Corrected version of MPPE kernel support (Frank Cusack)

[ppp.git] / linux / mppe / linux-2.4.18-pad.patch

diff --git a/linux/mppe/linux-2.4.18-pad.patch b/linux/mppe/linux-2.4.18-pad.patch
new file mode 100644 (file)
index 0000000..30c6971
--- /dev/null
+++ b/linux/mppe/linux-2.4.18-pad.patch
@@ -0,0 +1,59 @@
+--- linux/drivers/net/ppp_generic.c.orig       Mon Feb 25 11:37:59 2002
++++ linux/drivers/net/ppp_generic.c    Mon Mar 25 10:19:53 2002
+@@ -1006,8 +1006,15 @@
+       /* try to do packet compression */
+       if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0
+           && proto != PPP_LCP && proto != PPP_CCP) {
+-              new_skb = alloc_skb(ppp->dev->mtu + ppp->dev->hard_header_len,
+-                                  GFP_ATOMIC);
++              int new_skb_size = ppp->dev->mtu + ppp->dev->hard_header_len;
++              int compressor_skb_size = ppp->dev->mtu + PPP_HDRLEN;
++
++              if (ppp->xcomp->compress_proto == CI_MPPE) {
++                      /* CCP [must have] reduced MTU by MPPE_PAD. */
++                      new_skb_size += MPPE_PAD;
++                      compressor_skb_size += MPPE_PAD;
++              }
++              new_skb = alloc_skb(new_skb_size, GFP_ATOMIC);
+               if (new_skb == 0) {
+                       printk(KERN_ERR "PPP: no memory (comp pkt)\n");
+                       goto drop;
+@@ -1019,15 +1026,27 @@
+               /* compressor still expects A/C bytes in hdr */
+               len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2,
+                                          new_skb->data, skb->len + 2,
+-                                         ppp->dev->mtu + PPP_HDRLEN);
++                                         compressor_skb_size);
+               if (len > 0 && (ppp->flags & SC_CCP_UP)) {
+                       kfree_skb(skb);
+                       skb = new_skb;
+                       skb_put(skb, len);
+                       skb_pull(skb, 2);       /* pull off A/C bytes */
+-              } else {
++              } else if (len == 0) {
+                       /* didn't compress, or CCP not up yet */
+                       kfree_skb(new_skb);
++              } else {
++                      /*
++                       * (len < 0)
++                       * MPPE requires that we do not send unencrypted
++                       * frames.  The compressor will return -1 if we
++                       * should drop the frame.  We cannot simply test
++                       * the compress_proto because MPPE and MPPC share
++                       * the same number.
++                       */
++                      printk(KERN_ERR "ppp: compressor dropped pkt\n");
++                      kfree_skb(new_skb);
++                      goto drop;
+               }
+       }
+ 
+@@ -1515,7 +1534,7 @@
+       int len;
+ 
+       if (proto == PPP_COMP) {
+-              ns = dev_alloc_skb(ppp->mru + PPP_HDRLEN);
++              ns = dev_alloc_skb(ppp->mru + 128 + PPP_HDRLEN);
+               if (ns == 0) {
+                       printk(KERN_ERR "ppp_decompress_frame: no memory\n");
+                       goto err;