freebsd-skq/usr.sbin/jail/jail.c
Bjoern A. Zeeb 15ede76031 Check for IPv4 or IPv6 to be available by the kernel to not
provoke errors trying to query options not available.
Make it possible to compile out INET or INET6 only parts.

Reviewed by:	jamie
Sponsored by:	The FreeBSD Foundation
Sponsored by:	iXsystems
MFC after:	10 days
2011-05-29 21:03:40 +00:00

570 lines
14 KiB
C

/*-
* Copyright (c) 1999 Poul-Henning Kamp.
* Copyright (c) 2009 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/param.h>
#include <sys/jail.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <grp.h>
#include <jail.h>
#include <login_cap.h>
#include <netdb.h>
#include <paths.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
static struct jailparam *params;
static char **param_values;
static int nparams;
#ifdef INET6
static int ip6_ok;
static char *ip6_addr;
#endif
#ifdef INET
static int ip4_ok;
static char *ip4_addr;
#endif
#if defined(INET6) || defined(INET)
static void add_ip_addr(char **addrp, char *newaddr);
#endif
#ifdef INET6
static void add_ip_addr46(char *newaddr);
#endif
static void add_ip_addrinfo(int ai_flags, char *value);
static void quoted_print(FILE *fp, char *str);
static void set_param(const char *name, char *value);
static void usage(void);
static const char *perm_sysctl[][3] = {
{ "security.jail.set_hostname_allowed",
"allow.noset_hostname", "allow.set_hostname" },
{ "security.jail.sysvipc_allowed",
"allow.nosysvipc", "allow.sysvipc" },
{ "security.jail.allow_raw_sockets",
"allow.noraw_sockets", "allow.raw_sockets" },
{ "security.jail.chflags_allowed",
"allow.nochflags", "allow.chflags" },
{ "security.jail.mount_allowed",
"allow.nomount", "allow.mount" },
{ "security.jail.socket_unixiproute_only",
"allow.socket_af", "allow.nosocket_af" },
};
extern char **environ;
#define GET_USER_INFO do { \
pwd = getpwnam(username); \
if (pwd == NULL) { \
if (errno) \
err(1, "getpwnam: %s", username); \
else \
errx(1, "%s: no such user", username); \
} \
lcap = login_getpwclass(pwd); \
if (lcap == NULL) \
err(1, "getpwclass: %s", username); \
ngroups = ngroups_max; \
if (getgrouplist(username, pwd->pw_gid, groups, &ngroups) != 0) \
err(1, "getgrouplist: %s", username); \
} while (0)
int
main(int argc, char **argv)
{
login_cap_t *lcap = NULL;
struct passwd *pwd = NULL;
gid_t *groups;
size_t sysvallen;
int ch, cmdarg, i, jail_set_flags, jid, ngroups, sysval;
int hflag, iflag, Jflag, lflag, rflag, uflag, Uflag;
long ngroups_max;
unsigned pi;
char *jailname, *securelevel, *username, *JidFile;
char enforce_statfs[4];
static char *cleanenv;
const char *shell, *p = NULL;
FILE *fp;
hflag = iflag = Jflag = lflag = rflag = uflag = Uflag =
jail_set_flags = 0;
cmdarg = jid = -1;
jailname = securelevel = username = JidFile = cleanenv = NULL;
fp = NULL;
ngroups_max = sysconf(_SC_NGROUPS_MAX) + 1;
if ((groups = malloc(sizeof(gid_t) * ngroups_max)) == NULL)
err(1, "malloc");
while ((ch = getopt(argc, argv, "cdhilmn:r:s:u:U:J:")) != -1) {
