[apple/xnu.git] / bsd / netns / ns_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) 1982, 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.
 *
 *	@(#)ns_cksum.c	8.1 (Berkeley) 6/10/93
 */

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

/*
 * Checksum routine for Network Systems Protocol Packets (Big-Endian).
 *
 * This routine is very heavily used in the network
 * code and should be modified for each CPU to be as fast as possible.
 */

#define ADDCARRY(x)  { if ((x) > 65535) (x) -= 65535; }
#define FOLD(x) {l_util.l = (x); (x) = l_util.s[0] + l_util.s[1]; ADDCARRY(x);}

u_short
ns_cksum(m, len)
	register struct mbuf *m;
	register int len;
{
	register u_short *w;
	register int sum = 0;
	register int mlen = 0;
	register int sum2;

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

	for (;m && len; m = m->m_next) {
		if (m->m_len == 0)
			continue;
		/*
		 * Each trip around loop adds in
		 * word from one mbuf segment.
		 */
		w = mtod(m, u_short *);
		if (mlen == -1) {
			/*
			 * There is a byte left from the last segment;
			 * ones-complement add it into the checksum.
			 */
#if BYTE_ORDER == BIG_ENDIAN
			sum  += *(u_char *)w;
#else
			sum  += *(u_char *)w << 8;
#endif
			sum += sum;
			w = (u_short *)(1 + (char *)w);
			mlen = m->m_len - 1;
			len--;
			FOLD(sum);
		} else
			mlen = m->m_len;
		if (len < mlen)
			mlen = len;
		len -= mlen;
		/*
		 * We can do a 16 bit ones complement sum using
		 * 32 bit arithmetic registers for adding,
		 * with carries from the low added
		 * into the high (by normal carry-chaining)
		 * so long as we fold back before 16 carries have occured.
		 */
		if (1 & (int) w)
			goto uuuuglyy;
#ifndef TINY
/* -DTINY reduces the size from 1250 to 550, but slows it down by 22% */
		while ((mlen -= 32) >= 0) {
			sum += w[0]; sum += sum; sum += w[1]; sum += sum;
			sum += w[2]; sum += sum; sum += w[3]; sum += sum;
			sum += w[4]; sum += sum; sum += w[5]; sum += sum;
			sum += w[6]; sum += sum; sum += w[7]; sum += sum;
			FOLD(sum);
			sum += w[8]; sum += sum; sum += w[9]; sum += sum;
			sum += w[10]; sum += sum; sum += w[11]; sum += sum;
			sum += w[12]; sum += sum; sum += w[13]; sum += sum;
			sum += w[14]; sum += sum; sum += w[15]; sum += sum;
			FOLD(sum);
			w += 16;
		}
		mlen += 32;
#endif
		while ((mlen -= 8) >= 0) {
			sum += w[0]; sum += sum; sum += w[1]; sum += sum;
			sum += w[2]; sum += sum; sum += w[3]; sum += sum;
			FOLD(sum);
			w += 4;
		}
		mlen += 8;
		while ((mlen -= 2) >= 0) {
			sum += *w++; sum += sum;
		}
		goto commoncase;
uuuuglyy:
#if BYTE_ORDER == BIG_ENDIAN
#define ww(n) (((u_char *)w)[n + n + 1])
#define vv(n) (((u_char *)w)[n + n])
#else
#if BYTE_ORDER == LITTLE_ENDIAN
#define vv(n) (((u_char *)w)[n + n + 1])
#define ww(n) (((u_char *)w)[n + n])
#endif
#endif
		sum2 = 0;
#ifndef TINY
		while ((mlen -= 32) >= 0) {
		    sum += ww(0); sum += sum; sum += ww(1); sum += sum;
		    sum += ww(2); sum += sum; sum += ww(3); sum += sum;
		    sum += ww(4); sum += sum; sum += ww(5); sum += sum;
		    sum += ww(6); sum += sum; sum += ww(7); sum += sum;
		    FOLD(sum);
		    sum += ww(8); sum += sum; sum += ww(9); sum += sum;
		    sum += ww(10); sum += sum; sum += ww(11); sum += sum;
		    sum += ww(12); sum += sum; sum += ww(13); sum += sum;
