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* bpf: Add bpf_get_func_ip helper for kprobe programsJiri Olsa2021-07-151-1/+1
| | | | | | | | | | | | | | Adding bpf_get_func_ip helper for BPF_PROG_TYPE_KPROBE programs, so it's now possible to call bpf_get_func_ip from both kprobe and kretprobe programs. Taking the caller's address from 'struct kprobe::addr', which is defined for both kprobe and kretprobe. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Link: https://lore.kernel.org/bpf/20210714094400.396467-5-jolsa@kernel.org
* bpf: Add bpf_get_func_ip helper for tracing programsJiri Olsa2021-07-151-0/+7
| | | | | | | | | | | | | Adding bpf_get_func_ip helper for BPF_PROG_TYPE_TRACING programs, specifically for all trampoline attach types. The trampoline's caller IP address is stored in (ctx - 8) address. so there's no reason to actually call the helper, but rather fixup the call instruction and return [ctx - 8] value directly. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210714094400.396467-4-jolsa@kernel.org
* bpf: Introduce bpf timers.Alexei Starovoitov2021-07-151-0/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce 'struct bpf_timer { __u64 :64; __u64 :64; };' that can be embedded in hash/array/lru maps as a regular field and helpers to operate on it: // Initialize the timer. // First 4 bits of 'flags' specify clockid. // Only CLOCK_MONOTONIC, CLOCK_REALTIME, CLOCK_BOOTTIME are allowed. long bpf_timer_init(struct bpf_timer *timer, struct bpf_map *map, int flags); // Configure the timer to call 'callback_fn' static function. long bpf_timer_set_callback(struct bpf_timer *timer, void *callback_fn); // Arm the timer to expire 'nsec' nanoseconds from the current time. long bpf_timer_start(struct bpf_timer *timer, u64 nsec, u64 flags); // Cancel the timer and wait for callback_fn to finish if it was running. long bpf_timer_cancel(struct bpf_timer *timer); Here is how BPF program might look like: struct map_elem { int counter; struct bpf_timer timer; }; struct { __uint(type, BPF_MAP_TYPE_HASH); __uint(max_entries, 1000); __type(key, int); __type(value, struct map_elem); } hmap SEC(".maps"); static int timer_cb(void *map, int *key, struct map_elem *val); /* val points to particular map element that contains bpf_timer. */ SEC("fentry/bpf_fentry_test1") int BPF_PROG(test1, int a) { struct map_elem *val; int key = 0; val = bpf_map_lookup_elem(&hmap, &key); if (val) { bpf_timer_init(&val->timer, &hmap, CLOCK_REALTIME); bpf_timer_set_callback(&val->timer, timer_cb); bpf_timer_start(&val->timer, 1000 /* call timer_cb2 in 1 usec */, 0); } } This patch adds helper implementations that rely on hrtimers to call bpf functions as timers expire. The following patches add necessary safety checks. Only programs with CAP_BPF are allowed to use bpf_timer. The amount of timers used by the program is constrained by the memcg recorded at map creation time. The bpf_timer_init() helper needs explicit 'map' argument because inner maps are dynamic and not known at load time. While the bpf_timer_set_callback() is receiving hidden 'aux->prog' argument supplied by the verifier. The prog pointer is needed to do refcnting of bpf program to make sure that program doesn't get freed while the timer is armed. This approach relies on "user refcnt" scheme used in prog_array that stores bpf programs for bpf_tail_call. The bpf_timer_set_callback() will increment the prog refcnt which is paired with bpf_timer_cancel() that will drop the prog refcnt. The ops->map_release_uref is responsible for cancelling the timers and dropping prog refcnt when user space reference to a map reaches zero. This uref approach is done to make sure that Ctrl-C of user space process will not leave timers running forever unless the user space explicitly pinned a map that contained timers in bpffs. bpf_timer_init() and bpf_timer_set_callback() will return -EPERM if map doesn't have user references (is not held by open file descriptor from user space and not pinned in bpffs). The bpf_map_delete_elem() and bpf_map_update_elem() operations cancel and free the timer if given map element had it allocated. "bpftool map update" command can be used to cancel timers. The 'struct bpf_timer' is explicitly __attribute__((aligned(8))) because '__u64 :64' has 1 byte alignment of 8 byte padding. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20210715005417.78572-4-alexei.starovoitov@gmail.com
* bpf: Fix a typo of reuseport map in bpf.h.Kuniyuki Iwashima2021-07-141-1/+1
| | | | | | | | | | | | Fix s/BPF_MAP_TYPE_REUSEPORT_ARRAY/BPF_MAP_TYPE_REUSEPORT_SOCKARRAY/ typo in bpf.h. Fixes: 2dbb9b9e6df6 ("bpf: Introduce BPF_PROG_TYPE_SK_REUSEPORT") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210714124317.67526-1-kuniyu@amazon.co.jp
* bpf: Sync tools/include/uapi/linux/bpf.hAlexei Starovoitov2021-07-141-3/+0
| | | | | | | | Commit 47316f4a3053 missed updating tools/.../bpf.h. Sync it. Fixes: 47316f4a3053 ("bpf: Support input xdp_md context in BPF_PROG_TEST_RUN") Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: Support socket migration by eBPF.Kuniyuki Iwashima2021-06-151-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces a new bpf_attach_type for BPF_PROG_TYPE_SK_REUSEPORT to check if the attached eBPF program is capable of migrating sockets. When the eBPF program is attached, we run it for socket migration if the expected_attach_type is BPF_SK_REUSEPORT_SELECT_OR_MIGRATE or net.ipv4.tcp_migrate_req is enabled. Currently, the expected_attach_type is not enforced for the BPF_PROG_TYPE_SK_REUSEPORT type of program. Thus, this commit follows the earlier idea in the commit aac3fc320d94 ("bpf: Post-hooks for sys_bind") to fix up the zero expected_attach_type in bpf_prog_load_fixup_attach_type(). Moreover, this patch adds a new field (migrating_sk) to sk_reuseport_md to select a new listener based on the child socket. migrating_sk