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    Contents of /trunk/mkinitrd-magellan/busybox/networking/udhcp/dhcpd.c

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    Revision 532 - (show annotations) (download)
    Sat Sep 1 22:45:15 2007 UTC (16 years, 8 months ago) by niro
    File MIME type: text/plain
    File size: 6124 byte(s) 
    -import if magellan mkinitrd; it is a fork of redhats mkinitrd-5.0.8 with all magellan patches and features; deprecates magellan-src/mkinitrd
    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 "common.h"
    14 #include "dhcpd.h"
    15 #include "options.h"
    16
    17
    18 /* globals */
    19 struct dhcpOfferedAddr *leases;
    20 struct server_config_t server_config;
    21
    22
    23 int udhcpd_main(int argc, char *argv[])
    24 {
    25 fd_set rfds;
    26 struct timeval tv;
    27 int server_socket = -1, bytes, retval, max_sock;
    28 struct dhcpMessage packet;
    29 uint8_t *state, *server_id, *requested;
    30 uint32_t server_id_align, requested_align, static_lease_ip;
    31 unsigned long timeout_end, num_ips;
    32 struct option_set *option;
    33 struct dhcpOfferedAddr *lease, static_lease;
    34
    35 read_config(argc < 2 ? DHCPD_CONF_FILE : argv[1]);
    36
    37 /* Start the log, sanitize fd's, and write a pid file */
    38 udhcp_start_log_and_pid(server_config.pidfile);
    39
    40 if ((option = find_option(server_config.options, DHCP_LEASE_TIME))) {
    41 memcpy(&server_config.lease, option->data + 2, 4);
    42 server_config.lease = ntohl(server_config.lease);
    43 }
    44 else server_config.lease = LEASE_TIME;
    45
    46 /* Sanity check */
    47 num_ips = ntohl(server_config.end) - ntohl(server_config.start) + 1;
    48 if (server_config.max_leases > num_ips) {
    49 bb_error_msg("max_leases value (%lu) not sane, "
    50 "setting to %lu instead",
    51 server_config.max_leases, num_ips);
    52 server_config.max_leases = num_ips;
    53 }
    54
    55 leases = xzalloc(server_config.max_leases * sizeof(struct dhcpOfferedAddr));
    56 read_leases(server_config.lease_file);
    57
    58 if (read_interface(server_config.interface, &server_config.ifindex,
    59 &server_config.server, server_config.arp) < 0)
    60 return 1;
    61
    62 if (!ENABLE_FEATURE_UDHCP_DEBUG)
    63 udhcp_background(server_config.pidfile); /* hold lock during fork. */
    64
    65 /* Setup the signal pipe */
    66 udhcp_sp_setup();
    67
    68 timeout_end = time(0) + server_config.auto_time;
    69 while (1) { /* loop until universe collapses */
    70
    71 if (server_socket < 0) {
    72 server_socket = listen_socket(INADDR_ANY, SERVER_PORT, server_config.interface);
    73 }
    74
    75 max_sock = udhcp_sp_fd_set(&rfds, server_socket);
    76 if (server_config.auto_time) {
    77 tv.tv_sec = timeout_end - time(0);
    78 tv.tv_usec = 0;
    79 }
    80 if (!server_config.auto_time || tv.tv_sec > 0) {
    81 retval = select(max_sock + 1, &rfds, NULL, NULL,
    82 server_config.auto_time ? &tv : NULL);
    83 } else retval = 0; /* If we already timed out, fall through */
    84
    85 if (retval == 0) {
    86 write_leases();
    87 timeout_end = time(0) + server_config.auto_time;
    88 continue;
    89 } else if (retval < 0 && errno != EINTR) {
    90 DEBUG("error on select");
    91 continue;
    92 }
    93
    94 switch (udhcp_sp_read(&rfds)) {
    95 case SIGUSR1:
    96 bb_info_msg("Received a SIGUSR1");
    97 write_leases();
    98 /* why not just reset the timeout, eh */
    99 timeout_end = time(0) + server_config.auto_time;
    100 continue;
    101 case SIGTERM:
    102 bb_info_msg("Received a SIGTERM");
    103 return 0;
