/* Create a random xid */
-uint32_t random_xid(void)
+uint32_t FAST_FUNC random_xid(void)
{
static smallint initialized;
}
-/* initialize a packet with the proper defaults */
-static void init_packet(struct dhcpMessage *packet, char type)
+/* Initialize the packet with the proper defaults */
+static void init_packet(struct dhcp_packet *packet, char type)
{
udhcp_init_header(packet, type);
- memcpy(packet->chaddr, client_config.arp, 6);
+ memcpy(packet->chaddr, client_config.client_mac, 6);
if (client_config.clientid)
add_option_string(packet->options, client_config.clientid);
if (client_config.hostname)
add_option_string(packet->options, client_config.hostname);
if (client_config.fqdn)
add_option_string(packet->options, client_config.fqdn);
- add_option_string(packet->options, client_config.vendorclass);
+ if ((type != DHCPDECLINE) && (type != DHCPRELEASE))
+ add_option_string(packet->options, client_config.vendorclass);
}
/* Add a parameter request list for stubborn DHCP servers. Pull the data
* from the struct in options.c. Don't do bounds checking here because it
* goes towards the head of the packet. */
-static void add_requests(struct dhcpMessage *packet)
+static void add_param_req_option(struct dhcp_packet *packet)
{
uint8_t c;
int end = end_option(packet->options);
int i, len = 0;
- packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
for (i = 0; (c = dhcp_options[i].code) != 0; i++) {
- if (dhcp_options[i].flags & OPTION_REQ
+ if (((dhcp_options[i].flags & OPTION_REQ)
+ && !client_config.no_default_options)
|| (client_config.opt_mask[c >> 3] & (1 << (c & 7)))
) {
- packet->options[end + OPT_DATA + len++] = c;
+ packet->options[end + OPT_DATA + len] = c;
+ len++;
}
}
- packet->options[end + OPT_LEN] = len;
- packet->options[end + OPT_DATA + len] = DHCP_END;
+ if (len) {
+ packet->options[end + OPT_CODE] = DHCP_PARAM_REQ;
+ packet->options[end + OPT_LEN] = len;
+ packet->options[end + OPT_DATA + len] = DHCP_END;
+ }
+}
+/* RFC 2131
+ * 4.4.4 Use of broadcast and unicast
+ *
+ * The DHCP client broadcasts DHCPDISCOVER, DHCPREQUEST and DHCPINFORM
+ * messages, unless the client knows the address of a DHCP server.
+ * The client unicasts DHCPRELEASE messages to the server. Because
+ * the client is declining the use of the IP address supplied by the server,
+ * the client broadcasts DHCPDECLINE messages.
+ *
+ * When the DHCP client knows the address of a DHCP server, in either
+ * INIT or REBOOTING state, the client may use that address
+ * in the DHCPDISCOVER or DHCPREQUEST rather than the IP broadcast address.
+ * The client may also use unicast to send DHCPINFORM messages
+ * to a known DHCP server. If the client receives no response to DHCP
+ * messages sent to the IP address of a known DHCP server, the DHCP
+ * client reverts to using the IP broadcast address.
+ */
+
+static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet)
+{
+ return udhcp_send_raw_packet(packet,
+ /*src*/ INADDR_ANY, CLIENT_PORT,
+ /*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR,
+ client_config.ifindex);
}
+
#if ENABLE_FEATURE_UDHCPC_ARPING
-/* Unicast a DHCP decline message */
-int send_decline(uint32_t xid, uint32_t server)
+/* Broadcast a DHCP decline message */
+int FAST_FUNC send_decline(uint32_t xid, uint32_t server, uint32_t requested)
{
- struct dhcpMessage packet;
+ struct dhcp_packet packet;
init_packet(&packet, DHCPDECLINE);
packet.xid = xid;
- add_requests(&packet);
+ add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
+ add_simple_option(packet.options, DHCP_SERVER_ID, server);
bb_info_msg("Sending decline...");
- return udhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
- SERVER_PORT, MAC_BCAST_ADDR, client_config.ifindex);
+ return raw_bcast_from_client_config_ifindex(&packet);
}
#endif
+
/* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
-int send_discover(uint32_t xid, uint32_t requested)
+int FAST_FUNC send_discover(uint32_t xid, uint32_t requested)
{
- struct dhcpMessage packet;
+ struct dhcp_packet packet;
init_packet(&packet, DHCPDISCOVER);
packet.xid = xid;
/* Explicitly saying that we want RFC-compliant packets helps
* some buggy DHCP servers to NOT send bigger packets */
add_simple_option(packet.options, DHCP_MAX_SIZE, htons(576));
- add_requests(&packet);
+
+ add_param_req_option(&packet);
+
bb_info_msg("Sending discover...");
- return udhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
- SERVER_PORT, MAC_BCAST_ADDR, client_config.ifindex);
+ return raw_bcast_from_client_config_ifindex(&packet);
}
-/* Broadcasts a DHCP request message */
-int send_selecting(uint32_t xid, uint32_t server, uint32_t requested)
+/* Broadcast a DHCP request message */
+/* RFC 2131 3.1 paragraph 3:
+ * "The client _broadcasts_ a DHCPREQUEST message..."
