1/*-
2 * Copyright (c) 2005 Paolo Pisati <piso@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 */
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#ifdef _KERNEL
31#include <sys/libkern.h>
32#include <sys/param.h>
33#include <sys/lock.h>
34#include <sys/rwlock.h>
35#else
36#include <stdio.h>
37#include <string.h>
38#include <sys/types.h>
39#include <errno.h>
40#endif
41
42#include <netinet/in_systm.h>
43#include <netinet/in.h>
44#include <netinet/ip.h>
45
46#ifdef _KERNEL
47#include <netinet/libalias/alias_local.h>
48#include <netinet/libalias/alias_mod.h>
49#else
50#include "alias_local.h"
51#include "alias_mod.h"
52#endif
53
54/* Protocol and userland module handlers chains. */
55static TAILQ_HEAD(handler_chain, proto_handler) handler_chain =
56    TAILQ_HEAD_INITIALIZER(handler_chain);
57
58static int
59attach_handler(struct proto_handler *p)
60{
61	struct proto_handler *b;
62
63	TAILQ_FOREACH(b, &handler_chain, link) {
64		if ((b->pri == p->pri) &&
65		    (b->dir == p->dir) &&
66		    (b->proto == p->proto))
67			return (EEXIST);
68		if (b->pri > p->pri) {
69			TAILQ_INSERT_BEFORE(b, p, link);
70			return (0);
71		}
72	}
73
74	TAILQ_INSERT_TAIL(&handler_chain, p, link);
75
76	return (0);
77}
78
79int
80LibAliasAttachHandlers(struct proto_handler *p)
81{
82	int error;
83
84	while (p->dir != NODIR) {
85		error = attach_handler(p);
86		if (error)
87			return (error);
88		p++;
89	}
90
91	return (0);
92}
93
94/* XXXGL: should be void, but no good reason to break ABI */
95int
96LibAliasDetachHandlers(struct proto_handler *p)
97{
98
99	while (p->dir != NODIR) {
100		TAILQ_REMOVE(&handler_chain, p, link);
101		p++;
102	}
103
104	return (0);
105}
106
107int
108find_handler(int8_t dir, int8_t proto, struct libalias *la, struct ip *ip,
109    struct alias_data *ad)
110{
111	struct proto_handler *p;
112
113	TAILQ_FOREACH(p, &handler_chain, link)
114		if ((p->dir & dir) && (p->proto & proto) &&
115		    p->fingerprint(la, ad) == 0)
116			return (p->protohandler(la, ip, ad));
117
118	return (ENOENT);
119}
120
121struct proto_handler *
122first_handler(void)
123{
124
125	return (TAILQ_FIRST(&handler_chain));
126}
127
128#ifndef _KERNEL
129/* Dll manipulation code - this code is not thread safe... */
130SLIST_HEAD(dll_chain, dll) dll_chain = SLIST_HEAD_INITIALIZER(dll_chain);
131int
132attach_dll(struct dll *p)
133{
134	struct dll *b;
135
136	SLIST_FOREACH(b, &dll_chain, next) {
137		if (!strncmp(b->name, p->name, DLL_LEN))
138			return (EEXIST); /* Dll name conflict. */
139	}
140	SLIST_INSERT_HEAD(&dll_chain, p, next);
141	return (0);
142}
143
144void *
145detach_dll(char *p)
146{
147	struct dll *b, *b_tmp;
148	void *error;
149
150	b = NULL;
151	error = NULL;
152	SLIST_FOREACH_SAFE(b, &dll_chain, next, b_tmp)
153		if (!strncmp(b->name, p, DLL_LEN)) {
154			SLIST_REMOVE(&dll_chain, b, dll, next);
155			error = b;
156			break;
157		}
158	return (error);
159}
160
161struct dll *
162walk_dll_chain(void)
163{
164	struct dll *t;
165
166	t = SLIST_FIRST(&dll_chain);
167	if (t == NULL)
168		return (NULL);
169	SLIST_REMOVE_HEAD(&dll_chain, next);
170	return (t);
171}
172#endif /* !_KERNEL */
173