dispatch.c revision 2a0d4c4d6ba5addb33cd1bccecc55ca4a095f191
94e25967cda41b886e33ec254b917d21df21a187Bob Halley/*
94e25967cda41b886e33ec254b917d21df21a187Bob Halley * Copyright (C) 2004-2009 Internet Systems Consortium, Inc. ("ISC")
94e25967cda41b886e33ec254b917d21df21a187Bob Halley * Copyright (C) 1999-2003 Internet Software Consortium.
94e25967cda41b886e33ec254b917d21df21a187Bob Halley *
94e25967cda41b886e33ec254b917d21df21a187Bob Halley * Permission to use, copy, modify, and/or distribute this software for any
94e25967cda41b886e33ec254b917d21df21a187Bob Halley * purpose with or without fee is hereby granted, provided that the above
94e25967cda41b886e33ec254b917d21df21a187Bob Halley * copyright notice and this permission notice appear in all copies.
94e25967cda41b886e33ec254b917d21df21a187Bob Halley *
94e25967cda41b886e33ec254b917d21df21a187Bob Halley * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
94e25967cda41b886e33ec254b917d21df21a187Bob Halley * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
94e25967cda41b886e33ec254b917d21df21a187Bob Halley * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
94e25967cda41b886e33ec254b917d21df21a187Bob Halley * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
94e25967cda41b886e33ec254b917d21df21a187Bob Halley * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
94e25967cda41b886e33ec254b917d21df21a187Bob Halley * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
94e25967cda41b886e33ec254b917d21df21a187Bob Halley * PERFORMANCE OF THIS SOFTWARE.
94e25967cda41b886e33ec254b917d21df21a187Bob Halley */
94e25967cda41b886e33ec254b917d21df21a187Bob Halley
94e25967cda41b886e33ec254b917d21df21a187Bob Halley/* $Id: dispatch.c,v 1.168 2009/12/02 23:15:14 marka Exp $ */
94e25967cda41b886e33ec254b917d21df21a187Bob Halley
94e25967cda41b886e33ec254b917d21df21a187Bob Halley/*! \file */
94e25967cda41b886e33ec254b917d21df21a187Bob Halley
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <config.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <stdlib.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <sys/types.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <unistd.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <stdlib.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <isc/entropy.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <isc/mem.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <isc/mutex.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <isc/portset.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <isc/print.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <isc/random.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <isc/stats.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <isc/string.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <isc/task.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <isc/time.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <isc/util.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <dns/acl.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <dns/dispatch.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <dns/events.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <dns/log.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <dns/message.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <dns/portlist.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <dns/stats.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <dns/tcpmsg.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley#include <dns/types.h>
94e25967cda41b886e33ec254b917d21df21a187Bob Halley
94e25967cda41b886e33ec254b917d21df21a187Bob Halleytypedef ISC_LIST(dns_dispentry_t) dns_displist_t;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley
94e25967cda41b886e33ec254b917d21df21a187Bob Halleytypedef struct dispsocket dispsocket_t;
94e25967cda41b886e33ec254b917d21df21a187Bob Halleytypedef ISC_LIST(dispsocket_t) dispsocketlist_t;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley
94e25967cda41b886e33ec254b917d21df21a187Bob Halleytypedef struct dispportentry dispportentry_t;
94e25967cda41b886e33ec254b917d21df21a187Bob Halleytypedef ISC_LIST(dispportentry_t) dispportlist_t;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley
94e25967cda41b886e33ec254b917d21df21a187Bob Halley/* ARC4 Random generator state */
94e25967cda41b886e33ec254b917d21df21a187Bob Halleytypedef struct arc4ctx {
94e25967cda41b886e33ec254b917d21df21a187Bob Halley isc_uint8_t i;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley isc_uint8_t j;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley isc_uint8_t s[256];
94e25967cda41b886e33ec254b917d21df21a187Bob Halley int count;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley isc_entropy_t *entropy; /*%< entropy source for ARC4 */
94e25967cda41b886e33ec254b917d21df21a187Bob Halley isc_mutex_t *lock;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley} arc4ctx_t;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley
94e25967cda41b886e33ec254b917d21df21a187Bob Halleytypedef struct dns_qid {
94e25967cda41b886e33ec254b917d21df21a187Bob Halley unsigned int magic;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley unsigned int qid_nbuckets; /*%< hash table size */
94e25967cda41b886e33ec254b917d21df21a187Bob Halley unsigned int qid_increment; /*%< id increment on collision */
94e25967cda41b886e33ec254b917d21df21a187Bob Halley isc_mutex_t lock;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley dns_displist_t *qid_table; /*%< the table itself */
94e25967cda41b886e33ec254b917d21df21a187Bob Halley dispsocketlist_t *sock_table; /*%< socket table */
94e25967cda41b886e33ec254b917d21df21a187Bob Halley} dns_qid_t;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley
94e25967cda41b886e33ec254b917d21df21a187Bob Halleystruct dns_dispatchmgr {
94e25967cda41b886e33ec254b917d21df21a187Bob Halley /* Unlocked. */
94e25967cda41b886e33ec254b917d21df21a187Bob Halley unsigned int magic;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley isc_mem_t *mctx;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley dns_acl_t *blackhole;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley dns_portlist_t *portlist;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley isc_stats_t *stats;
94e25967cda41b886e33ec254b917d21df21a187Bob Halley isc_entropy_t *entropy; /*%< entropy source */
94e25967cda41b886e33ec254b917d21df21a187Bob Halley
94e25967cda41b886e33ec254b917d21df21a187Bob Halley /* Locked by "lock". */
94e25967cda41b886e33ec254b917d21df21a187Bob Halley isc_mutex_t lock;
unsigned int state;
ISC_LIST(dns_dispatch_t) list;
/* Locked by arc4_lock. */
isc_mutex_t arc4_lock;
arc4ctx_t arc4ctx; /*%< ARC4 context for QID */
/* 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_mempool_t *spool; /*%< memory pool for dispsocs */
/*%
* Locked by qid->lock if qid exists; otherwise, can be used without
* being locked.
* Memory footprint considerations: this is a simple implementation of
* available ports, i.e., an ordered array of the actual port numbers.
* This will require about 256KB of memory in the worst case (128KB for
* each of IPv4 and IPv6). We could reduce it by representing it as a
* more sophisticated way such as a list (or array) of ranges that are
* searched to identify a specific port. Our decision here is the saved
* memory isn't worth the implementation complexity, considering the
* fact that the whole BIND9 process (which is mainly named) already
* requires a pretty large memory footprint. We may, however, have to
* revisit the decision when we want to use it as a separate module for
* an environment where memory requirement is severer.
