MFC r270064,r270068,r270069,r270115,r270129,r270287,r270822,r271014,

  r271524,r273541,r282967,r283009,r283364.

Add support for reading i2c SFP/SFP+ data from NIC driver and
presenting most interesting fields via ifconfig -v.
This version supports Intel ixgbe driver only.

Tested on:      Cisco,Intel,Mellanox,ModuleTech,Molex transceivers

* Add new net/sff8436.h containing constants used to access
  QSFP+ data via i2c inteface. These constants has been taken
  from SFF-8436 "QSFP+ 10 Gbs 4X PLUGGABLE TRANSCEIVER" standard
  rev 4.8.
* Add support for printing QSFP+ information from 40G NICs
  such as Chelsio T5.

Example:
cxl1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=ec07bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,.....>
        ether 00:07:43:28:ad:08
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
        media: Ethernet 40Gbase-LR4 <full-duplex>
        status: active
        plugged: QSFP+ 40GBASE-LR4 (MPO Parallel Optic)
        vendor: OEM PN: OP-QSFP-40G-LR4 SN: 20140318001 DATE: 2014-03-18
        module temperature: 64.06 C voltage: 3.26 Volts
        lane 1: RX: 0.47 mW (-3.21 dBm) TX: 2.78 mW (4.46 dBm)
        lane 2: RX: 0.20 mW (-6.94 dBm) TX: 2.80 mW (4.47 dBm)
        lane 3: RX: 0.18 mW (-7.38 dBm) TX: 2.79 mW (4.47 dBm)
        lane 4: RX: 0.90 mW (-0.45 dBm) TX: 2.80 mW (4.48 dBm)

Tested on:      Chelsio T5
Tested on:      Mellanox/Huawei passive/active cables/transceivers.

Sponsored by:   Yandex LLC

4 files changed, 891 insertions, 0 deletions

diff --git a/sbin/ifconfig/Makefile b/sbin/ifconfig/Makefile
index 82fa06a..84509d7 100644
--- a/sbin/ifconfig/Makefile
+++ b/sbin/ifconfig/Makefile
@@ -35,6 +35,10 @@ SRCS+=	ifvxlan.c		# VXLAN support
 SRCS+=	ifgre.c			# GRE keys etc
 SRCS+=	ifgif.c			# GIF reversed header workaround
 
+SRCS+=	sfp.c			# SFP/SFP+ information
+DPADD+=	${LIBM}
+LDADD+=	-lm
+
 SRCS+=	ifieee80211.c regdomain.c # SIOC[GS]IEEE80211 support
 DPADD+=	${LIBBSDXML} ${LIBSBUF}
 LDADD+=	-lbsdxml -lsbuf
diff --git a/sbin/ifconfig/ifconfig.c b/sbin/ifconfig/ifconfig.c
index dafb0f0..21f21c9 100644
--- a/sbin/ifconfig/ifconfig.c
+++ b/sbin/ifconfig/ifconfig.c
@@ -1025,6 +1025,9 @@ status(const struct afswtch *afp, const struct sockaddr_dl *sdl,
 	if (ioctl(s, SIOCGIFSTATUS, &ifs) == 0) 
 		printf("%s", ifs.ascii);
 
+	if (verbose > 0)
+		sfp_status(s, &ifr, verbose);
+
 	close(s);
 	return;
 }
diff --git a/sbin/ifconfig/ifconfig.h b/sbin/ifconfig/ifconfig.h
index 95d423a..6df9acf 100644
--- a/sbin/ifconfig/ifconfig.h
+++ b/sbin/ifconfig/ifconfig.h
@@ -144,6 +144,8 @@ void	ifmaybeload(const char *name);
 typedef void clone_callback_func(int, struct ifreq *);
 void	clone_setdefcallback(const char *, clone_callback_func *);
 
+void	sfp_status(int s, struct ifreq *ifr, int verbose);
+
 /*
  * XXX expose this so modules that neeed to know of any pending
  * operations on ifmedia can avoid cmd line ordering confusion.
