Commit | Line | Data |
---|---|---|
cce93e4b | 1 | /* ip_icmp.c 4.26 82/12/14 */ |
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" |
6e7edb25 BJ |
8 | #include <time.h> |
9 | #include "../h/kernel.h" | |
10 | ||
11 | #include "../net/route.h" | |
fcfe450e BJ |
12 | #include "../netinet/in.h" |
13 | #include "../netinet/in_systm.h" | |
14 | #include "../netinet/ip.h" | |
15 | #include "../netinet/ip_icmp.h" | |
81a36a8d BJ |
16 | |
17 | /* | |
18 | * ICMP routines: error generation, receive packet processing, and | |
19 | * routines to turnaround packets back to the originator, and | |
20 | * host table maintenance routines. | |
21 | */ | |
67387c9c | 22 | int icmpprintfs = 0; |
81a36a8d BJ |
23 | |
24 | /* | |
72e4f44e SL |
25 | * Generate an error packet of type error |
26 | * in response to bad packet ip. | |
81a36a8d BJ |
27 | */ |
28 | icmp_error(oip, type, code) | |
29 | struct ip *oip; | |
72e4f44e | 30 | int type, code; |
81a36a8d | 31 | { |
72e4f44e SL |
32 | register unsigned oiplen = oip->ip_hl << 2; |
33 | register struct icmp *icp; | |
81a36a8d BJ |
34 | struct mbuf *m; |
35 | struct ip *nip; | |
36 | ||
39674d5f SL |
37 | if (icmpprintfs) |
38 | printf("icmp_error(%x, %d, %d)\n", oip, type, code); | |
81a36a8d BJ |
39 | /* |
40 | * Make sure that the old IP packet had 8 bytes of data to return; | |
41 | * if not, don't bother. Also don't EVER error if the old | |
42 | * packet protocol was ICMP. | |
43 | */ | |
39674d5f | 44 | if (oip->ip_len < 8 || oip->ip_p == IPPROTO_ICMP) |
81a36a8d BJ |
45 | goto free; |
46 | ||
47 | /* | |
72e4f44e | 48 | * First, formulate icmp message |
81a36a8d | 49 | */ |
cce93e4b | 50 | m = m_get(M_DONTWAIT, MT_HEADER); |
81a36a8d BJ |
51 | if (m == 0) |
52 | goto free; | |
72e4f44e SL |
53 | m->m_len = oiplen + 8 + ICMP_MINLEN; |
54 | m->m_off = MMAXOFF - m->m_len; | |
55 | icp = mtod(m, struct icmp *); | |
81a36a8d | 56 | icp->icmp_type = type; |
72e4f44e | 57 | icp->icmp_void = 0; |
81a36a8d | 58 | if (type == ICMP_PARAMPROB) { |
81a36a8d | 59 | icp->icmp_pptr = code; |
72e4f44e SL |
60 | code = 0; |
61 | } | |
62 | icp->icmp_code = code; | |
d52566dd | 63 | bcopy((caddr_t)oip, (caddr_t)&icp->icmp_ip, oiplen + 8); |
39674d5f SL |
64 | nip = &icp->icmp_ip; |
65 | nip->ip_len += oiplen; | |
39674d5f | 66 | nip->ip_len = htons((u_short)nip->ip_len); |
81a36a8d BJ |
67 | |
68 | /* | |
72e4f44e SL |
69 | * Now, copy old ip header in front of icmp |
70 | * message. This allows us to reuse any source | |
71 | * routing info present. | |
81a36a8d | 72 | */ |
72e4f44e SL |
73 | m->m_off -= oiplen; |
74 | nip = mtod(m, struct ip *); | |
75 | bcopy((caddr_t)oip, (caddr_t)nip, oiplen); | |
76 | nip->ip_len = m->m_len + oiplen; | |
77 | nip->ip_p = IPPROTO_ICMP; | |
78 | /* icmp_send adds ip header to m_off and m_len, so we deduct here */ | |
79 | m->m_off += oiplen; | |
