fqdncache.c

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	FqdncacheStats.misses++;
	f = fqdncacheAddNew(name, NULL, FQDN_PENDING);
	fqdncacheAddPending(f, handler, handlerData);
	f->request_time = current_time;
    } else if (f->status == FQDN_CACHED || f->status == FQDN_NEGATIVE_CACHED) {
	/* HIT */
	debug(35, 4) ("fqdncache_nbgethostbyaddr: HIT for '%s'\n", name);
	if (f->status == FQDN_NEGATIVE_CACHED)
	    FqdncacheStats.negative_hits++;
	else
	    FqdncacheStats.hits++;
	fqdncacheAddPending(f, handler, handlerData);
	fqdncache_call_pending(f);
	return;
    } else if (f->status == FQDN_PENDING || f->status == FQDN_DISPATCHED) {
	debug(35, 4) ("fqdncache_nbgethostbyaddr: PENDING for '%s'\n", name);
	FqdncacheStats.pending_hits++;
	fqdncacheAddPending(f, handler, handlerData);
	if (squid_curtime - f->expires > 600) {
	    debug(35, 0) ("fqdncache_nbgethostbyname: '%s' PENDING for %d seconds, aborting\n", name,
		(int) (squid_curtime + Config.negativeDnsTtl - f->expires));
	    fqdncacheChangeKey(f);
	    fqdncache_call_pending(f);
	}
	return;
    } else {
	debug(35, 1) ("fqdncache_nbgethostbyaddr: BAD status %d",
	    (int) f->status);
	assert(0);
    }
    /* for HIT, PENDING, DISPATCHED we've returned.  For MISS we submit */
    c = xcalloc(1, sizeof(*c));
    c->data = f;
    cbdataAdd(c, cbdataXfree, 0);
    f->status = FQDN_DISPATCHED;
    fqdncacheLockEntry(f);	/* lock while FQDN_DISPATCHED */
    dnsSubmit(f->name, fqdncacheHandleReply, c);
}

/* initialize the fqdncache */
void
fqdncache_init(void)
{
    int n;
    if (fqdn_table)
	return;
    debug(35, 3) ("Initializing FQDN Cache...\n");
    memset(&FqdncacheStats, '\0', sizeof(FqdncacheStats));
    memset(&lru_list, '\0', sizeof(lru_list));
    fqdncache_high = (long) (((float) Config.fqdncache.size *
	    (float) FQDN_HIGH_WATER) / (float) 100);
    fqdncache_low = (long) (((float) Config.fqdncache.size *
	    (float) FQDN_LOW_WATER) / (float) 100);
    n = hashPrime(fqdncache_high / 4);
    fqdn_table = hash_create((HASHCMP *) strcmp, n, hash4);
    cachemgrRegister("fqdncache",
	"FQDN Cache Stats and Contents",
	fqdnStats, 0, 1);
}

/* clean up the pending entries in dnsserver */
/* return 1 if we found the host, 0 otherwise */
int
fqdncacheUnregister(struct in_addr addr, void *data)
{
    char *name = inet_ntoa(addr);
    fqdncache_entry *f = NULL;
    fqdn_pending *p = NULL;
    int n = 0;
    debug(35, 3) ("fqdncacheUnregister: name '%s'\n", name);
    if ((f = fqdncache_get(name)) == NULL)
	return 0;
    if (f->status == FQDN_PENDING || f->status == FQDN_DISPATCHED) {
	for (p = f->pending_head; p; p = p->next) {
	    if (p->handlerData != data)
		continue;
	    p->handler = NULL;
	    n++;
	}
    }
    if (n == 0)
	debug_trap("fqdncacheUnregister: callback data not found");
    debug(35, 3) ("fqdncacheUnregister: unregistered %d handlers\n", n);
    return n;
}

