1 | #include <machine/rtems-bsd-kernel-space.h> |
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2 | |
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3 | /* |
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4 | * Copyright (c) 1982, 1986, 1988, 1991, 1993 |
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5 | * The Regents of the University of California. All rights reserved. |
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6 | * |
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7 | * Redistribution and use in source and binary forms, with or without |
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8 | * modification, are permitted provided that the following conditions |
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9 | * are met: |
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10 | * 1. Redistributions of source code must retain the above copyright |
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11 | * notice, this list of conditions and the following disclaimer. |
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12 | * 2. Redistributions in binary form must reproduce the above copyright |
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13 | * notice, this list of conditions and the following disclaimer in the |
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14 | * documentation and/or other materials provided with the distribution. |
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15 | * 4. Neither the name of the University nor the names of its contributors |
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16 | * may be used to endorse or promote products derived from this software |
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17 | * without specific prior written permission. |
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18 | * |
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19 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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20 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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23 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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24 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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25 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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26 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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27 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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28 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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29 | * SUCH DAMAGE. |
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30 | * |
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31 | * @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94 |
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32 | */ |
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33 | |
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34 | #include <sys/param.h> |
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35 | #include <sys/systm.h> |
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36 | #include <sys/proc.h> |
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37 | #include <sys/malloc.h> |
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38 | #define MBTYPES |
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39 | #include <sys/mbuf.h> |
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40 | #include <sys/kernel.h> |
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41 | #include <sys/syslog.h> |
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42 | #include <sys/domain.h> |
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43 | #include <sys/protosw.h> |
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44 | |
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45 | #include <vm/vm.h> |
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46 | #include <vm/vm_param.h> |
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47 | #include <vm/vm_kern.h> |
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48 | #include <vm/vm_extern.h> |
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49 | |
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50 | #if !defined(__rtems__) |
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51 | static void mbinit (void *) __attribute__ ((unused)); |
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52 | SYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbinit, NULL) |
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53 | #endif |
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54 | |
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55 | struct mbuf *mbutl; |
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56 | char *mclrefcnt; |
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57 | struct mbstat mbstat; |
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58 | struct mbuf *mmbfree; |
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59 | union mcluster *mclfree; |
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60 | int max_linkhdr; |
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61 | int max_protohdr; |
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62 | int max_hdr; |
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63 | int max_datalen; |
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64 | |
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65 | /* "number of clusters of pages" */ |
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66 | #define NCL_INIT 1 |
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67 | |
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68 | #define NMB_INIT 16 |
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69 | |
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70 | /* |
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71 | * When MGET failes, ask protocols to free space when short of memory, |
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72 | * then re-attempt to allocate an mbuf. |
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73 | */ |
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74 | struct mbuf * |
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75 | m_retry(int i, int t) |
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76 | { |
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77 | register struct mbuf *m; |
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78 | |
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79 | m_reclaim(); |
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80 | #define m_retry(i, t) (struct mbuf *)0 |
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81 | MGET(m, i, t); |
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82 | #undef m_retry |
