65 lines
3.2 KiB
C
65 lines
3.2 KiB
C
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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/bits/bits.h"
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#include "libc/dns/dnsheader.h"
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#include "libc/sysv/errfuns.h"
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/**
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* Serializes DNS message header to wire.
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*
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* @return number of bytes written (always 12) or -1 w/ errno
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* @see pascalifydnsname()
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*/
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int serializednsheader(uint8_t *buf, size_t size,
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const struct DnsHeader header) {
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if (size < 12) return enospc();
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buf[0x0] = header.id >> 010u;
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buf[0x1] = header.id >> 000u;
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buf[0x2] = header.bf1;
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buf[0x3] = header.bf2;
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buf[0x4] = header.qdcount >> 010u;
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buf[0x5] = header.qdcount >> 000u;
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buf[0x6] = header.ancount >> 010u;
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buf[0x7] = header.ancount >> 000u;
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buf[0x8] = header.nscount >> 010u;
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buf[0x9] = header.nscount >> 000u;
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buf[0xa] = header.arcount >> 010u;
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buf[0xb] = header.arcount >> 000u;
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return 12;
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}
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/**
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* Serializes DNS message header to wire.
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*
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* @return number of bytes read (always 12) or -1 w/ errno
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*/
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int deserializednsheader(struct DnsHeader *header, const uint8_t *buf,
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size_t size) {
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if (size < 12) return ebadmsg();
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header->id = read16be(buf + 0);
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header->bf1 = buf[2];
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header->bf2 = buf[3];
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header->qdcount = read16be(buf + 4);
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header->ancount = read16be(buf + 6);
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header->nscount = read16be(buf + 8);
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header->arcount = read16be(buf + 10);
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return 12;
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}
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