liblock/lockmail.c

   1 /*
   2 ** Copyright 2002-2006 Double Precision, Inc.  See COPYING for
   3 ** distribution information.
   4 */
   5
   6 #include        "config.h"
   7 #include        "liblock.h"
   8 #include        "mail.h"
   9 #include        <stdio.h>
  10 #include        <stdlib.h>
  11 #include        <string.h>
  12 #include        <unistd.h>
  13 #include        <errno.h>
  14 #include        <signal.h>
  15 #include        <sys/types.h>
  16 #include        <sys/stat.h>
  17 #if HAVE_SYS_WAIT_H
  18 #include <sys/wait.h>
  19 #endif
  20 #ifdef HAVE_FCNTL_H
  21 #include <fcntl.h>
  22 #endif
  23 #ifndef WEXITSTATUS
  24 #define WEXITSTATUS(stat_val) ((unsigned)(stat_val) >> 8)
  25 #endif
  26 #ifndef WIFEXITED
  27 #define WIFEXITED(stat_val) (((stat_val) & 255) == 0)
  28 #endif
  29
  30 #if HAVE_SYSEXITS_H
  31 #include <sysexits.h>
  32 #endif
  33
  34 #ifndef EX_TEMPFAIL
  35 #define EX_TEMPFAIL 75
  36 #endif
  37
  38 static const char rcsid[]="$Id: lockmail.c,v 1.6 2006/09/20 01:41:27 mrsam Exp $";
  39
  40 #define NTRIES_DEFAULT  60
  41 #define DELAY   5
  42
  43 static int sig=0;
  44
  45 static int catch(int signum)
  46 {
  47         sig=1;
  48         signal(SIGHUP, (RETSIGTYPE (*)(int))catch);
  49         signal(SIGTERM, (RETSIGTYPE (*)(int))catch);
  50         signal(SIGINT, (RETSIGTYPE (*)(int))catch);
  51         return 0;
  52 }
  53
  54 static int caught()
  55 {
  56         signal(SIGHUP, SIG_DFL);
  57         signal(SIGTERM, SIG_DFL);
  58         signal(SIGINT, SIG_DFL);
  59         return sig;
  60 }
  61
  62 int main(int argc, char **argv)
  63 {
  64         char **argvec;
  65         int n;
  66         int fd;
  67         pid_t pid, pid2;
  68         int waitstat;
  69         struct ll_mail *p;
  70         int ntries=NTRIES_DEFAULT;
  71         int readonly=0;
  72         int optchar;
  73
  74         while ((optchar=getopt(argc, argv, "+rt:")) != -1)
  75                 switch (optchar) {
  76                 case 'r':
  77                         readonly=1;
  78                         break;
  79                 case 't':
  80                         ntries=atoi(optarg);
  81                         if (ntries < 0)
  82                         {
  83                                 fprintf(stderr, "%s: invalid argument to -t\n",
  84                                         argv[0]);
  85                                 exit(EX_TEMPFAIL);
  86                         }
  87                         ntries= (ntries / DELAY) + 1;
  88                         break;
  89                 default:
  90                         exit(1);
  91                 }
  92
  93         if (argc - optind < 2)
  94         {
  95                 fprintf(stderr, "Usage: %s [-r] [-t time] mailfile program [args]...\n",
  96                         argv[0]);
  97                 exit(1);
  98         }
  99
 100         if ((argvec=malloc(sizeof(char *) * (argc - optind + 1))) == NULL)
 101         {
 102                 perror("malloc");
 103                 exit (1);
 104         }
 105
 106         for (n=optind+1; n<argc; n++)
 107                 argvec[n-optind - 1]=argv[n];
 108
 109         argvec[n-optind-1]=NULL;
 110
 111         /* Create the mail file, if it doesn't exist */
 112
 113         if ((n=open(argv[optind], O_RDWR|O_CREAT, 0600)) >= 0)
 114                 close(n);
 115
 116         signal(SIGUSR2, SIG_IGN);
 117         signal(SIGCHLD, SIG_DFL);
 118
 119         p=NULL;
 120
 121         for (n=0; n<ntries; sleep(DELAY), n++)
 122         {
 123                 if (p)
 124                         ll_mail_free(p);
 125
 126                 if ((p=ll_mail_alloc(argv[optind])) == NULL)
 127                 {
 128                         perror("malloc");
 129                         exit(1);
 130                 }
 131
 132                 signal(SIGHUP, (RETSIGTYPE (*)(int))catch);
 133                 signal(SIGTERM, (RETSIGTYPE (*)(int))catch);
 134                 signal(SIGINT, (RETSIGTYPE (*)(int))catch);
 135
 136                 if (ll_mail_lock(p) < 0)
 137                 {
 138                         if (errno == ENOENT)
 139                                 break; /* Mail file gone? */
 140                         if (caught())
 141                                 break;
 142                         continue;
 143                 }
 144
 145                 if ((fd=ll_mail_open(p)) < 0)
 146                 {
 147                         if (!readonly || (fd=ll_mail_open_ro(p)) < 0)
 148                         {
 149                                 if (caught())
 150                                         break;
 151                                 continue;
 152                         }
 153                 }
 154
 155                 if ((pid=fork()) < 0)
 156                 {
 157                         perror("fork");
 158                         exit(1);
 159                 }
 160
 161                 if (pid == 0)
 162                 {
 163                         setgid(getgid());
 164                         setuid(getuid());
 165
 166                         (void)caught();
 167                         execvp(argvec[0], argvec);
 168
 169                         perror(argvec[0]);
 170                         exit(1);
 171                 }
 172
 173                 while ((pid2=wait(&waitstat)) != pid)
 174                         ;
 175
 176                 ll_mail_free(p);
 177
 178                 if (WIFEXITED(waitstat))
 179                         exit(WEXITSTATUS(waitstat));
 180                 exit(EX_TEMPFAIL);
 181         }
 182         if (p)
 183                 ll_mail_free(p);
 184         exit(EX_TEMPFAIL);
 185         return (0);
 186 }
 187