[PATCH 6/6] ROSE: Print decoded addresses rather than hex numbers.

[PATCH 6/6] ROSE: Print decoded addresses rather than hex numbers.

[Ralf Baechle]

NETROM is a OSI layer 3 protocol sitting on top of AX.25.  It uses BCD-
encoded 10 digit telephone numbers as addresses.  Without this ip will
print a ROSE addresses like

  link/rose 12:34:56:78:90 brd 00:00:00:00:00

which is readable but ugly.  With this applied it ROSE addresses will be
printed as

  link/rose 1234567890 brd 0000000000

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 lib/ll_addr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/ll_addr.c b/lib/ll_addr.c
index 46e30c79..d6fd736b 100644
--- a/lib/ll_addr.c
+++ b/lib/ll_addr.c
@@ -43,6 +43,8 @@ const char *ll_addr_n2a(const unsigned char *addr, int alen, int type,
 		return ax25_ntop(AF_AX25, addr, buf, blen);
 	if (alen == 7 && type == ARPHRD_NETROM)
 		return netrom_ntop(AF_NETROM, addr, buf, blen);
+	if (alen == 5 && type == ARPHRD_ROSE)
+		return rose_ntop(AF_ROSE, addr, buf, blen);
 
 	snprintf(buf, blen, "%02x", addr[0]);
 	for (i = 1, l = 2; i < alen && l < blen; i++, l += 3)
-- 
2.31.1

[PATCH 1/6] AX.25: Add ax25_ntop implementation.

[Ralf Baechle]

AX.25 addresses are based on Amateur radio callsigns followed by an SSID
like XXXXXX-SS where the callsign is up to 6 characters which are either
letters or digits and the SSID is a decimal number in the range 0..15.
Amateur radio callsigns are assigned by a country's relevant authorities
and are 3..6 characters though a few countries have assigned callsigns
longer than that.  AX.25 is not able to handle such longer callsigns.

Being based on HDLC AX.25 encodes addresses by shifting them one bit left
thus zeroing bit 0, the HDLC extension bit for all but the last bit of
a packet's address field but for our purposes here we're not considering
the HDLC extension bit that is it will always be zero.

Linux' internal representation of AX.25 addresses in Linux is very similar
to this on the on-air or on-the-wire format.  The callsign is padded to
6 octets by adding spaces, followed by the SSID octet then all 7 octets
are left-shifted by one byte.

This for example turns "LINUX-1" where the callsign is LINUX and SSID is 1
into 98:92:9c:aa:b0:40:02.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 Makefile        |  3 ++
 include/utils.h |  2 ++
 lib/ax25_ntop.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 79 insertions(+)
 create mode 100644 lib/ax25_ntop.c

diff --git a/Makefile b/Makefile
index 5bc11477..551f528b 100644
--- a/Makefile
+++ b/Makefile
@@ -40,6 +40,9 @@ DEFINES+=-DCONFDIR=\"$(CONFDIR)\" \
          -DNETNS_RUN_DIR=\"$(NETNS_RUN_DIR)\" \
          -DNETNS_ETC_DIR=\"$(NETNS_ETC_DIR)\"
 
+#options for AX.25
+ADDLIB+=ax25_ntop.o
+
 #options for mpls
 ADDLIB+=mpls_ntop.o mpls_pton.o
 
diff --git a/include/utils.h b/include/utils.h
index 28eaad8e..31c1e442 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -209,6 +209,8 @@ bool matches(const char *prefix, const char *string);
 int inet_addr_match(const inet_prefix *a, const inet_prefix *b, int bits);
 int inet_addr_match_rta(const inet_prefix *m, const struct rtattr *rta);
 
