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Diffstat (limited to 'bin/named/client.c')
| -rw-r--r-- | bin/named/client.c | 2798 |
1 files changed, 2798 insertions, 0 deletions
diff --git a/bin/named/client.c b/bin/named/client.c new file mode 100644 index 0000000..164af7c --- /dev/null +++ b/bin/named/client.c @@ -0,0 +1,2798 @@ +/* + * Copyright (C) 2004-2008 Internet Systems Consortium, Inc. ("ISC") + * Copyright (C) 1999-2003 Internet Software Consortium. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH + * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE + * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ + +/* $Id: client.c,v 1.259 2008/11/16 20:57:54 marka Exp $ */ + +#include <config.h> + +#include <isc/formatcheck.h> +#include <isc/mutex.h> +#include <isc/once.h> +#include <isc/platform.h> +#include <isc/print.h> +#include <isc/stdio.h> +#include <isc/string.h> +#include <isc/task.h> +#include <isc/timer.h> +#include <isc/util.h> + +#include <dns/db.h> +#include <dns/dispatch.h> +#include <dns/events.h> +#include <dns/message.h> +#include <dns/peer.h> +#include <dns/rcode.h> +#include <dns/rdata.h> +#include <dns/rdataclass.h> +#include <dns/rdatalist.h> +#include <dns/rdataset.h> +#include <dns/resolver.h> +#include <dns/stats.h> +#include <dns/tsig.h> +#include <dns/view.h> +#include <dns/zone.h> + +#include <named/interfacemgr.h> +#include <named/log.h> +#include <named/notify.h> +#include <named/os.h> +#include <named/server.h> +#include <named/update.h> + +/*** + *** Client + ***/ + +/*! \file + * Client Routines + * + * Important note! + * + * All client state changes, other than that from idle to listening, occur + * as a result of events. This guarantees serialization and avoids the + * need for locking. + * + * If a routine is ever created that allows someone other than the client's + * task to change the client, then the client will have to be locked. + */ + +#define NS_CLIENT_TRACE +#ifdef NS_CLIENT_TRACE +#define CTRACE(m) ns_client_log(client, \ + NS_LOGCATEGORY_CLIENT, \ + NS_LOGMODULE_CLIENT, \ + ISC_LOG_DEBUG(3), \ + "%s", (m)) +#define MTRACE(m) isc_log_write(ns_g_lctx, \ + NS_LOGCATEGORY_GENERAL, \ + NS_LOGMODULE_CLIENT, \ + ISC_LOG_DEBUG(3), \ + "clientmgr @%p: %s", manager, (m)) +#else +#define CTRACE(m) ((void)(m)) +#define MTRACE(m) ((void)(m)) +#endif + +#define TCP_CLIENT(c) (((c)->attributes & NS_CLIENTATTR_TCP) != 0) + +#define TCP_BUFFER_SIZE (65535 + 2) +#define SEND_BUFFER_SIZE 4096 +#define RECV_BUFFER_SIZE 4096 + +#ifdef ISC_PLATFORM_USETHREADS +#define NMCTXS 100 +/*%< + * Number of 'mctx pools' for clients. (Should this be configurable?) + * When enabling threads, we use a pool of memory contexts shared by + * client objects, since concurrent access to a shared context would cause + * heavy contentions. The above constant is expected to be enough for + * completely avoiding contentions among threads for an authoritative-only + * server. + */ +#else +#define NMCTXS 0 +/*%< + * If named with built without thread, simply share manager's context. Using + * a separate context in this case would simply waste memory. + */ +#endif + +/*% nameserver client manager structure */ +struct ns_clientmgr { + /* Unlocked. */ + unsigned int magic; + isc_mem_t * mctx; + isc_taskmgr_t * taskmgr; + isc_timermgr_t * timermgr; + isc_mutex_t lock; + /* Locked by lock. */ + isc_boolean_t exiting; + client_list_t active; /*%< Active clients */ + client_list_t recursing; /*%< Recursing clients */ + client_list_t inactive; /*%< To be recycled */ +#if NMCTXS > 0 + /*%< mctx pool for clients. */ + unsigned int nextmctx; + isc_mem_t * mctxpool[NMCTXS]; +#endif +}; + +#define MANAGER_MAGIC ISC_MAGIC('N', 'S', 'C', 'm') +#define VALID_MANAGER(m) ISC_MAGIC_VALID(m, MANAGER_MAGIC) + +/*! + * Client object states. Ordering is significant: higher-numbered + * states are generally "more active", meaning that the client can + * have more dynamically allocated data, outstanding events, etc. + * In the list below, any such properties listed for state N + * also apply to any state > N. + * + * To force the client into a less active state, set client->newstate + * to that state and call exit_check(). This will cause any + * activities defined for higher-numbered states to be aborted. + */ + +#define NS_CLIENTSTATE_FREED 0 +/*%< + * The client object no longer exists. + */ + +#define NS_CLIENTSTATE_INACTIVE 1 +/*%< + * The client object exists and has a task and timer. + * Its "query" struct and sendbuf are initialized. + * It is on the client manager's list of inactive clients. + * It has a message and OPT, both in the reset state. + */ + +#define NS_CLIENTSTATE_READY 2 +/*%< + * The client object is either a TCP or a UDP one, and + * it is associated with a network interface. It is on the + * client manager's list of active clients. + * + * If it is a TCP client object, it has a TCP listener socket + * and an outstanding TCP listen request. + * + * If it is a UDP client object, it has a UDP listener socket + * and an outstanding UDP receive request. + */ + +#define NS_CLIENTSTATE_READING 3 +/*%< + * The client object is a TCP client object that has received + * a connection. It has a tcpsocket, tcpmsg, TCP quota, and an + * outstanding TCP read request. This state is not used for + * UDP client objects. + */ + +#define NS_CLIENTSTATE_WORKING 4 +/*%< + * The client object has received a request and is working + * on it. It has a view, and it may have any of a non-reset OPT, + * recursion quota, and an outstanding write request. + */ + +#define NS_CLIENTSTATE_MAX 9 +/*%< + * Sentinel value used to indicate "no state". When client->newstate + * has this value, we are not attempting to exit the current state. + * Must be greater than any valid state. + */ + +/* + * Enable ns_client_dropport() by default. + */ +#ifndef NS_CLIENT_DROPPORT +#define NS_CLIENT_DROPPORT 1 +#endif + +unsigned int ns_client_requests; + +static void client_read(ns_client_t *client); +static void client_accept(ns_client_t *client); +static void client_udprecv(ns_client_t *client); +static void clientmgr_destroy(ns_clientmgr_t *manager); +static isc_boolean_t exit_check(ns_client_t *client); +static void ns_client_endrequest(ns_client_t *client); +static void ns_client_checkactive(ns_client_t *client); +static void client_start(isc_task_t *task, isc_event_t *event); +static void client_request(isc_task_t *task, isc_event_t *event); +static void ns_client_dumpmessage(ns_client_t *client, const char *reason); + +void +ns_client_recursing(ns_client_t *client) { + REQUIRE(NS_CLIENT_VALID(client)); + + LOCK(&client->manager->lock); + ISC_LIST_UNLINK(*client->list, client, link); + ISC_LIST_APPEND(client->manager->recursing, client, link); + client->list = &client->manager->recursing; + UNLOCK(&client->manager->lock); +} + +void +ns_client_killoldestquery(ns_client_t *client) { + ns_client_t *oldest; + REQUIRE(NS_CLIENT_VALID(client)); + + LOCK(&client->manager->lock); + oldest = ISC_LIST_HEAD(client->manager->recursing); + if (oldest != NULL) { + ns_query_cancel(oldest); + ISC_LIST_UNLINK(*oldest->list, oldest, link); + ISC_LIST_APPEND(client->manager->active, oldest, link); + oldest->list = &client->manager->active; + } + UNLOCK(&client->manager->lock); +} + +void +ns_client_settimeout(ns_client_t *client, unsigned int seconds) { + isc_result_t result; + isc_interval_t interval; + + isc_interval_set(&interval, seconds, 0); + result = isc_timer_reset(client->timer, isc_timertype_once, NULL, + &interval, ISC_FALSE); + client->timerset = ISC_TRUE; + if (result != ISC_R_SUCCESS) { + ns_client_log(client, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, ISC_LOG_ERROR, + "setting timeout: %s", + isc_result_totext(result)); + /* Continue anyway. */ + } +} + +/*% + * Check for a deactivation or shutdown request and take appropriate + * action. Returns ISC_TRUE if either is in progress; in this case + * the caller must no longer use the client object as it may have been + * freed. + */ +static isc_boolean_t +exit_check(ns_client_t *client) { + ns_clientmgr_t *locked_manager = NULL; + ns_clientmgr_t *destroy_manager = NULL; + + REQUIRE(NS_CLIENT_VALID(client)); + + if (client->state <= client->newstate) + return (ISC_FALSE); /* Business as usual. */ + + INSIST(client->newstate < NS_CLIENTSTATE_WORKING); + + /* + * We need to detach from the view early when shutting down + * the server to break the following vicious circle: + * + * - The resolver will not shut down until the view refcount is zero + * - The view refcount does not go to zero until all clients detach + * - The client does not detach from the view until references is zero + * - references does not go to zero until the resolver has shut down + * + * Keep the view attached until any outstanding updates complete. + */ + if (client->nupdates == 0 && + client->newstate == NS_CLIENTSTATE_FREED && client->view != NULL) + dns_view_detach(&client->view); + + if (client->state == NS_CLIENTSTATE_WORKING) { + INSIST(client->newstate <= NS_CLIENTSTATE_READING); + /* + * Let the update processing complete. + */ + if (client->nupdates > 0) + return (ISC_TRUE); + /* + * We are trying to abort request processing. + */ + if (client->nsends > 0) { + isc_socket_t *socket; + if (TCP_CLIENT(client)) + socket = client->tcpsocket; + else + socket = client->udpsocket; + isc_socket_cancel(socket, client->task, + ISC_SOCKCANCEL_SEND); + } + + if (! (client->nsends == 0 && client->nrecvs == 0 && + client->references == 0)) + { + /* + * Still waiting for I/O cancel completion. + * or lingering references. + */ + return (ISC_TRUE); + } + /* + * I/O cancel is complete. Burn down all state + * related to the current request. Ensure that + * the client is on the active list and not the + * recursing list. + */ + LOCK(&client->manager->lock); + if (client->list == &client->manager->recursing) { + ISC_LIST_UNLINK(*client->list, client, link); + ISC_LIST_APPEND(client->manager->active, client, link); + client->list = &client->manager->active; + } + UNLOCK(&client->manager->lock); + ns_client_endrequest(client); + + client->state = NS_CLIENTSTATE_READING; + INSIST(client->recursionquota == NULL); + if (NS_CLIENTSTATE_READING == client->newstate) { + client_read(client); + client->newstate = NS_CLIENTSTATE_MAX; + return (ISC_TRUE); /* We're done. */ + } + } + + if (client->state == NS_CLIENTSTATE_READING) { + /* + * We are trying to abort the current TCP connection, + * if any. + */ + INSIST(client->recursionquota == NULL); + INSIST(client->newstate <= NS_CLIENTSTATE_READY); + if (client->nreads > 0) + dns_tcpmsg_cancelread(&client->tcpmsg); + if (! client->nreads == 0) { + /* Still waiting for read cancel completion. */ + return (ISC_TRUE); + } + + if (client->tcpmsg_valid) { + dns_tcpmsg_invalidate(&client->tcpmsg); + client->tcpmsg_valid = ISC_FALSE; + } + if (client->tcpsocket != NULL) { + CTRACE("closetcp"); + isc_socket_detach(&client->tcpsocket); + } + + if (client->tcpquota != NULL) + isc_quota_detach(&client->tcpquota); + + if (client->timerset) { + (void)isc_timer_reset(client->timer, + isc_timertype_inactive, + NULL, NULL, ISC_TRUE); + client->timerset = ISC_FALSE; + } + + client->peeraddr_valid = ISC_FALSE; + + client->state = NS_CLIENTSTATE_READY; + INSIST(client->recursionquota == NULL); + + /* + * Now the client is ready to accept a new TCP connection + * or UDP request, but we may have enough clients doing + * that already. Check whether this client needs to remain + * active and force it to go inactive if not. + */ + ns_client_checkactive(client); + + if (NS_CLIENTSTATE_READY == client->newstate) { + if (TCP_CLIENT(client)) { + client_accept(client); + } else + client_udprecv(client); + client->newstate = NS_CLIENTSTATE_MAX; + return (ISC_TRUE); + } + } + + if (client->state == NS_CLIENTSTATE_READY) { + INSIST(client->newstate <= NS_CLIENTSTATE_INACTIVE); + /* + * We are trying to enter the inactive state. + */ + if (client->naccepts > 0) + isc_socket_cancel(client->tcplistener, client->task, + ISC_SOCKCANCEL_ACCEPT); + + if (! (client->naccepts == 0)) { + /* Still waiting for accept cancel completion. */ + return (ISC_TRUE); + } + /* Accept cancel is complete. */ + + if (client->nrecvs > 0) + isc_socket_cancel(client->udpsocket, client->task, + ISC_SOCKCANCEL_RECV); + if (! (client->nrecvs == 0)) { + /* Still waiting for recv cancel completion. */ + return (ISC_TRUE); + } + /* Recv cancel is complete. */ + + if (client->nctls > 0) { + /* Still waiting for control event to be delivered */ + return (ISC_TRUE); + } + + /* Deactivate the client. */ + if (client->interface) + ns_interface_detach(&client->interface); + + INSIST(client->naccepts == 0); + INSIST(client->recursionquota == NULL); + if (client->tcplistener != NULL) + isc_socket_detach(&client->tcplistener); + + if (client->udpsocket != NULL) + isc_socket_detach(&client->udpsocket); + + if (client->dispatch != NULL) + dns_dispatch_detach(&client->dispatch); + + client->attributes = 0; + client->mortal = ISC_FALSE; + + LOCK(&client->manager->lock); + /* + * Put the client on the inactive list. If we are aiming for + * the "freed" state, it will be removed from the inactive + * list shortly, and we need to keep the manager locked until + * that has been done, lest the manager decide to reactivate + * the dying client inbetween. + */ + locked_manager = client->manager; + ISC_LIST_UNLINK(*client->list, client, link); + ISC_LIST_APPEND(client->manager->inactive, client, link); + client->list = &client->manager->inactive; + client->state = NS_CLIENTSTATE_INACTIVE; + INSIST(client->recursionquota == NULL); + + if (client->state == client->newstate) { + client->newstate = NS_CLIENTSTATE_MAX; + if (client->needshutdown) + isc_task_shutdown(client->task); + goto unlock; + } + } + + if (client->state == NS_CLIENTSTATE_INACTIVE) { + INSIST(client->newstate == NS_CLIENTSTATE_FREED); + /* + * We are trying to free the client. + * + * When "shuttingdown" is true, either the task has received + * its shutdown event or no shutdown event has ever been + * set up. Thus, we have no outstanding shutdown + * event at this point. + */ + REQUIRE(client->state == NS_CLIENTSTATE_INACTIVE); + + INSIST(client->recursionquota == NULL); + + ns_query_free(client); + isc_mem_put(client->mctx, client->recvbuf, RECV_BUFFER_SIZE); + isc_event_free((isc_event_t **)&client->sendevent); + isc_event_free((isc_event_t **)&client->recvevent); + isc_timer_detach(&client->timer); + + if (client->tcpbuf != NULL) + isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE); + if (client->opt != NULL) { + INSIST(dns_rdataset_isassociated(client->opt)); + dns_rdataset_disassociate(client->opt); + dns_message_puttemprdataset(client->message, &client->opt); + } + dns_message_destroy(&client->message); + if (client->manager != NULL) { + ns_clientmgr_t *manager = client->manager; + if (locked_manager == NULL) { + LOCK(&manager->lock); + locked_manager = manager; + } + ISC_LIST_UNLINK(*client->list, client, link); + client->list = NULL; + if (manager->exiting && + ISC_LIST_EMPTY(manager->active) && + ISC_LIST_EMPTY(manager->inactive) && + ISC_LIST_EMPTY(manager->recursing)) + destroy_manager = manager; + } + /* + * Detaching the task must be done after unlinking from + * the manager's lists because the manager accesses + * client->task. + */ + if (client->task != NULL) + isc_task_detach(&client->task); + + CTRACE("free"); + client->magic = 0; + /* + * Check that there are no other external references to + * the memory context. + */ + if (ns_g_clienttest && isc_mem_references(client->mctx) != 1) { + isc_mem_stats(client->mctx, stderr); + INSIST(0); + } + isc_mem_putanddetach(&client->mctx, client, sizeof(*client)); + + goto unlock; + } + + unlock: + if (locked_manager != NULL) { + UNLOCK(&locked_manager->lock); + locked_manager = NULL; + } + + /* + * Only now is it safe to destroy the client manager (if needed), + * because we have accessed its lock for the last time. + */ + if (destroy_manager != NULL) + clientmgr_destroy(destroy_manager); + + return (ISC_TRUE); +} + +/*% + * The client's task has received the client's control event + * as part of the startup process. + */ +static void +client_start(isc_task_t *task, isc_event_t *event) { + ns_client_t *client = (ns_client_t *) event->ev_arg; + + INSIST(task == client->task); + + UNUSED(task); + + INSIST(client->nctls == 1); + client->nctls--; + + if (exit_check(client)) + return; + + if (TCP_CLIENT(client)) { + client_accept(client); + } else { + client_udprecv(client); + } +} + + +/*% + * The client's task has received a shutdown event. + */ +static void +client_shutdown(isc_task_t *task, isc_event_t *event) { + ns_client_t *client; + + REQUIRE(event != NULL); + REQUIRE(event->ev_type == ISC_TASKEVENT_SHUTDOWN); + client = event->ev_arg; + REQUIRE(NS_CLIENT_VALID(client)); + REQUIRE(task == client->task); + + UNUSED(task); + + CTRACE("shutdown"); + + isc_event_free(&event); + + if (client->shutdown != NULL) { + (client->shutdown)(client->shutdown_arg, ISC_R_SHUTTINGDOWN); + client->shutdown = NULL; + client->shutdown_arg = NULL; + } + + client->newstate = NS_CLIENTSTATE_FREED; + client->needshutdown = ISC_FALSE; + (void)exit_check(client); +} + +static void +ns_client_endrequest(ns_client_t *client) { + INSIST(client->naccepts == 0); + INSIST(client->nreads == 0); + INSIST(client->nsends == 0); + INSIST(client->nrecvs == 0); + INSIST(client->nupdates == 0); + INSIST(client->state == NS_CLIENTSTATE_WORKING); + + CTRACE("endrequest"); + + if (client->next != NULL) { + (client->next)(client); + client->next = NULL; + } + + if (client->view != NULL) + dns_view_detach(&client->view); + if (client->opt != NULL) { + INSIST(dns_rdataset_isassociated(client->opt)); + dns_rdataset_disassociate(client->opt); + dns_message_puttemprdataset(client->message, &client->opt); + } + + client->udpsize = 512; + client->extflags = 0; + client->ednsversion = -1; + dns_message_reset(client->message, DNS_MESSAGE_INTENTPARSE); + + if (client->recursionquota != NULL) + isc_quota_detach(&client->recursionquota); + + /* + * Clear all client attributes that are specific to + * the request; that's all except the TCP flag. + */ + client->attributes &= NS_CLIENTATTR_TCP; +} + +static void +ns_client_checkactive(ns_client_t *client) { + if (client->mortal) { + /* + * This client object should normally go inactive + * at this point, but if we have fewer active client + * objects than desired due to earlier quota exhaustion, + * keep it active to make up for the shortage. + */ + isc_boolean_t need_another_client = ISC_FALSE; + if (TCP_CLIENT(client) && !ns_g_clienttest) { + LOCK(&client->interface->lock); + if (client->interface->ntcpcurrent < + client->interface->ntcptarget) + need_another_client = ISC_TRUE; + UNLOCK(&client->interface->lock); + } else { + /* + * The UDP client quota is enforced by making + * requests fail rather than by not listening + * for new ones. Therefore, there is always a + * full set of UDP clients listening. + */ + } + if (! need_another_client) { + /* + * We don't need this client object. Recycle it. + */ + if (client->newstate >= NS_CLIENTSTATE_INACTIVE) + client->newstate = NS_CLIENTSTATE_INACTIVE; + } + } +} + +void +ns_client_next(ns_client_t *client, isc_result_t result) { + int newstate; + + REQUIRE(NS_CLIENT_VALID(client)); + REQUIRE(client->state == NS_CLIENTSTATE_WORKING || + client->state == NS_CLIENTSTATE_READING); + + CTRACE("next"); + + if (result != ISC_R_SUCCESS) + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3), + "request failed: %s", isc_result_totext(result)); + + /* + * An error processing a TCP request may have left + * the connection out of sync. To be safe, we always + * sever the connection when result != ISC_R_SUCCESS. + */ + if (result == ISC_R_SUCCESS && TCP_CLIENT(client)) + newstate = NS_CLIENTSTATE_READING; + else + newstate = NS_CLIENTSTATE_READY; + + if (client->newstate > newstate) + client->newstate = newstate; + (void)exit_check(client); +} + + +static void +client_senddone(isc_task_t *task, isc_event_t *event) { + ns_client_t *client; + isc_socketevent_t *sevent = (isc_socketevent_t *) event; + + REQUIRE(sevent != NULL); + REQUIRE(sevent->ev_type == ISC_SOCKEVENT_SENDDONE); + client = sevent->ev_arg; + REQUIRE(NS_CLIENT_VALID(client)); + REQUIRE(task == client->task); + REQUIRE(sevent == client->sendevent); + + UNUSED(task); + + CTRACE("senddone"); + + if (sevent->result != ISC_R_SUCCESS) + ns_client_log(client, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, ISC_LOG_WARNING, + "error sending response: %s", + isc_result_totext(sevent->result)); + + INSIST(client->nsends > 0); + client->nsends--; + + if (client->tcpbuf != NULL) { + INSIST(TCP_CLIENT(client)); + isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE); + client->tcpbuf = NULL; + } + + if (exit_check(client)) + return; + + ns_client_next(client, ISC_R_SUCCESS); +} + +/*% + * We only want to fail with ISC_R_NOSPACE when called from + * ns_client_sendraw() and not when called from ns_client_send(), + * tcpbuffer is NULL when called from ns_client_sendraw() and + * length != 0. tcpbuffer != NULL when called from ns_client_send() + * and length == 0. + */ + +static isc_result_t +client_allocsendbuf(ns_client_t *client, isc_buffer_t *buffer, + isc_buffer_t *tcpbuffer, isc_uint32_t length, + unsigned char *sendbuf, unsigned char **datap) +{ + unsigned char *data; + isc_uint32_t bufsize; + isc_result_t result; + + INSIST(datap != NULL); + INSIST((tcpbuffer == NULL && length != 0) || + (tcpbuffer != NULL && length == 0)); + + if (TCP_CLIENT(client)) { + INSIST(client->tcpbuf == NULL); + if (length + 2 > TCP_BUFFER_SIZE) { + result = ISC_R_NOSPACE; + goto done; + } + client->tcpbuf = isc_mem_get(client->mctx, TCP_BUFFER_SIZE); + if (client->tcpbuf == NULL) { + result = ISC_R_NOMEMORY; + goto done; + } + data = client->tcpbuf; + if (tcpbuffer != NULL) { + isc_buffer_init(tcpbuffer, data, TCP_BUFFER_SIZE); + isc_buffer_init(buffer, data + 2, TCP_BUFFER_SIZE - 2); + } else { + isc_buffer_init(buffer, data, TCP_BUFFER_SIZE); + INSIST(length <= 0xffff); + isc_buffer_putuint16(buffer, (isc_uint16_t)length); + } + } else { + data = sendbuf; + if (client->udpsize < SEND_BUFFER_SIZE) + bufsize = client->udpsize; + else + bufsize = SEND_BUFFER_SIZE; + if (length > bufsize) { + result = ISC_R_NOSPACE; + goto done; + } + isc_buffer_init(buffer, data, bufsize); + } + *datap = data; + result = ISC_R_SUCCESS; + + done: + return (result); +} + +static isc_result_t +client_sendpkg(ns_client_t *client, isc_buffer_t *buffer) { + struct in6_pktinfo *pktinfo; + isc_result_t result; + isc_region_t r; + isc_sockaddr_t *address; + isc_socket_t *socket; + isc_netaddr_t netaddr; + int match; + unsigned int sockflags = ISC_SOCKFLAG_IMMEDIATE; + + if (TCP_CLIENT(client)) { + socket = client->tcpsocket; + address = NULL; + } else { + socket = client->udpsocket; + address = &client->peeraddr; + + isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr); + if (ns_g_server->blackholeacl != NULL && + dns_acl_match(&netaddr, NULL, + ns_g_server->blackholeacl, + &ns_g_server->aclenv, + &match, NULL) == ISC_R_SUCCESS && + match > 0) + return (DNS_R_BLACKHOLED); + sockflags |= ISC_SOCKFLAG_NORETRY; + } + + if ((client->attributes & NS_CLIENTATTR_PKTINFO) != 0 && + (client->attributes & NS_CLIENTATTR_MULTICAST) == 0) + pktinfo = &client->pktinfo; + else + pktinfo = NULL; + + isc_buffer_usedregion(buffer, &r); + + CTRACE("sendto"); + + result = isc_socket_sendto2(socket, &r, client->task, + address, pktinfo, + client->sendevent, sockflags); + if (result == ISC_R_SUCCESS || result == ISC_R_INPROGRESS) { + client->nsends++; + if (result == ISC_R_SUCCESS) + client_senddone(client->task, + (isc_event_t *)client->sendevent); + result = ISC_R_SUCCESS; + } + return (result); +} + +void +ns_client_sendraw(ns_client_t *client, dns_message_t *message) { + isc_result_t result; + unsigned char *data; + isc_buffer_t buffer; + isc_region_t r; + isc_region_t *mr; + unsigned char sendbuf[SEND_BUFFER_SIZE]; + + REQUIRE(NS_CLIENT_VALID(client)); + + CTRACE("sendraw"); + + mr = dns_message_getrawmessage(message); + if (mr == NULL) { + result = ISC_R_UNEXPECTEDEND; + goto done; + } + + result = client_allocsendbuf(client, &buffer, NULL, mr->length, + sendbuf, &data); + if (result != ISC_R_SUCCESS) + goto done; + + /* + * Copy message to buffer and fixup id. + */ + isc_buffer_availableregion(&buffer, &r); + result = isc_buffer_copyregion(&buffer, mr); + if (result != ISC_R_SUCCESS) + goto done; + r.base[0] = (client->message->id >> 8) & 0xff; + r.base[1] = client->message->id & 0xff; + + result = client_sendpkg(client, &buffer); + if (result == ISC_R_SUCCESS) + return; + + done: + if (client->tcpbuf != NULL) { + isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE); + client->tcpbuf = NULL; + } + ns_client_next(client, result); +} + +void +ns_client_send(ns_client_t *client) { + isc_result_t result; + unsigned char *data; + isc_buffer_t buffer; + isc_buffer_t tcpbuffer; + isc_region_t r; + dns_compress_t cctx; + isc_boolean_t cleanup_cctx = ISC_FALSE; + unsigned char sendbuf[SEND_BUFFER_SIZE]; + unsigned int dnssec_opts; + unsigned int preferred_glue; + isc_boolean_t opt_included = ISC_FALSE; + + REQUIRE(NS_CLIENT_VALID(client)); + + CTRACE("send"); + + if ((client->attributes & NS_CLIENTATTR_RA) != 0) + client->message->flags |= DNS_MESSAGEFLAG_RA; + + if ((client->attributes & NS_CLIENTATTR_WANTDNSSEC) != 0) + dnssec_opts = 0; + else + dnssec_opts = DNS_MESSAGERENDER_OMITDNSSEC; + + preferred_glue = 0; + if (client->view != NULL) { + if (client->view->preferred_glue == dns_rdatatype_a) + preferred_glue = DNS_MESSAGERENDER_PREFER_A; + else if (client->view->preferred_glue == dns_rdatatype_aaaa) + preferred_glue = DNS_MESSAGERENDER_PREFER_AAAA; + } + + /* + * XXXRTH The following doesn't deal with TCP buffer resizing. + */ + result = client_allocsendbuf(client, &buffer, &tcpbuffer, 0, + sendbuf, &data); + if (result != ISC_R_SUCCESS) + goto done; + + result = dns_compress_init(&cctx, -1, client->mctx); + if (result != ISC_R_SUCCESS) + goto done; + cleanup_cctx = ISC_TRUE; + + result = dns_message_renderbegin(client->message, &cctx, &buffer); + if (result != ISC_R_SUCCESS) + goto done; + + if (client->opt != NULL) { + result = dns_message_setopt(client->message, client->opt); + opt_included = ISC_TRUE; + client->opt = NULL; + if (result != ISC_R_SUCCESS) + goto done; + } + result = dns_message_rendersection(client->message, + DNS_SECTION_QUESTION, 0); + if (result == ISC_R_NOSPACE) { + client->message->flags |= DNS_MESSAGEFLAG_TC; + goto renderend; + } + if (result != ISC_R_SUCCESS) + goto done; + result = dns_message_rendersection(client->message, + DNS_SECTION_ANSWER, + DNS_MESSAGERENDER_PARTIAL | + dnssec_opts); + if (result == ISC_R_NOSPACE) { + client->message->flags |= DNS_MESSAGEFLAG_TC; + goto renderend; + } + if (result != ISC_R_SUCCESS) + goto done; + result = dns_message_rendersection(client->message, + DNS_SECTION_AUTHORITY, + DNS_MESSAGERENDER_PARTIAL | + dnssec_opts); + if (result == ISC_R_NOSPACE) { + client->message->flags |= DNS_MESSAGEFLAG_TC; + goto renderend; + } + if (result != ISC_R_SUCCESS) + goto done; + result = dns_message_rendersection(client->message, + DNS_SECTION_ADDITIONAL, + preferred_glue | dnssec_opts); + if (result != ISC_R_SUCCESS && result != ISC_R_NOSPACE) + goto done; + renderend: + result = dns_message_renderend(client->message); + + if (result != ISC_R_SUCCESS) + goto done; + + if (cleanup_cctx) { + dns_compress_invalidate(&cctx); + cleanup_cctx = ISC_FALSE; + } + + if (TCP_CLIENT(client)) { + isc_buffer_usedregion(&buffer, &r); + isc_buffer_putuint16(&tcpbuffer, (isc_uint16_t) r.length); + isc_buffer_add(&tcpbuffer, r.length); + result = client_sendpkg(client, &tcpbuffer); + } else + result = client_sendpkg(client, &buffer); + + /* update statistics (XXXJT: is it okay to access