+ */
+int FAST_FUNC send_select(uint32_t xid, uint32_t server, uint32_t requested)
{
- struct dhcpMessage packet;
+ struct dhcp_packet packet;
struct in_addr addr;
init_packet(&packet, DHCPREQUEST);
add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
add_simple_option(packet.options, DHCP_SERVER_ID, server);
+ add_param_req_option(&packet);
- add_requests(&packet);
addr.s_addr = requested;
bb_info_msg("Sending select for %s...", inet_ntoa(addr));
- return udhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
- SERVER_PORT, MAC_BCAST_ADDR, client_config.ifindex);
+ return raw_bcast_from_client_config_ifindex(&packet);
}
/* Unicasts or broadcasts a DHCP renew message */
-int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
+int FAST_FUNC send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
{
- struct dhcpMessage packet;
+ struct dhcp_packet packet;
init_packet(&packet, DHCPREQUEST);
packet.xid = xid;
packet.ciaddr = ciaddr;
- add_requests(&packet);
+ add_param_req_option(&packet);
bb_info_msg("Sending renew...");
if (server)
- return udhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
+ return udhcp_send_kernel_packet(&packet,
+ ciaddr, CLIENT_PORT,
+ server, SERVER_PORT);
- return udhcp_send_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
- SERVER_PORT, MAC_BCAST_ADDR, client_config.ifindex);
+ return raw_bcast_from_client_config_ifindex(&packet);
}
/* Unicasts a DHCP release message */
-int send_release(uint32_t server, uint32_t ciaddr)
+int FAST_FUNC send_release(uint32_t server, uint32_t ciaddr)
{
- struct dhcpMessage packet;
+ struct dhcp_packet packet;
init_packet(&packet, DHCPRELEASE);
packet.xid = random_xid();
packet.ciaddr = ciaddr;
- add_simple_option(packet.options, DHCP_REQUESTED_IP, ciaddr);
add_simple_option(packet.options, DHCP_SERVER_ID, server);
bb_info_msg("Sending release...");
/* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
-int get_raw_packet(struct dhcpMessage *payload, int fd)
+int FAST_FUNC udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
{
int bytes;
- struct udp_dhcp_packet packet;
+ struct ip_udp_dhcp_packet packet;
uint16_t check;
memset(&packet, 0, sizeof(packet));
bytes = safe_read(fd, &packet, sizeof(packet));
if (bytes < 0) {
- DEBUG("Cannot read on raw listening socket - ignoring");
- sleep(1); /* possible down interface, looping condition */
+ log1("Packet read error, ignoring");
+ /* NB: possible down interface, etc. Caller should pause. */
return bytes; /* returns -1 */
}
if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
- DEBUG("Packet is too short, ignoring");
+ log1("Packet is too short, ignoring");
return -2;
}
if (bytes < ntohs(packet.ip.tot_len)) {
/* packet is bigger than sizeof(packet), we did partial read */
- DEBUG("Oversized packet, ignoring");
+ log1("Oversized packet, ignoring");
return -2;
}
/* || bytes > (int) sizeof(packet) - can't happen */
|| ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
) {
- DEBUG("Unrelated/bogus packet");
+ log1("Unrelated/bogus packet, ignoring");
return -2;
}
check = packet.ip.check;
packet.ip.check = 0;
if (check != udhcp_checksum(&packet.ip, sizeof(packet.ip))) {
- DEBUG("Bad IP header checksum, ignoring");
+ log1("Bad IP header checksum, ignoring");
return -2;
}
check = packet.udp.check;
packet.udp.check = 0;
if (check && check != udhcp_checksum(&packet, bytes)) {
- bb_error_msg("packet with bad UDP checksum received, ignoring");
+ log1("Packet with bad UDP checksum received, ignoring");
return -2;
}
- memcpy(payload, &packet.data, bytes - (sizeof(packet.ip) + sizeof(packet.udp)));
+ memcpy(dhcp_pkt, &packet.data, bytes - (sizeof(packet.ip) + sizeof(packet.udp)));
- if (payload->cookie != htonl(DHCP_MAGIC)) {
- bb_error_msg("received bogus message (bad magic), ignoring");
+ if (dhcp_pkt->cookie != htonl(DHCP_MAGIC)) {
+ bb_info_msg("Packet with bad magic, ignoring");
return -2;
}
- DEBUG("Got valid DHCP packet");
+ log1("Got valid DHCP packet");
+ udhcp_dump_packet(dhcp_pkt);
return bytes - (sizeof(packet.ip) + sizeof(packet.udp));
}
projects / oweals / busybox.git / blobdiff