diff --git a/sbin/ifconfig/sfp.c b/sbin/ifconfig/sfp.c
new file mode 100644
index 0000000..7c090e1
--- /dev/null
+++ b/sbin/ifconfig/sfp.c
@@ -0,0 +1,882 @@
+/*-
+ * Copyright (c) 2014 Alexander V. Chernikov. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static const char rcsid[] =
+  "$FreeBSD$";
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+
+#include <net/if.h>
+#include <net/sff8436.h>
+#include <net/sff8472.h>
+
+#include <math.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "ifconfig.h"
+
+struct i2c_info {
+	int fd;			/* fd to issue SIOCGI2C */
+	int error;		/* Store first error */
+	int qsfp;		/* True if transceiver is QSFP */
+	int do_diag;		/* True if we need to request DDM */
+	struct ifreq *ifr;	/* Pointer to pre-filled ifreq */
+};
+
+static int read_i2c(struct i2c_info *ii, uint8_t addr, uint8_t off,
+    uint8_t len, uint8_t *buf);
+static void dump_i2c_data(struct i2c_info *ii, uint8_t addr, uint8_t off,
+    uint8_t len);
+
+struct _nv {
+	int v;
+	const char *n;
+};
+
+const char *find_value(struct _nv *x, int value);
+const char *find_zero_bit(struct _nv *x, int value, int sz);
+
+/* SFF-8472 Rev. 11.4 table 3.4: Connector values */
+static struct _nv conn[] = {
+	{ 0x00, "Unknown" },
+	{ 0x01, "SC" },
+	{ 0x02, "Fibre Channel Style 1 copper" },
+	{ 0x03, "Fibre Channel Style 2 copper" },
+	{ 0x04, "BNC/TNC" },
+	{ 0x05, "Fibre Channel coaxial" },
+	{ 0x06, "FiberJack" },
+	{ 0x07, "LC" },
+	{ 0x08, "MT-RJ" },
+	{ 0x09, "MU" },
+	{ 0x0A, "SG" },
+	{ 0x0B, "Optical pigtail" },
+	{ 0x0C, "MPO Parallel Optic" },
+	{ 0x20, "HSSDC II" },
+	{ 0x21, "Copper pigtail" },
+	{ 0x22, "RJ45" },
+	{ 0x23, "No separate connector" }, /* SFF-8436 */
+	{ 0, NULL }
+};
+
+/* SFF-8472 Rev. 11.4 table 3.5: Transceiver codes */
+/* 10G Ethernet/IB compliance codes, byte 3 */
+static struct _nv eth_10g[] = {
+	{ 0x80, "10G Base-ER" },
+	{ 0x40, "10G Base-LRM" },
+	{ 0x20, "10G Base-LR" },
+	{ 0x10, "10G Base-SR" },
+	{ 0x08, "1X SX" },
+	{ 0x04, "1X LX" },
+	{ 0x02, "1X Copper Active" },
+	{ 0x01, "1X Copper Passive" },
+	{ 0, NULL }
+};
+
+/* Ethernet compliance codes, byte 6 */
+static struct _nv eth_compat[] = {
+	{ 0x80, "BASE-PX" },
+	{ 0x40, "BASE-BX10" },
+	{ 0x20, "100BASE-FX" },
+	{ 0x10, "100BASE-LX/LX10" },
+	{ 0x08, "1000BASE-T" },
+	{ 0x04, "1000BASE-CX" },
+	{ 0x02, "1000BASE-LX" },
+	{ 0x01, "1000BASE-SX" },
+	{ 0, NULL }
+};
+
+/* FC link length, byte 7 */
+static struct _nv fc_len[] = {
+	{ 0x80, "very long distance" },
+	{ 0x40, "short distance" },
+	{ 0x20, "intermediate distance" },
+	{ 0x10, "long distance" },
+	{ 0x08, "medium distance" },
+	{ 0, NULL }
+};
+
+/* Channel/Cable technology, byte 7-8 */
+static struct _nv cab_tech[] = {
+	{ 0x0400, "Shortwave laser (SA)" },
+	{ 0x0200, "Longwave laser (LC)" },
+	{ 0x0100, "Electrical inter-enclosure (EL)" },
+	{ 0x80, "Electrical intra-enclosure (EL)" },
+	{ 0x40, "Shortwave laser (SN)" },