varies depending on if it is migrating a request in the accept queue or during 3WHS. - accept_queue : sock (ESTABLISHED/SYN_RECV) - 3WHS : request_sock (NEW_SYN_RECV) In the eBPF program, we can select a new listener by BPF_FUNC_sk_select_reuseport(). Also, we can cancel migration by returning SK_DROP. This feature is useful when listeners have different settings at the socket API level or when we want to free resources as soon as possible. - SK_PASS with selected_sk, select it as a new listener - SK_PASS with selected_sk NULL, fallbacks to the random selection - SK_DROP, cancel the migration. There is a noteworthy point. We select a listening socket in three places, but we do not have struct skb at closing a listener or retransmitting a SYN+ACK. On the other hand, some helper functions do not expect skb is NULL (e.g. skb_header_pointer() in BPF_FUNC_skb_load_bytes(), skb_tail_pointer() in BPF_FUNC_skb_load_bytes_relative()). So we allocate an empty skb temporarily before running the eBPF program. Suggested-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/netdev/20201123003828.xjpjdtk4ygl6tg6h@kafai-mbp.dhcp.thefacebook.com/ Link: https://lore.kernel.org/netdev/20201203042402.6cskdlit5f3mw4ru@kafai-mbp.dhcp.thefacebook.com/ Link: https://lore.kernel.org/netdev/20201209030903.hhow5r53l6fmozjn@kafai-mbp.dhcp.thefacebook.com/ Link: https://lore.kernel.org/bpf/20210612123224.12525-10-kuniyu@amazon.co.jp
* bpf: Support BPF_FUNC_get_socket_cookie() for BPF_PROG_TYPE_SK_REUSEPORT.Kuniyuki Iwashima2021-06-151-0/+1
| | | | | | | | | | | | | | | | | | | | We will call sock_reuseport.prog for socket migration in the next commit, so the eBPF program has to know which listener is closing to select a new listener. We can currently get a unique ID of each listener in the userspace by calling bpf_map_lookup_elem() for BPF_MAP_TYPE_REUSEPORT_SOCKARRAY map. This patch makes the pointer of sk available in sk_reuseport_md so that we can get the ID by BPF_FUNC_get_socket_cookie() in the eBPF program. Suggested-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/netdev/20201119001154.kapwihc2plp4f7zc@kafai-mbp.dhcp.thefacebook.com/ Link: https://lore.kernel.org/bpf/20210612123224.12525-9-kuniyu@amazon.co.jp
* xdp: Extend xdp_redirect_map with broadcast supportHangbin Liu2021-05-261-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds two flags BPF_F_BROADCAST and BPF_F_EXCLUDE_INGRESS to extend xdp_redirect_map for broadcast support. With BPF_F_BROADCAST the packet will be broadcasted to all the interfaces in the map. with BPF_F_EXCLUDE_INGRESS the ingress interface will be excluded when do broadcasting. When getting the devices in dev hash map via dev_map_hash_get_next_key(), there is a possibility that we fall back to the first key when a device was removed. This will duplicate packets on some interfaces. So just walk the whole buckets to avoid this issue. For dev array map, we also walk the whole map to find valid interfaces. Function bpf_clear_redirect_map() was removed in commit ee75aef23afe ("bpf, xdp: Restructure redirect actions"). Add it back as we need to use ri->map again. With test topology: +-------------------+ +-------------------+ | Host A (i40e 10G) | ---------- | eno1(i40e 10G) | +-------------------+ | | | Host B | +-------------------+ | | | Host C (i40e 10G) | ---------- | eno2(i40e 10G) | +-------------------+ | | | +------+ | | veth0 -- | Peer | | | veth1 -- | | | | veth2 -- | NS | | | +------+ | +-------------------+ On Host A: # pktgen/pktgen_sample03_burst_single_flow.sh -i eno1 -d $dst_ip -m $dst_mac -s 64 On Host B(Intel(R) Xeon(R) CPU E5-2690 v3 @ 2.60GHz, 128G Memory): Use xdp_redirect_map and xdp_redirect_map_multi in samples/bpf for testing. All the veth peers in the NS have a XDP_DROP program loaded. The forward_map max_entries in xdp_redirect_map_multi is modify to 4. Testing the performance impact on the regular xdp_redirect path with and without patch (to check impact of additional check for broadcast mode): 5.12 rc4 | redirect_map i40e->i40e | 2.0M | 9.7M 5.12 rc4 | redirect_map i40e->veth | 1.7M | 11.8M 5.12 rc4 + patch | redirect_map i40e->i40e | 2.0M | 9.6M 5.12 rc4 + patch | redirect_map i40e->veth | 1.7M | 11.7M Testing the performance when cloning packets with the redirect_map_multi test, using a redirect map size of 4, filled with 1-3 devices: 5.12 rc4 + patch | redirect_map multi i40e->veth (x1) | 1.7M | 11.4M 5.12 rc4 + patch | redirect_map multi i40e->veth (x2) | 1.1M | 4.3M 5.12 rc4 + patch | redirect_map multi i40e->veth (x3) | 0.8M | 2.6M Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/20210519090747.1655268-3-liuhangbin@gmail.com
* bpf: Add lookup_and_delete_elem support to hashtabDenis Salopek2021-05-241-0/+13
| | | | | | | | | | | | | Extend the existing bpf_map_lookup_and_delete_elem() functionality to hashtab map types, in addition to stacks and queues. Create a new hashtab bpf_map_ops function that does lookup and deletion of the element under the same bucket lock and add the created map_ops to bpf.h. Signed-off-by: Denis Salopek <denis.salopek@sartura.hr> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/4d18480a3e990ffbf14751ddef0325eed3be2966.1620763117.git.denis.salopek@sartura.hr
* bpf: Add cmd alias BPF_PROG_RUNAlexei Starovoitov2021-05-191-0/+1
| | | | | | | | | | | Add BPF_PROG_RUN command as an alias to BPF_RPOG_TEST_RUN to better indicate the full range of use cases done by the command. Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210519014032.20908-1-alexei.starovoitov@gmail.com
* bpf: Add bpf_sys_close() helper.Alexei Starovoitov2021-05-191-0/+7
| | | | | | | | | | | Add bpf_sys_close() helper to be used by the syscall/loader program to close intermediate FDs and other cleanup. Note this helper must never be allowed inside fdget/fdput bracketing. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210514003623.28033-11-alexei.starovoitov@gmail.com
