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
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
|
/* socket.c
BSD socket interface code... */
/*
* Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium.
* All rights reserved.
*
* 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 Internet Software Consortium 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 INTERNET SOFTWARE CONSORTIUM 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 INTERNET SOFTWARE CONSORTIUM 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.
*
* This software has been written for the Internet Software Consortium
* by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
* Enterprises. To learn more about the Internet Software Consortium,
* see ``http://www.vix.com/isc''. To learn more about Vixie
* Enterprises, see ``http://www.vix.com''.
*/
#ifndef lint
static char copyright[] =
"$Id: socket.c,v 1.16.2.2 1998/05/18 05:44:32 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium. All rights reserved.\n";
#endif /* not lint */
#include "dhcpd.h"
#ifdef USE_SOCKET_FALLBACK
# define USE_SOCKET_SEND
# define if_register_send if_register_fallback
# define send_packet send_fallback
#endif
#if defined (USE_SOCKET_SEND) || defined (USE_SOCKET_RECEIVE)
/* Generic interface registration routine... */
int if_register_socket (info, interface)
struct interface_info *info;
struct ifreq *interface;
{
struct sockaddr_in name;
int sock;
int flag;
static int
/* Make sure only one interface is registered. */
if (once)
error ("The standard socket API can only support %s",
"hosts with a single network interface.");
/* Technically, we need to know what interface every packet
comes in on, which means that we can only operate on a
machine with a single interface configured. However,
we generally don't expect to get broadcast packets on
point-to-point interfaces, so we can bend the rules a bit
and not count them. This won't allow DHCP-over-PPP,
but it's probably right in a lot of cases, and the issue
will have to be revisited when DHCP-over-PPP support is
done. Currently we determine whether an interface is
point-to-point by seeing if it has a link-level address.
This only works on 4.4BSD and derivative networking. */
#ifdef AF_LINK
if (info -> hw_address.hlen) /* XXX */
#endif
/* Set up the address we're going to bind to. */
name.sin_family = AF_INET;
name.sin_port = server_port;
name.sin_addr.s_addr = INADDR_ANY;
memset (name.sin_zero, 0, sizeof (name.sin_zero));
/* Make a socket... */
if ((sock = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
error ("Can't create dhcp socket: %m");
/* Set the REUSEADDR option so that we don't fail to start if
we're being restarted. */
flag = 1;
if (setsockopt (sock, SOL_SOCKET, SO_REUSEADDR,
(char *)&flag, sizeof flag) < 0)
error ("Can't set SO_REUSEADDR option on dhcp socket: %m");
/* Set the BROADCAST option so that we can broadcast DHCP responses. */
if (setsockopt (sock, SOL_SOCKET, SO_BROADCAST,
(char *)&flag, sizeof flag) < 0)
error ("Can't set SO_BROADCAST option on dhcp socket: %m");
/* Bind the socket to this interface's IP address. */
if (bind (sock, (struct sockaddr *)&name, sizeof name) < 0)
error ("Can't bind to dhcp address: %m");
return sock;
}
#endif /* USE_SOCKET_SEND || USE_SOCKET_RECEIVE */
#ifdef USE_SOCKET_SEND
void if_register_send (info, interface)
struct interface_info *info;
struct ifreq *interface;
{
#ifndef USE_SOCKET_RECEIVE
info -> wfdesc = if_register_socket (info, interface);
#else
info -> wfdesc = info -> rfdesc;
#endif
note ("Sending on Socket/%s/%s",
info -> name,
(info -> shared_network ?
info -> shared_network -> name : "unattached"));
}
#endif /* USE_SOCKET_SEND */
#ifdef USE_SOCKET_RECEIVE
void if_register_receive (info, interface)
struct interface_info *info;
struct ifreq *interface;
{
/* If we're using the socket API for sending and receiving,
we don't need to register this interface twice. */
info -> rfdesc = if_register_socket (info, interface);
note ("Listening on Socket/%s/%s",
info -> name,
(info -> shared_network ?
info -> shared_network -> name : "unattached"));
}
#endif /* USE_SOCKET_RECEIVE */
#ifdef USE_SOCKET_SEND
size_t send_packet (interface, packet, raw, len, from, to, hto)
struct interface_info *interface;
struct packet *packet;
struct dhcp_packet *raw;
size_t len;
struct in_addr from;
struct sockaddr_in *to;
struct hardware *hto;
{
int result;
#ifdef IGNORE_HOSTUNREACH
int retry = 0;
do {
#endif
result = sendto (interface -> wfdesc, (char *)raw, len, 0,
(struct sockaddr *)to, sizeof *to);
#ifdef IGNORE_HOSTUNREACH
} while (to -> sin_addr.s_addr == htonl (INADDR_BROADCAST) &&
result < 0 &&
(errno == EHOSTUNREACH ||
errno == ECONNREFUSED) &&
retry++ < 10);
#endif
return result;
}
#endif /* USE_SOCKET_SEND */
#ifdef USE_SOCKET_RECEIVE
size_t receive_packet (interface, buf, len, from, hfrom)
struct interface_info *interface;
unsigned char *buf;
size_t len;
struct sockaddr_in *from;
struct hardware *hfrom;
{
int flen = sizeof *from;
int result;
#ifdef IGNORE_HOSTUNREACH
int retry = 0;
do {
#endif
result = recvfrom (interface -> rfdesc, buf, len, 0,
(struct sockaddr *)from, &flen);
#ifdef IGNORE_HOSTUNREACH
} while (result < 0 &&
(errno == EHOSTUNREACH ||
errno == ECONNREFUSED) &&
retry++ < 10);
#endif
return result;
}
#endif /* USE_SOCKET_RECEIVE */
#ifdef USE_SOCKET_FALLBACK
/* This just reads in a packet and silently discards it. */
size_t fallback_discard (interface)
struct interface_info *interface;
{
char buf [1540];
struct sockaddr_in from;
int flen = sizeof from;
return recvfrom (interface -> wfdesc, buf, sizeof buf, 0,
(struct sockaddr *)&from, &flen);
}
#endif /* USE_SOCKET_RECEIVE */
|