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
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 /* Caller must leave room for ethernet, ip and udp headers in front!! */
55 ssize_t
sendudp(struct iodesc * d,void * pkt,size_t len)56 sendudp(struct iodesc *d, void *pkt, size_t len)
57 {
58 ssize_t cc;
59 struct udpiphdr *ui;
60 struct udphdr *uh;
61
62 #ifdef NET_DEBUG
63 if (debug) {
64 printf("sendudp: d=%lx called.\n", (long)d);
65 if (d) {
66 printf("saddr: %s:%d",
67 inet_ntoa(d->myip), ntohs(d->myport));
68 printf(" daddr: %s:%d\n",
69 inet_ntoa(d->destip), ntohs(d->destport));
70 }
71 }
72 #endif
73
74 ui = (struct udpiphdr *)pkt - 1;
75 bzero(ui, sizeof(*ui));
76
77 uh = (struct udphdr *)pkt - 1;
78 len += sizeof(*uh);
79
80 uh->uh_sport = d->myport;
81 uh->uh_dport = d->destport;
82 uh->uh_ulen = htons(len);
83
84 ui->ui_pr = IPPROTO_UDP;
85 ui->ui_len = uh->uh_ulen;
86 ui->ui_src = d->myip;
87 ui->ui_dst = d->destip;
88
89 #ifndef UDP_NO_CKSUM
90 uh->uh_sum = in_cksum(ui, len + sizeof (struct ip));
91 #endif
92
93 cc = sendip(d, uh, len, IPPROTO_UDP);
94 if (cc == -1)
95 return (-1);
96 if (cc != len)
97 panic("sendudp: bad write (%zd != %zd)", cc, len);
98 return (cc - sizeof(*uh));
99 }
100
101 /*
102 * Receive a UDP packet and validate it is for us.
103 */
104 ssize_t
readudp(struct iodesc * d,void ** pkt,void ** payload,time_t tleft)105 readudp(struct iodesc *d, void **pkt, void **payload, time_t tleft)
106 {
107 ssize_t n;
108 struct udphdr *uh;
109 void *ptr;
110
111 #ifdef NET_DEBUG
112 if (debug)
113 printf("readudp: called\n");
114 #endif
115
116 uh = NULL;
117 ptr = NULL;
118 n = readip(d, &ptr, (void **)&uh, tleft, IPPROTO_UDP);
119 if (n == -1 || n < sizeof(*uh) || n != ntohs(uh->uh_ulen)) {
120 free(ptr);
121 return (-1);
122 }
123
124 if (uh->uh_dport != d->myport) {
125 #ifdef NET_DEBUG
126 if (debug)
127 printf("readudp: bad dport %d != %d\n",
128 d->myport, ntohs(uh->uh_dport));
129 #endif
130 free(ptr);
131 return (-1);
132 }
133
134 #ifndef UDP_NO_CKSUM
135 if (uh->uh_sum) {
136 struct udpiphdr *ui;
137 struct ip *ip;
138 struct ip tip;
139
140 n = ntohs(uh->uh_ulen) + sizeof(*ip);
141
142 /* Check checksum (must save and restore ip header) */
143 ip = (struct ip *)uh - 1;
144 tip = *ip;
145 ui = (struct udpiphdr *)ip;
146 bzero(&ui->ui_x1, sizeof(ui->ui_x1));
147 ui->ui_len = uh->uh_ulen;
148 if (in_cksum(ui, n) != 0) {
149 #ifdef NET_DEBUG
150 if (debug)
151 printf("readudp: bad cksum\n");
152 #endif
153 free(ptr);
154 return (-1);
155 }
156 *ip = tip;
157 }
158 #endif
159 if (ntohs(uh->uh_ulen) < sizeof(*uh)) {
160 #ifdef NET_DEBUG
161 if (debug)
162 printf("readudp: bad udp len %d < %d\n",
163 ntohs(uh->uh_ulen), (int)sizeof(*uh));
164 #endif
165 free(ptr);
166 return (-1);
167 }
168
169 n = (n > (ntohs(uh->uh_ulen) - sizeof(*uh))) ?
170 ntohs(uh->uh_ulen) - sizeof(*uh) : n;
171 *pkt = ptr;
172 *payload = (void *)((uintptr_t)uh + sizeof(*uh));
173 return (n);
174 }
175