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freebsd-nq/contrib/bind9/lib/dns/dispatch.c
Doug Barton 995ea97467 Vendor import of BIND 9.4.2
2007-12-02 19:10:41 +00:00

2675 lines
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/*
* Copyright (C) 2004-2007 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 1999-2003 Internet Software Consortium.
*
* Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC 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 1.116.18.19 2007/08/28 07:20:04 tbox Exp $ */
/*! \file */
#include <config.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <isc/entropy.h>
#include <isc/mem.h>
#include <isc/mutex.h>
#include <isc/print.h>
#include <isc/string.h>
#include <isc/task.h>
#include <isc/time.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/portlist.h>
#include <dns/tcpmsg.h>
#include <dns/types.h>
typedef ISC_LIST(dns_dispentry_t) dns_displist_t;
typedef struct dns_nsid {
isc_uint16_t nsid_state;
isc_uint16_t *nsid_vtable;
isc_uint16_t *nsid_pool;
isc_uint16_t nsid_a1, nsid_a2, nsid_a3;
isc_uint16_t nsid_c1, nsid_c2, nsid_c3;
isc_uint16_t nsid_state2;
isc_boolean_t nsid_usepool;
} dns_nsid_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;
dns_nsid_t nsid;
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;
dns_portlist_t *portlist;
/* 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 void startrecv(dns_dispatch_t *);
static dns_messageid_t dns_randomid(dns_nsid_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);
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, isc_boolean_t usepool,
dns_qid_t **qidp);
static void qid_destroy(isc_mem_t *mctx, dns_qid_t **qidp);
static isc_uint16_t nsid_next(dns_nsid_t *nsid);
static isc_result_t nsid_init(isc_mem_t *mctx, dns_nsid_t *nsid, isc_boolean_t usepool);
static void nsid_destroy(isc_mem_t *mctx, dns_nsid_t *nsid);
#define LVL(x) ISC_LOG_DEBUG(x)
static void
mgr_log(dns_dispatchmgr_t *mgr, int level, const char *fmt, ...)
ISC_FORMAT_PRINTF(3, 4);
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, ...)
ISC_FORMAT_PRINTF(3, 4);
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, ...)
ISC_FORMAT_PRINTF(4, 5);
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);
}
}
/*
* Return an unpredictable message ID.
*/
static dns_messageid_t
dns_randomid(dns_nsid_t *nsid) {
isc_uint32_t id;
id = nsid_next(nsid);
return ((dns_messageid_t)id);
}
/*
* 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, free the buffer, 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 (ev->ev_type == ISC_SOCKEVENT_RECVDONE) {
/*
* Unless the receive event was imported from a listening
* interface, in which case the event type is
* DNS_EVENT_IMPORTRECVDONE, receive operation must be pending.
*/
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;
}
dns_dispatch_hash(&ev->timestamp, sizeof(&ev->timestamp));
dns_dispatch_hash(ev->region.base, ev->region.length);
/* response */
bucket = dns_hash(qid, &ev->address, id);
LOCK(&qid->lock);
resp = bucket_search(qid, &ev->address, id, bucket);
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 unlock;
}
/*
* Now that we have the original dispatch the query was sent
* from check that the address and port the response was
* sent to make sense.
*/
if (disp != resp->disp) {
isc_sockaddr_t a1;
isc_sockaddr_t a2;
/*
* Check that the socket types and ports match.
*/
if (disp->socktype != resp->disp->socktype ||
isc_sockaddr_getport(&disp->local) !=
isc_sockaddr_getport(&resp->disp->local)) {
free_buffer(disp, ev->region.base, ev->region.length);
goto unlock;
}
/*
* If both dispatches are bound to an address then fail as
* the addresses can't be equal (enforced by the IP stack).
*
* Note under Linux a packet can be sent out via IPv4 socket
* and the response be received via a IPv6 socket.
*
* Requests sent out via IPv6 should always come back in
* via IPv6.
*/
if (isc_sockaddr_pf(&resp->disp->local) == PF_INET6 &&
isc_sockaddr_pf(&disp->local) != PF_INET6) {
free_buffer(disp, ev->region.base, ev->region.length);
goto unlock;
}
isc_sockaddr_anyofpf(&a1, isc_sockaddr_pf(&resp->disp->local));
isc_sockaddr_anyofpf(&a2, isc_sockaddr_pf(&disp->local));
if (!isc_sockaddr_eqaddr(&a1, &resp->disp->local) &&
!isc_sockaddr_eqaddr(&a2, &disp->local)) {
free_buffer(disp, ev->region.base, ev->region.length);
goto unlock;
}
}
queue_response = resp->item_out;
rev = allocate_event(resp->disp);
if (rev == NULL) {
free_buffer(disp, ev->region.base, ev->region.length);
goto unlock;
}
/*
* 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_PTR(&rev));
}
unlock:
UNLOCK(&qid->lock);
/*
* 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, notify everyone as the
* various queues drain.