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83 | if (m != NULL) |
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84 | mbstat.m_wait++; |
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85 | else |
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86 | mbstat.m_drops++; |
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87 | return (m); |
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88 | } |
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89 | |
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90 | /* |
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91 | * As above; retry an MGETHDR. |
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92 | */ |
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93 | struct mbuf * |
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94 | m_retryhdr(int i, int t) |
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95 | { |
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96 | register struct mbuf *m; |
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97 | |
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98 | m_reclaim(); |
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99 | #define m_retryhdr(i, t) (struct mbuf *)0 |
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100 | MGETHDR(m, i, t); |
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101 | #undef m_retryhdr |
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102 | if (m != NULL) |
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103 | mbstat.m_wait++; |
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104 | else |
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105 | mbstat.m_drops++; |
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106 | return (m); |
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107 | } |
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108 | |
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109 | void |
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110 | m_reclaim(void) |
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111 | { |
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112 | register struct domain *dp; |
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113 | register struct protosw *pr; |
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114 | int s = splimp(); |
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115 | |
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116 | for (dp = domains; dp; dp = dp->dom_next) |
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117 | for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) |
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118 | if (pr->pr_drain) |
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119 | (*pr->pr_drain)(); |
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120 | splx(s); |
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121 | mbstat.m_drain++; |
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122 | } |
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123 | |
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124 | /* |
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125 | * Space allocation routines. |
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126 | * These are also available as macros |
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127 | * for critical paths. |
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128 | */ |
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129 | struct mbuf * |
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130 | m_get(int nowait, int type) |
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131 | { |
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132 | register struct mbuf *m; |
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133 | |
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134 | MGET(m, nowait, type); |
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135 | return (m); |
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136 | } |
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137 | |
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138 | struct mbuf * |
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139 | m_gethdr(int nowait, int type) |
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140 | { |
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141 | register struct mbuf *m; |
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142 | |
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143 | MGETHDR(m, nowait, type); |
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144 | return (m); |
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145 | } |
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146 | |
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147 | struct mbuf * |
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148 | m_getclr(int nowait, int type) |
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149 | { |
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150 | register struct mbuf *m; |
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151 | |
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152 | MGET(m, nowait, type); |
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153 | if (m == 0) |
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154 | return (0); |
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155 | bzero(mtod(m, caddr_t), MLEN); |
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156 | return (m); |
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157 | } |
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158 | |
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159 | struct mbuf * |
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160 | m_free(struct mbuf *m) |
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161 | { |
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162 | struct mbuf *n; |
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163 | |
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164 | MFREE(m, n); |
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165 | return (n); |
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166 | } |
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167 | |
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168 | void |
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169 | m_freem(struct mbuf *mb) |
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170 | { |
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171 | struct mbuf *n; |
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172 | |
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173 | if (mb == NULL) |
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174 | return; |
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175 | do { |
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176 | MFREE(mb, n); |
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177 | mb = n; |
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178 | } while (mb); |