* bpf: Add bpf_btf_find_by_name_kind() helper.Alexei Starovoitov2021-05-191-0/+7
| | | | | | | | | | | | | | | | | Add new helper: long bpf_btf_find_by_name_kind(char *name, int name_sz, u32 kind, int flags) Description Find BTF type with given name and kind in vmlinux BTF or in module's BTFs. Return Returns btf_id and btf_obj_fd in lower and upper 32 bits. It will be used by loader program to find btf_id to attach the program to and to find btf_ids of ksyms. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210514003623.28033-10-alexei.starovoitov@gmail.com
* bpf: Introduce fd_idxAlexei Starovoitov2021-05-191-5/+11
| | | | | | | | | | | | | | | | Typical program loading sequence involves creating bpf maps and applying map FDs into bpf instructions in various places in the bpf program. This job is done by libbpf that is using compiler generated ELF relocations to patch certain instruction after maps are created and BTFs are loaded. The goal of fd_idx is to allow bpf instructions to stay immutable after compilation. At load time the libbpf would still create maps as usual, but it wouldn't need to patch instructions. It would store map_fds into __u32 fd_array[] and would pass that pointer to sys_bpf(BPF_PROG_LOAD). Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210514003623.28033-9-alexei.starovoitov@gmail.com
* bpf: Introduce bpf_sys_bpf() helper and program type.Alexei Starovoitov2021-05-191-0/+8
| | | | | | | | | | | | | Add placeholders for bpf_sys_bpf() helper and new program type. Make sure to check that expected_attach_type is zero for future extensibility. Allow tracing helper functions to be used in this program type, since they will only execute from user context via bpf_prog_test_run. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210514003623.28033-2-alexei.starovoitov@gmail.com
* bpf: Add a bpf_snprintf helperFlorent Revest2021-04-191-0/+28
| | | | | | | | | | | | | | | | | | | | | | | The implementation takes inspiration from the existing bpf_trace_printk helper but there are a few differences: To allow for a large number of format-specifiers, parameters are provided in an array, like in bpf_seq_printf. Because the output string takes two arguments and the array of parameters also takes two arguments, the format string needs to fit in one argument. Thankfully, ARG_PTR_TO_CONST_STR is guaranteed to point to a zero-terminated read-only map so we don't need a format string length arg. Because the format-string is known at verification time, we also do a first pass of format string validation in the verifier logic. This makes debugging easier. Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210419155243.1632274-4-revest@chromium.org
* bpf: Return target info when a tracing bpf_link is queriedToke Høiland-Jørgensen2021-04-131-0/+2
| | | | | | | | | | | There is currently no way to discover the target of a tracing program attachment after the fact. Add this information to bpf_link_info and return it when querying the bpf_link fd. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210413091607.58945-1-toke@redhat.com
* libbpf: Clarify flags in ringbuf helpersPedro Tammela2021-04-121-0/+16
| | | | | | | | | | | In 'bpf_ringbuf_reserve()' we require the flag to '0' at the moment. For 'bpf_ringbuf_{discard,submit,output}' a flag of '0' might send a notification to the process if needed. Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210412192434.944343-1-pctammela@mojatatu.com
* bpf: Sync bpf headers in tooling infrastuctureDaniel Borkmann2021-04-121-5/+32
| | | | | | | | | | Synchronize tools/include/uapi/linux/bpf.h which was missing changes from various commits: - f3c45326ee71 ("bpf: Document PROG_TEST_RUN limitations") - e5e35e754c28 ("bpf: BPF-helper for MTU checking add length input") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
* sock_map: Introduce BPF_SK_SKB_VERDICTCong Wang2021-04-011-0/+1
| | | | | | | | | | | | | | Reusing BPF_SK_SKB_STREAM_VERDICT is possible but its name is confusing and more importantly we still want to distinguish them from user-space. So we can just reuse the stream verdict code but introduce a new type of eBPF program, skb_verdict. Users are not allowed to attach stream_verdict and skb_verdict programs to the same map. Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210331023237.41094-10-xiyou.wangcong@gmail.com
* bpf: Support bpf program calling kernel functionMartin KaFai Lau2021-03-261-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds support to BPF verifier to allow bpf program calling kernel function directly. The use case included in this set is to allow bpf-tcp-cc to directly call some tcp-cc helper functions (e.g. "tcp_cong_avoid_ai()"). Those functions have already been used by some kernel tcp-cc implementations. This set will also allow the bpf-tcp-cc program to directly call the kernel tcp-cc implementation, For example, a bpf_dctcp may only want to implement its own dctcp_cwnd_event() and reuse other dctcp_*() directly from the kernel tcp_dctcp.c instead of reimplementing (or copy-and-pasting) them. The tcp-cc kernel functions mentioned above will be white listed for the struct_ops bpf-tcp-cc programs to use in a later patch. The white listed functions are not bounded to a fixed ABI contract. Those functions have already been used by the existing kernel tcp-cc. If any of them has changed, both in-tree and out-of-tree kernel tcp-cc implementations have to be changed. The same goes for the struct_ops bpf-tcp-cc programs which have to be adjusted accordingly. This patch is to make the required changes in the bpf verifier. First change is in btf.c, it adds a case in "btf_check_func_arg_match()". When the passed in "btf->kernel_btf == true", it means matching the verifier regs' states with a kernel function. This will handle the