct rctl_rule *rule)
{
struct proc *p;
struct ucred *cred;
struct uidinfo *uip;
struct prison *pr;
struct prison_racct *prr;
struct loginclass *lc;
struct rctl_rule *rule2;
int match;
KASSERT(rctl_rule_fully_specified(rule), ("rule not fully specified"));
/*
* Some rules just don't make sense. Note that the one below
* cannot be rewritten using racct_is_deniable(); the RACCT_PCTCPU,
* for example, is not deniable in the racct sense, but the
* limit is enforced in a different way, so "deny" rules for %CPU
* do make sense.
*/
if (rule->rr_action == RCTL_ACTION_DENY &&
(rule->rr_resource == RACCT_CPU ||
rule->rr_resource == RACCT_WALLCLOCK))
return (EOPNOTSUPP);
if (rule->rr_per == RCTL_SUBJECT_TYPE_PROCESS &&
racct_is_sloppy(rule->rr_resource))
return (EOPNOTSUPP);
/*
* Make sure there are no duplicated rules. Also, for the "deny"
* rules, remove ones differing only by "amount".
*/
if (rule->rr_action == RCTL_ACTION_DENY) {
rule2 = rctl_rule_duplicate(rule, M_WAITOK);
rule2->rr_amount = RCTL_AMOUNT_UNDEFINED;
rctl_rule_remove(rule2);
rctl_rule_release(rule2);
} else
rctl_rule_remove(rule);
switch (rule->rr_subject_type) {
case RCTL_SUBJECT_TYPE_PROCESS:
p = rule->rr_subject.rs_proc;
KASSERT(p != NULL, ("rctl_rule_add: NULL proc"));
/*
* No resource limits for system processes.
*/
if (p->p_flag & P_SYSTEM)
return (EPERM);
rctl_racct_add_rule(p->p_racct, rule);
/*
* In case of per-process rule, we don't have anything more
* to do.
*/
return (0);
case RCTL_SUBJECT_TYPE_USER:
uip = rule->rr_subject.rs_uip;
KASSERT(uip != NULL, ("rctl_rule_add: NULL uip"));
rctl_racct_add_rule(uip->ui_racct, rule);
break;
case RCTL_SUBJECT_TYPE_LOGINCLASS:
lc = rule->rr_subject.rs_loginclass;
KASSERT(lc != NULL, ("rctl_rule_add: NULL loginclass"));
rctl_racct_add_rule(lc->lc_racct, rule);
break;
case RCTL_SUBJECT_TYPE_JAIL:
prr = rule->rr_subject.rs_prison_racct;
KASSERT(prr != NULL, ("rctl_rule_add: NULL pr"));
rctl_racct_add_rule(prr->prr_racct, rule);
break;
default:
panic("rctl_rule_add: unknown subject type %d",
rule->rr_subject_type);
}
/*
* Now go through all the processes and add the new rule to the ones
* it applies to.
*/
sx_assert(&allproc_lock, SA_LOCKED);
FOREACH_PROC_IN_SYSTEM(p) {
if (p->p_flag & P_SYSTEM)
continue;
cred = p->p_ucred;
switch (rule->rr_subject_type) {
case RCTL_SUBJECT_TYPE_USER:
if (cred->cr_uidinfo == rule->rr_subject.rs_uip ||
cred->cr_ruidinfo == rule->rr_subject.rs_uip)
break;
continue;
case RCTL_SUBJECT_TYPE_LOGINCLASS:
if (cred->cr_loginclass == rule->rr_subject.rs_loginclass)
break;
continue;
case RCTL_SUBJECT_TYPE_JAIL:
match = 0;
for (pr = cred->cr_prison; pr != NULL; pr = pr->pr_parent) {
if (pr->pr_prison_racct == rule->rr_subject.rs_prison_racct) {
match = 1;
break;
}
}
if (match)
break;
continue;
default:
panic("rctl_rule_add: unknown subject type %d",
rule->rr_subject_type);
}
rctl_racct_add_rule(p->p_racct, rule);
}
return (0);
}
static void
rctl_rule_remove_callback(struct racct *racct, void *arg2, void *arg3)
{
struct rctl_rule *filter = (struct rctl_rule *)arg2;
int found = 0;
rw_wlock(&rctl_lock);
found += rctl_racct_remove_rules(racct, filter);
rw_wunlock(&rctl_lock);
*((int *)arg3) += found;
}
/*
* Remove all rules that match the filter.
