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bind9/lib/dns/dispatch.c
Andreas Gustafsson 135b1206c9 don't retry UDP receives after they return an error - 
an error return from the socket library means the library has already
decided that the error is not retryable and likely to throw
us into an infinite loop if retried
2001-05-14 23:10:19 +00:00

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/*
* Copyright (C) 1999-2001 Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
* DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
* INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: dispatch.c,v 1.100 2001/05/14 23:10:19 gson Exp $ */
#include <config.h>
#include <stdlib.h>
#include <isc/entropy.h>
#include <isc/lfsr.h>
#include <isc/mem.h>
#include <isc/mutex.h>
#include <isc/print.h>
#include <isc/string.h>
#include <isc/task.h>
#include <isc/util.h>
#include <dns/acl.h>
#include <dns/dispatch.h>
#include <dns/events.h>
#include <dns/log.h>
#include <dns/message.h>
#include <dns/tcpmsg.h>
#include <dns/types.h>
typedef ISC_LIST(dns_dispentry_t) dns_displist_t;
typedef struct dns_qid {
unsigned int magic;
unsigned int qid_nbuckets; /* hash table size */
unsigned int qid_increment; /* id increment on collision */
isc_mutex_t lock;
isc_lfsr_t qid_lfsr1; /* state generator info */
isc_lfsr_t qid_lfsr2; /* state generator info */
dns_displist_t *qid_table; /* the table itself */
} dns_qid_t;
struct dns_dispatchmgr {
/* Unlocked. */
unsigned int magic;
isc_mem_t *mctx;
dns_acl_t *blackhole;
/* Locked by "lock". */
isc_mutex_t lock;
unsigned int state;
ISC_LIST(dns_dispatch_t) list;
/* locked by buffer lock */
dns_qid_t *qid;
isc_mutex_t buffer_lock;
unsigned int buffers; /* allocated buffers */
unsigned int buffersize; /* size of each buffer */
unsigned int maxbuffers; /* max buffers */
/* Locked internally. */
isc_mutex_t pool_lock;
isc_mempool_t *epool; /* memory pool for events */
isc_mempool_t *rpool; /* memory pool for replies */
isc_mempool_t *dpool; /* dispatch allocations */
isc_mempool_t *bpool; /* memory pool for buffers */
isc_entropy_t *entropy; /* entropy source */
};
#define MGR_SHUTTINGDOWN 0x00000001U
#define MGR_IS_SHUTTINGDOWN(l) (((l)->state & MGR_SHUTTINGDOWN) != 0)
#define IS_PRIVATE(d) (((d)->attributes & DNS_DISPATCHATTR_PRIVATE) != 0)
struct dns_dispentry {
unsigned int magic;
dns_dispatch_t *disp;
dns_messageid_t id;
unsigned int bucket;
isc_sockaddr_t host;
isc_task_t *task;
isc_taskaction_t action;
void *arg;
isc_boolean_t item_out;
ISC_LIST(dns_dispatchevent_t) items;
ISC_LINK(dns_dispentry_t) link;
};
#define INVALID_BUCKET (0xffffdead)
struct dns_dispatch {
/* Unlocked. */
unsigned int magic; /* magic */
dns_dispatchmgr_t *mgr; /* dispatch manager */
isc_task_t *task; /* internal task */
isc_socket_t *socket; /* isc socket attached to */
isc_sockaddr_t local; /* local address */
unsigned int maxrequests; /* max requests */
isc_event_t *ctlevent;
/* Locked by mgr->lock. */
ISC_LINK(dns_dispatch_t) link;
/* Locked by "lock". */
isc_mutex_t lock; /* locks all below */
isc_sockettype_t socktype;
unsigned int attributes;
unsigned int refcount; /* number of users */
dns_dispatchevent_t *failsafe_ev; /* failsafe cancel event */
unsigned int shutting_down : 1,
shutdown_out : 1,
connected : 1,
tcpmsg_valid : 1,
recv_pending : 1; /* is a recv() pending? */
isc_result_t shutdown_why;
unsigned int requests; /* how many requests we have */
unsigned int tcpbuffers; /* allocated buffers */
dns_tcpmsg_t tcpmsg; /* for tcp streams */
dns_qid_t *qid;
};
#define QID_MAGIC ISC_MAGIC('Q', 'i', 'd', ' ')
#define VALID_QID(e) ISC_MAGIC_VALID((e), QID_MAGIC)
#define RESPONSE_MAGIC ISC_MAGIC('D', 'r', 's', 'p')
#define VALID_RESPONSE(e) ISC_MAGIC_VALID((e), RESPONSE_MAGIC)
#define DISPATCH_MAGIC ISC_MAGIC('D', 'i', 's', 'p')
#define VALID_DISPATCH(e) ISC_MAGIC_VALID((e), DISPATCH_MAGIC)
#define DNS_DISPATCHMGR_MAGIC ISC_MAGIC('D', 'M', 'g', 'r')
#define VALID_DISPATCHMGR(e) ISC_MAGIC_VALID((e), DNS_DISPATCHMGR_MAGIC)
#define DNS_QID(disp) ((disp)->socktype == isc_sockettype_tcp) ? \
(disp)->qid : (disp)->mgr->qid
/*
* Statics.
*/
static dns_dispentry_t *bucket_search(dns_qid_t *, isc_sockaddr_t *,
dns_messageid_t, unsigned int);
static isc_boolean_t destroy_disp_ok(dns_dispatch_t *);
static void destroy_disp(isc_task_t *task, isc_event_t *event);
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 dns_randomid(dns_qid_t *);
static isc_uint32_t dns_hash(dns_qid_t *, isc_sockaddr_t *, dns_messageid_t);
static void free_buffer(dns_dispatch_t *disp, void *buf, unsigned int len);
static void *allocate_udp_buffer(dns_dispatch_t *disp);
static inline void free_event(dns_dispatch_t *disp, dns_dispatchevent_t *ev);
static inline dns_dispatchevent_t *allocate_event(dns_dispatch_t *disp);
static void do_cancel(dns_dispatch_t *disp, dns_dispentry_t *resp);
static dns_dispentry_t *linear_first(dns_qid_t *disp);
static dns_dispentry_t *linear_next(dns_qid_t *disp,
dns_dispentry_t *resp);
static void dispatch_free(dns_dispatch_t **dispp);
static isc_result_t dispatch_createudp(dns_dispatchmgr_t *mgr,
isc_socketmgr_t *sockmgr,
isc_taskmgr_t *taskmgr,
isc_sockaddr_t *localaddr,
unsigned int maxrequests,
unsigned int attributes,
dns_dispatch_t **dispp);
static isc_boolean_t destroy_mgr_ok(dns_dispatchmgr_t *mgr);
static void destroy_mgr(dns_dispatchmgr_t **mgrp);
static isc_result_t qid_allocate(dns_dispatchmgr_t *mgr, unsigned int buckets,
unsigned int increment, dns_qid_t **qidp);
static void qid_destroy(isc_mem_t *mctx, dns_qid_t **qidp);
#define LVL(x) ISC_LOG_DEBUG(x)
static void
mgr_log(dns_dispatchmgr_t *mgr, int level, const char *fmt, ...) {
char msgbuf[2048];
va_list ap;
if (! isc_log_wouldlog(dns_lctx, level))
return;
va_start(ap, fmt);
vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap);
va_end(ap);
isc_log_write(dns_lctx,
DNS_LOGCATEGORY_DISPATCH, DNS_LOGMODULE_DISPATCH,
level, "dispatchmgr %p: %s", mgr, msgbuf);
}
static void
dispatch_log(dns_dispatch_t *disp, int level, const char *fmt, ...) {
char msgbuf[2048];
va_list ap;
if (! isc_log_wouldlog(dns_lctx, level))
return;
va_start(ap, fmt);
vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap);
va_end(ap);
isc_log_write(dns_lctx,
DNS_LOGCATEGORY_DISPATCH, DNS_LOGMODULE_DISPATCH,
level, "dispatch %p: %s", disp, msgbuf);
}
static void
request_log(dns_dispatch_t *disp, dns_dispentry_t *resp,
int level, const char *fmt, ...)
