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2023-11-02bpf: Add __bpf_kfunc_{start,end}_defs macrosDave Marchevsky1-4/+2
BPF kfuncs are meant to be called from BPF programs. Accordingly, most kfuncs are not called from anywhere in the kernel, which the -Wmissing-prototypes warning is unhappy about. We've peppered __diag_ignore_all("-Wmissing-prototypes", ... everywhere kfuncs are defined in the codebase to suppress this warning. This patch adds two macros meant to bound one or many kfunc definitions. All existing kfunc definitions which use these __diag calls to suppress -Wmissing-prototypes are migrated to use the newly-introduced macros. A new __diag_ignore_all - for "-Wmissing-declarations" - is added to the __bpf_kfunc_start_defs macro based on feedback from Andrii on an earlier version of this patch [0] and another recent mailing list thread [1]. In the future we might need to ignore different warnings or do other kfunc-specific things. This change will make it easier to make such modifications for all kfunc defs. [0]: https://lore.kernel.org/bpf/CAEf4BzaE5dRWtK6RPLnjTW-MW9sx9K3Fn6uwqCTChK2Dcb1Xig@mail.gmail.com/ [1]: https://lore.kernel.org/bpf/ZT+2qCc%2FaXep0%2FLf@krava/ Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Suggested-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Cc: Jiri Olsa <olsajiri@gmail.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Acked-by: David Vernet <void@manifault.com> Acked-by: Yafang Shao <laoar.shao@gmail.com> Link: https://lore.kernel.org/r/20231031215625.2343848-1-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-15netfilter, bpf: Adjust timeouts of non-confirmed CTs in bpf_ct_insert_entry()Ilya Leoshkevich1-0/+2
bpf_nf testcase fails on s390x: bpf_skb_ct_lookup() cannot find the entry that was added by bpf_ct_insert_entry() within the same BPF function. The reason is that this entry is deleted by nf_ct_gc_expired(). The CT timeout starts ticking after the CT confirmation; therefore nf_conn.timeout is initially set to the timeout value, and __nf_conntrack_confirm() sets it to the deadline value. bpf_ct_insert_entry() sets IPS_CONFIRMED_BIT, but does not adjust the timeout, making its value meaningless and causing false positives. Fix the problem by making bpf_ct_insert_entry() adjust the timeout, like __nf_conntrack_confirm(). Fixes: 2cdaa3eefed8 ("netfilter: conntrack: restore IPS_CONFIRMED out of nf_conntrack_hash_check_insert()") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Florian Westphal <fw@strlen.de> Link: https://lore.kernel.org/bpf/20230830011128.1415752-3-iii@linux.ibm.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-03net: invert the netdevice.h vs xdp.h dependencyJakub Kicinski1-0/+1
xdp.h is far more specific and is included in only 67 other files vs netdevice.h's 1538 include sites. Make xdp.h include netdevice.h, instead of the other way around. This decreases the incremental allmodconfig builds size when xdp.h is touched from 5947 to 662 objects. Move bpf_prog_run_xdp() to xdp.h, seems appropriate and filter.h is a mega-header in its own right so it's nice to avoid xdp.h getting included there as well. The only unfortunate part is that the typedef for xdp_features_t has to move to netdevice.h, since its embedded in struct netdevice. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Jesper Dangaard Brouer <hawk@kernel.org> Link: https://lore.kernel.org/r/20230803010230.1755386-4-kuba@kernel.org Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-04-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netPaolo Abeni1-0/+1
No conflicts. Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-04-19netfilter: conntrack: restore IPS_CONFIRMED out of ↵Pablo Neira Ayuso1-0/+1
nf_conntrack_hash_check_insert() e6d57e9ff0ae ("netfilter: conntrack: fix rmmod double-free race") consolidates IPS_CONFIRMED bit set in nf_conntrack_hash_check_insert(). However, this breaks ctnetlink: # conntrack -I -p tcp --timeout 123 --src 1.2.3.4 --dst 5.6.7.8 --state ESTABLISHED --sport 1 --dport 4 -u SEEN_REPLY conntrack v1.4.6 (conntrack-tools): Operation failed: Device or resource busy This is a partial revert of the aforementioned commit to restore IPS_CONFIRMED. Fixes: e6d57e9ff0ae ("netfilter: conntrack: fix rmmod double-free race") Reported-by: Stéphane Graber <stgraber@stgraber.org> Tested-by: Stéphane Graber <stgraber@stgraber.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-04-05bpf: Remove unused arguments from btf_struct_access().Alexei Starovoitov1-2/+1
