| 1 | /* |
| 2 | * Copyright (c) 1984, 1985, 1986, 1987 Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms are permitted |
| 6 | * provided that this notice is preserved and that due credit is given |
| 7 | * to the University of California at Berkeley. The name of the University |
| 8 | * may not be used to endorse or promote products derived from this |
| 9 | * software without specific prior written permission. This software |
| 10 | * is provided ``as is'' without express or implied warranty. |
| 11 | * |
| 12 | * @(#)ns_error.c 7.3 (Berkeley) %G% |
| 13 | */ |
| 14 | |
| 15 | #include "param.h" |
| 16 | #include "systm.h" |
| 17 | #include "mbuf.h" |
| 18 | #include "protosw.h" |
| 19 | #include "socket.h" |
| 20 | #include "time.h" |
| 21 | #include "kernel.h" |
| 22 | |
| 23 | #include "../net/route.h" |
| 24 | |
| 25 | #include "ns.h" |
| 26 | #include "ns_pcb.h" |
| 27 | #include "idp.h" |
| 28 | #include "ns_error.h" |
| 29 | |
| 30 | #ifdef lint |
| 31 | #define NS_ERRPRINTFS 1 |
| 32 | #endif |
| 33 | |
| 34 | #ifdef NS_ERRPRINTFS |
| 35 | /* |
| 36 | * NS_ERR routines: error generation, receive packet processing, and |
| 37 | * routines to turnaround packets back to the originator. |
| 38 | */ |
| 39 | int ns_errprintfs = 0; |
| 40 | #endif |
| 41 | |
| 42 | /* |
| 43 | * Generate an error packet of type error |
| 44 | * in response to bad packet. |
| 45 | */ |
| 46 | |
| 47 | ns_error(om, type, param) |
| 48 | struct mbuf *om; |
| 49 | int type; |
| 50 | { |
| 51 | register struct ns_epidp *ep; |
| 52 | struct mbuf *m; |
| 53 | struct idp *nip; |
| 54 | register struct idp *oip = mtod(om, struct idp *); |
| 55 | extern int idpcksum; |
| 56 | |
| 57 | /* |
| 58 | * If this packet was sent to the echo port, |
| 59 | * and nobody was there, just echo it. |
| 60 | * (Yes, this is a wart!) |
| 61 | */ |
| 62 | if (type==NS_ERR_NOSOCK && |
| 63 | oip->idp_dna.x_port==htons(2) && |
| 64 | (type = ns_echo(oip)==0)) |
| 65 | return; |
| 66 | |
| 67 | #ifdef NS_ERRPRINTFS |
| 68 | if (ns_errprintfs) |
| 69 | printf("ns_err_error(%x, %d, %d)\n", oip, type, param); |
| 70 | #endif |
| 71 | /* |
| 72 | * Don't Generate error packets in response to multicasts. |
| 73 | */ |
| 74 | if (oip->idp_dna.x_host.c_host[0] & 1) |
| 75 | goto free; |
| 76 | |
| 77 | ns_errstat.ns_es_error++; |
| 78 | /* |
| 79 | * Make sure that the old IDP packet had 30 bytes of data to return; |
| 80 | * if not, don't bother. Also don't EVER error if the old |
| 81 | * packet protocol was NS_ERR. |
| 82 | */ |
| 83 | if (oip->idp_len < sizeof(struct idp)) { |
| 84 | ns_errstat.ns_es_oldshort++; |
| 85 | goto free; |
| 86 | } |
| 87 | if (oip->idp_pt == NSPROTO_ERROR) { |
| 88 | ns_errstat.ns_es_oldns_err++; |
| 89 | goto free; |
| 90 | } |
