18c2ecf20Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0 */
28c2ecf20Sopenharmony_ci#define MPPE_PAD                4      /* MPPE growth per frame */
38c2ecf20Sopenharmony_ci#define MPPE_MAX_KEY_LEN       16      /* largest key length (128-bit) */
48c2ecf20Sopenharmony_ci
58c2ecf20Sopenharmony_ci/* option bits for ccp_options.mppe */
68c2ecf20Sopenharmony_ci#define MPPE_OPT_40            0x01    /* 40 bit */
78c2ecf20Sopenharmony_ci#define MPPE_OPT_128           0x02    /* 128 bit */
88c2ecf20Sopenharmony_ci#define MPPE_OPT_STATEFUL      0x04    /* stateful mode */
98c2ecf20Sopenharmony_ci/* unsupported opts */
108c2ecf20Sopenharmony_ci#define MPPE_OPT_56            0x08    /* 56 bit */
118c2ecf20Sopenharmony_ci#define MPPE_OPT_MPPC          0x10    /* MPPC compression */
128c2ecf20Sopenharmony_ci#define MPPE_OPT_D             0x20    /* Unknown */
138c2ecf20Sopenharmony_ci#define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D)
148c2ecf20Sopenharmony_ci#define MPPE_OPT_UNKNOWN       0x40    /* Bits !defined in RFC 3078 were set */
158c2ecf20Sopenharmony_ci
168c2ecf20Sopenharmony_ci/*
178c2ecf20Sopenharmony_ci * This is not nice ... the alternative is a bitfield struct though.
188c2ecf20Sopenharmony_ci * And unfortunately, we cannot share the same bits for the option
198c2ecf20Sopenharmony_ci * names above since C and H are the same bit.  We could do a u_int32
208c2ecf20Sopenharmony_ci * but then we have to do a htonl() all the time and/or we still need
218c2ecf20Sopenharmony_ci * to know which octet is which.
228c2ecf20Sopenharmony_ci */
238c2ecf20Sopenharmony_ci#define MPPE_C_BIT             0x01    /* MPPC */
248c2ecf20Sopenharmony_ci#define MPPE_D_BIT             0x10    /* Obsolete, usage unknown */
258c2ecf20Sopenharmony_ci#define MPPE_L_BIT             0x20    /* 40-bit */
268c2ecf20Sopenharmony_ci#define MPPE_S_BIT             0x40    /* 128-bit */
278c2ecf20Sopenharmony_ci#define MPPE_M_BIT             0x80    /* 56-bit, not supported */
288c2ecf20Sopenharmony_ci#define MPPE_H_BIT             0x01    /* Stateless (in a different byte) */
298c2ecf20Sopenharmony_ci
308c2ecf20Sopenharmony_ci/* Does not include H bit; used for least significant octet only. */
318c2ecf20Sopenharmony_ci#define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT)
328c2ecf20Sopenharmony_ci
338c2ecf20Sopenharmony_ci/* Build a CI from mppe opts (see RFC 3078) */
348c2ecf20Sopenharmony_ci#define MPPE_OPTS_TO_CI(opts, ci)              \
358c2ecf20Sopenharmony_ci    do {                                       \
368c2ecf20Sopenharmony_ci       u_char *ptr = ci; /* u_char[4] */       \
378c2ecf20Sopenharmony_ci                                               \
388c2ecf20Sopenharmony_ci       /* H bit */                             \
398c2ecf20Sopenharmony_ci       if (opts & MPPE_OPT_STATEFUL)           \
408c2ecf20Sopenharmony_ci           *ptr++ = 0x0;                       \
418c2ecf20Sopenharmony_ci       else                                    \
428c2ecf20Sopenharmony_ci           *ptr++ = MPPE_H_BIT;                \
438c2ecf20Sopenharmony_ci       *ptr++ = 0;                             \
448c2ecf20Sopenharmony_ci       *ptr++ = 0;                             \
458c2ecf20Sopenharmony_ci                                               \
468c2ecf20Sopenharmony_ci       /* S,L bits */                          \
478c2ecf20Sopenharmony_ci       *ptr = 0;                               \
488c2ecf20Sopenharmony_ci       if (opts & MPPE_OPT_128)                \
498c2ecf20Sopenharmony_ci           *ptr |= MPPE_S_BIT;                 \
508c2ecf20Sopenharmony_ci       if (opts & MPPE_OPT_40)                 \
518c2ecf20Sopenharmony_ci           *ptr |= MPPE_L_BIT;                 \
528c2ecf20Sopenharmony_ci       /* M,D,C bits not supported */          \
538c2ecf20Sopenharmony_ci    } while (/* CONSTCOND */ 0)
548c2ecf20Sopenharmony_ci
558c2ecf20Sopenharmony_ci/* The reverse of the above */
568c2ecf20Sopenharmony_ci#define MPPE_CI_TO_OPTS(ci, opts)              \
578c2ecf20Sopenharmony_ci    do {                                       \
588c2ecf20Sopenharmony_ci       u_char *ptr = ci; /* u_char[4] */       \
598c2ecf20Sopenharmony_ci                                               \
608c2ecf20Sopenharmony_ci       opts = 0;                               \
618c2ecf20Sopenharmony_ci                                               \
628c2ecf20Sopenharmony_ci       /* H bit */                             \
638c2ecf20Sopenharmony_ci       if (!(ptr[0] & MPPE_H_BIT))             \
648c2ecf20Sopenharmony_ci           opts |= MPPE_OPT_STATEFUL;          \
658c2ecf20Sopenharmony_ci                                               \
668c2ecf20Sopenharmony_ci       /* S,L bits */                          \
678c2ecf20Sopenharmony_ci       if (ptr[3] & MPPE_S_BIT)                \
688c2ecf20Sopenharmony_ci           opts |= MPPE_OPT_128;               \
698c2ecf20Sopenharmony_ci       if (ptr[3] & MPPE_L_BIT)                \
708c2ecf20Sopenharmony_ci           opts |= MPPE_OPT_40;                \
718c2ecf20Sopenharmony_ci                                               \
728c2ecf20Sopenharmony_ci       /* M,D,C bits */                        \
738c2ecf20Sopenharmony_ci       if (ptr[3] & MPPE_M_BIT)                \
748c2ecf20Sopenharmony_ci           opts |= MPPE_OPT_56;                \
758c2ecf20Sopenharmony_ci       if (ptr[3] & MPPE_D_BIT)                \
768c2ecf20Sopenharmony_ci           opts |= MPPE_OPT_D;                 \
778c2ecf20Sopenharmony_ci       if (ptr[3] & MPPE_C_BIT)                \
788c2ecf20Sopenharmony_ci           opts |= MPPE_OPT_MPPC;              \
798c2ecf20Sopenharmony_ci                                               \
808c2ecf20Sopenharmony_ci       /* Other bits */                        \
818c2ecf20Sopenharmony_ci       if (ptr[0] & ~MPPE_H_BIT)               \
828c2ecf20Sopenharmony_ci           opts |= MPPE_OPT_UNKNOWN;           \
838c2ecf20Sopenharmony_ci       if (ptr[1] || ptr[2])                   \
848c2ecf20Sopenharmony_ci           opts |= MPPE_OPT_UNKNOWN;           \
858c2ecf20Sopenharmony_ci       if (ptr[3] & ~MPPE_ALL_BITS)            \
868c2ecf20Sopenharmony_ci           opts |= MPPE_OPT_UNKNOWN;           \
878c2ecf20Sopenharmony_ci    } while (/* CONSTCOND */ 0)
88