e4fbf98b18
* libmisc/limits.c: Fix support for the K limit identifier. * libmisc/limits.c: Add missing default limit for L and U.
612 lines
16 KiB
C
612 lines
16 KiB
C
/*
|
|
* Copyright (c) 1989 - 1994, Julianne Frances Haugh
|
|
* Copyright (c) 1996 - 1999, Marek Michałkiewicz
|
|
* Copyright (c) 2003 - 2006, Tomasz Kłoczko
|
|
* Copyright (c) 2007 - 2010, Nicolas François
|
|
* All rights reserved.
|
|
*
|
|
* 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.
|
|
* 3. The name of the copyright holders or contributors may not be used to
|
|
* endorse or promote products derived from this software without
|
|
* specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
|
|
* HOLDERS 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.
|
|
*/
|
|
|
|
/*
|
|
* Separated from setup.c. --marekm
|
|
* Resource limits thanks to Cristian Gafton.
|
|
* Enhancements of resource limit code by Thomas Orgis <thomas@orgis.org>
|
|
*/
|
|
|
|
#include <config.h>
|
|
|
|
#ifndef USE_PAM
|
|
|
|
#ident "$Id$"
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <stdio.h>
|
|
#include <ctype.h>
|
|
#include "prototypes.h"
|
|
#include "defines.h"
|
|
#include <pwd.h>
|
|
#include "getdef.h"
|
|
#ifdef HAVE_SYS_RESOURCE_H
|
|
#include <sys/resource.h>
|
|
#define LIMITS
|
|
#endif
|
|
#ifdef LIMITS
|
|
#ifndef LIMITS_FILE
|
|
#define LIMITS_FILE "/etc/limits"
|
|
#endif
|
|
#define LOGIN_ERROR_RLIMIT 1
|
|
#define LOGIN_ERROR_LOGIN 2
|
|
/* Set a limit on a resource */
|
|
/*
|
|
* rlimit - RLIMIT_XXXX
|
|
* value - string value to be read
|
|
* multiplier - value*multiplier is the actual limit
|
|
*/
|
|
static int setrlimit_value (unsigned int resource,
|
|
const char *value,
|
|
unsigned int multiplier)
|
|
{
|
|
struct rlimit rlim;
|
|
rlim_t limit;
|
|
|
|
/* The "-" is special, not belonging to a strange negative limit.
|
|
* It is infinity, in a controlled way.
|
|
*/
|
|
if ('-' == value[0]) {
|
|
limit = RLIM_INFINITY;
|
|
}
|
|
else {
|
|
/* We cannot use getlong here because it fails when there
|
|
* is more to the value than just this number!
|
|
* Also, we are limited to base 10 here (hex numbers will not
|
|
* work with the limit string parser as is anyway)
|
|
*/
|
|
char *endptr;
|
|
long longlimit = strtol (value, &endptr, 10);
|
|
if ((0 == longlimit) && (value == endptr)) {
|
|
/* No argument at all. No-op.
|
|
* FIXME: We could instead throw an error, though.
|
|
*/
|
|
return 0;
|
|
}
|
|
longlimit *= multiplier;
|
|
limit = (rlim_t)longlimit;
|
|
if (longlimit != limit)
|
|
{
|
|
/* FIXME: Again, silent error handling...
|
|
* Wouldn't screaming make more sense?
