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bind9/lib/dns/dispatch.c
T
Evan Hunt e76a7f764e Move isc_socket_cancel() calls into dispatch 
We now use dns_dispatch_cancel() for this purpose. NOTE: The caller
still has to track whether there are pending send or connect events in
the dispatch or dispatch entry; later this should be moved into the
dispatch module as well.

Also removed some public dns_dispatch_*() API calls that are no longer
used outside dispatch itself.
2021-10-02 11:39:56 -07:00

2888 lines
70 KiB
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/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, you can obtain one at https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
/*! \file */
#include <inttypes.h>
#include <stdbool.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <isc/mem.h>
#include <isc/mutex.h>
#include <isc/portset.h>
#include <isc/print.h>
#include <isc/random.h>
#include <isc/socket.h>
#include <isc/stats.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/stats.h>
#include <dns/types.h>
typedef ISC_LIST(dns_dispentry_t) dns_displist_t;
typedef struct dispsocket dispsocket_t;
typedef ISC_LIST(dispsocket_t) dispsocketlist_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_displist_t *qid_table; /*%< the table itself */
dispsocketlist_t *sock_table; /*%< socket table */
} dns_qid_t;
struct dns_dispatchmgr {
/* Unlocked. */
unsigned int magic;
isc_mem_t *mctx;
dns_acl_t *blackhole;
isc_stats_t *stats;
/* 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 */
isc_refcount_t irefs;
in_port_t *v4ports; /*%< available ports for IPv4 */
unsigned int nv4ports; /*%< # of available ports for IPv4 */
in_port_t *v6ports; /*%< available ports for IPv4 */
unsigned int nv6ports; /*%< # of available ports for IPv4 */
};
#define MGR_SHUTTINGDOWN 0x00000001U
#define MGR_IS_SHUTTINGDOWN(l) (((l)->state & MGR_SHUTTINGDOWN) != 0)
struct dns_dispentry {
unsigned int magic;
dns_dispatch_t *disp;
dns_messageid_t id;
in_port_t port;
unsigned int bucket;
isc_sockaddr_t host;
isc_task_t *task;
isc_taskaction_t action;
void *arg;
bool item_out;
dispsocket_t *dispsocket;
ISC_LIST(dns_dispatchevent_t) items;
ISC_LINK(dns_dispentry_t) link;
};
/*%
* Fixed UDP buffer size.
*/
#ifndef DNS_DISPATCH_UDPBUFSIZE
#define DNS_DISPATCH_UDPBUFSIZE 4096
#endif /* ifndef DNS_DISPATCH_UDPBUFSIZE */
struct dispsocket {
unsigned int magic;
isc_socket_t *socket;
dns_dispatch_t *disp;
isc_sockaddr_t host;
dns_dispentry_t *resp;
isc_task_t *task;
in_port_t port;
ISC_LINK(dispsocket_t) link;
unsigned int bucket;
ISC_LINK(dispsocket_t) blink;
};
typedef struct tcpmsg {
uint16_t size;
dns_dispatch_t *disp;
isc_buffer_t buffer;
isc_task_t *task;
isc_taskaction_t action;
void *arg;
isc_event_t event;
isc_result_t result;
isc_sockaddr_t address;
} tcpmsg_t;
/*%
* Number of tasks for each dispatch that use separate sockets for different
* transactions. This must be a power of 2 as it will divide 32 bit numbers
* to get an uniformly random tasks selection. See get_dispsocket().
*/
#define MAX_INTERNAL_TASKS 64
struct dns_dispatch {
/* Unlocked. */
unsigned int magic; /*%< magic */
dns_dispatchmgr_t *mgr; /*%< dispatch manager */
int ntasks;
/*%
* internal task buckets. We use multiple tasks to distribute various
* socket events well when using separate dispatch sockets. We use the
* 1st task (task[0]) for internal control events.
*/
isc_task_t *task[MAX_INTERNAL_TASKS];
isc_socket_t *socket; /*%< isc socket attached to */
isc_sockaddr_t local; /*%< local address */
in_port_t localport; /*%< local UDP port */
isc_sockaddr_t peer; /*%< peer address (TCP) */
isc_event_t *ctlevent;
isc_mem_t *sepool; /*%< pool for socket events */
/*% 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;
isc_refcount_t refcount;
dns_dispatchevent_t *failsafe_ev; /*%< failsafe cancel event */
unsigned int shutting_down : 1, shutdown_out : 1, recv_pending : 1,
tcpmsg_valid : 1;
isc_result_t shutdown_why;
ISC_LIST(dispsocket_t) activesockets;
ISC_LIST(dispsocket_t) inactivesockets;
unsigned int nsockets;
unsigned int requests; /*%< how many requests we have */
unsigned int tcpbuffers; /*%< allocated buffers */
tcpmsg_t tcpmsg;
};
#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 DISPSOCK_MAGIC ISC_MAGIC('D', 's', 'o', 'c')
#define VALID_DISPSOCK(e) ISC_MAGIC_VALID((e), DISPSOCK_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)
/*%
* Maximum number of dispatch sockets that can be pooled for reuse. The
* appropriate value may vary, but experiments have shown a busy caching server
* may need more than 1000 sockets concurrently opened. The maximum allowable
* number of dispatch sockets (per manager) will be set to the double of this
* value.
*/
#ifndef DNS_DISPATCH_POOLSOCKS
#define DNS_DISPATCH_POOLSOCKS 2048
#endif /* ifndef DNS_DISPATCH_POOLSOCKS */
/*%
* Quota to control the number of UDP dispatch sockets. If a dispatch has
* more than the quota of sockets, new queries will purge oldest ones, so
* that a massive number of outstanding queries won't prevent subsequent
* queries (especially if the older ones take longer time and result in
* timeout).
*/
#ifndef DNS_DISPATCH_SOCKSQUOTA
#define DNS_DISPATCH_SOCKSQUOTA 3072
#endif /* ifndef DNS_DISPATCH_SOCKSQUOTA */
/*%
* Number of buffers available for all dispatches in the buffery memory
* pool.
*/
#ifndef DNS_DISPATCH_MAXBUFFERS
#define DNS_DISPATCH_MAXBUFFERS 32768
#endif /* ifndef DNS_DISPATCH_MAXBUFFERS */
/*%
* Number of dispatch sockets available for all dispatches in the
* socket memory pool.
*/
#ifndef DNS_DISPATCH_MAXSOCKETS
#define DNS_DISPATCH_MAXSOCKETS 32768
#endif /* ifndef DNS_DISPATCH_MAXSOCKETS */
/*%
* Quota to control the number of concurrent requests that can be handled
* by each TCP dispatch. (UDP dispatches do not currently support socket
* sharing.)
*/
#ifndef DNS_DISPATCH_MAXREQUESTS
#define DNS_DISPATCH_MAXREQUESTS 32768
#endif /* ifndef DNS_DISPATCH_MAXREQUESTS */
/*%
* Number of buckets in the QID hash table, and the value to
* increment the QID by when attempting to avoid collisions.
* The number of buckets should be prime, and the increment
* should be the next higher prime number.
*/
#ifndef DNS_QID_BUCKETS
#define DNS_QID_BUCKETS 16411
#endif /* ifndef DNS_QID_BUCKETS */
#ifndef DNS_QID_INCREMENT
#define DNS_QID_INCREMENT 16433
#endif /* ifndef DNS_QID_INCREMENT */
/*
* Statics.
*/
static dns_dispentry_t *
entry_search(dns_qid_t *, const isc_sockaddr_t *, dns_messageid_t, in_port_t,
unsigned int);
static bool
destroy_disp_ok(dns_dispatch_t *);
static void
destroy_disp(isc_task_t *task, isc_event_t *event);
static void
destroy_dispsocket(dns_dispatch_t *, dispsocket_t **);
static void
deactivate_dispsocket(dns_dispatch_t *, dispsocket_t *);
static void
udp_recv(isc_task_t *, isc_event_t *);
static void
tcp_recv(isc_task_t *, isc_event_t *);
static isc_result_t
startrecv(dns_dispatch_t *, dispsocket_t *);
static uint32_t
dns_hash(dns_qid_t *, const isc_sockaddr_t *, dns_messageid_t, in_port_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_devent(dns_dispatch_t *disp, dns_dispatchevent_t *ev);
static inline dns_dispatchevent_t *
allocate_devent(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, const isc_sockaddr_t *localaddr,
unsigned int attributes, dns_dispatch_t **dispp);
static bool
destroy_mgr_ok(dns_dispatchmgr_t *mgr);
static void
destroy_mgr(dns_dispatchmgr_t **mgrp);
static void
qid_allocate(dns_dispatchmgr_t *mgr, dns_qid_t **qidp);
static void
qid_destroy(isc_mem_t *mctx, dns_qid_t **qidp);
static isc_result_t
open_socket(isc_socketmgr_t *mgr, const isc_sockaddr_t *local,
unsigned int options, isc_socket_t **sockp);
static isc_socket_t *
getentrysocket(dns_dispentry_t *resp);
static isc_socket_t *
getsocket(dns_dispatch_t *disp);
#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 inline void
inc_stats(dns_dispatchmgr_t *mgr, isc_statscounter_t counter) {
if (mgr->stats != NULL) {
isc_stats_increment(mgr->stats, counter);
}
}
static inline void
dec_stats(dns_dispatchmgr_t *mgr, isc_statscounter_t counter) {
if (mgr->stats != NULL) {
isc_stats_decrement(mgr->stats, counter);
}
}
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 a hash of the destination and message id.
