1 /* 2 * Copyright (c) 1980, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)popen.c 8.1 (Berkeley) 6/6/93 30 * $FreeBSD: src/usr.bin/mail/popen.c,v 1.2.6.3 2003/01/06 05:46:03 mikeh Exp $ 31 * $DragonFly: src/usr.bin/mail/popen.c,v 1.4 2004/09/08 03:01:11 joerg Exp $ 32 */ 33 34 #include "rcv.h" 35 #include <sys/wait.h> 36 #include <fcntl.h> 37 #include "extern.h" 38 39 #define READ 0 40 #define WRITE 1 41 42 struct fp { 43 FILE *fp; 44 int pipe; 45 int pid; 46 struct fp *link; 47 }; 48 static struct fp *fp_head; 49 50 struct child { 51 int pid; 52 char done; 53 char free; 54 int status; 55 struct child *link; 56 }; 57 static struct child *child; 58 static struct child *findchild(int); 59 static void delchild(struct child *); 60 static int file_pid(FILE *); 61 62 FILE * 63 Fopen(const char *path, const char *mode) 64 { 65 FILE *fp; 66 67 if ((fp = fopen(path, mode)) != NULL) { 68 register_file(fp, 0, 0); 69 fcntl(fileno(fp), F_SETFD, 1); 70 } 71 return (fp); 72 } 73 74 FILE * 75 Fdopen(int fd, const char *mode) 76 { 77 FILE *fp; 78 79 if ((fp = fdopen(fd, mode)) != NULL) { 80 register_file(fp, 0, 0); 81 fcntl(fileno(fp), F_SETFD, 1); 82 } 83 return (fp); 84 } 85 86 int 87 Fclose(FILE *fp) 88 { 89 unregister_file(fp); 90 return (fclose(fp)); 91 } 92 93 FILE * 94 Popen(char *cmd, const char *mode) 95 { 96 int p[2]; 97 int myside, hisside, fd0, fd1; 98 int pid; 99 sigset_t nset; 100 FILE *fp; 101 102 if (pipe(p) < 0) 103 return (NULL); 104 fcntl(p[READ], F_SETFD, 1); 105 fcntl(p[WRITE], F_SETFD, 1); 106 if (*mode == 'r') { 107 myside = p[READ]; 108 fd0 = -1; 109 hisside = fd1 = p[WRITE]; 110 } else { 111 myside = p[WRITE]; 112 hisside = fd0 = p[READ]; 113 fd1 = -1; 114 } 115 sigemptyset(&nset); 116 if ((pid = start_command(cmd, &nset, fd0, fd1, NULL, NULL, NULL)) < 0) { 117 close(p[READ]); 118 close(p[WRITE]); 119 return (NULL); 120 } 121 close(hisside); 122 if ((fp = fdopen(myside, mode)) != NULL) 123 register_file(fp, 1, pid); 124 return (fp); 125 } 126 127 int 128 Pclose(FILE *ptr) 129 { 130 int i; 131 sigset_t nset, oset; 132 133 i = file_pid(ptr); 134 unregister_file(ptr); 135 fclose(ptr); 136 sigemptyset(&nset); 137 sigaddset(&nset, SIGINT); 138 sigaddset(&nset, SIGHUP); 139 sigprocmask(SIG_BLOCK, &nset, &oset); 140 i = wait_child(i); 141 sigprocmask(SIG_SETMASK, &oset, NULL); 142 return (i); 143 } 144 145 void 146 close_all_files(void) 147 { 148 149 while (fp_head != NULL) 150 if (fp_head->pipe) 151 (void)Pclose(fp_head->fp); 152 else 153 (void)Fclose(fp_head->fp); 154 } 155 156 void 157 register_file(FILE *fp, int pipe, int pid) 158 { 159 struct fp *fpp; 160 161 if ((fpp = malloc(sizeof(*fpp))) == NULL) 162 err(1, "Out of memory"); 163 fpp->fp = fp; 164 fpp->pipe = pipe; 165 fpp->pid = pid; 166 fpp->link = fp_head; 167 fp_head = fpp; 168 } 169 170 void 171 unregister_file(FILE *fp) 172 { 173 struct fp **pp, *p; 174 175 for (pp = &fp_head; (p = *pp) != NULL; pp = &p->link) 176 if (p->fp == fp) { 177 *pp = p->link; 178 (void)free(p); 179 return; 180 } 181 errx(1, "Invalid file pointer"); 182 /*NOTREACHED*/ 183 } 184 185 int 186 file_pid(FILE *fp) 187 { 188 struct fp *p; 189 190 for (p = fp_head; p != NULL; p = p->link) 191 if (p->fp == fp) 192 return (p->pid); 193 errx(1, "Invalid file pointer"); 194 /*NOTREACHED*/ 195 } 196 197 /* 198 * Run a command without a shell, with optional arguments and splicing 199 * of stdin and stdout. The command name can be a sequence of words. 200 * Signals must be handled by the caller. 