|
|
*/
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
rlim.rlim_cur = limit;
|
|
rlim.rlim_max = limit;
|
|
if (setrlimit (resource, &rlim) != 0) {
|
|
return LOGIN_ERROR_RLIMIT;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int set_prio (const char *value)
|
|
{
|
|
long prio;
|
|
|
|
if ( (getlong (value, &prio) == 0)
|
|
|| (prio != (int) prio)) {
|
|
return 0;
|
|
}
|
|
if (setpriority (PRIO_PROCESS, 0, (int) prio) != 0) {
|
|
return LOGIN_ERROR_RLIMIT;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int set_umask (const char *value)
|
|
{
|
|
unsigned long int mask;
|
|
|
|
if ( (getulong (value, &mask) == 0)
|
|
|| (mask != (mode_t) mask)) {
|
|
return 0;
|
|
}
|
|
|
|
(void) umask ((mode_t) mask);
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* Counts the number of user logins and check against the limit */
|
|
static int check_logins (const char *name, const char *maxlogins)
|
|
{
|
|
#ifdef USE_UTMPX
|
|
struct utmpx *ut;
|
|
#else /* !USE_UTMPX */
|
|
struct utmp *ut;
|
|
#endif /* !USE_UTMPX */
|
|
unsigned long limit, count;
|
|
|
|
if (getulong (maxlogins, &limit) == 0) {
|
|
return 0;
|
|
}
|
|
|
|
if (0 == limit) { /* maximum 0 logins ? */
|
|
SYSLOG ((LOG_WARN, "No logins allowed for `%s'\n", name));
|
|
return LOGIN_ERROR_LOGIN;
|
|
}
|
|
|
|
count = 0;
|
|
#ifdef USE_UTMPX
|
|
setutxent ();
|
|
while ((ut = getutxent ()))
|
|
#else /* !USE_UTMPX */
|
|
setutent ();
|
|
while ((ut = getutent ()))
|
|
#endif /* !USE_UTMPX */
|
|
{
|
|
if (USER_PROCESS != ut->ut_type) {
|
|
continue;
|
|
}
|
|
if ('\0' == ut->ut_user[0]) {
|
|
continue;
|
|
}
|
|
if (strncmp (name, ut->ut_user, sizeof (ut->ut_user)) != 0) {
|
|
continue;
|
|
}
|
|
count++;
|
|
if (count > limit) {
|
|
break;
|
|
}
|
|
}
|
|
#ifdef USE_UTMPX
|
|
endutxent ();
|
|
#else /* !USE_UTMPX */
|
|
endutent ();
|
|
#endif /* !USE_UTMPX */
|
|
/*
|
|
* This is called after setutmp(), so the number of logins counted
|
|
* includes the user who is currently trying to log in.
|
|
*/
|
|
if (count > limit) {
|
|
SYSLOG ((LOG_WARN,
|
|
"Too many logins (max %lu) for %s\n",
|
|
limit, name));
|
|
return LOGIN_ERROR_LOGIN;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Function setup_user_limits - checks/set limits for the curent login
|
|
* Original idea from Joel Katz's lshell. Ported to shadow-login
|
|
* by Cristian Gafton - gafton@sorosis.ro
|
|
*
|
|
* We are passed a string of the form ('BASH' constants for ulimit)
|
|
* [Aa][Cc][Dd][Ff][Mm][Nn][Rr][Ss][Tt][Uu][Ll][Pp][Ii][Oo]
|
|
* (eg. 'C2F256D2048N5' or 'C2 F256 D2048 N5')
|
|
* where:
|
|
* [Aa]: a = RLIMIT_AS max address space (KB)
|
|
* [Cc]: c = RLIMIT_CORE max core file size (KB)
|
|
* [Dd]: d = RLIMIT_DATA max data size (KB)
|
|
* [Ff]: f = RLIMIT_FSIZE max file size (KB)
|
|
* [Ii]: i = RLIMIT_NICE max nice value (0..39 translates to 20..-19)
|
|
* [Kk]: k = file creation masK (umask)
|
|
* [Ll]: l = max number of logins for this user
|
|
* [Mm]: m = RLIMIT_MEMLOCK max locked-in-memory address space (KB)
|
|
* [Nn]: n = RLIMIT_NOFILE max number of open files
|
|
* [Oo]: o = RLIMIT_RTPRIO max real time priority (linux/sched.h 0..MAX_RT_PRIO)
|
|
* [Pp]: p = process priority -20..20 (negative = high, positive = low)
|
|
* [Rr]: r = RLIMIT_RSS max resident set size (KB)
|
|
* [Ss]: s = RLIMIT_STACK max stack size (KB)
|
|
* [Tt]: t = RLIMIT_CPU max CPU time (MIN)
|
|
* [Uu]: u = RLIMIT_NPROC max number of processes
|
|
*
|
|
* NOTE: Remember to extend the "no-limits" string below when adding a new
|
|
* limit...
|
|
*
|
|
* Return value:
|
|
* 0 = okay, of course
|
|
* LOGIN_ERROR_RLIMIT = error setting some RLIMIT
|
|
* LOGIN_ERROR_LOGIN = error - too many logins for this user
|
|
*
|
|
* buf - the limits string
|
|
* name - the username
|
|
*/
|
|
static int do_user_limits (const char *buf, const char *name)
|
|
{
|
|
const char *pp;
|
|
int retval = 0;
|
|
bool reported = false;
|
|
|
|
pp = buf;
|
|
/* Skip leading whitespace. */
|
|
while ((' ' == *pp) || ('\t' == *pp)) {
|
|
pp++;
|
|
}
|
|
|
|
/* The special limit string "-" results in no limit for all known
|
|
* limits.
|
|
* We achieve that by parsing a full limit string, parts of it
|
|
* being ignored if a limit type is not known to the system.