+const char *ax25_ntop(int af, const void *addr, char *str, socklen_t len);
+
 const char *mpls_ntop(int af, const void *addr, char *str, size_t len);
 int mpls_pton(int af, const char *src, void *addr, size_t alen);
 
diff --git a/lib/ax25_ntop.c b/lib/ax25_ntop.c
new file mode 100644
index 00000000..48098581
--- /dev/null
+++ b/lib/ax25_ntop.c
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#include <errno.h>
+#include <sys/socket.h>
+#include <netax25/ax25.h>
+
+#include "utils.h"
+
+/*
+ * AX.25 addresses are based on Amateur radio callsigns followed by an SSID
+ * like XXXXXX-SS where the callsign is up to 6 characters which are either
+ * letters or digits and the SSID is a decimal number in the range 0..15.
+ * Amateur radio callsigns are assigned by a country's relevant authorities
+ * and are 3..6 characters though a few countries have assigned callsigns
+ * longer than that.  AX.25 is not able to handle such longer callsigns.
+ *
+ * Being based on HDLC AX.25 encodes addresses by shifting them one bit left
+ * thus zeroing bit 0, the HDLC extension bit for all but the last bit of
+ * a packet's address field but for our purposes here we're not considering
+ * the HDLC extension bit that is it will always be zero.
+ *
+ * Linux' internal representation of AX.25 addresses in Linux is very similar
+ * to this on the on-air or on-the-wire format.  The callsign is padded to
+ * 6 octets by adding spaces, followed by the SSID octet then all 7 octets
+ * are left-shifted by one byte.
+ *
+ * This for example turns "LINUX-1" where the callsign is LINUX and SSID is 1
+ * into 98:92:9c:aa:b0:40:02.
+ */
+
+static const char *ax25_ntop1(const ax25_address *src, char *dst,
+			      socklen_t size)
+{
+	char c, *s;
+	int n;
+
+	for (n = 0, s = dst; n < 6; n++) {
+		c = (src->ax25_call[n] >> 1) & 0x7f;
+		if (c != ' ')
+			*s++ = c;
+	}
+
+	*s++ = '-';
+
+	n = ((src->ax25_call[6] >> 1) & 0x0f);
+	if (n > 9) {
+		*s++ = '1';
+		n -= 10;
+	}
+
+	*s++ = n + '0';
+	*s++ = '\0';
+
+	if (*dst == '\0' || *dst == '-') {
+		dst[0] = '*';
+		dst[1] = '\0';
+	}
+
+	return dst;
+}
+
+const char *ax25_ntop(int af, const void *addr, char *buf, socklen_t buflen)
+{
+	switch (af) {
+	case AF_AX25:
+		errno = 0;
+		return ax25_ntop1((ax25_address *)addr, buf, buflen);
+
+	default:
+		errno = EAFNOSUPPORT;
+	}
+
+	return NULL;
+}
-- 
2.31.1

[PATCH 2/6] AX.25: Print decoded addresses rather than hex numbers.

[Ralf Baechle]

Before this, ip would have printed the AX.25 address configured for an
AX.25 interface's default addresses as:

  link/ax25 98:92:9c:aa:b0:40:02 brd a2:a6:a8:40:40:40:00

which is pretty unreadable.  With this commit ip will decode AX.25
addresses like

  link/ax25 LINUX-1 brd QST-0

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 lib/ll_addr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/ll_addr.c b/lib/ll_addr.c
index 00b562ae..910e6daf 100644
--- a/lib/ll_addr.c
+++ b/lib/ll_addr.c
@@ -39,6 +39,8 @@ const char *ll_addr_n2a(const unsigned char *addr, int alen, int type,
 
 	if (alen == 16 && (type == ARPHRD_TUNNEL6 || type == ARPHRD_IP6GRE))
 		return inet_ntop(AF_INET6, addr, buf, blen);
+	if (alen == 7 && type == ARPHRD_AX25)
+		return ax25_ntop(AF_AX25, addr, buf, blen);
 
 	snprintf(buf, blen, "%02x", addr[0]);
 	for (i = 1, l = 2; i < alen && l < blen; i++, l += 3)
-- 
2.31.1

[PATCH 4/6] NETROM: Print decoded addresses rather than hex numbers.