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179 | } |
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180 | |
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181 | /* |
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182 | * Mbuffer utility routines. |
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183 | */ |
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184 | |
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185 | /* |
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186 | * Lesser-used path for M_PREPEND: |
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187 | * allocate new mbuf to prepend to chain, |
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188 | * copy junk along. |
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189 | */ |
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190 | struct mbuf * |
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191 | m_prepend(struct mbuf *m, int len, int how) |
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192 | { |
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193 | struct mbuf *mn; |
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194 | |
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195 | MGET(mn, how, m->m_type); |
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196 | if (mn == (struct mbuf *)NULL) { |
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197 | m_freem(m); |
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198 | return ((struct mbuf *)NULL); |
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199 | } |
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200 | if (m->m_flags & M_PKTHDR) { |
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201 | M_COPY_PKTHDR(mn, m); |
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202 | m->m_flags &= ~M_PKTHDR; |
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203 | } |
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204 | mn->m_next = m; |
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205 | m = mn; |
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206 | if (len < MHLEN) |
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207 | MH_ALIGN(m, len); |
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208 | m->m_len = len; |
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209 | return (m); |
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210 | } |
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211 | |
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212 | /* |
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213 | * Make a copy of an mbuf chain starting "off0" bytes from the beginning, |
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214 | * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf. |
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215 | * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller. |
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216 | */ |
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217 | static int MCFail; |
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218 | |
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219 | struct mbuf * |
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220 | m_copym(struct mbuf *m, int off0, uint32_t len, int wait) |
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221 | { |
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222 | struct mbuf *n, **np; |
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223 | int off = off0; |
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224 | struct mbuf *top; |
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225 | int copyhdr = 0; |
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226 | |
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227 | if (off < 0 || len < 0) |
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228 | panic("m_copym"); |
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229 | if (off == 0 && m->m_flags & M_PKTHDR) |
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230 | copyhdr = 1; |
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231 | while (off > 0) { |
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232 | if (m == NULL) |
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233 | panic("m_copym"); |
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234 | if (off < m->m_len) |
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235 | break; |
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236 | off -= m->m_len; |
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237 | m = m->m_next; |
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238 | } |
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239 | np = ⊤ |
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240 | top = 0; |
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241 | while (len > 0) { |
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242 | if (m == NULL) { |
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243 | if (len != M_COPYALL) |
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244 | panic("m_copym"); |
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245 | break; |
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246 | } |
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247 | MGET(n, wait, m->m_type); |
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248 | *np = n; |
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249 | if (n == NULL) |
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250 | goto nospace; |
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251 | if (copyhdr) { |
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252 | M_COPY_PKTHDR(n, m); |
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253 | if (len == M_COPYALL) |
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254 | n->m_pkthdr.len -= off0; |
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255 | else |
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256 | n->m_pkthdr.len = len; |
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257 | copyhdr = 0; |
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258 | } |
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259 | n->m_len = min(len, m->m_len - off); |
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260 | if (m->m_flags & M_EXT) { |
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261 | n->m_data = m->m_data + off; |
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262 | if(!m->m_ext.ext_ref) |
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263 | mclrefcnt[mtocl(m->m_ext.ext_buf)]++; |
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264 | else |
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265 | (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, |
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266 | m->m_ext.ext_size); |
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267 | n->m_ext = m->m_ext; |