const char *
fqdncache_gethostbyaddr(struct in_addr addr, int flags)
{
    char *name = inet_ntoa(addr);
    fqdncache_entry *f = NULL;
    struct in_addr ip;
    assert(name);
    FqdncacheStats.requests++;
    if ((f = fqdncache_get(name))) {
	if (fqdncacheExpiredEntry(f)) {
	    fqdncache_release(f);
	    f = NULL;
	}
    }
    if (f) {
	if (f->status == FQDN_NEGATIVE_CACHED) {
	    FqdncacheStats.negative_hits++;
	    dns_error_message = f->error_message;
	    return NULL;
	} else {
	    FqdncacheStats.hits++;
	    f->lastref = squid_curtime;
	    return f->names[0];
	}
    }
    /* check if it's already a FQDN address in text form. */
    if (!safe_inet_addr(name, &ip))
	return name;
    FqdncacheStats.misses++;
    if (flags & FQDN_LOOKUP_IF_MISS)
	fqdncache_nbgethostbyaddr(addr, dummy_handler, NULL);
    return NULL;
}


/* process objects list */
void
fqdnStats(StoreEntry * sentry)
{
    fqdncache_entry *f = NULL;
    int k;
    int ttl;
    if (fqdn_table == NULL)
	return;
    storeAppendPrintf(sentry, "FQDN Cache Statistics:\n");
    storeAppendPrintf(sentry, "FQDNcache Entries: %d\n",
	memInUse(MEM_FQDNCACHE_ENTRY));
    storeAppendPrintf(sentry, "FQDNcache Requests: %d\n",
	FqdncacheStats.requests);
    storeAppendPrintf(sentry, "FQDNcache Hits: %d\n",
	FqdncacheStats.hits);
    storeAppendPrintf(sentry, "FQDNcache Pending Hits: %d\n",
	FqdncacheStats.pending_hits);
    storeAppendPrintf(sentry, "FQDNcache Negative Hits: %d\n",
	FqdncacheStats.negative_hits);
    storeAppendPrintf(sentry, "FQDNcache Misses: %d\n",
	FqdncacheStats.misses);
    storeAppendPrintf(sentry, "Blocking calls to gethostbyaddr(): %d\n",
	FqdncacheStats.ghba_calls);
    storeAppendPrintf(sentry, "FQDN Cache Contents:\n\n");

    hash_first(fqdn_table);
    while ((f = (fqdncache_entry *) hash_next(fqdn_table))) {
	if (f->status == FQDN_PENDING || f->status == FQDN_DISPATCHED)
	    ttl = 0;
	else
	    ttl = (f->expires - squid_curtime);
	storeAppendPrintf(sentry, " %-32.32s %c %6d %d",
	    f->name,
	    fqdncache_status_char[f->status],
	    ttl,
	    (int) f->name_count);
	for (k = 0; k < (int) f->name_count; k++)
	    storeAppendPrintf(sentry, " %s", f->names[k]);
	storeAppendPrintf(sentry, "\n");
    }
}

static void
dummy_handler(const char *bufnotused, void *datanotused)
{
    return;
}

void
fqdncacheReleaseInvalid(const char *name)
{
    fqdncache_entry *f;
    if ((f = fqdncache_get(name)) == NULL)
	return;
    if (f->status != FQDN_NEGATIVE_CACHED)
	return;
    fqdncache_release(f);
}

const char *
fqdnFromAddr(struct in_addr addr)
{
    const char *n;
    static char buf[32];
    if (Config.onoff.log_fqdn && (n = fqdncache_gethostbyaddr(addr, 0)))
	return n;
    xstrncpy(buf, inet_ntoa(addr), 32);
    return buf;
}

static void
fqdncacheLockEntry(fqdncache_entry * f)
{
    if (f->locks++ == 0) {
	dlinkDelete(&f->lru, &lru_list);
	dlinkAdd(f, &f->lru, &lru_list);
    }
}

static void
fqdncacheUnlockEntry(fqdncache_entry * f)
{
    if (f->locks == 0) {
	debug_trap("fqdncacheUnlockEntry: Entry has no locks");
	return;
    }
    f->locks--;
    if (fqdncacheExpiredEntry(f))
	fqdncache_release(f);
}

