Commit | Line | Data |
---|---|---|
b012ee63 | 1 | /* ip_icmp.c 4.28 83/02/22 */ |
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" | |
81a36a8d BJ |
17 | |
18 | /* | |
19 | * ICMP routines: error generation, receive packet processing, and | |
20 | * routines to turnaround packets back to the originator, and | |
21 | * host table maintenance routines. | |
22 | */ | |
67387c9c | 23 | int icmpprintfs = 0; |
81a36a8d BJ |
24 | |
25 | /* | |
72e4f44e SL |
26 | * Generate an error packet of type error |
27 | * in response to bad packet ip. | |
81a36a8d BJ |
28 | */ |
29 | icmp_error(oip, type, code) | |
30 | struct ip *oip; | |
72e4f44e | 31 | int type, code; |
81a36a8d | 32 | { |
72e4f44e SL |
33 | register unsigned oiplen = oip->ip_hl << 2; |
34 | register struct icmp *icp; | |
81a36a8d BJ |
35 | struct mbuf *m; |
36 | struct ip *nip; | |
37 | ||
39674d5f SL |
38 | if (icmpprintfs) |
39 | printf("icmp_error(%x, %d, %d)\n", oip, type, code); | |
81a36a8d BJ |
40 | /* |
41 | * Make sure that the old IP packet had 8 bytes of data to return; | |
42 | * if not, don't bother. Also don't EVER error if the old | |
43 | * packet protocol was ICMP. | |
44 | */ | |
39674d5f | 45 | if (oip->ip_len < 8 || oip->ip_p == IPPROTO_ICMP) |
81a36a8d BJ |
46 | goto free; |
47 | ||
48 | /* | |
72e4f44e | 49 | * First, formulate icmp message |
81a36a8d | 50 | */ |
cce93e4b | 51 | m = m_get(M_DONTWAIT, MT_HEADER); |
81a36a8d BJ |
52 | if (m == 0) |
53 | goto free; | |
72e4f44e SL |
54 | m->m_len = oiplen + 8 + ICMP_MINLEN; |
55 | m->m_off = MMAXOFF - m->m_len; | |
56 | icp = mtod(m, struct icmp *); | |
81a36a8d | 57 | icp->icmp_type = type; |
72e4f44e | 58 | icp->icmp_void = 0; |
81a36a8d | 59 | if (type == ICMP_PARAMPROB) { |
81a36a8d | 60 | icp->icmp_pptr = code; |
72e4f44e SL |
61 | code = 0; |
62 | } | |
63 | icp->icmp_code = code; | |
d52566dd | 64 | bcopy((caddr_t)oip, (caddr_t)&icp->icmp_ip, oiplen + 8); |
39674d5f SL |
65 | nip = &icp->icmp_ip; |
66 | nip->ip_len += oiplen; | |
39674d5f | 67 | nip->ip_len = htons((u_short)nip->ip_len); |
81a36a8d BJ |
68 | |
69 | /* | |
72e4f44e SL |
70 | * Now, copy old ip header in front of icmp |
71 | * message. This allows us to reuse any source | |
72 | * routing info present. | |
81a36a8d | 73 | */ |
72e4f44e SL |
74 | m->m_off -= oiplen; |
75 | nip = mtod(m, struct ip *); | |
76 | bcopy((caddr_t)oip, (caddr_t)nip, oiplen); | |
77 | nip->ip_len = m->m_len + oiplen; | |
78 | nip->ip_p = IPPROTO_ICMP; | |
79 | /* icmp_send adds ip header to m_off and m_len, so we deduct here */ | |
80 | m->m_off += oiplen; | |
d52566dd | 81 | icmp_reflect(nip); |
81a36a8d | 82 | |
def04636 | 83 | free: |
81a36a8d BJ |
84 | m_freem(dtom(oip)); |
85 | } | |
86 | ||
72e4f44e SL |
87 | static char icmpmap[] = { |
88 | -1, -1, -1, | |
