Commit | Line | Data |
---|---|---|
b11be056 | 1 | /* ip_icmp.c 6.1 83/07/29 */ |
81a36a8d BJ |
2 | |
3 | #include "../h/param.h" | |
2b4b57cd | 4 | #include "../h/systm.h" |
81a36a8d | 5 | #include "../h/mbuf.h" |
cdad2eb1 | 6 | #include "../h/protosw.h" |
72e4f44e | 7 | #include "../h/socket.h" |
f4d55810 | 8 | #include "../h/time.h" |
6e7edb25 BJ |
9 | #include "../h/kernel.h" |
10 | ||
11 | #include "../net/route.h" | |
f4d55810 | 12 | |
fcfe450e BJ |
13 | #include "../netinet/in.h" |
14 | #include "../netinet/in_systm.h" | |
15 | #include "../netinet/ip.h" | |
16 | #include "../netinet/ip_icmp.h" | |
7b66c1fd | 17 | #include "../netinet/icmp_var.h" |
81a36a8d BJ |
18 | |
19 | /* | |
20 | * ICMP routines: error generation, receive packet processing, and | |
21 | * routines to turnaround packets back to the originator, and | |
22 | * host table maintenance routines. | |
23 | */ | |
67387c9c | 24 | int icmpprintfs = 0; |
81a36a8d BJ |
25 | |
26 | /* | |
72e4f44e SL |
27 | * Generate an error packet of type error |
28 | * in response to bad packet ip. | |
81a36a8d BJ |
29 | */ |
30 | icmp_error(oip, type, code) | |
31 | struct ip *oip; | |
755d8841 | 32 | int type, code; |
81a36a8d | 33 | { |
72e4f44e SL |
34 | register unsigned oiplen = oip->ip_hl << 2; |
35 | register struct icmp *icp; | |
81a36a8d BJ |
36 | struct mbuf *m; |
37 | struct ip *nip; | |
38 | ||
39674d5f SL |
39 | if (icmpprintfs) |
40 | printf("icmp_error(%x, %d, %d)\n", oip, type, code); | |
7b66c1fd | 41 | icmpstat.icps_error++; |
81a36a8d BJ |
42 | /* |
43 | * Make sure that the old IP packet had 8 bytes of data to return; | |
44 | * if not, don't bother. Also don't EVER error if the old | |
45 | * packet protocol was ICMP. | |
46 | */ | |
7b66c1fd SL |
47 | if (oip->ip_len < 8) { |
48 | icmpstat.icps_oldshort++; | |
81a36a8d | 49 | goto free; |
7b66c1fd SL |
50 | } |
51 | if (oip->ip_p == IPPROTO_ICMP) { | |
52 | icmpstat.icps_oldicmp++; | |
53 | goto free; | |
54 | } | |
81a36a8d BJ |
55 | |
56 | /* | |
72e4f44e | 57 | * First, formulate icmp message |
81a36a8d | 58 | */ |
cce93e4b | 59 | m = m_get(M_DONTWAIT, MT_HEADER); |
7b66c1fd | 60 | if (m == NULL) |
81a36a8d | 61 | goto free; |
72e4f44e SL |
62 | m->m_len = oiplen + 8 + ICMP_MINLEN; |
63 | m->m_off = MMAXOFF - m->m_len; | |
64 | icp = mtod(m, struct icmp *); | |
755d8841 | 65 | if ((u_int)type > ICMP_IREQREPLY) |
7b66c1fd SL |
66 | panic("icmp_error"); |
67 | icmpstat.icps_outhist[type]++; | |
81a36a8d | 68 | icp->icmp_type = type; |
72e4f44e | 69 | icp->icmp_void = 0; |
81a36a8d | 70 | if (type == ICMP_PARAMPROB) { |
81a36a8d | 71 | icp->icmp_pptr = code; |
72e4f44e SL |
72 | code = 0; |
73 | } | |
74 | icp->icmp_code = code; | |
d52566dd | 75 | bcopy((caddr_t)oip, (caddr_t)&icp->icmp_ip, oiplen + 8); |
39674d5f SL |
76 | nip = &icp->icmp_ip; |
77 | nip->ip_len += oiplen; | |
39674d5f | 78 | nip->ip_len = htons((u_short)nip->ip_len); |
81a36a8d BJ |
79 | |
80 | /* | |
72e4f44e SL |
81 | * Now, copy old ip header in front of icmp |
82 | * message. This allows us to reuse any source | |
83 | * routing info present. | |
81a36a8d | 84 | */ |
72e4f44e SL |
85 | m->m_off -= oiplen; |
86 | nip = mtod(m, struct ip *); | |
87 | bcopy((caddr_t)oip, (caddr_t)nip, oiplen); | |
88 | nip->ip_len = m->m_len + oiplen; | |
89 | nip->ip_p = IPPROTO_ICMP; | |
90 | /* icmp_send adds ip header to m_off and m_len, so we deduct here */ | |