    104 case 0: break; /* no signal */
    105 default: continue; /* signal or error (probably EINTR) */
    106 }
    107
    108 if ((bytes = udhcp_get_packet(&packet, server_socket)) < 0) { /* this waits for a packet - idle */
    109 if (bytes == -1 && errno != EINTR) {
    110 DEBUG("error on read, %s, reopening socket", strerror(errno));
    111 close(server_socket);
    112 server_socket = -1;
    113 }
    114 continue;
    115 }
    116
    117 if ((state = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) {
    118 bb_error_msg("cannot get option from packet, ignoring");
    119 continue;
    120 }
    121
    122 /* Look for a static lease */
    123 static_lease_ip = getIpByMac(server_config.static_leases, &packet.chaddr);
    124
    125 if (static_lease_ip) {
    126 bb_info_msg("Found static lease: %x", static_lease_ip);
    127
    128 memcpy(&static_lease.chaddr, &packet.chaddr, 16);
    129 static_lease.yiaddr = static_lease_ip;
    130 static_lease.expires = 0;
    131
    132 lease = &static_lease;
    133
    134 } else {
    135 lease = find_lease_by_chaddr(packet.chaddr);
    136 }
    137
    138 switch (state[0]) {
    139 case DHCPDISCOVER:
    140 DEBUG("Received DISCOVER");
    141
    142 if (sendOffer(&packet) < 0) {
    143 bb_error_msg("send OFFER failed");
    144 }
    145 break;
    146 case DHCPREQUEST:
    147 DEBUG("received REQUEST");
    148
    149 requested = get_option(&packet, DHCP_REQUESTED_IP);
    150 server_id = get_option(&packet, DHCP_SERVER_ID);
    151
    152 if (requested) memcpy(&requested_align, requested, 4);
    153 if (server_id) memcpy(&server_id_align, server_id, 4);
    154
    155 if (lease) {
    156 if (server_id) {
    157 /* SELECTING State */
    158 DEBUG("server_id = %08x", ntohl(server_id_align));
    159 if (server_id_align == server_config.server && requested &&
    160 requested_align == lease->yiaddr) {
    161 sendACK(&packet, lease->yiaddr);
    162 }
    163 } else {
    164 if (requested) {
    165 /* INIT-REBOOT State */
    166 if (lease->yiaddr == requested_align)
    167 sendACK(&packet, lease->yiaddr);
    168 else sendNAK(&packet);
    169 } else {
    170 /* RENEWING or REBINDING State */
    171 if (lease->yiaddr == packet.ciaddr)
    172 sendACK(&packet, lease->yiaddr);
    173 else {
    174 /* don't know what to do!!!! */
    175 sendNAK(&packet);
    176 }
    177 }
    178 }
    179
    180 /* what to do if we have no record of the client */
    181 } else if (server_id) {
    182 /* SELECTING State */
    183
    184 } else if (requested) {
    185 /* INIT-REBOOT State */
    186 if ((lease = find_lease_by_yiaddr(requested_align))) {
    187 if (lease_expired(lease)) {
    188 /* probably best if we drop this lease */
    189 memset(lease->chaddr, 0, 16);
    190 /* make some contention for this address */
    191 } else sendNAK(&packet);
    192 } else if (requested_align < server_config.start ||
    193 requested_align > server_config.end) {
    194 sendNAK(&packet);
    195 } /* else remain silent */
    196
    197 } else {
    198 /* RENEWING or REBINDING State */
    199 }
    200 break;
    201 case DHCPDECLINE:
    202 DEBUG("Received DECLINE");
    203 if (lease) {
    204 memset(lease->chaddr, 0, 16);
    205 lease->expires = time(0) + server_config.decline_time;
    206 }
    207 break;
    208 case DHCPRELEASE:
    209 DEBUG("Received RELEASE");
    210 if (lease) lease->expires = time(0);
    211 break;
    212 case DHCPINFORM:
    213 DEBUG("Received INFORM");
    214 send_inform(&packet);
    215 break;
    216 default:
    217 bb_info_msg("Unsupported DHCP message (%02x) - ignoring", state[0]);
    218 }
    219 }
    220
    221 return 0;
    222 }