*/
int
rctl_rule_remove(struct rctl_rule *filter)
{
int found = 0;
struct proc *p;
if (filter->rr_subject_type == RCTL_SUBJECT_TYPE_PROCESS &&
filter->rr_subject.rs_proc != NULL) {
p = filter->rr_subject.rs_proc;
rw_wlock(&rctl_lock);
found = rctl_racct_remove_rules(p->p_racct, filter);
rw_wunlock(&rctl_lock);
if (found)
return (0);
return (ESRCH);
}
loginclass_racct_foreach(rctl_rule_remove_callback, filter,
(void *)&found);
ui_racct_foreach(rctl_rule_remove_callback, filter,
(void *)&found);
prison_racct_foreach(rctl_rule_remove_callback, filter,
(void *)&found);
sx_assert(&allproc_lock, SA_LOCKED);
rw_wlock(&rctl_lock);
FOREACH_PROC_IN_SYSTEM(p) {
found += rctl_racct_remove_rules(p->p_racct, filter);
}
rw_wunlock(&rctl_lock);
if (found)
return (0);
return (ESRCH);
}
/*
* Appends a rule to the sbuf.
*/
static void
rctl_rule_to_sbuf(struct sbuf *sb, const struct rctl_rule *rule)
{
int64_t amount;
sbuf_printf(sb, "%s:", rctl_subject_type_name(rule->rr_subject_type));
switch (rule->rr_subject_type) {
case RCTL_SUBJECT_TYPE_PROCESS:
if (rule->rr_subject.rs_proc == NULL)
sbuf_printf(sb, ":");
else
sbuf_printf(sb, "%d:",
rule->rr_subject.rs_proc->p_pid);
break;
case RCTL_SUBJECT_TYPE_USER:
if (rule->rr_subject.rs_uip == NULL)
sbuf_printf(sb, ":");
else
sbuf_printf(sb, "%d:",
rule->rr_subject.rs_uip->ui_uid);
break;
case RCTL_SUBJECT_TYPE_LOGINCLASS:
if (rule->rr_subject.rs_loginclass == NULL)
sbuf_printf(sb, ":");
else
sbuf_printf(sb, "%s:",
rule->rr_subject.rs_loginclass->lc_name);
break;
case RCTL_SUBJECT_TYPE_JAIL:
if (rule->rr_subject.rs_prison_racct == NULL)
sbuf_printf(sb, ":");
else
sbuf_printf(sb, "%s:",
rule->rr_subject.rs_prison_racct->prr_name);
break;
default:
panic("rctl_rule_to_sbuf: unknown subject type %d",
rule->rr_subject_type);
}
amount = rule->rr_amount;
if (amount != RCTL_AMOUNT_UNDEFINED &&
racct_is_in_thousands(rule->rr_resource))
amount /= 1000;
sbuf_printf(sb, "%s:%s=%jd",
rctl_resource_name(rule->rr_resource),
rctl_action_name(rule->rr_action),
amount);
if (rule->rr_per != rule->rr_subject_type)
sbuf_printf(sb, "/%s", rctl_subject_type_name(rule->rr_per));
}
/*
* Routine used by RCTL syscalls to read in input string.
*/
static int
rctl_read_inbuf(char **inputstr, const char *inbufp, size_t inbuflen)
{
int error;
char *str;
if (inbuflen <= 0)
return (EINVAL);
str = malloc(inbuflen + 1, M_RCTL, M_WAITOK);
error = copyinstr(inbufp, str, inbuflen, NULL);
if (error != 0) {
free(str, M_RCTL);
return (error);
}
*inputstr = str;
return (0);
}
/*
* Routine used by RCTL syscalls to write out output string.
