zte's code,first commit

Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/app/busybox/src/networking/udhcp/packet.c b/ap/app/busybox/src/networking/udhcp/packet.c
new file mode 100644
index 0000000..33c9585
--- /dev/null
+++ b/ap/app/busybox/src/networking/udhcp/packet.c
@@ -0,0 +1,227 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Packet ops
+ *
+ * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
+ */
+#include "common.h"
+#include "dhcpd.h"
+#include <netinet/in.h>
+#include <netinet/if_ether.h>
+#include <netpacket/packet.h>
+
+void FAST_FUNC udhcp_init_header(struct dhcp_packet *packet, char type)
+{
+	memset(packet, 0, sizeof(*packet));
+	packet->op = BOOTREQUEST; /* if client to a server */
+	switch (type) {
+	case DHCPOFFER:
+	case DHCPACK:
+	case DHCPNAK:
+		packet->op = BOOTREPLY; /* if server to client */
+	}
+	packet->htype = 1; /* ethernet */
+	packet->hlen = 6;
+	packet->cookie = htonl(DHCP_MAGIC);
+	if (DHCP_END != 0)
+		packet->options[0] = DHCP_END;
+	udhcp_add_simple_option(packet, DHCP_MESSAGE_TYPE, type);
+}
+
+#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
+void FAST_FUNC udhcp_dump_packet(struct dhcp_packet *packet)
+{
+	char buf[sizeof(packet->chaddr)*2 + 1];
+
+	if (dhcp_verbose < 2)
+		return;
+
+	bb_info_msg(
+		//" op %x"
+		//" htype %x"
+		" hlen %x"
+		//" hops %x"
+		" xid %x"
+		//" secs %x"
+		//" flags %x"
+		" ciaddr %x"
+		" yiaddr %x"
+		" siaddr %x"
+		" giaddr %x"
+		//" chaddr %s"
+		//" sname %s"
+		//" file %s"
+		//" cookie %x"
+		//" options %s"
+		//, packet->op
+		//, packet->htype
+		, packet->hlen
+		//, packet->hops
+		, packet->xid
+		//, packet->secs
+		//, packet->flags
+		, packet->ciaddr
+		, packet->yiaddr
+		, packet->siaddr_nip
+		, packet->gateway_nip
+		//, packet->chaddr[16]
+		//, packet->sname[64]
+		//, packet->file[128]
+		//, packet->cookie
+		//, packet->options[]
+	);
+	*bin2hex(buf, (void *) packet->chaddr, sizeof(packet->chaddr)) = '\0';
+	bb_info_msg(" chaddr %s", buf);
+}
+#endif
+
+/* Read a packet from socket fd, return -1 on read error, -2 on packet error */
+int FAST_FUNC udhcp_recv_kernel_packet(struct dhcp_packet *packet, int fd)
+{
+	int bytes;
+
+	memset(packet, 0, sizeof(*packet));
+	bytes = safe_read(fd, packet, sizeof(*packet));
+	if (bytes < 0) {
+		log1("Packet read error, ignoring");
+		return bytes; /* returns -1 */
+	}
+
+	if (bytes < offsetof(struct dhcp_packet, options)
+	 || packet->cookie != htonl(DHCP_MAGIC)
+	) {
+		bb_info_msg("Packet with bad magic, ignoring");
+		return -2;
+	}
+	log1("Received a packet");
+	udhcp_dump_packet(packet);
+
+	return bytes;
+}
+
+/* Construct a ip/udp header for a packet, send packet */
+int FAST_FUNC udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
+		uint32_t source_nip, int source_port,
+		uint32_t dest_nip, int dest_port, const uint8_t *dest_arp,
+		int ifindex)
+{
+	struct sockaddr_ll dest_sll;
+	struct ip_udp_dhcp_packet packet;
+	unsigned padding;
+	int fd;
+	int result = -1;
+	const char *msg;
+
+	fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
+	if (fd < 0) {
+		msg = "socket(%s)";
+		goto ret_msg;
+	}
+
+	memset(&dest_sll, 0, sizeof(dest_sll));
+	memset(&packet, 0, offsetof(struct ip_udp_dhcp_packet, data));
+	packet.data = *dhcp_pkt; /* struct copy */
+
+	dest_sll.sll_family = AF_PACKET;
+	dest_sll.sll_protocol = htons(ETH_P_IP);
+	dest_sll.sll_ifindex = ifindex;
+	dest_sll.sll_halen = 6;
+	memcpy(dest_sll.sll_addr, dest_arp, 6);
+
+	if (bind(fd, (struct sockaddr *)&dest_sll, sizeof(dest_sll)) < 0) {
+		msg = "bind(%s)";
+		goto ret_close;
+	}
+
+	/* We were sending full-sized DHCP packets (zero padded),
+	 * but some badly configured servers were seen dropping them.
