BadVPN – Rev 1
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/**
* @file
*
* IPv6 addresses.
*/
/*
* Copyright (c) 2010 Inico Technologies Ltd.
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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.
*
* This file is part of the lwIP TCP/IP stack.
*
* Author: Ivan Delamer <delamer@inicotech.com>
*
* Functions for handling IPv6 addresses.
*
* Please coordinate changes and requests with Ivan Delamer
* <delamer@inicotech.com>
*/
#include "lwip/opt.h"
#if LWIP_IPV6 /* don't build if not configured for use in lwipopts.h */
#include "lwip/ip_addr.h"
#include "lwip/def.h"
/* used by IP6_ADDR_ANY(6) in ip6_addr.h */
const ip_addr_t ip6_addr_any = IPADDR6_INIT(0ul, 0ul, 0ul, 0ul);
#ifndef isprint
#define in_range(c, lo, up) ((u8_t)c >= lo && (u8_t)c <= up)
#define isprint(c) in_range(c, 0x20, 0x7f)
#define isdigit(c) in_range(c, '0', '9')
#define isxdigit(c) (isdigit(c) || in_range(c, 'a', 'f') || in_range(c, 'A', 'F'))
#define islower(c) in_range(c, 'a', 'z')
#define isspace(c) (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v')
#define xchar(i) ((char)((i) < 10 ? '0' + (i) : 'A' + (i) - 10))
#endif
/**
* Check whether "cp" is a valid ascii representation
* of an IPv6 address and convert to a binary address.
* Returns 1 if the address is valid, 0 if not.
*
* @param cp IPv6 address in ascii representation (e.g. "FF01::1")
* @param addr pointer to which to save the ip address in network order
* @return 1 if cp could be converted to addr, 0 on failure
*/
int
ip6addr_aton(const char *cp, ip6_addr_t *addr)
{
u32_t addr_index, zero_blocks, current_block_index, current_block_value;
const char *s;
/* Count the number of colons, to count the number of blocks in a "::" sequence
zero_blocks may be 1 even if there are no :: sequences */
zero_blocks = 8;
for (s = cp; *s != 0; s++) {
if (*s == ':') {
zero_blocks--;
} else if (!isxdigit(*s)) {
break;
}
}
/* parse each block */
addr_index = 0;
current_block_index = 0;
current_block_value = 0;
for (s = cp; *s != 0; s++) {
if (*s == ':') {
if (addr) {
if (current_block_index & 0x1) {
addr->addr[addr_index++] |= current_block_value;
}
else {
addr->addr[addr_index] = current_block_value << 16;
}
}
current_block_index++;
current_block_value = 0;
if (current_block_index > 7) {
/* address too long! */
return 0;
}
if (s[1] == ':') {
if (s[2] == ':') {
/* invalid format: three successive colons */
return 0;
}
s++;
/* "::" found, set zeros */
while (zero_blocks > 0) {
zero_blocks--;
if (current_block_index & 0x1) {
addr_index++;
} else {
if (addr) {
addr->addr[addr_index] = 0;
}
}
current_block_index++;
if (current_block_index > 7) {
/* address too long! */
return 0;
}
}
}
} else if (isxdigit(*s)) {
/* add current digit */
current_block_value = (current_block_value << 4) +
(isdigit(*s) ? (u32_t)(*s - '0') :
(u32_t)(10 + (islower(*s) ? *s - 'a' : *s - 'A')));
} else {
/* unexpected digit, space? CRLF? */
break;
}
}
if (addr) {
if (current_block_index & 0x1) {
addr->addr[addr_index++] |= current_block_value;
}
else {
addr->addr[addr_index] = current_block_value << 16;
}
}
/* convert to network byte order. */
if (addr) {
for (addr_index = 0; addr_index < 4; addr_index++) {
addr->addr[addr_index] = lwip_htonl(addr->addr[addr_index]);
}
}
if (current_block_index != 7) {
return 0;
}
ip6_addr_clear_zone(addr);
return 1;
}
/**
* Convert numeric IPv6 address into ASCII representation.
* returns ptr to static buffer; not reentrant!
*
* @param addr ip6 address in network order to convert
* @return pointer to a global static (!) buffer that holds the ASCII
* representation of addr
*/
char *
ip6addr_ntoa(const ip6_addr_t *addr)
{
static char str[40];
return ip6addr_ntoa_r(addr, str, 40);
}
/**
* Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used.
*
* @param addr ip6 address in network order to convert
* @param buf target buffer where the string is stored
* @param buflen length of buf
* @return either pointer to buf which now holds the ASCII
* representation of addr or NULL if buf was too small
*/
char *
ip6addr_ntoa_r(const ip6_addr_t *addr, char *buf, int buflen)
{
u32_t current_block_index, current_block_value, next_block_value;
s32_t i;
u8_t zero_flag, empty_block_flag;
i = 0;
empty_block_flag = 0; /* used to indicate a zero chain for "::' */
for (current_block_index = 0; current_block_index < 8; current_block_index++) {
/* get the current 16-bit block */
current_block_value = lwip_htonl(addr->addr[current_block_index >> 1]);
if ((current_block_index & 0x1) == 0) {
current_block_value = current_block_value >> 16;
}
current_block_value &= 0xffff;
/* Check for empty block. */
if (current_block_value == 0) {
if (current_block_index == 7 && empty_block_flag == 1) {
/* special case, we must render a ':' for the last block. */
buf[i++] = ':';
if (i >= buflen) {
return NULL;
}
break;
}
if (empty_block_flag == 0) {
/* generate empty block "::", but only if more than one contiguous zero block,
* according to current formatting suggestions RFC 5952. */
next_block_value = lwip_htonl(addr->addr[(current_block_index + 1) >> 1]);
if ((current_block_index & 0x1) == 0x01) {
next_block_value = next_block_value >> 16;
}
next_block_value &= 0xffff;
if (next_block_value == 0) {
empty_block_flag = 1;
buf[i++] = ':';
if (i >= buflen) {
return NULL;
}
continue; /* move on to next block. */
}
} else if (empty_block_flag == 1) {
/* move on to next block. */
continue;
}
} else if (empty_block_flag == 1) {
/* Set this flag value so we don't produce multiple empty blocks. */
empty_block_flag = 2;
}
if (current_block_index > 0) {
buf[i++] = ':';
if (i >= buflen) {
return NULL;
}
}
if ((current_block_value & 0xf000) == 0) {
zero_flag = 1;
} else {
buf[i++] = xchar(((current_block_value & 0xf000) >> 12));
zero_flag = 0;
if (i >= buflen) {
return NULL;
}
}
if (((current_block_value & 0xf00) == 0) && (zero_flag)) {
/* do nothing */
} else {
buf[i++] = xchar(((current_block_value & 0xf00) >> 8));
zero_flag = 0;
if (i >= buflen) {
return NULL;
}
}
if (((current_block_value & 0xf0) == 0) && (zero_flag)) {
/* do nothing */
}
else {
buf[i++] = xchar(((current_block_value & 0xf0) >> 4));
zero_flag = 0;
if (i >= buflen) {
return NULL;
}
}
buf[i++] = xchar((current_block_value & 0xf));
if (i >= buflen) {
return NULL;
}
}
buf[i] = 0;
return buf;
}
#endif /* LWIP_IPV6 */