Benjamin Beckmeyer <beb@xxxxxxxxxxxx> writes:
> Hi all,
>
> I hope you could help me with a static variable problem in xdp.
> Here is my source:
>
> static __u32 last_xid = 0;
>
> static __always_inline int profinet_process_packet(struct xdp_md *ctx, __u64 off) {
> void *data_end = (void *)(long)ctx->data_end;
> void *data = (void *)(long)ctx->data;
> struct profinet_hdr *p_hdr;
> __u16 profinet_frame_id;
> // static __u32 last_xid;
>
> p_hdr = data + off;
>
> if (p_hdr + 1 > data_end)
> return XDP_DROP;
>
> profinet_frame_id = bpf_htons(p_hdr->frame_id);
>
> if ((profinet_frame_id >= 0x0100 && profinet_frame_id <=0x7fff) ||
> (profinet_frame_id == 0x0020) ||
> (profinet_frame_id == 0xbbff) ||
> (profinet_frame_id == 0xfefc) ||
> (profinet_frame_id == 0xf7ff))
> return XDP_DROP;
>
> if (p_hdr->xid == last_xid)
> return XDP_DROP;
> else
> last_xid = p_hdr->xid;
>
> return XDP_PASS;
> }
>
> At the moment I'm using kernel version 6.0.2 and iproute2-6.0.0.
> I also tried to load the the filter with xdp_loader (xdp_tools).
>
> Output from ip:
> $ ip link set dev eth0 xdpgeneric obj xdp_prog_kern.o sec
> eks_filter
>
> Prog section 'eks_filter' rejected: Permission denied (13)!
> - Type: 6
> - Instructions: 48 (0 over limit)
> - License: GPL
>
> Verifier analysis:
>
> Error fetching program/map!
>
> Output from xdp_loader:
> $ ./xdp_loader -deth0 -A --filename xdp_prog_kern.o --pro
> gsec eks_filter
> libbpf: failed to guess program type based on ELF section name 'eks_filter'
> libbpf: supported section(type) names are: socket kprobe/ uprobe/
> kretprobe/ uretprobe/ classifier action tracepoint/ tp/ raw_tracepoint/
> raw_tp/ tp_btf/ xdp perf_event lwt_in lwt_out lwt_xmit lwt_seg6local
> cgroup_skb/ingress cgroup_skb/egress cgroup/skb cgroup/sock
> cgroup/post_bind4 cgroup/post_bind6 cgroup/dev sockops sk_skb/stream_parser
> sk_skb/stream_verdict sk_skb sk_msg lirc_mode2 flow_dissector cgroup/bind4
> cgroup/bind6 cgroup/connect4 cgroup/connect6 cgroup/sendmsg4
> cgroup/sendmsg6 cgroup/recvmsg4 cgroup/recvmsg6 cgroup/sysctl
> cgroup/getsockopt cgroup/setsockopt
> Success: Loaded BPF-object(xdp_prog_kern.o) and used section(eks_filter)
> - XDP prog attached on device:eth0(ifindex:2)
> - Pinning maps in /sys/fs/bpf/eth0/
> libbpf: failed to pin map: Operation not permitted
> ERR: pinning maps
This does not look like the output of the xdp-loader from xdp-tools; are
you using the code from the xdp-tutorial? Try using the one from
xdp-tools instead...
Also, there's a hint here:
> libbpf: failed to guess program type based on ELF section name 'eks_filter'
You should use SEC("xdp") for XDP programs instead of custom section
names, those are deprecated...
-Toke
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