[Ralf Baechle]

NETROM is an OSI layer 3 protocol sitting on top of AX.25.  It also uses
AX.25 addresses.  Without this commit ip will print NETROM address like

  link/generic 98:92:9c:aa:b0:40:02 brd 00:00:00:00:00:00:00

while with this commit the decoded result

  link/generic LINUX-1 brd *

is much more eye friendly.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 lib/ll_addr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/ll_addr.c b/lib/ll_addr.c
index 910e6daf..46e30c79 100644
--- a/lib/ll_addr.c
+++ b/lib/ll_addr.c
@@ -41,6 +41,8 @@ const char *ll_addr_n2a(const unsigned char *addr, int alen, int type,
 		return inet_ntop(AF_INET6, addr, buf, blen);
 	if (alen == 7 && type == ARPHRD_AX25)
 		return ax25_ntop(AF_AX25, addr, buf, blen);
+	if (alen == 7 && type == ARPHRD_NETROM)
+		return netrom_ntop(AF_NETROM, addr, buf, blen);
 
 	snprintf(buf, blen, "%02x", addr[0]);
 	for (i = 1, l = 2; i < alen && l < blen; i++, l += 3)
-- 
2.31.1

[PATCH 5/6] ROSE: Add rose_ntop implementation.

[Ralf Baechle]

ROSE addresses are ten digit numbers, basically like North American
telephone numbers.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 Makefile        |  3 +++
 include/utils.h |  2 ++
 lib/rose_ntop.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 61 insertions(+)
 create mode 100644 lib/rose_ntop.c

diff --git a/Makefile b/Makefile
index df894d54..5eddd504 100644
--- a/Makefile
+++ b/Makefile
@@ -43,6 +43,9 @@ DEFINES+=-DCONFDIR=\"$(CONFDIR)\" \
 #options for AX.25
 ADDLIB+=ax25_ntop.o
 
+#options for AX.25
+ADDLIB+=rose_ntop.o
+
 #options for mpls
 ADDLIB+=mpls_ntop.o mpls_pton.o
 
diff --git a/include/utils.h b/include/utils.h
index c685a392..ba981186 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -211,6 +211,8 @@ int inet_addr_match_rta(const inet_prefix *m, const struct rtattr *rta);
 
 const char *ax25_ntop(int af, const void *addr, char *str, socklen_t len);
 
+const char *rose_ntop(int af, const void *addr, char *buf, socklen_t buflen);
+
 const char *mpls_ntop(int af, const void *addr, char *str, size_t len);
 int mpls_pton(int af, const char *src, void *addr, size_t alen);
 
diff --git a/lib/rose_ntop.c b/lib/rose_ntop.c
new file mode 100644
index 00000000..c9ba712c
--- /dev/null
+++ b/lib/rose_ntop.c
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <string.h>
+#include <errno.h>
+
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/sockios.h>
+#include <linux/rose.h>
+
+#include "rt_names.h"
+#include "utils.h"
+
+static const char *rose_ntop1(const rose_address *src, char *dst,
+			      socklen_t size)
+{
+	char *p = dst;
+	int i;
+
+	if (size < 10)
+		return NULL;
+
+	for (i = 0; i < 5; i++) {
+		*p++ = '0' + ((src->rose_addr[i] >> 4) & 0xf);
+		*p++ = '0' + ((src->rose_addr[i]     ) & 0xf);
+	}
+
+	if (size == 10)
+		return dst;
+
+	*p = '\0';
+
+	return dst;
+}
+
+const char *rose_ntop(int af, const void *addr, char *buf, socklen_t buflen)
+{
+	switch (af) {
+	case AF_ROSE:
+		errno = 0;
+		return rose_ntop1((rose_address *)addr, buf, buflen);
+
+	default:
+		errno = EAFNOSUPPORT;
+	}
+
+	return NULL;
+}
-- 
2.31.1

[PATCH 3/6] NETROM: Add netrom_ntop implementation.

