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* bpf, netns: Keep attached programs in bpf_prog_arrayJakub Sitnicki2020-06-301-9/+10
| | | | | | | | | | | | | | | | | | | | | | | | Prepare for having multi-prog attachments for new netns attach types by storing programs to run in a bpf_prog_array, which is well suited for iterating over programs and running them in sequence. After this change bpf(PROG_QUERY) may block to allocate memory in bpf_prog_array_copy_to_user() for collected program IDs. This forces a change in how we protect access to the attached program in the query callback. Because bpf_prog_array_copy_to_user() can sleep, we switch from an RCU read lock to holding a mutex that serializes updaters. Because we allow only one BPF flow_dissector program to be attached to netns at all times, the bpf_prog_array pointed by net->bpf.run_array is always either detached (null) or one element long. No functional changes intended. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200625141357.910330-3-jakub@cloudflare.com
* flow_dissector: Pull BPF program assignment up to bpf-netnsJakub Sitnicki2020-06-301-11/+2
| | | | | | | | | | | | | | | | | Prepare for using bpf_prog_array to store attached programs by moving out code that updates the attached program out of flow dissector. Managing bpf_prog_array is more involved than updating a single bpf_prog pointer. This will let us do it all from one place, bpf/net_namespace.c, in the subsequent patch. No functional change intended. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200625141357.910330-2-jakub@cloudflare.com
* flow_dissector: Move out netns_bpf prog callbacksJakub Sitnicki2020-06-011-121/+4
| | | | | | | | | | | | | | | | Move functions to manage BPF programs attached to netns that are not specific to flow dissector to a dedicated module named bpf/net_namespace.c. The set of functions will grow with the addition of bpf_link support for netns attached programs. This patch prepares ground by creating a place for it. This is a code move with no functional changes intended. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200531082846.2117903-4-jakub@cloudflare.com
* net: Introduce netns_bpf for BPF programs attached to netnsJakub Sitnicki2020-06-011-36/+69
| | | | | | | | | | | | | | | | | | | | | | | | | In order to: (1) attach more than one BPF program type to netns, or (2) support attaching BPF programs to netns with bpf_link, or (3) support multi-prog attach points for netns we will need to keep more state per netns than a single pointer like we have now for BPF flow dissector program. Prepare for the above by extracting netns_bpf that is part of struct net, for storing all state related to BPF programs attached to netns. Turn flow dissector callbacks for querying/attaching/detaching a program into generic ones that operate on netns_bpf. Next patch will move the generic callbacks into their own module. This is similar to how it is organized for cgroup with cgroup_bpf. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20200531082846.2117903-3-jakub@cloudflare.com
* flow_dissector: Pull locking up from prog attach callbackJakub Sitnicki2020-06-011-20/+20
| | | | | | | | | | | | Split out the part of attach callback that happens with attach/detach lock acquired. This structures the prog attach callback in a way that opens up doors for moving the locking out of flow_dissector and into generic callbacks for attaching/detaching progs to netns in subsequent patches. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20200531082846.2117903-2-jakub@cloudflare.com
* flow_dissector: Parse multiple MPLS Label Stack EntriesGuillaume Nault2020-05-261-16/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current MPLS dissector only parses the first MPLS Label Stack Entry (second LSE can be parsed too, but only to set a key_id). This patch adds the possibility to parse several LSEs by making __skb_flow_dissect_mpls() return FLOW_DISSECT_RET_PROTO_AGAIN as long as the Bottom Of Stack bit hasn't been seen, up to a maximum of FLOW_DIS_MPLS_MAX entries. FLOW_DIS_MPLS_MAX is arbitrarily set to 7. This should be enough for many practical purposes, without wasting too much space. To record the parsed values, flow_dissector_key_mpls is modified to store an array of stack entries, instead of just the values of the first one. A bit field, "used_lses", is also added to keep track of the LSEs that have been set. The objective