[PATCH v2 3/3] VSOCK: Add virtio vsock vsockmon hooks

[ggarcia]

From: Gerard Garcia <ggar...@deic.uab.cat>

Add hooks to the virtio transport host driver to deliver a copy of
the received and sent messages to all vsockmon virtual network devices.

Signed-off-by: Gerard Garcia <ggar...@deic.uab.cat>
---
 drivers/vhost/vsock.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index e3b30ea..4670c3c 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -15,8 +15,10 @@
 #include <net/sock.h>
 #include <linux/virtio_vsock.h>
 #include <linux/vhost.h>
+#include <linux/skbuff.h>
 
 #include <net/af_vsock.h>
+#include <uapi/linux/vsockmon.h>
 #include "vhost.h"
 
 #define VHOST_VSOCK_DEFAULT_HOST_CID   2
@@ -45,6 +47,68 @@ struct vhost_vsock {
        u32 guest_cid;
 };
 
+static struct sk_buff *
+virtio_vsock_pkt_to_vsockmon_skb(struct virtio_vsock_pkt *pkt)
+{
+       struct sk_buff *skb;
+       struct af_vsockmon_hdr *hdr;
+       unsigned char *t_hdr, *payload;
+
+       u32 skb_len = sizeof(*hdr) + sizeof(pkt->hdr) +
+               pkt->len;
+
+       skb = alloc_skb(skb_len, GFP_ATOMIC);
+       if (!skb)
+               return NULL;
+
+       hdr = (struct af_vsockmon_hdr *) skb_put(skb, sizeof(*hdr));
+
+       hdr->src_cid = pkt->hdr.src_cid;
+       hdr->src_port = pkt->hdr.src_port;
+       hdr->dst_cid = pkt->hdr.dst_cid;
+       hdr->dst_port = pkt->hdr.dst_port;
+       hdr->t = cpu_to_le16(AF_VSOCK_T_VIRTIO);
+       hdr->len = cpu_to_le16(sizeof(pkt->hdr));
+
+       switch(cpu_to_le16(pkt->hdr.op)) {
+       case VIRTIO_VSOCK_OP_REQUEST:
+       case VIRTIO_VSOCK_OP_RESPONSE:
+               hdr->op = cpu_to_le16(AF_VSOCK_OP_CONNECT);
+               break;
+       case VIRTIO_VSOCK_OP_RST:
+       case VIRTIO_VSOCK_OP_SHUTDOWN:
+               hdr->op = cpu_to_le16(AF_VSOCK_OP_DISCONNECT);
+               break;
+       case VIRTIO_VSOCK_OP_RW:
+               hdr->op = cpu_to_le16(AF_VSOCK_OP_PAYLOAD);
+               break;
+       case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
+       case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
+               hdr->op = cpu_to_le16(AF_VSOCK_OP_CONTROL);
+               break;
+       default:
+               hdr->op = cpu_to_le16(AF_VSOCK_OP_UNKNOWN);
+               break;
+       }
+
+       t_hdr = skb_put(skb, sizeof(pkt->hdr));
+       memcpy(t_hdr, &pkt->hdr, sizeof(pkt->hdr));
+
+       if (pkt->len) {
+               payload = skb_put(skb, pkt->len);
+               memcpy(payload, pkt->buf, pkt->len);
+       }
+
+       return skb;
+}
+
+static void vsock_deliver_tap_pkt(struct virtio_vsock_pkt *pkt)
+{
+       struct sk_buff *skb = virtio_vsock_pkt_to_vsockmon_skb(pkt);
+       if (skb)
+               vsock_deliver_tap(skb);
+}
+
 static u32 vhost_transport_get_local_cid(void)
 {
        return VHOST_VSOCK_DEFAULT_HOST_CID;
@@ -168,6 +232,11 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
                                restart_tx = true;
                }
 
+               /* Deliver to monitoring devices all correctly transmitted
+                * packets.
+                */
+               vsock_deliver_tap_pkt(pkt);
+
                virtio_transport_free_pkt(pkt);
        }
        if (added)
@@ -338,6 +407,9 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work 
*work)
 
                len = pkt->len;
 
+               /* Deliver to monitoring devices all received packets */
+               vsock_deliver_tap_pkt(pkt);
+
                /* Only accept correctly addressed packets */
                if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid)
                        virtio_transport_recv_pkt(pkt);
-- 
2.9.1