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lwip/core/ipv4/ip_addr.c@0:d616ece2d859, 2010-09-18 (annotated)

Committer:: mbed714
Date:: Sat Sep 18 23:05:49 2010 +0000
Revision:: 0:d616ece2d859

Who changed what in which revision?

User	Revision	Line number	New contents of line
mbed714	0:d616ece2d859	1	/**
mbed714	0:d616ece2d859	2	* @file
mbed714	0:d616ece2d859	3	* This is the IPv4 address tools implementation.
mbed714	0:d616ece2d859	4	*
mbed714	0:d616ece2d859	5	*/
mbed714	0:d616ece2d859	6
mbed714	0:d616ece2d859	7	/*
mbed714	0:d616ece2d859	8	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
mbed714	0:d616ece2d859	9	* All rights reserved.
mbed714	0:d616ece2d859	10	*
mbed714	0:d616ece2d859	11	* Redistribution and use in source and binary forms, with or without modification,
mbed714	0:d616ece2d859	12	* are permitted provided that the following conditions are met:
mbed714	0:d616ece2d859	13	*
mbed714	0:d616ece2d859	14	* 1. Redistributions of source code must retain the above copyright notice,
mbed714	0:d616ece2d859	15	* this list of conditions and the following disclaimer.
mbed714	0:d616ece2d859	16	* 2. Redistributions in binary form must reproduce the above copyright notice,
mbed714	0:d616ece2d859	17	* this list of conditions and the following disclaimer in the documentation
mbed714	0:d616ece2d859	18	* and/or other materials provided with the distribution.
mbed714	0:d616ece2d859	19	* 3. The name of the author may not be used to endorse or promote products
mbed714	0:d616ece2d859	20	* derived from this software without specific prior written permission.
mbed714	0:d616ece2d859	21	*
mbed714	0:d616ece2d859	22	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
mbed714	0:d616ece2d859	23	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
mbed714	0:d616ece2d859	24	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
mbed714	0:d616ece2d859	25	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
mbed714	0:d616ece2d859	26	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
mbed714	0:d616ece2d859	27	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
mbed714	0:d616ece2d859	28	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
mbed714	0:d616ece2d859	29	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
mbed714	0:d616ece2d859	30	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
mbed714	0:d616ece2d859	31	* OF SUCH DAMAGE.
mbed714	0:d616ece2d859	32	*
mbed714	0:d616ece2d859	33	* This file is part of the lwIP TCP/IP stack.
mbed714	0:d616ece2d859	34	*
mbed714	0:d616ece2d859	35	* Author: Adam Dunkels <adam@sics.se>
mbed714	0:d616ece2d859	36	*
mbed714	0:d616ece2d859	37	*/
mbed714	0:d616ece2d859	38
mbed714	0:d616ece2d859	39	#include "lwip/opt.h"
mbed714	0:d616ece2d859	40	#include "lwip/ip_addr.h"
mbed714	0:d616ece2d859	41	#include "lwip/netif.h"
mbed714	0:d616ece2d859	42
mbed714	0:d616ece2d859	43	/* used by IP_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */
mbed714	0:d616ece2d859	44	const ip_addr_t ip_addr_any = { IPADDR_ANY };
mbed714	0:d616ece2d859	45	const ip_addr_t ip_addr_broadcast = { IPADDR_BROADCAST };
mbed714	0:d616ece2d859	46
mbed714	0:d616ece2d859	47	/**
mbed714	0:d616ece2d859	48	* Determine if an address is a broadcast address on a network interface
mbed714	0:d616ece2d859	49	*
mbed714	0:d616ece2d859	50	* @param addr address to be checked
mbed714	0:d616ece2d859	51	* @param netif the network interface against which the address is checked
mbed714	0:d616ece2d859	52	* @return returns non-zero if the address is a broadcast address
mbed714	0:d616ece2d859	53	*/
mbed714	0:d616ece2d859	54	u8_t
mbed714	0:d616ece2d859	55	ip4_addr_isbroadcast(u32_t addr, const struct netif *netif)
mbed714	0:d616ece2d859	56	{
mbed714	0:d616ece2d859	57	ip_addr_t ipaddr;