{
char msgbuf[2048];
char peerbuf[256];
va_list ap;
if (! isc_log_wouldlog(dns_lctx, level))
return;
va_start(ap, fmt);
vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap);
va_end(ap);
if (VALID_RESPONSE(resp)) {
isc_sockaddr_format(&resp->host, peerbuf, sizeof peerbuf);
isc_log_write(dns_lctx, DNS_LOGCATEGORY_DISPATCH,
DNS_LOGMODULE_DISPATCH, level,
"dispatch %p response %p %s: %s", disp, resp,
peerbuf, msgbuf);
} else {
isc_log_write(dns_lctx, DNS_LOGCATEGORY_DISPATCH,
DNS_LOGMODULE_DISPATCH, level,
"dispatch %p req/resp %p: %s", disp, resp,
msgbuf);
}
}
static void
reseed_lfsr(isc_lfsr_t *lfsr, void *arg)
{
dns_dispatchmgr_t *mgr = arg;
isc_result_t result;
isc_uint32_t val;
REQUIRE(VALID_DISPATCHMGR(mgr));
if (mgr->entropy != NULL) {
result = isc_entropy_getdata(mgr->entropy, &val, sizeof val,
NULL, 0);
INSIST(result == ISC_R_SUCCESS);
lfsr->count = (val & 0x1f) + 32;
lfsr->state = val;
return;
}
lfsr->count = (random() & 0x1f) + 32; /* From 32 to 63 states */
lfsr->state = random();
}
/*
* Return an unpredictable message ID.
*/
static dns_messageid_t
dns_randomid(dns_qid_t *qid) {
isc_uint32_t id;
id = isc_lfsr_generate32(&qid->qid_lfsr1, &qid->qid_lfsr2);
return (dns_messageid_t)(id & 0xFFFF);
}
/*
* Return a hash of the destination and message id.
*/
static isc_uint32_t
dns_hash(dns_qid_t *qid, isc_sockaddr_t *dest, dns_messageid_t id) {
unsigned int ret;
ret = isc_sockaddr_hash(dest, ISC_TRUE);
ret ^= id;
ret %= qid->qid_nbuckets;
INSIST(ret < qid->qid_nbuckets);
return (ret);
}
/*
* Find the first entry in 'qid'. Returns NULL if there are no entries.
*/
static dns_dispentry_t *
linear_first(dns_qid_t *qid) {
dns_dispentry_t *ret;
unsigned int bucket;
bucket = 0;
while (bucket < qid->qid_nbuckets) {
ret = ISC_LIST_HEAD(qid->qid_table[bucket]);
if (ret != NULL)
return (ret);
bucket++;
}
return (NULL);
}
/*
* Find the next entry after 'resp' in 'qid'. Return NULL if there are
* no more entries.
*/
static dns_dispentry_t *
linear_next(dns_qid_t *qid, dns_dispentry_t *resp) {
dns_dispentry_t *ret;
unsigned int bucket;
ret = ISC_LIST_NEXT(resp, link);
if (ret != NULL)
return (ret);
bucket = resp->bucket;
bucket++;
while (bucket < qid->qid_nbuckets) {
ret = ISC_LIST_HEAD(qid->qid_table[bucket]);
if (ret != NULL)
return (ret);
bucket++;
}
return (NULL);
}
/*
* The dispatch must be locked.
*/
static isc_boolean_t
destroy_disp_ok(dns_dispatch_t *disp)
{
if (disp->refcount != 0)
return (ISC_FALSE);
if (disp->recv_pending != 0)
return (ISC_FALSE);
if (disp->shutting_down == 0)
return (ISC_FALSE);
return (ISC_TRUE);
}
/*
* Called when refcount reaches 0 (and safe to destroy).
*
* The dispatcher must not be locked.
* The manager must be locked.
*/
static void
destroy_disp(isc_task_t *task, isc_event_t *event) {
dns_dispatch_t *disp;
dns_dispatchmgr_t *mgr;
isc_boolean_t killmgr;
INSIST(event->ev_type == DNS_EVENT_DISPATCHCONTROL);
UNUSED(task);
disp = event->ev_arg;
mgr = disp->mgr;
LOCK(&mgr->lock);
ISC_LIST_UNLINK(mgr->list, disp, link);
dispatch_log(disp, LVL(90),
"shutting down; detaching from sock %p, task %p",
disp->socket, disp->task);
isc_socket_detach(&disp->socket);
isc_task_detach(&disp->task);
isc_event_free(&event);
dispatch_free(&disp);
killmgr = destroy_mgr_ok(mgr);
UNLOCK(&mgr->lock);
if (killmgr)
destroy_mgr(&mgr);
}
/*
* Find an entry for query ID 'id' and socket address 'dest' in 'qid'.
* Return NULL if no such entry exists.
*/
static dns_dispentry_t *
bucket_search(dns_qid_t *qid, isc_sockaddr_t *dest, dns_messageid_t id,
unsigned int bucket)
{
dns_dispentry_t *res;
REQUIRE(bucket < qid->qid_nbuckets);
res = ISC_LIST_HEAD(qid->qid_table[bucket]);
while (res != NULL) {
if ((res->id == id) && isc_sockaddr_equal(dest, &res->host))
return (res);
res = ISC_LIST_NEXT(res, link);
}
return (NULL);
}
static void
free_buffer(dns_dispatch_t *disp, void *buf, unsigned int len) {
INSIST(buf != NULL && len != 0);
switch (disp->socktype) {
case isc_sockettype_tcp:
INSIST(disp->tcpbuffers > 0);
disp->tcpbuffers--;
isc_mem_put(disp->mgr->mctx, buf, len);
break;
case isc_sockettype_udp:
LOCK(&disp->mgr->buffer_lock);
INSIST(disp->mgr->buffers > 0);
INSIST(len == disp->mgr->buffersize);
disp->mgr->buffers--;
isc_mempool_put(disp->mgr->bpool, buf);
UNLOCK(&disp->mgr->buffer_lock);
break;
default:
INSIST(0);
break;
}
}
static void *
allocate_udp_buffer(dns_dispatch_t *disp) {
void *temp;
LOCK(&disp->mgr->buffer_lock);
temp = isc_mempool_get(disp->mgr->bpool);
if (temp != NULL)
disp->mgr->buffers++;
UNLOCK(&disp->mgr->buffer_lock);
return (temp);
}
static inline void
free_event(dns_dispatch_t *disp, dns_dispatchevent_t *ev) {
if (disp->failsafe_ev == ev) {
INSIST(disp->shutdown_out == 1);
disp->shutdown_out = 0;
return;
}
isc_mempool_put(disp->mgr->epool, ev);
}
static inline dns_dispatchevent_t *
allocate_event(dns_dispatch_t *disp) {
dns_dispatchevent_t *ev;
ev = isc_mempool_get(disp->mgr->epool);
if (ev == NULL)
return (NULL);
ISC_EVENT_INIT(ev, sizeof(*ev), 0, NULL, 0,
NULL, NULL, NULL, NULL, NULL);
return (ev);
}
/*
* General flow:
*
* If I/O result == CANCELED or error, free the buffer.
*
* If query:
* if no listeners: free the buffer, restart.
* if listener: allocate event, fill in details.
* If cannot allocate, free buffer, restart.
* if rq event queue is not empty, queue. else, send.
* restart.
*
* If response:
* Allocate event, fill in details.
* If cannot allocate, free buffer, restart.
* find target. If not found, free buffer, restart.
* if event queue is not empty, queue. else, send.
* restart.
