Commit | Line | Data |
---|---|---|
8ae0e4b4 KM |
1 | /* |
2 | * Copyright (c) 1982 Regents of the University of California. | |
3 | * All rights reserved. The Berkeley software License Agreement | |
4 | * specifies the terms and conditions for redistribution. | |
5 | * | |
6 | * @(#)ip_icmp.c 6.12 (Berkeley) %G% | |
7 | */ | |
81a36a8d | 8 | |
20666ad3 JB |
9 | #include "param.h" |
10 | #include "systm.h" | |
11 | #include "mbuf.h" | |
12 | #include "protosw.h" | |
13 | #include "socket.h" | |
14 | #include "time.h" | |
15 | #include "kernel.h" | |
6e7edb25 BJ |
16 | |
17 | #include "../net/route.h" | |
c175a1bd | 18 | #include "../net/if.h" |
f4d55810 | 19 | |
20666ad3 JB |
20 | #include "in.h" |
21 | #include "in_systm.h" | |
c175a1bd | 22 | #include "in_var.h" |
20666ad3 JB |
23 | #include "ip.h" |
24 | #include "ip_icmp.h" | |
25 | #include "icmp_var.h" | |
81a36a8d | 26 | |
a60889ab | 27 | #ifdef ICMPPRINTFS |
81a36a8d BJ |
28 | /* |
29 | * ICMP routines: error generation, receive packet processing, and | |
30 | * routines to turnaround packets back to the originator, and | |
31 | * host table maintenance routines. | |
32 | */ | |
67387c9c | 33 | int icmpprintfs = 0; |
a60889ab | 34 | #endif |
81a36a8d BJ |
35 | |
36 | /* | |
72e4f44e SL |
37 | * Generate an error packet of type error |
38 | * in response to bad packet ip. | |
81a36a8d BJ |
39 | */ |
40 | icmp_error(oip, type, code) | |
41 | struct ip *oip; | |
755d8841 | 42 | int type, code; |
81a36a8d | 43 | { |
72e4f44e SL |
44 | register unsigned oiplen = oip->ip_hl << 2; |
45 | register struct icmp *icp; | |
81a36a8d BJ |
46 | struct mbuf *m; |
47 | struct ip *nip; | |
48 | ||
a60889ab | 49 | #ifdef ICMPPRINTFS |
39674d5f SL |
50 | if (icmpprintfs) |
51 | printf("icmp_error(%x, %d, %d)\n", oip, type, code); | |
a60889ab | 52 | #endif |
7b66c1fd | 53 | icmpstat.icps_error++; |
81a36a8d BJ |
54 | /* |
55 | * Make sure that the old IP packet had 8 bytes of data to return; | |
56 | * if not, don't bother. Also don't EVER error if the old | |
57 | * packet protocol was ICMP. | |
58 | */ | |
7b66c1fd SL |
59 | if (oip->ip_len < 8) { |
60 | icmpstat.icps_oldshort++; | |
81a36a8d | 61 | goto free; |
7b66c1fd SL |
62 | } |
63 | if (oip->ip_p == IPPROTO_ICMP) { | |
64 | icmpstat.icps_oldicmp++; | |
65 | goto free; | |
66 | } | |
81a36a8d BJ |
67 | |
68 | /* | |
72e4f44e | 69 | * First, formulate icmp message |
81a36a8d | 70 | */ |
cce93e4b | 71 | m = m_get(M_DONTWAIT, MT_HEADER); |
7b66c1fd | 72 | if (m == NULL) |
81a36a8d | 73 | goto free; |
72e4f44e SL |
74 | m->m_len = oiplen + 8 + ICMP_MINLEN; |
75 | m->m_off = MMAXOFF - m->m_len; | |
76 | icp = mtod(m, struct icmp *); | |
755d8841 | 77 | if ((u_int)type > ICMP_IREQREPLY) |
7b66c1fd SL |
78 | panic("icmp_error"); |
79 | icmpstat.icps_outhist[type]++; | |
81a36a8d | 80 | icp->icmp_type = type; |
72e4f44e | 81 | icp->icmp_void = 0; |
81a36a8d | 82 | if (type == ICMP_PARAMPROB) { |
81a36a8d | 83 | icp->icmp_pptr = code; |
72e4f44e SL |
84 | code = 0; |
85 | } | |
86 | icp->icmp_code = code; | |
d52566dd | 87 | bcopy((caddr_t)oip, (caddr_t)&icp->icmp_ip, oiplen + 8); |
39674d5f SL |
88 | nip = &icp->icmp_ip; |
