From 5125d3032220be03a1e89a4e7e4b752620a45fee Mon Sep 17 00:00:00 2001 From: Kai Blin Date: Sat, 25 May 2013 13:15:31 +0200 Subject: [PATCH 2/2] dns: Support larger queries when asking forwarder This should fix bug #9632 Signed-off-by: Kai Blin --- source4/dns_server/dns_query.c | 13 +++++++++++++ source4/dns_server/dns_server.c | 2 ++ source4/dns_server/dns_server.h | 4 ++++ source4/dns_server/dns_utils.c | 21 +++++++++++++++++++++ 4 files changed, 40 insertions(+) diff --git a/source4/dns_server/dns_query.c b/source4/dns_server/dns_query.c index 4ad14b9..5414e1d 100644 --- a/source4/dns_server/dns_query.c +++ b/source4/dns_server/dns_query.c @@ -138,14 +138,17 @@ struct ask_forwarder_state { static void ask_forwarder_done(struct tevent_req *subreq); static struct tevent_req *ask_forwarder_send( + struct dns_server *dns, TALLOC_CTX *mem_ctx, struct tevent_context *ev, const char *forwarder, struct dns_name_question *question) { struct tevent_req *req, *subreq; struct ask_forwarder_state *state; + struct dns_res_rec *options; struct dns_name_packet out_packet = { 0, }; DATA_BLOB out_blob; enum ndr_err_code ndr_err; + WERROR werr; req = tevent_req_create(mem_ctx, &state, struct ask_forwarder_state); if (req == NULL) { @@ -166,6 +169,15 @@ static struct tevent_req *ask_forwarder_send( out_packet.qdcount = 1; out_packet.questions = question; + werr = dns_generate_options(dns, state, &options); + if (!W_ERROR_IS_OK(werr)) { + tevent_req_werror(req, werr); + return tevent_req_post(req, ev); + } + + out_packet.arcount = 1; + out_packet.additional = options; + ndr_err = ndr_push_struct_blob( &out_blob, state, &out_packet, (ndr_push_flags_fn_t)ndr_push_dns_name_packet); @@ -615,6 +627,7 @@ struct tevent_req *dns_server_process_query_send( in->questions[0].name)); subreq = ask_forwarder_send( + dns, state, ev, lpcfg_dns_forwarder(dns->task->lp_ctx), &in->questions[0]); if (tevent_req_nomem(subreq, req)) { diff --git a/source4/dns_server/dns_server.c b/source4/dns_server/dns_server.c index bb4605f..7ad4aca 100644 --- a/source4/dns_server/dns_server.c +++ b/source4/dns_server/dns_server.c @@ -791,6 +791,8 @@ static void dns_task_init(struct task_server *task) } dns->task = task; + /*FIXME: Make this a configurable option */ + dns->max_payload = 4096; dns->server_credentials = cli_credentials_init(dns); if (!dns->server_credentials) { diff --git a/source4/dns_server/dns_server.h b/source4/dns_server/dns_server.h index ef85730..efe4db8 100644 --- a/source4/dns_server/dns_server.h +++ b/source4/dns_server/dns_server.h @@ -56,6 +56,7 @@ struct dns_server { struct dns_server_zone *zones; struct dns_server_tkey_store *tkeys; struct cli_credentials *server_credentials; + uint16_t max_payload; }; struct dns_request_state { @@ -107,6 +108,9 @@ WERROR dns_name2dn(struct dns_server *dns, TALLOC_CTX *mem_ctx, const char *name, struct ldb_dn **_dn); +WERROR dns_generate_options(struct dns_server *dns, + TALLOC_CTX *mem_ctx, + struct dns_res_rec **options); struct dns_server_tkey *dns_find_tkey(struct dns_server_tkey_store *store, const char *name); WERROR dns_verify_tsig(struct dns_server *dns, diff --git a/source4/dns_server/dns_utils.c b/source4/dns_server/dns_utils.c index e03a409..21c7f5a 100644 --- a/source4/dns_server/dns_utils.c +++ b/source4/dns_server/dns_utils.c @@ -378,3 +378,24 @@ WERROR dns_name2dn(struct dns_server *dns, *_dn = dn; return WERR_OK; } + +WERROR dns_generate_options(struct dns_server *dns, + TALLOC_CTX *mem_ctx, + struct dns_res_rec **options) +{ + struct dns_res_rec *o; + + o = talloc_zero(mem_ctx, struct dns_res_rec); + if (o == NULL) { + return WERR_NOMEM; + } + o->name = '\0'; + o->rr_type = DNS_QTYPE_OPT; + /* This is ugly, but RFC2671 wants the payload size in this field */ + o->rr_class = (enum dns_qclass) dns->max_payload; + o->ttl = 0; + o->length = 0; + + *options = o; + return WERR_OK; +} -- 1.8.1.2