diff options
Diffstat (limited to 'contrib/bind9/lib/dns/dispatch.c')
| -rw-r--r-- | contrib/bind9/lib/dns/dispatch.c | 2199 |
1 files changed, 2199 insertions, 0 deletions
diff --git a/contrib/bind9/lib/dns/dispatch.c b/contrib/bind9/lib/dns/dispatch.c new file mode 100644 index 0000000..8534fe1 --- /dev/null +++ b/contrib/bind9/lib/dns/dispatch.c @@ -0,0 +1,2199 @@ +/* + * Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC") + * Copyright (C) 1999-2003 Internet Software Consortium. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH + * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE + * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ + +/* $Id: dispatch.c,v 1.101.2.6.2.10 2004/09/01 04:27:41 marka Exp $ */ + +#include <config.h> + +#include <stdlib.h> + +#include <isc/entropy.h> +#include <isc/lfsr.h> +#include <isc/mem.h> +#include <isc/mutex.h> +#include <isc/print.h> +#include <isc/string.h> +#include <isc/task.h> +#include <isc/util.h> + +#include <dns/acl.h> +#include <dns/dispatch.h> +#include <dns/events.h> +#include <dns/log.h> +#include <dns/message.h> +#include <dns/portlist.h> +#include <dns/tcpmsg.h> +#include <dns/types.h> + +typedef ISC_LIST(dns_dispentry_t) dns_displist_t; + +typedef struct dns_qid { + unsigned int magic; + unsigned int qid_nbuckets; /* hash table size */ + unsigned int qid_increment; /* id increment on collision */ + isc_mutex_t lock; + isc_lfsr_t qid_lfsr1; /* state generator info */ + isc_lfsr_t qid_lfsr2; /* state generator info */ + dns_displist_t *qid_table; /* the table itself */ +} dns_qid_t; + +struct dns_dispatchmgr { + /* Unlocked. */ + unsigned int magic; + isc_mem_t *mctx; + dns_acl_t *blackhole; + dns_portlist_t *portlist; + + /* Locked by "lock". */ + isc_mutex_t lock; + unsigned int state; + ISC_LIST(dns_dispatch_t) list; + + /* locked by buffer lock */ + dns_qid_t *qid; + isc_mutex_t buffer_lock; + unsigned int buffers; /* allocated buffers */ + unsigned int buffersize; /* size of each buffer */ + unsigned int maxbuffers; /* max buffers */ + + /* Locked internally. */ + isc_mutex_t pool_lock; + isc_mempool_t *epool; /* memory pool for events */ + isc_mempool_t *rpool; /* memory pool for replies */ + isc_mempool_t *dpool; /* dispatch allocations */ + isc_mempool_t *bpool; /* memory pool for buffers */ + + isc_entropy_t *entropy; /* entropy source */ +}; + +#define MGR_SHUTTINGDOWN 0x00000001U +#define MGR_IS_SHUTTINGDOWN(l) (((l)->state & MGR_SHUTTINGDOWN) != 0) + +#define IS_PRIVATE(d) (((d)->attributes & DNS_DISPATCHATTR_PRIVATE) != 0) + +struct dns_dispentry { + unsigned int magic; + dns_dispatch_t *disp; + dns_messageid_t id; + unsigned int bucket; + isc_sockaddr_t host; + isc_task_t *task; + isc_taskaction_t action; + void *arg; + isc_boolean_t item_out; + ISC_LIST(dns_dispatchevent_t) items; + ISC_LINK(dns_dispentry_t) link; +}; + +#define INVALID_BUCKET (0xffffdead) + +struct dns_dispatch { + /* Unlocked. */ + unsigned int magic; /* magic */ + dns_dispatchmgr_t *mgr; /* dispatch manager */ + isc_task_t *task; /* internal task */ + isc_socket_t *socket; /* isc socket attached to */ + isc_sockaddr_t local; /* local address */ + unsigned int maxrequests; /* max requests */ + isc_event_t *ctlevent; + + /* Locked by mgr->lock. */ + ISC_LINK(dns_dispatch_t) link; + + /* Locked by "lock". */ + isc_mutex_t lock; /* locks all below */ + isc_sockettype_t socktype; + unsigned int attributes; + unsigned int refcount; /* number of users */ + dns_dispatchevent_t *failsafe_ev; /* failsafe cancel event */ + unsigned int shutting_down : 1, + shutdown_out : 1, + connected : 1, + tcpmsg_valid : 1, + recv_pending : 1; /* is a recv() pending? */ + isc_result_t shutdown_why; + unsigned int requests; /* how many requests we have */ + unsigned int tcpbuffers; /* allocated buffers */ + dns_tcpmsg_t tcpmsg; /* for tcp streams */ + dns_qid_t *qid; +}; + +#define QID_MAGIC ISC_MAGIC('Q', 'i', 'd', ' ') +#define VALID_QID(e) ISC_MAGIC_VALID((e), QID_MAGIC) + +#define RESPONSE_MAGIC ISC_MAGIC('D', 'r', 's', 'p') +#define VALID_RESPONSE(e) ISC_MAGIC_VALID((e), RESPONSE_MAGIC) + +#define DISPATCH_MAGIC ISC_MAGIC('D', 'i', 's', 'p') +#define VALID_DISPATCH(e) ISC_MAGIC_VALID((e), DISPATCH_MAGIC) + +#define DNS_DISPATCHMGR_MAGIC ISC_MAGIC('D', 'M', 'g', 'r') +#define VALID_DISPATCHMGR(e) ISC_MAGIC_VALID((e), DNS_DISPATCHMGR_MAGIC) + +#define DNS_QID(disp) ((disp)->socktype == isc_sockettype_tcp) ? \ + (disp)->qid : (disp)->mgr->qid +/* + * Statics. + */ +static dns_dispentry_t *bucket_search(dns_qid_t *, isc_sockaddr_t *, + dns_messageid_t, unsigned int); +static isc_boolean_t destroy_disp_ok(dns_dispatch_t *); +static void destroy_disp(isc_task_t *task, isc_event_t *event); +static void udp_recv(isc_task_t *, isc_event_t *); +static void tcp_recv(isc_task_t *, isc_event_t *); +static void startrecv(dns_dispatch_t *); +static dns_messageid_t dns_randomid(dns_qid_t *); +static isc_uint32_t dns_hash(dns_qid_t *, isc_sockaddr_t *, dns_messageid_t); +static void free_buffer(dns_dispatch_t *disp, void *buf, unsigned int len); +static void *allocate_udp_buffer(dns_dispatch_t *disp); +static inline void free_event(dns_dispatch_t *disp, dns_dispatchevent_t *ev); +static inline dns_dispatchevent_t *allocate_event(dns_dispatch_t *disp); +static void do_cancel(dns_dispatch_t *disp); +static dns_dispentry_t *linear_first(dns_qid_t *disp); +static dns_dispentry_t *linear_next(dns_qid_t *disp, + dns_dispentry_t *resp); +static void dispatch_free(dns_dispatch_t **dispp); +static isc_result_t dispatch_createudp(dns_dispatchmgr_t *mgr, + isc_socketmgr_t *sockmgr, + isc_taskmgr_t *taskmgr, + isc_sockaddr_t *localaddr, + unsigned int maxrequests, + unsigned int attributes, + dns_dispatch_t **dispp); +static isc_boolean_t destroy_mgr_ok(dns_dispatchmgr_t *mgr); +static void destroy_mgr(dns_dispatchmgr_t **mgrp); +static isc_result_t qid_allocate(dns_dispatchmgr_t *mgr, unsigned int buckets, + unsigned int increment, dns_qid_t **qidp); +static void qid_destroy(isc_mem_t *mctx, dns_qid_t **qidp); + +#define LVL(x) ISC_LOG_DEBUG(x) + +static void +mgr_log(dns_dispatchmgr_t *mgr, int level, const char *fmt, ...) + ISC_FORMAT_PRINTF(3, 4); + +static void +mgr_log(dns_dispatchmgr_t *mgr, int level, const char *fmt, ...) { + char msgbuf[2048]; + va_list ap; + + if (! isc_log_wouldlog(dns_lctx, level)) + return; + + va_start(ap, fmt); + vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap); + va_end(ap); + + isc_log_write(dns_lctx, + DNS_LOGCATEGORY_DISPATCH, DNS_LOGMODULE_DISPATCH, + level, "dispatchmgr %p: %s", mgr, msgbuf); +} + +static void +dispatch_log(dns_dispatch_t *disp, int level, const char *fmt, ...) + ISC_FORMAT_PRINTF(3, 