*/
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)
#define IS_PRIVATE(d) (((d)->attributes & DNS_DISPATCHATTR_PRIVATE) != 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;
isc_boolean_t item_out;
dispsocket_t *dispsocket;
ISC_LIST(dns_dispatchevent_t) items;
ISC_LINK(dns_dispentry_t) link;
};
/*%
* 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
/*%
* Quota to control the number of 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
struct dispsocket {
unsigned int magic;
isc_socket_t *socket;
dns_dispatch_t *disp;
isc_sockaddr_t host;
in_port_t localport; /* XXX: should be removed later */
dispportentry_t *portentry;
dns_dispentry_t *resp;
isc_task_t *task;
ISC_LINK(dispsocket_t) link;
unsigned int bucket;
ISC_LINK(dispsocket_t) blink;
};
/*%
* A port table entry. We remember every port we first open in a table with a
* reference counter so that we can 'reuse' the same port (with different
* destination addresses) using the SO_REUSEADDR socket option.
*/
struct dispportentry {
in_port_t port;
unsigned int refs;
ISC_LINK(struct dispportentry) link;
};
#ifndef DNS_DISPATCH_PORTTABLESIZE
#define DNS_DISPATCH_PORTTABLESIZE 1024
#endif
#define INVALID_BUCKET (0xffffdead)
/*%
* 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 */
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;
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 */
dns_tcpmsg_t tcpmsg; /*%< for tcp streams */
dns_qid_t *qid;
arc4ctx_t arc4ctx; /*%< for QID/UDP port num */
dispportlist_t *port_table; /*%< hold ports 'owned' by us */
isc_mempool_t *portpool; /*%< port table entries */
};
#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)
#define DNS_QID(disp) ((disp)->socktype == isc_sockettype_tcp) ? \
(disp)->qid : (disp)->mgr->qid
#define DISP_ARC4CTX(disp) ((disp)->socktype == isc_sockettype_udp) ? \
(&(disp)->arc4ctx) : (&(disp)->mgr->arc4ctx)
/*%
* Locking a query port buffer is a bit tricky. We access the buffer without
* locking until qid is created. Technically, there is a possibility of race
* between the creation of qid and access to the port buffer; in practice,
* however, this should be safe because qid isn't created until the first
* dispatch is created and there should be no contending situation until then.
*/
#define PORTBUFLOCK(mgr) if ((mgr)->qid != NULL) LOCK(&((mgr)->qid->lock))
#define PORTBUFUNLOCK(mgr) if ((mgr)->qid != NULL) UNLOCK((&(mgr)->qid->lock))
/*
* Statics.
*/
static dns_dispentry_t *entry_search(dns_qid_t *, isc_sockaddr_t *,
dns_messageid_t, in_port_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 destroy_dispsocket(dns_dispatch_t *, dispsocket_t **);
static void deactivate_dispsocket(dns_dispatch_t *, dispsocket_t *);
static void udp_exrecv(isc_task_t *, isc_event_t *);
static void udp_shrecv(isc_task_t *, isc_event_t *);
static void udp_recv(isc_event_t *, dns_dispatch_t *, dispsocket_t *);
static void tcp_recv(isc_task_t *, isc_event_t *);
static isc_result_t startrecv(dns_dispatch_t *, dispsocket_t *);
static isc_uint32_t dns_hash(dns_qid_t *, 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_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 get_udpsocket(dns_dispatchmgr_t *mgr,
dns_dispatch_t *disp,
isc_socketmgr_t *sockmgr,
isc_sockaddr_t *localaddr,
isc_socket_t **sockp);
static isc_result_t dispatch_createudp(dns_dispatchmgr_t *mgr,
isc_socketmgr_t *sockmgr,
isc_taskmgr_t *taskmgr,
isc_sockaddr_t *localaddr,
unsigned int maxrequests,
unsigned int attributes,
dns_dispatch_t **dispp);
static isc_boolean_t destroy_mgr_ok(dns_dispatchmgr_t *mgr);
static void destroy_mgr(dns_dispatchmgr_t **mgrp);
static isc_result_t qid_allocate(dns_dispatchmgr_t *mgr, unsigned int buckets,
unsigned int increment, dns_qid_t **qidp,
isc_boolean_t needaddrtable);
static void qid_destroy(isc_mem_t *mctx, dns_qid_t **qidp);
static isc_result_t open_socket(isc_socketmgr_t *mgr, isc_sockaddr_t *local,
unsigned int options, isc_socket_t **sockp);
static isc_boolean_t portavailable(dns_dispatchmgr_t *mgr, isc_socket_t *sock,
isc_sockaddr_t *sockaddrp);
#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 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);
}
}
/*%
* ARC4 random number generator derived from OpenBSD.
* Only dispatch_random() and dispatch_uniformrandom() are expected
* to be called from general dispatch routines; the rest of them are subroutines
* for these two.
*
* The original copyright follows:
* Copyright (c) 1996, David Mazieres <dm@uun.org>
* Copyright (c) 2008, Damien Miller <djm@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
*/
#ifdef BIND9
static void
dispatch_initrandom(arc4ctx_t *actx, isc_entropy_t *entropy,
isc_mutex_t *lock)
{
int n;
for (n = 0; n < 256; n++)
actx->s[n] = n;
actx->i = 0;
actx->j = 0;
actx->count = 0;
actx->entropy = entropy; /* don't have to attach */
actx->lock = lock;
}
static void
dispatch_arc4addrandom(arc4ctx_t *actx, unsigned char *dat, int datlen) {
int n;
isc_uint8_t si;
actx->i--;
for (n = 0; n < 256; n++) {
actx->i = (actx->i + 1);
si = actx->s[actx->i];
actx->j = (actx->j + si + dat[n % datlen]);
actx->s[actx->i] = actx->s[actx->j];
actx->s[actx->j] = si;
}
actx->j = actx->i;
}
static inline isc_uint8_t
dispatch_arc4get8(arc4ctx_t *actx) {
isc_uint8_t si, sj;
actx->i = (actx->i + 1);
si = actx->s[actx->i];
actx->j = (actx->j + si);
sj = actx->s[actx->j];
actx->s[actx->i] = sj;
actx->s[actx->j] = si;
return (actx->s[(si + sj) & 0xff]);
}
static inline isc_uint16_t
dispatch_arc4get16(arc4ctx_t *actx) {
isc_uint16_t val;
val = dispatch_arc4get8(actx) << 8;
val |= dispatch_arc4get8(actx);
return (val);
}
static void
dispatch_arc4stir(arc4ctx_t *actx) {
int i;
union {
unsigned char rnd[128];
isc_uint32_t rnd32[32];
} rnd;
isc_result_t result;
if (actx->entropy != NULL) {
/*
* We accept any quality of random data to avoid blocking.
