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2b00f7ba65
freebsd-skq/usr.sbin/jail/command.c
Jamie Gritton 2b00f7ba65 Move the actual create/remove (IP__OP) handling into run_command, 
and the cost of an ugly single-use global variable.
2011-06-18 15:23:08 +00:00

854 lines
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/*-
* Copyright (c) 2011 James Gritton
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/event.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/user.h>
#include <sys/wait.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <kvm.h>
#include <login_cap.h>
#include <paths.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "jailp.h"
#define DEFAULT_STOP_TIMEOUT 10
#define PHASH_SIZE 256
LIST_HEAD(phhead, phash);
struct phash {
LIST_ENTRY(phash) le;
struct cfjail *j;
pid_t pid;
};
int paralimit = -1;
extern char **environ;
static int run_command(struct cfjail *j);
static void add_proc(struct cfjail *j, pid_t pid);
static void clear_procs(struct cfjail *j);
static struct cfjail *find_proc(pid_t pid);
static int term_procs(struct cfjail *j);
static int get_user_info(struct cfjail *j, const char *username,
const struct passwd **pwdp, login_cap_t **lcapp);
static int check_path(struct cfjail *j, const char *pname, const char *path,
int isfile, const char *umount_type);
static struct cfjails sleeping = TAILQ_HEAD_INITIALIZER(sleeping);
static struct cfjails runnable = TAILQ_HEAD_INITIALIZER(runnable);
static struct phhead phash[PHASH_SIZE];
static int kq;
/*
* Run the next command associated with a jail.
*/
int
next_command(struct cfjail *j)
{
const struct cfstring *comstring;
enum intparam comparam;
int rval, create_failed;
static struct cfstring dummystring = { .len = 1 };
rval = 0;
create_failed = (j->flags & (JF_STOP | JF_FAILED)) == JF_FAILED;
for (; (comparam = *j->comparam);
j->comparam += create_failed ? -1 : 1) {
if (j->comstring == NULL) {
switch (comparam) {
case IP_MOUNT_DEVFS:
if (!bool_param(j->intparams[IP_MOUNT_DEVFS]))
continue;
/* FALLTHROUGH */
case IP__OP:
case IP_STOP_TIMEOUT:
j->comstring = &dummystring;
break;
default:
if (j->intparams[comparam] == NULL)
continue;
j->comstring = create_failed
? TAILQ_LAST(&j->intparams[comparam]->val,
cfstrings)
: TAILQ_FIRST(&j->intparams[comparam]->val);
}
}
for (; j->comstring != NULL;
j->comstring = create_failed
? TAILQ_PREV(j->comstring, cfstrings, tq)
: TAILQ_NEXT(j->comstring, tq)) {
if (rval != 0)
return rval;
if (j->comstring->len == 0 || (create_failed &&
(comparam == IP_EXEC_PRESTART || comparam ==
IP_EXEC_START || comparam == IP_COMMAND ||
comparam == IP_EXEC_POSTSTART)))
continue;
if (paralimit == 0) {
requeue(j, &runnable);
return 1;
}
rval = run_command(j);
create_failed =
(j->flags & (JF_STOP | JF_FAILED)) == JF_FAILED;
}
}
return rval;
}
/*
* Check command exit status
*/
int
finish_command(struct cfjail *j)
{
int error;
if (!(j->flags & JF_SLEEPQ))
return 0;
j->flags &= ~JF_SLEEPQ;
if (*j->comparam != IP_STOP_TIMEOUT) {
paralimit++;
if (!TAILQ_EMPTY(&runnable))
requeue(TAILQ_FIRST(&runnable), &ready);
}
error = 0;
if (j->flags & JF_TIMEOUT) {
j->flags &= ~JF_TIMEOUT;
if (*j->comparam != IP_STOP_TIMEOUT) {
jail_warnx(j, "%s: timed out", j->comline);
failed(j);
error = -1;
} else if (verbose > 0)
jail_note(j, "timed out\n");
} else if (j->pstatus != 0) {
if (WIFSIGNALED(j->pstatus))
jail_warnx(j, "%s: exited on signal %d",
j->comline, WTERMSIG(j->pstatus));
else
jail_warnx(j, "%s: failed", j->comline);
j->pstatus = 0;
failed(j);
error = -1;
}
free(j->comline);
j->comline = NULL;
return error;
}
/*
* Check for finished processed or timeouts.