89 | nip->ip_len += oiplen; | |
39674d5f | 90 | nip->ip_len = htons((u_short)nip->ip_len); |
81a36a8d BJ |
91 | |
92 | /* | |
72e4f44e SL |
93 | * Now, copy old ip header in front of icmp |
94 | * message. This allows us to reuse any source | |
95 | * routing info present. | |
81a36a8d | 96 | */ |
72e4f44e SL |
97 | m->m_off -= oiplen; |
98 | nip = mtod(m, struct ip *); | |
99 | bcopy((caddr_t)oip, (caddr_t)nip, oiplen); | |
100 | nip->ip_len = m->m_len + oiplen; | |
101 | nip->ip_p = IPPROTO_ICMP; | |
102 | /* icmp_send adds ip header to m_off and m_len, so we deduct here */ | |
103 | m->m_off += oiplen; | |
d52566dd | 104 | icmp_reflect(nip); |
81a36a8d | 105 | |
def04636 | 106 | free: |
81a36a8d BJ |
107 | m_freem(dtom(oip)); |
108 | } | |
109 | ||
72e4f44e SL |
110 | static struct sockproto icmproto = { AF_INET, IPPROTO_ICMP }; |
111 | static struct sockaddr_in icmpsrc = { AF_INET }; | |
112 | static struct sockaddr_in icmpdst = { AF_INET }; | |
113 | ||
81a36a8d | 114 | /* |
d52566dd | 115 | * Process a received ICMP message. |
81a36a8d BJ |
116 | */ |
117 | icmp_input(m) | |
118 | struct mbuf *m; | |
119 | { | |
81a36a8d | 120 | register struct icmp *icp; |
d52566dd | 121 | register struct ip *ip = mtod(m, struct ip *); |
af8f6a21 | 122 | int icmplen = ip->ip_len, hlen = ip->ip_hl << 2; |
8046f415 MK |
123 | register int i; |
124 | int (*ctlfunc)(), code; | |
b454c3ea | 125 | extern u_char ip_protox[]; |
c175a1bd | 126 | extern struct in_addr in_makeaddr(); |
81a36a8d BJ |
127 | |
128 | /* | |
129 | * Locate icmp structure in mbuf, and check | |
130 | * that not corrupted and of at least minimum length. | |
131 | */ | |
a60889ab | 132 | #ifdef ICMPPRINTFS |
39674d5f SL |
133 | if (icmpprintfs) |
134 | printf("icmp_input from %x, len %d\n", ip->ip_src, icmplen); | |
a60889ab | 135 | #endif |
4d75f980 | 136 | if (icmplen < ICMP_MINLEN) { |
7b66c1fd | 137 | icmpstat.icps_tooshort++; |
72e4f44e | 138 | goto free; |
7b66c1fd | 139 | } |
8046f415 MK |
140 | /* THIS LENGTH CHECK STILL MISSES ANY IP OPTIONS IN ICMP_IP */ |
141 | i = MIN(icmplen, ICMP_ADVLENMIN + hlen); | |
142 | if ((m->m_off > MMAXOFF || m->m_len < i) && | |
143 | (m = m_pullup(m, i)) == 0) { | |
167351c2 MK |
144 | icmpstat.icps_tooshort++; |
145 | return; | |
146 | } | |
8046f415 | 147 | ip = mtod(m, struct ip *); |
81a36a8d BJ |
148 | m->m_len -= hlen; |
149 | m->m_off += hlen; | |
72e4f44e | 150 | icp = mtod(m, struct icmp *); |
8046f415 | 151 | if (in_cksum(m, icmplen)) { |
7b66c1fd | 152 | icmpstat.icps_checksum++; |
d52566dd | 153 | goto free; |
72e4f44e | 154 | } |
81a36a8d | 155 | |
a60889ab | 156 | #ifdef ICMPPRINTFS |
81a36a8d BJ |
157 | /* |
158 | * Message type specific processing. | |
159 | */ | |
39674d5f SL |
160 | if (icmpprintfs) |
161 | printf("icmp_input, type %d code %d\n", icp->icmp_type, | |
a60889ab KM |
162 | icp->icmp_code); |
163 | #endif | |
7b66c1fd SL |
164 | if (icp->icmp_type > ICMP_IREQREPLY) |
165 | goto free; | |
166 | icmpstat.icps_inhist[icp->icmp_type]++; | |
a60889ab | 167 | code = icp->icmp_code; |
7b66c1fd | 168 | switch (icp->icmp_type) { |
81a36a8d BJ |
169 | |
170 | case ICMP_UNREACH: | |
a60889ab KM |
