xref: /freebsd/stand/libsa/net.c (revision 74ca7bf1d4c7173d5575ba168bc4b5f6d181ff5a)
1 /*	$NetBSD: net.c,v 1.20 1997/12/26 22:41:30 scottr Exp $	*/
2 
3 /*
4  * Copyright (c) 1992 Regents of the University of California.
5  * All rights reserved.
6  *
7  * This software was developed by the Computer Systems Engineering group
8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9  * contributed to Berkeley.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp  (LBL)
36  */
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <sys/param.h>
42 #include <sys/socket.h>
43 
44 #include <string.h>
45 
46 #include <net/if.h>
47 #include <netinet/in.h>
48 #include <netinet/if_ether.h>
49 #include <netinet/in_systm.h>
50 
51 #include <netinet/in_pcb.h>
52 #include <netinet/ip.h>
53 #include <netinet/ip_var.h>
54 #include <netinet/udp.h>
55 #include <netinet/udp_var.h>
56 
57 #include "stand.h"
58 #include "net.h"
59 
60 /*
61  * Maximum wait time for sending and receiving before we give up and timeout.
62  * If set to 0, operations will eventually timeout completely, but send/recv
63  * timeouts must progress exponentially from MINTMO to MAXTMO before final
64  * timeout is hit.
65  */
66 #ifndef MAXWAIT
67 #define MAXWAIT 0	/* seconds */
68 #endif
69 
70 #if MAXWAIT < 0
71 #error MAXWAIT must not be a negative number
72 #endif
73 
74 /*
75  * Send a packet and wait for a reply, with exponential backoff.
76  *
77  * The send routine must return the actual number of bytes written,
78  * or -1 on error.
79  *
80  * The receive routine can indicate success by returning the number of
81  * bytes read; it can return 0 to indicate EOF; it can return -1 with a
82  * non-zero errno to indicate failure; finally, it can return -1 with a
83  * zero errno to indicate it isn't done yet.
84  */
85 ssize_t
86 sendrecv(struct iodesc *d,
87     ssize_t (*sproc)(struct iodesc *, void *, size_t),
88     void *sbuf, size_t ssize,
89     ssize_t (*rproc)(struct iodesc *, void **, void **, time_t, void *),
90     void **pkt, void **payload, void *recv_extra)
91 {
92 	ssize_t cc;
93 	time_t t, tmo, tlast;
94 	time_t tref;
95 	long tleft;
96 
97 #ifdef NET_DEBUG
98 	if (debug)
99 		printf("sendrecv: called\n");
100 #endif
101 
102 	tmo = MINTMO;
103 	tlast = 0;
104 	tleft = 0;
105 	tref = getsecs();
106 	t = getsecs();
107 	for (;;) {
108 		if (MAXWAIT > 0 && (getsecs() - tref) >= MAXWAIT) {
109 			errno = ETIMEDOUT;
110 			return -1;
111 		}
112 		if (tleft <= 0) {
113 			if (tmo >= MAXTMO) {
114 				errno = ETIMEDOUT;
115 				return -1;
116 			}
117 			cc = (*sproc)(d, sbuf, ssize);
118 			if (cc != -1 && cc < ssize)
119 				panic("sendrecv: short write! (%zd < %zd)",
120 				    cc, ssize);
121 
122 			tleft = tmo;
123 			tmo += MINTMO;
124 			if (tmo > MAXTMO)
125 				tmo = MAXTMO;
126 
127 			if (cc == -1) {
128 				/* Error on transmit; wait before retrying */
129 				while ((getsecs() - t) < tmo)
130 					;
131 				tleft = 0;
132 				continue;
133 			}
134 
135 			tlast = t;
136 		}
137 
138 		/* Try to get a packet and process it. */
139 		cc = (*rproc)(d, pkt, payload, tleft, recv_extra);
140 		/* Return on data, EOF or real error. */
141 		if (cc != -1 || (errno != 0 && errno != ETIMEDOUT))
142 			return (cc);
143 
144 		/* Timed out or didn't get the packet we're waiting for */
145 		t = getsecs();
146 		tleft -= t - tlast;
147 		tlast = t;
148 	}
149 }
150 
151 /*
152  * Like inet_addr() in the C library, but we only accept base-10.
153  * Return values are in network order.