+	{ 0x20, "Shortwave laser (SL)" },
+	{ 0x10, "Longwave laser (LL)" },
+	{ 0x08, "Active Cable" },
+	{ 0x04, "Passive Cable" },
+	{ 0, NULL }
+};
+
+/* FC Transmission media, byte 9 */
+static struct _nv fc_media[] = {
+	{ 0x80, "Twin Axial Pair" },
+	{ 0x40, "Twisted Pair" },
+	{ 0x20, "Miniature Coax" },
+	{ 0x10, "Viao Coax" },
+	{ 0x08, "Miltimode, 62.5um" },
+	{ 0x04, "Multimode, 50um" },
+	{ 0x02, "" },
+	{ 0x01, "Single Mode" },
+	{ 0, NULL }
+};
+
+/* FC Speed, byte 10 */
+static struct _nv fc_speed[] = {
+	{ 0x80, "1200 MBytes/sec" },
+	{ 0x40, "800 MBytes/sec" },
+	{ 0x20, "1600 MBytes/sec" },
+	{ 0x10, "400 MBytes/sec" },
+	{ 0x08, "3200 MBytes/sec" },
+	{ 0x04, "200 MBytes/sec" },
+	{ 0x01, "100 MBytes/sec" },
+	{ 0, NULL }
+};
+
+/* SFF-8436 Rev. 4.8 table 33: Specification compliance  */
+
+/* 10/40G Ethernet compliance codes, byte 128 + 3 */
+static struct _nv eth_1040g[] = {
+	{ 0x80, "Reserved" },
+	{ 0x40, "10GBASE-LRM" },
+	{ 0x20, "10GBASE-LR" },
+	{ 0x10, "10GBASE-SR" },
+	{ 0x08, "40GBASE-CR4" },
+	{ 0x04, "40GBASE-SR4" },
+	{ 0x02, "40GBASE-LR4" },
+	{ 0x01, "40G Active Cable" },
+	{ 0, NULL }
+};
+
+/* SFF-8636 Rev. 2.5 table 6.3: Revision compliance */
+static struct _nv rev_compl[] = {
+	{ 0x1, "SFF-8436 rev <=4.8" },
+	{ 0x2, "SFF-8436 rev <=4.8" },
+	{ 0x3, "SFF-8636 rev <=1.3" },
+	{ 0x4, "SFF-8636 rev <=1.4" },
+	{ 0x5, "SFF-8636 rev <=1.5" },
+	{ 0x6, "SFF-8636 rev <=2.0" },
+	{ 0x7, "SFF-8636 rev <=2.5" },
+	{ 0x0, "Unspecified" }
+};
+
+const char *
+find_value(struct _nv *x, int value)
+{
+	for (; x->n != NULL; x++)
+		if (x->v == value)
+			return (x->n);
+	return (NULL);
+}
+
+const char *
+find_zero_bit(struct _nv *x, int value, int sz)
+{
+	int v, m;
+	const char *s;
+
+	v = 1;
+	for (v = 1, m = 1 << (8 * sz); v < m; v *= 2) {
+		if ((value & v) == 0)
+			continue;
+		if ((s = find_value(x, value & v)) != NULL) {
+			value &= ~v;
+			return (s);
+		}
+	}
+
+	return (NULL);
+}
+
+static void
+convert_sff_identifier(char *buf, size_t size, uint8_t value)
+{
+	const char *x;
+
+	x = NULL;
+	if (value <= SFF_8024_ID_LAST)
+		x = sff_8024_id[value];
+	else {
+		if (value > 0x80)
+			x = "Vendor specific";
+		else
+			x = "Reserved";
+	}
+
+	snprintf(buf, size, "%s", x);
+}
+
+static void
+convert_sff_connector(char *buf, size_t size, uint8_t value)
+{
+	const char *x;
+
+	if ((x = find_value(conn, value)) == NULL) {
+		if (value >= 0x0D && value <= 0x1F)
+			x = "Unallocated";
+		else if (value >= 0x24 && value <= 0x7F)
+			x = "Unallocated";
+		else
+			x = "Vendor specific";
+	}
+
+	snprintf(buf, size, "%s", x);
+}
+
+static void
+convert_sff_rev_compliance(char *buf, size_t size, uint8_t value)
+{
+	const char *x;
+
+	if (value > 0x07)
+		x = "Unallocated";
+	else
+		x = find_value(rev_compl, value);
+
+	snprintf(buf, size, "%s", x);
+}
+
+static void
+get_sfp_identifier(struct i2c_info *ii, char *buf, size_t size)
