[RFC PATCH 2/4] eppic/vhost_net_buffers: Introduce changes for kernel 3.19

[Kamalesh Babulal]

Linux kernel commit 56b174256b69 ("net: add rbnode to struct sk_buff"),
moves sk_buff->next into an union of sk_buff->{next/prev/tstamp/rb_node}.
Introduce this structure member change, while traversing the socket
buffer list.

These changes are not compatible with previous kernel versions,
so add vhost_net_buffers script file for kernel version >= 3.19 to
kernel version <= 4.8.

Signed-off-by: Kamalesh Babulal <kamalesh at linux.vnet.ibm.com>
Cc: Atsushi Kumagai <ats-kumagai at wm.jp.nec.com>
---
 eppic_scripts/vhost_net_buffers_3_19_to_4_8.c | 104 ++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 eppic_scripts/vhost_net_buffers_3_19_to_4_8.c

diff --git a/eppic_scripts/vhost_net_buffers_3_19_to_4_8.c b/eppic_scripts/vhost_net_buffers_3_19_to_4_8.c
new file mode 100644
index 0000000..1260acb
--- /dev/null
+++ b/eppic_scripts/vhost_net_buffers_3_19_to_4_8.c
@@ -0,0 +1,104 @@
+string
+vhost_opt()
+{
+	    return "l";
+}
+
+string
+vhost_usage()
+{
+	    return "\n";
+}
+
+static void
+vhost_showusage()
+{
+	    printf("usage : net_ %s", vhost_usage());
+}
+
+string
+vhost_help()
+{
+	    return "Help";
+}
+
+void
+vhost_net(struct vhost_net *net)
+{
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		struct vhost_net_virtqueue *nvq = &net->vqs[i];
+		struct vhost_virtqueue *vq = &nvq->vq;
+		struct socket *sock = (struct socket *)vq->private_data;
+		struct sock *sk = sock->sk;
+
+		struct sk_buff_head *head = &(sk->sk_receive_queue);
+		struct sk_buff *next = sk->sk_receive_queue.next;
+
+		while (next != head)
+		{
+			struct sk_buff *buff = (struct sk_buff *) next;
+
+			if (buff->data_len) {
+				memset((char *)buff->data, 'L', buff->data_len);
+				memset((char *)&(buff->data_len), 'L', 0x4);
+			}
+
+			/*
+			 * .next is the first entry.
+			 */
+			next = (struct sk_buff *)(unsigned long)*buff;
+		}
+
+		head = (struct sk_buff_head *)&(sk->sk_write_queue);
+		next = (struct sk_buff *)sk->sk_write_queue.next;
+
+		while (next != head)
+		{
+			struct sk_buff *buff = (struct sk_buff *) next;
+
+			if (buff->data_len) {
+				memset((char *)buff->data, 'L', buff->data_len);
+				memset((char *)&(buff->data_len), 'L', 0x4);
+			}
+
+			/*
+			 * .next is the first entry.
+			 */
+			next = (struct sk_buff *)(unsigned long)*buff;
+		}
+	}
+}
+
+int
+vhost()
+{
+	struct list_head *head, *next;
+	struct task_struct *tsk;
+
+	tsk = &init_task;
+
+	head = (struct list_head *) &(tsk->tasks);
+	next = (struct list_head *) tsk->tasks.next;
+
+	while (next != head)
+	{
+		int i;
+		struct task_struct *task, *off = 0;
+
+		task = (struct task_struct *)((unsigned long)next - ((unsigned long)&(off->tasks)));
+
+		if (task->files && task->files->fdt) {
+			for (i = 0; i < task->files->fdt->max_fds; i++) {
+				if (task->files->fdt->fd[i] && task->files->fdt->fd[i]->f_op
+					&& task->files->fdt->fd[i]->f_op->open == &vhost_net_open)
+					vhost_net((struct vhost_net *)task->files->fdt->fd[i]->private_data);
+			}
+		}
+
+		next = (struct list_head *)task->tasks.next;
+	}
+
+	return 1;
+}
-- 
2.7.4