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Message-ID: <54C6BFEA.5020101@gmail.com>
Date: Mon, 26 Jan 2015 14:30:02 -0800
From: Florian Fainelli <f.fainelli@...il.com>
To: Stathis Voukelatos <stathisv70@...il.com>, netdev@...r.kernel.org,
linux-kernel@...r.kernel.org, devicetree@...r.kernel.org
CC: Stathis Voukelatos <stathis.voukelatos@...n.co.uk>,
abrestic@...omium.org
Subject: Re: [PATCH] net: Linn Ethernet Packet Sniffer driver
On 23/01/15 02:07, Stathis Voukelatos wrote:
> This patch adds support the Ethernet Packet Sniffer H/W module
> developed by Linn Products Ltd and found in the IMG Pistachio SoC.
> The module allows Ethernet packets to be parsed, matched against
> a user-defined pattern and timestamped. It sits between a 100M
> Ethernet MAC and PHY and is completely passive with respect to
> Ethernet frames.
Is there any latency penalty involved in capturing (or not) packets as
opposed to having this capture HW unused?
>
> Matched packet bytes and timestamp values are returned through a
> FIFO. Timestamps are provided to the module through an externally
> generated Gray-encoded counter.
>
> The command pattern for packet matching is stored in module RAM
> and consists of a sequence of 16-bit entries. Each entry includes
> an 8-bit command code and and 8-bit data value. Valid command
> codes are:
> 0 - Don't care
> 1 - Match: packet data must match command string byte
> 2 - Copy: packet data will be copied to FIFO
> 3 - Match/Stamp: if packet data matches string byte, a timestamp
> is copied into the FIFO
> 4 - Copy/Done: packet data will be copied into the FIFO.
> This command terminates the command string.
>
> The driver consists of two modules:
> - Core: it provides an API to user space using the Generic Netlink
> framework. Specific backend implementations, like the
> Ethernet Packet Sniffer, register one or more channels
> with the Core. For each channel a Genl family is created.
> User space can access a channel by sending Genl messages
> to the Genl family associated with the channel. Packet
> matching events are multicast.
Instead of having this new generic netlink family to control sniffing,
could we imagine registering a netdevice which does not nothing but
still allows for tools like tcpdump, af_packet and other capture tools
to work transparently and just leverage the HW capture?
>
> - Ethernet Packet Sniffer backend: provides the driver for the
> Linn Ethernet Packet Sniffer H/W modules.
>
> The split between a core and backend modules allows software-only
> implementations to be added for platforms where no H/W support
> is available.
>
> Based on 3.19-rc5
>
> Signed-off-by: Stathis Voukelatos <stathis.voukelatos@...n.co.uk>
> ---
> .../bindings/net/linn-ether-packet-sniffer.txt | 27 ++
> .../devicetree/bindings/vendor-prefixes.txt | 1 +
> MAINTAINERS | 7 +
> drivers/net/Kconfig | 2 +
> drivers/net/Makefile | 1 +
> drivers/net/pkt-sniffer/Kconfig | 23 ++
> drivers/net/pkt-sniffer/Makefile | 8 +
> drivers/net/pkt-sniffer/backends/ether/channel.c | 366 ++++++++++++++++++
> drivers/net/pkt-sniffer/backends/ether/channel.h | 76 ++++
> drivers/net/pkt-sniffer/backends/ether/hw.h | 46 +++
> drivers/net/pkt-sniffer/backends/ether/platform.c | 231 +++++++++++
> drivers/net/pkt-sniffer/core/dev_table.c | 124 ++++++
> drivers/net/pkt-sniffer/core/module.c | 37 ++
> drivers/net/pkt-sniffer/core/nl.c | 427 +++++++++++++++++++++
> drivers/net/pkt-sniffer/core/nl.h | 34 ++
> drivers/net/pkt-sniffer/core/snf_core.h | 64 +++
> include/linux/pkt_sniffer.h | 89 +++++
> 17 files changed, 1563 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/net/linn-ether-packet-sniffer.txt
> create mode 100644 drivers/net/pkt-sniffer/Kconfig
> create mode 100644 drivers/net/pkt-sniffer/Makefile
> create mode 100644 drivers/net/pkt-sniffer/backends/ether/channel.c
> create mode 100644 drivers/net/pkt-sniffer/backends/ether/channel.h
> create mode 100644 drivers/net/pkt-sniffer/backends/ether/hw.h
> create mode 100644 drivers/net/pkt-sniffer/backends/ether/platform.c
> create mode 100644 drivers/net/pkt-sniffer/core/dev_table.c
> create mode 100644 drivers/net/pkt-sniffer/core/module.c
> create mode 100644 drivers/net/pkt-sniffer/core/nl.c
> create mode 100644 drivers/net/pkt-sniffer/core/nl.h
> create mode 100644 drivers/net/pkt-sniffer/core/snf_core.h
> create mode 100644 include/linux/pkt_sniffer.h
>
> diff --git a/Documentation/devicetree/bindings/net/linn-ether-packet-sniffer.txt b/Documentation/devicetree/bindings/net/linn-ether-packet-sniffer.txt
> new file mode 100644
> index 0000000..6b6e105
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/linn-ether-packet-sniffer.txt
> @@ -0,0 +1,27 @@
> +* Linn Products Ethernet Packet Sniffer
> +
> +Required properties:
> +- compatible : must be "linn,eth-sniffer"
> +- reg : physical addresses and sizes of registers. Must contain 3 entries:
> + first entry: registers memory space
> + second entry: TX command memory
> + third entry: RX command memory
> +- reg-names : must contain the following 3 entries:
> + "regs", "tx-ram", "rx-ram"
> +- interrupts : sniffer interrupt specifier
> +- clocks : specify the system clock for the peripheral
> +- clock-names : must contain the "sys" entry
> +- fifo-block-words : number of words in one data FIFO entry
> +
> +Example:
> +
> +sniffer@...4a000 {
> + compatible = "linn,eth-sniffer";
> + reg = <0x1814a000 0x100>, <0x1814a400 0x400>, <0x1814a800 0x400>;
> + reg-names = "regs", "tx-ram", "rx-ram";
> + interrupts = <GIC_SHARED 58 IRQ_TYPE_LEVEL_HIGH>;
> + interrupt-names = "eth-sniffer-irq";
> + clocks = <&system_clk>;
> + clock-names = "sys";
> + fifo-block-words = <4>;
> + };
> diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
> index b1df0ad..2c96f35 100644
> --- a/Documentation/devicetree/bindings/vendor-prefixes.txt
> +++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
> @@ -90,6 +90,7 @@ lacie LaCie
> lantiq Lantiq Semiconductor
> lenovo Lenovo Group Ltd.
> lg LG Corporation
> +linn Linn Products Ltd.
