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 header_line *my_headerlist;
  40 struct stat statbuf;
  41 int i, j;
  42 void *reset_point;
  43
  44 mbox_path = string_sprintf("%s/scan/%s/%s.eml",
  45   spool_directory, message_id, message_id);
  46 if (mbox_fname) *mbox_fname = mbox_path;
  47
  48 reset_point = store_get(0);
  49
  50 /* Skip creation if already spooled out as mbox file */
  51 if (!spool_mbox_ok)
  52   {
  53   /* create temp directory inside scan dir, directory_make works recursively */
  54   temp_string = string_sprintf("scan/%s", message_id);
  55   if (!directory_make(spool_directory, temp_string, 0750, FALSE))
  56     {
  57     log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
  58       "scan directory %s/scan/%s", spool_directory, temp_string));
  59     goto OUT;
  60     }
  61
  62   /* open [message_id].eml file for writing */
  63
  64   if (!(mbox_file = modefopen(mbox_path, "wb", SPOOL_MODE)))
  65     {
  66     log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
  67       "scan file %s", mbox_path));
  68     goto OUT;
  69     }
  70
  71   /* Generate mailbox headers. The $received_for variable is (up to at least
  72   Exim 4.64) never set here, because it is only set when expanding the
  73   contents of the Received: header line. However, the code below will use it
  74   if it should become available in future. */
  75
  76   temp_string = expand_string(
  77     US"From ${if def:return_path{$return_path}{MAILER-DAEMON}} ${tod_bsdinbox}\n"
  78     "${if def:sender_address{X-Envelope-From: <${sender_address}>\n}}"
  79     "${if def:recipients{X-Envelope-To: ${recipients}\n}}");
  80
  81   if (temp_string)
  82     if (fwrite(temp_string, Ustrlen(temp_string), 1, mbox_file) != 1)
  83       {
  84       log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
  85           mailbox headers to %s", mbox_path);
  86       goto OUT;
  87       }
  88
  89   /* write all non-deleted header lines to mbox file */
  90
  91   for (my_headerlist = header_list; my_headerlist;
  92       my_headerlist = my_headerlist->next)
  93     if (my_headerlist->type != '*')
  94       if (fwrite(my_headerlist->text, my_headerlist->slen, 1, mbox_file) != 1)
  95         {
  96         log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
  97             message headers to %s", mbox_path);
  98         goto OUT;
  99         }
 100
 101   /* End headers */
 102   if (fwrite("\n", 1, 1, mbox_file) != 1)
 103     {
 104     log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
 105       message headers to %s", mbox_path);
 106     goto OUT;
 107     }
 108
 109   /* Copy body file.  If the main receive still has it open then it is holding
 110   a lock, and we must not close it (which releases the lock), so just use the
 111   global file handle. */
 112   if (source_file_override)
 113     l_data_file = Ufopen(source_file_override, "rb");
 114   else if (spool_data_file)
 115     l_data_file = spool_data_file;
 116   else
 117     {
 118     message_subdir[1] = '\0';
 119     for (i = 0; i < 2; i++)
 120       {
 121       message_subdir[0] = split_spool_directory == (i == 0) ? message_id[5] : 0;
 122       temp_string = spool_fname(US"input", message_subdir, message_id, US"-D");
 123       if ((l_data_file = Ufopen(temp_string, "rb"))) break;
 124       }
 125     }
 126
 127   if (!l_data_file)
 128     {
 129     log_write(0, LOG_MAIN|LOG_PANIC, "Could not open datafile for message %s",
 130       message_id);
 131     goto OUT;
 132     }
 133
 134   /* The code used to use this line, but it doesn't work in Cygwin.
 135
 136       (void)fread(data_buffer, 1, 18, l_data_file);
 137
 138      What's happening is that spool_mbox used to use an fread to jump over the
 139      file header. That fails under Cygwin because the header is locked, but
 140      doing an fseek succeeds. We have to output the leading newline
 141      explicitly, because the one in the file is parted of the locked area.  */
 142
 143   if (!source_file_override)
 144     (void)fseek(l_data_file, SPOOL_DATA_START_OFFSET, SEEK_SET);
 145
 146   do
 147     {
 148     uschar * s;
 149
 150     if (!f.spool_file_wireformat || source_file_override)
 151       j = fread(buffer, 1, sizeof(buffer), l_data_file);
 152     else                                                /* needs CRLF -> NL */
 153       if ((s = US fgets(CS buffer, sizeof(buffer), l_data_file)))
 154         {
 155         uschar * p = s + Ustrlen(s) - 1;
 156
 157         if (*p == '\n' && p[-1] == '\r')
 158           *--p = '\n';
 159         else if (*p == '\r')
 160           ungetc(*p--, l_data_file);
 161
 162         j = p - buffer;
 163         }
 164       else
 165         j = 0;
 166
 167     if (j > 0)
 168       if (fwrite(buffer, j, 1, mbox_file) != 1)
 169         {
 170         log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
 171             message body to %s", mbox_path);
 172         goto OUT;
 173         }
 174     } while (j > 0);
 175
 176   (void)fclose(mbox_file);
 177   mbox_file = NULL;
 178
 179   Ustrncpy(spooled_message_id, message_id, sizeof(spooled_message_id));
 180   spooled_message_id[sizeof(spooled_message_id)-1] = '\0';
 181   spool_mbox_ok = 1;
 182   }
 183
 184 /* get the size of the mbox message and open [message_id].eml file for reading*/
 185
 186 if (  !(yield = Ufopen(mbox_path,"rb"))
 187    || fstat(fileno(yield), &statbuf) != 0
 188    )
 189   log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
 190     "scan file %s", mbox_path));
 191 else
 192   *mbox_file_size = statbuf.st_size;
 193
 194 OUT:
 195 if (l_data_file && !spool_data_file) (void)fclose(l_data_file);
 196 if (mbox_file) (void)fclose(mbox_file);
 197 store_reset(reset_point);
 198 return yield;
 199 }
 200
 201
 202
 203
 204
 205 /* remove mbox spool file and temp directory */
 206 void
 207 unspool_mbox(void)
 208 {
 209 spam_ok = 0;
 210 malware_ok = 0;
 211
 212 if (spool_mbox_ok && !f.no_mbox_unspool)
 213   {
 214   uschar *mbox_path;
 215   uschar *file_path;
 216   struct dirent *entry;
 217   DIR *tempdir;
 218
 219   mbox_path = string_sprintf("%s/scan/%s", spool_directory, spooled_message_id);
 220
 221   if (!(tempdir = opendir(CS mbox_path)))
 222     {
 223     debug_printf("Unable to opendir(%s): %s\n", mbox_path, strerror(errno));
 224     /* Just in case we still can: */
 225     rmdir(CS mbox_path);
 226     return;
 227     }
 228   /* loop thru dir & delete entries */
 229   while((entry = readdir(tempdir)))
 230     {
 231     uschar *name = US entry->d_name;
 232     int dummy;
 233     if (Ustrcmp(name, US".") == 0 || Ustrcmp(name, US"..") == 0) continue;
 234
 235     file_path = string_sprintf("%s/%s", mbox_path, name);
 236     debug_printf("unspool_mbox(): unlinking '%s'\n", file_path);
 237     dummy = unlink(CS file_path); dummy = dummy;        /* compiler quietening */
 238     }
 239
 240   closedir(tempdir);
 241
 242   /* remove directory */
 243   rmdir(CS mbox_path);
 244   store_reset(mbox_path);
 245   }
 246 spool_mbox_ok = 0;
 247 }
 248
 249 #endif