chpst.c (7089B)
1 2 #include "parse.h" 3 4 #include <arg.h> 5 #include <common.h> 6 #include <fcntl.h> 7 #include <fmt.h> 8 #include <grp.h> 9 #include <stdbool.h> 10 #include <stdlib.h> 11 #include <string.h> 12 #include <sys/file.h> 13 #include <sys/resource.h> 14 #include <unistd.h> 15 16 void usage(void) { 17 print("Usage:\n" 18 " chpst [-vP012] [-u user[:group]] [-U user[:group]] [-b argv0] [-e dir]\n" 19 " [-/ root] [-C pwd] [-n nice] [-l|-L lock] [-m n] [-d n] [-o n] [-p n] [-f n]\n" 20 " [-c n] command ...\n" 21 " softlimit [-m n] [-a n] [-d n] [-o n] [-p n] [-f n] [-c n] [-r n] [-t n]\n" 22 " [-l n] [-s n] command ...\n" 23 " setuidgid user[:group] command ...\n" 24 " envuidgid user[:group] command ...\n" 25 " pgrphack command ...\n" 26 " setlock [-nNxX] lock command ...\n"); 27 } 28 29 void limit(int what, long l) { 30 struct rlimit r; 31 32 if (getrlimit(what, &r) == -1) 33 fprint(1, "error: unable to getrlimit: %r\n"); 34 35 if (l < 0) { 36 r.rlim_cur = 0; 37 } else if ((unsigned long) l > r.rlim_max) 38 r.rlim_cur = r.rlim_max; 39 else 40 r.rlim_cur = l; 41 42 if (setrlimit(what, &r) == -1) 43 fprint(1, "error: unable to setrlimit: %r\n"); 44 } 45 46 47 int main(int argc, char** argv) { 48 int lockfd, lockflags = 0, gid_len = 0; 49 char *arg0 = NULL, *root = NULL, *cd = NULL, *lock = NULL; 50 uid_t uid = 0; 51 gid_t gid[61]; 52 53 argv0 = argv[0]; 54 55 long limitd = -2, 56 limits = -2, 57 limitl = -2, 58 limita = -2, 59 limito = -2, 60 limitp = -2, 61 limitf = -2, 62 limitc = -2, 63 limitr = -2, 64 limitt = -2; 65 long nicelevel = 0; 66 bool ssid = false; 67 bool closestd[3] = { false, false, false }; 68 69 if (streq(argv0, "setuidgid") || streq(argv0, "envuidgid")) { 70 if (argc < 2) { 71 fprint(1, "%s <uid-gid> command...", argv0); 72 return 1; 73 } 74 gid_len = parse_ugid(argv[1], &uid, gid); 75 SHIFT(2); 76 } else if (streq(argv0, "pgrphack")) { 77 ssid = true; 78 SHIFT(1); 79 } else if (streq(argv0, "setlock")) { 80 ARGBEGIN { 81 case 'n': 82 lockflags = LOCK_EX | LOCK_NB; 83 break; 84 case 'N': 85 lockflags = LOCK_EX; 86 break; 87 case 'x': 88 case 'X': 89 fprint(1, "warning: '-%c' is ignored\n", ARGC()); 90 break; 91 default: 92 usage(); 93 return 1; 94 } 95 ARGEND; 96 97 if (argc < 1) { 98 fprint(1, "%s [-xXnN] command...", argv0); 99 return 1; 100 } 101 lock = argv[1]; 102 SHIFT(1); 103 } else if (streq(argv0, "softlimit")) { 104 ARGBEGIN { 105 case 'm': 106 limits = limitl = limita = limitd = atol(EARGF(usage())); 107 break; 108 case 'a': 109 limita = atol(EARGF(usage())); 110 break; 111 case 'd': 112 limitd = atol(EARGF(usage())); 113 break; 114 case 'o': 115 limito = atol(EARGF(usage())); 116 break; 117 case 'p': 118 limitp = atol(EARGF(usage())); 119 break; 120 case 'f': 121 limitf = atol(EARGF(usage())); 122 break; 123 case 'c': 124 limitc = atol(EARGF(usage())); 125 break; 126 case 'r': 127 limitr = atol(EARGF(usage())); 128 break; 129 case 't': 130 limitt = atol(EARGF(usage())); 131 break; 132 case 'l': 133 limitl = atol(EARGF(usage())); 134 break; 135 case 's': 136 limits = atol(EARGF(usage())); 137 break; 138 default: 139 usage(); 140 return 1; 141 } 142 ARGEND; 143 } else { 144 ARGBEGIN { 145 case 'u': 146 case 'U': 147 gid_len = parse_ugid(EARGF(usage()), &uid, gid); 148 break; 149 case 'b': 150 arg0 = EARGF(usage()); 151 break; 152 case '/': 153 root = EARGF(usage()); 154 break; 155 case 'C': 156 cd = EARGF(usage()); 157 break; 158 case 'n': 159 nicelevel = atol(EARGF(usage())); 160 break; 161 case 'l': 162 lock = EARGF(usage()); 163 lockflags = LOCK_EX | LOCK_NB; 164 break; 165 case 'L': 166 lock = EARGF(usage()); 167 lockflags = LOCK_EX; 168 break; 169 case 'v': // ignored 170 break; 171 case 'P': 172 ssid = true; 173 break; 174 case '0': 175 case '1': 176 case '2': 177 closestd[ARGC() - '0'] = true; 178 break; 179 case 'm': 180 limits = limitl = limita = limitd = atol(EARGF(usage())); 181 break; 182 case 'd': 183 limitd = atol(EARGF(usage())); 184 break; 185 case 'o': 186 limito = atol(EARGF(usage())); 187 break; 188 case 'p': 189 limitp = atol(EARGF(usage())); 190 break; 191 case 'f': 192 limitf = atol(EARGF(usage())); 193 break; 194 case 'c': 195 limitc = atol(EARGF(usage())); 196 break; 197 case 'r': 198 limitr = atol(EARGF(usage())); 199 break; 200 case 't': 201 limitt = atol(EARGF(usage())); 202 break; 203 case 'e': 204 fprint(1, "warning: '-%c' is ignored\n", ARGC()); 205 break; 206 default: 207 usage(); 208 return 1; 209 } 210 ARGEND; 211 } 212 213 if (argc == 0) { 214 fprint(1, "%s: command required\n", argv0); 215 return 1; 216 } 217 218 if (ssid) { 219 setsid(); 220 } 221 222 if (uid) { 223 setgroups(gid_len, gid); 224 setgid(gid[0]); 225 setuid(uid); 226 // $EUID 227 } 228 229 if (root) { 230 if (chroot(root) == -1) 231 fprint(1, "unable to change root directory: %r\n"); 232 233 // chdir to '/', otherwise the next command will complain 'directory not found' 234 chdir("/"); 235 } 236 237 if (cd) { 238 chdir(cd); 239 } 240 241 if (nicelevel != 0) { 242 if (nice(nicelevel) == -1) 243 fprint(1, "unable to set nice level: %r\n"); 244 } 245 246 if (limitd >= -1) { 247 #ifdef RLIMIT_DATA 248 limit(RLIMIT_DATA, limitd); 249 #else 250 if (verbose) 251 fprint(1, "system does not support RLIMIT_DATA\n"); 252 #endif 253 } 254 if (limits >= -1) { 255 #ifdef RLIMIT_STACK 256 limit(RLIMIT_STACK, limits); 257 #else 258 if (verbose) 259 fprint(1, "system does not support RLIMIT_STACK\n"); 260 #endif 261 } 262 if (limitl >= -1) { 263 #ifdef RLIMIT_MEMLOCK 264 limit(RLIMIT_MEMLOCK, limitl); 265 #else 266 if (verbose) 267 fprint(1, "system does not support RLIMIT_MEMLOCK\n"); 268 #endif 269 } 270 if (limita >= -1) { 271 #ifdef RLIMIT_VMEM 272 limit(RLIMIT_VMEM, limita); 273 #else 274 # ifdef RLIMIT_AS 275 limit(RLIMIT_AS, limita); 276 # else 277 if (verbose) 278 fprint(1, "system does neither support RLIMIT_VMEM nor RLIMIT_AS\n"); 279 # endif 280 #endif 281 } 282 if (limito >= -1) { 283 #ifdef RLIMIT_NOFILE 284 limit(RLIMIT_NOFILE, limito); 285 #else 286 # ifdef RLIMIT_OFILE 287 limit(RLIMIT_OFILE, limito); 288 # else 289 if (verbose) 290 fprint(1, "system does neither support RLIMIT_NOFILE nor RLIMIT_OFILE\n"); 291 # endif 292 #endif 293 } 294 if (limitp >= -1) { 295 #ifdef RLIMIT_NPROC 296 limit(RLIMIT_NPROC, limitp); 297 #else 298 if (verbose) 299 fprint(1, "system does not support RLIMIT_NPROC\n"); 300 #endif 301 } 302 if (limitf >= -1) { 303 #ifdef RLIMIT_FSIZE 304 limit(RLIMIT_FSIZE, limitf); 305 #else 306 if (verbose) 307 fprint(1, "system does not support RLIMIT_FSIZE\n"); 308 #endif 309 } 310 if (limitc >= -1) { 311 #ifdef RLIMIT_CORE 312 limit(RLIMIT_CORE, limitc); 313 #else 314 if (verbose) 315 fprint(1, "system does not support RLIMIT_CORE\n"); 316 #endif 317 } 318 if (limitr >= -1) { 319 #ifdef RLIMIT_RSS 320 limit(RLIMIT_RSS, limitr); 321 #else 322 if (verbose) 323 fprint(1, "system does not support RLIMIT_RSS\n"); 324 #endif 325 } 326 if (limitt >= -1) { 327 #ifdef RLIMIT_CPU 328 limit(RLIMIT_CPU, limitt); 329 #else 330 if (verbose) 331 fprint(1, "system does not support RLIMIT_CPU\n"); 332 #endif 333 } 334 335 if (lock) { 336 if ((lockfd = open(lock, O_WRONLY | O_APPEND)) == -1) 337 fprint(1, "unable to open lock: %r\n"); 338 339 if (flock(lockfd, lockflags) == -1) 340 fprint(1, "unable to lock: %r\n"); 341 } 342 343 for (int i = 0; i < 3; i++) 344 if (closestd[i] && close(i) == -1) 345 fprint(1, "unable to close std-%d: %r\n", i); 346 347 execvp(arg0 ? arg0 : *argv, argv); 348 fprint(1, "cannot execute: %r\n"); 349 }