> linux Linux-specific binding
> lsi LSI Corp. (LSI Logic)
> lltc Linear Technology Corporation
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 2fa3853..7dbc6e7 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -5708,6 +5708,13 @@ M: Sasha Levin <sasha.levin@...cle.com>
> S: Maintained
> F: tools/lib/lockdep/
>
> +LINN PACKET SNIFFER DRIVER
> +M: Stathis Voukelatos <stathis.voukelatos@...n.co.uk>
> +S: Maintained
> +F: include/linux/pkt_sniffer.h
> +F: drivers/net/pkt-sniffer/
> +F: Documentation/devicetree/bindings/net/linn-ether-packet-sniffer.txt
> +
> LINUX FOR IBM pSERIES (RS/6000)
> M: Paul Mackerras <paulus@...ibm.com>
> W: http://www.ibm.com/linux/ltc/projects/ppc
> diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
> index d6607ee..219c786 100644
> --- a/drivers/net/Kconfig
> +++ b/drivers/net/Kconfig
> @@ -380,4 +380,6 @@ config VMXNET3
>
> source "drivers/net/hyperv/Kconfig"
>
> +source "drivers/net/pkt-sniffer/Kconfig"
> +
> endif # NETDEVICES
> diff --git a/drivers/net/Makefile b/drivers/net/Makefile
> index e25fdd7..441111b 100644
> --- a/drivers/net/Makefile
> +++ b/drivers/net/Makefile
> @@ -66,3 +66,4 @@ obj-$(CONFIG_USB_NET_DRIVERS) += usb/
>
> obj-$(CONFIG_HYPERV_NET) += hyperv/
> obj-$(CONFIG_NTB_NETDEV) += ntb_netdev.o
> +obj-$(CONFIG_PKT_SNIFFER) += pkt-sniffer/
> diff --git a/drivers/net/pkt-sniffer/Kconfig b/drivers/net/pkt-sniffer/Kconfig
> new file mode 100644
> index 0000000..26b4f98
> --- /dev/null
> +++ b/drivers/net/pkt-sniffer/Kconfig
> @@ -0,0 +1,23 @@
> +menuconfig PKT_SNIFFER
> + tristate "Linn packet sniffer support"
> + ---help---
> + Say Y to add support for Linn packet sniffer drivers.
> +
> + The core driver can also be built as a module. If so, the module
> + will be called snf_core.
> +
> +if PKT_SNIFFER
> +
> +config PKT_SNIFFER_ETHER
> + tristate "Ethernet packet sniffer"
> + depends on MIPS
> + default n
> + help
> + Say Y here if you want to use the Linn Ethernet packet sniffer
> + module. It can be found in the upcoming Pistachio SoC by
> + Imagination Technologies.
> +
> + The driver can also be built as a module. If so, the module
> + will be called snf_ether.
> +
> +endif # PKT_SNIFFER
> diff --git a/drivers/net/pkt-sniffer/Makefile b/drivers/net/pkt-sniffer/Makefile
> new file mode 100644
> index 0000000..07e7339
> --- /dev/null
> +++ b/drivers/net/pkt-sniffer/Makefile
> @@ -0,0 +1,8 @@
> +snf_core-y += core/nl.o
> +snf_core-y += core/dev_table.o
> +snf_core-y += core/module.o
> +obj-$(CONFIG_PKT_SNIFFER) += snf_core.o
> +
> +snf_ether-y += backends/ether/platform.o
> +snf_ether-y += backends/ether/channel.o
> +obj-$(CONFIG_PKT_SNIFFER_ETHER) += snf_ether.o
> diff --git a/drivers/net/pkt-sniffer/backends/ether/channel.c b/drivers/net/pkt-sniffer/backends/ether/channel.c
> new file mode 100644
> index 0000000..d483b58
> --- /dev/null
> +++ b/drivers/net/pkt-sniffer/backends/ether/channel.c
> @@ -0,0 +1,366 @@
> +/*
> + * Ethernet Mii packet sniffer driver
> + * - channel functions
> + *
> + * Copyright (C) 2015 Linn Products Ltd
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * Written by:
> + * Stathis Voukelatos <stathis.voukelatos@...n.co.uk>
> + */
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/pkt_sniffer.h>
> +#include "../../core/snf_core.h"
> +#include "hw.h"
> +#include "channel.h"
> +
> +#define to_ether_snf_chan(dev) container_of(dev, struct ether_snf_chan, chan)
> +
> +static int esnf_start(struct snf_chan *dev);
> +static int esnf_stop(struct snf_chan *dev);
> +static int esnf_set_pattern(struct snf_chan *dev, const u8 *pattern, int count);
> +static int esnf_num_recs_avail(struct snf_chan *dev);
> +static int esnf_max_ptn_entries(struct snf_chan *dev);
> +static int esnf_max_match_bytes(struct snf_chan *dev);
> +static int validate_pattern(
> + struct ether_snf_chan *ch,
> + const u8 *buf,
> + int count);
> +static void read_fifo_data(struct ether_snf_chan *ch);
> +static u32 gray_decode(u32 gray);
> +
> +/* Initialises a sniffer channel */
> +int channel_init(
> + struct ether_snf_chan *ch,
> + struct platform_device *pdev,
> + void *regs,
> + int fifo_blk_words,
> + int tx)
> +{
> + struct resource *res;
> + u32 *ptr;
> + int i;
> +
> + ch->regs = regs;
> + ch->dev = &pdev->dev;
> + ch->data_irq_bit = tx ? TX_DATA_IRQ_BIT : RX_DATA_IRQ_BIT;
> + ch->full_irq_bit = tx ? TX_FULL_IRQ_BIT : RX_FULL_IRQ_BIT;
> + ch->reg_enable = ch->regs +
> + (tx ? TX_SNIFFER_ENABLE : RX_SNIFFER_ENABLE);
> + ch->reg_occ = ch->regs + (tx ? TX_FIFO_OCC : RX_FIFO_OCC);
> + ch->reg_fifo = ch->regs + (tx ? TX_FIFO_DAT : RX_FIFO_DAT);
> +
> + /* Retrieve and remap the address space for the command memory */
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> + tx ? "tx-ram" : "rx-ram");
> + if (!res)
> + return -ENOSYS;
> + ch->cmd_ram = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(ch->cmd_ram))
> + return PTR_ERR(ch->cmd_ram);
> +
> + /* It is 2 bytes/command, hence divide by 2 */
> + ch->max_cmds = resource_size(res) / 2;
> +
> + /* Initialise the command pattern RAM */
> + for (i = 0, ptr = ch->cmd_ram; i < resource_size(res); i += 4)
> + iowrite32((PTN_CMD_DONTCARE << 24) | (PTN_CMD_DONTCARE << 8),
> + ptr++);
> +
> + ch->fifo_blk_words = fifo_blk_words;
> + ch->started = 0;
> +
> + /* Register the channel methods */
> + ch->chan.start = esnf_start;
> + ch->chan.stop = esnf_stop;
> + ch->chan.set_pattern = esnf_set_pattern;
> + ch->chan.num_recs_avail = esnf_num_recs_avail;
> + ch->chan.max_ptn_entries = esnf_max_ptn_entries;
> + ch->chan.max_match_bytes = esnf_max_match_bytes;
> +
> + strncpy(ch->name, tx ? "TX" : "RX", MAX_CHAN_NAME_SIZE - 1);
> +
> + dev_dbg(ch->dev, "%s channel initialized\n", ch->name);
> +
> + return 0;
> +}
> +
> +/* Registers the channel with the sniffer core module */
> +int channel_register(struct ether_snf_chan *ch, const char *name)
> +{
> + int id;
> +
> + id = snf_channel_add(&ch->chan, name);
> + if (id < 0)
> + return id;
> +
> + ch->id = id;
> + dev_info(ch->dev, "%s channel added\n", ch->name);
> + return 0;
> +}
> +
> +/* Unregisters the channel */
> +int channel_unregister(struct ether_snf_chan *ch)
> +{
> + int ret;
> +
> + ch->chan.stop(&ch->chan);
> + ret = snf_channel_remove(ch->id);
> + if (!ret)