*/
static void
udp_recv(isc_task_t *task, isc_event_t *ev_in) {
isc_socketevent_t *ev = (isc_socketevent_t *)ev_in;
dns_dispatch_t *disp = ev_in->ev_arg;
dns_messageid_t id;
isc_result_t dres;
isc_buffer_t source;
unsigned int flags;
dns_dispentry_t *resp;
dns_dispatchevent_t *rev;
unsigned int bucket;
isc_boolean_t killit;
isc_boolean_t queue_response;
dns_dispatchmgr_t *mgr;
dns_qid_t *qid;
isc_netaddr_t netaddr;
int match;
UNUSED(task);
LOCK(&disp->lock);
mgr = disp->mgr;
qid = mgr->qid;
dispatch_log(disp, LVL(90),
"got packet: requests %d, buffers %d, recvs %d",
disp->requests, disp->mgr->buffers, disp->recv_pending);
if ((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) == 0) {
INSIST(disp->recv_pending != 0);
disp->recv_pending = 0;
}
if (disp->shutting_down) {
/*
* This dispatcher is shutting down.
*/
free_buffer(disp, ev->region.base, ev->region.length);
isc_event_free(&ev_in);
ev = NULL;
killit = destroy_disp_ok(disp);
UNLOCK(&disp->lock);
if (killit)
isc_task_send(disp->task, &disp->ctlevent);
return;
}
if (ev->result != ISC_R_SUCCESS) {
free_buffer(disp, ev->region.base, ev->region.length);
if (ev->result != ISC_R_CANCELED)
dispatch_log(disp, ISC_LOG_ERROR,
"odd socket result in udp_recv(): %s",
isc_result_totext(ev->result));
UNLOCK(&disp->lock);
isc_event_free(&ev_in);
return;
}
/*
* If this is from a blackholed address, drop it.
*/
isc_netaddr_fromsockaddr(&netaddr, &ev->address);
if (disp->mgr->blackhole != NULL &&
dns_acl_match(&netaddr, NULL, disp->mgr->blackhole,
NULL, &match, NULL) == ISC_R_SUCCESS &&
match > 0)
{
if (isc_log_wouldlog(dns_lctx, LVL(10))) {
char netaddrstr[ISC_NETADDR_FORMATSIZE];
isc_netaddr_format(&netaddr, netaddrstr,
sizeof(netaddrstr));
dispatch_log(disp, LVL(10),
"blackholed packet from %s",
netaddrstr);
}
free_buffer(disp, ev->region.base, ev->region.length);
goto restart;
}
/*
* Peek into the buffer to see what we can see.
*/
isc_buffer_init(&source, ev->region.base, ev->region.length);
isc_buffer_add(&source, ev->n);
dres = dns_message_peekheader(&source, &id, &flags);
if (dres != ISC_R_SUCCESS) {
free_buffer(disp, ev->region.base, ev->region.length);
dispatch_log(disp, LVL(10), "got garbage packet");
goto restart;
}
dispatch_log(disp, LVL(92),
"got valid DNS message header, /QR %c, id %u",
((flags & DNS_MESSAGEFLAG_QR) ? '1' : '0'), id);
/*
* Look at flags. If query, drop it. If response,
* look to see where it goes.
*/
queue_response = ISC_FALSE;
if ((flags & DNS_MESSAGEFLAG_QR) == 0) {
/* query */
free_buffer(disp, ev->region.base, ev->region.length);
goto restart;
} else {
/* response */
bucket = dns_hash(qid, &ev->address, id);
LOCK(&qid->lock);
resp = bucket_search(qid, &ev->address, id, bucket);
UNLOCK(&qid->lock);
dispatch_log(disp, LVL(90),
"search for response in bucket %d: %s",
bucket, (resp == NULL ? "not found" : "found"));
if (resp == NULL) {
free_buffer(disp, ev->region.base, ev->region.length);
goto restart;
}
queue_response = resp->item_out;
rev = allocate_event(resp->disp);
if (rev == NULL) {
free_buffer(disp, ev->region.base, ev->region.length);
goto restart;
}
}
/*
* At this point, rev contains the event we want to fill in, and
* resp contains the information on the place to send it to.
* Send the event off.
*/
isc_buffer_init(&rev->buffer, ev->region.base, ev->region.length);
isc_buffer_add(&rev->buffer, ev->n);
rev->result = ISC_R_SUCCESS;
rev->id = id;
rev->addr = ev->address;
rev->pktinfo = ev->pktinfo;
rev->attributes = ev->attributes;
if (queue_response) {
ISC_LIST_APPEND(resp->items, rev, ev_link);
} else {
ISC_EVENT_INIT(rev, sizeof(*rev), 0, NULL,
DNS_EVENT_DISPATCH,
resp->action, resp->arg, resp, NULL, NULL);
request_log(disp, resp, LVL(90),
"[a] Sent event %p buffer %p len %d to task %p",
rev, rev->buffer.base, rev->buffer.length,
resp->task);
resp->item_out = ISC_TRUE;
isc_task_send(resp->task, (isc_event_t **)&rev);
}
/*
* Restart recv() to get the next packet.
*/
restart:
startrecv(disp);
UNLOCK(&disp->lock);
isc_event_free(&ev_in);
}
/*
* General flow:
*
* If I/O result == CANCELED, EOF, or error, free the buffer
* and notify everyone as the various queues drain.
*
* If query:
* if no listeners: free the buffer, restart.
* if listener: allocate event, fill in details.
* If cannot allocate, free buffer, restart.
* if rq event queue is not empty, queue. else, send.
* restart.
*
* If response:
* Allocate event, fill in details.
* If cannot allocate, free buffer, restart.
* find target. If not found, free buffer, restart.
* if event queue is not empty, queue. else, send.
* restart.
*/
static void
tcp_recv(isc_task_t *task, isc_event_t *ev_in) {
dns_dispatch_t *disp = ev_in->ev_arg;
dns_tcpmsg_t *tcpmsg = &disp->tcpmsg;
dns_messageid_t id;
isc_result_t dres;
unsigned int flags;
dns_dispentry_t *resp;
dns_dispatchevent_t *rev;
unsigned int bucket;
isc_boolean_t killit;
isc_boolean_t queue_response;
dns_qid_t *qid;
UNUSED(task);
REQUIRE(VALID_DISPATCH(disp));
qid = disp->qid;
dispatch_log(disp, LVL(90),
"got TCP packet: requests %d, buffers %d, recvs %d",
disp->requests, disp->tcpbuffers, disp->recv_pending);
LOCK(&disp->lock);
INSIST(disp->recv_pending != 0);
disp->recv_pending = 0;
if (disp->refcount == 0) {
/*
* This dispatcher is shutting down. Force cancelation.
*/
tcpmsg->result = ISC_R_CANCELED;
}
if (tcpmsg->result != ISC_R_SUCCESS) {
switch (tcpmsg->result) {
case ISC_R_CANCELED:
break;
case ISC_R_EOF:
dispatch_log(disp, LVL(90), "shutting down on EOF");
do_cancel(disp, NULL);
break;
default:
dispatch_log(disp, ISC_LOG_ERROR,
"shutting down due to TCP "
"receive error: %s",
isc_result_totext(tcpmsg->result));
do_cancel(disp, NULL);
break;
}
/*
* The event is statically allocated in the tcpmsg
* structure, and destroy_disp() frees the tcpmsg, so we must
* free the event *before* calling destroy_disp().
*/
isc_event_free(&ev_in);
disp->shutting_down = 1;
disp->shutdown_why = tcpmsg->result;
/*
* If the recv() was canceled pass the word on.
*/
killit = destroy_disp_ok(disp);
UNLOCK(&disp->lock);
if (killit)
isc_task_send(disp->task, &disp->ctlevent);
return;
}
dispatch_log(disp, LVL(90), "result %d, length == %d, addr = %p",
tcpmsg->result,
tcpmsg->buffer.length, tcpmsg->buffer.base);
/*
* Peek into the buffer to see what we can see.