is to avoid defining a new FLOW_DISSECTOR_KEY_MPLS_XX for each level of the MPLS stack. TC flower is adapted for the new struct flow_dissector_key_mpls layout. Matching on several MPLS Label Stack Entries will be added in the next patch. The NFP and MLX5 drivers are also adapted: nfp_flower_compile_mac() and mlx5's parse_tunnel() now verify that the rule only uses the first LSE and fail if it doesn't. Finally, the behaviour of the FLOW_DISSECTOR_KEY_MPLS_ENTROPY key is slightly modified. Instead of recording the first Entropy Label, it now records the last one. This shouldn't have any consequences since there doesn't seem to have any user of FLOW_DISSECTOR_KEY_MPLS_ENTROPY in the tree. We'd probably better do a hash of all parsed MPLS labels instead (excluding reserved labels) anyway. That'd give better entropy and would probably also simplify the code. But that's not the purpose of this patch, so I'm keeping that as a future possible improvement. Signed-off-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* flow_dissector: Drop BPF flow dissector prog ref on netns cleanupJakub Sitnicki2020-05-211-5/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When attaching a flow dissector program to a network namespace with bpf(BPF_PROG_ATTACH, ...) we grab a reference to bpf_prog. If netns gets destroyed while a flow dissector is still attached, and there are no other references to the prog, we leak the reference and the program remains loaded. Leak can be reproduced by running flow dissector tests from selftests/bpf: # bpftool prog list # ./test_flow_dissector.sh ... selftests: test_flow_dissector [PASS] # bpftool prog list 4: flow_dissector name _dissect tag e314084d332a5338 gpl loaded_at 2020-05-20T18:50:53+0200 uid 0 xlated 552B jited 355B memlock 4096B map_ids 3,4 btf_id 4 # Fix it by detaching the flow dissector program when netns is going away. Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20200521083435.560256-1-jakub@cloudflare.com
* bpf: Use bpf_prog_run_pin_on_cpu() at simple call sites.David Miller2020-02-241-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All of these cases are strictly of the form: preempt_disable(); BPF_PROG_RUN(...); preempt_enable(); Replace this with bpf_prog_run_pin_on_cpu() which wraps BPF_PROG_RUN() with: migrate_disable(); BPF_PROG_RUN(...); migrate_enable(); On non RT enabled kernels this maps to preempt_disable/enable() and on RT enabled kernels this solely prevents migration, which is sufficient as there is no requirement to prevent reentrancy to any BPF program from a preempting task. The only requirement is that the program stays on the same CPU. Therefore, this is a trivially correct transformation. The seccomp loop does not need protection over the loop. It only needs protection per BPF filter program [ tglx: Converted to bpf_prog_run_pin_on_cpu() ] Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200224145643.691493094@linutronix.de
* flow_dissector: Fix to use new variables for port ranges in bpf hookYoshiki Komachi2020-01-271-2/+9
| | | | | | | | | | | | | This patch applies new flag (FLOW_DISSECTOR_KEY_PORTS_RANGE) and field (tp_range) to BPF flow dissector to generate appropriate flow keys when classified by specified port ranges. Fixes: 8ffb055beae5 ("cls_flower: Fix the behavior using port ranges with hw-offload") Signed-off-by: Yoshiki Komachi <komachi.yoshiki@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Petar Penkov <ppenkov@google.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200117070533.402240-2-komachi.yoshiki@gmail.com
* flow_dissector: fix document for skb_flow_get_icmp_tciLi RongQing2020-01-091-1/+1
| | | | | | | | | | | using correct input parameter name to fix the below warning: net/core/flow_dissector.c:242: warning: Function parameter or member 'thoff' not described in 'skb_flow_get_icmp_tci' net/core/flow_dissector.c:242: warning: Excess function parameter 'toff' description in 'skb_flow_get_icmp_tci' Signed-off-by: Li RongQing <lirongqing@baidu.com> Reviewed-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* treewide: Use sizeof_field() macroPankaj Bharadiya2019-12-091-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except at places where these are defined. Later patches will remove the unused definition of FIELD_SIZEOF(). This patch is generated using following script: EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h" git grep -l -e "\bFIELD_SIZEOF\b" | while read file; do if [[ "$file" =~ $EXCLUDE_FILES ]]; then continue fi sed -i -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file; done Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com> Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com Co-developed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: David Miller <davem@davemloft.net> # for net