> + dev_info(ch->dev, "%s channel removed\n", ch->name);
> + return ret;
> +}
> +
> +/* Process match event data */
> +void channel_data_available(struct ether_snf_chan *ch)
> +{
> + int ret;
> +
> + dev_dbg(ch->dev, "%s match event\n", ch->name);
> +
> + read_fifo_data(ch);
> + ret = snf_channel_notify_match(&ch->chan, &ch->evt);
> + if (ret < 0)
> + dev_err(ch->dev, "%s: event notification failed\n", ch->name);
> +}
> +
> +/* Channel methods */
> +
> +/* Enables the channel */
> +static int esnf_start(struct snf_chan *dev)
> +{
> + struct ether_snf_chan *ch = to_ether_snf_chan(dev);
> +
> + if (!ch->started) {
> + /* Enable interrupts */
> + iowrite32(ch->data_irq_bit | ch->full_irq_bit,
> + ch->regs + SET_INTERRUPT_ENABLE);
> + /* Enable the packet matching logic */
> + iowrite32(ENABLE_BIT, ch->reg_enable);
> +
> + ch->started = 1;
> + dev_info(ch->dev, "%s channel started\n", ch->name);
> + } else {
> + dev_dbg(ch->dev, "%s channel already running\n", ch->name);
> + }
> +
> + return 0;
> +}
> +
> +/* Disables the channel */
> +static int esnf_stop(struct snf_chan *dev)
> +{
> + struct ether_snf_chan *ch = to_ether_snf_chan(dev);
> +
> + if (ch->started) {
> + /* Disable interrupts */
> + iowrite32(ch->data_irq_bit | ch->full_irq_bit,
> + ch->regs + CLEAR_INTERRUPT_ENABLE);
> + /* Stop the sniffer channel */
> + iowrite32(0, ch->reg_enable);
> + /* Clear any pending interrupts */
> + iowrite32(ch->data_irq_bit | ch->full_irq_bit,
> + ch->regs + INTERRUPT_STATUS);
> +
> + ch->started = 0;
> + dev_info(ch->dev, "%s channel stopped\n", ch->name);
> + } else {
> + dev_dbg(ch->dev, "%s channel already stopped\n", ch->name);
> + }
> +
> + return 0;
> +}
> +
> +/* Sets the command string (pattern) for the channel
> + * The bytes in the pattern buffer are in the following order:
> + */
> +static int esnf_set_pattern(struct snf_chan *dev, const u8 *pattern, int count)
> +{
> + struct ether_snf_chan *ch = to_ether_snf_chan(dev);
> + int i, shift = 0;
> + u32 val = 0, *ptr;
> +
> + if (ch->started) {
> + dev_err(ch->dev,
> + "cannot apply cmd pattern. %s channel is active\n",
> + ch->name);
> + return -EBUSY;
> + }
> +
> + if (!validate_pattern(ch, pattern, count)) {
> + dev_err(ch->dev,
> + "invalid cmd pattern for %s channel\n",
> + ch->name);
> + return -EINVAL;
> + }
> +
> + for (ptr = ch->cmd_ram, i = 0, shift = 24; i < (2*count); i++) {
> + val |= ((u32)pattern[i]) << shift;
> + if (!shift) {
> + iowrite32(val, ptr++);
> + val = 0;
> + shift = 24;
> + } else {
> + shift -= 8;
> + }
> + }
> + if (shift)
> + iowrite32(val, ptr);
> +
> + return 0;
> +}
> +
> +/* Returns the number of pending match events that are
> + * available to retrieve
> + */
> +static int esnf_num_recs_avail(struct snf_chan *dev)
> +{
> + struct ether_snf_chan *ch = to_ether_snf_chan(dev);
> +
> + return ioread32(ch->reg_occ);
> +}
> +
> +/* Returns max number of commands supported by the channel */
> +static int esnf_max_ptn_entries(struct snf_chan *dev)
> +{
> + struct ether_snf_chan *ch = to_ether_snf_chan(dev);
> +
> + return ch->max_cmds;
> +}
> +
> +/* Returns max number of bytes that can be returned by a match */
> +static int esnf_max_match_bytes(struct snf_chan *dev)
> +{
> + struct ether_snf_chan *ch = to_ether_snf_chan(dev);
> +
> + /* Subtract the word that may be used for the timestamp */
> + return (ch->fifo_blk_words - 1) * 4;
> +}
> +
> +/* Checks if the supplied command string is compatible with the
> + * capabilities of the H/W
> + */
> +static int validate_pattern(struct ether_snf_chan *ch, const u8 *buf, int count)
> +{
> + int i, complete, max_copy_bytes;
> + int ts = 0;
> + int copy_before = 0;
> + int copy_after = 0;
> +
> + if (count > ch->max_cmds)
> + return 0;
> +
> + /* Iterate through the commands in the string */
> + for (i = 0, complete = 0; (i < count) && !complete; i++) {
> + u8 cmd = buf[2*i];
> +
> + switch (cmd) {
> + case PTN_CMD_DONTCARE:
> + case PTN_CMD_MATCH:
> + break;
> +
> + case PTN_CMD_MATCHSTAMP:
> + /* The timestamp needs to be word-aligned in the FIFO
> + * therefore, the number of 'copy' commands before it
> + * needs to be a multiple of 4
> + */
> + if (copy_before & 3)
> + return 0;
> + /* Signal that a timestamp will be present */
> + ts = 1;
> + break;
> +
> + case PTN_CMD_COPY:
> + /* Increment count of bytes that will be returned */
> + if (ts)
> + copy_after++;
> + else
> + copy_before++;
> + break;
> +
> + case PTN_CMD_COPYDONE:
> + /* Increment count of bytes that will be returned
> + * This command terminates the string
> + */
> + if (ts)
> + copy_after++;
> + else
> + copy_before++;
> + complete = 1;
> + break;
> +
> + default:
> + return 0;
> + }
> + }
> +
> + /* Check if the string was properly terminated
> + * and contained valid number of commands
> + */
> + if (complete) {
> + max_copy_bytes = ch->fifo_blk_words * 4;
> + if (ts)
> + max_copy_bytes -= 4;
> + if ((copy_before + copy_after) > max_copy_bytes)
> + return 0;
> + ch->ts_present = ts;
> + ch->nfb_before = copy_before;
> + ch->nfb_after = copy_after;
> + return 1;
> + } else {
> + return 0;
> + }
> +}
> +
> +/* Read a block from the data FIFO */
> +static void read_fifo_data(struct ether_snf_chan *ch)
> +{
> + int i;
> + u32 val, *ptr;
> + int ts = ch->ts_present;
> + int dw = ch->fifo_blk_words;
> + int bytes_before = ch->nfb_before;
> + int bytes_after = ch->nfb_after;
> +
> + ptr = (u32 *)ch->evt.data;
> + for (i = 0; i < dw; i++) {
> + val = ioread32(ch->reg_fifo);
> + if (bytes_before > 0) {
> + /* Bytes before the timestamp */
> + *ptr++ = cpu_to_be32(val);
> + bytes_before -= 4;
> + } else if (ts) {
> + /* Timestamp is Gray encoded */
> + ch->evt.ts = (u64)gray_decode(val);
> + ts = 0;
> + } else if (bytes_after > 0) {
> + /* Bytes after the timestamp */
> + *ptr++ = cpu_to_be32(val);
> + bytes_after -= 4;
> + }
> + }
> +
> + ch->evt.ts_valid = ch->ts_present;
> + ch->evt.len = ch->nfb_before + ch->nfb_after;
> +}
> +
> +/* Gray decoder */
> +static u32 gray_decode(u32 gray)
> +{
> + gray ^= (gray >> 16);
> + gray ^= (gray >> 8);
> + gray ^= (gray >> 4);
> + gray ^= (gray >> 2);
> + gray ^= (gray >> 1);
> + return gray;
> +}
> +
> diff --git a/drivers/net/pkt-sniffer/backends/ether/channel.h b/drivers/net/pkt-sniffer/backends/ether/channel.h
