auto import from //depot/cupcake/@135843
diff --git a/libnetutils/packet.c b/libnetutils/packet.c
new file mode 100644
index 0000000..9388345
--- /dev/null
+++ b/libnetutils/packet.c
@@ -0,0 +1,239 @@
+/*
+ * Copyright 2008, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/uio.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/udp.h>
+#include <linux/if_packet.h>
+#include <linux/if_ether.h>
+#include <errno.h>
+
+#ifdef ANDROID
+#define LOG_TAG "DHCP"
+#include <cutils/log.h>
+#else
+#include <stdio.h>
+#include <string.h>
+#define LOGD printf
+#define LOGW printf
+#endif
+
+#include "dhcpmsg.h"
+
+int fatal();
+
+int open_raw_socket(const char *ifname, uint8_t *hwaddr, int if_index)
+{
+ int s, flag;
+ struct sockaddr_ll bindaddr;
+
+ if((s = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP))) < 0) {
+ return fatal("socket(PF_PACKET)");
+ }
+
+ memset(&bindaddr, 0, sizeof(bindaddr));
+ bindaddr.sll_family = AF_PACKET;
+ bindaddr.sll_protocol = htons(ETH_P_IP);
+ bindaddr.sll_halen = ETH_ALEN;
+ memcpy(bindaddr.sll_addr, hwaddr, ETH_ALEN);
+ bindaddr.sll_ifindex = if_index;
+
+ if (bind(s, (struct sockaddr *)&bindaddr, sizeof(bindaddr)) < 0) {
+ return fatal("Cannot bind raw socket to interface");
+ }
+
+ return s;
+}
+
+static uint32_t checksum(void *buffer, unsigned int count, uint32_t startsum)
+{
+ uint16_t *up = (uint16_t *)buffer;
+ uint32_t sum = startsum;
+ uint32_t upper16;
+
+ while (count > 1) {
+ sum += *up++;
+ count -= 2;
+ }
+ if (count > 0) {
+ sum += (uint16_t) *(uint8_t *)up;
+ }
+ while ((upper16 = (sum >> 16)) != 0) {
+ sum = (sum & 0xffff) + upper16;
+ }
+ return sum;
+}
+
+static uint32_t finish_sum(uint32_t sum)
+{
+ return ~sum & 0xffff;
+}
+
+int send_packet(int s, int if_index, struct dhcp_msg *msg, int size,
+ uint32_t saddr, uint32_t daddr, uint32_t sport, uint32_t dport)
+{
+ struct iphdr ip;
+ struct udphdr udp;
+ struct iovec iov[3];
+ uint32_t udpsum;
+ uint16_t temp;
+ struct msghdr msghdr;
+ struct sockaddr_ll destaddr;
+
+ ip.version = IPVERSION;
+ ip.ihl = sizeof(ip) >> 2;
+ ip.tos = 0;
+ ip.tot_len = htons(sizeof(ip) + sizeof(udp) + size);
+ ip.id = 0;
+ ip.frag_off = 0;
+ ip.ttl = IPDEFTTL;
+ ip.protocol = IPPROTO_UDP;
+ ip.check = 0;
+ ip.saddr = saddr;
+ ip.daddr = daddr;
+ ip.check = finish_sum(checksum(&ip, sizeof(ip), 0));
+
+ udp.source = htons(sport);
+ udp.dest = htons(dport);
+ udp.len = htons(sizeof(udp) + size);
+ udp.check = 0;
+
+ /* Calculate checksum for pseudo header */
+ udpsum = checksum(&ip.saddr, sizeof(ip.saddr), 0);
+ udpsum = checksum(&ip.daddr, sizeof(ip.daddr), udpsum);
+ temp = htons(IPPROTO_UDP);
+ udpsum = checksum(&temp, sizeof(temp), udpsum);
+ temp = udp.len;
+ udpsum = checksum(&temp, sizeof(temp), udpsum);
+
+ /* Add in the checksum for the udp header */
+ udpsum = checksum(&udp, sizeof(udp), udpsum);
+
+ /* Add in the checksum for the data */
+ udpsum = checksum(msg, size, udpsum);
+ udp.check = finish_sum(udpsum);
+
+ iov[0].iov_base = (char *)&ip;
+ iov[0].iov_len = sizeof(ip);