static void
fqdncacheFreeEntry(void *data)
{
    fqdncache_entry *f = data;
    fqdn_pending *p = NULL;
    int k;
    while ((p = f->pending_head)) {
	f->pending_head = p->next;
	memFree(p, MEM_FQDNCACHE_PENDING);
    }
    for (k = 0; k < (int) f->name_count; k++)
	safe_free(f->names[k]);
    safe_free(f->name);
    safe_free(f->error_message);
    memFree(f, MEM_FQDNCACHE_ENTRY);
}

void
fqdncacheFreeMemory(void)
{
    hashFreeItems(fqdn_table, fqdncacheFreeEntry);
    hashFreeMemory(fqdn_table);
    fqdn_table = NULL;
}

static void
fqdncacheChangeKey(fqdncache_entry * f)
{
    static int index = 0;
    LOCAL_ARRAY(char, new_key, 256);
    hash_link *table_entry = hash_lookup(fqdn_table, f->name);
    if (table_entry == NULL) {
	debug(35, 0) ("fqdncacheChangeKey: Could not find key '%s'\n", f->name);
	return;
    }
    if (f != (fqdncache_entry *) table_entry) {
	debug_trap("fqdncacheChangeKey: f != table_entry!");
	return;
    }
    hash_remove_link(fqdn_table, table_entry);
    snprintf(new_key, 256, "%d/", ++index);
    strncat(new_key, f->name, 128);
    debug(35, 1) ("fqdncacheChangeKey: from '%s' to '%s'\n", f->name, new_key);
    safe_free(f->name);
    f->name = xstrdup(new_key);
    hash_join(fqdn_table, (hash_link *) f);
}

/* call during reconfigure phase to clear out all the
 * pending and dispatched reqeusts that got lost */
void
fqdncache_restart(void)
{
    fqdncache_entry *this;
    assert(fqdn_table);
    hash_first(fqdn_table);
    while ((this = (fqdncache_entry *) hash_next(fqdn_table))) {
	if (this->status == FQDN_CACHED)
	    continue;
	if (this->status == FQDN_NEGATIVE_CACHED)
	    continue;
    }
    fqdncache_high = (long) (((float) Config.fqdncache.size *
	    (float) FQDN_HIGH_WATER) / (float) 100);
    fqdncache_low = (long) (((float) Config.fqdncache.size *
	    (float) FQDN_LOW_WATER) / (float) 100);
}

#ifdef SQUID_SNMP
/*
 * The function to return the fqdn statistics via SNMP
 */

variable_list *
snmp_netFqdnFn(variable_list * Var, snint * ErrP)
{
    variable_list *Answer;

    debug(49, 5) ("snmp_netFqdnFn: Processing request:\n", Var->name[LEN_SQ_NET +
	    1]);
    snmpDebugOid(5, Var->name, Var->name_length);

    Answer = snmp_var_new(Var->name, Var->name_length);
    *ErrP = SNMP_ERR_NOERROR;
    Answer->val_len = sizeof(snint);
    Answer->val.integer = xmalloc(Answer->val_len);
    Answer->type = SMI_COUNTER32;

    switch (Var->name[LEN_SQ_NET + 1]) {
    case FQDN_ENT:
	*(Answer->val.integer) = memInUse(MEM_FQDNCACHE_ENTRY);
	Answer->type = SMI_GAUGE32;
	break;
    case FQDN_REQ:
	*(Answer->val.integer) = FqdncacheStats.requests;
	break;
    case FQDN_HITS:
	*(Answer->val.integer) = FqdncacheStats.hits;
	break;
    case FQDN_PENDHIT:
	*(Answer->val.integer) = FqdncacheStats.pending_hits;
	Answer->type = SMI_GAUGE32;
	break;
    case FQDN_NEGHIT:
	*(Answer->val.integer) = FqdncacheStats.negative_hits;
	break;
    case FQDN_MISS:
	*(Answer->val.integer) = FqdncacheStats.misses;
	break;
    case FQDN_GHBN:
	*(Answer->val.integer) = FqdncacheStats.ghba_calls;
	break;
    default:
	*ErrP = SNMP_ERR_NOSUCHNAME;
	snmp_var_free(Answer);
	return (NULL);
    }
    return Answer;
}

#endif /*SQUID_SNMP */