> new file mode 100644
> index 0000000..4f00b33
> --- /dev/null
> +++ b/drivers/net/pkt-sniffer/backends/ether/channel.h
> @@ -0,0 +1,76 @@
> +/*
> + * Ethernet Mii packet sniffer driver
> + * - channel interface
> + *
> + * Copyright (C) 2015 Linn Products Ltd
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * Written by:
> + * Stathis Voukelatos <stathis.voukelatos@...n.co.uk>
> + */
> +#ifndef _ETHER_SNIFFER_CHANNEL_H_
> +#define _ETHER_SNIFFER_CHANNEL_H_
> +
> +#include <linux/platform_device.h>
> +#include "../../core/snf_core.h"
> +
> +#define MAX_CHAN_NAME_SIZE 5
> +
> +struct ether_snf_chan {
> + /* Sniffer core structure */
> + struct snf_chan chan;
> + /* Pointer to device struct */
> + struct device *dev;
> + /* Registers */
> + u8 __iomem *regs;
> + /* Command string memory */
> + u32 __iomem *cmd_ram;
> + /* Bit number for the data IRQ */
> + int data_irq_bit;
> + /* Bit number for the FIFO full IRQ */
> + int full_irq_bit;
> + /* Channel enable register */
> + u8 __iomem *reg_enable;
> + /* Data FIFO register */
> + u8 __iomem *reg_fifo;
> + /* FIFO occupancy register */
> + u8 __iomem *reg_occ;
> + /* Max number of commands in the string */
> + int max_cmds;
> + /* Max matching bytes that can fit in a FIFO block */
> + int fifo_blk_words;
> + /* Number of bytes in the FIFO before the timestamp */
> + int nfb_before;
> + /* Number of bytes in the FIFO after the timestamp */
> + int nfb_after;
> + /* Timestamp present flag */
> + int ts_present;
> + /* ID assigned to channel by the sniffer core */
> + int id;
> + /* Channel active flag */
> + int started;
> + /* Channel name (only used by debug messages) */
> + char name[MAX_CHAN_NAME_SIZE];
> + /* Struct to hold data from a packet match */
> + struct snf_match_evt evt;
> +};
> +
> +int channel_init(
> + struct ether_snf_chan *ch,
> + struct platform_device *pdev,
> + void *regs,
> + int fifo_blk_words,
> + int tx);
> +int channel_register(struct ether_snf_chan *ch, const char *name);
> +int channel_unregister(struct ether_snf_chan *ch);
> +void channel_data_available(struct ether_snf_chan *ch);
> +
> +#endif
> diff --git a/drivers/net/pkt-sniffer/backends/ether/hw.h b/drivers/net/pkt-sniffer/backends/ether/hw.h
> new file mode 100644
> index 0000000..edb1093
> --- /dev/null
> +++ b/drivers/net/pkt-sniffer/backends/ether/hw.h
> @@ -0,0 +1,46 @@
> +/*
> + * Ethernet Mii packet sniffer driver
> + * - register map
> + *
> + * Copyright (C) 2015 Linn Products Ltd
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * Written by:
> + * Stathis Voukelatos <stathis.voukelatos@...n.co.uk>
> + */
> +#ifndef _ETHER_SNIFFER_HW_H_
> +#define _ETHER_SNIFFER_HW_H_
> +
> +#include <linux/bitops.h>
> +
> +/* Registers */
> +#define INTERRUPT_ENABLE 0x00
> +#define SET_INTERRUPT_ENABLE 0x04
> +#define CLEAR_INTERRUPT_ENABLE 0x08
> +#define INTERRUPT_STATUS 0x0c
> +#define TX_FIFO_DAT 0x10
> +#define RX_FIFO_DAT 0x14
> +#define TX_FIFO_OCC 0x18
> +#define RX_FIFO_OCC 0x1c
> +#define TX_SNIFFER_ENABLE 0x20
> +#define RX_SNIFFER_ENABLE 0x24
> +
> +/* IRQ register bits */
> +#define TX_DATA_IRQ_BIT BIT(0)
> +#define RX_DATA_IRQ_BIT BIT(1)
> +#define TX_FULL_IRQ_BIT BIT(2)
> +#define RX_FULL_IRQ_BIT BIT(3)
> +
> +/* Enable register bits */
> +#define ENABLE_BIT BIT(0)
> +
> +#endif
> +
> diff --git a/drivers/net/pkt-sniffer/backends/ether/platform.c b/drivers/net/pkt-sniffer/backends/ether/platform.c
> new file mode 100644
> index 0000000..78e7e1c
> --- /dev/null
> +++ b/drivers/net/pkt-sniffer/backends/ether/platform.c
> @@ -0,0 +1,231 @@
> +/*
> + * Ethernet Mii packet sniffer driver
> + *
> + * Copyright (C) 2015 Linn Products Ltd
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * Written by:
> + * Stathis Voukelatos <stathis.voukelatos@...n.co.uk>
> + */
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/clk.h>
> +#include "../../core/snf_core.h"
> +#include "hw.h"
> +#include "channel.h"
> +
> +static const char esnf_driver_name[] = "eth-sniffer";
> +
> +/* Names for the TX and RX channel.
> + * User space will used these names to access the channels
> + * through the generic netlink interface
> + */
> +static const char tx_channel_name[] = "snf_ether_tx";
> +static const char rx_channel_name[] = "snf_ether_rx";
> +
> +struct ether_snf {
> + u8 __iomem *regs;
> + int irq;
> + struct clk *sys_clk;
> + struct ether_snf_chan txc;
> + struct ether_snf_chan rxc;
> +};
> +
> +/* Interrupt thread function */
> +static irqreturn_t esnf_irq_thread(int irq, void *dev_id)
> +{
> + struct platform_device *pdev = (struct platform_device *)dev_id;
> + struct ether_snf *esnf = (struct ether_snf *)platform_get_drvdata(pdev);
> + u32 irq_status;
> +
> + if (unlikely(esnf->irq != irq))
> + return IRQ_NONE;
> +
> + irq_status = ioread32(esnf->regs + INTERRUPT_STATUS) &
> + ioread32(esnf->regs + INTERRUPT_ENABLE);
> +
> + dev_dbg(&pdev->dev, "irq: 0x%08x\n", irq_status);
> +
> + /* TX FIFO full */
> + if (unlikely(irq_status & TX_FULL_IRQ_BIT))
> + dev_notice(&pdev->dev, "TX FIFO full");
> +
> + /* RX FIFO full */
> + if (unlikely(irq_status & RX_FULL_IRQ_BIT))
> + dev_notice(&pdev->dev, "RX FIFO full");
> +
> + /* TX match data available */
> + if (irq_status & TX_DATA_IRQ_BIT) {
> + dev_dbg(&pdev->dev, "TX data");
> + channel_data_available(&esnf->txc);
> + }
> +
> + /* RX match data available */
> + if (irq_status & RX_DATA_IRQ_BIT) {
> + dev_dbg(&pdev->dev, "RX data");
> + channel_data_available(&esnf->rxc);
> + }
> +
> + /* Clear interrupts */
> + iowrite32(irq_status, esnf->regs + INTERRUPT_STATUS);
> +
> + return IRQ_HANDLED;
> +}
> +
> +/* Called when the packet sniffer device is bound with the driver */
> +static int esnf_driver_probe(struct platform_device *pdev)
> +{
> + struct ether_snf *esnf;
> + struct resource *res;
> + int ret, irq;
> + u32 fifo_blk_words;
> + void __iomem *regs;
> + struct device_node *ofn = pdev->dev.of_node;
> +
> + /* Allocate the device data structure */
> + esnf = devm_kzalloc(&pdev->dev, sizeof(*esnf), GFP_KERNEL);
> + if (!esnf)
> + return -ENOMEM;
> +
> + /* Retrieve and remap register memory space */
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
> + if (!res)
> + return -ENODEV;
> +
> + regs = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(regs))
