freebsd-skq/usr.sbin/jail/jail.c
Jamie Gritton 029cb9c79d In the old-style jail command line, explicitly set parameters from the
security.jail.* sysctls since jail_set(2) doesn't do it implicitly.

Approved by:	bz (mentor)
2009-06-10 15:26:35 +00:00

693 lines
17 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 <sys/uio.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <grp.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>
#define SJPARAM "security.jail.param"
#define ERRMSG_SIZE 256
struct param {
struct iovec name;
struct iovec value;
};
static struct param *params;
static char **param_values;
static int nparams;
static char *ip4_addr;
#ifdef INET6
static char *ip6_addr;
#endif
static void add_ip_addr(char **addrp, char *newaddr);
#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; \
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 iovec rparams[2];
struct passwd *pwd = NULL;
gid_t groups[NGROUPS];
size_t sysvallen;
int ch, cmdarg, i, jail_set_flags, jid, ngroups, sysval;
int hflag, iflag, Jflag, lflag, rflag, uflag, Uflag;
unsigned pi;
char *ep, *jailname, *securelevel, *username, *JidFile;
char errmsg[ERRMSG_SIZE], 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;
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 = strtoul(optarg, &ep, 10);
if (!*optarg || *ep) {
*(const void **)&rparams[0].iov_base = "name";
rparams[0].iov_len = sizeof("name");
rparams[1].iov_base = optarg;
rparams[1].iov_len = strlen(optarg) + 1;
jid = jail_get(rparams, 2, 0);
if (jid < 0)
errx(1, "unknown jail: %s", optarg);
}
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;
/*
* If the first argument (path) starts with a slash, and the third
* argument (IP address) starts with a digit, it is likely to be
* an old-style fixed-parameter command line.
*/
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) {
if (!strncmp(argv[i], "ip4.addr=", 9)) {
add_ip_addr(&ip4_addr, argv[i] + 9);
break;
}
#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]);
#ifdef INET6
add_ip_addr46(argv[2]);
#else
add_ip_addr(&ip4_addr, argv[2]);
#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);
}
}
}
if (ip4_addr != NULL)
set_param("ip4.addr", ip4_addr);
#ifdef INET6
if (ip6_addr != NULL)
set_param("ip6.addr", ip6_addr);
#endif
errmsg[0] = 0;
set_param("errmsg", errmsg);
if (Jflag) {
fp = fopen(JidFile, "w");
if (fp == NULL)
errx(1, "Could not create JidFile: %s", JidFile);
}
jid = jail_set(&params->name, 2 * nparams,
jail_set_flags ? jail_set_flags : JAIL_CREATE | JAIL_ATTACH);
if (jid < 0) {
if (errmsg[0] != '\0')
errx(1, "%s", errmsg);
err(1, "jail_set");
}
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].name.iov_base, "jid") &&
strcmp(params[i].name.iov_base, "errmsg")) {
fprintf(fp, " %s",
(char *)params[i].name.iov_base);
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].name.iov_base, "path"))
break;
#ifdef INET6
fprintf(fp, "%d\t%s\t%s\t%s%s%s\t%s\n",
jid, i < nparams
? (char *)params[i].value.iov_base : argv[0],
argv[1], ip4_addr ? ip4_addr : "",
ip4_addr && ip4_addr[0] && ip6_addr && ip6_addr[0]
? "," : "", ip6_addr ? ip6_addr : "", argv[3]);
#else
fprintf(fp, "%d\t%s\t%s\t%s\t%s\n",
jid, i < nparams
? (char *)params[i].value.iov_base : 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]);
}
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;
}
}
#ifdef INET6
static void
add_ip_addr46(char *value)
{
char *p, *np;
if (!value[0]) {
add_ip_addr(&ip4_addr, value);
add_ip_addr(&ip6_addr, value);
return;
}
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;
struct in_addr addr4;
int error;
char avalue4[INET_ADDRSTRLEN];
#ifdef INET6
struct in6_addr addr6;
char avalue6[INET6_ADDRSTRLEN];
#endif
/* Look up the hostname (or get the address) */
memset(&hints, 0, sizeof(hints));
hints.ai_socktype = SOCK_STREAM;
#ifdef INET6
hints.ai_family = PF_UNSPEC;
#else
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) {
case AF_INET:
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;
#ifdef INET6
case AF_INET6:
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 param *param;
char *ep, *p;
size_t buflen, mlen;
int i, nval, mib[CTL_MAXNAME];
struct {
int i;
char s[MAXPATHLEN];
} buf;
static int paramlistsize;
/* Separate the name from the value, if not done already. */
if (name == NULL) {
name = value;
if ((value = strchr(value, '=')))
*value++ = '\0';
}
/* Check for repeat parameters */
for (i = 0; i < nparams; i++)
if (!strcmp(name, params[i].name.iov_base)) {
memcpy(params + i, params + i + 1,
(--nparams - i) * sizeof(struct param));
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++;
*(const void **)&param->name.iov_base = name;
param->name.iov_len = strlen(name) + 1;
/* Trivial values - no value or errmsg. */
if (value == NULL) {
param->value.iov_base = NULL;
param->value.iov_len = 0;
return;
}
if (!strcmp(name, "errmsg")) {
param->value.iov_base = value;
param->value.iov_len = ERRMSG_SIZE;
return;
}
mib[0] = 0;
mib[1] = 3;
snprintf(buf.s, sizeof(buf.s), SJPARAM ".%s", name);
mlen = sizeof(mib) - 2 * sizeof(int);
if (sysctl(mib, 2, mib + 2, &mlen, buf.s, strlen(buf.s)) < 0)
errx(1, "unknown parameter: %s", name);
mib[1] = 4;
buflen = sizeof(buf);
if (sysctl(mib, (mlen / sizeof(int)) + 2, &buf, &buflen, NULL, 0) < 0)
err(1, "sysctl(0.4.%s)", name);
/*
* See if this is an array type.
