kernel/git/stable/linux.git/drivers/net/loopback.c, branch linux-4.11.y

net: Fix inconsistent teardown and release of private netdev state.

2017-07-05T12:41:34+00:00

[ Upstream commit cf124db566e6b036b8bcbe8decbed740bdfac8c6 ] Network devices can allocate reasources and private memory using netdev_ops->ndo_init(). However, the release of these resources can occur in one of two different places. Either netdev_ops->ndo_uninit() or netdev->destructor(). The decision of which operation frees the resources depends upon whether it is necessary for all netdev refs to be released before it is safe to perform the freeing. netdev_ops->ndo_uninit() presumably can occur right after the NETDEV_UNREGISTER notifier completes and the unicast and multicast address lists are flushed. netdev->destructor(), on the other hand, does not run until the netdev references all go away. Further complicating the situation is that netdev->destructor() almost universally does also a free_netdev(). This creates a problem for the logic in register_netdevice(). Because all callers of register_netdevice() manage the freeing of the netdev, and invoke free_netdev(dev) if register_netdevice() fails. If netdev_ops->ndo_init() succeeds, but something else fails inside of register_netdevice(), it does call ndo_ops->ndo_uninit(). But it is not able to invoke netdev->destructor(). This is because netdev->destructor() will do a free_netdev() and then the caller of register_netdevice() will do the same. However, this means that the resources that would normally be released by netdev->destructor() will not be. Over the years drivers have added local hacks to deal with this, by invoking their destructor parts by hand when register_netdevice() fails. Many drivers do not try to deal with this, and instead we have leaks. Let's close this hole by formalizing the distinction between what private things need to be freed up by netdev->destructor() and whether the driver needs unregister_netdevice() to perform the free_netdev(). netdev->priv_destructor() performs all actions to free up the private resources that used to be freed by netdev->destructor(), except for free_netdev(). netdev->needs_free_netdev is a boolean that indicates whether free_netdev() should be done at the end of unregister_netdevice(). Now, register_netdevice() can sanely release all resources after ndo_ops->ndo_init() succeeds, by invoking both ndo_ops->ndo_uninit() and netdev->priv_destructor(). And at the end of unregister_netdevice(), we invoke netdev->priv_destructor() and optionally call free_netdev(). Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-02-11T07:31:11+00:00

net: introduce device min_header_len

2017-02-08T18:56:37+00:00

The stack must not pass packets to device drivers that are shorter than the minimum link layer header length. Previously, packet sockets would drop packets smaller than or equal to dev->hard_header_len, but this has false positives. Zero length payload is used over Ethernet. Other link layer protocols support variable length headers. Support for validation of these protocols removed the min length check for all protocols. Introduce an explicit dev->min_header_len parameter and drop all packets below this value. Initially, set it to non-zero only for Ethernet and loopback. Other protocols can follow in a patch to net-next. Fixes: 9ed988cd5915 ("packet: validate variable length ll headers") Reported-by: Sowmini Varadhan Signed-off-by: Willem de Bruijn Acked-by: Eric Dumazet Acked-by: Sowmini Varadhan Signed-off-by: David S. Miller

net: make ndo_get_stats64 a void function

2017-01-08T22:51:44+00:00

The network device operation for reading statistics is only called in one place, and it ignores the return value. Having a structure return value is potentially confusing because some future driver could incorrectly assume that the return value was used. Fix all drivers with ndo_get_stats64 to have a void function. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller

Replace with globally

2016-12-24T19:46:01+00:00

This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*' sed -i -e "s!$PATT!#include !" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro Signed-off-by: Linus Torvalds

loopback: make use of NETIF_F_GSO_SOFTWARE

2016-06-03T23:37:21+00:00

NETIF_F_GSO_SOFTWARE was defined to list all GSO software types, so lets make use of it in loopback code. Note that veth/vxlan/others already uses it. Within this patch series, this patch causes lo to pick up SCTP GSO feature automatically (as it's added to NETIF_F_GSO_SOFTWARE) and thus avoiding segmentation if possible. Signed-off-by: Marcelo Ricardo Leitner Tested-by: Xin Long Signed-off-by: David S. Miller

sctp: Rename NETIF_F_SCTP_CSUM to NETIF_F_SCTP_CRC

2015-12-15T21:49:58+00:00

The SCTP checksum is really a CRC and is very different from the standards 1's complement checksum that serves as the checksum for IP protocols. This offload interface is also very different. Rename NETIF_F_SCTP_CSUM to NETIF_F_SCTP_CRC to highlight these differences. The term CSUM should be reserved in the stack to refer to the standard 1's complement IP checksum. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller

net: loopback: convert to using IFF_NO_QUEUE

2015-08-18T18:55:05+00:00

Signed-off-by: Phil Sutter Signed-off-by: David S. Miller

net: better IFF_XMIT_DST_RELEASE support

2014-10-07T17:22:11+00:00

Testing xmit_more support with netperf and connected UDP sockets, I found strange dst refcount false sharing. Current handling of IFF_XMIT_DST_RELEASE is not optimal. Dropping dst in validate_xmit_skb() is certainly too late in case packet was queued by cpu X but dequeued by cpu Y The logical point to take care of drop/force is in __dev_queue_xmit() before even taking qdisc lock. As Julian Anastasov pointed out, need for skb_dst() might come from some packet schedulers or classifiers. This patch adds new helper to cleanly express needs of various drivers or qdiscs/classifiers. Drivers that need skb_dst() in their ndo_start_xmit() should call following helper in their setup instead of the prior : dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; -> netif_keep_dst(dev); Instead of using a single bit, we use two bits, one being eventually rebuilt in bonding/team drivers. The other one, is permanent and blocks IFF_XMIT_DST_RELEASE being rebuilt in bonding/team. Eventually, we could add something smarter later. Signed-off-by: Eric Dumazet Cc: Julian Anastasov Signed-off-by: David S. Miller

net: set name_assign_type in alloc_netdev()

2014-07-15T23:12:48+00:00

Extend alloc_netdev{,_mq{,s}}() to take name_assign_type as argument, and convert all users to pass NET_NAME_UNKNOWN. Coccinelle patch: @@ expression sizeof_priv, name, setup, txqs, rxqs, count; @@ ( -alloc_netdev_mqs(sizeof_priv, name, setup, txqs, rxqs) +alloc_netdev_mqs(sizeof_priv, name, NET_NAME_UNKNOWN, setup, txqs, rxqs) | -alloc_netdev_mq(sizeof_priv, name, setup, count) +alloc_netdev_mq(sizeof_priv, name, NET_NAME_UNKNOWN, setup, count) | -alloc_netdev(sizeof_priv, name, setup) +alloc_netdev(sizeof_priv, name, NET_NAME_UNKNOWN, setup) ) v9: move comments here from the wrong commit Signed-off-by: Tom Gundersen Reviewed-by: David Herrmann Signed-off-by: David S. Miller