message->xxxkey?) */ + dns_generalstats_increment(ns_g_server->nsstats, + dns_nsstatscounter_response); + if (opt_included) { + dns_generalstats_increment(ns_g_server->nsstats, + dns_nsstatscounter_edns0out); + } + if (client->message->tsigkey != NULL) { + dns_generalstats_increment(ns_g_server->nsstats, + dns_nsstatscounter_tsigout); + } + if (client->message->sig0key != NULL) { + dns_generalstats_increment(ns_g_server->nsstats, + dns_nsstatscounter_sig0out); + } + if ((client->message->flags & DNS_MESSAGEFLAG_TC) != 0) + dns_generalstats_increment(ns_g_server->nsstats, + dns_nsstatscounter_truncatedresp); + + if (result == ISC_R_SUCCESS) + return; + + done: + if (client->tcpbuf != NULL) { + isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE); + client->tcpbuf = NULL; + } + + if (cleanup_cctx) + dns_compress_invalidate(&cctx); + + ns_client_next(client, result); +} + +#if NS_CLIENT_DROPPORT +#define DROPPORT_NO 0 +#define DROPPORT_REQUEST 1 +#define DROPPORT_RESPONSE 2 +/*% + * ns_client_dropport determines if certain requests / responses + * should be dropped based on the port number. + * + * Returns: + * \li 0: Don't drop. + * \li 1: Drop request. + * \li 2: Drop (error) response. + */ +static int +ns_client_dropport(in_port_t port) { + switch (port) { + case 7: /* echo */ + case 13: /* daytime */ + case 19: /* chargen */ + case 37: /* time */ + return (DROPPORT_REQUEST); + case 464: /* kpasswd */ + return (DROPPORT_RESPONSE); + } + return (DROPPORT_NO); +} +#endif + +void +ns_client_error(ns_client_t *client, isc_result_t result) { + dns_rcode_t rcode; + dns_message_t *message; + + REQUIRE(NS_CLIENT_VALID(client)); + + CTRACE("error"); + + message = client->message; + rcode = dns_result_torcode(result); + +#if NS_CLIENT_DROPPORT + /* + * Don't send FORMERR to ports on the drop port list. + */ + if (rcode == dns_rcode_formerr && + ns_client_dropport(isc_sockaddr_getport(&client->peeraddr)) != + DROPPORT_NO) { + char buf[64]; + isc_buffer_t b; + + isc_buffer_init(&b, buf, sizeof(buf) - 1); + if (dns_rcode_totext(rcode, &b) != ISC_R_SUCCESS) + isc_buffer_putstr(&b, "UNKNOWN RCODE"); + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10), + "dropped error (%.*s) response: suspicious port", + (int)isc_buffer_usedlength(&b), buf); + ns_client_next(client, ISC_R_SUCCESS); + return; + } +#endif + + /* + * Message may be an in-progress reply that we had trouble + * with, in which case QR will be set. We need to clear QR before + * calling dns_message_reply() to avoid triggering an assertion. + */ + message->flags &= ~DNS_MESSAGEFLAG_QR; + /* + * AA and AD shouldn't be set. + */ + message->flags &= ~(DNS_MESSAGEFLAG_AA | DNS_MESSAGEFLAG_AD); + result = dns_message_reply(message, ISC_TRUE); + if (result != ISC_R_SUCCESS) { + /* + * It could be that we've got a query with a good header, + * but a bad question section, so we try again with + * want_question_section set to ISC_FALSE. + */ + result = dns_message_reply(message, ISC_FALSE); + if (result != ISC_R_SUCCESS) { + ns_client_next(client, result); + return; + } + } + message->rcode = rcode; + + /* + * FORMERR loop avoidance: If we sent a FORMERR message + * with the same ID to the same client less than two + * seconds ago, assume that we are in an infinite error + * packet dialog with a server for some protocol whose + * error responses look enough like DNS queries to + * elicit a FORMERR response. Drop a packet to break + * the loop. + */ + if (rcode == dns_rcode_formerr) { + if (isc_sockaddr_equal(&client->peeraddr, + &client->formerrcache.addr) && + message->id == client->formerrcache.id && + client->requesttime - client->formerrcache.time < 2) { + /* Drop packet. */ + ns_client_log(client, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1), + "possible error packet loop, " + "FORMERR dropped"); + ns_client_next(client, result); + return; + } + client->formerrcache.addr = client->peeraddr; + client->formerrcache.time = client->requesttime; + client->formerrcache.id = message->id; + } + ns_client_send(client); +} + +static inline isc_result_t +client_addopt(ns_client_t *client) { + dns_rdataset_t *rdataset; + dns_rdatalist_t *rdatalist; + dns_rdata_t *rdata; + isc_result_t result; + dns_view_t *view; + dns_resolver_t *resolver; + isc_uint16_t udpsize; + + REQUIRE(client->opt == NULL); /* XXXRTH free old. */ + + rdatalist = NULL; + result = dns_message_gettemprdatalist(client->message, &rdatalist); + if (result != ISC_R_SUCCESS) + return (result); + rdata = NULL; + result = dns_message_gettemprdata(client->message, &rdata); + if (result != ISC_R_SUCCESS) + return (result); + rdataset = NULL; + result = dns_message_gettemprdataset(client->message, &rdataset); + if (result != ISC_R_SUCCESS) + return (result); + dns_rdataset_init(rdataset); + + rdatalist->type = dns_rdatatype_opt; + rdatalist->covers = 0; + + /* + * Set the maximum UDP buffer size. + */ + view = client->view; + resolver = (view != NULL) ? view->resolver : NULL; + if (resolver != NULL) + udpsize = dns_resolver_getudpsize(resolver); + else + udpsize = ns_g_udpsize; + rdatalist->rdclass = udpsize; + + /* + * Set EXTENDED-RCODE, VERSION and Z to 0. + */ + rdatalist->ttl = (client->extflags & DNS_MESSAGEEXTFLAG_REPLYPRESERVE); + + /* Set EDNS options if applicable */ + if (client->attributes & NS_CLIENTATTR_WANTNSID && + (ns_g_server->server_id != NULL || + ns_g_server->server_usehostname)) { + /* + * Space required for NSID data: + * 2 bytes for opt code + * + 2 bytes for NSID length + * + NSID itself + */ + char nsid[BUFSIZ], *nsidp; + isc_buffer_t *buffer = NULL; + + if (ns_g_server->server_usehostname) { + isc_result_t result; + result = ns_os_gethostname(nsid, sizeof(nsid)); + if (result != ISC_R_SUCCESS) { + goto no_nsid; + } + nsidp = nsid; + } else + nsidp = ns_g_server->server_id; + + rdata->length = strlen(nsidp) + 4; + result = isc_buffer_allocate(client->mctx, &buffer, + rdata->length); + if (result != ISC_R_SUCCESS) + goto no_nsid; + + isc_buffer_putuint16(buffer, DNS_OPT_NSID); + isc_buffer_putuint16(buffer, strlen(nsidp)); + isc_buffer_putstr(buffer, nsidp); + rdata->data = buffer->base; + dns_message_takebuffer(client->message, &buffer); + } else { +no_nsid: + rdata->data = NULL; + rdata->length = 0; + } + + rdata->rdclass = rdatalist->rdclass; + rdata->type = rdatalist->type; + rdata->flags = 0; + + ISC_LIST_INIT(rdatalist->rdata); + ISC_LIST_APPEND(rdatalist->rdata, rdata, link); + RUNTIME_CHECK(dns_rdatalist_tordataset(rdatalist, rdataset) + == ISC_R_SUCCESS); + + client->opt = rdataset; + + return (ISC_R_SUCCESS); +} + +static inline isc_boolean_t +allowed(isc_netaddr_t *addr, dns_name_t *signer, dns_acl_t *acl) { + int match; + isc_result_t result; + + if (acl == NULL) + return (ISC_TRUE); + result = dns_acl_match(addr, signer, acl, &ns_g_server->aclenv, + &match, NULL); + if (result == ISC_R_SUCCESS && match > 0) + return (ISC_TRUE); + return (ISC_FALSE); +} + +/* + * Callback to see if a non-recursive query coming from 'srcaddr' to + * 'destaddr', with optional key 'mykey' for class 'rdclass' would be + * delivered to 'myview'. + * + * We run this unlocked as both the view list and the interface list + * are updated when the approprite task has exclusivity. + */ +isc_boolean_t +ns_client_isself(dns_view_t *myview, dns_tsigkey_t *mykey, + isc_sockaddr_t *srcaddr, isc_sockaddr_t *dstaddr, + dns_rdataclass_t rdclass, void *arg) +{ + dns_view_t *view; + dns_tsigkey_t *key = NULL; + dns_name_t *tsig = NULL; + isc_netaddr_t netsrc; + isc_netaddr_t netdst; + + UNUSED(arg); + + if (!ns_interfacemgr_listeningon(ns_g_server->interfacemgr, dstaddr)) + return (ISC_FALSE); + + isc_netaddr_fromsockaddr(&netsrc, srcaddr); + isc_netaddr_fromsockaddr(&netdst, dstaddr); + + for (view = ISC_LIST_HEAD(ns_g_server->viewlist); + view != NULL; + view = ISC_LIST_NEXT(view, link)) { + + if (view->matchrecursiveonly) + continue; + + if (rdclass != view->rdclass) + continue; + + if (mykey != NULL) { + isc_boolean_t match; + isc_result_t result; + + result = dns_view_gettsig(view, &mykey->name, &key); + if (result != ISC_R_SUCCESS) + continue; + match = dst_key_compare(mykey->key, key->key); + dns_tsigkey_detach(&key); + if (!match) + continue; + tsig = dns_tsigkey_identity(mykey); + } + + if (allowed(&netsrc, tsig, view->matchclients) && + allowed(&netdst, tsig, view->matchdestinations)) + break; + } + return (ISC_TF(view == myview)); +} + +/* + * Handle an incoming request event from the socket (UDP case) + * or tcpmsg (TCP case). + */ +static void +client_request(isc_task_t *task, isc_event_t *event) { + ns_client_t *client; + isc_socketevent_t *sevent; + isc_result_t result; + isc_result_t sigresult = ISC_R_SUCCESS; + isc_buffer_t *buffer; + isc_buffer_t tbuffer; + dns_view_t *view; + dns_rdataset_t *opt; + dns_name_t *signame; + isc_boolean_t ra; /* Recursion available. */ + isc_netaddr_t netaddr; + isc_netaddr_t destaddr; + int match; + dns_messageid_t id; + unsigned int flags; + isc_boolean_t notimp; + dns_rdata_t rdata; + isc_uint16_t optcode; + + REQUIRE(event != NULL); + client = event->ev_arg; + REQUIRE(NS_CLIENT_VALID(client)); + REQUIRE(task == client->task); + + INSIST(client->recursionquota == NULL); + + INSIST(client->state == + TCP_CLIENT(client) ? + NS_CLIENTSTATE_READING : + NS_CLIENTSTATE_READY); + + ns_client_requests++; + + if (event->ev_type == ISC_SOCKEVENT_RECVDONE) { + INSIST(!TCP_CLIENT(client)); + sevent = (isc_socketevent_t *)event; + REQUIRE(sevent == client->recvevent); + isc_buffer_init(&tbuffer, sevent->region.base, sevent->n); + isc_buffer_add(&tbuffer, sevent->n); + buffer = &tbuffer; + result = sevent->result; + if (result == ISC_R_SUCCESS) { + client->peeraddr = sevent->address; + client->peeraddr_valid = ISC_TRUE; + } + if ((sevent->attributes & ISC_SOCKEVENTATTR_PKTINFO) != 0) { + client->attributes |= NS_CLIENTATTR_PKTINFO; + client->pktinfo = sevent->pktinfo; + } + if ((sevent->attributes & ISC_SOCKEVENTATTR_MULTICAST) != 0) + client->attributes |= NS_CLIENTATTR_MULTICAST; + client->nrecvs--; + } else { + INSIST(TCP_CLIENT(client)); + REQUIRE(event->ev_type == DNS_EVENT_TCPMSG); + REQUIRE(event->ev_sender == &client->tcpmsg); + buffer = &client->tcpmsg.buffer; + result = client->tcpmsg.result; + INSIST(client->nreads == 1); + /* + * client->peeraddr was set when the connection was accepted. + */ + client->nreads--; + } + + if (exit_check(client)) + goto cleanup; + client->state = client->newstate = NS_CLIENTSTATE_WORKING; + + isc_task_getcurrenttime(task, &client->requesttime); + client->now = client->requesttime; + + if (result != ISC_R_SUCCESS) { + if (TCP_CLIENT(client)) { + ns_client_next(client, result); + } else { + if (result != ISC_R_CANCELED) + isc_log_write(ns_g_lctx, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, + ISC_LOG_ERROR, + "UDP client handler shutting " + "down due to fatal receive " + "error: %s", + isc_result_totext(result)); + isc_task_shutdown(client->task); + } + goto cleanup; + } + + isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr); + +#if NS_CLIENT_DROPPORT + if (ns_client_dropport(isc_sockaddr_getport(&client->peeraddr)) == + DROPPORT_REQUEST) { + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10), + "dropped request: suspicious port"); + ns_client_next(client, ISC_R_SUCCESS); + goto cleanup; + } +#endif + + ns_client_log(client, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3), + "%s request", + TCP_CLIENT(client) ? "TCP" : "UDP"); + + /* + * Check the blackhole ACL for UDP only, since TCP is done in + * client_newconn. + */ + if (!TCP_CLIENT(client)) { + + if (ns_g_server->blackholeacl != NULL && + dns_acl_match(&netaddr, NULL, ns_g_server->blackholeacl, + &ns_g_server->aclenv, + &match, NULL) == ISC_R_SUCCESS && + match > 0) + { + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10), + "blackholed UDP datagram"); + ns_client_next(client, ISC_R_SUCCESS); + goto cleanup; + } + } + + /* + * Silently drop multicast requests for the present. + * XXXMPA look at when/if mDNS spec stabilizes. + */ + if ((client->attributes & NS_CLIENTATTR_MULTICAST) != 0) { + ns_client_log(client, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2), + "dropping multicast request"); + ns_client_next(client, DNS_R_REFUSED); + goto cleanup; + } + + result = dns_message_peekheader(buffer, &id, &flags); + if (result != ISC_R_SUCCESS) { + /* + * There isn't enough header to determine whether + * this was a request or a response. Drop it. + */ + ns_client_next(client, result); + goto cleanup; + } + + /* + * The client object handles requests, not responses. + * If this is a UDP response, forward it to the dispatcher. + * If it's a TCP response, discard it here. + */ + if ((flags & DNS_MESSAGEFLAG_QR) != 0) { + if (TCP_CLIENT(client)) { + CTRACE("unexpected response"); + ns_client_next(client, DNS_R_FORMERR); + goto cleanup; + } else { + dns_dispatch_importrecv(client->dispatch, event); + ns_client_next(client, ISC_R_SUCCESS); + goto cleanup; + } + } + + /* + * Update some statistics counters. Don't count responses. + */ + if (isc_sockaddr_pf(&client->peeraddr) == PF_INET) { + dns_generalstats_increment(ns_g_server->nsstats, + dns_nsstatscounter_requestv4); + } else { + dns_generalstats_increment(ns_g_server->nsstats, + dns_nsstatscounter_requestv6); + } + if (TCP_CLIENT(client)) + dns_generalstats_increment(ns_g_server->nsstats, + dns_nsstatscounter_tcp); + + /* + * It's a request. Parse it. + */ + result = dns_message_parse(client->message, buffer, 0); + if (result != ISC_R_SUCCESS) { + /* + * Parsing the request failed. Send a response + * (typically FORMERR or SERVFAIL). + */ + ns_client_error(client, result); + goto cleanup; + } + + dns_opcodestats_increment(ns_g_server->opcodestats, + client->message->opcode); + switch (client->message->opcode) { + case dns_opcode_query: + case dns_opcode_update: + case dns_opcode_notify: + notimp = ISC_FALSE; + break; + case dns_opcode_iquery: + default: + notimp = ISC_TRUE; + break; + } + + client->message->rcode = dns_rcode_noerror; + + /* RFC1123 section 6.1.3.2 */ + if ((client->attributes & NS_CLIENTATTR_MULTICAST) != 0) + client->message->flags &= ~DNS_MESSAGEFLAG_RD; + + /* + * Deal with EDNS. + */ + opt = dns_message_getopt(client->message); + if (opt != NULL) { + /* + * Set the client's UDP buffer size. + */ + client->udpsize = opt->rdclass; + + /* + * If the requested UDP buffer size is less than 512, + * ignore it and use 512. + */ + if (client->udpsize < 512) + client->udpsize = 512; + + /* + * Get the flags out of the OPT record. + */ + client->extflags = (isc_uint16_t)(opt->ttl & 0xFFFF); + + /* + * Do we understand this version of EDNS? + * + * XXXRTH need library support for this! + */ + client->ednsversion = (opt->ttl & 0x00FF0000) >> 16; + if (client->ednsversion > 0) { + dns_generalstats_increment(ns_g_server->nsstats, + dns_nsstatscounter_badednsver); + result = client_addopt(client); + if (result == ISC_R_SUCCESS) + result = DNS_R_BADVERS; + ns_client_error(client, result); + goto cleanup; + } + + /* Check for NSID request */ + result = dns_rdataset_first(opt); + if (result == ISC_R_SUCCESS) { + dns_rdata_init(&rdata); + dns_rdataset_current(opt, &rdata); + if (rdata.length >= 2) { + isc_buffer_t nsidbuf; + isc_buffer_init(&nsidbuf, + rdata.data, rdata.length); + isc_buffer_add(&nsidbuf, rdata.length); + optcode = isc_buffer_getuint16(&nsidbuf); + if (optcode == DNS_OPT_NSID) + client->attributes |= + NS_CLIENTATTR_WANTNSID; + } + } + + dns_generalstats_increment(ns_g_server->nsstats, + dns_nsstatscounter_edns0in); + + /* + * Create an OPT for our reply. + */ + result = client_addopt(client); + if (result != ISC_R_SUCCESS) { + ns_client_error(client, result); + goto cleanup; + } + } + + if (client->message->rdclass == 0) { + ns_client_log(client, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1), + "message class could not be determined"); + ns_client_dumpmessage(client, + "message class could not be determined"); + ns_client_error(client, notimp ? DNS_R_NOTIMP : DNS_R_FORMERR); + goto cleanup; + } + + /* + * Determine the destination address. If the receiving interface is + * bound to a specific address, we simply use it regardless of the + * address family. All IPv4 queries should fall into this case. + * Otherwise, if this is a TCP query, get the address from the + * receiving socket (this needs a system call and can be heavy). + * For IPv6 UDP queries, we get this from the pktinfo structure (if + * supported). + * If all the attempts fail (this can happen due to memory shortage, + * etc), we regard this as an error for safety. + */ + if ((client->interface->flags & NS_INTERFACEFLAG_ANYADDR) == 0) + isc_netaddr_fromsockaddr(&destaddr, &client->interface->addr); + else { + result = ISC_R_FAILURE; + + if (TCP_CLIENT(client)) { + isc_sockaddr_t destsockaddr; + + result = isc_socket_getsockname(client->tcpsocket, + &destsockaddr); + if (result == ISC_R_SUCCESS) + isc_netaddr_fromsockaddr(&destaddr, + &destsockaddr); + } + if (result != ISC_R_SUCCESS && + client->interface->addr.type.sa.sa_family == AF_INET6 && + (client->attributes & NS_CLIENTATTR_PKTINFO) != 0) { + isc_uint32_t zone = 0; + + /* + * XXXJT technically, we should convert the receiving + * interface ID to a proper scope zone ID. However, + * due to the fact there is no standard API for this, + * we only handle link-local addresses and use the + * interface index as link ID. Despite the assumption, + * it should cover most typical cases. + */ + if (IN6_IS_ADDR_LINKLOCAL(&client->pktinfo.ipi6_addr)) + zone = (isc_uint32_t)client->pktinfo.ipi6_ifindex; + + isc_netaddr_fromin6(&destaddr, + &client->pktinfo.ipi6_addr); + isc_netaddr_setzone(&destaddr, zone); + result = ISC_R_SUCCESS; + } + if (result != ISC_R_SUCCESS) { + UNEXPECTED_ERROR(__FILE__, __LINE__, + "failed to get request's " + "destination: %s", + isc_result_totext(result)); + ns_client_next(client, ISC_R_SUCCESS); + goto cleanup; + } + } + + /* + * Find a view that matches the client's source address. + */ + for (view = ISC_LIST_HEAD(ns_g_server->viewlist); + view != NULL; + view = ISC_LIST_NEXT(view, link)) { + if (client->message->rdclass == view->rdclass || + client->message->rdclass == dns_rdataclass_any) + { + dns_name_t *tsig = NULL; + + sigresult = dns_message_rechecksig(client->message, + view); + if (sigresult == ISC_R_SUCCESS) + tsig = dns_tsigkey_identity(client->message->tsigkey); + + if (allowed(&netaddr, tsig, view->matchclients) && + allowed(&destaddr, tsig, view->matchdestinations) && + !