* net: dsa: fix flow dissection on Tx pathAlexander Lobakin2019-12-061-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 43e665287f93 ("net-next: dsa: fix flow dissection") added an ability to override protocol and network offset during flow dissection for DSA-enabled devices (i.e. controllers shipped as switch CPU ports) in order to fix skb hashing for RPS on Rx path. However, skb_hash() and added part of code can be invoked not only on Rx, but also on Tx path if we have a multi-queued device and: - kernel is running on UP system or - XPS is not configured. The call stack in this two cases will be like: dev_queue_xmit() -> __dev_queue_xmit() -> netdev_core_pick_tx() -> netdev_pick_tx() -> skb_tx_hash() -> skb_get_hash(). The problem is that skbs queued for Tx have both network offset and correct protocol already set up even after inserting a CPU tag by DSA tagger, so calling tag_ops->flow_dissect() on this path actually only breaks flow dissection and hashing. This can be observed by adding debug prints just before and right after tag_ops->flow_dissect() call to the related block of code: Before the patch: Rx path (RPS): [ 19.240001] Rx: proto: 0x00f8, nhoff: 0 /* ETH_P_XDSA */ [ 19.244271] tag_ops->flow_dissect() [ 19.247811] Rx: proto: 0x0800, nhoff: 8 /* ETH_P_IP */ [ 19.215435] Rx: proto: 0x00f8, nhoff: 0 /* ETH_P_XDSA */ [ 19.219746] tag_ops->flow_dissect() [ 19.223241] Rx: proto: 0x0806, nhoff: 8 /* ETH_P_ARP */ [ 18.654057] Rx: proto: 0x00f8, nhoff: 0 /* ETH_P_XDSA */ [ 18.658332] tag_ops->flow_dissect() [ 18.661826] Rx: proto: 0x8100, nhoff: 8 /* ETH_P_8021Q */ Tx path (UP system): [ 18.759560] Tx: proto: 0x0800, nhoff: 26 /* ETH_P_IP */ [ 18.763933] tag_ops->flow_dissect() [ 18.767485] Tx: proto: 0x920b, nhoff: 34 /* junk */ [ 22.800020] Tx: proto: 0x0806, nhoff: 26 /* ETH_P_ARP */ [ 22.804392] tag_ops->flow_dissect() [ 22.807921] Tx: proto: 0x920b, nhoff: 34 /* junk */ [ 16.898342] Tx: proto: 0x86dd, nhoff: 26 /* ETH_P_IPV6 */ [ 16.902705] tag_ops->flow_dissect() [ 16.906227] Tx: proto: 0x920b, nhoff: 34 /* junk */ After: Rx path (RPS): [ 16.520993] Rx: proto: 0x00f8, nhoff: 0 /* ETH_P_XDSA */ [ 16.525260] tag_ops->flow_dissect() [ 16.528808] Rx: proto: 0x0800, nhoff: 8 /* ETH_P_IP */ [ 15.484807] Rx: proto: 0x00f8, nhoff: 0 /* ETH_P_XDSA */ [ 15.490417] tag_ops->flow_dissect() [ 15.495223] Rx: proto: 0x0806, nhoff: 8 /* ETH_P_ARP */ [ 17.134621] Rx: proto: 0x00f8, nhoff: 0 /* ETH_P_XDSA */ [ 17.138895] tag_ops->flow_dissect() [ 17.142388] Rx: proto: 0x8100, nhoff: 8 /* ETH_P_8021Q */ Tx path (UP system): [ 15.499558] Tx: proto: 0x0800, nhoff: 26 /* ETH_P_IP */ [ 20.664689] Tx: proto: 0x0806, nhoff: 26 /* ETH_P_ARP */ [ 18.565782] Tx: proto: 0x86dd, nhoff: 26 /* ETH_P_IPV6 */ In order to fix that we can add the check 'proto == htons(ETH_P_XDSA)' to prevent code from calling tag_ops->flow_dissect() on Tx. I also decided to initialize 'offset' variable so tagger callbacks can now safely leave it untouched without provoking a chaos. Fixes: 43e665287f93 ("net-next: dsa: fix flow dissection") Signed-off-by: Alexander Lobakin <alobakin@dlink.ru> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* cls_flower: Fix the behavior using port ranges with hw-offloadYoshiki Komachi2019-12-031-9/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent commit 5c72299fba9d ("net: sched: cls_flower: Classify packets using port ranges") had added filtering based on port ranges to tc flower. However the commit missed necessary changes in hw-offload code, so the feature gave rise to generating incorrect offloaded flow keys in NIC. One more detailed example is below: $ tc qdisc add dev eth0 ingress $ tc filter add dev eth0 ingress protocol ip flower ip_proto tcp \ dst_port 100-200 action drop With the setup above, an exact match filter with dst_port == 0 will be installed in NIC by hw-offload. IOW, the NIC will have a rule which is equivalent to the following one. $ tc qdisc add dev eth0 ingress $ tc filter add dev eth0 ingress protocol ip flower ip_proto tcp \ dst_port 0 action drop The behavior was caused by the flow