net.c revision 1.1 1 /*
2 * Copyright (c) 1992 Regents of the University of California.
3 * All rights reserved.
4 *
5 * This software was developed by the Computer Systems Engineering group
6 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
7 * contributed to Berkeley.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Lawrence Berkeley Laboratory and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * from @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp (LBL)
38 */
39
40 #include <sys/param.h>
41 #include <sys/socket.h>
42
43 #include <string.h>
44
45 #include <net/if.h>
46
47 #include <netinet/in.h>
48 #include <netinet/if_ether.h>
49 #include <netinet/in_systm.h>
50 #include <netinet/ip.h>
51 #include <netinet/ip_var.h>
52 #include <netinet/udp.h>
53 #include <netinet/udp_var.h>
54
55 #include <errno.h>
56
57 #include "stand.h"
58 #include "net.h"
59 #include "netif.h"
60
61 n_long myip;
62
63 /* Caller must leave room for ethernet, ip and udp headers in front!! */
64 int
65 sendudp(d, buf, len)
66 register struct iodesc *d;
67 register void *buf;
68 register int len;
69 {
70 register int cc;
71 register struct ip *ip;
72 register struct udpiphdr *ui;
73 register struct udphdr *uh;
74 register u_char *ea;
75 struct ip tip;
76
77 #ifdef NET_DEBUG
78 if (debug) {
79 printf("sendudp: d=%x called.\n", (u_int)d);
80 if (d) {
81 printf("saddr: %s:%d",
82 intoa(d->myip), d->myport);
83 printf(" daddr: %s:%d\n",
84 intoa(d->destip), d->destport);
85 }
86 }
87 #endif
88 uh = ((struct udphdr *)buf) - 1;
89 ip = ((struct ip *)uh) - 1;
90 len += sizeof(*ip) + sizeof(*uh);
91
92 bzero(ip, sizeof(*ip) + sizeof(*uh));
93
94 ip->ip_v = IPVERSION; /* half-char */
95 ip->ip_hl = sizeof(*ip) >> 2; /* half-char */
96 ip->ip_len = htons(len);
97 ip->ip_p = IPPROTO_UDP; /* char */
98 ip->ip_ttl = IP_TTL; /* char */
99 ip->ip_src.s_addr = htonl(d->myip);
100 ip->ip_dst.s_addr = htonl(d->destip);
101 ip->ip_sum = in_cksum(ip, sizeof(*ip)); /* short, but special */
102
103 uh->uh_sport = htons(d->myport);
104 uh->uh_dport = htons(d->destport);
105 uh->uh_ulen = htons(len - sizeof(*ip));
106
107 /* Calculate checksum (must save and restore ip header) */
108 tip = *ip;
109 ui = (struct udpiphdr *)ip;
110 ui->ui_next = 0;
111 ui->ui_prev = 0;
112 ui->ui_x1 = 0;
113 ui->ui_len = uh->uh_ulen;
114 uh->uh_sum = in_cksum(ui, len);
115 *ip = tip;
116
117 if (ip->ip_dst.s_addr == INADDR_BROADCAST || ip->ip_src.s_addr == 0 ||
118 mask == 0 || SAMENET(ip->ip_src.s_addr, ip->ip_dst.s_addr, mask))
119 ea = arpwhohas(d, ip->ip_dst.s_addr);
120 else
121 ea = arpwhohas(d, htonl(gateip));
122
123 cc = sendether(d, ip, len, ea, ETHERTYPE_IP);
124 if (cc < 0)
125 return (cc);
126 if (cc != len)
127 panic("sendudp: bad write (%d != %d)", cc, len);
128 return (cc - (sizeof(*ip) + sizeof(*uh)));
129 }
130
131 /* Check that packet is a valid udp packet for us */
132 void *
133 checkudp(d, pkt, lenp)
134 register struct iodesc *d;
135 register void *pkt;
136 register int *lenp;
137 {
138 register int hlen, len;
139 register struct ether_header *eh;
140 register struct ip *ip;
141 register struct udphdr *uh;