switch (ch) {
case 'd':
jail_set_flags |= JAIL_DYING;
break;
case 'h':
hflag = 1;
break;
case 'i':
iflag = 1;
break;
case 'J':
JidFile = optarg;
Jflag = 1;
break;
case 'n':
jailname = optarg;
break;
case 's':
securelevel = optarg;
break;
case 'u':
username = optarg;
uflag = 1;
break;
case 'U':
username = optarg;
Uflag = 1;
break;
case 'l':
lflag = 1;
break;
case 'c':
jail_set_flags |= JAIL_CREATE;
break;
case 'm':
jail_set_flags |= JAIL_UPDATE;
break;
case 'r':
jid = jail_getid(optarg);
if (jid < 0)
errx(1, "%s", jail_errmsg);
rflag = 1;
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
if (rflag) {
if (argc > 0 || iflag || Jflag || lflag || uflag || Uflag)
usage();
if (jail_remove(jid) < 0)
err(1, "jail_remove");
exit (0);
}
if (argc == 0)
usage();
if (uflag && Uflag)
usage();
if (lflag && username == NULL)
usage();
if (uflag)
GET_USER_INFO;
#ifdef INET6
ip6_ok = feature_present("inet6");
#endif
#ifdef INET
ip4_ok = feature_present("inet");
#endif
if (jailname)
set_param("name", jailname);
if (securelevel)
set_param("securelevel", securelevel);
if (jail_set_flags) {
for (i = 0; i < argc; i++) {
if (!strncmp(argv[i], "command=", 8)) {
cmdarg = i;
argv[cmdarg] += 8;
jail_set_flags |= JAIL_ATTACH;
break;
}
if (hflag) {
#ifdef INET
if (!strncmp(argv[i], "ip4.addr=", 9)) {
add_ip_addr(&ip4_addr, argv[i] + 9);
break;
}
#endif
#ifdef INET6
if (!strncmp(argv[i], "ip6.addr=", 9)) {
add_ip_addr(&ip6_addr, argv[i] + 9);
break;
}
#endif
if (!strncmp(argv[i], "host.hostname=", 14))
add_ip_addrinfo(0, argv[i] + 14);
}
set_param(NULL, argv[i]);
}
} else {
if (argc < 4 || argv[0][0] != '/')
errx(1, "%s\n%s",
"no -c or -m, so this must be an old-style command.",
"But it doesn't look like one.");
set_param("path", argv[0]);
set_param("host.hostname", argv[1]);
if (hflag)
add_ip_addrinfo(0, argv[1]);
#if defined(INET6) || defined(INET)
if (argv[2][0] != '\0')
#ifdef INET6
add_ip_addr46(argv[2]);
#else
add_ip_addr(&ip4_addr, argv[2]);
#endif
#endif
cmdarg = 3;
/* Emulate the defaults from security.jail.* sysctls */
sysvallen = sizeof(sysval);
if (sysctlbyname("security.jail.jailed", &sysval, &sysvallen,
NULL, 0) == 0 && sysval == 0) {
for (pi = 0; pi < sizeof(perm_sysctl) /
sizeof(perm_sysctl[0]); pi++) {
sysvallen = sizeof(sysval);
if (sysctlbyname(perm_sysctl[pi][0],
&sysval, &sysvallen, NULL, 0) == 0)
set_param(perm_sysctl[pi]
[sysval ? 2 : 1], NULL);
}
sysvallen = sizeof(sysval);
if (sysctlbyname("security.jail.enforce_statfs",
&sysval, &sysvallen, NULL, 0) == 0) {
snprintf(enforce_statfs,
sizeof(enforce_statfs), "%d", sysval);
set_param("enforce_statfs", enforce_statfs);
}
}
}
#ifdef INET
if (ip4_addr != NULL)
set_param("ip4.addr", ip4_addr);
#endif
#ifdef INET6
if (ip6_addr != NULL)
set_param("ip6.addr", ip6_addr);
#endif
if (Jflag) {
fp = fopen(JidFile, "w");
if (fp == NULL)
errx(1, "Could not create JidFile: %s", JidFile);
}
jid = jailparam_set(params, nparams,