4); + +static void +dispatch_log(dns_dispatch_t *disp, int level, const char *fmt, ...) { + char msgbuf[2048]; + va_list ap; + + if (! isc_log_wouldlog(dns_lctx, level)) + return; + + va_start(ap, fmt); + vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap); + va_end(ap); + + isc_log_write(dns_lctx, + DNS_LOGCATEGORY_DISPATCH, DNS_LOGMODULE_DISPATCH, + level, "dispatch %p: %s", disp, msgbuf); +} + +static void +request_log(dns_dispatch_t *disp, dns_dispentry_t *resp, + int level, const char *fmt, ...) + ISC_FORMAT_PRINTF(4, 5); + +static void +request_log(dns_dispatch_t *disp, dns_dispentry_t *resp, + int level, const char *fmt, ...) +{ + char msgbuf[2048]; + char peerbuf[256]; + va_list ap; + + if (! isc_log_wouldlog(dns_lctx, level)) + return; + + va_start(ap, fmt); + vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap); + va_end(ap); + + if (VALID_RESPONSE(resp)) { + isc_sockaddr_format(&resp->host, peerbuf, sizeof(peerbuf)); + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DISPATCH, + DNS_LOGMODULE_DISPATCH, level, + "dispatch %p response %p %s: %s", disp, resp, + peerbuf, msgbuf); + } else { + isc_log_write(dns_lctx, DNS_LOGCATEGORY_DISPATCH, + DNS_LOGMODULE_DISPATCH, level, + "dispatch %p req/resp %p: %s", disp, resp, + msgbuf); + } +} + +static void +reseed_lfsr(isc_lfsr_t *lfsr, void *arg) +{ + dns_dispatchmgr_t *mgr = arg; + isc_result_t result; + isc_uint32_t val; + + REQUIRE(VALID_DISPATCHMGR(mgr)); + + if (mgr->entropy != NULL) { + result = isc_entropy_getdata(mgr->entropy, &val, sizeof(val), + NULL, 0); + INSIST(result == ISC_R_SUCCESS); + lfsr->count = (val & 0x1f) + 32; + lfsr->state = val; + return; + } + + lfsr->count = (random() & 0x1f) + 32; /* From 32 to 63 states */ + lfsr->state = random(); +} + +/* + * Return an unpredictable message ID. + */ +static dns_messageid_t +dns_randomid(dns_qid_t *qid) { + isc_uint32_t id; + + id = isc_lfsr_generate32(&qid->qid_lfsr1, &qid->qid_lfsr2); + + return (dns_messageid_t)(id & 0xFFFF); +} + +/* + * Return a hash of the destination and message id. + */ +static isc_uint32_t +dns_hash(dns_qid_t *qid, isc_sockaddr_t *dest, dns_messageid_t id) { + unsigned int ret; + + ret = isc_sockaddr_hash(dest, ISC_TRUE); + ret ^= id; + ret %= qid->qid_nbuckets; + + INSIST(ret < qid->qid_nbuckets); + + return (ret); +} + +/* + * Find the first entry in 'qid'. Returns NULL if there are no entries. + */ +static dns_dispentry_t * +linear_first(dns_qid_t *qid) { + dns_dispentry_t *ret; + unsigned int bucket; + + bucket = 0; + + while (bucket < qid->qid_nbuckets) { + ret = ISC_LIST_HEAD(qid->qid_table[bucket]); + if (ret != NULL) + return (ret); + bucket++; + } + + return (NULL); +} + +/* + * Find the next entry after 'resp' in 'qid'. Return NULL if there are + * no more entries. + */ +static dns_dispentry_t * +linear_next(dns_qid_t *qid, dns_dispentry_t *resp) { + dns_dispentry_t *ret; + unsigned int bucket; + + ret = ISC_LIST_NEXT(resp, link); + if (ret != NULL) + return (ret); + + bucket = resp->bucket; + bucket++; + while (bucket < qid->qid_nbuckets) { + ret = ISC_LIST_HEAD(qid->qid_table[bucket]); + if (ret != NULL) + return (ret); + bucket++; + } + + return (NULL); +} + +/* + * The dispatch must be locked. + */ +static isc_boolean_t +destroy_disp_ok(dns_dispatch_t *disp) +{ + if (disp->refcount != 0) + return (ISC_FALSE); + + if (disp->recv_pending != 0) + return (ISC_FALSE); + + if (disp->shutting_down == 0) + return (ISC_FALSE); + + return (ISC_TRUE); +} + + +/* + * Called when refcount reaches 0 (and safe to destroy). + * + * The dispatcher must not be locked. + * The manager must be locked. + */ +static void +destroy_disp(isc_task_t *task, isc_event_t *event) { + dns_dispatch_t *disp; + dns_dispatchmgr_t *mgr; + isc_boolean_t killmgr; + + INSIST(event->ev_type == DNS_EVENT_DISPATCHCONTROL); + + UNUSED(task); + + disp = event->ev_arg; + mgr = disp->mgr; + + LOCK(&mgr->lock); + ISC_LIST_UNLINK(mgr->list, disp, link); + + dispatch_log(disp, LVL(90), + "shutting down; detaching from sock %p, task %p", + disp->socket, disp->task); + + isc_socket_detach(&disp->socket); + isc_task_detach(&disp->task); + isc_event_free(&event); + + dispatch_free(&disp); + + killmgr = destroy_mgr_ok(mgr); + UNLOCK(&mgr->lock); + if (killmgr) + destroy_mgr(&mgr); +} + + +/* + * Find an entry for query ID 'id' and socket address 'dest' in 'qid'. + * Return NULL if no such entry exists. + */ +static dns_dispentry_t * +bucket_search(dns_qid_t *qid, isc_sockaddr_t *dest, dns_messageid_t id, + unsigned int bucket) +{ + dns_dispentry_t *res; + + REQUIRE(bucket < qid->qid_nbuckets); + + res = ISC_LIST_HEAD(qid->qid_table[bucket]); + + while (res != NULL) { + if ((res->id == id) && isc_sockaddr_equal(dest, &res->host)) + return (res); + res = ISC_LIST_NEXT(res, link); + } + + return (NULL); +} + +static void +free_buffer(dns_dispatch_t *disp, void *buf, unsigned int len) { + INSIST(buf != NULL && len != 0); + + + switch (disp->socktype) { + case isc_sockettype_tcp: + INSIST(disp->tcpbuffers > 0); + disp->tcpbuffers--; + isc_mem_put(disp->mgr->mctx, buf, len); + break; + case isc_sockettype_udp: + LOCK(&disp->mgr->buffer_lock); + INSIST(disp->mgr->buffers > 0); + INSIST(len == disp->mgr->buffersize); + disp->mgr->buffers--; + isc_mempool_put(disp->mgr->bpool, buf); + UNLOCK(&disp->mgr->buffer_lock); + break; + default: + INSIST(0); + break; + } +} + +static void * +allocate_udp_buffer(dns_dispatch_t *disp) { + void *temp; + + LOCK(&disp->mgr->buffer_lock); + temp = isc_mempool_get(disp->mgr->bpool); + + if (temp != NULL) + disp->mgr->buffers++; + UNLOCK(&disp->mgr->buffer_lock); + + return (temp); +} + +static inline void +free_event(dns_dispatch_t *disp, dns_dispatchevent_t *ev) { + if (disp->failsafe_ev == ev) { + INSIST(disp->shutdown_out == 1); + disp->shutdown_out = 0; + + return; + } + + isc_mempool_put(disp->mgr->epool, ev); +} + +static inline dns_dispatchevent_t * +allocate_event(dns_dispatch_t *disp) { + dns_dispatchevent_t *ev; + + ev = isc_mempool_get(disp->mgr->epool); + if (ev == NULL) + return (NULL); + ISC_EVENT_INIT(ev, sizeof(*ev), 0, NULL, 0, + NULL, NULL, NULL, NULL, NULL); + + return (ev); +} + +/* + * General flow: + * + * If I/O result == CANCELED or error, free the buffer. + * + * If query, free the buffer, restart. + * + * If response: + * Allocate event, fill in details. + * If cannot allocate, free buffer, restart. + * find target. If not found, free buffer, restart. + * if event queue is not empty, queue. else, send. + * restart. + */ +static void +udp_recv(isc_task_t *task, isc_event_t *ev_in) { + isc_socketevent_t *ev = (isc_socketevent_t *)ev_in; + dns_dispatch_t *disp = ev_in->ev_arg; + dns_messageid_t id; + isc_result_t dres; + isc_buffer_t source; + unsigned int flags; + dns_dispentry_t *resp; + dns_dispatchevent_t *rev; + unsigned int bucket; + isc_boolean_t killit; + isc_boolean_t queue_response; + dns_dispatchmgr_t *mgr; + dns_qid_t *qid; + isc_netaddr_t netaddr; + int match; + + UNUSED(task); + + LOCK(&disp->lock); + + mgr = disp->mgr; + qid = mgr->qid; + + dispatch_log(disp, LVL(90), + "got packet: requests %d, buffers %d, recvs %d", + disp->requests, disp->mgr->buffers, disp->recv_pending); + + if (ev->ev_type == ISC_SOCKEVENT_RECVDONE) { + /* + * Unless the receive event was imported from a listening + * interface, in which case the event type is + * DNS_EVENT_IMPORTRECVDONE, receive operation must be pending. + */ + INSIST(disp->recv_pending != 0); + disp->recv_pending = 0; + } + + if (disp->shutting_down) { + /* + * This dispatcher is shutting down. + */ + free_buffer(disp, ev->region.base, ev->region.length); + + isc_event_free(&ev_in); + ev = NULL; + + killit = destroy_disp_ok(disp); + UNLOCK(&disp->lock); + if (killit) + isc_task_send(disp->task, &disp->ctlevent); + + return; + } + + if (ev->result != ISC_R_SUCCESS) { + free_buffer(disp, ev->region.base, ev->region.length); + + if (ev->result != ISC_R_CANCELED) + dispatch_log(disp, ISC_LOG_ERROR, + "odd socket result in udp_recv(): %s", + isc_result_totext(ev->result)); + + UNLOCK(&disp->lock); + isc_event_free(&ev_in); + return; + } + + /* + * If this is from a blackholed address, drop it. + */ + isc_netaddr_fromsockaddr(&netaddr, &ev->address); + if (disp->mgr->blackhole != NULL && + dns_acl_match(&netaddr, NULL, disp->mgr->blackhole, + NULL, &match, NULL) == ISC_R_SUCCESS && + match > 0) + { + if (isc_log_wouldlog(dns_lctx, LVL(10))) { + char netaddrstr[ISC_NETADDR_FORMATSIZE]; + isc_netaddr_format(&netaddr, netaddrstr, + sizeof(netaddrstr)); + dispatch_log(disp, LVL(10), + "blackholed packet from %s", + netaddrstr); + } + free_buffer(disp, ev->region.base, ev->region.length); + goto restart; + } + + /* + * Peek into the buffer to see what we can see. + */ + isc_buffer_init(&source, ev->region.base, ev->region.length); + isc_buffer_add(&source, ev->n); + dres = dns_message_peekheader(&source, &id, &flags); + if (dres != ISC_R_SUCCESS) { + free_buffer(disp, ev->region.base, ev->region.length); + dispatch_log(disp, LVL(10), "got garbage packet"); + goto restart; + } + + dispatch_log(disp, LVL(92), + "got valid DNS message header, /QR %c, id %u", + ((flags & DNS_MESSAGEFLAG_QR) ? '1' : '0'), id); + + /* + * Look at flags. If query, drop it. If response, + * look to see where it goes. + */ + queue_response = ISC_FALSE; + if ((flags & DNS_MESSAGEFLAG_QR) == 0) { + /* query */ + free_buffer(disp, ev->region.base, ev->region.length); + goto restart; + } + + /* response */ + bucket = dns_hash(qid, &ev->address, id); + LOCK(&qid->lock); + resp = bucket_search(qid, &ev->address, id, bucket); + dispatch_log(disp, LVL(90), + "search for response in bucket %d: %s", + bucket, (resp == NULL ? "not found" : "found")); + + if (resp == NULL) { + free_buffer(disp, ev->region.base, ev->region.length); + goto unlock; + } + queue_response = resp->item_out; + rev = allocate_event(resp->disp); + if (rev == NULL) { + free_buffer(disp, ev->region.base, ev->region.length); + goto unlock; + } + + /* + * At this point, rev contains the event we want to fill in, and + * resp contains the information on the place to send it to. + * Send the event off. + */ + isc_buffer_init(&rev->buffer, ev->region.base, ev->region.length); + isc_buffer_add(&rev->buffer, ev->n); + rev->result = ISC_R_SUCCESS; + rev->id = id; + rev->addr = ev->address; + rev->pktinfo = ev->pktinfo; + rev->attributes = ev->attributes; + if (queue_response) { + ISC_LIST_APPEND(resp->items, rev, ev_link); + } else { + ISC_EVENT_INIT(rev, sizeof(*rev), 0, NULL, + DNS_EVENT_DISPATCH, + resp->action, resp->arg, resp, NULL, NULL); + request_log(disp, resp, LVL(90), + "[a] Sent event %p buffer %p len %d to task %p", + rev, rev->buffer.base, rev->buffer.length, + resp->task); + resp->item_out = ISC_TRUE; + isc_task_send(resp->task, ISC_EVENT_PTR(&rev)); + } + unlock: + UNLOCK(&qid->lock); + + /* + * Restart recv() to get the next packet. + */ + restart: + startrecv(disp); + + UNLOCK(&disp->lock); + + isc_event_free(&ev_in); +} + +/* + * General flow: + * + * If I/O result == CANCELED, EOF, or error, notify everyone as the + * various queues drain. + * + * If query, restart. + * + * If response: + * Allocate event, fill in details. + * If cannot allocate, restart. + * find target. If not found, restart. + * if event queue is not empty, queue. else, send. + * restart. + */ +static void +tcp_recv(isc_task_t *task, isc_event_t *ev_in) { + dns_dispatch_t *disp = ev_in->ev_arg; + dns_tcpmsg_t *tcpmsg = &disp->tcpmsg; + dns_messageid_t id; + isc_result_t dres; + unsigned int flags; + dns_dispentry_t *resp; + dns_dispatchevent_t *rev; + unsigned int bucket; + isc_boolean_t killit; + isc_boolean_t queue_response; + dns_qid_t *qid; + int level; + char buf[ISC_SOCKADDR_FORMATSIZE]; + + UNUSED(task); + + REQUIRE(VALID_DISPATCH(disp)); + + qid = disp->qid; + + dispatch_log(disp, LVL(90), + "got TCP packet: requests %d, buffers %d, recvs %d", + disp->requests, disp->tcpbuffers, disp->recv_pending); + + LOCK(&disp->lock); + + INSIST(disp->recv_pending != 0); + disp->recv_pending = 0; + + if (disp->refcount == 0) { + /* + * This dispatcher is shutting down. Force cancelation. + */ + tcpmsg->result = ISC_R_CANCELED; + } + + if (tcpmsg->result != ISC_R_SUCCESS) { + switch (tcpmsg->result) { + case ISC_R_CANCELED: + break; + + case ISC_R_EOF: + dispatch_log(disp, LVL(90), "shutting down on EOF"); + do_cancel(disp); + break; + + case ISC_R_CONNECTIONRESET: + level = ISC_LOG_INFO; + goto logit; + + default: + level = ISC_LOG_ERROR; + logit: + isc_sockaddr_format(&tcpmsg->address, buf, sizeof(buf)); + dispatch_log(disp, level, "shutting down due to TCP " + "receive error: %s: %s", buf, + isc_result_totext(tcpmsg->result)); + do_cancel(disp); + break; + } + + /* + * The event is statically allocated in the tcpmsg + * structure, and destroy_disp() frees the tcpmsg, so we must + * free the event *before* calling destroy_disp(). + */ + isc_event_free(&ev_in); + + disp->shutting_down = 1; + disp->shutdown_why = tcpmsg->result; + + /* + * If the recv() was canceled pass the word on. + */ + killit = destroy_disp_ok(disp); + UNLOCK(&disp->lock); + if (killit) + isc_task_send(disp->task, &disp->ctlevent); + return; + } + + dispatch_log(disp, LVL(90), "result %d, length == %d, addr = %p", + tcpmsg->result, + tcpmsg->buffer.length, tcpmsg->buffer.base); + + /* + * Peek