dissector which extracts packet data into the flow key in the tc flower. More specifically, regardless of exact match or specified port ranges, fl_init_dissector() set the FLOW_DISSECTOR_KEY_PORTS flag in struct flow_dissector to extract port numbers from skb in skb_flow_dissect() called by fl_classify(). Note that device drivers received the same struct flow_dissector object as used in skb_flow_dissect(). Thus, offloaded drivers could not identify which of these is used because the FLOW_DISSECTOR_KEY_PORTS flag was set to struct flow_dissector in either case. This patch adds the new FLOW_DISSECTOR_KEY_PORTS_RANGE flag and the new tp_range field in struct fl_flow_key to recognize which filters are applied to offloaded drivers. At this point, when filters based on port ranges passed to drivers, drivers return the EOPNOTSUPP error because they do not support the feature (the newly created FLOW_DISSECTOR_KEY_PORTS_RANGE flag). Fixes: 5c72299fba9d ("net: sched: cls_flower: Classify packets using port ranges") Signed-off-by: Yoshiki Komachi <komachi.yoshiki@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller2019-11-021-26/+17
|\ | | | | | | | | | | | | | | | | The only slightly tricky merge conflict was the netdevsim because the mutex locking fix overlapped a lot of driver reload reorganization. The rest were (relatively) trivial in nature. Signed-off-by: David S. Miller <davem@davemloft.net>
| * net/flow_dissector: switch to siphashEric Dumazet2019-10-231-22/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | UDP IPv6 packets auto flowlabels are using a 32bit secret (static u32 hashrnd in net/core/flow_dissector.c) and apply jhash() over fields known by the receivers. Attackers can easily infer the 32bit secret and use this information to identify a device and/or user, since this 32bit secret is only set at boot time. Really, using jhash() to generate cookies sent on the wire is a serious security concern. Trying to change the rol32(hash, 16) in ip6_make_flowlabel() would be a dead end. Trying to periodically change the secret (like in sch_sfq.c) could change paths taken in the network for long lived flows. Let's switch to siphash, as we did in commit df453700e8d8 ("inet: switch IP ID generator to siphash") Using a cryptographically strong pseudo random function will solve this privacy issue and more generally remove other weak points in the stack. Packet schedulers using skb_get_hash_perturb() benefit from this change. Fixes: b56774163f99 ("ipv6: Enable auto flow labels by default") Fixes: 42240901f7c4 ("ipv6: Implement different admin modes for automatic flow labels") Fixes: 67800f9b1f4e ("ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel") Fixes: cb1ce2ef387b ("ipv6: Implement automatic flow label generation on transmit") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Jonathan Berger <jonathann1@walla.com> Reported-by: Amit Klein <aksecurity@gmail.com> Reported-by: Benny Pinkas <benny@pinkas.net> Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | flow_dissector: extract more ICMP informationMatteo Croce2019-10-301-24/+50
| | | | | | | | | | | | | | | | | | | | | | The ICMP flow dissector currently parses only the Type and Code fields. Some ICMP packets (echo, timestamp) have a 16 bit Identifier field which is used to correlate packets. Add such field in flow_dissector_key_icmp and replace skb_flow_get_be16() with a more complex function which populate this field. Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | flow_dissector: skip the ICMP dissector for non ICMP packetsMatteo Croce2019-10-301-9/+25
| | | | | | | | | | | | | | | | | | | | FLOW_DISSECTOR_KEY_ICMP is checked for every packet, not only ICMP ones. Even if the test overhead is probably negligible, move the ICMP dissector code under the big 'switch(ip_proto)' so it gets called only for ICMP packets. Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | flow_dissector: add meaningful commentsMatteo Croce2019-10-301-0/+6