PTR_TO_BTF_ID reg. It also maps PTR_TO_SOCK_COMMON, PTR_TO_SOCKET, and PTR_TO_TCP_SOCK to its kernel's btf_id. In the later libbpf patch, the insn calling a kernel function will look like: insn->code == (BPF_JMP | BPF_CALL) insn->src_reg == BPF_PSEUDO_KFUNC_CALL /* <- new in this patch */ insn->imm == func_btf_id /* btf_id of the running kernel */ [ For the future calling function-in-kernel-module support, an array of module btf_fds can be passed at the load time and insn->off can be used to index into this array. ] At the early stage of verifier, the verifier will collect all kernel function calls into "struct bpf_kfunc_desc". Those descriptors are stored in "prog->aux->kfunc_tab" and will be available to the JIT. Since this "add" operation is similar to the current "add_subprog()" and looking for the same insn->code, they are done together in the new "add_subprog_and_kfunc()". In the "do_check()" stage, the new "check_kfunc_call()" is added to verify the kernel function call instruction: 1. Ensure the kernel function can be used by a particular BPF_PROG_TYPE. A new bpf_verifier_ops "check_kfunc_call" is added to do that. The bpf-tcp-cc struct_ops program will implement this function in a later patch. 2. Call "btf_check_kfunc_args_match()" to ensure the regs can be used as the args of a kernel function. 3. Mark the regs' type, subreg_def, and zext_dst. At the later do_misc_fixups() stage, the new fixup_kfunc_call() will replace the insn->imm with the function address (relative to __bpf_call_base). If needed, the jit can find the btf_func_model by calling the new bpf_jit_find_kfunc_model(prog, insn). With the imm set to the function address, "bpftool prog dump xlated" will be able to display the kernel function calls the same way as it displays other bpf helper calls. gpl_compatible program is required to call kernel function. This feature currently requires JIT. The verifier selftests are adjusted because of the changes in the verbose log in add_subprog_and_kfunc(). Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210325015142.1544736-1-kafai@fb.com
* bpf: Add bpf_skb_adjust_room flag BPF_F_ADJ_ROOM_ENCAP_L2_ETHXuesen Huang2021-03-051-0/+5
| | | | | | | | | | | | | | | | bpf_skb_adjust_room sets the inner_protocol as skb->protocol for packets encapsulation. But that is not appropriate when pushing Ethernet header. Add an option to further specify encap L2 type and set the inner_protocol as ETH_P_TEB. Suggested-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Xuesen Huang <huangxuesen@kuaishou.com> Signed-off-by: Zhiyong Cheng <chengzhiyong@kuaishou.com> Signed-off-by: Li Wang <wangli09@kuaishou.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/bpf/20210304064046.6232-1-hxseverything@gmail.com
* bpf: Add PROG_TEST_RUN support for sk_lookup programsLorenz Bauer2021-03-041-1/+4
| | | | | | | | | | | | | | | | Allow to pass sk_lookup programs to PROG_TEST_RUN. User space provides the full bpf_sk_lookup struct as context. Since the context includes a socket pointer that can't be exposed to user space we define that PROG_TEST_RUN returns the cookie of the selected socket or zero in place of the socket pointer. We don't support testing programs that select a reuseport socket, since this would mean running another (unrelated) BPF program from the sk_lookup test handler. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210303101816.36774-3-lmb@cloudflare.com
* tools: Sync uapi bpf.h header with latest changesJoe Stringer2021-03-041-1/+711
| | | | | | | | | | Synchronize the header after all of the recent changes. Signed-off-by: Joe Stringer <joe@cilium.io> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20210302171947.2268128-16-joe@cilium.io
* scripts/bpf: Abstract eBPF API target parameterJoe Stringer2021-03-041-1/+1
| | | | | | | | | | | | Abstract out the target parameter so that upcoming commits, more than just the existing "helpers" target can be called to generate specific portions of docs from the eBPF UAPI headers. Signed-off-by: Joe Stringer <joe@cilium.io> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20210302171947.2268128-10-joe@cilium.io
* bpf: Add bpf_for_each_map_elem() helperYonghong Song2021-02-261-0/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bpf_for_each_map_elem() helper is introduced which iterates all map elements with a callback function. The helper signature looks like long bpf_for_each_map_elem(map, callback_fn, callback_ctx, flags) and for each map element, the callback_fn will be called. For example, like hashmap, the callback signature may look like long callback_fn(map, key, val, callback_ctx) There are two known use cases for this. One is from upstream ([1]) where a for_each_map_elem helper may help implement a timeout mechanism in a more generic way. Another is from our internal discussion for a firewall use case where a map contains all the rules. The packet data can be compared to all these rules to decide allow or deny the packet. For array maps, users can already use a bounded loop to traverse elements. Using this helper can avoid using bounded loop. For other type of maps (e.g., hash maps) where bounded loop is hard or impossible to use, this helper provides a convenient way to operate on all elements. For callback_fn, besides map and map element, a callback_ctx, allocated on caller stack, is also passed to the callback function. This callback_ctx argument can provide additional input and allow to write to caller stack for output. If the callback_fn returns 0, the helper will iterate through next element if available. If the callback_fn returns 1, the helper will stop iterating and returns to the bpf program. Other return values are not used for now. Currently, this helper is only available with jit. It is possible to make it work with interpreter with so effort but I leave it as the future work. [1]: https://lore.kernel.org/bpf/20210122205415.113822-1-xiyou.wangcong@gmail.com/ Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210226204925.3884923-1-yhs@fb.com