into the buffer to see what we can see. + */ + dres = dns_message_peekheader(&tcpmsg->buffer, &id, &flags); + if (dres != ISC_R_SUCCESS) { + dispatch_log(disp, LVL(10), "got garbage packet"); + goto restart; + } + + dispatch_log(disp, LVL(92), + "got valid DNS message header, /QR %c, id %u", + ((flags & DNS_MESSAGEFLAG_QR) ? '1' : '0'), id); + + /* + * Allocate an event to send to the query or response client, and + * allocate a new buffer for our use. + */ + + /* + * Look at flags. If query, drop it. If response, + * look to see where it goes. + */ + queue_response = ISC_FALSE; + if ((flags & DNS_MESSAGEFLAG_QR) == 0) { + /* + * Query. + */ + goto restart; + } + + /* + * Response. + */ + bucket = dns_hash(qid, &tcpmsg->address, id); + LOCK(&qid->lock); + resp = bucket_search(qid, &tcpmsg->address, id, bucket); + dispatch_log(disp, LVL(90), + "search for response in bucket %d: %s", + bucket, (resp == NULL ? "not found" : "found")); + + if (resp == NULL) + goto unlock; + queue_response = resp->item_out; + rev = allocate_event(disp); + if (rev == NULL) + goto unlock; + + /* + * At this point, rev contains the event we want to fill in, and + * resp contains the information on the place to send it to. + * Send the event off. + */ + dns_tcpmsg_keepbuffer(tcpmsg, &rev->buffer); + disp->tcpbuffers++; + rev->result = ISC_R_SUCCESS; + rev->id = id; + rev->addr = tcpmsg->address; + if (queue_response) { + ISC_LIST_APPEND(resp->items, rev, ev_link); + } else { + ISC_EVENT_INIT(rev, sizeof(*rev), 0, NULL, DNS_EVENT_DISPATCH, + resp->action, resp->arg, resp, NULL, NULL); + request_log(disp, resp, LVL(90), + "[b] Sent event %p buffer %p len %d to task %p", + rev, rev->buffer.base, rev->buffer.length, + resp->task); + resp->item_out = ISC_TRUE; + isc_task_send(resp->task, ISC_EVENT_PTR(&rev)); + } + unlock: + UNLOCK(&qid->lock); + + /* + * Restart recv() to get the next packet. + */ + restart: + startrecv(disp); + + UNLOCK(&disp->lock); + + isc_event_free(&ev_in); +} + +/* + * disp must be locked. + */ +static void +startrecv(dns_dispatch_t *disp) { + isc_result_t res; + isc_region_t region; + + if (disp->shutting_down == 1) + return; + + if ((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) != 0) + return; + + if (disp->recv_pending != 0) + return; + + if (disp->mgr->buffers >= disp->mgr->maxbuffers) + return; + + switch (disp->socktype) { + /* + * UDP reads are always maximal. + */ + case isc_sockettype_udp: + region.length = disp->mgr->buffersize; + region.base = allocate_udp_buffer(disp); + if (region.base == NULL) + return; + res = isc_socket_recv(disp->socket, ®ion, 1, + disp->task, udp_recv, disp); + if (res != ISC_R_SUCCESS) { + free_buffer(disp, region.base, region.length); + disp->shutdown_why = res; + disp->shutting_down = 1; + do_cancel(disp); + return; + } + INSIST(disp->recv_pending == 0); + disp->recv_pending = 1; + break; + + case isc_sockettype_tcp: + res = dns_tcpmsg_readmessage(&disp->tcpmsg, disp->task, + tcp_recv, disp); + if (res != ISC_R_SUCCESS) { + disp->shutdown_why = res; + disp->shutting_down = 1; + do_cancel(disp); + return; + } + INSIST(disp->recv_pending == 0); + disp->recv_pending = 1; + break; + } +} + +/* + * Mgr must be locked when calling this function. + */ +static isc_boolean_t +destroy_mgr_ok(dns_dispatchmgr_t *mgr) { + mgr_log(mgr, LVL(90), + "destroy_mgr_ok: shuttingdown=%d, listnonempty=%d, " + "epool=%d, rpool=%d, dpool=%d", + MGR_IS_SHUTTINGDOWN(mgr), !ISC_LIST_EMPTY(mgr->list), + isc_mempool_getallocated(mgr->epool), + isc_mempool_getallocated(mgr->rpool), + isc_mempool_getallocated(mgr->dpool)); + if (!MGR_IS_SHUTTINGDOWN(mgr)) + return (ISC_FALSE); + if (!ISC_LIST_EMPTY(mgr->list)) + return (ISC_FALSE); + if (isc_mempool_getallocated(mgr->epool) != 0) + return (ISC_FALSE); + if (isc_mempool_getallocated(mgr->rpool) != 0) + return (ISC_FALSE); + if (isc_mempool_getallocated(mgr->dpool) != 0) + return (ISC_FALSE); + + return (ISC_TRUE); +} + +/* + * Mgr must be unlocked when calling this function. + */ +static void +destroy_mgr(dns_dispatchmgr_t **mgrp) { + isc_mem_t *mctx; + dns_dispatchmgr_t *mgr; + + mgr = *mgrp; + *mgrp = NULL; + + mctx = mgr->mctx; + + mgr->magic = 0; + mgr->mctx = NULL; + DESTROYLOCK(&mgr->lock); + mgr->state = 0; + + isc_mempool_destroy(&mgr->epool); + isc_mempool_destroy(&mgr->rpool); + isc_mempool_destroy(&mgr->dpool); + isc_mempool_destroy(&mgr->bpool); + + DESTROYLOCK(&mgr->pool_lock); + + if (mgr->entropy != NULL) + isc_entropy_detach(&mgr->entropy); + if (mgr->qid != NULL) + qid_destroy(mctx, &mgr->qid); + + DESTROYLOCK(&mgr->buffer_lock); + + if (mgr->blackhole != NULL) + dns_acl_detach(&mgr->blackhole); + + if (mgr->portlist != NULL) + dns_portlist_detach(&mgr->portlist); + + isc_mem_put(mctx, mgr, sizeof(dns_dispatchmgr_t)); + isc_mem_detach(&mctx); +} + +static isc_result_t +create_socket(isc_socketmgr_t *mgr, isc_sockaddr_t *local, + isc_socket_t **sockp) +{ + isc_socket_t *sock; + isc_result_t result; + + sock = NULL; + result = isc_socket_create(mgr, isc_sockaddr_pf(local), + isc_sockettype_udp, &sock); + if (result != ISC_R_SUCCESS) + return (result); + +#ifndef ISC_ALLOW_MAPPED + isc_socket_ipv6only(sock, ISC_TRUE); +#endif + result = isc_socket_bind(sock, local); + if (result != ISC_R_SUCCESS) { + isc_socket_detach(&sock); + return (result); + } + + *sockp = sock; + return (ISC_R_SUCCESS); +} + +/* + * Publics. + */ + +isc_result_t +dns_dispatchmgr_create(isc_mem_t *mctx, isc_entropy_t *entropy, + dns_dispatchmgr_t **mgrp) +{ + dns_dispatchmgr_t *mgr; + isc_result_t result; + + REQUIRE(mctx != NULL); + REQUIRE(mgrp != NULL && *mgrp == NULL); + + mgr = isc_mem_get(mctx, sizeof(dns_dispatchmgr_t)); + if (mgr == NULL) + return (ISC_R_NOMEMORY); + + mgr->mctx = NULL; + isc_mem_attach(mctx, &mgr->mctx); + + mgr->blackhole = NULL; + mgr->portlist = NULL; + + result = isc_mutex_init(&mgr->lock); + if (result != ISC_R_SUCCESS) + goto deallocate; + + result = isc_mutex_init(&mgr->buffer_lock); + if (result != ISC_R_SUCCESS) + goto kill_lock; + + result = isc_mutex_init(&mgr->pool_lock); + if (result != ISC_R_SUCCESS) + goto kill_buffer_lock; + + mgr->epool = NULL; + if (isc_mempool_create(mgr->mctx, sizeof(dns_dispatchevent_t), + &mgr->epool) != ISC_R_SUCCESS) { + result = ISC_R_NOMEMORY; + goto kill_pool_lock; + } + + mgr->rpool = NULL; + if (isc_mempool_create(mgr->mctx, sizeof(dns_dispentry_t), + &mgr->rpool) != ISC_R_SUCCESS) { + result = ISC_R_NOMEMORY; + goto kill_epool; + } + + mgr->dpool = NULL; + if (isc_mempool_create(mgr->mctx, sizeof(dns_dispatch_t), + &mgr->dpool) != ISC_R_SUCCESS) { + result = ISC_R_NOMEMORY; + goto