*/
dres = dns_message_peekheader(&tcpmsg->buffer, &id, &flags);
if (dres != ISC_R_SUCCESS) {
dispatch_log(disp, LVL(10), "got garbage packet");
goto restart;
}
dispatch_log(disp, LVL(92),
"got valid DNS message header, /QR %c, id %u",
((flags & DNS_MESSAGEFLAG_QR) ? '1' : '0'), id);
/*
* Allocate an event to send to the query or response client, and
* allocate a new buffer for our use.
*/
/*
* Look at flags. If query, drop it. If response,
* look to see where it goes.
*/
queue_response = ISC_FALSE;
if ((flags & DNS_MESSAGEFLAG_QR) == 0) {
/*
* Query.
*/
goto restart;
} else {
/*
* Response.
*/
bucket = dns_hash(qid, &tcpmsg->address, id);
LOCK(&qid->lock);
resp = bucket_search(qid, &tcpmsg->address, id, bucket);
UNLOCK(&qid->lock);
dispatch_log(disp, LVL(90),
"search for response in bucket %d: %s",
bucket, (resp == NULL ? "not found" : "found"));
if (resp == NULL)
goto restart;
queue_response = resp->item_out;
rev = allocate_event(disp);
if (rev == NULL)
goto restart;
}
/*
* At this point, rev contains the event we want to fill in, and
* resp contains the information on the place to send it to.
* Send the event off.
*/
dns_tcpmsg_keepbuffer(tcpmsg, &rev->buffer);
disp->tcpbuffers++;
rev->result = ISC_R_SUCCESS;
rev->id = id;
rev->addr = tcpmsg->address;
if (queue_response) {
ISC_LIST_APPEND(resp->items, rev, ev_link);
} else {
ISC_EVENT_INIT(rev, sizeof(*rev), 0, NULL, DNS_EVENT_DISPATCH,
resp->action, resp->arg, resp, NULL, NULL);
request_log(disp, resp, LVL(90),
"[b] Sent event %p buffer %p len %d to task %p",
rev, rev->buffer.base, rev->buffer.length,
resp->task);
resp->item_out = ISC_TRUE;
isc_task_send(resp->task, (isc_event_t **)&rev);
}
/*
* Restart recv() to get the next packet.
*/
restart:
startrecv(disp);
UNLOCK(&disp->lock);
isc_event_free(&ev_in);
}
/*
* disp must be locked.
*/
static void
startrecv(dns_dispatch_t *disp) {
isc_result_t res;
isc_region_t region;
if (disp->shutting_down == 1)
return;
if ((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) != 0)
return;
if (disp->recv_pending != 0)
return;
if (disp->mgr->buffers >= disp->mgr->maxbuffers)
return;
switch (disp->socktype) {
/*
* UDP reads are always maximal.
*/
case isc_sockettype_udp:
region.length = disp->mgr->buffersize;
region.base = allocate_udp_buffer(disp);
if (region.base == NULL)
return;
res = isc_socket_recv(disp->socket, &region, 1,
disp->task, udp_recv, disp);
if (res != ISC_R_SUCCESS) {
free_buffer(disp, region.base, region.length);
disp->shutdown_why = res;
disp->shutting_down = 1;
do_cancel(disp, NULL);
return;
}
disp->recv_pending = 1;
break;
case isc_sockettype_tcp:
res = dns_tcpmsg_readmessage(&disp->tcpmsg, disp->task,
tcp_recv, disp);
if (res != ISC_R_SUCCESS) {
disp->shutdown_why = res;
disp->shutting_down = 1;
do_cancel(disp, NULL);
return;
}
disp->recv_pending = 1;
break;
}
}
/*
* Mgr must be locked when calling this function.
*/
static isc_boolean_t
destroy_mgr_ok(dns_dispatchmgr_t *mgr) {
mgr_log(mgr, LVL(90),
"destroy_mgr_ok: shuttingdown=%d, listnonempty=%d, "
"epool=%d, rpool=%d, dpool=%d",
MGR_IS_SHUTTINGDOWN(mgr), !ISC_LIST_EMPTY(mgr->list),
isc_mempool_getallocated(mgr->epool),
isc_mempool_getallocated(mgr->rpool),
isc_mempool_getallocated(mgr->dpool));
if (!MGR_IS_SHUTTINGDOWN(mgr))
return (ISC_FALSE);
if (!ISC_LIST_EMPTY(mgr->list))
return (ISC_FALSE);
if (isc_mempool_getallocated(mgr->epool) != 0)
return (ISC_FALSE);
if (isc_mempool_getallocated(mgr->rpool) != 0)
return (ISC_FALSE);
if (isc_mempool_getallocated(mgr->dpool) != 0)
return (ISC_FALSE);
return (ISC_TRUE);
}
/*
* Mgr must be unlocked when calling this function.
*/
static void
destroy_mgr(dns_dispatchmgr_t **mgrp) {
isc_mem_t *mctx;
dns_dispatchmgr_t *mgr;
mgr = *mgrp;
*mgrp = NULL;
mctx = mgr->mctx;
mgr->magic = 0;
mgr->mctx = NULL;
DESTROYLOCK(&mgr->lock);
mgr->state = 0;
isc_mempool_destroy(&mgr->epool);
isc_mempool_destroy(&mgr->rpool);
isc_mempool_destroy(&mgr->dpool);
isc_mempool_destroy(&mgr->bpool);
DESTROYLOCK(&mgr->pool_lock);
if (mgr->entropy != NULL)
isc_entropy_detach(&mgr->entropy);
if (mgr->qid != NULL)
qid_destroy(mctx, &mgr->qid);
DESTROYLOCK(&mgr->buffer_lock);
if (mgr->blackhole != NULL)
dns_acl_detach(&mgr->blackhole);
isc_mem_put(mctx, mgr, sizeof(dns_dispatchmgr_t));
isc_mem_detach(&mctx);
}
static isc_result_t
create_socket(isc_socketmgr_t *mgr, isc_sockaddr_t *local,
isc_socket_t **sockp)
{
isc_socket_t *sock;
isc_result_t result;
sock = NULL;
result = isc_socket_create(mgr, isc_sockaddr_pf(local),
isc_sockettype_udp, &sock);
if (result != ISC_R_SUCCESS)
return (result);
result = isc_socket_bind(sock, local);
if (result != ISC_R_SUCCESS) {
isc_socket_detach(&sock);
return (result);
}
*sockp = sock;
return (ISC_R_SUCCESS);
}
/*
* Publics.
