1 /* 2 * ---------------------------------------------------------------------------- 3 * "THE BEER-WARE LICENSE" (Revision 42): 4 * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you 5 * can do whatever you want with this stuff. If we meet some day, and you think 6 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 7 * ---------------------------------------------------------------------------- 8 */ 9 10 #include <sys/cdefs.h> 11 __FBSDID("$FreeBSD$"); 12 13 #include <sys/param.h> 14 #include <sys/jail.h> 15 16 #include <netinet/in.h> 17 #include <arpa/inet.h> 18 19 #include <err.h> 20 #include <errno.h> 21 #include <grp.h> 22 #include <login_cap.h> 23 #include <paths.h> 24 #include <pwd.h> 25 #include <stdio.h> 26 #include <stdlib.h> 27 #include <string.h> 28 #include <unistd.h> 29 30 static void usage(void); 31 extern char **environ; 32 33 #define GET_USER_INFO do { \ 34 pwd = getpwnam(username); \ 35 if (pwd == NULL) { \ 36 if (errno) \ 37 err(1, "getpwnam: %s", username); \ 38 else \ 39 errx(1, "%s: no such user", username); \ 40 } \ 41 lcap = login_getpwclass(pwd); \ 42 if (lcap == NULL) \ 43 err(1, "getpwclass: %s", username); \ 44 ngroups = NGROUPS; \ 45 if (getgrouplist(username, pwd->pw_gid, groups, &ngroups) != 0) \ 46 err(1, "getgrouplist: %s", username); \ 47 } while (0) 48 49 int 50 main(int argc, char **argv) 51 { 52 login_cap_t *lcap; 53 struct jail j; 54 struct passwd *pwd; 55 struct in_addr in; 56 int ch, groups[NGROUPS], i, iflag, lflag, ngroups, uflag, Uflag; 57 char path[PATH_MAX], *username; 58 static char *cleanenv; 59 const char *shell, *p; 60 61 iflag = lflag = uflag = Uflag = 0; 62 username = cleanenv = NULL; 63 64 while ((ch = getopt(argc, argv, "ilu:U:")) != -1) { 65 switch (ch) { 66 case 'i': 67 iflag = 1; 68 break; 69 case 'u': 70 username = optarg; 71 uflag = 1; 72 break; 73 case 'U': 74 username = optarg; 75 Uflag = 1; 76 break; 77 case 'l': 78 lflag = 1; 79 break; 80 default: 81 usage(); 82 } 83 } 84 argc -= optind; 85 argv += optind; 86 if (argc < 4) 87 usage(); 88 if (uflag && Uflag) 89 usage(); 90 if (lflag && username == NULL) 91 usage(); 92 if (uflag) 93 GET_USER_INFO; 94 if (realpath(argv[0], path) == NULL) 95 err(1, "realpath: %s", argv[0]); 96 if (chdir(path) != 0) 97 err(1, "chdir: %s", path); 98 memset(&j, 0, sizeof(j)); 99 j.version = 0; 100 j.path = path; 101 j.hostname = argv[1]; 102 if (inet_aton(argv[2], &in) == 0) 103 errx(1, "Could not make sense of ip-number: %s", argv[2]); 104 j.ip_number = ntohl(in.s_addr); 105 i = jail(&j); 106 if (i == -1) 107 err(1, "jail"); 108 if (iflag) { 109 printf("%d\n", i); 110 fflush(stdout); 111 } 112 if (username != NULL) { 113 if (Uflag) 114 GET_USER_INFO; 115 if (lflag) { 116 p = getenv("TERM"); 117 environ = &cleanenv; 118 } 119 if (setgroups(ngroups, groups) != 0) 120 err(1, "setgroups"); 121 if (setgid(pwd->pw_gid) != 0) 122 err(1, "setgid"); 123 if (setusercontext(lcap, pwd, pwd->pw_uid, 124 LOGIN_SETALL & ~LOGIN_SETGROUP) != 0) 125 err(1, "setusercontext"); 126 login_close(lcap); 127 } 128 if (lflag) { 129 if (*pwd->pw_shell) 130 shell = pwd->pw_shell; 131 else 132 shell = _PATH_BSHELL; 133 if (chdir(pwd->pw_dir) < 0) 134 errx(1, "no home directory"); 135 setenv("HOME", pwd->pw_dir, 1); 136 setenv("SHELL", shell, 1); 137 setenv("USER", pwd->pw_name, 1); 138 if (p) 139 setenv("TERM", p, 1); 140 } 141 if (execv(argv[3], argv + 3) != 0) 142 err(1, "execv: %s", argv[3]); 143 exit(0); 144 } 145 146 static void 147 usage(void) 148 { 149 150 (void)fprintf(stderr, "%s%s\n", 151 "usage: jail [-i] [-l -u username | -U username]", 152 " path hostname ip-number command ..."); 153 exit(1); 154 } 155