1 | /* |
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2 | * Copyright (c) 1988, 1992, 1993 |
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3 | * The Regents of the University of California. All rights reserved. |
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4 | * |
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5 | * Redistribution and use in source and binary forms, with or without |
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6 | * modification, are permitted provided that the following conditions |
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7 | * are met: |
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8 | * 1. Redistributions of source code must retain the above copyright |
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9 | * notice, this list of conditions and the following disclaimer. |
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10 | * 2. Redistributions in binary form must reproduce the above copyright |
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11 | * notice, this list of conditions and the following disclaimer in the |
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12 | * documentation and/or other materials provided with the distribution. |
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13 | * 3. All advertising materials mentioning features or use of this software |
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14 | * must display the following acknowledgement: |
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15 | * This product includes software developed by the University of |
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16 | * California, Berkeley and its contributors. |
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17 | * 4. Neither the name of the University nor the names of its contributors |
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18 | * may be used to endorse or promote products derived from this software |
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19 | * without specific prior written permission. |
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20 | * |
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21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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31 | * SUCH DAMAGE. |
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32 | * |
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33 | * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93 |
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34 | * $Id$ |
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35 | */ |
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36 | |
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37 | #include <sys/param.h> |
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38 | #include <sys/mbuf.h> |
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39 | |
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40 | #if (defined(__GNUC__) && (defined(__mc68000__) || defined(__m68k__))) |
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41 | |
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42 | #define REDUCE { sum = (sum & 0xFFFF) + (sum >> 16); if (sum > 0xFFFF) sum -= 0xFFFF; } |
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43 | |
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44 | /* |
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45 | * Motorola 68k version of Internet Protocol Checksum routine |
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46 | * W. Eric Norum |
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47 | * Saskatchewan Accelerator Laboratory |
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48 | * August, 1998 |
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49 | */ |
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50 | int |
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51 | in_cksum(m, len) |
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52 | struct mbuf *m; |
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53 | int len; |
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54 | { |
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55 | unsigned short *w; |
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56 | unsigned long sum = 0; |
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57 | int mlen = 0; |
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58 | int byte_swapped = 0; |
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59 | union { |
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60 | char c[2]; |
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61 | u_short s; |
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62 | } s_util; |
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63 | |
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64 | for ( ; m && len ; m = m->m_next) { |
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65 | if (m->m_len == 0) |
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66 | continue; |
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67 | w = mtod(m, u_short *); |
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68 | if (mlen == -1) { |
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69 | /* |
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70 | * The first byte of this mbuf is the continuation |
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71 | * of a word spanning between this mbuf and the |
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72 | * last mbuf. |
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73 | * |
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74 | * s_util.c[0] is already saved when scanning previous |
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75 | * mbuf. |
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76 | */ |
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77 | s_util.c[1] = *(char *)w; |
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78 | sum += s_util.s; |
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79 | w = (u_short *)((char *)w + 1); |
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80 | mlen = m->m_len - 1; |
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81 | len--; |
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82 | } else |
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83 | mlen = m->m_len; |
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84 | if (len < mlen) |
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85 | mlen = len; |
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86 | len -= mlen; |
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87 | |
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88 | /* |
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89 | * Force to longword boundary. |
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90 | */ |
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91 | if (3 & (int)w) { |
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92 | REDUCE; |
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93 | if ((1 & (int) w) && (mlen > 0)) { |
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94 | sum <<= 8; |
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95 | s_util.c[0] = *(u_char *)w; |
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96 | w = (u_short *)((char *)w + 1); |
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97 | mlen--; |
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98 | byte_swapped = 1; |
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99 | } |
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100 | if ((2 & (int) w) && (mlen >= 2)) { |
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101 | sum += *w++; |
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102 | mlen -= 2; |
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103 | } |
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104 | } |
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105 | |
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106 | /* |
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107 | * Sum all the longwords in the buffer. |
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108 | * See RFC 1071 -- Computing the Internet Checksum. |
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109 | * It should work for all 68k family members. |
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110 | */ |
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111 | { |
