lwdgabn.c revision 0c27b3fe77ac1d5094ba3521e8142d9e7973133f
/*
* Copyright (C) 2000, 2001, 2004-2007, 2009, 2016 Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
/* $Id: lwdgabn.c,v 1.24 2009/09/02 23:48:01 tbox Exp $ */
/*! \file */
#include <config.h>
#include <stdlib.h>
#include <isc/netaddr.h>
#include <isc/sockaddr.h>
#include <isc/socket.h>
#include <isc/string.h> /* Required for HP/UX (and others?) */
#include <isc/util.h>
#include <dns/adb.h>
#include <dns/events.h>
#include <dns/result.h>
#include <named/types.h>
#include <named/lwaddr.h>
#include <named/lwdclient.h>
#include <named/lwresd.h>
#include <named/lwsearch.h>
#include <named/sortlist.h>
#define NEED_V4(c) ((((c)->find_wanted & LWRES_ADDRTYPE_V4) != 0) \
&& ((c)->v4find == NULL))
#define NEED_V6(c) ((((c)->find_wanted & LWRES_ADDRTYPE_V6) != 0) \
&& ((c)->v6find == NULL))
static isc_result_t start_find(ns_lwdclient_t *);
static void restart_find(ns_lwdclient_t *);
static void init_gabn(ns_lwdclient_t *);
/*%
* Destroy any finds. This can be used to "start over from scratch" and
* should only be called when events are _not_ being generated by the finds.
*/
static void
cleanup_gabn(ns_lwdclient_t *client) {
ns_lwdclient_log(50, "cleaning up client %p", client);
if (client->v6find != NULL) {
if (client->v6find == client->v4find)
client->v6find = NULL;
else
dns_adb_destroyfind(&client->v6find);
}
if (client->v4find != NULL)
dns_adb_destroyfind(&client->v4find);
}
static void
setup_addresses(ns_lwdclient_t *client, dns_adbfind_t *find, unsigned int at) {
dns_adbaddrinfo_t *ai;
lwres_addr_t *addr;
int af;
const struct sockaddr *sa;
isc_result_t result;
if (at == DNS_ADBFIND_INET)
af = AF_INET;
else
af = AF_INET6;
ai = ISC_LIST_HEAD(find->list);
while (ai != NULL && client->gabn.naddrs < LWRES_MAX_ADDRS) {
sa = &ai->sockaddr.type.sa;
if (sa->sa_family != af)
goto next;
addr = &client->addrs[client->gabn.naddrs];
result = lwaddr_lwresaddr_fromsockaddr(addr, &ai->sockaddr);
if (result != ISC_R_SUCCESS)
goto next;
ns_lwdclient_log(50, "adding address %p, family %d, length %d",
addr->address, addr->family, addr->length);
client->gabn.naddrs++;
REQUIRE(!LWRES_LINK_LINKED(addr, link));
LWRES_LIST_APPEND(client->gabn.addrs, addr, link);
next:
ai = ISC_LIST_NEXT(ai, publink);
}
}
typedef struct {
isc_netaddr_t address;
int rank;
} rankedaddress;
static int
addr_compare(const void *av, const void *bv) {
const rankedaddress *a = (const rankedaddress *) av;
const rankedaddress *b = (const rankedaddress *) bv;
return (a->rank - b->rank);
}
static void
sort_addresses(ns_lwdclient_t *client) {
unsigned int naddrs;
rankedaddress *addrs;
isc_netaddr_t remote;
dns_addressorderfunc_t order;
const void *arg;
ns_lwresd_t *lwresd = client->clientmgr->listener->manager;
unsigned int i;
isc_result_t result;
naddrs = client->gabn.naddrs;
if (naddrs <= 1 || lwresd->view->sortlist == NULL)
return;
addrs = isc_mem_get(lwresd->mctx, sizeof(rankedaddress) * naddrs);
if (addrs == NULL)
return;
isc_netaddr_fromsockaddr(&remote, &client->address);
ns_sortlist_byaddrsetup(lwresd->view->sortlist,
&remote, &order, &arg);
if (order == NULL) {
isc_mem_put(lwresd->mctx, addrs,
sizeof(rankedaddress) * naddrs);
return;
}
for (i = 0; i < naddrs; i++) {
result = lwaddr_netaddr_fromlwresaddr(&addrs[i].address,
&client->addrs[i]);
INSIST(result == ISC_R_SUCCESS);
addrs[i].rank = (*order)(&addrs[i].address, arg);
}
qsort(addrs, naddrs, sizeof(rankedaddress), addr_compare);
for (i = 0; i < naddrs; i++) {
result = lwaddr_lwresaddr_fromnetaddr(&client->addrs[i],
&addrs[i].address);
INSIST(result == ISC_R_SUCCESS);
}
isc_mem_put(lwresd->mctx, addrs, sizeof(rankedaddress) * naddrs);
}
static void
generate_reply(ns_lwdclient_t *client) {
isc_result_t result;
int lwres;
isc_region_t r;
lwres_buffer_t lwb;
ns_lwdclientmgr_t *cm;
cm = client->clientmgr;
lwb.base = NULL;
ns_lwdclient_log(50, "generating gabn reply for client %p", client);
/*
* We must make certain the client->find is not still active.
