src/src/spool_mbox.c

   1 /* $Cambridge: exim/src/src/spool_mbox.c,v 1.15 2010/06/05 11:13:30 pdp Exp $ */
   2
   3 /*************************************************
   4 *     Exim - an Internet mail transport agent    *
   5 *************************************************/
   6
   7 /* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2003-???? */
   8 /* License: GPL */
   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 /* externals, we must reset them on unspooling */
  17 #ifdef WITH_OLD_DEMIME
  18 extern int demime_ok;
  19 extern struct file_extension *file_extensions;
  20 #endif
  21
  22 extern int malware_ok;
  23 extern int spam_ok;
  24
  25 int spool_mbox_ok = 0;
  26 uschar spooled_message_id[17];
  27
  28 /* returns a pointer to the FILE, and puts the size in bytes into mbox_file_size
  29  * normally, source_file_override is NULL */
  30
  31 FILE *spool_mbox(unsigned long *mbox_file_size, uschar *source_file_override) {
  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_file));
  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     (void)fwrite("\n", 1, 1, mbox_file);
 102
 103     /* copy body file */
 104     if (source_file_override == NULL) {
 105       message_subdir[1] = '\0';
 106       for (i = 0; i < 2; i++) {
 107         message_subdir[0] = (split_spool_directory == (i == 0))? message_id[5] : 0;
 108         temp_string = string_sprintf("%s/input/%s/%s-D", spool_directory,
 109           message_subdir, message_id);
 110         data_file = Ufopen(temp_string, "rb");
 111         if (data_file != NULL) break;
 112       };
 113     } else {
 114       data_file = Ufopen(source_file_override, "rb");
 115     };
 116
 117     if (data_file == NULL) {
 118       log_write(0, LOG_MAIN|LOG_PANIC, "Could not open datafile for message %s",
 119         message_id);
 120       goto OUT;
 121     };
 122
 123     /* The code used to use this line, but it doesn't work in Cygwin.
 124      *
 125      *  (void)fread(data_buffer, 1, 18, data_file);
 126      *
 127      * What's happening is that spool_mbox used to use an fread to jump over the
 128      * file header. That fails under Cygwin because the header is locked, but
 129      * doing an fseek succeeds. We have to output the leading newline
 130      * explicitly, because the one in the file is parted of the locked area.
 131      */
 132
 133     if (!source_file_override)
 134       (void)fseek(data_file, SPOOL_DATA_START_OFFSET, SEEK_SET);
 135
 136     do {
 137       j = fread(buffer, 1, sizeof(buffer), data_file);
 138
 139       if (j > 0) {
 140         i = fwrite(buffer, j, 1, mbox_file);
 141         if (i != 1) {
 142           log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
 143               message body to %s", mbox_path);
 144           goto OUT;
 145         };
 146       };
 147     } while (j > 0);
 148
 149     (void)fclose(mbox_file);
 150     mbox_file = NULL;
 151
 152     Ustrcpy(spooled_message_id, message_id);
 153     spool_mbox_ok = 1;
 154   };
 155
 156   /* get the size of the mbox message and open [message_id].eml file for reading*/
 157   if (Ustat(mbox_path, &statbuf) != 0 ||
 158       (yield = Ufopen(mbox_path,"rb")) == NULL) {
 159     log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
 160       "scan file %s", mbox_file));
 161     goto OUT;
 162   };
 163
 164   *mbox_file_size = statbuf.st_size;
 165
 166   OUT:
 167   if (data_file) (void)fclose(data_file);
 168   if (mbox_file) (void)fclose(mbox_file);
 169   store_reset(reset_point);
 170   return yield;
 171 }
 172
 173 /* remove mbox spool file, demimed files and temp directory */
 174 void unspool_mbox(void) {
 175
 176   /* reset all exiscan state variables */
 177   #ifdef WITH_OLD_DEMIME
 178   demime_ok = 0;
 179   demime_errorlevel = 0;
 180   demime_reason = NULL;
 181   file_extensions = NULL;
 182   #endif
 183
 184   spam_ok = 0;
 185   malware_ok = 0;
 186
 187   if (spool_mbox_ok && !no_mbox_unspool) {
 188     uschar *mbox_path;
 189     uschar *file_path;
 190     int n;
 191     struct dirent *entry;
 192     DIR *tempdir;
 193
 194     mbox_path = string_sprintf("%s/scan/%s", spool_directory, spooled_message_id);
 195
 196     tempdir = opendir(CS mbox_path);
 197     if (!tempdir) {
 198       debug_printf("Unable to opendir(%s): %s\n", mbox_path, strerror(errno));
 199       /* Just in case we still can: */
 200       rmdir(CS mbox_path);
 201       return;
 202     }
 203     /* loop thru dir & delete entries */
 204     while((entry = readdir(tempdir)) != NULL) {
 205       uschar *name = US entry->d_name;
 206       if (Ustrcmp(name, US".") == 0 || Ustrcmp(name, US"..") == 0) continue;
 207
 208       file_path = string_sprintf("%s/%s", mbox_path, name);
 209       debug_printf("unspool_mbox(): unlinking '%s'\n", file_path);
 210       n = unlink(CS file_path);
 211     };
 212
 213     closedir(tempdir);
 214
 215     /* remove directory */
 216     rmdir(CS mbox_path);
 217     store_reset(mbox_path);
 218   };
 219   spool_mbox_ok = 0;
 220 }
 221
 222 #endif