[Qemu-devel] Re: Re: Re: Atheros Wireless Device Emulation

[Clemens Kolbitsch]

Patch #8:

CRC32 helper code. Sorry if there is already some global function that could
be used for this purpose. Simply took the code from Wireshark (license and
header documentation unchanged obviously).


diff -Naur qemu/hw/atheros_wlan_crc32.c qemu-altered/hw/atheros_wlan_crc32.c
--- qemu/hw/atheros_wlan_crc32.c        1970-01-01 01:00:00.000000000 +0100
+++ qemu-altered/hw/atheros_wlan_crc32.c        2008-03-01 12:33:11.000000000 
+0100
@@ -0,0 +1,238 @@
+/* crc32.c
+ * CRC-32 routine
+ *
+ * $Id: crc32.c 18197 2006-05-21 05:12:17Z sahlberg $
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <address@hidden>
+ * Copyright 1998 Gerald Combs
+ *
+ * Copied from README.developer
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Credits:
+ *
+ * Table from Solomon Peachy
+ * Routine from Chris Waters
+ */
+
+#include "atheros_wlan_crc32.h"
+
+/*
+ * Table for the AUTODIN/HDLC/802.x CRC.
+ *
+ * Polynomial is
+ *
+ *  x^32 + x^26 + x^23 + x^22 + x^16 + x^12 + x^11 + x^8 + x^7 +
+ *      x^5 + x^4 + x^2 + x + 1
+ */
+const guint32 crc32_ccitt_table[256] = {
+        0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
+        0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
+        0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
+        0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
+        0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
+        0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
+        0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
+        0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
+        0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
+        0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
+        0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
+        0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+        0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
+        0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
+        0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
+        0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
+        0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
+        0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+        0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
+        0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
+        0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
+        0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
+        0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
+        0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+        0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
+        0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
+        0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
+        0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
+        0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
+        0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+        0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
+        0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
+        0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
+        0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
+        0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
+        0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+        0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
+        0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
+        0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
+        0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
+        0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
+        0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+        0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
+        0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
+        0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
+        0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
+        0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
+        0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+        0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
+        0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
+        0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
+        0x2d02ef8d
+};
+
+#define CRC32_CCITT_SEED    0xFFFFFFFF
+
+guint32
+crc32_ccitt(const guint8 *buf, guint len)
+{
+  return ( crc32_ccitt_seed(buf, len, CRC32_CCITT_SEED) );
+}
+
+guint32
+crc32_ccitt_seed(const guint8 *buf, guint len, guint32 seed)
+{
+  guint i;
+  guint32 crc32 = seed;
+
+  for (i = 0; i < len; i++)
+    crc32 = crc32_ccitt_table[(crc32 ^ buf[i]) & 0xff] ^ (crc32 >> 8);
+
+  return ( ~crc32 );
+}
+
+
+
+
+
+
+
+
+
+
+/*
+ * 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.
+ */
+
+#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(const vec_t *vec, int veclen)
+{
+       register const guint16 *w;
+       register int sum = 0;
+       register int mlen = 0;
+       int byte_swapped = 0;
+
+       union {
+               guint8  c[2];
+               guint16 s;
+       } s_util;
+       union {
+               guint16 s[2];
+               guint32 l;
+       } l_util;
+
+       for (; veclen != 0; vec++, veclen--) {
+               if (vec->len == 0)
+                       continue;
+               w = (const guint16 *)vec->ptr;
+               if (mlen == -1) {
+                       /*
+                       * The first byte of this chunk is the continuation
+                       * of a word spanning between this chunk and the
+                       * last chunk.
+                       *
+                       * s_util.c[0] is already saved when scanning previous
+                       * chunk.
+                       */
+                       s_util.c[1] = *(const guint8 *)w;
+                       sum += s_util.s;
+                       w = (const guint16 *)((const guint8 *)w + 1);
+                       mlen = vec->len - 1;
+               } else
+                       mlen = vec->len;
+               /*
+                       * Force to even boundary.
+               */
+                       if ((1 & (unsigned long) w) && (mlen > 0)) {
+                               REDUCE;
+                               sum <<= 8;
+                               s_util.c[0] = *(const guint8 *)w;
+                               w = (const guint16 *)((const guint8 *)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] = *(const guint8 *)w;
+                                       sum += s_util.s;
+                                       mlen = 0;
+                               } else
+                                       mlen = -1;
+                       } else if (mlen == -1)
+                               s_util.c[0] = *(const guint8 *)w;
+       }
+       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);
+}
+
+guint16 ip_checksum(const guint8 *ptr, int len)
+{
+       vec_t cksum_vec[1];
+
+       cksum_vec[0].ptr = ptr;
+       cksum_vec[0].len = len;
+       return in_cksum(&cksum_vec[0], 1);
+}
+
diff -Naur qemu/hw/atheros_wlan_crc32.h qemu-altered/hw/atheros_wlan_crc32.h
--- qemu/hw/atheros_wlan_crc32.h        1970-01-01 01:00:00.000000000 +0100
+++ qemu-altered/hw/atheros_wlan_crc32.h        2008-03-01 12:33:11.000000000 
+0100
@@ -0,0 +1,51 @@
+/* crc32.h
+ * Declaration of CRC-32 routine and table
+ *
+ * $Id: crc32.h 20485 2007-01-18 18:43:30Z guy $
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <address@hidden>
+ * Copyright 1998 Gerald Combs
+ *
+ * Copied from README.developer
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __CRC32_H_
+#define __CRC32_H_
+
+#define guint32 unsigned long
+#define guint16 unsigned short
+#define guint8 unsigned char
+#define guint unsigned int
+
+extern const guint32 crc32_ccitt_table[256];
+
+extern guint32 crc32_ccitt(const guint8 *buf, guint len);
+extern guint32 crc32_ccitt_seed(const guint8 *buf, guint len, guint32 seed);
+
+
+typedef struct {
+       const guint8 *ptr;
+       int     len;
+} vec_t;
+
+extern int in_cksum(const vec_t *vec, int veclen);
+extern guint16 ip_checksum(const guint8 *ptr, int len);
+
+
+
+#endif /* crc32.h */