From 0d89d2035fe063461a5ddb609b2c12e7fb006e44 Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Thu, 23 May 2013 21:02:52 +0000 Subject: MPLS: Add limited GSO support In the case where a non-MPLS packet is received and an MPLS stack is added it may well be the case that the original skb is GSO but the NIC used for transmit does not support GSO of MPLS packets. The aim of this code is to provide GSO in software for MPLS packets whose skbs are GSO. SKB Usage: When an implementation adds an MPLS stack to a non-MPLS packet it should do the following to skb metadata: * Set skb->inner_protocol to the old non-MPLS ethertype of the packet. skb->inner_protocol is added by this patch. * Set skb->protocol to the new MPLS ethertype of the packet. * Set skb->network_header to correspond to the end of the L3 header, including the MPLS label stack. I have posted a patch, "[PATCH v3.29] datapath: Add basic MPLS support to kernel" which adds MPLS support to the kernel datapath of Open vSwtich. That patch sets the above requirements in datapath/actions.c:push_mpls() and was used to exercise this code. The datapath patch is against the Open vSwtich tree but it is intended that it be added to the Open vSwtich code present in the mainline Linux kernel at some point. Features: I believe that the approach that I have taken is at least partially consistent with the handling of other protocols. Jesse, I understand that you have some ideas here. I am more than happy to change my implementation. This patch adds dev->mpls_features which may be used by devices to advertise features supported for MPLS packets. A new NETIF_F_MPLS_GSO feature is added for devices which support hardware MPLS GSO offload. Currently no devices support this and MPLS GSO always falls back to software. Alternate Implementation: One possible alternate implementation is to teach netif_skb_features() and skb_network_protocol() about MPLS, in a similar way to their understanding of VLANs. I believe this would avoid the need for net/mpls/mpls_gso.c and in particular the calls to __skb_push() and __skb_push() in mpls_gso_segment(). I have decided on the implementation in this patch as it should not introduce any overhead in the case where mpls_gso is not compiled into the kernel or inserted as a module. MPLS GSO suggested by Jesse Gross. Based in part on "v4 GRE: Add TCP segmentation offload for GRE" by Pravin B Shelar. Cc: Jesse Gross Cc: Pravin B Shelar Signed-off-by: Simon Horman Signed-off-by: David S. Miller --- net/core/ethtool.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/core/ethtool.c') diff --git a/net/core/ethtool.c b/net/core/ethtool.c index 22efdaa76ebf..4e6f63ade741 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c @@ -82,6 +82,7 @@ static const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] [NETIF_F_FSO_BIT] = "tx-fcoe-segmentation", [NETIF_F_GSO_GRE_BIT] = "tx-gre-segmentation", [NETIF_F_GSO_UDP_TUNNEL_BIT] = "tx-udp_tnl-segmentation", + [NETIF_F_GSO_MPLS_BIT] = "tx-mpls-segmentation", [NETIF_F_FCOE_CRC_BIT] = "tx-checksum-fcoe-crc", [NETIF_F_SCTP_CSUM_BIT] = "tx-checksum-sctp", -- cgit v1.2.3-59-g8ed1b From 600fed5e97afca10356952e334f362e82fc71466 Mon Sep 17 00:00:00 2001 From: Yan Burman Date: Mon, 3 Jun 2013 02:03:34 +0000 Subject: net/ethtool: Fix comment regarding location of dev_ethtool() call Signed-off-by: Yan Burman Signed-off-by: David S. Miller --- net/core/ethtool.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/core/ethtool.c') diff --git a/net/core/ethtool.c b/net/core/ethtool.c index 4e6f63ade741..cd23d314d68a 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c @@ -1414,7 +1414,7 @@ static int ethtool_get_module_eeprom(struct net_device *dev, modinfo.eeprom_len); } -/* The main entry point in this file. Called from net/core/dev.c */ +/* The main entry point in this file. Called from net/core/dev_ioctl.c */ int dev_ethtool(struct net *net, struct ifreq *ifr) { -- cgit v1.2.3-59-g8ed1b From c590b5e2f05b5e98e614382582b7ae4cddb37599 Mon Sep 17 00:00:00 2001 From: Michal Schmidt Date: Mon, 1 Jul 2013 17:23:30 +0200 Subject: ethtool: make .get_dump_data() harder to misuse by drivers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit As the patch "bnx2x: remove zeroing of dump data buffer" showed, it is too easy implement .get_dump_data incorrectly in a driver. Let's make sure drivers cannot get confused by userspace requesting a too big dump. Also WARN if the driver sets dump->len to something weird and make sure the length reported to userspace is the actual length of data copied to userspace. Signed-off-by: Michal Schmidt Reviewed-by: Ben Hutchings Signed-off-by: David S. Miller --- net/core/ethtool.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'net/core/ethtool.c') diff --git a/net/core/ethtool.c b/net/core/ethtool.c index 9255bbdf81ff..ab5fa6336c84 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c @@ -1320,10 +1320,19 @@ static int ethtool_get_dump_data(struct net_device *dev, if (ret) return ret; - len = (tmp.len > dump.len) ? dump.len : tmp.len; + len = min(tmp.len, dump.len); if (!len) return -EFAULT; + /* Don't ever let the driver think there's more space available + * than it requested with .get_dump_flag(). + */ + dump.len = len; + + /* Always allocate enough space to hold the whole thing so that the + * driver does not need to check the length and bother with partial + * dumping. + */ data = vzalloc(tmp.len); if (!data) return -ENOMEM; @@ -1331,6 +1340,16 @@ static int ethtool_get_dump_data(struct net_device *dev, if (ret) goto out; + /* There are two sane possibilities: + * 1. The driver's .get_dump_data() does not touch dump.len. + * 2. Or it may set dump.len to how much it really writes, which + * should be tmp.len (or len if it can do a partial dump). + * In any case respond to userspace with the actual length of data + * it's receiving. + */ + WARN_ON(dump.len != len && dump.len != tmp.len); + dump.len = len; + if (copy_to_user(useraddr, &dump, sizeof(dump))) { ret = -EFAULT; goto out; -- cgit v1.2.3-59-g8ed1b