net.c revision 197178 
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: head/lib/libstand/net.c 197178 2009-09-13 21:51:01Z emaste $");
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 * Send a packet and wait for a reply, with exponential backoff.
61 *
62 * The send routine must return the actual number of bytes written,
63 * or -1 on error.
64 *
65 * The receive routine can indicate success by returning the number of
66 * bytes read; it can return 0 to indicate EOF; it can return -1 with a
67 * non-zero errno to indicate failure; finally, it can return -1 with a
68 * zero errno to indicate it isn't done yet.
69 */
70ssize_t
71sendrecv(struct iodesc *d,
72	ssize_t (*sproc)(struct iodesc *, void *, size_t),
73	void *sbuf, size_t ssize,
74	ssize_t (*rproc)(struct iodesc *, void *, size_t, time_t),
75	void *rbuf, size_t rsize)
76{
77	ssize_t cc;
78	time_t t, tmo, tlast;
79	long tleft;
80
81#ifdef NET_DEBUG
82	if (debug)
83		printf("sendrecv: called\n");
84#endif
85
86	tmo = MINTMO;
87	tlast = 0;
88	tleft = 0;
89	t = getsecs();
90	for (;;) {
91		if (tleft <= 0) {
92			if (tmo >= MAXTMO) {
93				errno = ETIMEDOUT;
94				return -1;
95			}
96			cc = (*sproc)(d, sbuf, ssize);
97			if (cc != -1 && cc < ssize)
98				panic("sendrecv: short write! (%zd < %zd)",
99				    cc, ssize);
100
101			tleft = tmo;
102			tmo <<= 1;
103			if (tmo > MAXTMO)
104				tmo = MAXTMO;
105
106			if (cc == -1) {
107				/* Error on transmit; wait before retrying */
108				while ((getsecs() - t) < tmo)
109					;
110				tleft = 0;
111				continue;
112			}
113
114			tlast = t;
115		}
116
117		/* Try to get a packet and process it. */
118		cc = (*rproc)(d, rbuf, rsize, tleft);
119		/* Return on data, EOF or real error. */
120		if (cc != -1 || errno != 0)
121			return (cc);
122
123		/* Timed out or didn't get the packet we're waiting for */
124		t = getsecs();
125		tleft -= t - tlast;
126		tlast = t;
127	}
128}
129
130/*
131 * Like inet_addr() in the C library, but we only accept base-10.
132 * Return values are in network order.
133 */
134n_long
135inet_addr(char *cp)
136{
137	u_long val;
138	int n;
139	char c;
140	u_int parts[4];
141	u_int *pp = parts;
142
143	for (;;) {
144		/*
145		 * Collect number up to ``.''.
146		 * Values are specified as for C:
147		 * 0x=hex, 0=octal, other=decimal.
148		 */
149		val = 0;
150		while ((c = *cp) != '\0') {
151			if (c >= '0' && c <= '9') {
152				val = (val * 10) + (c - '0');
153				cp++;
154				continue;
155			}
156			break;
157		}
158		if (*cp == '.') {
159			/*
160			 * Internet format:
161			 *	a.b.c.d
162			 *	a.b.c	(with c treated as 16-bits)
163			 *	a.b	(with b treated as 24 bits)
164			 */
165			if (pp >= parts + 3 || val > 0xff)
166				goto bad;
167			*pp++ = val, cp++;
168		} else
169			break;
170	}
171	/*
172	 * Check for trailing characters.
173	 */
174	if (*cp != '\0')
175		goto bad;
176
177	/*
178	 * Concoct the address according to
179	 * the number of parts specified.
180	 */
181	n = pp - parts + 1;
182	switch (n) {
183
184	case 1:				/* a -- 32 bits */
185		break;
186
187	case 2:				/* a.b -- 8.24 bits */
188		if (val > 0xffffff)
189			goto bad;
190		val |= parts[0] << 24;
191		break;
192
193	case 3:				/* a.b.c -- 8.8.16 bits */
194		if (val > 0xffff)
195			goto bad;
196		val |= (parts[0] << 24) | (parts[1] << 16);
197		break;
198
199	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
200		if (val > 0xff)
201			goto bad;
202		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
203		break;
204	}
205
206	return (htonl(val));
207 bad:
208	return (htonl(INADDR_NONE));
209}
210
211char *
212inet_ntoa(struct in_addr ia)
213{
214	return (intoa(ia.s_addr));
215}
216
217/* Similar to inet_ntoa() */
218char *
219intoa(n_long addr)
220{
221	char *cp;
222	u_int byte;
223	int n;
224	static char buf[17];	/* strlen(".255.255.255.255") + 1 */
225
226	addr = ntohl(addr);
227	cp = &buf[sizeof buf];
228	*--cp = '\0';
229
230	n = 4;
231	do {
232		byte = addr & 0xff;
233		*--cp = byte % 10 + '0';
234		byte /= 10;
235		if (byte > 0) {
236			*--cp = byte % 10 + '0';
237			byte /= 10;
238			if (byte > 0)
239				*--cp = byte + '0';
240		}
241		*--cp = '.';
242		addr >>= 8;
243	} while (--n > 0);
244
245	return (cp+1);
246}
247
248static char *
249number(char *s, int *n)
250{
251	for (*n = 0; isdigit(*s); s++)
252		*n = (*n * 10) + *s - '0';
253	return s;
254}
255
256n_long
257ip_convertaddr(char *p)
258{
259#define IP_ANYADDR	0
260	n_long addr = 0, n;
261
262	if (p == (char *)0 || *p == '\0')
263		return IP_ANYADDR;
264	p = number(p, &n);
265	addr |= (n << 24) & 0xff000000;
266	if (*p == '\0' || *p++ != '.')
267		return IP_ANYADDR;
268	p = number(p, &n);
269	addr |= (n << 16) & 0xff0000;
270	if (*p == '\0' || *p++ != '.')
271		return IP_ANYADDR;
272	p = number(p, &n);
273	addr |= (n << 8) & 0xff00;
274	if (*p == '\0' || *p++ != '.')
275		return IP_ANYADDR;
276	p = number(p, &n);
277	addr |= n & 0xff;
278	if (*p != '\0')
279		return IP_ANYADDR;
280
281	return htonl(addr);
282}
283