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268 | n->m_flags |= M_EXT; |
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269 | } else |
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270 | bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), |
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271 | (unsigned)n->m_len); |
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272 | if (len != M_COPYALL) |
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273 | len -= n->m_len; |
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274 | off = 0; |
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275 | m = m->m_next; |
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276 | np = &n->m_next; |
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277 | } |
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278 | if (top == NULL) |
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279 | MCFail++; |
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280 | return (top); |
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281 | nospace: |
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282 | m_freem(top); |
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283 | MCFail++; |
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284 | return (NULL); |
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285 | } |
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286 | |
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287 | /* |
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288 | * Copy an entire packet, including header (which must be present). |
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289 | * An optimization of the common case `m_copym(m, 0, M_COPYALL, how)'. |
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290 | */ |
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291 | struct mbuf * |
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292 | m_copypacket(struct mbuf *m, int how) |
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293 | { |
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294 | struct mbuf *top, *n, *o; |
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295 | |
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296 | MGET(n, how, m->m_type); |
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297 | top = n; |
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298 | if (!n) |
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299 | goto nospace; |
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300 | |
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301 | M_COPY_PKTHDR(n, m); |
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302 | n->m_len = m->m_len; |
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303 | if (m->m_flags & M_EXT) { |
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304 | n->m_data = m->m_data; |
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305 | mclrefcnt[mtocl(m->m_ext.ext_buf)]++; |
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306 | n->m_ext = m->m_ext; |
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307 | n->m_flags |= M_EXT; |
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308 | } else { |
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309 | bcopy(mtod(m, char *), mtod(n, char *), n->m_len); |
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310 | } |
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311 | |
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312 | m = m->m_next; |
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313 | while (m) { |
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314 | MGET(o, how, m->m_type); |
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315 | if (!o) |
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316 | goto nospace; |
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317 | |
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318 | n->m_next = o; |
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319 | n = n->m_next; |
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320 | |
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321 | n->m_len = m->m_len; |
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322 | if (m->m_flags & M_EXT) { |
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323 | n->m_data = m->m_data; |
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324 | mclrefcnt[mtocl(m->m_ext.ext_buf)]++; |
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325 | n->m_ext = m->m_ext; |
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326 | n->m_flags |= M_EXT; |
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327 | } else { |
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328 | bcopy(mtod(m, char *), mtod(n, char *), n->m_len); |
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329 | } |
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330 | |
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331 | m = m->m_next; |
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332 | } |
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333 | return top; |
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334 | nospace: |
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335 | m_freem(top); |
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336 | MCFail++; |
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337 | return 0; |
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338 | } |
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339 | |
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340 | /* |
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341 | * Copy data from an mbuf chain starting "off" bytes from the beginning, |
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342 | * continuing for "len" bytes, into the indicated buffer. Return -1 if requested |
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343 | * size is bigger than available |
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344 | */ |
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345 | int |
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346 | m_copydata(const struct mbuf *m, int off, int len, caddr_t cp) |
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347 | { |
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348 | u_int count; |
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349 | |
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350 | if (off < 0 || len < 0) |
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351 | panic("m_copydata"); |
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352 | while (off > 0) { |
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353 | if (m == 0) { |
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354 | /*printf("m_copydata: offset > mbuf length ("); |
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355 | while(m0) { |
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356 | printf("[%d] ",m0->m_len); |
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357 | m0 = m0->m_next; |