*/
static int
rctl_write_outbuf(struct sbuf *outputsbuf, char *outbufp, size_t outbuflen)
{
int error;
if (outputsbuf == NULL)
return (0);
sbuf_finish(outputsbuf);
if (outbuflen < sbuf_len(outputsbuf) + 1) {
sbuf_delete(outputsbuf);
return (ERANGE);
}
error = copyout(sbuf_data(outputsbuf), outbufp,
sbuf_len(outputsbuf) + 1);
sbuf_delete(outputsbuf);
return (error);
}
static struct sbuf *
rctl_racct_to_sbuf(struct racct *racct, int sloppy)
{
int i;
int64_t amount;
struct sbuf *sb;
sb = sbuf_new_auto();
for (i = 0; i <= RACCT_MAX; i++) {
if (sloppy == 0 && racct_is_sloppy(i))
continue;
amount = racct->r_resources[i];
if (racct_is_in_thousands(i))
amount /= 1000;
sbuf_printf(sb, "%s=%jd,", rctl_resource_name(i), amount);
}
sbuf_setpos(sb, sbuf_len(sb) - 1);
return (sb);
}
int
rctl_get_racct(struct thread *td, struct rctl_get_racct_args *uap)
{
int error;
char *inputstr;
struct rctl_rule *filter;
struct sbuf *outputsbuf = NULL;
struct proc *p;
struct uidinfo *uip;
struct loginclass *lc;
struct prison_racct *prr;
error = priv_check(td, PRIV_RCTL_GET_RACCT);
if (error != 0)
return (error);
error = rctl_read_inbuf(&inputstr, uap->inbufp, uap->inbuflen);
if (error != 0)
return (error);
sx_slock(&allproc_lock);
error = rctl_string_to_rule(inputstr, &filter);
free(inputstr, M_RCTL);
if (error != 0) {
sx_sunlock(&allproc_lock);
return (error);
}
switch (filter->rr_subject_type) {
case RCTL_SUBJECT_TYPE_PROCESS:
p = filter->rr_subject.rs_proc;
if (p == NULL) {
error = EINVAL;
goto out;
}
if (p->p_flag & P_SYSTEM) {
error = EINVAL;
goto out;
}
outputsbuf = rctl_racct_to_sbuf(p->p_racct, 0);
break;
case RCTL_SUBJECT_TYPE_USER:
uip = filter->rr_subject.rs_uip;
if (uip == NULL) {
error = EINVAL;
goto out;
}
outputsbuf = rctl_racct_to_sbuf(uip->ui_racct, 1);
break;
case RCTL_SUBJECT_TYPE_LOGINCLASS:
lc = filter->rr_subject.rs_loginclass;
if (lc == NULL) {
error = EINVAL;
goto out;
}
outputsbuf = rctl_racct_to_sbuf(lc->lc_racct, 1);
break;
case RCTL_SUBJECT_TYPE_JAIL:
prr = filter->rr_subject.rs_prison_racct;
if (prr == NULL) {
error = EINVAL;
goto out;
}
outputsbuf = rctl_racct_to_sbuf(prr->prr_racct, 1);
break;
default:
error = EINVAL;
}
out:
rctl_rule_release(filter);
sx_sunlock(&allproc_lock);
if (error != 0)
return (error);
error = rctl_write_outbuf(outputsbuf, uap->outbufp, uap->outbuflen);
return (error);
}
static void
rctl_get_rules_callback(struct racct *racct, void *arg2, void *arg3)
{
struct rctl_rule *filter = (struct rctl_rule *)arg2;
struct rctl_rule_link *link;
struct sbuf *sb = (struct sbuf *)arg3;
rw_rlock(&rctl_lock);
LIST_FOREACH(link, &racct->r_rule_links, rrl_next) {
if (!rctl_rule_matches(link->rrl_rule, filter))
continue;
rctl_rule_to_sbuf(sb, link->rrl_rule);
sbuf_printf(sb, ",");
}
rw_runlock(&rctl_lock);
}
int
rctl_get_rules(struct thread *td, struct rctl_get_rules_args *uap)
{
int error;
size_t bufsize = RCTL_DEFAULT_BUFSIZE;
char *inputstr, *buf;
struct sbuf *sb;
struct rctl_rule *filter;
struct rctl_rule_link *link;
struct proc *p;
error = priv_check(td, PRIV_RCTL_GET_RULES);
if (error != 0)
return (error);
error = rctl_read_inbuf(&inputstr, uap->inbufp, uap->inbuflen);
if (error != 0)
return (error);
sx_slock(&allproc_lock);
error = rctl_string_to_rule(inputstr, &filter);
free(inputstr, M_RCTL);
if (error != 0) {
sx_sunlock(&allproc_lock);
return (error);
}
again:
buf = malloc(bufsize, M_RCTL, M_WAITOK);
sb = sbuf_new(NULL, buf, bufsize, SBUF_FIXEDLEN);
KASSERT(sb != NULL, ("sbuf_new failed"));
sx_assert(&allproc_lock, SA_LOCKED);
FOREACH_PROC_IN_SYSTEM(p) {
rw_rlock(&rctl_lock);
LIST_FOREACH(link, &p->p_racct->r_rule_links, rrl_next) {
/*
* Non-process rules will be added to the buffer later.
* Adding them here would result in duplicated output.
