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_file));
  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     (void)fwrite("\n", 1, 1, mbox_file);
 100
 101     /* copy body file */
 102     if (source_file_override == NULL) {
 103       message_subdir[1] = '\0';
 104       for (i = 0; i < 2; i++) {
 105         message_subdir[0] = (split_spool_directory == (i == 0))? message_id[5] : 0;
 106         temp_string = string_sprintf("%s/input/%s/%s-D", spool_directory,
 107           message_subdir, message_id);
 108         data_file = Ufopen(temp_string, "rb");
 109         if (data_file != NULL) break;
 110       };
 111     } else {
 112       data_file = Ufopen(source_file_override, "rb");
 113     };
 114
 115     if (data_file == NULL) {
 116       log_write(0, LOG_MAIN|LOG_PANIC, "Could not open datafile for message %s",
 117         message_id);
 118       goto OUT;
 119     };
 120
 121     /* The code used to use this line, but it doesn't work in Cygwin.
 122      *
 123      *  (void)fread(data_buffer, 1, 18, data_file);
 124      *
 125      * What's happening is that spool_mbox used to use an fread to jump over the
 126      * file header. That fails under Cygwin because the header is locked, but
 127      * doing an fseek succeeds. We have to output the leading newline
 128      * explicitly, because the one in the file is parted of the locked area.
 129      */
 130
 131     if (!source_file_override)
 132       (void)fseek(data_file, SPOOL_DATA_START_OFFSET, SEEK_SET);
 133
 134     do {
 135       j = fread(buffer, 1, sizeof(buffer), data_file);
 136
 137       if (j > 0) {
 138         i = fwrite(buffer, j, 1, mbox_file);
 139         if (i != 1) {
 140           log_write(0, LOG_MAIN|LOG_PANIC, "Error/short write while writing \
 141               message body to %s", mbox_path);
 142           goto OUT;
 143         };
 144       };
 145     } while (j > 0);
 146
 147     (void)fclose(mbox_file);
 148     mbox_file = NULL;
 149
 150     Ustrcpy(spooled_message_id, message_id);
 151     spool_mbox_ok = 1;
 152   };
 153
 154   /* get the size of the mbox message and open [message_id].eml file for reading*/
 155   if (Ustat(mbox_path, &statbuf) != 0 ||
 156       (yield = Ufopen(mbox_path,"rb")) == NULL) {
 157     log_write(0, LOG_MAIN|LOG_PANIC, "%s", string_open_failed(errno,
 158       "scan file %s", mbox_file));
 159     goto OUT;
 160   };
 161
 162   *mbox_file_size = statbuf.st_size;
 163
 164   OUT:
 165   if (data_file) (void)fclose(data_file);
 166   if (mbox_file) (void)fclose(mbox_file);
 167   store_reset(reset_point);
 168   return yield;
 169 }
 170
 171 /* remove mbox spool file, demimed files and temp directory */
 172 void unspool_mbox(void) {
 173
 174   /* reset all exiscan state variables */
 175   #ifdef WITH_OLD_DEMIME
 176   demime_ok = 0;
 177   demime_errorlevel = 0;
 178   demime_reason = NULL;
 179   file_extensions = NULL;
 180   #endif
 181
 182   spam_ok = 0;
 183   malware_ok = 0;
 184
 185   if (spool_mbox_ok && !no_mbox_unspool) {
 186     uschar *mbox_path;
 187     uschar *file_path;
 188     int n;
 189     struct dirent *entry;
 190     DIR *tempdir;
 191
 192     mbox_path = string_sprintf("%s/scan/%s", spool_directory, spooled_message_id);
 193
 194     tempdir = opendir(CS mbox_path);
 195     if (!tempdir) {
 196       debug_printf("Unable to opendir(%s): %s\n", mbox_path, strerror(errno));
 197       /* Just in case we still can: */
 198       rmdir(CS mbox_path);
 199       return;
 200     }
 201     /* loop thru dir & delete entries */
 202     while((entry = readdir(tempdir)) != NULL) {
 203       uschar *name = US entry->d_name;
 204       if (Ustrcmp(name, US".") == 0 || Ustrcmp(name, US"..") == 0) continue;
 205
 206       file_path = string_sprintf("%s/%s", mbox_path, name);
 207       debug_printf("unspool_mbox(): unlinking '%s'\n", file_path);
 208       n = unlink(CS file_path);
 209     };
 210
 211     closedir(tempdir);
 212
 213     /* remove directory */
 214     rmdir(CS mbox_path);
 215     store_reset(mbox_path);
 216   };
 217   spool_mbox_ok = 0;
 218 }
 219
 220 #endif