*
* If query, restart.
*
* If response:
* Allocate event, fill in details.
* If cannot allocate, restart.
* find target. If not found, 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;
int level;
char buf[ISC_SOCKADDR_FORMATSIZE];
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);
break;
case ISC_R_CONNECTIONRESET:
level = ISC_LOG_INFO;
goto logit;
default:
level = ISC_LOG_ERROR;
logit:
isc_sockaddr_format(&tcpmsg->address, buf, sizeof(buf));
dispatch_log(disp, level, "shutting down due to TCP "
"receive error: %s: %s", buf,
isc_result_totext(tcpmsg->result));
do_cancel(disp);
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;
}
dns_dispatch_hash(tcpmsg->buffer.base, tcpmsg->buffer.length);
/*
* Response.
*/
bucket = dns_hash(qid, &tcpmsg->address, id);
LOCK(&qid->lock);
resp = bucket_search(qid, &tcpmsg->address, id, bucket);
dispatch_log(disp, LVL(90),
"search for response in bucket %d: %s",
bucket, (resp == NULL ? "not found" : "found"));
if (resp == NULL)
goto unlock;
queue_response = resp->item_out;
rev = allocate_event(disp);
if (rev == NULL)
goto unlock;
/*
* 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_PTR(&rev));
}
unlock:
UNLOCK(&qid->lock);
/*
* 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);
return;
}
INSIST(disp->recv_pending == 0);
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);
return;
}
INSIST(disp->recv_pending == 0);
disp->recv_pending = 1;
break;
default:
INSIST(0);
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);
if (mgr->portlist != NULL)
dns_portlist_detach(&mgr->portlist);
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);
#ifndef ISC_ALLOW_MAPPED
isc_socket_ipv6only(sock, ISC_TRUE);
#endif
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;
mgr->portlist = 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(&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);
}
void
dns_dispatchmgr_setblackportlist(dns_dispatchmgr_t *mgr,
dns_portlist_t *portlist)
{
REQUIRE(VALID_DISPATCHMGR(mgr));
if (mgr->portlist != NULL)
dns_portlist_detach(&mgr->portlist);
if (portlist != NULL)
dns_portlist_attach(portlist, &mgr->portlist);
}
dns_portlist_t *
dns_dispatchmgr_getblackportlist(dns_dispatchmgr_t *mgr) {
REQUIRE(VALID_DISPATCHMGR(mgr));
return (mgr->portlist);
}
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) {
UNLOCK(&mgr->buffer_lock);
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, ISC_TRUE, &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);
}
static isc_boolean_t
blacklisted(dns_dispatchmgr_t *mgr, isc_socket_t *sock) {
isc_sockaddr_t sockaddr;
isc_result_t result;
if (mgr->portlist == NULL)
return (ISC_FALSE);
result = isc_socket_getsockname(sock, &sockaddr);
if (result != ISC_R_SUCCESS)
return (ISC_FALSE);
if (mgr->portlist != NULL &&
dns_portlist_match(mgr->portlist, isc_sockaddr_pf(&sockaddr),
isc_sockaddr_getport(&sockaddr)))
return (ISC_TRUE);
return (ISC_FALSE);
}
#define ATTRMATCH(_a1, _a2, _mask) (((_a1) & (_mask)) == ((_a2) & (_mask)))
static isc_boolean_t
local_addr_match(dns_dispatch_t *disp, isc_sockaddr_t *addr) {
isc_sockaddr_t sockaddr;
isc_result_t result;
if (addr == NULL)
return (ISC_TRUE);
/*
* Don't match wildcard ports against newly blacklisted ports.
*/
if (disp->mgr->portlist != NULL &&
isc_sockaddr_getport(addr) == 0 &&
isc_sockaddr_getport(&disp->local) == 0 &&
blacklisted(disp->mgr, disp->socket))
return (ISC_FALSE);
/*
* Check if we match the binding <address,port>.
* Wildcard ports match/fail here.
*/
if (isc_sockaddr_equal(&disp->local, addr))
return (ISC_TRUE);
if (isc_sockaddr_getport(addr) == 0)
return (ISC_FALSE);
/*
* Check if we match a bound wildcard port <address,port>.