((client->message->flags & DNS_MESSAGEFLAG_RD) + == 0 && view->matchrecursiveonly)) + { + dns_view_attach(view, &client->view); + break; + } + } + } + + if (view == NULL) { + char classname[DNS_RDATACLASS_FORMATSIZE]; + + /* + * Do a dummy TSIG verification attempt so that the + * response will have a TSIG if the query did, as + * required by RFC2845. + */ + isc_buffer_t b; + isc_region_t *r; + + dns_message_resetsig(client->message); + + r = dns_message_getrawmessage(client->message); + isc_buffer_init(&b, r->base, r->length); + isc_buffer_add(&b, r->length); + (void)dns_tsig_verify(&b, client->message, NULL, NULL); + + dns_rdataclass_format(client->message->rdclass, classname, + sizeof(classname)); + ns_client_log(client, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1), + "no matching view in class '%s'", classname); + ns_client_dumpmessage(client, "no matching view in class"); + ns_client_error(client, notimp ? DNS_R_NOTIMP : DNS_R_REFUSED); + goto cleanup; + } + + ns_client_log(client, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(5), + "using view '%s'", view->name); + + /* + * Check for a signature. We log bad signatures regardless of + * whether they ultimately cause the request to be rejected or + * not. We do not log the lack of a signature unless we are + * debugging. + */ + client->signer = NULL; + dns_name_init(&client->signername, NULL); + result = dns_message_signer(client->message, &client->signername); + if (result != ISC_R_NOTFOUND) { + signame = NULL; + if (dns_message_gettsig(client->message, &signame) != NULL) { + dns_generalstats_increment(ns_g_server->nsstats, + dns_nsstatscounter_tsigin); + } else { + dns_generalstats_increment(ns_g_server->nsstats, + dns_nsstatscounter_sig0in); + } + + } + if (result == ISC_R_SUCCESS) { + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3), + "request has valid signature"); + client->signer = &client->signername; + } else if (result == ISC_R_NOTFOUND) { + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3), + "request is not signed"); + } else if (result == DNS_R_NOIDENTITY) { + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3), + "request is signed by a nonauthoritative key"); + } else { + char tsigrcode[64]; + isc_buffer_t b; + dns_rcode_t status; + isc_result_t tresult; + + /* There is a signature, but it is bad. */ + dns_generalstats_increment(ns_g_server->nsstats, + dns_nsstatscounter_invalidsig); + signame = NULL; + if (dns_message_gettsig(client->message, &signame) != NULL) { + char namebuf[DNS_NAME_FORMATSIZE]; + char cnamebuf[DNS_NAME_FORMATSIZE]; + dns_name_format(signame, namebuf, sizeof(namebuf)); + status = client->message->tsigstatus; + isc_buffer_init(&b, tsigrcode, sizeof(tsigrcode) - 1); + tresult = dns_tsigrcode_totext(status, &b); + INSIST(tresult == ISC_R_SUCCESS); + tsigrcode[isc_buffer_usedlength(&b)] = '\0'; + if (client->message->tsigkey->generated) { + dns_name_format(client->message->tsigkey->creator, + cnamebuf, sizeof(cnamebuf)); + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, + ISC_LOG_ERROR, + "request has invalid signature: " + "TSIG %s (%s): %s (%s)", namebuf, + cnamebuf, + isc_result_totext(result), + tsigrcode); + } else { + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, + ISC_LOG_ERROR, + "request has invalid signature: " + "TSIG %s: %s (%s)", namebuf, + isc_result_totext(result), + tsigrcode); + } + } else { + status = client->message->sig0status; + isc_buffer_init(&b, tsigrcode, sizeof(tsigrcode) - 1); + tresult = dns_tsigrcode_totext(status, &b); + INSIST(tresult == ISC_R_SUCCESS); + tsigrcode[isc_buffer_usedlength(&b)] = '\0'; + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, ISC_LOG_ERROR, + "request has invalid signature: %s (%s)", + isc_result_totext(result), tsigrcode); + } + /* + * Accept update messages signed by unknown keys so that + * update forwarding works transparently through slaves + * that don't have all the same keys as the master. + */ + if (!(client->message->tsigstatus == dns_tsigerror_badkey && + client->message->opcode == dns_opcode_update)) { + ns_client_error(client, sigresult); + goto cleanup; + } + } + + /* + * Decide whether recursive service is available to this client. + * We do this here rather than in the query code so that we can + * set the RA bit correctly on all kinds of responses, not just + * responses to ordinary queries. Note if you can't query the + * cache there is no point in setting RA. + */ + ra = ISC_FALSE; + if (client->view->resolver != NULL && + client->view->recursion == ISC_TRUE && + ns_client_checkaclsilent(client, NULL, + client->view->recursionacl, + ISC_TRUE) == ISC_R_SUCCESS && + ns_client_checkaclsilent(client, NULL, + client->view->queryacl, + ISC_TRUE) == ISC_R_SUCCESS && + ns_client_checkaclsilent(client, &client->interface->addr, + client->view->recursiononacl, + ISC_TRUE) == ISC_R_SUCCESS && + ns_client_checkaclsilent(client, &client->interface->addr, + client->view->queryonacl, + ISC_TRUE) == ISC_R_SUCCESS) + ra = ISC_TRUE; + + if (ra == ISC_TRUE) + client->attributes |= NS_CLIENTATTR_RA; + + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, NS_LOGMODULE_CLIENT, + ISC_LOG_DEBUG(3), ra ? "recursion available" : + "recursion not available"); + + /* + * Adjust maximum UDP response size for this client. + */ + if (client->udpsize > 512) { + dns_peer_t *peer = NULL; + isc_uint16_t udpsize = view->maxudp; + (void) dns_peerlist_peerbyaddr(view->peers, &netaddr, &peer); + if (peer != NULL) + dns_peer_getmaxudp(peer, &udpsize); + if (client->udpsize > udpsize) + client->udpsize = udpsize; + } + + /* + * Dispatch the request. + */ + switch (client->message->opcode) { + case dns_opcode_query: + CTRACE("query"); + ns_query_start(client); + break; + case dns_opcode_update: + CTRACE("update"); + ns_client_settimeout(client, 60); + ns_update_start(client, sigresult); + break; + case dns_opcode_notify: + CTRACE("notify"); + ns_client_settimeout(client, 60); + ns_notify_start(client); + break; + case dns_opcode_iquery: + CTRACE("iquery"); + ns_client_error(client, DNS_R_NOTIMP); + break; + default: + CTRACE("unknown opcode"); + ns_client_error(client, DNS_R_NOTIMP); + } + + cleanup: + return; +} + +static void +client_timeout(isc_task_t *task, isc_event_t *event) { + ns_client_t *client; + + REQUIRE(event != NULL); + REQUIRE(event->ev_type == ISC_TIMEREVENT_LIFE || + event->ev_type == ISC_TIMEREVENT_IDLE); + client = event->ev_arg; + REQUIRE(NS_CLIENT_VALID(client)); + REQUIRE(task == client->task); + REQUIRE(client->timer != NULL); + + UNUSED(task); + + CTRACE("timeout"); + + isc_event_free(&event); + + if (client->shutdown != NULL) { + (client->shutdown)(client->shutdown_arg, ISC_R_TIMEDOUT); + client->shutdown = NULL; + client->shutdown_arg = NULL; + } + + if (client->newstate > NS_CLIENTSTATE_READY) + client->newstate = NS_CLIENTSTATE_READY; + (void)exit_check(client); +} + +static isc_result_t +get_clientmctx(ns_clientmgr_t *manager, isc_mem_t **mctxp) { + isc_mem_t *clientmctx; + isc_result_t result; + + /* + * Caller must be holding the manager lock. + */ + if (ns_g_clienttest) { + result = isc_mem_create(0, 0, mctxp); + if (result == ISC_R_SUCCESS) + isc_mem_setname(*mctxp, "client", NULL); + return (result); + } +#if NMCTXS > 0 + INSIST(manager->nextmctx < NMCTXS); + clientmctx = manager->mctxpool[manager->nextmctx]; + if (clientmctx == NULL) { + result = isc_mem_create(0, 0, &clientmctx); + if (result != ISC_R_SUCCESS) + return (result); + isc_mem_setname(clientmctx, "client", NULL); + + manager->mctxpool[manager->nextmctx] = clientmctx; + } + manager->nextmctx++; + if (manager->nextmctx == NMCTXS) + manager->nextmctx = 0; +#else + clientmctx = manager->mctx; +#endif + + isc_mem_attach(clientmctx, mctxp); + + return (ISC_R_SUCCESS); +} + +static isc_result_t +client_create(ns_clientmgr_t *manager, ns_client_t **clientp) { + ns_client_t *client; + isc_result_t result; + isc_mem_t *mctx = NULL; + + /* + * Caller must be holding the manager lock. + * + * Note: creating a client does not add the client to the + * manager's client list or set the client's manager pointer. + * The caller is responsible for that. + */ + + REQUIRE(clientp != NULL && *clientp == NULL); + + result = get_clientmctx(manager, &mctx); + if (result != ISC_R_SUCCESS) + return (result); + + client = isc_mem_get(mctx, sizeof(*client)); + if (client == NULL) { + isc_mem_detach(&mctx); + return (ISC_R_NOMEMORY); + } + client->mctx = mctx; + + client->task = NULL; + result = isc_task_create(manager->taskmgr, 0, &client->task); + if (result != ISC_R_SUCCESS) + goto cleanup_client; + isc_task_setname(client->task, "client", client); + + client->timer = NULL; + result = isc_timer_create(manager->timermgr, isc_timertype_inactive, + NULL, NULL, client->task, client_timeout, + client, &client->timer); + if (result != ISC_R_SUCCESS) + goto cleanup_task; + client->timerset = ISC_FALSE; + + client->message = NULL; + result = dns_message_create(client->mctx, DNS_MESSAGE_INTENTPARSE, + &client->message); + if (result != ISC_R_SUCCESS) + goto cleanup_timer; + + /* XXXRTH Hardwired constants */ + + client->sendevent = (isc_socketevent_t *) + isc_event_allocate(client->mctx, client, + ISC_SOCKEVENT_SENDDONE, + client_senddone, client, + sizeof(isc_socketevent_t)); + if (client->sendevent == NULL) { + result = ISC_R_NOMEMORY; + goto cleanup_message; + } + + client->recvbuf = isc_mem_get(client->mctx, RECV_BUFFER_SIZE); + if (client->recvbuf == NULL) { + result = ISC_R_NOMEMORY; + goto cleanup_sendevent; + } + + client->recvevent = (isc_socketevent_t *) + isc_event_allocate(client->mctx, client, + ISC_SOCKEVENT_RECVDONE, + client_request, client, + sizeof(isc_socketevent_t)); + if (client->recvevent == NULL) { + result = ISC_R_NOMEMORY; + goto cleanup_recvbuf; + } + + client->magic = NS_CLIENT_MAGIC; + client->manager = NULL; + client->state = NS_CLIENTSTATE_INACTIVE; + client->newstate = NS_CLIENTSTATE_MAX; + client->naccepts = 0; + client->nreads = 0; + client->nsends = 0; + client->nrecvs = 0; + client->nupdates = 0; + client->nctls = 0; + client->references = 0; + client->attributes = 0; + client->view = NULL; + client->dispatch = NULL; + client->udpsocket = NULL; + client->tcplistener = NULL; + client->tcpsocket = NULL; + client->tcpmsg_valid = ISC_FALSE; + client->tcpbuf = NULL; + client->opt = NULL; + client->udpsize = 512; + client->extflags = 0; + client->ednsversion = -1; + client->next = NULL; + client->shutdown = NULL; + client->shutdown_arg = NULL; + dns_name_init(&client->signername, NULL); + client->mortal = ISC_FALSE; + client->tcpquota = NULL; + client->recursionquota = NULL; + client->interface = NULL; + client->peeraddr_valid = ISC_FALSE; + ISC_EVENT_INIT(&client->ctlevent, sizeof(client->ctlevent), 0, NULL, + NS_EVENT_CLIENTCONTROL, client_start, client, client, + NULL, NULL); + /* + * Initialize FORMERR cache to sentinel value that will not match + * any actual FORMERR response. + */ + isc_sockaddr_any(&client->formerrcache.addr); + client->formerrcache.time = 0; + client->formerrcache.id = 0; + ISC_LINK_INIT(client, link); + client->list = NULL; + + /* + * We call the init routines for the various kinds of client here, + * after we have created an otherwise valid client, because some + * of them call routines that REQUIRE(NS_CLIENT_VALID(client)). + */ + result = ns_query_init(client); + if (result != ISC_R_SUCCESS) + goto cleanup_recvevent; + + result = isc_task_onshutdown(client->task, client_shutdown, client); + if (result != ISC_R_SUCCESS) + goto cleanup_query; + + client->needshutdown = ns_g_clienttest; + + CTRACE("create"); + + *clientp = client; + + return (ISC_R_SUCCESS); + + cleanup_query: + ns_query_free(client); + + cleanup_recvevent: + isc_event_free((isc_event_t **)&client->recvevent); + + cleanup_recvbuf: + isc_mem_put(client->mctx, client->recvbuf, RECV_BUFFER_SIZE); + + cleanup_sendevent: + isc_event_free((isc_event_t **)&client->sendevent); + + client->magic = 0; + + cleanup_message: + dns_message_destroy(&client->message); + + cleanup_timer: + isc_timer_detach(&client->timer); + + cleanup_task: + isc_task_detach(&client->task); + + cleanup_client: + isc_mem_putanddetach(&client->mctx, client, sizeof(*client)); + + return (result); +} + +static void +client_read(ns_client_t *client) { + isc_result_t result; + + CTRACE("read"); + + result = dns_tcpmsg_readmessage(&client->tcpmsg, client->task, + client_request, client); + if (result != ISC_R_SUCCESS) + goto fail; + + /* + * Set a timeout to limit the amount of time we will wait + * for a request on this TCP connection. + */ + ns_client_settimeout(client, 30); + + client->state = client->newstate = NS_CLIENTSTATE_READING; + INSIST(client->nreads == 0); + INSIST(client->recursionquota == NULL); + client->nreads++; + + return; + fail: + ns_client_next(client, result); +} + +static void +client_newconn(isc_task_t *task, isc_event_t *event) { + ns_client_t *client = event->ev_arg; + isc_socket_newconnev_t *nevent = (isc_socket_newconnev_t *)event; + isc_result_t result; + + REQUIRE(event->ev_type == ISC_SOCKEVENT_NEWCONN); + REQUIRE(NS_CLIENT_VALID(client)); + REQUIRE(client->task == task); + + UNUSED(task); + + INSIST(client->state == NS_CLIENTSTATE_READY); + + INSIST(client->naccepts == 1); + client->naccepts--; + + LOCK(&client->interface->lock); + INSIST(client->interface->ntcpcurrent > 0); + client->interface->ntcpcurrent--; + UNLOCK(&client->interface->lock); + + /* + * We must take ownership of the new socket before the exit + * check to make sure it gets destroyed if we decide to exit. + */ + if (nevent->result == ISC_R_SUCCESS) { + client->tcpsocket = nevent->newsocket; + isc_socket_setname(client->tcpsocket, "client-tcp", NULL); + client->state = NS_CLIENTSTATE_READING; + INSIST(client->recursionquota == NULL); + + (void)isc_socket_getpeername(client->tcpsocket, + &client->peeraddr); + client->peeraddr_valid = ISC_TRUE; + ns_client_log(client, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3), + "new TCP connection"); + } else { + /* + * XXXRTH What should we do? We're trying to accept but + * it didn't work. If we just give up, then TCP + * service may eventually stop. + * + * For now, we just go idle. + * + * Going idle is probably the right thing if the + * I/O was canceled. + */ + ns_client_log(client, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3), + "accept failed: %s", + isc_result_totext(nevent->result)); + } + + if (exit_check(client)) + goto freeevent; + + if (nevent->result == ISC_R_SUCCESS) { + int match; + isc_netaddr_t netaddr; + + isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr); + + if (ns_g_server->blackholeacl != NULL && + dns_acl_match(&netaddr, NULL, + ns_g_server->blackholeacl, + &ns_g_server->aclenv, + &match, NULL) == ISC_R_SUCCESS && + match > 0) + { + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10), + "blackholed connection attempt"); + client->newstate = NS_CLIENTSTATE_READY; + (void)exit_check(client); + goto freeevent; + } + + INSIST(client->tcpmsg_valid == ISC_FALSE); + dns_tcpmsg_init(client->mctx, client->tcpsocket, + &client->tcpmsg); + client->tcpmsg_valid = ISC_TRUE; + + /* + * Let a new client take our place immediately, before + * we wait for a request packet. If we don't, + * telnetting to port 53 (once per CPU) will + * deny service to legititmate TCP clients. + */ + result = isc_quota_attach(&ns_g_server->tcpquota, + &client->tcpquota); + if (result == ISC_R_SUCCESS) + result = ns_client_replace(client); + if (result != ISC_R_SUCCESS) { + ns_client_log(client, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, ISC_LOG_WARNING, + "no more TCP clients: %s", + isc_result_totext(result)); + } + + client_read(client); + } + + freeevent: + isc_event_free(&event); +} + +static void +client_accept(ns_client_t *client) { + isc_result_t result; + + CTRACE("accept"); + + result = isc_socket_accept(client->tcplistener, client->task, + client_newconn, client); + if (result != ISC_R_SUCCESS) { + UNEXPECTED_ERROR(__FILE__, __LINE__, + "isc_socket_accept() failed: %s", + isc_result_totext(result)); + /* + * XXXRTH What should we do? We're trying to accept but + * it didn't work. If we just give up, then TCP + * service may eventually stop. + * + * For now, we just go idle. + */ + return; + } + INSIST(client->naccepts == 0); + client->naccepts++; + LOCK(&client->interface->lock); + client->interface->ntcpcurrent++; + UNLOCK(&client->interface->lock); +} + +static void +client_udprecv(ns_client_t *client) { + isc_result_t result; + isc_region_t r; + + CTRACE("udprecv"); + + r.base = client->recvbuf; + r.length = RECV_BUFFER_SIZE; + result = isc_socket_recv2(client->udpsocket, &r, 1, + client->task, client->recvevent, 0); + if (result != ISC_R_SUCCESS) { + UNEXPECTED_ERROR(__FILE__, __LINE__, + "isc_socket_recv2() failed: %s", + isc_result_totext(result)); + /* + * This cannot happen in the current implementation, since + * isc_socket_recv2() cannot fail if flags == 0. + * + * If this does fail, we just go idle. + */ + return; + } + INSIST(client->nrecvs == 0); + client->nrecvs++; +} + +void +ns_client_attach(ns_client_t *source, ns_client_t **targetp) { + REQUIRE(NS_CLIENT_VALID(source)); + REQUIRE(targetp != NULL && *targetp == NULL); + + source->references++; + ns_client_log(source, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10), + "ns_client_attach: ref = %d", source->references); + *targetp = source; +} + +void +ns_client_detach(ns_client_t **clientp) { + ns_client_t *client = *clientp; + + client->references--; + INSIST(client->references >= 0); + *clientp = NULL; + ns_client_log(client, NS_LOGCATEGORY_CLIENT, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10), + "ns_client_detach: ref = %d", client->references); + (void)exit_check(client); +} + +isc_boolean_t +ns_client_shuttingdown(ns_client_t *client) { + return (ISC_TF(client->newstate == NS_CLIENTSTATE_FREED)); +} + +isc_result_t +ns_client_replace(ns_client_t *client) { + isc_result_t result; + + CTRACE("replace"); + + result = ns_clientmgr_createclients(client->manager, + 1, client->interface, + (TCP_CLIENT(client) ? + ISC_TRUE : ISC_FALSE)); + if (result != ISC_R_SUCCESS) + return (result); + + /* + * The responsibility for listening for new requests is hereby + * transferred to the new client. Therefore, the old client + * should refrain from listening for any more requests. + */ + client->mortal = ISC_TRUE; + + return (ISC_R_SUCCESS); +} + +/*** + *** Client Manager + ***/ + +static void +clientmgr_destroy(ns_clientmgr_t *manager) { +#if NMCTXS > 0 + int i; +#endif + + REQUIRE(ISC_LIST_EMPTY(manager->active)); + REQUIRE(ISC_LIST_EMPTY(manager->inactive)); + REQUIRE(ISC_LIST_EMPTY(manager->recursing)); + + MTRACE("clientmgr_destroy"); + +#if NMCTXS > 