2 * Copyright (c) 1996 by
3 * Sean Eric Fagan <sef@kithrup.com>
4 * David Nugent <davidn@blaze.net.au>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, is permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice immediately at the beginning of the file, without modification,
12 * this list of conditions, and the following disclaimer.
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 * 3. This work was done expressly for inclusion into FreeBSD. Other use
17 * is permitted provided this notation is included.
18 * 4. Absolutely no warranty of function or purpose is made by the authors.
19 * 5. Modifications may be freely made to this file providing the above
22 * High-level routines relating to use of the user capabilities database
24 * $FreeBSD: head/lib/libutil/login_class.c 256850 2013-10-21 16:46:12Z kib $
27 #include <sys/types.h>
28 #include <sys/resource.h>
29 #include <sys/rtprio.h>
37 #include <login_cap.h>
48 static struct login_res {
50 rlim_t (*who)(login_cap_t *, const char *, rlim_t, rlim_t);
53 { "cputime", login_getcaptime, RLIMIT_CPU },
54 { "filesize", login_getcapsize, RLIMIT_FSIZE },
55 { "datasize", login_getcapsize, RLIMIT_DATA },
56 { "stacksize", login_getcapsize, RLIMIT_STACK },
57 { "memoryuse", login_getcapsize, RLIMIT_RSS },
58 { "memorylocked", login_getcapsize, RLIMIT_MEMLOCK },
59 { "maxproc", login_getcapnum, RLIMIT_NPROC },
60 { "openfiles", login_getcapnum, RLIMIT_NOFILE },
61 { "coredumpsize", login_getcapsize, RLIMIT_CORE },
62 { "sbsize", login_getcapsize, RLIMIT_SBSIZE },
63 { "vmemoryuse", login_getcapsize, RLIMIT_VMEM },
64 #ifdef RLIMIT_POSIXLOCKS
65 { "posixlocks", login_getcapnum, RLIMIT_POSIXLOCKS },
72 setclassresources(login_cap_t *lc)
79 for (lr = resources; lr->what != NULL; ++lr) {
83 * The login.conf file can have <limit>, <limit>-max, and
84 * <limit>-cur entries.
85 * What we do is get the current current- and maximum- limits.
86 * Then, we try to get an entry for <limit> from the capability,
87 * using the current and max limits we just got as the
88 * default/error values.
89 * *Then*, we try looking for <limit>-cur and <limit>-max,
90 * again using the appropriate values as the default/error
94 if (getrlimit(lr->why, &rlim) != 0)
95 syslog(LOG_ERR, "getting %s resource limit: %m", lr->what);
99 rlim_t rcur = rlim.rlim_cur;
100 rlim_t rmax = rlim.rlim_max;
102 sprintf(name_cur, "%s-cur", lr->what);
103 sprintf(name_max, "%s-max", lr->what);
105 rcur = (*lr->who)(lc, lr->what, rcur, rcur);
106 rmax = (*lr->who)(lc, lr->what, rmax, rmax);
107 rlim.rlim_cur = (*lr->who)(lc, name_cur, rcur, rcur);
108 rlim.rlim_max = (*lr->who)(lc, name_max, rmax, rmax);
110 if (setrlimit(lr->why, &rlim) == -1)
111 syslog(LOG_WARNING, "set class '%s' resource limit %s: %m", lc->lc_class, lr->what);
118 static struct login_vars {
124 { "path", "PATH", NULL, 1},
125 { "cdpath", "CDPATH", NULL, 1},
126 { "manpath", "MANPATH", NULL, 1},
127 { NULL, NULL, NULL, 0}
129 { "lang", "LANG", NULL, 1},
130 { "charset", "MM_CHARSET", NULL, 1},
131 { "timezone", "TZ", NULL, 1},
132 { "term", "TERM", NULL, 0},
133 { NULL, NULL, NULL, 0}
137 substvar(const char * var, const struct passwd * pwd, int hlen, int pch, int nlen)
148 for (q = var; *q != '\0'; ++q) {
149 tildes += (*q == '~');
150 dollas += (*q == '$');
154 np = malloc(strlen(var) + (dollas * nlen)
155 - dollas + (tildes * (pch+hlen))
163 * This loop does user username and homedir substitutions
164 * for unescaped $ (username) and ~ (homedir)
166 while (*(p += strcspn(p, "~$")) != '\0') {
169 if (p > np && *(p-1) == '\\') /* Escaped: */
170 memmove(p - 1, p, l + 1); /* Slide-out the backslash */
171 else if (*p == '~') {
172 int v = pch && *(p+1) != '/'; /* Avoid double // */
173 memmove(p + hlen + v, p + 1, l); /* Subst homedir */
174 memmove(p, pwd->pw_dir, hlen);
179 else /* if (*p == '$') */ {
180 memmove(p + nlen, p + 1, l); /* Subst username */
181 memmove(p, pwd->pw_name, nlen);
194 setclassenvironment(login_cap_t *lc, const struct passwd * pwd, int paths)
196 struct login_vars *vars = paths ? pathvars : envars;
197 int hlen = pwd ? strlen(pwd->pw_dir) : 0;
198 int nlen = pwd ? strlen(pwd->pw_name) : 0;
201 if (hlen && pwd->pw_dir[hlen-1] != '/')
204 while (vars->tag != NULL) {
205 const char * var = paths ? login_getpath(lc, vars->tag, NULL)
206 : login_getcapstr(lc, vars->tag, NULL, NULL);
208 char * np = substvar(var, pwd, hlen, pch, nlen);
211 setenv(vars->var, np, vars->overwrite);
213 } else if (vars->def != NULL) {
214 setenv(vars->var, vars->def, 0);
220 * If we're not processing paths, then see if there is a setenv list by
221 * which the admin and/or user may set an arbitrary set of env vars.