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358 | } |
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359 | printf(")\n");*/ |
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360 | return -1; |
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361 | } |
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362 | if (off < m->m_len) |
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363 | break; |
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364 | off -= m->m_len; |
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365 | m = m->m_next; |
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366 | } |
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367 | while (len > 0) { |
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368 | if (m == 0) { |
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369 | /*printf("m_copydata: length > mbuf length ("); |
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370 | while(m0) { |
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371 | printf("[%d] ",m0->m_len); |
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372 | m0 = m0->m_next; |
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373 | } |
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374 | printf(")\n");*/ |
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375 | |
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376 | return -1; |
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377 | } |
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378 | count = min(m->m_len - off, len); |
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379 | bcopy(mtod(m, caddr_t) + off, cp, count); |
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380 | len -= count; |
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381 | cp += count; |
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382 | off = 0; |
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383 | m = m->m_next; |
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384 | } |
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385 | return 0; |
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386 | } |
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387 | |
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388 | /* |
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389 | * Concatenate mbuf chain n to m. |
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390 | * Both chains must be of the same type (e.g. MT_DATA). |
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391 | * Any m_pkthdr is not updated. |
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392 | */ |
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393 | void |
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394 | m_cat(struct mbuf *m, struct mbuf *n) |
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395 | { |
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396 | while (m->m_next) |
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397 | m = m->m_next; |
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398 | while (n) { |
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399 | if (m->m_flags & M_EXT || |
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400 | m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) { |
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401 | /* just join the two chains */ |
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402 | m->m_next = n; |
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403 | return; |
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404 | } |
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405 | /* splat the data from one into the other */ |
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406 | bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, |
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407 | (u_int)n->m_len); |
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408 | m->m_len += n->m_len; |
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409 | n = m_free(n); |
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410 | } |
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411 | } |
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412 | |
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413 | void |
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414 | m_adj(struct mbuf *mp, int req_len) |
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415 | { |
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416 | int len = req_len; |
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417 | struct mbuf *m; |
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418 | int count; |
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419 | |
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420 | if ((m = mp) == NULL) |
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421 | return; |
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422 | if (len >= 0) { |
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423 | /* |
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424 | * Trim from head. |
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425 | */ |
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426 | while (m != NULL && len > 0) { |
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427 | if (m->m_len <= len) { |
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428 | len -= m->m_len; |
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429 | m->m_len = 0; |
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430 | m = m->m_next; |
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431 | } else { |
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432 | m->m_len -= len; |
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433 | m->m_data += len; |
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434 | len = 0; |
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435 | } |
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436 | } |
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437 | m = mp; |
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438 | if (mp->m_flags & M_PKTHDR) |
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439 | m->m_pkthdr.len -= (req_len - len); |
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440 | } else { |
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441 | /* |
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442 | * Trim from tail. Scan the mbuf chain, |
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443 | * calculating its length and finding the last mbuf. |
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444 | * If the adjustment only affects this mbuf, then just |
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445 | * adjust and return. Otherwise, rescan and truncate |
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446 | * after the remaining size. |
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447 | */ |