+	 * Apparently they drop all DHCP packets >576 *ethernet* octets big,
+	 * whereas they may only drop packets >576 *IP* octets big
+	 * (which for typical Ethernet II means 590 octets: 6+6+2 + 576).
+	 *
+	 * In order to work with those buggy servers,
+	 * we truncate packets after end option byte.
+	 */
+	padding = DHCP_OPTIONS_BUFSIZE - 1 - udhcp_end_option(packet.data.options);
+
+	packet.ip.protocol = IPPROTO_UDP;
+	packet.ip.saddr = source_nip;
+	packet.ip.daddr = dest_nip;
+	packet.udp.source = htons(source_port);
+	packet.udp.dest = htons(dest_port);
+	/* size, excluding IP header: */
+	packet.udp.len = htons(UDP_DHCP_SIZE - padding);
+	/* for UDP checksumming, ip.len is set to UDP packet len */
+	packet.ip.tot_len = packet.udp.len;
+	packet.udp.check = inet_cksum((uint16_t *)&packet,
+			IP_UDP_DHCP_SIZE - padding);
+	/* but for sending, it is set to IP packet len */
+	packet.ip.tot_len = htons(IP_UDP_DHCP_SIZE - padding);
+	packet.ip.ihl = sizeof(packet.ip) >> 2;
+	packet.ip.version = IPVERSION;
+	packet.ip.ttl = IPDEFTTL;
+	packet.ip.check = inet_cksum((uint16_t *)&packet.ip, sizeof(packet.ip));
+
+	udhcp_dump_packet(dhcp_pkt);
+	result = sendto(fd, &packet, IP_UDP_DHCP_SIZE - padding, /*flags:*/ 0,
+			(struct sockaddr *) &dest_sll, sizeof(dest_sll));
+	msg = "sendto";
+ ret_close:
+	close(fd);
+	if (result < 0) {
+ ret_msg:
+		bb_perror_msg(msg, "PACKET");
+	}
+	return result;
+}
+
+/* Let the kernel do all the work for packet generation */
+int FAST_FUNC udhcp_send_kernel_packet(struct dhcp_packet *dhcp_pkt,
+		uint32_t source_nip, int source_port,
+		uint32_t dest_nip, int dest_port)
+{
+	struct sockaddr_in sa;
+	unsigned padding;
+	int fd;
+	int result = -1;
+	const char *msg;
+
+	fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
+	if (fd < 0) {
+		msg = "socket(%s)";
+		goto ret_msg;
+	}
+	setsockopt_reuseaddr(fd);
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sin_family = AF_INET;
+	sa.sin_port = htons(source_port);
+	sa.sin_addr.s_addr = source_nip;
+	if (bind(fd, (struct sockaddr *)&sa, sizeof(sa)) == -1) {
+		msg = "bind(%s)";
+		goto ret_close;
+	}
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sin_family = AF_INET;
+	sa.sin_port = htons(dest_port);
+	sa.sin_addr.s_addr = dest_nip;
+	if (connect(fd, (struct sockaddr *)&sa, sizeof(sa)) == -1) {
+		msg = "connect";
+		goto ret_close;
+	}
+
+	udhcp_dump_packet(dhcp_pkt);
+	padding = DHCP_OPTIONS_BUFSIZE - 1 - udhcp_end_option(dhcp_pkt->options);
+	result = safe_write(fd, dhcp_pkt, DHCP_SIZE - padding);
+	msg = "write";
+ ret_close:
+	close(fd);
+	if (result < 0) {
+ ret_msg:
+		bb_perror_msg(msg, "UDP");
+	}
+	return result;
+}