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-rw-r--r--lib/libutil/login_class.c561
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diff --git a/lib/libutil/login_class.c b/lib/libutil/login_class.c
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+/*-
+ * Copyright (c) 1996 by
+ * Sean Eric Fagan <sef@kithrup.com>
+ * David Nugent <davidn@blaze.net.au>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, is permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice immediately at the beginning of the file, without modification,
+ * 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. This work was done expressly for inclusion into FreeBSD. Other use
+ * is permitted provided this notation is included.
+ * 4. Absolutely no warranty of function or purpose is made by the authors.
+ * 5. Modifications may be freely made to this file providing the above
+ * conditions are met.
+ *
+ * High-level routines relating to use of the user capabilities database
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/cpuset.h>
+#include <sys/mac.h>
+#include <sys/resource.h>
+#include <sys/rtprio.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+
+#include <ctype.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <login_cap.h>
+#include <paths.h>
+#include <pwd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <unistd.h>
+
+
+static struct login_res {
+ const char *what;
+ rlim_t (*who)(login_cap_t *, const char *, rlim_t, rlim_t);
+ int why;
+} resources[] = {
+ { "cputime", login_getcaptime, RLIMIT_CPU },
+ { "filesize", login_getcapsize, RLIMIT_FSIZE },
+ { "datasize", login_getcapsize, RLIMIT_DATA },
+ { "stacksize", login_getcapsize, RLIMIT_STACK },
+ { "memoryuse", login_getcapsize, RLIMIT_RSS },
+ { "memorylocked", login_getcapsize, RLIMIT_MEMLOCK },
+ { "maxproc", login_getcapnum, RLIMIT_NPROC },
+ { "openfiles", login_getcapnum, RLIMIT_NOFILE },
+ { "coredumpsize", login_getcapsize, RLIMIT_CORE },
+ { "sbsize", login_getcapsize, RLIMIT_SBSIZE },
+ { "vmemoryuse", login_getcapsize, RLIMIT_VMEM },
+ { "pseudoterminals", login_getcapnum, RLIMIT_NPTS },
+ { "swapuse", login_getcapsize, RLIMIT_SWAP },
+ { NULL, 0, 0 }
+};
+
+
+void
+setclassresources(login_cap_t *lc)
+{
+ struct login_res *lr;
+
+ if (lc == NULL)
+ return;
+
+ for (lr = resources; lr->what != NULL; ++lr) {
+ struct rlimit rlim;
+
+ /*
+ * The login.conf file can have <limit>, <limit>-max, and
+ * <limit>-cur entries.
+ * What we do is get the current current- and maximum- limits.
+ * Then, we try to get an entry for <limit> from the capability,
+ * using the current and max limits we just got as the
+ * default/error values.
+ * *Then*, we try looking for <limit>-cur and <limit>-max,
+ * again using the appropriate values as the default/error
+ * conditions.
+ */
+
+ if (getrlimit(lr->why, &rlim) != 0)
+ syslog(LOG_ERR, "getting %s resource limit: %m", lr->what);
+ else {
+ char name_cur[40];
+ char name_max[40];
+ rlim_t rcur = rlim.rlim_cur;
+ rlim_t rmax = rlim.rlim_max;
+
+ sprintf(name_cur, "%s-cur", lr->what);
+ sprintf(name_max, "%s-max", lr->what);
+
+ rcur = (*lr->who)(lc, lr->what, rcur, rcur);
+ rmax = (*lr->who)(lc, lr->what, rmax, rmax);
+ rlim.rlim_cur = (*lr->who)(lc, name_cur, rcur, rcur);
