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_type {
32 	OSMTPD_TYPE_FILTER,
33 	OSMTPD_TYPE_REPORT
34 };
35 
36 enum osmtpd_phase {
37 	OSMTPD_PHASE_CONNECT,
38 	OSMTPD_PHASE_HELO,
39 	OSMTPD_PHASE_EHLO,
40 	OSMTPD_PHASE_STARTTLS,
41 	OSMTPD_PHASE_AUTH,
42 	OSMTPD_PHASE_MAIL_FROM,
43 	OSMTPD_PHASE_RCPT_TO,
44 	OSMTPD_PHASE_DATA,
45 	OSMTPD_PHASE_DATA_LINE,
46 	OSMTPD_PHASE_RSET,
47 	OSMTPD_PHASE_QUIT,
48 	OSMTPD_PHASE_NOOP,
49 	OSMTPD_PHASE_HELP,
50 	OSMTPD_PHASE_WIZ,
51 	OSMTPD_PHASE_COMMIT,
52 	OSMTPD_PHASE_LINK_CONNECT,
53 	OSMTPD_PHASE_LINK_DISCONNECT,
54 	OSMTPD_PHASE_LINK_GREETING,
55 	OSMTPD_PHASE_LINK_IDENTIFY,
56 	OSMTPD_PHASE_LINK_TLS,
57 	OSMTPD_PHASE_TX_BEGIN,
58 	OSMTPD_PHASE_TX_MAIL,
59 	OSMTPD_PHASE_TX_RCPT,
60 	OSMTPD_PHASE_TX_ENVELOPE,
61 	OSMTPD_PHASE_TX_DATA,
62 	OSMTPD_PHASE_TX_COMMIT,
63 	OSMTPD_PHASE_TX_ROLLBACK,
64 	OSMTPD_PHASE_PROTOCOL_CLIENT,
65 	OSMTPD_PHASE_PROTOCOL_SERVER,
66 	OSMTPD_PHASE_FILTER_RESPONSE,
67 	OSMTPD_PHASE_TIMEOUT
68 };
69 
70 #define OSMTPD_NEED_SRC 1 << 0
71 #define OSMTPD_NEED_DST 1 << 1
72 #define OSMTPD_NEED_RDNS 1 << 2
73 #define OSMTPD_NEED_FCRDNS 1 << 3
74 #define OSMTPD_NEED_IDENTITY 1 << 4
75 #define OSMTPD_NEED_GREETING 1 << 5
76 #define OSMTPD_NEED_CIPHERS 1 << 6
77 #define OSMTPD_NEED_MSGID 1 << 7
78 #define OSMTPD_NEED_MAILFROM 1 << 8
79 #define OSMTPD_NEED_RCPTTO 1 << 9
80 #define OSMTPD_NEED_EVPID 1 << 10
81 
82 struct osmtpd_ctx {
83 	enum osmtpd_type	 type;
84 	enum osmtpd_phase	 phase;
85 	int			 version_major;
86 	int			 version_minor;
87 	struct timespec		 tm;
88 	int			 incoming;
89 	uint64_t		 reqid;
90 	uint64_t		 token;
91 	struct sockaddr_storage	 src;
92 	struct sockaddr_storage	 dst;
93 	char			*rdns;
94 	enum osmtpd_status	 fcrdns;
95 	/* HELO/EHLO identity */
96 	char			*identity;
97 	struct greeting {
98 		char			*identity;
99 		/* textstring not supplied by smtpd */
100 	}			 greeting;
101 	char			*ciphers;
102 	uint32_t		 msgid;
103 	char			*mailfrom;
104 	char			**rcptto;
105 	uint64_t		 evpid;
106 	void			*local_session;
107 	void			*local_message;
108 };
109 
110 void osmtpd_register_conf(void (*)(const char *, const char *));
111 void osmtpd_register_filter_connect(void (*)(struct osmtpd_ctx *, const char *,
112     struct sockaddr_storage *));
113 void osmtpd_register_filter_helo(void (*)(struct osmtpd_ctx *, const char *));
114 void osmtpd_register_filter_ehlo(void (*)(struct osmtpd_ctx *, const char *));
115 void osmtpd_register_filter_starttls(void (*)(struct osmtpd_ctx *));
116 void osmtpd_register_filter_auth(void (*)(struct osmtpd_ctx *, const char *));
117 void osmtpd_register_filter_mailfrom(void (*)(struct osmtpd_ctx *,
118     const char *));
119 void osmtpd_register_filter_rcptto(void (*)(struct osmtpd_ctx *, const char *));
120 void osmtpd_register_filter_data(void (*)(struct osmtpd_ctx *));
121 void osmtpd_register_filter_dataline(void (*)(struct osmtpd_ctx *,
122     const char *));
123 void osmtpd_register_filter_rset(void (*)(struct osmtpd_ctx *));
124 void osmtpd_register_filter_quit(void (*)(struct osmtpd_ctx *));
125 void osmtpd_register_filter_noop(void (*)(struct osmtpd_ctx *));
