Commit | Line | Data |
---|---|---|
67387c9c | 1 | /* ip_icmp.c 4.16 82/05/02 */ |
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" |
cdad2eb1 | 8 | #include "../h/clock.h" |
8a13b737 BJ |
9 | #include "../net/in.h" |
10 | #include "../net/in_systm.h" | |
d52566dd BJ |
11 | #include "../net/ip.h" |
12 | #include "../net/ip_icmp.h" | |
81a36a8d BJ |
13 | |
14 | /* | |
15 | * ICMP routines: error generation, receive packet processing, and | |
16 | * routines to turnaround packets back to the originator, and | |
17 | * host table maintenance routines. | |
18 | */ | |
67387c9c | 19 | int icmpprintfs = 0; |
81a36a8d BJ |
20 | |
21 | /* | |
72e4f44e SL |
22 | * Generate an error packet of type error |
23 | * in response to bad packet ip. | |
81a36a8d BJ |
24 | */ |
25 | icmp_error(oip, type, code) | |
26 | struct ip *oip; | |
72e4f44e | 27 | int type, code; |
81a36a8d | 28 | { |
72e4f44e SL |
29 | register unsigned oiplen = oip->ip_hl << 2; |
30 | register struct icmp *icp; | |
81a36a8d BJ |
31 | struct mbuf *m; |
32 | struct ip *nip; | |
8a13b737 | 33 | COUNT(ICMP_ERROR); |
81a36a8d | 34 | |
39674d5f SL |
35 | if (icmpprintfs) |
36 | printf("icmp_error(%x, %d, %d)\n", oip, type, code); | |
81a36a8d BJ |
37 | /* |
38 | * Make sure that the old IP packet had 8 bytes of data to return; | |
39 | * if not, don't bother. Also don't EVER error if the old | |
40 | * packet protocol was ICMP. | |
41 | */ | |
39674d5f | 42 | if (oip->ip_len < 8 || oip->ip_p == IPPROTO_ICMP) |
81a36a8d BJ |
43 | goto free; |
44 | ||
45 | /* | |
72e4f44e | 46 | * First, formulate icmp message |
81a36a8d | 47 | */ |
ef9b4258 | 48 | m = m_get(M_DONTWAIT); |
81a36a8d BJ |
49 | if (m == 0) |
50 | goto free; | |
72e4f44e SL |
51 | m->m_len = oiplen + 8 + ICMP_MINLEN; |
52 | m->m_off = MMAXOFF - m->m_len; | |
53 | icp = mtod(m, struct icmp *); | |
81a36a8d | 54 | icp->icmp_type = type; |
72e4f44e | 55 | icp->icmp_void = 0; |
81a36a8d | 56 | if (type == ICMP_PARAMPROB) { |
81a36a8d | 57 | icp->icmp_pptr = code; |
72e4f44e SL |
58 | code = 0; |
59 | } | |
60 | icp->icmp_code = code; | |
d52566dd | 61 | bcopy((caddr_t)oip, (caddr_t)&icp->icmp_ip, oiplen + 8); |
39674d5f SL |
62 | nip = &icp->icmp_ip; |
63 | nip->ip_len += oiplen; | |
64 | #if vax || pdp11 | |
65 | nip->ip_len = htons((u_short)nip->ip_len); | |
66 | #endif | |
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 *); |
39674d5f | 107 | int icmplen = ip->ip_len, hlen = ip->ip_hl << 2, i, (*ctlfunc)(); |
b454c3ea | 108 | extern u_char ip_protox[]; |
8a13b737 | 109 | COUNT(ICMP_INPUT); |
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 | */ | |
39674d5f SL |
147 | #if vax || pdp11 |
148 | icp->icmp_ip.ip_len = ntohs(icp->icmp_ip.ip_len); | |
149 | #endif | |
d52566dd BJ |
150 | if (icmplen < ICMP_ADVLENMIN || icmplen < ICMP_ADVLEN(icp)) |
151 | goto free; | |
39674d5f SL |
152 | if (icmpprintfs) |
153 | printf("deliver to protocol %d\n", icp->icmp_ip.ip_p); | |
154 | if (ctlfunc = protosw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput) | |
155 | (*ctlfunc)(icmpmap[i] + icp->icmp_code, (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: | |
189 | icmp_reflect(ip); | |
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; |
8a13b737 | 202 | COUNT(ICMP_REFLECT); |
81a36a8d | 203 | |
72e4f44e SL |
204 | t = ip->ip_dst; |
205 | ip->ip_dst = ip->ip_src; | |
206 | ip->ip_src = t; | |
81a36a8d BJ |
207 | icmp_send(ip); |
208 | } | |
209 | ||
67387c9c | 210 | int generateicmpmsgs = 1; |
72e4f44e | 211 | |
81a36a8d | 212 | /* |
72e4f44e SL |
213 | * Send an icmp packet back to the ip level, |
214 | * after supplying a checksum. | |
81a36a8d | 215 | */ |
cdad2eb1 | 216 | icmp_send(ip) |
81a36a8d | 217 | struct ip *ip; |
81a36a8d | 218 | { |
72e4f44e SL |
219 | register int hlen = ip->ip_hl << 2; |
220 | register struct icmp *icp; | |
221 | register struct mbuf *m = dtom(ip); | |
d52566dd | 222 | |
72e4f44e SL |
223 | COUNT(ICMP_SEND); |
224 | if (!generateicmpmsgs) | |
225 | return; | |
226 | icp = mtod(m, struct icmp *); | |
227 | icp->icmp_cksum = 0; | |
228 | icp->icmp_cksum = in_cksum(m, ip->ip_len - hlen); | |
229 | m->m_off -= hlen; | |
230 | m->m_len += hlen; | |
39674d5f SL |
231 | if (icmpprintfs) |
232 | printf("icmp_send dst %x src %x\n", ip->ip_dst, ip->ip_src); | |
72e4f44e | 233 | (void) ip_output(m, 0, 0, 0); |
d52566dd BJ |
234 | } |
235 | ||
cdad2eb1 | 236 | n_time |
2b4b57cd | 237 | iptime() |
d52566dd | 238 | { |
cdad2eb1 | 239 | int s = spl6(); |
2752c877 | 240 | u_long t; |
d52566dd | 241 | |
8a13b737 | 242 | COUNT(IPTIME); |
cdad2eb1 BJ |
243 | t = (time % SECDAY) * 1000 + lbolt * hz; |
244 | splx(s); | |
245 | return (htonl(t)); | |
d52566dd | 246 | } |