- * Standard PPP header.
- */
-struct ppp_header {
- u_char ph_address; /* Address Field */
- u_char ph_control; /* Control Field */
- u_short ph_protocol; /* Protocol Field */
-};
-
-#define PPP_HDRLEN 4 /* sizeof(struct ppp_header) must be 4 */
-#define PPP_FCSLEN 2 /* octets for FCS */
-
-#define PPP_ADDRESS(p) (((u_char *)(p))[0])
-#define PPP_CONTROL(p) (((u_char *)(p))[1])
-#define PPP_PROTOCOL(p) ((((u_char *)(p))[2] << 8) + ((u_char *)(p))[3])
-
-/*
- * Significant octet values.
- */
-#define PPP_ALLSTATIONS 0xff /* All-Stations broadcast address */
-#define PPP_UI 0x03 /* Unnumbered Information */
-#define PPP_FLAG 0x7e /* Flag Sequence */
-#define PPP_ESCAPE 0x7d /* Asynchronous Control Escape */
-#define PPP_TRANS 0x20 /* Asynchronous transparency modifier */
-
-/*
- * Protocol field values.
- */
-#define PPP_IP 0x21 /* Internet Protocol */
-#define PPP_XNS 0x25 /* Xerox NS */
-#define PPP_VJC_COMP 0x2d /* VJ compressed TCP */
-#define PPP_VJC_UNCOMP 0x2f /* VJ uncompressed TCP */
-#define PPP_COMP 0xfd /* compressed packet */
-#define PPP_LCP 0xc021 /* Link Control Protocol */
-#define PPP_CCP 0x80fd /* Compression Control Protocol */
-
-/*
- * Important FCS values.
- */
-#define PPP_INITFCS 0xffff /* Initial FCS value */
-#define PPP_GOODFCS 0xf0b8 /* Good final FCS value */
-#define PPP_FCS(fcs, c) (((fcs) >> 8) ^ fcstab[((fcs) ^ (c)) & 0xff])
-
-/*
- * Packet sizes
- */
-#define PPP_MTU 1500 /* Default MTU (size of Info field) */
-#define PPP_MRU 1500 /* Default MRU (max receive unit) */
-#define PPP_MAXMRU 65000 /* Largest MRU we allow */
-
-/* Extended asyncmap - allows any character to be escaped. */
-typedef u_long ext_accm[8];
-
-/*
- * What to do with network protocol (NP) packets.
- */
-enum NPmode {
- NPMODE_PASS, /* pass the packet through */
- NPMODE_DROP, /* silently drop the packet */
- NPMODE_ERROR, /* return an error */
- NPMODE_QUEUE /* save it up for later. */
-};
-
-/*
- * Supported network protocols. These values are used for
- * indexing sc_npmode.
- */
-#define NP_IP 0 /* Internet Protocol */
-#define NUM_NP 1 /* Number of NPs. */
-
-/*
- * Structure describing each ppp unit.