appl/login/limits_conf.c

   1 /*
   2  * Copyright (c) 2005 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "login_locl.h"
  35
  36 RCSID("$Id$");
  37
  38 #include <errno.h>
  39 #include <limits.h>
  40 #ifdef HAVE_SYS_RESOURCE_H
  41 #include <sys/resource.h>
  42 #endif
  43
  44 struct limit {
  45     const char *name;
  46     int resource;
  47     int scale;
  48     int has_limit;
  49     struct rlimit limit;
  50 } limits[] = {
  51 #define LIM(X, S) { #X, RLIMIT_##X, S, 0, {0, 0} }
  52     LIM(CORE, 1024),
  53     LIM(CPU, 60),
  54     LIM(DATA, 1024),
  55     LIM(FSIZE, 1024),
  56 #ifdef RLIMIT_MEMLOCK
  57     LIM(MEMLOCK, 1024),
  58 #endif
  59     LIM(NOFILE, 1),
  60 #ifdef RLIMIT_NPROC
  61     LIM(NPROC, 1),
  62 #endif
  63 #ifdef RLIMIT_RSS
  64     LIM(RSS, 1024),
  65 #endif
  66     LIM(STACK, 1024),
  67
  68 #ifdef RLIMIT_AS
  69     LIM(AS, 1024),
  70 #endif
  71 #ifdef RLIMIT_LOCKS
  72     LIM(LOCKS, 1),
  73 #endif
  74     /*
  75       maxlogins
  76       priority
  77     */
  78     { NULL, 0, 0, 0, {0, 0}  }
  79 };
  80
  81 static struct limit *
  82 find_limit(const char *name)
  83 {
  84     struct limit *l;
  85     for(l = limits; l->name != NULL; l++)
  86         if(strcasecmp(name, l->name) == 0)
  87             return l;
  88     return NULL;
  89 }
  90
  91 /* this function reads limits.conf files similar to pam_limits
  92    unimplemented features include:
  93         % maxlogins
  94         "-" no limits,
  95         priorities etc that are not set via setrlimit
  96    XXX uses static storage, and clobbers getgr*
  97 */
  98
  99 int
 100 read_limits_conf(const char *file, const struct passwd *pwd)
 101 {
 102     FILE *f;
 103     char *args[4];
 104     int lineno = 0;
 105     char buf[1024];
 106     struct limit *l;
 107     rlim_t value;
 108
 109     f = fopen(file, "r");
 110     if(f == NULL) {
 111         if(errno != ENOENT && errno != ENOTDIR)
 112             syslog(LOG_ERR, "%s: %m", file);
 113         return -1;
 114     }
 115
 116     while(fgets(buf, sizeof(buf), f) != NULL) {
 117         char *last = NULL;
 118         char *end = NULL;
 119         int level;
 120
 121         lineno++;
 122
 123         if(buf[0] == '\0') {
 124             syslog(LOG_ERR, "%s: line %d: NUL character", file, lineno);
 125             continue;
 126         }
 127         if(buf[strlen(buf) - 1] != '\n') {
 128             /* file did not end with a newline, figure out if we're at
 129                the EOF, or if our buffer was too small */
 130             int eof = 1;
 131             int c;
 132             while((c = fgetc(f)) != EOF) {
 133                 eof = 0;
 134                 if(c == '\n')
 135                     break;
 136             }
 137             if(!eof) {
 138                 syslog(LOG_ERR, "%s: line %d: line too long", file, lineno);
 139                 continue;
 140             }
 141         }
 142         buf[strcspn(buf, "#\r\n")] = '\0';
 143         if((args[0] = strtok_r(buf, " \t", &last)) == NULL ||
 144            (args[1] = strtok_r(NULL, " \t", &last)) == NULL ||
 145            (args[2] = strtok_r(NULL, " \t", &last)) == NULL ||
 146            (args[3] = strtok_r(NULL, " \t", &last)) == NULL) {
 147             if(args[0] != NULL) /* this would include comment lines */
 148                 syslog(LOG_ERR, "%s: line %d: malformed line", file, lineno);
 149             continue;
 150         }
 151
 152         l = find_limit(args[2]);
 153         if(l == NULL) {
 154             syslog(LOG_ERR, "%s: line %d: unknown limit %s", file, lineno, args[2]);
 155             continue;
 156         }
 157         if(strcmp(args[3], "-") == 0) {
 158             value = RLIM_INFINITY;
 159         } else {
 160             errno = 0;
 161             value = strtol(args[3], &end, 10);
 162             if(*end != '\0') {
 163                 syslog(LOG_ERR, "%s: line %d: bad value %s", file, lineno, args[3]);
 164                 continue;
 165             }
 166             if((value == LONG_MIN || value == LONG_MAX) && errno == ERANGE) {
 167                 syslog(LOG_ERR, "%s: line %d: bad value %s", file, lineno, args[3]);
 168                 continue;
 169             }
 170             if(value * l->scale < value)
 171                 value = RLIM_INFINITY;
 172             else
 173                 value *= l->scale;
 174         }
 175         level = 0;
 176         /* XXX unclear: if you set group hard and user soft limit,
 177            should the hard limit still apply? this code doesn't. */
 178         if(strcmp(args[0], pwd->pw_name) == 0)
 179             level = 3;
 180         if(*args[0] == '@') {
 181             struct group *gr;
 182             gr = getgrnam(args[0] + 1);
 183             if(gr != NULL && gr->gr_gid == pwd->pw_gid)
 184                 level = 2;
 185         }
 186         if(strcmp(args[0], "*") == 0)
 187             level = 1;
 188         if(level == 0 || level < l->has_limit) /* not for us */
 189             continue;
 190         if(l->has_limit < level) {
 191             if(getrlimit(l->resource, &l->limit) < 0)
 192                 continue;
 193             l->has_limit = level;
 194         }
 195
 196         /* XXX unclear: if you soft to more than default hard, should
 197            we set hard to soft? this code doesn't. */
 198         if(strcasecmp(args[1], "soft") == 0 || strcmp(args[1], "-") == 0)
 199             l->limit.rlim_cur = value;
 200         if(strcasecmp(args[1], "hard") == 0 || strcmp(args[1], "-") == 0)
 201             l->limit.rlim_max = value;
 202     }
 203     fclose(f);
 204     for(l = limits; l->name != NULL; l++) {
 205         if(l->has_limit) {
 206             if(l->limit.rlim_cur > l->limit.rlim_max)
 207                 l->limit.rlim_cur = l->limit.rlim_max;
 208             if(setrlimit(l->resource, &l->limit) != 0)
 209                 syslog(LOG_ERR, "setrlimit RLIM_%s failed: %m", l->name);
 210         }
 211         l->has_limit = 0;
 212     }
 213     return 0;
 214 }