*/
struct cfjail *
next_proc(int nonblock)
{
struct kevent ke;
struct timespec ts;
struct timespec *tsp;
struct cfjail *j;
if (!TAILQ_EMPTY(&sleeping)) {
again:
tsp = NULL;
if ((j = TAILQ_FIRST(&sleeping)) && j->timeout.tv_sec) {
clock_gettime(CLOCK_REALTIME, &ts);
ts.tv_sec = j->timeout.tv_sec - ts.tv_sec;
ts.tv_nsec = j->timeout.tv_nsec - ts.tv_nsec;
if (ts.tv_nsec < 0) {
ts.tv_sec--;
ts.tv_nsec += 1000000000;
}
if (ts.tv_sec < 0 ||
(ts.tv_sec == 0 && ts.tv_nsec == 0)) {
j->flags |= JF_TIMEOUT;
clear_procs(j);
return j;
}
tsp = &ts;
}
if (nonblock) {
ts.tv_sec = 0;
ts.tv_nsec = 0;
tsp = &ts;
}
switch (kevent(kq, NULL, 0, &ke, 1, tsp)) {
case -1:
if (errno != EINTR)
err(1, "kevent");
goto again;
case 0:
if (!nonblock) {
j = TAILQ_FIRST(&sleeping);
j->flags |= JF_TIMEOUT;
clear_procs(j);
return j;
}
break;
case 1:
(void)waitpid(ke.ident, NULL, WNOHANG);
if ((j = find_proc(ke.ident))) {
j->pstatus = ke.data;
return j;
}
goto again;
}
}
return NULL;
}
/*
* Run a single command for a jail, possible inside the jail.
*/
int
run_command(struct cfjail *j)
{
const struct passwd *pwd;
const struct cfstring *comstring, *s;
login_cap_t *lcap;
char **argv;
char *cs, *addr, *comcs, *devpath;
const char *jidstr, *conslog, *path, *ruleset, *term, *username;
enum intparam comparam;
size_t comlen;
pid_t pid;
int argc, bg, clean, consfd, down, fib, i, injail, sjuser, timeout;
static char *cleanenv;
/* Perform some operations that aren't actually commands */
comparam = *j->comparam;
down = j->flags & (JF_STOP | JF_FAILED);
switch (comparam) {
case IP_STOP_TIMEOUT:
return term_procs(j);
case IP__OP:
if (down) {
if (jail_remove(j->jid) == 0 && verbose >= 0 &&
(verbose > 0 || (j->flags & JF_STOP
? note_remove : j->name != NULL)))
jail_note(j, "removed\n");
j->jid = -1;
if (j->flags & JF_STOP)
dep_done(j, DF_LIGHT);
else
j->flags &= ~JF_PERSIST;
} else {
if (create_jail(j) < 0) {
failed(j);
return -1;
}
if (verbose >= 0 && (j->name || verbose > 0))
jail_note(j, "created\n");
dep_done(j, DF_LIGHT);
}
requeue(j, &ready);
return 1;
}
/*
* Collect exec arguments. Internal commands for network and
* mounting build their own argument lists.
