diff --git a/include/net/ax25.h b/include/net/ax25.h
index 69374cd1a857a05e1a8c8d0673afcb75f7badbfb..41acb093caaed4d18cddbb24d7394cbde47858cf 100644
--- a/include/net/ax25.h
+++ b/include/net/ax25.h
@@ -283,14 +283,16 @@ extern struct sock *ax25_make_new(struct sock *, struct ax25_dev *);
 
 /* ax25_addr.c */
 extern ax25_address null_ax25_address;
-extern char *ax2asc(char *buf, ax25_address *);
-extern void asc2ax(ax25_address *addr, char *callsign);
-extern int  ax25cmp(ax25_address *, ax25_address *);
-extern int  ax25digicmp(ax25_digi *, ax25_digi *);
-extern unsigned char *ax25_addr_parse(unsigned char *, int, ax25_address *, ax25_address *, ax25_digi *, int *, int *);
-extern int  ax25_addr_build(unsigned char *, ax25_address *, ax25_address *, ax25_digi *, int, int);
-extern int  ax25_addr_size(ax25_digi *);
-extern void ax25_digi_invert(ax25_digi *, ax25_digi *);
+extern char *ax2asc(char *buf, const ax25_address *);
+extern void asc2ax(ax25_address *addr, const char *callsign);
+extern int ax25cmp(const ax25_address *, const ax25_address *);
+extern int ax25digicmp(const ax25_digi *, const ax25_digi *);
+extern const unsigned char *ax25_addr_parse(const unsigned char *, int,
+	ax25_address *, ax25_address *, ax25_digi *, int *, int *);
+extern int  ax25_addr_build(unsigned char *, const ax25_address *,
+	const ax25_address *, const ax25_digi *, int, int);
+extern int  ax25_addr_size(const ax25_digi *);
+extern void ax25_digi_invert(const ax25_digi *, ax25_digi *);
 
 /* ax25_dev.c */
 extern ax25_dev *ax25_dev_list;
diff --git a/net/ax25/ax25_addr.c b/net/ax25/ax25_addr.c
index 5f0896ad0042d59662d33e351853a83538e13a96..5524f9cb7b83bb53f0f905ca1adb7b66bf65f8e2 100644
--- a/net/ax25/ax25_addr.c
+++ b/net/ax25/ax25_addr.c
@@ -39,7 +39,7 @@ EXPORT_SYMBOL(null_ax25_address);
 /*
  *	ax25 -> ascii conversion
  */
-char *ax2asc(char *buf, ax25_address *a)
+char *ax2asc(char *buf, const ax25_address *a)
 {
 	char c, *s;
 	int n;
@@ -72,7 +72,7 @@ EXPORT_SYMBOL(ax2asc);
 /*
  *	ascii -> ax25 conversion
  */
-void asc2ax(ax25_address *addr, char *callsign)
+void asc2ax(ax25_address *addr, const char *callsign)
 {
 	char *s;
 	int n;
@@ -107,7 +107,7 @@ EXPORT_SYMBOL(asc2ax);
 /*
  *	Compare two ax.25 addresses
  */
-int ax25cmp(ax25_address *a, ax25_address *b)
+int ax25cmp(const ax25_address *a, const ax25_address *b)
 {
 	int ct = 0;
 
@@ -128,7 +128,7 @@ EXPORT_SYMBOL(ax25cmp);
 /*
  *	Compare two AX.25 digipeater paths.
  */
-int ax25digicmp(ax25_digi *digi1, ax25_digi *digi2)
+int ax25digicmp(const ax25_digi *digi1, const ax25_digi *digi2)
 {
 	int i;
 
@@ -149,7 +149,9 @@ int ax25digicmp(ax25_digi *digi1, ax25_digi *digi2)
  *	Given an AX.25 address pull of to, from, digi list, command/response and the start of data
  *
  */
-unsigned char *ax25_addr_parse(unsigned char *buf, int len, ax25_address *src, ax25_address *dest, ax25_digi *digi, int *flags, int *dama)
+const unsigned char *ax25_addr_parse(const unsigned char *buf, int len,
+	ax25_address *src, ax25_address *dest, ax25_digi *digi, int *flags,
+	int *dama)
 {
 	int d = 0;
 
@@ -204,7 +206,8 @@ unsigned char *ax25_addr_parse(unsigned char *buf, int len, ax25_address *src, a
 /*
  *	Assemble an AX.25 header from the bits
  */
-int ax25_addr_build(unsigned char *buf, ax25_address *src, ax25_address *dest, ax25_digi *d, int flag, int modulus)
+int ax25_addr_build(unsigned char *buf, const ax25_address *src,
+	const ax25_address *dest, const ax25_digi *d, int flag, int modulus)
 {
 	int len = 0;
 	int ct  = 0;
@@ -261,7 +264,7 @@ int ax25_addr_build(unsigned char *buf, ax25_address *src, ax25_address *dest, a
 	return len;
 }
 
-int ax25_addr_size(ax25_digi *dp)
+int ax25_addr_size(const ax25_digi *dp)
 {
 	if (dp == NULL)
 		return 2 * AX25_ADDR_LEN;
@@ -272,7 +275,7 @@ int ax25_addr_size(ax25_digi *dp)
 /*
  *	Reverse Digipeat List. May not pass both parameters as same struct
  */
-void ax25_digi_invert(ax25_digi *in, ax25_digi *out)
+void ax25_digi_invert(const ax25_digi *in, ax25_digi *out)
 {
 	int ct;