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112 | unsigned long tcnt = mlen, t1; |
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113 | __asm__ volatile ( |
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114 | "movel %2,%3\n\t" |
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115 | "lsrl #6,%2 | count/64 = # loop traversals\n\t" |
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116 | "andl #0x3c,%3 | Then find fractions of a chunk\n\t" |
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117 | "negl %3\n\t | Each long uses 4 instruction bytes\n\t" |
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118 | "andi #0xf,%%cc | Clear X (extended carry flag)\n\t" |
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119 | "jmp %%pc@(lcsum2_lbl-.-2:b,%3) | Jump into loop\n" |
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120 | "lcsum1_lbl: | Begin inner loop...\n\t" |
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121 | "movel %1@+,%3 | 0: Fetch 32-bit word\n\t" |
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122 | "addxl %3,%0 | Add word + previous carry\n\t" |
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123 | "movel %1@+,%3 | 1: Fetch 32-bit word\n\t" |
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124 | "addxl %3,%0 | Add word + previous carry\n\t" |
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125 | "movel %1@+,%3 | 2: Fetch 32-bit word\n\t" |
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126 | "addxl %3,%0 | Add word + previous carry\n\t" |
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127 | "movel %1@+,%3 | 3: Fetch 32-bit word\n\t" |
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128 | "addxl %3,%0 | Add word + previous carry\n\t" |
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129 | "movel %1@+,%3 | 4: Fetch 32-bit word\n\t" |
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130 | "addxl %3,%0 | Add word + previous carry\n\t" |
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131 | "movel %1@+,%3 | 5: Fetch 32-bit word\n\t" |
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132 | "addxl %3,%0 | Add word + previous carry\n\t" |
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133 | "movel %1@+,%3 | 6: Fetch 32-bit word\n\t" |
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134 | "addxl %3,%0 | Add word + previous carry\n\t" |
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135 | "movel %1@+,%3 | 7: Fetch 32-bit word\n\t" |
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136 | "addxl %3,%0 | Add word + previous carry\n\t" |
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137 | "movel %1@+,%3 | 8: Fetch 32-bit word\n\t" |
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138 | "addxl %3,%0 | Add word + previous carry\n\t" |
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139 | "movel %1@+,%3 | 9: Fetch 32-bit word\n\t" |
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140 | "addxl %3,%0 | Add word + previous carry\n\t" |
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141 | "movel %1@+,%3 | A: Fetch 32-bit word\n\t" |
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142 | "addxl %3,%0 | Add word + previous carry\n\t" |
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143 | "movel %1@+,%3 | B: Fetch 32-bit word\n\t" |
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144 | "addxl %3,%0 | Add word + previous carry\n\t" |
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145 | "movel %1@+,%3 | C: Fetch 32-bit word\n\t" |
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146 | "addxl %3,%0 | Add word + previous carry\n\t" |
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147 | "movel %1@+,%3 | D: Fetch 32-bit word\n\t" |
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148 | "addxl %3,%0 | Add word + previous carry\n\t" |
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149 | "movel %1@+,%3 | E: Fetch 32-bit word\n\t" |
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150 | "addxl %3,%0 | Add word + previous carry\n\t" |
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151 | "movel %1@+,%3 | F: Fetch 32-bit word\n\t" |
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152 | "addxl %3,%0 | Add word + previous carry\n" |
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153 | "lcsum2_lbl:\n\tdbf %2,lcsum1_lbl | (NB- dbra doesn't affect X)\n\t" |
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154 | "movel %0,%3 | Fold 32 bit sum to 16 bits\n\t" |
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155 | "swap %3 | (NB- swap doesn't affect X)\n\t" |
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156 | "addxw %3,%0 |\n\t" |
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157 | "moveq #0,%3 | Add in last carry\n\t" |
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158 | "addxw %3,%0 |\n\t" |
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159 | "andl #0xffff,%0 | Mask to 16-bit sum\n" : |
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160 | "=d" (sum), "=a" (w), "=d" (tcnt) , "=d" (t1) : |
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161 | "0" (sum), "1" (w), "2" (tcnt) : |
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162 | "cc", "memory"); |
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163 | } |
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164 | mlen &= 3; |
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165 | |
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166 | /* |
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167 | * Soak up the last 1, 2 or 3 bytes |
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168 | */ |
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169 | while ((mlen -= 2) >= 0) |
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170 | sum += *w++; |
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171 | if (byte_swapped) { |
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172 | REDUCE; |
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173 | sum <<= 8; |
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174 | byte_swapped = 0; |
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175 | if (mlen == -1) { |
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176 | s_util.c[1] = *(char *)w; |
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177 | sum += s_util.s; |
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178 | mlen = 0; |
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179 | } else |
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180 | mlen = -1; |
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181 | } else if (mlen == -1) |
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182 | s_util.c[0] = *(char *)w; |
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183 | } |
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184 | if (len) |
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185 | sum = 0xDEAD; |
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186 | if (mlen == -1) { |
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187 | /* The last mbuf has odd # of bytes. Follow the |
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188 | standard (the odd byte may be shifted left by 8 bits |
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189 | or not as determined by endian-ness of the machine) */ |
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190 | s_util.c[1] = 0; |
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191 | sum += s_util.s; |
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192 | } |
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193 | REDUCE; |
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194 | return (~sum & 0xffff); |
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195 | } |
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196 | |
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197 | |
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198 | #else |
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199 | /* |
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200 | * Checksum routine for Internet Protocol family headers (Portable Version). |
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201 | * |
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202 | * This routine is very heavily used in the network |
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203 | * code and should be modified for each CPU to be as fast as possible. |
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204 | */ |