|
|
* Though, there will be complaining for unknown limit types.
|
|
*/
|
|
if (strcmp (pp, "-") == 0) {
|
|
/* Remember to extend this, too, when adding new limits!
|
|
* Oh... but "unlimited" does not make sense for umask,
|
|
* or does it? (K-)
|
|
*/
|
|
pp = "A- C- D- F- I- L- M- N- O- P- R- S- T- U-";
|
|
}
|
|
|
|
while ('\0' != *pp) {
|
|
switch (*pp++) {
|
|
#ifdef RLIMIT_AS
|
|
case 'a':
|
|
case 'A':
|
|
/* RLIMIT_AS - max address space (KB) */
|
|
retval |= setrlimit_value (RLIMIT_AS, pp, 1024);
|
|
break;
|
|
#endif
|
|
#ifdef RLIMIT_CORE
|
|
case 'c':
|
|
case 'C':
|
|
/* RLIMIT_CORE - max core file size (KB) */
|
|
retval |= setrlimit_value (RLIMIT_CORE, pp, 1024);
|
|
break;
|
|
#endif
|
|
#ifdef RLIMIT_DATA
|
|
case 'd':
|
|
case 'D':
|
|
/* RLIMIT_DATA - max data size (KB) */
|
|
retval |= setrlimit_value (RLIMIT_DATA, pp, 1024);
|
|
break;
|
|
#endif
|
|
#ifdef RLIMIT_FSIZE
|
|
case 'f':
|
|
case 'F':
|
|
/* RLIMIT_FSIZE - Maximum filesize (KB) */
|
|
retval |= setrlimit_value (RLIMIT_FSIZE, pp, 1024);
|
|
break;
|
|
#endif
|
|
#ifdef RLIMIT_NICE
|
|
case 'i':
|
|
case 'I':
|
|
/* RLIMIT_NICE - max scheduling priority (0..39) */
|
|
retval |= setrlimit_value (RLIMIT_NICE, pp, 1);
|
|
break;
|
|
#endif
|
|
case 'k':
|
|
case 'K':
|
|
retval |= set_umask (pp);
|
|
break;
|
|
case 'l':
|
|
case 'L':
|
|
/* LIMIT the number of concurrent logins */
|
|
retval |= check_logins (name, pp);
|
|
break;
|
|
#ifdef RLIMIT_MEMLOCK
|
|
case 'm':
|
|
case 'M':
|
|
/* RLIMIT_MEMLOCK - max locked-in-memory address space (KB) */
|
|
retval |= setrlimit_value (RLIMIT_MEMLOCK, pp, 1024);
|
|
break;
|
|
#endif
|
|
#ifdef RLIMIT_NOFILE
|
|
case 'n':
|
|
case 'N':
|
|
/* RLIMIT_NOFILE - max number of open files */
|
|
retval |= setrlimit_value (RLIMIT_NOFILE, pp, 1);
|
|
break;
|
|
#endif
|
|
#ifdef RLIMIT_RTPRIO
|
|
case 'o':
|
|
case 'O':
|
|
/* RLIMIT_RTPRIO - max real time priority (0..MAX_RT_PRIO) */
|
|
retval |= setrlimit_value (RLIMIT_RTPRIO, pp, 1);
|
|
break;
|
|
#endif
|
|
case 'p':
|
|
case 'P':
|
|
retval |= set_prio (pp);
|
|
break;
|
|
#ifdef RLIMIT_RSS
|
|
case 'r':
|
|
case 'R':
|
|
/* RLIMIT_RSS - max resident set size (KB) */
|
|
retval |= setrlimit_value (RLIMIT_RSS, pp, 1024);
|
|
break;
|
|
#endif
|
|
#ifdef RLIMIT_STACK
|
|
case 's':
|
|
case 'S':
|
|
/* RLIMIT_STACK - max stack size (KB) */
|
|
retval |= setrlimit_value (RLIMIT_STACK, pp, 1024);
|
|
break;
|
|
#endif
|
|
#ifdef RLIMIT_CPU
|
|
case 't':
|
|
case 'T':
|
|
/* RLIMIT_CPU - max CPU time (MIN) */
|
|
retval |= setrlimit_value (RLIMIT_CPU, pp, 60);
|
|
break;
|
|
#endif
|
|
#ifdef RLIMIT_NPROC
|
|
case 'u':
|
|
case 'U':
|
|
/* RLIMIT_NPROC - max number of processes */
|
|
retval |= setrlimit_value (RLIMIT_NPROC, pp, 1);
|
|
break;
|
|
#endif
|
|
default:
|
|
/* Only report invalid strings once */
|
|
/* Note: A string can be invalid just because a
|
|
* specific (theoretically valid) setting is not
|
|
* supported by this build.
