From d2aa125d629080c4f3e31f23b7f612ef6b8492ac Mon Sep 17 00:00:00 2001 From: Maxim Mikityanskiy Date: Thu, 21 Feb 2019 12:39:57 +0000 Subject: net: Don't set transport offset to invalid value If the socket was created with socket(AF_PACKET, SOCK_RAW, 0), skb->protocol will be unset, __skb_flow_dissect() will fail, and skb_probe_transport_header() will fall back to the offset_hint, making the resulting skb_transport_offset incorrect. If, however, there is no transport header in the packet, transport_header shouldn't be set to an arbitrary value. Fix it by leaving the transport offset unset if it couldn't be found, to be explicit rather than to fill it with some wrong value. It changes the behavior, but if some code relied on the old behavior, it would be broken anyway, as the old one is incorrect. Signed-off-by: Maxim Mikityanskiy Signed-off-by: David S. Miller --- include/linux/skbuff.h | 5 +---- include/linux/virtio_net.h | 2 +- 2 files changed, 2 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 2069fb90a559..27beb549ffbe 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2429,8 +2429,7 @@ static inline void skb_pop_mac_header(struct sk_buff *skb) skb->mac_header = skb->network_header; } -static inline void skb_probe_transport_header(struct sk_buff *skb, - const int offset_hint) +static inline void skb_probe_transport_header(struct sk_buff *skb) { struct flow_keys_basic keys; @@ -2439,8 +2438,6 @@ static inline void skb_probe_transport_header(struct sk_buff *skb, if (skb_flow_dissect_flow_keys_basic(skb, &keys, NULL, 0, 0, 0, 0)) skb_set_transport_header(skb, keys.control.thoff); - else if (offset_hint >= 0) - skb_set_transport_header(skb, offset_hint); } static inline void skb_mac_header_rebuild(struct sk_buff *skb) diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 71f2394abbf7..6728bf581e98 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -62,7 +62,7 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb, * probe and drop if does not match one of the above types. */ if (gso_type) { - skb_probe_transport_header(skb, -1); + skb_probe_transport_header(skb); if (!skb_transport_header_was_set(skb)) return -EINVAL; } -- cgit v1.2.3 From e78b2915517e8fcadb1bc130ad6aeac7099e510c Mon Sep 17 00:00:00 2001 From: Maxim Mikityanskiy Date: Thu, 21 Feb 2019 12:39:58 +0000 Subject: net: Introduce parse_protocol header_ops callback Introduce a new optional header_ops callback called parse_protocol and a wrapper function dev_parse_header_protocol, similar to dev_parse_header. The new callback's purpose is to extract the protocol number from the L2 header, the format of which is known to the driver, but not to the upper layers of the stack. Signed-off-by: Maxim Mikityanskiy Signed-off-by: David S. Miller --- include/linux/netdevice.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'include/linux') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index aab4d9f6613d..6997f62cb6a0 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -274,6 +274,7 @@ struct header_ops { const struct net_device *dev, const unsigned char *haddr); bool (*validate)(const char *ll_header, unsigned int len); + __be16 (*parse_protocol)(const struct sk_buff *skb); }; /* These flag bits are private to the generic network queueing @@ -2939,6 +2940,15 @@ static inline int dev_parse_header(const struct sk_buff *skb, return dev->header_ops->parse(skb, haddr); } +static inline __be16 dev_parse_header_protocol(const struct sk_buff *skb) +{ + const struct net_device *dev = skb->dev; + + if (!dev->header_ops || !dev->header_ops->parse_protocol) + return 0; + return dev->header_ops->parse_protocol(skb); +} + /* ll_header must have at least hard_header_len allocated */ static inline bool dev_validate_header(const struct net_device *dev, char *ll_header, int len) -- cgit v1.2.3 From ace53b2e2945c83850964070af158be01d564e67 Mon Sep 17 00:00:00 2001 From: Maxim Mikityanskiy Date: Thu, 21 Feb 2019 12:39:59 +0000 Subject: net/ethernet: Add parse_protocol header_ops support The previous commit introduced parse_protocol callback which should extract the protocol number from the L2 header. Make all Ethernet devices support it. Signed-off-by: Maxim Mikityanskiy Signed-off-by: David S. Miller --- include/linux/etherdevice.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h index 2c0af7b00715..e2f3b21cd72a 100644 --- a/include/linux/etherdevice.h +++ b/include/linux/etherdevice.h @@ -44,6 +44,7 @@ int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type); void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev, const unsigned char *haddr); +__be16 eth_header_parse_protocol(const struct sk_buff *skb); int eth_prepare_mac_addr_change(struct net_device *dev, void *p); void eth_commit_mac_addr_change(struct net_device *dev, void *p); int eth_mac_addr(struct net_device *dev, void *p); -- cgit v1.2.3