Remove unused arguments from btf_struct_access() callback. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230404045029.82870-3-alexei.starovoitov@gmail.com
2023-03-26bpf: Remove now-unnecessary NULL checks for KF_RELEASE kfuncsDavid Vernet1-2/+0
Now that we're not invoking kfunc destructors when the kptr in a map was NULL, we no longer require NULL checks in many of our KF_RELEASE kfuncs. This patch removes those NULL checks. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230325213144.486885-3-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nfJakub Kicinski1-1/+0
Pablo Neira Ayuso says: ==================== Netfilter fixes for net 1) Fix broken listing of set elements when table has an owner. 2) Fix conntrack refcount leak in ctnetlink with related conntrack entries, from Hangyu Hua. 3) Fix use-after-free/double-free in ctnetlink conntrack insert path, from Florian Westphal. 4) Fix ip6t_rpfilter with VRF, from Phil Sutter. 5) Fix use-after-free in ebtables reported by syzbot, also from Florian. 6) Use skb->len in xt_length to deal with IPv6 jumbo packets, from Xin Long. 7) Fix NETLINK_LISTEN_ALL_NSID with ctnetlink, from Florian Westphal. 8) Fix memleak in {ip_,ip6_,arp_}tables in ENOMEM error case, from Pavel Tikhomirov. * git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: netfilter: x_tables: fix percpu counter block leak on error path when creating new netns netfilter: ctnetlink: make event listener tracking global netfilter: xt_length: use skb len to match in length_mt6 netfilter: ebtables: fix table blob use-after-free netfilter: ip6t_rpfilter: Fix regression with VRF interfaces netfilter: conntrack: fix rmmod double-free race netfilter: ctnetlink: fix possible refcount leak in ctnetlink_create_conntrack() netfilter: nf_tables: allow to fetch set elements when table has an owner ==================== Link: https://lore.kernel.org/r/20230222092137.88637-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-02-22netfilter: conntrack: fix rmmod double-free raceFlorian Westphal1-1/+0
nf_conntrack_hash_check_insert() callers free the ct entry directly, via nf_conntrack_free. This isn't safe anymore because nf_conntrack_hash_check_insert() might place the entry into the conntrack table and then delteted the entry again because it found that a conntrack extension has been removed at the same time. In this case, the just-added entry is removed again and an error is returned to the caller. Problem is that another cpu might have picked up this entry and incremented its reference count. This results in a use-after-free/double-free, once by the other cpu and once by the caller of nf_conntrack_hash_check_insert(). Fix this by making nf_conntrack_hash_check_insert() not fail anymore after the insertion, just like before the 'Fixes' commit. This is safe because a racing nf_ct_iterate() has to wait for us to release the conntrack hash spinlocks. While at it, make the function return -EAGAIN in the rmmod (genid changed) case, this makes nfnetlink replay the command (suggested by Pablo Neira). Fixes: c56716c69ce1 ("netfilter: extensions: introduce extension genid count") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-02-02bpf: Add __bpf_kfunc tag to all kfuncsDavid Vernet1-10/+10
Now that we have the __bpf_kfunc tag, we should use add it to all existing kfuncs to ensure that they'll never be elided in LTO builds. Signed-off-by: David Vernet <void@manifault.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20230201173016.342758-4-void@manifault.com
2022-11-15bpf: Refactor btf_struct_accessKumar Kartikeya Dwivedi1-10/+7
Instead of having to pass multiple arguments that describe the register, pass the bpf_reg_state into the btf_struct_access callback. Currently, all call sites simply reuse the btf and btf_id of the reg they want to check the access of. The only exception to this pattern is the callsite in check_ptr_to_map_access, hence for that case create a dummy reg to simulate PTR_TO_BTF_ID access. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20221114191547.1694267-8-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-10-03net: netfilter: move bpf_ct_set_nat_info kfunc in nf_nat_bpf.cLorenzo Bianconi1-50/+0