*/
isc_result_t
dns_dispatchmgr_create(isc_mem_t *mctx, isc_entropy_t *entropy,
dns_dispatchmgr_t **mgrp)
{
dns_dispatchmgr_t *mgr;
isc_result_t result;
REQUIRE(mctx != NULL);
REQUIRE(mgrp != NULL && *mgrp == NULL);
mgr = isc_mem_get(mctx, sizeof(dns_dispatchmgr_t));
if (mgr == NULL)
return (ISC_R_NOMEMORY);
mgr->mctx = NULL;
isc_mem_attach(mctx, &mgr->mctx);
mgr->blackhole = NULL;
result = isc_mutex_init(&mgr->lock);
if (result != ISC_R_SUCCESS)
goto deallocate;
result = isc_mutex_init(&mgr->buffer_lock);
if (result != ISC_R_SUCCESS)
goto kill_lock;
result = isc_mutex_init(&mgr->pool_lock);
if (result != ISC_R_SUCCESS)
goto kill_buffer_lock;
mgr->epool = NULL;
if (isc_mempool_create(mgr->mctx, sizeof(dns_dispatchevent_t),
&mgr->epool) != ISC_R_SUCCESS) {
result = ISC_R_NOMEMORY;
goto kill_pool_lock;
}
mgr->rpool = NULL;
if (isc_mempool_create(mgr->mctx, sizeof(dns_dispentry_t),
&mgr->rpool) != ISC_R_SUCCESS) {
result = ISC_R_NOMEMORY;
goto kill_epool;
}
mgr->dpool = NULL;
if (isc_mempool_create(mgr->mctx, sizeof(dns_dispatch_t),
&mgr->dpool) != ISC_R_SUCCESS) {
result = ISC_R_NOMEMORY;
goto kill_rpool;
}
isc_mempool_setname(mgr->epool, "dispmgr_epool");
isc_mempool_setfreemax(mgr->epool, 1024);
isc_mempool_associatelock(mgr->epool, &mgr->pool_lock);
isc_mempool_setname(mgr->rpool, "dispmgr_rpool");
isc_mempool_setfreemax(mgr->rpool, 1024);
isc_mempool_associatelock(mgr->rpool, &mgr->pool_lock);
isc_mempool_setname(mgr->dpool, "dispmgr_dpool");
isc_mempool_setfreemax(mgr->dpool, 1024);
isc_mempool_associatelock(mgr->dpool, &mgr->pool_lock);
mgr->buffers = 0;
mgr->buffersize = 0;
mgr->maxbuffers = 0;
mgr->bpool = NULL;
mgr->entropy = NULL;
mgr->qid = NULL;
mgr->state = 0;
ISC_LIST_INIT(mgr->list);
mgr->magic = DNS_DISPATCHMGR_MAGIC;
if (entropy != NULL)
isc_entropy_attach(entropy, &mgr->entropy);
*mgrp = mgr;
return (ISC_R_SUCCESS);
kill_rpool:
isc_mempool_destroy(&mgr->rpool);
kill_epool:
isc_mempool_destroy(&mgr->epool);
kill_pool_lock:
DESTROYLOCK(&mgr->pool_lock);
kill_buffer_lock:
DESTROYLOCK(&mgr->buffer_lock);
kill_lock:
DESTROYLOCK(&mgr->lock);
deallocate:
isc_mem_put(mctx, mgr, sizeof(dns_dispatchmgr_t));
isc_mem_detach(&mgr->mctx);
return (result);
}
void
dns_dispatchmgr_setblackhole(dns_dispatchmgr_t *mgr, dns_acl_t *blackhole) {
REQUIRE(VALID_DISPATCHMGR(mgr));
if (mgr->blackhole != NULL)
dns_acl_detach(&mgr->blackhole);
dns_acl_attach(blackhole, &mgr->blackhole);
}
dns_acl_t *
dns_dispatchmgr_getblackhole(dns_dispatchmgr_t *mgr) {
REQUIRE(VALID_DISPATCHMGR(mgr));
return (mgr->blackhole);
}
static isc_result_t
dns_dispatchmgr_setudp(dns_dispatchmgr_t *mgr,
unsigned int buffersize, unsigned int maxbuffers,
unsigned int buckets, unsigned int increment)
{
isc_result_t result;
REQUIRE(VALID_DISPATCHMGR(mgr));
REQUIRE(buffersize >= 512 && buffersize < (64 * 1024));
REQUIRE(maxbuffers > 0);
REQUIRE(buckets < 2097169); /* next prime > 65536 * 32 */
REQUIRE(increment > buckets);
/*
* Keep some number of items around. This should be a config
* option. For now, keep 8, but later keep at least two even
* if the caller wants less. This allows us to ensure certain
* things, like an event can be "freed" and the next allocation
* will always succeed.
*
* Note that if limits are placed on anything here, we use one
* event internally, so the actual limit should be "wanted + 1."
*
* XXXMLG
*/
if (maxbuffers < 8)
maxbuffers = 8;
LOCK(&mgr->buffer_lock);
if (mgr->bpool != NULL) {
isc_mempool_setmaxalloc(mgr->bpool, maxbuffers);
mgr->maxbuffers = maxbuffers;
UNLOCK(&mgr->buffer_lock);
return (ISC_R_SUCCESS);
}
if (isc_mempool_create(mgr->mctx, buffersize,
&mgr->bpool) != ISC_R_SUCCESS) {
return (ISC_R_NOMEMORY);
}
isc_mempool_setname(mgr->bpool, "dispmgr_bpool");
isc_mempool_setmaxalloc(mgr->bpool, maxbuffers);
isc_mempool_associatelock(mgr->bpool, &mgr->pool_lock);
result = qid_allocate(mgr, buckets, increment, &mgr->qid);
if (result != ISC_R_SUCCESS)
goto cleanup;
mgr->buffersize = buffersize;
mgr->maxbuffers = maxbuffers;
UNLOCK(&mgr->buffer_lock);
return (ISC_R_SUCCESS);
cleanup:
isc_mempool_destroy(&mgr->bpool);
UNLOCK(&mgr->buffer_lock);
return (ISC_R_NOMEMORY);
}
void
dns_dispatchmgr_destroy(dns_dispatchmgr_t **mgrp) {
dns_dispatchmgr_t *mgr;
isc_boolean_t killit;
REQUIRE(mgrp != NULL);
REQUIRE(VALID_DISPATCHMGR(*mgrp));
mgr = *mgrp;
*mgrp = NULL;
LOCK(&mgr->lock);
mgr->state |= MGR_SHUTTINGDOWN;
killit = destroy_mgr_ok(mgr);
UNLOCK(&mgr->lock);
mgr_log(mgr, LVL(90), "destroy: killit=%d", killit);
if (killit)
destroy_mgr(&mgr);
}
#define ATTRMATCH(_a1, _a2, _mask) (((_a1) & (_mask)) == ((_a2) & (_mask)))
static isc_boolean_t
local_addr_match(dns_dispatch_t *disp, isc_sockaddr_t *addr) {
in_port_t port;
if (addr == NULL)
return (ISC_TRUE);
port = isc_sockaddr_getport(addr);
if (port == 0)
return (isc_sockaddr_eqaddr(&disp->local, addr));
else
return (isc_sockaddr_equal(&disp->local, addr));
}
/*
* Requires mgr be locked.
*
* No dispatcher can be locked by this thread when calling this function.
*
*
* NOTE:
* If a matching dispatcher is found, it is locked after this function
* returns, and must be unlocked by the caller.
*/
static isc_result_t
dispatch_find(dns_dispatchmgr_t *mgr, isc_sockaddr_t *local,
unsigned int attributes, unsigned int mask,
dns_dispatch_t **dispp)
{
dns_dispatch_t *disp;
isc_result_t result;
/*
* Make certain that we will not match a private dispatch.
*/
attributes &= ~DNS_DISPATCHATTR_PRIVATE;
mask |= DNS_DISPATCHATTR_PRIVATE;
disp = ISC_LIST_HEAD(mgr->list);
while (disp != NULL) {
LOCK(&disp->lock);
if ((disp->shutting_down == 0)
&& ATTRMATCH(disp->attributes, attributes, mask)
&& local_addr_match(disp, local))
break;
UNLOCK(&disp->lock);
disp = ISC_LIST_NEXT(disp, link);
}
if (disp == NULL) {
result = ISC_R_NOTFOUND;
goto out;
}
*dispp = disp;
result = ISC_R_SUCCESS;
out:
return (result);
}
static isc_result_t
qid_allocate(dns_dispatchmgr_t *mgr, unsigned int buckets,
unsigned int increment, dns_qid_t **qidp)
{
dns_qid_t *qid;
unsigned int i;
REQUIRE(VALID_DISPATCHMGR(mgr));
REQUIRE(buckets < 2097169); /* next prime > 65536 * 32 */
REQUIRE(increment > buckets);
REQUIRE(qidp != NULL && *qidp == NULL);
qid = isc_mem_get(mgr->mctx, sizeof(*qid));
if (qid == NULL)
return (ISC_R_NOMEMORY);
qid->qid_table = isc_mem_get(mgr->mctx,
buckets * sizeof(dns_displist_t));
if (qid->qid_table == NULL) {
isc_mem_put(mgr->mctx, qid, sizeof(*qid));
return (ISC_R_NOMEMORY);
}
if (isc_mutex_init(&qid->lock) != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__, "isc_mutex_init failed");
isc_mem_put(mgr->mctx, qid->qid_table,
buckets * sizeof(dns_displist_t));
isc_mem_put(mgr->mctx, qid, sizeof(*qid));
return (ISC_R_UNEXPECTED);
}
for (i = 0 ; i < buckets ; i++)
ISC_LIST_INIT(qid->qid_table[i]);
qid->qid_nbuckets = buckets;
qid->qid_increment = increment;
qid->magic = QID_MAGIC;
/*
* Initialize to a 32-bit LFSR. Both of these are from Applied
* Cryptography.
