freebsd-dev/usr.sbin/jail/jail.c
delphij 493bad4a2a Initialize lcap and pwd to NULL. This allows a WARNS=6 clean build,
hence bump it to 6.

Note that the last commit message was not quite accurate.  While the
assumption exists in the code, it's not possible to have an
uninitialized p there because if lflag is set when username is NULL
then execution would be terminated earlier.
2004-11-17 10:01:48 +00:00

156 lines
3.4 KiB
C

/*
* ----------------------------------------------------------------------------
* "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);
}