mbed714	0:d616ece2d859	58	ip4_addr_set_u32(&ipaddr, addr);
mbed714	0:d616ece2d859	59
mbed714	0:d616ece2d859	60	/* all ones (broadcast) or all zeroes (old skool broadcast) */
mbed714	0:d616ece2d859	61	if ((~addr == IPADDR_ANY) \|\|
mbed714	0:d616ece2d859	62	(addr == IPADDR_ANY)) {
mbed714	0:d616ece2d859	63	return 1;
mbed714	0:d616ece2d859	64	/* no broadcast support on this network interface? */
mbed714	0:d616ece2d859	65	} else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0) {
mbed714	0:d616ece2d859	66	/* the given address cannot be a broadcast address
mbed714	0:d616ece2d859	67	* nor can we check against any broadcast addresses */
mbed714	0:d616ece2d859	68	return 0;
mbed714	0:d616ece2d859	69	/* address matches network interface address exactly? => no broadcast */
mbed714	0:d616ece2d859	70	} else if (addr == ip4_addr_get_u32(&netif->ip_addr)) {
mbed714	0:d616ece2d859	71	return 0;
mbed714	0:d616ece2d859	72	/* on the same (sub) network... */
mbed714	0:d616ece2d859	73	} else if (ip_addr_netcmp(&ipaddr, &(netif->ip_addr), &(netif->netmask))
mbed714	0:d616ece2d859	74	/* ...and host identifier bits are all ones? =>... */
mbed714	0:d616ece2d859	75	&& ((addr & ~ip4_addr_get_u32(&netif->netmask)) ==
mbed714	0:d616ece2d859	76	(IPADDR_BROADCAST & ~ip4_addr_get_u32(&netif->netmask)))) {
mbed714	0:d616ece2d859	77	/* => network broadcast address */
mbed714	0:d616ece2d859	78	return 1;
mbed714	0:d616ece2d859	79	} else {
mbed714	0:d616ece2d859	80	return 0;
mbed714	0:d616ece2d859	81	}
mbed714	0:d616ece2d859	82	}
mbed714	0:d616ece2d859	83
mbed714	0:d616ece2d859	84	/** Checks if a netmask is valid (starting with ones, then only zeros)
mbed714	0:d616ece2d859	85	*
mbed714	0:d616ece2d859	86	* @param netmask the IPv4 netmask to check (in network byte order!)
mbed714	0:d616ece2d859	87	* @return 1 if the netmask is valid, 0 if it is not
mbed714	0:d616ece2d859	88	*/
mbed714	0:d616ece2d859	89	u8_t
mbed714	0:d616ece2d859	90	ip4_addr_netmask_valid(u32_t netmask)
mbed714	0:d616ece2d859	91	{
mbed714	0:d616ece2d859	92	u32_t mask;
mbed714	0:d616ece2d859	93	u32_t nm_hostorder = lwip_htonl(netmask);
mbed714	0:d616ece2d859	94
mbed714	0:d616ece2d859	95	/* first, check for the first zero */
mbed714	0:d616ece2d859	96	for (mask = 1U << 31 ; mask != 0; mask >>= 1) {
mbed714	0:d616ece2d859	97	if ((nm_hostorder & mask) == 0) {
mbed714	0:d616ece2d859	98	break;
mbed714	0:d616ece2d859	99	}
mbed714	0:d616ece2d859	100	}
mbed714	0:d616ece2d859	101	/* then check that there is no one */
mbed714	0:d616ece2d859	102	for (; mask != 0; mask >>= 1) {
mbed714	0:d616ece2d859	103	if ((nm_hostorder & mask) != 0) {
mbed714	0:d616ece2d859	104	/* there is a one after the first zero -> invalid */
mbed714	0:d616ece2d859	105	return 0;
mbed714	0:d616ece2d859	106	}
mbed714	0:d616ece2d859	107	}
mbed714	0:d616ece2d859	108	/* no one after the first zero -> valid */
mbed714	0:d616ece2d859	109	return 1;
mbed714	0:d616ece2d859	110	}
mbed714	0:d616ece2d859	111
mbed714	0:d616ece2d859	112	/* Here for now until needed in other places in lwIP */
mbed714	0:d616ece2d859	113	#ifndef isprint
mbed714	0:d616ece2d859	114	#define in_range(c, lo, up) ((u8_t)c >= lo && (u8_t)c <= up)
mbed714	0:d616ece2d859	115	#define isprint(c) in_range(c, 0x20, 0x7f)
mbed714	0:d616ece2d859	116	#define isdigit(c) in_range(c, '0', '9')
mbed714	0:d616ece2d859	117	#define isxdigit(c) (isdigit(c) \|\| in_range(c, 'a', 'f') \|\| in_range(c, 'A', 'F'))
mbed714	0:d616ece2d859	118	#define islower(c) in_range(c, 'a', 'z')
mbed714	0:d616ece2d859	119	#define isspace(c) (c == ' ' \|\| c == '\f' \|\| c == '\n' \|\| c == '\r' \|\| c == '\t' \|\| c == '\v')
mbed714	0:d616ece2d859	120	#endif
mbed714	0:d616ece2d859	121
mbed714	0:d616ece2d859	122	/**
mbed714	0:d616ece2d859	123	* Ascii internet address interpretation routine.