*/
static uint32_t
dns_hash(dns_qid_t *qid, const isc_sockaddr_t *dest, dns_messageid_t id,
in_port_t port) {
uint32_t ret;
ret = isc_sockaddr_hash(dest, true);
ret ^= ((uint32_t)id << 16) | port;
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 = NULL;
unsigned int 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 = NULL;
unsigned int bucket;
ret = ISC_LIST_NEXT(resp, link);
if (ret != NULL) {
return (ret);
}
bucket = resp->bucket + 1;
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 bool
destroy_disp_ok(dns_dispatch_t *disp) {
if (isc_refcount_current(&disp->refcount) != 0) {
return (false);
}
if (disp->recv_pending != 0) {
return (false);
}
if (!ISC_LIST_EMPTY(disp->activesockets)) {
return (false);
}
if (disp->shutting_down == 0) {
return (false);
}
return (true);
}
/*
* Called when refcount reaches 0 (and safe to destroy).
*
* The dispatcher must be locked.
* The manager must not be locked.
*/
static void
destroy_disp(isc_task_t *task, isc_event_t *event) {
dns_dispatch_t *disp = NULL;
dns_dispatchmgr_t *mgr = NULL;
bool killmgr;
dispsocket_t *dispsocket = NULL;
int i;
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",
disp->socket);
if (disp->sepool != NULL) {
isc_mem_destroy(&disp->sepool);
}
if (disp->socket != NULL) {
isc_socket_detach(&disp->socket);
}
while ((dispsocket = ISC_LIST_HEAD(disp->inactivesockets)) != NULL) {
ISC_LIST_UNLINK(disp->inactivesockets, dispsocket, link);
destroy_dispsocket(disp, &dispsocket);
}
for (i = 0; i < disp->ntasks; i++) {
isc_task_detach(&disp->task[i]);
}
isc_event_free(&event);
dispatch_free(&disp);
killmgr = destroy_mgr_ok(mgr);
UNLOCK(&mgr->lock);
if (killmgr) {
destroy_mgr(&mgr);
}
}
/*%
* Find a dispsocket for socket address 'dest', and port number 'port'.
* Return NULL if no such entry exists. Requires qid->lock to be held.
*/
static dispsocket_t *
socket_search(dns_qid_t *qid, const isc_sockaddr_t *dest, in_port_t port,
unsigned int bucket) {
dispsocket_t *dispsock = NULL;
REQUIRE(VALID_QID(qid));
REQUIRE(bucket < qid->qid_nbuckets);
dispsock = ISC_LIST_HEAD(qid->sock_table[bucket]);
while (dispsock != NULL) {
if (dispsock->port == port &&
isc_sockaddr_equal(dest, &dispsock->host)) {
return (dispsock);
}
dispsock = ISC_LIST_NEXT(dispsock, blink);
}
return (NULL);
}
/*%
* Make a new socket for a single dispatch with a random port number.
* The caller must hold the disp->lock
*/
static isc_result_t
get_dispsocket(dns_dispatch_t *disp, const isc_sockaddr_t *dest,
isc_socketmgr_t *sockmgr, dispsocket_t **dispsockp,
in_port_t *portp) {
int i;
dns_dispatchmgr_t *mgr = disp->mgr;
dns_qid_t *qid = mgr->qid;
isc_socket_t *sock = NULL;
isc_result_t result = ISC_R_FAILURE;
in_port_t port;
isc_sockaddr_t localaddr;
unsigned int bucket = 0;
dispsocket_t *dispsock = NULL;
unsigned int nports;
in_port_t *ports = NULL;
if (isc_sockaddr_pf(&disp->local) == AF_INET) {
nports = mgr->nv4ports;
ports = mgr->v4ports;
} else {
nports = mgr->nv6ports;
ports = mgr->v6ports;
}
if (nports == 0) {
return (ISC_R_ADDRNOTAVAIL);
}
dispsock = ISC_LIST_HEAD(disp->inactivesockets);
if (dispsock != NULL) {
ISC_LIST_UNLINK(disp->inactivesockets, dispsock, link);
sock = dispsock->socket;
dispsock->socket = NULL;
} else {
dispsock = isc_mem_get(mgr->mctx, sizeof(*dispsock));
disp->nsockets++;
*dispsock = (dispsocket_t){ .disp = disp };
isc_task_attach(disp->task[isc_random_uniform(disp->ntasks)],
&dispsock->task);
ISC_LINK_INIT(dispsock, link);
ISC_LINK_INIT(dispsock, blink);
dispsock->magic = DISPSOCK_MAGIC;
}
/*
* Pick up a random UDP port and open a new socket with it. Avoid
* choosing ports that share the same destination because it will be
* very likely to fail in bind(2) or connect(2).
*/
localaddr = disp->local;
for (i = 0; i < 64; i++) {
port = ports[isc_random_uniform(nports)];
isc_sockaddr_setport(&localaddr, port);
LOCK(&qid->lock);
bucket = dns_hash(qid, dest, 0, port);
if (socket_search(qid, dest, port, bucket) != NULL) {
UNLOCK(&qid->lock);
continue;
}
UNLOCK(&qid->lock);
result = open_socket(sockmgr, &localaddr,
ISC_SOCKET_REUSEADDRESS, &sock);
if (result == ISC_R_SUCCESS) {
break;
} else if (result == ISC_R_NOPERM) {
char buf[ISC_SOCKADDR_FORMATSIZE];
isc_sockaddr_format(&localaddr, buf, sizeof(buf));
dispatch_log(disp, ISC_LOG_WARNING,
"open_socket(%s) -> %s: continuing", buf,
isc_result_totext(result));
} else if (result != ISC_R_ADDRINUSE) {
break;
}
}
if (result != ISC_R_SUCCESS) {
if (sock != NULL) {
isc_socket_detach(&sock);
}
destroy_dispsocket(disp, &dispsock);
return (result);
}
dispsock->socket = sock;
dispsock->host = *dest;
dispsock->bucket = bucket;
dispsock->port = port;
LOCK(&qid->lock);
ISC_LIST_APPEND(qid->sock_table[bucket], dispsock, blink);
UNLOCK(&qid->lock);
*dispsockp = dispsock;
*portp = port;
return (ISC_R_SUCCESS);
}
/*%
* Destroy a dedicated dispatch socket.
*/
static void
destroy_dispsocket(dns_dispatch_t *disp, dispsocket_t **dispsockp) {
dispsocket_t *dispsock = NULL;
dns_qid_t *qid = disp->mgr->qid;
/*
* The dispatch must be locked.
*/
REQUIRE(dispsockp != NULL && *dispsockp != NULL);
dispsock = *dispsockp;
*dispsockp = NULL;
REQUIRE(!ISC_LINK_LINKED(dispsock, link));
disp->nsockets--;
dispsock->magic = 0;
if (dispsock->socket != NULL) {
isc_socket_detach(&dispsock->socket);
}
if (ISC_LINK_LINKED(dispsock, blink)) {
LOCK(&qid->lock);
ISC_LIST_UNLINK(qid->sock_table[dispsock->bucket], dispsock,
blink);
UNLOCK(&qid->lock);
}
if (dispsock->task != NULL) {
isc_task_detach(&dispsock->task);
}
isc_mem_put(disp->mgr->mctx, dispsock, sizeof(*dispsock));
}
/*%
* Deactivate a dedicated dispatch socket. Move it to the inactive list for
* future reuse unless the total number of sockets are exceeding the maximum.
*/
static void
deactivate_dispsocket(dns_dispatch_t *disp, dispsocket_t *dispsock) {
isc_result_t result;
dns_qid_t *qid = disp->mgr->qid;
/*
* The dispatch must be locked.
*/
ISC_LIST_UNLINK(disp->activesockets, dispsock, link);
if (dispsock->resp != NULL) {
INSIST(dispsock->resp->dispsocket == dispsock);
dispsock->resp->dispsocket = NULL;
}
if (disp->nsockets > DNS_DISPATCH_POOLSOCKS) {
destroy_dispsocket(disp, &dispsock);
} else {
result = isc_socket_close(dispsock->socket);
LOCK(&qid->lock);
ISC_LIST_UNLINK(qid->sock_table[dispsock->bucket], dispsock,
blink);
UNLOCK(&qid->lock);
if (result == ISC_R_SUCCESS) {
ISC_LIST_APPEND(disp->inactivesockets, dispsock, link);
} else {
/*
* If the underlying system does not allow this
* optimization, destroy this temporary structure (and
* create a new one for a new transaction).
*/
INSIST(result == ISC_R_NOTIMPLEMENTED);
destroy_dispsocket(disp, &dispsock);
}
}
}
/*
* Find an entry for query ID 'id', socket address 'dest', and port number
* 'port'.
* Return NULL if no such entry exists.
