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/*
* pam_limits - impose resource limits when opening a user session
*
* 1.6 - modified for PLD (added process priority settings)
* by Marcin Korzonek <mkorz@shadow.eu.org>
* 1.5 - Elliot Lee's "max system logins patch"
* 1.4 - addressed bug in configuration file parser
* 1.3 - modified the configuration file format
* 1.2 - added 'debug' and 'conf=' arguments
* 1.1 - added @group support
* 1.0 - initial release - Linux ONLY
*
* See end for Copyright information
*/
#if !defined(linux) && !defined(__linux)
#error THIS CODE IS KNOWN TO WORK ONLY ON LINUX !!!
#endif
#include <glib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <errno.h>
#include <syslog.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/resource.h>
#include <limits.h>
#include <utmp.h>
#ifndef UT_USER /* some systems have ut_name instead of ut_user */
#define UT_USER ut_user
#endif
#include <grp.h>
#include <pwd.h>
/* Module defines */
#ifndef LIMITS_FILE
#define LIMITS_FILE "/etc/security/limits.conf"
#endif
#define LINE_LENGTH 1024
#define LIMITS_DEF_USER 0 /* limit was set by an user entry */
#define LIMITS_DEF_GROUP 1 /* limit was set by a group entry */
#define LIMITS_DEF_ALLGROUP 2 /* limit was set by a group entry */
#define LIMITS_DEF_ALL 3 /* limit was set by an default entry */
#define LIMITS_DEF_DEFAULT 4 /* limit was set by an default entry */
#define LIMITS_DEF_NONE 5 /* this limit was not set yet */
struct user_limits_struct {
int supported;
int src_soft;
int src_hard;
struct rlimit limit;
};
/* internal data */
struct pam_limit_s {
int priority; /* the priority to run user process with */
struct user_limits_struct limits[RLIM_NLIMITS];
struct passwd *pwd;
};
#define LIMIT_PRI RLIM_NLIMITS+1
#define LIMIT_SOFT 1
#define LIMIT_HARD 2
#define LIMITED_OK 0 /* limit setting appeared to work */
#define LIMIT_ERR 1 /* error setting a limit */
#define LOGIN_ERR 2 /* too many logins err */
typedef enum {
LIMHANDLE_OK = 0,
LIMHANDLE_ERROR = -1,
LIMHANDLE_IGNORE = 1
} limhandle_t;
static limhandle_t init_limits(struct pam_limit_s *pl) {
int i, r;
for(i = 0; i < RLIM_NLIMITS; i++) {
errno = 0;
r = getrlimit(i, &pl->limits[i].limit);
if (r == -1) {
pl->limits[i].supported = 0;
if (errno != EINVAL) {
g_printerr("Couldn't getrlimit: %s\n", g_strerror(errno));
return LIMHANDLE_ERROR;
}
} else {
pl->limits[i].supported = 1;
pl->limits[i].src_soft = LIMITS_DEF_NONE;
pl->limits[i].src_hard = LIMITS_DEF_NONE;
}
}
errno = 0;
pl->priority = getpriority (PRIO_PROCESS, 0);
if (pl->priority == -1 && errno != 0) {
g_printerr("Couldn't getpriority: %s\n", g_strerror(errno));
return LIMHANDLE_ERROR;
}
return LIMHANDLE_OK;
}
static void
process_limit (int source, const char *lim_type,
const char *lim_item, const char *lim_value,
struct pam_limit_s *pl) {
int limit_item;
int limit_type = 0;
int int_value = 0;
rlim_t rlimit_value = 0;
char *endptr;
const char *value_orig = lim_value;
/*
if (ctrl & PAM_DEBUG_ARG)
pam_syslog(pamh, LOG_DEBUG, "%s: processing %s %s %s for %s",
__FUNCTION__, lim_type, lim_item, lim_value,
limits_def_names[source]);*/
if (strcmp(lim_item, "cpu") == 0) {
limit_item = RLIMIT_CPU;
} else if (strcmp(lim_item, "fsize") == 0) {
limit_item = RLIMIT_FSIZE;
} else if (strcmp(lim_item, "data") == 0) {
limit_item = RLIMIT_DATA;
} else if (strcmp(lim_item, "stack") == 0) {
limit_item = RLIMIT_STACK;
} else if (strcmp(lim_item, "core") == 0) {
limit_item = RLIMIT_CORE;
} else if (strcmp(lim_item, "rss") == 0) {
limit_item = RLIMIT_RSS;
} else if (strcmp(lim_item, "nproc") == 0) {
limit_item = RLIMIT_NPROC;
} else if (strcmp(lim_item, "nofile") == 0) {
limit_item = RLIMIT_NOFILE;
} else if (strcmp(lim_item, "memlock") == 0) {
limit_item = RLIMIT_MEMLOCK;
} else if (strcmp(lim_item, "as") == 0) {
limit_item = RLIMIT_AS;
#ifdef RLIMIT_LOCKS
} else if (strcmp(lim_item, "locks") == 0) {
limit_item = RLIMIT_LOCKS;
