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
   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 *
  30 spool_mbox(unsigned long *mbox_file_size, const uschar *source_file_override)
  31 {
  32   uschar message_subdir[2];
  33   uschar buffer[16384];
  34   uschar *temp_string;
  35   uschar *mbox_path;
  36   FILE *mbox_file = NULL;
  37   FILE *data_file = NULL;
  38   FILE *yield = NULL;
  39   header_line *my_headerlist;
  40   struct stat statbuf;
  41   int i, j;
  42   void *reset_point = store_get(0);
  43
  44   mbox_path = string_sprintf("%s/scan/%s/%s.eml", spool_directory, message_id,
  45     message_id);
  46
  47   /* Skip creation if already spooled out as mbox file */
  48   if (!spool_mbox_ok) {
  49     /* create temp directory inside scan dir, directory_make works recursively */
  50     temp_string = string_sprintf("scan/%s", message_id);
  51     if (!directory_make(spool_directory, temp_string, 0750, FALSE)) {
  52       log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
  53         "scan directory %s/scan/%s", spool_directory, temp_string));
  54       goto OUT;
  55     };
  56
  57     /* open [message_id].eml file for writing */
  58     mbox_file = modefopen(mbox_path, "wb", SPOOL_MODE);
  59     if (mbox_file == NULL) {
  60       log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
  61         "scan file %s", mbox_path));
  62       goto OUT;
  63     };
  64
  65     /* Generate mailbox headers. The $received_for variable is (up to at least
  66     Exim 4.64) never set here, because it is only set when expanding the
  67     contents of the Received: header line. However, the code below will use it
  68     if it should become available in future. */
  69
  70     temp_string = expand_string(
  71       US"From ${if def:return_path{$return_path}{MAILER-DAEMON}} ${tod_bsdinbox}\n"
  72       "${if def:sender_address{X-Envelope-From: <${sender_address}>\n}}"
  73       "${if def:recipients{X-Envelope-To: ${recipients}\n}}");
  74
  75     if (temp_string != NULL) {
  76       i = fwrite(temp_string, Ustrlen(temp_string), 1, mbox_file);
  77       if (i != 1) {
  78         log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
  79             mailbox headers to %s", mbox_path);
  80         goto OUT;
  81       };
  82     };
  83
  84     /* write all header lines to mbox file */
  85     my_headerlist = header_list;
  86     for (my_headerlist = header_list; my_headerlist != NULL;
  87       my_headerlist = my_headerlist->next)
  88     {
  89       /* skip deleted headers */
  90       if (my_headerlist->type == '*') continue;
  91
  92       i = fwrite(my_headerlist->text, my_headerlist->slen, 1, mbox_file);
  93       if (i != 1) {
  94         log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
  95             message headers to %s", mbox_path);
  96         goto OUT;
  97       };
  98     };
  99
 100     /* End headers */
 101     if (fwrite("\n", 1, 1, mbox_file) != 1) {
 102       log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
 103         message headers to %s", mbox_path);
 104       goto OUT;
 105     }
 106
 107     /* copy body file */
 108     if (source_file_override == NULL) {
 109       message_subdir[1] = '\0';
 110       for (i = 0; i < 2; i++) {
 111         message_subdir[0] = (split_spool_directory == (i == 0))? message_id[5] : 0;
 112         temp_string = string_sprintf("%s/input/%s/%s-D", spool_directory,
 113           message_subdir, message_id);
 114         data_file = Ufopen(temp_string, "rb");
 115         if (data_file != NULL) break;
 116       };
 117     } else {
 118       data_file = Ufopen(source_file_override, "rb");
 119     };
 120
 121     if (data_file == NULL) {
 122       log_write(0, LOG_MAIN|LOG_PANIC, "Could not open datafile for message %s",
 123         message_id);
 124       goto OUT;
 125     };
 126
 127     /* The code used to use this line, but it doesn't work in Cygwin.
 128      *
 129      *  (void)fread(data_buffer, 1, 18, data_file);
 130      *
 131      * What's happening is that spool_mbox used to use an fread to jump over the
 132      * file header. That fails under Cygwin because the header is locked, but
 133      * doing an fseek succeeds. We have to output the leading newline
 134      * explicitly, because the one in the file is parted of the locked area.
 135      */
 136
 137     if (!source_file_override)
 138       (void)fseek(data_file, SPOOL_DATA_START_OFFSET, SEEK_SET);
 139
 140     do {
 141       j = fread(buffer, 1, sizeof(buffer), data_file);
 142
 143       if (j > 0) {
 144         i = fwrite(buffer, j, 1, mbox_file);
 145         if (i != 1) {
 146           log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
 147               message body to %s", mbox_path);
 148           goto OUT;
 149         };
 150       };
 151     } while (j > 0);
 152
 153     (void)fclose(mbox_file);
 154     mbox_file = NULL;
 155
 156     Ustrcpy(spooled_message_id, message_id);
 157     spool_mbox_ok = 1;
 158   };
 159
 160   /* get the size of the mbox message and open [message_id].eml file for reading*/
 161   if (Ustat(mbox_path, &statbuf) != 0 ||
 162       (yield = Ufopen(mbox_path,"rb")) == NULL) {
 163     log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
 164       "scan file %s", mbox_path));
 165     goto OUT;
 166   };
 167
 168   *mbox_file_size = statbuf.st_size;
 169
 170   OUT:
 171   if (data_file) (void)fclose(data_file);
 172   if (mbox_file) (void)fclose(mbox_file);
 173   store_reset(reset_point);
 174   return yield;
 175 }
 176
 177 /* remove mbox spool file, demimed files and temp directory */
 178 void unspool_mbox(void) {
 179
 180   /* reset all exiscan state variables */
 181   #ifdef WITH_OLD_DEMIME
 182   demime_ok = 0;
 183   demime_errorlevel = 0;
 184   demime_reason = NULL;
 185   file_extensions = NULL;
 186   #endif
 187
 188   spam_ok = 0;
 189   malware_ok = 0;
 190
 191   if (spool_mbox_ok && !no_mbox_unspool) {
 192     uschar *mbox_path;
 193     uschar *file_path;
 194     int n;
 195     struct dirent *entry;
 196     DIR *tempdir;
 197
 198     mbox_path = string_sprintf("%s/scan/%s", spool_directory, spooled_message_id);
 199
 200     tempdir = opendir(CS mbox_path);
 201     if (!tempdir) {
 202       debug_printf("Unable to opendir(%s): %s\n", mbox_path, strerror(errno));
 203       /* Just in case we still can: */
 204       rmdir(CS mbox_path);
 205       return;
 206     }
 207     /* loop thru dir & delete entries */
 208     while((entry = readdir(tempdir)) != NULL) {
 209       uschar *name = US entry->d_name;
 210       if (Ustrcmp(name, US".") == 0 || Ustrcmp(name, US"..") == 0) continue;
 211
 212       file_path = string_sprintf("%s/%s", mbox_path, name);
 213       debug_printf("unspool_mbox(): unlinking '%s'\n", file_path);
 214       n = unlink(CS file_path);
 215     };
 216
 217     closedir(tempdir);
 218
 219     /* remove directory */
 220     rmdir(CS mbox_path);
 221     store_reset(mbox_path);
 222   };
 223   spool_mbox_ok = 0;
 224 }
 225
 226 #endif