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448 | len = -len; |
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449 | count = 0; |
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450 | for (;;) { |
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451 | count += m->m_len; |
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452 | if (m->m_next == (struct mbuf *)0) |
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453 | break; |
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454 | m = m->m_next; |
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455 | } |
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456 | if (m->m_len >= len) { |
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457 | m->m_len -= len; |
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458 | if (mp->m_flags & M_PKTHDR) |
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459 | mp->m_pkthdr.len -= len; |
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460 | return; |
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461 | } |
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462 | count -= len; |
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463 | if (count < 0) |
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464 | count = 0; |
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465 | /* |
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466 | * Correct length for chain is "count". |
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467 | * Find the mbuf with last data, adjust its length, |
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468 | * and toss data from remaining mbufs on chain. |
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469 | */ |
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470 | m = mp; |
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471 | if (m->m_flags & M_PKTHDR) |
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472 | m->m_pkthdr.len = count; |
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473 | for (; m; m = m->m_next) { |
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474 | if (m->m_len >= count) { |
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475 | m->m_len = count; |
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476 | break; |
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477 | } |
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478 | count -= m->m_len; |
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479 | } |
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480 | while (m->m_next) |
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481 | (m = m->m_next) ->m_len = 0; |
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482 | } |
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483 | } |
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484 | |
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485 | /* |
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486 | * Rearange an mbuf chain so that len bytes are contiguous |
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487 | * and in the data area of an mbuf (so that mtod and dtom |
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488 | * will work for a structure of size len). Returns the resulting |
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489 | * mbuf chain on success, frees it and returns null on failure. |
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490 | * If there is room, it will add up to max_protohdr-len extra bytes to the |
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491 | * contiguous region in an attempt to avoid being called next time. |
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492 | */ |
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493 | static int MPFail; |
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494 | |
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495 | struct mbuf * |
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496 | m_pullup(struct mbuf *n, int len) |
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497 | { |
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498 | struct mbuf *m; |
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499 | int count; |
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500 | int space; |
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501 | |
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502 | /* |
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503 | * If first mbuf has no cluster, and has room for len bytes |
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504 | * without shifting current data, pullup into it, |
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505 | * otherwise allocate a new mbuf to prepend to the chain. |
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506 | */ |
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507 | if ((n->m_flags & M_EXT) == 0 && |
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508 | n->m_data + len < &n->m_dat[MLEN] && n->m_next) { |
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509 | if (n->m_len >= len) |
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510 | return (n); |
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511 | m = n; |
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512 | n = n->m_next; |
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513 | len -= m->m_len; |
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514 | } else { |
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515 | if (len > MHLEN) |
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516 | goto bad; |
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517 | MGET(m, M_DONTWAIT, n->m_type); |
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518 | if (m == NULL) |
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519 | goto bad; |
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520 | m->m_len = 0; |
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521 | if (n->m_flags & M_PKTHDR) { |
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522 | M_COPY_PKTHDR(m, n); |
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523 | n->m_flags &= ~M_PKTHDR; |
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524 | } |
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525 | } |
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526 | space = &m->m_dat[MLEN] - (m->m_data + m->m_len); |
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527 | do { |
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528 | count = min(min(max(len, max_protohdr), space), n->m_len); |
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529 | bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, |
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530 | (unsigned)count); |
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531 | len -= count; |
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532 | m->m_len += count; |
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533 | n->m_len -= count; |
