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 option 19 * names above since C and H are the same bit. We could do a u_int32 20 * but then we have to do a htonl() all the time and/or we still need 21 * 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