*/
comstring = j->comstring;
bg = 0;
switch (comparam) {
case IP__IP4_IFADDR:
argv = alloca(8 * sizeof(char *));
*(const char **)&argv[0] = _PATH_IFCONFIG;
if ((cs = strchr(comstring->s, '|'))) {
argv[1] = alloca(cs - comstring->s + 1);
strlcpy(argv[1], comstring->s, cs - comstring->s + 1);
addr = cs + 1;
} else {
*(const char **)&argv[1] =
string_param(j->intparams[IP_INTERFACE]);
addr = comstring->s;
}
*(const char **)&argv[2] = "inet";
if (!(cs = strchr(addr, '/'))) {
argv[3] = addr;
*(const char **)&argv[4] = "netmask";
*(const char **)&argv[5] = "255.255.255.255";
argc = 6;
} else if (strchr(cs + 1, '.')) {
argv[3] = alloca(cs - addr + 1);
strlcpy(argv[3], addr, cs - addr + 1);
*(const char **)&argv[4] = "netmask";
*(const char **)&argv[5] = cs + 1;
argc = 6;
} else {
argv[3] = addr;
argc = 4;
}
*(const char **)&argv[argc] = down ? "-alias" : "alias";
argv[argc + 1] = NULL;
break;
#ifdef INET6
case IP__IP6_IFADDR:
argv = alloca(8 * sizeof(char *));
*(const char **)&argv[0] = _PATH_IFCONFIG;
if ((cs = strchr(comstring->s, '|'))) {
argv[1] = alloca(cs - comstring->s + 1);
strlcpy(argv[1], comstring->s, cs - comstring->s + 1);
addr = cs + 1;
} else {
*(const char **)&argv[1] =
string_param(j->intparams[IP_INTERFACE]);
addr = comstring->s;
}
*(const char **)&argv[2] = "inet6";
argv[3] = addr;
if (!(cs = strchr(addr, '/'))) {
*(const char **)&argv[4] = "prefixlen";
*(const char **)&argv[5] = "128";
argc = 6;
} else
argc = 4;
*(const char **)&argv[argc] = down ? "-alias" : "alias";
argv[argc + 1] = NULL;
break;
#endif
case IP_VNET_INTERFACE:
argv = alloca(5 * sizeof(char *));
*(const char **)&argv[0] = _PATH_IFCONFIG;
argv[1] = comstring->s;
*(const char **)&argv[2] = down ? "-vnet" : "vnet";
jidstr = string_param(j->intparams[KP_JID]);
*(const char **)&argv[3] =
jidstr ? jidstr : string_param(j->intparams[KP_NAME]);
argv[4] = NULL;
break;
case IP_MOUNT:
case IP__MOUNT_FROM_FSTAB:
argv = alloca(8 * sizeof(char *));
comcs = alloca(comstring->len + 1);
strcpy(comcs, comstring->s);
argc = 0;
for (cs = strtok(comcs, " \t\f\v\r\n"); cs && argc < 4;
cs = strtok(NULL, " \t\f\v\r\n"))
argv[argc++] = cs;
if (argc == 0)
return 0;
if (argc < 3) {
jail_warnx(j, "%s: %s: missing information",
j->intparams[comparam]->name, comstring->s);
failed(j);
return -1;
}
if (check_path(j, j->intparams[comparam]->name, argv[1], 0,
down ? argv[2] : NULL) < 0) {
failed(j);
return -1;
}
if (down) {
argv[4] = NULL;
argv[3] = argv[1];
*(const char **)&argv[0] = "/sbin/umount";
} else {
if (argc == 4) {
argv[7] = NULL;
argv[6] = argv[1];
argv[5] = argv[0];
argv[4] = argv[3];
*(const char **)&argv[3] = "-o";
} else {
argv[5] = NULL;
argv[4] = argv[1];
argv[3] = argv[0];
}
*(const char **)&argv[0] = _PATH_MOUNT;
}
*(const char **)&argv[1] = "-t";
break;
case IP_MOUNT_DEVFS:
path = string_param(j->intparams[KP_PATH]);
if (path == NULL) {
jail_warnx(j, "mount.devfs: no path");
failed(j);
return -1;
}
devpath = alloca(strlen(path) + 5);
sprintf(devpath, "%s/dev", path);
if (check_path(j, "mount.devfs", devpath, 0,
down ? "devfs" : NULL) < 0) {
failed(j);
return -1;
}
if (down) {
argv = alloca(3 * sizeof(char *));
