external/ibm-public/postfix/dist/src/global/mail_run.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      mail_run 3
   6 /* SUMMARY
   7 /*      run mail component program
   8 /* SYNOPSIS
   9 /*      #include <mail_run.h>
  10 /*
  11 /*      int     mail_run_foreground(dir, argv)
  12 /*      const char *dir;
  13 /*      char    **argv;
  14 /*
  15 /*      int     mail_run_background(dir, argv)
  16 /*      const char *dir;
  17 /*      char    **argv;
  18 /*
  19 /*      NORETURN mail_run_replace(dir, argv)
  20 /*      const char *dir;
  21 /*      char    **argv;
  22 /* DESCRIPTION
  23 /*      This module runs programs that live in the mail program directory.
  24 /*      Each routine takes a directory and a command-line array. The program
  25 /*      pathname is built by prepending the directory and a slash to the
  26 /*      command name.
  27 /*
  28 /*      mail_run_foreground() runs the named command in the foreground and
  29 /*      waits until the command terminates.
  30 /*
  31 /*      mail_run_background() runs the named command in the background.
  32 /*
  33 /*      mail_run_replace() attempts to replace the current process by
  34 /*      an instance of the named command. This function never returns.
  35 /*
  36 /*      Arguments:
  37 /* .IP argv
  38 /*      A null-terminated command-line vector. The first array element
  39 /*      is the base name of the program to be executed.
  40 /* DIAGNOSTICS
  41 /*      The result is (-1) if the command could not be run. Otherwise,
  42 /*      mail_run_foreground() returns the termination status of the
  43 /*      command. mail_run_background() returns the process id in case
  44 /*      of success.
  45 /* CONFIGURATION PARAMETERS
  46 /*      fork_attempts: number of attempts to fork() a process;
  47 /*      fork_delay: delay in seconds between fork() attempts.
  48 /* LICENSE
  49 /* .ad
  50 /* .fi
  51 /*      The Secure Mailer license must be distributed with this software.
  52 /* AUTHOR(S)
  53 /*      Wietse Venema
  54 /*      IBM T.J. Watson Research
  55 /*      P.O. Box 704
  56 /*      Yorktown Heights, NY 10598, USA
  57 /*--*/
  58
  59 /* System library. */
  60
  61 #include <sys_defs.h>
  62 #include <sys/wait.h>
  63 #include <unistd.h>
  64 #include <errno.h>
  65
  66 /* Utility library. */
  67
  68 #include <msg.h>
  69 #include <stringops.h>
  70 #include <mymalloc.h>
  71
  72 /* Global library. */
  73
  74 #include "mail_params.h"
  75 #include "mail_run.h"
  76
  77 /* mail_run_foreground - run command in foreground */
  78
  79 int     mail_run_foreground(const char *dir, char **argv)
  80 {
  81     int     count;
  82     char   *path;
  83     WAIT_STATUS_T status;
  84     int     pid;
  85     int     wpid;
  86
  87 #define RETURN(x) { myfree(path); return(x); }
  88
  89     path = concatenate(dir, "/", argv[0], (char *) 0);
  90
  91     for (count = 0; count < var_fork_tries; count++) {
  92         switch (pid = fork()) {
  93         case -1:
  94             msg_warn("fork %s: %m", path);
  95             break;
  96         case 0:
  97             /* Reset the msg_cleanup() handlers in the child process. */
  98             (void) msg_cleanup((MSG_CLEANUP_FN) 0);
  99             execv(path, argv);
 100             msg_fatal("execv %s: %m", path);
 101         default:
 102             do {
 103                 wpid = waitpid(pid, &status, 0);
 104             } while (wpid == -1 && errno == EINTR);
 105             RETURN(wpid == -1 ? -1 :
 106                    WIFEXITED(status) ? WEXITSTATUS(status) : 1)
 107         }
 108         sleep(var_fork_delay);
 109     }
 110     RETURN(-1);
 111 }
 112
 113 /* mail_run_background - run command in background */
 114
 115 int     mail_run_background(const char *dir, char **argv)
 116 {
 117     int     count;
 118     char   *path;
 119     int     pid;
 120
 121 #define RETURN(x) { myfree(path); return(x); }
 122
 123     path = concatenate(dir, "/", argv[0], (char *) 0);
 124
 125     for (count = 0; count < var_fork_tries; count++) {
 126         switch (pid = fork()) {
 127         case -1:
 128             msg_warn("fork %s: %m", path);
 129             break;
 130         case 0:
 131             /* Reset the msg_cleanup() handlers in the child process. */
 132             (void) msg_cleanup((MSG_CLEANUP_FN) 0);
 133             execv(path, argv);
 134             msg_fatal("execv %s: %m", path);
 135         default:
 136             RETURN(pid);
 137         }
 138         sleep(var_fork_delay);
 139     }
 140     RETURN(-1);
 141 }
 142
 143 /* mail_run_replace - run command, replacing current process */
 144
 145 NORETURN mail_run_replace(const char *dir, char **argv)
 146 {
 147     char   *path;
 148
 149     path = concatenate(dir, "/", argv[0], (char *) 0);
 150     execv(path, argv);
 151     msg_fatal("execv %s: %m", path);
 152 }