src/src/spool_mbox.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2003 - 2015
   6  * License: GPL
   7  * Copyright (c) The Exim Maintainers 2016 - 2018
   8  */
   9
  10 /* Code for setting up a MBOX style spool file inside a /scan/<msgid>
  11 sub directory of exim's spool directory. */
  12
  13 #include "exim.h"
  14 #ifdef WITH_CONTENT_SCAN
  15
  16 extern int malware_ok;
  17 extern int spam_ok;
  18
  19 int spool_mbox_ok = 0;
  20 uschar spooled_message_id[MESSAGE_ID_LENGTH+1];
  21
  22 /*
  23 Create an MBOX-style message file from the spooled files.
  24
  25 Returns a pointer to the FILE, and puts the size in bytes into mbox_file_size.
  26 If mbox_fname is non-null, fill in a pointer to the name.
  27 Normally, source_file_override is NULL
  28 */
  29
  30 FILE *
  31 spool_mbox(unsigned long *mbox_file_size, const uschar *source_file_override,
  32   uschar ** mbox_fname)
  33 {
  34 uschar message_subdir[2];
  35 uschar buffer[16384];
  36 uschar *temp_string;
  37 uschar *mbox_path;
  38 FILE *mbox_file = NULL, *l_data_file = NULL, *yield = NULL;
  39 struct stat statbuf;
  40 int j;
  41 rmark reset_point;
  42
  43 mbox_path = string_sprintf("%s/scan/%s/%s.eml",
  44   spool_directory, message_id, message_id);
  45 if (mbox_fname) *mbox_fname = mbox_path;
  46
  47 reset_point = store_mark();
  48
  49 /* Skip creation if already spooled out as mbox file */
  50 if (!spool_mbox_ok)
  51   {
  52   /* create temp directory inside scan dir, directory_make works recursively */
  53   temp_string = string_sprintf("scan/%s", message_id);
  54   if (!directory_make(spool_directory, temp_string, 0750, FALSE))
  55     {
  56     log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
  57       "scan directory %s/scan/%s", spool_directory, temp_string));
  58     goto OUT;
  59     }
  60
  61   /* open [message_id].eml file for writing */
  62
  63   if (!(mbox_file = modefopen(mbox_path, "wb", SPOOL_MODE)))
  64     {
  65     log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
  66       "scan file %s", mbox_path));
  67     goto OUT;
  68     }
  69
  70   /* Generate mailbox headers. The $received_for variable is (up to at least
  71   Exim 4.64) never set here, because it is only set when expanding the
  72   contents of the Received: header line. However, the code below will use it
  73   if it should become available in future. */
  74
  75   temp_string = expand_string(
  76     US"From ${if def:return_path{$return_path}{MAILER-DAEMON}} ${tod_bsdinbox}\n"
  77     "${if def:sender_address{X-Envelope-From: <${sender_address}>\n}}"
  78     "${if def:recipients{X-Envelope-To: ${recipients}\n}}");
  79
  80   if (temp_string)
  81     if (fwrite(temp_string, Ustrlen(temp_string), 1, mbox_file) != 1)
  82       {
  83       log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
  84           mailbox headers to %s", mbox_path);
  85       goto OUT;
  86       }
  87
  88   /* write all non-deleted header lines to mbox file */
  89
  90   for (header_line * my_headerlist = header_list; my_headerlist;
  91       my_headerlist = my_headerlist->next)
  92     if (my_headerlist->type != '*')
  93       if (fwrite(my_headerlist->text, my_headerlist->slen, 1, mbox_file) != 1)
  94         {
  95         log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
  96             message headers to %s", mbox_path);
  97         goto OUT;
  98         }
  99
 100   /* End headers */
 101   if (fwrite("\n", 1, 1, mbox_file) != 1)
 102     {
 103     log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
 104       message headers to %s", mbox_path);
 105     goto OUT;
 106     }
 107
 108   /* Copy body file.  If the main receive still has it open then it is holding
 109   a lock, and we must not close it (which releases the lock), so just use the
 110   global file handle. */
 111   if (source_file_override)
 112     l_data_file = Ufopen(source_file_override, "rb");
 113   else if (spool_data_file)
 114     l_data_file = spool_data_file;
 115   else
 116     {
 117     message_subdir[1] = '\0';
 118     for (int i = 0; i < 2; i++)
 119       {
 120       set_subdir_str(message_subdir, message_id, i);
 121       temp_string = spool_fname(US"input", message_subdir, message_id, US"-D");
 122       if ((l_data_file = Ufopen(temp_string, "rb"))) break;
 123       }
 124     }
 125
 126   if (!l_data_file)
 127     {
 128     log_write(0, LOG_MAIN|LOG_PANIC, "Could not open datafile for message %s",
 129       message_id);
 130     goto OUT;
 131     }
 132
 133   /* The code used to use this line, but it doesn't work in Cygwin.