* If it is either the v4 or v6 answer, just set it to NULL and
* let the cleanup code destroy it. Otherwise, destroy it now.
*/
if (client->find == client->v4find || client->find == client->v6find)
client->find = NULL;
else
if (client->find != NULL)
dns_adb_destroyfind(&client->find);
/*
* perhaps there are some here?
*/
if (NEED_V6(client) && client->v4find != NULL)
client->v6find = client->v4find;
/*
* Run through the finds we have and wire them up to the gabn
* structure.
*/
LWRES_LIST_INIT(client->gabn.addrs);
if (client->v4find != NULL)
setup_addresses(client, client->v4find, DNS_ADBFIND_INET);
if (client->v6find != NULL)
setup_addresses(client, client->v6find, DNS_ADBFIND_INET6);
/*
* If there are no addresses, try the next element in the search
* path, if there are any more. Otherwise, fall through into
* the error handling code below.
*/
if (client->gabn.naddrs == 0) {
do {
result = ns_lwsearchctx_next(&client->searchctx);
if (result == ISC_R_SUCCESS) {
cleanup_gabn(client);
result = start_find(client);
if (result == ISC_R_SUCCESS)
return;
}
} while (result == ISC_R_SUCCESS);
}
/*
* Render the packet.
*/
client->pkt.recvlength = LWRES_RECVLENGTH;
client->pkt.authtype = 0; /* XXXMLG */
client->pkt.authlength = 0;
/*
* If there are no addresses, return failure.
*/
if (client->gabn.naddrs != 0)
client->pkt.result = LWRES_R_SUCCESS;
else
client->pkt.result = LWRES_R_NOTFOUND;
sort_addresses(client);
lwres = lwres_gabnresponse_render(cm->lwctx, &client->gabn,
&client->pkt, &lwb);
if (lwres != LWRES_R_SUCCESS)
goto out;
r.base = lwb.base;
r.length = lwb.used;
client->sendbuf = r.base;
client->sendlength = r.length;
result = ns_lwdclient_sendreply(client, &r);
if (result != ISC_R_SUCCESS)
goto out;
NS_LWDCLIENT_SETSEND(client);
/*
* All done!
*/
cleanup_gabn(client);
return;
out:
cleanup_gabn(client);
if (lwb.base != NULL)
lwres_context_freemem(client->clientmgr->lwctx,
lwb.base, lwb.length);
ns_lwdclient_errorpktsend(client, LWRES_R_FAILURE);
}
/*
* Take the current real name, move it to an alias slot (if any are
* open) then put this new name in as the real name for the target.
*
* Return success if it can be rendered, otherwise failure. Note that
* not having enough alias slots open is NOT a failure.
*/
static isc_result_t
add_alias(ns_lwdclient_t *client) {
isc_buffer_t b;
isc_result_t result;
isc_uint16_t naliases;
b = client->recv_buffer;
/*
* Render the new name to the buffer.
*/
result = dns_name_totext(dns_fixedname_name(&client->target_name),
ISC_TRUE, &client->recv_buffer);
if (result != ISC_R_SUCCESS)
return (result);
/*
* Are there any open slots?
*/
naliases = client->gabn.naliases;
if (naliases < LWRES_MAX_ALIASES) {
client->gabn.aliases[naliases] = client->gabn.realname;
client->gabn.aliaslen[naliases] = client->gabn.realnamelen;
client->gabn.naliases++;
}
/*
* Save this name away as the current real name.
*/
client->gabn.realname = (char *)(b.base) + b.used;
client->gabn.realnamelen = client->recv_buffer.used - b.used;
return (ISC_R_SUCCESS);
}
static isc_result_t
store_realname(ns_lwdclient_t *client) {
isc_buffer_t b;
isc_result_t result;
dns_name_t *tname;
b = client->recv_buffer;
tname = dns_fixedname_name(&client->target_name);
result = ns_lwsearchctx_current(&client->searchctx, tname);
if (result != ISC_R_SUCCESS)
return (result);
/*
* Render the new name to the buffer.