*/
static dns_dispentry_t *
entry_search(dns_qid_t *qid, const isc_sockaddr_t *dest, dns_messageid_t id,
in_port_t port, unsigned int bucket) {
dns_dispentry_t *res = NULL;
REQUIRE(VALID_QID(qid));
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) &&
res->port == port) {
return (res);
}
res = ISC_LIST_NEXT(res, link);
}
return (NULL);
}
static void
free_buffer(dns_dispatch_t *disp, void *buf, unsigned int len) {
REQUIRE(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 == DNS_DISPATCH_UDPBUFSIZE);
disp->mgr->buffers--;
UNLOCK(&disp->mgr->buffer_lock);
isc_mem_put(disp->mgr->mctx, buf, len);
break;
default:
INSIST(0);
ISC_UNREACHABLE();
}
}
static void *
allocate_udp_buffer(dns_dispatch_t *disp) {
LOCK(&disp->mgr->buffer_lock);
if (disp->mgr->buffers >= DNS_DISPATCH_MAXBUFFERS) {
UNLOCK(&disp->mgr->buffer_lock);
return (NULL);
}
disp->mgr->buffers++;
UNLOCK(&disp->mgr->buffer_lock);
return (isc_mem_get(disp->mgr->mctx, DNS_DISPATCH_UDPBUFSIZE));
}
static inline void
free_sevent(isc_event_t *ev) {
isc_mem_t *pool = ev->ev_destroy_arg;
isc_socketevent_t *sev = (isc_socketevent_t *)ev;
isc_mem_put(pool, sev, sizeof(*sev));
}
static inline isc_socketevent_t *
allocate_sevent(dns_dispatch_t *disp, isc_socket_t *sock, isc_eventtype_t type,
isc_taskaction_t action, const void *arg) {
isc_socketevent_t *ev = NULL;
void *deconst_arg;
ev = isc_mem_get(disp->sepool, sizeof(*ev));
DE_CONST(arg, deconst_arg);
ISC_EVENT_INIT(ev, sizeof(*ev), 0, NULL, type, action, deconst_arg,
sock, free_sevent, disp->sepool);
ev->result = ISC_R_UNSET;
ISC_LINK_INIT(ev, ev_link);
ev->region.base = NULL;
ev->n = 0;
ev->offset = 0;
ev->attributes = 0;
return (ev);
}
static inline void
free_devent(dns_dispatch_t *disp, dns_dispatchevent_t *ev) {
if (disp->failsafe_ev == ev) {
INSIST(disp->shutdown_out == 1);
disp->shutdown_out = 0;
return;
}
isc_refcount_decrement(&disp->mgr->irefs);
isc_mem_put(disp->mgr->mctx, ev, sizeof(*ev));
}
static inline dns_dispatchevent_t *
allocate_devent(dns_dispatch_t *disp) {
dns_dispatchevent_t *ev = NULL;
ev = isc_mem_get(disp->mgr->mctx, sizeof(*ev));
isc_refcount_increment0(&disp->mgr->irefs);
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;
dispsocket_t *dispsock = NULL;
dns_dispatch_t *disp = NULL;
dns_messageid_t id;
isc_result_t dres;
isc_buffer_t source;
unsigned int flags;
dns_dispentry_t *resp = NULL;
dns_dispatchevent_t *rev = NULL;
bool killit;
bool queue_response;
dns_dispatchmgr_t *mgr = NULL;
isc_netaddr_t netaddr;
int match;
int result;
UNUSED(task);
REQUIRE(ev->ev_type == ISC_SOCKEVENT_RECVDONE);
dispsock = ev_in->ev_arg;
REQUIRE(VALID_DISPSOCK(dispsock));
disp = dispsock->disp;
LOCK(&disp->lock);
mgr = disp->mgr;
LOCK(&disp->mgr->buffer_lock);
dispatch_log(disp, LVL(90),
"got packet: requests %d, buffers %d, recvs %d",
disp->requests, disp->mgr->buffers, disp->recv_pending);
UNLOCK(&disp->mgr->buffer_lock);
if (ev->result == ISC_R_CANCELED || dispsock->resp == NULL) {
/*
* dispsock->resp can be NULL if this transaction was canceled
* just after receiving a response. Since this socket is
* exclusively used and there should be at most one receive
* event the canceled event should have no effect. So
* we can (and should) deactivate the socket right now.
*/
deactivate_dispsocket(disp, dispsock);
dispsock = NULL;
}
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[0], &disp->ctlevent);
}
return;
}
if (dispsock == NULL) {
free_buffer(disp, ev->region.base, ev->region.length);
isc_event_free(&ev_in);
UNLOCK(&disp->lock);
return;
}
resp = dispsock->resp;
id = resp->id;
if (ev->result != ISC_R_SUCCESS) {
/*
* This is most likely a network error on a
* connected socket. It makes no sense to
* check the address or parse the packet, but it
* will help to return the error to the caller.
*/
goto sendresponse;
}
/*
* 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) != 0) ? '1' : '0'), id);
/*
* Look at flags. If query, drop it. If response,
* look to see where it goes.
*/
if ((flags & DNS_MESSAGEFLAG_QR) == 0) {
/* query */
free_buffer(disp, ev->region.base, ev->region.length);
goto restart;
}
/*
* The QID and the address must match the expected ones.
*/
if (resp->id != id || !isc_sockaddr_equal(&ev->address, &resp->host)) {
dispatch_log(disp, LVL(90), "response doesn't match");
inc_stats(mgr, dns_resstatscounter_mismatch);
free_buffer(disp, ev->region.base, ev->region.length);
goto restart;
}
/*
* 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 restart;
}
/*
* If each dispatch is bound to a different address
* then fail.
*
* 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 restart;
}
isc_sockaddr_anyofpf(&a1, isc_sockaddr_pf(&resp->disp->local));
isc_sockaddr_anyofpf(&a2, isc_sockaddr_pf(&disp->local));
if (!isc_sockaddr_eqaddr(&disp->local, &resp->disp->local) &&
!isc_sockaddr_eqaddr(&a1, &resp->disp->local) &&
!isc_sockaddr_eqaddr(&a2, &disp->local))
{
free_buffer(disp, ev->region.base, ev->region.length);
goto restart;
}
}
sendresponse:
queue_response = resp->item_out;
rev = allocate_devent(resp->disp);
/*
* 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 = ev->result;
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 = true;
isc_task_send(resp->task, ISC_EVENT_PTR(&rev));
}
/*
* Restart recv() to get the next packet.
*/
restart:
result = startrecv(disp, dispsock);
if (result != ISC_R_SUCCESS) {
deactivate_dispsocket(disp, dispsock);
}
isc_event_free(&ev_in);
UNLOCK(&disp->lock);
}
/*
* 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;
tcpmsg_t *tcpmsg = &disp->tcpmsg;
dns_messageid_t id;
isc_result_t dres;
unsigned int flags;
dns_dispentry_t *resp = NULL;
dns_dispatchevent_t *rev = NULL;
unsigned int bucket;
bool killit;
bool queue_response;
dns_qid_t *qid = NULL;
int level;
char buf[ISC_SOCKADDR_FORMATSIZE];
UNUSED(task);
REQUIRE(VALID_DISPATCH(disp));
qid = disp->mgr->qid;
LOCK(&disp->lock);
dispatch_log(disp, LVL(90),
"got TCP packet: requests %d, buffers %d, recvs %d",
disp->requests, disp->tcpbuffers, disp->recv_pending);
INSIST(disp->recv_pending != 0);
disp->recv_pending = 0;
if (isc_refcount_current(&disp->refcount) == 0) {
/*
* This dispatcher is shutting down. Force cancellation.
*/
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[0], &disp->ctlevent);
}
return;
}
dispatch_log(disp, LVL(90), "result %d, length == %d, addr = %p",
tcpmsg->result, disp->tcpmsg.buffer.length,
disp->tcpmsg.buffer.base);
/*
* Peek into the buffer to see what we can see.
*/
dres = dns_message_peekheader(&disp->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) != 0) ? '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.
*/
if ((flags & DNS_MESSAGEFLAG_QR) == 0) {
/*
* Query.
*/
goto restart;
}
/*
* Response.
*/
bucket = dns_hash(qid, &tcpmsg->address, id, disp->localport);
LOCK(&qid->lock);
resp = entry_search(qid, &tcpmsg->address, id, disp->localport, 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_devent(disp);
/*
* 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.
*/
rev->buffer = disp->tcpmsg.buffer;
disp->tcpmsg.buffer.base = NULL;
disp->tcpmsg.buffer.length = 0;
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 = true;
isc_task_send(resp->task, ISC_EVENT_PTR(&rev));
}
unlock:
UNLOCK(&qid->lock);
/*
* Restart recv() to get the next packet.