mbed714	0:d616ece2d859	124	* The value returned is in network order.
mbed714	0:d616ece2d859	125	*
mbed714	0:d616ece2d859	126	* @param cp IP address in ascii represenation (e.g. "127.0.0.1")
mbed714	0:d616ece2d859	127	* @return ip address in network order
mbed714	0:d616ece2d859	128	*/
mbed714	0:d616ece2d859	129	u32_t
mbed714	0:d616ece2d859	130	ipaddr_addr(const char *cp)
mbed714	0:d616ece2d859	131	{
mbed714	0:d616ece2d859	132	ip_addr_t val;
mbed714	0:d616ece2d859	133
mbed714	0:d616ece2d859	134	if (ipaddr_aton(cp, &val)) {
mbed714	0:d616ece2d859	135	return ip4_addr_get_u32(&val);
mbed714	0:d616ece2d859	136	}
mbed714	0:d616ece2d859	137	return (IPADDR_NONE);
mbed714	0:d616ece2d859	138	}
mbed714	0:d616ece2d859	139
mbed714	0:d616ece2d859	140	/**
mbed714	0:d616ece2d859	141	* Check whether "cp" is a valid ascii representation
mbed714	0:d616ece2d859	142	* of an Internet address and convert to a binary address.
mbed714	0:d616ece2d859	143	* Returns 1 if the address is valid, 0 if not.
mbed714	0:d616ece2d859	144	* This replaces inet_addr, the return value from which
mbed714	0:d616ece2d859	145	* cannot distinguish between failure and a local broadcast address.
mbed714	0:d616ece2d859	146	*
mbed714	0:d616ece2d859	147	* @param cp IP address in ascii represenation (e.g. "127.0.0.1")
mbed714	0:d616ece2d859	148	* @param addr pointer to which to save the ip address in network order
mbed714	0:d616ece2d859	149	* @return 1 if cp could be converted to addr, 0 on failure
mbed714	0:d616ece2d859	150	*/
mbed714	0:d616ece2d859	151	int
mbed714	0:d616ece2d859	152	ipaddr_aton(const char cp, ip_addr_t addr)
mbed714	0:d616ece2d859	153	{
mbed714	0:d616ece2d859	154	u32_t val;
mbed714	0:d616ece2d859	155	u8_t base;
mbed714	0:d616ece2d859	156	char c;
mbed714	0:d616ece2d859	157	u32_t parts[4];
mbed714	0:d616ece2d859	158	u32_t *pp = parts;
mbed714	0:d616ece2d859	159
mbed714	0:d616ece2d859	160	c = *cp;
mbed714	0:d616ece2d859	161	for (;;) {
mbed714	0:d616ece2d859	162	/*
mbed714	0:d616ece2d859	163	* Collect number up to ``.''.
mbed714	0:d616ece2d859	164	* Values are specified as for C:
mbed714	0:d616ece2d859	165	* 0x=hex, 0=octal, 1-9=decimal.