 134
 135       (void)fread(data_buffer, 1, 18, l_data_file);
 136
 137      What's happening is that spool_mbox used to use an fread to jump over the
 138      file header. That fails under Cygwin because the header is locked, but
 139      doing an fseek succeeds. We have to output the leading newline
 140      explicitly, because the one in the file is parted of the locked area.  */
 141
 142   if (!source_file_override)
 143     (void)fseek(l_data_file, SPOOL_DATA_START_OFFSET, SEEK_SET);
 144
 145   do
 146     {
 147     uschar * s;
 148
 149     if (!f.spool_file_wireformat || source_file_override)
 150       j = fread(buffer, 1, sizeof(buffer), l_data_file);
 151     else                                                /* needs CRLF -> NL */
 152       if ((s = US fgets(CS buffer, sizeof(buffer), l_data_file)))
 153         {
 154         uschar * p = s + Ustrlen(s) - 1;
 155
 156         if (*p == '\n' && p[-1] == '\r')
 157           *--p = '\n';
 158         else if (*p == '\r')
 159           ungetc(*p--, l_data_file);
 160
 161         j = p - buffer;
 162         }
 163       else
 164         j = 0;
 165
 166     if (j > 0)
 167       if (fwrite(buffer, j, 1, mbox_file) != 1)
 168         {
 169         log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
 170             message body to %s", mbox_path);
 171         goto OUT;
 172         }
 173     } while (j > 0);
 174
 175   (void)fclose(mbox_file);
 176   mbox_file = NULL;
 177
 178   Ustrncpy(spooled_message_id, message_id, sizeof(spooled_message_id));
 179   spooled_message_id[sizeof(spooled_message_id)-1] = '\0';
 180   spool_mbox_ok = 1;
 181   }
 182
 183 /* get the size of the mbox message and open [message_id].eml file for reading*/
 184
 185 if (  !(yield = Ufopen(mbox_path,"rb"))
 186    || fstat(fileno(yield), &statbuf) != 0
 187    )
 188   log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
 189     "scan file %s", mbox_path));
 190 else
 191   *mbox_file_size = statbuf.st_size;
 192
 193 OUT:
 194 if (l_data_file && !spool_data_file) (void)fclose(l_data_file);
 195 if (mbox_file) (void)fclose(mbox_file);
 196 store_reset(reset_point);
 197 return yield;
 198 }
 199
 200
 201
 202
 203
 204 /* remove mbox spool file and temp directory */
 205 void
 206 unspool_mbox(void)
 207 {
 208 spam_ok = 0;
 209 malware_ok = 0;
 210
 211 if (spool_mbox_ok && !f.no_mbox_unspool)
 212   {
 213   uschar *file_path;
 214   struct dirent *entry;
 215   DIR *tempdir;
 216   rmark reset_point = store_mark();
 217   uschar * mbox_path = string_sprintf("%s/scan/%s", spool_directory, spooled_message_id);
 218
 219   if (!(tempdir = opendir(CS mbox_path)))
 220     {
 221     debug_printf("Unable to opendir(%s): %s\n", mbox_path, strerror(errno));
 222     /* Just in case we still can: */
 223     rmdir(CS mbox_path);
 224     return;
 225     }
 226   /* loop thru dir & delete entries */
 227   while((entry = readdir(tempdir)))
 228     {
 229     uschar *name = US entry->d_name;
 230     int dummy;
 231     if (Ustrcmp(name, US".") == 0 || Ustrcmp(name, US"..") == 0) continue;
 232
 233     file_path = string_sprintf("%s/%s", mbox_path, name);
 234     debug_printf("unspool_mbox(): unlinking '%s'\n", file_path);
 235     dummy = unlink(CS file_path); dummy = dummy;        /* compiler quietening */
 236     }
 237
 238   closedir(tempdir);
 239
 240   /* remove directory */
 241   rmdir(CS mbox_path);
 242   store_reset(reset_point);
 243   }
 244 spool_mbox_ok = 0;
 245 }
 246
 247 #endif