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/*
* Copyright (c) 2004, Apple Computer, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "mdnsderived.h"
#include "cstddef"
#include "cstring"
#ifdef _WIN32
#define strncasecmp _strnicmp
#endif
namespace ZeroConf {
namespace Internal {
// DomainEndsInDot returns 1 if name ends with a dot, 0 otherwise
// (DNSServiceConstructFullName depends this returning 1 for true, rather than any non-zero value meaning true)
static int DomainEndsInDot(const char *dom)
{
while (dom[0] && dom[1]) {
if (dom[0] == '\\') { // advance past escaped byte sequence
if ('0' <= dom[1] && dom[1] <= '9' &&
'0' <= dom[2] && dom[2] <= '9' &&
'0' <= dom[3] && dom[3] <= '9')
{
dom += 4; // If "\ddd" then skip four
} else {
dom += 2; // else if "\x" then skip two
}
} else {
dom++; // else goto next character
}
}
return (dom[0] == '.');
}
// Note: Need to make sure we don't write more than kDNSServiceMaxDomainName (1009) bytes to fullName
// In earlier builds this constant was defined to be 1005, so to avoid buffer overruns on clients
// compiled with that constant we'll actually limit the output to 1005 bytes.
DNSServiceErrorType myDNSServiceConstructFullName(char *const fullName,
const char *const service, // May be NULL
const char *const regtype,
const char *const domain)
{
const size_t len = !regtype ? 0 : strlen(regtype) - DomainEndsInDot(regtype);
char *fn = fullName;
char *const lim = fullName + 1005;
const char *s = service;
const char *r = regtype;
const char *d = domain;
// regtype must be at least "x._udp" or "x._tcp"
if (len < 6 || !domain || !domain[0]) return kDNSServiceErr_BadParam;
if (strncasecmp((regtype + len - 4), "_tcp", 4) && strncasecmp((regtype + len - 4), "_udp", 4)) return kDNSServiceErr_BadParam;
if (service && *service)
{
while (*s)
{
unsigned char c = *s++; // Needs to be unsigned, or values like 0xFF will be interpreted as < 32
if (c <= ' ') // Escape non-printable characters
{
if (fn + 4 >= lim) goto fail;
*fn++ = '\\';
*fn++ = '0' + (c / 100);
*fn++ = '0' + (c / 10) % 10;
c = '0' + (c ) % 10;
}
else if (c == '.' || (c == '\\')) // Escape dot and backslash literals
{
if (fn + 2 >= lim) goto fail;
*fn++ = '\\';
}
else
if (fn + 1 >= lim) goto fail;
*fn++ = (char)c;
}
*fn++ = '.';
}
while (*r) if (fn + 1 >= lim) goto fail; else *fn++ = *r++;
if (!DomainEndsInDot(regtype)) { if (fn + 1 >= lim) goto fail; else *fn++ = '.'; }
while (*d) if (fn + 1 >= lim) goto fail; else *fn++ = *d++;
if (!DomainEndsInDot(domain)) { if (fn + 1 >= lim) goto fail; else *fn++ = '.'; }
*fn = '\0';
return kDNSServiceErr_NoError;
fail:
*fn = '\0';
return kDNSServiceErr_BadParam;
}
uint16_t txtRecordGetCount(uint16_t txtLen, const void *txtRecord)
{
uint16_t count = 0;
uint8_t *p = (uint8_t*)txtRecord;
uint8_t *e = p + txtLen;
while (p<e) { p += 1 + p[0]; count++; }
return((p>e) ? (uint16_t)0 : count);
}
DNSServiceErrorType txtRecordGetItemAtIndex(uint16_t txtLen, const void *txtRecord,
uint16_t itemIndex, uint16_t keyBufLen, char *key, uint8_t *valueLen, const void **value)
{
uint16_t count = 0;
uint8_t *p = (uint8_t*)txtRecord;
uint8_t *e = p + txtLen;
while (p<e && count<itemIndex) { p += 1 + p[0]; count++; } // Find requested item
if (p<e && p + 1 + p[0] <= e) { // If valid
uint8_t *x = p+1;
unsigned long len = 0;
e = p + 1 + p[0];
while (x+len<e && x[len] != '=') len++;
if (len >= keyBufLen) return(kDNSServiceErr_NoMemory);
memcpy(key, x, len);
key[len] = 0;
if (x+len<e) { // If we found '='
*value = x + len + 1;
*valueLen = (uint8_t)(p[0] - (len + 1));
} else {
*value = NULL;
*valueLen = 0;
}
return(kDNSServiceErr_NoError);
}
return(kDNSServiceErr_Invalid);
}
} // namespace ZeroConf
} // namespace Internal
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