linux/mppe/linux-2.4.18-pad.patch

   1 --- linux/drivers/net/ppp_generic.c.orig        Mon Feb 25 11:37:59 2002
   2 +++ linux/drivers/net/ppp_generic.c     Mon Mar 25 10:19:53 2002
   3 @@ -1006,8 +1006,15 @@
   4         /* try to do packet compression */
   5         if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
   6             && proto != PPP_LCP && proto != PPP_CCP) {
   7 -               new_skb = alloc_skb(ppp->dev->mtu + ppp->dev->hard_header_len,
   8 -                                   GFP_ATOMIC);
   9 +               int new_skb_size = ppp->dev->mtu + ppp->dev->hard_header_len;
  10 +               int compressor_skb_size = ppp->dev->mtu + PPP_HDRLEN;
  11 +
  12 +               if (ppp->xcomp->compress_proto == CI_MPPE) {
  13 +                       /* CCP [must have] reduced MTU by MPPE_PAD. */
  14 +                       new_skb_size += MPPE_PAD;
  15 +                       compressor_skb_size += MPPE_PAD;
  16 +               }
  17 +               new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
  18                 if (new_skb == 0) {
  19                         printk(KERN_ERR "PPP: no memory (comp pkt)\n");
  20                         goto drop;
  21 @@ -1019,15 +1026,27 @@
  22                 /* compressor still expects A/C bytes in hdr */
  23                 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
  24                                            new_skb->data, skb->len + 2,
  25 -                                          ppp->dev->mtu + PPP_HDRLEN);
  26 +                                          compressor_skb_size);
  27                 if (len > 0 && (ppp->flags & SC_CCP_UP)) {
  28                         kfree_skb(skb);
  29                         skb = new_skb;
  30                         skb_put(skb, len);
  31                         skb_pull(skb, 2);       /* pull off A/C bytes */
  32 -               } else {
  33 +               } else if (len == 0) {
  34                         /* didn't compress, or CCP not up yet */
  35                         kfree_skb(new_skb);
  36 +               } else {
  37 +                       /*
  38 +                        * (len < 0)
  39 +                        * MPPE requires that we do not send unencrypted
  40 +                        * frames.  The compressor will return -1 if we
  41 +                        * should drop the frame.  We cannot simply test
  42 +                        * the compress_proto because MPPE and MPPC share
  43 +                        * the same number.
  44 +                        */
  45 +                       printk(KERN_ERR "ppp: compressor dropped pkt\n");
  46 +                       kfree_skb(new_skb);
  47 +                       goto drop;
  48                 }
  49         }
  50
  51 @@ -1515,7 +1534,7 @@
  52         int len;
  53
  54         if (proto == PPP_COMP) {
  55 -               ns = dev_alloc_skb(ppp->mru + PPP_HDRLEN);
  56 +               ns = dev_alloc_skb(ppp->mru + 128 + PPP_HDRLEN);
  57                 if (ns == 0) {
  58                         printk(KERN_ERR "ppp_decompress_frame: no memory\n");
  59                         goto err;