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1.1 root 1: /*
2: * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3: *
4: * @APPLE_LICENSE_HEADER_START@
5: *
6: * The contents of this file constitute Original Code as defined in and
7: * are subject to the Apple Public Source License Version 1.1 (the
8: * "License"). You may not use this file except in compliance with the
9: * License. Please obtain a copy of the License at
10: * http://www.apple.com/publicsource and read it before using this file.
11: *
12: * This Original Code and all software distributed under the License are
13: * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14: * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15: * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16: * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
17: * License for the specific language governing rights and limitations
18: * under the License.
19: *
20: * @APPLE_LICENSE_HEADER_END@
21: */
22: /*
23: * Copyright 1997 Massachusetts Institute of Technology
24: *
25: * Permission to use, copy, modify, and distribute this software and
26: * its documentation for any purpose and without fee is hereby
27: * granted, provided that both the above copyright notice and this
28: * permission notice appear in all copies, that both the above
29: * copyright notice and this permission notice appear in all
30: * supporting documentation, and that the name of M.I.T. not be used
31: * in advertising or publicity pertaining to distribution of the
32: * software without specific, written prior permission. M.I.T. makes
33: * no representations about the suitability of this software for any
34: * purpose. It is provided "as is" without express or implied
35: * warranty.
36: *
37: * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
38: * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
39: * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
40: * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
41: * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
42: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
43: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
44: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
45: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
46: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
47: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
48: * SUCH DAMAGE.
49: *
50: */
51:
52: #include <sys/param.h>
53: #include <sys/systm.h>
54: #include <sys/malloc.h>
55: #include <sys/socket.h>
56: #include <sys/socketvar.h>
57:
58: #include <net/hostcache.h>
59: #include <net/if.h>
60: #include <net/if_var.h>
61: #include <net/route.h>
62:
63: #include <netinet/in.h>
64: #include <netinet/in_hostcache.h>
65: #include <netinet/tcp.h>
66: #include <netinet/tcp_timer.h>
67: #include <netinet/tcp_var.h>
68:
69: /*
70: * Manage the IP per-host cache (really a thin veneer over the generic
71: * per-host cache code).
72: */
73:
74: /* Look up an entry -- can be called from interrupt context. */
75: struct in_hcentry *
76: inhc_lookup(struct sockaddr_in *sin)
77: {
78: struct hcentry *hc;
79:
80: hc = hc_get((struct sockaddr *)sin);
81: return ((struct in_hcentry *)hc);
82: }
83:
84: /* Look up and possibly create an entry -- must be called from user mode. */
85: struct in_hcentry *
86: inhc_alloc(struct sockaddr_in *sin)
87: {
88: struct in_hcentry *inhc;
89: struct rtentry *rt;
90: int error;
91: /* xxx mutual exclusion for smp */
92:
93: inhc = inhc_lookup(sin);
94: if (inhc != 0)
95: return inhc;
96:
97: rt = rtalloc1(inhc->inhc_hc.hc_host, 1, 0);
98: if (rt == 0)
99: return 0;
100:
101: MALLOC(inhc, struct in_hcentry *, sizeof *inhc, M_HOSTCACHE, M_WAITOK);
102: bzero(inhc, sizeof *inhc);
103: inhc->inhc_hc.hc_host = dup_sockaddr((struct sockaddr *)sin, 1);
104: if (in_broadcast(sin->sin_addr, rt->rt_ifp))
105: inhc->inhc_flags |= INHC_BROADCAST;
106: else if (((struct sockaddr_in *)rt->rt_ifa->ifa_addr)->sin_addr.s_addr
107: == sin->sin_addr.s_addr)
108: inhc->inhc_flags |= INHC_LOCAL;
109: else if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
110: inhc->inhc_flags |= INHC_MULTICAST;
111: inhc->inhc_pmtu = rt->rt_rmx.rmx_mtu;
112: inhc->inhc_recvpipe = rt->rt_rmx.rmx_recvpipe;
113: inhc->inhc_sendpipe = rt->rt_rmx.rmx_sendpipe;
114: inhc->inhc_ssthresh = rt->rt_rmx.rmx_ssthresh;
115: if (rt->rt_rmx.rmx_locks & RTV_RTT)
116: inhc->inhc_rttmin = rt->rt_rmx.rmx_rtt
117: / (RTM_RTTUNIT / TCP_RTT_SCALE);
118: inhc->inhc_hc.hc_rt = rt;
119: error = hc_insert(&inhc->inhc_hc);
120: if (error != 0) {
121: RTFREE(rt);
122: FREE(inhc, M_HOSTCACHE);
123: return 0;
124: }
125: /*
126: * We don't return the structure directly because hc_get() needs
127: * to be allowed to do its own processing.
128: */
129: return (inhc_lookup(sin));
130: }
131:
132: /*
133: * This is Van Jacobson's hash function for IPv4 addresses.
134: * It is designed to work with a power-of-two-sized hash table.
135: */
136: static u_long
137: inhc_hash(struct sockaddr *sa, u_long nbuckets)
138: {
139: u_long ip;
140:
141: ip = ((struct sockaddr_in *)sa)->sin_addr.s_addr;
142: return ((ip ^ (ip >> 23) ^ (ip >> 17)) & ~(nbuckets - 1));
143: }
144:
145: /*
146: * We don't need to do any special work... if there are no references,
147: * as the caller has already ensured, then it's OK to kill.
148: */
149: static int
150: inhc_delete(struct hcentry *hc)
151: {
152: return 0;
153: }
154:
155: /*
156: * Return the next increment for the number of buckets in the hash table.
157: * Zero means ``do not bump''.
158: */
159: static u_long
160: inhc_bump(u_long oldsize)
161: {
162: if (oldsize < 512)
163: return (oldsize << 1);
164: return 0;
165: }
166:
167: static struct hccallback inhc_cb = {
168: inhc_hash, inhc_delete, inhc_bump
169: };
170:
171: int
172: inhc_init(void)
173: {
174:
175: return (hc_init(AF_INET, &inhc_cb, 128, 0));
176: }
177:
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