www.pudn.com > lwip-1.3.0.rar > inet.c
/**
* @file
* Functions common to all TCP/IPv4 modules, such as the byte order functions.
*
*/
/*
* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
* 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: Adam Dunkels
*
*/
#include "lwip/opt.h"
#include "lwip/inet.h"
/* Here for now until needed in other places in lwIP */
#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')
#endif
/**
* Ascii internet address interpretation routine.
* The value returned is in network order.
*
* @param cp IP address in ascii represenation (e.g. "127.0.0.1")
* @return ip address in network order
*/
u32_t
inet_addr(const char *cp)
{
struct in_addr val;
if (inet_aton(cp, &val)) {
return (val.s_addr);
}
return (INADDR_NONE);
}
/**
* Check whether "cp" is a valid ascii representation
* of an Internet address and convert to a binary address.
* Returns 1 if the address is valid, 0 if not.
* This replaces inet_addr, the return value from which
* cannot distinguish between failure and a local broadcast address.
*
* @param cp IP address in ascii represenation (e.g. "127.0.0.1")
* @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
inet_aton(const char *cp, struct in_addr *addr)
{
u32_t val;
int base, n, c;
u32_t parts[4];
u32_t *pp = parts;
c = *cp;
for (;;) {
/*
* Collect number up to ``.''.
* Values are specified as for C:
* 0x=hex, 0=octal, 1-9=decimal.
*/
if (!isdigit(c))
return (0);
val = 0;
base = 10;
if (c == '0') {
c = *++cp;
if (c == 'x' || c == 'X') {
base = 16;
c = *++cp;
} else
base = 8;
}
for (;;) {
if (isdigit(c)) {
val = (val * base) + (int)(c - '0');
c = *++cp;
} else if (base == 16 && isxdigit(c)) {
val = (val << 4) | (int)(c + 10 - (islower(c) ? 'a' : 'A'));
c = *++cp;
} else
break;
}
if (c == '.') {
/*
* Internet format:
* a.b.c.d
* a.b.c (with c treated as 16 bits)
* a.b (with b treated as 24 bits)
*/
if (pp >= parts + 3)
return (0);
*pp++ = val;
c = *++cp;
} else
break;
}
/*
* Check for trailing characters.
*/
if (c != '\0' && (!isprint(c) || !isspace(c)))
return (0);
/*
* Concoct the address according to
* the number of parts specified.
*/
n = pp - parts + 1;
switch (n) {
case 0:
return (0); /* initial nondigit */
case 1: /* a -- 32 bits */
break;
case 2: /* a.b -- 8.24 bits */
if (val > 0xffffffUL)
return (0);
val |= parts[0] << 24;
break;
case 3: /* a.b.c -- 8.8.16 bits */
if (val > 0xffff)
return (0);
val |= (parts[0] << 24) | (parts[1] << 16);
break;
case 4: /* a.b.c.d -- 8.8.8.8 bits */
if (val > 0xff)
return (0);
val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
break;
}
if (addr)
addr->s_addr = htonl(val);
return (1);
}
/**
* Convert numeric IP address into decimal dotted ASCII representation.
* returns ptr to static buffer; not reentrant!
*
* @param addr ip address in network order to convert
* @return pointer to a global static (!) buffer that holds the ASCII
* represenation of addr
*/
char *
inet_ntoa(struct in_addr addr)
{
static char str[16];
u32_t s_addr = addr.s_addr;
char inv[3];
char *rp;
u8_t *ap;
u8_t rem;
u8_t n;
u8_t i;
rp = str;
ap = (u8_t *)&s_addr;
for(n = 0; n < 4; n++) {
i = 0;
do {
rem = *ap % (u8_t)10;
*ap /= (u8_t)10;
inv[i++] = '0' + rem;
} while(*ap);
while(i--)
*rp++ = inv[i];
*rp++ = '.';
ap++;
}
*--rp = 0;
return str;
}
/**
* These are reference implementations of the byte swapping functions.
* Again with the aim of being simple, correct and fully portable.
* Byte swapping is the second thing you would want to optimize. You will
* need to port it to your architecture and in your cc.h:
*
* #define LWIP_PLATFORM_BYTESWAP 1
* #define LWIP_PLATFORM_HTONS(x)
* #define LWIP_PLATFORM_HTONL(x)
*
* Note ntohs() and ntohl() are merely references to the htonx counterparts.
*/
#if (LWIP_PLATFORM_BYTESWAP == 0) && (BYTE_ORDER == LITTLE_ENDIAN)
/**
* Convert an u16_t from host- to network byte order.
*
* @param n u16_t in host byte order
* @return n in network byte order
*/
u16_t
htons(u16_t n)
{
return ((n & 0xff) << 8) | ((n & 0xff00) >> 8);
}
/**
* Convert an u16_t from network- to host byte order.
*
* @param n u16_t in network byte order
* @return n in host byte order
*/
u16_t
ntohs(u16_t n)
{
return htons(n);
}
/**
* Convert an u32_t from host- to network byte order.
*
* @param n u32_t in host byte order
* @return n in network byte order
*/
u32_t
htonl(u32_t n)
{
return ((n & 0xff) << 24) |
((n & 0xff00) << 8) |
((n & 0xff0000UL) >> 8) |
((n & 0xff000000UL) >> 24);
}
/**
* Convert an u32_t from network- to host byte order.
*
* @param n u32_t in network byte order
* @return n in host byte order
*/
u32_t
ntohl(u32_t n)
{
return htonl(n);
}
#endif /* (LWIP_PLATFORM_BYTESWAP == 0) && (BYTE_ORDER == LITTLE_ENDIAN) */