1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
|
/* Taken from $NetBSD: net.c,v 1.20 1997/12/26 22:41:30 scottr Exp $ */
/*
* Copyright (c) 1992 Regents of the University of California.
* All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#) Header: net.c,v 1.9 93/08/06 19:32:15 leres Exp (LBL)
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/socket.h>
#include <string.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include "stand.h"
#include "net.h"
/* Caller must leave room for ethernet, ip and udp headers in front!! */
ssize_t
sendudp(struct iodesc *d, void *pkt, size_t len)
{
ssize_t cc;
struct udpiphdr *ui;
struct udphdr *uh;
#ifdef NET_DEBUG
if (debug) {
printf("sendudp: d=%lx called.\n", (long)d);
if (d) {
printf("saddr: %s:%d",
inet_ntoa(d->myip), ntohs(d->myport));
printf(" daddr: %s:%d\n",
inet_ntoa(d->destip), ntohs(d->destport));
}
}
#endif
ui = (struct udpiphdr *)pkt - 1;
bzero(ui, sizeof(*ui));
uh = (struct udphdr *)pkt - 1;
len += sizeof(*uh);
uh->uh_sport = d->myport;
uh->uh_dport = d->destport;
uh->uh_ulen = htons(len);
ui->ui_pr = IPPROTO_UDP;
ui->ui_len = uh->uh_ulen;
ui->ui_src = d->myip;
ui->ui_dst = d->destip;
#ifndef UDP_NO_CKSUM
uh->uh_sum = in_cksum(ui, len + sizeof (struct ip));
#endif
cc = sendip(d, uh, len, IPPROTO_UDP);
if (cc == -1)
return (-1);
if (cc != len)
panic("sendudp: bad write (%zd != %zd)", cc, len);
return (cc - sizeof(*uh));
}
/*
* Receive a UDP packet and validate it is for us.
*/
ssize_t
readudp(struct iodesc *d, void **pkt, void **payload, time_t tleft)
{
ssize_t n;
struct udphdr *uh;
void *ptr;
#ifdef NET_DEBUG
if (debug)
printf("readudp: called\n");
#endif
uh = NULL;
ptr = NULL;
n = readip(d, &ptr, (void **)&uh, tleft, IPPROTO_UDP);
if (n == -1 || n < sizeof(*uh) || n != ntohs(uh->uh_ulen)) {
free(ptr);
return (-1);
}
if (uh->uh_dport != d->myport) {
#ifdef NET_DEBUG
if (debug)
printf("readudp: bad dport %d != %d\n",
d->myport, ntohs(uh->uh_dport));
#endif
free(ptr);
return (-1);
}
#ifndef UDP_NO_CKSUM
if (uh->uh_sum) {
struct udpiphdr *ui;
struct ip *ip;
struct ip tip;
n = ntohs(uh->uh_ulen) + sizeof(*ip);
/* Check checksum (must save and restore ip header) */
ip = (struct ip *)uh - 1;
tip = *ip;
ui = (struct udpiphdr *)ip;
bzero(&ui->ui_x1, sizeof(ui->ui_x1));
ui->ui_len = uh->uh_ulen;
if (in_cksum(ui, n) != 0) {
#ifdef NET_DEBUG
if (debug)
printf("readudp: bad cksum\n");
#endif
free(ptr);
return (-1);
}
*ip = tip;
}
#endif
if (ntohs(uh->uh_ulen) < sizeof(*uh)) {
#ifdef NET_DEBUG
if (debug)
printf("readudp: bad udp len %d < %d\n",
ntohs(uh->uh_ulen), (int)sizeof(*uh));
#endif
free(ptr);
return (-1);
}
n = (n > (ntohs(uh->uh_ulen) - sizeof(*uh))) ?
ntohs(uh->uh_ulen) - sizeof(*uh) : n;
*pkt = ptr;
*payload = (void *)((uintptr_t)uh + sizeof(*uh));
return (n);
}
|
