--- /dev/null
+/******************************************************************************
+ * Copyright (c) 2004, 2008 IBM Corporation
+ * All rights reserved.
+ * This program and the accompanying materials
+ * are made available under the terms of the BSD License
+ * which accompanies this distribution, and is available at
+ * http://www.opensource.org/licenses/bsd-license.php
+ *
+ * Contributors:
+ * IBM Corporation - initial implementation
+ *****************************************************************************/
+
+
+/*>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ALGORITHMS <<<<<<<<<<<<<<<<<<<<<<<<<<<<<*/
+
+/** \file netbase.c <pre>
+ * *********************** Receive-handle diagram *************************
+ *
+ * Note: Every layer calls out required upper layer
+ *
+ * lower
+ * | MAC/LLC Receive packet (receive_ether)
+ * | |
+ * | NETWORK +-----------+---------+
+ * | | |
+ * | IPv4 (handle_ipv4) IPv6 (handle_ipv4)
+ * | ARP (handle_arp) ICMP & NDP
+ * | ICMP |
+ * | | |
+ * | +---------+---------+
+ * | |
+ * | TRANSPORT +---------+---------+
+ * | | |
+ * | TCP (handle_tcp) UDP (handle_udp)
+ * | |
+ * | APPLICATION +----------------+-----------+
+ * V | |
+ * upper DNS (handle_dns) BootP / DHCP (handle_bootp_client)
+ *
+ * ************************************************************************
+ * </pre> */
+
+
+/*>>>>>>>>>>>>>>>>>>>>>>> DEFINITIONS & DECLARATIONS <<<<<<<<<<<<<<<<<<<<*/
+
+#include <ethernet.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <ipv4.h>
+#include <ipv6.h>
+
+
+/*>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LOCAL VARIABLES <<<<<<<<<<<<<<<<<<<<<<<<<*/
+
+static uint8_t ether_packet[ETH_MTU_SIZE];
+static uint8_t own_mac[6] = {0, 0, 0, 0, 0, 0};
+static uint8_t multicast_mac[] = {0x01, 0x00, 0x5E};
+static const uint8_t broadcast_mac[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+
+/*>>>>>>>>>>>>>>>>>>>>>>>>>>>>> IMPLEMENTATION <<<<<<<<<<<<<<<<<<<<<<<<<<*/
+
+/**
+ * Ethernet: Set the own MAC address to initializes ethernet layer.
+ *
+ * @param own_mac own hardware-address (MAC)
+ */
+void
+set_mac_address(const uint8_t * _own_mac) {
+ if (_own_mac)
+ memcpy(own_mac, _own_mac, 6);
+ else
+ memset(own_mac, 0, 6);
+}
+
+/**
+ * Ethernet: Set the own MAC address to initializes ethernet layer.
+ *
+ * @return own hardware-address (MAC)
+ */
+const uint8_t *
+get_mac_address(void) {
+ return own_mac;
+}
+
+/**
+ * Ethernet: Check if given multicast address is a multicast MAC address
+ * starting with 0x3333
+ *
+ * @return true or false
+ */
+static uint8_t
+is_multicast_mac(uint8_t * mac) {
+
+ uint16_t mc = 0x3333;
+ if (memcmp(mac, &mc, 2) == 0)
+ return 1;
+
+ return 0;
+}
+
+
+/**
+ * Ethernet: Receives an ethernet-packet and handles it according to
+ * Receive-handle diagram.
+ *
+ * @param fd socket fd
+ * @return ZERO - packet was handled or no packets received;
+ * NON ZERO - error condition occurs.
+ */
+int32_t
+receive_ether(int fd) {
+ int32_t bytes_received;
+ struct ethhdr * ethh;
+
+ memset(ether_packet, 0, ETH_MTU_SIZE);
+ bytes_received = recv(fd, ether_packet, ETH_MTU_SIZE, 0);
+
+ if (!bytes_received) // No messages
+ return 0;
+
+ if (bytes_received < sizeof(struct ethhdr))
+ return -1; // packet is too small
+
+ ethh = (struct ethhdr *) ether_packet;
+
+ if(memcmp(ethh->dest_mac, broadcast_mac, 6) != 0
+ && memcmp(ethh->dest_mac, multicast_mac, 3) != 0
+ && memcmp(ethh->dest_mac, own_mac, 6 ) != 0
+ && !is_multicast_mac(ethh->dest_mac))
+ return -1; // packet is too small
+
+ switch (htons(ethh -> type)) {
+ case ETHERTYPE_IP:
+ return handle_ipv4(fd, (uint8_t*) (ethh + 1),
+ bytes_received - sizeof(struct ethhdr));
+
+ case ETHERTYPE_IPv6:
+ return handle_ipv6(fd, ether_packet + sizeof(struct ethhdr),
+ bytes_received - sizeof(struct ethhdr));
+
+ case ETHERTYPE_ARP:
+ return handle_arp(fd, (uint8_t*) (ethh + 1),
+ bytes_received - sizeof(struct ethhdr));
+ default:
+ break;
+ }
+ return -1; // unknown protocol
+}
+
+/**
+ * Ethernet: Sends an ethernet frame via the initialized file descriptor.
+ *
+ * @return number of transmitted bytes
+ */
+int
+send_ether(int fd, void* buffer, int len)
+{
+ return send(fd, buffer, len, 0);
+}
+
+/**
+ * Ethernet: Creates Ethernet-packet. Places Ethernet-header in a packet and
+ * fills it with corresponding information.
+ * <p>
+ * Use this function with similar functions for other network layers
+ * (fill_arphdr, fill_iphdr, fill_udphdr, fill_dnshdr, fill_btphdr).
+ *
+ * @param packet Points to the place where eth-header must be placed.
+ * @param eth_type Type of the next level protocol (e.g. IP or ARP).
+ * @param src_mac Sender MAC address
+ * @param dest_mac Receiver MAC address
+ * @see ethhdr
+ * @see fill_arphdr
+ * @see fill_iphdr
+ * @see fill_udphdr
+ * @see fill_dnshdr
+ * @see fill_btphdr
+ */
+void
+fill_ethhdr(uint8_t * packet, uint16_t eth_type,
+ const uint8_t * src_mac, const uint8_t * dest_mac) {
+ struct ethhdr * ethh = (struct ethhdr *) packet;
+
+ ethh -> type = htons(eth_type);
+ memcpy(ethh -> src_mac, src_mac, 6);
+ memcpy(ethh -> dest_mac, dest_mac, 6);
+}
Code Review / kvmfornfv.git / blobdiff