external/ibm-public/postfix/dist/src/smtpd/smtpd_milter.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      smtpd_milter 3
   6 /* SUMMARY
   7 /*      SMTP server milter glue
   8 /* SYNOPSIS
   9 /*      #include <smtpd.h>
  10 /*      #include <smtpd_milter.h>
  11 /*
  12 /*      const char *smtpd_milter_eval(name, context)
  13 /*      const char *name;
  14 /*      void    *context;
  15 /* DESCRIPTION
  16 /*      smtpd_milter_eval() is a milter(3) call-back routine to
  17 /*      expand Sendmail macros before they are sent to filters.
  18 /* DIAGNOSTICS
  19 /*      Panic: interface violations. Fatal errors: out of memory.
  20 /*      internal protocol errors.
  21 /* LICENSE
  22 /* .ad
  23 /* .fi
  24 /*      The Secure Mailer license must be distributed with this software.
  25 /* AUTHOR(S)
  26 /*      Wietse Venema
  27 /*      IBM T.J. Watson Research
  28 /*      P.O. Box 704
  29 /*      Yorktown Heights, NY 10598, USA
  30 /*--*/
  31
  32 /* System library. */
  33
  34 #include <sys_defs.h>
  35
  36 /* Utility library. */
  37
  38 #include <split_at.h>
  39
  40 /* Global library. */
  41
  42 #include <mail_params.h>
  43 #include <quote_821_local.h>
  44
  45 /* Milter library. */
  46
  47 #include <milter.h>
  48
  49 /* Application-specific. */
  50
  51 #include <smtpd.h>
  52 #include <smtpd_sasl_glue.h>
  53 #include <smtpd_resolve.h>
  54 #include <smtpd_milter.h>
  55
  56  /*
  57   * SLMs.
  58   */
  59 #define STR(x)  vstring_str(x)
  60
  61 /* smtpd_milter_eval - evaluate milter macro */
  62
  63 const char *smtpd_milter_eval(const char *name, void *ptr)
  64 {
  65     SMTPD_STATE *state = (SMTPD_STATE *) ptr;
  66     const RESOLVE_REPLY *reply;
  67     char   *cp;
  68
  69     /*
  70      * On-the-fly initialization.
  71      */
  72     if (state->expand_buf == 0)
  73         state->expand_buf = vstring_alloc(10);
  74
  75     /*
  76      * Canonicalize the name.
  77      */
  78     if (*name != '{') {                         /* } */
  79         vstring_sprintf(state->expand_buf, "{%s}", name);
  80         name = STR(state->expand_buf);
  81     }
  82
  83     /*
  84      * System macros.
  85      */
  86     if (strcmp(name, S8_MAC_DAEMON_NAME) == 0)
  87         return (var_milt_daemon_name);
  88     if (strcmp(name, S8_MAC_V) == 0)
  89         return (var_milt_v);
  90
  91     /*
  92      * Connect macros.
  93      */
  94     if (strcmp(name, S8_MAC__) == 0) {
  95         vstring_sprintf(state->expand_buf, "%s [%s]",
  96                         state->reverse_name, state->addr);
  97         if (strcasecmp(state->name, state->reverse_name) != 0)
  98             vstring_strcat(state->expand_buf, " (may be forged)");
  99         return (STR(state->expand_buf));
 100     }
 101     if (strcmp(name, S8_MAC_J) == 0)
 102         return (var_myhostname);
 103     if (strcmp(name, S8_MAC_CLIENT_ADDR) == 0)
 104         return (state->rfc_addr);
 105     if (strcmp(name, S8_MAC_CLIENT_PORT) == 0)
 106         return (strcmp(state->port, CLIENT_PORT_UNKNOWN) ? state->port : "0");
 107     if (strcmp(name, S8_MAC_CLIENT_CONN) == 0) {
 108         vstring_sprintf(state->expand_buf, "%d", state->conn_count);
 109         return (STR(state->expand_buf));
 110     }
 111     if (strcmp(name, S8_MAC_CLIENT_NAME) == 0)
 112         return (state->name);
 113     if (strcmp(name, S8_MAC_CLIENT_PTR) == 0)
 114         return (state->reverse_name);
 115     if (strcmp(name, S8_MAC_CLIENT_RES) == 0)
 116         return (state->name_status == SMTPD_PEER_CODE_OK ? "OK" :
 117                 state->name_status == SMTPD_PEER_CODE_FORGED ? "FORGED" :
 118               state->name_status == SMTPD_PEER_CODE_TEMP ? "TEMP" : "FAIL");
 119
 120     /*
 121      * HELO macros.
