minix/lib/liblwip/core/ipv4/ip_addr.c

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/**
* @file
* This is the IPv4 address tools implementation.
*
*/
/*
* 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>
*
*/
#include "lwip/opt.h"
#include "lwip/ip_addr.h"
#include "lwip/netif.h"
/* used by IP_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */
const ip_addr_t ip_addr_any = { IPADDR_ANY };
const ip_addr_t ip_addr_broadcast = { IPADDR_BROADCAST };
/**
* Determine if an address is a broadcast address on a network interface
*
* @param addr address to be checked
* @param netif the network interface against which the address is checked
* @return returns non-zero if the address is a broadcast address
*/
u8_t
ip4_addr_isbroadcast(u32_t addr, const struct netif *netif)
{
ip_addr_t ipaddr;
ip4_addr_set_u32(&ipaddr, addr);
/* all ones (broadcast) or all zeroes (old skool broadcast) */
if ((~addr == IPADDR_ANY) ||
(addr == IPADDR_ANY)) {
return 1;
/* no broadcast support on this network interface? */
} else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0) {
/* the given address cannot be a broadcast address
* nor can we check against any broadcast addresses */
return 0;
/* address matches network interface address exactly? => no broadcast */
} else if (addr == ip4_addr_get_u32(&netif->ip_addr)) {
return 0;
/* on the same (sub) network... */
} else if (ip_addr_netcmp(&ipaddr, &(netif->ip_addr), &(netif->netmask))
/* ...and host identifier bits are all ones? =>... */
&& ((addr & ~ip4_addr_get_u32(&netif->netmask)) ==
(IPADDR_BROADCAST & ~ip4_addr_get_u32(&netif->netmask)))) {
/* => network broadcast address */
return 1;
} else {
return 0;
}
}
/** Checks if a netmask is valid (starting with ones, then only zeros)
*
* @param netmask the IPv4 netmask to check (in network byte order!)
* @return 1 if the netmask is valid, 0 if it is not
*/
u8_t
ip4_addr_netmask_valid(u32_t netmask)
{
u32_t mask;
u32_t nm_hostorder = lwip_htonl(netmask);
/* first, check for the first zero */
for (mask = 1U << 31 ; mask != 0; mask >>= 1) {
if ((nm_hostorder & mask) == 0) {
break;
}
}
/* then check that there is no one */
for (; mask != 0; mask >>= 1) {
if ((nm_hostorder & mask) != 0) {
/* there is a one after the first zero -> invalid */
return 0;
}
}
/* no one after the first zero -> valid */
return 1;
}
/* 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
ipaddr_addr(const char *cp)
{
ip_addr_t val;
if (ipaddr_aton(cp, &val)) {
return ip4_addr_get_u32(&val);
}
return (IPADDR_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
ipaddr_aton(const char *cp, ip_addr_t *addr)
{
u32_t val;
u8_t base;
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, 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' && !isspace(c)) {
return (0);
}
/*
* Concoct the address according to
* the number of parts specified.
*/
switch (pp - parts + 1) {
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;
default:
LWIP_ASSERT("unhandled", 0);
break;
}
if (addr) {
ip4_addr_set_u32(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 *
ipaddr_ntoa(const ip_addr_t *addr)
{
static char str[16];
return ipaddr_ntoa_r(addr, str, 16);
}
/**
* Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used.
*
* @param addr ip 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 *ipaddr_ntoa_r(const ip_addr_t *addr, char *buf, int buflen)
{
u32_t s_addr;
char inv[3];
char *rp;
u8_t *ap;
u8_t rem;
u8_t n;
u8_t i;
int len = 0;
s_addr = ip4_addr_get_u32(addr);
rp = buf;
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--) {
if (len++ >= buflen) {
return NULL;
}
*rp++ = inv[i];
}
if (len++ >= buflen) {
return NULL;
}
*rp++ = '.';
ap++;
}
*--rp = 0;
return buf;
}