377 lines
9.7 KiB
C
377 lines
9.7 KiB
C
/*-
|
|
* 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
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/time.h>
|
|
#include <sys/resource.h>
|
|
#include <fcntl.h>
|
|
#include <pwd.h>
|
|
#include <syslog.h>
|
|
#include <login_cap.h>
|
|
#include <paths.h>
|
|
|
|
|
|
#undef UNKNOWN
|
|
#define UNKNOWN "su"
|
|
|
|
|
|
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 },
|
|
{ "coredumpsize", login_getcapsize, RLIMIT_CORE },
|
|
{ "memoryuse", login_getcapsize, RLIMIT_RSS },
|
|
{ "memorylocked", login_getcapsize, RLIMIT_MEMLOCK },
|
|
{ "maxproc", login_getcapnum, RLIMIT_NPROC },
|
|
{ "openfiles", login_getcapnum, RLIMIT_NOFILE },
|
|
{ NULL, 0, 0 }
|
|
};
|
|
|
|
|
|
|
|
void
|
|
setclassresources(login_cap_t *lc)
|
|
{
|
|
struct login_res *lr = resources;
|
|
|
|
if (lc == NULL)
|
|
return;
|
|
|
|
while (lr->what != NULL) {
|
|
struct rlimit rlim,
|
|
newlim;
|
|
char cur[40],
|
|
max[40];
|
|
rlim_t rcur,
|
|
rmax;
|
|
|
|
sprintf(cur, "%s-cur", lr->what);
|
|
sprintf(max, "%s-max", lr->what);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
|
|
getrlimit(lr->why, &rlim);
|
|
rcur = rlim.rlim_cur;
|
|
rmax = rlim.rlim_max;
|
|
|
|
rcur = (*lr->who)(lc, lr->what, rcur, rcur);
|
|
rmax = (*lr->who)(lc, lr->what, rmax, rmax);
|
|
newlim.rlim_cur = (*lr->who)(lc, cur, rcur, rcur);
|
|
newlim.rlim_max = (*lr->who)(lc, max, rmax, rmax);
|
|
|
|
if (setrlimit(lr->why, &newlim) == -1)
|
|
syslog(LOG_WARNING, "set class '%s' resource limit %s: %m", lc->lc_class, lr->what);
|
|
|
|
++lr;
|
|
}
|
|
}
|
|
|
|
static struct login_vars {
|
|
const char * tag;
|
|
const char * var;
|
|
const char * def;
|
|
} pathvars[] = {
|
|
{ "path", "PATH", NULL },
|
|
{ "manpath", "MANPATH", NULL },
|
|
{ NULL, NULL, NULL }
|
|
}, envars[] = {
|
|
{ "lang", "LANG", NULL },
|
|
{ "charset", "MM_CHARSET", NULL },
|
|
{ "timezone", "TZ", NULL },
|
|
{ "term", "TERM", UNKNOWN },
|
|
{ NULL, NULL, NULL }
|
|
};
|
|
|
|
static char *
|
|
substvar(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;
|
|
|
|
if (pwd != NULL) {
|
|
/*
|
|
* Count the number of ~'s in var to substitute
|
|
*/
|
|
p = var;
|
|
while ((p = strchr(p, '~')) != NULL) {
|
|
++tildes;
|
|
++p;
|
|
}
|
|
|
|
/*
|
|
* Count the number of $'s in var to substitute
|
|
*/
|
|
p = var;
|
|
while ((p = strchr(p, '$')) != NULL) {
|
|
++dollas;
|
|
++p;
|
|
}
|
|
}
|
|
|
|
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, "~$")) != '\0') {
|
|
int l = strlen(p);
|
|
|
|
if (p > var && *(p-1) == '\\') /* Escaped: */
|
|
memmove(p - 1, p, l + 1); /* Slide-out the backslash */
|
|
else if (*p == '~') {
|
|
int v = pch && *(p+1) != '/'; /* Avoid double // */
|
|
memmove(p + hlen + v, p + 1, l); /* Subst homedir */
|
|
memmove(p, pwd->pw_dir, hlen);
|
|
if (v)
|
|
p[hlen] = '/';
|
|
p += hlen + v;
|
|
}
|
|
else /* if (*p == '$') */ {
|
|
