a3c77c67a4
This patch merges a lot of duplicated code in the slip and slirp drivers, abstracts out the slip protocol, and makes the slip driver work in 2.6. Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
105 lines
2.1 KiB
C
105 lines
2.1 KiB
C
#ifndef __UM_SLIP_COMMON_H
|
|
#define __UM_SLIP_COMMON_H
|
|
|
|
#define BUF_SIZE 1500
|
|
/* two bytes each for a (pathological) max packet of escaped chars + *
|
|
* terminating END char + initial END char */
|
|
#define ENC_BUF_SIZE (2 * BUF_SIZE + 2)
|
|
|
|
/* SLIP protocol characters. */
|
|
#define SLIP_END 0300 /* indicates end of frame */
|
|
#define SLIP_ESC 0333 /* indicates byte stuffing */
|
|
#define SLIP_ESC_END 0334 /* ESC ESC_END means END 'data' */
|
|
#define SLIP_ESC_ESC 0335 /* ESC ESC_ESC means ESC 'data' */
|
|
|
|
static inline int slip_unesc(unsigned char c, unsigned char *buf, int *pos,
|
|
int *esc)
|
|
{
|
|
int ret;
|
|
|
|
switch(c){
|
|
case SLIP_END:
|
|
*esc = 0;
|
|
ret=*pos;
|
|
*pos=0;
|
|
return(ret);
|
|
case SLIP_ESC:
|
|
*esc = 1;
|
|
return(0);
|
|
case SLIP_ESC_ESC:
|
|
if(*esc){
|
|
*esc = 0;
|
|
c = SLIP_ESC;
|
|
}
|
|
break;
|
|
case SLIP_ESC_END:
|
|
if(*esc){
|
|
*esc = 0;
|
|
c = SLIP_END;
|
|
}
|
|
break;
|
|
}
|
|
buf[(*pos)++] = c;
|
|
return(0);
|
|
}
|
|
|
|
static inline int slip_esc(unsigned char *s, unsigned char *d, int len)
|
|
{
|
|
unsigned char *ptr = d;
|
|
unsigned char c;
|
|
|
|
/*
|
|
* Send an initial END character to flush out any
|
|
* data that may have accumulated in the receiver
|
|
* due to line noise.
|
|
*/
|
|
|
|
*ptr++ = SLIP_END;
|
|
|
|
/*
|
|
* For each byte in the packet, send the appropriate
|
|
* character sequence, according to the SLIP protocol.
|
|
*/
|
|
|
|
while (len-- > 0) {
|
|
switch(c = *s++) {
|
|
case SLIP_END:
|
|
*ptr++ = SLIP_ESC;
|
|
*ptr++ = SLIP_ESC_END;
|
|
break;
|
|
case SLIP_ESC:
|
|
*ptr++ = SLIP_ESC;
|
|
*ptr++ = SLIP_ESC_ESC;
|
|
break;
|
|
default:
|
|
*ptr++ = c;
|
|
break;
|
|
}
|
|
}
|
|
*ptr++ = SLIP_END;
|
|
return (ptr - d);
|
|
}
|
|
|
|
struct slip_proto {
|
|
unsigned char ibuf[ENC_BUF_SIZE];
|
|
unsigned char obuf[ENC_BUF_SIZE];
|
|
int more; /* more data: do not read fd until ibuf has been drained */
|
|
int pos;
|
|
int esc;
|
|
};
|
|
|
|
#define SLIP_PROTO_INIT { \
|
|
.ibuf = { '\0' }, \
|
|
.obuf = { '\0' }, \
|
|
.more = 0, \
|
|
.pos = 0, \
|
|
.esc = 0 \
|
|
}
|
|
|
|
extern int slip_proto_read(int fd, void *buf, int len,
|
|
struct slip_proto *slip);
|
|
extern int slip_proto_write(int fd, void *buf, int len,
|
|
struct slip_proto *slip);
|
|
|
|
#endif
|