lib/roken/simple_exec.c

   1 /*
   2  * Copyright (c) 1998 - 2001, 2004 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifdef HAVE_CONFIG_H
  35 #include <config.h>
  36 RCSID("$Id$");
  37 #endif
  38
  39 #include <stdarg.h>
  40 #include <stdlib.h>
  41 #ifdef HAVE_SYS_TYPES_H
  42 #include <sys/types.h>
  43 #endif
  44 #ifdef HAVE_SYS_WAIT_H
  45 #include <sys/wait.h>
  46 #endif
  47 #ifdef HAVE_UNISTD_H
  48 #include <unistd.h>
  49 #endif
  50 #include <errno.h>
  51
  52 #include "roken.h"
  53
  54 #define EX_NOEXEC       126
  55 #define EX_NOTFOUND     127
  56
  57 /* return values:
  58    -1   on `unspecified' system errors
  59    -2   on fork failures
  60    -3   on waitpid errors
  61    -4   exec timeout
  62    0-   is return value from subprocess
  63    126  if the program couldn't be executed
  64    127  if the program couldn't be found
  65    128- is 128 + signal that killed subprocess
  66
  67    possible values `func' can return:
  68    ((time_t)-2)         exit loop w/o killing child and return
  69                         `exec timeout'/-4 from simple_exec
  70    ((time_t)-1)         kill child with SIGTERM and wait for child to exit
  71    0                    don't timeout again
  72    n                    seconds to next timeout
  73    */
  74
  75 static int sig_alarm;
  76
  77 static RETSIGTYPE
  78 sigtimeout(int sig)
  79 {
  80     sig_alarm = 1;
  81     SIGRETURN(0);
  82 }
  83
  84 int ROKEN_LIB_FUNCTION
  85 wait_for_process_timed(pid_t pid, time_t (*func)(void *),
  86                        void *ptr, time_t timeout)
  87 {
  88     RETSIGTYPE (*old_func)(int sig) = NULL;
  89     unsigned int oldtime = 0;
  90     int ret;
  91
  92     sig_alarm = 0;
  93
  94     if (func) {
  95         old_func = signal(SIGALRM, sigtimeout);
  96         oldtime = alarm(timeout);
  97     }
  98
  99     while(1) {
 100         int status;
 101
 102         while(waitpid(pid, &status, 0) < 0) {
 103             if (errno != EINTR) {
 104                 ret = -3;
 105                 goto out;
 106             }
 107             if (func == NULL)
 108                 continue;
 109             if (sig_alarm == 0)
 110                 continue;
 111             timeout = (*func)(ptr);
 112             if (timeout == (time_t)-1) {
 113                 kill(pid, SIGTERM);
 114                 continue;
 115             } else if (timeout == (time_t)-2) {
 116                 ret = -4;
 117                 goto out;
 118             }
 119             alarm(timeout);
 120         }
 121         if(WIFSTOPPED(status))
 122             continue;
 123         if(WIFEXITED(status)) {
 124             ret = WEXITSTATUS(status);
 125             break;
 126         }
 127         if(WIFSIGNALED(status)) {
 128             ret = WTERMSIG(status) + 128;
 129             break;
 130         }
 131     }
 132  out:
 133     if (func) {
 134         signal(SIGALRM, old_func);
 135         alarm(oldtime);
 136     }
 137     return ret;
 138 }
 139
 140 int ROKEN_LIB_FUNCTION
 141 wait_for_process(pid_t pid)
 142 {
 143     return wait_for_process_timed(pid, NULL, NULL, 0);
 144 }
 145
 146 int ROKEN_LIB_FUNCTION
 147 pipe_execv(FILE **stdin_fd, FILE **stdout_fd, FILE **stderr_fd,
 148            const char *file, ...)
