Merge branch 'ax.25-netrom-rose' into next

Ralf Baechle  says:

====================

net-tools contain support for these three protocol but are deprecated and
no longer installed by default by many distributions.  Iproute2 otoh has
no support at all and will dump the addresses of these protocols which
actually are pretty human readable as hex numbers:

 # ip link show dev bpq0
3: bpq0: <UP,LOWER_UP> mtu 256 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/ax25 88:98:60:a0:92:40:02 brd a2:a6:a8:40:40:40:00
 # ip link show dev nr0
4: nr0: <NOARP,UP,LOWER_UP> mtu 236 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/netrom 88:98:60:a0:92:40:0a brd 00:00:00:00:00:00:00
 # ip link show dev rose0
8: rose0: <NOARP,UP,LOWER_UP> mtu 249 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/rose 65:09:33:30:00 brd 00:00:00:00:00

This series adds basic support for the three protocols to print addresses:

 # ip link show dev bpq0
3: bpq0: <UP,LOWER_UP> mtu 256 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/ax25 DL0PI-1 brd QST-0
 # ip link show dev nr0
4: nr0: <NOARP,UP,LOWER_UP> mtu 236 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/netrom DL0PI-5 brd *
 # ip link show dev rose0
8: rose0: <NOARP,UP,LOWER_UP> mtu 249 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/rose 6509333000 brd 0000000000

====================

Signed-off-by: David Ahern <dsahern@kernel.org>

Makefile

@@ -40,9 +40,18 @@ 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 AX.25
+ADDLIB+=rose_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

include/utils.h

@@ -198,9 +198,15 @@ 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 *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);
 
+const char *netrom_ntop(int af, const void *addr, char *str, socklen_t len);
+
 extern int __iproute2_hz_internal;
 int __get_hz(void);
 

lib/ax25_ntop.c

@@ -0,0 +1,82 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#include <errno.h>
+#include <sys/socket.h>
+#include <netax25/ax25.h>
+
+#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 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
+ * 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 bit.
+ *
+ * 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.
+ */
+
+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;
+}

lib/ll_addr.c

@@ -39,6 +39,12 @@ 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);
+	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)

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;
+}

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;
+}