uclibc-ng/libc/inet/addr.c

/* Copyright (C) 1995,1996 Robert de Bath <rdebath@cix.compulink.co.uk>
 * This file is part of the Linux-8086 C library and is distributed
 * under the GNU Library General Public License.
 */

/*
 * Manuel Novoa III       Dec 2000
 *
 * Converted to use my new (un)signed long (long) to string routines, which
 * are smaller than the previous functions and don't require static buffers.
 * In the process, removed the reference to strcat and cut object size of
 * inet_ntoa in half (from 190 bytes down to 94).
 *
 * Manuel Novoa III       Feb 2002
 *
 * Changed to use _int10tostr.
 */

#define __FORCE_GLIBC
#include <features.h>
#define _STDIO_UTILITY			/* For _int10tostr. */
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <netinet/in.h>

int inet_aton(const char *cp, struct in_addr *addrptr);

#ifdef L_inet_aton
int inet_aton(cp, addrptr)
const char *cp;
struct in_addr *addrptr;
{
	in_addr_t addr;
	int value;
	int part;

	addr = 0;
	for (part = 1; part <= 4; part++) {

		if (!isdigit(*cp))
			return 0;

		value = 0;
		while (isdigit(*cp)) {
			value *= 10;
			value += *cp++ - '0';
			if (value > 255)
				return 0;
		}

		if (part < 4) {
			if (*cp++ != '.')
				return 0;
		} else {
			char c = *cp++;
			if (c != '\0' && !isspace(c))
			return 0;
		}

		addr <<= 8;
		addr |= value;
	}

	/*  W. Richard Stevens in his book UNIX Network Programming,
	 *  Volume 1, second edition, on page 71 says:
	 *
	 *  An undocumented feature of inet_aton is that if addrptr is
	 *  a null pointer, the function still performs it validation
	 *  of the input string, but does not store the result.
	 */
	if (addrptr) {
	    addrptr->s_addr = htonl(addr);
	}

	return 1;
}
#endif

#ifdef L_inet_addr
in_addr_t inet_addr(const char *cp)
{
	struct in_addr a;

	if (!inet_aton(cp, &a))
		return INADDR_NONE;
	else
		return a.s_addr;
}
#endif

#ifdef L_inet_ntoa

#define INET_NTOA_MAX_LEN	16	/* max 12 digits + 3 '.'s + 1 nul */

char *inet_ntoa_r(struct in_addr in, char buf[INET_NTOA_MAX_LEN])
{
	in_addr_t addr = ntohl(in.s_addr);
	int i;
	char *p, *q;
   
	q = 0;
	p = buf + INET_NTOA_MAX_LEN - 1; /* cannot use sizeof(buf) here */
	for (i=0 ; i < 4 ; i++ ) {
		p = _int10tostr(p, addr & 0xff) - 1;
		addr >>= 8;
		if (q) {
			*q = '.';
		}
		q = p;
	}

	return p+1;
}

char *inet_ntoa(struct in_addr in)
{
	static char buf[INET_NTOA_MAX_LEN];
	return(inet_ntoa_r(in, buf));
}
#endif

#ifdef L_inet_makeaddr
/*
 * Formulate an Internet address from network + host.  Used in
 * building addresses stored in the ifnet structure.
 */
struct in_addr inet_makeaddr(in_addr_t net, in_addr_t host)
{
        in_addr_t addr;

        if (net < 128)
                addr = (net << IN_CLASSA_NSHIFT) | (host & IN_CLASSA_HOST);
        else if (net < 65536)
                addr = (net << IN_CLASSB_NSHIFT) | (host & IN_CLASSB_HOST);
        else if (net < 16777216UL)
                addr = (net << IN_CLASSC_NSHIFT) | (host & IN_CLASSC_HOST);
        else
                addr = net | host;
        addr = htonl(addr);
        return (*(struct in_addr *)&addr);
}

#endif

#ifdef L_inet_lnaof
/*
 * Return the local network address portion of an
 * internet address; handles class a/b/c network
 * number formats.
 */
in_addr_t inet_lnaof(struct in_addr in)
{
	in_addr_t i = ntohl(in.s_addr);

	if (IN_CLASSA(i))
		return ((i)&IN_CLASSA_HOST);
	else if (IN_CLASSB(i))
		return ((i)&IN_CLASSB_HOST);
	else
		return ((i)&IN_CLASSC_HOST);
}
#endif

#ifdef L_inet_netof

/*
 * Return the network number from an internet
 * address; handles class a/b/c network #'s.
 */
in_addr_t
inet_netof(struct in_addr in)
{
        in_addr_t i = ntohl(in.s_addr);

        if (IN_CLASSA(i))
                return (((i)&IN_CLASSA_NET) >> IN_CLASSA_NSHIFT);
        else if (IN_CLASSB(i))
                return (((i)&IN_CLASSB_NET) >> IN_CLASSB_NSHIFT);
        else
                return (((i)&IN_CLASSC_NET) >> IN_CLASSC_NSHIFT);
}

#endif