201 * "Mask" contains the signals to ignore in the new process. 202 * SIGINT is enabled unless it's in the mask. 203 */ 204 /*VARARGS4*/ 205 int 206 run_command(char *cmd, sigset_t *mask, int infd, int outfd, char *a0, char *a1, 207 char *a2) 208 { 209 int pid; 210 211 if ((pid = start_command(cmd, mask, infd, outfd, a0, a1, a2)) < 0) 212 return (-1); 213 return (wait_command(pid)); 214 } 215 216 /*VARARGS4*/ 217 int 218 start_command(char *cmd, sigset_t *mask, int infd, int outfd, char *a0, 219 char *a1, char *a2) 220 { 221 int pid; 222 223 if ((pid = fork()) < 0) { 224 warn("fork"); 225 return (-1); 226 } 227 if (pid == 0) { 228 char *argv[100]; 229 int i = getrawlist(cmd, argv, sizeof(argv) / sizeof(*argv)); 230 231 if ((argv[i++] = a0) != NULL && 232 (argv[i++] = a1) != NULL && 233 (argv[i++] = a2) != NULL) 234 argv[i] = NULL; 235 prepare_child(mask, infd, outfd); 236 execvp(argv[0], argv); 237 warn("%s", argv[0]); 238 _exit(1); 239 } 240 return (pid); 241 } 242 243 void 244 prepare_child(sigset_t *nset, int infd, int outfd) 245 { 246 int i; 247 sigset_t eset; 248 249 /* 250 * All file descriptors other than 0, 1, and 2 are supposed to be 251 * close-on-exec. 252 */ 253 if (infd >= 0) 254 dup2(infd, 0); 255 if (outfd >= 0) 256 dup2(outfd, 1); 257 for (i = 1; i < NSIG; i++) 258 if (nset != NULL && sigismember(nset, i)) 259 (void)signal(i, SIG_IGN); 260 if (nset == NULL || !sigismember(nset, SIGINT)) 261 (void)signal(SIGINT, SIG_DFL); 262 sigemptyset(&eset); 263 sigprocmask(SIG_SETMASK, &eset, NULL); 264 } 265 266 int 267 wait_command(int pid) 268 { 269 if (wait_child(pid) < 0) { 270 printf("Fatal error in process.\n"); 271 return (-1); 272 } 273 return (0); 274 } 275 276 static struct child * 277 findchild(int pid) 278 { 279 struct child **cpp; 280 281 for (cpp = &child; *cpp != NULL && (*cpp)->pid != pid; 282 cpp = &(*cpp)->link) 283 ; 284 if (*cpp == NULL) { 285 *cpp = malloc(sizeof(struct child)); 286 if (*cpp == NULL) 287 err(1, "Out of memory"); 288 (*cpp)->pid = pid; 289 (*cpp)->done = (*cpp)->free = 0; 290 (*cpp)->link = NULL; 291 } 292 return (*cpp); 293 } 294 295 static void 296 delchild(struct child *cp) 297 { 298 struct child **cpp; 299 300 for (cpp = &child; *cpp != cp; cpp = &(*cpp)->link) 301 ; 302 *cpp = cp->link; 303 free(cp); 304 } 305 306 /*ARGSUSED*/ 307 void 308 sigchild(int signo) 309 { 310 int pid; 311 int status; 312 struct child *cp; 313 314 while ((pid = waitpid((pid_t)-1, &status, WNOHANG)) > 0) { 315 cp = findchild(pid); 316 if (cp->free) 317 delchild(cp); 318 else { 319 cp->done = 1; 320 cp->status = status; 321 } 322 } 323 } 324 325 int wait_status; 326 327 /* 328 * Wait for a specific child to die. 329 */ 330 int 331 wait_child(int pid) 332 { 333 sigset_t nset, oset; 334 struct child *cp = findchild(pid); 335 336 sigemptyset(&nset); 337 sigaddset(&nset, SIGCHLD); 338 sigprocmask(SIG_BLOCK, &nset, &oset); 339 340 while (!cp->done) 341 (void)sigsuspend(&oset); 342 wait_status = cp->status; 343 delchild(cp); 344 sigprocmask(SIG_SETMASK, &oset, NULL); 345 return ((WIFEXITED(wait_status) && WEXITSTATUS(wait_status)) ? -1 : 0); 346 } 347 348 /* 349 * Mark a child as don't care. 350 */ 351 void 352 free_child(int pid) 353 { 354 sigset_t nset, oset; 355 struct child *cp = findchild(pid); 356 357 sigemptyset(&nset); 358 sigaddset(&nset, SIGCHLD); 359 sigprocmask(SIG_BLOCK, &nset, &oset); 360 361 if (cp->done) 362 delchild(cp); 363 else 364 cp->free = 1; 365 sigprocmask(SIG_SETMASK, &oset, NULL); 366 } 367