kernel/linux.git/net/core/skbuff.c, branch linux-5.3.y

net: Fixed updating of ethertype in skb_mpls_push()

2019-12-18T15:05:56+00:00

[ Upstream commit d04ac224b1688f005a84f764cfe29844f8e9da08 ] The skb_mpls_push was not updating ethertype of an ethernet packet if the packet was originally received from a non ARPHRD_ETHER device. In the below OVS data path flow, since the device corresponding to port 7 is an l3 device (ARPHRD_NONE) the skb_mpls_push function does not update the ethertype of the packet even though the previous push_eth action had added an ethernet header to the packet. recirc_id(0),in_port(7),eth_type(0x0800),ipv4(tos=0/0xfc,ttl=64,frag=no), actions:push_eth(src=00:00:00:00:00:00,dst=00:00:00:00:00:00), push_mpls(label=13,tc=0,ttl=64,bos=1,eth_type=0x8847),4 Fixes: 8822e270d697 ("net: core: move push MPLS functionality from OvS to core helper") Signed-off-by: Martin Varghese Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

Fixed updating of ethertype in function skb_mpls_pop

2019-12-18T15:05:55+00:00

[ Upstream commit 040b5cfbcefa263ccf2c118c4938308606bb7ed8 ] The skb_mpls_pop was not updating ethertype of an ethernet packet if the packet was originally received from a non ARPHRD_ETHER device. In the below OVS data path flow, since the device corresponding to port 7 is an l3 device (ARPHRD_NONE) the skb_mpls_pop function does not update the ethertype of the packet even though the previous push_eth action had added an ethernet header to the packet. recirc_id(0),in_port(7),eth_type(0x8847), mpls(label=12/0xfffff,tc=0/0,ttl=0/0x0,bos=1/1), actions:push_eth(src=00:00:00:00:00:00,dst=00:00:00:00:00:00), pop_mpls(eth_type=0x800),4 Fixes: ed246cee09b9 ("net: core: move pop MPLS functionality from OvS to core helper") Signed-off-by: Martin Varghese Acked-by: Pravin B Shelar Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net/sched: fix corrupted L2 header with MPLS 'push' and 'pop' actions

2019-10-29T08:22:00+00:00

[ Upstream commit fa4e0f8855fcba600e0be2575ee29c69166f74bd ] the following script: # tc qdisc add dev eth0 clsact # tc filter add dev eth0 egress protocol ip matchall \ > action mpls push protocol mpls_uc label 0x355aa bos 1 causes corruption of all IP packets transmitted by eth0. On TC egress, we can't rely on the value of skb->mac_len, because it's 0 and a MPLS 'push' operation will result in an overwrite of the first 4 octets in the packet L2 header (e.g. the Destination Address if eth0 is an Ethernet); the same error pattern is present also in the MPLS 'pop' operation. Fix this error in act_mpls data plane, computing 'mac_len' as the difference between the network header and the mac header (when not at TC ingress), and use it in MPLS 'push'/'pop' core functions. v2: unbreak 'make htmldocs' because of missing documentation of 'mac_len' in skb_mpls_pop(), reported by kbuild test robot CC: Lorenzo Bianconi Fixes: 2a2ea50870ba ("net: sched: add mpls manipulation actions to TC") Reviewed-by: Simon Horman Acked-by: John Hurley Signed-off-by: Davide Caratti Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: avoid errors when trying to pop MLPS header on non-MPLS packets

2019-10-29T08:21:59+00:00

[ Upstream commit dedc5a08da07874c6e0d411e7f39c5c2cf137014 ] the following script: # tc qdisc add dev eth0 clsact # tc filter add dev eth0 egress matchall action mpls pop implicitly makes the kernel drop all packets transmitted by eth0, if they don't have a MPLS header. This behavior is uncommon: other encapsulations (like VLAN) just let the packet pass unmodified. Since the result of MPLS 'pop' operation would be the same regardless of the presence / absence of MPLS header(s) in the original packet, we can let skb_mpls_pop() return 0 when dealing with non-MPLS packets. For the OVS use-case, this is acceptable because __ovs_nla_copy_actions() already ensures that MPLS 'pop' operation only occurs with packets having an MPLS Ethernet type (and there are no other callers in current code, so the semantic change should be ok). v2: better documentation of use-cases for skb_mpls_pop(), thanks to Simon Horman Fixes: 2a2ea50870ba ("net: sched: add mpls manipulation actions to TC") Reviewed-by: Simon Horman Acked-by: John Hurley Signed-off-by: Davide Caratti Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: gso: Fix skb_segment splat when splitting gso_size mangled skb having linear-headed frag_list

