87 lines
		
	
	
	
		
			4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			87 lines
		
	
	
	
		
			4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
|   | #define MPPE_PAD                4      /* MPPE growth per frame */
 | ||
|  | #define MPPE_MAX_KEY_LEN       16      /* largest key length (128-bit) */
 | ||
|  | 
 | ||
|  | /* option bits for ccp_options.mppe */ | ||
|  | #define MPPE_OPT_40            0x01    /* 40 bit */
 | ||
|  | #define MPPE_OPT_128           0x02    /* 128 bit */
 | ||
|  | #define MPPE_OPT_STATEFUL      0x04    /* stateful mode */
 | ||
|  | /* unsupported opts */ | ||
|  | #define MPPE_OPT_56            0x08    /* 56 bit */
 | ||
|  | #define MPPE_OPT_MPPC          0x10    /* MPPC compression */
 | ||
|  | #define MPPE_OPT_D             0x20    /* Unknown */
 | ||
|  | #define MPPE_OPT_UNSUPPORTED (MPPE_OPT_56|MPPE_OPT_MPPC|MPPE_OPT_D)
 | ||
|  | #define MPPE_OPT_UNKNOWN       0x40    /* Bits !defined in RFC 3078 were set */
 | ||
|  | 
 | ||
|  | /*
 | ||
|  |  * This is not nice ... the alternative is a bitfield struct though. | ||
|  |  * And unfortunately, we cannot share the same bits for the option | ||
|  |  * names above since C and H are the same bit.  We could do a u_int32 | ||
|  |  * but then we have to do a htonl() all the time and/or we still need | ||
|  |  * to know which octet is which. | ||
|  |  */ | ||
|  | #define MPPE_C_BIT             0x01    /* MPPC */
 | ||
|  | #define MPPE_D_BIT             0x10    /* Obsolete, usage unknown */
 | ||
|  | #define MPPE_L_BIT             0x20    /* 40-bit */
 | ||
|  | #define MPPE_S_BIT             0x40    /* 128-bit */
 | ||
|  | #define MPPE_M_BIT             0x80    /* 56-bit, not supported */
 | ||
|  | #define MPPE_H_BIT             0x01    /* Stateless (in a different byte) */
 | ||
|  | 
 | ||
|  | /* Does not include H bit; used for least significant octet only. */ | ||
|  | #define MPPE_ALL_BITS (MPPE_D_BIT|MPPE_L_BIT|MPPE_S_BIT|MPPE_M_BIT|MPPE_H_BIT)
 | ||
|  | 
 | ||
|  | /* Build a CI from mppe opts (see RFC 3078) */ | ||
|  | #define MPPE_OPTS_TO_CI(opts, ci)              \
 | ||
|  |     do {                                       \ | ||
|  |        u_char *ptr = ci; /* u_char[4] */       \ | ||
|  |                                                \ | ||
|  |        /* H bit */                             \ | ||
|  |        if (opts & MPPE_OPT_STATEFUL)           \ | ||
|  |            *ptr++ = 0x0;                       \ | ||
|  |        else                                    \ | ||
|  |            *ptr++ = MPPE_H_BIT;                \ | ||
|  |        *ptr++ = 0;                             \ | ||
|  |        *ptr++ = 0;                             \ | ||
|  |                                                \ | ||
|  |        /* S,L bits */                          \ | ||
|  |        *ptr = 0;                               \ | ||
|  |        if (opts & MPPE_OPT_128)                \ | ||
|  |            *ptr |= MPPE_S_BIT;                 \ | ||
|  |        if (opts & MPPE_OPT_40)                 \ | ||
|  |            *ptr |= MPPE_L_BIT;                 \ | ||
|  |        /* M,D,C bits not supported */          \ | ||
|  |     } while (/* CONSTCOND */ 0) | ||
|  | 
 | ||
|  | /* The reverse of the above */ | ||
|  | #define MPPE_CI_TO_OPTS(ci, opts)              \
 | ||
|  |     do {                                       \ | ||
|  |        u_char *ptr = ci; /* u_char[4] */       \ | ||
|  |                                                \ | ||
|  |        opts = 0;                               \ | ||
|  |                                                \ | ||
|  |        /* H bit */                             \ | ||
|  |        if (!(ptr[0] & MPPE_H_BIT))             \ | ||
|  |            opts |= MPPE_OPT_STATEFUL;          \ | ||
|  |                                                \ | ||
|  |        /* S,L bits */                          \ | ||
|  |        if (ptr[3] & MPPE_S_BIT)                \ | ||
|  |            opts |= MPPE_OPT_128;               \ | ||
|  |        if (ptr[3] & MPPE_L_BIT)                \ | ||
|  |            opts |= MPPE_OPT_40;                \ | ||
|  |                                                \ | ||
|  |        /* M,D,C bits */                        \ | ||
|  |        if (ptr[3] & MPPE_M_BIT)                \ | ||
|  |            opts |= MPPE_OPT_56;                \ | ||
|  |        if (ptr[3] & MPPE_D_BIT)                \ | ||
|  |            opts |= MPPE_OPT_D;                 \ | ||
|  |        if (ptr[3] & MPPE_C_BIT)                \ | ||
|  |            opts |= MPPE_OPT_MPPC;              \ | ||
|  |                                                \ | ||
|  |        /* Other bits */                        \ | ||
|  |        if (ptr[0] & ~MPPE_H_BIT)               \ | ||
|  |            opts |= MPPE_OPT_UNKNOWN;           \ | ||
|  |        if (ptr[1] || ptr[2])                   \ | ||
|  |            opts |= MPPE_OPT_UNKNOWN;           \ | ||
|  |        if (ptr[3] & ~MPPE_ALL_BITS)            \ | ||
|  |            opts |= MPPE_OPT_UNKNOWN;           \ | ||
|  |     } while (/* CONSTCOND */ 0) |