d52566dd | 80 | icmp_reflect(nip); |
81a36a8d | 81 | |
def04636 | 82 | free: |
81a36a8d BJ |
83 | m_freem(dtom(oip)); |
84 | } | |
85 | ||
72e4f44e SL |
86 | static char icmpmap[] = { |
87 | -1, -1, -1, | |
88 | PRC_UNREACH_NET, PRC_QUENCH, PRC_REDIRECT_NET, | |
89 | -1, -1, -1, | |
90 | -1, -1, PRC_TIMXCEED_INTRANS, | |
91 | PRC_PARAMPROB, -1, -1, | |
92 | -1, -1 | |
93 | }; | |
94 | ||
95 | static struct sockproto icmproto = { AF_INET, IPPROTO_ICMP }; | |
96 | static struct sockaddr_in icmpsrc = { AF_INET }; | |
97 | static struct sockaddr_in icmpdst = { AF_INET }; | |
98 | ||
81a36a8d | 99 | /* |
d52566dd | 100 | * Process a received ICMP message. |
81a36a8d BJ |
101 | */ |
102 | icmp_input(m) | |
103 | struct mbuf *m; | |
104 | { | |
81a36a8d | 105 | register struct icmp *icp; |
d52566dd | 106 | register struct ip *ip = mtod(m, struct ip *); |
af8f6a21 SL |
107 | int icmplen = ip->ip_len, hlen = ip->ip_hl << 2; |
108 | int i, (*ctlfunc)(), type; | |
b454c3ea | 109 | extern u_char ip_protox[]; |
81a36a8d BJ |
110 | |
111 | /* | |
112 | * Locate icmp structure in mbuf, and check | |
113 | * that not corrupted and of at least minimum length. | |
114 | */ | |
39674d5f SL |
115 | if (icmpprintfs) |
116 | printf("icmp_input from %x, len %d\n", ip->ip_src, icmplen); | |
72e4f44e SL |
117 | if (icmplen < ICMP_MINLEN) |
118 | goto free; | |
81a36a8d BJ |
119 | m->m_len -= hlen; |
120 | m->m_off += hlen; | |
121 | /* need routine to make sure header is in this mbuf here */ | |
72e4f44e | 122 | icp = mtod(m, struct icmp *); |
81a36a8d BJ |
123 | i = icp->icmp_cksum; |
124 | icp->icmp_cksum = 0; | |
72e4f44e SL |
125 | if (i != in_cksum(m, icmplen)) { |
126 | printf("icmp: cksum %x\n", i); | |
d52566dd | 127 | goto free; |
72e4f44e | 128 | } |
81a36a8d BJ |
129 | |
130 | /* | |
131 | * Message type specific processing. | |
132 | */ | |
39674d5f SL |
133 | if (icmpprintfs) |
134 | printf("icmp_input, type %d code %d\n", icp->icmp_type, | |
135 | icp->icmp_code); | |
72e4f44e | 136 | switch (i = icp->icmp_type) { |
81a36a8d BJ |
137 | |
138 | case ICMP_UNREACH: | |
139 | case ICMP_TIMXCEED: | |
140 | case ICMP_PARAMPROB: | |
81a36a8d | 141 | case ICMP_REDIRECT: |
72e4f44e | 142 | case ICMP_SOURCEQUENCH: |
81a36a8d BJ |
143 | /* |
144 | * Problem with previous datagram; advise | |
145 | * higher level routines. | |
146 | */ | |
a1edc12b | 147 | icp->icmp_ip.ip_len = ntohs((u_short)icp->icmp_ip.ip_len); |
d52566dd BJ |
148 | if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp)) |
149 | goto free; | |
39674d5f SL |
150 | if (icmpprintfs) |
151 | printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); | |
af8f6a21 | 152 | type = i == ICMP_PARAMPROB ? 0 : icp->icmp_code; |
59965020 | 153 | if (ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput) |
af8f6a21 | 154 | (*ctlfunc)(icmpmap[i] + type, (caddr_t)icp); |