+{
+	uint8_t data;
+
+	read_i2c(ii, SFF_8472_BASE, SFF_8472_ID, 1, &data);
+	convert_sff_identifier(buf, size, data);
+}
+
+static void
+get_sfp_connector(struct i2c_info *ii, char *buf, size_t size)
+{
+	uint8_t data;
+
+	read_i2c(ii, SFF_8472_BASE, SFF_8472_CONNECTOR, 1, &data);
+	convert_sff_connector(buf, size, data);
+}
+
+static void
+get_qsfp_identifier(struct i2c_info *ii, char *buf, size_t size)
+{
+	uint8_t data;
+
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_ID, 1, &data);
+	convert_sff_identifier(buf, size, data);
+}
+
+static void
+get_qsfp_connector(struct i2c_info *ii, char *buf, size_t size)
+{
+	uint8_t data;
+
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_CONNECTOR, 1, &data);
+	convert_sff_connector(buf, size, data);
+}
+
+static void
+printf_sfp_transceiver_descr(struct i2c_info *ii, char *buf, size_t size)
+{
+	char xbuf[12];
+	const char *tech_class, *tech_len, *tech_tech, *tech_media, *tech_speed;
+
+	tech_class = NULL;
+	tech_len = NULL;
+	tech_tech = NULL;
+	tech_media = NULL;
+	tech_speed = NULL;
+
+	/* Read bytes 3-10 at once */
+	read_i2c(ii, SFF_8472_BASE, SFF_8472_TRANS_START, 8, &xbuf[3]);
+
+	/* Check 10G ethernet first */
+	tech_class = find_zero_bit(eth_10g, xbuf[3], 1);
+	if (tech_class == NULL) {
+		/* No match. Try 1G */
+		tech_class = find_zero_bit(eth_compat, xbuf[6], 1);
+	}
+
+	tech_len = find_zero_bit(fc_len, xbuf[7], 1);
+	tech_tech = find_zero_bit(cab_tech, xbuf[7] << 8 | xbuf[8], 2);
+	tech_media = find_zero_bit(fc_media, xbuf[9], 1);
+	tech_speed = find_zero_bit(fc_speed, xbuf[10], 1);
+
+	printf("Class: %s\n", tech_class);
+	printf("Length: %s\n", tech_len);
+	printf("Tech: %s\n", tech_tech);
+	printf("Media: %s\n", tech_media);
+	printf("Speed: %s\n", tech_speed);
+}
+
+static void
+get_sfp_transceiver_class(struct i2c_info *ii, char *buf, size_t size)
+{
+	const char *tech_class;
+	uint8_t code;
+
+	unsigned char qbuf[8];
+	read_i2c(ii, SFF_8472_BASE, SFF_8472_TRANS_START, 8, (uint8_t *)qbuf);
+
+	/* Check 10G Ethernet/IB first */
+	read_i2c(ii, SFF_8472_BASE, SFF_8472_TRANS_START, 1, &code);
+	tech_class = find_zero_bit(eth_10g, code, 1);
+	if (tech_class == NULL) {
+		/* No match. Try Ethernet 1G */
+		read_i2c(ii, SFF_8472_BASE, SFF_8472_TRANS_START + 3,
+		    1, (caddr_t)&code);
+		tech_class = find_zero_bit(eth_compat, code, 1);
+	}
+
+	if (tech_class == NULL)
+		tech_class = "Unknown";
+
+	snprintf(buf, size, "%s", tech_class);
+}
+
+static void
+get_qsfp_transceiver_class(struct i2c_info *ii, char *buf, size_t size)
+{
+	const char *tech_class;
+	uint8_t code;
+
+	/* Check 10/40G Ethernet class only */
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_CODE_E1040G, 1, &code);
+	tech_class = find_zero_bit(eth_1040g, code, 1);
+	if (tech_class == NULL)
+		tech_class = "Unknown";
+
+	snprintf(buf, size, "%s", tech_class);
+}
+
+/*
+ * Print SFF-8472/SFF-8436 string to supplied buffer.
