diff options
| author |   David S. Miller <davem@davemloft.net> | 2016-10-13 09:36:58 -0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-10-13 09:36:58 -0400 |
| commit | 0f505b1ae6794242240e40f7904c8b345fa38c41 (patch) | |
| tree | d5c763c23ce3faa611fa00b386f9a095ad364315 /include | |
| parent | Merge branch 's390-net' (diff) | |
| parent | net: deprecate eth_change_mtu, remove usage (diff) | |
Merge branch 'centralize-netdevice-mtu-bounds-checking'
Jarod Wilson says:
====================
net: centralize net_device MTU bounds checking
While looking into an MTU issue with sfc, I started noticing that almost
every NIC driver with an ndo_change_mtu function implemented almost
exactly the same range checks, and in many cases, that was the only
practical thing their ndo_change_mtu function was doing. Quite a few
drivers have either 68, 64, 60 or 46 as their minimum MTU value checked,
and then various sizes from 1500 to 65535 for their maximum MTU value. We
can remove a whole lot of redundant code here if we simple store min_mtu
and max_mtu in net_device, and check against those in net/core/dev.c's
dev_set_mtu().
This pair of patches looks to introduce centralized MTU range checking
infrastructure, while maintaining compatibility with all existing drivers,
and start to make use of it, converting all eth_change_mtu/ether_setup users
over to this new infra.
Assuming these pass review muster, I've got a ton of follow-on patches to
clean up MTU settings for everything in the kernel with an ndo_change_mtu.
This work is all staged in a (rebasing) git tree here:
https://github.com/jarodwilson/linux-muck
The master branch is based on net-next from Oct 7, and carries these two
patches, plus a ton of follow-on patches to eliminate MTU range checks
and change_mtu functions where possible. All patches were successfully
built across 160 various arch and config combos by the 0-day folks.
(Thanks to Andrew Lunn for the suggestion to get that going).
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/netdevice.h | 4 | ||||
| -rw-r--r-- | include/uapi/linux/if_ether.h | 2 |
2 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 136ae6bbe81e..fbdf923af4d3 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1506,6 +1506,8 @@ enum netdev_priv_flags { * @if_port: Selectable AUI, TP, ... * @dma: DMA channel * @mtu: Interface MTU value + * @min_mtu: Interface Minimum MTU value + * @max_mtu: Interface Maximum MTU value * @type: Interface hardware type * @hard_header_len: Maximum hardware header length. * @@ -1726,6 +1728,8 @@ struct net_device { unsigned char dma; unsigned int mtu; + unsigned int min_mtu; + unsigned int max_mtu; unsigned short type; unsigned short hard_header_len; diff --git a/include/uapi/linux/if_ether.h b/include/uapi/linux/if_ether.h index 117d02e0fc31..864d6f2b2cb0 100644 --- a/include/uapi/linux/if_ether.h +++ b/include/uapi/linux/if_ether.h @@ -35,6 +35,8 @@ #define ETH_FRAME_LEN 1514 /* Max. octets in frame sans FCS */ #define ETH_FCS_LEN 4 /* Octets in the FCS */ +#define ETH_MIN_MTU 68 /* Min IPv4 MTU per RFC791 */ + /* * These are the defined Ethernet Protocol ID's. */ |