|
|
* It is just a warning in syslog anyway. The line
|
|
* is still processed
|
|
*/
|
|
if (!reported) {
|
|
SYSLOG ((LOG_WARN,
|
|
"Invalid limit string: '%s'",
|
|
pp-1));
|
|
reported = true;
|
|
retval |= LOGIN_ERROR_RLIMIT;
|
|
}
|
|
}
|
|
/* After parsing one limit setting (or just complaining
|
|
* about it), one still needs to skip its argument to
|
|
* prevent a bogus warning on trying to parse that as
|
|
* limit specification.
|
|
* So, let's skip all digits, "-" and our limited set of
|
|
* whitespace.
|
|
*/
|
|
while ( isdigit (*pp)
|
|
|| ('-' == *pp)
|
|
|| (' ' == *pp)
|
|
|| ('\t' ==*pp)) {
|
|
pp++;
|
|
}
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
/* Check if user uname is in the group gname.
|
|
* Can I be sure that gr_mem contains no UID as string?
|
|
* Returns true when user is in the group, false when not.
|
|
* Any error is treated as false.
|
|
*/
|
|
static bool user_in_group (const char *uname, const char *gname)
|
|
{
|
|
struct group *groupdata;
|
|
|
|
if (uname == NULL || gname == NULL){
|
|
return false;
|
|
}
|
|
|
|
/* We are not claiming to be re-entrant!
|
|
* In case of paranoia or a multithreaded login program,
|
|
* one needs to add some mess for getgrnam_r. */
|
|
groupdata = getgrnam (gname);
|
|
if (NULL == groupdata) {
|
|
SYSLOG ((LOG_WARN, "Nonexisting group `%s' in limits file.",
|
|
gname));
|
|
return false;
|
|
}
|
|
|
|
return is_on_list (groupdata->gr_mem, uname);
|
|
}
|
|
|
|
static int setup_user_limits (const char *uname)
|
|
{
|
|
FILE *fil;
|
|
char buf[1024];
|
|
char name[1024];
|
|
char limits[1024];
|
|
char deflimits[1024];
|
|
char tempbuf[1024];
|
|
|
|
/* init things */
|
|
memzero (buf, sizeof (buf));
|
|
memzero (name, sizeof (name));
|
|
memzero (limits, sizeof (limits));
|
|
memzero (deflimits, sizeof (deflimits));
|
|
memzero (tempbuf, sizeof (tempbuf));
|
|
|
|
/* start the checks */
|
|
fil = fopen (LIMITS_FILE, "r");
|
|
if (fil == NULL) {
|
|
return 0;
|
|
}
|
|
/* The limits file have the following format:
|
|
* - '#' (comment) chars only as first chars on a line;
|
|
* - username must start on first column (or *, or @group)
|
|
*
|
|
* FIXME: A better (smarter) checking should be done
|
|
*/
|
|
while (fgets (buf, 1024, fil) != NULL) {
|
|
if (('#' == buf[0]) || ('\n' == buf[0])) {
|
|
continue;
|
|
}
|
|
memzero (tempbuf, sizeof (tempbuf));
|
|
/* a valid line should have a username, then spaces,
|
|
* then limits
|
|
* we allow the format:
|
|
* username L2 D2048 R4096
|
|
* where spaces={' ',\t}. Also, we reject invalid limits.
|
|
* Imposing a limit should be done with care, so a wrong
|
|
* entry means no care anyway :-).
|
|
*
|
|
* A '-' as a limits strings means no limits
|
|
*
|
|
* The username can also be:
|
|
* '*': the default limits (only the last is taken into
|
|
* account)
|
|
* @group: the limit applies to the members of the group
|
|
*
|
|
* To clarify: The first entry with matching user name rules,
|
|
* everything after it is ignored. If there is no user entry,
|
|
* the last encountered entry for a matching group rules.
|
|
* If there is no matching group entry, the default limits rule.
|
|
*/
|
|
if (sscanf (buf, "%s%[ACDFIKLMNOPRSTUacdfiklmnoprstu0-9 \t-]",
|
|
name, tempbuf) == 2) {
|
|
if (strcmp (name, uname) == 0) {
|
|
strcpy (limits, tempbuf);
|
|
break;
|
|
} else if (strcmp (name, "*") == 0) {
|
|
strcpy (deflimits, tempbuf);
|
|
} else if (name[0] == '@') {
|
|
/* If the user is in the group, the group
|
|
* limits apply unless later a line for
|
|
* the specific user is found.
