Philip Gladstone 3a5e5f10e2 Take 2: Add regular sends to mdns. Check for (some) buffer overflows. Make it handle unicast
Merging as suggested by @TerryE (and squashing at the same time. Turns out that this feature is enabled for this repo).

* Squashed commit of the following:

commit f985f10d9d2ee035f5a6ee6245c60d9904d98cc1
Author: philip <philip@gladstonefamily.net>
Date:   Sun Mar 27 21:52:46 2016 -0400

    Better mdns code

commit 6ee49ee106274bc63f6309047e57f7bc9828523e
Author: philip <philip@gladstonefamily.net>
Date:   Fri Mar 25 23:25:11 2016 -0400

    Update the docs

commit 7e455541c6f2531824cfb2419d051f1306935fdf
Author: philip <philip@gladstonefamily.net>
Date:   Thu Mar 24 21:58:16 2016 -0400

    Add retries and buffer checking to mdns

    Get the length right

    Now it seems to work

* Might work for combined mode

* Fix crash

* Simplified various bits of code. Changed the LUA interface

Added checking (to some degree) incoming quyery types

Move the defaults to the right place

Added reference to the RFC`
2016-04-03 14:10:52 -04:00

130 lines
3.7 KiB
C

#include "c_string.h"
#include "c_stdlib.h"
// const char *c_strstr(const char * __s1, const char * __s2){
// }
// char *c_strncat(char * s1, const char * s2, size_t n){
// }
// size_t c_strcspn(const char * s1, const char * s2){
// }
// const char *c_strpbrk(const char * s1, const char * s2){
// }
// int c_strcoll(const char * s1, const char * s2){
// }
//
char *c_strdup(const char *c) {
int len = os_strlen(c) + 1;
char *ret = os_malloc(len);
if (ret) {
memcpy(ret, c, len);
}
return ret;
}
/* $OpenBSD: strlcpy.c,v 1.8 2003/06/17 21:56:24 millert Exp $ */
/*
* Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Copy src to string dst of size siz. At most siz-1 characters
* will be copied. Always NUL terminates (unless siz == 0).
* Returns strlen(src); if retval >= siz, truncation occurred.
*/
size_t
c_strlcpy(char *dst, const char *src, size_t siz)
{
register char *d = dst;
register const char *s = src;
register size_t n = siz;
/* Copy as many bytes as will fit */
if (n != 0 && --n != 0) {
do {
if ((*d++ = *s++) == 0)
break;
} while (--n != 0);
}
/* Not enough room in dst, add NUL and traverse rest of src */
if (n == 0) {
if (siz != 0)
*d = '\0'; /* NUL-terminate dst */
while (*s++)
;
}
return(s - src - 1); /* count does not include NUL */
}
/* $OpenBSD: strlcat.c,v 1.11 2003/06/17 21:56:24 millert Exp $ */
/*
* Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* Appends src to string dst of size siz (unlike strncat, siz is the
* full size of dst, not space left). At most siz-1 characters
* will be copied. Always NUL terminates (unless siz <= strlen(dst)).
* Returns strlen(src) + MIN(siz, strlen(initial dst)).
* If retval >= siz, truncation occurred.
*/
size_t
c_strlcat(char *dst, const char *src, size_t siz)
{
register char *d = dst;
register const char *s = src;
register size_t n = siz;
size_t dlen;
/* Find the end of dst and adjust bytes left but don't go past end */
while (n-- != 0 && *d != '\0')
d++;
dlen = d - dst;
n = siz - dlen;
if (n == 0)
return(dlen + strlen(s));
while (*s != '\0') {
if (n != 1) {
*d++ = *s;
n--;
}
s++;
}
*d = '\0';
return(dlen + (s - src)); /* count does not include NUL */
}