*(const char **)&argv[0] = "/sbin/umount";
argv[1] = devpath;
argv[2] = NULL;
} else {
argv = alloca(4 * sizeof(char *));
*(const char **)&argv[0] = _PATH_BSHELL;
*(const char **)&argv[1] = "-c";
ruleset = string_param(j->intparams
[IP_MOUNT_DEVFS_RULESET]);
argv[2] = alloca(strlen(path) +
(ruleset ? strlen(ruleset) + 1 : 0) + 56);
sprintf(argv[2], ". /etc/rc.subr; load_rc_config .; "
"devfs_mount_jail %s/dev%s%s", path,
ruleset ? " " : "", ruleset ? ruleset : "");
argv[3] = NULL;
}
break;
case IP_COMMAND:
if (j->name != NULL)
goto default_command;
argc = 0;
TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
argc++;
argv = alloca((argc + 1) * sizeof(char *));
argc = 0;
TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
argv[argc++] = s->s;
argv[argc] = NULL;
j->comstring = NULL;
break;
default:
default_command:
if ((cs = strpbrk(comstring->s, "!\"$&'()*;<>?[\\]`{|}~")) &&
!(cs[0] == '&' && cs[1] == '\0')) {
argv = alloca(4 * sizeof(char *));
*(const char **)&argv[0] = _PATH_BSHELL;
*(const char **)&argv[1] = "-c";
argv[2] = comstring->s;
argv[3] = NULL;
} else {
if (cs) {
*cs = 0;
bg = 1;
}
comcs = alloca(comstring->len + 1);
strcpy(comcs, comstring->s);
argc = 0;
for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
cs = strtok(NULL, " \t\f\v\r\n"))
argc++;
argv = alloca((argc + 1) * sizeof(char *));
strcpy(comcs, comstring->s);
argc = 0;
for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
cs = strtok(NULL, " \t\f\v\r\n"))
argv[argc++] = cs;
argv[argc] = NULL;
}
}
if (argv[0] == NULL)
return 0;
if (int_param(j->intparams[IP_EXEC_TIMEOUT], &timeout) &&
timeout != 0) {
clock_gettime(CLOCK_REALTIME, &j->timeout);
j->timeout.tv_sec += timeout;
} else
j->timeout.tv_sec = 0;
injail = comparam == IP_EXEC_START || comparam == IP_COMMAND ||
comparam == IP_EXEC_STOP;
clean = bool_param(j->intparams[IP_EXEC_CLEAN]);
username = string_param(j->intparams[injail
? IP_EXEC_JAIL_USER : IP_EXEC_SYSTEM_USER]);
sjuser = bool_param(j->intparams[IP_EXEC_SYSTEM_JAIL_USER]);
consfd = 0;
if (injail &&
(conslog = string_param(j->intparams[IP_EXEC_CONSOLELOG]))) {
if (check_path(j, "exec.consolelog", conslog, 1, NULL) < 0) {
failed(j);
return -1;
}
consfd =
open(conslog, O_WRONLY | O_CREAT | O_APPEND, DEFFILEMODE);
if (consfd < 0) {
jail_warnx(j, "open %s: %s", conslog, strerror(errno));
failed(j);
return -1;
}
}
comlen = 0;
for (i = 0; argv[i]; i++)
comlen += strlen(argv[i]) + 1;
j->comline = cs = emalloc(comlen);
for (i = 0; argv[i]; i++) {
strcpy(cs, argv[i]);
if (argv[i + 1]) {
cs += strlen(argv[i]) + 1;
cs[-1] = ' ';
}
}
if (verbose > 0)
jail_note(j, "run command%s%s%s: %s\n",
injail ? " in jail" : "", username ? " as " : "",
username ? username : "", j->comline);
pid = fork();
if (pid < 0)
err(1, "fork");
if (pid > 0) {
if (bg) {
free(j->comline);
j->comline = NULL;
requeue(j, &ready);
} else {
paralimit--;
add_proc(j, pid);
}
return 1;
}
if (bg)
setsid();
/* Set up the environment and run the command */
pwd = NULL;
lcap = NULL;
if ((clean || username) && injail && sjuser &&
get_user_info(j, username, &pwd, &lcap) < 0)
exit(1);
if (injail) {
