[PATCH net-next v4 2/3] Linn packet sniffer core framework
From: Stathis Voukelatos
Date: Tue Feb 24 2015 - 11:50:19 EST
The framework registers each backend sniffer channel as a netdev,
which can be accessed from user space through a raw packet socket.
Packets received from user space are treated as a command string
configuration. Each match event from the backend driver will
generate a packet with the matching bytes plus an optional
timestamp, if configured by the command string.
Signed-off-by: Stathis Voukelatos <stathis.voukelatos@xxxxxxxxxx>
---
MAINTAINERS | 6 +
drivers/net/ethernet/Kconfig | 1 +
drivers/net/ethernet/Makefile | 1 +
drivers/net/ethernet/linn/Kconfig | 25 ++
drivers/net/ethernet/linn/Makefile | 19 ++
.../net/ethernet/linn/pkt-sniffer/core/Makefile | 19 ++
.../net/ethernet/linn/pkt-sniffer/core/snf_core.c | 344 +++++++++++++++++++++
.../net/ethernet/linn/pkt-sniffer/core/snf_core.h | 60 ++++
8 files changed, 475 insertions(+)
create mode 100644 drivers/net/ethernet/linn/Kconfig
create mode 100644 drivers/net/ethernet/linn/Makefile
create mode 100644 drivers/net/ethernet/linn/pkt-sniffer/core/Makefile
create mode 100644 drivers/net/ethernet/linn/pkt-sniffer/core/snf_core.c
create mode 100644 drivers/net/ethernet/linn/pkt-sniffer/core/snf_core.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 0597c5b..6186c0c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5828,6 +5828,12 @@ M: Sasha Levin <sasha.levin@xxxxxxxxxx>
S: Maintained
F: tools/lib/lockdep/
+LINN PACKET SNIFFER DRIVER
+M: Stathis Voukelatos <stathis.voukelatos@xxxxxxxxxx>
+S: Maintained
+F: drivers/net/ethernet/linn/
+F: Documentation/devicetree/bindings/net/linn-ether-packet-sniffer.txt
+
LINUX FOR IBM pSERIES (RS/6000)
M: Paul Mackerras <paulus@xxxxxxxxxx>
W: http://www.ibm.com/linux/ltc/projects/ppc
diff --git a/drivers/net/ethernet/Kconfig b/drivers/net/ethernet/Kconfig
index eadcb05..ee4b3ed 100644
--- a/drivers/net/ethernet/Kconfig
+++ b/drivers/net/ethernet/Kconfig
@@ -103,6 +103,7 @@ config LANTIQ_ETOP
---help---
Support for the MII0 inside the Lantiq SoC
+source "drivers/net/ethernet/linn/Kconfig"
source "drivers/net/ethernet/marvell/Kconfig"
source "drivers/net/ethernet/mellanox/Kconfig"
source "drivers/net/ethernet/micrel/Kconfig"
diff --git a/drivers/net/ethernet/Makefile b/drivers/net/ethernet/Makefile
index 1367afc..f8071d3 100644
--- a/drivers/net/ethernet/Makefile
+++ b/drivers/net/ethernet/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_NET_VENDOR_HP) += hp/
obj-$(CONFIG_NET_VENDOR_IBM) += ibm/
obj-$(CONFIG_NET_VENDOR_INTEL) += intel/
obj-$(CONFIG_NET_VENDOR_I825XX) += i825xx/
+obj-$(CONFIG_NET_VENDOR_LINN) += linn/
obj-$(CONFIG_NET_VENDOR_XSCALE) += xscale/
obj-$(CONFIG_IP1000) += icplus/
obj-$(CONFIG_JME) += jme.o
diff --git a/drivers/net/ethernet/linn/Kconfig b/drivers/net/ethernet/linn/Kconfig
new file mode 100644
index 0000000..6654f4e
--- /dev/null
+++ b/drivers/net/ethernet/linn/Kconfig
@@ -0,0 +1,25 @@
+#
+# Linn device configuration
+#
+
+config NET_VENDOR_LINN
+ bool "Linn devices"
+ ---help---
+ Say Y to add support for Linn Products devices.
+
+ Note that the answer to this question doesn't directly affect the
+ kernel: saying N will just cause the configurator to skip all
+ the questions about Linn devices. If you say Y, you will be asked for
+ your specific device in the following questions.
+
+if NET_VENDOR_LINN
+
+menuconfig PKT_SNIFFER
+ tristate "Packet sniffer support"
+ ---help---
+ Say Y to add support for the packet sniffer driver framework.
+
+ The core driver can also be built as a module. If so, the module
+ will be called snf_core.