| | | | | | | | | | | | | | Documents two piece of code which can't be understood at a glance. Signed-off-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | flow_dissector: Allow updating the flow dissector program atomicallyJakub Sitnicki2019-10-111-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is currently not possible to detach the flow dissector program and attach a new one in an atomic fashion, that is with a single syscall. Attempts to do so will be met with EEXIST error. This makes updates to flow dissector program hard. Traffic steering that relies on BPF-powered flow dissection gets disrupted while old program has been already detached but the new one has not been attached yet. There is also a window of opportunity to attach a flow dissector to a non-root namespace while updating the root flow dissector, thus blocking the update. Lastly, the behavior is inconsistent with cgroup BPF programs, which can be replaced with a single bpf(BPF_PROG_ATTACH, ...) syscall without any restrictions. Allow attaching a new flow dissector program when another one is already present with a restriction that it can't be the same program. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Stanislav Fomichev <sdf@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191011082946.22695-2-jakub@cloudflare.com
* | bpf/flow_dissector: add mode to enforce global BPF flow dissectorStanislav Fomichev2019-10-071-4/+34
|/ | | | | | | | | | | | | | Always use init_net flow dissector BPF program if it's attached and fall back to the per-net namespace one. Also, deny installing new programs if there is already one attached to the root namespace. Users can still detach their BPF programs, but can't attach any new ones (-EEXIST). Cc: Petar Penkov <ppenkov@google.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller2019-08-271-1/+1
|\ | | | | | | | | | | | | Minor conflict in r8169, bug fix had two versions in net and net-next, take the net-next hunks. Signed-off-by: David S. Miller <davem@davemloft.net>
| * flow_dissector: Fix potential use-after-free on BPF_PROG_DETACHJakub Sitnicki2019-08-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Call to bpf_prog_put(), with help of call_rcu(), queues an RCU-callback to free the program once a grace period has elapsed. The callback can run together with new RCU readers that started after the last grace period. New RCU readers can potentially see the "old" to-be-freed or already-freed pointer to the program object before the RCU update-side NULLs it. Reorder the operations so that the RCU update-side resets the protected pointer before the end of the grace period after which the program will be freed. Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") Reported-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Acked-by: Petar Penkov <ppenkov@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | bpf/flow_dissector: support ipv6 flow_label and ↵Stanislav Fomichev2019-07-251-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL Add support for exporting ipv6 flow label via bpf_flow_keys. Export flow label from bpf_flow.c and also return early when BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL is passed. Acked-by: Petar Penkov <ppenkov@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Acked-by: Song Liu <songliubraving@fb.com> Cc: Song Liu <songliubraving@fb.com> Cc: Willem de Bruijn <willemb@google.com> Cc: Petar Penkov <ppenkov@google.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | bpf/flow_dissector: pass input flags to BPF flow dissector programStanislav Fomichev2019-07-251-2/+10
|/ | | | | | | | | | | | | | | | | | | | C flow dissector supports input flags that tell it to customize parsing by either stopping early or trying to parse as deep as possible. Pass those flags to the BPF flow dissector so it can make the same decisions. In the next commits I'll add support for those flags to our reference bpf_flow.c v3: * Export copy of flow dissector flags instead of moving (Alexei Starovoitov) Acked-by: Petar Penkov <ppenkov@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Acked-by: Song Liu <songliubraving@fb.com> Cc: Song Liu <songliubraving@fb.com> Cc: Willem de Bruijn <willemb@google.com> Cc: Petar Penkov <ppenkov@google.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* net/flow_dissector: add connection tracking dissectionPaul Blakey2019-07-091-0/+44
| | | | | | | | | | Retreives connection tracking zone, mark, label, and state from a SKB. Signed-off-by: Paul Blakey <paulb@mellanox.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* flow_dissector: add support for ingress ifindex dissectionJiri Pirko2019-06-191-0/+16
| | | | | | | | | | Add new key meta that contains ingress ifindex value and add a function to dissect this from skb. The key and function is prepared to cover other potential skb metadata values dissection. Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* flow_dissector: remove unused FLOW_DISSECTOR_F_STOP_AT_L3 flagStanislav Fomichev2019-06-031-9/+1
