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1/* SPDX-License-Identifier: GPL-2.0 */2#define MPPE_PAD 4 /* MPPE growth per frame */3#define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */4 5/* option bits for ccp_options.mppe */6#define MPPE_OPT_40 0x01 /* 40 bit */7#define MPPE_OPT_128 0x02 /* 128 bit */8#define MPPE_OPT_STATEFUL 0x04 /* stateful mode */9/* unsupported opts */10#define MPPE_OPT_56 0x08 /* 56 bit */11#define MPPE_OPT_MPPC 0x10 /* MPPC compression */12#define MPPE_OPT_D 0x20 /* Unknown */13#define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D)14#define MPPE_OPT_UNKNOWN 0x40 /* Bits !defined in RFC 3078 were set */15 16/*17 * This is not nice ... the alternative is a bitfield struct though.18 * And unfortunately, we cannot share the same bits for the option19 * names above since C and H are the same bit. We could do a u_int3220 * but then we have to do a htonl() all the time and/or we still need21 * to know which octet is which.22 */23#define MPPE_C_BIT 0x01 /* MPPC */24#define MPPE_D_BIT 0x10 /* Obsolete, usage unknown */25#define MPPE_L_BIT 0x20 /* 40-bit */26#define MPPE_S_BIT 0x40 /* 128-bit */27#define MPPE_M_BIT 0x80 /* 56-bit, not supported */28#define MPPE_H_BIT 0x01 /* Stateless (in a different byte) */29 30/* Does not include H bit; used for least significant octet only. */31#define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT)32 33/* Build a CI from mppe opts (see RFC 3078) */34#define MPPE_OPTS_TO_CI(opts, ci) \35 do { \36 u_char *ptr = ci; /* u_char[4] */ \37 \38 /* H bit */ \39 if (opts & MPPE_OPT_STATEFUL) \40 *ptr++ = 0x0; \41 else \42 *ptr++ = MPPE_H_BIT; \43 *ptr++ = 0; \44 *ptr++ = 0; \45 \46 /* S,L bits */ \47 *ptr = 0; \48 if (opts & MPPE_OPT_128) \49 *ptr |= MPPE_S_BIT; \50 if (opts & MPPE_OPT_40) \51 *ptr |= MPPE_L_BIT; \52 /* M,D,C bits not supported */ \53 } while (/* CONSTCOND */ 0)54 55/* The reverse of the above */56#define MPPE_CI_TO_OPTS(ci, opts) \57 do { \58 u_char *ptr = ci; /* u_char[4] */ \59 \60 opts = 0; \61 \62 /* H bit */ \63 if (!(ptr[0] & MPPE_H_BIT)) \64 opts |= MPPE_OPT_STATEFUL; \65 \66 /* S,L bits */ \67 if (ptr[3] & MPPE_S_BIT) \68 opts |= MPPE_OPT_128; \69 if (ptr[3] & MPPE_L_BIT) \70 opts |= MPPE_OPT_40; \71 \72 /* M,D,C bits */ \73 if (ptr[3] & MPPE_M_BIT) \74 opts |= MPPE_OPT_56; \75 if (ptr[3] & MPPE_D_BIT) \76 opts |= MPPE_OPT_D; \77 if (ptr[3] & MPPE_C_BIT) \78 opts |= MPPE_OPT_MPPC; \79 \80 /* Other bits */ \81 if (ptr[0] & ~MPPE_H_BIT) \82 opts |= MPPE_OPT_UNKNOWN; \83 if (ptr[1] || ptr[2]) \84 opts |= MPPE_OPT_UNKNOWN; \85 if (ptr[3] & ~MPPE_ALL_BITS) \86 opts |= MPPE_OPT_UNKNOWN; \87 } while (/* CONSTCOND */ 0)88