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This commit is contained in:
Michael Graff
1999-06-18 02:01:42 +00:00
parent 422d79178c
commit a8dcebd041
2 changed files with 226 additions and 111 deletions
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287
lib/dns/dispatch.c
View File

@@ -24,6 +24,7 @@
#include <isc/assertions.h>
#include <isc/error.h>
#include <isc/mem.h>
#include <isc/mutex.h>
#include <isc/socket.h>
@@ -31,16 +32,19 @@
#include <dns/result.h>
#include <dns/dispatch.h>
typedef struct dns_resentry dns_resentry_t;
#include "../isc/util.h"
struct dns_resentry {
unsigned int magic;
dns_messageid_t id;
unsigned int bucket;
isc_sockaddr_t dest;
isc_task_t *task;
isc_taskaction_t action;
void *arg;
ISC_LINK(dns_resentry_t) link;
};
#define INVALID_BUCKET (0xffffdead);
struct dns_dispatch {
/* Unlocked. */
@@ -55,19 +59,30 @@ struct dns_dispatch {
unsigned int refcount; /* number of users */
isc_mempool_t *epool; /* memory pool for events */
isc_mempool_t *bpool; /* memory pool for buffers */
isc_mempool_t *mpool; /* resentries allocated here */
ISC_LIST(dns_dispatchevent_t) rq_handlers; /* request handler list */
isc_mempool_t *rpool; /* resentries allocated here */
ISC_LIST(dns_resentry_t) rq_handlers; /* request handler list */
isc_int32_t qid_state; /* state generator info */
unsigned int qid_hashsize; /* hash table size */
ISC_LIST(dns_dispatchevent_t) *qid_table; /* the table itself */
unsigned int qid_mask; /* mask for hash table */
ISC_LIST(dns_resentry_t) *qid_table; /* the table itself */
};
#define REQUEST_MAGIC 0x53912051 /* "random" value */
#define VALID_REQUEST(e) ((e) != NULL && (e)->magic == REQUEST_MAGIC)
#define RESPONSE_MAGIC 0x15021935 /* "random" value */
#define VALID_RESPONSE(e) ((e) != NULL && (e)->magic == RESPONSE_MAGIC)
#define DISPATCH_MAGIC 0x69385829 /* "random" value */
#define VALID_DISPATCH(e) ((e) != NULL && (e)->magic == DISPATCH_MAGIC)
/*
* Initializes a response table.
* Initializes a response table. The hash table becomes 2^hashsize
* entries large.
*
* Requires:
*
* "hashsize" > 1.
* 0 <= "hashsize" <= 24.
*
* Returns:
*
@@ -77,7 +92,20 @@ struct dns_dispatch {
static dns_result_t
restable_initialize(dns_dispatch_t *disp, unsigned int hashsize)
{
return (DNS_R_UNKNOWN);
unsigned int count;
REQUIRE(hashsize <= 24);
INSIST(disp->qid_table == NULL);
count = (1 << hashsize);
disp->qid_table = isc_mem_get(disp->mctx, count * sizeof(void *));
if (disp->qid_table == NULL)
return (DNS_R_NOMEMORY);
disp->qid_mask = count - 1;
disp->qid_hashsize = count;
return (DNS_R_SUCCESS);
}
/*
@@ -90,100 +118,175 @@ restable_initialize(dns_dispatch_t *disp, unsigned int hashsize)
static void
restable_invalidate(dns_dispatch_t *disp)
{
REQUIRE(disp->qid_table != NULL);
isc_mem_put(disp->mctx, disp->qid_table,
disp->qid_hashsize * sizeof(void *));
disp->qid_table = NULL;
disp->qid_hashsize = 0;
}
/*
* Add a response entry to the response table.
* "*id" is filled in with the assigned message ID.
*
* The task, action, and arg are stored, and will be part of the data
* returned on match operations.
*
* Requires:
*
* "id" be non-NULL.
*
* "task" "action" and "arg" be set as appropriate.
*
* "dest" be non-NULL and valid.
*
* Ensures:
*
* <id, dest> is a unique tuple. That means incoming messages
* are identifiable.
*
* Returns:
*
* DNS_R_SUCCESS -- all is well.
* DNS_R_NOMEMORY -- memory could not be allocated.
* DNS_R_NOMORE -- no more message ids can be allocated
* for this destination.
*/
static dns_result_t
restable_addresponse(dns_dispatch_t *disp, dns_messageid_t *id,
isc_sockaddr_t *dest, isc_task_t *task,
isc_taskaction_t action, void *arg)
dns_result_t
dns_dispatch_addresponse(dns_dispatch_t *disp, isc_sockaddr_t *dest,
isc_task_t *task, isc_taskaction_t action, void *arg,
dns_messageid_t *idp, dns_resentry_t **resp)
{
return (DNS_R_UNKNOWN);
dns_resentry_t *res;
unsigned int bucket;
dns_messageid_t id;
int i;
isc_boolean_t ok;
REQUIRE(VALID_DISPATCH(disp));
REQUIRE(task != NULL);
REQUIRE(dest != NULL);
REQUIRE(resp != NULL && *resp == NULL);
REQUIRE(idp != NULL);
LOCK(&disp->lock);
/*
* Try somewhat hard to find an unique ID.