Remove circular dependency between nf_nat module and nf_conntrack one moving bpf_ct_set_nat_info kfunc in nf_nat_bpf.c Fixes: 0fabd2aa199f ("net: netfilter: add bpf_ct_set_nat_info kfunc helper") Suggested-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Yauheni Kaliuta <ykaliuta@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/r/51a65513d2cda3eeb0754842e8025ab3966068d8.1664490511.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-22net: netfilter: add bpf_ct_set_nat_info kfunc helperLorenzo Bianconi1-1/+46
Introduce bpf_ct_set_nat_info kfunc helper in order to set source and destination nat addresses/ports in a new allocated ct entry not inserted in the connection tracking table yet. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Link: https://lore.kernel.org/r/9567db2fdfa5bebe7b7cc5870f7a34549418b4fc.1663778601.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-21bpf: Move nf_conn extern declarations to filter.hDaniel Xu1-0/+1
We're seeing the following new warnings on netdev/build_32bit and netdev/build_allmodconfig_warn CI jobs: ../net/core/filter.c:8608:1: warning: symbol 'nf_conn_btf_access_lock' was not declared. Should it be static? ../net/core/filter.c:8611:5: warning: symbol 'nfct_bsa' was not declared. Should it be static? Fix by ensuring extern declaration is present while compiling filter.o. Fixes: 864b656f82cc ("bpf: Add support for writing to nf_conn:mark") Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Link: https://lore.kernel.org/r/2bd2e0283df36d8a4119605878edb1838d144174.1663683114.git.dxu@dxuuu.xyz Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-09-21bpf: Rename nfct_bsa to nfct_btf_struct_accessDaniel Xu1-2/+2
The former name was a little hard to guess. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Link: https://lore.kernel.org/r/73adc72385c8b162391fbfb404f0b6d4c5cc55d7.1663683114.git.dxu@dxuuu.xyz Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-09-11bpf: Add support for writing to nf_conn:markDaniel Xu1-1/+65
Support direct writes to nf_conn:mark from TC and XDP prog types. This is useful when applications want to store per-connection metadata. This is also particularly useful for applications that run both bpf and iptables/nftables because the latter can trivially access this metadata. One example use case would be if a bpf prog is responsible for advanced packet classification and iptables/nftables is later used for routing due to pre-existing/legacy code. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> Link: https://lore.kernel.org/r/ebca06dea366e3e7e861c12f375a548cc4c61108.1662568410.git.dxu@dxuuu.xyz Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-22net: netfilter: Add kfuncs to set and change CT statusLorenzo Bianconi1-0/+32
Introduce bpf_ct_set_status and bpf_ct_change_status kfunc helpers in order to set nf_conn field of allocated entry or update nf_conn status field of existing inserted entry. Use nf_ct_change_status_common to share the permitted status field changes between netlink and BPF side by refactoring ctnetlink_change_status. It is required to introduce two kfuncs taking nf_conn___init and nf_conn instead of sharing one because KF_TRUSTED_ARGS flag causes strict type checking. This would disallow passing nf_conn___init to kfunc taking nf_conn, and vice versa. We cannot remove the KF_TRUSTED_ARGS flag as we only want to accept refcounted pointers and not e.g. ct->master. Hence, bpf_ct_set_* kfuncs are meant to be used on allocated CT, and bpf_ct_change_* kfuncs are meant to be used on inserted or looked up CT entry. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20220721134245.2450-10-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-22net: netfilter: Add kfuncs to set and change CT timeoutKumar Kartikeya Dwivedi1-3/+35