142 register struct udpiphdr *ui;
143 struct ip tip;
144
145 #ifdef NET_DEBUG
146 if (debug)
147 printf("checkudp: called\n");
148 #endif
149 eh = pkt;
150 ip = (struct ip *)(eh + 1);
151 uh = (struct udphdr *)(ip + 1);
152
153 /* Must be to us */
154 if (bcmp(d->myea, eh->ether_dhost, 6) != 0 && /* by byte */
155 bcmp(bcea, eh->ether_dhost, 6) != 0) { /* by byte */
156 #ifdef NET_DEBUG
157 if (debug)
158 printf("checkudp: not ours. myea=%s bcea=%s\n",
159 ether_sprintf(d->myea), ether_sprintf(bcea));
160 #endif
161 return (NULL);
162 }
163
164 /* And ip */
165 if (ntohs(eh->ether_type) != ETHERTYPE_IP) {
166 #ifdef NET_DEBUG
167 if (debug)
168 printf("checkudp: not IP. ether_type=%x\n", eh->ether_type);
169 #endif
170 return (NULL);
171 }
172
173 /* Check ip header */
174 if (ip->ip_v != IPVERSION || ip->ip_p != IPPROTO_UDP) { /* half char */
175 #ifdef NET_DEBUG
176 if (debug)
177 printf("checkudp: IP version or not UDP. ip_v=%d ip_p=%d\n", ip->ip_v, ip->ip_p);
178 #endif
179 return (NULL);
180 }
181
182 hlen = ip->ip_hl << 2;
183 if (hlen < sizeof(*ip) || in_cksum(ip, hlen) != 0) {
184 #ifdef NET_DEBUG
185 if (debug)
186 printf("checkudp: short hdr or bad cksum.\n");
187 #endif
188 return (NULL);
189 }
190 NTOHS(ip->ip_len);
191 if (*lenp - sizeof(*eh) < ip->ip_len) {
192 #ifdef NET_DEBUG
193 if (debug)
194 printf("checkudp: bad length %d < %d.\n",
195 *lenp - sizeof(*eh), ip->ip_len);
196 #endif
197 return (NULL);
198 }
199 if (d->myip && ntohl(ip->ip_dst.s_addr) != d->myip) {
200 #ifdef NET_DEBUG
201 if (debug) {
202 printf("checkudp: bad saddr %s != ",
203 intoa(d->myip));
204 printf("%s\n",
205 intoa(ntohl(ip->ip_dst.s_addr)));
206 }
207 #endif
208 return (NULL);
209 }
210
211 /* If there were ip options, make them go away */
212 if (hlen != sizeof(*ip)) {
213 bcopy(((u_char *)ip) + hlen, uh,
214 *lenp - (sizeof(*eh) + hlen));
215 ip->ip_len = sizeof(*ip);
216 *lenp -= hlen - sizeof(*ip);
217 }
218 if (ntohs(uh->uh_dport) != d->myport) {
219 #ifdef NET_DEBUG
220 if (debug)
221 printf("checkudp: bad dport %d != %d\n",
222 d->myport, ntohs(uh->uh_dport));
223 #endif
224 return (NULL);
225 }
226
227 if (uh->uh_sum) {
228 len = ntohs(uh->uh_ulen);
229 if (len > RECV_SIZE - (sizeof(*eh) + sizeof(*ip))) {
230 printf("checkudp: huge packet, udp len %d\n", len);
231 return (NULL);
232 }
233
234 /* Check checksum (must save and restore ip header) */
235 tip = *ip;
236 ui = (struct udpiphdr *)ip;
237 ui->ui_next = 0;
238 ui->ui_prev = 0;
239 ui->ui_x1 = 0;
240 ui->ui_len = uh->uh_ulen;
241 if (in_cksum(ui, len + sizeof(*ip)) != 0) {
242 #ifdef NET_DEBUG
243 if (debug)
244 printf("checkudp: bad cksum\n");
245 #endif
246 *ip = tip;
247 return (NULL);
248 }
249 *ip = tip;
250 }
251 NTOHS(uh->uh_dport);
252 NTOHS(uh->uh_sport);
253 NTOHS(uh->uh_ulen);
254 if (uh->uh_ulen < sizeof(*uh)) {
255 #ifdef NET_DEBUG
256 if (debug)
257 printf("checkudp: bad udp len %d < %d\n",
258 uh->uh_ulen, sizeof(*uh));
259 #endif
260 return (NULL);
261 }
262 *lenp -= sizeof(*eh) + sizeof(*ip) + sizeof(*uh);
263 return (uh + 1);
264 }
265
266 /*
267 * Send a packet and wait for a reply, with exponential backoff.