> + return PTR_ERR(regs);
> +
> + esnf->regs = regs;
> +
> + /* Read the FIFO block size from the DT */
> + if (!ofn)
> + return -ENODEV;
> +
> + ret = of_property_read_u32(
> + ofn,
> + "fifo-block-words",
> + &fifo_blk_words);
> + if (ret < 0)
> + return ret;
> +
> + if (((fifo_blk_words - 1)*4) > MAX_MATCH_BYTES) {
> + dev_err(&pdev->dev,
> + "Invalid FIFO block size entry in device tree\n");
> + return -EINVAL;
> + }
> +
> + esnf->sys_clk = devm_clk_get(&pdev->dev, "sys");
> + if (IS_ERR(esnf->sys_clk)) {
> + ret = PTR_ERR(esnf->sys_clk);
> + return ret;
> + }
> + ret = clk_prepare_enable(esnf->sys_clk);
> + if (ret < 0)
> + return ret;
> +
> + /* Initialise the TX and RX channels */
> + ret = channel_init(&esnf->txc, pdev, regs, fifo_blk_words, 1);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "Failed to init TX channel (%d)\n", ret);
> + goto fail1;
> + }
> + ret = channel_init(&esnf->rxc, pdev, regs, fifo_blk_words, 0);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "Failed to init RX channel (%d)\n", ret);
> + goto fail1;
> + }
> +
> + /* Register the channels with the sniffer core module */
> + ret = channel_register(&esnf->txc, tx_channel_name);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "Failed to register TX chan (%d)\n", ret);
> + goto fail1;
> + }
> + ret = channel_register(&esnf->rxc, rx_channel_name);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "Failed to register RX chan (%d)\n", ret);
> + goto fail2;
> + }
> +
> + platform_set_drvdata(pdev, esnf);
> +
> + /* Register the interrupt handler */
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0)
> + goto fail3;
> + esnf->irq = irq;
> + ret = devm_request_threaded_irq(
> + &pdev->dev,
> + irq,
> + NULL,
> + esnf_irq_thread,
> + IRQF_ONESHOT,
> + esnf_driver_name,
> + pdev);
> + if (ret < 0)
> + goto fail3;
> +
> + return 0;
> +
> +fail3:
> + channel_unregister(&esnf->rxc);
> +fail2:
> + channel_unregister(&esnf->txc);
> +fail1:
> + clk_disable_unprepare(esnf->sys_clk);
> + return ret;
> +}
> +
> +/* Called when the packet sniffer device unregisters with the driver */
> +static int esnf_driver_remove(struct platform_device *pdev)
> +{
> + struct ether_snf *esnf = (struct ether_snf *)platform_get_drvdata(pdev);
> + int ret;
> +
> + ret = channel_unregister(&esnf->txc);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "Failed to unregister TX chan (%d)\n", ret);
> + return ret;
> + }
> + ret = channel_unregister(&esnf->rxc);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "Failed to unregister RX chan (%d)\n", ret);
> + return ret;
> + }
> + clk_disable_unprepare(esnf->sys_clk);
> + return 0;
> +}
> +
> +static const struct of_device_id esnf_of_match_table[] = {
> + { .compatible = "linn,eth-sniffer", .data = NULL },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, esnf_of_match_table);
> +
> +static struct platform_driver esnf_platform_driver = {
> + .driver = {
> + .name = esnf_driver_name,
> + .of_match_table = esnf_of_match_table,
> + },
> + .probe = esnf_driver_probe,
> + .remove = esnf_driver_remove,
> +};
> +
> +module_platform_driver(esnf_platform_driver);
> +
> +MODULE_DESCRIPTION("Linn Ethernet Packet Sniffer");
> +MODULE_AUTHOR("Linn Products Ltd");
> +MODULE_LICENSE("GPL v2");
> +
> diff --git a/drivers/net/pkt-sniffer/core/dev_table.c b/drivers/net/pkt-sniffer/core/dev_table.c
> new file mode 100644
> index 0000000..3a07838
> --- /dev/null
> +++ b/drivers/net/pkt-sniffer/core/dev_table.c
> @@ -0,0 +1,124 @@
> +/*
> + * Packet sniffer core driver: channel management
> + *
> + * Copyright (C) 2014 Linn Products Ltd
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * Written by:
> + * Stathis Voukelatos <stathis.voukelatos@...n.co.uk>
> + */
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include "snf_core.h"
> +#include "nl.h"
> +
> +#define MAX_CHANNELS 256
> +
> +static DEFINE_MUTEX(tlock);
> +
> +static struct snf_chan *dev_tab[MAX_CHANNELS];
> +static unsigned int ref_count[MAX_CHANNELS];
> +
> +static inline int verify_args(int id)
> +{
> + return (id < MAX_CHANNELS);
> +}
> +
> +/* Registers a sniffer channel and returns and id for it */
> +int snf_channel_add(struct snf_chan *dev, const char *name)
> +{
> + int i;
> + int ret = -EEXIST;
> +
> + mutex_lock(&tlock);
> +
> + for (i = 0; i < MAX_CHANNELS; i++) {
> + if (!dev_tab[i]) {
> + /* Initialise the netlink interface for the channel */
> + ret = snf_netlink_init(i, dev, name);
> + if (ret < 0)
> + goto fail;
> +
> + dev_tab[i] = dev;
> + ref_count[i] = 0;
> + mutex_unlock(&tlock);
> + return i;
> + }
> + }
> +
> +fail:
> + mutex_unlock(&tlock);
> + return ret;
> +}
> +EXPORT_SYMBOL(snf_channel_add);
> +
> +/* Removes a sniffer channel */
> +int snf_channel_remove(int id)
> +{
> + int ret = 0;
> + struct snf_chan *dev;
> +
> + if (!verify_args(id))
> + return -EINVAL;
> +
> + mutex_lock(&tlock);
> +
> + dev = dev_tab[id];
> +
> + if (!dev) {
> + ret = -ENODEV;
> + goto fail;
> + }
> +
> + if (ref_count[id] > 0) {
> + ret = -EBUSY;
> + goto fail;
> + }
> +
> + dev_tab[id] = NULL;
> +
> + /* Release netlink API resources */
> + snf_netlink_release(dev);
> +
> +fail:
> + mutex_unlock(&tlock);
> + return ret;
> +}
> +EXPORT_SYMBOL(snf_channel_remove);
> +
> +/* Returns a pointer to the specified sniffer channel
> + * and increments its reference counter
> + */
> +struct snf_chan *snf_channel_get(int id)
> +{
> + struct snf_chan *dev;
> +
> + if (!verify_args(id))
> + return NULL;
> +
> + mutex_lock(&tlock);
> + dev = dev_tab[id];
> + if (dev)
> + ref_count[id]++;
> + mutex_unlock(&tlock);
> +
> + return dev;
> +}
> +
> +/* Decrements the reference counter for the channel */
> +void snf_channel_put(int id)
> +{
> + mutex_lock(&tlock);
> + if (ref_count[id] > 0)
> + ref_count[id]--;
> + mutex_unlock(&tlock);
> +}
> +
> diff --git a/drivers/net/pkt-sniffer/core/module.c b/drivers/net/pkt-sniffer/core/module.c
> new file mode 100644
> index 0000000..af6a1aa
> --- /dev/null
> +++ b/drivers/net/pkt-sniffer/core/module.c
> @@ -0,0 +1,37 @@
> +/*
> + * Packet sniffer core driver:
> + * - backend channel management
> + * - interface to userland via generic netlink
> + *
> + * Copyright (C) 2015 Linn Products Ltd
