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/******************************************************************************
* 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
*****************************************************************************/
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <time.h>
#include <ethernet.h>
#include <ipv4.h>
#include <udp.h>
#include <dhcp.h>
#define DEBUG 0
static char * response_buffer;
#if DEBUG
static void
print_ip(char *ip)
{
printf("%d.%d.%d.%d\n", ip[0], ip[1], ip[2], ip[3]);
}
#endif
/* IP header checksum calculation */
static unsigned short
checksum(unsigned short *packet, int words)
{
unsigned long checksum;
for (checksum = 0; words > 0; words--)
checksum += *packet++;
checksum = (checksum >> 16) + (checksum & 0xffff);
checksum += (checksum >> 16);
return ~checksum;
}
static int
send_bootp(filename_ip_t * fn_ip)
{
#if DEBUG
int i;
#endif
unsigned int packetsize =
sizeof(struct iphdr) + sizeof(struct ethhdr) +
sizeof(struct udphdr) + sizeof(struct btphdr);
unsigned char packet[packetsize];
struct iphdr *iph;
struct udphdr *udph;
struct btphdr *btph;
iph = (struct iphdr *) packet;
udph = (struct udphdr *) (iph + 1);
btph = (struct btphdr *) (udph + 1);
memset(packet, 0, packetsize);
fill_iphdr((uint8_t *) iph, htons(packetsize - sizeof(struct ethhdr)),
IPTYPE_UDP, 0, fn_ip->server_ip);
fill_udphdr((uint8_t *) udph,
htons(sizeof(struct udphdr) + sizeof(struct btphdr)),
htons(UDPPORT_BOOTPC), htons(UDPPORT_BOOTPS));
btph->op = 1;
btph->htype = 1;
btph->hlen = 6;
strcpy((char *) btph->file, "bla");
memcpy(btph->chaddr, get_mac_address(), 6);
#if DEBUG
printf("Sending packet\n");
printf("Packet is ");
for (i = 0; i < packetsize; i++)
printf(" %02x", packet[i]);
printf(".\n");
#endif
send_ipv4(fn_ip->fd, packet, iph->ip_len);
#if DEBUG
printf("%d bytes transmitted over socket.\n", i);
#endif
return 0;
}
static int
receive_bootp(filename_ip_t * fn_ip)
{
int len, old_sum;
unsigned int packetsize = 2000;
unsigned char packet[packetsize];
struct iphdr *iph;
struct udphdr *udph;
struct btphdr *btph;
#if DEBUG
struct ethhdr *ethh;
ethh = (struct ethhdr *) packet;
#endif
iph = (struct iphdr *) (packet + sizeof(struct ethhdr));
udph = (struct udphdr *) (iph + 1);
btph = (struct btphdr *) (udph + 1);
memset(packet, 0, packetsize);
/* setting up a timer with a timeout of one second */
set_timer(TICKS_SEC);
do {
/* let's receive a packet */
len = recv(fn_ip->fd, packet, packetsize, 0);
#if DEBUG
int j;
printf("%d bytes received, %d expected \n", len, packetsize);
if (len == 346) {
printf("Rec packet\n");
printf("Packet is ");
for (j = 0; j < len; j++) {
if (j % 16 == 0)
printf("\n");
printf(" %02x", packet[j]);
}
printf(".\n");
}
#endif
if (len == 0)
continue;
/* check if the ip checksum is correct */
old_sum = iph->ip_sum;
iph->ip_sum = 0x00;
if (old_sum !=
checksum((unsigned short *) iph, sizeof(struct iphdr) >> 1))
/* checksum failed */
continue;
/* is it a udp packet */
if (iph->ip_p != IPTYPE_UDP)
continue;
/* check if the source port and destination port and the packet
* say that it is a bootp answer */
if (udph->uh_dport != htons(UDPPORT_BOOTPC) || udph->uh_sport != htons(UDPPORT_BOOTPS))
