l2tpns/arp.c
fred_nerk b43583c01d * Fri Mar 5 2004 David Parrish <david@dparrish.com> 1.1.0
- Change all strcpy() calls to strncpy() to avoid buffer overflow potential
- Add ICMP host unreachable support
- Logging to syslog if log_file = "syslog:facility"
- Now requires libcli 1.5
- All configuration moves to a config structure
- Ability to modify and write config on the fly through command-line interface
- Config file support is removed, and now handled by the cli
- Show hostname in cli prompt
- Keep current state type for tunnels
- Add uptime command do CLI, which also shows real-time bandwidth utilisation
- Add goodbye command to cluster master, which forces droppping a slave
- Cache IP address allocation, so that reconnecting users get the same address
- Fix tunnel resend timeouts, so that dead tunnels will be cleaned up
- Allocate tunnels and radius without using a linked list which had issues
- Fix some off-by-one errors in tunnel and session and radius arrays
- Save and reload ip address pool when dieing
- Check version and size of reloaded data when restarting
- Remove plugin_config support
- Remove old support for TBF which didn't work anyway. HTB is required to do throttling now.
- Add COPYING and Changes files
2004-03-05 00:09:03 +00:00

57 lines
1.5 KiB
C

#include <string.h>
#include <unistd.h>
#include <net/ethernet.h>
#include <net/if_arp.h>
#include <linux/if_packet.h>
#include "l2tpns.h"
/* Most of this code is based on keepalived:vrrp_arp.c */
struct arp_buf {
struct ether_header eth;
struct arphdr arp;
/* Data bit - variably sized, so not present in |struct arphdr| */
unsigned char ar_sha[ETH_ALEN]; /* Sender hardware address */
ipt ar_sip; /* Sender IP address. */
unsigned char ar_tha[ETH_ALEN]; /* Target hardware address */
ipt ar_tip; /* Target ip */
} __attribute__((packed));
void sendarp(int ifr_idx, const unsigned char* mac, ipt ip)
{
int fd;
struct sockaddr_ll sll;
struct arp_buf buf;
/* Ethernet */
memset(buf.eth.ether_dhost, 0xFF, ETH_ALEN);
memcpy(buf.eth.ether_shost, mac, ETH_ALEN);
buf.eth.ether_type = htons(ETHERTYPE_ARP);
/* ARP */
buf.arp.ar_hrd = htons(ARPHRD_ETHER);
buf.arp.ar_pro = htons(ETHERTYPE_IP);
buf.arp.ar_hln = ETH_ALEN;
buf.arp.ar_pln = 4; //IPPROTO_ADDR_LEN;
buf.arp.ar_op = htons(ARPOP_REQUEST);
/* Data */
memcpy(buf.ar_sha, mac, ETH_ALEN);
memcpy(&buf.ar_sip, &ip, sizeof(ip));
memcpy(buf.ar_tha, mac, ETH_ALEN);
memcpy(&buf.ar_tip, &ip, sizeof(ip));
/* Now actually send the thing */
fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_RARP));
memset(&sll, 0, sizeof(sll));
sll.sll_family = AF_PACKET;
strncpy(sll.sll_addr, mac, sizeof(sll.sll_addr) - 1);
sll.sll_halen = ETH_ALEN;
sll.sll_ifindex = ifr_idx;
sendto(fd, &buf, sizeof(buf), 0, (struct sockaddr*)&sll, sizeof(sll));
close(fd);
}