* bpf: Remove blank line in bpf helper description commentHangbin Liu2021-02-261-1/+0
| | | | | | | | | | | | | | Commit 34b2021cc616 ("bpf: Add BPF-helper for MTU checking") added an extra blank line in bpf helper description. This will make bpf_helpers_doc.py stop building bpf_helper_defs.h immediately after bpf_check_mtu(), which will affect future added functions. Fixes: 34b2021cc616 ("bpf: Add BPF-helper for MTU checking") Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/20210223131457.1378978-1-liuhangbin@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* bpf: Add BPF-helper for MTU checkingJesper Dangaard Brouer2021-02-131-0/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This BPF-helper bpf_check_mtu() works for both XDP and TC-BPF programs. The SKB object is complex and the skb->len value (accessible from BPF-prog) also include the length of any extra GRO/GSO segments, but without taking into account that these GRO/GSO segments get added transport (L4) and network (L3) headers before being transmitted. Thus, this BPF-helper is created such that the BPF-programmer don't need to handle these details in the BPF-prog. The API is designed to help the BPF-programmer, that want to do packet context size changes, which involves other helpers. These other helpers usually does a delta size adjustment. This helper also support a delta size (len_diff), which allow BPF-programmer to reuse arguments needed by these other helpers, and perform the MTU check prior to doing any actual size adjustment of the packet context. It is on purpose, that we allow the len adjustment to become a negative result, that will pass the MTU check. This might seem weird, but it's not this helpers responsibility to "catch" wrong len_diff adjustments. Other helpers will take care of these checks, if BPF-programmer chooses to do actual size adjustment. V14: - Improve man-page desc of len_diff. V13: - Enforce flag BPF_MTU_CHK_SEGS cannot use len_diff. V12: - Simplify segment check that calls skb_gso_validate_network_len. - Helpers should return long V9: - Use dev->hard_header_len (instead of ETH_HLEN) - Annotate with unlikely req from Daniel - Fix logic error using skb_gso_validate_network_len from Daniel V6: - Took John's advice and dropped BPF_MTU_CHK_RELAX - Returned MTU is kept at L3-level (like fib_lookup) V4: Lot of changes - ifindex 0 now use current netdev for MTU lookup - rename helper from bpf_mtu_check to bpf_check_mtu - fix bug for GSO pkt length (as skb->len is total len) - remove __bpf_len_adj_positive, simply allow negative len adj Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/161287790461.790810.3429728639563297353.stgit@firesoul
* bpf: bpf_fib_lookup return MTU value as output when looked upJesper Dangaard Brouer2021-02-131-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | The BPF-helpers for FIB lookup (bpf_xdp_fib_lookup and bpf_skb_fib_lookup) can perform MTU check and return BPF_FIB_LKUP_RET_FRAG_NEEDED. The BPF-prog don't know the MTU value that caused this rejection. If the BPF-prog wants to implement PMTU (Path MTU Discovery) (rfc1191) it need to know this MTU value for the ICMP packet. Patch change lookup and result struct bpf_fib_lookup, to contain this MTU value as output via a union with 'tot_len' as this is the value used for the MTU lookup. V5: - Fixed uninit value spotted by Dan Carpenter. - Name struct output member mtu_result Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/161287789952.790810.13134700381067698781.stgit@firesoul
* bpf: Expose bpf_get_socket_cookie to tracing programsFlorent Revest2021-02-111-0/+8
| | | | | | | | | | | | This needs a new helper that: - can work in a sleepable context (using sock_gen_cookie) - takes a struct sock pointer and checks that it's not NULL Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: KP Singh <kpsingh@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210210111406.785541-2-revest@chromium.org
* bpf: Be less specific about socket cookies guaranteesFlorent Revest2021-02-111-4/+4
| | | | | | | | | | | | | Since "92acdc58ab11 bpf, net: Rework cookie generator as per-cpu one" socket cookies are not guaranteed to be non-decreasing. The bpf_get_socket_cookie helper descriptions are currently specifying that cookies are non-decreasing but we don't want users to rely on that. Reported-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: KP Singh <kpsingh@kernel.org> Link: https://lore.kernel.org/bpf/20210210111406.785541-1-revest@chromium.org
* bpf: Count the number of times recursion was preventedAlexei Starovoitov2021-02-111-0/+1
| | | | | | | | | | | Add per-program counter for number of times recursion prevention mechanism was triggered and expose it via show_fdinfo and bpf_prog_info. Teach bpftool to print it. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210210033634.62081-7-alexei.starovoitov@gmail.com
* bpf: Add instructions for atomic_[cmp]xchgBrendan Jackman2021-01-141-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds two atomic opcodes, both of which include the BPF_FETCH flag. XCHG without the BPF_FETCH flag would naturally encode atomic_set. This is not supported because it would be of limited value to userspace (it doesn't imply any barriers). CMPXCHG without BPF_FETCH woulud be an atomic compare-and-write. We don't have such an operation in the kernel so it isn't provided to BPF either. There are two significant design decisions made for the CMPXCHG instruction: - To solve the issue that this operation fundamentally has 3 operands, but we only have two register fields. Therefore the operand we compare against (the kernel's API calls it 'old') is hard-coded to be R0. x86 has similar design (and A64 doesn't have this problem). A potential alternative might be to encode the other operand's register number in the immediate field. - The kernel's atomic_cmpxchg returns the old value, while the C11 userspace APIs return a boolean indicating the comparison result. Which should BPF do? A64 returns the old value. x86 returns the old value in the hard-coded register (and also sets a flag). That means return-old-value is easier to JIT, so that's what we use. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210114181751.768687-8-jackmanb@google.com