*/
id = randomid(disp);
bucket = hash(disp, dest, id);
ok = ISC_FALSE;
for (i = 0 ; i < 64 ; i++) {
if (bucket_search(disp, dest, id, bucket) == 0) {
ok = ISC_TRUE;
break;
}
id = randomid(disp);
bucket = hash(disp, dest, id);
}
if (!ok) {
UNLOCK(&disp->lock);
return (DNS_R_NOMORE);
}
res = isc_mempool_get(disp->rpool);
if (res == NULL) {
UNLOCK(&disp->lock);
return (DNS_R_NOMEMORY);
}
res->magic = RESPONSE_MAGIC;
res->id = id;
res->bucket = bucket;
res->dest = *dest;
res->task = task;
res->action = action;
res->arg = arg;
ISC_LINK_INIT(res, link);
ISC_LIST_APPEND(disp->qid_table[bucket], res, link);
UNLOCK(&disp->lock);
*idp = id;
*resp = res;
return (DNS_R_SUCCESS);
}
/*
* Find the entry for the given id and sockaddr.
*
* If entry is NULL, the return code is used merely as an existance test.
* If "entry" is non-NULL, *entry will be set to point to the resentry.
*
* Requires:
*
* "sockaddr" is non-NULL and valid.
*
* if "entry" is non-NULL, "*entry" be NULL.
*
* Returns:
*
* DNS_R_SUCCESS -- item found.
* DNS_R_NOTFOUND -- item not present.
*/
static dns_result_t
restable_find(dns_dispatch_t *disp, dns_messageid_t id,
isc_sockaddr_t *sockaddr, dns_resentry_t **entry)
void
dns_dispatch_removeresponse(dns_dispatch_t *disp, dns_resentry_t **resp,
dns_dispatchevent_t **sockevent)
{
return (DNS_R_UNKNOWN);
dns_resentry_t *res;
dns_dispatchevent_t *ev;
unsigned int bucket;
REQUIRE(VALID_DISPATCH(disp));
REQUIRE(resp != NULL);
REQUIRE(VALID_RESPONSE(*resp));
res = *resp;
*resp = NULL;
if (sockevent != NULL) {
REQUIRE(*sockevent != NULL);
ev = *sockevent;
*sockevent = NULL;
} else {
ev = NULL;
}
LOCK(&disp->lock);
res->magic = 0;
bucket = res->bucket;
ISC_LIST_UNLINK(disp->qid_table[bucket], res, link);
isc_mempool_put(disp->rpool, res);
UNLOCK(&disp->lock);
}
/*
* Find an item and remove it from the response table. This is more
* efficient than using restable_find() followed by _remove().
*
* Requires:
*
* "sockaddr" is non-NULL and valid.
*
* Returns:
*
* DNS_R_SUCCESS -- all is well.
* DNS_R_NOTFOUND -- item not present.
*/
static dns_result_t
restable_findremove(dns_dispatch_t *disp, dns_messageid_t id,
isc_sockaddr_t *sockaddr)
dns_result_t
dns_dispatch_addrequest(dns_dispatch_t *disp,
isc_task_t *task, isc_taskaction_t action, void *arg,
dns_resentry_t **resp)
{
return (DNS_R_UNKNOWN);
dns_resentry_t *res;
REQUIRE(VALID_DISPATCH(disp));
REQUIRE(task != NULL);
REQUIRE(resp != NULL && *resp == NULL);
LOCK(&disp->lock);
res = isc_mempool_get(disp->rpool);
if (res == NULL) {
UNLOCK(&disp->lock);
return (DNS_R_NOMEMORY);
}
res->magic = REQUEST_MAGIC;
res->bucket = INVALID_BUCKET;
res->task = task;
res->action = action;
res->arg = arg;
ISC_LINK_INIT(res, link);
ISC_LIST_APPEND(disp->rq_handlers, res, link);
UNLOCK(&disp->lock);
*resp = res;
return (DNS_R_SUCCESS);
}
/*
* Remove an entry from the response table.
*
* Requires:
*
* "entry" is non-NULL, and "*entry" is non-NULL and points to a
* valid entry.
*
* Ensures:
*
* "*entry" is NULL.
