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 #include <sys/sysctl.h> 16 17 #include <netinet/in.h> 18 #include <arpa/inet.h> 19 20 #include <err.h> 21 #include <errno.h> 22 #include <grp.h> 23 #include <login_cap.h> 24 #include <paths.h> 25 #include <pwd.h> 26 #include <stdio.h> 27 #include <stdlib.h> 28 #include <string.h> 29 #include <unistd.h> 30 31 static void usage(void); 32 extern char **environ; 33 34 #define GET_USER_INFO do { \ 35 pwd = getpwnam(username); \ 36 if (pwd == NULL) { \ 37 if (errno) \ 38 err(1, "getpwnam: %s", username); \ 39 else \ 40 errx(1, "%s: no such user", username); \ 41 } \ 42 lcap = login_getpwclass(pwd); \ 43 if (lcap == NULL) \ 44 err(1, "getpwclass: %s", username); \ 45 ngroups = NGROUPS; \ 46 if (getgrouplist(username, pwd->pw_gid, groups, &ngroups) != 0) \ 47 err(1, "getgrouplist: %s", username); \ 48 } while (0) 49 50 int 51 main(int argc, char **argv) 52 { 53 login_cap_t *lcap = NULL; 54 struct jail j; 55 struct passwd *pwd = NULL; 56 struct in_addr in; 57 gid_t groups[NGROUPS]; 58 int ch, i, iflag, Jflag, lflag, ngroups, securelevel, uflag, Uflag; 59 char path[PATH_MAX], *ep, *username, *JidFile; 60 static char *cleanenv; 61 const char *shell, *p = NULL; 62 long ltmp; 63 FILE *fp; 64 65 iflag = Jflag = lflag = uflag = Uflag = 0; 66 securelevel = -1; 67 username = JidFile = cleanenv = NULL; 68 fp = NULL; 69 70 while ((ch = getopt(argc, argv, "ils:u:U:J:")) != -1) { 71 switch (ch) { 72 case 'i': 73 iflag = 1; 74 break; 75 case 'J': 76 JidFile = optarg; 77 Jflag = 1; 78 break; 79 case 's': 80 ltmp = strtol(optarg, &ep, 0); 81 if (*ep || ep == optarg || ltmp > INT_MAX || !ltmp) 82 errx(1, "invalid securelevel: `%s'", optarg); 83 securelevel = ltmp; 84 break; 85 case 'u': 86 username = optarg; 87 uflag = 1; 88 break; 89 case 'U': 90 username = optarg; 91 Uflag = 1; 92 break; 93 case 'l': 94 lflag = 1; 95 break; 96 default: 97 usage(); 98 } 99 } 100 argc -= optind; 101 argv += optind; 102 if (argc < 4) 103 usage(); 104 if (uflag && Uflag) 105 usage(); 106 if (lflag && username == NULL) 107 usage(); 108 if (uflag) 109 GET_USER_INFO; 110 if (realpath(argv[0], path) == NULL) 111 err(1, "realpath: %s", argv[0]); 112 if (chdir(path) != 0) 113 err(1, "chdir: %s", path); 114 memset(&j, 0, sizeof(j)); 115 j.version = 0; 116 j.path = path; 117 j.hostname = argv[1]; 118 if (inet_aton(argv[2], &in) == 0) 119 errx(1, "Could not make sense of ip-number: %s", argv[2]); 120 j.ip_number = ntohl(in.s_addr); 121 if (Jflag) { 122 fp = fopen(JidFile, "w"); 123 if (fp == NULL) 124 errx(1, "Could not create JidFile: %s", JidFile); 125 } 126 i = jail(&j); 127 if (i == -1) 128 err(1, "jail"); 129 if (iflag) { 130 printf("%d\n", i); 131 fflush(stdout); 132 } 133 if (Jflag) { 134 if (fp != NULL) { 135 fprintf(fp, "%d\t%s\t%s\t%s\t%s\n", 136 i, j.path, j.hostname, argv[2], argv[3]); 137 (void)fclose(fp); 138 } else { 139 errx(1, "Could not write JidFile: %s", JidFile); 140 } 141 } 142 if (securelevel > 0) { 143 if (sysctlbyname("kern.securelevel", NULL, 0, &securelevel, 144 sizeof(securelevel))) 145 err(1, "Can not set securelevel to %d", securelevel); 146 } 147 if (username != NULL) { 148 if (Uflag) 149 GET_USER_INFO; 150 if (lflag) { 151 p = getenv("TERM"); 152 environ = &cleanenv; 153 } 154 if (setgroups(ngroups, groups) != 0) 155 err(1, "setgroups"); 156 if (setgid(pwd->pw_gid) != 0) 157 err(1, "setgid"); 158 if (setusercontext(lcap, pwd, pwd->pw_uid, 159 LOGIN_SETALL & ~LOGIN_SETGROUP & ~LOGIN_SETLOGIN) != 0) 160 err(1, "setusercontext"); 161 login_close(lcap); 162 } 163 if (lflag) { 164 if (*pwd->pw_shell) 165 shell = pwd->pw_shell; 166 else 167 shell = _PATH_BSHELL; 168 if (chdir(pwd->pw_dir) < 0) 169 errx(1, "no home directory"); 170 setenv("HOME", pwd->pw_dir, 1); 171 setenv("SHELL", shell, 1); 172 setenv("USER", pwd->pw_name, 1); 173 if (p) 174 setenv("TERM", p, 1); 175 } 176 if (execv(argv[3], argv + 3) != 0) 177 err(1, "execv: %s", argv[3]); 178 exit(0); 179 } 180 181 static void 182 usage(void) 183 { 184 185 (void)fprintf(stderr, "%s%s%s\n", 186 "usage: jail [-i] [-J jid_file] [-s securelevel] [-l -u ", 187 "username | -U username]", 188 " path hostname ip-number command ..."); 189 exit(1); 190 } 191