50 lines
2.8 KiB
C
50 lines
2.8 KiB
C
/*-*- 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/alg/alg.h"
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#include "libc/dns/dns.h"
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#include "libc/dns/hoststxt.h"
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/**
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* Compares hostnames in HOSTS.TXT table.
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* @see dnsnamecmp(), parsehoststxt()
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*/
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static int cmphoststxt(const struct HostsTxtEntry *e1,
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const struct HostsTxtEntry *e2, const char *strings) {
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if (e1 == e2) return 0;
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return dnsnamecmp(&strings[e1->name], &strings[e2->name]);
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}
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/**
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* Sorts entries in HOSTS.TXT table.
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*
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* This function enables resolvehoststxt() to be called so hard-coded
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* hostname lookups take logarithmic time; you can blackhole all the
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* spam you want, in your /etc/hosts file.
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*
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* The sorted order, defined by dnsnamecmp(), also makes it possible to
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* efficiently search for subdomains, once the initial sort is done.
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*/
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void sorthoststxt(struct HostsTxt *ht) {
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if (ht->entries.p) {
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qsort_r(ht->entries.p, ht->entries.i, sizeof(*ht->entries.p),
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(void *)cmphoststxt, ht->strings.p);
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}
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}
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