* bpf: Add BPF_FETCH field / create atomic_fetch_add instructionBrendan Jackman2021-01-141-0/+3
| | | | | | | | | | | | | The BPF_FETCH field can be set in bpf_insn.imm, for BPF_ATOMIC instructions, in order to have the previous value of the atomically-modified memory location loaded into the src register after an atomic op is carried out. Suggested-by: Yonghong Song <yhs@fb.com> Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20210114181751.768687-7-jackmanb@google.com
* bpf: Rename BPF_XADD and prepare to encode other atomics in .immBrendan Jackman2021-01-141-2/+3
| | | | | | | | | | | | | | | | | | | | | A subsequent patch will add additional atomic operations. These new operations will use the same opcode field as the existing XADD, with the immediate discriminating different operations. In preparation, rename the instruction mode BPF_ATOMIC and start calling the zero immediate BPF_ADD. This is possible (doesn't break existing valid BPF progs) because the immediate field is currently reserved MBZ and BPF_ADD is zero. All uses are removed from the tree but the BPF_XADD definition is kept around to avoid breaking builds for people including kernel headers. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Björn Töpel <bjorn.topel@gmail.com> Link: https://lore.kernel.org/bpf/20210114181751.768687-5-jackmanb@google.com
* bpf: Clarify return value of probe str helpersBrendan Jackman2021-01-121-5/+5
| | | | | | | | | | | | | When the buffer is too small to contain the input string, these helpers return the length of the buffer, not the length of the original string. This tries to make the docs totally clear about that, since "the length of the [copied ]string" could also refer to the length of the input. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: KP Singh <kpsingh@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210112123422.2011234-1-jackmanb@google.com
* Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski2020-12-141-0/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf-next 2020-12-14 1) Expose bpf_sk_storage_*() helpers to iterator programs, from Florent Revest. 2) Add AF_XDP selftests based on veth devs to BPF selftests, from Weqaar Janjua. 3) Support for finding BTF based kernel attach targets through libbpf's bpf_program__set_attach_target() API, from Andrii Nakryiko. 4) Permit pointers on stack for helper calls in the verifier, from Yonghong Song. 5) Fix overflows in hash map elem size after rlimit removal, from Eric Dumazet. 6) Get rid of direct invocation of llc in BPF selftests, from Andrew Delgadillo. 7) Fix xsk_recvmsg() to reorder socket state check before access, from Björn Töpel. 8) Add new libbpf API helper to retrieve ring buffer epoll fd, from Brendan Jackman. 9) Batch of minor BPF selftest improvements all over the place, from Florian Lehner, KP Singh, Jiri Olsa and various others. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (31 commits) selftests/bpf: Add a test for ptr_to_map_value on stack for helper access bpf: Permits pointers on stack for helper calls libbpf: Expose libbpf ring_buffer epoll_fd selftests/bpf: Add set_attach_target() API selftest for module target libbpf: Support modules in bpf_program__set_attach_target() API selftests/bpf: Silence ima_setup.sh when not running in verbose mode. selftests/bpf: Drop the need for LLVM's llc selftests/bpf: fix bpf_testmod.ko recompilation logic samples/bpf: Fix possible hang in xdpsock with multiple threads selftests/bpf: Make selftest compilation work on clang 11 selftests/bpf: Xsk selftests - adding xdpxceiver to .gitignore selftests/bpf: Drop tcp-{client,server}.py from Makefile selftests/bpf: Xsk selftests - Bi-directional Sockets - SKB, DRV selftests/bpf: Xsk selftests - Socket Teardown - SKB, DRV selftests/bpf: Xsk selftests - DRV POLL, NOPOLL selftests/bpf: Xsk selftests - SKB POLL, NOPOLL selftests/bpf: Xsk selftests framework bpf: Only provide bpf_sock_from_file with CONFIG_NET bpf: Return -ENOTSUPP when attaching to non-kernel BTF xsk: Validate socket state in xsk_recvmsg, prior touching socket members ... ==================== Link: https://lore.kernel.org/r/20201214214316.20642-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * bpf: Add a bpf_sock_from_file helperFlorent Revest2020-12-041-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While eBPF programs can check whether a file is a socket by file->f_op == &socket_file_ops, they cannot convert the void private_data pointer to a struct socket BTF pointer. In order to do this a new helper wrapping sock_from_file is added. This is useful to tracing programs but also other program types inheriting this set of helpers such as iterators or LSM programs. Signed-off-by: Florent Revest <revest@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: KP Singh <kpsingh@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20201204113609.1850150-2-revest@google.com
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2020-12-111-2/+2
