1 /* Taken from $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 * @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp (LBL)
36 */
37
38 #include <sys/cdefs.h>
39
40 #include <sys/param.h>
41 #include <sys/socket.h>
42
43 #include <string.h>
44
45 #include <net/if.h>
46 #include <netinet/in.h>
47 #include <netinet/if_ether.h>
48 #include <netinet/in_systm.h>
49
50 #include <netinet/ip.h>
51 #include <netinet/ip_var.h>
52 #include <netinet/udp.h>
53 #include <netinet/udp_var.h>
54
55 #include "stand.h"
56 #include "net.h"
57
58 /* Caller must leave room for ethernet, ip and udp headers in front!! */
59 ssize_t
sendudp(struct iodesc * d,void * pkt,size_t len)60 sendudp(struct iodesc *d, void *pkt, size_t len)
61 {
62 ssize_t cc;
63 struct udpiphdr *ui;
64 struct udphdr *uh;
65
66 #ifdef NET_DEBUG
67 if (debug) {
68 printf("sendudp: d=%lx called.\n", (long)d);
69 if (d) {
70 printf("saddr: %s:%d",
71 inet_ntoa(d->myip), ntohs(d->myport));
72 printf(" daddr: %s:%d\n",
73 inet_ntoa(d->destip), ntohs(d->destport));
74 }
75 }
76 #endif
77
78 ui = (struct udpiphdr *)pkt - 1;
79 bzero(ui, sizeof (*ui));
80
81 uh = (struct udphdr *)pkt - 1;
82 len += sizeof (*uh);
83
84 uh->uh_sport = d->myport;
85 uh->uh_dport = d->destport;
86 uh->uh_ulen = htons(len);
87
88 ui->ui_pr = IPPROTO_UDP;
89 ui->ui_len = uh->uh_ulen;
90 ui->ui_src = d->myip;
91 ui->ui_dst = d->destip;
92
93 #ifndef UDP_NO_CKSUM
94 uh->uh_sum = in_cksum(ui, len + sizeof (struct ip));
95 #endif
96
97 cc = sendip(d, uh, len, IPPROTO_UDP);
98 if (cc == -1)
99 return (-1);
100 if (cc != len)
101 panic("sendudp: bad write (%zd != %zd)", cc, len);
102 return (cc - sizeof (*uh));
103 }
104
105 /*
106 * Receive a UDP packet and validate it is for us.
107 */
108 ssize_t
readudp(struct iodesc * d,void ** pkt,void ** payload,time_t tleft)109 readudp(struct iodesc *d, void **pkt, void **payload, time_t tleft)
110 {
111 ssize_t n;
112 struct udphdr *uh;
113 void *ptr;
114
115 #ifdef NET_DEBUG
116 if (debug)
117 printf("readudp: called\n");
118 #endif
119
120 uh = NULL;
121 ptr = NULL;
122 n = readip(d, &ptr, (void **)&uh, tleft, IPPROTO_UDP);
123 if (n == -1 || n < sizeof (*uh) || n != ntohs(uh->uh_ulen)) {
124 free(ptr);
125 return (-1);
126 }
127
128 if (uh->uh_dport != d->myport) {
129 #ifdef NET_DEBUG
130 if (debug)
131 printf("readudp: bad dport %d != %d\n",
132 d->myport, ntohs(uh->uh_dport));
133 #endif
134 free(ptr);
135 return (-1);
136 }
137
138 #ifndef UDP_NO_CKSUM
139 if (uh->uh_sum) {
140 struct udpiphdr *ui;
141 void *ip;
142 struct ip tip;
143
144 n = ntohs(uh->uh_ulen) + sizeof (struct ip);
145
146 /*
147 * Check checksum (must save and restore ip header).
148 * Note we do use void *ip here to make gcc to stop
149 * complaining about possibly unaligned pointer values.
150 * We do allocate buffer in pxe.c/efinet.c and care is
151 * taken to get headers aligned properly.
152 */
153 ip = (struct ip *)uh - 1;
154 tip = *(struct ip *)ip;
155 ui = ip;
156 bzero(&ui->ui_x1, sizeof (ui->ui_x1));
157 ui->ui_len = uh->uh_ulen;
158 if (in_cksum(ui, n) != 0) {
159 #ifdef NET_DEBUG
160 if (debug)
161 printf("readudp: bad cksum\n");
162 #endif
163 free(ptr);
164 return (-1);
165 }
166 *(struct ip *)ip = tip;
167 }
168 #endif
169 if (ntohs(uh->uh_ulen) < sizeof (*uh)) {
170 #ifdef NET_DEBUG
171 if (debug)
172 printf("readudp: bad udp len %d < %d\n",
173 ntohs(uh->uh_ulen), (int)sizeof (*uh));
174 #endif
175 free(ptr);
176 return (-1);
177 }
178
179 n = (n > (ntohs(uh->uh_ulen) - sizeof (*uh))) ?
180 ntohs(uh->uh_ulen) - sizeof (*uh) : n;
181 *pkt = ptr;
182 *payload = (void *)((uintptr_t)uh + sizeof (*uh));
183 return (n);
184 }
185