*
* lfsr1:
* x^32 + x^7 + x^5 + x^3 + x^2 + x + 1
*
* lfsr2:
* x^32 + x^7 + x^6 + x^2 + 1
*/
isc_lfsr_init(&qid->qid_lfsr1, 0, 32, 0x80000057U,
0, reseed_lfsr, mgr);
isc_lfsr_init(&qid->qid_lfsr2, 0, 32, 0x800000c2U,
0, reseed_lfsr, mgr);
*qidp = qid;
return (ISC_R_SUCCESS);
}
static void
qid_destroy(isc_mem_t *mctx, dns_qid_t **qidp) {
dns_qid_t *qid;
REQUIRE(qidp != NULL);
qid = *qidp;
REQUIRE(VALID_QID(qid));
*qidp = NULL;
qid->magic = 0;
isc_mem_put(mctx, qid->qid_table,
qid->qid_nbuckets * sizeof(dns_displist_t));
DESTROYLOCK(&qid->lock);
isc_mem_put(mctx, qid, sizeof(*qid));
}
/*
* Allocate and set important limits.
*/
static isc_result_t
dispatch_allocate(dns_dispatchmgr_t *mgr, unsigned int maxrequests,
dns_dispatch_t **dispp)
{
dns_dispatch_t *disp;
isc_result_t res;
REQUIRE(VALID_DISPATCHMGR(mgr));
REQUIRE(dispp != NULL && *dispp == NULL);
/*
* Set up the dispatcher, mostly. Don't bother setting some of
* the options that are controlled by tcp vs. udp, etc.
*/
disp = isc_mempool_get(mgr->dpool);
if (disp == NULL)
return (ISC_R_NOMEMORY);
disp->magic = 0;
disp->mgr = mgr;
disp->maxrequests = maxrequests;
disp->attributes = 0;
ISC_LINK_INIT(disp, link);
disp->refcount = 1;
disp->recv_pending = 0;
memset(&disp->local, 0, sizeof disp->local);
disp->shutting_down = 0;
disp->shutdown_out = 0;
disp->connected = 0;
disp->tcpmsg_valid = 0;
disp->shutdown_why = ISC_R_UNEXPECTED;
disp->requests = 0;
disp->tcpbuffers = 0;
disp->qid = NULL;
if (isc_mutex_init(&disp->lock) != ISC_R_SUCCESS) {
res = ISC_R_UNEXPECTED;
UNEXPECTED_ERROR(__FILE__, __LINE__, "isc_mutex_init failed");
goto deallocate;
}
disp->failsafe_ev = allocate_event(disp);
if (disp->failsafe_ev == NULL) {
res = ISC_R_NOMEMORY;
goto kill_lock;
}
disp->magic = DISPATCH_MAGIC;
*dispp = disp;
return (ISC_R_SUCCESS);
/*
* error returns
*/
kill_lock:
DESTROYLOCK(&disp->lock);
deallocate:
isc_mempool_put(mgr->dpool, disp);
return (res);
}
/*
* MUST be unlocked, and not used by anthing.
*/
static void
dispatch_free(dns_dispatch_t **dispp)
{
dns_dispatch_t *disp;
dns_dispatchmgr_t *mgr;
REQUIRE(VALID_DISPATCH(*dispp));
disp = *dispp;
*dispp = NULL;
mgr = disp->mgr;
REQUIRE(VALID_DISPATCHMGR(mgr));
if (disp->tcpmsg_valid) {
dns_tcpmsg_invalidate(&disp->tcpmsg);
disp->tcpmsg_valid = 0;
}
INSIST(disp->tcpbuffers == 0);
INSIST(disp->requests == 0);
INSIST(disp->recv_pending == 0);
isc_mempool_put(mgr->epool, disp->failsafe_ev);
disp->failsafe_ev = NULL;
if (disp->qid != NULL)
qid_destroy(mgr->mctx, &disp->qid);
disp->mgr = NULL;
DESTROYLOCK(&disp->lock);
disp->magic = 0;
isc_mempool_put(mgr->dpool, disp);
}
isc_result_t
dns_dispatch_createtcp(dns_dispatchmgr_t *mgr, isc_socket_t *sock,
isc_taskmgr_t *taskmgr, unsigned int buffersize,
unsigned int maxbuffers, unsigned int maxrequests,
unsigned int buckets, unsigned int increment,
unsigned int attributes, dns_dispatch_t **dispp)
{
isc_result_t result;
dns_dispatch_t *disp;
UNUSED(maxbuffers);
UNUSED(buffersize);
REQUIRE(VALID_DISPATCHMGR(mgr));
REQUIRE(isc_socket_gettype(sock) == isc_sockettype_tcp);
REQUIRE((attributes & DNS_DISPATCHATTR_TCP) != 0);
REQUIRE((attributes & DNS_DISPATCHATTR_UDP) == 0);
attributes |= DNS_DISPATCHATTR_PRIVATE; /* XXXMLG */
LOCK(&mgr->lock);
/*
* dispatch_allocate() checks mgr for us.
* qid_allocate() checks buckets and increment for us.
*/
disp = NULL;
result = dispatch_allocate(mgr, maxrequests, &disp);
if (result != ISC_R_SUCCESS) {
UNLOCK(&mgr->lock);
return (result);
}
result = qid_allocate(mgr, buckets, increment, &disp->qid);
if (result != ISC_R_SUCCESS)
goto deallocate_dispatch;
disp->socktype = isc_sockettype_tcp;
disp->socket = NULL;
isc_socket_attach(sock, &disp->socket);
disp->task = NULL;
result = isc_task_create(taskmgr, 0, &disp->task);
if (result != ISC_R_SUCCESS)
goto kill_socket;
disp->ctlevent = isc_event_allocate(mgr->mctx, disp,
DNS_EVENT_DISPATCHCONTROL,
destroy_disp, disp,
sizeof(isc_event_t));
if (disp->ctlevent == NULL)
goto kill_task;
isc_task_setname(disp->task, "tcpdispatch", disp);
dns_tcpmsg_init(mgr->mctx, disp->socket, &disp->tcpmsg);
disp->tcpmsg_valid = 1;
disp->attributes = attributes;
/*
* Append it to the dispatcher list.
*/
ISC_LIST_APPEND(mgr->list, disp, link);
UNLOCK(&mgr->lock);
mgr_log(mgr, LVL(90), "created TCP dispatcher %p", disp);
dispatch_log(disp, LVL(90), "created task %p", disp->task);
*dispp = disp;
return (ISC_R_SUCCESS);
/*
* Error returns.
*/
kill_task:
isc_task_detach(&disp->task);
kill_socket:
isc_socket_detach(&disp->socket);
deallocate_dispatch:
dispatch_free(&disp);
UNLOCK(&mgr->lock);
return (result);
}
isc_result_t
dns_dispatch_getudp(dns_dispatchmgr_t *mgr, isc_socketmgr_t *sockmgr,
isc_taskmgr_t *taskmgr, isc_sockaddr_t *localaddr,
unsigned int buffersize,
unsigned int maxbuffers, unsigned int maxrequests,
unsigned int buckets, unsigned int increment,
unsigned int attributes, unsigned int mask,
dns_dispatch_t **dispp)
{
isc_result_t result;
dns_dispatch_t *disp;
REQUIRE(VALID_DISPATCHMGR(mgr));
REQUIRE(sockmgr != NULL);
REQUIRE(localaddr != NULL);
REQUIRE(taskmgr != NULL);
REQUIRE(buffersize >= 512 && buffersize < (64 * 1024));
REQUIRE(maxbuffers > 0);
REQUIRE(buckets < 2097169); /* next prime > 65536 * 32 */
REQUIRE(increment > buckets);
REQUIRE(dispp != NULL && *dispp == NULL);
REQUIRE((attributes & DNS_DISPATCHATTR_TCP) == 0);
result = dns_dispatchmgr_setudp(mgr, buffersize, maxbuffers,
buckets, increment);
if (result != ISC_R_SUCCESS)
return (result);
LOCK(&mgr->lock);
/*
* First, see if we have a dispatcher that matches.