* Treat non-arrays as an array of one.
*/
p = strchr(buf.s, '\0');
nval = 1;
if (p - 2 >= buf.s && !strcmp(p - 2, ",a")) {
if (value[0] == '\0' ||
(value[0] == '-' && value[1] == '\0')) {
param->value.iov_base = value;
param->value.iov_len = 0;
return;
}
p[-2] = 0;
for (p = strchr(value, ','); p; p = strchr(p + 1, ',')) {
*p = '\0';
nval++;
}
}
/* Set the values according to the parameter type. */
switch (buf.i & CTLTYPE) {
case CTLTYPE_INT:
case CTLTYPE_UINT:
param->value.iov_len = nval * sizeof(int);
break;
case CTLTYPE_LONG:
case CTLTYPE_ULONG:
param->value.iov_len = nval * sizeof(long);
break;
case CTLTYPE_STRUCT:
if (!strcmp(buf.s, "S,in_addr"))
param->value.iov_len = nval * sizeof(struct in_addr);
#ifdef INET6
else if (!strcmp(buf.s, "S,in6_addr"))
param->value.iov_len = nval * sizeof(struct in6_addr);
#endif
else
errx(1, "%s: unknown parameter structure (%s)",
name, buf.s);
break;
case CTLTYPE_STRING:
if (!strcmp(name, "path")) {
param->value.iov_base = malloc(MAXPATHLEN);
if (param->value.iov_base == NULL)
err(1, "malloc");
if (realpath(value, param->value.iov_base) == NULL)
err(1, "%s: realpath(%s)", name, value);
if (chdir(param->value.iov_base) != 0)
err(1, "chdir: %s",
(char *)param->value.iov_base);
} else
param->value.iov_base = value;
param->value.iov_len = strlen(param->value.iov_base) + 1;
return;
default:
errx(1, "%s: unknown parameter type %d (%s)",
name, buf.i, buf.s);
}
param->value.iov_base = malloc(param->value.iov_len);
for (i = 0; i < nval; i++) {
switch (buf.i & CTLTYPE) {
case CTLTYPE_INT:
((int *)param->value.iov_base)[i] =
strtol(value, &ep, 10);
if (ep[0] != '\0')
errx(1, "%s: non-integer value \"%s\"",
name, value);
break;
case CTLTYPE_UINT:
((unsigned *)param->value.iov_base)[i] =
strtoul(value, &ep, 10);
if (ep[0] != '\0')
errx(1, "%s: non-integer value \"%s\"",
name, value);
break;
case CTLTYPE_LONG:
((long *)param->value.iov_base)[i] =
strtol(value, &ep, 10);
if (ep[0] != '\0')
errx(1, "%s: non-integer value \"%s\"",
name, value);
break;
case CTLTYPE_ULONG:
((unsigned long *)param->value.iov_base)[i] =
strtoul(value, &ep, 10);
if (ep[0] != '\0')
errx(1, "%s: non-integer value \"%s\"",
name, value);
break;
case CTLTYPE_STRUCT:
if (!strcmp(buf.s, "S,in_addr")) {
if (inet_pton(AF_INET, value,
&((struct in_addr *)
param->value.iov_base)[i]) != 1)
errx(1, "%s: not an IPv4 address: %s",
name, value);
}
#ifdef INET6
else if (!strcmp(buf.s, "S,in6_addr")) {
if (inet_pton(AF_INET6, value,
&((struct in6_addr *)
param->value.iov_base)[i]) != 1)
errx(1, "%s: not an IPv6 address: %s",
name, value);
}
#endif
}
if (i > 0)
value[-1] = ',';
value = strchr(value, '\0') + 1;
}
}
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);
}