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 #include <config.h>
  35
  36 #include <stdarg.h>
  37 #include <stdlib.h>
  38 #ifdef HAVE_SYS_TYPES_H
  39 #include <sys/types.h>
  40 #endif
  41 #ifdef HAVE_SYS_WAIT_H
  42 #include <sys/wait.h>
  43 #endif
  44 #ifdef HAVE_UNISTD_H
  45 #include <unistd.h>
  46 #endif
  47 #include <errno.h>
  48
  49 #include "roken.h"
  50
  51 #define EX_NOEXEC       126
  52 #define EX_NOTFOUND     127
  53
  54 /* return values:
  55    -1   on `unspecified' system errors
  56    -2   on fork failures
  57    -3   on waitpid errors
  58    -4   exec timeout
  59    0-   is return value from subprocess
  60    126  if the program couldn't be executed
  61    127  if the program couldn't be found
  62    128- is 128 + signal that killed subprocess
  63
  64    possible values `func' can return:
  65    ((time_t)-2)         exit loop w/o killing child and return
  66                         `exec timeout'/-4 from simple_exec
  67    ((time_t)-1)         kill child with SIGTERM and wait for child to exit
  68    0                    don't timeout again
  69    n                    seconds to next timeout
  70    */
  71
  72 static int sig_alarm;
  73
  74 static RETSIGTYPE
  75 sigtimeout(int sig)
  76 {
  77     sig_alarm = 1;
  78     SIGRETURN(0);
  79 }
  80
  81 int ROKEN_LIB_FUNCTION
  82 wait_for_process_timed(pid_t pid, time_t (*func)(void *),
  83                        void *ptr, time_t timeout)
  84 {
  85     RETSIGTYPE (*old_func)(int sig) = NULL;
  86     unsigned int oldtime = 0;
  87     int ret;
  88
  89     sig_alarm = 0;
  90
  91     if (func) {
  92         old_func = signal(SIGALRM, sigtimeout);
  93         oldtime = alarm(timeout);
  94     }
  95
  96     while(1) {
  97         int status;
  98
  99         while(waitpid(pid, &status, 0) < 0) {
 100             if (errno != EINTR) {
 101                 ret = -3;
 102                 goto out;
 103             }
 104             if (func == NULL)
 105                 continue;
 106             if (sig_alarm == 0)
 107                 continue;
 108             timeout = (*func)(ptr);
 109             if (timeout == (time_t)-1) {
 110                 kill(pid, SIGTERM);
 111                 continue;
 112             } else if (timeout == (time_t)-2) {
 113                 ret = -4;
 114                 goto out;
 115             }
 116             alarm(timeout);
 117         }
 118         if(WIFSTOPPED(status))
 119             continue;
 120         if(WIFEXITED(status)) {
 121             ret = WEXITSTATUS(status);
 122             break;
 123         }
 124         if(WIFSIGNALED(status)) {
 125             ret = WTERMSIG(status) + 128;
 126             break;
 127         }
 128     }
 129  out:
 130     if (func) {
 131         signal(SIGALRM, old_func);
 132         alarm(oldtime);
 133     }
 134     return ret;
 135 }
 136
 137 int ROKEN_LIB_FUNCTION
 138 wait_for_process(pid_t pid)
 139 {
 140     return wait_for_process_timed(pid, NULL, NULL, 0);
 141 }
 142
 143 int ROKEN_LIB_FUNCTION
 144 pipe_execv(FILE **stdin_fd, FILE **stdout_fd, FILE **stderr_fd,
 145            const char *file, ...)