*/
disp = NULL;
result = dispatch_find(mgr, localaddr, attributes, mask, &disp);
if (result == ISC_R_SUCCESS) {
disp->refcount++;
if (disp->maxrequests < maxrequests)
disp->maxrequests = maxrequests;
if ((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) == 0 &&
(attributes & DNS_DISPATCHATTR_NOLISTEN) != 0)
{
disp->attributes |= DNS_DISPATCHATTR_NOLISTEN;
if (disp->recv_pending != 0)
isc_socket_cancel(disp->socket, NULL,
ISC_SOCKCANCEL_RECV);
}
UNLOCK(&disp->lock);
UNLOCK(&mgr->lock);
*dispp = disp;
return (ISC_R_SUCCESS);
}
/*
* Nope, create one.
*/
result = dispatch_createudp(mgr, sockmgr, taskmgr, localaddr,
maxrequests, attributes, &disp);
if (result != ISC_R_SUCCESS) {
UNLOCK(&mgr->lock);
return (result);
}
UNLOCK(&mgr->lock);
*dispp = disp;
return (ISC_R_SUCCESS);
}
/*
* mgr should be locked.
*/
static isc_result_t
dispatch_createudp(dns_dispatchmgr_t *mgr, isc_socketmgr_t *sockmgr,
isc_taskmgr_t *taskmgr,
isc_sockaddr_t *localaddr,
unsigned int maxrequests,
unsigned int attributes,
dns_dispatch_t **dispp)
{
isc_result_t result;
dns_dispatch_t *disp;
isc_socket_t *sock;
/*
* dispatch_allocate() checks mgr for us.
*/
disp = NULL;
result = dispatch_allocate(mgr, maxrequests, &disp);
if (result != ISC_R_SUCCESS)
return (result);
result = create_socket(sockmgr, localaddr, &sock);
if (result != ISC_R_SUCCESS)
goto deallocate_dispatch;
disp->socktype = isc_sockettype_udp;
disp->socket = sock;
disp->local = *localaddr;
disp->task = NULL;
result = isc_task_create(taskmgr, 0, &disp->task);
if (result != ISC_R_SUCCESS)
goto kill_socket;
disp->ctlevent = isc_event_allocate(mgr->mctx, disp,
DNS_EVENT_DISPATCHCONTROL,
destroy_disp, disp,
sizeof(isc_event_t));
if (disp->ctlevent == NULL)
goto kill_task;
isc_task_setname(disp->task, "udpdispatch", disp);
attributes &= ~DNS_DISPATCHATTR_TCP;
attributes |= DNS_DISPATCHATTR_UDP;
disp->attributes = attributes;
/*
* Append it to the dispatcher list.
*/
ISC_LIST_APPEND(mgr->list, disp, link);
mgr_log(mgr, LVL(90), "created UDP dispatcher %p", disp);
dispatch_log(disp, LVL(90), "created task %p", disp->task);
dispatch_log(disp, LVL(90), "created socket %p", disp->socket);
*dispp = disp;
return (ISC_R_SUCCESS);
/*
* Error returns.
*/
kill_task:
isc_task_detach(&disp->task);
kill_socket:
isc_socket_detach(&disp->socket);
deallocate_dispatch:
dispatch_free(&disp);
return (result);
}
void
dns_dispatch_attach(dns_dispatch_t *disp, dns_dispatch_t **dispp) {
REQUIRE(VALID_DISPATCH(disp));
REQUIRE(dispp != NULL && *dispp == NULL);
LOCK(&disp->lock);
disp->refcount++;
UNLOCK(&disp->lock);
*dispp = disp;
}
/*
* It is important to lock the manager while we are deleting the dispatch,
* since dns_dispatch_getudp will call dispatch_find, which returns to
* the caller a dispatch but does not attach to it until later. _getudp
* locks the manager, however, so locking it here will keep us from attaching
* to a dispatcher that is in the process of going away.
*/
void
dns_dispatch_detach(dns_dispatch_t **dispp) {
dns_dispatch_t *disp;
isc_boolean_t killit;
REQUIRE(dispp != NULL && VALID_DISPATCH(*dispp));
disp = *dispp;
*dispp = NULL;
LOCK(&disp->lock);
INSIST(disp->refcount > 0);
disp->refcount--;
killit = ISC_FALSE;
if (disp->refcount == 0) {
if (disp->recv_pending > 0)
isc_socket_cancel(disp->socket, NULL,
ISC_SOCKCANCEL_RECV);
disp->shutting_down = 1;
}
dispatch_log(disp, LVL(90), "detach: refcount %d", disp->refcount);
killit = destroy_disp_ok(disp);
UNLOCK(&disp->lock);
if (killit)
isc_task_send(disp->task, &disp->ctlevent);
}
isc_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_dispentry_t **resp)
{
dns_dispentry_t *res;
unsigned int bucket;
dns_messageid_t id;
int i;
isc_boolean_t ok;
dns_qid_t *qid;
REQUIRE(VALID_DISPATCH(disp));
REQUIRE(task != NULL);
REQUIRE(dest != NULL);
REQUIRE(resp != NULL && *resp == NULL);
REQUIRE(idp != NULL);
LOCK(&disp->lock);
if (disp->shutting_down == 1) {
UNLOCK(&disp->lock);
return (ISC_R_SHUTTINGDOWN);
}
if (disp->requests >= disp->maxrequests) {
UNLOCK(&disp->lock);
return (ISC_R_QUOTA);
}
/*
* Try somewhat hard to find an unique ID.
*/
qid = DNS_QID(disp);
LOCK(&qid->lock);
id = dns_randomid(qid);
bucket = dns_hash(qid, dest, id);
ok = ISC_FALSE;
for (i = 0 ; i < 64 ; i++) {
if (bucket_search(qid, dest, id, bucket) == NULL) {
ok = ISC_TRUE;
break;
}
id += qid->qid_increment;
id &= 0x0000ffff;
bucket = dns_hash(qid, dest, id);
}
UNLOCK(&qid->lock);
if (!ok) {
UNLOCK(&disp->lock);
return (ISC_R_NOMORE);
}
res = isc_mempool_get(disp->mgr->rpool);
if (res == NULL) {
UNLOCK(&disp->lock);
return (ISC_R_NOMEMORY);
}
disp->refcount++;
disp->requests++;
res->task = NULL;
isc_task_attach(task, &res->task);
res->disp = disp;
res->id = id;
res->bucket = bucket;
res->host = *dest;
res->action = action;
res->arg = arg;
res->item_out = ISC_FALSE;
ISC_LIST_INIT(res->items);
ISC_LINK_INIT(res, link);
res->magic = RESPONSE_MAGIC;
LOCK(&qid->lock);
ISC_LIST_APPEND(qid->qid_table[bucket], res, link);
UNLOCK(&qid->lock);
request_log(disp, res, LVL(90),
"attached to task %p", res->task);
if (((disp->attributes & DNS_DISPATCHATTR_UDP) != 0) ||
((disp->attributes & DNS_DISPATCHATTR_CONNECTED) != 0))
startrecv(disp);
UNLOCK(&disp->lock);
*idp = id;
*resp = res;
return (ISC_R_SUCCESS);
}
void
dns_dispatch_starttcp(dns_dispatch_t *disp) {
REQUIRE(VALID_DISPATCH(disp));
dispatch_log(disp, LVL(90), "starttcp %p", disp->task);
LOCK(&disp->lock);
disp->attributes |= DNS_DISPATCHATTR_CONNECTED;
startrecv(disp);
UNLOCK(&disp->lock);
}
void
dns_dispatch_removeresponse(dns_dispentry_t **resp,
dns_dispatchevent_t **sockevent)
{
dns_dispatchmgr_t *mgr;
dns_dispatch_t *disp;
dns_dispentry_t *res;
dns_dispatchevent_t *ev;
unsigned int bucket;
isc_boolean_t killit;
unsigned int n;
isc_eventlist_t events;
dns_qid_t *qid;
REQUIRE(resp != NULL);
REQUIRE(VALID_RESPONSE(*resp));
res = *resp;
*resp = NULL;
disp = res->disp;
REQUIRE(VALID_DISPATCH(disp));
mgr = disp->mgr;
REQUIRE(VALID_DISPATCHMGR(mgr));
qid = DNS_QID(disp);
if (sockevent != NULL) {
REQUIRE(*sockevent != NULL);
ev = *sockevent;
*sockevent = NULL;
} else {
ev = NULL;
}
LOCK(&disp->lock);
INSIST(disp->requests > 0);
disp->requests--;
INSIST(disp->refcount > 0);
disp->refcount--;
killit = ISC_FALSE;
if (disp->refcount == 0) {
if (disp->recv_pending > 0)
isc_socket_cancel(disp->socket, NULL,
ISC_SOCKCANCEL_RECV);
disp->shutting_down = 1;
}
bucket = res->bucket;
LOCK(&qid->lock);
ISC_LIST_UNLINK(qid->qid_table[bucket], res, link);
UNLOCK(&qid->lock);
if (ev == NULL && res->item_out) {
/*
* We've posted our event, but the caller hasn't gotten it
* yet. Take it back.