mbed714	0:d616ece2d859	166	*/
mbed714	0:d616ece2d859	167	if (!isdigit(c))
mbed714	0:d616ece2d859	168	return (0);
mbed714	0:d616ece2d859	169	val = 0;
mbed714	0:d616ece2d859	170	base = 10;
mbed714	0:d616ece2d859	171	if (c == '0') {
mbed714	0:d616ece2d859	172	c = *++cp;
mbed714	0:d616ece2d859	173	if (c == 'x' \|\| c == 'X') {
mbed714	0:d616ece2d859	174	base = 16;
mbed714	0:d616ece2d859	175	c = *++cp;
mbed714	0:d616ece2d859	176	} else
mbed714	0:d616ece2d859	177	base = 8;
mbed714	0:d616ece2d859	178	}
mbed714	0:d616ece2d859	179	for (;;) {
mbed714	0:d616ece2d859	180	if (isdigit(c)) {
mbed714	0:d616ece2d859	181	val = (val * base) + (int)(c - '0');
mbed714	0:d616ece2d859	182	c = *++cp;
mbed714	0:d616ece2d859	183	} else if (base == 16 && isxdigit(c)) {
mbed714	0:d616ece2d859	184	val = (val << 4) \| (int)(c + 10 - (islower(c) ? 'a' : 'A'));
mbed714	0:d616ece2d859	185	c = *++cp;
mbed714	0:d616ece2d859	186	} else
mbed714	0:d616ece2d859	187	break;
mbed714	0:d616ece2d859	188	}
mbed714	0:d616ece2d859	189	if (c == '.') {
mbed714	0:d616ece2d859	190	/*
mbed714	0:d616ece2d859	191	* Internet format:
mbed714	0:d616ece2d859	192	* a.b.c.d
mbed714	0:d616ece2d859	193	* a.b.c (with c treated as 16 bits)
mbed714	0:d616ece2d859	194	* a.b (with b treated as 24 bits)
mbed714	0:d616ece2d859	195	*/
mbed714	0:d616ece2d859	196	if (pp >= parts + 3) {
mbed714	0:d616ece2d859	197	return (0);
mbed714	0:d616ece2d859	198	}
mbed714	0:d616ece2d859	199	*pp++ = val;
mbed714	0:d616ece2d859	200	c = *++cp;
mbed714	0:d616ece2d859	201	} else
mbed714	0:d616ece2d859	202	break;
mbed714	0:d616ece2d859	203	}
mbed714	0:d616ece2d859	204	/*
mbed714	0:d616ece2d859	205	* Check for trailing characters.
mbed714	0:d616ece2d859	206	*/
mbed714	0:d616ece2d859	207	if (c != '\0' && !isspace(c)) {
mbed714	0:d616ece2d859	208	return (0);
mbed714	0:d616ece2d859	209	}
mbed714	0:d616ece2d859	210	/*
mbed714	0:d616ece2d859	211	* Concoct the address according to
mbed714	0:d616ece2d859	212	* the number of parts specified.
mbed714	0:d616ece2d859	213	*/
mbed714	0:d616ece2d859	214	switch (pp - parts + 1) {
mbed714	0:d616ece2d859	215
mbed714	0:d616ece2d859	216	case 0:
mbed714	0:d616ece2d859	217	return (0); /* initial nondigit */
mbed714	0:d616ece2d859	218
mbed714	0:d616ece2d859	219	case 1: /* a -- 32 bits */
mbed714	0:d616ece2d859	220	break;
mbed714	0:d616ece2d859	221
mbed714	0:d616ece2d859	222	case 2: /* a.b -- 8.24 bits */
mbed714	0:d616ece2d859	223	if (val > 0xffffffUL) {
mbed714	0:d616ece2d859	224	return (0);
mbed714	0:d616ece2d859	225	}
mbed714	0:d616ece2d859	226	val \|= parts[0] << 24;
mbed714	0:d616ece2d859	227	break;
mbed714	0:d616ece2d859	228
mbed714	0:d616ece2d859	229	case 3: /* a.b.c -- 8.8.16 bits */
mbed714	0:d616ece2d859	230	if (val > 0xffff) {
mbed714	0:d616ece2d859	231	return (0);
mbed714	0:d616ece2d859	232	}
mbed714	0:d616ece2d859	233	val \|= (parts[0] << 24) \| (parts[1] << 16);
mbed714	0:d616ece2d859	234	break;
mbed714	0:d616ece2d859	235
mbed714	0:d616ece2d859	236	case 4: /* a.b.c.d -- 8.8.8.8 bits */
mbed714	0:d616ece2d859	237	if (val > 0xff) {
mbed714	0:d616ece2d859	238	return (0);
mbed714	0:d616ece2d859	239	}
mbed714	0:d616ece2d859	240	val \|= (parts[0] << 24) \| (parts[1] << 16) \| (parts[2] << 8);
mbed714	0:d616ece2d859	241	break;
mbed714	0:d616ece2d859	242	default:
mbed714	0:d616ece2d859	243	LWIP_ASSERT("unhandled", 0);
mbed714	0:d616ece2d859	244	break;
mbed714	0:d616ece2d859	245	}
mbed714	0:d616ece2d859	246	if (addr) {
mbed714	0:d616ece2d859	247	ip4_addr_set_u32(addr, htonl(val));
mbed714	0:d616ece2d859	248	}
mbed714	0:d616ece2d859	249	return (1);
mbed714	0:d616ece2d859	250	}
mbed714	0:d616ece2d859	251
mbed714	0:d616ece2d859	252	/**
mbed714	0:d616ece2d859	253	* Convert numeric IP address into decimal dotted ASCII representation.