*/
static void
restable_remove(dns_dispatch_t *disp, dns_resentry_t **entry)
void
dns_dispatch_removerequest(dns_dispatch_t *disp, dns_resentry_t **resp,
dns_dispatchevent_t **sockevent)
{
dns_resentry_t *res;
dns_dispatchevent_t *ev;
REQUIRE(VALID_DISPATCH(disp));
REQUIRE(resp != NULL);
REQUIRE(VALID_REQUEST(*resp));
res = *resp;
*resp = NULL;
if (sockevent != NULL) {
REQUIRE(*sockevent != NULL);
ev = *sockevent;
*sockevent = NULL;
} else {
ev = NULL;
}
LOCK(&disp->lock);
res->magic = 0;
ISC_LIST_UNLINK(disp->rq_handlers, res, link);
isc_mempool_put(disp->rpool, res);
UNLOCK(&disp->lock);
}

50
lib/dns/include/dns/dispatch.h
View File

@@ -71,6 +71,7 @@ struct dns_dispatchevent_t {
};
typedef struct dns_dispatch dns_dispatch_t;
typedef struct dns_resentry dns_resentry_t; /* XXX name change */
/*
* Private attributes of events
@@ -87,7 +88,7 @@ dns_result_t
dns_dispatch_create(isc_mem_t *mctx, isc_socket_t *sock, isc_task_t *task,
unsigned int maxbuffersize, unsigned int copythresh,
unsigned int maxbuffers, unsigned int maxrequests,
dns_dispatch_t **dsock);
dns_dispatch_t **disp);
/*
* Create a new dns_dispatch and attach it to the provided isc_socket_t.
*
@@ -121,7 +122,7 @@ dns_dispatch_create(isc_mem_t *mctx, isc_socket_t *sock, isc_task_t *task,
*/
void
dns_dispatch_destroy(dns_dispatch_t **dsock);
dns_dispatch_destroy(dns_dispatch_t **disp);
/*
* Destroys dispatch. All buffers and other bits must be returned to the
* dispatch before this is called.
@@ -137,19 +138,26 @@ dns_dispatch_destroy(dns_dispatch_t **dsock);
*/
dns_result_t
dns_dispatch_addresponse(dns_dispatch_t *dsock, isc_sockaddr_t *dest,
dns_dispatch_addresponse(dns_dispatch_t *disp, isc_sockaddr_t *dest,
isc_task_t *task, isc_taskaction_t action, void *arg,
isc_uint16_t *id);
isc_uint16_t *idp, dns_resentry_t **resp);
/*
* Add a response entry for this dispatch.
*
* "*id" is filled in with the assigned message ID.
* "*idp" is filled in with the assigned message ID, and *resp is filled in
* to contain the magic token used to request event flow stop.
*
* Events are generated each time a packet comes in until the dispatch's quota
* maximum is reached.
*
* Requires:
* < mumble >
* "idp" be non-NULL.
*
* "task" "action" and "arg" be set as appropriate.
*
* "dest" be non-NULL and valid.
*
* "resp" be non-NULL and *resp be NULL
*
* Ensures:
*
@@ -157,20 +165,24 @@ dns_dispatch_addresponse(dns_dispatch_t *dsock, isc_sockaddr_t *dest,
* are identifiable.
*
* Returns:
* < mumble >
*
* DNS_R_SUCCESS -- all is well.
* DNS_R_NOMEMORY -- memory could not be allocated.
* DNS_R_NOMORE -- no more message ids can be allocated
* for this destination.
*/
dns_result_t
dns_dispatch_removeresponse(dns_dispatch_t *dsock,
dns_dispatchevent_t **sockevent,
isc_sockaddr_t *dest, isc_uint16_t id);
void
dns_dispatch_removeresponse(dns_dispatch_t *disp, dns_resentry_t **resp,
dns_dispatchevent_t **sockevent);
/*
* Stops the flow of responses for the provided id and destination.
* If "sockevent" is non-NULL, the dispatch event and associated buffer is
* also returned to the system.
*
* Requires:
* < mumble >
* "resp" != NULL and "*resp" contain a value previously allocated
* by dns_dispatch_addresponse();
*
* Ensures:
* < mumble >
@@ -180,8 +192,9 @@ dns_dispatch_removeresponse(dns_dispatch_t *dsock,
*/
dns_result_t
dns_dispatch_addrequest(dns_dispatch_t *dsock,
isc_task_t *task, isc_taskaction_t action, void *arg);
dns_dispatch_addrequest(dns_dispatch_t *disp,
isc_task_t *task, isc_taskaction_t action, void *arg,
dns_resentry_t **resp);
/*
* Aranges for a one-shot request handler. Only one request will ever be
* handled per call to this function. (Or should this be automatically
@@ -197,10 +210,9 @@ dns_dispatch_addrequest(dns_dispatch_t *dsock,
* < mumble >
*/
dns_result_t
dns_dispatch_removerequest(dns_dispatch_t *dsock,
isc_task_t *task, isc_taskaction_t action,
void *arg);
void
dns_dispatch_removerequest(dns_dispatch_t *disp, dns_resentry_t **resp,
dns_dispatchevent_t **sockevent);
/*
* Stops the flow of responses for the provided id and destination.
* If "sockevent" is non-NULL, the dispatch event and associated buffer is
@@ -217,7 +229,7 @@ dns_dispatch_removerequest(dns_dispatch_t *dsock,
*/
void
dns_dispatch_freeevent(dns_dispatch_t *dsock, dns_dispatchevent_t **sockevent);
dns_dispatch_freeevent(dns_dispatch_t *disp, dns_dispatchevent_t **sockevent);
/*
* Return a dispatchevent and associated buffer to the dispatch. This needs
* to be called if more events are desired but a particular event is fully