+ iov[1].iov_base = (char *)&udp;
+ iov[1].iov_len = sizeof(udp);
+ iov[2].iov_base = (char *)msg;
+ iov[2].iov_len = size;
+ memset(&destaddr, 0, sizeof(destaddr));
+ destaddr.sll_family = AF_PACKET;
+ destaddr.sll_protocol = htons(ETH_P_IP);
+ destaddr.sll_ifindex = if_index;
+ destaddr.sll_halen = ETH_ALEN;
+ memcpy(destaddr.sll_addr, "\xff\xff\xff\xff\xff\xff", ETH_ALEN);
+
+ msghdr.msg_name = &destaddr;
+ msghdr.msg_namelen = sizeof(destaddr);
+ msghdr.msg_iov = iov;
+ msghdr.msg_iovlen = sizeof(iov) / sizeof(struct iovec);
+ msghdr.msg_flags = 0;
+ msghdr.msg_control = 0;
+ msghdr.msg_controllen = 0;
+ return sendmsg(s, &msghdr, 0);
+}
+
+int receive_packet(int s, struct dhcp_msg *msg)
+{
+ int nread;
+ int is_valid;
+ struct dhcp_packet {
+ struct iphdr ip;
+ struct udphdr udp;
+ struct dhcp_msg dhcp;
+ } packet;
+ int dhcp_size;
+ uint32_t sum;
+ uint16_t temp;
+ uint32_t saddr, daddr;
+
+ nread = read(s, &packet, sizeof(packet));
+ if (nread < 0) {
+ return -1;
+ }
+ /*
+ * The raw packet interface gives us all packets received by the
+ * network interface. We need to filter out all packets that are
+ * not meant for us.
+ */
+ is_valid = 0;
+ if (nread < (int)(sizeof(struct iphdr) + sizeof(struct udphdr))) {
+#if VERBOSE
+ LOGD("Packet is too small (%d) to be a UDP datagram", nread);
+#endif
+ } else if (packet.ip.version != IPVERSION || packet.ip.ihl != (sizeof(packet.ip) >> 2)) {
+#if VERBOSE
+ LOGD("Not a valid IP packet");
+#endif
+ } else if (nread < ntohs(packet.ip.tot_len)) {
+#if VERBOSE
+ LOGD("Packet was truncated (read %d, needed %d)", nread, ntohs(packet.ip.tot_len));
+#endif
+ } else if (packet.ip.protocol != IPPROTO_UDP) {
+#if VERBOSE
+ LOGD("IP protocol (%d) is not UDP", packet.ip.protocol);
+#endif
+ } else if (packet.udp.dest != htons(PORT_BOOTP_CLIENT)) {
+#if VERBOSE
+ LOGD("UDP dest port (%d) is not DHCP client", ntohs(packet.udp.dest));
+#endif
+ } else {
+ is_valid = 1;
+ }
+
+ if (!is_valid) {
+ return -1;
+ }
+
+ /* Seems like it's probably a valid DHCP packet */
+ /* validate IP header checksum */
+ sum = finish_sum(checksum(&packet.ip, sizeof(packet.ip), 0));
+ if (sum != 0) {
+ LOGW("IP header checksum failure (0x%x)", packet.ip.check);
+ return -1;
+ }
+ /*
+ * Validate the UDP checksum.
+ * Since we don't need the IP header anymore, we "borrow" it
+ * to construct the pseudo header used in the checksum calculation.
+ */
+ dhcp_size = ntohs(packet.udp.len) - sizeof(packet.udp);
+ saddr = packet.ip.saddr;
+ daddr = packet.ip.daddr;
+ nread = ntohs(packet.ip.tot_len);
+ memset(&packet.ip, 0, sizeof(packet.ip));
+ packet.ip.saddr = saddr;
+ packet.ip.daddr = daddr;
+ packet.ip.protocol = IPPROTO_UDP;
+ packet.ip.tot_len = packet.udp.len;
+ temp = packet.udp.check;
+ packet.udp.check = 0;
+ sum = finish_sum(checksum(&packet, nread, 0));
+ packet.udp.check = temp;
+ if (temp != sum) {
+ LOGW("UDP header checksum failure (0x%x should be 0x%x)", sum, temp);
+ return -1;
+ }
+ memcpy(msg, &packet.dhcp, dhcp_size);
+ return dhcp_size;
+}