diff options
Diffstat (limited to 'arch/um/drivers/slip_proto.h')
-rw-r--r-- | arch/um/drivers/slip_proto.h | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/arch/um/drivers/slip_proto.h b/arch/um/drivers/slip_proto.h new file mode 100644 index 00000000000..7206361ace4 --- /dev/null +++ b/arch/um/drivers/slip_proto.h @@ -0,0 +1,93 @@ +/* + * Copyright (C) 2002 Jeff Dike (jdike@karaya.com) + * Licensed under the GPL + */ + +#ifndef __UM_SLIP_PROTO_H__ +#define __UM_SLIP_PROTO_H__ + +/* 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,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); +} + +#endif + +/* + * Overrides for Emacs so that we follow Linus's tabbing style. + * Emacs will notice this stuff at the end of the file and automatically + * adjust the settings for this buffer only. This must remain at the end + * of the file. + * --------------------------------------------------------------------------- + * Local variables: + * c-file-style: "linux" + * End: + */ |