| | | | | | | This flag is not used by any caller, remove it. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* treewide: Add SPDX license identifier for missed filesThomas Gleixner2019-05-211-0/+1
| | | | | | | | | | | | | | | | | Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* flow_dissector: disable preemption around BPF callsEric Dumazet2019-05-131-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Various things in eBPF really require us to disable preemption before running an eBPF program. syzbot reported : BUG: assuming atomic context at net/core/flow_dissector.c:737 in_atomic(): 0, irqs_disabled(): 0, pid: 24710, name: syz-executor.3 2 locks held by syz-executor.3/24710: #0: 00000000e81a4bf1 (&tfile->napi_mutex){+.+.}, at: tun_get_user+0x168e/0x3ff0 drivers/net/tun.c:1850 #1: 00000000254afebd (rcu_read_lock){....}, at: __skb_flow_dissect+0x1e1/0x4bb0 net/core/flow_dissector.c:822 CPU: 1 PID: 24710 Comm: syz-executor.3 Not tainted 5.1.0+ #6 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 __cant_sleep kernel/sched/core.c:6165 [inline] __cant_sleep.cold+0xa3/0xbb kernel/sched/core.c:6142 bpf_flow_dissect+0xfe/0x390 net/core/flow_dissector.c:737 __skb_flow_dissect+0x362/0x4bb0 net/core/flow_dissector.c:853 skb_flow_dissect_flow_keys_basic include/linux/skbuff.h:1322 [inline] skb_probe_transport_header include/linux/skbuff.h:2500 [inline] skb_probe_transport_header include/linux/skbuff.h:2493 [inline] tun_get_user+0x2cfe/0x3ff0 drivers/net/tun.c:1940 tun_chr_write_iter+0xbd/0x156 drivers/net/tun.c:2037 call_write_iter include/linux/fs.h:1872 [inline] do_iter_readv_writev+0x5fd/0x900 fs/read_write.c:693 do_iter_write fs/read_write.c:970 [inline] do_iter_write+0x184/0x610 fs/read_write.c:951 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1015 do_writev+0x15b/0x330 fs/read_write.c:1058 __do_sys_writev fs/read_write.c:1131 [inline] __se_sys_writev fs/read_write.c:1128 [inline] __x64_sys_writev+0x75/0xb0 fs/read_write.c:1128 do_syscall_64+0x103/0x670 arch/x86/entry/common.c:298 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Petar Penkov <ppenkov@google.com> Cc: Stanislav Fomichev <sdf@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* bpf: support BPF_PROG_QUERY for BPF_FLOW_DISSECTOR attach_typeStanislav Fomichev2019-04-251-0/+39
| | | | | | | | | | | | | | | | | | | | | | | target_fd is target namespace. If there is a flow dissector BPF program attached to that namespace, its (single) id is returned. v5: * drop net ref right after rcu unlock (Daniel Borkmann) v4: * add missing put_net (Jann Horn) v3: * add missing inline to skb_flow_dissector_prog_query static def (kbuild test robot <lkp@intel.com>) v2: * don't sleep in rcu critical section (Jakub Kicinski) * check input prog_cnt (exit early) Cc: Jann Horn <jannh@google.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* flow_dissector: handle no-skb use caseStanislav Fomichev2019-04-231-27/+25
| | | | | | | | | | | When called without skb, gather all required data from the __skb_flow_dissect's arguments and use recently introduces no-skb mode of bpf flow dissector. Note: WARN_ON_ONCE(!net) will now trigger for eth_get_headlen users. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* net: plumb network namespace into __skb_flow_dissectStanislav Fomichev2019-04-231-10/+17
| | | | | | | | | | | | | This new argument will be used in the next patches for the eth_get_headlen use case. eth_get_headlen calls flow dissector with only data (without skb) so there is currently no way to pull attached BPF flow dissector program. With this new argument, we can amend the callers to explicitly pass network namespace so we can use attached BPF program. Signed-off-by: Stanislav Fomichev <sdf@google.com> Reviewed-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* flow_dissector: switch kernel context to struct bpf_flow_dissectorStanislav Fomichev2019-04-231-25/+20
| | | | | | | | | | | | | | struct bpf_flow_dissector has a small subset of sk_buff fields that flow dissector BPF program is allowed to access and an optional pointer to real skb. Real skb is used only in bpf_skb_load_bytes helper to read non-linear data. The real motivation for this is to be able to call flow dissector from eth_get_headlen context where we don't have an skb and need to dissect raw bytes. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2019-04-051-1/+3
