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 }
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 }
79 };
80 
81 static struct limit *
find_limit(const char * name)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
read_limits_conf(const char * file,const struct passwd * pwd)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 }
215