*/
if (link->rrl_rule->rr_subject_type !=
RCTL_SUBJECT_TYPE_PROCESS)
continue;
if (!rctl_rule_matches(link->rrl_rule, filter))
continue;
rctl_rule_to_sbuf(sb, link->rrl_rule);
sbuf_printf(sb, ",");
}
rw_runlock(&rctl_lock);
}
loginclass_racct_foreach(rctl_get_rules_callback, filter, sb);
ui_racct_foreach(rctl_get_rules_callback, filter, sb);
prison_racct_foreach(rctl_get_rules_callback, filter, sb);
if (sbuf_error(sb) == ENOMEM) {
sbuf_delete(sb);
free(buf, M_RCTL);
bufsize *= 4;
goto again;
}
/*
* Remove trailing ",".
*/
if (sbuf_len(sb) > 0)
sbuf_setpos(sb, sbuf_len(sb) - 1);
error = rctl_write_outbuf(sb, uap->outbufp, uap->outbuflen);
rctl_rule_release(filter);
sx_sunlock(&allproc_lock);
free(buf, M_RCTL);
return (error);
}
int
rctl_get_limits(struct thread *td, struct rctl_get_limits_args *uap)
{
int error;
size_t bufsize = RCTL_DEFAULT_BUFSIZE;
char *inputstr, *buf;
struct sbuf *sb;
struct rctl_rule *filter;
struct rctl_rule_link *link;
error = priv_check(td, PRIV_RCTL_GET_LIMITS);
if (error != 0)
return (error);
error = rctl_read_inbuf(&inputstr, uap->inbufp, uap->inbuflen);
if (error != 0)
return (error);
sx_slock(&allproc_lock);
error = rctl_string_to_rule(inputstr, &filter);
free(inputstr, M_RCTL);
if (error != 0) {
sx_sunlock(&allproc_lock);
return (error);
}
if (filter->rr_subject_type == RCTL_SUBJECT_TYPE_UNDEFINED) {
rctl_rule_release(filter);
sx_sunlock(&allproc_lock);
return (EINVAL);
}
if (filter->rr_subject_type != RCTL_SUBJECT_TYPE_PROCESS) {
rctl_rule_release(filter);
sx_sunlock(&allproc_lock);
return (EOPNOTSUPP);
}
if (filter->rr_subject.rs_proc == NULL) {
rctl_rule_release(filter);
sx_sunlock(&allproc_lock);
return (EINVAL);
}
again:
buf = malloc(bufsize, M_RCTL, M_WAITOK);
sb = sbuf_new(NULL, buf, bufsize, SBUF_FIXEDLEN);
KASSERT(sb != NULL, ("sbuf_new failed"));
rw_rlock(&rctl_lock);
LIST_FOREACH(link, &filter->rr_subject.rs_proc->p_racct->r_rule_links,
rrl_next) {
rctl_rule_to_sbuf(sb, link->rrl_rule);
sbuf_printf(sb, ",");
}
rw_runlock(&rctl_lock);
if (sbuf_error(sb) == ENOMEM) {
sbuf_delete(sb);
free(buf, M_RCTL);
bufsize *= 4;
goto again;
}
/*
* Remove trailing ",".
*/
if (sbuf_len(sb) > 0)
sbuf_setpos(sb, sbuf_len(sb) - 1);
error = rctl_write_outbuf(sb, uap->outbufp, uap->outbuflen);
rctl_rule_release(filter);
sx_sunlock(&allproc_lock);
free(buf, M_RCTL);
return (error);
}
int
rctl_add_rule(struct thread *td, struct rctl_add_rule_args *uap)
{
int error;
struct rctl_rule *rule;
char *inputstr;
error = priv_check(td, PRIV_RCTL_ADD_RULE);
if (error != 0)
return (error);
error = rctl_read_inbuf(&inputstr, uap->inbufp, uap->inbuflen);
if (error != 0)
return (error);
sx_slock(&allproc_lock);
error = rctl_string_to_rule(inputstr, &rule);
free(inputstr, M_RCTL);
if (error != 0) {
sx_sunlock(&allproc_lock);
return (error);
}
/*
* The 'per' part of a rule is optional.
