| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | /* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ |
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| 3 | #include "vmlinux.h" |
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| 4 | #include <bpf/bpf_helpers.h> |
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| 5 | #include <bpf/bpf_tracing.h> |
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| 6 | #include <bpf/bpf_core_read.h> |
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| 7 | #include "bpf_kfuncs.h" |
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| 8 | |
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| 9 | struct { |
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| 10 | __uint(type, BPF_MAP_TYPE_TASK_STORAGE); |
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| 11 | __uint(map_flags, BPF_F_NO_PREALLOC); |
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| 12 | __type(key, int); |
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| 13 | __type(value, long); |
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| 14 | } enter_id SEC(".maps" ); |
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| 15 | |
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| 16 | #define IFNAMSIZ 16 |
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| 17 | |
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| 18 | int ifindex, ingress_ifindex; |
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| 19 | char name[IFNAMSIZ]; |
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| 20 | unsigned int inum; |
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| 21 | unsigned int meta_len, frag0_len, kskb_len, kskb2_len; |
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| 22 | |
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| 23 | SEC("?xdp" ) |
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| 24 | int md_xdp(struct xdp_md *ctx) |
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| 25 | { |
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| 26 | struct xdp_buff *kctx = bpf_cast_to_kern_ctx(ctx); |
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| 27 | struct net_device *dev; |
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| 28 | |
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| 29 | dev = kctx->rxq->dev; |
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| 30 | ifindex = dev->ifindex; |
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| 31 | inum = dev->nd_net.net->ns.inum; |
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| 32 | __builtin_memcpy(name, dev->name, IFNAMSIZ); |
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| 33 | ingress_ifindex = ctx->ingress_ifindex; |
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| 34 | return XDP_PASS; |
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| 35 | } |
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| 36 | |
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| 37 | SEC("?tc" ) |
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| 38 | int md_skb(struct __sk_buff *skb) |
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| 39 | { |
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| 40 | struct sk_buff *kskb = bpf_cast_to_kern_ctx(skb); |
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| 41 | struct skb_shared_info *shared_info; |
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| 42 | struct sk_buff *kskb2; |
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| 43 | |
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| 44 | kskb_len = kskb->len; |
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| 45 | |
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| 46 | /* Simulate the following kernel macro: |
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| 47 | * #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) |
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| 48 | */ |
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| 49 | shared_info = bpf_core_cast(kskb->head + kskb->end, struct skb_shared_info); |
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| 50 | meta_len = shared_info->meta_len; |
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| 51 | frag0_len = shared_info->frag_list->len; |
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| 52 | |
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| 53 | /* kskb2 should be equal to kskb */ |
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| 54 | kskb2 = bpf_core_cast(kskb, typeof(*kskb2)); |
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| 55 | kskb2_len = kskb2->len; |
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| 56 | return 0; |
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| 57 | } |
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| 58 | |
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| 59 | SEC("?tp_btf/sys_enter" ) |
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| 60 | int BPF_PROG(untrusted_ptr, struct pt_regs *regs, long id) |
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| 61 | { |
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| 62 | struct task_struct *task, *task_dup; |
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| 63 | |
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| 64 | task = bpf_get_current_task_btf(); |
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| 65 | task_dup = bpf_core_cast(task, struct task_struct); |
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| 66 | (void)bpf_task_storage_get(&enter_id, task_dup, 0, 0); |
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| 67 | return 0; |
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| 68 | } |
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| 69 | |
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| 70 | SEC("?tracepoint/syscalls/sys_enter_nanosleep" ) |
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| 71 | int kctx_u64(void *ctx) |
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| 72 | { |
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| 73 | u64 *kctx = bpf_core_cast(ctx, u64); |
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| 74 | |
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| 75 | (void)kctx; |
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| 76 | return 0; |
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| 77 | } |
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| 78 | |
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| 79 | char _license[] SEC("license" ) = "GPL" ; |
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| 80 | |
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