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534 | space -= count; |
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535 | if (n->m_len) |
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536 | n->m_data += count; |
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537 | else |
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538 | n = m_free(n); |
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539 | } while (len > 0 && n); |
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540 | if (len > 0) { |
---|
541 | (void) m_free(m); |
---|
542 | goto bad; |
---|
543 | } |
---|
544 | m->m_next = n; |
---|
545 | return (m); |
---|
546 | bad: |
---|
547 | m_freem(n); |
---|
548 | MPFail++; |
---|
549 | return (NULL); |
---|
550 | } |
---|
551 | |
---|
552 | /* |
---|
553 | * Partition an mbuf chain in two pieces, returning the tail -- |
---|
554 | * all but the first len0 bytes. In case of failure, it returns NULL and |
---|
555 | * attempts to restore the chain to its original state. |
---|
556 | */ |
---|
557 | struct mbuf * |
---|
558 | m_split(struct mbuf *m0, int len0, int wait) |
---|
559 | { |
---|
560 | struct mbuf *m, *n; |
---|
561 | u_int len = len0, remain; |
---|
562 | |
---|
563 | for (m = m0; m && len > m->m_len; m = m->m_next) |
---|
564 | len -= m->m_len; |
---|
565 | if (m == NULL) |
---|
566 | return (NULL); |
---|
567 | remain = m->m_len - len; |
---|
568 | if (m0->m_flags & M_PKTHDR) { |
---|
569 | MGETHDR(n, wait, m0->m_type); |
---|
570 | if (n == NULL) |
---|
571 | return (NULL); |
---|
572 | n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif; |
---|
573 | n->m_pkthdr.len = m0->m_pkthdr.len - len0; |
---|
574 | m0->m_pkthdr.len = len0; |
---|
575 | if (m->m_flags & M_EXT) |
---|
576 | goto extpacket; |
---|
577 | if (remain > MHLEN) { |
---|
578 | /* m can't be the lead packet */ |
---|
579 | MH_ALIGN(n, 0); |
---|
580 | n->m_next = m_split(m, len, wait); |
---|
581 | if (n->m_next == 0) { |
---|
582 | (void) m_free(n); |
---|
583 | return (0); |
---|
584 | } else |
---|
585 | return (n); |
---|
586 | } else |
---|
587 | MH_ALIGN(n, remain); |
---|
588 | } else if (remain == 0) { |
---|
589 | n = m->m_next; |
---|
590 | m->m_next = NULL; |
---|
591 | return (n); |
---|
592 | } else { |
---|
593 | MGET(n, wait, m->m_type); |
---|
594 | if (n == 0) |
---|
595 | return (0); |
---|
596 | M_ALIGN(n, remain); |
---|
597 | } |
---|
598 | extpacket: |
---|
599 | if (m->m_flags & M_EXT) { |
---|
600 | n->m_flags |= M_EXT; |
---|
601 | n->m_ext = m->m_ext; |
---|
602 | if(!m->m_ext.ext_ref) |
---|
603 | mclrefcnt[mtocl(m->m_ext.ext_buf)]++; |
---|
604 | else |
---|
605 | (*(m->m_ext.ext_ref))(m->m_ext.ext_buf, |
---|
606 | m->m_ext.ext_size); |
---|
607 | m->m_ext.ext_size = 0; /* For Accounting XXXXXX danger */ |
---|
608 | n->m_data = m->m_data + len; |
---|
609 | } else { |
---|
610 | bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain); |
---|
611 | } |
---|
612 | n->m_len = remain; |
---|
613 | m->m_len = len; |
---|
614 | n->m_next = m->m_next; |
---|
615 | m->m_next = NULL; |
---|
616 | return (n); |
---|
617 | } |
---|
618 | /* |
---|
619 | * Routine to copy from device local memory into mbufs. |
---|
620 | */ |
---|
621 | struct mbuf * |
---|
622 | m_devget(char *buf, int totlen, int off0, struct ifnet *ifp, |
---|
623 | void (*copy)(char *from, caddr_t to, u_int len)) |
---|
624 | { |
---|
625 | struct mbuf *m; |
---|
626 | struct mbuf *top = NULL, **mp = ⊤ |
---|
627 | int len; |
---|
628 | int off = off0; |
---|
629 | char *cp; |
---|
630 | char *epkt; |
---|
631 | |
---|
632 | cp = buf; |
---|
633 | epkt = cp + totlen; |
---|
634 | if (off) { |
---|
635 | cp += off + 2 * sizeof(u_short); |
---|
636 | totlen -= 2 * sizeof(u_short); |
---|
637 | } |
---|
638 | MGETHDR(m, M_DONTWAIT, MT_DATA); |
---|
639 | if (m == 0) |
---|
640 | return (0); |
---|
641 | m->m_pkthdr.rcvif = ifp; |
---|
642 | m->m_pkthdr.len = totlen; |
---|
643 | m->m_len = MHLEN; |
---|
644 | |
---|
645 | while (totlen > 0) { |
---|
646 | if (top) { |
---|
647 | MGET(m, M_DONTWAIT, MT_DATA); |
---|
648 | if (m == 0) { |
---|
649 | m_freem(top); |
---|
650 | return (0); |
---|
651 | } |
---|
652 | m->m_len = MLEN; |
---|
653 | } |
---|
654 | len = min(totlen, epkt - cp); |
---|
655 | if (len >= MINCLSIZE) { |
---|
656 | MCLGET(m, M_DONTWAIT); |
---|
657 | if (m->m_flags & M_EXT) |
---|
658 | m->m_len = len = min(len, MCLBYTES); |
---|
659 | else |
---|
660 | len = m->m_len; |
---|
661 | } else { |
---|
662 | /* |
---|
663 | * Place initial small packet/header at end of mbuf. |
---|
664 | */ |
---|
665 | if (len < m->m_len) { |
---|
666 | if (top == 0 && len + max_linkhdr <= m->m_len) |
---|
667 | m->m_data += max_linkhdr; |
---|
668 | m->m_len = len; |
---|
669 | } else |
---|
670 | len = m->m_len; |
---|
671 | } |
---|
672 | if (copy) |
---|
673 | copy(cp, mtod(m, caddr_t), (u_int)len); |
---|
674 | else |
---|
675 | bcopy(cp, mtod(m, caddr_t), (u_int)len); |
---|
676 | cp += len; |
---|
677 | *mp = m; |
---|
678 | mp = &m->m_next; |
---|
679 | totlen -= len; |
---|
680 | if (cp == epkt) |
---|
681 | cp = buf; |
---|
682 | } |
---|
683 | return (top); |
---|
684 | } |
---|
685 | |
---|
686 | /* |
---|
687 | * Copy data from a buffer back into the indicated mbuf chain, |
---|
688 | * starting "off" bytes from the beginning, extending the mbuf |
---|
689 | * chain if necessary. |
---|
690 | */ |
---|
691 | int |
---|
692 | m_copyback(struct mbuf *m0, int off, int len, caddr_t cp) |
---|
693 | { |
---|
694 | int mlen; |
---|
695 | struct mbuf *m = m0, *n; |
---|
696 | int totlen = 0; |
---|
697 | |
---|
698 | if (m0 == NULL) |
---|
699 | return 0; |
---|
700 | while (off > (mlen = m->m_len)) { |
---|
701 | off -= mlen; |
---|
702 | totlen += mlen; |
---|
703 | if (m->m_next == NULL) { |
---|
704 | n = m_getclr(M_DONTWAIT, m->m_type); |
---|
705 | if (n == NULL) { |
---|
706 | /*panic("m_copyback() : malformed chain\n");*/ |
---|
707 | return -1; |
---|
708 | } |
---|
709 | n->m_len = min(MLEN, len + off); |
---|
710 | m->m_next = n; |
---|
711 | } |
---|
712 | m = m->m_next; |
---|
713 | } |
---|
714 | while (len > 0) { |
---|
715 | mlen = min (m->m_len - off, len); |
---|
716 | bcopy(cp, off + mtod(m, caddr_t), (u_int)mlen); |
---|
717 | cp += mlen; |
---|
718 | len -= mlen; |
---|
719 | mlen += off; |
---|
720 | off = 0; |
---|
721 | totlen += mlen; |
---|
722 | if (len == 0) { |
---|
723 | /* m->m_len = mlen; */ |
---|
724 | break; |
---|
725 | } |
---|
726 | if (m->m_next == NULL) { |
---|
727 | n = m_get(M_DONTWAIT, m->m_type); |
---|
728 | if (n == 0) { |
---|
729 | /*panic("m_copyback() : malformed chain 2\n");*/ |
---|
730 | return -1; |
---|
731 | }; |
---|
732 | n->m_len = min(MLEN, len); |
---|
733 | m->m_next = n; |
---|
734 | } |
---|
735 | /* m->m_len = mlen; */ |
---|
736 | m = m->m_next; |
---|
737 | } |
---|
738 | /*out:*/ |
---|
739 | if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen)) |
---|
740 | m->m_pkthdr.len = totlen; |
---|
741 | return 0; |
---|
742 | } |
---|