File: /usr/src/linux/net/ipv6/protocol.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * PF_INET6 protocol dispatch tables.
7 *
8 * Version: $Id: protocol.c,v 1.10 2001/05/18 02:25:49 davem Exp $
9 *
10 * Authors: Pedro Roque <roque@di.fc.ul.pt>
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version
15 * 2 of the License, or (at your option) any later version.
16 */
17
18 /*
19 * Changes:
20 *
21 * Vince Laviano (vince@cs.stanford.edu) 16 May 2001
22 * - Removed unused variable 'inet6_protocol_base'
23 * - Modified inet6_del_protocol() to correctly maintain copy bit.
24 */
25
26 #include <linux/errno.h>
27 #include <linux/types.h>
28 #include <linux/socket.h>
29 #include <linux/sockios.h>
30 #include <linux/sched.h>
31 #include <linux/net.h>
32 #include <linux/in6.h>
33 #include <linux/netdevice.h>
34 #include <linux/if_arp.h>
35 #include <linux/brlock.h>
36
37 #include <net/sock.h>
38 #include <net/snmp.h>
39
40 #include <net/ipv6.h>
41 #include <net/protocol.h>
42
43 struct inet6_protocol *inet6_protos[MAX_INET_PROTOS];
44
45 void inet6_add_protocol(struct inet6_protocol *prot)
46 {
47 unsigned char hash;
48 struct inet6_protocol *p2;
49
50 hash = prot->protocol & (MAX_INET_PROTOS - 1);
51 br_write_lock_bh(BR_NETPROTO_LOCK);
52 prot->next = inet6_protos[hash];
53 inet6_protos[hash] = prot;
54 prot->copy = 0;
55
56 /*
57 * Set the copy bit if we need to.
58 */
59
60 p2 = (struct inet6_protocol *) prot->next;
61 while(p2 != NULL) {
62 if (p2->protocol == prot->protocol) {
63 prot->copy = 1;
64 break;
65 }
66 p2 = (struct inet6_protocol *) p2->next;
67 }
68 br_write_unlock_bh(BR_NETPROTO_LOCK);
69 }
70
71 /*
72 * Remove a protocol from the hash tables.
73 */
74
75 int inet6_del_protocol(struct inet6_protocol *prot)
76 {
77 struct inet6_protocol *p;
78 struct inet6_protocol *lp = NULL;
79 unsigned char hash;
80
81 hash = prot->protocol & (MAX_INET_PROTOS - 1);
82 br_write_lock_bh(BR_NETPROTO_LOCK);
83 if (prot == inet6_protos[hash]) {
84 inet6_protos[hash] = (struct inet6_protocol *) inet6_protos[hash]->next;
85 br_write_unlock_bh(BR_NETPROTO_LOCK);
86 return(0);
87 }
88
89 p = (struct inet6_protocol *) inet6_protos[hash];
90
91 if (p != NULL && p->protocol == prot->protocol)
92 lp = p;
93
94 while(p != NULL) {
95 /*
96 * We have to worry if the protocol being deleted is
97 * the last one on the list, then we may need to reset
98 * someone's copied bit.
99 */
100 if (p->next != NULL && p->next == prot) {
101 /*
102 * if we are the last one with this protocol and
103 * there is a previous one, reset its copy bit.
104 */
105 if (prot->copy == 0 && lp != NULL)
106 lp->copy = 0;
107 p->next = prot->next;
108 br_write_unlock_bh(BR_NETPROTO_LOCK);
109 return(0);
110 }
111 if (p->next != NULL && p->next->protocol == prot->protocol)
112 lp = p->next;
113
114 p = (struct inet6_protocol *) p->next;
115 }
116 br_write_unlock_bh(BR_NETPROTO_LOCK);
117 return(-1);
118 }
119