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.voukela...@linn.co.uk> --- MAINTAINERS | 6 + drivers/net/Kconfig | 2 + drivers/net/Makefile | 2 + drivers/net/pkt-sniffer/Kconfig | 8 + drivers/net/pkt-sniffer/Makefile | 3 + drivers/net/pkt-sniffer/core/module.c | 37 +++++ drivers/net/pkt-sniffer/core/netdev.c | 254 ++++++++++++++++++++++++++++++++ drivers/net/pkt-sniffer/core/snf_core.h | 60 ++++++++ include/uapi/linux/pkt_sniffer.h | 33 +++++ 9 files changed, 405 insertions(+) create mode 100644 drivers/net/pkt-sniffer/Kconfig create mode 100644 drivers/net/pkt-sniffer/Makefile create mode 100644 drivers/net/pkt-sniffer/core/module.c create mode 100644 drivers/net/pkt-sniffer/core/netdev.c create mode 100644 drivers/net/pkt-sniffer/core/snf_core.h create mode 100644 include/uapi/linux/pkt_sniffer.h diff --git a/MAINTAINERS b/MAINTAINERS index aaa039d..7d882de 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5754,6 +5754,12 @@ M: Sasha Levin <sasha.le...@oracle.com> S: Maintained F: tools/lib/lockdep/ +LINN PACKET SNIFFER DRIVER +M: Stathis Voukelatos <stathis.voukela...@linn.co.uk> +S: Maintained +F: drivers/net/pkt-sniffer/ +F: Documentation/devicetree/bindings/net/linn-ether-packet-sniffer.txt + LINUX FOR IBM pSERIES (RS/6000) M: Paul Mackerras <pau...@au.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..56ed84e 100644 --- a/drivers/net/Makefile +++ b/drivers/net/Makefile @@ -66,3 +66,5 @@ 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..53ffcc1 --- /dev/null +++ b/drivers/net/pkt-sniffer/Kconfig @@ -0,0 +1,8 @@ +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. + diff --git a/drivers/net/pkt-sniffer/Makefile b/drivers/net/pkt-sniffer/Makefile new file mode 100644 index 0000000..31dc396 --- /dev/null +++ b/drivers/net/pkt-sniffer/Makefile @@ -0,0 +1,3 @@ +snf_core-y += core/netdev.o +snf_core-y += core/module.o +obj-$(CONFIG_PKT_SNIFFER) += snf_core.o diff --git a/drivers/net/pkt-sniffer/core/module.c b/drivers/net/pkt-sniffer/core/module.c new file mode 100644 index 0000000..1dbed1f --- /dev/null +++ b/drivers/net/pkt-sniffer/core/module.c @@ -0,0 +1,37 @@ +/* + * Packet sniffer core driver: + * - backend channel management + * - interface to userland as a network I/F + * + * 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.voukela...@linn.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/netdev.c b/drivers/net/pkt-sniffer/core/netdev.c new file mode 100644 index 0000000..ba25cc0 --- /dev/null +++ b/drivers/net/pkt-sniffer/core/netdev.c @@ -0,0 +1,254 @@ +#include <linux/module.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; + + spin_lock_irqsave(&priv->lock, flags); + /* Stop the hardware */ + sch->stop(sch); + /* Set the new command pattern */ + ret = sch->set_pattern(sch, skb->data, skb->len / 2); + /* Restart the hardware */ + 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); + 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..73a30ff --- /dev/null +++ b/drivers/net/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.voukela...@linn.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 *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 + diff --git a/include/uapi/linux/pkt_sniffer.h b/include/uapi/linux/pkt_sniffer.h new file mode 100644 index 0000000..39e9957 --- /dev/null +++ b/include/uapi/linux/pkt_sniffer.h @@ -0,0 +1,33 @@ +/* + * 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.voukela...@linn.co.uk> + */ +#ifndef __PKT_SNIFFER_H +#define __PKT_SNIFFER_H + +/* Commands for the command string + * It consists of a series of bytes in the following format: + * -------------------------------- + * | CMD | DATA | CMD | DATA | .... + * -------------------------------- + */ +#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 + +#endif -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