+ * All (vendor-specific) strings are padded right with '0x20'.
+ */
+static void
+convert_sff_name(char *buf, size_t size, char *xbuf)
+{
+	char *p;
+
+	for (p = &xbuf[16]; *(p - 1) == 0x20; p--)
+		;
+	*p = '\0';
+	snprintf(buf, size, "%s", xbuf);
+}
+
+static void
+convert_sff_date(char *buf, size_t size, char *xbuf)
+{
+
+	snprintf(buf, size, "20%c%c-%c%c-%c%c", xbuf[0], xbuf[1],
+	    xbuf[2], xbuf[3], xbuf[4], xbuf[5]);
+}
+
+static void
+get_sfp_vendor_name(struct i2c_info *ii, char *buf, size_t size)
+{
+	char xbuf[17];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8472_BASE, SFF_8472_VENDOR_START, 16, (uint8_t *)xbuf);
+	convert_sff_name(buf, size, xbuf);
+}
+
+static void
+get_sfp_vendor_pn(struct i2c_info *ii, char *buf, size_t size)
+{
+	char xbuf[17];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8472_BASE, SFF_8472_PN_START, 16, (uint8_t *)xbuf);
+	convert_sff_name(buf, size, xbuf);
+}
+
+static void
+get_sfp_vendor_sn(struct i2c_info *ii, char *buf, size_t size)
+{
+	char xbuf[17];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8472_BASE, SFF_8472_SN_START, 16, (uint8_t *)xbuf);
+	convert_sff_name(buf, size, xbuf);
+}
+
+static void
+get_sfp_vendor_date(struct i2c_info *ii, char *buf, size_t size)
+{
+	char xbuf[6];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	/* Date code, see Table 3.8 for description */
+	read_i2c(ii, SFF_8472_BASE, SFF_8472_DATE_START, 6, (uint8_t *)xbuf);
+	convert_sff_date(buf, size, xbuf);
+}
+
+static void
+get_qsfp_vendor_name(struct i2c_info *ii, char *buf, size_t size)
+{
+	char xbuf[17];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_VENDOR_START, 16, (uint8_t *)xbuf);
+	convert_sff_name(buf, size, xbuf);
+}
+
+static void
+get_qsfp_vendor_pn(struct i2c_info *ii, char *buf, size_t size)
+{
+	char xbuf[17];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_PN_START, 16, (uint8_t *)xbuf);
+	convert_sff_name(buf, size, xbuf);
+}
+
+static void
+get_qsfp_vendor_sn(struct i2c_info *ii, char *buf, size_t size)
+{
+	char xbuf[17];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_SN_START, 16, (uint8_t *)xbuf);
+	convert_sff_name(buf, size, xbuf);
+}
+
+static void
+get_qsfp_vendor_date(struct i2c_info *ii, char *buf, size_t size)
+{
+	char xbuf[6];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_DATE_START, 6, (uint8_t *)xbuf);
+	convert_sff_date(buf, size, xbuf);
+}
+
+static void
+print_sfp_vendor(struct i2c_info *ii, char *buf, size_t size)
+{
+	char xbuf[80];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	if (ii->qsfp != 0) {
+		get_qsfp_vendor_name(ii, xbuf, 20);
+		get_qsfp_vendor_pn(ii, &xbuf[20], 20);
+		get_qsfp_vendor_sn(ii, &xbuf[40], 20);
+		get_qsfp_vendor_date(ii, &xbuf[60], 20);
+	} else {
+		get_sfp_vendor_name(ii, xbuf, 20);
+		get_sfp_vendor_pn(ii, &xbuf[20], 20);
+		get_sfp_vendor_sn(ii, &xbuf[40], 20);
+		get_sfp_vendor_date(ii, &xbuf[60], 20);
+	}
+
+	snprintf(buf, size, "vendor: %s PN: %s SN: %s DATE: %s",
+	    xbuf, &xbuf[20],  &xbuf[40], &xbuf[60]);
+}
+
+/*
+ * Converts internal templerature (SFF-8472, SFF-8436)
+ * 16-bit unsigned value to human-readable representation:
+ * 
+ * Internally measured Module temperature are represented
+ * as a 16-bit signed twos complement value in increments of
+ * 1/256 degrees Celsius, yielding a total range of –128C to +128C
+ * that is considered valid between –40 and +125C.