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * Written by:
> + * Stathis Voukelatos <stathis.voukelatos@...n.co.uk>
> + */
> +#include <linux/module.h>
> +#include <linux/init.h>
> +
> +static int __init snf_core_init(void)
> +{
> + return 0;
> +}
> +
> +static void __exit snf_core_cleanup(void)
> +{
> +}
> +
> +module_init(snf_core_init);
> +module_exit(snf_core_cleanup);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Core packet sniffer driver");
> +MODULE_AUTHOR("Linn Products Ltd");
> diff --git a/drivers/net/pkt-sniffer/core/nl.c b/drivers/net/pkt-sniffer/core/nl.c
> new file mode 100644
> index 0000000..6839147
> --- /dev/null
> +++ b/drivers/net/pkt-sniffer/core/nl.c
> @@ -0,0 +1,427 @@
> +/*
> + * Packet sniffer core driver: generic netlink interface
> + *
> + * Copyright (C) 2015 Linn Products Ltd
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * Written by:
> + * Stathis Voukelatos <stathis.voukelatos@...n.co.uk>
> + */
> +#include <linux/version.h>
> +#include <net/netlink.h>
> +#include <net/genetlink.h>
> +#include <linux/slab.h>
> +#include <linux/module.h>
> +#include <linux/pkt_sniffer.h>
> +#include "snf_core.h"
> +#include "nl.h"
> +
> +/* Netlink API data for a sniffer channel */
> +struct snf_netlink {
> + /* genl family */
> + struct genl_family fml;
> + /* genl operations */
> + struct genl_ops *ops;
> + /* genl mcast group, where sniffer match
> + * events will be sent
> + */
> + struct genl_multicast_group grp;
> +};
> +
> +/* Attribute policies */
> +static struct nla_policy snf_policy[SNF_ATTR_MAX + 1] = {
> + [SNF_ATTR_PATTERN] = { .type = NLA_NESTED },
> +};
> +
> +static struct nla_policy snf_ptn_policy[SNF_ATTR_PTN_MAX + 1] = {
> + [SNF_ATTR_PTN_ENTRY] = { .type = NLA_U16 },
> +};
> +
> +/* Generic Netlink family template definition */
> +static int pre_doit_func(const struct genl_ops *ops,
> + struct sk_buff *skb,
> + struct genl_info *info);
> +
> +static void post_doit_func(const struct genl_ops *ops,
> + struct sk_buff *skb,
> + struct genl_info *info);
> +
> +static struct genl_family snf_family_tmpl = {
> + .id = GENL_ID_GENERATE,
> + .hdrsize = 0,
> + .version = SNF_GNL_VERSION,
> + .maxattr = SNF_ATTR_MAX,
> + .pre_doit = pre_doit_func,
> + .post_doit = post_doit_func
> +};
> +
> +static int send_reply_uint32(
> + struct genl_info *info,
> + int cmd,
> + int attr,
> + u32 val);
> +
> +/* Generic Netlink operations template definition */
> +
> +static int do_it_start(struct sk_buff *skb, struct genl_info *info);
> +static int do_it_stop(struct sk_buff *skb, struct genl_info *info);
> +static int do_it_set_pattern(struct sk_buff *skb, struct genl_info *info);
> +static int do_it_num_rec_avail(struct sk_buff *skb, struct genl_info *info);
> +static int do_it_ptn_max_cmds(struct sk_buff *skb, struct genl_info *info);
> +static int do_it_max_match_bytes(struct sk_buff *skb, struct genl_info *info);
> +
> +#define SNF_GENL_OP(_cmd, _func) \
> + { \
> + .cmd = _cmd, \
> + .policy = snf_policy, \
> + .doit = _func, \
> + .dumpit = NULL, \
> + .flags = 0, \
> + .internal_flags = 0 \
> + }
> +
> +#define SNF_CHAN_OPS \
> + { \
> + SNF_GENL_OP(SNF_CMD_START, do_it_start), \
> + SNF_GENL_OP(SNF_CMD_STOP, do_it_stop), \
> + SNF_GENL_OP(SNF_CMD_SETPATTERN, do_it_set_pattern), \
> + SNF_GENL_OP(SNF_CMD_NUMRECAVAIL, do_it_num_rec_avail), \
> + SNF_GENL_OP(SNF_CMD_PTNMAXCMDS, do_it_ptn_max_cmds), \
> + SNF_GENL_OP(SNF_CMD_MAXMATCHBYTES, do_it_max_match_bytes) \
> + }
> +
> +static struct genl_ops snf_ops_tmpl[] = SNF_CHAN_OPS;
> +
> +#define NUM_GENL_OPS ARRAY_SIZE(snf_ops_tmpl)
> +
> +/* Multicast a netlink event containing data from a sniffer match event.
> + * Data are included in the netlink message as a nested attribute
> + * containing the timestamp (optional) and matching packet bytes
> +*/
> +int snf_channel_notify_match(struct snf_chan *dev, struct snf_match_evt *mt)
> +{
> + int i, ret = 0;
> + struct sk_buff *msg = NULL;
> + void *msg_hdr, *nest_hdr;
> + struct snf_netlink *nl = (struct snf_netlink *)dev->cstate;
> +
> + if (!nl) {
> + ret = -EINVAL;
> + goto fail;
> + }
> +
> + msg = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
> + if (!msg) {
> + ret = -ENOMEM;
> + goto fail;
> + }
> +
> + msg_hdr = genlmsg_put(msg,
> + 0,
> + 0,
> + &nl->fml,
> + 0,
> + SNF_CMD_MATCHEVENT);
> + if (!msg_hdr) {
> + ret = -EMSGSIZE;
> + goto fail;
> + }
> +
> + /* Add the nested attribute with the data */
> + if ((mt->ts_valid) || (mt->len > 0)) {
> + nest_hdr = nla_nest_start(msg, SNF_ATTR_MATCHEVENT);
> + if (!nest_hdr) {
> + ret = -EMSGSIZE;
> + goto fail;
> + }
> + if (mt->ts_valid) {
> + ret = nla_put_u64(msg, SNF_ATTR_MATCH_TS, mt->ts);
> + if (ret < 0)
> + goto fail;
> + }
> + for (i = 0; i < mt->len; i++) {
> + ret = nla_put_u8(msg,
> + SNF_ATTR_MATCH_PKTBYTE,
> + mt->data[i]);
> + if (ret < 0)
> + goto fail;
> + }
> + nla_nest_end(msg, nest_hdr);
> + }
> +
> + ret = genlmsg_end(msg, msg_hdr);
> + if (ret < 0)
> + goto fail;
> + ret = genlmsg_multicast(&nl->fml, msg, 0, 0, GFP_ATOMIC);
> +
> + /* The ESRCH code is returned when there is no socket listening on the
> + * multicast group, so we do not really treat is as an error
> + */
> + if (ret == -ESRCH)
> + ret = 0;
> + return ret;
> +
> +fail:
> + if (msg)
> + nlmsg_free(msg);
> + return ret;
> +}
> +EXPORT_SYMBOL(snf_channel_notify_match);
> +
> +/* Initialise the generic netlink API for a sniffer channel
> + * Registers family, ops and multicast group for events
> + */
> +int snf_netlink_init(int id, struct snf_chan *dev, const char *name)
> +{
> + int i, ret;
> + struct snf_netlink *nl = NULL;
> +
> + nl = kmalloc(sizeof(*nl), GFP_KERNEL);
> + if (!nl) {
> + ret = -ENOMEM;
> + goto fail1;
> + }
> +
> + nl->fml = snf_family_tmpl;
> +
> + /* Set the family name */
> + strncpy(nl->fml.name, name, GENL_NAMSIZ-1);
> +
> + /* Allocate ops array and copy template data */
> + nl->ops = kmalloc(sizeof(snf_ops_tmpl), GFP_KERNEL);
> + if (!nl->ops) {
> + ret = -ENOMEM;
> + goto fail2;
> + }
> + memcpy(nl->ops, snf_ops_tmpl, sizeof(snf_ops_tmpl));
> +
> + /* In the internal_flags field we store the id
> + * of the device the ops belong to
> + */
> + for (i = 0; i < NUM_GENL_OPS; i++)
> + nl->ops[i].internal_flags = id;
> +