*/
result = dns_name_totext(tname, ISC_TRUE, &client->recv_buffer);
if (result != ISC_R_SUCCESS)
return (result);
/*
* Save this name away as the current real name.
*/
client->gabn.realname = (char *) b.base + b.used;
client->gabn.realnamelen = client->recv_buffer.used - b.used;
return (ISC_R_SUCCESS);
}
static void
process_gabn_finddone(isc_task_t *task, isc_event_t *ev) {
ns_lwdclient_t *client = ev->ev_arg;
isc_eventtype_t evtype;
isc_boolean_t claimed;
ns_lwdclient_log(50, "find done for task %p, client %p", task, client);
evtype = ev->ev_type;
isc_event_free(&ev);
/*
* No more info to be had? If so, we have all the good stuff
* right now, so we can render things.
*/
claimed = ISC_FALSE;
if (evtype == DNS_EVENT_ADBNOMOREADDRESSES) {
if (NEED_V4(client)) {
client->v4find = client->find;
claimed = ISC_TRUE;
}
if (NEED_V6(client)) {
client->v6find = client->find;
claimed = ISC_TRUE;
}
if (client->find != NULL) {
if (claimed)
client->find = NULL;
else
dns_adb_destroyfind(&client->find);
}
generate_reply(client);
return;
}
/*
* We probably don't need this find anymore. We're either going to
* reissue it, or an error occurred. Either way, we're done with
* it.
*/
if ((client->find != client->v4find)
&& (client->find != client->v6find)) {
dns_adb_destroyfind(&client->find);
} else {
client->find = NULL;
}
/*
* We have some new information we can gather. Run off and fetch
* it.
*/
if (evtype == DNS_EVENT_ADBMOREADDRESSES) {
restart_find(client);
return;
}
/*
* An error or other strangeness happened. Drop this query.
*/
cleanup_gabn(client);
ns_lwdclient_errorpktsend(client, LWRES_R_FAILURE);
}
static void
restart_find(ns_lwdclient_t *client) {
unsigned int options;
isc_result_t result;
isc_boolean_t claimed;
ns_lwdclient_log(50, "starting find for client %p", client);
/*
* Issue a find for the name contained in the request. We won't
* set the bit that says "anything is good enough" -- we want it
* all.
*/
options = 0;
options |= DNS_ADBFIND_WANTEVENT;
options |= DNS_ADBFIND_RETURNLAME;
/*
* Set the bits up here to mark that we want this address family
* and that we do not currently have a find pending. We will
* set that bit again below if it turns out we will get an event.
*/
if (NEED_V4(client))
options |= DNS_ADBFIND_INET;
if (NEED_V6(client))
options |= DNS_ADBFIND_INET6;
find_again:
INSIST(client->find == NULL);
result = dns_adb_createfind(client->clientmgr->view->adb,
client->clientmgr->task,
process_gabn_finddone, client,
dns_fixedname_name(&client->target_name),
dns_rootname, 0, options, 0,
dns_fixedname_name(&client->target_name),
client->clientmgr->view->dstport,
&client->find);
/*
* Did we get an alias? If so, save it and re-issue the query.
*/
if (result == DNS_R_ALIAS) {
ns_lwdclient_log(50, "found alias, restarting query");
dns_adb_destroyfind(&client->find);
cleanup_gabn(client);
result = add_alias(client);
if (result != ISC_R_SUCCESS) {
ns_lwdclient_log(50,
"out of buffer space adding alias");
ns_lwdclient_errorpktsend(client, LWRES_R_FAILURE);
return;
}
goto find_again;
}
ns_lwdclient_log(50, "find returned %d (%s)", result,
isc_result_totext(result));
/*
* Did we get an error?
*/
if (result != ISC_R_SUCCESS) {
if (client->find != NULL)
dns_adb_destroyfind(&client->find);
cleanup_gabn(client);
ns_lwdclient_errorpktsend(client, LWRES_R_FAILURE);
return;
}
claimed = ISC_FALSE;
/*
* Did we get our answer to V4 addresses?
*/
if (NEED_V4(client)
&& ((client->find->query_pending & DNS_ADBFIND_INET) == 0)) {
ns_lwdclient_log(50, "client %p ipv4 satisfied by find %p",
client, client->find);
claimed = ISC_TRUE;
client->v4find = client->find;
}
/*
* Did we get our answer to V6 addresses?
*/
if (NEED_V6(client)
&& ((client->find->query_pending & DNS_ADBFIND_INET6) == 0)) {
ns_lwdclient_log(50, "client %p ipv6 satisfied by find %p",
client, client->find);
claimed = ISC_TRUE;
client->v6find = client->find;
}
/*
* If we're going to get an event, set our internal pending flag
* and return. When we get an event back we'll do the right
* thing, basically by calling this function again, perhaps with a
* new target name.