jail_set_flags ? jail_set_flags : JAIL_CREATE | JAIL_ATTACH);
if (jid < 0)
errx(1, "%s", jail_errmsg);
if (iflag) {
printf("%d\n", jid);
fflush(stdout);
}
if (Jflag) {
if (jail_set_flags) {
fprintf(fp, "jid=%d", jid);
for (i = 0; i < nparams; i++)
if (strcmp(params[i].jp_name, "jid")) {
fprintf(fp, " %s",
(char *)params[i].jp_name);
if (param_values[i]) {
putc('=', fp);
quoted_print(fp,
param_values[i]);
}
}
fprintf(fp, "\n");
} else {
for (i = 0; i < nparams; i++)
if (!strcmp(params[i].jp_name, "path"))
break;
#if defined(INET6) && defined(INET)
fprintf(fp, "%d\t%s\t%s\t%s%s%s\t%s\n",
jid, i < nparams
? (char *)params[i].jp_value : argv[0],
argv[1], ip4_addr ? ip4_addr : "",
ip4_addr && ip4_addr[0] && ip6_addr && ip6_addr[0]
? "," : "", ip6_addr ? ip6_addr : "", argv[3]);
#elif defined(INET6)
fprintf(fp, "%d\t%s\t%s\t%s\t%s\n",
jid, i < nparams
? (char *)params[i].jp_value : argv[0],
argv[1], ip6_addr ? ip6_addr : "", argv[3]);
#elif defined(INET)
fprintf(fp, "%d\t%s\t%s\t%s\t%s\n",
jid, i < nparams
? (char *)params[i].jp_value : argv[0],
argv[1], ip4_addr ? ip4_addr : "", argv[3]);
#endif
}
(void)fclose(fp);
}
if (cmdarg < 0)
exit(0);
if (username != NULL) {
if (Uflag)
GET_USER_INFO;
if (lflag) {
p = getenv("TERM");
environ = &cleanenv;
}
if (setgroups(ngroups, groups) != 0)
err(1, "setgroups");
if (setgid(pwd->pw_gid) != 0)
err(1, "setgid");
if (setusercontext(lcap, pwd, pwd->pw_uid,
LOGIN_SETALL & ~LOGIN_SETGROUP & ~LOGIN_SETLOGIN) != 0)
err(1, "setusercontext");
login_close(lcap);
}
if (lflag) {
if (*pwd->pw_shell)
shell = pwd->pw_shell;
else
shell = _PATH_BSHELL;
if (chdir(pwd->pw_dir) < 0)
errx(1, "no home directory");
setenv("HOME", pwd->pw_dir, 1);
setenv("SHELL", shell, 1);
setenv("USER", pwd->pw_name, 1);
if (p)
setenv("TERM", p, 1);
}
execvp(argv[cmdarg], argv + cmdarg);
err(1, "execvp: %s", argv[cmdarg]);
}
#if defined(INET6) || defined(INET)
static void
add_ip_addr(char **addrp, char *value)
{
int addrlen;
char *addr;
if (!*addrp) {
*addrp = strdup(value);
if (!*addrp)
err(1, "malloc");
} else if (value[0]) {
addrlen = strlen(*addrp) + strlen(value) + 2;
addr = malloc(addrlen);
if (!addr)
err(1, "malloc");
snprintf(addr, addrlen, "%s,%s", *addrp, value);
free(*addrp);
*addrp = addr;
}
}
#endif
#ifdef INET6
static void
add_ip_addr46(char *value)
{
char *p, *np;
for (p = value;; p = np + 1)
{
np = strchr(p, ',');
if (np)
*np = '\0';
add_ip_addrinfo(AI_NUMERICHOST, p);
if (!np)
break;
}
}
#endif
static void
add_ip_addrinfo(int ai_flags, char *value)
{
struct addrinfo hints, *ai0, *ai;
int error;
#ifdef INET
char avalue4[INET_ADDRSTRLEN];
struct in_addr addr4;
#endif
#ifdef INET6
char avalue6[INET6_ADDRSTRLEN];
struct in6_addr addr6;
#endif
/* Look up the hostname (or get the address) */
memset(&hints, 0, sizeof(hints));
hints.ai_socktype = SOCK_STREAM;
#if defined(INET6) && defined(INET)
hints.ai_family = PF_UNSPEC;
#elif defined(INET6)
hints.ai_family = PF_INET6;
#elif defined(INET)