*/
restart:
(void)startrecv(disp, NULL);
isc_event_free(&ev_in);
UNLOCK(&disp->lock);
}
static void
recv_tcpmsg(isc_task_t *task, isc_event_t *ev_in) {
isc_socketevent_t *ev = (isc_socketevent_t *)ev_in;
tcpmsg_t *tcpmsg = ev_in->ev_arg;
isc_event_t *dev = &tcpmsg->event;
UNUSED(task);
tcpmsg->address = ev->address;
if (ev->result != ISC_R_SUCCESS) {
tcpmsg->result = ev->result;
goto send_and_free;
}
tcpmsg->result = ISC_R_SUCCESS;
isc_buffer_add(&tcpmsg->buffer, ev->n);
send_and_free:
isc_task_send(tcpmsg->task, &dev);
tcpmsg->task = NULL;
isc_event_free(&ev_in);
}
static void
recv_tcplen(isc_task_t *task, isc_event_t *ev_in) {
isc_socketevent_t *ev = (isc_socketevent_t *)ev_in;
tcpmsg_t *tcpmsg = ev_in->ev_arg;
isc_event_t *dev = &tcpmsg->event;
isc_region_t region;
isc_result_t result;
tcpmsg->address = ev->address;
if (ev->result != ISC_R_SUCCESS) {
tcpmsg->result = ev->result;
goto send_and_free;
}
/*
* Success.
*/
tcpmsg->size = ntohs(tcpmsg->size);
if (tcpmsg->size == 0) {
tcpmsg->result = ISC_R_UNEXPECTEDEND;
goto send_and_free;
}
region.base = isc_mem_get(tcpmsg->disp->mgr->mctx, tcpmsg->size);
region.length = tcpmsg->size;
if (region.base == NULL) {
tcpmsg->result = ISC_R_NOMEMORY;
goto send_and_free;
}
isc_buffer_init(&tcpmsg->buffer, region.base, region.length);
result = isc_socket_recv(tcpmsg->disp->socket, &region, 0, task,
recv_tcpmsg, tcpmsg);
if (result != ISC_R_SUCCESS) {
tcpmsg->result = result;
goto send_and_free;
}
isc_event_free(&ev_in);
return;
send_and_free:
isc_task_send(tcpmsg->task, &dev);
tcpmsg->task = NULL;
isc_event_free(&ev_in);
return;
}
static isc_result_t
tcp_readmessage(tcpmsg_t *tcpmsg, isc_task_t *task, isc_taskaction_t action,
void *arg) {
isc_result_t result;
isc_region_t region;
REQUIRE(task != NULL);
REQUIRE(tcpmsg->task == NULL); /* not currently in use */
if (tcpmsg->buffer.base != NULL) {
isc_mem_put(tcpmsg->disp->mgr->mctx, tcpmsg->buffer.base,
tcpmsg->buffer.length);
tcpmsg->buffer.base = NULL;
tcpmsg->buffer.length = 0;
}
tcpmsg->task = task;
tcpmsg->action = action;
tcpmsg->arg = arg;
tcpmsg->result = ISC_R_UNEXPECTED; /* unknown right now */
ISC_EVENT_INIT(&tcpmsg->event, sizeof(isc_event_t), 0, 0,
DNS_EVENT_TCPMSG, action, arg, tcpmsg, NULL, NULL);
region.base = (unsigned char *)&tcpmsg->size;
region.length = 2; /* uint16_t */
result = isc_socket_recv(tcpmsg->disp->socket, &region, 0, tcpmsg->task,
recv_tcplen, tcpmsg);
if (result != ISC_R_SUCCESS) {
tcpmsg->task = NULL;
}
return (result);
}
/*
* disp must be locked.
*/
static isc_result_t
startrecv(dns_dispatch_t *disp, dispsocket_t *dispsock) {
isc_result_t res;
isc_region_t region;
isc_socket_t *sock = NULL;
isc_socketevent_t *sev = NULL;
if (disp->shutting_down == 1) {
return (ISC_R_SUCCESS);
}
if (dispsock == NULL) {
if (disp->socktype == isc_sockettype_udp ||
disp->recv_pending != 0) {
return (ISC_R_SUCCESS);
}
sock = disp->socket;
} else {
sock = dispsock->socket;
}
switch (disp->socktype) {
/*
* UDP reads are always maximal.
*/
case isc_sockettype_udp:
region.length = DNS_DISPATCH_UDPBUFSIZE;
region.base = allocate_udp_buffer(disp);
if (region.base == NULL) {
return (ISC_R_NOMEMORY);
}
sev = allocate_sevent(disp, sock, ISC_SOCKEVENT_RECVDONE,
udp_recv, dispsock);
res = isc_socket_recv2(sock, &region, 1, dispsock->task, sev,
0);
if (res != ISC_R_SUCCESS) {
free_buffer(disp, region.base, region.length);
return (res);
}
break;
case isc_sockettype_tcp:
res = tcp_readmessage(&disp->tcpmsg, disp->task[0], tcp_recv,
disp);
if (res != ISC_R_SUCCESS) {
disp->shutdown_why = res;
disp->shutting_down = 1;
do_cancel(disp);
return (ISC_R_SUCCESS); /* recover by cancel */
}
INSIST(disp->recv_pending == 0);
disp->recv_pending = 1;
break;
default:
INSIST(0);
ISC_UNREACHABLE();
}
return (ISC_R_SUCCESS);
}
/*
* Mgr must be locked when calling this function.
*/
static bool
destroy_mgr_ok(dns_dispatchmgr_t *mgr) {
mgr_log(mgr, LVL(90),
"destroy_mgr_ok: shuttingdown=%d, listnonempty=%d, ",
MGR_IS_SHUTTINGDOWN(mgr), !ISC_LIST_EMPTY(mgr->list));
if (!MGR_IS_SHUTTINGDOWN(mgr)) {
return (false);
}
if (!ISC_LIST_EMPTY(mgr->list)) {
return (false);
}
if (isc_refcount_current(&mgr->irefs) != 0) {
return (false);
}
return (true);
}
/*
* Mgr must be unlocked when calling this function.
*/
static void
destroy_mgr(dns_dispatchmgr_t **mgrp) {
dns_dispatchmgr_t *mgr = NULL;
mgr = *mgrp;
*mgrp = NULL;
mgr->magic = 0;
isc_mutex_destroy(&mgr->lock);
mgr->state = 0;
if (mgr->qid != NULL) {
qid_destroy(mgr->mctx, &mgr->qid);
}
isc_mutex_destroy(&mgr->buffer_lock);
if (mgr->blackhole != NULL) {
dns_acl_detach(&mgr->blackhole);
}
if (mgr->stats != NULL) {
isc_stats_detach(&mgr->stats);
}
if (mgr->v4ports != NULL) {
isc_mem_put(mgr->mctx, mgr->v4ports,
mgr->nv4ports * sizeof(in_port_t));
}
if (mgr->v6ports != NULL) {
isc_mem_put(mgr->mctx, mgr->v6ports,
mgr->nv6ports * sizeof(in_port_t));
}
isc_mem_putanddetach(&mgr->mctx, mgr, sizeof(dns_dispatchmgr_t));
}
static isc_result_t
open_socket(isc_socketmgr_t *mgr, const isc_sockaddr_t *local,
unsigned int options, isc_socket_t **sockp) {
isc_socket_t *sock = NULL;
isc_result_t result;
sock = *sockp;
if (sock != NULL) {
result = isc_socket_open(sock);
if (result != ISC_R_SUCCESS) {
return (result);
}
} else {
result = isc_socket_create(mgr, isc_sockaddr_pf(local),
isc_sockettype_udp, &sock);
if (result != ISC_R_SUCCESS) {
return (result);
}
}
isc_socket_setname(sock, "dispatcher", NULL);
#ifndef ISC_ALLOW_MAPPED
isc_socket_ipv6only(sock, true);
#endif /* ifndef ISC_ALLOW_MAPPED */
result = isc_socket_bind(sock, local, options);
if (result != ISC_R_SUCCESS) {
if (*sockp == NULL) {
isc_socket_detach(&sock);
} else {
isc_socket_close(sock);
}
return (result);
}
*sockp = sock;
return (ISC_R_SUCCESS);
}
/*%
* Create a temporary port list to set the initial default set of dispatch
* ports: [1024, 65535]. This is almost meaningless as the application will
* normally set the ports explicitly, but is provided to fill some minor corner
* cases.
*/
static void
create_default_portset(isc_mem_t *mctx, isc_portset_t **portsetp) {
isc_portset_create(mctx, portsetp);
isc_portset_addrange(*portsetp, 1024, 65535);
}
static isc_result_t
setavailports(dns_dispatchmgr_t *mgr, isc_portset_t *v4portset,
isc_portset_t *v6portset) {
in_port_t *v4ports, *v6ports, p = 0;
unsigned int nv4ports, nv6ports, i4 = 0, i6 = 0;
nv4ports = isc_portset_nports(v4portset);
nv6ports = isc_portset_nports(v6portset);
v4ports = NULL;
if (nv4ports != 0) {
v4ports = isc_mem_get(mgr->mctx, sizeof(in_port_t) * nv4ports);
}
v6ports = NULL;
if (nv6ports != 0) {
v6ports = isc_mem_get(mgr->mctx, sizeof(in_port_t) * nv6ports);
}
do {
if (isc_portset_isset(v4portset, p)) {
INSIST(i4 < nv4ports);
v4ports[i4++] = p;
}
if (isc_portset_isset(v6portset, p)) {
INSIST(i6 < nv6ports);
v6ports[i6++] = p;
}
} while (p++ < 65535);
INSIST(i4 == nv4ports && i6 == nv6ports);
if (mgr->v4ports != NULL) {
isc_mem_put(mgr->mctx, mgr->v4ports,
mgr->nv4ports * sizeof(in_port_t));
}
mgr->v4ports = v4ports;
mgr->nv4ports = nv4ports;
if (mgr->v6ports != NULL) {
isc_mem_put(mgr->mctx, mgr->v6ports,
mgr->nv6ports * sizeof(in_port_t));
}
mgr->v6ports = v6ports;
mgr->nv6ports = nv6ports;
return (ISC_R_SUCCESS);
}
/*
* Publics.
