X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;ds=sidebyside;f=networking%2Fudhcp%2Fclientpacket.c;h=21c1a7bd56a15987ee70aa17f66cd051797eba4d;hb=bcbd37df2495359195b0deda7c85deacc9b3ff13;hp=b8190ba43ef694dd4a19d98f31c9d9cfd4faf357;hpb=8e5b6f58a27d840cabf491634e956407d147ddb6;p=oweals%2Fbusybox.git

diff --git a/networking/udhcp/clientpacket.c b/networking/udhcp/clientpacket.c
index b8190ba43..21c1a7bd5 100644
--- a/networking/udhcp/clientpacket.c
+++ b/networking/udhcp/clientpacket.c
@@ -25,7 +25,7 @@
 
 
 /* Create a random xid */
-uint32_t random_xid(void)
+uint32_t FAST_FUNC random_xid(void)
 {
 	static smallint initialized;
 
@@ -37,64 +37,96 @@ uint32_t random_xid(void)
 }
 
 
-/* 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;
@@ -104,17 +136,21 @@ int send_discover(uint32_t xid, uint32_t requested)
 	/* 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);
@@ -122,44 +158,43 @@ int send_selecting(uint32_t xid, uint32_t server, uint32_t requested)
 
 	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...");
@@ -168,28 +203,28 @@ int send_release(uint32_t server, uint32_t ciaddr)
 
 
 /* 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;
 	}
 
@@ -203,7 +238,7 @@ int get_raw_packet(struct dhcpMessage *payload, int fd)
 	/* || 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;
 	}
 
@@ -211,7 +246,7 @@ int get_raw_packet(struct dhcpMessage *payload, int fd)
 	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;
 	}
 
@@ -222,16 +257,17 @@ int get_raw_packet(struct dhcpMessage *payload, int fd)
 	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));
 }