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205 | |
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206 | #define ADDCARRY(x) (x > 65535 ? x -= 65535 : x) |
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207 | #define REDUCE \ |
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208 | {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);} |
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209 | |
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210 | int |
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211 | in_cksum(m, len) |
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212 | register struct mbuf *m; |
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213 | register int len; |
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214 | { |
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215 | register u_short *w; |
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216 | register int sum = 0; |
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217 | register int mlen = 0; |
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218 | int byte_swapped = 0; |
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219 | |
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220 | union { |
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221 | char c[2]; |
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222 | u_short s; |
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223 | } s_util; |
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224 | union { |
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225 | u_short s[2]; |
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226 | long l; |
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227 | } l_util; |
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228 | |
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229 | for (;m && len; m = m->m_next) { |
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230 | if (m->m_len == 0) |
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231 | continue; |
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232 | w = mtod(m, u_short *); |
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233 | if (mlen == -1) { |
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234 | /* |
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235 | * The first byte of this mbuf is the continuation |
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236 | * of a word spanning between this mbuf and the |
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237 | * last mbuf. |
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238 | * |
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239 | * s_util.c[0] is already saved when scanning previous |
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240 | * mbuf. |
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241 | */ |
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242 | s_util.c[1] = *(char *)w; |
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243 | sum += s_util.s; |
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244 | w = (u_short *)((char *)w + 1); |
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245 | mlen = m->m_len - 1; |
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246 | len--; |
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247 | } else |
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248 | mlen = m->m_len; |
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249 | if (len < mlen) |
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250 | mlen = len; |
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251 | len -= mlen; |
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252 | /* |
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253 | * Force to even boundary. |
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254 | */ |
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255 | if ((1 & (int) w) && (mlen > 0)) { |
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256 | REDUCE; |
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257 | sum <<= 8; |
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258 | s_util.c[0] = *(u_char *)w; |
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259 | w = (u_short *)((char *)w + 1); |
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260 | mlen--; |
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261 | byte_swapped = 1; |
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262 | } |
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263 | /* |
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264 | * Unroll the loop to make overhead from |
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265 | * branches &c small. |
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266 | */ |
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267 | while ((mlen -= 32) >= 0) { |
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268 | sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3]; |
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269 | sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7]; |
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270 | sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11]; |
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271 | sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15]; |
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272 | w += 16; |
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273 | } |
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274 | mlen += 32; |
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275 | while ((mlen -= 8) >= 0) { |
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276 | sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3]; |
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277 | w += 4; |
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278 | } |
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279 | mlen += 8; |
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280 | if (mlen == 0 && byte_swapped == 0) |
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281 | continue; |
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282 | REDUCE; |
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283 | while ((mlen -= 2) >= 0) { |
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284 | sum += *w++; |
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285 | } |
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286 | if (byte_swapped) { |
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287 | REDUCE; |
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288 | sum <<= 8; |
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289 | byte_swapped = 0; |
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290 | if (mlen == -1) { |
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291 | s_util.c[1] = *(char *)w; |
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292 | sum += s_util.s; |
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293 | mlen = 0; |
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294 | } else |
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295 | mlen = -1; |
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296 | } else if (mlen == -1) |
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297 | s_util.c[0] = *(char *)w; |
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298 | } |
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299 | if (len) |
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300 | printf("cksum: out of data\n"); |
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301 | if (mlen == -1) { |
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302 | /* The last mbuf has odd # of bytes. Follow the |
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303 | standard (the odd byte may be shifted left by 8 bits |
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304 | or not as determined by endian-ness of the machine) */ |
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305 | s_util.c[1] = 0; |
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306 | sum += s_util.s; |
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307 | } |
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308 | REDUCE; |
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309 | return (~sum & 0xffff); |
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310 | } |
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311 | #endif |
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