[apple/xnu.git] / bsd / netinet / in_cksum.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1988, 1992, 1993
 *	The Regents of the University of California.  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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 *
 *	@(#)in_cksum.c	8.1 (Berkeley) 6/10/93
 */

#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/kdebug.h>

#define DBG_FNC_IN_CKSUM	NETDBG_CODE(DBG_NETIP, (3 << 8))

/*
 * Checksum routine for Internet Protocol family headers (Portable Version).
 *
 * This routine is very heavily used in the network
 * code and should be modified for each CPU to be as fast as possible.
 */


#if defined(ppc)

int
in_cksum(m, len)
	register struct mbuf *m;
	register int len;
{
	register u_short *w;
	register int sum = 0;
	register int mlen = 0;
	int starting_on_odd  = 0;


	KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_START, len,0,0,0,0);

	for (;m && len; m = m->m_next) {
		if (m->m_len == 0)
			continue;
		mlen = m->m_len;
		w = mtod(m, u_short *);

		if (len < mlen)
			mlen = len;

		sum = xsum_assym(w, mlen, sum, starting_on_odd);
		len -= mlen;
		if (mlen & 0x1)
		{
		    if (starting_on_odd)
			starting_on_odd = 0;
		    else
			starting_on_odd = 1;
		}
	}

	KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_END, 0,0,0,0,0);
	return (~sum & 0xffff);
}

#else


#define ADDCARRY(x)  (x > 65535 ? x -= 65535 : x)
#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);}


int
in_cksum(m, len)
	register struct mbuf *m;
	register int len;
{
	register u_short *w;
	register int sum = 0;
	register int mlen = 0;
	int byte_swapped = 0;

	union {
		char	c[2];
		u_short	s;
	} s_util;
	union {
		u_short s[2];
		long	l;
	} l_util;

	KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_START, len,0,0,0,0);

	for (;m && len; m = m->m_next) {
		if (m->m_len == 0)
			continue;
		w = mtod(m, u_short *);
		if (mlen == -1) {
			/*
			 * The first byte of this mbuf is the continuation
			 * of a word spanning between this mbuf and the
			 * last mbuf.
			 *
			 * s_util.c[0] is already saved when scanning previous
			 * mbuf.
			 */
			s_util.c[1] = *(char *)w;
			sum += s_util.s;
			w = (u_short *)((char *)w + 1);
			mlen = m->m_len - 1;
			len--;
		} else
			mlen = m->m_len;
		if (len < mlen)
			mlen = len;
		len -= mlen;
		/*
		 * Force to even boundary.
		 */
		if ((1 & (int) w) && (mlen > 0)) {
			REDUCE;
			sum <<= 8;
			s_util.c[0] = *(u_char *)w;
			w = (u_short *)((char *)w + 1);
			mlen--;
			byte_swapped = 1;
		}
		/*
		 * Unroll the loop to make overhead from
		 * branches &c small.
		 */
		while ((mlen -= 32) >= 0) {
			sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
			sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
			sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
			sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
			w += 16;
		}
		mlen += 32;
		while ((mlen -= 8) >= 0) {
			sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
			w += 4;
		}
		mlen += 8;
		if (mlen == 0 && byte_swapped == 0)
			continue;
		REDUCE;
		while ((mlen -= 2) >= 0) {
			sum += *w++;
		}
		if (byte_swapped) {
			REDUCE;
			sum <<= 8;
			byte_swapped = 0;
			if (mlen == -1) {
				s_util.c[1] = *(char *)w;
				sum += s_util.s;
				mlen = 0;
			} else
				mlen = -1;
		} else if (mlen == -1)
			s_util.c[0] = *(char *)w;
	}
	if (len)
		printf("cksum: out of data\n");
	if (mlen == -1) {
		/* The last mbuf has odd # of bytes. Follow the
		   standard (the odd byte may be shifted left by 8 bits
		   or not as determined by endian-ness of the machine) */
		s_util.c[1] = 0;
		sum += s_util.s;
	}
	REDUCE;
	KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_END, 0,0,0,0,0);
	return (~sum & 0xffff);
}