+
+endif # NET_VENDOR_LINN
diff --git a/drivers/net/ethernet/linn/Makefile b/drivers/net/ethernet/linn/Makefile
new file mode 100644
index 0000000..f3338f3
--- /dev/null
+++ b/drivers/net/ethernet/linn/Makefile
@@ -0,0 +1,19 @@
+###############################################################################
+# Makefile for the Linn Products device drivers
+#
+# 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@xxxxxxxxxx>
+###############################################################################
+
+obj-$(CONFIG_PKT_SNIFFER) += pkt-sniffer/core/
diff --git a/drivers/net/ethernet/linn/pkt-sniffer/core/Makefile b/drivers/net/ethernet/linn/pkt-sniffer/core/Makefile
new file mode 100644
index 0000000..4dc8f11
--- /dev/null
+++ b/drivers/net/ethernet/linn/pkt-sniffer/core/Makefile
@@ -0,0 +1,19 @@
+###############################################################################
+# Makefile for the Linn packet sniffer framework driver
+#
+# Copyright (C) 2015 Linn Products Ltd
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2
+# as published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# Written by:
+# Stathis Voukelatos <stathis.voukelatos@xxxxxxxxxx>
+###############################################################################
+
+obj-$(CONFIG_PKT_SNIFFER) += snf_core.o
diff --git a/drivers/net/ethernet/linn/pkt-sniffer/core/snf_core.c b/drivers/net/ethernet/linn/pkt-sniffer/core/snf_core.c
new file mode 100644
index 0000000..9490943
--- /dev/null
+++ b/drivers/net/ethernet/linn/pkt-sniffer/core/snf_core.c
@@ -0,0 +1,344 @@
+/*
+ * The Linn packet sniffer allows incoming or outgoing data packets
+ * to be parsed, matched against a user-defined data pattern and
+ * timestamped.
+ *
+ * Packet filtering is driven by a user-supplied command string
+ * which consists of a series of interleaved command and data bytes.
+ * ie. the command string has the following format:
+ * --------------------------------
+ * | CMD | DATA | CMD | DATA | ....
+ * --------------------------------
+ * The supported commands and their function is documented in the
+ * corresponding backend driver.
+ * Data returned to the user for each matched packet include selected
+ * data bytes from the packet and optionally a timestamp.
+ *
+ * This module is the packet sniffer core driver that handles
+ * the interface between the H/W backend modules and user space:
+ *
+ * - Each backend sniffer channel is registered as a netdev, eg. Ethernet
+ * TX and RX are two different channels.
+ *
+ * - Access from user space is through AF_PACKET sockets bound to
+ * the netdev
+ *
+ * - User space supplies the command string by writing a packet to a socket.
+ * The packet will contain interleaved commands and data values as
+ * shown above.
+ *
+ * - Data from each packet match event are also returned through an AF_PACKET
+ * socket. Timestamps use the existing kernel timestamping framework,
+ * ie. they are returned to the user through a socket control message
+ * (ancillary data).
+ *
+ * Example usage:
+ * - Open a socket
+ * fd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
+ * - Bind it to the netdev
+ * strcpy(ifr.ifr_name, "snfethrx0");
+ * ioctl(fd, SIOCGIFINDEX, &ifr);
+ * ll.sll_family = AF_PACKET;
+ * ll.sll_ifindex = ifr.ifr_ifindex;
+ * bind(fd, (struct sockaddr *) &ll, sizeof(ll));
+ * - Enable timestamping at the driver and socket level
+ * ioctl(fd, SIOCSHWTSTAMP, &ifr);
+ * opt = SOF_TIMESTAMPING_RX_HARDWARE | SOF_TIMESTAMPING_RAW_HARDWARE;
+ * setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING, &opt, sizeof(opt));
+ * - Configure a command string
+ * char buf[4] = {0x03, 0xAB, 0x4, 0x00};
+ * write(fd, buf, 4);
+ * - Wait for a packet match
+ * select(fd+1, &rfds, NULL, NULL, NULL);
+ * - Read data
+ * recvmsg(fd, &msg, 0);
+ * - Timestamp will be available through a control message
+ * cmsg = CMSG_FIRSTHDR(&msg);
+ * if (cmsg->cmsg_type == SO_TIMESTAMPING)
+ * struct timespec *scmt = CMSG_DATA(cmsg);
+ *
+ * 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@xxxxxxxxxx>
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/net_tstamp.h>
+#include <linux/if_arp.h>
+#include <linux/spinlock.h>
+#include "snf_core.h"
+
+struct snf_ndev_state {
+ struct snf_chan *chan;
+ bool rx_tstamp_enabled;
+ spinlock_t lock;
+};
+
+static int hw_timestamp_set(struct net_device *dev, struct ifreq *ifr)
+{
+ struct snf_ndev_state *priv = netdev_priv(dev);
+ struct hwtstamp_config tconf;
+
+ if (copy_from_user(&tconf, ifr->ifr_data, sizeof(tconf)))
+ return -EFAULT;
+
+ /* No TX timestamping supported.