81a36a8d BJ |
155 | goto free; |
156 | ||
157 | case ICMP_ECHO: | |
158 | icp->icmp_type = ICMP_ECHOREPLY; | |
159 | goto reflect; | |
160 | ||
161 | case ICMP_TSTAMP: | |
d52566dd BJ |
162 | if (icmplen < ICMP_TSLEN) |
163 | goto free; | |
81a36a8d | 164 | icp->icmp_type = ICMP_TSTAMPREPLY; |
2b4b57cd | 165 | icp->icmp_rtime = iptime(); |
81a36a8d BJ |
166 | icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ |
167 | goto reflect; | |
168 | ||
169 | case ICMP_IREQ: | |
170 | /* fill in source address zero fields! */ | |
171 | goto reflect; | |
172 | ||
173 | case ICMP_ECHOREPLY: | |
174 | case ICMP_TSTAMPREPLY: | |
175 | case ICMP_IREQREPLY: | |
d52566dd BJ |
176 | if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp)) |
177 | goto free; | |
72e4f44e SL |
178 | icmpsrc.sin_addr = ip->ip_src; |
179 | icmpdst.sin_addr = ip->ip_dst; | |
180 | raw_input(dtom(icp), &icmproto, (struct sockaddr *)&icmpsrc, | |
181 | (struct sockaddr *)&icmpdst); | |
81a36a8d BJ |
182 | goto free; |
183 | ||
184 | default: | |
185 | goto free; | |
186 | } | |
187 | reflect: | |
188 | icmp_reflect(ip); | |
af8f6a21 | 189 | return; |
81a36a8d BJ |
190 | free: |
191 | m_freem(dtom(ip)); | |
192 | } | |
193 | ||
194 | /* | |
195 | * Reflect the ip packet back to the source | |
72e4f44e | 196 | * TODO: rearrange ip source routing options. |
81a36a8d BJ |
197 | */ |
198 | icmp_reflect(ip) | |
199 | struct ip *ip; | |
200 | { | |
2b4b57cd | 201 | struct in_addr t; |
81a36a8d | 202 | |
72e4f44e SL |
203 | t = ip->ip_dst; |
204 | ip->ip_dst = ip->ip_src; | |
205 | ip->ip_src = t; | |
81a36a8d BJ |
206 | icmp_send(ip); |
207 | } | |
208 | ||
209 | /* | |
72e4f44e SL |
210 | * Send an icmp packet back to the ip level, |
211 | * after supplying a checksum. | |
81a36a8d | 212 | */ |
cdad2eb1 | 213 | icmp_send(ip) |
81a36a8d | 214 | struct ip *ip; |
81a36a8d | 215 | { |
af8f6a21 | 216 | register int hlen; |
72e4f44e | 217 | register struct icmp *icp; |
af8f6a21 | 218 | register struct mbuf *m; |
d52566dd | 219 | |
af8f6a21 SL |
220 | m = dtom(ip); |
221 | hlen = ip->ip_hl << 2; | |
72e4f44e SL |
222 | icp = mtod(m, struct icmp *); |
223 | icp->icmp_cksum = 0; | |
224 | icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen); | |
225 | m->m_off -= hlen; | |
226 | m->m_len += hlen; | |
39674d5f SL |
227 | if (icmpprintfs) |
228 | printf("icmp_send dst %x src %x\n", ip->ip_dst, ip->ip_src); | |
a1edc12b | 229 | (void) ip_output(m, (struct mbuf *)0, (struct route *)0, 0); |
d52566dd BJ |
230 | } |
231 | ||
cdad2eb1 | 232 | n_time |
2b4b57cd | 233 | iptime() |
d52566dd | 234 | { |
cdad2eb1 | 235 | int s = spl6(); |
2752c877 | 236 | u_long t; |
d52566dd | 237 | |
b2ac7f3b | 238 | t = (time.tv_sec % (24*60*60)) * 1000 + time.tv_usec / 1000; |
cdad2eb1 BJ |
239 | splx(s); |
240 | return (htonl(t)); | |
d52566dd | 241 | } |