[Ralf Baechle]

NETROM uses AX.25 addresses so this is a simple wrapper around ax25_ntop1.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
 Makefile          |  3 +++
 include/utils.h   |  2 ++
 lib/ax25_ntop.c   | 22 +++++++++++++++-------
 lib/netrom_ntop.c | 23 +++++++++++++++++++++++
 4 files changed, 43 insertions(+), 7 deletions(-)
 create mode 100644 lib/netrom_ntop.c

diff --git a/Makefile b/Makefile
index 551f528b..df894d54 100644
--- a/Makefile
+++ b/Makefile
@@ -46,6 +46,9 @@ ADDLIB+=ax25_ntop.o
 #options for mpls
 ADDLIB+=mpls_ntop.o mpls_pton.o
 
+#options for NETROM
+ADDLIB+=netrom_ntop.o
+
 CC := gcc
 HOSTCC ?= $(CC)
 DEFINES += -D_GNU_SOURCE
diff --git a/include/utils.h b/include/utils.h
index 31c1e442..c685a392 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -214,6 +214,8 @@ const char *ax25_ntop(int af, const void *addr, char *str, socklen_t len);
 const char *mpls_ntop(int af, const void *addr, char *str, size_t len);
 int mpls_pton(int af, const char *src, void *addr, size_t alen);
 
+const char *netrom_ntop(int af, const void *addr, char *str, socklen_t len);
+
 extern int __iproute2_hz_internal;
 int __get_hz(void);
 
diff --git a/lib/ax25_ntop.c b/lib/ax25_ntop.c
index 48098581..cfd0e04b 100644
--- a/lib/ax25_ntop.c
+++ b/lib/ax25_ntop.c
@@ -6,13 +6,22 @@
 
 #include "utils.h"
 
+const char *ax25_ntop1(const ax25_address *src, char *dst, socklen_t size);
+
 /*
  * AX.25 addresses are based on Amateur radio callsigns followed by an SSID
- * like XXXXXX-SS where the callsign is up to 6 characters which are either
- * letters or digits and the SSID is a decimal number in the range 0..15.
+ * like XXXXXX-SS where the callsign consists of up to 6 ASCII characters
+ * which are either letters or digits and the SSID is a decimal number in the
+ * range 0..15.
  * Amateur radio callsigns are assigned by a country's relevant authorities
  * and are 3..6 characters though a few countries have assigned callsigns
  * longer than that.  AX.25 is not able to handle such longer callsigns.
+ * There are further restrictions on the format of valid callsigns by
+ * applicable national and international law.  Linux doesn't need to care and
+ * will happily accept anything that consists of 6 ASCII characters in the
+ * range of A-Z and 0-9 for a callsign such as the default AX.25 MAC address
+ * LINUX-1 and the default broadcast address QST-0.
+ * The SSID is just a number and not encoded in ASCII digits.
  *
  * Being based on HDLC AX.25 encodes addresses by shifting them one bit left
  * thus zeroing bit 0, the HDLC extension bit for all but the last bit of
@@ -22,14 +31,13 @@
  * Linux' internal representation of AX.25 addresses in Linux is very similar
  * to this on the on-air or on-the-wire format.  The callsign is padded to
  * 6 octets by adding spaces, followed by the SSID octet then all 7 octets
- * are left-shifted by one byte.
+ * are left-shifted by one bit.
  *
- * This for example turns "LINUX-1" where the callsign is LINUX and SSID is 1
- * into 98:92:9c:aa:b0:40:02.
+ * For example, for the address "LINUX-1" the callsign is LINUX and SSID is 1
+ * the internal format is 98:92:9c:aa:b0:40:02.
  */
 
-static const char *ax25_ntop1(const ax25_address *src, char *dst,
-			      socklen_t size)
+const char *ax25_ntop1(const ax25_address *src, char *dst, socklen_t size)
 {
 	char c, *s;
 	int n;
diff --git a/lib/netrom_ntop.c b/lib/netrom_ntop.c
new file mode 100644
index 00000000..3dd6cb0b
--- /dev/null
+++ b/lib/netrom_ntop.c
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <sys/socket.h>
+#include <errno.h>
+#include <linux/ax25.h>
+
+#include "utils.h"
+
+const char *ax25_ntop1(const ax25_address *src, char *dst, socklen_t size);
+
+const char *netrom_ntop(int af, const void *addr, char *buf, socklen_t buflen)
+{
+	switch (af) {
+	case AF_NETROM:
+		errno = 0;
+		return ax25_ntop1((ax25_address *)addr, buf, buflen);
+
+	default:
+		errno = EAFNOSUPPORT;
+	}
+
+	return NULL;
+}
-- 
2.31.1