*/
result = isc_entropy_getdata(actx->entropy, rnd.rnd,
sizeof(rnd), NULL, 0);
RUNTIME_CHECK(result == ISC_R_SUCCESS);
} else {
for (i = 0; i < 32; i++)
isc_random_get(&rnd.rnd32[i]);
}
dispatch_arc4addrandom(actx, rnd.rnd, sizeof(rnd.rnd));
/*
* Discard early keystream, as per recommendations in:
* http://www.wisdom.weizmann.ac.il/~itsik/RC4/Papers/Rc4_ksa.ps
*/
for (i = 0; i < 256; i++)
(void)dispatch_arc4get8(actx);
/*
* Derived from OpenBSD's implementation. The rationale is not clear,
* but should be conservative enough in safety, and reasonably large
* for efficiency.
*/
actx->count = 1600000;
}
static isc_uint16_t
dispatch_random(arc4ctx_t *actx) {
isc_uint16_t result;
if (actx->lock != NULL)
LOCK(actx->lock);
actx->count -= sizeof(isc_uint16_t);
if (actx->count <= 0)
dispatch_arc4stir(actx);
result = dispatch_arc4get16(actx);
if (actx->lock != NULL)
UNLOCK(actx->lock);
return (result);
}
#else
/*
* For general purpose library, we don't have to be too strict about the
* quality of random values. Performance doesn't matter much, either.
* So we simply use the isc_random module to keep the library as small as
* possible.
*/
static void
dispatch_initrandom(arc4ctx_t *actx, isc_entropy_t *entropy,
isc_mutex_t *lock)
{
UNUSED(actx);
UNUSED(entropy);
UNUSED(lock);
return;
}
static isc_uint16_t
dispatch_random(arc4ctx_t *actx) {
isc_uint32_t r;
UNUSED(actx);
isc_random_get(&r);
return (r & 0xffff);
}
#endif /* BIND9 */
static isc_uint16_t
dispatch_uniformrandom(arc4ctx_t *actx, isc_uint16_t upper_bound) {
isc_uint16_t min, r;
if (upper_bound < 2)
return (0);
/*
* Ensure the range of random numbers [min, 0xffff] be a multiple of
* upper_bound and contain at least a half of the 16 bit range.
*/
if (upper_bound > 0x8000)
min = 1 + ~upper_bound; /* 0x8000 - upper_bound */
else
min = (isc_uint16_t)(0x10000 % (isc_uint32_t)upper_bound);
/*
* This could theoretically loop forever but each retry has
* p > 0.5 (worst case, usually far better) of selecting a
* number inside the range we need, so it should rarely need
* to re-roll.
*/
for (;;) {
r = dispatch_random(actx);
if (r >= min)
break;
}
return (r % upper_bound);
}
/*
* 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,
in_port_t port)
{
unsigned int ret;
ret = isc_sockaddr_hash(dest, ISC_TRUE);
ret ^= (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;
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 (!ISC_LIST_EMPTY(disp->activesockets))
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;
dispsocket_t *dispsocket;
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, task %p",
disp->socket, disp->task[0]); /* XXXX */
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);
}
/*%
* Manipulate port table per dispatch: find an entry for a given port number,
* create a new entry, and decrement a given entry with possible clean-up.
*/
static dispportentry_t *
port_search(dns_dispatch_t *disp, in_port_t port) {
dispportentry_t *portentry;
REQUIRE(disp->port_table != NULL);
portentry = ISC_LIST_HEAD(disp->port_table[port %
DNS_DISPATCH_PORTTABLESIZE]);
while (portentry != NULL) {
if (portentry->port == port)
return (portentry);
portentry = ISC_LIST_NEXT(portentry, link);
}
return (NULL);
}
static dispportentry_t *
new_portentry(dns_dispatch_t *disp, in_port_t port) {
dispportentry_t *portentry;
REQUIRE(disp->port_table != NULL);
portentry = isc_mempool_get(disp->portpool);
if (portentry == NULL)
return (portentry);
portentry->port = port;
portentry->refs = 0;
ISC_LINK_INIT(portentry, link);
ISC_LIST_APPEND(disp->port_table[port % DNS_DISPATCH_PORTTABLESIZE],
portentry, link);
return (portentry);
}
/*%
* The caller must not hold the qid->lock.
*/
static void
deref_portentry(dns_dispatch_t *disp, dispportentry_t **portentryp) {
dispportentry_t *portentry = *portentryp;
dns_qid_t *qid;
REQUIRE(disp->port_table != NULL);
REQUIRE(portentry != NULL && portentry->refs > 0);
qid = DNS_QID(disp);
LOCK(&qid->lock);
portentry->refs--;
if (portentry->refs == 0) {
ISC_LIST_UNLINK(disp->port_table[portentry->port %
DNS_DISPATCH_PORTTABLESIZE],
portentry, link);
isc_mempool_put(disp->portpool, portentry);
}
*portentryp = NULL;
UNLOCK(&qid->lock);
}
/*%
* Find a dispsocket for socket address 'dest', and port number 'port'.
* Return NULL if no such entry exists.
*/
static dispsocket_t *
socket_search(dns_qid_t *qid, isc_sockaddr_t *dest, in_port_t port,
unsigned int bucket)
{
dispsocket_t *dispsock;
REQUIRE(bucket < qid->qid_nbuckets);
dispsock = ISC_LIST_HEAD(qid->sock_table[bucket]);
while (dispsock != NULL) {
if (dispsock->portentry != NULL &&
dispsock->portentry->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 and qid->lock.