hints.ai_family = PF_INET;
#endif
hints.ai_flags = ai_flags;
error = getaddrinfo(value, NULL, &hints, &ai0);
if (error != 0)
errx(1, "hostname %s: %s", value, gai_strerror(error));
/* Convert the addresses to ASCII so set_param can convert them back. */
for (ai = ai0; ai; ai = ai->ai_next)
switch (ai->ai_family) {
#ifdef INET
case AF_INET:
if (!ip4_ok && (ai_flags & AI_NUMERICHOST) == 0)
break;
memcpy(&addr4, &((struct sockaddr_in *)
(void *)ai->ai_addr)->sin_addr, sizeof(addr4));
if (inet_ntop(AF_INET, &addr4, avalue4,
INET_ADDRSTRLEN) == NULL)
err(1, "inet_ntop");
add_ip_addr(&ip4_addr, avalue4);
break;
#endif
#ifdef INET6
case AF_INET6:
if (!ip6_ok && (ai_flags & AI_NUMERICHOST) == 0)
break;
memcpy(&addr6, &((struct sockaddr_in6 *)
(void *)ai->ai_addr)->sin6_addr, sizeof(addr6));
if (inet_ntop(AF_INET6, &addr6, avalue6,
INET6_ADDRSTRLEN) == NULL)
err(1, "inet_ntop");
add_ip_addr(&ip6_addr, avalue6);
break;
#endif
}
freeaddrinfo(ai0);
}
static void
quoted_print(FILE *fp, char *str)
{
int c, qc;
char *p = str;
/* An empty string needs quoting. */
if (!*p) {
fputs("\"\"", fp);
return;
}
/*
* The value will be surrounded by quotes if it contains spaces
* or quotes.
*/
qc = strchr(p, '\'') ? '"'
: strchr(p, '"') ? '\''
: strchr(p, ' ') || strchr(p, '\t') ? '"'
: 0;
if (qc)
putc(qc, fp);
while ((c = *p++)) {
if (c == '\\' || c == qc)
putc('\\', fp);
putc(c, fp);
}
if (qc)
putc(qc, fp);
}
static void
set_param(const char *name, char *value)
{
struct jailparam *param;
int i;
static int paramlistsize;
/* Separate the name from the value, if not done already. */
if (name == NULL) {
name = value;
if ((value = strchr(value, '=')))
*value++ = '\0';
}
/* jail_set won't chdir along with its chroot, so do it here. */
if (!strcmp(name, "path") && chdir(value) < 0)
err(1, "chdir: %s", value);
/* Check for repeat parameters */
for (i = 0; i < nparams; i++)
if (!strcmp(name, params[i].jp_name)) {
jailparam_free(params + i, 1);
memcpy(params + i, params + i + 1,
(--nparams - i) * sizeof(struct jailparam));
break;
}
/* Make sure there is room for the new param record. */
if (!nparams) {
paramlistsize = 32;
params = malloc(paramlistsize * sizeof(*params));
param_values = malloc(paramlistsize * sizeof(*param_values));
if (params == NULL || param_values == NULL)
err(1, "malloc");
} else if (nparams >= paramlistsize) {
paramlistsize *= 2;
params = realloc(params, paramlistsize * sizeof(*params));
param_values = realloc(param_values,
paramlistsize * sizeof(*param_values));
if (params == NULL)
err(1, "realloc");
}
/* Look up the paramter. */
param_values[nparams] = value;
param = params + nparams++;
if (jailparam_init(param, name) < 0 ||
jailparam_import(param, value) < 0)
errx(1, "%s", jail_errmsg);
}
static void
usage(void)
{
(void)fprintf(stderr,
"usage: jail [-d] [-h] [-i] [-J jid_file] "
"[-l -u username | -U username]\n"
" [-c | -m] param=value ... [command=command ...]\n"
" jail [-r jail]\n");
exit(1);
}