+ *
+ */
+static void
+convert_sff_temp(char *buf, size_t size, uint8_t *xbuf)
+{
+	double d;
+
+	d = (double)xbuf[0];
+	d += (double)xbuf[1] / 256;
+
+	snprintf(buf, size, "%.2f C", d);
+}
+
+/*
+ * Retrieves supplied voltage (SFF-8472, SFF-8436).
+ * 16-bit usigned value, treated as range 0..+6.55 Volts
+ */
+static void
+convert_sff_voltage(char *buf, size_t size, uint8_t *xbuf)
+{
+	double d;
+
+	d = (double)((xbuf[0] << 8) | xbuf[1]);
+	snprintf(buf, size, "%.2f Volts", d / 10000);
+}
+
+/*
+ * Converts value in @xbuf to both milliwats and dBm
+ * human representation.
+ */
+static void
+convert_sff_power(struct i2c_info *ii, char *buf, size_t size, uint8_t *xbuf)
+{
+	uint16_t mW;
+	double dbm;
+
+	mW = (xbuf[0] << 8) + xbuf[1];
+
+	/* Convert mw to dbm */
+	dbm = 10.0 * log10(1.0 * mW / 10000);
+
+	/*
+	 * Assume internally-calibrated data.
+	 * This is always true for SFF-8346, and explicitly
+	 * checked for SFF-8472.
+	 */
+
+	/* Table 3.9, bit 5 is set, internally calibrated */
+	snprintf(buf, size, "%d.%02d mW (%.2f dBm)",
+    	    mW / 10000, (mW % 10000) / 100, dbm);
+}
+
+static void
+get_sfp_temp(struct i2c_info *ii, char *buf, size_t size)
+{
+	uint8_t xbuf[2];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8472_DIAG, SFF_8472_TEMP, 2, xbuf);
+	convert_sff_temp(buf, size, xbuf);
+}
+
+static void
+get_sfp_voltage(struct i2c_info *ii, char *buf, size_t size)
+{
+	uint8_t xbuf[2];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8472_DIAG, SFF_8472_VCC, 2, xbuf);
+	convert_sff_voltage(buf, size, xbuf);
+}
+
+static void
+get_qsfp_temp(struct i2c_info *ii, char *buf, size_t size)
+{
+	uint8_t xbuf[2];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_TEMP, 2, xbuf);
+	convert_sff_temp(buf, size, xbuf);
+}
+
+static void
+get_qsfp_voltage(struct i2c_info *ii, char *buf, size_t size)
+{
+	uint8_t xbuf[2];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_VCC, 2, xbuf);
+	convert_sff_voltage(buf, size, xbuf);
+}
+
+static void
+get_sfp_rx_power(struct i2c_info *ii, char *buf, size_t size)
+{
+	uint8_t xbuf[2];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8472_DIAG, SFF_8472_RX_POWER, 2, xbuf);
+	convert_sff_power(ii, buf, size, xbuf);
+}
+
+static void
+get_sfp_tx_power(struct i2c_info *ii, char *buf, size_t size)
+{
+	uint8_t xbuf[2];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8472_DIAG, SFF_8472_TX_POWER, 2, xbuf);
+	convert_sff_power(ii, buf, size, xbuf);
+}
+
+static void
+get_qsfp_rx_power(struct i2c_info *ii, char *buf, size_t size, int chan)
+{
+	uint8_t xbuf[2];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_RX_CH1_MSB + (chan-1)*2, 2, xbuf);
+	convert_sff_power(ii, buf, size, xbuf);
+}
+
+static void
+get_qsfp_tx_power(struct i2c_info *ii, char *buf, size_t size, int chan)
+{
+	uint8_t xbuf[2];
+
+	memset(xbuf, 0, sizeof(xbuf));
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_TX_CH1_MSB + (chan-1)*2, 2, xbuf);
+	convert_sff_power(ii, buf, size, xbuf);
+}
+
+static void
+get_qsfp_rev_compliance(struct i2c_info *ii, char *buf, size_t size)
+{
+	uint8_t xbuf;
+
+	xbuf = 0;
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_STATUS, 1, &xbuf);
+	convert_sff_rev_compliance(buf, size, xbuf);
+}
+
+static uint32_t 
+get_qsfp_br(struct i2c_info *ii)
+{
+	uint8_t xbuf;
+	uint32_t rate;
+
+	xbuf = 0;
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_BITRATE, 1, &xbuf);
+	rate = xbuf * 100;
+	if (xbuf == 0xFF) {
+		read_i2c(ii, SFF_8436_BASE, SFF_8636_BITRATE, 1, &xbuf);
+		rate = xbuf * 250;
+	}
+
+	return (rate);
+}
+
+/*
+ * Reads i2c data from opened kernel socket.