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) {
|
|
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, 1);
|
|
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) {
|
|
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;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* 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 = login_getclassbyname(classname, NULL);
|
|
flags &= (LOGIN_SETRESOURCES| LOGIN_SETPRIORITY|LOGIN_SETUMASK);
|
|
rc = setusercontext(lc, NULL, 0, flags);
|
|
login_close(lc);
|
|
return rc;
|
|
}
|
|
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
int i;
|
|
login_cap_t * llc = NULL;
|
|
|
|
if (lc == NULL)
|
|
{
|
|
if (pwd != NULL && (lc = login_getclass(pwd)) != NULL)
|
|
llc = lc; /* free this when we're done */
|
|
}
|
|
|
|
if (flags & LOGIN_SETPATH)
|
|
pathvars[0].def = uid ? _PATH_DEFPATH : _PATH_STDPATH;
|
|
|
|
/*
|
|
* Set the process priority
|
|
*/
|
|
if (flags & LOGIN_SETPRIORITY) {
|
|
int pri = (int)login_getcapnum(lc, "priority", LOGIN_DEFPRI, LOGIN_DEFPRI);
|
|
pri = (pri < PRIO_MIN) ? PRIO_MIN : (pri > PRIO_MAX) ? PRIO_MAX : pri;
|
|
if (setpriority(PRIO_PROCESS, 0, pri) != 0)
|
|
syslog(LOG_WARNING, "setpriority '%s': %m", pwd->pw_name);
|
|
}
|
|
|
|
/*
|
|
* Set resources
|
|
*/
|
|
if (flags & LOGIN_SETRESOURCES)
|
|
setclassresources(lc);
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
/*
|
|
* Setup the user's group permissions
|
|
*/
|
|
if (flags & LOGIN_SETGROUP) {
|
|
if (setgid(pwd->pw_gid) != 0)
|
|
syslog(LOG_WARNING, "setgid %ld: %m", (long)pwd->pw_gid);
|
|
if (initgroups(pwd->pw_name, pwd->pw_gid) == -1)
|
|
syslog(LOG_WARNING, "initgroups '%s': %m", pwd->pw_name);
|
|
}
|
|
|
|
/*
|
|
* FreeBSD extension: here we (might) loop and do this twice.
|
|
* First, for the class we have been given, and next for
|
|
* any user overrides in ~/.login.conf the user's home directory.
|
|
*/
|
|
if (flags & LOGIN_SETUMASK)
|
|
umask(LOGIN_DEFUMASK); /* Set default umask up front */
|
|
|
|
i = 0;
|
|
while (i < 2 && lc != NULL) {
|
|
|
|
if (flags & LOGIN_SETUMASK) {
|
|
rlim_t tmp = login_getcapnum(lc, "umask", RLIM_INFINITY, RLIM_INFINITY);
|
|
if (tmp != RLIM_INFINITY)
|
|
umask((mode_t)tmp);
|
|
}
|
|
|
|
if (flags & LOGIN_SETPATH)
|
|
setclassenvironment(lc, pwd, 1);
|
|
|
|
if (flags & LOGIN_SETENV)
|
|
setclassenvironment(lc, pwd, 0);
|
|
|
|
if (i++ == 0) /* Play it again, Sam */
|
|
lc = (pwd == NULL) ? NULL : login_getuserclass(pwd);
|
|
}
|
|
|
|
login_close(lc); /* User's private 'me' class */
|
|
login_close(llc); /* Class we opened */
|
|
|
|
/*
|
|
* This needs to be done after all of the above.
|
|
* Do it last so we avoid getting killed and dropping core
|
|
*/
|
|
if ((flags & LOGIN_SETUSER) && setuid(uid) != 0) {
|
|
syslog(LOG_ERR, "setuid %ld: %m", uid);
|
|
login_close(llc);
|
|
return -1; /* Paranoia again */
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|