> + snprintf(nl->grp.name, GENL_NAMSIZ-1, SNF_EVENT_GRP);
> +
> + ret = _genl_register_family_with_ops_grps(
> + &nl->fml,
> + nl->ops,
> + NUM_GENL_OPS,
> + &nl->grp,
> + 1);
> + if (ret < 0) {
> + pr_err("%s: failed to register family %s (%d)\n",
> + KBUILD_MODNAME, name, ret);
> + goto fail3;
> + }
> +
> + pr_info("%s: registered genl family for channel %d: %s\n",
> + KBUILD_MODNAME, id, name);
> + dev->cstate = nl;
> +
> + return 0;
> +
> +fail3:
> + kfree(nl->ops);
> +fail2:
> + kfree(nl);
> +fail1:
> + return ret;
> +}
> +
> +/* Shuts down the netlink API for a sniffer channel
> + * and frees resources
> + */
> +void snf_netlink_release(struct snf_chan *dev)
> +{
> + struct snf_netlink *nl = (struct snf_netlink *)dev->cstate;
> + /* Unregister family and free ops
> + * NOTE: this will also unregister the ops and the mcast group
> + */
> + genl_unregister_family(&nl->fml);
> + pr_info("%s: unregistered genl family: %s\n",
> + KBUILD_MODNAME, nl->fml.name);
> +
> + kfree(nl->ops);
> + kfree(nl);
> + dev->cstate = NULL;
> +}
> +
> +/* pre_doit function that retrieves a pointer to the sniffer channel device
> + * from the instance and channel number stored in the ops internal_flag field
> + */
> +static int pre_doit_func(const struct genl_ops *ops,
> + struct sk_buff *skb,
> + struct genl_info *info)
> +{
> + info->user_ptr[0] = snf_channel_get(ops->internal_flags);
> + return info->user_ptr[0] ? 0 : -ENODEV;
> +}
> +
> +/* post_doit function that releases a sniffer channel device */
> +static void post_doit_func(const struct genl_ops *ops,
> + struct sk_buff *skb,
> + struct genl_info *info)
> +{
> + snf_channel_put(ops->internal_flags);
> +}
> +
> +/* doit command handlers */
> +
> +/* Start the sniffer channel */
> +static int do_it_start(struct sk_buff *skb, struct genl_info *info)
> +{
> + struct snf_chan *dev = (struct snf_chan *)info->user_ptr[0];
> +
> + return dev->start(dev);
> +}
> +
> +/* Stop the sniffer channel */
> +static int do_it_stop(struct sk_buff *skb, struct genl_info *info)
> +{
> + int ret;
> + struct snf_match_evt mt;
> + struct snf_chan *dev = (struct snf_chan *)info->user_ptr[0];
> +
> + ret = dev->stop(dev);
> + if (ret < 0)
> + return ret;
> +
> + /* Multicast an empty match event to notify any user-space
> + * listeners that the sniffer is stopping
> + */
> + memset(&mt, 0, sizeof(mt));
> + return snf_channel_notify_match(dev, &mt);
> +}
> +
> +/* Set the command pattern. The string is received in a nested
> + * attribute containing a sequence of 16-bit valued.
> + * Each value consists of a command (8 bits) and data (8 bits)
> +*/
> +static int do_it_set_pattern(struct sk_buff *skb, struct genl_info *info)
> +{
> + int ret = 0;
> + int rem, count;
> + struct nlattr *nla;
> + u16 entry;
> + u8 *buf = NULL;
> + struct snf_chan *dev = (struct snf_chan *)info->user_ptr[0];
> + int max_entries = dev->max_ptn_entries(dev);
> +
> + if (!info->attrs[SNF_ATTR_PATTERN]) {
> + ret = -EINVAL;
> + goto fail;
> + }
> +
> + ret = nla_validate_nested(info->attrs[SNF_ATTR_PATTERN],
> + SNF_ATTR_PTN_ENTRY, snf_ptn_policy);
> + if (ret < 0)
> + goto fail;
> +
> + buf = kmalloc(max_entries*2, GFP_KERNEL);
> + if (!buf) {
> + ret = -ENOMEM;
> + goto fail;
> + }
> +
> + /* Iterate over the contents of the nested attribute
> + * and extract into the buffer
> + */
> + count = 0;
> + nla_for_each_nested(nla, info->attrs[SNF_ATTR_PATTERN], rem) {
> + if (count >= max_entries) {
> + ret = -EINVAL;
> + goto fail;
> + }
> + entry = nla_get_u16(nla);
> + buf[2*count] = PTNENTRY_CMD(entry);
> + buf[2*count + 1] = PTNENTRY_DATA(entry);
> + count++;
> + }
> +
> + ret = dev->set_pattern(dev, buf, count);
> +
> +fail:
> + kfree(buf);
> + return ret;
> +}
> +
> +/* Number of pending match events */
> +static int do_it_num_rec_avail(struct sk_buff *skb, struct genl_info *info)
> +{
> + struct snf_chan *dev = (struct snf_chan *)info->user_ptr[0];
> +
> + return send_reply_uint32(
> + info,
> + SNF_CMD_NUMRECAVAIL,
> + SNF_ATTR_NUMRECAVAIL,
> + dev->num_recs_avail(dev));
> +}
> +
> +/* Max number of commands that are supported in the command pattern */
> +static int do_it_ptn_max_cmds(struct sk_buff *skb, struct genl_info *info)
> +{
> + struct snf_chan *dev = (struct snf_chan *)info->user_ptr[0];
> +
> + return send_reply_uint32(
> + info,
> + SNF_CMD_PTNMAXCMDS,
> + SNF_ATTR_PTNMAXCMDS,
> + dev->max_ptn_entries(dev));
> +}
> +
> +/* Max bytes that can be returned by a packet match event */
> +static int do_it_max_match_bytes(struct sk_buff *skb, struct genl_info *info)
> +{
> + struct snf_chan *dev = (struct snf_chan *)info->user_ptr[0];
> +
> + return send_reply_uint32(
> + info,
> + SNF_CMD_MAXMATCHBYTES,
> + SNF_ATTR_MAXMATCHBYTES,
> + dev->max_match_bytes(dev));
> +}
> +
> +/* Helper function for sending a reply containing a single u32 attribute */
> +static int send_reply_uint32(struct genl_info *info, int cmd, int attr, u32 val)
> +{
> + void *hdr;
> + int ret = 0;
> + struct sk_buff *msg;
> + struct snf_chan *dev = (struct snf_chan *)info->user_ptr[0];
> + struct snf_netlink *nl = (struct snf_netlink *)dev->cstate;
> +
> + msg = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
> + if (!msg) {
> + ret = -ENOMEM;
> + goto fail;
> + }
> +
> + hdr = genlmsg_put_reply(msg, info, &nl->fml, 0, cmd);
> + if (!hdr) {
> + ret = -EMSGSIZE;
> + goto fail;
> + }
> + ret = nla_put_u32(msg, attr, val);
> + if (ret < 0)
> + goto fail;
> + ret = genlmsg_end(msg, hdr);
> + if (ret < 0)
> + goto fail;
> +
> + return genlmsg_reply(msg, info);
> +
> +fail:
> + if (msg)
> + nlmsg_free(msg);
> + return ret;
> +}
> +
> diff --git a/drivers/net/pkt-sniffer/core/nl.h b/drivers/net/pkt-sniffer/core/nl.h
> new file mode 100644
> index 0000000..f7bf579
> --- /dev/null
> +++ b/drivers/net/pkt-sniffer/core/nl.h
> @@ -0,0 +1,34 @@
> +/*
> + * Packet sniffer core driver: generic netlink interface
> + *
> + * Copyright (C) 2015 Linn Products Ltd
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * Written by:
> + * Stathis Voukelatos <stathis.voukelatos@...n.co.uk>
> + */
> +#ifndef __SNF_NL_H
> +#define __SNF_NL_H
> +
> +#include <net/genetlink.h>
> +#include "snf_core.h"
> +
> +/* Initialise netlink interface for a sniffer channel,
> + * register netlink families etc.