+ rlim.rlim_max = (*lr->who)(lc, name_max, rmax, rmax);
+
+ if (setrlimit(lr->why, &rlim) == -1)
+ syslog(LOG_WARNING, "set class '%s' resource limit %s: %m", lc->lc_class, lr->what);
+ }
+ }
+}
+
+
+
+static struct login_vars {
+ const char *tag;
+ const char *var;
+ const char *def;
+ int overwrite;
+} pathvars[] = {
+ { "path", "PATH", NULL, 1},
+ { "cdpath", "CDPATH", NULL, 1},
+ { "manpath", "MANPATH", NULL, 1},
+ { NULL, NULL, NULL, 0}
+}, envars[] = {
+ { "lang", "LANG", NULL, 1},
+ { "charset", "MM_CHARSET", NULL, 1},
+ { "timezone", "TZ", NULL, 1},
+ { "term", "TERM", NULL, 0},
+ { NULL, NULL, NULL, 0}
+};
+
+static char *
+substvar(const char * var, const struct passwd * pwd, int hlen, int pch, int nlen)
+{
+ char *np = NULL;
+
+ if (var != NULL) {
+ int tildes = 0;
+ int dollas = 0;
+ char *p;
+ const char *q;
+
+ if (pwd != NULL) {
+ for (q = var; *q != '\0'; ++q) {
+ tildes += (*q == '~');
+ dollas += (*q == '$');
+ }
+ }
+
+ np = malloc(strlen(var) + (dollas * nlen)
+ - dollas + (tildes * (pch+hlen))
+ - tildes + 1);
+
+ if (np != NULL) {
+ p = strcpy(np, var);
+
+ if (pwd != NULL) {
+ /*
+ * This loop does user username and homedir substitutions
+ * for unescaped $ (username) and ~ (homedir)
+ */
+ while (*(p += strcspn(p, "~$")) != '\0') {
+ int l = strlen(p);
+
+ if (p > np && *(p-1) == '\\') /* Escaped: */
+ memmove(p - 1, p, l + 1); /* Slide-out the backslash */
+ else if (*p == '~') {
+ int v = pch && *(p+1) != '/'; /* Avoid double // */
+ memmove(p + hlen + v, p + 1, l); /* Subst homedir */
+ memmove(p, pwd->pw_dir, hlen);
+ if (v)
+ p[hlen] = '/';
+ p += hlen + v;
+ }
+ else /* if (*p == '$') */ {
+ memmove(p + nlen, p + 1, l); /* Subst username */
+ memmove(p, pwd->pw_name, nlen);
+ p += nlen;
+ }
+ }
+ }
+ }
+ }
+
+ return (np);
+}
+
+
+void
+setclassenvironment(login_cap_t *lc, const struct passwd * pwd, int paths)
+{
+ struct login_vars *vars = paths ? pathvars : envars;
+ int hlen = pwd ? strlen(pwd->pw_dir) : 0;
+ int nlen = pwd ? strlen(pwd->pw_name) : 0;
+ char pch = 0;
+
+ if (hlen && pwd->pw_dir[hlen-1] != '/')
+ ++pch;
+
+ while (vars->tag != NULL) {
+ const char * var = paths ? login_getpath(lc, vars->tag, NULL)
+ : login_getcapstr(lc, vars->tag, NULL, NULL);
+
+ char * np = substvar(var, pwd, hlen, pch, nlen);
+
+ if (np != NULL) {
+ setenv(vars->var, np, vars->overwrite);
+ free(np);
+ } else if (vars->def != NULL) {
+ setenv(vars->var, vars->def, 0);
+ }
+ ++vars;
+ }
+
+ /*
+ * If we're not processing paths, then see if there is a setenv list by
+ * which the admin and/or user may set an arbitrary set of env vars.
+ */
+ if (!paths) {
+ const char **set_env = login_getcaplist(lc, "setenv", ",");
+
+ if (set_env != NULL) {
+ while (*set_env != NULL) {
+ char *p = strchr(*set_env, '=');
+
+ if (p != NULL) { /* Discard invalid entries */
+ char *np;
+
+ *p++ = '\0';
+ if ((np = substvar(p, pwd, hlen, pch, nlen)) != NULL) {
+ setenv(*set_env, np, 1);
+ free(np);
+ }
+ }
+ ++set_env;
+ }
+ }
+ }
+}
+
+
+static int
+list2cpuset(const char *list, cpuset_t *mask)
+{
+ enum { NONE, NUM, DASH } state;
+ int lastnum;
+ int curnum;
+ const char *l;
+
+ state = NONE;
+ curnum = lastnum = 0;
+ for (l = list; *l != '\0';) {
+ if (isdigit(*l)) {
+ curnum = atoi(l);