#endif
#ifdef RLIMIT_SIGPENDING
} else if (strcmp(lim_item, "sigpending") == 0) {
limit_item = RLIMIT_SIGPENDING;
#endif
#ifdef RLIMIT_MSGQUEUE
} else if (strcmp(lim_item, "msgqueue") == 0) {
limit_item = RLIMIT_MSGQUEUE;
#endif
#ifdef RLIMIT_NICE
} else if (strcmp(lim_item, "nice") == 0) {
limit_item = RLIMIT_NICE;
#endif
#ifdef RLIMIT_RTPRIO
} else if (strcmp(lim_item, "rtprio") == 0) {
limit_item = RLIMIT_RTPRIO;
#endif
} else if (strcmp(lim_item, "priority") == 0) {
limit_item = LIMIT_PRI;
} else {
g_printerr("unknown limit item '%s'\n", lim_item);
return;
}
if (strcmp(lim_type,"soft")==0) {
limit_type=LIMIT_SOFT;
} else if (strcmp(lim_type, "hard")==0) {
limit_type=LIMIT_HARD;
} else if (strcmp(lim_type,"-")==0) {
limit_type=LIMIT_SOFT | LIMIT_HARD;
} else {
g_printerr("unknown limit type '%s'\n", lim_type);
return;
}
if (limit_item != LIMIT_PRI
#ifdef RLIMIT_NICE
&& limit_item != RLIMIT_NICE
#endif
&& (strcmp(lim_value, "-1") == 0
|| strcmp(lim_value, "-") == 0 || strcmp(lim_value, "unlimited") == 0
|| strcmp(lim_value, "infinity") == 0)) {
int_value = -1;
rlimit_value = RLIM_INFINITY;
} else if (limit_item == LIMIT_PRI
#ifdef RLIMIT_NICE
|| limit_item == RLIMIT_NICE
#endif
) {
long temp;
temp = strtol (lim_value, &endptr, 10);
temp = temp < INT_MAX ? temp : INT_MAX;
int_value = temp > INT_MIN ? temp : INT_MIN;
if (int_value == 0 && value_orig == endptr) {
g_printerr("wrong limit value '%s' for limit type '%s'\n",
lim_value, lim_type);
return;
}
} else {
#ifdef __USE_FILE_OFFSET64
rlimit_value = strtoull (lim_value, &endptr, 10);
#else
rlimit_value = strtoul (lim_value, &endptr, 10);
#endif
if (rlimit_value == 0 && value_orig == endptr) {
g_printerr("wrong limit value '%s' for limit type '%s'",
lim_value, lim_type);
return;
}
}
switch(limit_item) {
case RLIMIT_CPU:
if (rlimit_value != RLIM_INFINITY)
rlimit_value *= 60;
break;
case RLIMIT_FSIZE:
case RLIMIT_DATA:
case RLIMIT_STACK:
case RLIMIT_CORE:
case RLIMIT_RSS:
case RLIMIT_MEMLOCK:
case RLIMIT_AS:
if (rlimit_value != RLIM_INFINITY)
rlimit_value *= 1024;
break;
#ifdef RLIMIT_NICE
case RLIMIT_NICE:
if (int_value > 19)
int_value = 19;
rlimit_value = 19 - int_value;
break;
#endif
}
if (limit_item != LIMIT_PRI) {
if (limit_type & LIMIT_SOFT) {
if (pl->limits[limit_item].src_soft < source) {
return;
} else {
pl->limits[limit_item].limit.rlim_cur = rlimit_value;
pl->limits[limit_item].src_soft = source;
}
}
if (limit_type & LIMIT_HARD) {
if (pl->limits[limit_item].src_hard < source) {
return;
} else {
pl->limits[limit_item].limit.rlim_max = rlimit_value;
pl->limits[limit_item].src_hard = source;
}
}
} else {
/* recent kernels support negative priority limits (=raise priority) */
if (limit_item == LIMIT_PRI) {
pl->priority = int_value;
}
}
return;
}
static gboolean pam_modutil_user_in_group_nam_nam(struct passwd *pwd, const char *group) {
struct group *grp;
size_t i;
grp = getgrnam(group);
if (pwd == NULL || grp == NULL) return FALSE;
if (pwd->pw_gid == grp->gr_gid) return TRUE;
for (i = 0; (grp->gr_mem != NULL) && (grp->gr_mem[i] != NULL); i++) {
if (strcmp(pwd->pw_name, grp->gr_mem[i]) == 0) {
return TRUE;
}
}
return FALSE;
}
static int parse_config_file(const char *conf_file, struct passwd *pwd, struct pam_limit_s *pl) {
FILE *fil;
char buf[LINE_LENGTH];
fil = fopen(conf_file, "r");
if (fil == NULL) {
g_printerr("cannot read settings from '%s': %s", conf_file, g_strerror(errno));
return -1;
}
/* init things */
memset(buf, 0, sizeof(buf));
/* start the show */
while (fgets(buf, LINE_LENGTH, fil) != NULL) {
char domain[LINE_LENGTH];
char ltype[LINE_LENGTH];
char item[LINE_LENGTH];
char value[LINE_LENGTH];
int i;
size_t j;
char *tptr;
tptr = buf;
/* skip the leading white space */
while (*tptr && isspace(*tptr))
tptr++;
strncpy(buf, tptr, sizeof(buf)-1);
buf[sizeof(buf)-1] = '\0';
/* Rip off the comments */
tptr = strchr(buf,'#');
if (tptr)
*tptr = '\0';
/* Rip off the newline char */
