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Code Issues Releases Wiki Activity

Start moving the dispatcher code to allow it to be used for wire format as well as for lightweight resolver daemon stuff.

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This commit is contained in:
Michael Graff
2000-01-07 01:17:47 +00:00
parent 8a9b755d32
commit 0941f35ad9
6 changed files with 69 additions and 35 deletions
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68
lib/dns/dispatch.c
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@@ -45,7 +45,7 @@
struct dns_dispentry {
unsigned int magic;
dns_messageid_t id;
isc_uint32_t id;
unsigned int bucket;
isc_sockaddr_t host;
isc_task_t *task;
@@ -87,6 +87,7 @@ struct dns_dispatch {
ISC_LIST(dns_dispentry_t) rq_handlers; /* request handler list */
ISC_LIST(dns_dispatchevent_t) rq_events; /* holder for rq events */
dns_tcpmsg_t tcpmsg; /* for tcp streams */
dns_dispatchmethods_t methods; /* methods to use */
isc_lfsr_t qid_lfsr1; /* state generator info */
isc_lfsr_t qid_lfsr2; /* state generator info */
unsigned int qid_nbuckets; /* hash table size */
@@ -112,8 +113,8 @@ static void destroy(dns_dispatch_t *);
static void udp_recv(isc_task_t *, isc_event_t *);
static void tcp_recv(isc_task_t *, isc_event_t *);
static inline void startrecv(dns_dispatch_t *);
static dns_messageid_t randomid(dns_dispatch_t *);
static unsigned int hash(dns_dispatch_t *, isc_sockaddr_t *, dns_messageid_t);
static isc_uint32_t dns_randomid(dns_dispatch_t *);
static isc_uint32_t dns_hash(dns_dispatch_t *, isc_sockaddr_t *, isc_uint32_t);
static void free_buffer(dns_dispatch_t *disp, void *buf, unsigned int len);
static void *allocate_buffer(dns_dispatch_t *disp, unsigned int len);
static inline void free_event(dns_dispatch_t *disp, dns_dispatchevent_t *ev);
@@ -138,16 +139,38 @@ reseed_lfsr(isc_lfsr_t *lfsr, void *arg)
/*
* Return an unpredictable message ID.
*/
static inline dns_messageid_t
randomid(dns_dispatch_t *disp)
static isc_uint32_t
dns_randomid(dns_dispatch_t *disp)
{
isc_uint32_t id;
id = isc_lfsr_generate32(&disp->qid_lfsr1, &disp->qid_lfsr2);
return ((dns_messageid_t)(id & 0x0000ffff));
return (id & 0x0000ffffU);
}
/*
* Return a hash of the destination and message id.
*/
static isc_uint32_t
dns_hash(dns_dispatch_t *disp, isc_sockaddr_t *dest, isc_uint32_t id)
{
unsigned int ret;
ret = isc_sockaddr_hash(dest, ISC_TRUE);
ret ^= (id & 0x0000ffff); /* important to mask off garbage bits */
ret %= disp->qid_nbuckets;
INSIST(ret < disp->qid_nbuckets);
return (ret);
}
static dns_dispatchmethods_t dns_wire_methods = {
dns_randomid,
dns_hash
};
static dns_dispentry_t *
linear_first(dns_dispatch_t *disp)
{
@@ -187,23 +210,6 @@ linear_next(dns_dispatch_t *disp, dns_dispentry_t *resp)
return (NULL);
}
/*
* Return a hash of the destination and message id.
*/
static unsigned int
hash(dns_dispatch_t *disp, isc_sockaddr_t *dest, dns_messageid_t id)
{
unsigned int ret;
ret = isc_sockaddr_hash(dest, ISC_TRUE);
ret ^= (id & 0x0000ffff); /* important to mask off garbage bits */
ret %= disp->qid_nbuckets;
INSIST(ret < disp->qid_nbuckets);
return (ret);
}
/*
* Called when refcount reaches 0 (and safe to destroy)
*/
@@ -476,7 +482,7 @@ udp_recv(isc_task_t *task, isc_event_t *ev_in)
/* query */
} else {
/* response */
bucket = hash(disp, &ev->address, id);
bucket = disp->methods.hash(disp, &ev->address, id);
resp = bucket_search(disp, &ev->address, id, bucket);
XDEBUG(("Search for response in bucket %d: %s\n",
bucket, (resp == NULL ? "NOT FOUND" : "FOUND")));
@@ -662,7 +668,7 @@ tcp_recv(isc_task_t *task, isc_event_t *ev_in)
/* query */
} else {
/* response */
bucket = hash(disp, &tcpmsg->address, id);
bucket = disp->methods.hash(disp, &tcpmsg->address, id);
resp = bucket_search(disp, &tcpmsg->address, id, bucket);
XDEBUG(("Search for response in bucket %d: %s\n",
bucket, (resp == NULL ? "NOT FOUND" : "FOUND")));
@@ -785,6 +791,7 @@ dns_dispatch_create(isc_mem_t *mctx, isc_socket_t *sock, isc_task_t *task,
unsigned int maxbuffersize,
unsigned int maxbuffers, unsigned int maxrequests,
unsigned int buckets, unsigned int increment,
dns_dispatchmethods_t *methods,
dns_dispatch_t **dispp)
{
dns_dispatch_t *disp;
@@ -831,6 +838,11 @@ dns_dispatch_create(isc_mem_t *mctx, isc_socket_t *sock, isc_task_t *task,
ISC_LIST_INIT(disp->rq_handlers);
ISC_LIST_INIT(disp->rq_events);
if (methods == NULL)
disp->methods = dns_wire_methods;
else
disp->methods = *methods;
disp->qid_table = isc_mem_get(disp->mctx,
buckets * sizeof(dns_displist_t));
if (disp->qid_table == NULL) {
@@ -1023,8 +1035,8 @@ dns_dispatch_addresponse(dns_dispatch_t *disp, isc_sockaddr_t *dest,
/*
* Try somewhat hard to find an unique ID.
*/
id = randomid(disp);
bucket = hash(disp, dest, id);
id = disp->methods.randomid(disp);
bucket = disp->methods.hash(disp, dest, id);
ok = ISC_FALSE;
for (i = 0 ; i < 64 ; i++) {
if (bucket_search(disp, dest, id, bucket) == NULL) {
@@ -1033,7 +1045,7 @@ dns_dispatch_addresponse(dns_dispatch_t *disp, isc_sockaddr_t *dest,
}
id += disp->qid_increment;
id &= 0x0000ffff;
bucket = hash(disp, dest, id);
bucket = disp->methods.hash(disp, dest, id);
}
if (!ok) {