*/
if (!isc_sockaddr_eqaddr(&disp->local, addr))
return (ISC_FALSE);
result = isc_socket_getsockname(disp->socket, &sockaddr);
if (result != ISC_R_SUCCESS)
return (ISC_FALSE);
return (isc_sockaddr_equal(&sockaddr, 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, isc_boolean_t usepool, dns_qid_t **qidp)
{
dns_qid_t *qid;
unsigned int i;
isc_result_t result;
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);
}
result = nsid_init(mgr->mctx, &qid->nsid, usepool);
if (result != ISC_R_SUCCESS) {
isc_mem_put(mgr->mctx, qid->qid_table,
buckets * sizeof(dns_displist_t));
isc_mem_put(mgr->mctx, qid, sizeof(*qid));
return (ISC_R_NOMEMORY);
}
result = isc_mutex_init(&qid->lock);
if (result != ISC_R_SUCCESS) {
nsid_destroy(mgr->mctx, &qid->nsid);
isc_mem_put(mgr->mctx, qid->qid_table,
buckets * sizeof(dns_displist_t));
isc_mem_put(mgr->mctx, qid, sizeof(*qid));
return (result);
}
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;
*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;
nsid_destroy(mctx, &qid->nsid);
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 result;
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;
result = isc_mutex_init(&disp->lock);
if (result != ISC_R_SUCCESS)
goto deallocate;
disp->failsafe_ev = allocate_event(disp);
if (disp->failsafe_ev == NULL) {
result = 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 (result);
}
/*
* 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, ISC_FALSE, &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) {
result = ISC_R_NOMEMORY;
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, disp->task,
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.
*/
#ifndef DNS_DISPATCH_HELD
#define DNS_DISPATCH_HELD 20U
#endif
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 = NULL;
isc_socket_t *held[DNS_DISPATCH_HELD];
unsigned int i = 0, j = 0;
/*
* dispatch_allocate() checks mgr for us.
*/
disp = NULL;
result = dispatch_allocate(mgr, maxrequests, &disp);
if (result != ISC_R_SUCCESS)
return (result);
/*
* Try to allocate a socket that is not on the blacklist.
* Hold up to DNS_DISPATCH_HELD sockets to prevent the OS
* from returning the same port to us too quickly.
*/
memset(held, 0, sizeof(held));
getsocket:
result = create_socket(sockmgr, localaddr, &sock);
if (result != ISC_R_SUCCESS)
goto deallocate_dispatch;
if (isc_sockaddr_getport(localaddr) == 0 && blacklisted(mgr, sock)) {
if (held[i] != NULL)
isc_socket_detach(&held[i]);
held[i++] = sock;
sock = NULL;
if (i == DNS_DISPATCH_HELD)
i = 0;
if (j++ == 0xffffU) {
mgr_log(mgr, ISC_LOG_ERROR, "avoid-v%s-udp-ports: "
"unable to allocate a non-blacklisted port",
isc_sockaddr_pf(localaddr) == AF_INET ?
"4" : "6");
result = ISC_R_FAILURE;
goto deallocate_dispatch;
}
goto getsocket;
}
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) {
result = ISC_R_NOMEMORY;
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;
goto cleanheld;
/*
* Error returns.
*/
kill_task:
isc_task_detach(&disp->task);
kill_socket:
isc_socket_detach(&disp->socket);
deallocate_dispatch:
dispatch_free(&disp);
cleanheld:
for (i = 0; i < DNS_DISPATCH_HELD; i++)
if (held[i] != NULL)
isc_socket_detach(&held[i]);
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, disp->task,
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->nsid);
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);
}
if (!ok) {
UNLOCK(&qid->lock);
UNLOCK(&disp->lock);
return (ISC_R_NOMORE);
}
res = isc_mempool_get(disp->mgr->rpool);
if (res == NULL) {
UNLOCK(&qid->lock);
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;
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, disp->task,
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);
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_dispatchevent_t *ev;
dns_dispentry_t *resp;
dns_qid_t *qid;
if (disp->shutdown_out == 1)
return;
qid = DNS_QID(disp);
/*
* Search for the first response handler without packets outstanding.
*/
LOCK(&qid->lock);
for (resp = linear_first(qid);
resp != NULL && resp->item_out != ISC_FALSE;
/* Empty. */)
resp = linear_next(qid, resp);
/*
* No one to send the cancel event to, so nothing to do.