*/
isc_result_t
dns_dispatchmgr_create(isc_mem_t *mctx, dns_dispatchmgr_t **mgrp) {
dns_dispatchmgr_t *mgr = NULL;
isc_portset_t *v4portset = NULL;
isc_portset_t *v6portset = NULL;
REQUIRE(mctx != NULL);
REQUIRE(mgrp != NULL && *mgrp == NULL);
mgr = isc_mem_get(mctx, sizeof(dns_dispatchmgr_t));
*mgr = (dns_dispatchmgr_t){ 0 };
isc_mem_attach(mctx, &mgr->mctx);
isc_mutex_init(&mgr->lock);
isc_mutex_init(&mgr->buffer_lock);
isc_refcount_init(&mgr->irefs, 0);
ISC_LIST_INIT(mgr->list);
create_default_portset(mctx, &v4portset);
create_default_portset(mctx, &v6portset);
setavailports(mgr, v4portset, v6portset);
isc_portset_destroy(mctx, &v4portset);
isc_portset_destroy(mctx, &v6portset);
qid_allocate(mgr, &mgr->qid);
mgr->magic = DNS_DISPATCHMGR_MAGIC;
*mgrp = mgr;
return (ISC_R_SUCCESS);
}
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);
}
isc_result_t
dns_dispatchmgr_setavailports(dns_dispatchmgr_t *mgr, isc_portset_t *v4portset,
isc_portset_t *v6portset) {
REQUIRE(VALID_DISPATCHMGR(mgr));
return (setavailports(mgr, v4portset, v6portset));
}
void
dns_dispatchmgr_destroy(dns_dispatchmgr_t **mgrp) {
dns_dispatchmgr_t *mgr = NULL;
bool 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);
}
}
void
dns_dispatchmgr_setstats(dns_dispatchmgr_t *mgr, isc_stats_t *stats) {
REQUIRE(VALID_DISPATCHMGR(mgr));
REQUIRE(ISC_LIST_EMPTY(mgr->list));
REQUIRE(mgr->stats == NULL);
isc_stats_attach(stats, &mgr->stats);
}
static void
qid_allocate(dns_dispatchmgr_t *mgr, dns_qid_t **qidp) {
dns_qid_t *qid = NULL;
unsigned int i;
REQUIRE(qidp != NULL && *qidp == NULL);
qid = isc_mem_get(mgr->mctx, sizeof(*qid));
*qid = (dns_qid_t){ .qid_nbuckets = DNS_QID_BUCKETS,
.qid_increment = DNS_QID_INCREMENT };
qid->qid_table = isc_mem_get(mgr->mctx,
DNS_QID_BUCKETS * sizeof(dns_displist_t));
qid->sock_table = isc_mem_get(
mgr->mctx, DNS_QID_BUCKETS * sizeof(dispsocketlist_t));
isc_mutex_init(&qid->lock);
for (i = 0; i < qid->qid_nbuckets; i++) {
ISC_LIST_INIT(qid->qid_table[i]);
ISC_LIST_INIT(qid->sock_table[i]);
}
qid->magic = QID_MAGIC;
*qidp = qid;
}
static void
qid_destroy(isc_mem_t *mctx, dns_qid_t **qidp) {
dns_qid_t *qid = NULL;
REQUIRE(qidp != NULL);
qid = *qidp;
*qidp = NULL;
REQUIRE(VALID_QID(qid));
qid->magic = 0;
isc_mem_put(mctx, qid->qid_table,
qid->qid_nbuckets * sizeof(dns_displist_t));
isc_mem_put(mctx, qid->sock_table,
qid->qid_nbuckets * sizeof(dispsocketlist_t));
isc_mutex_destroy(&qid->lock);
isc_mem_put(mctx, qid, sizeof(*qid));
}
/*
* Allocate and set important limits.
*/
static void
dispatch_allocate(dns_dispatchmgr_t *mgr, isc_sockettype_t type, int pf,
unsigned int attributes, dns_dispatch_t **dispp) {
dns_dispatch_t *disp = NULL;
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_mem_get(mgr->mctx, sizeof(*disp));
isc_refcount_increment0(&mgr->irefs);
*disp = (dns_dispatch_t){ .mgr = mgr,
.socktype = type,
.shutdown_why = ISC_R_UNEXPECTED };
isc_refcount_init(&disp->refcount, 1);
ISC_LINK_INIT(disp, link);
ISC_LIST_INIT(disp->activesockets);
ISC_LIST_INIT(disp->inactivesockets);
switch (type) {
case isc_sockettype_tcp:
disp->attributes |= DNS_DISPATCHATTR_TCP;
break;
case isc_sockettype_udp:
disp->attributes |= DNS_DISPATCHATTR_UDP;
break;
default:
INSIST(0);
ISC_UNREACHABLE();
}
switch (pf) {
case PF_INET:
disp->attributes |= DNS_DISPATCHATTR_IPV4;
break;
case PF_INET6:
disp->attributes |= DNS_DISPATCHATTR_IPV6;
break;
default:
INSIST(0);
ISC_UNREACHABLE();
}
/*
* Set whatever attributes were passed in that haven't been
* reset automatically by the code above.
*/
attributes &= ~(DNS_DISPATCHATTR_UDP | DNS_DISPATCHATTR_TCP |
DNS_DISPATCHATTR_IPV4 | DNS_DISPATCHATTR_IPV6);
disp->attributes |= attributes;
isc_mutex_init(&disp->lock);
disp->failsafe_ev = allocate_devent(disp);
disp->magic = DISPATCH_MAGIC;
*dispp = disp;
}
/*
* MUST be unlocked, and not used by anything.
*/
static void
dispatch_free(dns_dispatch_t **dispp) {
dns_dispatch_t *disp = NULL;
dns_dispatchmgr_t *mgr = NULL;
REQUIRE(VALID_DISPATCH(*dispp));
disp = *dispp;
*dispp = NULL;
mgr = disp->mgr;
REQUIRE(VALID_DISPATCHMGR(mgr));
if (disp->tcpmsg_valid) {
if (disp->tcpmsg.buffer.base != NULL) {
isc_mem_put(disp->mgr->mctx, disp->tcpmsg.buffer.base,
disp->tcpmsg.buffer.length);
disp->tcpmsg.buffer.base = NULL;
disp->tcpmsg.buffer.length = 0;
}
disp->tcpmsg_valid = 0;
}
INSIST(disp->tcpbuffers == 0);
INSIST(disp->requests == 0);
INSIST(disp->recv_pending == 0);
INSIST(ISC_LIST_EMPTY(disp->activesockets));
INSIST(ISC_LIST_EMPTY(disp->inactivesockets));
isc_refcount_decrement(&mgr->irefs);
isc_mem_put(mgr->mctx, disp->failsafe_ev, sizeof(*disp->failsafe_ev));
disp->failsafe_ev = NULL;
disp->mgr = NULL;
isc_mutex_destroy(&disp->lock);
disp->magic = 0;
isc_refcount_decrement(&mgr->irefs);
isc_mem_put(mgr->mctx, disp, sizeof(*disp));
}
isc_result_t
dns_dispatch_createtcp(dns_dispatchmgr_t *mgr, isc_socketmgr_t *sockmgr,
isc_taskmgr_t *taskmgr, const isc_sockaddr_t *localaddr,
const isc_sockaddr_t *destaddr, unsigned int attributes,
isc_dscp_t dscp, dns_dispatch_t **dispp) {
isc_result_t result;
dns_dispatch_t *disp = NULL;
isc_sockaddr_t src;
int pf;
REQUIRE(VALID_DISPATCHMGR(mgr));
REQUIRE(sockmgr != NULL);
REQUIRE(destaddr != NULL);
LOCK(&mgr->lock);
pf = isc_sockaddr_pf(destaddr);
dispatch_allocate(mgr, isc_sockettype_tcp, pf, attributes, &disp);
disp->peer = *destaddr;
if (localaddr != NULL) {
disp->local = *localaddr;
} else {
switch (pf) {
case AF_INET:
isc_sockaddr_any(&disp->local);
break;
case AF_INET6:
isc_sockaddr_any6(&disp->local);
break;
}
}
disp->ntasks = 1;
disp->task[0] = NULL;
result = isc_task_create(taskmgr, 50, &disp->task[0]);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
result = isc_socket_create(sockmgr, isc_sockaddr_pf(destaddr),
isc_sockettype_tcp, &disp->socket);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
if (localaddr == NULL) {
isc_sockaddr_anyofpf(&src, pf);
} else {
src = *localaddr;
isc_sockaddr_setport(&src, 0);
}
result = isc_socket_bind(disp->socket, &src, 0);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
isc_socket_dscp(disp->socket, dscp);
disp->ctlevent =
isc_event_allocate(mgr->mctx, disp, DNS_EVENT_DISPATCHCONTROL,
destroy_disp, disp, sizeof(isc_event_t));
isc_task_setname(disp->task[0], "tcpdispatch", disp);
disp->tcpmsg = (tcpmsg_t){ .disp = disp, .result = ISC_R_UNEXPECTED };
disp->tcpmsg_valid = 1;
/*
* Append it to the dispatcher list.