| 91 | |
| 92 | /* |
| 93 | * First, formulate ns_err message |
| 94 | */ |
| 95 | m = m_get(M_DONTWAIT, MT_HEADER); |
| 96 | if (m == NULL) |
| 97 | goto free; |
| 98 | m->m_len = sizeof(*ep); |
| 99 | m->m_off = MMAXOFF - m->m_len; |
| 100 | ep = mtod(m, struct ns_epidp *); |
| 101 | if ((u_int)type > NS_ERR_TOO_BIG) |
| 102 | panic("ns_err_error"); |
| 103 | ns_errstat.ns_es_outhist[ns_err_x(type)]++; |
| 104 | ep->ns_ep_errp.ns_err_num = htons((u_short)type); |
| 105 | ep->ns_ep_errp.ns_err_param = htons((u_short)param); |
| 106 | bcopy((caddr_t)oip, (caddr_t)&ep->ns_ep_errp.ns_err_idp, 42); |
| 107 | nip = &ep->ns_ep_idp; |
| 108 | nip->idp_len = sizeof(*ep); |
| 109 | nip->idp_len = htons((u_short)nip->idp_len); |
| 110 | nip->idp_pt = NSPROTO_ERROR; |
| 111 | nip->idp_tc = 0; |
| 112 | nip->idp_dna = oip->idp_sna; |
| 113 | nip->idp_sna = oip->idp_dna; |
| 114 | if (idpcksum) { |
| 115 | nip->idp_sum = 0; |
| 116 | nip->idp_sum = ns_cksum(dtom(nip), sizeof(*ep)); |
| 117 | } else |
| 118 | nip->idp_sum = 0xffff; |
| 119 | (void) ns_output(dtom(nip), (struct route *)0, 0); |
| 120 | |
| 121 | free: |
| 122 | m_freem(dtom(oip)); |
| 123 | } |
| 124 | |
| 125 | ns_printhost(p) |
| 126 | register struct ns_addr *p; |
| 127 | { |
| 128 | |
| 129 | printf("<net:%x%x,host:%x%x%x,port:%x>", |
| 130 | p->x_net.s_net[0], |
| 131 | p->x_net.s_net[1], |
| 132 | p->x_host.s_host[0], |
| 133 | p->x_host.s_host[1], |
| 134 | p->x_host.s_host[2], |
| 135 | p->x_port); |
| 136 | |
| 137 | } |
| 138 | |
| 139 | /* |
| 140 | * Process a received NS_ERR message. |
| 141 | */ |
| 142 | ns_err_input(m) |
| 143 | struct mbuf *m; |
| 144 | { |
| 145 | register struct ns_errp *ep; |
| 146 | register struct ns_epidp *epidp = mtod(m, struct ns_epidp *); |
| 147 | register int i; |
| 148 | int type, code, param; |
| 149 | |
| 150 | /* |
| 151 | * Locate ns_err structure in mbuf, and check |
| 152 | * that not corrupted and of at least minimum length. |
| 153 | */ |
| 154 | #ifdef NS_ERRPRINTFS |
| 155 | if (ns_errprintfs) { |
| 156 | printf("ns_err_input from "); |
| 157 | ns_printhost(&epidp->ns_ep_idp.idp_sna); |
| 158 | printf("len %d\n", ntohs(epidp->ns_ep_idp.idp_len)); |
| 159 | } |
| 160 | #endif |
| 161 | i = sizeof (struct ns_epidp); |
| 162 | if ((m->m_off > MMAXOFF || m->m_len < i) && |
| 163 | (m = m_pullup(m, i)) == 0) { |
| 164 | ns_errstat.ns_es_tooshort++; |
| 165 | return; |
| 166 | } |
| 167 | ep = &(mtod(m, struct ns_epidp *)->ns_ep_errp); |
| 168 | type = ntohs(ep->ns_err_num); |
| 169 | param = ntohs(ep->ns_err_param); |
| 170 | ns_errstat.ns_es_inhist[ns_err_x(type)]++; |
| 171 | |
| 172 | #ifdef NS_ERRPRINTFS |
| 173 | /* |
| 174 | * Message type specific processing. |
| 175 | */ |
| 176 | if (ns_errprintfs) |
