63 lines
3.0 KiB
C
63 lines
3.0 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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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/bits/pushpop.h"
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#include "libc/dce.h"
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#include "libc/dns/resolvconf.h"
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#include "libc/fmt/fmt.h"
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#include "libc/macros.h"
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#include "libc/runtime/runtime.h"
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#include "libc/sock/sock.h"
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#include "libc/stdio/stdio.h"
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static struct ResolvConf *g_resolvconf;
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static struct ResolvConfInitialStaticMemory {
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struct ResolvConf rv;
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struct sockaddr_in nameservers[3];
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} g_resolvconf_init;
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/**
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* Returns singleton with DNS server address.
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*/
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const struct ResolvConf *getresolvconf(void) {
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int rc;
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FILE *f;
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struct ResolvConfInitialStaticMemory *init;
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init = &g_resolvconf_init;
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if (!g_resolvconf) {
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g_resolvconf = &init->rv;
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pushmov(&init->rv.nameservers.n, ARRAYLEN(init->nameservers));
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init->rv.nameservers.p = init->nameservers;
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__cxa_atexit(freeresolvconf, &g_resolvconf, NULL);
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if (!IsWindows()) {
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if ((f = fopen("/etc/resolv.conf", "r"))) {
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rc = parseresolvconf(g_resolvconf, f);
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} else {
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rc = -1;
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}
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fclose(f);
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} else {
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rc = getntnameservers(g_resolvconf);
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}
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if (rc == -1 && !IsTiny()) {
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fprintf(stderr, "%s: %m\n", "nameserver discovery failed");
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}
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}
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return g_resolvconf;
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}
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