src/src/spool_mbox.c

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