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/* Copyright 2002 Yon Uriarte and Jeff Dike
* Licensed under the GPL
*/
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/signal.h>
#include "nethub.h"
#include "switch.h"
#include "hash.h"
struct hash_entry {
struct hash_entry *next;
struct hash_entry *prev;
time_t last_seen;
void *port;
unsigned char dst[ETH_ALEN];
};
static int calc_hash(char *src)
{
return ((*(u_int32_t *) &src[0] % HASH_MOD) ^ src[4] ^ src[5] ) % HASH_SIZE ;
}
static struct hash_entry *find_entry(struct nethub *nh,
char *dst)
{
struct hash_entry *e;
int k = calc_hash(dst);
for(e = nh->h[k]; e; e = e->next){
if(!memcmp(&e->dst, dst, ETH_ALEN)) return(e);
}
return(NULL);
}
void *find_in_hash(struct nethub *nh,
char *dst)
{
struct hash_entry *e = find_entry(nh, dst);
if(e == NULL) return(NULL);
return(e->port);
}
void insert_into_hash(struct nethub *nh,
char *src, void *port)
{
struct hash_entry *new;
int k = calc_hash(src);
new = find_in_hash(nh, src);
if(new != NULL) return;
new = malloc(sizeof(*new));
if(new == NULL){
perror("Failed to malloc hash entry");
return;
}
memcpy(&new->dst, src, ETH_ALEN );
if(nh->h[k] != NULL) nh->h[k]->prev = new;
new->next = nh->h[k];
new->prev = NULL;
new->port = port;
new->last_seen = 0;
nh->h[k] = new;
}
void update_entry_time(struct nethub *nh,
char *src)
{
struct hash_entry *e;
e = find_entry(nh, src);
if(e == NULL) return;
e->last_seen = time(NULL);
}
static void delete_hash_entry(struct nethub *nh,
struct hash_entry *old)
{
int k = calc_hash(old->dst);
if(old->prev != NULL) old->prev->next = old->next;
if(old->next != NULL) old->next->prev = old->prev;
if(nh->h[k] == old) nh->h[k] = old->next;
free(old);
}
void delete_hash(struct nethub *nh,
char *dst)
{
struct hash_entry *old = find_entry(nh, dst);
if(old == NULL) return;
delete_hash_entry(nh, old);
}
static void for_all_hash(struct nethub *nh,
void (*f)(struct nethub *nh,
struct hash_entry *,
void *),
void *arg)
{
int i;
struct hash_entry *e, *next;
for(i = 0; i < HASH_SIZE; i++){
for(e = nh->h[i]; e; e = next){
next = e->next;
(*f)(nh, e, arg);
}
}
}
struct printer {
time_t now;
char *(*port_id)(void *);
};
static void print_hash_entry(struct nethub *nh,
struct hash_entry *e, void *arg)
{
struct printer *p = arg;
fprintf(stderr, "Hash: %d Addr: %02x:%02x:%02x:%02x:%02x:%02x to port: %s "
"age %ld secs\n", calc_hash(e->dst),
e->dst[0], e->dst[1], e->dst[2], e->dst[3], e->dst[4], e->dst[5],
(*p->port_id)(e->port), (int) p->now - e->last_seen);
}
void print_hash(struct nethub *nh,
char *(*port_id)(void *))
{
struct printer p = ((struct printer) { now : time(NULL),
port_id : port_id });
for_all_hash(nh, print_hash_entry, &p);
}
static void gc(struct nethub *nh,
struct hash_entry *e,
void *now)
{
time_t t = *(time_t *) now;
if(e->last_seen + GC_EXPIRE < t)
delete_hash_entry(nh, e);
}
void hash_periodic(struct nethub *nh)
{
time_t t = time(NULL);
for_all_hash(nh, &gc, &t);
}
void hash_init(struct nethub *nh)
{
/* nothing right now */
}
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