*/
ISC_LIST_INIT(events);
n = isc_task_unsend(res->task, res, DNS_EVENT_DISPATCH,
NULL, &events);
/*
* We had better have gotten it back.
*/
INSIST(n == 1);
ev = (dns_dispatchevent_t *)ISC_LIST_HEAD(events);
}
if (ev != NULL) {
REQUIRE(res->item_out == ISC_TRUE);
res->item_out = ISC_FALSE;
if (ev->buffer.base != NULL)
free_buffer(disp, ev->buffer.base, ev->buffer.length);
free_event(disp, ev);
}
request_log(disp, res, LVL(90), "detaching from task %p", res->task);
isc_task_detach(&res->task);
/*
* Free any buffered requests as well
*/
ev = ISC_LIST_HEAD(res->items);
while (ev != NULL) {
ISC_LIST_UNLINK(res->items, ev, ev_link);
if (ev->buffer.base != NULL)
free_buffer(disp, ev->buffer.base, ev->buffer.length);
free_event(disp, ev);
ev = ISC_LIST_HEAD(res->items);
}
res->magic = 0;
isc_mempool_put(disp->mgr->rpool, res);
if (disp->shutting_down == 1)
do_cancel(disp, NULL);
else
startrecv(disp);
killit = destroy_disp_ok(disp);
UNLOCK(&disp->lock);
if (killit)
isc_task_send(disp->task, &disp->ctlevent);
}
static void
do_cancel(dns_dispatch_t *disp, dns_dispentry_t *resp) {
dns_dispatchevent_t *ev;
dns_qid_t *qid;
if (disp->shutdown_out == 1)
return;
qid = DNS_QID(disp);
/*
* Search for the first response handler without packets outstanding.
*/
if (resp == NULL) {
LOCK(&qid->lock);
resp = linear_first(qid);
if (resp == NULL) {
/* no first item? */
UNLOCK(&qid->lock);
return;
}
do {
if (resp->item_out == ISC_FALSE)
break;
resp = linear_next(qid, resp);
} while (resp != NULL);
UNLOCK(&qid->lock);
}
/*
* No one to send the cancel event to, so nothing to do.
*/
if (resp == NULL)
return;
/*
* Send the shutdown failsafe event to this resp.
*/
ev = disp->failsafe_ev;
ISC_EVENT_INIT(ev, sizeof (*ev), 0, NULL, DNS_EVENT_DISPATCH,
resp->action, resp->arg, resp, NULL, NULL);
ev->result = disp->shutdown_why;
ev->buffer.base = NULL;
ev->buffer.length = 0;
disp->shutdown_out = 1;
request_log(disp, resp, LVL(10),
"cancel: failsafe event %p -> task %p",
ev, resp->task);
resp->item_out = ISC_TRUE;
isc_task_send(resp->task, (isc_event_t **)&ev);
}
isc_socket_t *
dns_dispatch_getsocket(dns_dispatch_t *disp) {
REQUIRE(VALID_DISPATCH(disp));
return (disp->socket);
}
isc_result_t
dns_dispatch_getlocaladdress(dns_dispatch_t *disp, isc_sockaddr_t *addrp) {
REQUIRE(VALID_DISPATCH(disp));
REQUIRE(addrp != NULL);
if (disp->socktype == isc_sockettype_udp) {
*addrp = disp->local;
return (ISC_R_SUCCESS);
}
return (ISC_R_NOTIMPLEMENTED);
}
void
dns_dispatch_cancel(dns_dispatch_t *disp) {
REQUIRE(VALID_DISPATCH(disp));
LOCK(&disp->lock);
if (disp->shutting_down == 1) {
UNLOCK(&disp->lock);
return;
}
disp->shutdown_why = ISC_R_CANCELED;
disp->shutting_down = 1;
do_cancel(disp, NULL);
UNLOCK(&disp->lock);
return;
}
void
dns_dispatch_changeattributes(dns_dispatch_t *disp,
unsigned int attributes, unsigned int mask)
{
REQUIRE(VALID_DISPATCH(disp));
/* XXXMLG
* Should check for valid attributes here!
*/
LOCK(&disp->lock);
if ((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) != 0 &&
(attributes & DNS_DISPATCHATTR_NOLISTEN) == 0)
{
disp->attributes &= ~DNS_DISPATCHATTR_NOLISTEN;
startrecv(disp);
}
disp->attributes &= ~mask;
disp->attributes |= (attributes & mask);
UNLOCK(&disp->lock);
}
void
dns_dispatch_importrecv(dns_dispatch_t *disp, isc_event_t *event) {
void *buf;
isc_socketevent_t *sevent, *newsevent;
REQUIRE(VALID_DISPATCH(disp));
REQUIRE((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) != 0);
REQUIRE(event != NULL);
sevent = (isc_socketevent_t *)event;
INSIST(sevent->n <= disp->mgr->buffersize);
newsevent = (isc_socketevent_t *)
isc_event_allocate(disp->mgr->mctx, NULL,
ISC_SOCKEVENT_RECVDONE, udp_recv,
disp, sizeof(isc_socketevent_t));
if (newsevent == NULL)
return;
buf = allocate_udp_buffer(disp);
if (buf == NULL) {
isc_event_free((isc_event_t **)&newsevent);
return;
}
memcpy(buf, sevent->region.base, sevent->n);
newsevent->region.base = buf;
newsevent->region.length = disp->mgr->buffersize;
newsevent->n = sevent->n;
newsevent->result = sevent->result;
newsevent->address = sevent->address;
newsevent->timestamp = sevent->timestamp;
newsevent->pktinfo = sevent->pktinfo;
newsevent->attributes = sevent->attributes;
isc_task_send(disp->task, (isc_event_t **)&newsevent);
}
#if 0
void
dns_dispatchmgr_dump(dns_dispatchmgr_t *mgr) {
dns_dispatch_t *disp;
char foo[1024];
disp = ISC_LIST_HEAD(mgr->list);
while (disp != NULL) {
isc_sockaddr_format(&disp->local, foo, sizeof foo);
printf("\tdispatch %p, addr %s\n", disp, foo);
disp = ISC_LIST_NEXT(disp, link);
}
}
#endif
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