1 /*
2  * Copyright (c) 2019 Martijn van Duren <martijn@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 #include <sys/socket.h>
17 
18 #ifndef __dead
19 #define __dead __attribute__((__noreturn__))
20 #endif
21 #ifndef __unused
22 #define __unused __attribute__((unused))
23 #endif
24 
25 enum osmtpd_status {
26 	OSMTPD_STATUS_OK,
27 	OSMTPD_STATUS_TEMPFAIL,
28 	OSMTPD_STATUS_PERMFAIL
29 };
30 
31 enum osmtpd_auth_status {
32 	OSMTPD_AUTH_PASS,
33 	OSMTPD_AUTH_FAIL,
34 	OSMTPD_AUTH_ERROR,
35 };
36 
37 enum osmtpd_type {
38 	OSMTPD_TYPE_FILTER,
39 	OSMTPD_TYPE_REPORT
40 };
41 
42 enum osmtpd_phase {
43 	OSMTPD_PHASE_CONNECT,
44 	OSMTPD_PHASE_HELO,
45 	OSMTPD_PHASE_EHLO,
46 	OSMTPD_PHASE_STARTTLS,
47 	OSMTPD_PHASE_AUTH,
48 	OSMTPD_PHASE_MAIL_FROM,
49 	OSMTPD_PHASE_RCPT_TO,
50 	OSMTPD_PHASE_DATA,
51 	OSMTPD_PHASE_DATA_LINE,
52 	OSMTPD_PHASE_RSET,
53 	OSMTPD_PHASE_QUIT,
54 	OSMTPD_PHASE_NOOP,
55 	OSMTPD_PHASE_HELP,
56 	OSMTPD_PHASE_WIZ,
57 	OSMTPD_PHASE_COMMIT,
58 	OSMTPD_PHASE_LINK_CONNECT,
59 	OSMTPD_PHASE_LINK_DISCONNECT,
60 	OSMTPD_PHASE_LINK_GREETING,
61 	OSMTPD_PHASE_LINK_IDENTIFY,
62 	OSMTPD_PHASE_LINK_TLS,
63 	OSMTPD_PHASE_LINK_AUTH,
64 	OSMTPD_PHASE_TX_BEGIN,
65 	OSMTPD_PHASE_TX_MAIL,
66 	OSMTPD_PHASE_TX_RCPT,
67 	OSMTPD_PHASE_TX_ENVELOPE,
68 	OSMTPD_PHASE_TX_DATA,
69 	OSMTPD_PHASE_TX_COMMIT,
70 	OSMTPD_PHASE_TX_ROLLBACK,
71 	OSMTPD_PHASE_PROTOCOL_CLIENT,
72 	OSMTPD_PHASE_PROTOCOL_SERVER,
73 	OSMTPD_PHASE_FILTER_RESPONSE,
74 	OSMTPD_PHASE_TIMEOUT
75 };
76 
77 #define OSMTPD_NEED_SRC 1 << 0
78 #define OSMTPD_NEED_DST 1 << 1
79 #define OSMTPD_NEED_RDNS 1 << 2
80 #define OSMTPD_NEED_FCRDNS 1 << 3
81 #define OSMTPD_NEED_IDENTITY 1 << 4
82 #define OSMTPD_NEED_GREETING 1 << 5
83 #define OSMTPD_NEED_CIPHERS 1 << 6
84 #define OSMTPD_NEED_MSGID 1 << 7
85 #define OSMTPD_NEED_USERNAME 1 << 8
86 #define OSMTPD_NEED_MAILFROM 1 << 9
87 #define OSMTPD_NEED_RCPTTO 1 << 10
88 #define OSMTPD_NEED_EVPID 1 << 11
89 
90 struct osmtpd_ctx {
91 	enum osmtpd_type	 type;
92 	enum osmtpd_phase	 phase;
93 	int			 version_major;
94 	int			 version_minor;
95 	struct timespec		 tm;
96 	int			 incoming;
97 	uint64_t		 reqid;
98 	uint64_t		 token;
99 	struct sockaddr_storage	 src;
100 	struct sockaddr_storage	 dst;
101 	char			*rdns;
102 	enum osmtpd_status	 fcrdns;
103 	/* HELO/EHLO identity */
104 	char			*identity;
105 	struct greeting {
106 		char			*identity;
107 		/* textstring not supplied by smtpd */
108 	}			 greeting;
109 	char			*ciphers;
110 	uint32_t		 msgid;
111 	char			*username;
112 	char			*mailfrom;
113 	char			**rcptto;
114 	uint64_t		 evpid;
115 	void			*local_session;
116 	void			*local_message;
117 };
118 
119 void osmtpd_register_conf(void (*)(const char *, const char *));
120 void osmtpd_register_filter_connect(void (*)(struct osmtpd_ctx *, const char *,
121     struct sockaddr_storage *));
122 void osmtpd_register_filter_helo(void (*)(struct osmtpd_ctx *, const char *));
123 void osmtpd_register_filter_ehlo(void (*)(struct osmtpd_ctx *, const char *));
124 void osmtpd_register_filter_starttls(void (*)(struct osmtpd_ctx *));
125 void osmtpd_register_filter_auth(void (*)(struct osmtpd_ctx *, const char *));
126 void osmtpd_register_filter_mailfrom(void (*)(struct osmtpd_ctx *,
127     const char *));
128 void osmtpd_register_filter_rcptto(void (*)(struct osmtpd_ctx *, const char *));
129 void osmtpd_register_filter_data(void (*)(struct osmtpd_ctx *));
130 void osmtpd_register_filter_dataline(void (*)(struct osmtpd_ctx *,