126 void osmtpd_register_filter_help(void (*)(struct osmtpd_ctx *));
127 void osmtpd_register_filter_wiz(void (*)(struct osmtpd_ctx *));
128 void osmtpd_register_filter_commit(void (*)(struct osmtpd_ctx *));
129 void osmtpd_register_report_connect(int, void (*)(struct osmtpd_ctx *,
130     const char *, enum osmtpd_status, struct sockaddr_storage *,
131     struct sockaddr_storage *));
132 void osmtpd_register_report_disconnect(int, void (*)(struct osmtpd_ctx *));
133 void osmtpd_register_report_greeting(int, void (*)(struct osmtpd_ctx *,
134     const char *));
135 void osmtpd_register_report_identify(int, void (*)(struct osmtpd_ctx *,
136     const char *));
137 void osmtpd_register_report_tls(int, void (*)(struct osmtpd_ctx *,
138     const char *));
139 void osmtpd_register_report_begin(int, void (*)(struct osmtpd_ctx *, uint32_t));
140 void osmtpd_register_report_mail(int, void (*)(struct osmtpd_ctx *, uint32_t,
141     const char *, enum osmtpd_status));
142 void osmtpd_register_report_rcpt(int, void (*)(struct osmtpd_ctx *, uint32_t,
143     const char *, enum osmtpd_status));
144 void osmtpd_register_report_envelope(int, void (*)(struct osmtpd_ctx *, uint32_t,
145     uint64_t));
146 void osmtpd_register_report_data(int, void (*)(struct osmtpd_ctx *, uint32_t,
147     enum osmtpd_status));
148 void osmtpd_register_report_commit(int, void (*)(struct osmtpd_ctx *, uint32_t,
149     size_t));
150 void osmtpd_register_report_rollback(int, void (*)(struct osmtpd_ctx *,
151     uint32_t));
152 void osmtpd_register_report_client(int, void (*)(struct osmtpd_ctx *,
153     const char *));
154 void osmtpd_register_report_server(int, void (*)(struct osmtpd_ctx *,
155     const char *));
156 void osmtpd_register_report_response(int, void (*)(struct osmtpd_ctx *,
157     const char *));
158 void osmtpd_register_report_timeout(int, void (*)(struct osmtpd_ctx *));
159 void osmtpd_local_session(void *(*)(struct osmtpd_ctx *),
160     void (*)(struct osmtpd_ctx *, void *));
161 void osmtpd_local_message(void *(*)(struct osmtpd_ctx *),
162     void (*)(struct osmtpd_ctx *, void *));
163 void osmtpd_need(int);
164 
165 void osmtpd_filter_proceed(struct osmtpd_ctx *);
166 void osmtpd_filter_reject(struct osmtpd_ctx *, int, const char *, ...)
167 	__attribute__((__format__ (printf, 3, 4)));
168 void osmtpd_filter_reject_enh(struct osmtpd_ctx *, int, int, int, int,
169     const char *, ...)
170 	__attribute__((__format__ (printf, 6, 7)));
171 void osmtpd_filter_disconnect(struct osmtpd_ctx *, const char *, ...)
172 	__attribute__((__format__ (printf, 2, 3)));
173 void osmtpd_filter_disconnect_enh(struct osmtpd_ctx *, int, int, int,
174     const char *, ...)
175 	__attribute__((__format__ (printf, 5, 6)));
176 void osmtpd_filter_rewrite(struct osmtpd_ctx *, const char *, ...)
177 	__attribute__((__format__ (printf, 2, 3)));
178 void osmtpd_filter_dataline(struct osmtpd_ctx *, const char *, ...)
179 	__attribute__((__format__ (printf, 2, 3)));
180 void osmtpd_run(void);
181 __dead void osmtpd_err(int eval, const char *fmt, ...);
182 __dead void osmtpd_errx(int eval, const char *fmt, ...);