--- /dev/null
+--- linux-2.2.20/include/linux/ppp-comp.h.orig Sun Mar 25 08:31:04 2001
++++ linux-2.2.20/include/linux/ppp-comp.h Tue Mar 19 09:39:19 2002
+@@ -187,6 +187,100 @@
+ #define DEFLATE_CHK_SEQUENCE 0
+
+ /*
++ * Definitions for MPPE.
++ */
++
++#define CI_MPPE 18 /* config option for MPPE */
++#define CILEN_MPPE 6 /* length of config option */
++
++#define MPPE_PAD 4 /* MPPE growth per frame */
++#define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */
++
++/* option bits for ccp_options.mppe */
++#define MPPE_OPT_40 0x01 /* 40 bit */
++#define MPPE_OPT_128 0x02 /* 128 bit */
++#define MPPE_OPT_STATEFUL 0x04 /* stateful mode */
++/* unsupported opts */
++#define MPPE_OPT_56 0x08 /* 56 bit */
++#define MPPE_OPT_MPPC 0x10 /* MPPC compression */
++#define MPPE_OPT_D 0x20 /* Unknown */
++#define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D)
++#define MPPE_OPT_UNKNOWN 0x40 /* Bits !defined in RFC 3078 were set */
++
++/*
++ * This is not nice ... the alternative is a bitfield struct though.
++ * And unfortunately, we cannot share the same bits for the option
++ * names above since C and H are the same bit. We could do a u_int32
++ * but then we have to do a htonl() all the time and/or we still need
++ * to know which octet is which.
++ */
++#define MPPE_C_BIT 0x01 /* MPPC */
++#define MPPE_D_BIT 0x10 /* Obsolete, usage unknown */
++#define MPPE_L_BIT 0x20 /* 40-bit */
++#define MPPE_S_BIT 0x40 /* 128-bit */
++#define MPPE_M_BIT 0x80 /* 56-bit, not supported */
++#define MPPE_H_BIT 0x01 /* Stateless (in a different byte) */
++
++/* Does not include H bit; used for least significant octet only. */
++#define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT)
++
++/* Build a CI from mppe opts (see RFC 3078) */
++#define MPPE_OPTS_TO_CI(opts, ci) \
++ do { \
++ u_char *ptr = ci; /* u_char[4] */ \
++ \
++ /* H bit */ \
++ if (opts & MPPE_OPT_STATEFUL) \
++ *ptr++ = 0x0; \
++ else \
++ *ptr++ = MPPE_H_BIT; \
++ *ptr++ = 0; \
++ *ptr++ = 0; \
++ \
++ /* S,L bits */ \
++ *ptr = 0; \
++ if (opts & MPPE_OPT_128) \
++ *ptr |= MPPE_S_BIT; \
++ if (opts & MPPE_OPT_40) \
++ *ptr |= MPPE_L_BIT; \
++ /* M,D,C bits not supported */ \
++ } while (/* CONSTCOND */ 0)
++
++/* The reverse of the above */
++#define MPPE_CI_TO_OPTS(ci, opts) \
++ do { \
++ u_char *ptr = ci; /* u_char[4] */ \
++ \
++ opts = 0; \
++ \
++ /* H bit */ \
++ if (!(ptr[0] & MPPE_H_BIT)) \
++ opts |= MPPE_OPT_STATEFUL; \
++ \
++ /* S,L bits */ \
++ if (ptr[3] & MPPE_S_BIT) \
++ opts |= MPPE_OPT_128; \
++ if (ptr[3] & MPPE_L_BIT) \
++ opts |= MPPE_OPT_40; \
++ \
++ /* M,D,C bits */ \
++ if (ptr[3] & MPPE_M_BIT) \
++ opts |= MPPE_OPT_56; \
++ if (ptr[3] & MPPE_D_BIT) \
++ opts |= MPPE_OPT_D; \
++ if (ptr[3] & MPPE_C_BIT) \
++ opts |= MPPE_OPT_MPPC; \
++ \
++ /* Other bits */ \
++ if (ptr[0] & ~MPPE_H_BIT) \
++ opts |= MPPE_OPT_UNKNOWN; \
++ if (ptr[1] || ptr[2]) \
++ opts |= MPPE_OPT_UNKNOWN; \
++ if (ptr[3] & ~MPPE_ALL_BITS) \
++ opts |= MPPE_OPT_UNKNOWN; \
++ } while (/* CONSTCOND */ 0)
++
++/*
+ * Definitions for other, as yet unsupported, compression methods.
+ */
+