1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright 1991-2003 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 *
26 * udp.c, Code implementing the UDP internet protocol.
27 */
28
29#pragma ident	"%Z%%M%	%I%	%E% SMI"
30
31#include <sys/types.h>
32#include <socket_impl.h>
33#include <socket_inet.h>
34#include <sys/salib.h>
35#include <sys/socket.h>
36#include <netinet/in_systm.h>
37#include <netinet/in.h>
38#include <netinet/ip.h>
39#include <netinet/udp.h>
40
41#include "udp_inet.h"
42#include "ipv4.h"
43#include "ipv4_impl.h"
44#include "mac.h"
45#include "mac_impl.h"
46#include "v4_sum_impl.h"
47#include <sys/bootdebug.h>
48
49/* Checksum all architectures */
50static int udp_cksum_flag = TRUE;	/* checksum on if set */
51
52/*
53 * Initialize the udp-specific parts of a socket.
54 */
55void
56udp_socket_init(struct inetboot_socket *isp)
57{
58	isp->type = INETBOOT_DGRAM;
59	isp->proto = IPPROTO_UDP;
60	isp->input[TRANSPORT_LVL] = udp_input;
61	isp->output[TRANSPORT_LVL] = udp_output;
62	isp->close[TRANSPORT_LVL] = NULL;
63	isp->headerlen[TRANSPORT_LVL] = udp_header_len;
64	isp->ports = udp_ports;
65}
66
67/*
68 * Return the size of an UDP header
69 */
70/* ARGSUSED */
71int
72udp_header_len(struct inetgram *igm)
73{
74	return (sizeof (struct udphdr));
75}
76
77/*
78 * Return the requested port number in network order.
79 */
80in_port_t
81udp_ports(uint16_t *udphp, enum Ports request)
82{
83	if (request == SOURCE)
84		return (((struct udphdr *)udphp)->uh_sport);
85	return (((struct udphdr *)udphp)->uh_dport);
86}
87
88/*
89 * Process the IPv4 datagram that IPv4 has given us. We:
90 *
91 *	1) Checksum the datagram if checksum is turned on.
92 *	2) Strip the udp header from the inetgram.
93 *	3) Return the number of TRANSPORT frames for success, -1 if a
94 *		failure occurred.
95 *
96 * Arguments: index: index into the open socket table, ip is the inetgram
97 * we got from IPv4, which will contain the udp header and all the data.
98 */
99int
100udp_input(int index)
101{
102	int frames = 0, header_len;
103	struct inetgram	*igp, *ugp = NULL;
104	struct udphdr	*udphp;
105	mblk_t *mp;
106
107#ifdef DEBUG
108	printf("udp_input(%d) ###############################\n", index);
109#endif
110	while ((igp = sockets[index].inq) != NULL) {
111		if (igp->igm_level != TRANSPORT_LVL) {
112#ifdef	DEBUG
113			printf("udp_input(%d): level %d datagram discarded.\n",
114			    index, igp->igm_level);
115#endif	/* DEBUG */
116			del_gram(&sockets[index].inq, igp, TRUE);
117			continue;
118		}
119		mp = igp->igm_mp;
120		udphp = (struct udphdr *)(mp->b_rptr +
121		    IPH_HDR_LENGTH(mp->b_rptr));
122		header_len = (sockets[index].headerlen[TRANSPORT_LVL])(NULL);
123		mp->b_rptr = ((unsigned char *)udphp) + header_len;
124		mp->b_wptr = ((unsigned char *)udphp) + ntohs(udphp->uh_ulen);
125
126		/* generate checksum */
127		if (udp_cksum_flag && udphp->uh_sum != 0) {
128			if (udp_chksum(udphp, &igp->igm_saddr.sin_addr,
129			    &igp->igm_target, sockets[index].proto) != 0) {
130				dprintf("udp_input(%d): bad udp chksum "
131				    "from %s.\n", index,
132				    inet_ntoa(igp->igm_saddr.sin_addr));
133				del_gram(&sockets[index].inq, igp, TRUE);
134				continue;
135			}
136		}
137
138		/* validate port number */
139		if (sockets[index].bind.sin_port != udphp->uh_dport) {
140			dprintf("udp_input(%d): Unexpected port number: "
141			    "%d != %d from %s.\n", index,
142			    ntohs(udphp->uh_dport), ntohs(
143			    sockets[index].bind.sin_port),
144			    inet_ntoa(igp->igm_saddr.sin_addr));
145			del_gram(&sockets[index].inq, igp, TRUE);
146			continue;
147		}
148
149		igp->igm_level = APP_LVL;
150		del_gram(&sockets[index].inq, igp, FALSE);
151		add_grams(&ugp, igp);
152		frames++;
153	}
154	add_grams(&sockets[index].inq, ugp);
155
156	return (frames);
157}
158
159/*
160 * Create a UDP datagram given the data and sockaddr_in we got from sendto().
161 * We will calculate the checksum if checksumming is turned on, and fill in
162 * appropriate length and port fields. We convert the inetgram from a
163 * block of data into a udp datagram... Returns the number of bytes contained
164 * in the udp datagram (including header).
165 *
166 * Arguments: index: index into the open socket table, ogp is the inetgram
167 * we got from sendto(), which will contain just the data and sockaddr_in.
168 */
169int
170udp_output(int index, struct inetgram *ogp)
171{
172	struct udphdr	*udphp;
173	mblk_t		*mp;
174
175#ifdef	DEBUG
176	printf("udp_output(%d): 0x%x, %d\n", index, ogp->igm_mp,
177	    ogp->igm_mp->b_wptr - ogp->igm_mp->b_rptr);
178#endif	/* DEBUG */
179
180	mp = ogp->igm_mp;
181	mp->b_rptr -= sizeof (struct udphdr);
182	udphp = (struct udphdr *)(mp->b_rptr);
183
184	udphp->uh_dport = ogp->igm_saddr.sin_port;
185	if (sockets[index].bound)
186		udphp->uh_sport = sockets[index].bind.sin_port;
187	else
188		udphp->uh_sport = ogp->igm_saddr.sin_port;
189	udphp->uh_ulen = htons(mp->b_wptr - mp->b_rptr);
190	udphp->uh_sum = 0;
191
192	if (udp_cksum_flag) {
193		udphp->uh_sum = udp_chksum(udphp, &sockets[index].bind.sin_addr,
194		    &ogp->igm_saddr.sin_addr, sockets[index].proto);
195	}
196
197	ogp->igm_level = NETWORK_LVL;
198
199	return (0);
200}
201