89 | PRC_UNREACH_NET, PRC_QUENCH, PRC_REDIRECT_NET, | |
90 | -1, -1, -1, | |
91 | -1, -1, PRC_TIMXCEED_INTRANS, | |
92 | PRC_PARAMPROB, -1, -1, | |
93 | -1, -1 | |
94 | }; | |
95 | ||
96 | static struct sockproto icmproto = { AF_INET, IPPROTO_ICMP }; | |
97 | static struct sockaddr_in icmpsrc = { AF_INET }; | |
98 | static struct sockaddr_in icmpdst = { AF_INET }; | |
99 | ||
81a36a8d | 100 | /* |
d52566dd | 101 | * Process a received ICMP message. |
81a36a8d BJ |
102 | */ |
103 | icmp_input(m) | |
104 | struct mbuf *m; | |
105 | { | |
81a36a8d | 106 | register struct icmp *icp; |
d52566dd | 107 | register struct ip *ip = mtod(m, struct ip *); |
af8f6a21 SL |
108 | int icmplen = ip->ip_len, hlen = ip->ip_hl << 2; |
109 | int i, (*ctlfunc)(), type; | |
b454c3ea | 110 | extern u_char ip_protox[]; |
81a36a8d BJ |
111 | |
112 | /* | |
113 | * Locate icmp structure in mbuf, and check | |
114 | * that not corrupted and of at least minimum length. | |
115 | */ | |
39674d5f SL |
116 | if (icmpprintfs) |
117 | printf("icmp_input from %x, len %d\n", ip->ip_src, icmplen); | |
72e4f44e SL |
118 | if (icmplen < ICMP_MINLEN) |
119 | goto free; | |
81a36a8d BJ |
120 | m->m_len -= hlen; |
121 | m->m_off += hlen; | |
122 | /* need routine to make sure header is in this mbuf here */ | |
72e4f44e | 123 | icp = mtod(m, struct icmp *); |
81a36a8d BJ |
124 | i = icp->icmp_cksum; |
125 | icp->icmp_cksum = 0; | |
72e4f44e SL |
126 | if (i != in_cksum(m, icmplen)) { |
127 | printf("icmp: cksum %x\n", i); | |
d52566dd | 128 | goto free; |
72e4f44e | 129 | } |
81a36a8d BJ |
130 | |
131 | /* | |
132 | * Message type specific processing. | |
133 | */ | |
39674d5f SL |
134 | if (icmpprintfs) |
135 | printf("icmp_input, type %d code %d\n", icp->icmp_type, | |
136 | icp->icmp_code); | |
72e4f44e | 137 | switch (i = icp->icmp_type) { |
81a36a8d BJ |
138 | |
139 | case ICMP_UNREACH: | |
140 | case ICMP_TIMXCEED: | |
141 | case ICMP_PARAMPROB: | |
81a36a8d | 142 | case ICMP_REDIRECT: |
72e4f44e | 143 | case ICMP_SOURCEQUENCH: |
81a36a8d BJ |
144 | /* |
145 | * Problem with previous datagram; advise | |
146 | * higher level routines. | |
147 | */ | |
a1edc12b | 148 | icp->icmp_ip.ip_len = ntohs((u_short)icp->icmp_ip.ip_len); |
d52566dd BJ |
149 | if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp)) |
150 | goto free; | |
39674d5f SL |
151 | if (icmpprintfs) |
152 | printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); | |
af8f6a21 | 153 | type = i == ICMP_PARAMPROB ? 0 : icp->icmp_code; |
59965020 | 154 | if (ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput) |
af8f6a21 | 155 | (*ctlfunc)(icmpmap[i] + type, (caddr_t)icp); |
81a36a8d BJ |
156 | goto free; |
157 | ||
158 | case ICMP_ECHO: | |
159 | icp->icmp_type = ICMP_ECHOREPLY; | |
160 | goto reflect; | |