/* jail_attach won't chdir along with its chroot. */
path = string_param(j->intparams[KP_PATH]);
if (path && chdir(path) < 0) {
jail_warnx(j, "chdir %s: %s", path, strerror(errno));
exit(1);
}
if (int_param(j->intparams[IP_EXEC_FIB], &fib) &&
setfib(fib) < 0) {
jail_warnx(j, "setfib: %s", strerror(errno));
exit(1);
}
if (jail_attach(j->jid) < 0) {
jail_warnx(j, "jail_attach: %s", strerror(errno));
exit(1);
}
}
if (clean || username) {
if (!(injail && sjuser) &&
get_user_info(j, username, &pwd, &lcap) < 0)
exit(1);
if (clean) {
term = getenv("TERM");
environ = &cleanenv;
setenv("PATH", "/bin:/usr/bin", 0);
setenv("TERM", term, 1);
}
if (setusercontext(lcap, pwd, pwd->pw_uid, username
? LOGIN_SETALL & ~LOGIN_SETGROUP & ~LOGIN_SETLOGIN
: LOGIN_SETPATH | LOGIN_SETENV) < 0) {
jail_warnx(j, "setusercontext %s: %s", pwd->pw_name,
strerror(errno));
exit(1);
}
login_close(lcap);
setenv("USER", pwd->pw_name, 1);
setenv("HOME", pwd->pw_dir, 1);
setenv("SHELL",
*pwd->pw_shell ? pwd->pw_shell : _PATH_BSHELL, 1);
if (clean && chdir(pwd->pw_dir) < 0) {
jail_warnx(j, "chdir %s: %s",
pwd->pw_dir, strerror(errno));
exit(1);
}
endpwent();
}
if (consfd != 0 && (dup2(consfd, 1) < 0 || dup2(consfd, 2) < 0)) {
jail_warnx(j, "exec.consolelog: %s", strerror(errno));
exit(1);
}
closefrom(3);
execvp(argv[0], argv);
jail_warnx(j, "exec %s: %s", argv[0], strerror(errno));
exit(1);
}
/*
* Add a process to the hash, tied to a jail.
*/
static void
add_proc(struct cfjail *j, pid_t pid)
{
struct kevent ke;
struct cfjail *tj;
struct phash *ph;
if (!kq && (kq = kqueue()) < 0)
err(1, "kqueue");
EV_SET(&ke, pid, EVFILT_PROC, EV_ADD, NOTE_EXIT, 0, NULL);
if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0)
err(1, "kevent");
ph = emalloc(sizeof(struct phash));
ph->j = j;
ph->pid = pid;
LIST_INSERT_HEAD(&phash[pid % PHASH_SIZE], ph, le);
j->nprocs++;
j->flags |= JF_SLEEPQ;
if (j->timeout.tv_sec == 0)
requeue(j, &sleeping);
else {
/* File the jail in the sleep queue acording to its timeout. */
TAILQ_REMOVE(j->queue, j, tq);
TAILQ_FOREACH(tj, &sleeping, tq) {
if (!tj->timeout.tv_sec ||
j->timeout.tv_sec < tj->timeout.tv_sec ||
(j->timeout.tv_sec == tj->timeout.tv_sec &&
j->timeout.tv_nsec <= tj->timeout.tv_nsec)) {
TAILQ_INSERT_BEFORE(tj, j, tq);
break;
}
}
if (tj == NULL)
TAILQ_INSERT_TAIL(&sleeping, j, tq);
j->queue = &sleeping;
}
}
/*
* Remove any processes from the hash that correspond to a jail.
*/
static void
clear_procs(struct cfjail *j)
{
struct kevent ke;
struct phash *ph, *tph;
int i;
j->nprocs = 0;
for (i = 0; i < PHASH_SIZE; i++)
LIST_FOREACH_SAFE(ph, &phash[i], le, tph)
if (ph->j == j) {
EV_SET(&ke, ph->pid, EVFILT_PROC, EV_DELETE,
NOTE_EXIT, 0, NULL);
(void)kevent(kq, &ke, 1, NULL, 0, NULL);
LIST_REMOVE(ph, le);
free(ph);
}
}
/*
* Find the jail that corresponds to an exited process.
*/
static struct cfjail *
find_proc(pid_t pid)
{
struct cfjail *j;
struct phash *ph;
LIST_FOREACH(ph, &phash[pid % PHASH_SIZE], le)
if (ph->pid == pid) {
j = ph->j;
LIST_REMOVE(ph, le);
free(ph);
return --j->nprocs ? NULL : j;
}
return NULL;
}
/*
* Send SIGTERM to all processes in a jail and wait for them to die.
