Fix select and poll use in LWPs.
[dragonfly.git] / usr.sbin / IPXrouted / sap_tables.c
blobcaa137bf71c46ef1586ad393333768942cd93fe2
1 /*
2 * Copyright (c) 1995 John Hay. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. All advertising materials mentioning features or use of this software
13 * must display the following acknowledgement:
14 * This product includes software developed by John Hay.
15 * 4. Neither the name of the author nor the names of any co-contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY John Hay AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL John Hay OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
31 * $FreeBSD: src/usr.sbin/IPXrouted/sap_tables.c,v 1.7 1999/08/28 01:15:04 peter Exp $
32 * $DragonFly: src/usr.sbin/IPXrouted/sap_tables.c,v 1.3 2004/03/11 09:38:59 hmp Exp $
35 #include "defs.h"
36 #include <string.h>
37 #include <stdlib.h>
39 #define FIXLEN(s) { if ((s)->sa_len == 0) (s)->sa_len = sizeof (*(s));}
41 sap_hash sap_head[SAPHASHSIZ];
43 void
44 sapinit(void)
46 int i;
48 for (i=0; i<SAPHASHSIZ; i++)
49 sap_head[i].forw = sap_head[i].back =
50 (struct sap_entry *)&sap_head[i];
54 * This hash use the first 14 letters of the ServName and the ServType
55 * to create a 32 bit hash value.
57 int
58 saphash(u_short ServType, char *ServName)
60 int hsh, i;
61 char name[SERVNAMELEN];
63 bzero(name, SERVNAMELEN);
64 strncpy(name, ServName, SERVNAMELEN);
65 ServName = name;
67 hsh = 0;
69 #define SMVAL 33
71 hsh = hsh * SMVAL + (ServType & 0xff);
72 hsh = hsh * SMVAL + (ServType >> 8);
74 for (i=0;i<14;i++) {
75 hsh = hsh * SMVAL + *ServName++;
76 ServName++;
79 #undef SMVAL
81 return hsh;
85 * Look for an exact match on ServType and ServName. It is
86 * mostly used by the function that process SAP RESPONSE packets.
88 * A hash is created and used to index into the hash table. Then
89 * that list is walk through searching for a match.
91 * If no match is found NULL is returned.
93 struct sap_entry *
94 sap_lookup(u_short ServType, char *ServName)
96 struct sap_entry *sap;
97 struct sap_hash *sh;
98 int hsh;
100 hsh = saphash(ServType, ServName);
101 sh = &sap_head[hsh & SAPHASHMASK];
103 for(sap = sh->forw; sap != (sap_entry *)sh; sap = sap->forw) {
104 if ((hsh == sap->hash) &&
105 (ServType == sap->sap.ServType) &&
106 (strncmp(ServName, sap->sap.ServName, SERVNAMELEN) == 0)) {
107 return sap;
110 return NULL;
114 * This returns the nearest service of the specified type. If no
115 * suitable service is found or if that service is on the interface
116 * where the request came from, NULL is returned.
118 * When checking interfaces clones must be considered also.
120 * XXX TODO:
121 * Maybe we can use RIP tables to get the fastest service (ticks).
123 struct sap_entry *
124 sap_nearestserver(ushort ServType, struct interface *ifp)
126 struct sap_entry *sap;
127 struct sap_entry *csap;
128 struct sap_hash *sh;
129 struct sap_entry *best = NULL;
130 int besthops = HOPCNT_INFINITY;
132 sh = sap_head;
134 for (; sh < &sap_head[SAPHASHSIZ]; sh++)
135 for(sap = sh->forw; sap != (sap_entry *)sh; sap = sap->forw) {
136 if (ServType != sap->sap.ServType)
137 continue;
139 if (ntohs(sap->sap.hops) < besthops) {
140 best = sap;
141 besthops = ntohs(best->sap.hops);
143 next:;
145 return best;
149 * Add a entry to the SAP table.
151 * If the malloc fail, the entry will silently be thrown away.
153 void
154 sap_add(struct sap_info *si, struct sockaddr *from)
156 struct sap_entry *nsap;
157 struct sap_hash *sh;
159 if (ntohs(si->hops) == HOPCNT_INFINITY)
160 return;
162 FIXLEN(from);
163 nsap = malloc(sizeof(struct sap_entry));
164 if (nsap == NULL)
165 return;
167 nsap->sap = *si;
168 nsap->source = *from;
169 nsap->clone = NULL;
170 nsap->ifp = if_ifwithnet(from);
171 nsap->state = RTS_CHANGED;
172 nsap->timer = 0;
173 nsap->hash = saphash(si->ServType, si->ServName);
175 sh = &sap_head[nsap->hash & SAPHASHMASK];
177 insque(nsap, sh);
178 TRACE_SAP_ACTION("ADD", nsap);
182 * Change an existing SAP entry. If a clone exist for the old one,
183 * check if it is cheaper. If it is change tothe clone, otherwise
184 * delete all the clones.
