net.c revision 346477 
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 * 4. 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: stable/11/stand/libsa/net.c 346477 2019-04-21 03:43:27Z kevans $");
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/ip.h>
52#include <netinet/ip_var.h>
53#include <netinet/udp.h>
54#include <netinet/udp_var.h>
55
56#include "stand.h"
57#include "net.h"
58
59/*
60 * Maximum wait time for sending and receiving before we give up and timeout.
61 * If set to 0, operations will eventually timeout completely, but send/recv
62 * timeouts must progress exponentially from MINTMO to MAXTMO before final
63 * timeout is hit.
64 */
65#ifndef MAXWAIT
66#define MAXWAIT 0	/* seconds */
67#endif
68
69#if MAXWAIT < 0
70#error MAXWAIT must not be a negative number
71#endif
72
73/*
74 * Send a packet and wait for a reply, with exponential backoff.
75 *
76 * The send routine must return the actual number of bytes written,
77 * or -1 on error.
78 *
79 * The receive routine can indicate success by returning the number of
80 * bytes read; it can return 0 to indicate EOF; it can return -1 with a
81 * non-zero errno to indicate failure; finally, it can return -1 with a
82 * zero errno to indicate it isn't done yet.
83 */
84ssize_t
85sendrecv(struct iodesc *d,
86    ssize_t (*sproc)(struct iodesc *, void *, size_t),
87    void *sbuf, size_t ssize,
88    ssize_t (*rproc)(struct iodesc *, void **, void **, time_t, void *),
89    void **pkt, void **payload, void *recv_extra)
90{
91	ssize_t cc;
92	time_t t, tmo, tlast;
93	time_t tref;
94	long tleft;
95
96#ifdef NET_DEBUG
97	if (debug)
98		printf("sendrecv: called\n");
99#endif
100
101	tmo = MINTMO;
102	tlast = 0;
103	tleft = 0;
104	tref = getsecs();
105	t = getsecs();
106	for (;;) {
107		if (MAXWAIT > 0 && (getsecs() - tref) >= MAXWAIT) {
108			errno = ETIMEDOUT;
109			return -1;
110		}
111		if (tleft <= 0) {
112			if (tmo >= MAXTMO) {
113				errno = ETIMEDOUT;
114				return -1;
115			}
116			cc = (*sproc)(d, sbuf, ssize);
117			if (cc != -1 && cc < ssize)
118				panic("sendrecv: short write! (%zd < %zd)",
119				    cc, ssize);
120
121			tleft = tmo;
122			tmo += MINTMO;
123			if (tmo > MAXTMO)
124				tmo = MAXTMO;
125
126			if (cc == -1) {
127				/* Error on transmit; wait before retrying */
128				while ((getsecs() - t) < tmo)
129					;
130				tleft = 0;
131				continue;
132			}
133
134			tlast = t;
135		}
136
137		/* Try to get a packet and process it. */
138		cc = (*rproc)(d, pkt, payload, tleft, recv_extra);
139		/* Return on data, EOF or real error. */
140		if (cc != -1 || (errno != 0 && errno != ETIMEDOUT))
141			return (cc);
142
143		/* Timed out or didn't get the packet we're waiting for */
144		t = getsecs();
145		tleft -= t - tlast;
146		tlast = t;
147	}
148}
149
150/*
151 * Like inet_addr() in the C library, but we only accept base-10.
152 * Return values are in network order.
153 */
154n_long
155inet_addr(char *cp)
156{
157	u_long val;
158	int n;
159	char c;
160	u_int parts[4];
161	u_int *pp = parts;
162
163	for (;;) {
164		/*
165		 * Collect number up to ``.''.
166		 * Values are specified as for C:
167		 * 0x=hex, 0=octal, other=decimal.
168		 */
169		val = 0;
170		while ((c = *cp) != '\0') {
171			if (c >= '0' && c <= '9') {
172				val = (val * 10) + (c - '0');
173				cp++;
174				continue;
175			}
176			break;
177		}
178		if (*cp == '.') {
179			/*
180			 * Internet format:
181			 *	a.b.c.d
182			 *	a.b.c	(with c treated as 16-bits)
183			 *	a.b	(with b treated as 24 bits)
184			 */
185			if (pp >= parts + 3 || val > 0xff)
186				goto bad;
187			*pp++ = val, cp++;
188		} else
189			break;
190	}
191	/*
192	 * Check for trailing characters.
193	 */
194	if (*cp != '\0')
195		goto bad;
196
197	/*
198	 * Concoct the address according to
199	 * the number of parts specified.
200	 */
201	n = pp - parts + 1;
202	switch (n) {
203
204	case 1:				/* a -- 32 bits */
205		break;
206
207	case 2:				/* a.b -- 8.24 bits */
208		if (val > 0xffffff)
209			goto bad;
210		val |= parts[0] << 24;
211		break;
212
213	case 3:				/* a.b.c -- 8.8.16 bits */
214		if (val > 0xffff)
215			goto bad;
216		val |= (parts[0] << 24) | (parts[1] << 16);
217		break;
218
219	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
220		if (val > 0xff)
221			goto bad;
222		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
223		break;
224	}
225
226	return (htonl(val));
227 bad:
228	return (htonl(INADDR_NONE));
229}
230
231char *
232inet_ntoa(struct in_addr ia)
233{
234	return (intoa(ia.s_addr));
235}
236
237/* Similar to inet_ntoa() */
238char *
239intoa(n_long addr)
240{
241	char *cp;
242	u_int byte;
243	int n;
244	static char buf[17];	/* strlen(".255.255.255.255") + 1 */
245
246	addr = ntohl(addr);
247	cp = &buf[sizeof buf];
248	*--cp = '\0';
249
250	n = 4;
251	do {
252		byte = addr & 0xff;
253		*--cp = byte % 10 + '0';
254		byte /= 10;
255		if (byte > 0) {
256			*--cp = byte % 10 + '0';
257			byte /= 10;
258			if (byte > 0)
259				*--cp = byte + '0';
260		}
261		*--cp = '.';
262		addr >>= 8;
263	} while (--n > 0);
264
265	return (cp+1);
266}
267
268static char *
269number(char *s, n_long *n)
270{
271	for (*n = 0; isdigit(*s); s++)
272		*n = (*n * 10) + *s - '0';
273	return s;
274}
275
276n_long
277ip_convertaddr(char *p)
278{
279#define IP_ANYADDR	0
280	n_long addr = 0, n;
281
282	if (p == NULL || *p == '\0')
283		return IP_ANYADDR;
284	p = number(p, &n);
285	addr |= (n << 24) & 0xff000000;
286	if (*p == '\0' || *p++ != '.')
287		return IP_ANYADDR;
288	p = number(p, &n);
289	addr |= (n << 16) & 0xff0000;
290	if (*p == '\0' || *p++ != '.')
291		return IP_ANYADDR;
292	p = number(p, &n);
293	addr |= (n << 8) & 0xff00;
294	if (*p == '\0' || *p++ != '.')
295		return IP_ANYADDR;
296	p = number(p, &n);
297	addr |= n & 0xff;
298	if (*p != '\0')
299		return IP_ANYADDR;
300
301	return htonl(addr);
302}
303