| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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| 2 | #define MPPE_PAD 4 /* MPPE growth per frame */ |
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| 3 | #define MPPE_MAX_KEY_LEN 16 /* largest key length (128-bit) */ |
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| 4 | |
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| 5 | /* option bits for ccp_options.mppe */ |
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| 6 | #define MPPE_OPT_40 0x01 /* 40 bit */ |
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| 7 | #define MPPE_OPT_128 0x02 /* 128 bit */ |
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| 8 | #define MPPE_OPT_STATEFUL 0x04 /* stateful mode */ |
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| 9 | /* unsupported opts */ |
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| 10 | #define MPPE_OPT_56 0x08 /* 56 bit */ |
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| 11 | #define MPPE_OPT_MPPC 0x10 /* MPPC compression */ |
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| 12 | #define MPPE_OPT_D 0x20 /* Unknown */ |
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| 13 | #define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D) |
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| 14 | #define MPPE_OPT_UNKNOWN 0x40 /* Bits !defined in RFC 3078 were set */ |
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| 15 | |
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| 16 | /* |
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| 17 | * This is not nice ... the alternative is a bitfield struct though. |
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| 18 | * And unfortunately, we cannot share the same bits for the option |
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| 19 | * names above since C and H are the same bit. We could do a u_int32 |
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| 20 | * but then we have to do a htonl() all the time and/or we still need |
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| 21 | * to know which octet is which. |
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| 22 | */ |
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| 23 | #define MPPE_C_BIT 0x01 /* MPPC */ |
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| 24 | #define MPPE_D_BIT 0x10 /* Obsolete, usage unknown */ |
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| 25 | #define MPPE_L_BIT 0x20 /* 40-bit */ |
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| 26 | #define MPPE_S_BIT 0x40 /* 128-bit */ |
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| 27 | #define MPPE_M_BIT 0x80 /* 56-bit, not supported */ |
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| 28 | #define MPPE_H_BIT 0x01 /* Stateless (in a different byte) */ |
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| 29 | |
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| 30 | /* Does not include H bit; used for least significant octet only. */ |
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| 31 | #define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT) |
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| 32 | |
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| 33 | /* Build a CI from mppe opts (see RFC 3078) */ |
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| 34 | #define MPPE_OPTS_TO_CI(opts, ci) \ |
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| 35 | do { \ |
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| 36 | u_char *ptr = ci; /* u_char[4] */ \ |
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| 37 | \ |
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| 38 | /* H bit */ \ |
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| 39 | if (opts & MPPE_OPT_STATEFUL) \ |
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| 40 | *ptr++ = 0x0; \ |
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| 41 | else \ |
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| 42 | *ptr++ = MPPE_H_BIT; \ |
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| 43 | *ptr++ = 0; \ |
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| 44 | *ptr++ = 0; \ |
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| 45 | \ |
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| 46 | /* S,L bits */ \ |
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| 47 | *ptr = 0; \ |
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| 48 | if (opts & MPPE_OPT_128) \ |
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| 49 | *ptr |= MPPE_S_BIT; \ |
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| 50 | if (opts & MPPE_OPT_40) \ |
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| 51 | *ptr |= MPPE_L_BIT; \ |
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| 52 | /* M,D,C bits not supported */ \ |
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| 53 | } while (/* CONSTCOND */ 0) |
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| 54 | |
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| 55 | /* The reverse of the above */ |
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| 56 | #define MPPE_CI_TO_OPTS(ci, opts) \ |
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| 57 | do { \ |
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| 58 | u_char *ptr = ci; /* u_char[4] */ \ |
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| 59 | \ |
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| 60 | opts = 0; \ |
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| 61 | \ |
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| 62 | /* H bit */ \ |
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| 63 | if (!(ptr[0] & MPPE_H_BIT)) \ |
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| 64 | opts |= MPPE_OPT_STATEFUL; \ |
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| 65 | \ |
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| 66 | /* S,L bits */ \ |
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| 67 | if (ptr[3] & MPPE_S_BIT) \ |
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| 68 | opts |= MPPE_OPT_128; \ |
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| 69 | if (ptr[3] & MPPE_L_BIT) \ |
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| 70 | opts |= MPPE_OPT_40; \ |
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| 71 | \ |
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| 72 | /* M,D,C bits */ \ |
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| 73 | if (ptr[3] & MPPE_M_BIT) \ |
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| 74 | opts |= MPPE_OPT_56; \ |
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| 75 | if (ptr[3] & MPPE_D_BIT) \ |
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| 76 | opts |= MPPE_OPT_D; \ |
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| 77 | if (ptr[3] & MPPE_C_BIT) \ |
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| 78 | opts |= MPPE_OPT_MPPC; \ |
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| 79 | \ |
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| 80 | /* Other bits */ \ |
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| 81 | if (ptr[0] & ~MPPE_H_BIT) \ |
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| 82 | opts |= MPPE_OPT_UNKNOWN; \ |
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| 83 | if (ptr[1] || ptr[2]) \ |
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| 84 | opts |= MPPE_OPT_UNKNOWN; \ |
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| 85 | if (ptr[3] & ~MPPE_ALL_BITS) \ |
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| 86 | opts |= MPPE_OPT_UNKNOWN; \ |
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| 87 | } while (/* CONSTCOND */ 0) |
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| 88 | |
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