*/
static isc_result_t
get_dispsocket(dns_dispatch_t *disp, isc_sockaddr_t *dest,
isc_socketmgr_t *sockmgr, dns_qid_t *qid,
dispsocket_t **dispsockp, in_port_t *portp)
{
int i;
isc_uint32_t r;
dns_dispatchmgr_t *mgr = disp->mgr;
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;
unsigned int nports;
in_port_t *ports;
unsigned int bindoptions;
dispportentry_t *portentry = NULL;
if (isc_sockaddr_pf(&disp->local) == AF_INET) {
nports = disp->mgr->nv4ports;
ports = disp->mgr->v4ports;
} else {
nports = disp->mgr->nv6ports;
ports = disp->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_mempool_get(mgr->spool);
if (dispsock == NULL)
return (ISC_R_NOMEMORY);
disp->nsockets++;
dispsock->socket = NULL;
dispsock->disp = disp;
dispsock->resp = NULL;
dispsock->portentry = NULL;
isc_random_get(&r);
dispsock->task = NULL;
isc_task_attach(disp->task[r % 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[dispatch_uniformrandom(DISP_ARC4CTX(disp),
nports)];
isc_sockaddr_setport(&localaddr, port);
bucket = dns_hash(qid, dest, 0, port);
if (socket_search(qid, dest, port, bucket) != NULL)
continue;
bindoptions = 0;
portentry = port_search(disp, port);
if (portentry != NULL)
bindoptions |= ISC_SOCKET_REUSEADDRESS;
result = open_socket(sockmgr, &localaddr, bindoptions, &sock);
if (result == ISC_R_SUCCESS) {
if (portentry == NULL) {
portentry = new_portentry(disp, port);
if (portentry == NULL) {
result = ISC_R_NOMEMORY;
break;
}
}
portentry->refs++;
break;
} else if (result != ISC_R_ADDRINUSE)
break;
}
if (result == ISC_R_SUCCESS) {
dispsock->socket = sock;
dispsock->host = *dest;
dispsock->portentry = portentry;
dispsock->bucket = bucket;
ISC_LIST_APPEND(qid->sock_table[bucket], dispsock, blink);
*dispsockp = dispsock;
*portp = port;
} else {
/*
* We could keep it in the inactive list, but since this should
* be an exceptional case and might be resource shortage, we'd
* rather destroy it.
*/
if (sock != NULL)
isc_socket_detach(&sock);
destroy_dispsocket(disp, &dispsock);
}
return (result);
}
/*%
* Destroy a dedicated dispatch socket.
*/
static void
destroy_dispsocket(dns_dispatch_t *disp, dispsocket_t **dispsockp) {
dispsocket_t *dispsock;
dns_qid_t *qid;
/*
* The dispatch must be locked.
*/
REQUIRE(dispsockp != NULL && *dispsockp != NULL);
dispsock = *dispsockp;
REQUIRE(!ISC_LINK_LINKED(dispsock, link));
disp->nsockets--;
dispsock->magic = 0;
if (dispsock->portentry != NULL)
deref_portentry(disp, &dispsock->portentry);
if (dispsock->socket != NULL)
isc_socket_detach(&dispsock->socket);
if (ISC_LINK_LINKED(dispsock, blink)) {
qid = DNS_QID(disp);
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_mempool_put(disp->mgr->spool, dispsock);
*dispsockp = NULL;
}
/*%
* 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;
/*
* 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;
}
INSIST(dispsock->portentry != NULL);
deref_portentry(disp, &dispsock->portentry);
#ifdef BIND9
if (disp->nsockets > DNS_DISPATCH_POOLSOCKS)
destroy_dispsocket(disp, &dispsock);
else {
result = isc_socket_close(dispsock->socket);
qid = DNS_QID(disp);
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);
}
}
#else
/* This kind of optimization isn't necessary for normal use */
UNUSED(qid);
UNUSED(result);
destroy_dispsocket(disp, &dispsock);
#endif
}
/*
* 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, isc_sockaddr_t *dest, dns_messageid_t id,
in_port_t port, 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) &&
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) {
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);
}
static void
udp_exrecv(isc_task_t *task, isc_event_t *ev) {
dispsocket_t *dispsock = ev->ev_arg;
UNUSED(task);
REQUIRE(VALID_DISPSOCK(dispsock));
udp_recv(ev, dispsock->disp, dispsock);
}
static void
udp_shrecv(isc_task_t *task, isc_event_t *ev) {
dns_dispatch_t *disp = ev->ev_arg;
UNUSED(task);
REQUIRE(VALID_DISPATCH(disp));
udp_recv(ev, disp, NULL);
}
/*
* 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_event_t *ev_in, dns_dispatch_t *disp, dispsocket_t *dispsock) {
isc_socketevent_t *ev = (isc_socketevent_t *)ev_in;
dns_messageid_t id;
isc_result_t dres;
isc_buffer_t source;
unsigned int flags;
dns_dispentry_t *resp = NULL;
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;
int result;
isc_boolean_t qidlocked = ISC_FALSE;
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 (dispsock == NULL && 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 (dispsock != NULL &&
(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 been 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 ((disp->attributes & DNS_DISPATCHATTR_EXCLUSIVE) != 0) {
if (dispsock != NULL) {
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;
}
} else {
free_buffer(disp, ev->region.base, ev->region.length);
UNLOCK(&disp->lock);
isc_event_free(&ev_in);
return;
}
} else 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;
}
/*
* Search for the corresponding response. If we are using an exclusive
* socket, we've already identified it and we can skip the search; but
* the ID and the address must match the expected ones.
*/
if (resp == NULL) {
bucket = dns_hash(qid, &ev->address, id, disp->localport);
LOCK(&qid->lock);
qidlocked = ISC_TRUE;
resp = entry_search(qid, &ev->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) {
inc_stats(mgr, dns_resstatscounter_mismatch);
free_buffer(disp, ev->region.base, ev->region.length);
goto unlock;
}
} else if (resp->id != id || !isc_sockaddr_equal(&ev->address,
&resp->host)) {
dispatch_log(disp, LVL(90),
"response to an exclusive socket doesn't match");
inc_stats(mgr, dns_resstatscounter_mismatch);
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;
}
}
sendresponse:
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 = 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 = ISC_TRUE;
isc_task_send(resp->task, ISC_EVENT_PTR(&rev));
}
unlock:
if (qidlocked)
UNLOCK(&qid->lock);
/*
* Restart recv() to get the next packet.
*/
restart:
result = startrecv(disp, dispsock);
if (result != ISC_R_SUCCESS && dispsock != NULL) {
/*
* XXX: wired. There seems to be no recovery process other than
* deactivate this socket anyway (since we cannot start
* receiving, we won't be able to receive a cancel event
* from the user).
