cosmopolitan/third_party/musl/dn_expand.c
Justine Tunney 1a96de6eda
Add libresolv from Musl Libc
Locally modified to get nameservers from Windows Registry when
`\etc\resolv.conf` isn't defined.
2023-12-08 20:04:10 -08:00

65 lines
3.6 KiB
C

/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8 -*-│
│ vi: set noet ft=c ts=8 tw=8 fenc=utf-8 :vi │
╚──────────────────────────────────────────────────────────────────────────────╝
│ │
│ Musl Libc │
│ Copyright © 2005-2014 Rich Felker, et al. │
│ │
│ Permission is hereby granted, free of charge, to any person obtaining │
│ a copy of this software and associated documentation files (the │
│ "Software"), to deal in the Software without restriction, including │
│ without limitation the rights to use, copy, modify, merge, publish, │
│ distribute, sublicense, and/or sell copies of the Software, and to │
│ permit persons to whom the Software is furnished to do so, subject to │
│ the following conditions: │
│ │
│ The above copyright notice and this permission notice shall be │
│ included in all copies or substantial portions of the Software. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, │
│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF │
│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. │
│ IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY │
│ CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, │
│ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE │
│ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │
│ │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "third_party/musl/resolv.internal.h"
asm(".ident\t\"\\n\\n\
Musl libc (MIT License)\\n\
Copyright 2005-2014 Rich Felker, et. al.\"");
asm(".include \"libc/disclaimer.inc\"");
int __dn_expand(const unsigned char *base, const unsigned char *end, const unsigned char *src, char *dest, int space)
{
const unsigned char *p = src;
char *dend, *dbegin = dest;
int len = -1, i, j;
if (p==end || space <= 0) return -1;
dend = dest + (space > 254 ? 254 : space);
/* detect reference loop using an iteration counter */
for (i=0; i < end-base; i+=2) {
/* loop invariants: p<end, dest<dend */
if (*p & 0xc0) {
if (p+1==end) return -1;
j = ((p[0] & 0x3f) << 8) | p[1];
if (len < 0) len = p+2-src;
if (j >= end-base) return -1;
p = base+j;
} else if (*p) {
if (dest != dbegin) *dest++ = '.';
j = *p++;
if (j >= end-p || j >= dend-dest) return -1;
while (j--) *dest++ = *p++;
} else {
*dest = 0;
if (len < 0) len = p+1-src;
return len;
}
}
return -1;
}
__weak_reference(__dn_expand, dn_expand);