kill_rpool; + } + + isc_mempool_setname(mgr->epool, "dispmgr_epool"); + isc_mempool_setfreemax(mgr->epool, 1024); + isc_mempool_associatelock(mgr->epool, &mgr->pool_lock); + + isc_mempool_setname(mgr->rpool, "dispmgr_rpool"); + isc_mempool_setfreemax(mgr->rpool, 1024); + isc_mempool_associatelock(mgr->rpool, &mgr->pool_lock); + + isc_mempool_setname(mgr->dpool, "dispmgr_dpool"); + isc_mempool_setfreemax(mgr->dpool, 1024); + isc_mempool_associatelock(mgr->dpool, &mgr->pool_lock); + + mgr->buffers = 0; + mgr->buffersize = 0; + mgr->maxbuffers = 0; + mgr->bpool = NULL; + mgr->entropy = NULL; + mgr->qid = NULL; + mgr->state = 0; + ISC_LIST_INIT(mgr->list); + mgr->magic = DNS_DISPATCHMGR_MAGIC; + + if (entropy != NULL) + isc_entropy_attach(entropy, &mgr->entropy); + + *mgrp = mgr; + return (ISC_R_SUCCESS); + + kill_rpool: + isc_mempool_destroy(&mgr->rpool); + kill_epool: + isc_mempool_destroy(&mgr->epool); + kill_pool_lock: + DESTROYLOCK(&mgr->pool_lock); + kill_buffer_lock: + DESTROYLOCK(&mgr->buffer_lock); + kill_lock: + DESTROYLOCK(&mgr->lock); + deallocate: + isc_mem_put(mctx, mgr, sizeof(dns_dispatchmgr_t)); + isc_mem_detach(&mctx); + + return (result); +} + +void +dns_dispatchmgr_setblackhole(dns_dispatchmgr_t *mgr, dns_acl_t *blackhole) { + REQUIRE(VALID_DISPATCHMGR(mgr)); + if (mgr->blackhole != NULL) + dns_acl_detach(&mgr->blackhole); + dns_acl_attach(blackhole, &mgr->blackhole); +} + +dns_acl_t * +dns_dispatchmgr_getblackhole(dns_dispatchmgr_t *mgr) { + REQUIRE(VALID_DISPATCHMGR(mgr)); + return (mgr->blackhole); +} + +void +dns_dispatchmgr_setblackportlist(dns_dispatchmgr_t *mgr, + dns_portlist_t *portlist) +{ + REQUIRE(VALID_DISPATCHMGR(mgr)); + if (mgr->portlist != NULL) + dns_portlist_detach(&mgr->portlist); + if (portlist != NULL) + dns_portlist_attach(portlist, &mgr->portlist); +} + +dns_portlist_t * +dns_dispatchmgr_getblackportlist(dns_dispatchmgr_t *mgr) { + REQUIRE(VALID_DISPATCHMGR(mgr)); + return (mgr->portlist); +} + +static isc_result_t +dns_dispatchmgr_setudp(dns_dispatchmgr_t *mgr, + unsigned int buffersize, unsigned int maxbuffers, + unsigned int buckets, unsigned int increment) +{ + isc_result_t result; + + REQUIRE(VALID_DISPATCHMGR(mgr)); + REQUIRE(buffersize >= 512 && buffersize < (64 * 1024)); + REQUIRE(maxbuffers > 0); + REQUIRE(buckets < 2097169); /* next prime > 65536 * 32 */ + REQUIRE(increment > buckets); + + /* + * Keep some number of items around. This should be a config + * option. For now, keep 8, but later keep at least two even + * if the caller wants less. This allows us to ensure certain + * things, like an event can be "freed" and the next allocation + * will always succeed. + * + * Note that if limits are placed on anything here, we use one + * event internally, so the actual limit should be "wanted + 1." + * + * XXXMLG + */ + + if (maxbuffers < 8) + maxbuffers = 8; + + LOCK(&mgr->buffer_lock); + if (mgr->bpool != NULL) { + isc_mempool_setmaxalloc(mgr->bpool, maxbuffers); + mgr->maxbuffers = maxbuffers; + UNLOCK(&mgr->buffer_lock); + return (ISC_R_SUCCESS); + } + + if (isc_mempool_create(mgr->mctx, buffersize, + &mgr->bpool) != ISC_R_SUCCESS) { + return (ISC_R_NOMEMORY); + } + + isc_mempool_setname(mgr->bpool, "dispmgr_bpool"); + isc_mempool_setmaxalloc(mgr->bpool, maxbuffers); + isc_mempool_associatelock(mgr->bpool, &mgr->pool_lock); + + result = qid_allocate(mgr, buckets, increment, &mgr->qid); + if (result != ISC_R_SUCCESS) + goto cleanup; + + mgr->buffersize = buffersize; + mgr->maxbuffers = maxbuffers; + UNLOCK(&mgr->buffer_lock); + return (ISC_R_SUCCESS); + + cleanup: + isc_mempool_destroy(&mgr->bpool); + UNLOCK(&mgr->buffer_lock); + return (ISC_R_NOMEMORY); +} + +void +dns_dispatchmgr_destroy(dns_dispatchmgr_t **mgrp) { + dns_dispatchmgr_t *mgr; + isc_boolean_t killit; + + REQUIRE(mgrp != NULL); + REQUIRE(VALID_DISPATCHMGR(*mgrp)); + + mgr = *mgrp; + *mgrp = NULL; + + LOCK(&mgr->lock); + mgr->state |= MGR_SHUTTINGDOWN; + + killit = destroy_mgr_ok(mgr); + UNLOCK(&mgr->lock); + + mgr_log(mgr, LVL(90), "destroy: killit=%d", killit); + + if (killit) + destroy_mgr(&mgr); +} + +static isc_boolean_t +blacklisted(dns_dispatchmgr_t *mgr, isc_socket_t *sock) { + isc_sockaddr_t sockaddr; + isc_result_t result; + + if (mgr->portlist == NULL) + return (ISC_FALSE); + + result = isc_socket_getsockname(sock, &sockaddr); + if (result != ISC_R_SUCCESS) + return (ISC_FALSE); + + if (mgr->portlist != NULL && + dns_portlist_match(mgr->portlist, isc_sockaddr_pf(&sockaddr), + isc_sockaddr_getport(&sockaddr))) + return (ISC_TRUE); + return (ISC_FALSE); +} + +#define ATTRMATCH(_a1, _a2, _mask) (((_a1) & (_mask)) == ((_a2) & (_mask))) + +static isc_boolean_t +local_addr_match(dns_dispatch_t *disp, isc_sockaddr_t *addr) { + isc_sockaddr_t sockaddr; + isc_result_t result; + + if (addr == NULL) + return (ISC_TRUE); + + /* + * Don't match wildcard ports against newly blacklisted ports. + */ + if (disp->mgr->portlist != NULL && + isc_sockaddr_getport(addr) == 0 && + isc_sockaddr_getport(&disp->local) == 0 && + blacklisted(disp->mgr, disp->socket)) + return (ISC_FALSE); + + /* + * Check if we match the binding <address,port>. + * Wildcard ports match/fail here. + */ + if (isc_sockaddr_equal(&disp->local, addr)) + return (ISC_TRUE); + if (isc_sockaddr_getport(addr) == 0) + return (ISC_FALSE); + + /* + * Check if we match a bound wildcard port <address,port>. + */ + if (!isc_sockaddr_eqaddr(&disp->local, addr)) + return (ISC_FALSE); + result = isc_socket_getsockname(disp->socket, &sockaddr); + if (result != ISC_R_SUCCESS) + return (ISC_FALSE); + + return (isc_sockaddr_equal(&sockaddr, addr)); +} + +/* + * Requires mgr be locked. + * + * No dispatcher can be locked by this thread when calling this function. + * + * + * NOTE: + * If a matching dispatcher is found, it is locked after this function + * returns, and must be unlocked by the caller. + */ +static isc_result_t +dispatch_find(dns_dispatchmgr_t *mgr, isc_sockaddr_t *local, + unsigned int attributes, unsigned int mask, + dns_dispatch_t **dispp) +{ + dns_dispatch_t *disp; + isc_result_t result; + + /* + * Make certain that we will not match a private dispatch. + */ + attributes &= ~DNS_DISPATCHATTR_PRIVATE; + mask |= DNS_DISPATCHATTR_PRIVATE; + + disp = ISC_LIST_HEAD(mgr->list); + while (disp != NULL) { + LOCK(&disp->lock); + if ((disp->shutting_down == 0) + && ATTRMATCH(disp->attributes, attributes, mask) + && local_addr_match(disp, local)) + break; + UNLOCK(&disp->lock); + disp = ISC_LIST_NEXT(disp, link); + } + + if (disp == NULL) { + result = ISC_R_NOTFOUND; + goto out; + } + + *dispp = disp; + result = ISC_R_SUCCESS; + out: + + return (result); +} + +static isc_result_t +qid_allocate(dns_dispatchmgr_t *mgr, unsigned int buckets, + unsigned int increment, dns_qid_t **qidp) +{ + dns_qid_t *qid; + unsigned int i; + + REQUIRE(VALID_DISPATCHMGR(mgr)); + REQUIRE(buckets < 2097169); /* next prime > 65536 * 32 */ + REQUIRE(increment > buckets); + REQUIRE(qidp != NULL && *qidp == NULL); + + qid = isc_mem_get(mgr->mctx, sizeof(*qid)); + if (qid == NULL) + return (ISC_R_NOMEMORY); + + qid->qid_table = isc_mem_get(mgr->mctx, + buckets * sizeof(dns_displist_t)); + if (qid->qid_table == NULL) { + isc_mem_put(mgr->mctx, qid, sizeof(*qid)); + return (ISC_R_NOMEMORY); + } + + if (isc_mutex_init(&qid->lock) != ISC_R_SUCCESS) { + UNEXPECTED_ERROR(__FILE__, __LINE__, "isc_mutex_init failed"); + isc_mem_put(mgr->mctx, qid->qid_table, + buckets * sizeof(dns_displist_t)); + isc_mem_put(mgr->mctx, qid, sizeof(*qid)); + return (ISC_R_UNEXPECTED); + } + + for (i = 0; i < buckets; i++) + ISC_LIST_INIT(qid->qid_table[i]); + + qid->qid_nbuckets = buckets; + qid->qid_increment = increment; + qid->magic = QID_MAGIC; + + /* + * Initialize to a 32-bit LFSR. Both of these are from Applied + * Cryptography. + * + * lfsr1: + * x^32 + x^7 + x^5 + x^3 + x^2 + x + 1 + * + * lfsr2: + * x^32 + x^7 + x^6 + x^2 + 1 + */ + isc_lfsr_init(&qid->qid_lfsr1, 0, 32, 0x80000057U, + 0, reseed_lfsr, mgr); + isc_lfsr_init(&qid->qid_lfsr2, 0, 32, 0x80000062U, + 0, reseed_lfsr, mgr); + *qidp = qid; + return (ISC_R_SUCCESS); +} + +static void +qid_destroy(isc_mem_t *mctx, dns_qid_t **qidp) { + dns_qid_t *qid; + + REQUIRE(qidp != NULL); + qid = *qidp; + + REQUIRE(VALID_QID(qid)); + + *qidp = NULL; + qid->magic = 0; + isc_mem_put(mctx, qid->qid_table, + qid->qid_nbuckets * sizeof(dns_displist_t)); + DESTROYLOCK(&qid->lock); + isc_mem_put(mctx, qid, sizeof(*qid)); +} + +/* + * Allocate and set important limits. + */ +static isc_result_t +dispatch_allocate(dns_dispatchmgr_t *mgr, unsigned int maxrequests, + dns_dispatch_t **dispp) +{ + dns_dispatch_t *disp; + isc_result_t res; + + REQUIRE(VALID_DISPATCHMGR(mgr)); + REQUIRE(dispp != NULL && *dispp == NULL); + + /* + * Set up the dispatcher, mostly. Don't bother setting some of + * the options that are controlled by tcp vs. udp, etc. + */ + + disp = isc_mempool_get(mgr->dpool); + if (disp == NULL) + return (ISC_R_NOMEMORY); + + disp->magic = 0; + disp->mgr = mgr; + disp->maxrequests = maxrequests; + disp->attributes = 0; + ISC_LINK_INIT(disp, link); + disp->refcount = 1; + disp->recv_pending = 0; + memset(&disp->local, 0, sizeof(disp->local)); + disp->shutting_down = 0; + disp->shutdown_out = 0; + disp->connected = 0; + disp->tcpmsg_valid = 0; + disp->shutdown_why = ISC_R_UNEXPECTED; + disp->requests = 0; + disp->tcpbuffers = 0; + disp->qid = NULL; + + if (isc_mutex_init(&disp->lock) != ISC_R_SUCCESS) { + res = ISC_R_UNEXPECTED; + UNEXPECTED_ERROR(__FILE__, __LINE__, "isc_mutex_init failed"); + goto deallocate; + } + + disp->failsafe_ev = allocate_event(disp); + if (disp->failsafe_ev == NULL) { + res = ISC_R_NOMEMORY; + goto kill_lock; + } + + disp->magic = DISPATCH_MAGIC; + + *dispp = disp; + return (ISC_R_SUCCESS); + + /* + * error returns + */ + kill_lock: + DESTROYLOCK(&disp->lock); + deallocate: + isc_mempool_put(mgr->dpool, disp); + + return (res); +} + + +/* + * MUST be unlocked, and not used by anthing. + */ +static void +dispatch_free(dns_dispatch_t **dispp) +{ + dns_dispatch_t *disp; + dns_dispatchmgr_t *mgr; + + REQUIRE(VALID_DISPATCH(*dispp)); + disp = *dispp; + *dispp = NULL; + + mgr = disp->mgr; + REQUIRE(VALID_DISPATCHMGR(mgr)); + + if (disp->tcpmsg_valid) { + dns_tcpmsg_invalidate(&disp->tcpmsg); + disp->tcpmsg_valid = 0; + } + + INSIST(disp->tcpbuffers == 0); + INSIST(disp->requests == 0); + INSIST(disp->recv_pending == 0); + + isc_mempool_put(mgr->epool, disp->failsafe_ev); + disp->failsafe_ev = NULL; + + if (disp->qid != NULL) + qid_destroy(mgr->mctx, &disp->qid); + disp->mgr = NULL; + DESTROYLOCK(&disp->lock); + disp->magic = 0; + isc_mempool_put(mgr->dpool, disp); +} + +isc_result_t +dns_dispatch_createtcp(dns_dispatchmgr_t *mgr, isc_socket_t *sock, + isc_taskmgr_t *taskmgr, unsigned int buffersize, + unsigned int maxbuffers, unsigned int maxrequests, + unsigned int buckets, unsigned int increment, + unsigned int attributes, dns_dispatch_t **dispp) +{ + isc_result_t result; + dns_dispatch_t *disp; + + UNUSED(maxbuffers); + UNUSED(buffersize); + + REQUIRE(VALID_DISPATCHMGR(mgr)); + REQUIRE(isc_socket_gettype(sock) == isc_sockettype_tcp); + REQUIRE((attributes & DNS_DISPATCHATTR_TCP) != 0); + REQUIRE((attributes & DNS_DISPATCHATTR_UDP) == 0); + + attributes |= DNS_DISPATCHATTR_PRIVATE; /* XXXMLG */ + + LOCK(&mgr->lock); + + /* + * dispatch_allocate() checks mgr for us. + * qid_allocate() checks buckets and increment for us. + */ + disp = NULL; + result = dispatch_allocate(mgr, maxrequests, &disp); + if (result != ISC_R_SUCCESS) { + UNLOCK(&mgr->lock); + return (result); + } + + result = qid_allocate(mgr, buckets, increment, &disp->qid); + if (result != ISC_R_SUCCESS) + goto deallocate_dispatch; + + disp->socktype = isc_sockettype_tcp; + disp->socket = NULL; + isc_socket_attach(sock, &disp->socket); + + disp->task = NULL; + result = isc_task_create(taskmgr, 0, &disp->task); + if (result != ISC_R_SUCCESS) + goto kill_socket; + + disp->ctlevent = isc_event_allocate(mgr->mctx, disp, + DNS_EVENT_DISPATCHCONTROL, + destroy_disp, disp, + sizeof(isc_event_t)); + if (disp->ctlevent == NULL) + goto kill_task; + + isc_task_setname(disp->task, "tcpdispatch", disp); + + dns_tcpmsg_init(mgr->mctx, disp->socket, &disp->tcpmsg); + disp->tcpmsg_valid = 1; + + disp->attributes = attributes; + + /* + * Append it to the dispatcher list. + */ + ISC_LIST_APPEND(mgr->list, disp, link); + UNLOCK(&mgr->lock); + + mgr_log(mgr, LVL(90), "created TCP dispatcher %p", disp); + dispatch_log(disp, LVL(90), "created task %p", disp->task); + + *dispp = disp; + + return (ISC_R_SUCCESS); + + /* + * Error returns. + */ + kill_task: + isc_task_detach(&disp->task); + kill_socket: + isc_socket_detach(&disp->socket); + deallocate_dispatch: + dispatch_free(&disp); + + UNLOCK(&mgr->lock); + + return (result); +} + +isc_result_t +dns_dispatch_getudp(dns_dispatchmgr_t *mgr, isc_socketmgr_t *sockmgr, + isc_taskmgr_t *taskmgr, isc_sockaddr_t *localaddr, + unsigned int buffersize, + unsigned int maxbuffers, unsigned int maxrequests, + unsigned int buckets, unsigned int increment, + unsigned int attributes, unsigned int mask, + dns_dispatch_t **dispp) +{ + isc_result_t result; + dns_dispatch_t *disp; + + REQUIRE(VALID_DISPATCHMGR(mgr)); + REQUIRE(sockmgr != NULL); + REQUIRE(localaddr != NULL); + REQUIRE(taskmgr != NULL); + REQUIRE(buffersize >= 