diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/type_cast.c')
-rw-r--r-- | tools/testing/selftests/bpf/progs/type_cast.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/type_cast.c b/tools/testing/selftests/bpf/progs/type_cast.c new file mode 100644 index 000000000000..eb78e6f03129 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/type_cast.c @@ -0,0 +1,83 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include <bpf/bpf_core_read.h> + +struct { + __uint(type, BPF_MAP_TYPE_TASK_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, long); +} enter_id SEC(".maps"); + +#define IFNAMSIZ 16 + +int ifindex, ingress_ifindex; +char name[IFNAMSIZ]; +unsigned int inum; +unsigned int meta_len, frag0_len, kskb_len, kskb2_len; + +void *bpf_cast_to_kern_ctx(void *) __ksym; +void *bpf_rdonly_cast(void *, __u32) __ksym; + +SEC("?xdp") +int md_xdp(struct xdp_md *ctx) +{ + struct xdp_buff *kctx = bpf_cast_to_kern_ctx(ctx); + struct net_device *dev; + + dev = kctx->rxq->dev; + ifindex = dev->ifindex; + inum = dev->nd_net.net->ns.inum; + __builtin_memcpy(name, dev->name, IFNAMSIZ); + ingress_ifindex = ctx->ingress_ifindex; + return XDP_PASS; +} + +SEC("?tc") +int md_skb(struct __sk_buff *skb) +{ + struct sk_buff *kskb = bpf_cast_to_kern_ctx(skb); + struct skb_shared_info *shared_info; + struct sk_buff *kskb2; + + kskb_len = kskb->len; + + /* Simulate the following kernel macro: + * #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) + */ + shared_info = bpf_rdonly_cast(kskb->head + kskb->end, + bpf_core_type_id_kernel(struct skb_shared_info)); + meta_len = shared_info->meta_len; + frag0_len = shared_info->frag_list->len; + + /* kskb2 should be equal to kskb */ + kskb2 = bpf_rdonly_cast(kskb, bpf_core_type_id_kernel(struct sk_buff)); + kskb2_len = kskb2->len; + return 0; +} + +SEC("?tp_btf/sys_enter") +int BPF_PROG(untrusted_ptr, struct pt_regs *regs, long id) +{ + struct task_struct *task, *task_dup; + long *ptr; + + task = bpf_get_current_task_btf(); + task_dup = bpf_rdonly_cast(task, bpf_core_type_id_kernel(struct task_struct)); + (void)bpf_task_storage_get(&enter_id, task_dup, 0, 0); + return 0; +} + +SEC("?tracepoint/syscalls/sys_enter_nanosleep") +int kctx_u64(void *ctx) +{ + u64 *kctx = bpf_rdonly_cast(ctx, bpf_core_type_id_kernel(u64)); + + (void)kctx; + return 0; +} + +char _license[] SEC("license") = "GPL"; |