*/
if (rule->rr_per == RCTL_SUBJECT_TYPE_UNDEFINED &&
rule->rr_subject_type != RCTL_SUBJECT_TYPE_UNDEFINED)
rule->rr_per = rule->rr_subject_type;
if (!rctl_rule_fully_specified(rule)) {
error = EINVAL;
goto out;
}
error = rctl_rule_add(rule);
out:
rctl_rule_release(rule);
sx_sunlock(&allproc_lock);
return (error);
}
int
rctl_remove_rule(struct thread *td, struct rctl_remove_rule_args *uap)
{
int error;
struct rctl_rule *filter;
char *inputstr;
error = priv_check(td, PRIV_RCTL_REMOVE_RULE);
if (error != 0)
return (error);
error = rctl_read_inbuf(&inputstr, uap->inbufp, uap->inbuflen);
if (error != 0)
return (error);
sx_slock(&allproc_lock);
error = rctl_string_to_rule(inputstr, &filter);
free(inputstr, M_RCTL);
if (error != 0) {
sx_sunlock(&allproc_lock);
return (error);
}
error = rctl_rule_remove(filter);
rctl_rule_release(filter);
sx_sunlock(&allproc_lock);
return (error);
}
/*
* Update RCTL rule list after credential change.
*/
void
rctl_proc_ucred_changed(struct proc *p, struct ucred *newcred)
{
int rulecnt, i;
struct rctl_rule_link *link, *newlink;
struct uidinfo *newuip;
struct loginclass *newlc;
struct prison_racct *newprr;
LIST_HEAD(, rctl_rule_link) newrules;
newuip = newcred->cr_ruidinfo;
newlc = newcred->cr_loginclass;
newprr = newcred->cr_prison->pr_prison_racct;
LIST_INIT(&newrules);
again:
/*
* First, count the rules that apply to the process with new
* credentials.
*/
rulecnt = 0;
rw_rlock(&rctl_lock);
LIST_FOREACH(link, &p->p_racct->r_rule_links, rrl_next) {
if (link->rrl_rule->rr_subject_type ==
RCTL_SUBJECT_TYPE_PROCESS)
rulecnt++;
}
LIST_FOREACH(link, &newuip->ui_racct->r_rule_links, rrl_next)
rulecnt++;
LIST_FOREACH(link, &newlc->lc_racct->r_rule_links, rrl_next)
rulecnt++;
LIST_FOREACH(link, &newprr->prr_racct->r_rule_links, rrl_next)
rulecnt++;
rw_runlock(&rctl_lock);
/*
* Create temporary list. We've dropped the rctl_lock in order
* to use M_WAITOK.
*/
for (i = 0; i < rulecnt; i++) {
newlink = uma_zalloc(rctl_rule_link_zone, M_WAITOK);
newlink->rrl_rule = NULL;
LIST_INSERT_HEAD(&newrules, newlink, rrl_next);
}
newlink = LIST_FIRST(&newrules);
/*
* Assign rules to the newly allocated list entries.
*/
rw_wlock(&rctl_lock);
LIST_FOREACH(link, &p->p_racct->r_rule_links, rrl_next) {
if (link->rrl_rule->rr_subject_type ==
RCTL_SUBJECT_TYPE_PROCESS) {
if (newlink == NULL)
goto goaround;
rctl_rule_acquire(link->rrl_rule);
newlink->rrl_rule = link->rrl_rule;
newlink = LIST_NEXT(newlink, rrl_next);
rulecnt--;
}
}
LIST_FOREACH(link, &newuip->ui_racct->r_rule_links, rrl_next) {
if (newlink == NULL)
goto goaround;
rctl_rule_acquire(link->rrl_rule);
newlink->rrl_rule = link->rrl_rule;
newlink = LIST_NEXT(newlink, rrl_next);
rulecnt--;
}
LIST_FOREACH(link, &newlc->lc_racct->r_rule_links, rrl_next) {
if (newlink == NULL)
goto goaround;
rctl_rule_acquire(link->rrl_rule);
newlink->rrl_rule = link->rrl_rule;
newlink = LIST_NEXT(newlink, rrl_next);
rulecnt--;
}
LIST_FOREACH(link, &newprr->prr_racct->r_rule_links, rrl_next) {
if (newlink == NULL)
goto goaround;
rctl_rule_acquire(link->rrl_rule);
newlink->rrl_rule = link->rrl_rule;
newlink = LIST_NEXT(newlink, rrl_next);
rulecnt--;
}
if (rulecnt == 0) {
/*
* Free the old rule list.
*/
while (!LIST_EMPTY(&p->p_racct->r_rule_links)) {
link = LIST_FIRST(&p->p_racct->r_rule_links);
LIST_REMOVE(link, rrl_next);
rctl_rule_release(link->rrl_rule);
uma_zfree(rctl_rule_link_zone, link);
}
/*
* Replace lists and we're done.