186 void
187 sap_change(struct sap_entry *sap,
188 struct sap_info *si,
189 struct sockaddr *from)
191 struct sap_entry *osap = NULL;
193 FIXLEN(from);
194 TRACE_SAP_ACTION("CHANGE FROM", sap);
196 * If the hopcount (metric) is HOPCNT_INFINITY (16) it means that
197 * a service has gone down. We should keep it like that for 30
198 * seconds, so that it will get broadcast and then change to a
199 * clone if one exist.
201 if (sap->clone && (ntohs(si->hops) != HOPCNT_INFINITY)) {
203 * There are three possibilities:
204 * 1. The new path is cheaper than the old one.
205 * Free all the clones.
207 * 2. The new path is the same cost as the old ones.
208 * If it is on the list of clones remove it
209 * from the clone list and free it.
211 * 3. The new path is more expensive than the old one.
212 * Use the values of the first clone and take it
213 * out of the list, to be freed at the end.
215 osap = sap->clone;
216 if (ntohs(osap->sap.hops) > ntohs(si->hops)) {
217 struct sap_entry *nsap;
219 while (osap) {
220 nsap = osap->clone;
221 TRACE_SAP_ACTION("DELETE", osap);
222 free(osap);
223 osap = nsap;
225 sap->clone = NULL;
226 } else if (ntohs(osap->sap.hops) == ntohs(si->hops)) {
227 struct sap_entry *psap;
229 psap = sap;
230 while (osap) {
231 if (equal(&osap->source, from)) {
232 psap->clone = osap->clone;
233 TRACE_SAP_ACTION("DELETE", osap);
234 free(osap);
235 osap = psap->clone;
236 } else {
237 psap = osap;
238 osap = osap->clone;
241 } else {
242 from = &osap->source;
243 si = &osap->sap;
244 sap->clone = osap->clone;
247 sap->sap = *si;
248 sap->source = *from;
249 sap->ifp = if_ifwithnet(from);
250 sap->state = RTS_CHANGED;
251 if (ntohs(si->hops) == HOPCNT_INFINITY)
252 sap->timer = EXPIRE_TIME;
253 else
254 sap->timer = 0;
256 if (osap) {
257 TRACE_SAP_ACTION("DELETE", osap);
258 free(osap);
260 TRACE_SAP_ACTION("CHANGE TO", sap);
264 * Add a clone to the specified SAP entry. A clone is a different
265 * route to the same service. We must know about them when we use
266 * the split horizon algorithm.
268 * If the malloc fail, the entry will silently be thrown away.
270 void
271 sap_add_clone(struct sap_entry *sap,
272 struct sap_info *clone,
273 struct sockaddr *from)
275 struct sap_entry *nsap;
276 struct sap_entry *csap;
278 if (ntohs(clone->hops) == HOPCNT_INFINITY)
279 return;
281 FIXLEN(from);
282 nsap = malloc(sizeof(struct sap_entry));
283 if (nsap == NULL)
284 return;
286 if (ftrace)
287 fprintf(ftrace, "CLONE ADD %04.4X %s.\n",
288 ntohs(clone->ServType),
289 clone->ServName);
291 nsap->sap = *clone;
292 nsap->source = *from;
293 nsap->clone = NULL;
294 nsap->ifp = if_ifwithnet(from);
295 nsap->state = RTS_CHANGED;
296 nsap->timer = 0;
297 nsap->hash = saphash(clone->ServType, clone->ServName);
299 csap = sap;
300 while (csap->clone)
301 csap = csap->clone;
302 csap->clone = nsap;
303 TRACE_SAP_ACTION("ADD CLONE", nsap);
307 * Remove a SAP entry from the table and free the memory
308 * used by it.
310 * If the service have clone, do a sap_change to it and free
311 * the clone.
313 void
314 sap_delete(struct sap_entry *sap)
316 if (sap->clone) {
317 sap_change(sap, &sap->clone->sap, &sap->clone->source);
318 return;
320 remque(sap);
321 TRACE_SAP_ACTION("DELETE", sap);
322 free(sap);