Introduce bpf_ct_set_timeout and bpf_ct_change_timeout kfunc helpers in order to change nf_conn timeout. This is same as ctnetlink_change_timeout, hence code is shared between both by extracting it out to __nf_ct_change_timeout. It is also updated to return an error when it sees IPS_FIXED_TIMEOUT_BIT bit in ct->status, as that check was missing. It is required to introduce two kfuncs taking nf_conn___init and nf_conn instead of sharing one because KF_TRUSTED_ARGS flag causes strict type checking. This would disallow passing nf_conn___init to kfunc taking nf_conn, and vice versa. We cannot remove the KF_TRUSTED_ARGS flag as we only want to accept refcounted pointers and not e.g. ct->master. Apart from this, bpf_ct_set_timeout is only called for newly allocated CT so it doesn't need to inspect the status field just yet. Sharing the helpers even if it was possible would make timeout setting helper sensitive to order of setting status and timeout after allocation. Hence, bpf_ct_set_* kfuncs are meant to be used on allocated CT, and bpf_ct_change_* kfuncs are meant to be used on inserted or looked up CT entry. Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20220721134245.2450-9-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-22net: netfilter: Add kfuncs to allocate and insert CTLorenzo Bianconi1-21/+187
Introduce bpf_xdp_ct_alloc, bpf_skb_ct_alloc and bpf_ct_insert_entry kfuncs in order to insert a new entry from XDP and TC programs. Introduce bpf_nf_ct_tuple_parse utility routine to consolidate common code. We extract out a helper __nf_ct_set_timeout, used by the ctnetlink and nf_conntrack_bpf code, extract it out to nf_conntrack_core, so that nf_conntrack_bpf doesn't need a dependency on CONFIG_NF_CT_NETLINK. Later this helper will be reused as a helper to set timeout of allocated but not yet inserted CT entry. The allocation functions return struct nf_conn___init instead of nf_conn, to distinguish allocated CT from an already inserted or looked up CT. This is later used to enforce restrictions on what kfuncs allocated CT can be used with. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20220721134245.2450-8-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-22net: netfilter: Deduplicate code in bpf_{xdp,skb}_ct_lookupKumar Kartikeya Dwivedi1-34/+18
Move common checks inside the common function, and maintain the only difference the two being how to obtain the struct net * from ctx. No functional change intended. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20220721134245.2450-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-07-22bpf: Switch to new kfunc flags infrastructureKumar Kartikeya Dwivedi1-38/+11
Instead of populating multiple sets to indicate some attribute and then researching the same BTF ID in them, prepare a single unified BTF set which indicates whether a kfunc is allowed to be called, and also its attributes if any at the same time. Now, only one call is needed to perform the lookup for both kfunc availability and its attributes. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20220721134245.2450-4-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-04-06net: netfilter: Reports ct direction in CT lookup helpers for XDP and TC-BPFLorenzo Bianconi1-7/+15
Report connection tracking tuple direction in bpf_skb_ct_lookup/bpf_xdp_ct_lookup helpers. Direction will be used to implement snat/dnat through xdp ebpf program. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/aa1aaac89191cfc64078ecef36c0a48c302321b9.1648908601.git.lorenzo@kernel.org
2022-03-06bpf: Replace __diag_ignore with unified __diag_ignore_allKumar Kartikeya Dwivedi1-2/+3
Currently, -Wmissing-prototypes warning is ignored for GCC, but not clang. This leads to clang build warning in W=1 mode. Since the flag used by both compilers is same, we can use the unified __diag_ignore_all macro that works for all supported versions and compilers which have __diag macro support (currently GCC >= 8.0, and Clang >= 11.0). Also add nf_conntrack_bpf.h include to prevent missing prototype warning for register_nf_conntrack_bpf. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20220304224645.3677453-8-memxor@gmail.com
2022-01-19net/netfilter: Add unstable CT lookup helpers for XDP and TC-BPFKumar Kartikeya Dwivedi1-0/+257
This change adds conntrack lookup helpers using the unstable kfunc call interface for the XDP and TC-BPF hooks. The primary usecase is implementing a synproxy in XDP, see Maxim's patchset [0]. Export get_net_ns_by_id as nf_conntrack_bpf.c needs to call it. This object is only built when CONFIG_DEBUG_INFO_BTF_MODULES is enabled. [0]: https://lore.kernel.org/bpf/20211019144655.3483197-1-maximmi@nvidia.com Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20220114163953.1455836-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>