+ * This interface only receives packets from the sniffer backend
+ */
+ if (tconf.tx_type != HWTSTAMP_TX_OFF)
+ return -ERANGE;
+
+ if (tconf.rx_filter != HWTSTAMP_FILTER_NONE) {
+ /* If timestamping is not enabled in the command string then
+ * we cannot return any RX timestamps
+ */
+ if (!priv->chan->ts_enabled(priv->chan))
+ return -ERANGE;
+ priv->rx_tstamp_enabled = true;
+ tconf.rx_filter = HWTSTAMP_FILTER_ALL;
+ } else {
+ priv->rx_tstamp_enabled = false;
+ }
+
+ return copy_to_user(ifr->ifr_data, &tconf, sizeof(tconf)) ? -EFAULT : 0;
+}
+
+static int hw_timestamp_get(struct net_device *dev, struct ifreq *ifr)
+{
+ struct snf_ndev_state *priv = netdev_priv(dev);
+ struct hwtstamp_config tconf;
+
+ memset(&tconf, 0, sizeof(tconf));
+ tconf.tx_type = HWTSTAMP_TX_OFF;
+ /* We also need to check here that the current command string
+ * will cause timestamps to be generated
+ */
+ tconf.rx_filter = (priv->rx_tstamp_enabled &&
+ priv->chan->ts_enabled(priv->chan)) ?
+ HWTSTAMP_FILTER_ALL : HWTSTAMP_FILTER_NONE;
+
+ return copy_to_user(ifr->ifr_data, &tconf, sizeof(tconf)) ? -EFAULT : 0;
+}
+
+static int snf_init(struct net_device *dev)
+{
+ struct snf_ndev_state *priv = netdev_priv(dev);
+
+ /* Two bytes per command string entry */
+ dev->mtu = priv->chan->max_ptn_entries(priv->chan) * 2;
+ return 0;
+}
+
+static int snf_open(struct net_device *dev)
+{
+ struct snf_ndev_state *priv = netdev_priv(dev);
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&priv->lock, flags);
+ ret = priv->chan->start(priv->chan);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ return ret;
+}
+
+static int snf_stop(struct net_device *dev)
+{
+ struct snf_ndev_state *priv = netdev_priv(dev);
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&priv->lock, flags);
+ ret = priv->chan->stop(priv->chan);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ return ret;
+}
+
+static int snf_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+ switch (cmd) {
+ case SIOCSHWTSTAMP:
+ return hw_timestamp_set(dev, ifr);
+
+ case SIOCGHWTSTAMP:
+ return hw_timestamp_get(dev, ifr);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static int snf_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct snf_ndev_state *priv = netdev_priv(dev);
+ struct snf_chan *sch = priv->chan;
+ unsigned long flags;
+ int ret;
+
+ /* When a packet is sent to the netdev it is assumed to
+ * contain a new command string. So apply it.