*/
ISC_LIST_APPEND(mgr->list, disp, link);
UNLOCK(&mgr->lock);
if (isc_log_wouldlog(dns_lctx, 90)) {
mgr_log(mgr, LVL(90),
"dns_dispatch_createtcp: created TCP dispatch %p",
disp);
dispatch_log(disp, LVL(90), "created task %p", disp->task[0]);
}
*dispp = disp;
return (ISC_R_SUCCESS);
cleanup:
isc_socket_detach(&disp->socket);
dispatch_free(&disp);
UNLOCK(&mgr->lock);
return (result);
}
#define ATTRMATCH(_a1, _a2, _mask) (((_a1) & (_mask)) == ((_a2) & (_mask)))
isc_result_t
dns_dispatch_gettcp(dns_dispatchmgr_t *mgr, const isc_sockaddr_t *destaddr,
const isc_sockaddr_t *localaddr, bool *connected,
dns_dispatch_t **dispp) {
dns_dispatch_t *disp = NULL;
isc_result_t result;
isc_sockaddr_t peeraddr;
isc_sockaddr_t sockname;
unsigned int attributes, mask;
bool match = false;
REQUIRE(VALID_DISPATCHMGR(mgr));
REQUIRE(destaddr != NULL);
REQUIRE(dispp != NULL && *dispp == NULL);
/* First pass */
attributes = DNS_DISPATCHATTR_TCP | DNS_DISPATCHATTR_CONNECTED;
mask = DNS_DISPATCHATTR_TCP | DNS_DISPATCHATTR_PRIVATE |
DNS_DISPATCHATTR_CONNECTED;
LOCK(&mgr->lock);
disp = ISC_LIST_HEAD(mgr->list);
while (disp != NULL && !match) {
LOCK(&disp->lock);
if ((disp->shutting_down == 0) &&
ATTRMATCH(disp->attributes, attributes, mask) &&
(localaddr == NULL ||
isc_sockaddr_eqaddr(localaddr, &disp->local)))
{
result = isc_socket_getsockname(disp->socket,
&sockname);
if (result == ISC_R_SUCCESS) {
result = isc_socket_getpeername(disp->socket,
&peeraddr);
}
if (result == ISC_R_SUCCESS &&
isc_sockaddr_equal(destaddr, &peeraddr) &&
(localaddr == NULL ||
isc_sockaddr_eqaddr(localaddr, &sockname)))
{
/* attach */
isc_refcount_increment(&disp->refcount);
*dispp = disp;
match = true;
if (connected != NULL) {
*connected = true;
}
}
}
UNLOCK(&disp->lock);
disp = ISC_LIST_NEXT(disp, link);
}
if (match || connected == NULL) {
UNLOCK(&mgr->lock);
return (match ? ISC_R_SUCCESS : ISC_R_NOTFOUND);
}
/* Second pass, only if connected != NULL */
attributes = DNS_DISPATCHATTR_TCP;
disp = ISC_LIST_HEAD(mgr->list);
while (disp != NULL && !match) {
LOCK(&disp->lock);
if ((disp->shutting_down == 0) &&
ATTRMATCH(disp->attributes, attributes, mask) &&
(localaddr == NULL ||
isc_sockaddr_eqaddr(localaddr, &disp->local)) &&
isc_sockaddr_equal(destaddr, &disp->peer))
{
/* attach */
isc_refcount_increment(&disp->refcount);
*dispp = disp;
match = true;
}
UNLOCK(&disp->lock);
disp = ISC_LIST_NEXT(disp, link);
}
UNLOCK(&mgr->lock);
return (match ? ISC_R_SUCCESS : ISC_R_NOTFOUND);
}
isc_result_t
dns_dispatch_createudp(dns_dispatchmgr_t *mgr, isc_socketmgr_t *sockmgr,
isc_taskmgr_t *taskmgr, const isc_sockaddr_t *localaddr,
unsigned int attributes, dns_dispatch_t **dispp) {
isc_result_t result;
dns_dispatch_t *disp = NULL;
REQUIRE(VALID_DISPATCHMGR(mgr));
REQUIRE(sockmgr != NULL);
REQUIRE(localaddr != NULL);
REQUIRE(taskmgr != NULL);
REQUIRE(dispp != NULL && *dispp == NULL);
LOCK(&mgr->lock);
result = dispatch_createudp(mgr, sockmgr, taskmgr, localaddr,
attributes, &disp);
if (result == ISC_R_SUCCESS) {
*dispp = disp;
}
UNLOCK(&mgr->lock);
return (result);
}
static isc_result_t
dispatch_createudp(dns_dispatchmgr_t *mgr, isc_socketmgr_t *sockmgr,
isc_taskmgr_t *taskmgr, const isc_sockaddr_t *localaddr,
unsigned int attributes, dns_dispatch_t **dispp) {
isc_result_t result = ISC_R_SUCCESS;
dns_dispatch_t *disp = NULL;
isc_socket_t *sock = NULL;
isc_sockaddr_t sa_any;
int pf, i = 0;
pf = isc_sockaddr_pf(localaddr);
dispatch_allocate(mgr, isc_sockettype_udp, pf, attributes, &disp);
/*
* For dispatches with a specified source address, we open a
* socket to make sure that address is available on the system,
* but we don't keep it open; sockets used for sending requests
* will be created later on demand.
*/
isc_sockaddr_anyofpf(&sa_any, pf);
if (!isc_sockaddr_eqaddr(&sa_any, localaddr)) {
result = open_socket(sockmgr, localaddr, 0, &sock);
if (sock != NULL) {
isc_socket_detach(&sock);
}
if (result != ISC_R_SUCCESS) {
goto deallocate_dispatch;
}
}
if (isc_log_wouldlog(dns_lctx, 90)) {
char addrbuf[ISC_SOCKADDR_FORMATSIZE];
isc_sockaddr_format(localaddr, addrbuf,
ISC_SOCKADDR_FORMATSIZE);
mgr_log(mgr, LVL(90),
"dispatch_createudp: created UDP dispatch for %s",
addrbuf);
}
disp->socket = sock;
disp->local = *localaddr;
disp->ntasks = MAX_INTERNAL_TASKS;
for (i = 0; i < disp->ntasks; i++) {
disp->task[i] = NULL;
result = isc_task_create(taskmgr, 0, &disp->task[i]);
if (result != ISC_R_SUCCESS) {
while (--i >= 0) {
isc_task_shutdown(disp->task[i]);
isc_task_detach(&disp->task[i]);
}
goto kill_socket;
}
isc_task_setname(disp->task[i], "udpdispatch", disp);
}
disp->ctlevent =
isc_event_allocate(mgr->mctx, disp, DNS_EVENT_DISPATCHCONTROL,
destroy_disp, disp, sizeof(isc_event_t));
disp->sepool = NULL;
isc_mem_create(&disp->sepool);
isc_mem_setname(disp->sepool, "disp_sepool");
/*
* 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[0]); /* XXX */
if (disp->socket != NULL) {
dispatch_log(disp, LVL(90), "created socket %p", disp->socket);
}
*dispp = disp;
return (result);
/*
* Error returns.
