86 lines
2.9 KiB
C
86 lines
2.9 KiB
C
/*
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* util/edns.c - handle base EDNS options.
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*
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* Copyright (c) 2018, NLnet Labs. All rights reserved.
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*
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* This software is open source.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* Neither the name of the NLNET LABS nor the names of its contributors may
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* be used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* \file
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*
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* This file contains functions for base EDNS options.
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*/
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#include "config.h"
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#include "util/edns.h"
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#include "util/config_file.h"
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#include "util/netevent.h"
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#include "util/regional.h"
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#include "util/data/msgparse.h"
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#include "util/data/msgreply.h"
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#include "edns.h"
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static int edns_keepalive(struct edns_data* edns_out, struct edns_data* edns_in,
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struct comm_point* c, struct regional* region)
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{
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if(c->type == comm_udp)
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return 1;
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/* To respond with a Keepalive option, the client connection
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* must have received one message with a TCP Keepalive EDNS option,
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* and that option must have 0 length data. Subsequent messages
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* sent on that connection will have a TCP Keepalive option.
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*/
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if(c->tcp_keepalive ||
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edns_opt_list_find(edns_in->opt_list, LDNS_EDNS_KEEPALIVE)) {
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int keepalive = c->tcp_timeout_msec / 100;
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uint8_t data[2];
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data[0] = (uint8_t)((keepalive >> 8) & 0xff);
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data[1] = (uint8_t)(keepalive & 0xff);
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if(!edns_opt_list_append(&edns_out->opt_list, LDNS_EDNS_KEEPALIVE,
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sizeof(data), data, region))
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return 0;
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c->tcp_keepalive = 1;
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}
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return 1;
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}
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int apply_edns_options(struct edns_data* edns_out, struct edns_data* edns_in,
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struct config_file* cfg, struct comm_point* c, struct regional* region)
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{
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if(cfg->do_tcp_keepalive &&
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!edns_keepalive(edns_out, edns_in, c, region))
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return 0;
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return 1;
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}
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