cosmopolitan/libc/dns/parsehoststxt.c

72 lines
3.4 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/alg/arraylist.internal.h"
#include "libc/dns/dns.h"
#include "libc/dns/hoststxt.h"
#include "libc/runtime/runtime.h"
#include "libc/sock/sock.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/af.h"
/**
* Parses HOSTS.TXT contents.
*
* Hostnames were invented by Peggy Karp; her format looks like this:
*
* # this is a comment
* # IP CANON [ALT...]
* 203.0.113.1 lol.example. lol
* 203.0.113.2 cat.example. cat
*
* @param htp points to a HostsTxt object, which should be zero
* initialized by the caller; or if it already contains items,
* this function will append
* @param f is the file content; see fopen() and fmemopen()
* @return 0 on success, or -1 w/ errno
* @see hoststxtsort() which is the logical next step
*/
int parsehoststxt(struct HostsTxt *ht, FILE *f) {
int rc;
char *line;
size_t linesize;
rc = 0;
line = NULL;
linesize = 0;
while ((getline(&line, &linesize, f)) != -1) {
struct HostsTxtEntry entry;
char *addr, *name, *tok, *comment;
if ((comment = strchr(line, '#'))) *comment = '\0';
if ((addr = strtok_r(line, " \t\r\n\v", &tok)) &&
inet_pton(AF_INET, addr, entry.ip) == 1) {
entry.canon = ht->strings.i;
while ((name = strtok_r(NULL, " \t\r\n\v", &tok))) {
entry.name = ht->strings.i;
if (concat(&ht->strings, name, strnlen(name, DNS_NAME_MAX) + 1) == -1 ||
append(&ht->entries, &entry) == -1) {
rc = -1;
}
}
}
}
free(line);
return rc | ferror(f);
}