src/core/inet.c - third_party/lwip - Git at Google

 /*
  * 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 <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;

   LWIP_DEBUGF(INET_DEBUG, ("lwip_chksum(%p, %d)\n", (void *)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);
     LWIP_DEBUGF(INET_DEBUG, ("inet: chksum: odd byte %d\n", (unsigned int)(*(u8_t *)dataptr)));
   } else {
     LWIP_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) {
     LWIP_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);
     /*LWIP_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);
     }
     /*LWIP_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);
   }
   LWIP_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);
 }

 /* Here for now until needed in other places in lwIP */
 #ifndef isascii
 #define in_range(c, lo, up)  ((u8_t)c >= lo && (u8_t)c <= up)
 #define isascii(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.
   */

  /*  */
  /* 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!
  */
 char *inet_ntoa(struct in_addr addr)
 {
   static char str[16];
   u32_t s_addr = addr.s_addr;
   char inv[3];
   char *rp;
   char *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;
 }


 #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 */
	/*
	* 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 <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;

	LWIP_DEBUGF(INET_DEBUG, ("lwip_chksum(%p, %d)\n", (void *)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);
	LWIP_DEBUGF(INET_DEBUG, ("inet: chksum: odd byte %d\n", (unsigned int)((u8_t )dataptr)));
	} else {
	LWIP_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) {
	LWIP_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);
	/LWIP_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);
	}
	/LWIP_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);
	}
	LWIP_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);
	}

	/* Here for now until needed in other places in lwIP */
	#ifndef isascii
	#define in_range(c, lo, up) ((u8_t)c >= lo && (u8_t)c <= up)
	#define isascii(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.
	*/

	/* */
	/* 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!
	*/
	char *inet_ntoa(struct in_addr addr)
	{
	static char str[16];
	u32_t s_addr = addr.s_addr;
	char inv[3];
	char *rp;
	char *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;
	}


	#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 */