1 /*
2 * Copyright (c) 1984, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * %sccs.include.redist.c%
6 *
7 * @(#)ns_error.c 8.2 (Berkeley) 02/09/95
8 */
9
10 #include <sys/param.h>
11 #include <sys/systm.h>
12 #include <sys/malloc.h>
13 #include <sys/mbuf.h>
14 #include <sys/protosw.h>
15 #include <sys/socket.h>
16 #include <sys/socketvar.h>
17 #include <sys/time.h>
18 #include <sys/kernel.h>
19
20 #include <net/route.h>
21
22 #include <netns/ns.h>
23 #include <netns/ns_pcb.h>
24 #include <netns/idp.h>
25 #include <netns/ns_error.h>
26
27 #ifdef lint
28 #define NS_ERRPRINTFS 1
29 #endif
30
31 #ifdef NS_ERRPRINTFS
32 /*
33 * NS_ERR routines: error generation, receive packet processing, and
34 * routines to turnaround packets back to the originator.
35 */
36 int ns_errprintfs = 0;
37 #endif
38
ns_err_x(c)39 ns_err_x(c)
40 {
41 register u_short *w, *lim, *base = ns_errstat.ns_es_codes;
42 u_short x = c;
43
44 /*
45 * zero is a legit error code, handle specially
46 */
47 if (x == 0)
48 return (0);
49 lim = base + NS_ERR_MAX - 1;
50 for (w = base + 1; w < lim; w++) {
51 if (*w == 0)
52 *w = x;
53 if (*w == x)
54 break;
55 }
56 return (w - base);
57 }
58
59 /*
60 * Generate an error packet of type error
61 * in response to bad packet.
62 */
63
64 ns_error(om, type, param)
65 struct mbuf *om;
66 int type;
67 {
68 register struct ns_epidp *ep;
69 struct mbuf *m;
70 struct idp *nip;
71 register struct idp *oip = mtod(om, struct idp *);
72 extern int idpcksum;
73
74 /*
75 * If this packet was sent to the echo port,
76 * and nobody was there, just echo it.
77 * (Yes, this is a wart!)
78 */
79 if (type == NS_ERR_NOSOCK &&
80 oip->idp_dna.x_port == htons(2) &&
81 (type = ns_echo(om))==0)
82 return;
83
84 #ifdef NS_ERRPRINTFS
85 if (ns_errprintfs)
86 printf("ns_err_error(%x, %d, %d)\n", oip, type, param);
87 #endif
88 /*
89 * Don't Generate error packets in response to multicasts.
90 */
91 if (oip->idp_dna.x_host.c_host[0] & 1)
92 goto freeit;
93
94 ns_errstat.ns_es_error++;
95 /*
96 * Make sure that the old IDP packet had 30 bytes of data to return;
97 * if not, don't bother. Also don't EVER error if the old
98 * packet protocol was NS_ERR.
99 */
100 if (oip->idp_len < sizeof(struct idp)) {
101 ns_errstat.ns_es_oldshort++;
102 goto freeit;
103 }
104 if (oip->idp_pt == NSPROTO_ERROR) {
105 ns_errstat.ns_es_oldns_err++;
106 goto freeit;
107 }
108
109 /*
110 * First, formulate ns_err message
111 */
112 m = m_gethdr(M_DONTWAIT, MT_HEADER);
113 if (m == NULL)
114 goto freeit;
115 m->m_len = sizeof(*ep);
116 MH_ALIGN(m, m->m_len);
117 ep = mtod(m, struct ns_epidp *);
118 if ((u_int)type > NS_ERR_TOO_BIG)
119 panic("ns_err_error");
120 ns_errstat.ns_es_outhist[ns_err_x(type)]++;
121 ep->ns_ep_errp.ns_err_num = htons((u_short)type);
122 ep->ns_ep_errp.ns_err_param = htons((u_short)param);
123 bcopy((caddr_t)oip, (caddr_t)&ep->ns_ep_errp.ns_err_idp, 42);
124 nip = &ep->ns_ep_idp;
125 nip->idp_len = sizeof(*ep);
126 nip->idp_len = htons((u_short)nip->idp_len);
127 nip->idp_pt = NSPROTO_ERROR;
128 nip->idp_tc = 0;
129 nip->idp_dna = oip->idp_sna;
130 nip->idp_sna = oip->idp_dna;
131 if (idpcksum) {
132 nip->idp_sum = 0;
133 nip->idp_sum = ns_cksum(m, sizeof(*ep));
134 } else
135 nip->idp_sum = 0xffff;
136 (void) ns_output(m, (struct route *)0, 0);
137
138 freeit:
139 m_freem(om);
140 }
141
ns_printhost(p)142 ns_printhost(p)
143 register struct ns_addr *p;
144 {
145
146 printf("<net:%x%x,host:%x%x%x,port:%x>",
147 p->x_net.s_net[0],
148 p->x_net.s_net[1],
149 p->x_host.s_host[0],
150 p->x_host.s_host[1],
151 p->x_host.s_host[2],
152 p->x_port);
153
154 }
155
156 /*
157 * Process a received NS_ERR message.
