summaryrefslogtreecommitdiffstats
path: root/c/src/exec/libnetworking/netinet/in_cksum.c
diff options
context:
space:
mode:
Diffstat (limited to 'c/src/exec/libnetworking/netinet/in_cksum.c')
-rw-r--r--c/src/exec/libnetworking/netinet/in_cksum.c308
1 files changed, 308 insertions, 0 deletions
diff --git a/c/src/exec/libnetworking/netinet/in_cksum.c b/c/src/exec/libnetworking/netinet/in_cksum.c
new file mode 100644
index 0000000000..f834d629d2
--- /dev/null
+++ b/c/src/exec/libnetworking/netinet/in_cksum.c
@@ -0,0 +1,308 @@
+/*
+ * 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
+ * $Id$
+ */
+
+#include <sys/param.h>
+#include <sys/mbuf.h>
+
+#if (defined(__GNUC__) && (defined(__mc68000__) || defined(__m68k__)))
+
+#define REDUCE { sum = (sum & 0xFFFF) + (sum >> 16); if (sum > 0xFFFF) sum -= 0xFFFF; }
+
+/*
+ * Motorola 68k version of Internet Protocol Checksum routine
+ * W. Eric Norum
+ * Saskatchewan Accelerator Laboratory
+ * August, 1998
+ */
+int
+in_cksum(m, len)
+ struct mbuf *m;
+ int len;
+{
+ unsigned short *w;
+ unsigned long sum = 0;
+ int mlen = 0;
+ int byte_swapped = 0;
+ union {
+ char c[2];
+ u_short s;
+ } s_util;
+
+ 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 longword boundary.
+ */
+ if (3 & (int)w) {
+ REDUCE;
+ if ((1 & (int) w) && (mlen > 0)) {
+ sum <<= 8;
+ s_util.c[0] = *(u_char *)w;
+ w = (u_short *)((char *)w + 1);
+ mlen--;
+ byte_swapped = 1;
+ }
+ if ((2 & (int) w) && (mlen >= 2)) {
+ sum += *w++;
+ mlen -= 2;
+ }
+ }
+
+ /*
+ * Sum all the longwords in the buffer.
+ * See RFC 1071 -- Computing the Internet Checksum.
+ * It should work for all 68k family members.
+ */
+ {
+ unsigned long tcnt = mlen, t1;
+ __asm__ volatile (
+ "movel %2,%3\n\t"
+ "lsrl #6,%2 | count/64 = # loop traversals\n\t"
+ "andl #0x3c,%3 | Then find fractions of a chunk\n\t"
+ "negl %3\n\t | Each long uses 4 instruction bytes\n\t"
+ "andi #0xf,%%cc | Clear X (extended carry flag)\n\t"
+ "jmp %%pc@(lcsum2_lbl-.-2:b,%3) | Jump into loop\n"
+ "lcsum1_lbl: | Begin inner loop...\n\t"
+ "movel %1@+,%3 | 0: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | 1: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | 2: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | 3: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | 4: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | 5: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | 6: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | 7: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | 8: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | 9: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | A: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | B: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | C: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | D: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | E: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n\t"
+ "movel %1@+,%3 | F: Fetch 32-bit word\n\t"
+ "addxl %3,%0 | Add word + previous carry\n"
+ "lcsum2_lbl:\n\tdbf %2,lcsum1_lbl | (NB- dbra doesn't affect X)\n\t"
+ "movel %0,%3 | Fold 32 bit sum to 16 bits\n\t"
+ "swap %3 | (NB- swap doesn't affect X)\n\t"
+ "addxw %3,%0 |\n\t"
+ "moveq #0,%3 | Add in last carry\n\t"
+ "addxw %3,%0 |\n\t"
+ "andl #0xffff,%0 | Mask to 16-bit sum\n" :
+ "=d" (sum), "=a" (w), "=d" (tcnt) , "=d" (t1) :
+ "0" (sum), "1" (w), "2" (tcnt) :
+ "cc", "memory");
+ }
+ mlen &= 3;
+
+ /*
+ * Soak up the last 1, 2 or 3 bytes
+ */
+ 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)
+ sum = 0xDEAD;
+ 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;
+ return (~sum & 0xffff);
+}
+
+
+#else
+/*
+ * 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.
+ */
+
+
+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;
+
+ 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;
+ return (~sum & 0xffff);
+}
+#endif
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-19 05:33:06 +0000