local.c

   1 #include <err.h>
   2 #include <errno.h>
   3 #include <fcntl.h>
   4 #include <paths.h>
   5 #include <stdint.h>
   6 #include <stdio.h>
   7 #include <syslog.h>
   8 #include <unistd.h>
   9
  10 #include "dma.h"
  11
  12 int
  13 deliver_local(struct qitem *it)
  14 {
  15         char fn[PATH_MAX+1];
  16         char line[1000];
  17         const char *sender;
  18         const char *newline = "\n";
  19         size_t linelen;
  20         int mbox;
  21         int error;
  22         int hadnl = 0;
  23         off_t mboxlen;
  24         time_t now = time(NULL);
  25
  26         error = snprintf(fn, sizeof(fn), "%s/%s", _PATH_MAILDIR, it->addr);
  27         if (error < 0 || (size_t)error >= sizeof(fn)) {
  28                 syslog(LOG_NOTICE, "local delivery deferred: %m");
  29                 return (1);
  30         }
  31
  32         /* wait for a maximum of 100s to get the lock to the file */
  33         do_timeout(100, 0);
  34
  35         /* mailx removes users mailspool file if empty, so open with O_CREAT */
  36         mbox = open_locked(fn, O_WRONLY|O_APPEND|O_CREAT, 0660);
  37         if (mbox < 0) {
  38                 int e = errno;
  39
  40                 do_timeout(0, 0);
  41                 if (e == EINTR)
  42                         syslog(LOG_NOTICE, "local delivery deferred: can not lock `%s'", fn);
  43                 else
  44                         syslog(LOG_NOTICE, "local delivery deferred: can not open `%s': %m", fn);
  45                 return (1);
  46         }
  47         do_timeout(0, 0);
  48
  49         mboxlen = lseek(mbox, 0, SEEK_END);
  50
  51         /* New mails start with \nFrom ...., unless we're at the beginning of the mbox */
  52         if (mboxlen == 0)
  53                 newline = "";
  54
  55         /* If we're bouncing a message, claim it comes from MAILER-DAEMON */
  56         sender = it->sender;
  57         if (strcmp(sender, "") == 0)
  58                 sender = "MAILER-DAEMON";
  59
  60         if (fseek(it->mailf, 0, SEEK_SET) != 0) {
  61                 syslog(LOG_NOTICE, "local delivery deferred: can not seek: %m");
  62                 goto out;
  63         }
  64
  65         error = snprintf(line, sizeof(line), "%sFrom %s\t%s", newline, sender, ctime(&now));
  66         if (error < 0 || (size_t)error >= sizeof(line)) {
  67                 syslog(LOG_NOTICE, "local delivery deferred: can not write header: %m");
  68                 goto out;
  69         }
  70         if (write(mbox, line, error) != error)
  71                 goto wrerror;
  72
  73         while (!feof(it->mailf)) {
  74                 if (fgets(line, sizeof(line), it->mailf) == NULL)
  75                         break;
  76                 linelen = strlen(line);
  77                 if (linelen == 0 || line[linelen - 1] != '\n') {
  78                         syslog(LOG_CRIT, "local delivery failed: corrupted queue file");
  79                         snprintf(errmsg, sizeof(errmsg), "corrupted queue file");
  80                         error = -1;
  81                         goto chop;
  82                 }
  83
  84                 if (hadnl && strncmp(line, "From ", 5) == 0) {
  85                         const char *gt = ">";
  86
  87                         if (write(mbox, gt, 1) != 1)
  88                                 goto wrerror;
  89                         hadnl = 0;
  90                 } else if (strcmp(line, "\n") == 0) {
  91                         hadnl = 1;
  92                 } else {
  93                         hadnl = 0;
  94                 }
  95                 if ((size_t)write(mbox, line, linelen) != linelen)
  96                         goto wrerror;
  97         }
  98         close(mbox);
  99         return (0);
 100
 101 wrerror:
 102         syslog(LOG_ERR, "local delivery failed: write error: %m");
 103         error = 1;
 104 chop:
 105         if (ftruncate(mbox, mboxlen) != 0)
 106                 syslog(LOG_WARNING, "error recovering mbox `%s': %m", fn);
 107 out:
 108         close(mbox);
 109         return (error);
 110 }