161 | ||
162 | case ICMP_TSTAMP: | |
d52566dd BJ |
163 | if (icmplen < ICMP_TSLEN) |
164 | goto free; | |
81a36a8d | 165 | icp->icmp_type = ICMP_TSTAMPREPLY; |
2b4b57cd | 166 | icp->icmp_rtime = iptime(); |
81a36a8d BJ |
167 | icp->icmp_ttime = icp->icmp_rtime; /* bogus, do later! */ |
168 | goto reflect; | |
169 | ||
170 | case ICMP_IREQ: | |
171 | /* fill in source address zero fields! */ | |
172 | goto reflect; | |
173 | ||
174 | case ICMP_ECHOREPLY: | |
175 | case ICMP_TSTAMPREPLY: | |
176 | case ICMP_IREQREPLY: | |
d52566dd BJ |
177 | if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp)) |
178 | goto free; | |
72e4f44e SL |
179 | icmpsrc.sin_addr = ip->ip_src; |
180 | icmpdst.sin_addr = ip->ip_dst; | |
181 | raw_input(dtom(icp), &icmproto, (struct sockaddr *)&icmpsrc, | |
182 | (struct sockaddr *)&icmpdst); | |
81a36a8d BJ |
183 | goto free; |
184 | ||
185 | default: | |
186 | goto free; | |
187 | } | |
188 | reflect: | |
b012ee63 | 189 | ip->ip_len += hlen; /* since ip_input deducts this */ |
81a36a8d | 190 | icmp_reflect(ip); |
af8f6a21 | 191 | return; |
81a36a8d BJ |
192 | free: |
193 | m_freem(dtom(ip)); | |
194 | } | |
195 | ||
196 | /* | |
197 | * Reflect the ip packet back to the source | |
72e4f44e | 198 | * TODO: rearrange ip source routing options. |
81a36a8d BJ |
199 | */ |
200 | icmp_reflect(ip) | |
201 | struct ip *ip; | |
202 | { | |
2b4b57cd | 203 | struct in_addr t; |
81a36a8d | 204 | |
72e4f44e SL |
205 | t = ip->ip_dst; |
206 | ip->ip_dst = ip->ip_src; | |
207 | ip->ip_src = t; | |
81a36a8d BJ |
208 | icmp_send(ip); |
209 | } | |
210 | ||
211 | /* | |
72e4f44e SL |
212 | * Send an icmp packet back to the ip level, |
213 | * after supplying a checksum. | |
81a36a8d | 214 | */ |
cdad2eb1 | 215 | icmp_send(ip) |
81a36a8d | 216 | struct ip *ip; |
81a36a8d | 217 | { |
af8f6a21 | 218 | register int hlen; |
72e4f44e | 219 | register struct icmp *icp; |
af8f6a21 | 220 | register struct mbuf *m; |
d52566dd | 221 | |
af8f6a21 SL |
222 | m = dtom(ip); |
223 | hlen = ip->ip_hl << 2; | |
72e4f44e SL |
224 | icp = mtod(m, struct icmp *); |
225 | icp->icmp_cksum = 0; | |
226 | icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen); | |
227 | m->m_off -= hlen; | |
228 | m->m_len += hlen; | |
39674d5f SL |
229 | if (icmpprintfs) |
230 | printf("icmp_send dst %x src %x\n", ip->ip_dst, ip->ip_src); | |
a1edc12b | 231 | (void) ip_output(m, (struct mbuf *)0, (struct route *)0, 0); |
d52566dd BJ |
232 | } |
233 | ||
cdad2eb1 | 234 | n_time |
2b4b57cd | 235 | iptime() |
d52566dd | 236 | { |
cdad2eb1 | 237 | int s = spl6(); |
2752c877 | 238 | u_long t; |
d52566dd | 239 | |
b2ac7f3b | 240 | t = (time.tv_sec % (24*60*60)) * 1000 + time.tv_usec / 1000; |
cdad2eb1 BJ |
241 | splx(s); |
242 | return (htonl(t)); | |
d52566dd | 243 | } |