+ */
+static int
+read_i2c(struct i2c_info *ii, uint8_t addr, uint8_t off, uint8_t len,
+    uint8_t *buf)
+{
+	struct ifi2creq req;
+	int i, l;
+
+	if (ii->error != 0)
+		return (ii->error);
+
+	ii->ifr->ifr_data = (caddr_t)&req;
+
+	i = 0;
+	l = 0;
+	memset(&req, 0, sizeof(req));
+	req.dev_addr = addr;
+	req.offset = off;
+	req.len = len;
+
+	while (len > 0) {
+		l = (len > sizeof(req.data)) ? sizeof(req.data) : len;
+		req.len = l;
+		if (ioctl(ii->fd, SIOCGI2C, ii->ifr) != 0) {
+			ii->error = errno;
+			return (errno);
+		}
+
+		memcpy(&buf[i], req.data, l);
+		len -= l;
+		i += l;
+		req.offset += l;
+	}
+
+	return (0);
+}
+
+static void
+dump_i2c_data(struct i2c_info *ii, uint8_t addr, uint8_t off, uint8_t len)
+{
+	unsigned char buf[16];
+	int i, read;
+
+	while (len > 0) {
+		memset(buf, 0, sizeof(buf));
+		read = (len > sizeof(buf)) ? sizeof(buf) : len;
+		read_i2c(ii, addr, off, read, buf);
+		if (ii->error != 0) {
+			fprintf(stderr, "Error reading i2c info\n");
+			return;
+		}
+
+		printf("\t");
+		for (i = 0; i < read; i++)
+			printf("%02X ", buf[i]);
+		printf("\n");
+		len -= read;
+		off += read;
+	}
+}
+
+static void
+print_qsfp_status(struct i2c_info *ii, int verbose)
+{
+	char buf[80], buf2[40], buf3[40];
+	uint8_t diag_type;
+	uint32_t bitrate;
+	int i;
+
+	/* Read diagnostic monitoring type */
+	read_i2c(ii, SFF_8436_BASE, SFF_8436_DIAG_TYPE, 1, (caddr_t)&diag_type);
+	if (ii->error != 0)
+		return;
+
+	/*
+	 * Read monitoring data it is supplied.
+	 * XXX: It is not exactly clear from standard
+	 * how one can specify lack of measurements (passive cables case).