268 *
269 * The send routine must return the actual number of bytes written.
270 *
271 * The receive routine can indicate success by returning the number of
272 * bytes read; it can return 0 to indicate EOF; it can return -1 with a
273 * non-zero errno to indicate failure; finally, it can return -1 with a
274 * zero errno to indicate it isn't done yet.
275 */
276 int
277 sendrecv(d, sproc, sbuf, ssize, rproc, rbuf, rsize)
278 register struct iodesc *d;
279 register int (*sproc)(struct iodesc *, void *, int);
280 register void *sbuf;
281 register int ssize;
282 register int (*rproc)(struct iodesc *, void *, int);
283 register void *rbuf;
284 register int rsize;
285 {
286 register int cc;
287 register time_t t, tmo, tlast, tleft;
288
289 #ifdef NET_DEBUG
290 if (debug)
291 printf("sendrecv: called\n");
292 #endif
293 tmo = MINTMO;
294 tlast = tleft = 0;
295 t = getsecs();
296 for (;;) {
297 if (tleft <= 0) {
298 cc = (*sproc)(d, sbuf, ssize);
299 if (cc < ssize)
300 panic("sendrecv: short write! (%d < %d)",
301 cc, ssize);
302
303 tleft = tmo;
304 tmo <<= 1;
305 if (tmo > MAXTMO)
306 tmo = MAXTMO;
307 tlast = t;
308 }
309
310 cc = netif_get(d, rbuf, rsize, tleft);
311 if (cc >= 0) {
312 /* Got a packet, process it */
313 cc = (*rproc)(d, rbuf, cc);
314 /* Return on data, EOF or real error */
315 if (cc >= 0 || errno != 0)
316 return (cc);
317 }
318 /* Timed out or didn't get the packet we're waiting for */
319 t = getsecs();
320 tleft -= t - tlast;
321 tlast = t;
322 }
323 }
324
325 /* Similar to inet_ntoa() */
326 char *
327 intoa(addr)
328 n_long addr;
329 {
330 register char *cp;
331 register u_int byte;
332 register int n;
333 static char buf[17]; /* strlen(".255.255.255.255") + 1 */
334
335 cp = &buf[sizeof buf];
336 *--cp = '\0';
337
338 n = 4;
339 do {
340 byte = addr & 0xff;
341 *--cp = byte % 10 + '0';
342 byte /= 10;
343 if (byte > 0) {
344 *--cp = byte % 10 + '0';
345 byte /= 10;
346 if (byte > 0)
347 *--cp = byte + '0';
348 }
349 *--cp = '.';
350 addr >>= 8;
351 } while (--n > 0);
352
353 return (cp+1);
354 }
355
356 static char *
357 number(s, n)
358 char *s;
359 int *n;
360 {
361 for (*n = 0; isdigit(*s); s++)
362 *n = (*n * 10) + *s - '0';
363 return s;
364 }
365
366 n_long
367 ip_convertaddr(p)
368 char *p;
369 {
370 #define IP_ANYADDR 0
371 n_long addr = 0, n;
372
373 if (p == (char *)0 || *p == '\0')
374 return IP_ANYADDR;
375 p = number(p, &n);
376 addr |= (n << 24) & 0xff000000;
377 if (*p == '\0' || *p++ != '.')
378 return IP_ANYADDR;
379 p = number(p, &n);
380 addr |= (n << 16) & 0xff0000;
381 if (*p == '\0' || *p++ != '.')
382 return IP_ANYADDR;
383 p = number(p, &n);
384 addr |= (n << 8) & 0xff00;
385 if (*p == '\0' || *p++ != '.')
386 return IP_ANYADDR;
387 p = number(p, &n);
388 addr |= n & 0xff;
389 if (*p != '\0')
390 return IP_ANYADDR;
391
392 return ntohl(addr);
393 }
394