 149 {
 150     int in_fd[2], out_fd[2], err_fd[2];
 151     pid_t pid;
 152     va_list ap;
 153     char **argv;
 154
 155     if(stdin_fd != NULL)
 156         pipe(in_fd);
 157     if(stdout_fd != NULL)
 158         pipe(out_fd);
 159     if(stderr_fd != NULL)
 160         pipe(err_fd);
 161     pid = fork();
 162     switch(pid) {
 163     case 0:
 164         va_start(ap, file);
 165         argv = vstrcollect(&ap);
 166         va_end(ap);
 167         if(argv == NULL)
 168             exit(-1);
 169
 170         /* close pipes we're not interested in */
 171         if(stdin_fd != NULL)
 172             close(in_fd[1]);
 173         if(stdout_fd != NULL)
 174             close(out_fd[0]);
 175         if(stderr_fd != NULL)
 176             close(err_fd[0]);
 177
 178         /* pipe everything caller doesn't care about to /dev/null */
 179         if(stdin_fd == NULL)
 180             in_fd[0] = open(_PATH_DEVNULL, O_RDONLY);
 181         if(stdout_fd == NULL)
 182             out_fd[1] = open(_PATH_DEVNULL, O_WRONLY);
 183         if(stderr_fd == NULL)
 184             err_fd[1] = open(_PATH_DEVNULL, O_WRONLY);
 185
 186         /* move to proper descriptors */
 187         if(in_fd[0] != STDIN_FILENO) {
 188             dup2(in_fd[0], STDIN_FILENO);
 189             close(in_fd[0]);
 190         }
 191         if(out_fd[1] != STDOUT_FILENO) {
 192             dup2(out_fd[1], STDOUT_FILENO);
 193             close(out_fd[1]);
 194         }
 195         if(err_fd[1] != STDERR_FILENO) {
 196             dup2(err_fd[1], STDERR_FILENO);
 197             close(err_fd[1]);
 198         }
 199
 200         closefrom(3);
 201
 202         execv(file, argv);
 203         exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
 204     case -1:
 205         if(stdin_fd != NULL) {
 206             close(in_fd[0]);
 207             close(in_fd[1]);
 208         }
 209         if(stdout_fd != NULL) {
 210             close(out_fd[0]);
 211             close(out_fd[1]);
 212         }
 213         if(stderr_fd != NULL) {
 214             close(err_fd[0]);
 215             close(err_fd[1]);
 216         }
 217         return -2;
 218     default:
 219         if(stdin_fd != NULL) {
 220             close(in_fd[0]);
 221             *stdin_fd = fdopen(in_fd[1], "w");
 222         }
 223         if(stdout_fd != NULL) {
 224             close(out_fd[1]);
 225             *stdout_fd = fdopen(out_fd[0], "r");
 226         }
 227         if(stderr_fd != NULL) {
 228             close(err_fd[1]);
 229             *stderr_fd = fdopen(err_fd[0], "r");
 230         }
 231     }
 232     return pid;
 233 }
 234
 235 int ROKEN_LIB_FUNCTION
 236 simple_execvp_timed(const char *file, char *const args[],
 237                     time_t (*func)(void *), void *ptr, time_t timeout)
 238 {
 239     pid_t pid = fork();
 240     switch(pid){
 241     case -1:
 242         return -2;
 243     case 0:
 244         execvp(file, args);
 245         exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
 246     default:
 247         return wait_for_process_timed(pid, func, ptr, timeout);
 248     }
 249 }
 250
 251 int ROKEN_LIB_FUNCTION
 252 simple_execvp(const char *file, char *const args[])
 253 {
 254     return simple_execvp_timed(file, args, NULL, NULL, 0);
 255 }
 256
 257 /* gee, I'd like a execvpe */
 258 int ROKEN_LIB_FUNCTION
 259 simple_execve_timed(const char *file, char *const args[], char *const envp[],
 260                     time_t (*func)(void *), void *ptr, time_t timeout)
 261 {
 262     pid_t pid = fork();
 263     switch(pid){
 264     case -1:
 265         return -2;
 266     case 0:
 267         execve(file, args, envp);
 268         exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
 269     default:
 270         return wait_for_process_timed(pid, func, ptr, timeout);
 271     }
 272 }
 273
 274 int ROKEN_LIB_FUNCTION
 275 simple_execve(const char *file, char *const args[], char *const envp[])
 276 {
 277     return simple_execve_timed(file, args, envp, NULL, NULL, 0);
 278 }
 279
 280 int ROKEN_LIB_FUNCTION
 281 simple_execlp(const char *file, ...)
 282 {
 283     va_list ap;
 284     char **argv;
 285     int ret;
 286
 287     va_start(ap, file);
 288     argv = vstrcollect(&ap);
 289     va_end(ap);
 290     if(argv == NULL)
 291         return -1;
 292     ret = simple_execvp(file, argv);
 293     free(argv);
 294     return ret;
 295 }
 296
 297 int ROKEN_LIB_FUNCTION
 298 simple_execle(const char *file, ... /* ,char *const envp[] */)
 299 {
 300     va_list ap;
 301     char **argv;
 302     char *const* envp;
 303     int ret;
 304
 305     va_start(ap, file);
 306     argv = vstrcollect(&ap);
 307     envp = va_arg(ap, char **);
 308     va_end(ap);
 309     if(argv == NULL)
 310         return -1;
 311     ret = simple_execve(file, argv, envp);
 312     free(argv);
 313     return ret;
 314 }
 315
 316 int ROKEN_LIB_FUNCTION
 317 simple_execl(const char *file, ...)
 318 {
 319     va_list ap;
 320     char **argv;
 321     int ret;
 322
 323     va_start(ap, file);
 324     argv = vstrcollect(&ap);
 325     va_end(ap);
 326     if(argv == NULL)
 327         return -1;
 328     ret = simple_execve(file, argv, environ);
 329     free(argv);
 330     return ret;
 331 }