91 | m->m_off += oiplen; | |
d52566dd | 92 | icmp_reflect(nip); |
81a36a8d | 93 | |
def04636 | 94 | free: |
81a36a8d BJ |
95 | m_freem(dtom(oip)); |
96 | } | |
97 | ||
72e4f44e SL |
98 | static char icmpmap[] = { |
99 | -1, -1, -1, | |
100 | PRC_UNREACH_NET, PRC_QUENCH, PRC_REDIRECT_NET, | |
101 | -1, -1, -1, | |
102 | -1, -1, PRC_TIMXCEED_INTRANS, | |
103 | PRC_PARAMPROB, -1, -1, | |
104 | -1, -1 | |
105 | }; | |
106 | ||
107 | static struct sockproto icmproto = { AF_INET, IPPROTO_ICMP }; | |
108 | static struct sockaddr_in icmpsrc = { AF_INET }; | |
109 | static struct sockaddr_in icmpdst = { AF_INET }; | |
110 | ||
81a36a8d | 111 | /* |
d52566dd | 112 | * Process a received ICMP message. |
81a36a8d BJ |
113 | */ |
114 | icmp_input(m) | |
115 | struct mbuf *m; | |
116 | { | |
81a36a8d | 117 | register struct icmp *icp; |
d52566dd | 118 | register struct ip *ip = mtod(m, struct ip *); |
af8f6a21 | 119 | int icmplen = ip->ip_len, hlen = ip->ip_hl << 2; |
7b66c1fd | 120 | int (*ctlfunc)(), code, i; |
b454c3ea | 121 | extern u_char ip_protox[]; |
81a36a8d BJ |
122 | |
123 | /* | |
124 | * Locate icmp structure in mbuf, and check | |
125 | * that not corrupted and of at least minimum length. | |
126 | */ | |
39674d5f SL |
127 | if (icmpprintfs) |
128 | printf("icmp_input from %x, len %d\n", ip->ip_src, icmplen); | |
7b66c1fd SL |
129 | if (icmplen < ICMP_MINLEN) { |
130 | icmpstat.icps_tooshort++; | |
72e4f44e | 131 | goto free; |
7b66c1fd | 132 | } |
81a36a8d BJ |
133 | m->m_len -= hlen; |
134 | m->m_off += hlen; | |
135 | /* need routine to make sure header is in this mbuf here */ | |
72e4f44e | 136 | icp = mtod(m, struct icmp *); |
81a36a8d BJ |
137 | i = icp->icmp_cksum; |
138 | icp->icmp_cksum = 0; | |
72e4f44e | 139 | if (i != in_cksum(m, icmplen)) { |
7b66c1fd | 140 | icmpstat.icps_checksum++; |
d52566dd | 141 | goto free; |
72e4f44e | 142 | } |
81a36a8d BJ |
143 | |
144 | /* | |
145 | * Message type specific processing. | |
146 | */ | |
39674d5f SL |
147 | if (icmpprintfs) |
148 | printf("icmp_input, type %d code %d\n", icp->icmp_type, | |
149 | icp->icmp_code); | |
7b66c1fd SL |
150 | if (icp->icmp_type > ICMP_IREQREPLY) |
151 | goto free; | |
152 | icmpstat.icps_inhist[icp->icmp_type]++; | |
153 | switch (icp->icmp_type) { | |
81a36a8d BJ |
154 | |
155 | case ICMP_UNREACH: | |
156 | case ICMP_TIMXCEED: | |
157 | case ICMP_PARAMPROB: | |
72e4f44e | 158 | case ICMP_SOURCEQUENCH: |
81a36a8d BJ |
159 | /* |
160 | * Problem with previous datagram; advise | |
161 | * higher level routines. | |
162 | */ | |
a1edc12b | 163 | icp->icmp_ip.ip_len = ntohs((u_short)icp->icmp_ip.ip_len); |
7b66c1fd SL |
164 | if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp)) { |
165 | icmpstat.icps_badlen++; | |
d52566dd | 166 | goto free; |
7b66c1fd | 167 | } |
39674d5f SL |
168 | if (icmpprintfs) |
169 | printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); | |
7b66c1fd | 170 | code = icp->icmp_type == ICMP_PARAMPROB ? 0 : icp->icmp_code; |
59965020 | 171 | if (ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput) |
7b66c1fd | 172 | (*ctlfunc)(icmpmap[icp->icmp_type]+code, (caddr_t)icp); |
81a36a8d BJ |
173 | goto free; |
174 | ||
175 | case ICMP_ECHO: | |
176 | icp->icmp_type = ICMP_ECHOREPLY; | |
177 | goto reflect; | |
178 | ||
179 | case ICMP_TSTAMP: | |
7b66c1fd SL |
180 | if (icmplen < ICMP_TSLEN) { |
181 | icmpstat.icps_badlen++; | |
d52566dd | 182 | goto free; |
