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Diffstat (limited to 'arch/um/drivers/slip_proto.h')
-rw-r--r--arch/um/drivers/slip_proto.h93
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 000000000000..7206361ace45
--- /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:
+ */