| 177 | printf("ns_err_input, type %d param %d\n", type, param); |
| 178 | #endif |
| 179 | if (type >= NS_ERR_TOO_BIG) { |
| 180 | goto badcode; |
| 181 | } |
| 182 | ns_errstat.ns_es_outhist[ns_err_x(type)]++; |
| 183 | switch (type) { |
| 184 | |
| 185 | case NS_ERR_UNREACH_HOST: |
| 186 | code = PRC_UNREACH_NET; |
| 187 | goto deliver; |
| 188 | |
| 189 | case NS_ERR_TOO_OLD: |
| 190 | code = PRC_TIMXCEED_INTRANS; |
| 191 | goto deliver; |
| 192 | |
| 193 | case NS_ERR_TOO_BIG: |
| 194 | code = PRC_MSGSIZE; |
| 195 | goto deliver; |
| 196 | |
| 197 | case NS_ERR_FULLUP: |
| 198 | code = PRC_QUENCH; |
| 199 | goto deliver; |
| 200 | |
| 201 | case NS_ERR_NOSOCK: |
| 202 | code = PRC_UNREACH_PORT; |
| 203 | goto deliver; |
| 204 | |
| 205 | case NS_ERR_UNSPEC_T: |
| 206 | case NS_ERR_BADSUM_T: |
| 207 | case NS_ERR_BADSUM: |
| 208 | case NS_ERR_UNSPEC: |
| 209 | code = PRC_PARAMPROB; |
| 210 | goto deliver; |
| 211 | |
| 212 | deliver: |
| 213 | /* |
| 214 | * Problem with datagram; advise higher level routines. |
| 215 | */ |
| 216 | #ifdef NS_ERRPRINTFS |
| 217 | if (ns_errprintfs) |
| 218 | printf("deliver to protocol %d\n", |
| 219 | ep->ns_err_idp.idp_pt); |
| 220 | #endif |
| 221 | switch(ep->ns_err_idp.idp_pt) { |
| 222 | case NSPROTO_SPP: |
| 223 | spp_ctlinput(code, (caddr_t)ep); |
| 224 | break; |
| 225 | |
| 226 | default: |
| 227 | idp_ctlinput(code, (caddr_t)ep); |
| 228 | } |
| 229 | |
| 230 | goto free; |
| 231 | |
| 232 | default: |
| 233 | badcode: |
| 234 | ns_errstat.ns_es_badcode++; |
| 235 | goto free; |
| 236 | |
| 237 | } |
| 238 | free: |
| 239 | m_freem(m); |
| 240 | } |
| 241 | |
| 242 | #ifdef notdef |
| 243 | u_long |
| 244 | nstime() |
| 245 | { |
| 246 | int s = splclock(); |
| 247 | u_long t; |
| 248 | |
| 249 | t = (time.tv_sec % (24*60*60)) * 1000 + time.tv_usec / 1000; |
| 250 | splx(s); |
| 251 | return (htonl(t)); |
| 252 | } |
| 253 | #endif |
| 254 | |
| 255 | ns_echo(idp) |
| 256 | register struct idp *idp; |
| 257 | { |
| 258 | struct mbuf *m = dtom(idp); |
| 259 | register struct echo { |
| 260 | struct idp ec_idp; |
| 261 | u_short ec_op; /* Operation, 1 = request, 2 = reply */ |
| 262 | } *ec = (struct echo *)idp; |
| 263 | struct ns_addr temp; |
| 264 | |
| 265 | if (idp->idp_pt!=NSPROTO_ECHO) return(NS_ERR_NOSOCK); |
| 266 | if (ec->ec_op!=htons(1)) return(NS_ERR_UNSPEC); |
| 267 | |
| 268 | ec->ec_op = htons(2); |
| 269 | |
| 270 | temp = idp->idp_dna; |
| 271 | idp->idp_dna = idp->idp_sna; |
| 272 | idp->idp_sna = temp; |
| 273 | |
| 274 | if (idp->idp_sum != 0xffff) { |
| 275 | idp->idp_sum = 0; |
| 276 | idp->idp_sum = ns_cksum(m, |
| 277 | (int)(((ntohs(idp->idp_len) - 1)|1)+1)); |
| 278 | } |
| 279 | (void) ns_output(m, (struct route *)0, NS_FORWARDING); |
| 280 | return(0); |
| 281 | } |