|\ | | | | | | | | | | | | | | | | Minor comment merge conflict in mlx5. Staging driver has a fixup due to the skb->xmit_more changes in 'net-next', but was removed in 'net'. Signed-off-by: David S. Miller <davem@davemloft.net>
| * flow_dissector: fix clamping of BPF flow_keys for non-zero nhoffStanislav Fomichev2019-04-031-1/+2
| | | | | | | | | | | | | | | | | | | | Don't allow BPF program to set flow_keys->nhoff to less than initial value. We currently don't read the value afterwards in anything but the tests, but it's still a good practice to return consistent values to the test programs. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * net/flow_dissector: pass flow_keys->n_proto to BPF programsStanislav Fomichev2019-04-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | This is a preparation for the next commit that would prohibit access to the most fields of __sk_buff from the BPF programs. Instead of requiring BPF flow dissector programs to look into skb, pass all input data in the flow_keys. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* | net/core: Document __skb_flow_dissect() flags argumentBart Van Assche2019-03-271-0/+2
|/ | | | | | | | | | | | This patch avoids that the following warning is reported when building with W=1: warning: Function parameter or member 'flags' not described in '__skb_flow_dissect' Cc: Tom Herbert <tom@herbertland.com> Fixes: cd79a2382aa5 ("flow_dissector: Add flags argument to skb_flow_dissector functions") # v4.3. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/flow_dissector: move bpf case into __skb_flow_bpf_dissectStanislav Fomichev2019-01-291-38/+54
| | | | | | | | | | This way, we can reuse it for flow dissector in BPF_PROG_TEST_RUN. No functional changes. Signed-off-by: Stanislav Fomichev <sdf@google.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2018-12-201-1/+5
|\ | | | | | | | | | | | | | | | | | | Lots of conflicts, by happily all cases of overlapping changes, parallel adds, things of that nature. Thanks to Stephen Rothwell, Saeed Mahameed, and others for their guidance in these resolutions. Signed-off-by: David S. Miller <davem@davemloft.net>
| * net/flow_dissector: correctly cap nhoff and thoff in case of BPFStanislav Fomichev2018-12-071-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | We want to make sure that the following condition holds: 0 <= nhoff <= thoff <= skb->len BPF program can set out-of-bounds nhoff and thoff, which is dangerous, see recent commit d0c081b49137 ("flow_dissector: properly cap thoff field")'. Signed-off-by: Stanislav Fomichev <sdf@google.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * selftests/bpf: use thoff instead of nhoff in BPF flow dissectorStanislav Fomichev2018-12-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | We are returning thoff from the flow dissector, not the nhoff. Pass thoff along with nhoff to the bpf program (initially thoff == nhoff) and expect flow dissector amend/return thoff, not nhoff. This avoids confusion, when by the time bpf flow dissector exits, nhoff == thoff, which doesn't make much sense. Signed-off-by: Stanislav Fomichev <sdf@google.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2018-11-111-2/+2
|\|
| * flow_dissector: do not dissect l4 ports for fragments배석진2018-11-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Only first fragment has the sport/dport information, not the following ones. If we want consistent hash for all fragments, we need to ignore ports even for first fragment. This bug is visible for IPv6 traffic, if incoming fragments do not have a flow label, since skb_get_hash() will give different results for first fragment and following ones. It is also visible if any routing rule wants dissection and sport or dport. See commit 5e5d6fed3741 ("ipv6: route: dissect flow in input path if fib rules need it") for details. [edumazet] rewrote the changelog completely. Fixes: 06635a35d13d ("flow_dissect: use programable dissector in skb_flow_dissect and friends") Signed-off-by: 배석진 <soukjin.bae@samsung.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net/vlan: include the shift in skb_vlan_tag_get_prio()Michał Mirosław2018-11-071-2/+1
|/ | | | | Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2018-09-251-0/+140