*/
if (resp == NULL)
goto unlock;
/*
* 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_PTR(&ev));
unlock:
UNLOCK(&qid->lock);
}
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);
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 ((mask & DNS_DISPATCHATTR_NOLISTEN) != 0) {
if ((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) != 0 &&
(attributes & DNS_DISPATCHATTR_NOLISTEN) == 0) {
disp->attributes &= ~DNS_DISPATCHATTR_NOLISTEN;
startrecv(disp);
} else 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, disp->task,
ISC_SOCKCANCEL_RECV);
}
}
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,
DNS_EVENT_IMPORTRECVDONE, udp_recv,
disp, sizeof(isc_socketevent_t));
if (newsevent == NULL)
return;
buf = allocate_udp_buffer(disp);
if (buf == NULL) {
isc_event_free(ISC_EVENT_PTR(&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_PTR(&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
/*
* Allow the user to pick one of two ID randomization algorithms.
*
* The first algorithm is an adaptation of the sequence shuffling
* algorithm discovered by Carter Bays and S. D. Durham [ACM Trans. Math.
* Software 2 (1976), 59-64], as documented as Algorithm B in Chapter
* 3.2.2 in Volume 2 of Knuth's "The Art of Computer Programming". We use
* a randomly selected linear congruential random number generator with a
* modulus of 2^16, whose increment is a randomly picked odd number, and
* whose multiplier is picked from a set which meets the following
* criteria:
* Is of the form 8*n+5, which ensures "high potency" according to
* principle iii in the summary chapter 3.6. This form also has a
* gcd(a-1,m) of 4 which is good according to principle iv.
*
* Is between 0.01 and 0.99 times the modulus as specified by
* principle iv.
*
* Passes the spectral test "with flying colors" (ut >= 1) in
* dimensions 2 through 6 as calculated by Algorithm S in Chapter
* 3.3.4 and the ratings calculated by formula 35 in section E.
*
* Of the multipliers that pass this test, pick the set that is
* best according to the theoretical bounds of the serial
* correlation test. This was calculated using a simplified
* version of Knuth's Theorem K in Chapter 3.3.3.
*
* These criteria may not be important for this use, but we might as well
* pick from the best generators since there are so many possible ones and
* we don't have that many random bits to do the picking.
*
* We use a modulus of 2^16 instead of something bigger so that we will
* tend to cycle through all the possible IDs before repeating any,
* however the shuffling will perturb this somewhat. Theoretically there
* is no minimimum interval between two uses of the same ID, but in
* practice it seems to be >64000.
*
* Our adaptatation of Algorithm B mixes the hash state which has
* captured various random events into the shuffler to perturb the
* sequence.
*
* One disadvantage of this algorithm is that if the generator parameters
* were to be guessed, it would be possible to mount a limited brute force
* attack on the ID space since the IDs are only shuffled within a limited
* range.
*
* The second algorithm uses the same random number generator to populate
* a pool of 65536 IDs. The hash state is used to pick an ID from a window
* of 4096 IDs in this pool, then the chosen ID is swapped with the ID
* at the beginning of the window and the window position is advanced.
* This means that the interval between uses of the ID will be no less
* than 65536-4096. The ID sequence in the pool will become more random
* over time.
*
* For both algorithms, two more linear congruential random number generators
* are selected. The ID from the first part of algorithm is used to seed
* the first of these generators, and its output is used to seed the second.
* The strategy is use these generators as 1 to 1 hashes to obfuscate the
* properties of the generator used in the first part of either algorithm.
*
* The first algorithm may be suitable for use in a client resolver since
* its memory requirements are fairly low and it's pretty random out of
* the box. It is somewhat succeptible to a limited brute force attack,
* so the second algorithm is probably preferable for a longer running
* program that issues a large number of queries and has time to randomize
* the pool.
*/
#define NSID_SHUFFLE_TABLE_SIZE 100 /* Suggested by Knuth */
/*
* Pick one of the next 4096 IDs in the pool.
* There is a tradeoff here between randomness and how often and ID is reused.
*/
#define NSID_LOOKAHEAD 4096 /* Must be a power of 2 */
#define NSID_SHUFFLE_ONLY 1 /* algorithm 1 */
#define NSID_USE_POOL 2 /* algorithm 2 */
#define NSID_HASHSHIFT 3
#define NSID_HASHROTATE(v) \
(((v) << NSID_HASHSHIFT) | ((v) >> ((sizeof(v) * 8) - NSID_HASHSHIFT)))
static isc_uint32_t nsid_hash_state;
/*
* Keep a running hash of various bits of data that we'll use to
* stir the ID pool or perturb the ID generator
*/
static void
nsid_hash(void *data, size_t len) {
unsigned char *p = data;
/*
* Hash function similar to the one we use for hashing names.