		    sum += ww(14); sum += sum; sum += ww(15); sum += sum;
		    FOLD(sum);
		    sum2 += vv(0); sum2 += sum2; sum2 += vv(1); sum2 += sum2;
		    sum2 += vv(2); sum2 += sum2; sum2 += vv(3); sum2 += sum2;
		    sum2 += vv(4); sum2 += sum2; sum2 += vv(5); sum2 += sum2;
		    sum2 += vv(6); sum2 += sum2; sum2 += vv(7); sum2 += sum2;
		    FOLD(sum2);
		    sum2 += vv(8); sum2 += sum2; sum2 += vv(9); sum2 += sum2;
		    sum2 += vv(10); sum2 += sum2; sum2 += vv(11); sum2 += sum2;
		    sum2 += vv(12); sum2 += sum2; sum2 += vv(13); sum2 += sum2;
		    sum2 += vv(14); sum2 += sum2; sum2 += vv(15); sum2 += sum2;
		    FOLD(sum2);
		    w += 16;
		}
		mlen += 32;
#endif
		while ((mlen -= 8) >= 0) {
		    sum += ww(0); sum += sum; sum += ww(1); sum += sum;
		    sum += ww(2); sum += sum; sum += ww(3); sum += sum;
		    FOLD(sum);
		    sum2 += vv(0); sum2 += sum2; sum2 += vv(1); sum2 += sum2;
		    sum2 += vv(2); sum2 += sum2; sum2 += vv(3); sum2 += sum2;
		    FOLD(sum2);
		    w += 4;
		}
		mlen += 8;
		while ((mlen -= 2) >= 0) {
			sum += ww(0); sum += sum;
			sum2 += vv(0); sum2 += sum2;
			w++;
		}
		sum += (sum2 << 8);
commoncase:
		if (mlen == -1) {
#if BYTE_ORDER == BIG_ENDIAN
			sum += *(u_char *)w << 8;
#else
			sum += *(u_char *)w;
#endif
		}
		FOLD(sum);
	}
	if (mlen == -1) {
		/* We had an odd number of bytes to sum; assume a garbage
		   byte of zero and clean up */
		sum += sum;
		FOLD(sum);
	}
	/*
	 * sum has already been kept to low sixteen bits.
	 * just examine result and exit.
	 */
	if(sum==0xffff) sum = 0;
	return (sum);
}
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) 1982, 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	* @(#)ns_cksum.c 8.1 (Berkeley) 6/10/93
	55	*/
	56
	57	#include <sys/param.h>
	58	#include <sys/mbuf.h>
	59
	60	/*
	61	* Checksum routine for Network Systems Protocol Packets (Big-Endian).
	62	*
	63	* This routine is very heavily used in the network
	64	* code and should be modified for each CPU to be as fast as possible.
65	*/
66
67	#define ADDCARRY(x) { if ((x) > 65535) (x) -= 65535; }
68	#define FOLD(x) {l_util.l = (x); (x) = l_util.s[0] + l_util.s[1]; ADDCARRY(x);}
69
70	u_short
71	ns_cksum(m, len)
72	register struct mbuf *m;
73	register int len;
74	{
75	register u_short *w;
76	register int sum = 0;
77	register int mlen = 0;
78	register int sum2;
79
80	union {
81	u_short s[2];
82	long l;
83	} l_util;
84
85	for (;m && len; m = m->m_next) {
86	if (m->m_len == 0)
87	continue;
88	/*
89	* Each trip around loop adds in
90	* word from one mbuf segment.
91	*/
92	w = mtod(m, u_short *);
93	if (mlen == -1) {
94	/*
95	* There is a byte left from the last segment;
96	* ones-complement add it into the checksum.
97	*/
98	#if BYTE_ORDER == BIG_ENDIAN
99	sum += (u_char )w;
100	#else
101	sum += (u_char )w << 8;
102	#endif
103	sum += sum;
104	w = (u_short )(1 + (char )w);
105	mlen = m->m_len - 1;
106	len--;
107	FOLD(sum);
108	} else
109	mlen = m->m_len;
110	if (len < mlen)
111	mlen = len;
112	len -= mlen;
113	/*
114	* We can do a 16 bit ones complement sum using
115	* 32 bit arithmetic registers for adding,
116	* with carries from the low added
117	* into the high (by normal carry-chaining)
118	* so long as we fold back before 16 carries have occured.
119	*/
120	if (1 & (int) w)
121	goto uuuuglyy;