158 */
159 ns_err_input(m)
160 struct mbuf *m;
161 {
162 register struct ns_errp *ep;
163 register struct ns_epidp *epidp = mtod(m, struct ns_epidp *);
164 register int i;
165 int type, code, param;
166
167 /*
168 * Locate ns_err structure in mbuf, and check
169 * that not corrupted and of at least minimum length.
170 */
171 #ifdef NS_ERRPRINTFS
172 if (ns_errprintfs) {
173 printf("ns_err_input from ");
174 ns_printhost(&epidp->ns_ep_idp.idp_sna);
175 printf("len %d\n", ntohs(epidp->ns_ep_idp.idp_len));
176 }
177 #endif
178 i = sizeof (struct ns_epidp);
179 if (((m->m_flags & M_EXT) || m->m_len < i) &&
180 (m = m_pullup(m, i)) == 0) {
181 ns_errstat.ns_es_tooshort++;
182 return;
183 }
184 ep = &(mtod(m, struct ns_epidp *)->ns_ep_errp);
185 type = ntohs(ep->ns_err_num);
186 param = ntohs(ep->ns_err_param);
187 ns_errstat.ns_es_inhist[ns_err_x(type)]++;
188
189 #ifdef NS_ERRPRINTFS
190 /*
191 * Message type specific processing.
192 */
193 if (ns_errprintfs)
194 printf("ns_err_input, type %d param %d\n", type, param);
195 #endif
196 if (type >= NS_ERR_TOO_BIG) {
197 goto badcode;
198 }
199 ns_errstat.ns_es_outhist[ns_err_x(type)]++;
200 switch (type) {
201
202 case NS_ERR_UNREACH_HOST:
203 code = PRC_UNREACH_NET;
204 goto deliver;
205
206 case NS_ERR_TOO_OLD:
207 code = PRC_TIMXCEED_INTRANS;
208 goto deliver;
209
210 case NS_ERR_TOO_BIG:
211 code = PRC_MSGSIZE;
212 goto deliver;
213
214 case NS_ERR_FULLUP:
215 code = PRC_QUENCH;
216 goto deliver;
217
218 case NS_ERR_NOSOCK:
219 code = PRC_UNREACH_PORT;
220 goto deliver;
221
222 case NS_ERR_UNSPEC_T:
223 case NS_ERR_BADSUM_T:
224 case NS_ERR_BADSUM:
225 case NS_ERR_UNSPEC:
226 code = PRC_PARAMPROB;
227 goto deliver;
228
229 deliver:
230 /*
231 * Problem with datagram; advise higher level routines.
232 */
233 #ifdef NS_ERRPRINTFS
234 if (ns_errprintfs)
235 printf("deliver to protocol %d\n",
236 ep->ns_err_idp.idp_pt);
237 #endif
238 switch(ep->ns_err_idp.idp_pt) {
239 case NSPROTO_SPP:
240 spp_ctlinput(code, (caddr_t)ep);
241 break;
242
243 default:
244 idp_ctlinput(code, (caddr_t)ep);
245 }
246
247 goto freeit;
248
249 default:
250 badcode:
251 ns_errstat.ns_es_badcode++;
252 goto freeit;
253
254 }
255 freeit:
256 m_freem(m);
257 }
258
259 #ifdef notdef
260 u_long
nstime()261 nstime()
262 {
263 int s = splclock();
264 u_long t;
265
266 t = (time.tv_sec % (24*60*60)) * 1000 + time.tv_usec / 1000;
267 splx(s);
268 return (htonl(t));
269 }
270 #endif
271
272 ns_echo(m)
273 struct mbuf *m;
274 {
275 register struct idp *idp = mtod(m, struct idp *);
276 register struct echo {
277 struct idp ec_idp;
278 u_short ec_op; /* Operation, 1 = request, 2 = reply */
279 } *ec = (struct echo *)idp;
280 struct ns_addr temp;
281
282 if (idp->idp_pt!=NSPROTO_ECHO) return(NS_ERR_NOSOCK);
283 if (ec->ec_op!=htons(1)) return(NS_ERR_UNSPEC);
284
285 ec->ec_op = htons(2);
286
287 temp = idp->idp_dna;
288 idp->idp_dna = idp->idp_sna;
289 idp->idp_sna = temp;
290
291 if (idp->idp_sum != 0xffff) {
292 idp->idp_sum = 0;
293 idp->idp_sum = ns_cksum(m,
294 (int)(((ntohs(idp->idp_len) - 1)|1)+1));
295 }
296 (void) ns_output(m, (struct route *)0, NS_FORWARDING);
297 return(0);
298 }
299