* We don't fold case or toss the upper bit here, though.
* This hash doesn't do much interesting when fed binary zeros,
* so there may be a better hash function.
* This function doesn't need to be very strong since we're
* only using it to stir the pool, but it should be reasonably
* fast.
*/
/*
* We don't care about locking access to nsid_hash_state.
* In fact races make the result even more non deteministic.
*/
while (len-- > 0U) {
nsid_hash_state = NSID_HASHROTATE(nsid_hash_state);
nsid_hash_state += *p++;
}
}
/*
* Table of good linear congruential multipliers for modulus 2^16
* in order of increasing serial correlation bounds (so trim from
* the end).
*/
static const isc_uint16_t nsid_multiplier_table[] = {
17565, 25013, 11733, 19877, 23989, 23997, 24997, 25421,
26781, 27413, 35901, 35917, 35973, 36229, 38317, 38437,
39941, 40493, 41853, 46317, 50581, 51429, 53453, 53805,
11317, 11789, 12045, 12413, 14277, 14821, 14917, 18989,
19821, 23005, 23533, 23573, 23693, 27549, 27709, 28461,
29365, 35605, 37693, 37757, 38309, 41285, 45261, 47061,
47269, 48133, 48597, 50277, 50717, 50757, 50805, 51341,
51413, 51581, 51597, 53445, 11493, 14229, 20365, 20653,
23485, 25541, 27429, 29421, 30173, 35445, 35653, 36789,
36797, 37109, 37157, 37669, 38661, 39773, 40397, 41837,
41877, 45293, 47277, 47845, 49853, 51085, 51349, 54085,
56933, 8877, 8973, 9885, 11365, 11813, 13581, 13589,
13613, 14109, 14317, 15765, 15789, 16925, 17069, 17205,
17621, 17941, 19077, 19381, 20245, 22845, 23733, 24869,
25453, 27213, 28381, 28965, 29245, 29997, 30733, 30901,
34877, 35485, 35613, 36133, 36661, 36917, 38597, 40285,
40693, 41413, 41541, 41637, 42053, 42349, 45245, 45469,
46493, 48205, 48613, 50861, 51861, 52877, 53933, 54397,
55669, 56453, 56965, 58021, 7757, 7781, 8333, 9661,
12229, 14373, 14453, 17549, 18141, 19085, 20773, 23701,
24205, 24333, 25261, 25317, 27181, 30117, 30477, 34757,
34885, 35565, 35885, 36541, 37957, 39733, 39813, 41157,
41893, 42317, 46621, 48117, 48181, 49525, 55261, 55389,
56845, 7045, 7749, 7965, 8469, 9133, 9549, 9789,
10173, 11181, 11285, 12253, 13453, 13533, 13757, 14477,
15053, 16901, 17213, 17269, 17525, 17629, 18605, 19013,
19829, 19933, 20069, 20093, 23261, 23333, 24949, 25309,
27613, 28453, 28709, 29301, 29541, 34165, 34413, 37301,
37773, 38045, 38405, 41077, 41781, 41925, 42717, 44437,
44525, 44613, 45933, 45941, 47077, 50077, 50893, 52117,
5293, 55069, 55989, 58125, 59205, 6869, 14685, 15453,
16821, 17045, 17613, 18437, 21029, 22773, 22909, 25445,
25757, 26541, 30709, 30909, 31093, 31149, 37069, 37725,
37925, 38949, 39637, 39701, 40765, 40861, 42965, 44813,
45077, 45733, 47045, 50093, 52861, 52957, 54181, 56325,
56365, 56381, 56877, 57013, 5741, 58101, 58669, 8613,
10045, 10261, 10653, 10733, 11461, 12261, 14069, 15877,
17757, 21165, 23885, 24701, 26429, 26645, 27925, 28765,
29197, 30189, 31293, 39781, 39909, 40365, 41229, 41453,
41653, 42165, 42365, 47421, 48029, 48085, 52773, 5573,
57037, 57637, 58341, 58357, 58901, 6357, 7789, 9093,
