libs/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
  39 #define NTRIES_DEFAULT  60
  40 #define DELAY   5
  41
  42 static int sig=0;
  43
  44 static int catch(int signum)
  45 {
  46         sig=1;
  47         signal(SIGHUP, (RETSIGTYPE (*)(int))catch);
  48         signal(SIGTERM, (RETSIGTYPE (*)(int))catch);
  49         signal(SIGINT, (RETSIGTYPE (*)(int))catch);
  50         return 0;
  51 }
  52
  53 static int caught()
  54 {
  55         signal(SIGHUP, SIG_DFL);
  56         signal(SIGTERM, SIG_DFL);
  57         signal(SIGINT, SIG_DFL);
  58         return sig;
  59 }
  60
  61 int main(int argc, char **argv)
  62 {
  63         char **argvec;
  64         int n;
  65         int fd;
  66         pid_t pid, pid2;
  67         int waitstat;
  68         struct ll_mail *p;
  69         int ntries=NTRIES_DEFAULT;
  70         int readonly=0;
  71         int optchar;
  72
  73         while ((optchar=getopt(argc, argv, "+rt:")) != -1)
  74                 switch (optchar) {
  75                 case 'r':
  76                         readonly=1;
  77                         break;
  78                 case 't':
  79                         ntries=atoi(optarg);
  80                         if (ntries < 0)
  81                         {
  82                                 fprintf(stderr, "%s: invalid argument to -t\n",
  83                                         argv[0]);
  84                                 exit(EX_TEMPFAIL);
  85                         }
  86                         ntries= (ntries / DELAY) + 1;
  87                         break;
  88                 default:
  89                         exit(1);
  90                 }
  91
  92         if (argc - optind < 2)
  93         {
  94                 fprintf(stderr, "Usage: %s [-r] [-t time] mailfile program [args]...\n",
  95                         argv[0]);
  96                 exit(1);
  97         }
  98
  99         if ((argvec=malloc(sizeof(char *) * (argc - optind + 1))) == NULL)
 100         {
 101                 perror("malloc");
 102                 exit (1);
 103         }
 104
 105         for (n=optind+1; n<argc; n++)
 106                 argvec[n-optind - 1]=argv[n];
 107
 108         argvec[n-optind-1]=NULL;
 109
 110         /* Create the mail file, if it doesn't exist */
 111
 112         if ((n=open(argv[optind], O_RDWR|O_CREAT, 0600)) >= 0)
 113                 close(n);
 114
 115         signal(SIGUSR2, SIG_IGN);
 116         signal(SIGCHLD, SIG_DFL);
 117
 118         p=NULL;
 119
 120         for (n=0; n<ntries; sleep(DELAY), n++)
 121         {
 122                 if (p)
 123                         ll_mail_free(p);
 124
 125                 if ((p=ll_mail_alloc(argv[optind])) == NULL)
 126                 {
 127                         perror("malloc");
 128                         exit(1);
 129                 }
 130
 131                 signal(SIGHUP, (RETSIGTYPE (*)(int))catch);
 132                 signal(SIGTERM, (RETSIGTYPE (*)(int))catch);
 133                 signal(SIGINT, (RETSIGTYPE (*)(int))catch);
 134
 135                 if (ll_mail_lock(p) < 0)
 136                 {
 137                         if (errno == ENOENT)
 138                                 break; /* Mail file gone? */
 139                         if (caught())
 140                                 break;
 141                         continue;
 142                 }
 143
 144                 if ((fd=ll_mail_open(p)) < 0)
 145                 {
 146                         if (!readonly || (fd=ll_mail_open_ro(p)) < 0)
 147                         {
 148                                 if (caught())
 149                                         break;
 150                                 continue;
 151                         }
 152                 }
 153
 154                 if ((pid=fork()) < 0)
 155                 {
 156                         perror("fork");
 157                         exit(1);
 158                 }
 159
 160                 if (pid == 0)
 161                 {
 162                         if (setgid(getgid()) < 0 ||
 163                             setuid(getuid()) < 0)
 164                         {
 165                                 perror("setuid/setgid");
 166                                 exit(1);
 167                         }
 168
 169                         (void)caught();
 170                         execvp(argvec[0], argvec);
 171
 172                         perror(argvec[0]);
 173                         exit(1);
 174                 }
 175
 176                 while ((pid2=wait(&waitstat)) != pid)
 177                         ;
 178
 179                 ll_mail_free(p);
 180
 181                 if (WIFEXITED(waitstat))
 182                         exit(WEXITSTATUS(waitstat));
 183                 exit(EX_TEMPFAIL);
 184         }
 185         if (p)
 186                 ll_mail_free(p);
 187         exit(EX_TEMPFAIL);
 188         return (0);
 189 }
 190