1/*	$NetBSD: udp.c,v 1.13 2019/03/31 20:08:45 christos 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. All advertising materials mentioning features or use of this software
20 *    must display the following acknowledgement:
21 *	This product includes software developed by the University of
22 *	California, Lawrence Berkeley Laboratory and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 *    may be used to endorse or promote products derived from this software
25 *    without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp  (LBL)
40 */
41
42#include <sys/param.h>
43#include <sys/socket.h>
44
45#ifdef _STANDALONE
46#include <lib/libkern/libkern.h>
47#else
48#include <string.h>
49#endif
50
51#include <net/if.h>
52#include <net/if_ether.h>
53
54#include <netinet/in.h>
55#include <netinet/in_systm.h>
56#include <netinet/ip.h>
57#include <netinet/ip_var.h>
58#include <netinet/udp.h>
59#include <netinet/udp_var.h>
60
61#include "stand.h"
62#include "net.h"
63
64
65/* Caller must leave room for ethernet, ip and udp headers in front!! */
66ssize_t
67sendudp(struct iodesc *d, void *pkt, size_t len)
68{
69	ssize_t cc;
70	struct udphdr *uh;
71
72#ifdef NET_DEBUG
73 	if (debug) {
74		printf("%s: d=%p called.\n", __func__, d);
75		if (d) {
76			printf("saddr: %s:%d",
77			    inet_ntoa(d->myip), ntohs(d->myport));
78			printf(" daddr: %s:%d\n",
79			    inet_ntoa(d->destip), ntohs(d->destport));
80		}
81	}
82#endif
83
84	uh = (struct udphdr *)pkt - 1;
85	len += sizeof(*uh);
86
87	(void)memset(uh, 0, sizeof(*uh));
88
89	uh->uh_sport = d->myport;
90	uh->uh_dport = d->destport;
91	uh->uh_ulen = htons(len);
92
93	cc = sendip(d, uh, len, IPPROTO_UDP);
94	if (cc == -1)
95		return -1;
96	if ((size_t)cc != len)
97		panic("%s: bad write (%zd != %zu)", __func__, cc, len);
98	return (cc - sizeof(*uh));
99}
100
101/*
102 * Receive a UDP packet and validate it is for us.
103 * Caller leaves room for the headers (Ether, IP, UDP)
104 */
105ssize_t
106readudp(struct iodesc *d, void *pkt, size_t len, saseconds_t tleft)
107{
108	ssize_t n;
109	struct udphdr *uh;
110
111	uh = (struct udphdr *)pkt - 1;
112	n = readip(d, uh, len + sizeof(*uh), tleft, IPPROTO_UDP);
113	if (n == -1 || (size_t)n < sizeof(*uh))
114		return -1;
115
116	if (uh->uh_dport != d->myport) {
117#ifdef NET_DEBUG
118		if (debug)
119			printf("%s: bad dport %d != %d\n", __func__,
120			    ntohs(d->myport), ntohs(uh->uh_dport));
121#endif
122		return -1;
123	}
124
125	if (ntohs(uh->uh_ulen) < sizeof(*uh)) {
126#ifdef NET_DEBUG
127		if (debug)
128			printf("%s: bad udp len %d < %zu\n", __func__,
129				ntohs(uh->uh_ulen), sizeof(*uh));
130#endif
131		return -1;
132	}
133
134	n -= sizeof(*uh);
135	return n;
136}
137