source: MondoRescue/branches/2.2.9/mindi-busybox/networking/udhcp/dhcpd.c@ 2142

Last change on this file since 2142 was 1765, checked in by Bruno Cornec, 16 years ago

Update to busybox 1.7.2
File size: 6.7 KB
Line 
1/* vi: set sw=4 ts=4: */
2/* dhcpd.c
3 *
4 * udhcp Server
5 * Copyright (C) 1999 Matthew Ramsay <matthewr@moreton.com.au>
6 * Chris Trew <ctrew@moreton.com.au>
7 *
8 * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
9 *
10 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
11 */
12
13#include <syslog.h>
14#include "common.h"
15#include "dhcpd.h"
16#include "options.h"
17
18
19/* globals */
20struct dhcpOfferedAddr *leases;
21struct server_config_t server_config;
22
23
24int udhcpd_main(int argc, char **argv);
25int udhcpd_main(int argc, char **argv)
26{
27 fd_set rfds;
28 struct timeval tv;
29 int server_socket = -1, bytes, retval, max_sock;
30 struct dhcpMessage packet;
31 uint8_t *state, *server_id, *requested;
32 uint32_t server_id_align, requested_align, static_lease_ip;
33 unsigned timeout_end;
34 unsigned num_ips;
35 unsigned opt;
36 struct option_set *option;
37 struct dhcpOfferedAddr *lease, static_lease;
38
39 opt = getopt32(argv, "fS");
40 argv += optind;
41
42 if (!(opt & 1)) { /* no -f */
43 bb_daemonize_or_rexec(0, argv);
44 logmode &= ~LOGMODE_STDIO;
45 }
46
47 if (opt & 2) { /* -S */
48 openlog(applet_name, LOG_PID, LOG_LOCAL0);
49 logmode |= LOGMODE_SYSLOG;
50 }
51
52 /* Would rather not do read_config before daemonization -
53 * otherwise NOMMU machines will parse config twice */
54 read_config(argv[0] ? argv[0] : DHCPD_CONF_FILE);
55
56 /* Make sure fd 0,1,2 are open */
57 bb_sanitize_stdio();
58 /* Equivalent of doing a fflush after every \n */
59 setlinebuf(stdout);
60
61 /* Create pidfile */
62 write_pidfile(server_config.pidfile);
63 /* if (!..) bb_perror_msg("cannot create pidfile %s", pidfile); */
64
65 bb_info_msg("%s (v%s) started", applet_name, BB_VER);
66
67 option = find_option(server_config.options, DHCP_LEASE_TIME);
68 server_config.lease = LEASE_TIME;
69 if (option) {
70 memcpy(&server_config.lease, option->data + 2, 4);
71 server_config.lease = ntohl(server_config.lease);
72 }
73
74 /* Sanity check */
75 num_ips = server_config.end_ip - server_config.start_ip + 1;
76 if (server_config.max_leases > num_ips) {
77 bb_error_msg("max_leases=%u is too big, setting to %u",
78 (unsigned)server_config.max_leases, num_ips);
79 server_config.max_leases = num_ips;
80 }
81
82 leases = xzalloc(server_config.max_leases * sizeof(*leases));
83 read_leases(server_config.lease_file);
84
85 if (read_interface(server_config.interface, &server_config.ifindex,
86 &server_config.server, server_config.arp)) {
87 retval = 1;
88 goto ret;
89 }
90
91 /* Setup the signal pipe */
92 udhcp_sp_setup();
93
94 timeout_end = monotonic_sec() + server_config.auto_time;
95 while (1) { /* loop until universe collapses */
96
97 if (server_socket < 0) {
98 server_socket = listen_socket(/*INADDR_ANY,*/ SERVER_PORT,
99 server_config.interface);
100 }
101
102 max_sock = udhcp_sp_fd_set(&rfds, server_socket);
103 if (server_config.auto_time) {
104 tv.tv_sec = timeout_end - monotonic_sec();
105 tv.tv_usec = 0;
106 }
107 retval = 0;
108 if (!server_config.auto_time || tv.tv_sec > 0) {
109 retval = select(max_sock + 1, &rfds, NULL, NULL,
110 server_config.auto_time ? &tv : NULL);
111 }
112 if (retval == 0) {
113 write_leases();
114 timeout_end = monotonic_sec() + server_config.auto_time;
115 continue;
116 }
117 if (retval < 0 && errno != EINTR) {
118 DEBUG("error on select");
119 continue;
120 }
121
122 switch (udhcp_sp_read(&rfds)) {
123 case SIGUSR1:
124 bb_info_msg("Received a SIGUSR1");
125 write_leases();
