external/ibm-public/postfix/dist/src/cleanup/cleanup_masquerade.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      cleanup_masquerade 3
   6 /* SUMMARY
   7 /*      address masquerading
   8 /* SYNOPSIS
   9 /*      #include <cleanup.h>
  10 /*
  11 /*      int     cleanup_masquerade_external(addr, masq_domains)
  12 /*      VSTRING *addr;
  13 /*      ARGV    *masq_domains;
  14 /*
  15 /*      int     cleanup_masquerade_internal(addr, masq_domains)
  16 /*      VSTRING *addr;
  17 /*      ARGV    *masq_domains;
  18 /*
  19 /*      int     cleanup_masquerade_tree(tree, masq_domains)
  20 /*      TOK822  *tree;
  21 /*      ARGV    *masq_domains;
  22 /* DESCRIPTION
  23 /*      This module masquerades addresses, that is, it strips subdomains
  24 /*      below domain names that are listed in the masquerade_domains
  25 /*      configuration parameter, except for user names listed in the
  26 /*      masquerade_exceptions configuration parameter.
  27 /*      These functions return non-zero when the address was changed.
  28 /*
  29 /*      cleanup_masquerade_external() rewrites the external (quoted) string
  30 /*      form of an address.
  31 /*
  32 /*      cleanup_masquerade_internal() is a wrapper around the
  33 /*      cleanup_masquerade_external() routine that transforms from
  34 /*      internal (quoted) string form to external form and back.
  35 /*
  36 /*      cleanup_masquerade_tree() is a wrapper around the
  37 /*      cleanup_masquerade_external() routine that transforms from
  38 /*      internal parse tree form to external form and back.
  39 /* DIAGNOSTICS
  40 /* LICENSE
  41 /* .ad
  42 /* .fi
  43 /*      The Secure Mailer license must be distributed with this software.
  44 /* AUTHOR(S)
  45 /*      Wietse Venema
  46 /*      IBM T.J. Watson Research
  47 /*      P.O. Box 704
  48 /*      Yorktown Heights, NY 10598, USA
  49 /*--*/
  50
  51 /* System library. */
  52
  53 #include <sys_defs.h>
  54 #include <string.h>
  55
  56 #ifdef STRCASECMP_IN_STRINGS_H
  57 #include <strings.h>
  58 #endif
  59
  60 /* Utility library. */
  61
  62 #include <msg.h>
  63 #include <vstring.h>
  64 #include <argv.h>
  65 #include <htable.h>
  66 #include <mymalloc.h>
  67 #include <stringops.h>
  68
  69 /* Global library. */
  70
  71 #include <mail_params.h>
  72 #include <tok822.h>
  73 #include <quote_822_local.h>
  74
  75 /* Application-specific. */
  76
  77 #include "cleanup.h"
  78
  79 #define STR     vstring_str
  80
  81 /* cleanup_masquerade_external - masquerade address external form */
  82
  83 int     cleanup_masquerade_external(VSTRING *addr, ARGV *masq_domains)
  84 {
  85     char   *domain;
  86     ssize_t domain_len;
  87     char  **masqp;
  88     char   *masq;
  89     ssize_t masq_len;
  90     char   *parent;
  91     int     truncate;
  92     int     did_rewrite = 0;
  93
  94     /* Stuff for excluded names. */
  95     char   *name;
  96     int     excluded;
  97
  98     /*
  99      * Find the domain part.
 100      */
 101     if ((domain = strrchr(STR(addr), '@')) == 0)
 102         return (0);
 103     domain += 1;
 104     domain_len = strlen(domain);
 105
 106     /*
 107      * Don't masquerade excluded names (regardless of domain).
 108      */
 109     if (*var_masq_exceptions) {
 110         name = mystrndup(STR(addr), domain - 1 - STR(addr));
 111         excluded = (string_list_match(cleanup_masq_exceptions, lowercase(name)) != 0);
 112         myfree(name);
 113         if (excluded)
 114             return (0);
 115     }
 116
 117     /*
 118      * If any parent domain matches the list of masquerade domains, replace
 119      * the domain in the address and terminate. If the domain matches a
 120      * masquerade domain, leave it alone. Order of specification matters.