+	 */
+	if (diag_type != 0)
+		ii->do_diag = 1;
+	ii->qsfp = 1;
+
+	/* Transceiver type */
+	get_qsfp_identifier(ii, buf, sizeof(buf));
+	get_qsfp_transceiver_class(ii, buf2, sizeof(buf2));
+	get_qsfp_connector(ii, buf3, sizeof(buf3));
+	if (ii->error == 0)
+		printf("\tplugged: %s %s (%s)\n", buf, buf2, buf3);
+	print_sfp_vendor(ii, buf, sizeof(buf));
+	if (ii->error == 0)
+		printf("\t%s\n", buf);
+
+	if (verbose > 1) {
+		get_qsfp_rev_compliance(ii, buf, sizeof(buf));
+		if (ii->error == 0)
+			printf("\tcompliance level: %s\n", buf);
+
+		bitrate = get_qsfp_br(ii);
+		if (ii->error == 0 && bitrate > 0)
+			printf("\tnominal bitrate: %u Mbps\n", bitrate);
+	}
+
+	/* Request current measurements if they are provided: */
+	if (ii->do_diag != 0) {
+		get_qsfp_temp(ii, buf, sizeof(buf));
+		get_qsfp_voltage(ii, buf2, sizeof(buf2));
+		printf("\tmodule temperature: %s voltage: %s\n", buf, buf2);
+		for (i = 1; i <= 4; i++) {
+			get_qsfp_rx_power(ii, buf, sizeof(buf), i);
+			get_qsfp_tx_power(ii, buf2, sizeof(buf2), i);
+			printf("\tlane %d: RX: %s TX: %s\n", i, buf, buf2);
+		}
+	}
+
+	if (verbose > 2) {
+		printf("\n\tSFF8436 DUMP (0xA0 128..255 range):\n");
+		dump_i2c_data(ii, SFF_8436_BASE, 128, 128);
+		printf("\n\tSFF8436 DUMP (0xA0 0..81 range):\n");
+		dump_i2c_data(ii, SFF_8436_BASE, 0, 82);
+	}
+}
+
+static void
+print_sfp_status(struct i2c_info *ii, int verbose)
+{
+	char buf[80], buf2[40], buf3[40];
+	uint8_t diag_type, flags;
+
+	/* Read diagnostic monitoring type */
+	read_i2c(ii, SFF_8472_BASE, SFF_8472_DIAG_TYPE, 1, (caddr_t)&diag_type);
+	if (ii->error != 0)
+		return;
+
+	/*
+	 * Read monitoring data IFF it is supplied AND is
+	 * internally calibrated
+	 */
+	flags = SFF_8472_DDM_DONE | SFF_8472_DDM_INTERNAL;
+	if ((diag_type & flags) == flags)
+		ii->do_diag = 1;
+
+	/* Transceiver type */
+	get_sfp_identifier(ii, buf, sizeof(buf));
+	get_sfp_transceiver_class(ii, buf2, sizeof(buf2));
+	get_sfp_connector(ii, buf3, sizeof(buf3));
+	if (ii->error == 0)
+		printf("\tplugged: %s %s (%s)\n", buf, buf2, buf3);
+	print_sfp_vendor(ii, buf, sizeof(buf));
+	if (ii->error == 0)
+		printf("\t%s\n", buf);
+
+	if (verbose > 5)
+		printf_sfp_transceiver_descr(ii, buf, sizeof(buf));
+	/*
+	 * Request current measurements iff they are provided:
+	 */
+	if (ii->do_diag != 0) {
+		get_sfp_temp(ii, buf, sizeof(buf));
+		get_sfp_voltage(ii, buf2, sizeof(buf2));
+		printf("\tmodule temperature: %s Voltage: %s\n", buf, buf2);
+		get_sfp_rx_power(ii, buf, sizeof(buf));
+		get_sfp_tx_power(ii, buf2, sizeof(buf2));
+		printf("\tRX: %s TX: %s\n", buf, buf2);
+	}
+
+	if (verbose > 2) {
+		printf("\n\tSFF8472 DUMP (0xA0 0..127 range):\n");
+		dump_i2c_data(ii, SFF_8472_BASE, 0, 128);
+	}
+}
+
+void
+sfp_status(int s, struct ifreq *ifr, int verbose)
+{
+	struct i2c_info ii;
+	uint8_t id_byte;
+
+	/* Prepare necessary into pass to i2c reader */
+	memset(&ii, 0, sizeof(ii));
+	ii.fd = s;
+	ii.ifr = ifr;
+
+	/*
+	 * Try to read byte 0 from i2c:
+	 * Both SFF-8472 and SFF-8436 use it as
+	 * 'identification byte'.
+	 * Stop reading status on zero as value - 
+	 * this might happen in case of empty transceiver slot.
+	 */
+	id_byte = 0;
+	read_i2c(&ii, SFF_8472_BASE, SFF_8472_ID, 1, (caddr_t)&id_byte);
+	if (ii.error != 0 || id_byte == 0)
+		return;
+
+	switch (id_byte) {
+	case SFF_8024_ID_QSFP:
+	case SFF_8024_ID_QSFPPLUS:
+		print_qsfp_status(&ii, verbose);
+		break;
+	default:
+		print_sfp_status(&ii, verbose);
+	};
+}
+