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/*
* ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
* ----------------------------------------------------------------------------
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/jail.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <err.h>
#include <errno.h>
#include <grp.h>
#include <login_cap.h>
#include <paths.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
static void usage(void);
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 jail j;
struct passwd *pwd = NULL;
struct in_addr in;
gid_t groups[NGROUPS];
int ch, i, iflag, lflag, ngroups, uflag, Uflag;
char path[PATH_MAX], *username;
static char *cleanenv;
const char *shell, *p = NULL;
iflag = lflag = uflag = Uflag = 0;
username = cleanenv = NULL;
while ((ch = getopt(argc, argv, "ilu:U:")) != -1) {
switch (ch) {
case 'i':
iflag = 1;
break;
case 'u':
username = optarg;
uflag = 1;
break;
case 'U':
username = optarg;
Uflag = 1;
break;
case 'l':
lflag = 1;
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
if (argc < 4)
usage();
if (uflag && Uflag)
usage();
if (lflag && username == NULL)
usage();
if (uflag)
GET_USER_INFO;
if (realpath(argv[0], path) == NULL)
err(1, "realpath: %s", argv[0]);
if (chdir(path) != 0)
err(1, "chdir: %s", path);
memset(&j, 0, sizeof(j));
j.version = 0;
j.path = path;
j.hostname = argv[1];
if (inet_aton(argv[2], &in) == 0)
errx(1, "Could not make sense of ip-number: %s", argv[2]);
j.ip_number = ntohl(in.s_addr);
i = jail(&j);
if (i == -1)
err(1, "jail");
if (iflag) {
printf("%d\n", i);
fflush(stdout);
}
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) != 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);
}
if (execv(argv[3], argv + 3) != 0)
err(1, "execv: %s", argv[3]);
exit(0);
}
static void
usage(void)
{
(void)fprintf(stderr, "%s%s\n",
"usage: jail [-i] [-l -u username | -U username]",
" path hostname ip-number command ...");
exit(1);
}
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