69 lines
3.4 KiB
C
69 lines
3.4 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/arraylist.h"
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#include "libc/dns/dns.h"
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#include "libc/dns/resolvconf.h"
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#include "libc/mem/mem.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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#include "libc/str/str.h"
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#include "libc/sysv/consts/af.h"
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#include "libc/sysv/consts/inaddr.h"
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/**
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* Parses /etc/resolv.conf file.
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*
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* The content of the file usually looks like this:
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*
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* nameserver 8.8.8.8
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* nameserver 8.8.4.4
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*
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* @param resolv points to a ResolvConf object, which should be zero
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* initialized by the caller; or if it already contains items,
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* this function will append
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* @param f is an open stream with file content
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* @return number of nameservers appended, or -1 w/ errno
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*/
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int parseresolvconf(struct ResolvConf *resolv, struct FILE *f) {
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/* TODO(jart): options ndots:5 */
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int rc = 0;
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char *line;
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size_t linesize;
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struct sockaddr_in nameserver;
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line = NULL;
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linesize = 0;
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nameserver.sin_family = AF_INET;
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nameserver.sin_port = htons(DNS_PORT);
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while (getline(&line, &linesize, f) != -1) {
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char *directive, *value, *tok, *comment;
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if ((comment = strchr(line, '#'))) *comment = '\0';
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if ((directive = strtok_r(line, " \t\r\n\v", &tok)) &&
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(value = strtok_r(NULL, " \t\r\n\v", &tok))) {
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if ((strcmp(directive, "nameserver") == 0 &&
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inet_pton(AF_INET, value, &nameserver.sin_addr.s_addr) == 1)) {
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if (append(&resolv->nameservers, &nameserver) != -1) ++rc;
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}
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}
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}
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free(line);
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return rc | ferror(f);
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}
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