X-Git-Url: https://git.ozlabs.org/?a=blobdiff_plain;ds=sidebyside;f=linux%2Fmppe%2Fppp_mppe_compress.c;h=051213273970fa4affb73b00d68c0c1bafe1945e;hb=98b641cbee0c4489e83320962ddf652eb9070f03;hp=33885df433211f92c433a65ef0548a30469b98e3;hpb=b02bd2ca354d02096940e3926bd7e37bfd0359ab;p=ppp.git

diff --git a/linux/mppe/ppp_mppe_compress.c b/linux/mppe/ppp_mppe_compress.c
index 33885df..0512132 100644
--- a/linux/mppe/ppp_mppe_compress.c
+++ b/linux/mppe/ppp_mppe_compress.c
@@ -1,11 +1,9 @@
 /*
- *  ==FILEVERSION 20020521==
- *
  * ppp_mppe_compress.c - interface MPPE to the PPP code.
- * This version is for use with Linux kernel 2.2.19+ and 2.4.x.
+ * This version is for use with Linux kernel 2.2.19+, 2.4.18+ and 2.6.2+.
  *
  * By Frank Cusack <frank@google.com>.
- * Copyright (c) 2002 Google, Inc.
+ * Copyright (c) 2002,2003,2004 Google, Inc.
  * All rights reserved.
  *
  * Permission to use, copy, modify, and distribute this software and its
@@ -13,10 +11,16 @@
  * notice appears in all copies.  This software is provided without any
  * warranty, express or implied.
  *
+ * Changelog:
+ *      2/15/04 - TS: added #include <version.h> and testing for Kernel
+ *                    version before using 
+ *                    MOD_DEC_USAGE_COUNT/MOD_INC_USAGE_COUNT which are
+ *                    deprecated in 2.6
  */
 
 #include <linux/module.h>
 #include <linux/kernel.h>
+#include <linux/version.h>
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/slab.h>
@@ -170,7 +174,11 @@ mppe_alloc(unsigned char *options, int optlen)
     if (state == NULL)
 	return NULL;
 
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0))
+    try_module_get(THIS_MODULE);
+#else
     MOD_INC_USE_COUNT;
+#endif
     memset(state, 0, sizeof(*state));
 
     /* Save keys. */
@@ -194,7 +202,11 @@ mppe_free(void *arg)
 
     if (state) {
 	kfree(state);
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0))
+	module_put(THIS_MODULE);
+#else
 	MOD_DEC_USE_COUNT;
+#endif
     }
 }
 
@@ -416,14 +428,19 @@ mppe_decompress(void *arg, unsigned char *ibuf, int isize, unsigned char *obuf,
 	return DECOMP_ERROR;
     }
 
-    /* Make sure we have enough room to decrypt the packet. */
-    if (osize < isize - MPPE_OVHD - 2) {
+    /*
+     * Make sure we have enough room to decrypt the packet.
+     * Note that for our test we only subtract 1 byte whereas in
+     * mppe_compress() we added 2 bytes (+MPPE_OVHD);
+     * this is to account for possible PFC.
+     */
+    if (osize < isize - MPPE_OVHD - 1) {
 	printk(KERN_DEBUG "mppe_decompress[%d]: osize too small! "
 	       "(have: %d need: %d)\n", state->unit,
-	       osize, isize - MPPE_OVHD - 2);
+	       osize, isize - MPPE_OVHD - 1);
 	return DECOMP_ERROR;
     }
-    osize = isize - MPPE_OVHD - 2;
+    osize = isize - MPPE_OVHD - 2;	/* assume no PFC */
 
     ccount = MPPE_CCOUNT(ibuf);
     if (state->debug >= 7)
@@ -525,8 +542,26 @@ mppe_decompress(void *arg, unsigned char *ibuf, int isize, unsigned char *obuf,
     isize -= PPP_HDRLEN + MPPE_OVHD;	/* -6 */
 					/* net osize: isize-4 */
 
-    /* And finally, decrypt the packet. */
-    arcfour_decrypt(&state->arcfour_context, ibuf, isize, obuf);
+    /*
+     * Decrypt the first byte in order to check if it is
+     * a compressed or uncompressed protocol field.
+     */
+    arcfour_decrypt(&state->arcfour_context, ibuf, 1, obuf);
+
+    /*
+     * Do PFC decompression.
+     * This would be nicer if we were given the actual sk_buff
+     * instead of a char *.
+     */
+    if ((obuf[0] & 0x01) != 0) {
+	obuf[1] = obuf[0];
+	obuf[0] = 0;
+	obuf++;
+	osize++;
+    }
+
+    /* And finally, decrypt the rest of the packet. */
+    arcfour_decrypt(&state->arcfour_context, ibuf + 1, isize - 1, obuf + 1);
 
     state->stats.unc_bytes += osize;
     state->stats.unc_packets++;