|
|
*/
|
|
if (user_in_group (uname, name+1)) {
|
|
strcpy (limits, tempbuf);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
(void) fclose (fil);
|
|
if (limits[0] == '\0') {
|
|
/* no user specific limits */
|
|
if (deflimits[0] == '\0') { /* no default limits */
|
|
return 0;
|
|
}
|
|
strcpy (limits, deflimits); /* use the default limits */
|
|
}
|
|
return do_user_limits (limits, uname);
|
|
}
|
|
#endif /* LIMITS */
|
|
|
|
|
|
static void setup_usergroups (const struct passwd *info)
|
|
{
|
|
const struct group *grp;
|
|
|
|
/*
|
|
* if not root, and UID == GID, and username is the same as primary
|
|
* group name, set umask group bits to be the same as owner bits
|
|
* (examples: 022 -> 002, 077 -> 007).
|
|
*/
|
|
if ((0 != info->pw_uid) && (info->pw_uid == info->pw_gid)) {
|
|
/* local, no need for xgetgrgid */
|
|
grp = getgrgid (info->pw_gid);
|
|
if ( (NULL != grp)
|
|
&& (strcmp (info->pw_name, grp->gr_name) == 0)) {
|
|
mode_t tmpmask;
|
|
tmpmask = umask (0777);
|
|
tmpmask = (tmpmask & ~070) | ((tmpmask >> 3) & 070);
|
|
(void) umask (tmpmask);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* set the process nice, ulimit, and umask from the password file entry
|
|
*/
|
|
|
|
void setup_limits (const struct passwd *info)
|
|
{
|
|
char *cp;
|
|
|
|
if (getdef_bool ("USERGROUPS_ENAB")) {
|
|
setup_usergroups (info);
|
|
}
|
|
|
|
/*
|
|
* See if the GECOS field contains values for NICE, UMASK or ULIMIT.
|
|
* If this feature is enabled in /etc/login.defs, we make those
|
|
* values the defaults for this login session.
|
|
*/
|
|
|
|
if (getdef_bool ("QUOTAS_ENAB")) {
|
|
#ifdef LIMITS
|
|
if (info->pw_uid != 0) {
|
|
if ((setup_user_limits (info->pw_name) & LOGIN_ERROR_LOGIN) != 0) {
|
|
(void) fputs (_("Too many logins.\n"), stderr);
|
|
(void) sleep (2); /* XXX: Should be FAIL_DELAY */
|
|
exit (EXIT_FAILURE);
|
|
}
|
|
}
|
|
#endif
|
|
for (cp = info->pw_gecos; cp != NULL; cp = strchr (cp, ',')) {
|
|
if (',' == *cp) {
|
|
cp++;
|
|
}
|
|
|
|
if (strncmp (cp, "pri=", 4) == 0) {
|
|
long int inc;
|
|
if ( (getlong (cp + 4, &inc) == 1)
|
|
&& (inc >= -20) && (inc <= 20)) {
|
|
errno = 0;
|
|
if ( (nice ((int) inc) != -1)
|
|
|| (0 != errno)) {
|
|
continue;
|
|
}
|
|
}
|
|
|
|
/* Failed to parse or failed to nice() */
|
|
SYSLOG ((LOG_WARN,
|
|
"Can't set the nice value for user %s",
|
|
info->pw_name));
|
|
|
|
continue;
|
|
}
|
|
if (strncmp (cp, "ulimit=", 7) == 0) {
|
|
long int blocks;
|
|
if ( (getlong (cp + 7, &blocks) == 0)
|
|
|| (blocks != (int) blocks)
|
|
|| (set_filesize_limit ((int) blocks) != 0)) {
|
|
SYSLOG ((LOG_WARN,
|
|
"Can't set the ulimit for user %s",
|
|
info->pw_name));
|
|
}
|
|
continue;
|
|
}
|
|
if (strncmp (cp, "umask=", 6) == 0) {
|
|
unsigned long int mask;
|
|
if ( (getulong (cp + 6, &mask) == 0)
|
|
|| (mask != (mode_t) mask)) {
|
|
SYSLOG ((LOG_WARN,
|
|
"Can't set umask value for user %s",
|
|
info->pw_name));
|
|
} else {
|
|
(void) umask ((mode_t) mask);
|
|
}
|
|
|
|
continue;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#else /* !USE_PAM */
|
|
extern int errno; /* warning: ANSI C forbids an empty source file */
|
|
#endif /* !USE_PAM */
|
|
|