/* $NetBSD: client.c,v 1.4.4.2 2024/02/29 12:34:29 martin Exp $ */ /* * Copyright (C) Internet Systems Consortium, Inc. ("ISC") * * SPDX-License-Identifier: MPL-2.0 * * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, you can obtain one at https://mozilla.org/MPL/2.0/. * * See the COPYRIGHT file distributed with this work for additional * information regarding copyright ownership. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DNS_CLIENT_MAGIC ISC_MAGIC('D', 'N', 'S', 'c') #define DNS_CLIENT_VALID(c) ISC_MAGIC_VALID(c, DNS_CLIENT_MAGIC) #define RCTX_MAGIC ISC_MAGIC('R', 'c', 't', 'x') #define RCTX_VALID(c) ISC_MAGIC_VALID(c, RCTX_MAGIC) #define UCTX_MAGIC ISC_MAGIC('U', 'c', 't', 'x') #define UCTX_VALID(c) ISC_MAGIC_VALID(c, UCTX_MAGIC) #define MAX_RESTARTS 16 #ifdef TUNE_LARGE #define RESOLVER_NTASKS 523 #else /* ifdef TUNE_LARGE */ #define RESOLVER_NTASKS 31 #endif /* TUNE_LARGE */ #define CHECK(r) \ do { \ result = (r); \ if (result != ISC_R_SUCCESS) \ goto cleanup; \ } while (0) /*% * DNS client object */ struct dns_client { /* Unlocked */ unsigned int magic; unsigned int attributes; isc_mutex_t lock; isc_mem_t *mctx; isc_appctx_t *actx; isc_taskmgr_t *taskmgr; isc_task_t *task; isc_nm_t *nm; isc_timermgr_t *timermgr; dns_dispatchmgr_t *dispatchmgr; dns_dispatch_t *dispatchv4; dns_dispatch_t *dispatchv6; unsigned int find_timeout; unsigned int find_udpretries; isc_refcount_t references; /* Locked */ dns_viewlist_t viewlist; ISC_LIST(struct resctx) resctxs; }; #define DEF_FIND_TIMEOUT 5 #define DEF_FIND_UDPRETRIES 3 /*% * Internal state for a single name resolution procedure */ typedef struct resctx { /* Unlocked */ unsigned int magic; isc_mutex_t lock; dns_client_t *client; bool want_dnssec; bool want_validation; bool want_cdflag; bool want_tcp; /* Locked */ ISC_LINK(struct resctx) link; isc_task_t *task; dns_view_t *view; unsigned int restarts; dns_fixedname_t name; dns_rdatatype_t type; dns_fetch_t *fetch; dns_namelist_t namelist; isc_result_t result; dns_clientresevent_t *event; bool canceled; dns_rdataset_t *rdataset; dns_rdataset_t *sigrdataset; } resctx_t; /*% * Argument of an internal event for synchronous name resolution. */ typedef struct resarg { /* Unlocked */ isc_appctx_t *actx; dns_client_t *client; isc_mutex_t lock; /* Locked */ isc_result_t result; isc_result_t vresult; dns_namelist_t *namelist; dns_clientrestrans_t *trans; bool canceled; } resarg_t; static void client_resfind(resctx_t *rctx, dns_fetchevent_t *event); static void cancelresolve(dns_clientrestrans_t *trans); static void destroyrestrans(dns_clientrestrans_t **transp); /* * Try honoring the operating system's preferred ephemeral port range. */ static isc_result_t setsourceports(isc_mem_t *mctx, dns_dispatchmgr_t *manager) { isc_portset_t *v4portset = NULL, *v6portset = NULL; in_port_t udpport_low, udpport_high; isc_result_t result; result = isc_portset_create(mctx, &v4portset); if (result != ISC_R_SUCCESS) { goto cleanup; } result = isc_net_getudpportrange(AF_INET, &udpport_low, &udpport_high); if (result != ISC_R_SUCCESS) { goto cleanup; } isc_portset_addrange(v4portset, udpport_low, udpport_high); result = isc_portset_create(mctx, &v6portset); if (result != ISC_R_SUCCESS) { goto cleanup; } result = isc_net_getudpportrange(AF_INET6, &udpport_low, &udpport_high); if (result != ISC_R_SUCCESS) { goto cleanup; } isc_portset_addrange(v6portset, udpport_low, udpport_high); result = dns_dispatchmgr_setavailports(manager, v4portset, v6portset); cleanup: if (v4portset != NULL) { isc_portset_destroy(mctx, &v4portset); } if (v6portset != NULL) { isc_portset_destroy(mctx, &v6portset); } return (result); } static isc_result_t getudpdispatch(int family, dns_dispatchmgr_t *dispatchmgr, dns_dispatch_t **dispp, const isc_sockaddr_t *localaddr) { dns_dispatch_t *disp = NULL; isc_result_t result; isc_sockaddr_t anyaddr; if (localaddr == NULL) { isc_sockaddr_anyofpf(&anyaddr, family); localaddr = &anyaddr; } result = dns_dispatch_createudp(dispatchmgr, localaddr, &disp); if (result == ISC_R_SUCCESS) { *dispp = disp; } return (result); } static isc_result_t createview(isc_mem_t *mctx, dns_rdataclass_t rdclass, isc_taskmgr_t *taskmgr, unsigned int ntasks, isc_nm_t *nm, isc_timermgr_t *timermgr, dns_dispatchmgr_t *dispatchmgr, dns_dispatch_t *dispatchv4, dns_dispatch_t *dispatchv6, dns_view_t **viewp) { isc_result_t result; dns_view_t *view = NULL; result = dns_view_create(mctx, rdclass, DNS_CLIENTVIEW_NAME, &view); if (result != ISC_R_SUCCESS) { return (result); } /* Initialize view security roots */ result = dns_view_initsecroots(view, mctx); if (result != ISC_R_SUCCESS) { dns_view_detach(&view); return (result); } result = dns_view_createresolver(view, taskmgr, ntasks, 1, nm, timermgr, 0, dispatchmgr, dispatchv4, dispatchv6); if (result != ISC_R_SUCCESS) { dns_view_detach(&view); return (result); } result = dns_db_create(mctx, "rbt", dns_rootname, dns_dbtype_cache, rdclass, 0, NULL, &view->cachedb); if (result != ISC_R_SUCCESS) { dns_view_detach(&view); return (result); } *viewp = view; return (ISC_R_SUCCESS); } isc_result_t dns_client_create(isc_mem_t *mctx, isc_appctx_t *actx, isc_taskmgr_t *taskmgr, isc_nm_t *nm, isc_timermgr_t *timermgr, unsigned int options, dns_client_t **clientp, const isc_sockaddr_t *localaddr4, const isc_sockaddr_t *localaddr6) { isc_result_t result; dns_client_t *client = NULL; dns_dispatch_t *dispatchv4 = NULL; dns_dispatch_t *dispatchv6 = NULL; dns_view_t *view = NULL; REQUIRE(mctx != NULL); REQUIRE(taskmgr != NULL); REQUIRE(timermgr != NULL); REQUIRE(nm != NULL); REQUIRE(clientp != NULL && *clientp == NULL); UNUSED(options); client = isc_mem_get(mctx, sizeof(*client)); *client = (dns_client_t){ .actx = actx, .taskmgr = taskmgr, .timermgr = timermgr, .nm = nm }; isc_mutex_init(&client->lock); result = isc_task_create(client->taskmgr, 0, &client->task); if (result != ISC_R_SUCCESS) { goto cleanup_lock; } result = dns_dispatchmgr_create(mctx, nm, &client->dispatchmgr); if (result != ISC_R_SUCCESS) { goto cleanup_task; } (void)setsourceports(mctx, client->dispatchmgr); /* * If only one address family is specified, use it. * If neither family is specified, or if both are, use both. */ client->dispatchv4 = NULL; if (localaddr4 != NULL || localaddr6 == NULL) { result = getudpdispatch(AF_INET, client->dispatchmgr, &dispatchv4, localaddr4); if (result == ISC_R_SUCCESS) { client->dispatchv4 = dispatchv4; } } client->dispatchv6 = NULL; if (localaddr6 != NULL || localaddr4 == NULL) { result = getudpdispatch(AF_INET6, client->dispatchmgr, &dispatchv6, localaddr6); if (result == ISC_R_SUCCESS) { client->dispatchv6 = dispatchv6; } } /* We need at least one of the dispatchers */ if (dispatchv4 == NULL && dispatchv6 == NULL) { INSIST(result != ISC_R_SUCCESS); goto cleanup_dispatchmgr; } isc_refcount_init(&client->references, 1); /* Create the default view for class IN */ result = createview(mctx, dns_rdataclass_in, taskmgr, RESOLVER_NTASKS, nm, timermgr, client->dispatchmgr, dispatchv4, dispatchv6, &view); if (result != ISC_R_SUCCESS) { goto cleanup_references; } ISC_LIST_INIT(client->viewlist); ISC_LIST_APPEND(client->viewlist, view, link); dns_view_freeze(view); /* too early? */ ISC_LIST_INIT(client->resctxs); isc_mem_attach(mctx, &client->mctx); client->find_timeout = DEF_FIND_TIMEOUT; client->find_udpretries = DEF_FIND_UDPRETRIES; client->magic = DNS_CLIENT_MAGIC; *clientp = client; return (ISC_R_SUCCESS); cleanup_references: isc_refcount_decrementz(&client->references); isc_refcount_destroy(&client->references); cleanup_dispatchmgr: if (dispatchv4 != NULL) { dns_dispatch_detach(&dispatchv4); } if (dispatchv6 != NULL) { dns_dispatch_detach(&dispatchv6); } dns_dispatchmgr_detach(&client->dispatchmgr); cleanup_task: isc_task_detach(&client->task); cleanup_lock: isc_mutex_destroy(&client->lock); isc_mem_put(mctx, client, sizeof(*client)); return (result); } static void destroyclient(dns_client_t *client) { dns_view_t *view = NULL; isc_refcount_destroy(&client->references); while ((view = ISC_LIST_HEAD(client->viewlist)) != NULL) { ISC_LIST_UNLINK(client->viewlist, view, link); dns_view_detach(&view); } if (client->dispatchv4 != NULL) { dns_dispatch_detach(&client->dispatchv4); } if (client->dispatchv6 != NULL) { dns_dispatch_detach(&client->dispatchv6); } dns_dispatchmgr_detach(&client->dispatchmgr); isc_task_detach(&client->task); isc_mutex_destroy(&client->lock); client->magic = 0; isc_mem_putanddetach(&client->mctx, client, sizeof(*client)); } void dns_client_detach(dns_client_t **clientp) { dns_client_t *client = NULL; REQUIRE(clientp != NULL); REQUIRE(DNS_CLIENT_VALID(*clientp)); client = *clientp; *clientp = NULL; if (isc_refcount_decrement(&client->references) == 1) { destroyclient(client); } } isc_result_t dns_client_setservers(dns_client_t *client, dns_rdataclass_t rdclass, const dns_name_t *name_space, isc_sockaddrlist_t *addrs) { isc_result_t result; dns_view_t *view = NULL; REQUIRE(DNS_CLIENT_VALID(client)); REQUIRE(addrs != NULL); if (name_space == NULL) { name_space = dns_rootname; } LOCK(&client->lock); result = dns_viewlist_find(&client->viewlist, DNS_CLIENTVIEW_NAME, rdclass, &view); if (result != ISC_R_SUCCESS) { UNLOCK(&client->lock); return (result); } UNLOCK(&client->lock); result = dns_fwdtable_add(view->fwdtable, name_space, addrs, dns_fwdpolicy_only); dns_view_detach(&view); return (result); } isc_result_t dns_client_clearservers(dns_client_t *client, dns_rdataclass_t rdclass, const dns_name_t *name_space) { isc_result_t result; dns_view_t *view = NULL; REQUIRE(DNS_CLIENT_VALID(client)); if (name_space == NULL) { name_space = dns_rootname; } LOCK(&client->lock); result = dns_viewlist_find(&client->viewlist, DNS_CLIENTVIEW_NAME, rdclass, &view); if (result != ISC_R_SUCCESS) { UNLOCK(&client->lock); return (result); } UNLOCK(&client->lock); result = dns_fwdtable_delete(view->fwdtable, name_space); dns_view_detach(&view); return (result); } static isc_result_t getrdataset(isc_mem_t *mctx, dns_rdataset_t **rdatasetp) { dns_rdataset_t *rdataset; REQUIRE(mctx != NULL); REQUIRE(rdatasetp != NULL && *rdatasetp == NULL); rdataset = isc_mem_get(mctx, sizeof(*rdataset)); dns_rdataset_init(rdataset); *rdatasetp = rdataset; return (ISC_R_SUCCESS); } static void putrdataset(isc_mem_t *mctx, dns_rdataset_t **rdatasetp) { dns_rdataset_t *rdataset; REQUIRE(rdatasetp != NULL); rdataset = *rdatasetp; *rdatasetp = NULL; REQUIRE(rdataset != NULL); if (dns_rdataset_isassociated(rdataset)) { dns_rdataset_disassociate(rdataset); } isc_mem_put(mctx, rdataset, sizeof(*rdataset)); } static void fetch_done(isc_task_t *task, isc_event_t *event) { resctx_t *rctx = event->ev_arg; dns_fetchevent_t *fevent; REQUIRE(event->ev_type == DNS_EVENT_FETCHDONE); REQUIRE(RCTX_VALID(rctx)); REQUIRE(rctx->task == task); fevent = (dns_fetchevent_t *)event; client_resfind(rctx, fevent); } static isc_result_t start_fetch(resctx_t *rctx) { isc_result_t result; int fopts = 0; /* * The caller must be holding the rctx's lock. */ REQUIRE(rctx->fetch == NULL); if (!rctx->want_cdflag) { fopts |= DNS_FETCHOPT_NOCDFLAG; } if (!rctx->want_validation) { fopts |= DNS_FETCHOPT_NOVALIDATE; } if (rctx->want_tcp) { fopts |= DNS_FETCHOPT_TCP; } result = dns_resolver_createfetch( rctx->view->resolver, dns_fixedname_name(&rctx->name), rctx->type, NULL, NULL, NULL, NULL, 0, fopts, 0, NULL, rctx->task, fetch_done, rctx, rctx->rdataset, rctx->sigrdataset, &rctx->fetch); return (result); } static isc_result_t view_find(resctx_t *rctx, dns_db_t **dbp, dns_dbnode_t **nodep, dns_name_t *foundname) { isc_result_t result; dns_name_t *name = dns_fixedname_name(&rctx->name); dns_rdatatype_t type; if (rctx->type == dns_rdatatype_rrsig) { type = dns_rdatatype_any; } else { type = rctx->type; } result = dns_view_find(rctx->view, name, type, 0, 0, false, false, dbp, nodep, foundname, rctx->rdataset, rctx->sigrdataset); return (result); } static void client_resfind(resctx_t *rctx, dns_fetchevent_t *event) { isc_mem_t *mctx; isc_result_t tresult, result = ISC_R_SUCCESS; isc_result_t vresult = ISC_R_SUCCESS; bool want_restart; bool send_event = false; dns_name_t *name = NULL, *prefix = NULL; dns_fixedname_t foundname, fixed; dns_rdataset_t *trdataset = NULL; dns_rdata_t rdata = DNS_RDATA_INIT; unsigned int nlabels; int order; dns_namereln_t namereln; dns_rdata_cname_t cname; dns_rdata_dname_t dname; REQUIRE(RCTX_VALID(rctx)); LOCK(&rctx->lock); mctx = rctx->view->mctx; name = dns_fixedname_name(&rctx->name); do { dns_name_t *fname = NULL; dns_name_t *ansname = NULL; dns_db_t *db = NULL; dns_dbnode_t *node = NULL; rctx->restarts++; want_restart = false; if (event == NULL && !rctx->canceled) { fname = dns_fixedname_initname(&foundname); INSIST(!dns_rdataset_isassociated(rctx->rdataset)); INSIST(rctx->sigrdataset == NULL || !dns_rdataset_isassociated(rctx->sigrdataset)); result = view_find(rctx, &db, &node, fname); if (result == ISC_R_NOTFOUND) { /* * We don't know anything about the name. * Launch a fetch. */ if (node != NULL) { INSIST(db != NULL); dns_db_detachnode(db, &node); } if (db != NULL) { dns_db_detach(&db); } result = start_fetch(rctx); if (result != ISC_R_SUCCESS) { putrdataset(mctx, &rctx->rdataset); if (rctx->sigrdataset != NULL) { putrdataset(mctx, &rctx->sigrdataset); } send_event = true; } goto done; } } else { INSIST(event != NULL); INSIST(event->fetch == rctx->fetch); dns_resolver_destroyfetch(&rctx->fetch); db = event->db; node = event->node; result = event->result; vresult = event->vresult; fname = event->foundname; INSIST(event->rdataset == rctx->rdataset); INSIST(event->sigrdataset == rctx->sigrdataset); } /* * If we've been canceled, forget about the result. */ if (rctx->canceled) { result = ISC_R_CANCELED; } else { /* * Otherwise, get some resource for copying the * result. */ dns_name_t *aname = dns_fixedname_name(&rctx->name); ansname = isc_mem_get(mctx, sizeof(*ansname)); dns_name_init(ansname, NULL); dns_name_dup(aname, mctx, ansname); } switch (result) { case ISC_R_SUCCESS: send_event = true; /* * This case is handled in the main line below. */ break; case DNS_R_CNAME: /* * Add the CNAME to the answer list. */ trdataset = rctx->rdataset; ISC_LIST_APPEND(ansname->list, rctx->rdataset, link); rctx->rdataset = NULL; if (rctx->sigrdataset != NULL) { ISC_LIST_APPEND(ansname->list, rctx->sigrdataset, link); rctx->sigrdataset = NULL; } ISC_LIST_APPEND(rctx->namelist, ansname, link); ansname = NULL; /* * Copy the CNAME's target into the lookup's * query name and start over. */ tresult = dns_rdataset_first(trdataset); if (tresult != ISC_R_SUCCESS) { goto done; } dns_rdataset_current(trdataset, &rdata); tresult = dns_rdata_tostruct(&rdata, &cname, NULL); dns_rdata_reset(&rdata); if (tresult != ISC_R_SUCCESS) { goto done; } dns_name_copy(&cname.cname, name); dns_rdata_freestruct(&cname); want_restart = true; goto done; case DNS_R_DNAME: /* * Add the DNAME to the answer list. */ trdataset = rctx->rdataset; ISC_LIST_APPEND(ansname->list, rctx->rdataset, link); rctx->rdataset = NULL; if (rctx->sigrdataset != NULL) { ISC_LIST_APPEND(ansname->list, rctx->sigrdataset, link); rctx->sigrdataset = NULL; } ISC_LIST_APPEND(rctx->namelist, ansname, link); ansname = NULL; namereln = dns_name_fullcompare(name, fname, &order, &nlabels); INSIST(namereln == dns_namereln_subdomain); /* * Get the target name of the DNAME. */ tresult = dns_rdataset_first(trdataset); if (tresult != ISC_R_SUCCESS) { result = tresult; goto done; } dns_rdataset_current(trdataset, &rdata); tresult = dns_rdata_tostruct(&rdata, &dname, NULL); dns_rdata_reset(&rdata); if (tresult != ISC_R_SUCCESS) { result = tresult; goto done; } /* * Construct the new query name and start over. */ prefix = dns_fixedname_initname(&fixed); dns_name_split(name, nlabels, prefix, NULL); tresult = dns_name_concatenate(prefix, &dname.dname, name, NULL); dns_rdata_freestruct(&dname); if (tresult == ISC_R_SUCCESS) { want_restart = true; } else { result = tresult; } goto done; case DNS_R_NCACHENXDOMAIN: case DNS_R_NCACHENXRRSET: ISC_LIST_APPEND(ansname->list, rctx->rdataset, link); ISC_LIST_APPEND(rctx->namelist, ansname, link); ansname = NULL; rctx->rdataset = NULL; /* What about sigrdataset? */ if (rctx->sigrdataset != NULL) { putrdataset(mctx, &rctx->sigrdataset); } send_event = true; goto done; default: if (rctx->rdataset != NULL) { putrdataset(mctx, &rctx->rdataset); } if (rctx->sigrdataset != NULL) { putrdataset(mctx, &rctx->sigrdataset); } send_event = true; goto done; } if (rctx->type == dns_rdatatype_any) { int n = 0; dns_rdatasetiter_t *rdsiter = NULL; tresult = dns_db_allrdatasets(db, node, NULL, 0, 0, &rdsiter); if (tresult != ISC_R_SUCCESS) { result = tresult; goto done; } tresult = dns_rdatasetiter_first(rdsiter); while (tresult == ISC_R_SUCCESS) { dns_rdatasetiter_current(rdsiter, rctx->rdataset); if (rctx->rdataset->type != 0) { ISC_LIST_APPEND(ansname->list, rctx->rdataset, link); n++; rctx->rdataset = NULL; } else { /* * We're not interested in this * rdataset. */ dns_rdataset_disassociate( rctx->rdataset); } tresult = dns_rdatasetiter_next(rdsiter); if (tresult == ISC_R_SUCCESS && rctx->rdataset == NULL) { tresult = getrdataset(mctx, &rctx->rdataset); if (tresult != ISC_R_SUCCESS) { result = tresult; POST(result); break; } } } if (rctx->rdataset != NULL) { putrdataset(mctx, &rctx->rdataset); } if (rctx->sigrdataset != NULL) { putrdataset(mctx, &rctx->sigrdataset); } if (n == 0) { /* * We didn't match any rdatasets (which means * something went wrong in this * implementation). */ result = DNS_R_SERVFAIL; /* better code? */ POST(result); } else { ISC_LIST_APPEND(rctx->namelist, ansname, link); ansname = NULL; } dns_rdatasetiter_destroy(&rdsiter); if (tresult != ISC_R_NOMORE) { result = DNS_R_SERVFAIL; /* ditto */ } else { result = ISC_R_SUCCESS; } goto done; } else { /* * This is the "normal" case -- an ordinary question * to which we've got the answer. */ ISC_LIST_APPEND(ansname->list, rctx->rdataset, link); rctx->rdataset = NULL; if (rctx->sigrdataset != NULL) { ISC_LIST_APPEND(ansname->list, rctx->sigrdataset, link); rctx->sigrdataset = NULL; } ISC_LIST_APPEND(rctx->namelist, ansname, link); ansname = NULL; } done: /* * Free temporary resources */ if (ansname != NULL) { dns_rdataset_t *rdataset; while ((rdataset = ISC_LIST_HEAD(ansname->list)) != NULL) { ISC_LIST_UNLINK(ansname->list, rdataset, link); putrdataset(mctx, &rdataset); } dns_name_free(ansname, mctx); isc_mem_put(mctx, ansname, sizeof(*ansname)); } if (node != NULL) { dns_db_detachnode(db, &node); } if (db != NULL) { dns_db_detach(&db); } if (event != NULL) { isc_event_free(ISC_EVENT_PTR(&event)); } /* * Limit the number of restarts. */ if (want_restart && rctx->restarts == MAX_RESTARTS) { want_restart = false; result = ISC_R_QUOTA; send_event = true; } /* * Prepare further find with new resources */ if (want_restart) { INSIST(rctx->rdataset == NULL && rctx->sigrdataset == NULL); result = getrdataset(mctx, &rctx->rdataset); if (result == ISC_R_SUCCESS && rctx->want_dnssec) { result = getrdataset(mctx, &rctx->sigrdataset); if (result != ISC_R_SUCCESS) { putrdataset(mctx, &rctx->rdataset); } } if (result != ISC_R_SUCCESS) { want_restart = false; send_event = true; } } } while (want_restart); if (send_event) { isc_task_t *task; while ((name = ISC_LIST_HEAD(rctx->namelist)) != NULL) { ISC_LIST_UNLINK(rctx->namelist, name, link); ISC_LIST_APPEND(rctx->event->answerlist, name, link); } rctx->event->result = result; rctx->event->vresult = vresult; task = rctx->event->ev_sender; rctx->event->ev_sender = rctx; isc_task_sendanddetach(&task, ISC_EVENT_PTR(&rctx->event)); } UNLOCK(&rctx->lock); } static void suspend(isc_task_t *task, isc_event_t *event) { isc_appctx_t *actx = event->ev_arg; UNUSED(task); isc_app_ctxsuspend(actx); isc_event_free(&event); } static void resolve_done(isc_task_t *task, isc_event_t *event) { resarg_t *resarg = event->ev_arg; dns_clientresevent_t *rev = (dns_clientresevent_t *)event; dns_name_t *name = NULL; dns_client_t *client = resarg->client; isc_result_t result; UNUSED(task); LOCK(&resarg->lock); resarg->result = rev->result; resarg->vresult = rev->vresult; while ((name = ISC_LIST_HEAD(rev->answerlist)) != NULL) { ISC_LIST_UNLINK(rev->answerlist, name, link); ISC_LIST_APPEND(*resarg->namelist, name, link); } destroyrestrans(&resarg->trans); isc_event_free(&event); resarg->client = NULL; if (!resarg->canceled) { UNLOCK(&resarg->lock); /* * We may or may not be running. isc__appctx_onrun will * fail if we are currently running otherwise we post a * action to call isc_app_ctxsuspend when we do start * running. */ result = isc_app_ctxonrun(resarg->actx, client->mctx, task, suspend, resarg->actx); if (result == ISC_R_ALREADYRUNNING) { isc_app_ctxsuspend(resarg->actx); } } else { /* * We have already exited from the loop (due to some * unexpected event). Just clean the arg up. */ UNLOCK(&resarg->lock); isc_mutex_destroy(&resarg->lock); isc_mem_put(client->mctx, resarg, sizeof(*resarg)); } dns_client_detach(&client); } isc_result_t dns_client_resolve(dns_client_t *client, const dns_name_t *name, dns_rdataclass_t rdclass, dns_rdatatype_t type, unsigned int options, dns_namelist_t *namelist) { isc_result_t result; resarg_t *resarg = NULL; REQUIRE(DNS_CLIENT_VALID(client)); REQUIRE(client->actx != NULL); REQUIRE(namelist != NULL && ISC_LIST_EMPTY(*namelist)); resarg = isc_mem_get(client->mctx, sizeof(*resarg)); *resarg = (resarg_t){ .actx = client->actx, .client = client, .result = DNS_R_SERVFAIL, .namelist = namelist, }; isc_mutex_init(&resarg->lock); result = dns_client_startresolve(client, name, rdclass, type, options, client->task, resolve_done, resarg, &resarg->trans); if (result != ISC_R_SUCCESS) { isc_mutex_destroy(&resarg->lock); isc_mem_put(client->mctx, resarg, sizeof(*resarg)); return (result); } /* * Start internal event loop. It blocks until the entire process * is completed. */ result = isc_app_ctxrun(client->actx); LOCK(&resarg->lock); if (result == ISC_R_SUCCESS || result == ISC_R_SUSPEND) { result = resarg->result; } if (result != ISC_R_SUCCESS && resarg->vresult != ISC_R_SUCCESS) { /* * If this lookup failed due to some error in DNSSEC * validation, return the validation error code. * XXX: or should we pass the validation result separately? */ result = resarg->vresult; } if (resarg->trans != NULL) { /* * Unusual termination (perhaps due to signal). We need some * tricky cleanup process. */ resarg->canceled = true; cancelresolve(resarg->trans); UNLOCK(&resarg->lock); /* resarg will be freed in the event handler. */ } else { UNLOCK(&resarg->lock); isc_mutex_destroy(&resarg->lock); isc_mem_put(client->mctx, resarg, sizeof(*resarg)); } return (result); } isc_result_t dns_client_startresolve(dns_client_t *client, const dns_name_t *name, dns_rdataclass_t rdclass, dns_rdatatype_t type, unsigned int options, isc_task_t *task, isc_taskaction_t action, void *arg, dns_clientrestrans_t **transp) { dns_view_t *view = NULL; dns_clientresevent_t *event = NULL; resctx_t *rctx = NULL; isc_task_t *tclone = NULL; isc_mem_t *mctx; isc_result_t result; dns_rdataset_t *rdataset, *sigrdataset; bool want_dnssec, want_validation, want_cdflag, want_tcp; REQUIRE(DNS_CLIENT_VALID(client)); REQUIRE(transp != NULL && *transp == NULL); LOCK(&client->lock); result = dns_viewlist_find(&client->viewlist, DNS_CLIENTVIEW_NAME, rdclass, &view); UNLOCK(&client->lock); if (result != ISC_R_SUCCESS) { return (result); } mctx = client->mctx; rdataset = NULL; sigrdataset = NULL; want_dnssec = ((options & DNS_CLIENTRESOPT_NODNSSEC) == 0); want_validation = ((options & DNS_CLIENTRESOPT_NOVALIDATE) == 0); want_cdflag = ((options & DNS_CLIENTRESOPT_NOCDFLAG) == 0); want_tcp = ((options & DNS_CLIENTRESOPT_TCP) != 0); /* * Prepare some intermediate resources */ tclone = NULL; isc_task_attach(task, &tclone); event = (dns_clientresevent_t *)isc_event_allocate( mctx, tclone, DNS_EVENT_CLIENTRESDONE, action, arg, sizeof(*event)); event->result = DNS_R_SERVFAIL; ISC_LIST_INIT(event->answerlist); rctx = isc_mem_get(mctx, sizeof(*rctx)); isc_mutex_init(&rctx->lock); result = getrdataset(mctx, &rdataset); if (result != ISC_R_SUCCESS) { goto cleanup; } rctx->rdataset = rdataset; if (want_dnssec) { result = getrdataset(mctx, &sigrdataset); if (result != ISC_R_SUCCESS) { goto cleanup; } } rctx->sigrdataset = sigrdataset; dns_fixedname_init(&rctx->name); dns_name_copy(name, dns_fixedname_name(&rctx->name)); rctx->client = client; ISC_LINK_INIT(rctx, link); rctx->canceled = false; rctx->task = client->task; rctx->type = type; rctx->view = view; rctx->restarts = 0; rctx->fetch = NULL; rctx->want_dnssec = want_dnssec; rctx->want_validation = want_validation; rctx->want_cdflag = want_cdflag; rctx->want_tcp = want_tcp; ISC_LIST_INIT(rctx->namelist); rctx->event = event; rctx->magic = RCTX_MAGIC; isc_refcount_increment(&client->references); LOCK(&client->lock); ISC_LIST_APPEND(client->resctxs, rctx, link); UNLOCK(&client->lock); *transp = (dns_clientrestrans_t *)rctx; client_resfind(rctx, NULL); return (ISC_R_SUCCESS); cleanup: if (rdataset != NULL) { putrdataset(client->mctx, &rdataset); } if (sigrdataset != NULL) { putrdataset(client->mctx, &sigrdataset); } isc_mutex_destroy(&rctx->lock); isc_mem_put(mctx, rctx, sizeof(*rctx)); isc_event_free(ISC_EVENT_PTR(&event)); isc_task_detach(&tclone); dns_view_detach(&view); return (result); } /*%< * Cancel an ongoing resolution procedure started via * dns_client_startresolve(). * * If the resolution procedure has not completed, post its CLIENTRESDONE * event with a result code of #ISC_R_CANCELED. */ static void cancelresolve(dns_clientrestrans_t *trans) { resctx_t *rctx = NULL; REQUIRE(trans != NULL); rctx = (resctx_t *)trans; REQUIRE(RCTX_VALID(rctx)); LOCK(&rctx->lock); if (!rctx->canceled) { rctx->canceled = true; if (rctx->fetch != NULL) { dns_resolver_cancelfetch(rctx->fetch); } } UNLOCK(&rctx->lock); } void dns_client_freeresanswer(dns_client_t *client, dns_namelist_t *namelist) { dns_name_t *name; dns_rdataset_t *rdataset; REQUIRE(DNS_CLIENT_VALID(client)); REQUIRE(namelist != NULL); while ((name = ISC_LIST_HEAD(*namelist)) != NULL) { ISC_LIST_UNLINK(*namelist, name, link); while ((rdataset = ISC_LIST_HEAD(name->list)) != NULL) { ISC_LIST_UNLINK(name->list, rdataset, link); putrdataset(client->mctx, &rdataset); } dns_name_free(name, client->mctx); isc_mem_put(client->mctx, name, sizeof(*name)); } } /*% * Destroy name resolution transaction state identified by '*transp'. * * The caller must have received the CLIENTRESDONE event (either because the * resolution completed or because cancelresolve() was called). */ static void destroyrestrans(dns_clientrestrans_t **transp) { resctx_t *rctx = NULL; isc_mem_t *mctx = NULL; dns_client_t *client = NULL; REQUIRE(transp != NULL); rctx = (resctx_t *)*transp; *transp = NULL; REQUIRE(RCTX_VALID(rctx)); REQUIRE(rctx->fetch == NULL); REQUIRE(rctx->event == NULL); client = rctx->client; REQUIRE(DNS_CLIENT_VALID(client)); mctx = client->mctx; dns_view_detach(&rctx->view); /* * Wait for the lock in client_resfind to be released before * destroying the lock. */ LOCK(&rctx->lock); UNLOCK(&rctx->lock); LOCK(&client->lock); INSIST(ISC_LINK_LINKED(rctx, link)); ISC_LIST_UNLINK(client->resctxs, rctx, link); UNLOCK(&client->lock); INSIST(ISC_LIST_EMPTY(rctx->namelist)); isc_mutex_destroy(&rctx->lock); rctx->magic = 0; isc_mem_put(mctx, rctx, sizeof(*rctx)); } isc_result_t dns_client_addtrustedkey(dns_client_t *client, dns_rdataclass_t rdclass, dns_rdatatype_t rdtype, const dns_name_t *keyname, isc_buffer_t *databuf) { isc_result_t result; dns_view_t *view = NULL; dns_keytable_t *secroots = NULL; dns_name_t *name = NULL; char rdatabuf[DST_KEY_MAXSIZE]; unsigned char digest[ISC_MAX_MD_SIZE]; dns_rdata_ds_t ds; dns_decompress_t dctx; dns_rdata_t rdata; isc_buffer_t b; REQUIRE(DNS_CLIENT_VALID(client)); LOCK(&client->lock); result = dns_viewlist_find(&client->viewlist, DNS_CLIENTVIEW_NAME, rdclass, &view); UNLOCK(&client->lock); CHECK(result); CHECK(dns_view_getsecroots(view, &secroots)); DE_CONST(keyname, name); if (rdtype != dns_rdatatype_dnskey && rdtype != dns_rdatatype_ds) { result = ISC_R_NOTIMPLEMENTED; goto cleanup; } isc_buffer_init(&b, rdatabuf, sizeof(rdatabuf)); dns_decompress_init(&dctx, -1, DNS_DECOMPRESS_NONE); dns_rdata_init(&rdata); isc_buffer_setactive(databuf, isc_buffer_usedlength(databuf)); CHECK(dns_rdata_fromwire(&rdata, rdclass, rdtype, databuf, &dctx, 0, &b)); dns_decompress_invalidate(&dctx); if (rdtype == dns_rdatatype_ds) { CHECK(dns_rdata_tostruct(&rdata, &ds, NULL)); } else { CHECK(dns_ds_fromkeyrdata(name, &rdata, DNS_DSDIGEST_SHA256, digest, &ds)); } CHECK(dns_keytable_add(secroots, false, false, name, &ds, NULL, NULL)); cleanup: if (view != NULL) { dns_view_detach(&view); } if (secroots != NULL) { dns_keytable_detach(&secroots); } return (result); }