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 | |