| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | #include <linux/bpf.h> |
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| 3 | #include <bpf/bpf_helpers.h> |
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| 4 | |
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| 5 | SEC("xdp" ) |
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| 6 | int _xdp_adjust_tail_grow(struct xdp_md *xdp) |
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| 7 | { |
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| 8 | int data_len = bpf_xdp_get_buff_len(xdp); |
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| 9 | int offset = 0; |
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| 10 | /* SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) */ |
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| 11 | #if defined(__TARGET_ARCH_s390) |
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| 12 | int tailroom = 512; |
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| 13 | #else |
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| 14 | int tailroom = 320; |
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| 15 | #endif |
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| 16 | |
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| 17 | /* Data length determine test case */ |
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| 18 | |
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| 19 | if (data_len == 54) { /* sizeof(pkt_v4) */ |
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| 20 | offset = 4096; /* test too large offset */ |
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| 21 | } else if (data_len == 74) { /* sizeof(pkt_v6) */ |
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| 22 | offset = 40; |
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| 23 | } else if (data_len == 64) { |
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| 24 | offset = 128; |
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| 25 | } else if (data_len == 128) { |
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| 26 | /* Max tail grow 3520 */ |
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| 27 | offset = 4096 - 256 - tailroom - data_len; |
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| 28 | } else if (data_len == 9000) { |
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| 29 | offset = 10; |
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| 30 | } else if (data_len == 9001) { |
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| 31 | offset = 4096; |
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| 32 | } else { |
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| 33 | return XDP_ABORTED; /* No matching test */ |
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| 34 | } |
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| 35 | |
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| 36 | if (bpf_xdp_adjust_tail(xdp, offset)) |
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| 37 | return XDP_DROP; |
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| 38 | return XDP_TX; |
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| 39 | } |
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| 40 | |
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| 41 | char _license[] SEC("license" ) = "GPL" ; |
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| 42 | |
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