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
36#include <sys/param.h>
37#include <sys/socket.h>
38
39#include <string.h>
40
41#include <net/if.h>
42#include <netinet/in.h>
43#include <netinet/if_ether.h>
44#include <netinet/in_systm.h>
45
46#include <netinet/ip.h>
47#include <netinet/ip_var.h>
48#include <netinet/udp.h>
49#include <netinet/udp_var.h>
50
51#include "stand.h"
52#include "net.h"
53
54/*
55 * Maximum wait time for sending and receiving before we give up and timeout.
56 * If set to 0, operations will eventually timeout completely, but send/recv
57 * timeouts must progress exponentially from MINTMO to MAXTMO before final
58 * timeout is hit.
59 */
60#ifndef MAXWAIT
61#define MAXWAIT 300	/* seconds */
62#endif
63
64#if MAXWAIT < 0
65#error MAXWAIT must not be a negative number
66#endif
67
68/*
69 * Send a packet and wait for a reply, with exponential backoff.
70 *
71 * The send routine must return the actual number of bytes written,
72 * or -1 on error.
73 *
74 * The receive routine can indicate success by returning the number of
75 * bytes read; it can return 0 to indicate EOF; it can return -1 with a
76 * non-zero errno to indicate failure; finally, it can return -1 with a
77 * zero errno to indicate it isn't done yet.
78 */
79ssize_t
80sendrecv(struct iodesc *d,
81    ssize_t (*sproc)(struct iodesc *, void *, size_t),
82    void *sbuf, size_t ssize,
83    ssize_t (*rproc)(struct iodesc *, void **, void **, time_t, void *),
84    void **pkt, void **payload, void *recv_extra)
85{
86	ssize_t cc;
87	time_t t, tmo, tlast;
88	time_t tref;
89	long tleft;
90
91#ifdef NET_DEBUG
92	if (debug)
93		printf("sendrecv: called\n");
94#endif
95
96	tmo = MINTMO;
97	tlast = 0;
98	tleft = 0;
99	tref = t = getsecs();
100	for (;;) {
101		if (MAXWAIT > 0 && (t - tref) >= MAXWAIT) {
102			errno = ETIMEDOUT;
103			return -1;
104		}
105		if (tleft <= 0) {
106			if (tmo >= MAXTMO) {
107				errno = ETIMEDOUT;
108				return -1;
109			}
110			cc = (*sproc)(d, sbuf, ssize);
111			if (cc != -1 && cc < ssize)
112				panic("sendrecv: short write! (%zd < %zd)",
113				    cc, ssize);
114
115			tleft = tmo;
116			tmo += MINTMO;
117			if (tmo > MAXTMO)
118				tmo = MAXTMO;
119
120			if (cc == -1) {
121				/* Error on transmit; wait before retrying */
122				while ((getsecs() - t) < tmo)
123					;
124				tleft = 0;
125				continue;
126			}
127
128			tlast = t;
129		}
130
131		/* Try to get a packet and process it. */
132		cc = (*rproc)(d, pkt, payload, tleft, recv_extra);
133		/* Return on data, EOF or real error. */
134		if (cc != -1 || (errno != 0 && errno != ETIMEDOUT))
135			return (cc);
136
137		/* Timed out or didn't get the packet we're waiting for */
138		t = getsecs();
139		tleft -= t - tlast;
140		tlast = t;
141	}
142}
143
144/*
145 * Like inet_addr() in the C library, but we only accept base-10.
146 * Return values are in network order.
147 */
148n_long
149inet_addr(char *cp)
150{
151	u_long val;
152	int n;
153	char c;
154	u_int parts[4];
155	u_int *pp = parts;
156
157	for (;;) {
158		/*
159		 * Collect number up to ``.''.
160		 * Values are specified as for C:
161		 * 0x=hex, 0=octal, other=decimal.
162		 */
163		val = 0;
164		while ((c = *cp) != '\0') {
165			if (c >= '0' && c <= '9') {
166				val = (val * 10) + (c - '0');
167				cp++;
168				continue;
169			}
170			break;
171		}
172		if (*cp == '.') {
173			/*
174			 * Internet format:
175			 *	a.b.c.d
176			 *	a.b.c	(with c treated as 16-bits)
177			 *	a.b	(with b treated as 24 bits)
178			 */
179			if (pp >= parts + 3 || val > 0xff)
180				goto bad;
181			*pp++ = val, cp++;
182		} else
183			break;
184	}
185	/*
186	 * Check for trailing characters.
187	 */
188	if (*cp != '\0')
189		goto bad;
190
191	/*
192	 * Concoct the address according to
193	 * the number of parts specified.
194	 */
195	n = pp - parts + 1;
196	switch (n) {
197
198	case 1:				/* a -- 32 bits */
199		break;
200
201	case 2:				/* a.b -- 8.24 bits */
202		if (val > 0xffffff)
203			goto bad;
204		val |= parts[0] << 24;
205		break;
206
207	case 3:				/* a.b.c -- 8.8.16 bits */
208		if (val > 0xffff)
209			goto bad;
210		val |= (parts[0] << 24) | (parts[1] << 16);
211		break;
212
213	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
214		if (val > 0xff)
215			goto bad;
216		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
217		break;
218	}
219
220	return (htonl(val));
221 bad:
222	return (htonl(INADDR_NONE));
223}
224
225char *
226inet_ntoa(struct in_addr ia)
227{
228	return (intoa(ia.s_addr));
229}
230
231/* Similar to inet_ntoa() */
232char *
233intoa(n_long addr)
234{
235	char *cp;
236	u_int byte;
237	int n;
238	static char buf[17];	/* strlen(".255.255.255.255") + 1 */
239
240	addr = ntohl(addr);
241	cp = &buf[sizeof buf];
242	*--cp = '\0';
243
244	n = 4;
245	do {
246		byte = addr & 0xff;
247		*--cp = byte % 10 + '0';
248		byte /= 10;
249		if (byte > 0) {
250			*--cp = byte % 10 + '0';
251			byte /= 10;
252			if (byte > 0)
253				*--cp = byte + '0';
254		}
255		*--cp = '.';
256		addr >>= 8;
257	} while (--n > 0);
258
259	return (cp+1);
260}
261
262static char *
263number(char *s, n_long *n)
264{
265	for (*n = 0; isdigit(*s); s++)
266		*n = (*n * 10) + *s - '0';
267	return s;
268}
269
270n_long
271ip_convertaddr(char *p)
272{
273#define IP_ANYADDR	0
274	n_long addr = 0, n;
275
276	if (p == NULL || *p == '\0')
277		return IP_ANYADDR;
278	p = number(p, &n);
279	addr |= (n << 24) & 0xff000000;
280	if (*p == '\0' || *p++ != '.')
281		return IP_ANYADDR;
282	p = number(p, &n);
283	addr |= (n << 16) & 0xff0000;
284	if (*p == '\0' || *p++ != '.')
285		return IP_ANYADDR;
286	p = number(p, &n);
287	addr |= (n << 8) & 0xff00;
288	if (*p == '\0' || *p++ != '.')
289		return IP_ANYADDR;
290	p = number(p, &n);
291	addr |= n & 0xff;
292	if (*p != '\0')
293		return IP_ANYADDR;
294
295	return htonl(addr);
296}
297