From 46795c0e3e82395de00477a747e2d2bd20c39517 Mon Sep 17 00:00:00 2001 From: Kai Blin Date: Tue, 3 Apr 2012 08:00:57 +0200 Subject: [PATCH] WIP: libdns: Also do TCP requests --- libcli/dns/dns.c | 171 ++++++++++++++++++++++++++++++++++++++++++-- libcli/dns/libdns.h | 28 ++++++++ 2 files changed, 194 insertions(+), 5 deletions(-) diff --git a/libcli/dns/dns.c b/libcli/dns/dns.c index ac0c9e49959..ea0975d3f7b 100644 --- a/libcli/dns/dns.c +++ b/libcli/dns/dns.c @@ -39,8 +39,8 @@ struct dns_udp_request_state { }; /* Declare callback functions used below. */ -static void dns_request_get_reply(struct tevent_req *subreq); -static void dns_request_done(struct tevent_req *subreq); +static void dns_udp_request_get_reply(struct tevent_req *subreq); +static void dns_udp_request_done(struct tevent_req *subreq); struct tevent_req *dns_udp_request_send(TALLOC_CTX *mem_ctx, struct tevent_context *ev, @@ -92,11 +92,11 @@ struct tevent_req *dns_udp_request_send(TALLOC_CTX *mem_ctx, return tevent_req_post(req, ev); } - tevent_req_set_callback(subreq, dns_request_get_reply, req); + tevent_req_set_callback(subreq, dns_udp_request_get_reply, req); return req; } -static void dns_request_get_reply(struct tevent_req *subreq) +static void dns_udp_request_get_reply(struct tevent_req *subreq) { struct tevent_req *req = tevent_req_callback_data(subreq, struct tevent_req); @@ -123,6 +123,167 @@ static void dns_request_get_reply(struct tevent_req *subreq) return; } + tevent_req_set_callback(subreq, dns_udp_request_done, req); + return; +} + +static void dns_udp_request_done(struct tevent_req *subreq) +{ + struct tevent_req *req = tevent_req_callback_data(subreq, + struct tevent_req); + struct dns_udp_request_state *state = tevent_req_data(req, + struct dns_udp_request_state); + + ssize_t len; + int err = 0; + + len = tdgram_recvfrom_recv(subreq, &err, state, &state->reply, NULL); + TALLOC_FREE(subreq); + + if (len == -1 && err != 0) { + tevent_req_werror(req, unix_to_werror(err)); + return; + } + + state->reply_len = len; + dump_data(10, state->reply, state->reply_len); + tevent_req_done(req); +} + +WERROR dns_udp_request_recv(struct tevent_req *req, + TALLOC_CTX *mem_ctx, + uint8_t **reply, + size_t *reply_len) +{ + struct dns_udp_request_state *state = tevent_req_data(req, + struct dns_udp_request_state); + WERROR w_error; + + if (tevent_req_is_werror(req, &w_error)) { + tevent_req_received(req); + return w_error; + } + + *reply = talloc_move(mem_ctx, &state->reply); + *reply_len = state->reply_len; + tevent_req_received(req); + + return WERR_OK; +} + +struct dns_tcp_request_state { + struct tevent_context *ev; + struct tstream_context *stream; + const uint8_t *query; + size_t query_len; + uint8_t *reply; + size_t reply_len; +}; + +static void dns_tcp_request_connected(struct tevent_req *subreq); +static void dns_tcp_request_get_reply(struct tevent_req *subreq); +static void dns_tcp_request_done(struct tevent_req *subreq); + +struct tevent_req *dns_tcp_request_send(TALLOC_CTX *mem_ctx, + struct tevent_context *ev, + const char *server_addr_string, + const uint8_t *query, + size_t query_len) +{ + struct tevent_req *req, *subreq; + struct dns_tcp_request_state *state; + struct tsocket_address *local_addr, *server_addr; + struct tstream_context *stream; + int ret; + + req = tevent_req_create(mem_ctx, &state, struct dns_tcp_request_state); + if (req == NULL) { + return NULL; + } + + state->ev = ev; + state->query = query; + state->query_len = query_len; + + dump_data(10, query, query_len); + + ret = tsocket_address_inet_from_strings(state, "ip", NULL, 