+ if (curnum > CPU_SETSIZE)
+ errx(EXIT_FAILURE,
+ "Only %d cpus supported", CPU_SETSIZE);
+ while (isdigit(*l))
+ l++;
+ switch (state) {
+ case NONE:
+ lastnum = curnum;
+ state = NUM;
+ break;
+ case DASH:
+ for (; lastnum <= curnum; lastnum++)
+ CPU_SET(lastnum, mask);
+ state = NONE;
+ break;
+ case NUM:
+ default:
+ return (0);
+ }
+ continue;
+ }
+ switch (*l) {
+ case ',':
+ switch (state) {
+ case NONE:
+ break;
+ case NUM:
+ CPU_SET(curnum, mask);
+ state = NONE;
+ break;
+ case DASH:
+ return (0);
+ break;
+ }
+ break;
+ case '-':
+ if (state != NUM)
+ return (0);
+ state = DASH;
+ break;
+ default:
+ return (0);
+ }
+ l++;
+ }
+ switch (state) {
+ case NONE:
+ break;
+ case NUM:
+ CPU_SET(curnum, mask);
+ break;
+ case DASH:
+ return (0);
+ }
+ return (1);
+}
+
+
+void
+setclasscpumask(login_cap_t *lc)
+{
+ const char *maskstr;
+ cpuset_t maskset;
+ cpusetid_t setid;
+
+ maskstr = login_getcapstr(lc, "cpumask", NULL, NULL);
+ CPU_ZERO(&maskset);
+ if (maskstr == NULL)
+ return;
+ if (strcasecmp("default", maskstr) == 0)
+ return;
+ if (!list2cpuset(maskstr, &maskset)) {
+ syslog(LOG_WARNING,
+ "list2cpuset(%s) invalid mask specification", maskstr);
+ return;
+ }
+
+ if (cpuset(&setid) != 0) {
+ syslog(LOG_ERR, "cpuset(): %s", strerror(errno));
+ return;
+ }
+
+ if (cpuset_setaffinity(CPU_LEVEL_CPUSET, CPU_WHICH_PID, -1,
+ sizeof(maskset), &maskset) != 0)
+ syslog(LOG_ERR, "cpuset_setaffinity(%s): %s", maskstr,
+ strerror(errno));
+}
+
+
+/*
+ * setclasscontext()
+ *
+ * For the login class <class>, set various class context values
+ * (limits, mainly) to the values for that class. Which values are
+ * set are controlled by <flags> -- see <login_class.h> for the
+ * possible values.
+ *
+ * setclasscontext() can only set resources, priority, and umask.
+ */
+
+int
+setclasscontext(const char *classname, unsigned int flags)
+{
+ int rc;
+ login_cap_t *lc;
+
+ lc = login_getclassbyname(classname, NULL);
+
+ flags &= LOGIN_SETRESOURCES | LOGIN_SETPRIORITY |
+ LOGIN_SETUMASK | LOGIN_SETPATH;
+
+ rc = lc ? setusercontext(lc, NULL, 0, flags) : -1;
+ login_close(lc);
+ return (rc);
+}
+
+
+
+/*
+ * Private function which takes care of processing
+ */
+
+static mode_t
+setlogincontext(login_cap_t *lc, const struct passwd *pwd,
+ mode_t mymask, unsigned long flags)
+{
+ if (lc) {
+ /* Set resources */
+ if (flags & LOGIN_SETRESOURCES)
+ setclassresources(lc);
+ /* See if there's a umask override */
+ if (flags & LOGIN_SETUMASK)
+ mymask = (mode_t)login_getcapnum(lc, "umask", mymask, mymask);
+ /* Set paths */
+ if (flags & LOGIN_SETPATH)
+ setclassenvironment(lc, pwd, 1);
+ /* Set environment */
+ if (flags & LOGIN_SETENV)
+ setclassenvironment(lc, pwd, 0);
+ /* Set cpu affinity */
+ if (flags & LOGIN_SETCPUMASK)
+ setclasscpumask(lc);
+ }
+ return (mymask);
+}
+
+
+
+/*
+ * setusercontext()
+ *
+ * Given a login class <lc> and a user in <pwd>, with a uid <uid>,
+ * set the context as in setclasscontext(). <flags> controls which
+ * values are set.
+ *
+ * The difference between setclasscontext() and setusercontext() is
+ * that the former sets things up for an already-existing process,
+ * while the latter sets things up from a root context. Such as might
+ * be called from login(1).
