sap_output.c revision 11820
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: sap_output.c,v 1.4 1995/10/11 18:57:28 jhay Exp $ 32 */ 33 34/* 35 * Routing Table Management Daemon 36 */ 37#include "defs.h" 38 39/* 40 * Apply the function "f" to all non-passive 41 * interfaces. If the interface supports the 42 * use of broadcasting use it, otherwise address 43 * the output to the known router. 44 */ 45void 46sap_supply_toall(void) 47{ 48 register struct interface *ifp; 49 struct sockaddr dst; 50 register struct sockaddr_ipx *ipx_dst; 51 register int flags; 52 extern struct interface *ifnet; 53 54 ipx_dst = (struct sockaddr_ipx *)&dst; 55 56 for (ifp = ifnet; ifp; ifp = ifp->int_next) { 57 if (ifp->int_flags & IFF_PASSIVE) 58 continue; 59 60 dst = ifp->int_flags & IFF_BROADCAST ? ifp->int_broadaddr : 61 ifp->int_flags & IFF_POINTOPOINT ? ifp->int_dstaddr : 62 ifp->int_addr; 63 if (ipx_dst->sipx_addr.x_port == 0) 64 ipx_dst->sipx_addr.x_port = htons(IPXPORT_SAP); 65 66 flags = ifp->int_flags & IFF_INTERFACE ? MSG_DONTROUTE : 0; 67 sap_supply(&dst, flags, ifp, SAP_WILDCARD); 68 } 69} 70 71void 72sapsndmsg(dst, flags, ifp) 73 struct sockaddr *dst; 74 int flags; 75 struct interface *ifp; 76{ 77 struct sockaddr t_dst; 78 struct sockaddr_ipx *ipx_dst; 79 80 t_dst = *dst; 81 ipx_dst = (struct sockaddr_ipx *)&t_dst; 82 83 if (ipx_dst->sipx_addr.x_port == 0) 84 ipx_dst->sipx_addr.x_port = htons(IPXPORT_SAP); 85 86 (*afswitch[dst->sa_family].af_output) 87 (sapsock, flags, &t_dst, 88 sizeof (struct sap_packet) + sizeof(u_short)); 89 TRACE_SAP_OUTPUT(ifp, &t_dst, 90 sizeof (struct sap_packet) + sizeof(u_short)); 91} 92 93/* 94 * Supply dst with the contents of the SAP tables. If the ServType == 95 * SAP_WILDCARD (0xFFFF) supply the whole table, otherwise only the 96 * services that are of ServType. If this won't fit in one packet, chop 97 * it up into several. 98 * 99 * This must be done using the split horizon algorithm. 100 * 1. Don't send SAP info to the interface from where it was received. 101 * 2. If a service is received from more than one interface and the cost is 102 * the same, don't publish it on either interface. I am calling this 103 * clones. 104 */ 105void 106sap_supply(dst, flags, ifp, ServType) 107 struct sockaddr *dst; 108 int flags; 109 struct interface *ifp; 110 int ServType; 111{ 112 register struct sap_entry *sap; 113 register struct sap_entry *csap; /* Clone route */ 114 register struct sap_hash *sh; 115 register struct sap_info *n = sap_msg->sap; 116 struct sap_hash *base = sap_head; 117 struct sockaddr_ipx *sipx = (struct sockaddr_ipx *) dst; 118 af_output_t *output = afswitch[dst->sa_family].af_output; 119 int size, metric; 120 121 if (sipx->sipx_port == 0) 122 sipx->sipx_port = htons(IPXPORT_SAP); 123 124 sap_msg->sap_cmd = ntohs(SAP_RESP); 125 126 for (sh = base; sh < &base[SAPHASHSIZ]; sh++) 127 for (sap = sh->forw; sap != (struct sap_entry *)sh; sap = sap->forw) { 128 size = (char *)n - (char *)sap_msg; 129 if (size > MAXPACKETSIZE - sizeof (struct sap_info)) { 130 (*output)(sapsock, flags, dst, size); 131 TRACE_SAP_OUTPUT(ifp, dst, size); 132 n = sap_msg->sap; 133 } 134 135 /* 136 * Check for the servicetype except if the ServType is 137 * a wildcard (0xFFFF). 138 */ 139 if ((ServType != SAP_WILDCARD) && 140 (ServType != sap->sap.ServType)) 141 continue; 142 143 /* 144 * This should do rule one and two of the split horizon 145 * algorithm. 146 */ 147 if (sap->ifp == ifp) 148 continue; 149 150 /* 151 * Rule 2. 152 * Look if we have clones (different routes to the same 153 * place with exactly the same cost). 154 * 155 * We should not publish on any of the clone interfaces. 156 */ 157 csap = sap->clone; 158 while (csap) { 159 if (csap->ifp == ifp) 160 continue; 161 csap = csap->clone; 162 } 163 164 /* 165 * Don't advertise services with more than 15 hops. It 166 * will be confused with a service that has gone down. 167 */ 168 if (ntohs(sap->sap.hops) == (HOPCNT_INFINITY - 1)) 169 continue; 170 metric = min(ntohs(sap->sap.hops) + 1, HOPCNT_INFINITY); 171 172 *n = sap->sap; 173 n->hops = htons(metric); 174 n++; 175 } 176 if (n != sap_msg->sap) { 177 size = (char *)n - (char *)sap_msg; 178 (*output)(sapsock, flags, dst, size); 179 TRACE_SAP_OUTPUT(ifp, dst, size); 180 } 181} 182 183