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | xdp_return_frame_bulk() needs to pass a xdp_buff to __xdp_return(). strlcpy got converted to strscpy but here it makes no functional difference, so just keep the right code. Conflicts: net/netfilter/nf_tables_api.c Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * bpf: Fix enum names for bpf_this_cpu_ptr() and bpf_per_cpu_ptr() helpersAndrii Nakryiko2020-12-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | Remove bpf_ prefix, which causes these helpers to be reported in verifier dump as bpf_bpf_this_cpu_ptr() and bpf_bpf_per_cpu_ptr(), respectively. Lets fix it as long as it is still possible before UAPI freezes on these helpers. Fixes: eaa6bcb71ef6 ("bpf: Introduce bpf_per_cpu_ptr()") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | bpf: Allow to specify kernel module BTFs when attaching BPF programsAndrii Nakryiko2020-12-031-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | Add ability for user-space programs to specify non-vmlinux BTF when attaching BTF-powered BPF programs: raw_tp, fentry/fexit/fmod_ret, LSM, etc. For this, attach_prog_fd (now with the alias name attach_btf_obj_fd) should specify FD of a module or vmlinux BTF object. For backwards compatibility reasons, 0 denotes vmlinux BTF. Only kernel BTF (vmlinux or module) can be specified. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201203204634.1325171-11-andrii@kernel.org
* | bpf: Add a BPF helper for getting the IMA hash of an inodeKP Singh2020-11-261-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a wrapper function to get the IMA hash of an inode. This helper is useful in fingerprinting files (e.g executables on execution) and using these fingerprints in detections like an executable unlinking itself. Since the ima_inode_hash can sleep, it's only allowed for sleepable LSM hooks. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20201124151210.1081188-3-kpsingh@chromium.org
* | bpf: Add bpf_ktime_get_coarse_ns helperDmitrii Banshchikov2020-11-181-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The helper uses CLOCK_MONOTONIC_COARSE source of time that is less accurate but more performant. We have a BPF CGROUP_SKB firewall that supports event logging through bpf_perf_event_output(). Each event has a timestamp and currently we use bpf_ktime_get_ns() for it. Use of bpf_ktime_get_coarse_ns() saves ~15-20 ns in time required for event logging. bpf_ktime_get_ns(): EgressLogByRemoteEndpoint 113.82ns 8.79M bpf_ktime_get_coarse_ns(): EgressLogByRemoteEndpoint 95.40ns 10.48M Signed-off-by: Dmitrii Banshchikov <me@ubique.spb.ru> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20201117184549.257280-1-me@ubique.spb.ru
* | bpf: Add bpf_bprm_opts_set helperKP Singh2020-11-181-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The helper allows modification of certain bits on the linux_binprm struct starting with the secureexec bit which can be updated using the BPF_F_BPRM_SECUREEXEC flag. secureexec can be set by the LSM for privilege gaining executions to set the AT_SECURE auxv for glibc. When set, the dynamic linker disables the use of certain environment variables (like LD_PRELOAD). Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20201117232929.2156341-1-kpsingh@chromium.org
* | bpf: Assign ID to vmlinux BTF and return extra info for BTF in GET_OBJ_INFOAndrii Nakryiko2020-11-101-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allocate ID for vmlinux BTF. This makes it visible when iterating over all BTF objects in the system. To allow distinguishing vmlinux BTF (and later kernel module BTF) from user-provided BTFs, expose extra kernel_btf flag, as well as BTF name ("vmlinux" for vmlinux BTF, will equal to module's name for module BTF). We might want to later allow specifying BTF name for user-provided BTFs as well, if that makes sense. But currently this is reserved only for in-kernel BTFs. Having in-kernel BTFs exposed IDs will allow to extend BPF APIs that require in-kernel BTF type with ability to specify BTF types from kernel modules, not just vmlinux BTF. This will be implemented in a follow up patch set for fentry/fexit/fmod_ret/lsm/etc. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20201110011932.3201430-3-andrii@kernel.org
* | bpf: Implement get_current_task_btf and RET_PTR_TO_BTF_IDKP Singh2020-11-061-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The currently available bpf_get_current_task returns an unsigned integer which can be used along with BPF_CORE_READ to read data from the task_struct but still cannot be used as an input argument to a helper that accepts an ARG_PTR_TO_BTF_ID of type task_struct. In order to implement this helper a new return type, RET_PTR_TO_BTF_ID, is added. This is similar to RET_PTR_TO_BTF_ID_OR_NULL but does not require checking the nullness of returned pointer. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20201106103747.2780972-6-kpsingh@chromium.org
* | bpf: Implement task local storageKP Singh2020-11-061-0/+39
|/ | | | | | | | | | | | | | | | | | | | | | | Similar to bpf_local_storage for sockets and inodes add local storage for task_struct. The life-cycle of storage is managed with the life-cycle of the task_struct. i.e. the storage is destroyed along with the owning task with a callback to the bpf_task_storage_free from the task_free LSM hook. The BPF LSM allocates an __rcu pointer to the bpf_local_storage in the security blob which are now stackable and can co-exist with other LSMs. The userspace map operations can be done by using a pid fd as a key passed to the lookup, update and delete operations. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20201106103747.2780972-3-kpsingh@chromium.org
* bpf: Fix bpf_redirect_neigh helper api to support supplying nexthopToke Høiland-Jørgensen2020-10-221-4/+18
| | | | | | | | | | | | | | | | | Based on the discussion in [0], update the bpf_redirect_neigh() helper to accept an optional parameter specifying the nexthop information. This makes it possible to combine bpf_fib_lookup() and bpf_redirect_neigh() without incurring a duplicate FIB lookup - since the FIB lookup helper will return the nexthop information even if no neighbour is present, this can simply be passed on to bpf_redirect_neigh() if bpf_fib_lookup() returns BPF_FIB_LKUP_RET_NO_NEIGH. Thus fix & extend it before helper API is frozen. [0] https://lore.kernel.org/bpf/393e17fc-d187-3a8d-2f0d-a627c7c63fca@iogearbox.net/ Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/bpf/160322915615.32199.1187570224032024535.stgit@toke.dk