mbed714	0:d616ece2d859	254	* returns ptr to static buffer; not reentrant!
mbed714	0:d616ece2d859	255	*
mbed714	0:d616ece2d859	256	* @param addr ip address in network order to convert
mbed714	0:d616ece2d859	257	* @return pointer to a global static (!) buffer that holds the ASCII
mbed714	0:d616ece2d859	258	* represenation of addr
mbed714	0:d616ece2d859	259	*/
mbed714	0:d616ece2d859	260	char *
mbed714	0:d616ece2d859	261	ipaddr_ntoa(const ip_addr_t *addr)
mbed714	0:d616ece2d859	262	{
mbed714	0:d616ece2d859	263	static char str[16];
mbed714	0:d616ece2d859	264	return ipaddr_ntoa_r(addr, str, 16);
mbed714	0:d616ece2d859	265	}
mbed714	0:d616ece2d859	266
mbed714	0:d616ece2d859	267	/**
mbed714	0:d616ece2d859	268	* Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used.
mbed714	0:d616ece2d859	269	*
mbed714	0:d616ece2d859	270	* @param addr ip address in network order to convert
mbed714	0:d616ece2d859	271	* @param buf target buffer where the string is stored
mbed714	0:d616ece2d859	272	* @param buflen length of buf
mbed714	0:d616ece2d859	273	* @return either pointer to buf which now holds the ASCII
mbed714	0:d616ece2d859	274	* representation of addr or NULL if buf was too small
mbed714	0:d616ece2d859	275	*/
mbed714	0:d616ece2d859	276	char ipaddr_ntoa_r(const ip_addr_t addr, char *buf, int buflen)
mbed714	0:d616ece2d859	277	{
mbed714	0:d616ece2d859	278	u32_t s_addr;
mbed714	0:d616ece2d859	279	char inv[3];
mbed714	0:d616ece2d859	280	char *rp;
mbed714	0:d616ece2d859	281	u8_t *ap;
mbed714	0:d616ece2d859	282	u8_t rem;
mbed714	0:d616ece2d859	283	u8_t n;
mbed714	0:d616ece2d859	284	u8_t i;
mbed714	0:d616ece2d859	285	int len = 0;
mbed714	0:d616ece2d859	286
mbed714	0:d616ece2d859	287	s_addr = ip4_addr_get_u32(addr);
mbed714	0:d616ece2d859	288
mbed714	0:d616ece2d859	289	rp = buf;
mbed714	0:d616ece2d859	290	ap = (u8_t *)&s_addr;
mbed714	0:d616ece2d859	291	for(n = 0; n < 4; n++) {
mbed714	0:d616ece2d859	292	i = 0;
mbed714	0:d616ece2d859	293	do {
mbed714	0:d616ece2d859	294	rem = *ap % (u8_t)10;
mbed714	0:d616ece2d859	295	*ap /= (u8_t)10;
mbed714	0:d616ece2d859	296	inv[i++] = '0' + rem;
mbed714	0:d616ece2d859	297	} while(*ap);
mbed714	0:d616ece2d859	298	while(i--) {
mbed714	0:d616ece2d859	299	if (len++ >= buflen) {
mbed714	0:d616ece2d859	300	return NULL;
mbed714	0:d616ece2d859	301	}
mbed714	0:d616ece2d859	302	*rp++ = inv[i];
mbed714	0:d616ece2d859	303	}
mbed714	0:d616ece2d859	304	if (len++ >= buflen) {
mbed714	0:d616ece2d859	305	return NULL;
mbed714	0:d616ece2d859	306	}
mbed714	0:d616ece2d859	307	*rp++ = '.';
mbed714	0:d616ece2d859	308	ap++;
mbed714	0:d616ece2d859	309	}
mbed714	0:d616ece2d859	310	*--rp = 0;
mbed714	0:d616ece2d859	311	return buf;
mbed714	0:d616ece2d859	312	}

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Type:	Library
Created:	18 Sep 2010
Imports:	1
Forks:	0
Commits:	1
Dependents:	0
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lwip/core/ipv4/ip_addr.c@0:d616ece2d859, 2010-09-18 (annotated)

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