*
* XXX: Is there any way to switch list heads instead
* of iterating here?
*/
while (!LIST_EMPTY(&newrules)) {
newlink = LIST_FIRST(&newrules);
LIST_REMOVE(newlink, rrl_next);
LIST_INSERT_HEAD(&p->p_racct->r_rule_links,
newlink, rrl_next);
}
rw_wunlock(&rctl_lock);
return;
}
goaround:
rw_wunlock(&rctl_lock);
/*
* Rule list changed while we were not holding the rctl_lock.
* Free the new list and try again.
*/
while (!LIST_EMPTY(&newrules)) {
newlink = LIST_FIRST(&newrules);
LIST_REMOVE(newlink, rrl_next);
if (newlink->rrl_rule != NULL)
rctl_rule_release(newlink->rrl_rule);
uma_zfree(rctl_rule_link_zone, newlink);
}
goto again;
}
/*
* Assign RCTL rules to the newly created process.
*/
int
rctl_proc_fork(struct proc *parent, struct proc *child)
{
int error;
struct rctl_rule_link *link;
struct rctl_rule *rule;
LIST_INIT(&child->p_racct->r_rule_links);
/*
* No limits for kernel processes.
*/
if (child->p_flag & P_SYSTEM)
return (0);
/*
* Nothing to inherit from P_SYSTEM parents.
*/
if (parent->p_racct == NULL) {
KASSERT(parent->p_flag & P_SYSTEM,
("non-system process without racct; p = %p", parent));
return (0);
}
rw_wlock(&rctl_lock);
/*
* Go through limits applicable to the parent and assign them
* to the child. Rules with 'process' subject have to be duplicated
* in order to make their rr_subject point to the new process.
*/
LIST_FOREACH(link, &parent->p_racct->r_rule_links, rrl_next) {
if (link->rrl_rule->rr_subject_type ==
RCTL_SUBJECT_TYPE_PROCESS) {
rule = rctl_rule_duplicate(link->rrl_rule, M_NOWAIT);
if (rule == NULL)
goto fail;
KASSERT(rule->rr_subject.rs_proc == parent,
("rule->rr_subject.rs_proc != parent"));
rule->rr_subject.rs_proc = child;
error = rctl_racct_add_rule_locked(child->p_racct,
rule);
rctl_rule_release(rule);
if (error != 0)
goto fail;
} else {
error = rctl_racct_add_rule_locked(child->p_racct,
link->rrl_rule);
if (error != 0)
goto fail;
}
}
rw_wunlock(&rctl_lock);
return (0);
fail:
while (!LIST_EMPTY(&child->p_racct->r_rule_links)) {
link = LIST_FIRST(&child->p_racct->r_rule_links);
LIST_REMOVE(link, rrl_next);
rctl_rule_release(link->rrl_rule);
uma_zfree(rctl_rule_link_zone, link);
}
rw_wunlock(&rctl_lock);
return (EAGAIN);
}
/*
* Release rules attached to the racct.
*/
void
rctl_racct_release(struct racct *racct)
{
struct rctl_rule_link *link;
rw_wlock(&rctl_lock);
while (!LIST_EMPTY(&racct->r_rule_links)) {
link = LIST_FIRST(&racct->r_rule_links);
LIST_REMOVE(link, rrl_next);
rctl_rule_release(link->rrl_rule);
uma_zfree(rctl_rule_link_zone, link);
}
rw_wunlock(&rctl_lock);
}
static void
rctl_init(void)
{
rctl_rule_link_zone = uma_zcreate("rctl_rule_link",
sizeof(struct rctl_rule_link), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
rctl_rule_zone = uma_zcreate("rctl_rule", sizeof(struct rctl_rule),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
}
#else /* !RCTL */
int
rctl_get_racct(struct thread *td, struct rctl_get_racct_args *uap)
{
return (ENOSYS);
}
int
rctl_get_rules(struct thread *td, struct rctl_get_rules_args *uap)
{
return (ENOSYS);
}
int
rctl_get_limits(struct thread *td, struct rctl_get_limits_args *uap)
{
return (ENOSYS);
}
int
rctl_add_rule(struct thread *td, struct rctl_add_rule_args *uap)
{
return (ENOSYS);
}
int
rctl_remove_rule(struct thread *td, struct rctl_remove_rule_args *uap)
{
return (ENOSYS);
}
#endif /* !RCTL */
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