continue;
/* check if it is a Boot Reply */
if (btph->op != 2)
continue;
/* Comparing our mac address with the one in the bootp reply */
if (memcmp(get_mac_address(), btph->chaddr, ETH_ALEN))
continue;
if(response_buffer)
memcpy(response_buffer, btph, 1720);
fn_ip->own_ip = btph->yiaddr;
fn_ip->server_ip = btph->siaddr;
strcpy((char *) fn_ip->filename, (char *) btph->file);
#if DEBUG
printf("\nThese are the details of the bootp reply:\n");
printf("Our IP address: ");
print_ip((char*) &fn_ip->own_ip);
printf("Next server IP address: ");
print_ip((char*) &fn_ip->server_ip);
printf("Boot file name: %s\n", btph->file);
printf("Packet is: %s\n", btph->file);
for (j = 0; j < len; j++) {
if (j % 16 == 0)
printf("\n");
printf(" %02x", packet[j]);
}
printf(".\n");
printf("fn_ip->own_mac: %02x:%02x:%02x:%02x:%02x:%02x\n",
get_mac_address()[0], get_mac_address()[1],
get_mac_address()[2], get_mac_address()[3],
get_mac_address()[4], get_mac_address()[5]);
printf("Header ethh->dest_mac: %02x:%02x:%02x:%02x:%02x:%02x\n",
ethh->dest_mac[0], ethh->dest_mac[1], ethh->dest_mac[2],
ethh->dest_mac[3], ethh->dest_mac[4], ethh->dest_mac[5]);
printf("Header ethh->src_mac: %02x:%02x:%02x:%02x:%02x:%02x\n",
ethh->src_mac[0], ethh->src_mac[1], ethh->src_mac[2],
ethh->src_mac[3], ethh->src_mac[4], ethh->src_mac[5]);
printf("Header ethh->typ: %x\n",ethh->type);
printf("Header iph->ip_hlv: %x\n",iph->ip_hlv);
printf("Header iph->ip_len: %x\n",iph->ip_len);
printf("Header iph->ip_id: %x\n",iph->ip_id);
printf("Header iph->ip_off: %x\n",iph->ip_off);
printf("Header iph->ip_ttl: %x\n",iph->ip_ttl);
printf("Header iph->ip_p: %x\n",iph->ip_p);
printf("Header iph->ip_sum: %x\n",iph->ip_sum);
printf("Header iph->ip_src: %x\n",iph->ip_src);
printf("Header iph->ip_dst: %x\n",iph->ip_dst);
printf("Header btph->op: %x\n",btph->op);
printf("Header btph->htype: %x\n",btph->htype);
printf("Header btph->hlen: %x\n",btph->hlen);
printf("Header btph->hops: %x\n",btph->hops);
printf("Header btph->xid: %x\n",btph->xid);
printf("Header btph->secs: %x\n",btph->secs);
printf("Header btph->ciaddr: %x\n",btph->ciaddr);
printf("Header btph->yiaddr: %x\n",btph->yiaddr);
printf("Header btph->siaddr: %x\n",btph->siaddr);
printf("Header btph->giaddr: %x\n",btph->giaddr);
printf("Header btph->chaddr: %02x:%02x:%02x:%02x:%02x:%02x:\n",
btph->chaddr[0], btph->chaddr[1], btph->chaddr[2],
btph->chaddr[3], btph->chaddr[4], btph->chaddr[5]);
#endif
return 0;
/* only do this for the time specified during set_timer() */
} while (get_timer() > 0);
return -1;
}
int
bootp(char *ret_buffer, filename_ip_t * fn_ip, unsigned int retries)
{
int i = (int) retries+1;
fn_ip->own_ip = 0;
printf(" ");
response_buffer = ret_buffer;
do {
printf("\b\b%02d", i);
if (!i--) {
printf("\nGiving up after %d bootp requests\n",
retries+1);
return -1;
}
send_bootp(fn_ip);
/* if the timer in receive_bootp expired it will return
* -1 and we will just send another bootp request just
* in case the previous one was lost. And because we don't
* trust the network cable we keep on doing this 30 times */
} while (receive_bootp(fn_ip) != 0);
printf("\b\b\b");
return 0;
}
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