512 && buffersize < (64 * 1024)); + REQUIRE(maxbuffers > 0); + REQUIRE(buckets < 2097169); /* next prime > 65536 * 32 */ + REQUIRE(increment > buckets); + REQUIRE(dispp != NULL && *dispp == NULL); + REQUIRE((attributes & DNS_DISPATCHATTR_TCP) == 0); + + result = dns_dispatchmgr_setudp(mgr, buffersize, maxbuffers, + buckets, increment); + if (result != ISC_R_SUCCESS) + return (result); + + LOCK(&mgr->lock); + + /* + * First, see if we have a dispatcher that matches. + */ + disp = NULL; + result = dispatch_find(mgr, localaddr, attributes, mask, &disp); + if (result == ISC_R_SUCCESS) { + disp->refcount++; + + if (disp->maxrequests < maxrequests) + disp->maxrequests = maxrequests; + + if ((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) == 0 && + (attributes & DNS_DISPATCHATTR_NOLISTEN) != 0) + { + disp->attributes |= DNS_DISPATCHATTR_NOLISTEN; + if (disp->recv_pending != 0) + isc_socket_cancel(disp->socket, disp->task, + ISC_SOCKCANCEL_RECV); + } + + UNLOCK(&disp->lock); + UNLOCK(&mgr->lock); + + *dispp = disp; + + return (ISC_R_SUCCESS); + } + + /* + * Nope, create one. + */ + result = dispatch_createudp(mgr, sockmgr, taskmgr, localaddr, + maxrequests, attributes, &disp); + if (result != ISC_R_SUCCESS) { + UNLOCK(&mgr->lock); + return (result); + } + + UNLOCK(&mgr->lock); + *dispp = disp; + return (ISC_R_SUCCESS); +} + +/* + * mgr should be locked. + */ +static isc_result_t +dispatch_createudp(dns_dispatchmgr_t *mgr, isc_socketmgr_t *sockmgr, + isc_taskmgr_t *taskmgr, + isc_sockaddr_t *localaddr, + unsigned int maxrequests, + unsigned int attributes, + dns_dispatch_t **dispp) +{ + isc_result_t result; + dns_dispatch_t *disp; + isc_socket_t *sock; + + /* + * dispatch_allocate() checks mgr for us. + */ + disp = NULL; + result = dispatch_allocate(mgr, maxrequests, &disp); + if (result != ISC_R_SUCCESS) + return (result); + + /* + * This assumes that the IP stack will *not* quickly reallocate + * the same port. If it does continually reallocate the same port + * then we need a mechanism to hold all the blacklisted sockets + * until we find a usable socket. + */ + getsocket: + result = create_socket(sockmgr, localaddr, &sock); + if (result != ISC_R_SUCCESS) + goto deallocate_dispatch; + if (isc_sockaddr_getport(localaddr) == 0 && blacklisted(mgr, sock)) { + isc_socket_detach(&sock); + goto getsocket; + } + + disp->socktype = isc_sockettype_udp; + disp->socket = sock; + disp->local = *localaddr; + + disp->task = NULL; + result = isc_task_create(taskmgr, 0, &disp->task); + if (result != ISC_R_SUCCESS) + goto kill_socket; + + disp->ctlevent = isc_event_allocate(mgr->mctx, disp, + DNS_EVENT_DISPATCHCONTROL, + destroy_disp, disp, + sizeof(isc_event_t)); + if (disp->ctlevent == NULL) + goto kill_task; + + isc_task_setname(disp->task, "udpdispatch", disp); + + attributes &= ~DNS_DISPATCHATTR_TCP; + attributes |= DNS_DISPATCHATTR_UDP; + disp->attributes = attributes; + + /* + * Append it to the dispatcher list. + */ + ISC_LIST_APPEND(mgr->list, disp, link); + + mgr_log(mgr, LVL(90), "created UDP dispatcher %p", disp); + dispatch_log(disp, LVL(90), "created task %p", disp->task); + dispatch_log(disp, LVL(90), "created socket %p", disp->socket); + + *dispp = disp; + + return (ISC_R_SUCCESS); + + /* + * Error returns. + */ + kill_task: + isc_task_detach(&disp->task); + kill_socket: + isc_socket_detach(&disp->socket); + deallocate_dispatch: + dispatch_free(&disp); + + return (result); +} + +void +dns_dispatch_attach(dns_dispatch_t *disp, dns_dispatch_t **dispp) { + REQUIRE(VALID_DISPATCH(disp)); + REQUIRE(dispp != NULL && *dispp == NULL); + + LOCK(&disp->lock); + disp->refcount++; + UNLOCK(&disp->lock); + + *dispp = disp; +} + +/* + * It is important to lock the manager while we are deleting the dispatch, + * since dns_dispatch_getudp will call dispatch_find, which returns to + * the caller a dispatch but does not attach to it until later. _getudp + * locks the manager, however, so locking it here will keep us from attaching + * to a dispatcher that is in the process of going away. + */ +void +dns_dispatch_detach(dns_dispatch_t **dispp) { + dns_dispatch_t *disp; + isc_boolean_t killit; + + REQUIRE(dispp != NULL && VALID_DISPATCH(*dispp)); + + disp = *dispp; + *dispp = NULL; + + LOCK(&disp->lock); + + INSIST(disp->refcount > 0); + disp->refcount--; + killit = ISC_FALSE; + if (disp->refcount == 0) { + if (disp->recv_pending > 0) + isc_socket_cancel(disp->socket, disp->task, + ISC_SOCKCANCEL_RECV); + disp->shutting_down = 1; + } + + dispatch_log(disp, LVL(90), "detach: refcount %d", disp->refcount); + + killit = destroy_disp_ok(disp); + UNLOCK(&disp->lock); + if (killit) + isc_task_send(disp->task, &disp->ctlevent); +} + +isc_result_t +dns_dispatch_addresponse(dns_dispatch_t *disp, isc_sockaddr_t *dest, + isc_task_t *task, isc_taskaction_t action, void *arg, + dns_messageid_t *idp, dns_dispentry_t **resp) +{ + dns_dispentry_t *res; + unsigned int bucket; + dns_messageid_t id; + int i; + isc_boolean_t ok; + dns_qid_t *qid; + + REQUIRE(VALID_DISPATCH(disp)); + REQUIRE(task != NULL); + REQUIRE(dest != NULL); + REQUIRE(resp != NULL && *resp == NULL); + REQUIRE(idp != NULL); + + LOCK(&disp->lock); + + if (disp->shutting_down == 1) { + UNLOCK(&disp->lock); + return (ISC_R_SHUTTINGDOWN); + } + + if (disp->requests >= disp->maxrequests) { + UNLOCK(&disp->lock); + return (ISC_R_QUOTA); + } + + /* + * Try somewhat hard to find an unique ID. + */ + qid = DNS_QID(disp); + LOCK(&qid->lock); + id = dns_randomid(qid); + bucket = dns_hash(qid, dest, id); + ok = ISC_FALSE; + for (i = 0; i < 64; i++) { + if (bucket_search(qid, dest, id, bucket) == NULL) { + ok = ISC_TRUE; + break; + } + id += qid->qid_increment; + id &= 0x0000ffff; + bucket = dns_hash(qid, dest, id); + } + + if (!ok) { + UNLOCK(&qid->lock); + UNLOCK(&disp->lock); + return (ISC_R_NOMORE); + } + + res = isc_mempool_get(disp->mgr->rpool); + if (res == NULL) { + UNLOCK(&qid->lock); + UNLOCK(&disp->lock); + return (ISC_R_NOMEMORY); + } + + disp->refcount++; + disp->requests++; + res->task = NULL; + isc_task_attach(task, &res->task); + res->disp = disp; + res->id = id; + res->bucket = bucket; + res->host = *dest; + res->action = action; + res->arg = arg; + res->item_out = ISC_FALSE; + ISC_LIST_INIT(res->items); + ISC_LINK_INIT(res, link); + res->magic = RESPONSE_MAGIC; + ISC_LIST_APPEND(qid->qid_table[bucket], res, link); + UNLOCK(&qid->lock); + + request_log(disp, res, LVL(90), + "attached to task %p", res->task); + + if (((disp->attributes & DNS_DISPATCHATTR_UDP) != 0) || + ((disp->attributes & DNS_DISPATCHATTR_CONNECTED) != 0)) + startrecv(disp); + + UNLOCK(&disp->lock); + + *idp = id; + *resp = res; + + return (ISC_R_SUCCESS); +} + +void +dns_dispatch_starttcp(dns_dispatch_t *disp) { + + REQUIRE(VALID_DISPATCH(disp)); + + dispatch_log(disp, LVL(90), "starttcp %p", disp->task); + + LOCK(&disp->lock); + disp->attributes |= DNS_DISPATCHATTR_CONNECTED; + startrecv(disp); + UNLOCK(&disp->lock); +} + +void +dns_dispatch_removeresponse(dns_dispentry_t **resp, + dns_dispatchevent_t **sockevent) +{ + dns_dispatchmgr_t *mgr; + dns_dispatch_t *disp; + dns_dispentry_t *res; + dns_dispatchevent_t *ev; + unsigned int bucket; + isc_boolean_t killit; + unsigned int n; + isc_eventlist_t events; + dns_qid_t *qid; + + REQUIRE(resp != NULL); + REQUIRE(VALID_RESPONSE(*resp)); + + res = *resp; + *resp = NULL; + + disp = res->disp; + REQUIRE(VALID_DISPATCH(disp)); + mgr = disp->mgr; + REQUIRE(VALID_DISPATCHMGR(mgr)); + + qid = DNS_QID(disp); + + if (sockevent != NULL) { + REQUIRE(*sockevent != NULL); + ev = *sockevent; + *sockevent = NULL; + } else { + ev = NULL; + } + + LOCK(&disp->lock); + + INSIST(disp->requests > 0); + disp->requests--; + INSIST(disp->refcount > 0); + disp->refcount--; + killit = ISC_FALSE; + if (disp->refcount == 0) { + if (disp->recv_pending > 0) + isc_socket_cancel(disp->socket, disp->task, + ISC_SOCKCANCEL_RECV); + disp->shutting_down = 1; + } + + bucket = res->bucket; + + LOCK(&qid->lock); + ISC_LIST_UNLINK(qid->qid_table[bucket], res, link); + UNLOCK(&qid->lock); + + if (ev == NULL && res->item_out) { + /* + * We've posted our event, but the caller hasn't gotten it + * yet. Take it back. + */ + ISC_LIST_INIT(events); + n = isc_task_unsend(res->task, res, DNS_EVENT_DISPATCH, + NULL, &events); + /* + * We had better have gotten it back. + */ + INSIST(n == 1); + ev = (dns_dispatchevent_t *)ISC_LIST_HEAD(events); + } + + if (ev != NULL) { + REQUIRE(res->item_out == ISC_TRUE); + res->item_out = ISC_FALSE; + if (ev->buffer.base != NULL) + free_buffer(disp, ev->buffer.base, ev->buffer.length); + free_event(disp, ev); + } + + request_log(disp, res, LVL(90), "detaching from task %p", res->task); + isc_task_detach(&res->task); + + /* + * Free any buffered requests as well + */ + ev = ISC_LIST_HEAD(res->items); + while (ev != NULL) { + ISC_LIST_UNLINK(res->items, ev, ev_link); + if (ev->buffer.base != NULL) + free_buffer(disp, ev->buffer.base, ev->buffer.length); + free_event(disp, ev); + ev = ISC_LIST_HEAD(res->items); + } + res->magic = 0; + isc_mempool_put(disp->mgr->rpool, res); + if (disp->shutting_down == 1) + do_cancel(disp); + else + startrecv(disp); + + killit = destroy_disp_ok(disp); + UNLOCK(&disp->lock); + if (killit) + isc_task_send(disp->task, &disp->ctlevent); +} + +static void +do_cancel(dns_dispatch_t *disp) { + dns_dispatchevent_t *ev; + dns_dispentry_t *resp; + dns_qid_t *qid; + + if (disp->shutdown_out == 1) + return; + + qid = DNS_QID(disp); + + /* + * Search for the first response handler without packets outstanding. + */ + LOCK(&qid->lock); + for (resp = linear_first(qid); + resp != NULL && resp->item_out != ISC_FALSE; + /* Empty. */) + resp = linear_next(qid, resp); + /* + * No one to send the cancel event to, so nothing to do. + */ + if (resp == NULL) + goto unlock; + + /* + * Send the shutdown failsafe event to this resp. + */ + ev = disp->failsafe_ev; + ISC_EVENT_INIT(ev, sizeof(*ev), 0, NULL, DNS_EVENT_DISPATCH, + resp->action, resp->arg, resp, NULL, NULL); + ev->result = disp->shutdown_why; + ev->buffer.base = NULL; + ev->buffer.length = 0; + disp->shutdown_out = 1; + request_log(disp, resp, LVL(10), + "cancel: failsafe event %p -> task %p", + ev, resp->task); + resp->item_out = ISC_TRUE; + isc_task_send(resp->task, ISC_EVENT_PTR(&ev)); + unlock: + UNLOCK(&qid->lock); +} + +isc_socket_t * +dns_dispatch_getsocket(dns_dispatch_t *disp) { + REQUIRE(VALID_DISPATCH(disp)); + + return (disp->socket); +} + +isc_result_t +dns_dispatch_getlocaladdress(dns_dispatch_t *disp, isc_sockaddr_t *addrp) { + + REQUIRE(VALID_DISPATCH(disp)); + REQUIRE(addrp != NULL); + + if (disp->socktype == isc_sockettype_udp) { + *addrp = disp->local; + return (ISC_R_SUCCESS); + } + return (ISC_R_NOTIMPLEMENTED); +} + +void +dns_dispatch_cancel(dns_dispatch_t *disp) { + REQUIRE(VALID_DISPATCH(disp)); + + LOCK(&disp->lock); + + if (disp->shutting_down == 1) { + UNLOCK(&disp->lock); + return; + } + + disp->shutdown_why = ISC_R_CANCELED; + disp->shutting_down = 1; + do_cancel(disp); + + UNLOCK(&disp->lock); + + return; +} + +void +dns_dispatch_changeattributes(dns_dispatch_t *disp, + unsigned int attributes, unsigned int mask) +{ + REQUIRE(VALID_DISPATCH(disp)); + + /* XXXMLG + * Should check for valid attributes here! + */ + + LOCK(&disp->lock); + + if ((mask & DNS_DISPATCHATTR_NOLISTEN) != 0) { + if ((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) != 0 && + (attributes & DNS_DISPATCHATTR_NOLISTEN) == 0) { + disp->attributes &= ~DNS_DISPATCHATTR_NOLISTEN; + startrecv(disp); + } else if ((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) + == 0 && + (attributes & DNS_DISPATCHATTR_NOLISTEN) != 0) { + disp->attributes |= DNS_DISPATCHATTR_NOLISTEN; + if (disp->recv_pending != 0) + isc_socket_cancel(disp->socket, disp->task, + ISC_SOCKCANCEL_RECV); + } + } + + disp->attributes &= ~mask; + disp->attributes |= (attributes & mask); + UNLOCK(&disp->lock); +} + +void +dns_dispatch_importrecv(dns_dispatch_t *disp, isc_event_t *event) { + void *buf; + isc_socketevent_t *sevent, *newsevent; + + REQUIRE(VALID_DISPATCH(disp)); + REQUIRE((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) != 0); + REQUIRE(event != NULL); + + sevent = (isc_socketevent_t *)event; + + INSIST(sevent->n <= disp->mgr->buffersize); + newsevent = (isc_socketevent_t *) + isc_event_allocate(disp->mgr->mctx, NULL, + DNS_EVENT_IMPORTRECVDONE, udp_recv, + disp, sizeof(isc_socketevent_t)); + if (newsevent == NULL) + return; + + buf = allocate_udp_buffer(disp); + if (buf == NULL) { + isc_event_free(ISC_EVENT_PTR(&newsevent)); + return; + } + memcpy(buf, sevent->region.base, sevent->n); + newsevent->region.base = buf; + newsevent->region.length = disp->mgr->buffersize; + newsevent->n = sevent->n; + newsevent->result = sevent->result; + newsevent->address = sevent->address; + newsevent->timestamp = sevent->timestamp; + newsevent->pktinfo = sevent->pktinfo; + newsevent->attributes = sevent->attributes; + + isc_task_send(disp->task, ISC_EVENT_PTR(&newsevent)); +} + +#if 0 +void +dns_dispatchmgr_dump(dns_dispatchmgr_t *mgr) { + dns_dispatch_t *disp; + char foo[1024]; + + disp = ISC_LIST_HEAD(mgr->list); + while (disp != NULL) { + isc_sockaddr_format(&disp->local, foo, sizeof(foo)); + printf("\tdispatch %p, addr %s\n", disp, foo); + disp = ISC_LIST_NEXT(disp, link); + } +} +#endif |
