1 /*	$NetBSD: smtpd_milter.c,v 1.1.1.1 2009/06/23 10:08:56 tron Exp $	*/
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 }
229