 146 {
 147     int in_fd[2], out_fd[2], err_fd[2];
 148     pid_t pid;
 149     va_list ap;
 150     char **argv;
 151
 152     if(stdin_fd != NULL)
 153         pipe(in_fd);
 154     if(stdout_fd != NULL)
 155         pipe(out_fd);
 156     if(stderr_fd != NULL)
 157         pipe(err_fd);
 158     pid = fork();
 159     switch(pid) {
 160     case 0:
 161         va_start(ap, file);
 162         argv = vstrcollect(&ap);
 163         va_end(ap);
 164         if(argv == NULL)
 165             exit(-1);
 166
 167         /* close pipes we're not interested in */
 168         if(stdin_fd != NULL)
 169             close(in_fd[1]);
 170         if(stdout_fd != NULL)
 171             close(out_fd[0]);
 172         if(stderr_fd != NULL)
 173             close(err_fd[0]);
 174
 175         /* pipe everything caller doesn't care about to /dev/null */
 176         if(stdin_fd == NULL)
 177             in_fd[0] = open(_PATH_DEVNULL, O_RDONLY);
 178         if(stdout_fd == NULL)
 179             out_fd[1] = open(_PATH_DEVNULL, O_WRONLY);
 180         if(stderr_fd == NULL)
 181             err_fd[1] = open(_PATH_DEVNULL, O_WRONLY);
 182
 183         /* move to proper descriptors */
 184         if(in_fd[0] != STDIN_FILENO) {
 185             dup2(in_fd[0], STDIN_FILENO);
 186             close(in_fd[0]);
 187         }
 188         if(out_fd[1] != STDOUT_FILENO) {
 189             dup2(out_fd[1], STDOUT_FILENO);
 190             close(out_fd[1]);
 191         }
 192         if(err_fd[1] != STDERR_FILENO) {
 193             dup2(err_fd[1], STDERR_FILENO);
 194             close(err_fd[1]);
 195         }
 196
 197         closefrom(3);
 198
 199         execv(file, argv);
 200         exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
 201     case -1:
 202         if(stdin_fd != NULL) {
 203             close(in_fd[0]);
 204             close(in_fd[1]);
 205         }
 206         if(stdout_fd != NULL) {
 207             close(out_fd[0]);
 208             close(out_fd[1]);
 209         }
 210         if(stderr_fd != NULL) {
 211             close(err_fd[0]);
 212             close(err_fd[1]);
 213         }
 214         return -2;
 215     default:
 216         if(stdin_fd != NULL) {
 217             close(in_fd[0]);
 218             *stdin_fd = fdopen(in_fd[1], "w");
 219         }
 220         if(stdout_fd != NULL) {
 221             close(out_fd[1]);
 222             *stdout_fd = fdopen(out_fd[0], "r");
 223         }
 224         if(stderr_fd != NULL) {
 225             close(err_fd[1]);
 226             *stderr_fd = fdopen(err_fd[0], "r");
 227         }
 228     }
 229     return pid;
 230 }
 231
 232 int ROKEN_LIB_FUNCTION
 233 simple_execvp_timed(const char *file, char *const args[],
 234                     time_t (*func)(void *), void *ptr, time_t timeout)
 235 {
 236     pid_t pid = fork();
 237     switch(pid){
 238     case -1:
 239         return -2;
 240     case 0:
 241         execvp(file, args);
 242         exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
 243     default:
 244         return wait_for_process_timed(pid, func, ptr, timeout);
 245     }
 246 }
 247
 248 int ROKEN_LIB_FUNCTION
 249 simple_execvp(const char *file, char *const args[])
 250 {
 251     return simple_execvp_timed(file, args, NULL, NULL, 0);
 252 }
 253
 254 /* gee, I'd like a execvpe */
 255 int ROKEN_LIB_FUNCTION
 256 simple_execve_timed(const char *file, char *const args[], char *const envp[],
 257                     time_t (*func)(void *), void *ptr, time_t timeout)
 258 {
 259     pid_t pid = fork();
 260     switch(pid){
 261     case -1:
 262         return -2;
 263     case 0:
 264         execve(file, args, envp);
 265         exit((errno == ENOENT) ? EX_NOTFOUND : EX_NOEXEC);
 266     default:
 267         return wait_for_process_timed(pid, func, ptr, timeout);
 268     }
 269 }
 270
 271 int ROKEN_LIB_FUNCTION
 272 simple_execve(const char *file, char *const args[], char *const envp[])
 273 {
 274     return simple_execve_timed(file, args, envp, NULL, NULL, 0);
 275 }
 276
 277 int ROKEN_LIB_FUNCTION
 278 simple_execlp(const char *file, ...)
 279 {
 280     va_list ap;
 281     char **argv;
 282     int ret;
 283
 284     va_start(ap, file);
 285     argv = vstrcollect(&ap);
 286     va_end(ap);
 287     if(argv == NULL)
 288         return -1;
 289     ret = simple_execvp(file, argv);
 290     free(argv);
 291     return ret;
 292 }
 293
 294 int ROKEN_LIB_FUNCTION
 295 simple_execle(const char *file, ... /* ,char *const envp[] */)
 296 {
 297     va_list ap;
 298     char **argv;
 299     char *const* envp;
 300     int ret;
 301
 302     va_start(ap, file);
 303     argv = vstrcollect(&ap);
 304     envp = va_arg(ap, char **);
 305     va_end(ap);
 306     if(argv == NULL)
 307         return -1;
 308     ret = simple_execve(file, argv, envp);
 309     free(argv);
 310     return ret;
 311 }