2019-09-07T15:58:48+00:00

Historically, support for frag_list packets entering skb_segment() was limited to frag_list members terminating on exact same gso_size boundaries. This is verified with a BUG_ON since commit 89319d3801d1 ("net: Add frag_list support to skb_segment"), quote: As such we require all frag_list members terminate on exact MSS boundaries. This is checked using BUG_ON. As there should only be one producer in the kernel of such packets, namely GRO, this requirement should not be difficult to maintain. However, since commit 6578171a7ff0 ("bpf: add bpf_skb_change_proto helper"), the "exact MSS boundaries" assumption no longer holds: An eBPF program using bpf_skb_change_proto() DOES modify 'gso_size', but leaves the frag_list members as originally merged by GRO with the original 'gso_size'. Example of such programs are bpf-based NAT46 or NAT64. This lead to a kernel BUG_ON for flows involving: - GRO generating a frag_list skb - bpf program performing bpf_skb_change_proto() or bpf_skb_adjust_room() - skb_segment() of the skb See example BUG_ON reports in [0]. In commit 13acc94eff12 ("net: permit skb_segment on head_frag frag_list skb"), skb_segment() was modified to support the "gso_size mangling" case of a frag_list GRO'ed skb, but *only* for frag_list members having head_frag==true (having a page-fragment head). Alas, GRO packets having frag_list members with a linear kmalloced head (head_frag==false) still hit the BUG_ON. This commit adds support to skb_segment() for a 'head_skb' packet having a frag_list whose members are *non* head_frag, with gso_size mangled, by disabling SG and thus falling-back to copying the data from the given 'head_skb' into the generated segmented skbs - as suggested by Willem de Bruijn [1]. Since this approach involves the penalty of skb_copy_and_csum_bits() when building the segments, care was taken in order to enable this solution only when required: - untrusted gso_size, by testing SKB_GSO_DODGY is set (SKB_GSO_DODGY is set by any gso_size mangling functions in net/core/filter.c) - the frag_list is non empty, its item is a non head_frag, *and* the headlen of the given 'head_skb' does not match the gso_size. [0] https://lore.kernel.org/netdev/20190826170724.25ff616f@pixies/ https://lore.kernel.org/netdev/9265b93f-253d-6b8c-f2b8-4b54eff1835c@fb.com/ [1] https://lore.kernel.org/netdev/CA+FuTSfVsgNDi7c=GUU8nMg2hWxF2SjCNLXetHeVPdnxAW5K-w@mail.gmail.com/ Fixes: 6578171a7ff0 ("bpf: add bpf_skb_change_proto helper") Suggested-by: Willem de Bruijn Cc: Daniel Borkmann Cc: Eric Dumazet Cc: Alexander Duyck Signed-off-by: Shmulik Ladkani Reviewed-by: Willem de Bruijn Reviewed-by: Alexander Duyck Signed-off-by: David S. Miller

skbuff: fix compilation warnings in skb_dump()

2019-07-16T21:12:06+00:00

The commit 6413139dfc64 ("skbuff: increase verbosity when dumping skb data") introduced a few compilation warnings. net/core/skbuff.c:766:32: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] level, sk->sk_family, sk->sk_type, sk->sk_protocol); ^~~~~~~~~~~ net/core/skbuff.c:766:45: warning: format specifies type 'unsigned short' but the argument has type 'unsigned int' [-Wformat] level, sk->sk_family, sk->sk_type, sk->sk_protocol); ^~~~~~~~~~~~~~~ Fix them by using the proper types. Fixes: 6413139dfc64 ("skbuff: increase verbosity when dumping skb data") Signed-off-by: Qian Cai Reviewed-by: Nathan Chancellor Acked-by: Willem de Bruijn Signed-off-by: David S. Miller

net: sched: add mpls manipulation actions to TC

2019-07-09T02:50:13+00:00

Currently, TC offers the ability to match on the MPLS fields of a packet through the use of the flow_dissector_key_mpls struct. However, as yet, TC actions do not allow the modification or manipulation of such fields. Add a new module that registers TC action ops to allow manipulation of MPLS. This includes the ability to push and pop headers as well as modify the contents of new or existing headers. A further action to decrement the TTL field of an MPLS header is also provided with a new helper added to support this. Examples of the usage of the new action with flower rules to push and pop MPLS labels are: tc filter add dev eth0 protocol ip parent ffff: flower \ action mpls push protocol mpls_uc label 123 \ action mirred egress redirect dev eth1 tc filter add dev eth0 protocol mpls_uc parent ffff: flower \ action mpls pop protocol ipv4 \ action mirred egress redirect dev eth1 Signed-off-by: John Hurley Reviewed-by: Jakub Kicinski Reviewed-by: Simon Horman Reviewed-by: Willem de Bruijn Acked-by: Cong Wang Signed-off-by: David S. Miller

net: core: add MPLS update core helper and use in OvS

2019-07-09T02:50:13+00:00

Open vSwitch allows the updating of an existing MPLS header on a packet. In preparation for supporting similar functionality in TC, move this to a common skb helper function. Signed-off-by: John Hurley Reviewed-by: Jakub Kicinski Reviewed-by: Simon Horman Reviewed-by: Willem de Bruijn Acked-by: Cong Wang Signed-off-by: David S. Miller

net: core: move pop MPLS functionality from OvS to core helper

2019-07-09T02:50:13+00:00

Open vSwitch provides code to pop an MPLS header to a packet. In preparation for supporting this in TC, move the pop code to an skb helper that can be reused. Remove the, now unused, update_ethertype static function from OvS. Signed-off-by: John Hurley Reviewed-by: Jakub Kicinski Reviewed-by: Simon Horman Reviewed-by: Willem de Bruijn Acked-by: Cong Wang Signed-off-by: David S. Miller

net: core: move push MPLS functionality from OvS to core helper

2019-07-09T02:50:13+00:00

Open vSwitch provides code to push an MPLS header to a packet. In preparation for supporting this in TC, move the push code to an skb helper that can be reused. Signed-off-by: John Hurley Reviewed-by: Jakub Kicinski Reviewed-by: Simon Horman Reviewed-by: Willem de Bruijn Acked-by: Cong Wang Signed-off-by: David S. Miller