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First complete version of DNS-client-id EDNS0 and ARP tracking code.

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This commit is contained in:
Simon Kelley
2015-12-28 23:17:15 +00:00
parent 11867dc28c
commit 33702ab1f8
12 changed files with 309 additions and 162 deletions
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148
src/arp.c
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@@ -16,26 +16,31 @@
#include "dnsmasq.h"
#define ARP_FREE 0
#define ARP_FOUND 1
#define ARP_NEW 2
#define ARP_EMPTY 3
/* Time between forced re-loads from kernel. */
#define INTERVAL 90
#define ARP_MARK 0
#define ARP_FOUND 1 /* Confirmed */
#define ARP_NEW 2 /* Newly created */
#define ARP_EMPTY 3 /* No MAC addr */
struct arp_record {
short hwlen, status;
unsigned short hwlen, status;
int family;
unsigned char hwaddr[DHCP_CHADDR_MAX];
struct all_addr addr;
struct arp_record *next;
};
static struct arp_record *arps = NULL, *old = NULL;
static struct arp_record *arps = NULL, *old = NULL, *freelist = NULL;
static time_t last = 0;
static int filter_mac(int family, char *addrp, char *mac, size_t maclen, void *parmv)
{
int match = 0;
struct arp_record *arp;
(void)parmv;
if (maclen > DHCP_CHADDR_MAX)
return 1;
@@ -58,16 +63,18 @@ static int filter_mac(int family, char *addrp, char *mac, size_t maclen, void *p
}
#endif
if (arp->status != ARP_EMPTY && arp->hwlen == maclen && memcmp(arp->hwaddr, mac, maclen) == 0)
arp->status = ARP_FOUND;
else
if (arp->status == ARP_EMPTY)
{
/* existing address, MAC changed or arrived new. */
/* existing address, was negative. */
arp->status = ARP_NEW;
arp->hwlen = maclen;
arp->family = family;
memcpy(arp->hwaddr, mac, maclen);
}
else if (arp->hwlen == maclen && memcmp(arp->hwaddr, mac, maclen) == 0)
/* Existing entry matches - confirm. */
arp->status = ARP_FOUND;
else
continue;
break;
}
@@ -75,10 +82,10 @@ static int filter_mac(int family, char *addrp, char *mac, size_t maclen, void *p
if (!arp)
{
/* New entry */
if (old)
if (freelist)
{
arp = old;
old = old->next;
arp = freelist;
freelist = freelist->next;
}
else if (!(arp = whine_malloc(sizeof(struct arp_record))))
return 1;
@@ -101,81 +108,72 @@ static int filter_mac(int family, char *addrp, char *mac, size_t maclen, void *p
}
/* If in lazy mode, we cache absence of ARP entries. */
int find_mac(union mysockaddr *addr, unsigned char *mac, int lazy)
int find_mac(union mysockaddr *addr, unsigned char *mac, int lazy, time_t now)
{
struct arp_record *arp, **up;
int updated = 0;
again:
for (arp = arps; arp; arp = arp->next)
{
if (addr->sa.sa_family == arp->family)
{
if (arp->addr.addr.addr4.s_addr != addr->in.sin_addr.s_addr)
continue;
}
/* If the database is less then INTERVAL old, look in there */
if (difftime(now, last) < INTERVAL)
for (arp = arps; arp; arp = arp->next)
{
if (addr->sa.sa_family == arp->family)
{
if (arp->addr.addr.addr4.s_addr != addr->in.sin_addr.s_addr)
continue;
}
#ifdef HAVE_IPV6
else
{
if (!IN6_ARE_ADDR_EQUAL(&arp->addr.addr.addr6, &addr->in6.sin6_addr))
continue;
}
else
{
if (!IN6_ARE_ADDR_EQUAL(&arp->addr.addr.addr6, &addr->in6.sin6_addr))
continue;
}
#endif
/* Only accept poitive entries unless in lazy mode. */
if (arp->status != ARP_EMPTY || lazy || updated)
{
if (mac && arp->hwlen != 0)
memcpy(mac, arp->hwaddr, arp->hwlen);
return arp->hwlen;
}
}
/* Only accept poitive entries unless in lazy mode. */
if (arp->status != ARP_EMPTY || lazy || updated)
{
if (mac && arp->hwlen != 0)
memcpy(mac, arp->hwaddr, arp->hwlen);
return arp->hwlen;
}
}
/* Not found, try the kernel */
if (!updated)
{
updated = 1;
last = now;
/* Mark all non-negative entries */
for (arp = arps, up = &arps; arp; arp = arp->next)
if (arp->status != ARP_EMPTY)
arp->status = ARP_FREE;
arp->status = ARP_MARK;
iface_enumerate(AF_UNSPEC, NULL, filter_mac);
/* Remove all unconfirmed entries to old list, announce new ones. */
/* Remove all unconfirmed entries to old list. */
for (arp = arps, up = &arps; arp; arp = arp->next)
if (arp->status == ARP_FREE)
if (arp->status == ARP_MARK)
{
*up = arp->next;
arp->next = old;
old = arp;
}
else
{
up = &arp->next;
if (arp->status == ARP_NEW)
{
char a[ADDRSTRLEN], m[ADDRSTRLEN];
union mysockaddr pa;
pa.sa.sa_family = arp->family;
pa.in.sin_addr.s_addr = arp->addr.addr.addr4.s_addr;
prettyprint_addr(&pa, a);
print_mac(m, arp->hwaddr, arp->hwlen);
my_syslog(LOG_INFO, _("new arp: %s %s"), a, m);
}
}
up = &arp->next;
goto again;
}
/* record failure, so we don't consult the kernel each time
we're asked for this address */
if (old)
if (freelist)
{
arp = old;
old = old->next;
arp = freelist;
freelist = freelist->next;
}
else
arp = whine_malloc(sizeof(struct arp_record));
@@ -198,4 +196,36 @@ int find_mac(union mysockaddr *addr, unsigned char *mac, int lazy)
return 0;
}
int do_arp_script_run(void)
{
struct arp_record *arp;
/* Notify any which went, then move to free list */
if (old)
{
#ifdef HAVE_SCRIPT
if (option_bool(OPT_DNS_CLIENT))
queue_arp(ACTION_ARP_OLD, old->hwaddr, old->hwlen, old->family, &old->addr);
#endif
arp = old;
old = arp->next;
arp->next = freelist;
freelist = arp;
return 1;
}
for (arp = arps; arp; arp = arp->next)
if (arp->status == ARP_NEW)
{
#ifdef HAVE_SCRIPT
if (option_bool(OPT_DNS_CLIENT))
queue_arp(ACTION_ARP, arp->hwaddr, arp->hwlen, arp->family, &arp->addr);
#endif
arp->status = ARP_FOUND;
return 1;
}
return 0;
}