external/ibm-public/postfix/dist/src/global/delivered_hdr.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      delivered_hdr 3
   6 /* SUMMARY
   7 /*      process Delivered-To: headers
   8 /* SYNOPSIS
   9 /*      #include <delivered_hdr.h>
  10 /*
  11 /*      DELIVERED_HDR_INFO *delivered_hdr_init(stream, offset, flags)
  12 /*      VSTREAM *stream;
  13 /*      off_t   offset;
  14 /*      int     flags;
  15 /*
  16 /*      int     delivered_hdr_find(info, address)
  17 /*      DELIVERED_HDR_INFO *info;
  18 /*      const char *address;
  19 /*
  20 /*      void    delivered_hdr_free(info)
  21 /*      DELIVERED_HDR_INFO *info;
  22 /* DESCRIPTION
  23 /*      This module processes addresses in Delivered-To: headers.
  24 /*      These headers are added by some mail delivery systems, for the
  25 /*      purpose of breaking mail forwarding loops. N.B. This solves
  26 /*      a different problem than the Received: hop count limit. Hop
  27 /*      counts are used to limit the impact of mail routing problems.
  28 /*
  29 /*      delivered_hdr_init() extracts Delivered-To: header addresses
  30 /*      from the specified message, and returns a table with the
  31 /*      result. The file seek pointer is changed.
  32 /*
  33 /*      delivered_hdr_find() looks up the address in the lookup table,
  34 /*      and returns non-zero when the address was found. The
  35 /*      address argument must be in internalized form.
  36 /*
  37 /*      delivered_hdr_free() releases storage that was allocated by
  38 /*      delivered_hdr_init().
  39 /*
  40 /*      Arguments:
  41 /* .IP stream
  42 /*      The open queue file.
  43 /* .IP offset
  44 /*      Offset of the first message content record.
  45 /* .IP flags
  46 /*      Zero, or the bit-wise OR ot:
  47 /* .RS
  48 /* .IP FOLD_ADDR_USER
  49 /*      Case fold the address local part.
  50 /* .IP FOLD_ADDR_HOST
  51 /*      Case fold the address domain part.
  52 /* .IP FOLD_ADDR_ALL
  53 /*      Alias for (FOLD_ADDR_USER | FOLD_ADDR_HOST).
  54 /* .RE
  55 /* .IP info
  56 /*      Extracted Delivered-To: addresses information.
  57 /* .IP address
  58 /*      A recipient address, internal form.
  59 /* DIAGNOSTICS
  60 /*      Fatal errors: out of memory.
  61 /* SEE ALSO
  62 /*      mail_copy(3), producer of Delivered-To: and other headers.
  63 /* LICENSE
  64 /* .ad
  65 /* .fi
  66 /*      The Secure Mailer license must be distributed with this software.
  67 /* AUTHOR(S)
  68 /*      Wietse Venema
  69 /*      IBM T.J. Watson Research
  70 /*      P.O. Box 704
  71 /*      Yorktown Heights, NY 10598, USA
  72 /*--*/
  73
  74 /* System library. */
  75
  76 #include <sys_defs.h>
  77 #include <unistd.h>
  78 #include <string.h>
  79 #include <ctype.h>
  80
  81 /* Utility library. */
  82
  83 #include <msg.h>
  84 #include <mymalloc.h>
  85 #include <htable.h>
  86 #include <vstring.h>
  87 #include <vstream.h>
  88 #include <vstring_vstream.h>
  89 #include <stringops.h>
  90
  91 /* Global library. */
  92
  93 #include <record.h>
  94 #include <rec_type.h>
  95 #include <is_header.h>
  96 #include <quote_822_local.h>
  97 #include <header_opts.h>
  98 #include <delivered_hdr.h>
  99 #include <fold_addr.h>
 100
 101  /*
 102   * Application-specific.
 103   */
 104 struct DELIVERED_HDR_INFO {
 105     int     flags;
 106     VSTRING *buf;
 107     HTABLE *table;
 108 };
 109
 110 #define STR(x) vstring_str(x)
 111
 112 /* delivered_hdr_init - extract delivered-to information from the message */
 113
 114 DELIVERED_HDR_INFO *delivered_hdr_init(VSTREAM *fp, off_t offset, int flags)
 115 {
 116     char   *cp;
 117     DELIVERED_HDR_INFO *info;
 118     const HEADER_OPTS *hdr;
 119
 120     /*
 121      * Sanity check.
 122      */
 123     info = (DELIVERED_HDR_INFO *) mymalloc(sizeof(*info));
 124     info->flags = flags;
 125     info->buf = vstring_alloc(10);
 126     info->table = htable_create(0);
 127
 128     if (vstream_fseek(fp, offset, SEEK_SET) < 0)
 129         msg_fatal("seek queue file %s: %m", VSTREAM_PATH(fp));
 130
 131     /*
 132      * XXX Assume that mail_copy() produces delivered-to headers that fit in
 133      * a REC_TYPE_NORM record. Lowercase the delivered-to addresses for
 134      * consistency.
 135      *
 136      * XXX Don't get bogged down by gazillions of delivered-to headers.
 137      */
 138 #define DELIVERED_HDR_LIMIT     1000
 139
 140     while (rec_get(fp, info->buf, 0) == REC_TYPE_NORM
 141            && info->table->used < DELIVERED_HDR_LIMIT) {
 142         if (is_header(STR(info->buf))) {
 143             if ((hdr = header_opts_find(STR(info->buf))) != 0
 144                 && hdr->type == HDR_DELIVERED_TO) {
 145                 cp = STR(info->buf) + strlen(hdr->name) + 1;
 146                 while (ISSPACE(*cp))
 147                     cp++;
 148                 if (info->flags & FOLD_ADDR_ALL)
 149                     fold_addr(cp, info->flags);
 150                 if (msg_verbose)
 151                     msg_info("delivered_hdr_init: %s", cp);
 152                 htable_enter(info->table, cp, (char *) 0);
 153             }
 154         } else if (ISSPACE(STR(info->buf)[0])) {
 155             continue;
 156         } else {
 157             break;
 158         }
 159     }
 160     return (info);
 161 }
 162
 163 /* delivered_hdr_find - look up recipient in delivered table */
 164
 165 int     delivered_hdr_find(DELIVERED_HDR_INFO *info, const char *address)
 166 {
 167     HTABLE_INFO *ht;
 168
 169     /*
 170      * mail_copy() uses quote_822_local() when writing the Delivered-To:
 171      * header. We must therefore apply the same transformation when looking
 172      * up the recipient. Lowercase the delivered-to address for consistency.
 173      */
 174     quote_822_local(info->buf, address);
 175     if (info->flags & FOLD_ADDR_ALL)
 176         fold_addr(STR(info->buf), info->flags);
 177     ht = htable_locate(info->table, STR(info->buf));
 178     return (ht != 0);
 179 }
 180
 181 /* delivered_hdr_free - destructor */
 182
 183 void    delivered_hdr_free(DELIVERED_HDR_INFO *info)
 184 {
 185     vstring_free(info->buf);
 186     htable_free(info->table, (void (*) (char *)) 0);
 187     myfree((char *) info);
 188 }