+ */
+ spin_lock_irqsave(&priv->lock, flags);
+ sch->stop(sch);
+ ret = sch->set_pattern(sch, skb->data, skb->len / 2);
+ sch->start(sch);
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ if (ret < 0) {
+ dev->stats.tx_dropped++;
+ } else {
+ dev->stats.tx_packets++;
+ dev->stats.tx_bytes += skb->len;
+ }
+
+ dev_kfree_skb(skb);
+ return NETDEV_TX_OK;
+}
+
+static const struct net_device_ops snf_netdev_ops = {
+ .ndo_init = snf_init,
+ .ndo_open = snf_open,
+ .ndo_stop = snf_stop,
+ .ndo_start_xmit = snf_start_xmit,
+ .ndo_do_ioctl = snf_ioctl
+};
+
+static void snf_setup(struct net_device *dev)
+{
+ dev->netdev_ops = &snf_netdev_ops;
+ dev->tx_queue_len = 1;
+ dev->flags = IFF_NOARP;
+ dev->type = ARPHRD_NONE;
+}
+
+/* Initialise netdev for a sniffer channel */
+int snf_channel_add(struct snf_chan *sch, const char *name)
+{
+ int ret;
+ struct net_device *ndev;
+ struct snf_ndev_state *priv;
+
+ ndev = alloc_netdev(sizeof(*priv), name, NET_NAME_UNKNOWN, snf_setup);
+ if (!ndev)
+ return -ENOMEM;
+
+ priv = netdev_priv(ndev);
+ priv->chan = sch;
+ priv->rx_tstamp_enabled = false;
+ spin_lock_init(&priv->lock);
+
+ ret = register_netdev(ndev);
+ if (ret < 0) {
+ free_netdev(ndev);
+ return ret;
+ }
+
+ sch->cstate = ndev;
+ return 0;
+}
+EXPORT_SYMBOL(snf_channel_add);
+
+/* Release netdev for a sniffer channel and free resources */
+int snf_channel_remove(struct snf_chan *sch)
+{
+ struct net_device *ndev = (struct net_device *)sch->cstate;
+
+ unregister_netdev(ndev);
+ free_netdev(ndev);
+ return 0;
+}
+EXPORT_SYMBOL(snf_channel_remove);
+
+/* Send a packet to user space for a sniffer match event */
+int snf_channel_notify_match(struct snf_chan *sch, struct snf_match_evt *mt)
+{
+ struct net_device *ndev = (struct net_device *)sch->cstate;
+ struct snf_ndev_state *priv = netdev_priv(ndev);
+ struct sk_buff *skb;
+ struct skb_shared_hwtstamps *skts;
+
+ skb = netdev_alloc_skb(ndev, mt->len);
+ if (!skb) {
+ ndev->stats.rx_dropped++;
+ return -ENOMEM;
+ }
+
+ skb_put(skb, mt->len);
+ skb_copy_to_linear_data(skb, mt->data, mt->len);
+ if (mt->ts_valid && priv->rx_tstamp_enabled) {
+ skts = skb_hwtstamps(skb);
+ skts->hwtstamp = ns_to_ktime(mt->ts);
+ }
+ ndev->stats.rx_packets++;
+ ndev->stats.rx_bytes += mt->len;
+ netif_rx(skb);
+ return 0;
+}
+EXPORT_SYMBOL(snf_channel_notify_match);
+
+/* Suspend the interface */
+int snf_channel_suspend(struct snf_chan *sch)
+{
+ struct net_device *ndev = (struct net_device *)sch->cstate;
+ struct snf_ndev_state *priv = netdev_priv(ndev);
+ unsigned long flags;
+ int ret;
+
+ if (!netif_running(ndev))
+ return 0;
+
+ spin_lock_irqsave(&priv->lock, flags);
+ ret = sch->stop(sch);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ netif_device_detach(ndev);
+ return ret;
+}
+EXPORT_SYMBOL(snf_channel_suspend);
+
+/* Resume the interface */
+int snf_channel_resume(struct snf_chan *sch)
+{
+ struct net_device *ndev = (struct net_device *)sch->cstate;
+ struct snf_ndev_state *priv = netdev_priv(ndev);
+ unsigned long flags;
+ int ret;
+
+ if (!netif_running(ndev))
+ return 0;
+
+ netif_device_attach(ndev);
+ spin_lock_irqsave(&priv->lock, flags);
+ ret = sch->start(sch);
+ spin_unlock_irqrestore(&priv->lock, flags);
+ return ret;
+}
+EXPORT_SYMBOL(snf_channel_resume);
+
+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/ethernet/linn/pkt-sniffer/core/snf_core.h b/drivers/net/ethernet/linn/pkt-sniffer/core/snf_core.h
new file mode 100644
index 0000000..73a30ff
--- /dev/null
+++ b/drivers/net/ethernet/linn/pkt-sniffer/core/snf_core.h
@@ -0,0 +1,60 @@
+/*
+ * 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@xxxxxxxxxx>
+ */
+#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 *sch);
+ int (*stop)(struct snf_chan *sch);
+ int (*set_pattern)(struct snf_chan *sch, const u8 *pattern, int count);
+ int (*max_ptn_entries)(struct snf_chan *sch);
+ int (*ts_enabled)(struct snf_chan *sch);
+ 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 */
+};
+
+/* Registers a sniffer channel */
+int snf_channel_add(struct snf_chan *sch, const char *name);
+
+/* Removes a sniffer channel */
+int snf_channel_remove(struct snf_chan *sch);
+
+/* Send a packet to user space for a sniffer match event */
+int snf_channel_notify_match(struct snf_chan *sch, struct snf_match_evt *mt);
+
+/* Suspend and resume operations */
+int snf_channel_suspend(struct snf_chan *sch);
+int snf_channel_resume(struct snf_chan *sch);
+
+#endif
+
--
1.9.1
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