--- /dev/null
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/if_arp.h>
+#include <net/rtnetlink.h>
+#include <net/sock.h>
+#include <net/af_vsock.h>
+#include <uapi/linux/vsockmon.h>
+#include <linux/virtio_vsock.h>
+
+/* Virtio transport max packet size plus header */
+#define DEFAULT_MTU (VIRTIO_VSOCK_MAX_PKT_BUF_SIZE + \
+ sizeof(struct af_vsockmon_hdr))
+
+struct pcpu_lstats {
+ u64 rx_packets;
+ u64 rx_bytes;
+ struct u64_stats_sync syncp;
+};
+
+static int vsockmon_dev_init(struct net_device *dev)
+{
+ dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
+ if (!dev->lstats)
+ return -ENOMEM;
+ return 0;
+}
+
+static void vsockmon_dev_uninit(struct net_device *dev)
+{
+ free_percpu(dev->lstats);
+}
+
+struct vsockmon {
+ struct vsock_tap vt;
+};
+
+static int vsockmon_open(struct net_device *dev)
+{
+ struct vsockmon *vsockmon = netdev_priv(dev);
+
+ vsockmon->vt.dev = dev;
+ vsockmon->vt.module = THIS_MODULE;
+ return vsock_add_tap(&vsockmon->vt);
+}
+
+static int vsockmon_close(struct net_device *dev)
+{
+ struct vsockmon *vsockmon = netdev_priv(dev);
+
+ return vsock_remove_tap(&vsockmon->vt);
+}
+
+static netdev_tx_t vsockmon_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ int len = skb->len;
+ struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats);
+
+ u64_stats_update_begin(&stats->syncp);
+ stats->rx_bytes += len;
+ stats->rx_packets++;
+ u64_stats_update_end(&stats->syncp);
+
+ dev_kfree_skb(skb);
+
+ return NETDEV_TX_OK;
+}
+
+static void
+vsockmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
+{
+ int i;
+ u64 bytes = 0, packets = 0;
+
+ for_each_possible_cpu(i) {
+ const struct pcpu_lstats *vstats;
+ u64 tbytes, tpackets;
+ unsigned int start;
+
+ vstats = per_cpu_ptr(dev->lstats, i);
+
+ do {
+ start = u64_stats_fetch_begin_irq(&vstats->syncp);
+ tbytes = vstats->rx_bytes;
+ tpackets = vstats->rx_packets;
+ } while (u64_stats_fetch_retry_irq(&vstats->syncp, start));
+
+ packets += tpackets;
+ bytes += tbytes;
+ }
+
+ stats->rx_packets = packets;
+ stats->tx_packets = 0;
+
+ stats->rx_bytes = bytes;
+ stats->tx_bytes = 0;
+}
+
+static int vsockmon_is_valid_mtu(int new_mtu)
+{
+ return new_mtu >= (int)sizeof(struct af_vsockmon_hdr);
+}
+
+static int vsockmon_change_mtu(struct net_device *dev, int new_mtu)
+{
+ if (!vsockmon_is_valid_mtu(new_mtu))
+ return -EINVAL;
+
+ dev->mtu = new_mtu;
+ return 0;
+}
+
+static const struct net_device_ops vsockmon_ops = {
+ .ndo_init = vsockmon_dev_init,
+ .ndo_uninit = vsockmon_dev_uninit,
+ .ndo_open = vsockmon_open,
+ .ndo_stop = vsockmon_close,
+ .ndo_start_xmit = vsockmon_xmit,
+ .ndo_get_stats64 = vsockmon_get_stats64,
+ .ndo_change_mtu = vsockmon_change_mtu,
+};
+
+static u32 always_on(struct net_device *dev)
+{
+ return 1;
+}
+
+static const struct ethtool_ops vsockmon_ethtool_ops = {
+ .get_link = always_on,
+};
+
+static void vsockmon_setup(struct net_device *dev)
+{
+ dev->type = ARPHRD_VSOCKMON;
+ dev->priv_flags |= IFF_NO_QUEUE;
+
+ dev->netdev_ops = &vsockmon_ops;
+ dev->ethtool_ops = &vsockmon_ethtool_ops;
+ dev->destructor = free_netdev;
+
+ dev->features = NETIF_F_SG | NETIF_F_FRAGLIST |
+ NETIF_F_HIGHDMA | NETIF_F_LLTX;
+
+ dev->flags = IFF_NOARP;
+
+ dev->mtu = DEFAULT_MTU;
+}
+
+static struct rtnl_link_ops vsockmon_link_ops __read_mostly = {
+ .kind = "vsockmon",
+ .priv_size = sizeof(struct vsockmon),
+ .setup = vsockmon_setup,
+};
+
+static __init int vsockmon_register(void)
+{
+ return rtnl_link_register(&vsockmon_link_ops);
+}
+
+static __exit void vsockmon_unregister(void)
+{
+ rtnl_link_unregister(&vsockmon_link_ops);
+}
+
+module_init(vsockmon_register);
+module_exit(vsockmon_unregister);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Gerard Garcia <ggarcia@deic.uab.cat>");
+MODULE_DESCRIPTION("Vsock monitoring device. Based on nlmon device.");
+MODULE_ALIAS_RTNL_LINK("vsockmon");
--- /dev/null
+#ifndef _UAPI_VSOCKMON_H
+#define _UAPI_VSOCKMON_H
+
+#include <linux/virtio_vsock.h>
+
+/*
+ * vsockmon is the AF_VSOCK packet capture device. Packets captured have the
+ * following layout:
+ *
+ * +-----------------------------------+
+ * | vsockmon header |
+ * | (struct af_vsockmon_hdr) |
+ * +-----------------------------------+
+ * | transport header |
+ * | (af_vsockmon_hdr->len bytes long) |
+ * +-----------------------------------+
+ * | payload |
+ * | (until end of packet) |
+ * +-----------------------------------+
+ *
+ * The vsockmon header is a transport-independent description of the packet.
+ * It duplicates some of the information from the transport header so that
+ * no transport-specific knowledge is necessary to process packets.
+ *
+ * The transport header is useful for low-level transport-specific packet
+ * analysis. Transport type is given in af_vsockmon_hdr->transport and
+ * transport header length is given in af_vsockmon_hdr->len.
+ *
+ * If af_vsockmon_hdr->op is AF_VSOCK_OP_PAYLOAD then the payload follows the
+ * transport header. Other ops do not have a payload.
+ */
+
+struct af_vsockmon_hdr {
+ __le64 src_cid;
+ __le64 dst_cid;
+ __le32 src_port;
+ __le32 dst_port;
+ __le16 op; /* enum af_vsockmon_op */
+ __le16 transport; /* enum af_vsockmon_transport */
+ __le16 len; /* Transport header length */
+ __u8 reserved[2];
+};
+
+enum af_vsockmon_op {
+ AF_VSOCK_OP_UNKNOWN = 0,
+ AF_VSOCK_OP_CONNECT = 1,
+ AF_VSOCK_OP_DISCONNECT = 2,
+ AF_VSOCK_OP_CONTROL = 3,
+ AF_VSOCK_OP_PAYLOAD = 4,
+};
+
+enum af_vsockmon_transport {
+ AF_VSOCK_TRANSPORT_UNKNOWN = 0,
+ AF_VSOCK_TRANSPORT_NO_INFO = 1, /* No transport information */
+
+ /* Transport header type: struct virtio_vsock_hdr */
+ AF_VSOCK_TRANSPORT_VIRTIO = 2,
+};
+
+#endif
projects / platform / kernel / linux-rpi3.git / commitdiff