*/
kill_socket:
if (disp->socket != NULL) {
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);
isc_refcount_increment(&disp->refcount);
*dispp = disp;
}
void
dns_dispatch_detach(dns_dispatch_t **dispp) {
dns_dispatch_t *disp = NULL;
dispsocket_t *dispsock = NULL;
bool killit;
REQUIRE(dispp != NULL && VALID_DISPATCH(*dispp));
disp = *dispp;
*dispp = NULL;
LOCK(&disp->lock);
if (isc_refcount_decrement(&disp->refcount) == 1) {
if (disp->recv_pending > 0) {
isc_socket_cancel(disp->socket, disp->task[0],
ISC_SOCKCANCEL_RECV);
}
for (dispsock = ISC_LIST_HEAD(disp->activesockets);
dispsock != NULL; dispsock = ISC_LIST_NEXT(dispsock, link))
{
isc_socket_cancel(dispsock->socket, dispsock->task,
ISC_SOCKCANCEL_RECV);
}
disp->shutting_down = 1;
}
dispatch_log(disp, LVL(90), "detach: refcount %" PRIuFAST32,
isc_refcount_current(&disp->refcount));
killit = destroy_disp_ok(disp);
UNLOCK(&disp->lock);
if (killit) {
isc_task_send(disp->task[0], &disp->ctlevent);
}
}
isc_result_t
dns_dispatch_addresponse(dns_dispatch_t *disp, unsigned int options,
const isc_sockaddr_t *dest, isc_task_t *task,
isc_taskaction_t action, void *arg,
dns_messageid_t *idp, dns_dispentry_t **resp,
isc_socketmgr_t *sockmgr) {
dns_dispentry_t *res = NULL;
unsigned int bucket;
in_port_t localport = 0;
dns_messageid_t id;
int i = 0;
bool ok = false;
dns_qid_t *qid = NULL;
dispsocket_t *dispsocket = NULL;
isc_result_t result;
REQUIRE(VALID_DISPATCH(disp));
REQUIRE(task != NULL);
REQUIRE(dest != NULL);
REQUIRE(resp != NULL && *resp == NULL);
REQUIRE(idp != NULL);
REQUIRE(disp->socktype == isc_sockettype_tcp || sockmgr != NULL);
LOCK(&disp->lock);
if (disp->shutting_down == 1) {
UNLOCK(&disp->lock);
return (ISC_R_SHUTTINGDOWN);
}
if (disp->requests >= DNS_DISPATCH_MAXREQUESTS) {
UNLOCK(&disp->lock);
return (ISC_R_QUOTA);
}
qid = disp->mgr->qid;
if (disp->socktype == isc_sockettype_udp &&
disp->nsockets > DNS_DISPATCH_SOCKSQUOTA)
{
dispsocket_t *oldestsocket = NULL;
dns_dispentry_t *oldestresp = NULL;
dns_dispatchevent_t *rev = NULL;
/*
* Kill oldest outstanding query if the number of sockets
* exceeds the quota to keep the room for new queries.
*/
oldestsocket = ISC_LIST_HEAD(disp->activesockets);
oldestresp = oldestsocket->resp;
if (oldestresp != NULL && !oldestresp->item_out) {
rev = allocate_devent(oldestresp->disp);
rev->buffer.base = NULL;
rev->result = ISC_R_CANCELED;
rev->id = oldestresp->id;
ISC_EVENT_INIT(rev, sizeof(*rev), 0, NULL,
DNS_EVENT_DISPATCH, oldestresp->action,
oldestresp->arg, oldestresp, NULL, NULL);
oldestresp->item_out = true;
isc_task_send(oldestresp->task, ISC_EVENT_PTR(&rev));
inc_stats(disp->mgr, dns_resstatscounter_dispabort);
}
/*
* Move this entry to the tail so that it won't (easily) be
* examined before actually being canceled.
*/
ISC_LIST_UNLINK(disp->activesockets, oldestsocket, link);
ISC_LIST_APPEND(disp->activesockets, oldestsocket, link);
}
if (disp->socktype == isc_sockettype_udp) {
/*
* Get a separate UDP socket with a random port number.
*/
result = get_dispsocket(disp, dest, sockmgr, &dispsocket,
&localport);
if (result != ISC_R_SUCCESS) {
UNLOCK(&disp->lock);
inc_stats(disp->mgr, dns_resstatscounter_dispsockfail);
return (result);
}
}
/*
* Try somewhat hard to find a unique ID. Start with
* a random number unless DNS_DISPATCHOPT_FIXEDID is set,
* in which case we start with the ID passed in via *idp.
*/
if ((options & DNS_DISPATCHOPT_FIXEDID) != 0) {
id = *idp;
} else {
id = (dns_messageid_t)isc_random16();
}
LOCK(&qid->lock);
do {
dns_dispentry_t *entry = NULL;
bucket = dns_hash(qid, dest, id, localport);
entry = entry_search(qid, dest, id, localport, bucket);
if (entry == NULL) {
ok = true;
break;
}
id += qid->qid_increment;
id &= 0x0000ffff;
} while (i++ < 64);
UNLOCK(&qid->lock);
if (!ok) {
UNLOCK(&disp->lock);
return (ISC_R_NOMORE);
}
res = isc_mem_get(disp->mgr->mctx, sizeof(*res));
isc_refcount_increment0(&disp->mgr->irefs);
*res = (dns_dispentry_t){ .disp = disp,
.id = id,
.port = localport,
.bucket = bucket,
.host = *dest,
.action = action,
.arg = arg,
.dispsocket = dispsocket };
isc_task_attach(task, &res->task);
ISC_LIST_INIT(res->items);
ISC_LINK_INIT(res, link);
res->magic = RESPONSE_MAGIC;
isc_refcount_increment(&disp->refcount);
disp->requests++;
if (dispsocket != NULL) {
dispsocket->resp = res;
}
LOCK(&qid->lock);
ISC_LIST_APPEND(qid->qid_table[bucket], res, link);
UNLOCK(&qid->lock);
inc_stats(disp->mgr, (disp->socktype == isc_sockettype_udp)
? dns_resstatscounter_disprequdp
: dns_resstatscounter_dispreqtcp);
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))
{
result = startrecv(disp, dispsocket);
if (result != ISC_R_SUCCESS) {
LOCK(&qid->lock);
ISC_LIST_UNLINK(qid->qid_table[bucket], res, link);
UNLOCK(&qid->lock);
if (dispsocket != NULL) {
destroy_dispsocket(disp, &dispsocket);
}
isc_refcount_decrement(&disp->refcount);
disp->requests--;
dec_stats(disp->mgr,
(disp->socktype == isc_sockettype_udp)
? dns_resstatscounter_disprequdp
: dns_resstatscounter_dispreqtcp);
UNLOCK(&disp->lock);
isc_task_detach(&res->task);
isc_refcount_decrement(&disp->mgr->irefs);
isc_mem_put(disp->mgr->mctx, res, sizeof(*res));
return (result);
}
}
if (dispsocket != NULL) {
ISC_LIST_APPEND(disp->activesockets, dispsocket, link);
}
UNLOCK(&disp->lock);
INSIST(disp->socktype == isc_sockettype_tcp || res->dispsocket != NULL);
*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[0]);
LOCK(&disp->lock);
if ((disp->attributes & DNS_DISPATCHATTR_CONNECTED) == 0) {
disp->attributes |= DNS_DISPATCHATTR_CONNECTED;
(void)startrecv(disp, NULL);
}
UNLOCK(&disp->lock);
}
isc_result_t
dns_dispatch_getnext(dns_dispentry_t *resp, dns_dispatchevent_t **sockevent) {
dns_dispatch_t *disp = NULL;
dns_dispatchevent_t *ev = NULL;
REQUIRE(VALID_RESPONSE(resp));
REQUIRE(sockevent != NULL && *sockevent != NULL);
disp = resp->disp;
REQUIRE(VALID_DISPATCH(disp));
ev = *sockevent;
*sockevent = NULL;
LOCK(&disp->lock);
REQUIRE(resp->item_out);
resp->item_out = false;
if (ev->buffer.base != NULL) {
free_buffer(disp, ev->buffer.base, ev->buffer.length);
}
free_devent(disp, ev);
if (disp->shutting_down == 1) {
UNLOCK(&disp->lock);
return (ISC_R_SHUTTINGDOWN);
}
ev = ISC_LIST_HEAD(resp->items);
if (ev != NULL) {
ISC_LIST_UNLINK(resp->items, ev, ev_link);
ISC_EVENT_INIT(ev, sizeof(*ev), 0, NULL, DNS_EVENT_DISPATCH,
resp->action, resp->arg, resp, NULL, NULL);
request_log(disp, resp, LVL(90),
"[c] Sent event %p buffer %p len %d to task %p", ev,
ev->buffer.base, ev->buffer.length, resp->task);
resp->item_out = true;
isc_task_send(resp->task, ISC_EVENT_PTR(&ev));
}
UNLOCK(&disp->lock);
return (ISC_R_SUCCESS);
}
void
dns_dispatch_removeresponse(dns_dispentry_t **resp,
dns_dispatchevent_t **sockevent) {
dns_dispatchmgr_t *mgr = NULL;
dns_dispatch_t *disp = NULL;
dns_dispentry_t *res = NULL;
dispsocket_t *dispsock = NULL;
dns_dispatchevent_t *ev = NULL;
unsigned int bucket;
bool killit;
unsigned int n;
isc_eventlist_t events;
dns_qid_t *qid = NULL;
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 = mgr->qid;
if (sockevent != NULL) {
REQUIRE(*sockevent != NULL);
ev = *sockevent;
*sockevent = NULL;
} else {
ev = NULL;
}
LOCK(&disp->lock);
INSIST(disp->requests > 0);
disp->requests--;
dec_stats(disp->mgr, (disp->socktype == isc_sockettype_udp)