154  */
155 n_long
156 inet_addr(char *cp)
157 {
158 	u_long val;
159 	int n;
160 	char c;
161 	u_int parts[4];
162 	u_int *pp = parts;
163 
164 	for (;;) {
165 		/*
166 		 * Collect number up to ``.''.
167 		 * Values are specified as for C:
168 		 * 0x=hex, 0=octal, other=decimal.
169 		 */
170 		val = 0;
171 		while ((c = *cp) != '\0') {
172 			if (c >= '0' && c <= '9') {
173 				val = (val * 10) + (c - '0');
174 				cp++;
175 				continue;
176 			}
177 			break;
178 		}
179 		if (*cp == '.') {
180 			/*
181 			 * Internet format:
182 			 *	a.b.c.d
183 			 *	a.b.c	(with c treated as 16-bits)
184 			 *	a.b	(with b treated as 24 bits)
185 			 */
186 			if (pp >= parts + 3 || val > 0xff)
187 				goto bad;
188 			*pp++ = val, cp++;
189 		} else
190 			break;
191 	}
192 	/*
193 	 * Check for trailing characters.
194 	 */
195 	if (*cp != '\0')
196 		goto bad;
197 
198 	/*
199 	 * Concoct the address according to
200 	 * the number of parts specified.
201 	 */
202 	n = pp - parts + 1;
203 	switch (n) {
204 
205 	case 1:				/* a -- 32 bits */
206 		break;
207 
208 	case 2:				/* a.b -- 8.24 bits */
209 		if (val > 0xffffff)
210 			goto bad;
211 		val |= parts[0] << 24;
212 		break;
213 
214 	case 3:				/* a.b.c -- 8.8.16 bits */
215 		if (val > 0xffff)
216 			goto bad;
217 		val |= (parts[0] << 24) | (parts[1] << 16);
218 		break;
219 
220 	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
221 		if (val > 0xff)
222 			goto bad;
223 		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
224 		break;
225 	}
226 
227 	return (htonl(val));
228  bad:
229 	return (htonl(INADDR_NONE));
230 }
231 
232 char *
233 inet_ntoa(struct in_addr ia)
234 {
235 	return (intoa(ia.s_addr));
236 }
237 
238 /* Similar to inet_ntoa() */
239 char *
240 intoa(n_long addr)
241 {
242 	char *cp;
243 	u_int byte;
244 	int n;
245 	static char buf[17];	/* strlen(".255.255.255.255") + 1 */
246 
247 	addr = ntohl(addr);
248 	cp = &buf[sizeof buf];
249 	*--cp = '\0';
250 
251 	n = 4;
252 	do {
253 		byte = addr & 0xff;
254 		*--cp = byte % 10 + '0';
255 		byte /= 10;
256 		if (byte > 0) {
257 			*--cp = byte % 10 + '0';
258 			byte /= 10;
259 			if (byte > 0)
260 				*--cp = byte + '0';
261 		}
262 		*--cp = '.';
263 		addr >>= 8;
264 	} while (--n > 0);
265 
266 	return (cp+1);
267 }
268 
269 static char *
270 number(char *s, int *n)
271 {
272 	for (*n = 0; isdigit(*s); s++)
273 		*n = (*n * 10) + *s - '0';
274 	return s;
275 }
276 
277 n_long
278 ip_convertaddr(char *p)
279 {
280 #define IP_ANYADDR	0
281 	n_long addr = 0, n;
282 
283 	if (p == (char *)0 || *p == '\0')
284 		return IP_ANYADDR;
285 	p = number(p, &n);
286 	addr |= (n << 24) & 0xff000000;
287 	if (*p == '\0' || *p++ != '.')
288 		return IP_ANYADDR;
289 	p = number(p, &n);
290 	addr |= (n << 16) & 0xff0000;
291 	if (*p == '\0' || *p++ != '.')
292 		return IP_ANYADDR;
293 	p = number(p, &n);
294 	addr |= (n << 8) & 0xff00;
295 	if (*p == '\0' || *p++ != '.')
296 		return IP_ANYADDR;
297 	p = number(p, &n);
298 	addr |= n & 0xff;
299 	if (*p != '\0')
300 		return IP_ANYADDR;
301 
302 	return htonl(addr);
303 }
304