224 const char **set_env = login_getcaplist(lc, "setenv", ",");
226 if (set_env != NULL) {
227 while (*set_env != NULL) {
228 char *p = strchr(*set_env, '=');
230 if (p != NULL) { /* Discard invalid entries */
234 if ((np = substvar(p, pwd, hlen, pch, nlen)) != NULL) {
235 setenv(*set_env, np, 1);
250 * For the login class <class>, set various class context values
251 * (limits, mainly) to the values for that class. Which values are
252 * set are controlled by <flags> -- see <login_class.h> for the
255 * setclasscontext() can only set resources, priority, and umask.
259 setclasscontext(const char *classname, unsigned int flags)
264 lc = login_getclassbyname(classname, NULL);
266 flags &= LOGIN_SETRESOURCES | LOGIN_SETPRIORITY |
267 LOGIN_SETUMASK | LOGIN_SETPATH;
269 rc = lc ? setusercontext(lc, NULL, 0, flags) : -1;
277 * Private function which takes care of processing
281 setlogincontext(login_cap_t *lc, const struct passwd *pwd,
282 mode_t mymask, unsigned long flags)
286 if (flags & LOGIN_SETRESOURCES)
287 setclassresources(lc);
288 /* See if there's a umask override */
289 if (flags & LOGIN_SETUMASK)
290 mymask = (mode_t)login_getcapnum(lc, "umask", mymask, mymask);
292 if (flags & LOGIN_SETPATH)
293 setclassenvironment(lc, pwd, 1);
294 /* Set environment */
295 if (flags & LOGIN_SETENV)
296 setclassenvironment(lc, pwd, 0);
306 * Given a login class <lc> and a user in <pwd>, with a uid <uid>,
307 * set the context as in setclasscontext(). <flags> controls which
310 * The difference between setclasscontext() and setusercontext() is
311 * that the former sets things up for an already-existing process,
312 * while the latter sets things up from a root context. Such as might
313 * be called from login(1).
318 setusercontext(login_cap_t *lc, const struct passwd *pwd, uid_t uid, unsigned int flags)
322 login_cap_t *llc = NULL;
326 if (pwd != NULL && (lc = login_getpwclass(pwd)) != NULL)
327 llc = lc; /* free this when we're done */
330 if (flags & LOGIN_SETPATH)
331 pathvars[0].def = uid ? _PATH_DEFPATH : _PATH_STDPATH;
333 /* we need a passwd entry to set these */
335 flags &= ~(LOGIN_SETGROUP | LOGIN_SETLOGIN);
337 /* Set the process priority */
338 if (flags & LOGIN_SETPRIORITY) {
339 p = login_getcapnum(lc, "priority", LOGIN_DEFPRI, LOGIN_DEFPRI);
342 rtp.type = RTP_PRIO_IDLE;
343 rtp.prio = p - PRIO_MAX - 1;
344 p = (rtp.prio > RTP_PRIO_MAX) ? 31 : p;
345 if (rtprio(RTP_SET, 0, &rtp))
346 syslog(LOG_WARNING, "rtprio '%s' (%s): %m",
347 pwd ? pwd->pw_name : "-",
348 lc ? lc->lc_class : LOGIN_DEFCLASS);
349 } else if (p < PRIO_MIN) {
350 rtp.type = RTP_PRIO_REALTIME;
351 rtp.prio = abs(p - PRIO_MIN + RTP_PRIO_MAX);
352 p = (rtp.prio > RTP_PRIO_MAX) ? 1 : p;
353 if (rtprio(RTP_SET, 0, &rtp))
354 syslog(LOG_WARNING, "rtprio '%s' (%s): %m",
355 pwd ? pwd->pw_name : "-",
356 lc ? lc->lc_class : LOGIN_DEFCLASS);
358 if (setpriority(PRIO_PROCESS, 0, (int)p) != 0)
359 syslog(LOG_WARNING, "setpriority '%s' (%s): %m",
360 pwd ? pwd->pw_name : "-",
361 lc ? lc->lc_class : LOGIN_DEFCLASS);
365 /* Setup the user's group permissions */
366 if (flags & LOGIN_SETGROUP) {
367 if (setgid(pwd->pw_gid) != 0) {
368 syslog(LOG_ERR, "setgid(%lu): %m", (u_long)pwd->pw_gid);
372 if (initgroups(pwd->pw_name, pwd->pw_gid) == -1) {
373 syslog(LOG_ERR, "initgroups(%s,%lu): %m", pwd->pw_name,
374 (u_long)pwd->pw_gid);
380 /* Set the sessions login */
381 if ((flags & LOGIN_SETLOGIN) && setlogin(pwd->pw_name) != 0) {
382 syslog(LOG_ERR, "setlogin(%s): %m", pwd->pw_name);
387 mymask = (flags & LOGIN_SETUMASK) ? umask(LOGIN_DEFUMASK) : 0;
388 mymask = setlogincontext(lc, pwd, mymask, flags);
391 /* This needs to be done after anything that needs root privs */
392 if ((flags & LOGIN_SETUSER) && setuid(uid) != 0) {
393 syslog(LOG_ERR, "setuid(%lu): %m", (u_long)uid);
394 return (-1); /* Paranoia again */
398 * Now, we repeat some of the above for the user's private entries
400 if (getuid() == uid && (lc = login_getuserclass(pwd)) != NULL) {
401 mymask = setlogincontext(lc, pwd, mymask, flags);
405 /* Finally, set any umask we've found */
406 if (flags & LOGIN_SETUMASK)