*/
deactivate_dispsocket(disp, dispsock);
}
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[0], &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;
}
/*
* 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_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:
(void)startrecv(disp, NULL);
UNLOCK(&disp->lock);
isc_event_free(&ev_in);
}
/*
* 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 *socket;
if (disp->shutting_down == 1)
return (ISC_R_SUCCESS);
if ((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) != 0)
return (ISC_R_SUCCESS);
if (disp->recv_pending != 0 && dispsock == NULL)
return (ISC_R_SUCCESS);
if (disp->mgr->buffers >= disp->mgr->maxbuffers)
return (ISC_R_NOMEMORY);
if ((disp->attributes & DNS_DISPATCHATTR_EXCLUSIVE) != 0 &&
dispsock == NULL)
return (ISC_R_SUCCESS);
if (dispsock != NULL)
socket = dispsock->socket;
else
socket = disp->socket;
INSIST(socket != NULL);
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 (ISC_R_NOMEMORY);
if (dispsock != NULL) {
res = isc_socket_recv(socket, &region, 1,
dispsock->task, udp_exrecv,
dispsock);
if (res != ISC_R_SUCCESS) {
free_buffer(disp, region.base, region.length);
return (res);
}
} else {
res = isc_socket_recv(socket, &region, 1,
disp->task[0], udp_shrecv, 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 (ISC_R_SUCCESS); /* recover by cancel */
}
INSIST(disp->recv_pending == 0);
disp->recv_pending = 1;
}
break;
case isc_sockettype_tcp:
res = dns_tcpmsg_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);
break;
}
return (ISC_R_SUCCESS);
}
/*
* 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;
DESTROYLOCK(&mgr->arc4_lock);
isc_mempool_destroy(&mgr->epool);
isc_mempool_destroy(&mgr->rpool);
isc_mempool_destroy(&mgr->dpool);
isc_mempool_destroy(&mgr->bpool);
isc_mempool_destroy(&mgr->spool);
DESTROYLOCK(&mgr->pool_lock);
#ifdef BIND9
if (mgr->entropy != NULL)
isc_entropy_detach(&mgr->entropy);
#endif /* BIND9 */
if (mgr->qid != NULL)
qid_destroy(mctx, &mgr->qid);
DESTROYLOCK(&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(mctx, mgr->v4ports,
mgr->nv4ports * sizeof(in_port_t));
}
if (mgr->v6ports != NULL) {
isc_mem_put(mctx, mgr->v6ports,
mgr->nv6ports * sizeof(in_port_t));
}
isc_mem_put(mctx, mgr, sizeof(dns_dispatchmgr_t));
isc_mem_detach(&mctx);
}
static isc_result_t
open_socket(isc_socketmgr_t *mgr, isc_sockaddr_t *local,
unsigned int options, isc_socket_t **sockp)
{
isc_socket_t *sock;
isc_result_t result;
sock = *sockp;
if (sock == NULL) {
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);
} else {
#ifdef BIND9
result = isc_socket_open(sock);
if (result != ISC_R_SUCCESS)
return (result);
#else
INSIST(0);
#endif
}
#ifndef ISC_ALLOW_MAPPED
isc_socket_ipv6only(sock, ISC_TRUE);
#endif
result = isc_socket_bind(sock, local, options);
if (result != ISC_R_SUCCESS) {
if (*sockp == NULL)
isc_socket_detach(&sock);
else {
#ifdef BIND9
isc_socket_close(sock);
#else
INSIST(0);
#endif
}
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 isc_result_t
create_default_portset(isc_mem_t *mctx, isc_portset_t **portsetp) {
isc_result_t result;
result = isc_portset_create(mctx, portsetp);
if (result != ISC_R_SUCCESS)
return (result);
isc_portset_addrange(*portsetp, 1024, 65535);
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;
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));
if (mgr == NULL)
return (ISC_R_NOMEMORY);
mgr->mctx = NULL;
isc_mem_attach(mctx, &mgr->mctx);
mgr->blackhole = NULL;
mgr->stats = NULL;
result = isc_mutex_init(&mgr->lock);
if (result != ISC_R_SUCCESS)
goto deallocate;
result = isc_mutex_init(&mgr->arc4_lock);
if (result != ISC_R_SUCCESS)
goto kill_lock;
result = isc_mutex_init(&mgr->buffer_lock);
if (result != ISC_R_SUCCESS)
goto kill_arc4_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->spool = NULL;
mgr->entropy = NULL;
mgr->qid = NULL;
mgr->state = 0;
ISC_LIST_INIT(mgr->list);
mgr->v4ports = NULL;
mgr->v6ports = NULL;
mgr->nv4ports = 0;
mgr->nv6ports = 0;
mgr->magic = DNS_DISPATCHMGR_MAGIC;
result = create_default_portset(mctx, &v4portset);
if (result == ISC_R_SUCCESS) {
result = create_default_portset(mctx, &v6portset);
if (result == ISC_R_SUCCESS) {
result = dns_dispatchmgr_setavailports(mgr,
v4portset,
v6portset);
}
}
if (v4portset != NULL)
isc_portset_destroy(mctx, &v4portset);
if (v6portset != NULL)
isc_portset_destroy(mctx, &v6portset);
if (result != ISC_R_SUCCESS)
goto kill_dpool;
#ifdef BIND9
if (entropy != NULL)
isc_entropy_attach(entropy, &mgr->entropy);
#else
UNUSED(entropy);
#endif
dispatch_initrandom(&mgr->arc4ctx, mgr->entropy, &mgr->arc4_lock);
*mgrp = mgr;
return (ISC_R_SUCCESS);
kill_dpool:
isc_mempool_destroy(&mgr->dpool);
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_arc4_lock:
DESTROYLOCK(&mgr->arc4_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));
UNUSED(portlist);
/* This function is deprecated: use dns_dispatchmgr_setavailports(). */
return;
}
dns_portlist_t *
dns_dispatchmgr_getblackportlist(dns_dispatchmgr_t *mgr) {
REQUIRE(VALID_DISPATCHMGR(mgr));
return (NULL); /* this function is deprecated */
}
isc_result_t
dns_dispatchmgr_setavailports(dns_dispatchmgr_t *mgr, isc_portset_t *v4portset,
isc_portset_t *v6portset)
{
in_port_t *v4ports, *v6ports, p;
unsigned int nv4ports, nv6ports, i4, i6;
REQUIRE(VALID_DISPATCHMGR(mgr));
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);
if (v4ports == NULL)
return (ISC_R_NOMEMORY);
}
v6ports = NULL;
if (nv6ports != 0) {
v6ports = isc_mem_get(mgr->mctx, sizeof(in_port_t) * nv6ports);
if (v6ports == NULL) {
if (v4ports != NULL) {
isc_mem_put(mgr->mctx, v4ports,
sizeof(in_port_t) *
isc_portset_nports(v4portset));
}
return (ISC_R_NOMEMORY);
}
}
p = 0;
i4 = 0;
i6 = 0;
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);
PORTBUFLOCK(mgr);
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;
PORTBUFUNLOCK(mgr);
return (ISC_R_SUCCESS);
}
static isc_result_t
dns_dispatchmgr_setudp(dns_dispatchmgr_t *mgr,
unsigned int buffersize, unsigned int maxbuffers,
unsigned int maxrequests, 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);
/* Create or adjust buffer pool */
if (mgr->bpool != NULL) {
/*
* We only increase the maxbuffers to avoid accidental buffer
* shortage. Ideally we'd separate the manager-wide maximum
* from per-dispatch limits and respect the latter within the
* global limit. But at this moment that's deemed to be
* overkilling and isn't worth additional implementation
* complexity.