*
* If we have both v4 and v6, and we are still getting an event,
* we have a programming error, so die hard.
*/
if ((client->find->options & DNS_ADBFIND_WANTEVENT) != 0) {
ns_lwdclient_log(50, "event will be sent");
INSIST(client->v4find == NULL || client->v6find == NULL);
return;
}
ns_lwdclient_log(50, "no event will be sent");
if (claimed)
client->find = NULL;
else
dns_adb_destroyfind(&client->find);
/*
* We seem to have everything we asked for, or at least we are
* able to respond with things we've learned.
*/
generate_reply(client);
}
static isc_result_t
start_find(ns_lwdclient_t *client) {
isc_result_t result;
/*
* Initialize the real name and alias arrays in the reply we're
* going to build up.
*/
init_gabn(client);
result = store_realname(client);
if (result != ISC_R_SUCCESS)
return (result);
restart_find(client);
return (ISC_R_SUCCESS);
}
static void
init_gabn(ns_lwdclient_t *client) {
int i;
/*
* Initialize the real name and alias arrays in the reply we're
* going to build up.
*/
for (i = 0; i < LWRES_MAX_ALIASES; i++) {
client->aliases[i] = NULL;
client->aliaslen[i] = 0;
}
for (i = 0; i < LWRES_MAX_ADDRS; i++) {
client->addrs[i].family = 0;
client->addrs[i].length = 0;
memset(client->addrs[i].address, 0, LWRES_ADDR_MAXLEN);
LWRES_LINK_INIT(&client->addrs[i], link);
}
client->gabn.naliases = 0;
client->gabn.naddrs = 0;
client->gabn.realname = NULL;
client->gabn.aliases = client->aliases;
client->gabn.realnamelen = 0;
client->gabn.aliaslen = client->aliaslen;
LWRES_LIST_INIT(client->gabn.addrs);
client->gabn.base = NULL;
client->gabn.baselen = 0;
/*
* Set up the internal buffer to point to the receive region.
*/
isc_buffer_init(&client->recv_buffer, client->buffer, LWRES_RECVLENGTH);
}
/*
* When we are called, we can be assured that:
*
* client->sockaddr contains the address we need to reply to,
*
* client->pkt contains the packet header data,
*
* the packet "checks out" overall -- any MD5 hashes or crypto
* bits have been verified,
*
* "b" points to the remaining data after the packet header
* was parsed off.
*
* We are in a the RECVDONE state.
*
* From this state we will enter the SEND state if we happen to have
* everything we need or we need to return an error packet, or to the
* FINDWAIT state if we need to look things up.
*/
void
ns_lwdclient_processgabn(ns_lwdclient_t *client, lwres_buffer_t *b) {
isc_result_t result;
lwres_gabnrequest_t *req;
ns_lwdclientmgr_t *cm;
isc_buffer_t namebuf;
REQUIRE(NS_LWDCLIENT_ISRECVDONE(client));
cm = client->clientmgr;
req = NULL;
result = lwres_gabnrequest_parse(client->clientmgr->lwctx,
b, &client->pkt, &req);
if (result != LWRES_R_SUCCESS)
goto out;
if (req->name == NULL)
goto out;
isc_buffer_init(&namebuf, req->name, req->namelen);
isc_buffer_add(&namebuf, req->namelen);
dns_fixedname_init(&client->target_name);
dns_fixedname_init(&client->query_name);
result = dns_name_fromtext(dns_fixedname_name(&client->query_name),
&namebuf, NULL, 0, NULL);
if (result != ISC_R_SUCCESS)
goto out;
ns_lwsearchctx_init(&client->searchctx,
cm->listener->manager->search,
dns_fixedname_name(&client->query_name),
cm->listener->manager->ndots);
ns_lwsearchctx_first(&client->searchctx);
client->find_wanted = req->addrtypes;
ns_lwdclient_log(50, "client %p looking for addrtypes %08x",
client, client->find_wanted);
/*
* We no longer need to keep this around.
*/
lwres_gabnrequest_free(client->clientmgr->lwctx, &req);
/*
* Start the find.
*/
result = start_find(client);
if (result != ISC_R_SUCCESS)
goto out;
return;
/*
* We're screwed. Return an error packet to our caller.
*/
out:
if (req != NULL)
lwres_gabnrequest_free(client->clientmgr->lwctx, &req);
ns_lwdclient_errorpktsend(client, LWRES_R_FAILURE);
}