122	#ifndef TINY
123	/* -DTINY reduces the size from 1250 to 550, but slows it down by 22% */
124	while ((mlen -= 32) >= 0) {
125	sum += w[0]; sum += sum; sum += w[1]; sum += sum;
126	sum += w[2]; sum += sum; sum += w[3]; sum += sum;
127	sum += w[4]; sum += sum; sum += w[5]; sum += sum;
128	sum += w[6]; sum += sum; sum += w[7]; sum += sum;
129	FOLD(sum);
130	sum += w[8]; sum += sum; sum += w[9]; sum += sum;
131	sum += w[10]; sum += sum; sum += w[11]; sum += sum;
132	sum += w[12]; sum += sum; sum += w[13]; sum += sum;
133	sum += w[14]; sum += sum; sum += w[15]; sum += sum;
134	FOLD(sum);
135	w += 16;
136	}
137	mlen += 32;
138	#endif
139	while ((mlen -= 8) >= 0) {
140	sum += w[0]; sum += sum; sum += w[1]; sum += sum;
141	sum += w[2]; sum += sum; sum += w[3]; sum += sum;
142	FOLD(sum);
143	w += 4;
144	}
145	mlen += 8;
146	while ((mlen -= 2) >= 0) {
147	sum += *w++; sum += sum;
148	}
149	goto commoncase;
150	uuuuglyy:
151	#if BYTE_ORDER == BIG_ENDIAN
152	#define ww(n) (((u_char *)w)[n + n + 1])
153	#define vv(n) (((u_char *)w)[n + n])
154	#else
155	#if BYTE_ORDER == LITTLE_ENDIAN
156	#define vv(n) (((u_char *)w)[n + n + 1])
157	#define ww(n) (((u_char *)w)[n + n])
158	#endif
159	#endif
160	sum2 = 0;
161	#ifndef TINY
162	while ((mlen -= 32) >= 0) {
163	sum += ww(0); sum += sum; sum += ww(1); sum += sum;
164	sum += ww(2); sum += sum; sum += ww(3); sum += sum;
165	sum += ww(4); sum += sum; sum += ww(5); sum += sum;
166	sum += ww(6); sum += sum; sum += ww(7); sum += sum;
167	FOLD(sum);
168	sum += ww(8); sum += sum; sum += ww(9); sum += sum;
169	sum += ww(10); sum += sum; sum += ww(11); sum += sum;
170	sum += ww(12); sum += sum; sum += ww(13); sum += sum;
171	sum += ww(14); sum += sum; sum += ww(15); sum += sum;
172	FOLD(sum);
173	sum2 += vv(0); sum2 += sum2; sum2 += vv(1); sum2 += sum2;
174	sum2 += vv(2); sum2 += sum2; sum2 += vv(3); sum2 += sum2;
175	sum2 += vv(4); sum2 += sum2; sum2 += vv(5); sum2 += sum2;
176	sum2 += vv(6); sum2 += sum2; sum2 += vv(7); sum2 += sum2;
177	FOLD(sum2);
178	sum2 += vv(8); sum2 += sum2; sum2 += vv(9); sum2 += sum2;
179	sum2 += vv(10); sum2 += sum2; sum2 += vv(11); sum2 += sum2;
180	sum2 += vv(12); sum2 += sum2; sum2 += vv(13); sum2 += sum2;
181	sum2 += vv(14); sum2 += sum2; sum2 += vv(15); sum2 += sum2;
182	FOLD(sum2);
183	w += 16;
184	}
185	mlen += 32;
186	#endif
187	while ((mlen -= 8) >= 0) {
188	sum += ww(0); sum += sum; sum += ww(1); sum += sum;
189	sum += ww(2); sum += sum; sum += ww(3); sum += sum;
190	FOLD(sum);
191	sum2 += vv(0); sum2 += sum2; sum2 += vv(1); sum2 += sum2;
192	sum2 += vv(2); sum2 += sum2; sum2 += vv(3); sum2 += sum2;
193	FOLD(sum2);
194	w += 4;
195	}
196	mlen += 8;
197	while ((mlen -= 2) >= 0) {
198	sum += ww(0); sum += sum;
199	sum2 += vv(0); sum2 += sum2;
200	w++;
201	}
202	sum += (sum2 << 8);
203	commoncase:
204	if (mlen == -1) {
205	#if BYTE_ORDER == BIG_ENDIAN
206	sum += (u_char )w << 8;
207	#else
208	sum += (u_char )w;
209	#endif
210	}
211	FOLD(sum);
212	}
213	if (mlen == -1) {
214	/* We had an odd number of bytes to sum; assume a garbage
215	byte of zero and clean up */
216	sum += sum;
217	FOLD(sum);
218	}
219	/*
220	* sum has already been kept to low sixteen bits.
221	* just examine result and exit.
222	*/
223	if(sum==0xffff) sum = 0;
224	return (sum);
225	}