lwip/src/core/inet.c

354 lines
9.8 KiB
C

/*
* Copyright (c) 2001-2003 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 <adam@sics.se>
*
*/
/*-----------------------------------------------------------------------------------*/
/* inet.c
*
* Functions common to all TCP/IP modules, such as the Internet checksum and the
* byte order functions.
*
*/
/*-----------------------------------------------------------------------------------*/
#include "lwip/opt.h"
#include "lwip/arch.h"
#include "lwip/def.h"
#include "lwip/inet.h"
/*-----------------------------------------------------------------------------------*/
static u16_t
lwip_chksum(void *dataptr, int len)
{
u32_t acc;
DEBUGF(INET_DEBUG, ("lwip_chksum(%p, %d)\n", dataptr, len));
for(acc = 0; len > 1; len -= 2) {
/* acc = acc + *((u16_t *)dataptr)++;*/
acc += *(u16_t *)dataptr;
dataptr = (void *)((u16_t *)dataptr + 1);
}
/* add up any odd byte */
if (len == 1) {
acc += htons((u16_t)((*(u8_t *)dataptr) & 0xff) << 8);
DEBUGF(INET_DEBUG, ("inet: chksum: odd byte %d\n", *(u8_t *)dataptr));
} else {
DEBUGF(INET_DEBUG, ("inet: chksum: no odd byte\n"));
}
acc = (acc >> 16) + (acc & 0xffffUL);
if ((acc & 0xffff0000) != 0) {
acc = (acc >> 16) + (acc & 0xffffUL);
}
return (u16_t)acc;
}
/*-----------------------------------------------------------------------------------*/
/* inet_chksum_pseudo:
*
* Calculates the pseudo Internet checksum used by TCP and UDP for a pbuf chain.
*/
/*-----------------------------------------------------------------------------------*/
u16_t
inet_chksum_pseudo(struct pbuf *p,
struct ip_addr *src, struct ip_addr *dest,
u8_t proto, u16_t proto_len)
{
u32_t acc;
struct pbuf *q;
u8_t swapped;
acc = 0;
swapped = 0;
/* iterate through all pbuf in chain */
for(q = p; q != NULL; q = q->next) {
DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n", (void *) q, (void *)q->next));
acc += lwip_chksum(q->payload, q->len);
/*DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%lx \n", acc));*/
while (acc >> 16) {
acc = (acc & 0xffffUL) + (acc >> 16);
}
if (q->len % 2 != 0) {
swapped = 1 - swapped;
acc = ((acc & 0xff) << 8) | ((acc & 0xff00UL) >> 8);
}
/*DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%lx \n", acc));*/
}
if (swapped) {
acc = ((acc & 0xff) << 8) | ((acc & 0xff00UL) >> 8);
}
acc += (src->addr & 0xffffUL);
acc += ((src->addr >> 16) & 0xffffUL);
acc += (dest->addr & 0xffffUL);
acc += ((dest->addr >> 16) & 0xffffUL);
acc += (u32_t)htons((u16_t)proto);
acc += (u32_t)htons(proto_len);
while (acc >> 16) {
acc = (acc & 0xffffUL) + (acc >> 16);
}
DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%lx\n", acc));
return ~(acc & 0xffffUL);
}
/*-----------------------------------------------------------------------------------*/
/* inet_chksum:
*
* Calculates the Internet checksum over a portion of memory. Used primarely for IP
* and ICMP.
*/
/*-----------------------------------------------------------------------------------*/
u16_t
inet_chksum(void *dataptr, u16_t len)
{
u32_t acc;
acc = lwip_chksum(dataptr, len);
while (acc >> 16) {
acc = (acc & 0xffff) + (acc >> 16);
}
return ~(acc & 0xffff);
}
/*-----------------------------------------------------------------------------------*/
u16_t
inet_chksum_pbuf(struct pbuf *p)
{
u32_t acc;
struct pbuf *q;
u8_t swapped;
acc = 0;
swapped = 0;
for(q = p; q != NULL; q = q->next) {
acc += lwip_chksum(q->payload, q->len);
while (acc >> 16) {
acc = (acc & 0xffffUL) + (acc >> 16);
}
if (q->len % 2 != 0) {
swapped = 1 - swapped;
acc = (acc & 0x00ffUL << 8) | (acc & 0xff00UL >> 8);
}
}
if (swapped) {
acc = ((acc & 0x00ffUL) << 8) | ((acc & 0xff00UL) >> 8);
}
return ~(acc & 0xffffUL);
}
/*-----------------------------------------------------------------------------------*/
/*
* Ascii internet address interpretation routine.
* The value returned is in network order.
*/
/* */
/* inet_addr */
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.
*/
/* */
/* inet_aton */
int inet_aton(const char *cp, struct in_addr *addr)
{
u32_t val;
int base, n;
char 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, isdigit=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 (isascii(c) && isdigit(c)) {
val = (val * base) + (c - '0');
c = *++cp;
} else if (base == 16 && isascii(c) && isxdigit(c)) {
val = (val << 4) |
(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' && (!isascii(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 > 0xffffff)
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!
*/
u8_t *inet_ntoa(u32_t addr)
{
static u8_t str[16];
u8_t inv[3];
u8_t *rp;
u8_t *ap;
u8_t rem;
u8_t n;
u8_t i;
rp = str;
ap = (u8_t *)&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;
}
/*-----------------------------------------------------------------------------------*/
#ifndef BYTE_ORDER
#error BYTE_ORDER is not defined
#endif
#if BYTE_ORDER == LITTLE_ENDIAN
/*-----------------------------------------------------------------------------------*/
u16_t
htons(u16_t n)
{
return ((n & 0xff) << 8) | ((n & 0xff00) >> 8);
}
/*-----------------------------------------------------------------------------------*/
u16_t
ntohs(u16_t n)
{
return htons(n);
}
/*-----------------------------------------------------------------------------------*/
u32_t
htonl(u32_t n)
{
return ((n & 0xff) << 24) |
((n & 0xff00) << 8) |
((n & 0xff0000) >> 8) |
((n & 0xff000000) >> 24);
}
/*-----------------------------------------------------------------------------------*/
u32_t
ntohl(u32_t n)
{
return htonl(n);
}
/*-----------------------------------------------------------------------------------*/
#endif /* BYTE_ORDER == LITTLE_ENDIAN */