#endif
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
	11	*
	12	* This Original Code and all software distributed under the License are
	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/*
	23	* Copyright (c) 1988, 1992, 1993
	24	* The Regents of the University of California. All rights reserved.
	25	*
	26	* Redistribution and use in source and binary forms, with or without
	27	* modification, are permitted provided that the following conditions
	28	* are met:
	29	* 1. Redistributions of source code must retain the above copyright
	30	* notice, this list of conditions and the following disclaimer.
	31	* 2. Redistributions in binary form must reproduce the above copyright
	32	* notice, this list of conditions and the following disclaimer in the
	33	* documentation and/or other materials provided with the distribution.
	34	* 3. All advertising materials mentioning features or use of this software
	35	* must display the following acknowledgement:
	36	* This product includes software developed by the University of
	37	* California, Berkeley and its contributors.
	38	* 4. Neither the name of the University nor the names of its contributors
	39	* may be used to endorse or promote products derived from this software
	40	* without specific prior written permission.
	41	*
	42	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	43	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	44	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	45	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	46	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	47	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	48	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	49	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	50	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	51	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	52	* SUCH DAMAGE.
	53	*
	54	* @(#)in_cksum.c 8.1 (Berkeley) 6/10/93
	55	*/
	56
	57	#include <sys/param.h>
	58	#include <sys/mbuf.h>
	59	#include <sys/kdebug.h>
	60
	61	#define DBG_FNC_IN_CKSUM NETDBG_CODE(DBG_NETIP, (3 << 8))
	62
	63	/*
	64	* Checksum routine for Internet Protocol family headers (Portable Version).
65	*
66	* This routine is very heavily used in the network
67	* code and should be modified for each CPU to be as fast as possible.
68	*/
69
70
71
72	#if defined(ppc)
73
74	int
75	in_cksum(m, len)
76	register struct mbuf *m;
77	register int len;
78	{
79	register u_short *w;
80	register int sum = 0;
81	register int mlen = 0;
82	int starting_on_odd = 0;
83
84
85	KERNEL_DEBUG(DBG_FNC_IN_CKSUM \| DBG_FUNC_START, len,0,0,0,0);
86
87	for (;m && len; m = m->m_next) {
88	if (m->m_len == 0)
89	continue;
90	mlen = m->m_len;
91	w = mtod(m, u_short *);
92
93	if (len < mlen)
94	mlen = len;
95
96	sum = xsum_assym(w, mlen, sum, starting_on_odd);
97	len -= mlen;
98	if (mlen & 0x1)
99	{
100	if (starting_on_odd)
101	starting_on_odd = 0;
102	else
103	starting_on_odd = 1;
104	}
105	}
106
107	KERNEL_DEBUG(DBG_FNC_IN_CKSUM \| DBG_FUNC_END, 0,0,0,0,0);
108	return (~sum & 0xffff);
109	}
110
111	#else
112
113
114	#define ADDCARRY(x) (x > 65535 ? x -= 65535 : x)
115	#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);}
116
117
118
119	int
120	in_cksum(m, len)
121	register struct mbuf *m;
122	register int len;
123	{
124	register u_short *w;
125	register int sum = 0;
126	register int mlen = 0;
127	int byte_swapped = 0;
128
129	union {
130	char c[2];
131	u_short s;
132	} s_util;
133	union {
134	u_short s[2];
135	long l;
136	} l_util;
137
138	KERNEL_DEBUG(DBG_FNC_IN_CKSUM \| DBG_FUNC_START, len,0,0,0,0);
139
140	for (;m && len; m = m->m_next) {
141	if (m->m_len == 0)
142	continue;
143	w = mtod(m, u_short *);
144	if (mlen == -1) {
145	/*
146	* The first byte of this mbuf is the continuation
147	* of a word spanning between this mbuf and the
148	* last mbuf.
149	*
150	* s_util.c[0] is already saved when scanning previous
151	* mbuf.
152	*/
153	s_util.c[1] = (char )w;
154	sum += s_util.s;
155	w = (u_short )((char )w + 1);
156	mlen = m->m_len - 1;
157	len--;
158	} else
159	mlen = m->m_len;
160	if (len < mlen)
161	mlen = len;
162	len -= mlen;
163	/*
164	* Force to even boundary.
165	*/
166	if ((1 & (int) w) && (mlen > 0)) {
167	REDUCE;
168	sum <<= 8;
169	s_util.c[0] = (u_char )w;
170	w = (u_short )((char )w + 1);
171	mlen--;
172	byte_swapped = 1;
173	}
174	/*
175	* Unroll the loop to make overhead from
176	* branches &c small.
177	*/
178	while ((mlen -= 32) >= 0) {
179	sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
180	sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
181	sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
182	sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
183	w += 16;
184	}
185	mlen += 32;
186	while ((mlen -= 8) >= 0) {
187	sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
188	w += 4;
189	}
190	mlen += 8;
191	if (mlen == 0 && byte_swapped == 0)
192	continue;
193	REDUCE;
194	while ((mlen -= 2) >= 0) {
195	sum += *w++;
196	}
197	if (byte_swapped) {
198	REDUCE;
199	sum <<= 8;
200	byte_swapped = 0;
201	if (mlen == -1) {
202	s_util.c[1] = (char )w;
203	sum += s_util.s;
204	mlen = 0;
205	} else
206	mlen = -1;
207	} else if (mlen == -1)
208	s_util.c[0] = (char )w;
209	}
210	if (len)
211	printf("cksum: out of data\n");
212	if (mlen == -1) {
213	/* The last mbuf has odd # of bytes. Follow the
214	standard (the odd byte may be shifted left by 8 bits
215	or not as determined by endian-ness of the machine) */
216	s_util.c[1] = 0;
217	sum += s_util.s;
218	}
219	REDUCE;
220	KERNEL_DEBUG(DBG_FNC_IN_CKSUM \| DBG_FUNC_END, 0,0,0,0,0);
221	return (~sum & 0xffff);
222	}
223
224	#endif