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author | Joanne Koong <joannelkoong@gmail.com> | 2023-03-01 18:49:51 +0300 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2023-03-01 20:55:24 +0300 |
commit | 05421aecd4ed65da0dc17b0c3c13779ef334e9e5 (patch) | |
tree | 4c1ab9ebfeaa8c17c0e8ac8b7ef63c9ae29dbdc6 /net/core/filter.c | |
parent | b5964b968ac64c2ec2debee7518499113b27c34e (diff) | |
download | linux-05421aecd4ed65da0dc17b0c3c13779ef334e9e5.tar.xz |
bpf: Add xdp dynptrs
Add xdp dynptrs, which are dynptrs whose underlying pointer points
to a xdp_buff. The dynptr acts on xdp data. xdp dynptrs have two main
benefits. One is that they allow operations on sizes that are not
statically known at compile-time (eg variable-sized accesses).
Another is that parsing the packet data through dynptrs (instead of
through direct access of xdp->data and xdp->data_end) can be more
ergonomic and less brittle (eg does not need manual if checking for
being within bounds of data_end).
For reads and writes on the dynptr, this includes reading/writing
from/to and across fragments. Data slices through the bpf_dynptr_data
API are not supported; instead bpf_dynptr_slice() and
bpf_dynptr_slice_rdwr() should be used.
For examples of how xdp dynptrs can be used, please see the attached
selftests.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Link: https://lore.kernel.org/r/20230301154953.641654-9-joannelkoong@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'net/core/filter.c')
-rw-r--r-- | net/core/filter.c | 37 |
1 files changed, 35 insertions, 2 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index f3afa31a9b10..c692046fa7f6 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3839,7 +3839,7 @@ static const struct bpf_func_proto sk_skb_change_head_proto = { .arg3_type = ARG_ANYTHING, }; -BPF_CALL_1(bpf_xdp_get_buff_len, struct xdp_buff*, xdp) +BPF_CALL_1(bpf_xdp_get_buff_len, struct xdp_buff*, xdp) { return xdp_get_buff_len(xdp); } @@ -3999,6 +3999,11 @@ static const struct bpf_func_proto bpf_xdp_load_bytes_proto = { .arg4_type = ARG_CONST_SIZE, }; +int __bpf_xdp_load_bytes(struct xdp_buff *xdp, u32 offset, void *buf, u32 len) +{ + return ____bpf_xdp_load_bytes(xdp, offset, buf, len); +} + BPF_CALL_4(bpf_xdp_store_bytes, struct xdp_buff *, xdp, u32, offset, void *, buf, u32, len) { @@ -4026,6 +4031,11 @@ static const struct bpf_func_proto bpf_xdp_store_bytes_proto = { .arg4_type = ARG_CONST_SIZE, }; +int __bpf_xdp_store_bytes(struct xdp_buff *xdp, u32 offset, void *buf, u32 len) +{ + return ____bpf_xdp_store_bytes(xdp, offset, buf, len); +} + static int bpf_xdp_frags_increase_tail(struct xdp_buff *xdp, int offset) { struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp); @@ -11648,6 +11658,19 @@ __bpf_kfunc int bpf_dynptr_from_skb(struct sk_buff *skb, u64 flags, return 0; } + +__bpf_kfunc int bpf_dynptr_from_xdp(struct xdp_buff *xdp, u64 flags, + struct bpf_dynptr_kern *ptr__uninit) +{ + if (flags) { + bpf_dynptr_set_null(ptr__uninit); + return -EINVAL; + } + + bpf_dynptr_init(ptr__uninit, xdp, BPF_DYNPTR_TYPE_XDP, 0, xdp_get_buff_len(xdp)); + + return 0; +} __diag_pop(); int bpf_dynptr_from_skb_rdonly(struct sk_buff *skb, u64 flags, @@ -11668,11 +11691,20 @@ BTF_SET8_START(bpf_kfunc_check_set_skb) BTF_ID_FLAGS(func, bpf_dynptr_from_skb) BTF_SET8_END(bpf_kfunc_check_set_skb) +BTF_SET8_START(bpf_kfunc_check_set_xdp) +BTF_ID_FLAGS(func, bpf_dynptr_from_xdp) +BTF_SET8_END(bpf_kfunc_check_set_xdp) + static const struct btf_kfunc_id_set bpf_kfunc_set_skb = { .owner = THIS_MODULE, .set = &bpf_kfunc_check_set_skb, }; +static const struct btf_kfunc_id_set bpf_kfunc_set_xdp = { + .owner = THIS_MODULE, + .set = &bpf_kfunc_check_set_xdp, +}; + static int __init bpf_kfunc_init(void) { int ret; @@ -11685,6 +11717,7 @@ static int __init bpf_kfunc_init(void) ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LWT_OUT, &bpf_kfunc_set_skb); ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LWT_IN, &bpf_kfunc_set_skb); ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LWT_XMIT, &bpf_kfunc_set_skb); - return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LWT_SEG6LOCAL, &bpf_kfunc_set_skb); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_LWT_SEG6LOCAL, &bpf_kfunc_set_skb); + return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &bpf_kfunc_set_xdp); } late_initcall(bpf_kfunc_init); |