10125, 10709, 10765, 11957, 12469, 13437, 13509, 14773,
15437, 15773, 17813, 18829, 19565, 20237, 23461, 23685,
23725, 23941, 24877, 25461, 26405, 29509, 30285, 35181,
37229, 37893, 38565, 40293, 44189, 44581, 45701, 47381,
47589, 48557, 4941, 51069, 5165, 52797, 53149, 5341,
56301, 56765, 58581, 59493, 59677, 6085, 6349, 8293,
8501, 8517, 11597, 11709, 12589, 12693, 13517, 14909,
17397, 18085, 21101, 21269, 22717, 25237, 25661, 29189,
30101, 31397, 33933, 34213, 34661, 35533, 36493, 37309,
40037, 4189, 42909, 44309, 44357, 44389, 4541, 45461,
46445, 48237, 54149, 55301, 55853, 56621, 56717, 56901,
5813, 58437, 12493, 15365, 15989, 17829, 18229, 19341,
21013, 21357, 22925, 24885, 26053, 27581, 28221, 28485,
30605, 30613, 30789, 35437, 36285, 37189, 3941, 41797,
4269, 42901, 43293, 44645, 45221, 46893, 4893, 50301,
50325, 5189, 52109, 53517, 54053, 54485, 5525, 55949,
56973, 59069, 59421, 60733, 61253, 6421, 6701, 6709,
7101, 8669, 15797, 19221, 19837, 20133, 20957, 21293,
21461, 22461, 29085, 29861, 30869, 34973, 36469, 37565,
38125, 38829, 39469, 40061, 40117, 44093, 47429, 48341,
50597, 51757, 5541, 57629, 58405, 59621, 59693, 59701,
61837, 7061, 10421, 11949, 15405, 20861, 25397, 25509,
25893, 26037, 28629, 28869, 29605, 30213, 34205, 35637,
36365, 37285, 3773, 39117, 4021, 41061, 42653, 44509,
4461, 44829, 4725, 5125, 52269, 56469, 59085, 5917,
60973, 8349, 17725, 18637, 19773, 20293, 21453, 22533,
24285, 26333, 26997, 31501, 34541, 34805, 37509, 38477,
41333, 44125, 46285, 46997, 47637, 48173, 4925, 50253,
50381, 50917, 51205, 51325, 52165, 52229, 5253, 5269,
53509, 56253, 56341, 5821, 58373, 60301, 61653, 61973,
62373, 8397, 11981, 14341, 14509, 15077, 22261, 22429,
24261, 28165, 28685, 30661, 34021, 34445, 39149, 3917,
43013, 43317, 44053, 44101, 4533, 49541, 49981, 5277,
54477, 56357, 57261, 57765, 58573, 59061, 60197, 61197,
62189, 7725, 8477, 9565, 10229, 11437, 14613, 14709,
16813, 20029, 20677, 31445, 3165, 31957, 3229, 33541,
36645, 3805, 38973, 3965, 4029, 44293, 44557, 46245,
48917, 4909, 51749, 53709, 55733, 56445, 5925, 6093,
61053, 62637, 8661, 9109, 10821, 11389, 13813, 14325,
15501, 16149, 18845, 22669, 26437, 29869, 31837, 33709,
33973, 34173, 3677, 3877, 3981, 39885, 42117, 4421,
44221, 44245, 44693, 46157, 47309, 5005, 51461, 52037,
55333, 55693, 56277, 58949, 6205, 62141, 62469, 6293,
10101, 12509, 14029, 17997, 20469, 21149, 25221, 27109,
2773, 2877, 29405, 31493, 31645, 4077, 42005, 42077,
42469, 42501, 44013, 48653, 49349, 4997, 50101, 55405,
56957, 58037, 59429, 60749, 61797, 62381, 62837, 6605,
10541, 23981, 24533, 2701, 27333, 27341, 31197, 33805,
3621, 37381, 3749, 3829, 38533, 42613, 44381, 45901,
48517, 51269, 57725, 59461, 60045, 62029, 13805, 14013,
15461, 16069, 16157, 18573, 2309, 23501, 28645, 3077,
31541, 36357, 36877, 3789, 39429, 39805, 47685, 47949,
49413, 5485, 56757, 57549, 57805, 58317, 59549, 62213,
62613, 62853, 62933, 8909, 12941, 16677, 20333, 21541,
24429, 26077, 26421, 2885, 31269, 33381, 3661, 40925,
42925, 45173, 4525, 4709, 53133, 55941, 57413, 57797,