131     const char *));
132 void osmtpd_register_filter_rset(void (*)(struct osmtpd_ctx *));
133 void osmtpd_register_filter_quit(void (*)(struct osmtpd_ctx *));
134 void osmtpd_register_filter_noop(void (*)(struct osmtpd_ctx *));
135 void osmtpd_register_filter_help(void (*)(struct osmtpd_ctx *));
136 void osmtpd_register_filter_wiz(void (*)(struct osmtpd_ctx *));
137 void osmtpd_register_filter_commit(void (*)(struct osmtpd_ctx *));
138 void osmtpd_register_report_connect(int, void (*)(struct osmtpd_ctx *,
139     const char *, enum osmtpd_status, struct sockaddr_storage *,
140     struct sockaddr_storage *));
141 void osmtpd_register_report_disconnect(int, void (*)(struct osmtpd_ctx *));
142 void osmtpd_register_report_greeting(int, void (*)(struct osmtpd_ctx *,
143     const char *));
144 void osmtpd_register_report_identify(int, void (*)(struct osmtpd_ctx *,
145     const char *));
146 void osmtpd_register_report_tls(int, void (*)(struct osmtpd_ctx *,
147     const char *));
148 void osmtpd_register_report_auth(int, void (*)(struct osmtpd_ctx *,
149     const char *, enum osmtpd_auth_status));
150 void osmtpd_register_report_begin(int, void (*)(struct osmtpd_ctx *, uint32_t));
151 void osmtpd_register_report_mail(int, void (*)(struct osmtpd_ctx *, uint32_t,
152     const char *, enum osmtpd_status));
153 void osmtpd_register_report_rcpt(int, void (*)(struct osmtpd_ctx *, uint32_t,
154     const char *, enum osmtpd_status));
155 void osmtpd_register_report_envelope(int, void (*)(struct osmtpd_ctx *, uint32_t,
156     uint64_t));
157 void osmtpd_register_report_data(int, void (*)(struct osmtpd_ctx *, uint32_t,
158     enum osmtpd_status));
159 void osmtpd_register_report_commit(int, void (*)(struct osmtpd_ctx *, uint32_t,
160     size_t));
161 void osmtpd_register_report_rollback(int, void (*)(struct osmtpd_ctx *,
162     uint32_t));
163 void osmtpd_register_report_client(int, void (*)(struct osmtpd_ctx *,
164     const char *));
165 void osmtpd_register_report_server(int, void (*)(struct osmtpd_ctx *,
166     const char *));
167 void osmtpd_register_report_response(int, void (*)(struct osmtpd_ctx *,
168     const char *));
169 void osmtpd_register_report_timeout(int, void (*)(struct osmtpd_ctx *));
170 void osmtpd_local_session(void *(*)(struct osmtpd_ctx *),
171     void (*)(struct osmtpd_ctx *, void *));
172 void osmtpd_local_message(void *(*)(struct osmtpd_ctx *),
173     void (*)(struct osmtpd_ctx *, void *));
174 void osmtpd_need(int);
175 
176 void osmtpd_filter_proceed(struct osmtpd_ctx *);
177 void osmtpd_filter_reject(struct osmtpd_ctx *, int, const char *, ...)
178 	__attribute__((__format__ (printf, 3, 4)));
179 void osmtpd_filter_reject_enh(struct osmtpd_ctx *, int, int, int, int,
180     const char *, ...)
181 	__attribute__((__format__ (printf, 6, 7)));
182 void osmtpd_filter_disconnect(struct osmtpd_ctx *, const char *, ...)
183 	__attribute__((__format__ (printf, 2, 3)));
184 void osmtpd_filter_disconnect_enh(struct osmtpd_ctx *, int, int, int,
185     const char *, ...)
186 	__attribute__((__format__ (printf, 5, 6)));
187 void osmtpd_filter_rewrite(struct osmtpd_ctx *, const char *, ...)
188 	__attribute__((__format__ (printf, 2, 3)));
189 void osmtpd_filter_dataline(struct osmtpd_ctx *, const char *, ...)
190 	__attribute__((__format__ (printf, 2, 3)));
191 void osmtpd_run(void);
192 __dead void osmtpd_err(int eval, const char *fmt, ...);
193 __dead void osmtpd_errx(int eval, const char *fmt, ...);