sys/src/9/ip/loopbackmedium.c

   1 #include "u.h"
   2 #include "../port/lib.h"
   3 #include "mem.h"
   4 #include "dat.h"
   5 #include "fns.h"
   6 #include "../port/error.h"
   7
   8 #include "ip.h"
   9
  10 enum
  11 {
  12         Maxtu=  16*1024,
  13 };
  14
  15 typedef struct LB LB;
  16 struct LB
  17 {
  18         Proc    *readp;
  19         Queue   *q;
  20         Fs      *f;
  21 };
  22
  23 static void loopbackread(void *a);
  24
  25 static void
  26 loopbackbind(Ipifc *ifc, int, char**)
  27 {
  28         LB *lb;
  29
  30         lb = smalloc(sizeof(*lb));
  31         lb->f = ifc->conv->p->f;
  32         lb->q = qopen(1024*1024, Qmsg, nil, nil);
  33         ifc->arg = lb;
  34         ifc->mbps = 1000;
  35
  36         kproc("loopbackread", loopbackread, ifc);
  37
  38 }
  39
  40 static void
  41 loopbackunbind(Ipifc *ifc)
  42 {
  43         LB *lb = ifc->arg;
  44
  45         if(lb->readp)
  46                 postnote(lb->readp, 1, "unbind", 0);
  47
  48         /* wait for reader to die */
  49         while(lb->readp != 0)
  50                 tsleep(&up->sleep, return0, 0, 300);
  51
  52         /* clean up */
  53         qfree(lb->q);
  54         free(lb);
  55 }
  56
  57 static void
  58 loopbackbwrite(Ipifc *ifc, Block *bp, int, uchar*)
  59 {
  60         LB *lb;
  61
  62         lb = ifc->arg;
  63         if(qpass(lb->q, bp) < 0)
  64                 ifc->outerr++;
  65         ifc->out++;
  66 }
  67
  68 static void
  69 loopbackread(void *a)
  70 {
  71         Ipifc *ifc;
  72         Block *bp;
  73         LB *lb;
  74
  75         ifc = a;
  76         lb = ifc->arg;
  77         lb->readp = up; /* hide identity under a rock for unbind */
  78         if(waserror()){
  79                 lb->readp = 0;
  80                 pexit("hangup", 1);
  81         }
  82         for(;;){
  83                 bp = qbread(lb->q, Maxtu);
  84                 if(bp == nil)
  85                         continue;
  86                 ifc->in++;
  87                 if(!canrlock(ifc)){
  88                         freeb(bp);
  89                         continue;
  90                 }
  91                 if(waserror()){
  92                         runlock(ifc);
  93                         nexterror();
  94                 }
  95                 if(ifc->lifc == nil)
  96                         freeb(bp);
  97                 else
  98                         ipiput4(lb->f, ifc, bp);
  99                 runlock(ifc);
 100                 poperror();
 101         }
 102 }
 103
 104 Medium loopbackmedium =
 105 {
 106 .hsize=         0,
 107 .mintu=         0,
 108 .maxtu=         Maxtu,
 109 .maclen=        0,
 110 .name=          "loopback",
 111 .bind=          loopbackbind,
 112 .unbind=        loopbackunbind,
 113 .bwrite=        loopbackbwrite,
 114 };
 115
 116 void
 117 loopbackmediumlink(void)
 118 {
 119         addipmedium(&loopbackmedium);
 120 }