7b66c1fd | 183 | } |
81a36a8d | 184 | icp->icmp_type = ICMP_TSTAMPREPLY; |
2b4b57cd | 185 | icp->icmp_rtime = iptime(); |
81a36a8d BJ |
186 | icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ |
187 | goto reflect; | |
188 | ||
189 | case ICMP_IREQ: | |
190 | /* fill in source address zero fields! */ | |
191 | goto reflect; | |
192 | ||
a469458a | 193 | case ICMP_REDIRECT: |
81a36a8d BJ |
194 | case ICMP_ECHOREPLY: |
195 | case ICMP_TSTAMPREPLY: | |
196 | case ICMP_IREQREPLY: | |
7b66c1fd SL |
197 | if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp)) { |
198 | icmpstat.icps_badlen++; | |
d52566dd | 199 | goto free; |
7b66c1fd | 200 | } |
a469458a SL |
201 | /* |
202 | * Short circuit routing redirects to force | |
203 | * immediate change in the kernel's routing | |
204 | * tables. The message is also handed to anyone | |
205 | * listening on a raw socket (e.g. the routing | |
206 | * daemon for use in updating it's tables). | |
207 | */ | |
208 | if (icp->icmp_type == ICMP_REDIRECT) { | |
209 | icmpsrc.sin_addr = icp->icmp_ip.ip_dst; | |
210 | icmpdst.sin_addr = icp->icmp_gwaddr; | |
211 | rtredirect((struct sockaddr *)&icmpsrc, | |
212 | (struct sockaddr *)&icmpdst); | |
213 | } | |
72e4f44e SL |
214 | icmpsrc.sin_addr = ip->ip_src; |
215 | icmpdst.sin_addr = ip->ip_dst; | |
216 | raw_input(dtom(icp), &icmproto, (struct sockaddr *)&icmpsrc, | |
217 | (struct sockaddr *)&icmpdst); | |
fd15a680 | 218 | return; |
81a36a8d BJ |
219 | |
220 | default: | |
221 | goto free; | |
222 | } | |
223 | reflect: | |
b012ee63 | 224 | ip->ip_len += hlen; /* since ip_input deducts this */ |
7b66c1fd | 225 | icmpstat.icps_reflect++; |
81a36a8d | 226 | icmp_reflect(ip); |
af8f6a21 | 227 | return; |
81a36a8d BJ |
228 | free: |
229 | m_freem(dtom(ip)); | |
230 | } | |
231 | ||
232 | /* | |
233 | * Reflect the ip packet back to the source | |
72e4f44e | 234 | * TODO: rearrange ip source routing options. |
81a36a8d BJ |
235 | */ |
236 | icmp_reflect(ip) | |
237 | struct ip *ip; | |
238 | { | |
2b4b57cd | 239 | struct in_addr t; |
81a36a8d | 240 | |
72e4f44e SL |
241 | t = ip->ip_dst; |
242 | ip->ip_dst = ip->ip_src; | |
243 | ip->ip_src = t; | |
81a36a8d BJ |
244 | icmp_send(ip); |
245 | } | |
246 | ||
247 | /* | |
72e4f44e SL |
248 | * Send an icmp packet back to the ip level, |
249 | * after supplying a checksum. | |
81a36a8d | 250 | */ |
cdad2eb1 | 251 | icmp_send(ip) |
81a36a8d | 252 | struct ip *ip; |
81a36a8d | 253 | { |
af8f6a21 | 254 | register int hlen; |
72e4f44e | 255 | register struct icmp *icp; |
af8f6a21 | 256 | register struct mbuf *m; |
d52566dd | 257 | |
af8f6a21 SL |
258 | m = dtom(ip); |
259 | hlen = ip->ip_hl << 2; | |
72e4f44e SL |
260 | icp = mtod(m, struct icmp *); |
261 | icp->icmp_cksum = 0; | |
262 | icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen); | |
263 | m->m_off -= hlen; | |
264 | m->m_len += hlen; | |
39674d5f SL |
265 | if (icmpprintfs) |
266 | printf("icmp_send dst %x src %x\n", ip->ip_dst, ip->ip_src); | |
a1edc12b | 267 | (void) ip_output(m, (struct mbuf *)0, (struct route *)0, 0); |
d52566dd BJ |
268 | } |
269 | ||
cdad2eb1 | 270 | n_time |
2b4b57cd | 271 | iptime() |
d52566dd | 272 | { |
cdad2eb1 | 273 | int s = spl6(); |
2752c877 | 274 | u_long t; |
d52566dd | 275 | |
b2ac7f3b | 276 | t = (time.tv_sec % (24*60*60)) * 1000 + time.tv_usec / 1000; |
cdad2eb1 BJ |
277 | splx(s); |
278 | return (htonl(t)); | |
d52566dd | 279 | } |