62125, 62237, 62733, 6773, 12317, 13197, 16533, 16933,
18245, 2213, 2477, 29757, 33293, 35517, 40133, 40749,
4661, 49941, 62757, 7853, 8149, 8573, 11029, 13421,
21549, 22709, 22725, 24629, 2469, 26125, 2669, 34253,
36709, 41013, 45597, 46637, 52285, 52333, 54685, 59013,
60997, 61189, 61981, 62605, 62821, 7077, 7525, 8781,
10861, 15277, 2205, 22077, 28517, 28949, 32109, 33493,
4661, 49941, 62757, 7853, 8149, 8573, 11029, 13421,
21549, 22709, 22725, 24629, 2469, 26125, 2669, 34253,
36709, 41013, 45597, 46637, 52285, 52333, 54685, 59013,
60997, 61189, 61981, 62605, 62821, 7077, 7525, 8781,
10861, 15277, 2205, 22077, 28517, 28949, 32109, 33493,
3685, 39197, 39869, 42621, 44997, 48565, 5221, 57381,
61749, 62317, 63245, 63381, 23149, 2549, 28661, 31653,
33885, 36341, 37053, 39517, 42805, 45853, 48997, 59349,
60053, 62509, 63069, 6525, 1893, 20181, 2365, 24893,
27397, 31357, 32277, 33357, 34437, 36677, 37661, 43469,
43917, 50997, 53869, 5653, 13221, 16741, 17893, 2157,
28653, 31789, 35301, 35821, 61613, 62245, 12405, 14517,
17453, 18421, 3149, 3205, 40341, 4109, 43941, 46869,
48837, 50621, 57405, 60509, 62877, 8157, 12933, 12957,
16501, 19533, 3461, 36829, 52357, 58189, 58293, 63053,
17109, 1933, 32157, 37701, 59005, 61621, 13029, 15085,
16493, 32317, 35093, 5061, 51557, 62221, 20765, 24613,
2629, 30861, 33197, 33749, 35365, 37933, 40317, 48045,
56229, 61157, 63797, 7917, 17965, 1917, 1973, 20301,
2253, 33157, 58629, 59861, 61085, 63909, 8141, 9221,
14757, 1581, 21637, 26557, 33869, 34285, 35733, 40933,
42517, 43501, 53653, 61885, 63805, 7141, 21653, 54973,
31189, 60061, 60341, 63357, 16045, 2053, 26069, 33997,
43901, 54565, 63837, 8949, 17909, 18693, 32349, 33125,
37293, 48821, 49053, 51309, 64037, 7117, 1445, 20405,
23085, 26269, 26293, 27349, 32381, 33141, 34525, 36461,
37581, 43525, 4357, 43877, 5069, 55197, 63965, 9845,
12093, 2197, 2229, 32165, 33469, 40981, 42397, 8749,
10853, 1453, 18069, 21693, 30573, 36261, 37421, 42533
};
#define NSID_MULT_TABLE_SIZE \
((sizeof nsid_multiplier_table)/(sizeof nsid_multiplier_table[0]))
#define NSID_RANGE_MASK (NSID_LOOKAHEAD - 1)
#define NSID_POOL_MASK 0xFFFF /* used to wrap the pool index */
#define NSID_SHUFFLE_ONLY 1
#define NSID_USE_POOL 2
static isc_uint16_t
nsid_next(dns_nsid_t *nsid) {
isc_uint16_t id, compressed_hash;
isc_uint16_t j;
compressed_hash = ((nsid_hash_state >> 16) ^
(nsid_hash_state)) & 0xFFFF;
if (nsid->nsid_usepool) {
isc_uint16_t pick;
pick = compressed_hash & NSID_RANGE_MASK;
pick = (nsid->nsid_state + pick) & NSID_POOL_MASK;
id = nsid->nsid_pool[pick];
if (pick != 0) {
/* Swap two IDs to stir the pool */
nsid->nsid_pool[pick] =
nsid->nsid_pool[nsid->nsid_state];
nsid->nsid_pool[nsid->nsid_state] = id;
}
/* increment the base pointer into the pool */
if (nsid->nsid_state == 65535)
nsid->nsid_state = 0;
else
nsid->nsid_state++;
} else {
/*
* This is the original Algorithm B
* j = ((u_long) NSID_SHUFFLE_TABLE_SIZE * nsid_state2) >> 16;
*
* We'll perturb it with some random stuff ...