0 + for (i = 0; i < NMCTXS; i++) { + if (manager->mctxpool[i] != NULL) + isc_mem_detach(&manager->mctxpool[i]); + } +#endif + + DESTROYLOCK(&manager->lock); + manager->magic = 0; + isc_mem_put(manager->mctx, manager, sizeof(*manager)); +} + +isc_result_t +ns_clientmgr_create(isc_mem_t *mctx, isc_taskmgr_t *taskmgr, + isc_timermgr_t *timermgr, ns_clientmgr_t **managerp) +{ + ns_clientmgr_t *manager; + isc_result_t result; +#if NMCTXS > 0 + int i; +#endif + + manager = isc_mem_get(mctx, sizeof(*manager)); + if (manager == NULL) + return (ISC_R_NOMEMORY); + + result = isc_mutex_init(&manager->lock); + if (result != ISC_R_SUCCESS) + goto cleanup_manager; + + manager->mctx = mctx; + manager->taskmgr = taskmgr; + manager->timermgr = timermgr; + manager->exiting = ISC_FALSE; + ISC_LIST_INIT(manager->active); + ISC_LIST_INIT(manager->inactive); + ISC_LIST_INIT(manager->recursing); +#if NMCTXS > 0 + manager->nextmctx = 0; + for (i = 0; i < NMCTXS; i++) + manager->mctxpool[i] = NULL; /* will be created on-demand */ +#endif + manager->magic = MANAGER_MAGIC; + + MTRACE("create"); + + *managerp = manager; + + return (ISC_R_SUCCESS); + + cleanup_manager: + isc_mem_put(manager->mctx, manager, sizeof(*manager)); + + return (result); +} + +void +ns_clientmgr_destroy(ns_clientmgr_t **managerp) { + ns_clientmgr_t *manager; + ns_client_t *client; + isc_boolean_t need_destroy = ISC_FALSE; + + REQUIRE(managerp != NULL); + manager = *managerp; + REQUIRE(VALID_MANAGER(manager)); + + MTRACE("destroy"); + + LOCK(&manager->lock); + + manager->exiting = ISC_TRUE; + + for (client = ISC_LIST_HEAD(manager->recursing); + client != NULL; + client = ISC_LIST_NEXT(client, link)) + isc_task_shutdown(client->task); + + for (client = ISC_LIST_HEAD(manager->active); + client != NULL; + client = ISC_LIST_NEXT(client, link)) + isc_task_shutdown(client->task); + + for (client = ISC_LIST_HEAD(manager->inactive); + client != NULL; + client = ISC_LIST_NEXT(client, link)) + isc_task_shutdown(client->task); + + if (ISC_LIST_EMPTY(manager->active) && + ISC_LIST_EMPTY(manager->inactive) && + ISC_LIST_EMPTY(manager->recursing)) + need_destroy = ISC_TRUE; + + UNLOCK(&manager->lock); + + if (need_destroy) + clientmgr_destroy(manager); + + *managerp = NULL; +} + +isc_result_t +ns_clientmgr_createclients(ns_clientmgr_t *manager, unsigned int n, + ns_interface_t *ifp, isc_boolean_t tcp) +{ + isc_result_t result = ISC_R_SUCCESS; + unsigned int i; + ns_client_t *client; + + REQUIRE(VALID_MANAGER(manager)); + REQUIRE(n > 0); + + MTRACE("createclients"); + + /* + * We MUST lock the manager lock for the entire client creation + * process. If we didn't do this, then a client could get a + * shutdown event and disappear out from under us. + */ + + LOCK(&manager->lock); + + for (i = 0; i < n; i++) { + isc_event_t *ev; + /* + * Allocate a client. First try to get a recycled one; + * if that fails, make a new one. + */ + client = NULL; + if (!ns_g_clienttest) + client = ISC_LIST_HEAD(manager->inactive); + if (client != NULL) { + MTRACE("recycle"); + ISC_LIST_UNLINK(manager->inactive, client, link); + client->list = NULL; + } else { + MTRACE("create new"); + result = client_create(manager, &client); + if (result != ISC_R_SUCCESS) + break; + } + + ns_interface_attach(ifp, &client->interface); + client->state = NS_CLIENTSTATE_READY; + INSIST(client->recursionquota == NULL); + + if (tcp) { + client->attributes |= NS_CLIENTATTR_TCP; + isc_socket_attach(ifp->tcpsocket, + &client->tcplistener); + } else { + isc_socket_t *sock; + + dns_dispatch_attach(ifp->udpdispatch, + &client->dispatch); + sock = dns_dispatch_getsocket(client->dispatch); + isc_socket_attach(sock, &client->udpsocket); + } + client->manager = manager; + ISC_LIST_APPEND(manager->active, client, link); + client->list = &manager->active; + + INSIST(client->nctls == 0); + client->nctls++; + ev = &client->ctlevent; + isc_task_send(client->task, &ev); + } + if (i != 0) { + /* + * We managed to create at least one client, so we + * declare victory. + */ + result = ISC_R_SUCCESS; + } + + UNLOCK(&manager->lock); + + return (result); +} + +isc_sockaddr_t * +ns_client_getsockaddr(ns_client_t *client) { + return (&client->peeraddr); +} + +isc_result_t +ns_client_checkaclsilent(ns_client_t *client, isc_sockaddr_t *sockaddr, + dns_acl_t *acl, isc_boolean_t default_allow) +{ + isc_result_t result; + int match; + isc_netaddr_t netaddr; + + if (acl == NULL) { + if (default_allow) + goto allow; + else + goto deny; + } + + + if (sockaddr == NULL) + isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr); + else + isc_netaddr_fromsockaddr(&netaddr, sockaddr); + + result = dns_acl_match(&netaddr, client->signer, acl, + &ns_g_server->aclenv, + &match, NULL); + + if (result != ISC_R_SUCCESS) + goto deny; /* Internal error, already logged. */ + if (match > 0) + goto allow; + goto deny; /* Negative match or no match. */ + + allow: + return (ISC_R_SUCCESS); + + deny: + return (DNS_R_REFUSED); +} + +isc_result_t +ns_client_checkacl(ns_client_t *client, isc_sockaddr_t *sockaddr, + const char *opname, dns_acl_t *acl, + isc_boolean_t default_allow, int log_level) +{ + isc_result_t result = + ns_client_checkaclsilent(client, sockaddr, acl, default_allow); + + if (result == ISC_R_SUCCESS) + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3), + "%s approved", opname); + else + ns_client_log(client, DNS_LOGCATEGORY_SECURITY, + NS_LOGMODULE_CLIENT, + log_level, "%s denied", opname); + return (result); +} + +static void +ns_client_name(ns_client_t *client, char *peerbuf, size_t len) { + if (client->peeraddr_valid) + isc_sockaddr_format(&client->peeraddr, peerbuf, len); + else + snprintf(peerbuf, len, "@%p", client); +} + +void +ns_client_logv(ns_client_t *client, isc_logcategory_t *category, + isc_logmodule_t *module, int level, const char *fmt, va_list ap) +{ + char msgbuf[2048]; + char peerbuf[ISC_SOCKADDR_FORMATSIZE]; + const char *name = ""; + const char *sep = ""; + + vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap); + ns_client_name(client, peerbuf, sizeof(peerbuf)); + if (client->view != NULL && strcmp(client->view->name, "_bind") != 0 && + strcmp(client->view->name, "_default") != 0) { + name = client->view->name; + sep = ": view "; + } + + isc_log_write(ns_g_lctx, category, module, level, + "client %s%s%s: %s", peerbuf, sep, name, msgbuf); +} + +void +ns_client_log(ns_client_t *client, isc_logcategory_t *category, + isc_logmodule_t *module, int level, const char *fmt, ...) +{ + va_list ap; + + if (! isc_log_wouldlog(ns_g_lctx, level)) + return; + + va_start(ap, fmt); + ns_client_logv(client, category, module, level, fmt, ap); + va_end(ap); +} + +void +ns_client_aclmsg(const char *msg, dns_name_t *name, dns_rdatatype_t type, + dns_rdataclass_t rdclass, char *buf, size_t len) +{ + char namebuf[DNS_NAME_FORMATSIZE]; + char typebuf[DNS_RDATATYPE_FORMATSIZE]; + char classbuf[DNS_RDATACLASS_FORMATSIZE]; + + dns_name_format(name, namebuf, sizeof(namebuf)); + dns_rdatatype_format(type, typebuf, sizeof(typebuf)); + dns_rdataclass_format(rdclass, classbuf, sizeof(classbuf)); + (void)snprintf(buf, len, "%s '%s/%s/%s'", msg, namebuf, typebuf, + classbuf); +} + +static void +ns_client_dumpmessage(ns_client_t *client, const char *reason) { + isc_buffer_t buffer; + char *buf = NULL; + int len = 1024; + isc_result_t result; + + /* + * Note that these are multiline debug messages. We want a newline + * to appear in the log after each message. + */ + + do { + buf = isc_mem_get(client->mctx, len); + if (buf == NULL) + break; + isc_buffer_init(&buffer, buf, len); + result = dns_message_totext(client->message, + &dns_master_style_debug, + 0, &buffer); + if (result == ISC_R_NOSPACE) { + isc_mem_put(client->mctx, buf, len); + len += 1024; + } else if (result == ISC_R_SUCCESS) + ns_client_log(client, NS_LOGCATEGORY_UNMATCHED, + NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1), + "%s\n%.*s", reason, + (int)isc_buffer_usedlength(&buffer), + buf); + } while (result == ISC_R_NOSPACE); + + if (buf != NULL) + isc_mem_put(client->mctx, buf, len); +} + +void +ns_client_dumprecursing(FILE *f, ns_clientmgr_t *manager) { + ns_client_t *client; + char namebuf[DNS_NAME_FORMATSIZE]; + char peerbuf[ISC_SOCKADDR_FORMATSIZE]; + const char *name; + const char *sep; + + REQUIRE(VALID_MANAGER(manager)); + + LOCK(&manager->lock); + client = ISC_LIST_HEAD(manager->recursing); + while (client != NULL) { + ns_client_name(client, peerbuf, sizeof(peerbuf)); + if (client->view != NULL && + strcmp(client->view->name, "_bind") != 0 && + strcmp(client->view->name, "_default") != 0) { + name = client->view->name; + sep = ": view "; + } else { + name = ""; + sep = ""; + } + dns_name_format(client->query.qname, namebuf, sizeof(namebuf)); + fprintf(f, "; client %s%s%s: '%s' requesttime %d\n", + peerbuf, sep, name, namebuf, client->requesttime); + client = ISC_LIST_NEXT(client, link); + } + UNLOCK(&manager->lock); +} + +void +ns_client_qnamereplace(ns_client_t *client, dns_name_t *name) { + + if (client->manager != NULL) + LOCK(&client->manager->lock); + if (client->query.restarts > 0) { + /* + * client->query.qname was dynamically allocated. + */ + dns_message_puttempname(client->message, + &client->query.qname); + } + client->query.qname = name; + if (client->manager != NULL) + UNLOCK(&client->manager->lock); +} |