126 /* why not just reset the timeout, eh */
127 timeout_end = monotonic_sec() + server_config.auto_time;
128 continue;
129 case SIGTERM:
130 bb_info_msg("Received a SIGTERM");
131 goto ret0;
132 case 0: break; /* no signal */
133 default: continue; /* signal or error (probably EINTR) */
134 }
135
136 bytes = udhcp_get_packet(&packet, server_socket); /* this waits for a packet - idle */
137 if (bytes < 0) {
138 if (bytes == -1 && errno != EINTR) {
139 DEBUG("error on read, %s, reopening socket", strerror(errno));
140 close(server_socket);
141 server_socket = -1;
142 }
143 continue;
144 }
145
146 state = get_option(&packet, DHCP_MESSAGE_TYPE);
147 if (state == NULL) {
148 bb_error_msg("cannot get option from packet, ignoring");
149 continue;
150 }
151
152 /* Look for a static lease */
153 static_lease_ip = getIpByMac(server_config.static_leases, &packet.chaddr);
154
155 if (static_lease_ip) {
156 bb_info_msg("Found static lease: %x", static_lease_ip);
157
158 memcpy(&static_lease.chaddr, &packet.chaddr, 16);
159 static_lease.yiaddr = static_lease_ip;
160 static_lease.expires = 0;
161
162 lease = &static_lease;
163 } else {
164 lease = find_lease_by_chaddr(packet.chaddr);
165 }
166
167 switch (state[0]) {
168 case DHCPDISCOVER:
169 DEBUG("Received DISCOVER");
170
171 if (sendOffer(&packet) < 0) {
172 bb_error_msg("send OFFER failed");
173 }
174 break;
175 case DHCPREQUEST:
176 DEBUG("received REQUEST");
177
178 requested = get_option(&packet, DHCP_REQUESTED_IP);
179 server_id = get_option(&packet, DHCP_SERVER_ID);
180
181 if (requested) memcpy(&requested_align, requested, 4);
182 if (server_id) memcpy(&server_id_align, server_id, 4);
183
184 if (lease) {
185 if (server_id) {
186 /* SELECTING State */
187 DEBUG("server_id = %08x", ntohl(server_id_align));
188 if (server_id_align == server_config.server && requested
189 && requested_align == lease->yiaddr
190 ) {
191 sendACK(&packet, lease->yiaddr);
192 }
193 } else if (requested) {
194 /* INIT-REBOOT State */
195 if (lease->yiaddr == requested_align)
196 sendACK(&packet, lease->yiaddr);
197 else
198 sendNAK(&packet);
199 } else if (lease->yiaddr == packet.ciaddr) {
200 /* RENEWING or REBINDING State */
201 sendACK(&packet, lease->yiaddr);
202 } else {
203 /* don't know what to do!!!! */
204 sendNAK(&packet);
205 }
206
207 /* what to do if we have no record of the client */
208 } else if (server_id) {
209 /* SELECTING State */
210
211 } else if (requested) {
212 /* INIT-REBOOT State */
213 lease = find_lease_by_yiaddr(requested_align);
214 if (lease) {
215 if (lease_expired(lease)) {
216 /* probably best if we drop this lease */
217 memset(lease->chaddr, 0, 16);
218 /* make some contention for this address */
219 } else
220 sendNAK(&packet);
221 } else {
222 uint32_t r = ntohl(requested_align);
223 if (r < server_config.start_ip
224 || r > server_config.end_ip
225 ) {
226 sendNAK(&packet);
227 }
228 /* else remain silent */
229 }
230
231 } else {
232 /* RENEWING or REBINDING State */
233 }
234 break;
235 case DHCPDECLINE:
236 DEBUG("Received DECLINE");
237 if (lease) {
238 memset(lease->chaddr, 0, 16);
239 lease->expires = time(0) + server_config.decline_time;
240 }
241 break;
242 case DHCPRELEASE:
243 DEBUG("Received RELEASE");
244 if (lease)
245 lease->expires = time(0);
246 break;
247 case DHCPINFORM:
248 DEBUG("Received INFORM");
249 send_inform(&packet);
250 break;
251 default:
252 bb_info_msg("Unsupported DHCP message (%02x) - ignoring", state[0]);
253 }
254 }
255 ret0:
256 retval = 0;
257 ret:
258 /*if (server_config.pidfile) - server_config.pidfile is never NULL */
259 remove_pidfile(server_config.pidfile);
260 return retval;
261}
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