*/
if (maxbuffers > mgr->maxbuffers) {
isc_mempool_setmaxalloc(mgr->bpool, maxbuffers);
mgr->maxbuffers = maxbuffers;
}
} else {
result = isc_mempool_create(mgr->mctx, buffersize, &mgr->bpool);
if (result != ISC_R_SUCCESS) {
UNLOCK(&mgr->buffer_lock);
return (result);
}
isc_mempool_setname(mgr->bpool, "dispmgr_bpool");
isc_mempool_setmaxalloc(mgr->bpool, maxbuffers);
isc_mempool_associatelock(mgr->bpool, &mgr->pool_lock);
}
/* Create or adjust socket pool */
if (mgr->spool != NULL) {
isc_mempool_setmaxalloc(mgr->spool, DNS_DISPATCH_POOLSOCKS * 2);
UNLOCK(&mgr->buffer_lock);
return (ISC_R_SUCCESS);
}
result = isc_mempool_create(mgr->mctx, sizeof(dispsocket_t),
&mgr->spool);
if (result != ISC_R_SUCCESS) {
UNLOCK(&mgr->buffer_lock);
goto cleanup;
}
isc_mempool_setname(mgr->spool, "dispmgr_spool");
isc_mempool_setmaxalloc(mgr->spool, maxrequests);
isc_mempool_associatelock(mgr->spool, &mgr->pool_lock);
result = qid_allocate(mgr, buckets, increment, &mgr->qid, ISC_TRUE);
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);
if (mgr->spool != NULL)
isc_mempool_destroy(&mgr->spool);
UNLOCK(&mgr->buffer_lock);
return (result);
}
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);
}
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 int
port_cmp(const void *key, const void *ent) {
in_port_t p1 = *(const in_port_t *)key;
in_port_t p2 = *(const in_port_t *)ent;
if (p1 < p2)
return (-1);
else if (p1 == p2)
return (0);
else
return (1);
}
static isc_boolean_t
portavailable(dns_dispatchmgr_t *mgr, isc_socket_t *sock,
isc_sockaddr_t *sockaddrp)
{
isc_sockaddr_t sockaddr;
isc_result_t result;
in_port_t *ports, port;
unsigned int nports;
isc_boolean_t available = ISC_FALSE;
REQUIRE(sock != NULL || sockaddrp != NULL);
PORTBUFLOCK(mgr);
if (sock != NULL) {
sockaddrp = &sockaddr;
result = isc_socket_getsockname(sock, sockaddrp);
if (result != ISC_R_SUCCESS)
goto unlock;
}
if (isc_sockaddr_pf(sockaddrp) == AF_INET) {
ports = mgr->v4ports;
nports = mgr->nv4ports;
} else {
ports = mgr->v6ports;
nports = mgr->nv6ports;
}
if (ports == NULL)
goto unlock;
port = isc_sockaddr_getport(sockaddrp);
if (bsearch(&port, ports, nports, sizeof(in_port_t), port_cmp) != NULL)
available = ISC_TRUE;
unlock:
PORTBUFUNLOCK(mgr);
return (available);
}
#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;
REQUIRE(disp->socket != NULL);
if (addr == NULL)
return (ISC_TRUE);
/*
* Don't match wildcard ports unless the port is available in the
* current configuration.
*/
if (isc_sockaddr_getport(addr) == 0 &&
isc_sockaddr_getport(&disp->local) == 0 &&
!portavailable(disp->mgr, disp->socket, NULL)) {
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 or exclusive dispatch.
*/
attributes &= ~(DNS_DISPATCHATTR_PRIVATE|DNS_DISPATCHATTR_EXCLUSIVE);
mask |= (DNS_DISPATCHATTR_PRIVATE|DNS_DISPATCHATTR_EXCLUSIVE);
disp = ISC_LIST_HEAD(mgr->list);
while (disp != NULL) {
LOCK(&disp->lock);
if ((disp->shutting_down == 0)
&& ATTRMATCH(disp->attributes, attributes, mask)
&& local_addr_match(disp, local))
break;
UNLOCK(&disp->lock);
disp = ISC_LIST_NEXT(disp, link);
}
if (disp == NULL) {
result = ISC_R_NOTFOUND;
goto out;
}
*dispp = disp;
result = ISC_R_SUCCESS;
out:
return (result);
}
static isc_result_t
qid_allocate(dns_dispatchmgr_t *mgr, unsigned int buckets,
unsigned int increment, dns_qid_t **qidp,
isc_boolean_t needsocktable)
{
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);
}
qid->sock_table = NULL;
if (needsocktable) {
qid->sock_table = isc_mem_get(mgr->mctx, buckets *
sizeof(dispsocketlist_t));
if (qid->sock_table == NULL) {
isc_mem_put(mgr->mctx, qid, sizeof(*qid));
isc_mem_put(mgr->mctx, qid->qid_table,
buckets * sizeof(dns_displist_t));
return (ISC_R_NOMEMORY);
}
}
result = isc_mutex_init(&qid->lock);
if (result != ISC_R_SUCCESS) {
if (qid->sock_table != NULL) {
isc_mem_put(mgr->mctx, qid->sock_table,
buckets * sizeof(dispsocketlist_t));
}
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]);
if (qid->sock_table != NULL)
ISC_LIST_INIT(qid->sock_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;
isc_mem_put(mctx, qid->qid_table,
qid->qid_nbuckets * sizeof(dns_displist_t));
if (qid->sock_table != NULL) {
isc_mem_put(mctx, qid->sock_table,
qid->qid_nbuckets * sizeof(dispsocketlist_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->localport = 0;
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;
ISC_LIST_INIT(disp->activesockets);
ISC_LIST_INIT(disp->inactivesockets);
disp->nsockets = 0;
dispatch_initrandom(&disp->arc4ctx, mgr->entropy, NULL);
disp->port_table = NULL;
disp->portpool = 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 anything.