*/
static int
term_procs(struct cfjail *j)
{
struct kinfo_proc *ki;
int i, noted, pcnt, timeout;
static kvm_t *kd;
if (!int_param(j->intparams[IP_STOP_TIMEOUT], &timeout))
timeout = DEFAULT_STOP_TIMEOUT;
else if (timeout == 0)
return 0;
if (kd == NULL) {
kd = kvm_open(NULL, NULL, NULL, O_RDONLY, "jail");
if (kd == NULL)
exit(1);
}
ki = kvm_getprocs(kd, KERN_PROC_PROC, 0, &pcnt);
if (ki == NULL)
exit(1);
noted = 0;
for (i = 0; i < pcnt; i++)
if (ki[i].ki_jid == j->jid &&
kill(ki[i].ki_pid, SIGTERM) == 0) {
add_proc(j, ki[i].ki_pid);
if (verbose > 0) {
if (!noted) {
noted = 1;
jail_note(j, "sent SIGTERM to:");
}
printf(" %d", ki[i].ki_pid);
}
}
if (noted)
printf("\n");
if (j->nprocs > 0) {
clock_gettime(CLOCK_REALTIME, &j->timeout);
j->timeout.tv_sec += timeout;
return 1;
}
return 0;
}
/*
* Look up a user in the passwd and login.conf files.
*/
static int
get_user_info(struct cfjail *j, const char *username,
const struct passwd **pwdp, login_cap_t **lcapp)
{
const struct passwd *pwd;
*pwdp = pwd = username ? getpwnam(username) : getpwuid(getuid());
if (pwd == NULL) {
if (errno)
jail_warnx(j, "getpwnam%s%s: %s", username ? " " : "",
username ? username : "", strerror(errno));
else if (username)
jail_warnx(j, "%s: no such user", username);
else
jail_warnx(j, "unknown uid %d", getuid());
return -1;
}
*lcapp = login_getpwclass(pwd);
if (*lcapp == NULL) {
jail_warnx(j, "getpwclass %s: %s", pwd->pw_name,
strerror(errno));
return -1;
}
/* Set the groups while the group file is still available */
if (initgroups(pwd->pw_name, pwd->pw_gid) < 0) {
jail_warnx(j, "initgroups %s: %s", pwd->pw_name,
strerror(errno));
return -1;
}
return 0;
}
/*
* Make sure a mount or consolelog path is a valid absolute pathname
* with no symlinks.
*/
static int
check_path(struct cfjail *j, const char *pname, const char *path, int isfile,
const char *umount_type)
{
struct stat st, mpst;
struct statfs stfs;
char *tpath, *p;
const char *jailpath;
size_t jplen;
if (path[0] != '/') {
jail_warnx(j, "%s: %s: not an absolute pathname",
pname, path);
return -1;
}
/*
* Only check for symlinks in components below the jail's path,
* since that's where the security risk lies.
*/
jailpath = string_param(j->intparams[KP_PATH]);
if (jailpath == NULL)
jailpath = "";
jplen = strlen(jailpath);
if (!strncmp(path, jailpath, jplen) && path[jplen] == '/') {
tpath = alloca(strlen(path) + 1);
strcpy(tpath, path);
for (p = tpath + jplen; p != NULL; ) {
p = strchr(p + 1, '/');
if (p)
*p = '\0';
if (lstat(tpath, &st) < 0) {
if (errno == ENOENT && isfile && !p)
break;
jail_warnx(j, "%s: %s: %s", pname, tpath,
strerror(errno));
return -1;
}
if (S_ISLNK(st.st_mode)) {
jail_warnx(j, "%s: %s is a symbolic link",
pname, tpath);
return -1;
}
if (p)
*p = '/';
}
}
if (umount_type != NULL) {
if (stat(path, &st) < 0 || statfs(path, &stfs) < 0) {
jail_warnx(j, "%s: %s: %s", pname, path,
strerror(errno));
return -1;
}
if (stat(stfs.f_mntonname, &mpst) < 0) {
jail_warnx(j, "%s: %s: %s", pname, stfs.f_mntonname,
strerror(errno));
return -1;
}
if (st.st_ino != mpst.st_ino) {
jail_warnx(j, "%s: %s: not a mount point",
pname, path);
return -1;
}
if (strcmp(stfs.f_fstypename, umount_type)) {
jail_warnx(j, "%s: %s: not a %s mount",
pname, path, umount_type);
return -1;
}
}
return 0;
}
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