diplodocus.org Git - nmh/blob - docs/historical/mh-6.8.5/miscellany/sendmail/spooler.c

   1 /* spooler.c --  MH style mailer to write to /usr/spool/mail/<user>
   2  *
   3  *     Mlocal, P=/etc/spooler,  F=lsDFSmn, S=10, R=20, A=spooler $u
   4  */
   5
   6
   7 #define FLOCK   /* uses flock() if defined, lockf() otherwise. */
   8
   9 #include <stdio.h>
  10 #include <sys/types.h>
  11 #include <sys/stat.h>
  12 #include <sys/file.h>
  13 #include <pwd.h>
  14 #include "sysexits.h"
  15
  16 #define SPOOLDIR "/usr/spool/mail"
  17
  18 char *delim = "\1\1\1\1\n";
  19 char *ME = "/etc/spooler";
  20
  21 FILE *mboxopen();
  22 FILE *fp_in;
  23
  24 main( argc, argv )
  25 int argc;
  26 char **argv;
  27 {
  28     register int rc, anyerrs;
  29     char tmpfile[100];
  30
  31     if( *++argv == NULL ) {
  32         fprintf( stderr, "%s: no recipients.\n", ME );
  33         exit( EX_USAGE );
  34     }
  35
  36     if( argc == 2 ) {           /* single recipient, don't need tmp copy */
  37         fp_in = stdin;
  38         rc = localmail( *argv );
  39     }
  40     else {
  41         if(( rc = copyfile( tmpfile )) == 0 ) {     /* sets fp_in */
  42             for( anyerrs = 0; *argv; argv++ ) {
  43                 rewind( fp_in );
  44                 if(( rc = localmail( *argv )))
  45                     anyerrs++;
  46             }
  47             if( !anyerrs )
  48                 unlink( tmpfile );
  49         }
  50     }
  51
  52     exit( rc );
  53 }
  54
  55
  56
  57 localmail( user )
  58 char   *user;
  59 {
  60     register FILE *fp;
  61     register int count, n;
  62     register char buf[BUFSIZ];
  63     register char mailbox[BUFSIZ];
  64     register struct stat sb;
  65
  66     sprintf( mailbox, "%s/%s", SPOOLDIR, user );
  67
  68     if( stat( mailbox, &sb ) == -1 ) {
  69         if( create_mbox( mailbox, user ))
  70             return(EX_TEMPFAIL);
  71     }
  72
  73     if(( fp = mboxopen( mailbox )) == 0 )
  74         return(EX_TEMPFAIL);
  75     fwrite( delim, sizeof(char), strlen(delim), fp );
  76     while(( count = fread( buf, sizeof(char), BUFSIZ, fp_in))) {
  77         n = fwrite( buf, sizeof(char), count, fp );
  78         if( n != count ) {
  79             fprintf( stderr, "%s write error: %d read, %d written\n",
  80                 ME, count, n );
  81             mboxclose(fp);
  82             return(-1);
  83         }
  84     }
  85     fwrite( delim, sizeof(char), strlen(delim), fp );
  86     mboxclose(fp);
  87
  88     return(0);
  89 }
  90
  91
  92 create_mbox( mbox, user )
  93 register char *mbox, *user;
  94 {
  95     register int fd;
  96     register struct passwd *pw;
  97
  98     if(( fd = creat( mbox, 0600 )) == -1 )
  99         return -1;
 100     if(( pw = getpwnam( user )) != NULL ) {
 101         fchown( fd, pw->pw_uid, pw->pw_gid );
 102     }
 103     close( fd );
 104
 105     return 0;
 106 }
 107
 108
 109 FILE *
 110 mboxopen( mailbox )
 111 register char *mailbox;
 112 {
 113     register FILE *fp;
 114     register int i;
 115
 116     if(( fp = fopen( mailbox, "a" )) == NULL ) {
 117         fprintf( stderr, "%s:  Can't open %s for appending\n", ME, mailbox );
 118         return(0);
 119     }
 120
 121     /* lock the mailbox */
 122
 123 #define NLOCKTRYS 20        /* almost a 2 min. wait should be enough even */
 124                             /* after a long vacation */
 125
 126     for( i = 0; i < NLOCKTRYS; i++ ) {
 127 #ifdef FLOCK
 128         if( flock( fileno(fp), LOCK_EX | LOCK_NB ) == 0)    /* got it ok */
 129 #else
 130         if( lockf( fileno(fp), F_TLOCK, 0) == 0 )
 131 #endif FLOCK
 132             break;
 133         /* fprintf(stderr, "can't lock, sleeping 5 sec...\n"); */
 134         sleep(5);
 135     }
 136 /*
 137  *  If lockf worked perfectly (ie, rpc.lockd didn't die) this would be
 138  *  just fine.
 139  */
 140 #ifdef DontDoThis
 141     if( i == NLOCKTRYS ) {
 142         fprintf( stderr, "%s:  Can't lock %s\n", ME, mailbox);
 143         return(0);
 144     }
 145 #endif
 146
 147     fseek( fp, 0, 2 );
 148
 149     return(fp);
 150 }
 151
 152
 153 mboxclose(fp)
 154 FILE *fp;
 155 {
 156 /*todo: unlockit.  --not really necessary */
 157     fclose(fp);
 158 }
 159
 160
 161
 162 /*
 163  *  collect stdin to a tmp file
 164  */
 165 copyfile( tmpfile )
 166 register char *tmpfile;
 167 {
 168     struct stat sb;
 169     register int pid, count, n;
 170     register char buf[BUFSIZ];
 171     register FILE *fp;
 172
 173     pid = getpid();
 174
 175     while( 1 ) {
 176         sprintf( tmpfile, "/tmp/spooler.%05d", pid );
 177         if( stat( tmpfile, &sb ) == -1 )    /* ok, this file doesn't exist */
 178             break;
 179         pid++;
 180     }
 181
 182     if(( fp = fopen( tmpfile, "w" )) == NULL ) {
 183         fprintf( stderr, "%s:  Can't open %s\n", ME, tmpfile );
 184         return(EX_TEMPFAIL);
 185     }
 186
 187     while(( count = fread( buf, sizeof(char), BUFSIZ, stdin ))) {
 188         n = fwrite( buf, sizeof(char), count, fp );
 189         if( n != count ) {
 190             fprintf( stderr, "%s: copyfile, write error: %d read, %d written\n",
 191                 ME, count, n );
 192             fclose(fp);
 193             return(-1);
 194         }
 195     }
 196
 197     fp_in = freopen( tmpfile, "r", fp );
 198     if( fp_in == NULL ) {
 199         fprintf( stderr, "%s: freopen on %s failed\n", ME, tmpfile );
 200         return(-1);
 201     }
 202
 203     return(0);
 204 }