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf-next 2018-09-25 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Allow for RX stack hardening by implementing the kernel's flow dissector in BPF. Idea was originally presented at netconf 2017 [0]. Quote from merge commit: [...] Because of the rigorous checks of the BPF verifier, this provides significant security guarantees. In particular, the BPF flow dissector cannot get inside of an infinite loop, as with CVE-2013-4348, because BPF programs are guaranteed to terminate. It cannot read outside of packet bounds, because all memory accesses are checked. Also, with BPF the administrator can decide which protocols to support, reducing potential attack surface. Rarely encountered protocols can be excluded from dissection and the program can be updated without kernel recompile or reboot if a bug is discovered. [...] Also, a sample flow dissector has been implemented in BPF as part of this work, from Petar and Willem. [0] http://vger.kernel.org/netconf2017_files/rx_hardening_and_udp_gso.pdf 2) Add support for bpftool to list currently active attachment points of BPF networking programs providing a quick overview similar to bpftool's perf subcommand, from Yonghong. 3) Fix a verifier pruning instability bug where a union member from the register state was not cleared properly leading to branches not being pruned despite them being valid candidates, from Alexei. 4) Various smaller fast-path optimizations in XDP's map redirect code, from Jesper. 5) Enable to recognize BPF_MAP_TYPE_REUSEPORT_SOCKARRAY maps in bpftool, from Roman. 6) Remove a duplicate check in libbpf that probes for function storage, from Taeung. 7) Fix an issue in test_progs by avoid checking for errno since on success its value should not be checked, from Mauricio. 8) Fix unused variable warning in bpf_getsockopt() helper when CONFIG_INET is not configured, from Anders. 9) Fix a compilation failure in the BPF sample code's use of bpf_flow_keys, from Prashant. 10) Minor cleanups in BPF code, from Yue and Zhong. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * flow_dissector: lookup netns by skb->sk if skb->dev is NULLWillem de Bruijn2018-09-251-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BPF flow dissectors are configured per network namespace. __skb_flow_dissect looks up the netns through dev_net(skb->dev). In some dissector paths skb->dev is NULL, such as for Unix sockets. In these cases fall back to looking up the netns by socket. Analyzing the codepaths leading to __skb_flow_dissect I did not find a case where both skb->dev and skb->sk are NULL. Warn and fall back to standard flow dissector if one is found. Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") Reported-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| * flow_dissector: implements flow dissector BPF hookPetar Penkov2018-09-141-0/+134
| | | | | | | | | | | | | | | | | | | | Adds a hook for programs of type BPF_PROG_TYPE_FLOW_DISSECTOR and attach type BPF_FLOW_DISSECTOR that is executed in the flow dissector path. The BPF program is per-network namespace. Signed-off-by: Petar Penkov <ppenkov@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | net: core: Use FIELD_SIZEOF directly instead of reimplementing its functionzhong jiang2018-09-191-5/+5
|/ | | | | | | | FIELD_SIZEOF is defined as a macro to calculate the specified value. Therefore, We prefer to use the macro rather than calculating its value. Signed-off-by: zhong jiang <zhongjiang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* flow_dissector: allow dissection of tunnel options from metadataSimon Horman2018-08-071-1/+18
| | | | | | | | | | | | | | | | | | Allow the existing 'dissection' of tunnel metadata to 'dissect' options already present in tunnel metadata. This dissection is controlled by a new dissector key, FLOW_DISSECTOR_KEY_ENC_OPTS. This dissection only occurs when skb_flow_dissect_tunnel_info() is called, currently only the Flower classifier makes that call. So there should be no impact on other users of the flow dissector. This is in preparation for allowing the flower classifier to match on Geneve options. Signed-off-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* flow_dissector: Dissect tos and ttl from the tunnel infoOr Gerlitz2018-07-191-1/+13
| | | | | | | | | | Add dissection of the tos and ttl from the ip tunnel headers fields in case a match is needed on them. Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Roi Dayan <roid@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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