171 | if (code > 5) |
172 | goto badcode; | |
173 | code += PRC_UNREACH_NET; | |
174 | goto deliver; | |
175 | ||
81a36a8d | 176 | case ICMP_TIMXCEED: |
a60889ab KM |
177 | if (code > 1) |
178 | goto badcode; | |
179 | code += PRC_TIMXCEED_INTRANS; | |
180 | goto deliver; | |
181 | ||
81a36a8d | 182 | case ICMP_PARAMPROB: |
a60889ab KM |
183 | if (code) |
184 | goto badcode; | |
185 | code = PRC_PARAMPROB; | |
186 | goto deliver; | |
187 | ||
72e4f44e | 188 | case ICMP_SOURCEQUENCH: |
a60889ab KM |
189 | if (code) |
190 | goto badcode; | |
191 | code = PRC_QUENCH; | |
192 | deliver: | |
81a36a8d | 193 | /* |
a60889ab | 194 | * Problem with datagram; advise higher level routines. |
81a36a8d | 195 | */ |
a1edc12b | 196 | icp->icmp_ip.ip_len = ntohs((u_short)icp->icmp_ip.ip_len); |
7b66c1fd SL |
197 | if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp)) { |
198 | icmpstat.icps_badlen++; | |
d52566dd | 199 | goto free; |
7b66c1fd | 200 | } |
a60889ab | 201 | #ifdef ICMPPRINTFS |
39674d5f SL |
202 | if (icmpprintfs) |
203 | printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); | |
a60889ab | 204 | #endif |
59965020 | 205 | if (ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput) |
a60889ab KM |
206 | (*ctlfunc)(code, (caddr_t)icp); |
207 | goto free; | |
208 | ||
209 | badcode: | |
210 | icmpstat.icps_badcode++; | |
81a36a8d BJ |
211 | goto free; |
212 | ||
213 | case ICMP_ECHO: | |
214 | icp->icmp_type = ICMP_ECHOREPLY; | |
215 | goto reflect; | |
216 | ||
217 | case ICMP_TSTAMP: | |
7b66c1fd SL |
218 | if (icmplen < ICMP_TSLEN) { |
219 | icmpstat.icps_badlen++; | |
d52566dd | 220 | goto free; |
7b66c1fd | 221 | } |
81a36a8d | 222 | icp->icmp_type = ICMP_TSTAMPREPLY; |
2b4b57cd | 223 | icp->icmp_rtime = iptime(); |
81a36a8d BJ |
224 | icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ |
225 | goto reflect; | |
226 | ||
227 | case ICMP_IREQ: | |
c175a1bd MK |
228 | #define satosin(sa) ((struct sockaddr_in *)(sa)) |
229 | if (in_netof(ip->ip_src) == 0) | |
230 | ip->ip_src = in_makeaddr( | |
231 | in_netof(satosin(&in_ifaddr->ia_addr)->sin_addr), | |
232 | in_lnaof(ip->ip_src)); | |
233 | icp->icmp_type = ICMP_IREQREPLY; | |
81a36a8d BJ |
234 | goto reflect; |
235 | ||
a469458a | 236 | case ICMP_REDIRECT: |
7b66c1fd SL |
237 | if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp)) { |
238 | icmpstat.icps_badlen++; | |
d52566dd | 239 | goto free; |
7b66c1fd | 240 | } |
a469458a SL |
241 | /* |
242 | * Short circuit routing redirects to force | |
243 | * immediate change in the kernel's routing | |
244 | * tables. The message is also handed to anyone | |
245 | * listening on a raw socket (e.g. the routing | |
fbc81152 | 246 | * daemon for use in updating its tables). |
a469458a | 247 | */ |
167351c2 | 248 | icmpdst.sin_addr = icp->icmp_gwaddr; |
fbc81152 MK |
249 | if (code == ICMP_REDIRECT_NET || code == ICMP_REDIRECT_TOSNET) { |
250 | icmpsrc.sin_addr = | |
c175a1bd | 251 | in_makeaddr(in_netof(icp->icmp_ip.ip_dst), INADDR_ANY); |
fbc81152 MK |
252 | rtredirect((struct sockaddr *)&icmpsrc, |
253 | (struct sockaddr *)&icmpdst, RTF_GATEWAY); | |
0270e817 | 254 | pfctlinput(PRC_REDIRECT_NET, (caddr_t)icp); |