*/
static void
dispatch_free(dns_dispatch_t **dispp)
{
dns_dispatch_t *disp;
dns_dispatchmgr_t *mgr;
int i;
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);
INSIST(ISC_LIST_EMPTY(disp->activesockets));
INSIST(ISC_LIST_EMPTY(disp->inactivesockets));
isc_mempool_put(mgr->epool, disp->failsafe_ev);
disp->failsafe_ev = NULL;
if (disp->qid != NULL)
qid_destroy(mgr->mctx, &disp->qid);
if (disp->port_table != NULL) {
for (i = 0; i < DNS_DISPATCH_PORTTABLESIZE; i++)
INSIST(ISC_LIST_EMPTY(disp->port_table[i]));
isc_mem_put(mgr->mctx, disp->port_table,
sizeof(disp->port_table[0]) *
DNS_DISPATCH_PORTTABLESIZE);
}
if (disp->portpool != NULL)
isc_mempool_destroy(&disp->portpool);
disp->mgr = NULL;
DESTROYLOCK(&disp->lock);
disp->magic = 0;
isc_mempool_put(mgr->dpool, disp);
}
isc_result_t
dns_dispatch_createtcp(dns_dispatchmgr_t *mgr, isc_socket_t *sock,
isc_taskmgr_t *taskmgr, unsigned int buffersize,
unsigned int maxbuffers, unsigned int maxrequests,
unsigned int buckets, unsigned int increment,
unsigned int attributes, dns_dispatch_t **dispp)
{
isc_result_t result;
dns_dispatch_t *disp;
UNUSED(maxbuffers);
UNUSED(buffersize);
REQUIRE(VALID_DISPATCHMGR(mgr));
REQUIRE(isc_socket_gettype(sock) == isc_sockettype_tcp);
REQUIRE((attributes & DNS_DISPATCHATTR_TCP) != 0);
REQUIRE((attributes & DNS_DISPATCHATTR_UDP) == 0);
attributes |= DNS_DISPATCHATTR_PRIVATE; /* XXXMLG */
LOCK(&mgr->lock);
/*
* dispatch_allocate() checks mgr for us.
* qid_allocate() checks buckets and increment for us.
*/
disp = NULL;
result = dispatch_allocate(mgr, maxrequests, &disp);
if (result != ISC_R_SUCCESS) {
UNLOCK(&mgr->lock);
return (result);
}
result = qid_allocate(mgr, buckets, increment, &disp->qid, ISC_FALSE);
if (result != ISC_R_SUCCESS)
goto deallocate_dispatch;
disp->socktype = isc_sockettype_tcp;
disp->socket = NULL;
isc_socket_attach(sock, &disp->socket);
disp->ntasks = 1;
disp->task[0] = NULL;
result = isc_task_create(taskmgr, 0, &disp->task[0]);
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[0], "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[0]);
*dispp = disp;
return (ISC_R_SUCCESS);
/*
* Error returns.
*/
kill_task:
isc_task_detach(&disp->task[0]);
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 = NULL;
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,
maxrequests, buckets, increment);
if (result != ISC_R_SUCCESS)
return (result);
LOCK(&mgr->lock);
if ((attributes & DNS_DISPATCHATTR_EXCLUSIVE) != 0) {
REQUIRE(isc_sockaddr_getport(localaddr) == 0);
goto createudp;
}
/*
* See if we have a dispatcher that matches.
*/
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[0],
ISC_SOCKCANCEL_RECV);
}
UNLOCK(&disp->lock);
UNLOCK(&mgr->lock);
*dispp = disp;
return (ISC_R_SUCCESS);
}
createudp:
/*
* 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
get_udpsocket(dns_dispatchmgr_t *mgr, dns_dispatch_t *disp,
isc_socketmgr_t *sockmgr, isc_sockaddr_t *localaddr,
isc_socket_t **sockp)
{
unsigned int i, j;
isc_socket_t *held[DNS_DISPATCH_HELD];
isc_sockaddr_t localaddr_bound;
isc_socket_t *sock = NULL;
isc_result_t result = ISC_R_SUCCESS;
isc_boolean_t anyport;
INSIST(sockp != NULL && *sockp == NULL);
localaddr_bound = *localaddr;
anyport = ISC_TF(isc_sockaddr_getport(localaddr) == 0);
if (anyport) {
unsigned int nports;
in_port_t *ports;
/*
* If no port is specified, we first try to pick up a random
* port by ourselves.
*/
if (isc_sockaddr_pf(&disp->local) == AF_INET) {
nports = disp->mgr->nv4ports;
ports = disp->mgr->v4ports;
} else {
nports = disp->mgr->nv6ports;
ports = disp->mgr->v6ports;
}
if (nports == 0)
return (ISC_R_ADDRNOTAVAIL);
for (i = 0; i < 1024; i++) {
in_port_t prt;
prt = ports[dispatch_uniformrandom(
DISP_ARC4CTX(disp),
nports)];
isc_sockaddr_setport(&localaddr_bound, prt);
result = open_socket(sockmgr, &localaddr_bound,
0, &sock);
if (result == ISC_R_SUCCESS ||
result != ISC_R_ADDRINUSE) {
disp->localport = prt;
*sockp = sock;
return (result);
}
}
/*
* If this fails 1024 times, we then ask the kernel for
* choosing one.
*/
} else {
/* Allow to reuse address for non-random ports. */
result = open_socket(sockmgr, localaddr,
ISC_SOCKET_REUSEADDRESS, &sock);
if (result == ISC_R_SUCCESS)
*sockp = sock;
return (result);
}
memset(held, 0, sizeof(held));
i = 0;
for (j = 0; j < 0xffffU; j++) {
result = open_socket(sockmgr, localaddr, 0, &sock);
if (result != ISC_R_SUCCESS)
goto end;
else if (!anyport)
break;
else if (portavailable(mgr, sock, NULL))
break;
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 "
"an available port",
isc_sockaddr_pf(localaddr) == AF_INET ? "4" : "6");
result = ISC_R_FAILURE;
goto end;
}
*sockp = sock;
end:
for (i = 0; i < DNS_DISPATCH_HELD; i++) {
if (held[i] != NULL)
isc_socket_detach(&held[i]);
}
return (result);
}
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;
int i = 0;
/*
* dispatch_allocate() checks mgr for us.