 122      */
 123 #ifdef USE_TLS
 124 #define IF_ENCRYPTED(x) (state->tls_context ? (x) : 0)
 125 #define IF_TRUSTED(x) (TLS_CERT_IS_TRUSTED(state->tls_context) ? (x) : 0)
 126
 127     if (strcmp(name, S8_MAC_TLS_VERSION) == 0)
 128         return (IF_ENCRYPTED(state->tls_context->protocol));
 129     if (strcmp(name, S8_MAC_CIPHER) == 0)
 130         return (IF_ENCRYPTED(state->tls_context->cipher_name));
 131     if (strcmp(name, S8_MAC_CIPHER_BITS) == 0) {
 132         if (state->tls_context == 0)
 133             return (0);
 134         vstring_sprintf(state->expand_buf, "%d",
 135                         IF_ENCRYPTED(state->tls_context->cipher_usebits));
 136         return (STR(state->expand_buf));
 137     }
 138     if (strcmp(name, S8_MAC_CERT_SUBJECT) == 0)
 139         return (IF_TRUSTED(state->tls_context->peer_CN));
 140     if (strcmp(name, S8_MAC_CERT_ISSUER) == 0)
 141         return (IF_TRUSTED(state->tls_context->issuer_CN));
 142 #endif
 143
 144     /*
 145      * MAIL FROM macros.
 146      */
 147 #define IF_SASL_ENABLED(s) (smtpd_sasl_is_active(state) && (s) ? (s) : 0)
 148
 149     if (strcmp(name, S8_MAC_I) == 0)
 150         return (state->queue_id);
 151 #ifdef USE_SASL_AUTH
 152     if (strcmp(name, S8_MAC_AUTH_TYPE) == 0)
 153         return (IF_SASL_ENABLED(state->sasl_method));
 154     if (strcmp(name, S8_MAC_AUTH_AUTHEN) == 0)
 155         return (IF_SASL_ENABLED(state->sasl_username));
 156     if (strcmp(name, S8_MAC_AUTH_AUTHOR) == 0)
 157         return (IF_SASL_ENABLED(state->sasl_sender));
 158 #endif
 159     if (strcmp(name, S8_MAC_MAIL_ADDR) == 0) {
 160         if (state->sender == 0)
 161             return (0);
 162         if (state->sender[0] == 0)
 163             return ("");
 164         reply = smtpd_resolve_addr(state->sender);
 165         /* Sendmail 8.13 does not externalize the null string. */
 166         if (STR(reply->recipient)[0])
 167             quote_821_local(state->expand_buf, STR(reply->recipient));
 168         else
 169             vstring_strcpy(state->expand_buf, STR(reply->recipient));
 170         return (STR(state->expand_buf));
 171     }
 172     if (strcmp(name, S8_MAC_MAIL_HOST) == 0) {
 173         if (state->sender == 0)
 174             return (0);
 175         reply = smtpd_resolve_addr(state->sender);
 176         return (STR(reply->nexthop));
 177     }
 178     if (strcmp(name, S8_MAC_MAIL_MAILER) == 0) {
 179         if (state->sender == 0)
 180             return (0);
 181         reply = smtpd_resolve_addr(state->sender);
 182         return (STR(reply->transport));
 183     }
 184
 185     /*
 186      * RCPT TO macros.
 187      */
 188     if (strcmp(name, S8_MAC_RCPT_ADDR) == 0) {
 189         if (state->recipient == 0)
 190             return (0);
 191         if (state->recipient[0] == 0)
 192             return ("");
 193         if (state->milter_reject_text) {
 194             /* 554 5.7.1 <user@example.com>: Relay access denied */
 195             vstring_strcpy(state->expand_buf, state->milter_reject_text + 4);
 196             cp = split_at(STR(state->expand_buf), ' ');
 197             return (cp ? split_at(cp, ' ') : cp);
 198         }
 199         reply = smtpd_resolve_addr(state->recipient);
 200         /* Sendmail 8.13 does not externalize the null string. */
 201         if (STR(reply->recipient)[0])
 202             quote_821_local(state->expand_buf, STR(reply->recipient));
 203         else
 204             vstring_strcpy(state->expand_buf, STR(reply->recipient));
 205         return (STR(state->expand_buf));
 206     }
 207     if (strcmp(name, S8_MAC_RCPT_HOST) == 0) {
 208         if (state->recipient == 0)
 209             return (0);
 210         if (state->milter_reject_text) {
 211             /* 554 5.7.1 <user@example.com>: Relay access denied */
 212             vstring_strcpy(state->expand_buf, state->milter_reject_text + 4);
 213             (void) split_at(STR(state->expand_buf), ' ');
 214             return (STR(state->expand_buf));
 215         }
 216         reply = smtpd_resolve_addr(state->recipient);
 217         return (STR(reply->nexthop));
 218     }
 219     if (strcmp(name, S8_MAC_RCPT_MAILER) == 0) {
 220         if (state->recipient == 0)
 221             return (0);
 222         if (state->milter_reject_text)
 223             return (S8_RCPT_MAILER_ERROR);
 224         reply = smtpd_resolve_addr(state->recipient);
 225         return (STR(reply->transport));
 226     }
 227     return (0);
 228 }