tptr = strchr(buf,'\n');
if (tptr)
*tptr = '\0';
/* Anything left ? */
if (!strlen(buf)) {
memset(buf, 0, sizeof(buf));
continue;
}
memset(domain, 0, sizeof(domain));
memset(ltype, 0, sizeof(ltype));
memset(item, 0, sizeof(item));
memset(value, 0, sizeof(value));
i = sscanf(buf,"%s%s%s%s", domain, ltype, item, value);
/*
D(("scanned line[%d]: domain[%s], ltype[%s], item[%s], value[%s]",
i, domain, ltype, item, value));
*/
for(j=0; j < strlen(ltype); j++)
ltype[j]=tolower(ltype[j]);
for(j=0; j < strlen(item); j++)
item[j]=tolower(item[j]);
for(j=0; j < strlen(value); j++)
value[j]=tolower(value[j]);
if (i == 4) { /* a complete line */
if (strcmp(pwd->pw_name, domain) == 0) /* this user have a limit */
process_limit(LIMITS_DEF_USER, ltype, item, value, pl);
else if (domain[0]=='@') {
if (pam_modutil_user_in_group_nam_nam(pwd, domain+1))
process_limit(LIMITS_DEF_GROUP, ltype, item, value, pl);
} else if (domain[0]=='%') {
if (strcmp(domain,"%") == 0)
process_limit(LIMITS_DEF_ALL, ltype, item, value, pl);
else if (pam_modutil_user_in_group_nam_nam(pwd, domain+1)) {
process_limit(LIMITS_DEF_ALLGROUP, ltype, item, value, pl);
}
} else if (strcmp(domain, "*") == 0) {
process_limit(LIMITS_DEF_DEFAULT, ltype, item, value, pl);
}
} else if (i == 2 && ltype[0] == '-') { /* Probably a no-limit line */
if (strcmp(pwd->pw_name, domain) == 0) {
fclose(fil);
return LIMHANDLE_IGNORE;
} else if (domain[0] == '@' && pam_modutil_user_in_group_nam_nam(pwd, domain+1)) {
fclose(fil);
return LIMHANDLE_IGNORE;
}
} else {
g_printerr("invalid line '%s' - skipped\n", buf);
}
}
fclose(fil);
return LIMHANDLE_OK;
}
static int setup_limits(struct pam_limit_s *pl) {
int i;
int status;
int retval = LIMHANDLE_OK;
for (i=0, status=LIMITED_OK; i<RLIM_NLIMITS; i++) {
if (!pl->limits[i].supported) {
/* skip it if its not known to the system */
continue;
}
if (pl->limits[i].src_soft == LIMITS_DEF_NONE &&
pl->limits[i].src_hard == LIMITS_DEF_NONE) {
/* skip it if its not initialized */
continue;
}
if (pl->limits[i].limit.rlim_cur > pl->limits[i].limit.rlim_max)
pl->limits[i].limit.rlim_cur = pl->limits[i].limit.rlim_max;
status |= setrlimit(i, &pl->limits[i].limit);
}
if (status) {
retval = LIMHANDLE_ERROR;
}
status = setpriority(PRIO_PROCESS, 0, pl->priority);
if (status != 0) {
retval = LIMHANDLE_ERROR;
}
return retval;
}
/* now the session stuff */
int pam_set_limits(const char *conf_file, const char *username);
int pam_set_limits(const char *conf_file, const char *username) {
int retval;
struct pam_limit_s pl;
struct passwd *pwd;
pwd = getpwnam(username);
if (NULL == pwd) return LIMHANDLE_ERROR;
if (!conf_file) conf_file = LIMITS_FILE;
memset(&pl, 0, sizeof(pl));
retval = init_limits(&pl);
if (retval != LIMHANDLE_OK) {
g_printerr("cannot initialize\n");
return retval;
}
retval = parse_config_file(conf_file, pwd, &pl);
if (retval == LIMHANDLE_IGNORE) {
return LIMHANDLE_OK;
}
if (retval != LIMHANDLE_OK) {
g_printerr("error parsing the configuration file\n");
return retval;
}
retval = setup_limits(&pl);
if (retval != LIMHANDLE_OK) {
return retval;
}
return LIMHANDLE_OK;
}
/*
* Copyright (c) Cristian Gafton, 1996-1997, <gafton@redhat.com>
* 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, and the entire permission notice in its entirety,
* including the disclaimer of warranties.
* 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 author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* ALTERNATIVELY, this product may be distributed under the terms of
* the GNU Public License, in which case the provisions of the GPL are
* required INSTEAD OF the above restrictions. (This clause is
* necessary due to a potential bad interaction between the GPL and
* the restrictions contained in a BSD-style copyright.)
*
* THIS SOFTWARE IS PROVIDED ``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 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.
*/