2 Commits

Author	SHA1	Message	Date
Daniel T. Lee	8fdf5b780a	samples: bpf: Add max_pckt_size option at xdp_adjust_tail ... Currently, at xdp_adjust_tail_kern.c, MAX_PCKT_SIZE is limited to 600. To make this size flexible, static global variable 'max_pcktsz' is added. By updating new packet size from the user space, xdp_adjust_tail_kern.o will use this value as a new max packet size. This static global variable can be accesible from .data section with bpf_object__find_map* from user space, since it is considered as internal map (accessible with .bss/.data/.rodata suffix). If no '-P <MAX_PCKT_SIZE>' option is used, the size of maximum packet will be 600 as a default. For clarity, change the helper to fetch map from 'bpf_map__next' to 'bpf_object__find_map_fd_by_name'. Also, changed the way to test prog_fd, map_fd from '!= 0' to '< 0', since fd could be 0 when stdin is closed. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20191007172117.3916-1-danieltimlee@gmail.com	2019-10-07 20:22:27 -07:00
Nikita V. Shirokov	c6ffd1ff78	bpf: add bpf_xdp_adjust_tail sample prog ... adding bpf's sample program which is using bpf_xdp_adjust_tail helper by generating ICMPv4 "packet to big" message if ingress packet's size is bigger then 600 bytes Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>	2018-04-18 23:34:17 +02:00