atm-04-min-frame-size.patch

   1 the minimum frame size for token ring (802.5) pdus is 16 octets.  also,
   2 count the pdus that failed to copy as dropped.  also, skb_copy_expand()
   3 now seems to be the right way to do this.
   4
   5 Index: linux/net/atm/lec.c
   6 ===================================================================
   7 RCS file: /home/chas/CVSROOT/linux/net/atm/lec.c,v
   8 retrieving revision 1.5
   9 retrieving revision 1.6
  10 diff -u -d -b -w -r1.5 -r1.6
  11 --- linux/net/atm/lec.c 22 Feb 2003 19:23:22 -0000      1.5
  12 +++ linux/net/atm/lec.c 24 Feb 2003 13:24:45 -0000      1.6
  13 @@ -223,7 +223,8 @@
  14          struct lecdatahdr_8023 *lec_h;
  15          struct atm_vcc *send_vcc;
  16         struct lec_arp_table *entry;
  17 -        unsigned char *nb, *dst;
  18 +        unsigned char *dst;
  19 +       int min_frame_size;
  20  #ifdef CONFIG_TR
  21          unsigned char rdesc[ETH_ALEN]; /* Token Ring route descriptor */
  22  #endif
  23 @@ -294,26 +295,24 @@
  24  #endif /* DUMP_PACKETS > 0 */
  25
  26          /* Minimum ethernet-frame size */
  27 -        if (skb->len <62) {
  28 -                if (skb->truesize < 62) {
  29 -                        printk("%s:data packet %d / %d\n",
  30 -                               dev->name,
  31 -                               skb->len,skb->truesize);
  32 -                        nb=(unsigned char*)kmalloc(64, GFP_ATOMIC);
  33 -                        if (nb == NULL) {
  34 +#ifdef CONFIG_TR
  35 +        if (priv->is_trdev)
  36 +                min_frame_size = LEC_MINIMUM_8025_SIZE;
  37 +       else
  38 +#endif
  39 +        min_frame_size = LEC_MINIMUM_8023_SIZE;
  40 +        if (skb->len < min_frame_size) {
  41 +                if (skb->truesize < min_frame_size) {
  42 +                        skb2 = skb_copy_expand(skb, 0,
  43 +                            min_frame_size - skb->truesize, GFP_ATOMIC);
  44                                  dev_kfree_skb(skb);
  45 +                        if (skb2 == NULL) {
  46 +                                priv->stats.tx_dropped++;
  47                                  return 0;
  48                          }
  49 -                        memcpy(nb,skb->data,skb->len);
  50 -                        kfree(skb->head);
  51 -                        skb->head = skb->data = nb;
  52 -                        skb->tail = nb+62;
  53 -                        skb->end = nb+64;
  54 -                        skb->len=62;
  55 -                        skb->truesize = 64;
  56 -                } else {
  57 -                        skb->len = 62;
  58 +                        skb = skb2;
  59                  }
  60 +               skb_put(skb, min_frame_size - skb->len);
  61          }
  62
  63          /* Send to right vcc */
  64 Index: linux/net/atm/lec.h
  65 ===================================================================
  66 RCS file: /home/chas/CVSROOT/linux/net/atm/lec.h,v
  67 retrieving revision 1.2
  68 retrieving revision 1.3
  69 diff -u -d -b -w -r1.2 -r1.3
  70 --- linux/net/atm/lec.h 22 Feb 2003 19:29:27 -0000      1.2
  71 +++ linux/net/atm/lec.h 24 Feb 2003 13:24:46 -0000      1.3
  72 @@ -38,6 +38,9 @@
  73    unsigned char h_source[ETH_ALEN];
  74  };
  75
  76 +#define LEC_MINIMUM_8023_SIZE   62
  77 +#define LEC_MINIMUM_8025_SIZE   16
  78 +
  79  /*
  80   * Operations that LANE2 capable device can do. Two first functions
  81   * are used to make the device do things. See spec 3.1.3 and 3.1.4.
  82 -
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