? dns_resstatscounter_disprequdp
: dns_resstatscounter_dispreqtcp);
if (isc_refcount_decrement(&disp->refcount) == 1) {
if (disp->recv_pending > 0) {
isc_socket_cancel(disp->socket, disp->task[0],
ISC_SOCKCANCEL_RECV);
}
for (dispsock = ISC_LIST_HEAD(disp->activesockets);
dispsock != NULL; dispsock = ISC_LIST_NEXT(dispsock, link))
{
isc_socket_cancel(dispsock->socket, dispsock->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);
res->item_out = false;
if (ev->buffer.base != NULL) {
free_buffer(disp, ev->buffer.base, ev->buffer.length);
}
free_devent(disp, ev);
}
request_log(disp, res, LVL(90), "detaching from task %p", res->task);
isc_task_detach(&res->task);
if (res->dispsocket != NULL) {
isc_socket_cancel(res->dispsocket->socket,
res->dispsocket->task, ISC_SOCKCANCEL_RECV);
res->dispsocket->resp = NULL;
}
/*
* Free any buffered responses 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_devent(disp, ev);
ev = ISC_LIST_HEAD(res->items);
}
res->magic = 0;
isc_refcount_decrement(&disp->mgr->irefs);
isc_mem_put(disp->mgr->mctx, res, sizeof(*res));
if (disp->shutting_down == 1) {
do_cancel(disp);
} else {
(void)startrecv(disp, NULL);
}
killit = destroy_disp_ok(disp);
UNLOCK(&disp->lock);
if (killit) {
isc_task_send(disp->task[0], &disp->ctlevent);
}
}
isc_result_t
dns_dispatch_connect(dns_dispatch_t *disp, dns_dispentry_t *resp,
isc_task_t *task, isc_taskaction_t action, void *arg) {
isc_socket_t *sock = NULL;
isc_sockaddr_t *address = NULL;
if (resp != NULL) {
REQUIRE(VALID_RESPONSE(resp));
sock = resp->dispsocket->socket;
address = &resp->host;
} else if (disp != NULL) {
REQUIRE(VALID_DISPATCH(disp));
sock = disp->socket;
address = &disp->peer;
} else {
INSIST(0);
ISC_UNREACHABLE();
}
return (isc_socket_connect(sock, address, task, action, arg));
}
isc_result_t
dns_dispatch_send(dns_dispentry_t *resp, bool tcp, isc_task_t *task,
isc_socketevent_t *sendevent, isc_region_t *r,
const isc_sockaddr_t *address, isc_dscp_t dscp,
isc_taskaction_t action, void *arg) {
isc_result_t result;
isc_socket_t *sock = NULL;
REQUIRE(VALID_RESPONSE(resp));
REQUIRE(sendevent != NULL);
memset(sendevent, 0, sizeof(isc_socketevent_t));
ISC_EVENT_INIT(sendevent, sizeof(isc_socketevent_t), 0, NULL,
ISC_SOCKEVENT_SENDDONE, action, arg, NULL, NULL, NULL);
sock = getentrysocket(resp);
if (dscp == -1) {
sendevent->attributes &= ~ISC_SOCKEVENTATTR_DSCP;
sendevent->dscp = 0;
} else {
sendevent->attributes |= ISC_SOCKEVENTATTR_DSCP;
sendevent->dscp = dscp;
if (tcp) {
isc_socket_dscp(sock, dscp);
}
}
if (tcp) {
address = NULL;
}
result = isc_socket_sendto2(sock, r, task, address, NULL, sendevent, 0);
return (result);
}
void
dns_dispatch_cancel(dns_dispatch_t *disp, dns_dispentry_t *resp, bool sending,
bool connecting) {
isc_socket_t *sock = NULL;
REQUIRE(disp != NULL || resp != NULL);
if (resp != NULL) {
REQUIRE(VALID_RESPONSE(resp));
sock = getentrysocket(resp);
} else if (disp != NULL) {
REQUIRE(VALID_DISPATCH(disp));
sock = getsocket(disp);
} else {
INSIST(0);
ISC_UNREACHABLE();
}
if (sock == NULL) {
return;
}
if (connecting) {
isc_socket_cancel(sock, NULL, ISC_SOCKCANCEL_CONNECT);
}
if (sending) {
isc_socket_cancel(sock, NULL, ISC_SOCKCANCEL_SEND);
}
}
/*
* disp must be locked.
*/
static void
do_cancel(dns_dispatch_t *disp) {
dns_dispatchevent_t *ev = NULL;
dns_dispentry_t *resp = NULL;
dns_qid_t *qid = disp->mgr->qid;
if (disp->shutdown_out == 1) {
return;
}
/*
* Search for the first response handler without packets outstanding
* unless a specific handler is given.
*/
LOCK(&qid->lock);
for (resp = linear_first(qid); resp != NULL && resp->item_out;
/* 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 = true;
isc_task_send(resp->task, ISC_EVENT_PTR(&ev));
unlock:
UNLOCK(&qid->lock);
}
static isc_socket_t *
getsocket(dns_dispatch_t *disp) {
REQUIRE(VALID_DISPATCH(disp));
return (disp->socket);
}
static isc_socket_t *
getentrysocket(dns_dispentry_t *resp) {
REQUIRE(VALID_RESPONSE(resp));
if (resp->disp->socktype == isc_sockettype_tcp) {
return (resp->disp->socket);
} else if (resp->dispsocket != NULL) {
return (resp->dispsocket->socket);
} else {
return (NULL);
}
}
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);
}
isc_result_t
dns_dispentry_getlocaladdress(dns_dispentry_t *resp, isc_sockaddr_t *addrp) {
REQUIRE(VALID_RESPONSE(resp));
REQUIRE(addrp != NULL);
if (resp->disp->socktype == isc_sockettype_tcp) {
return (isc_socket_getsockname(resp->disp->socket, addrp));
}
if (resp->dispsocket != NULL) {
return (isc_socket_getsockname(resp->dispsocket->socket,
addrp));
}
return (ISC_R_NOTIMPLEMENTED);
}
unsigned int
dns_dispatch_getattributes(dns_dispatch_t *disp) {
REQUIRE(VALID_DISPATCH(disp));
/*
* We don't bother locking disp here; it's the caller's responsibility
* to use only non volatile flags.
*/
return (disp->attributes);
}
void
dns_dispatch_changeattributes(dns_dispatch_t *disp, unsigned int attributes,
unsigned int mask) {
REQUIRE(VALID_DISPATCH(disp));
LOCK(&disp->lock);
disp->attributes &= ~mask;
disp->attributes |= (attributes & mask);
UNLOCK(&disp->lock);
}
dns_dispatch_t *
dns_dispatchset_get(dns_dispatchset_t *dset) {
dns_dispatch_t *disp = NULL;
/* check that dispatch set is configured */
if (dset == NULL || dset->ndisp == 0) {
return (NULL);
}
LOCK(&dset->lock);
disp = dset->dispatches[dset->cur];
dset->cur++;
if (dset->cur == dset->ndisp) {
dset->cur = 0;
}
UNLOCK(&dset->lock);
return (disp);
}
isc_result_t
dns_dispatchset_create(isc_mem_t *mctx, isc_socketmgr_t *sockmgr,
isc_taskmgr_t *taskmgr, dns_dispatch_t *source,
dns_dispatchset_t **dsetp, int n) {
isc_result_t result;
dns_dispatchset_t *dset = NULL;
dns_dispatchmgr_t *mgr = NULL;
int i, j;
REQUIRE(VALID_DISPATCH(source));
REQUIRE((source->attributes & DNS_DISPATCHATTR_UDP) != 0);
REQUIRE(dsetp != NULL && *dsetp == NULL);
mgr = source->mgr;
dset = isc_mem_get(mctx, sizeof(dns_dispatchset_t));
*dset = (dns_dispatchset_t){ .ndisp = n };
isc_mutex_init(&dset->lock);
dset->dispatches = isc_mem_get(mctx, sizeof(dns_dispatch_t *) * n);
isc_mem_attach(mctx, &dset->mctx);
dset->dispatches[0] = NULL;
dns_dispatch_attach(source, &dset->dispatches[0]);
LOCK(&mgr->lock);
for (i = 1; i < n; i++) {
dset->dispatches[i] = NULL;
result = dispatch_createudp(mgr, sockmgr, taskmgr,
&source->local, source->attributes,
&dset->dispatches[i]);
if (result != ISC_R_SUCCESS) {
goto fail;
}
}
UNLOCK(&mgr->lock);
*dsetp = dset;
return (ISC_R_SUCCESS);
fail:
UNLOCK(&mgr->lock);
for (j = 0; j < i; j++) {
dns_dispatch_detach(&(dset->dispatches[j]));
}
isc_mem_put(mctx, dset->dispatches, sizeof(dns_dispatch_t *) * n);
if (dset->mctx == mctx) {
isc_mem_detach(&dset->mctx);
}
isc_mutex_destroy(&dset->lock);
isc_mem_put(mctx, dset, sizeof(dns_dispatchset_t));
return (result);
}
void
dns_dispatchset_destroy(dns_dispatchset_t **dsetp) {
dns_dispatchset_t *dset = NULL;
int i;
REQUIRE(dsetp != NULL && *dsetp != NULL);
dset = *dsetp;
*dsetp = NULL;
for (i = 0; i < dset->ndisp; i++) {
dns_dispatch_detach(&(dset->dispatches[i]));
}
isc_mem_put(dset->mctx, dset->dispatches,
sizeof(dns_dispatch_t *) * dset->ndisp);
isc_mutex_destroy(&dset->lock);
isc_mem_putanddetach(&dset->mctx, dset, sizeof(dns_dispatchset_t));
}
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