*/
disp = NULL;
result = dispatch_allocate(mgr, maxrequests, &disp);
if (result != ISC_R_SUCCESS)
return (result);
if ((attributes & DNS_DISPATCHATTR_EXCLUSIVE) == 0) {
result = get_udpsocket(mgr, disp, sockmgr, localaddr, &sock);
if (result != ISC_R_SUCCESS)
goto deallocate_dispatch;
} else {
isc_sockaddr_t sa_any;
/*
* For dispatches using exclusive sockets with a specific
* source address, we only check if the specified address is
* available on the system. Query sockets will be created later
* on demand.
*/
isc_sockaddr_anyofpf(&sa_any, isc_sockaddr_pf(localaddr));
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;
}
disp->port_table = isc_mem_get(mgr->mctx,
sizeof(disp->port_table[0]) *
DNS_DISPATCH_PORTTABLESIZE);
if (disp->port_table == NULL)
goto deallocate_dispatch;
for (i = 0; i < DNS_DISPATCH_PORTTABLESIZE; i++)
ISC_LIST_INIT(disp->port_table[i]);
result = isc_mempool_create(mgr->mctx, sizeof(dispportentry_t),
&disp->portpool);
if (result != ISC_R_SUCCESS)
goto deallocate_dispatch;
isc_mempool_setname(disp->portpool, "disp_portpool");
isc_mempool_setfreemax(disp->portpool, 128);
}
disp->socktype = isc_sockettype_udp;
disp->socket = sock;
disp->local = *localaddr;
if ((attributes & DNS_DISPATCHATTR_EXCLUSIVE) != 0)
disp->ntasks = MAX_INTERNAL_TASKS;
else
disp->ntasks = 1;
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));
if (disp->ctlevent == NULL) {
result = ISC_R_NOMEMORY;
goto kill_task;
}
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[0]); /* XXX */
if (disp->socket != NULL)
dispatch_log(disp, LVL(90), "created socket %p", disp->socket);
*dispp = disp;
return (result);
/*
* Error returns.
*/
kill_task:
for (i = 0; i < disp->ntasks; i++)
isc_task_detach(&disp->task[i]);
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);
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;
dispsocket_t *dispsock;
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[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 %d", 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_addresponse2(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,
isc_socketmgr_t *sockmgr)
{
dns_dispentry_t *res;
unsigned int bucket;
in_port_t localport = 0;
dns_messageid_t id;
int i;
isc_boolean_t ok;
dns_qid_t *qid;
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);
if ((disp->attributes & DNS_DISPATCHATTR_EXCLUSIVE) != 0)
REQUIRE(sockmgr != 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);
}
if ((disp->attributes & DNS_DISPATCHATTR_EXCLUSIVE) != 0 &&
disp->nsockets > DNS_DISPATCH_SOCKSQUOTA) {
dispsocket_t *oldestsocket;
dns_dispentry_t *oldestresp;
dns_dispatchevent_t *rev;
/*
* 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_event(oldestresp->disp);
if (rev != NULL) {
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 = ISC_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);
}
qid = DNS_QID(disp);
LOCK(&qid->lock);
if ((disp->attributes & DNS_DISPATCHATTR_EXCLUSIVE) != 0) {
/*
* Get a separate UDP socket with a random port number.
*/
result = get_dispsocket(disp, dest, sockmgr, qid, &dispsocket,
&localport);
if (result != ISC_R_SUCCESS) {
UNLOCK(&qid->lock);
UNLOCK(&disp->lock);
inc_stats(disp->mgr, dns_resstatscounter_dispsockfail);
return (result);
}
} else {
localport = disp->localport;
}
/*
* Try somewhat hard to find an unique ID.
*/
id = (dns_messageid_t)dispatch_random(DISP_ARC4CTX(disp));
bucket = dns_hash(qid, dest, id, localport);
ok = ISC_FALSE;
for (i = 0; i < 64; i++) {
if (entry_search(qid, dest, id, localport, bucket) == NULL) {
ok = ISC_TRUE;
break;
}
id += qid->qid_increment;
id &= 0x0000ffff;
bucket = dns_hash(qid, dest, id, localport);
}
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);
if (dispsocket != NULL)
destroy_dispsocket(disp, &dispsocket);
return (ISC_R_NOMEMORY);
}
disp->refcount++;
disp->requests++;
res->task = NULL;
isc_task_attach(task, &res->task);
res->disp = disp;
res->id = id;
res->port = localport;
res->bucket = bucket;
res->host = *dest;
res->action = action;
res->arg = arg;
res->dispsocket = dispsocket;
if (dispsocket != NULL)
dispsocket->resp = res;
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)) {
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);
disp->refcount--;
disp->requests--;
UNLOCK(&disp->lock);
isc_task_detach(&res->task);
isc_mempool_put(disp->mgr->rpool, res);
return (result);
}
}
if (dispsocket != NULL)
ISC_LIST_APPEND(disp->activesockets, dispsocket, link);
UNLOCK(&disp->lock);
*idp = id;
*resp = res;
if ((disp->attributes & DNS_DISPATCHATTR_EXCLUSIVE) != 0)
INSIST(res->dispsocket != NULL);
return (ISC_R_SUCCESS);
}
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)
{
REQUIRE(VALID_DISPATCH(disp));
REQUIRE((disp->attributes & DNS_DISPATCHATTR_EXCLUSIVE) == 0);
return (dns_dispatch_addresponse2(disp, dest, task, action, arg,
idp, resp, NULL));
}
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);
disp->attributes |= DNS_DISPATCHATTR_CONNECTED;
(void)startrecv(disp, NULL);
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;
dispsocket_t *dispsock;
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[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 == 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);
if (res->dispsocket != NULL) {
isc_socket_cancel(res->dispsocket->socket,
res->dispsocket->task, ISC_SOCKCANCEL_RECV);
res->dispsocket->resp = NULL;
}
/*
* 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
(void)startrecv(disp, NULL);
killit = destroy_disp_ok(disp);
UNLOCK(&disp->lock);
if (killit)
isc_task_send(disp->task[0], &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
* unless a specific hander 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 = 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_socket_t *
dns_dispatch_getentrysocket(dns_dispentry_t *resp) {
REQUIRE(VALID_RESPONSE(resp));
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);
}
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;
}
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));
/* Exclusive attribute can only be set on creation */
REQUIRE((attributes & DNS_DISPATCHATTR_EXCLUSIVE) == 0);
/* Also, a dispatch with randomport specified cannot start listening */
REQUIRE((disp->attributes & DNS_DISPATCHATTR_EXCLUSIVE) == 0 ||
(attributes & DNS_DISPATCHATTR_NOLISTEN) == 0);
/* 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;
(void)startrecv(disp, NULL);
} 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[0],
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_shrecv,
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[0], 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