fbc81152 MK |
255 | } else { |
256 | icmpsrc.sin_addr = icp->icmp_ip.ip_dst; | |
257 | rtredirect((struct sockaddr *)&icmpsrc, | |
258 | (struct sockaddr *)&icmpdst, RTF_GATEWAY | RTF_HOST); | |
0270e817 | 259 | pfctlinput(PRC_REDIRECT_HOST, (caddr_t)icp); |
fbc81152 | 260 | } |
167351c2 MK |
261 | /* FALL THROUGH */ |
262 | ||
263 | case ICMP_ECHOREPLY: | |
264 | case ICMP_TSTAMPREPLY: | |
265 | case ICMP_IREQREPLY: | |
72e4f44e SL |
266 | icmpsrc.sin_addr = ip->ip_src; |
267 | icmpdst.sin_addr = ip->ip_dst; | |
268 | raw_input(dtom(icp), &icmproto, (struct sockaddr *)&icmpsrc, | |
269 | (struct sockaddr *)&icmpdst); | |
fd15a680 | 270 | return; |
81a36a8d BJ |
271 | |
272 | default: | |
273 | goto free; | |
274 | } | |
275 | reflect: | |
b012ee63 | 276 | ip->ip_len += hlen; /* since ip_input deducts this */ |
7b66c1fd | 277 | icmpstat.icps_reflect++; |
06730e5a | 278 | icmpstat.icps_outhist[icp->icmp_type]++; |
81a36a8d | 279 | icmp_reflect(ip); |
af8f6a21 | 280 | return; |
81a36a8d BJ |
281 | free: |
282 | m_freem(dtom(ip)); | |
283 | } | |
284 | ||
285 | /* | |
286 | * Reflect the ip packet back to the source | |
72e4f44e | 287 | * TODO: rearrange ip source routing options. |
81a36a8d BJ |
288 | */ |
289 | icmp_reflect(ip) | |
290 | struct ip *ip; | |
291 | { | |
c175a1bd MK |
292 | register struct in_addr t; |
293 | register struct in_ifaddr *ia; | |
81a36a8d | 294 | |
72e4f44e | 295 | t = ip->ip_dst; |
c175a1bd MK |
296 | if (t.s_addr == INADDR_ANY) |
297 | t = IA_SIN(in_ifaddr)->sin_addr; | |
298 | else for (ia = in_ifaddr; ia; ia = ia->ia_next) | |
299 | if (t.s_addr == satosin(&ia->ia_broadaddr)->sin_addr.s_addr && | |
300 | (ia->ia_ifp->if_flags & IFF_BROADCAST)) { | |
301 | t = IA_SIN(ia)->sin_addr; | |
302 | break; | |
303 | } | |
72e4f44e SL |
304 | ip->ip_dst = ip->ip_src; |
305 | ip->ip_src = t; | |
81a36a8d BJ |
306 | icmp_send(ip); |
307 | } | |
308 | ||
309 | /* | |
72e4f44e SL |
310 | * Send an icmp packet back to the ip level, |
311 | * after supplying a checksum. | |
81a36a8d | 312 | */ |
cdad2eb1 | 313 | icmp_send(ip) |
81a36a8d | 314 | struct ip *ip; |
81a36a8d | 315 | { |
af8f6a21 | 316 | register int hlen; |
72e4f44e | 317 | register struct icmp *icp; |
af8f6a21 | 318 | register struct mbuf *m; |
d52566dd | 319 | |
af8f6a21 SL |
320 | m = dtom(ip); |
321 | hlen = ip->ip_hl << 2; | |
72e4f44e SL |
322 | icp = mtod(m, struct icmp *); |
323 | icp->icmp_cksum = 0; | |
324 | icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen); | |
325 | m->m_off -= hlen; | |
326 | m->m_len += hlen; | |
a60889ab | 327 | #ifdef ICMPPRINTFS |
39674d5f SL |
328 | if (icmpprintfs) |
329 | printf("icmp_send dst %x src %x\n", ip->ip_dst, ip->ip_src); | |
a60889ab | 330 | #endif |
a1edc12b | 331 | (void) ip_output(m, (struct mbuf *)0, (struct route *)0, 0); |
d52566dd BJ |
332 | } |
333 | ||
cdad2eb1 | 334 | n_time |
2b4b57cd | 335 | iptime() |
d52566dd | 336 | { |
cdad2eb1 | 337 | int s = spl6(); |
2752c877 | 338 | u_long t; |
d52566dd | 339 | |
b2ac7f3b | 340 | t = (time.tv_sec % (24*60*60)) * 1000 + time.tv_usec / 1000; |
cdad2eb1 BJ |
341 | splx(s); |
342 | return (htonl(t)); | |
d52566dd | 343 | } |