sap_output.c revision 22997
1/* 2 * Copyright (c) 1995 John Hay. All rights reserved. 3 * 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. 18 * 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. 30 * 31 * $Id$ 32 */ 33 34/* 35 * Routing Table Management Daemon 36 */ 37#include <unistd.h> 38#include "defs.h" 39 40/* 41 * Apply the function "f" to all non-passive 42 * interfaces. If the interface supports the 43 * use of broadcasting use it, otherwise address 44 * the output to the known router. 45 */ 46void 47sap_supply_toall(void) 48{ 49 register struct interface *ifp; 50 struct sockaddr dst; 51 register struct sockaddr_ipx *ipx_dst; 52 register int flags; 53 extern struct interface *ifnet; 54 55 ipx_dst = (struct sockaddr_ipx *)&dst; 56 57 for (ifp = ifnet; ifp; ifp = ifp->int_next) { 58 if (ifp->int_flags & IFF_PASSIVE) 59 continue; 60 61 dst = ifp->int_flags & IFF_BROADCAST ? ifp->int_broadaddr : 62 ifp->int_flags & IFF_POINTOPOINT ? ifp->int_dstaddr : 63 ifp->int_addr; 64 65 ipx_dst->sipx_addr.x_port = htons(IPXPORT_SAP); 66 67 flags = ifp->int_flags & IFF_INTERFACE ? MSG_DONTROUTE : 0; 68 sap_supply(&dst, flags, ifp, SAP_WILDCARD); 69 } 70} 71 72void 73sapsndmsg(dst, flags, ifp) 74 struct sockaddr *dst; 75 int flags; 76 struct interface *ifp; 77{ 78 struct sockaddr t_dst; 79 struct sockaddr_ipx *ipx_dst; 80 81 t_dst = *dst; 82 ipx_dst = (struct sockaddr_ipx *)&t_dst; 83 84 if (ipx_dst->sipx_addr.x_port == 0) 85 ipx_dst->sipx_addr.x_port = htons(IPXPORT_SAP); 86 87 (*afswitch[dst->sa_family].af_output) 88 (sapsock, flags, &t_dst, 89 sizeof (struct sap_packet) + sizeof(u_short)); 90 TRACE_SAP_OUTPUT(ifp, &t_dst, 91 sizeof (struct sap_packet) + sizeof(u_short)); 92} 93 94/* 95 * Supply dst with the contents of the SAP tables. If the ServType == 96 * SAP_WILDCARD (0xFFFF) supply the whole table, otherwise only the 97 * services that are of ServType. If this won't fit in one packet, chop 98 * it up into several. 99 * 100 * This must be done using the split horizon algorithm. 101 * 1. Don't send SAP info to the interface from where it was received. 102 * 2. If a service is received from more than one interface and the cost is 103 * the same, don't publish it on either interface. I am calling this 104 * clones. 105 */ 106void 107sap_supply(dst, flags, ifp, ServType) 108 struct sockaddr *dst; 109 int flags; 110 struct interface *ifp; 111 int ServType; 112{ 113 register struct sap_entry *sap; 114 register struct sap_entry *csap; /* Clone route */ 115 register struct sap_hash *sh; 116 register struct sap_info *n = sap_msg->sap; 117 struct sap_hash *base = sap_head; 118 struct sockaddr_ipx *sipx = (struct sockaddr_ipx *) dst; 119 af_output_t *output = afswitch[dst->sa_family].af_output; 120 int size, metric; 121 int delay = 0; 122 123 if (sipx->sipx_port == 0) 124 sipx->sipx_port = htons(IPXPORT_SAP); 125 126 sap_msg->sap_cmd = ntohs(SAP_RESP); 127 128 for (sh = base; sh < &base[SAPHASHSIZ]; sh++) 129 for (sap = sh->forw; sap != (struct sap_entry *)sh; sap = sap->forw) { 130 size = (char *)n - (char *)sap_msg; 131 if (size >= ((MAXSAPENTRIES * sizeof (struct sap_info)) + 132 sizeof (sap_msg->sap_cmd))) { 133 (*output)(sapsock, flags, dst, size); 134 TRACE_SAP_OUTPUT(ifp, dst, size); 135 n = sap_msg->sap; 136 delay++; 137 if(delay == 2) { 138 usleep(20000); 139 delay = 0; 140 } 141 } 142 143 /* 144 * Check for the servicetype except if the ServType is 145 * a wildcard (0xFFFF). 146 */ 147 if ((ServType != SAP_WILDCARD) && 148 (ServType != sap->sap.ServType)) 149 continue; 150 151 /* 152 * This should do rule one and two of the split horizon 153 * algorithm. 154 */ 155 if (sap->ifp == ifp) 156 continue; 157 158 /* 159 * Rule 2. 160 * Look if we have clones (different routes to the same 161 * place with exactly the same cost). 162 * 163 * We should not publish on any of the clone interfaces. 164 */ 165 csap = sap->clone; 166 while (csap) { 167 if (csap->ifp == ifp) 168 goto next; 169 csap = csap->clone; 170 } 171 172 /* 173 * Don't advertise services with more than 15 hops. It 174 * will be confused with a service that has gone down. 175 */ 176 if (ntohs(sap->sap.hops) == (HOPCNT_INFINITY - 1)) 177 continue; 178 metric = min(ntohs(sap->sap.hops) + 1, HOPCNT_INFINITY); 179 180 *n = sap->sap; 181 n->hops = htons(metric); 182 n++; 183next: 184 } 185 if (n != sap_msg->sap) { 186 size = (char *)n - (char *)sap_msg; 187 (*output)(sapsock, flags, dst, size); 188 TRACE_SAP_OUTPUT(ifp, dst, size); 189 } 190} 191 192