* bpf: Allow for map-in-map with dynamic inner array map entriesDaniel Borkmann2020-10-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recent work in f4d05259213f ("bpf: Add map_meta_equal map ops") and 134fede4eecf ("bpf: Relax max_entries check for most of the inner map types") added support for dynamic inner max elements for most map-in-map types. Exceptions were maps like array or prog array where the map_gen_lookup() callback uses the maps' max_entries field as a constant when emitting instructions. We recently implemented Maglev consistent hashing into Cilium's load balancer which uses map-in-map with an outer map being hash and inner being array holding the Maglev backend table for each service. This has been designed this way in order to reduce overall memory consumption given the outer hash map allows to avoid preallocating a large, flat memory area for all services. Also, the number of service mappings is not always known a-priori. The use case for dynamic inner array map entries is to further reduce memory overhead, for example, some services might just have a small number of back ends while others could have a large number. Right now the Maglev backend table for small and large number of backends would need to have the same inner array map entries which adds a lot of unneeded overhead. Dynamic inner array map entries can be realized by avoiding the inlined code generation for their lookup. The lookup will still be efficient since it will be calling into array_map_lookup_elem() directly and thus avoiding retpoline. The patch adds a BPF_F_INNER_MAP flag to map creation which therefore skips inline code generation and relaxes array_map_meta_equal() check to ignore both maps' max_entries. This also still allows to have faster lookups for map-in-map when BPF_F_INNER_MAP is not specified and hence dynamic max_entries not needed. Example code generation where inner map is dynamic sized array: # bpftool p d x i 125 int handle__sys_enter(void * ctx): ; int handle__sys_enter(void *ctx) 0: (b4) w1 = 0 ; int key = 0; 1: (63) *(u32 *)(r10 -4) = r1 2: (bf) r2 = r10 ; 3: (07) r2 += -4 ; inner_map = bpf_map_lookup_elem(&outer_arr_dyn, &key); 4: (18) r1 = map[id:468] 6: (07) r1 += 272 7: (61) r0 = *(u32 *)(r2 +0) 8: (35) if r0 >= 0x3 goto pc+5 9: (67) r0 <<= 3 10: (0f) r0 += r1 11: (79) r0 = *(u64 *)(r0 +0) 12: (15) if r0 == 0x0 goto pc+1 13: (05) goto pc+1 14: (b7) r0 = 0 15: (b4) w6 = -1 ; if (!inner_map) 16: (15) if r0 == 0x0 goto pc+6 17: (bf) r2 = r10 ; 18: (07) r2 += -4 ; val = bpf_map_lookup_elem(inner_map, &key); 19: (bf) r1 = r0 | No inlining but instead 20: (85) call array_map_lookup_elem#149280 | call to array_map_lookup_elem() ; return val ? *val : -1; | for inner array lookup. 21: (15) if r0 == 0x0 goto pc+1 ; return val ? *val : -1; 22: (61) r6 = *(u32 *)(r0 +0) ; } 23: (bc) w0 = w6 24: (95) exit Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20201010234006.7075-4-daniel@iogearbox.net
* bpf: Add redirect_peer helperDaniel Borkmann2020-10-111-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add an efficient ingress to ingress netns switch that can be used out of tc BPF programs in order to redirect traffic from host ns ingress into a container veth device ingress without having to go via CPU backlog queue [0]. For local containers this can also be utilized and path via CPU backlog queue only needs to be taken once, not twice. On a high level this borrows from ipvlan which does similar switch in __netif_receive_skb_core() and then iterates via another_round. This helps to reduce latency for mentioned use cases. Pod to remote pod with redirect(), TCP_RR [1]: # percpu_netperf 10.217.1.33 RT_LATENCY: 122.450 (per CPU: 122.666 122.401 122.333 122.401 ) MEAN_LATENCY: 121.210 (per CPU: 121.100 121.260 121.320 121.160 ) STDDEV_LATENCY: 120.040 (per CPU: 119.420 119.910 125.460 115.370 ) MIN_LATENCY: 46.500 (per CPU: 47.000 47.000 47.000 45.000 ) P50_LATENCY: 118.500 (per CPU: 118.000 119.000 118.000 119.000 ) P90_LATENCY: 127.500 (per CPU: 127.000 128.000 127.000 128.000 ) P99_LATENCY: 130.750 (per CPU: 131.000 131.000 129.000 132.000 ) TRANSACTION_RATE: 32666.400 (per CPU: 8152.200 8169.842 8174.439 8169.897 ) Pod to remote pod with redirect_peer(), TCP_RR: # percpu_netperf 10.217.1.33 RT_LATENCY: 44.449 (per CPU: 43.767 43.127 45.279 45.622 ) MEAN_LATENCY: 45.065 (per CPU: 44.030 45.530 45.190 45.510 ) STDDEV_LATENCY: 84.823 (per CPU: 66.770 97.290 84.380 90.850 ) MIN_LATENCY: 33.500 (per CPU: 33.000 33.000 34.000 34.000 ) P50_LATENCY: 43.250 (per CPU: 43.000 43.000 43.000 44.000 ) P90_LATENCY: 46.750 (per CPU: 46.000 47.000 47.000 47.000 ) P99_LATENCY: 52.750 (per CPU: 51.000 54.000 53.000 53.000 ) TRANSACTION_RATE: 90039.500 (per CPU: 22848.186 23187.089 22085.077 21919.130 ) [0] https://linuxplumbersconf.org/event/7/contributions/674/attachments/568/1002/plumbers_2020_cilium_load_balancer.pdf [1] https://github.com/borkmann/netperf_scripts/blob/master/percpu_netperf Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201010234006.7075-3-daniel@iogearbox.net
* bpf: Improve bpf_redirect_neigh helper descriptionDaniel Borkmann2020-10-111-3/+7
| | | | | | | | | | | Follow-up to address David's feedback that we should better describe internals of the bpf_redirect_neigh() helper. Suggested-by: David Ahern <dsahern@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: David Ahern <dsahern@gmail.com> Link: https://lore.kernel.org/bpf/20201010234006.7075-2-daniel@iogearbox.net
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