[RFC PATCH 5/5] kni: support multiple userspace process working with kni module

[Hemant Agrawal <hemant.agrawal@nxp.com>]

in case of multiple application using the same KNI module,
protect that one application will only clean it's own devices.

Signed-off-by: Hemant Agrawal <hemant.agrawal@nxp.com>
---
 lib/librte_eal/linuxapp/kni/kni_dev.h  |  1 +
 lib/librte_eal/linuxapp/kni/kni_misc.c | 21 +++++++++++++++------
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/lib/librte_eal/linuxapp/kni/kni_dev.h b/lib/librte_eal/linuxapp/kni/kni_dev.h
index 72385ab..c8c856d 100644
--- a/lib/librte_eal/linuxapp/kni/kni_dev.h
+++ b/lib/librte_eal/linuxapp/kni/kni_dev.h
@@ -61,6 +61,7 @@ struct kni_dev {
 	uint32_t core_id;            /* Core ID to bind */
 	char name[RTE_KNI_NAMESIZE]; /* Network device name */
 	struct task_struct *pthread;
+	void *usrctxt; /* User space process context*/
 
 	/* wait queue for req/resp */
 	wait_queue_head_t wq;
diff --git a/lib/librte_eal/linuxapp/kni/kni_misc.c b/lib/librte_eal/linuxapp/kni/kni_misc.c
index 4f99a5e..84f8a99 100644
--- a/lib/librte_eal/linuxapp/kni/kni_misc.c
+++ b/lib/librte_eal/linuxapp/kni/kni_misc.c
@@ -234,6 +234,9 @@ struct kni_net {
 
 	down_write(&knet->kni_list_lock);
 	list_for_each_entry_safe(dev, n, &knet->kni_list_head, list) {
+		/* check for the matching user context */
+		if (dev->usrctxt != inode)
+			continue;
 		/* Stop kernel thread for multiple mode */
 		if (multiple_kthread_on && dev->pthread != NULL) {
 			kthread_stop(dev->pthread);
@@ -311,9 +314,10 @@ struct kni_net {
 }
 
 static int
-kni_ioctl_create(struct net *net, uint32_t ioctl_num,
+kni_ioctl_create(struct inode *inode, uint32_t ioctl_num,
 		unsigned long ioctl_param)
 {
+	struct net *net = current->nsproxy->net_ns;
 	struct kni_net *knet = net_generic(net, kni_net_id);
 	int ret;
 	struct rte_kni_device_info dev_info;
@@ -374,7 +378,8 @@ struct kni_net {
 	dev_net_set(net_dev, net);
 
 	kni = netdev_priv(net_dev);
-
+	
+	kni->usrctxt = inode;
 	kni->net_dev = net_dev;
 	kni->group_id = dev_info.group_id;
 	kni->core_id = dev_info.core_id;
@@ -493,9 +498,10 @@ struct kni_net {
 }
 
 static int
-kni_ioctl_release(struct net *net, uint32_t ioctl_num,
+kni_ioctl_release(struct inode *inode, uint32_t ioctl_num,
 		unsigned long ioctl_param)
 {
+	struct net *net = current->nsproxy->net_ns;
 	struct kni_net *knet = net_generic(net, kni_net_id);
 	int ret = -EINVAL;
 	struct kni_dev *dev, *n;
@@ -516,6 +522,10 @@ struct kni_net {
 
 	down_write(&knet->kni_list_lock);
 	list_for_each_entry_safe(dev, n, &knet->kni_list_head, list) {
+		/* only the owner user process can remove it*/
+		if (dev->usrctxt != inode)
+			continue;
+
 		if (strncmp(dev->name, dev_info.name, RTE_KNI_NAMESIZE) != 0)
 			continue;
 
@@ -540,7 +550,6 @@ struct kni_net {
 kni_ioctl(struct inode *inode, uint32_t ioctl_num, unsigned long ioctl_param)
 {
 	int ret = -EINVAL;
-	struct net *net = current->nsproxy->net_ns;
 
 	pr_debug("IOCTL num=0x%0x param=0x%0lx\n", ioctl_num, ioctl_param);
 
@@ -552,10 +561,10 @@ struct kni_net {
 		/* For test only, not used */
 		break;
 	case _IOC_NR(RTE_KNI_IOCTL_CREATE):
-		ret = kni_ioctl_create(net, ioctl_num, ioctl_param);
+		ret = kni_ioctl_create(inode, ioctl_num, ioctl_param);
 		break;
 	case _IOC_NR(RTE_KNI_IOCTL_RELEASE):
-		ret = kni_ioctl_release(net, ioctl_num, ioctl_param);
+		ret = kni_ioctl_release(inode, ioctl_num, ioctl_param);
 		break;
 	default:
 		pr_debug("IOCTL default\n");
-- 
1.9.1