> + */
> +int snf_netlink_init(int id, struct snf_chan *dev, const char *name);
> +
> +/* Shutdown netlink interface, unregister
> + * families etc.
> + */
> +void snf_netlink_release(struct snf_chan *dev);
> +
> +#endif
> diff --git a/drivers/net/pkt-sniffer/core/snf_core.h b/drivers/net/pkt-sniffer/core/snf_core.h
> new file mode 100644
> index 0000000..062de70
> --- /dev/null
> +++ b/drivers/net/pkt-sniffer/core/snf_core.h
> @@ -0,0 +1,64 @@
> +/*
> + * Packet sniffer core driver
> + * - this header provides the interface to specific backend packet
> + * sniffer implementations
> + *
> + * Copyright (C) 2015 Linn Products Ltd
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * Written by:
> + * Stathis Voukelatos <stathis.voukelatos@...n.co.uk>
> + */
> +#ifndef __SNF_CORE_H
> +#define __SNF_CORE_H
> +
> +#include <linux/types.h>
> +
> +/* This is a global maximum. Each backend will have its own limit */
> +#define MAX_MATCH_BYTES 512
> +
> +/* Sniffer channel data structure */
> +struct snf_chan {
> + int (*start)(struct snf_chan *dev);
> + int (*stop)(struct snf_chan *dev);
> + int (*set_pattern)(struct snf_chan *dev, const u8 *pattern, int count);
> + int (*num_recs_avail)(struct snf_chan *dev);
> + int (*max_ptn_entries)(struct snf_chan *dev);
> + int (*max_match_bytes)(struct snf_chan *dev);
> +
> + void *cstate;
> +};
> +
> +/* Data from a sniffer match event */
> +struct snf_match_evt {
> + int ts_valid; /* flag indicating if timestamp is present */
> + u64 ts; /* timestamp value */
> + u8 data[MAX_MATCH_BYTES]; /* packet data bytes matched by sniffer */
> + int len; /* number of valid bytes in the 'data' buffer */
> +};
> +
> +/* Adds a sniffer channel to the registry */
> +int snf_channel_add(struct snf_chan *dev, const char *name);
> +
> +/* Removes the channel with the specified id from the registry */
> +int snf_channel_remove(int id);
> +
> +/* Returns handle to a channel and increments reference count */
> +struct snf_chan *snf_channel_get(int id);
> +
> +/* Decrements reference count for the specified channel */
> +void snf_channel_put(int id);
> +
> +/* Multicast a notification to user space for a sniffer match event */
> +int snf_channel_notify_match(struct snf_chan *dev, struct snf_match_evt *mt);
> +
> +#endif
> +
> diff --git a/include/linux/pkt_sniffer.h b/include/linux/pkt_sniffer.h
> new file mode 100644
> index 0000000..3e73d14
> --- /dev/null
> +++ b/include/linux/pkt_sniffer.h
> @@ -0,0 +1,89 @@
> +/*
> + * Linn packet sniffer driver interface
> + *
> + * Copyright (C) 2015 Linn Products Ltd
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * Written by:
> + * Stathis Voukelatos <stathis.voukelatos@...n.co.uk>
> + */
> +#ifndef __PKT_SNIFFER_H
> +#define __PKT_SNIFFER_H
> +
> +/* Commands for the pattern string */
> +#define PTN_CMD_DONTCARE 0
> +#define PTN_CMD_MATCH 1
> +#define PTN_CMD_COPY 2
> +#define PTN_CMD_MATCHSTAMP 3
> +#define PTN_CMD_COPYDONE 4
> +
> +/* Creates an entry for the pattern string.
> + * An entry consists of a command byte and a data byte
> +*/
> +#define MAKE_PTN_ENTRY(cmd, data) (((((int)cmd) & 0xff) << 8) | (data & 0xff))
> +/* Gets the cmd and data portion of a pattern string entry */
> +#define PTNENTRY_CMD(val) (((val) >> 8) & 0xff)
> +#define PTNENTRY_DATA(val) ((val) & 0xff)
> +
> +/* Generic Netlink commands */
> +enum {
> + SNF_CMD_UNSPEC,
> + SNF_CMD_START, /* start the sniffer */
> + SNF_CMD_STOP, /* stop the sniffer */
> + SNF_CMD_SETPATTERN, /* set the command pattern */
> + SNF_CMD_NUMRECAVAIL, /* number of pending match events */
> + SNF_CMD_MATCHEVENT, /* match event notification */
> + SNF_CMD_PTNMAXCMDS, /* max number of commands supported */
> + SNF_CMD_MAXMATCHBYTES, /* max number of bytes in match event */
> + __SNF_CMD_MAX
> +};
> +#define SNF_CMD_MAX (__SNF_CMD_MAX - 1)
> +
> +/* Generic Netlink attributes */
> +enum {
> + SNF_ATTR_UNSPEC,
> + SNF_ATTR_PTNMAXCMDS, /* max number of commands supported */
> + SNF_ATTR_PATTERN, /* nested attribute containing commands */
> + SNF_ATTR_NUMRECAVAIL, /* number of pending match events */
> + SNF_ATTR_MATCHEVENT, /* nested attribute for a match event */
> + SNF_ATTR_MAXMATCHBYTES, /* max bytes in a match event */
> + __SNF_ATTR_MAX
> +};
> +#define SNF_ATTR_MAX (__SNF_ATTR_MAX - 1)
> +
> +/* Attributes that are included in the nested attribute
> + * for the command string
> + */
> +enum {
> + SNF_ATTR_PTN_UNSPEC,
> + SNF_ATTR_PTN_ENTRY, /* command entry containing a command id */
> + __SNF_ATTR_PTN_MAX /* and data byte */
> +};
> +#define SNF_ATTR_PTN_MAX (__SNF_ATTR_PTN_MAX - 1)
> +
> +/* Attributes included in the nested attribute
> + * of a match event notification
> + */
> +enum {
> + SNF_ATTR_MATCH_UNSPEC,
> + SNF_ATTR_MATCH_TS, /* timestamp (returned with a match event) */
> + SNF_ATTR_MATCH_PKTBYTE, /* packet data (returned with a match event) */
> + __SNF_ATTR_MATCH_MAX
> +};
> +#define SNF_ATTR_MATCH_MAX (__SNF_ATTR_MATCH_MAX - 1)
> +
> +/* Family version */
> +#define SNF_GNL_VERSION 1
> +
> +/* Multicast group name */
> +#define SNF_EVENT_GRP "snf_evt_grp"
> +
> +#endif
>
--
Florian
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