+ *
+ */
+
+int
+setusercontext(login_cap_t *lc, const struct passwd *pwd, uid_t uid, unsigned int flags)
+{
+ quad_t p;
+ mode_t mymask;
+ login_cap_t *llc = NULL;
+ struct sigaction sa, prevsa;
+ struct rtprio rtp;
+ int error;
+
+ if (lc == NULL) {
+ if (pwd != NULL && (lc = login_getpwclass(pwd)) != NULL)
+ llc = lc; /* free this when we're done */
+ }
+
+ if (flags & LOGIN_SETPATH)
+ pathvars[0].def = uid ? _PATH_DEFPATH : _PATH_STDPATH;
+
+ /* we need a passwd entry to set these */
+ if (pwd == NULL)
+ flags &= ~(LOGIN_SETGROUP | LOGIN_SETLOGIN | LOGIN_SETMAC);
+
+ /* Set the process priority */
+ if (flags & LOGIN_SETPRIORITY) {
+ p = login_getcapnum(lc, "priority", LOGIN_DEFPRI, LOGIN_DEFPRI);
+
+ if (p > PRIO_MAX) {
+ rtp.type = RTP_PRIO_IDLE;
+ rtp.prio = p - PRIO_MAX - 1;
+ p = (rtp.prio > RTP_PRIO_MAX) ? 31 : p;
+ if (rtprio(RTP_SET, 0, &rtp))
+ syslog(LOG_WARNING, "rtprio '%s' (%s): %m",
+ pwd->pw_name, lc ? lc->lc_class : LOGIN_DEFCLASS);
+ } else if (p < PRIO_MIN) {
+ rtp.type = RTP_PRIO_REALTIME;
+ rtp.prio = abs(p - PRIO_MIN + RTP_PRIO_MAX);
+ p = (rtp.prio > RTP_PRIO_MAX) ? 1 : p;
+ if (rtprio(RTP_SET, 0, &rtp))
+ syslog(LOG_WARNING, "rtprio '%s' (%s): %m",
+ pwd->pw_name, lc ? lc->lc_class : LOGIN_DEFCLASS);
+ } else {
+ if (setpriority(PRIO_PROCESS, 0, (int)p) != 0)
+ syslog(LOG_WARNING, "setpriority '%s' (%s): %m",
+ pwd->pw_name, lc ? lc->lc_class : LOGIN_DEFCLASS);
+ }
+ }
+
+ /* Setup the user's group permissions */
+ if (flags & LOGIN_SETGROUP) {
+ if (setgid(pwd->pw_gid) != 0) {
+ syslog(LOG_ERR, "setgid(%lu): %m", (u_long)pwd->pw_gid);
+ login_close(llc);
+ return (-1);
+ }
+ if (initgroups(pwd->pw_name, pwd->pw_gid) == -1) {
+ syslog(LOG_ERR, "initgroups(%s,%lu): %m", pwd->pw_name,
+ (u_long)pwd->pw_gid);
+ login_close(llc);
+ return (-1);
+ }
+ }
+
+ /* Set up the user's MAC label. */
+ if ((flags & LOGIN_SETMAC) && mac_is_present(NULL) == 1) {
+ const char *label_string;
+ mac_t label;
+
+ label_string = login_getcapstr(lc, "label", NULL, NULL);
+ if (label_string != NULL) {
+ if (mac_from_text(&label, label_string) == -1) {
+ syslog(LOG_ERR, "mac_from_text('%s') for %s: %m",
+ pwd->pw_name, label_string);
+ return (-1);
+ }
+ if (mac_set_proc(label) == -1)
+ error = errno;
+ else
+ error = 0;
+ mac_free(label);
+ if (error != 0) {
+ syslog(LOG_ERR, "mac_set_proc('%s') for %s: %s",
+ label_string, pwd->pw_name, strerror(error));
+ return (-1);
+ }
+ }
+ }
+
+ /* Set the sessions login */
+ if ((flags & LOGIN_SETLOGIN) && setlogin(pwd->pw_name) != 0) {
+ syslog(LOG_ERR, "setlogin(%s): %m", pwd->pw_name);
+ login_close(llc);
+ return (-1);
+ }
+
+ /* Inform the kernel about current login class */
+ if (lc != NULL && lc->lc_class != NULL && (flags & LOGIN_SETLOGINCLASS)) {
+ /*
+ * XXX: This is a workaround to fail gracefully in case the kernel
+ * does not support setloginclass(2).
+ */
+ bzero(&sa, sizeof(sa));
+ sa.sa_handler = SIG_IGN;
+ sigfillset(&sa.sa_mask);
+ sigaction(SIGSYS, &sa, &prevsa);
+ error = setloginclass(lc->lc_class);
+ sigaction(SIGSYS, &prevsa, NULL);
+ if (error != 0) {
+ syslog(LOG_ERR, "setloginclass(%s): %m", lc->lc_class);
+#ifdef notyet
+ login_close(llc);
+ return (-1);
+#endif
+ }
+ }
+
+ mymask = (flags & LOGIN_SETUMASK) ? umask(LOGIN_DEFUMASK) : 0;
+ mymask = setlogincontext(lc, pwd, mymask, flags);
+ login_close(llc);
+
+ /* This needs to be done after anything that needs root privs */
+ if ((flags & LOGIN_SETUSER) && setuid(uid) != 0) {
+ syslog(LOG_ERR, "setuid(%lu): %m", (u_long)uid);
+ return (-1); /* Paranoia again */
+ }
+
+ /*
+ * Now, we repeat some of the above for the user's private entries
+ */
+ if (getuid() == uid && (lc = login_getuserclass(pwd)) != NULL) {
+ mymask = setlogincontext(lc, pwd, mymask, flags);
+ login_close(lc);
+ }
+
+ /* Finally, set any umask we've found */
+ if (flags & LOGIN_SETUMASK)
+ umask(mymask);
+
+ return (0);
+}
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