2.3.2/src/vde_l3/pfifo.c

   1 /*
   2  * tc pfifo module
   3  * Usage: tc set <dev> pfifo limit <packets>
   4  *
   5  * */
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <stdio.h>
   9
  10 #include <config.h>
  11 #include <vde.h>
  12 #include <vdecommon.h>
  13 #include "vde_buff.h"
  14 #include "vde_l3.h"
  15
  16 /** Private per-interface structure
  17  *
  18  */
  19 struct tc_pfifo
  20 {
  21         uint32_t qlen;
  22         uint32_t limit;
  23         uint32_t dropped;
  24 };
  25
  26 #define pfifo_tcpriv(x) (struct tc_pfifo*)(tcpriv(x))
  27
  28 /*
  29  * Enqueue function. Try to add the packet 'vdb' to the output queue
  30  * of the interface 'vif'
  31  *
  32  * return value: 1 = packet was enqueued, 0 = packet was rejected
  33  */
  34 int pfifo_enqueue(struct vde_buff *vdb, struct vde_iface *vif)
  35 {
  36         struct tc_pfifo *pfifo = pfifo_tcpriv(vif);
  37         if (pfifo->qlen < pfifo->limit){
  38                 pfifo->qlen++;
  39                 ufifo_enqueue(vdb,vif);
  40                 return 1;
  41         }else{
  42                 /* Queue Full: dropping. */
  43                 free(vdb);
  44                 pfifo->dropped++;
  45                 return 0;
  46         }
  47 }
  48
  49 /* Dequeue function. Interface is ready to send the packet.
  50  *
  51  */
  52 int pfifo_dequeue(struct vde_iface *vif)
  53 {
  54         struct tc_pfifo *pfifo = pfifo_tcpriv(vif);
  55         (void)ufifo_dequeue(vif);
  56         if(pfifo->qlen > 0)
  57                 pfifo->qlen--;
  58         return (pfifo->qlen > 0);
  59 }
  60
  61
  62
  63 /* Function to initialize the queue on the given interface.
  64  */
  65 int pfifo_init(struct vde_iface *vif, char *args)
  66 {
  67         struct tc_pfifo *pfifo=(struct tc_pfifo *)malloc(sizeof(struct tc_pfifo));
  68         int arglen = strlen(args) - 1;
  69
  70         if ((arglen < 6) || strncmp(args,"limit ",6) || (sscanf(args+6, "%u",&(pfifo->limit)) < 1) )
  71                 return 0;
  72
  73         pfifo->qlen = 0;
  74         pfifo->dropped = 0;
  75         vif->policy_name="pfifo";
  76         memcpy(vif->tc_priv, pfifo, sizeof(struct tc_pfifo));
  77         return 1;
  78 }
  79
  80 char *pfifo_tc_stats(struct vde_iface *vif)
  81 {
  82         struct tc_pfifo *pfifo = pfifo_tcpriv(vif);
  83         char *statistics=(char*)malloc(256);
  84         snprintf(statistics,255,"Limit: %u packets. Dropped: %u packets.", pfifo->limit, pfifo->dropped);
  85         return statistics;
  86
  87 }
  88
  89
  90 /*
  91  * Module symbol to load into module list.
  92  *
  93  */
  94 struct routing_policy module_routing_policy=
  95 {
  96         .name="pfifo",
  97         .help="Packet Fifo queue\nUsage: tc set <dev> pfifo limit <packets>\n",
  98         .policy_init = pfifo_init,
  99         .enqueue = pfifo_enqueue,
 100         .dequeue = pfifo_dequeue,
 101         .tc_stats = pfifo_tc_stats
 102 };
 103
 104 static void
 105 __attribute__ ((constructor))
 106 init (void)
 107 {
 108         fprintf(stderr,"Loading library: pfifo.so\n");
 109
 110 }
 111
 112         static void
 113         __attribute__ ((destructor))
 114 fini (void)
 115 {
 116
 117 }