0, + &local_addr); + if (ret != 0) { + tevent_req_werror(req, unix_to_werror(ret)); + return tevent_req_post(req, ev); + } + + ret = tsocket_address_inet_from_strings(state, "ip", server_addr_string, + DNS_SERVICE_PORT, &server_addr); + if (ret != 0) { + tevent_req_werror(req, unix_to_werror(ret)); + return tevent_req_post(req, ev); + } + + subreq = tstream_inet_tcp_connect_send(state, ev, local_addr, server_addr); + if (tevent_req_nomem(subreq, req)) { + return tevent_req_post(req, ev); + } + + tevent_req_set_callback(subreq, dns_tcp_request_connected, req); + return req; +} + +static void dns_tcp_request_connected(struct tevent_req *subreq) +{ + struct tevent_req *req = tevent_req_callback_data(subreq, + struct tevent_req); + struct dns_udp_request_state *state = tevent_req_data(req, + struct dns_udp_request_state); + + int ret; + int err = 0; + + ret = tstream_inet_tcp_connect_recv(subreq, &err, state, &state->stream, + NULL); + TALLOC_FREE(subreq); + if (ret != 0) { + tevent_req_error(req, unix_to_werror(err)); + return; + } + + subreq = tstream_sendto_send(state, ev, stream, query, query_len, NULL); + if (tevent_req_nomem(subreq, req)) { + return tevent_req_post(req, ev); + } + + tevent_req_set_callback(subreq, dns_request_get_reply, req); + return; +} + +static void dns_request_get_reply(struct tevent_req *subreq) +{ + struct tevent_req *req = tevent_req_callback_data(subreq, + struct tevent_req); + struct dns_udp_request_state *state = tevent_req_data(req, + struct dns_udp_request_state); + ssize_t len; + int err = 0; + + len = tstream_sendto_recv(subreq, &err); + TALLOC_FREE(subreq); + + if (len == -1 && err != 0) { + tevent_req_werror(req, unix_to_werror(err)); + return; + } + + if (len != state->query_len) { + tevent_req_werror(req, WERR_NET_WRITE_FAULT); + return; + } + + subreq = tstream_recvfrom_send(state, state->ev, state->stream); + if (tevent_req_nomem(subreq, req)) { + return; + } + tevent_req_set_callback(subreq, dns_request_done, req); return; } @@ -137,7 +298,7 @@ static void dns_request_done(struct tevent_req *subreq) ssize_t len; int err = 0; - len = tdgram_recvfrom_recv(subreq, &err, state, &state->reply, NULL); + len = tstream_recvfrom_recv(subreq, &err, state, &state->reply, NULL); TALLOC_FREE(subreq); if (len == -1 && err != 0) { diff --git a/libcli/dns/libdns.h b/libcli/dns/libdns.h index 31474ebc530..ca2788f3378 100644 --- a/libcli/dns/libdns.h +++ b/libcli/dns/libdns.h @@ -50,4 +50,32 @@ WERROR dns_udp_request_recv(struct tevent_req *req, uint8_t **reply, size_t *reply_len); +/** Send an dns request to a dns server using TCP + * + *@param mem_ctx talloc memory context to use + *@param ev tevent context to use + *@param server_address address of the server as a string + *@param query dns query to send + *@param query_len length of the query + *@return tevent_req with the active request or NULL on out-of-memory + */ +struct tevent_req *dns_tcp_request_send(TALLOC_CTX *mem_ctx, + struct tevent_context *ev, + const char *server_address, + const uint8_t *query, + size_t query_len); + +/** Get the dns response from a dns server via UDP + * + *@param req tevent_req struct returned from dns_request_send + *@param mem_ctx talloc memory context to use for the reply string + *@param reply buffer that will be allocated and filled with the dns reply + *@param reply_len length of the reply buffer + *@return WERROR code depending on the async request result + */ +WERROR dns_tcp_request_recv(struct tevent_req *req, + TALLOC_CTX *mem_ctx, + uint8_t **reply, + size_t *reply_len); + #endif /*__LIBDNS_H__*/ -- 2.34.1