*/
j = ((isc_uint32_t) NSID_SHUFFLE_TABLE_SIZE *
(nsid->nsid_state2 ^ compressed_hash)) >> 16;
nsid->nsid_state2 = id = nsid->nsid_vtable[j];
nsid->nsid_state = (((isc_uint32_t) nsid->nsid_a1 * nsid->nsid_state) +
nsid->nsid_c1) & 0xFFFF;
nsid->nsid_vtable[j] = nsid->nsid_state;
}
/* Now lets obfuscate ... */
id = (((isc_uint32_t) nsid->nsid_a2 * id) + nsid->nsid_c2) & 0xFFFF;
id = (((isc_uint32_t) nsid->nsid_a3 * id) + nsid->nsid_c3) & 0xFFFF;
return (id);
}
static isc_result_t
nsid_init(isc_mem_t *mctx, dns_nsid_t *nsid, isc_boolean_t usepool) {
isc_time_t now;
pid_t mypid;
isc_uint16_t a1ndx, a2ndx, a3ndx, c1ndx, c2ndx, c3ndx;
int i;
isc_time_now(&now);
mypid = getpid();
/* Initialize the state */
memset(nsid, 0, sizeof(*nsid));
nsid_hash(&now, sizeof now);
nsid_hash(&mypid, sizeof mypid);
/*
* Select our random number generators and initial seed.
* We could really use more random bits at this point,
* but we'll try to make a silk purse out of a sows ear ...
*/
/* generator 1 */
a1ndx = ((isc_uint32_t) NSID_MULT_TABLE_SIZE *
(nsid_hash_state & 0xFFFF)) >> 16;
nsid->nsid_a1 = nsid_multiplier_table[a1ndx];
c1ndx = (nsid_hash_state >> 9) & 0x7FFF;
nsid->nsid_c1 = 2 * c1ndx + 1;
/* generator 2, distinct from 1 */
a2ndx = ((isc_uint32_t) (NSID_MULT_TABLE_SIZE - 1) *
((nsid_hash_state >> 10) & 0xFFFF)) >> 16;
if (a2ndx >= a1ndx)
a2ndx++;
nsid->nsid_a2 = nsid_multiplier_table[a2ndx];
c2ndx = nsid_hash_state % 32767;
if (c2ndx >= c1ndx)
c2ndx++;
nsid->nsid_c2 = 2*c2ndx + 1;
/* generator 3, distinct from 1 and 2 */
a3ndx = ((isc_uint32_t) (NSID_MULT_TABLE_SIZE - 2) *
((nsid_hash_state >> 20) & 0xFFFF)) >> 16;
if (a3ndx >= a1ndx || a3ndx >= a2ndx)
a3ndx++;
if (a3ndx >= a1ndx && a3ndx >= a2ndx)
a3ndx++;
nsid->nsid_a3 = nsid_multiplier_table[a3ndx];
c3ndx = nsid_hash_state % 32766;
if (c3ndx >= c1ndx || c3ndx >= c2ndx)
c3ndx++;
if (c3ndx >= c1ndx && c3ndx >= c2ndx)
c3ndx++;
nsid->nsid_c3 = 2*c3ndx + 1;
nsid->nsid_state =
((nsid_hash_state >> 16) ^ (nsid_hash_state)) & 0xFFFF;
nsid->nsid_usepool = usepool;
if (nsid->nsid_usepool) {
nsid->nsid_pool = isc_mem_get(mctx, 0x10000 * sizeof(isc_uint16_t));
if (nsid->nsid_pool == NULL)
return (ISC_R_NOMEMORY);
for (i = 0; ; i++) {
nsid->nsid_pool[i] = nsid->nsid_state;
nsid->nsid_state =
(((u_long) nsid->nsid_a1 * nsid->nsid_state) +
nsid->nsid_c1) & 0xFFFF;
if (i == 0xFFFF)
break;
}
} else {
nsid->nsid_vtable = isc_mem_get(mctx, NSID_SHUFFLE_TABLE_SIZE *
(sizeof(isc_uint16_t)) );
if (nsid->nsid_vtable == NULL)
return (ISC_R_NOMEMORY);
for (i = 0; i < NSID_SHUFFLE_TABLE_SIZE; i++) {
nsid->nsid_vtable[i] = nsid->nsid_state;
nsid->nsid_state =
(((isc_uint32_t) nsid->nsid_a1 * nsid->nsid_state) +
nsid->nsid_c1) & 0xFFFF;
}
nsid->nsid_state2 = nsid->nsid_state;
}
return (ISC_R_SUCCESS);
}
static void
nsid_destroy(isc_mem_t *mctx, dns_nsid_t *nsid) {
if (nsid->nsid_usepool)
isc_mem_put(mctx, nsid->nsid_pool,
0x10000 * sizeof(isc_uint16_t));
else
isc_mem_put(mctx, nsid->nsid_vtable,
NSID_SHUFFLE_TABLE_SIZE * (sizeof(isc_uint16_t)) );
memset(nsid, 0, sizeof(*nsid));
}
void
dns_dispatch_hash(void *data, size_t len) {
nsid_hash(data, len);
}
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