 121      */
 122     for (masqp = masq_domains->argv; (masq = *masqp) != 0; masqp++) {
 123         for (truncate = 1; *masq == '!'; masq++)
 124             truncate = !truncate;
 125         masq_len = strlen(masq);
 126         if (masq_len == 0)
 127             continue;
 128         if (masq_len == domain_len) {
 129             if (strcasecmp(masq, domain) == 0)
 130                 break;
 131         } else if (masq_len < domain_len) {
 132             parent = domain + domain_len - masq_len;
 133             if (parent[-1] == '.' && strcasecmp(masq, parent) == 0) {
 134                 if (truncate) {
 135                     if (msg_verbose)
 136                         msg_info("masquerade: %s -> %s", domain, masq);
 137                     vstring_truncate(addr, domain - STR(addr));
 138                     vstring_strcat(addr, masq);
 139                     did_rewrite = 1;
 140                 }
 141                 break;
 142             }
 143         }
 144     }
 145     return (did_rewrite);
 146 }
 147
 148 /* cleanup_masquerade_tree - masquerade address node */
 149
 150 int     cleanup_masquerade_tree(TOK822 *tree, ARGV *masq_domains)
 151 {
 152     VSTRING *temp = vstring_alloc(100);
 153     int     did_rewrite;
 154
 155     tok822_externalize(temp, tree->head, TOK822_STR_DEFL);
 156     did_rewrite = cleanup_masquerade_external(temp, masq_domains);
 157     tok822_free_tree(tree->head);
 158     tree->head = tok822_scan(STR(temp), &tree->tail);
 159
 160     vstring_free(temp);
 161     return (did_rewrite);
 162 }
 163
 164 /* cleanup_masquerade_internal - masquerade address internal form */
 165
 166 int     cleanup_masquerade_internal(VSTRING *addr, ARGV *masq_domains)
 167 {
 168     VSTRING *temp = vstring_alloc(100);
 169     int     did_rewrite;
 170
 171     quote_822_local(temp, STR(addr));
 172     did_rewrite = cleanup_masquerade_external(temp, masq_domains);
 173     unquote_822_local(addr, STR(temp));
 174
 175     vstring_free(temp);
 176     return (did_rewrite);
 177 }
 178
 179  /*
 180   * Code for stand-alone testing. Instead of using main.cf, specify the strip
 181   * list and the candidate domain on the command line. Specify null arguments
 182   * for data that should be empty.
 183   */
 184 #ifdef TEST
 185
 186 #include <vstream.h>
 187
 188 char   *var_masq_exceptions;
 189 STRING_LIST *cleanup_masq_exceptions;
 190
 191 int     main(int argc, char **argv)
 192 {
 193     VSTRING *addr;
 194     ARGV   *masq_domains;
 195
 196     if (argc != 4)
 197         msg_fatal("usage: %s exceptions masquerade_list address", argv[0]);
 198
 199     var_masq_exceptions = argv[1];
 200     cleanup_masq_exceptions =
 201         string_list_init(MATCH_FLAG_NONE, var_masq_exceptions);
 202     masq_domains = argv_split(argv[2], " ,\t\r\n");
 203     addr = vstring_alloc(1);
 204     if (strchr(argv[3], '@') == 0)
 205         msg_fatal("address must be in user@domain form");
 206     vstring_strcpy(addr, argv[3]);
 207
 208     vstream_printf("----------\n");
 209     vstream_printf("exceptions: %s\n", argv[1]);
 210     vstream_printf("masq_list:  %s\n", argv[2]);
 211     vstream_printf("address:    %s\n", argv[3]);
 212
 213     cleanup_masquerade_external(addr, masq_domains);
 214
 215     vstream_printf("result:     %s\n", STR(addr));
 216     vstream_fflush(VSTREAM_OUT);
 217
 218     vstring_free(addr);
 219     argv_free(masq_domains);
 220
 221     return (0);
 222 }
 223
 224 #endif