On Mon, Oct 7, 2019 at 9:06 AM Daniel T. Lee <danieltimlee@xxxxxxxxx> wrote: > > 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. > > 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@xxxxxxxxx> > > --- > Changes in v6: > - Remove redundant error message > Changes in v5: > - Change pcktsz map to static global variable > Changes in v4: > - make pckt_size no less than ICMP_TOOBIG_SIZE > - Fix code style > Changes in v2: > - Change the helper to fetch map from 'bpf_map__next' to > 'bpf_object__find_map_fd_by_name'. This should go into commit message, that's netdev preference. Otherwise looks good! Acked-by: Andrii Nakryiko <andriin@xxxxxx> > > samples/bpf/xdp_adjust_tail_kern.c | 7 +++++-- > samples/bpf/xdp_adjust_tail_user.c | 29 ++++++++++++++++++++--------- > 2 files changed, 25 insertions(+), 11 deletions(-) > > diff --git a/samples/bpf/xdp_adjust_tail_kern.c b/samples/bpf/xdp_adjust_tail_kern.c > index 411fdb21f8bc..c616508befb9 100644 > --- a/samples/bpf/xdp_adjust_tail_kern.c > +++ b/samples/bpf/xdp_adjust_tail_kern.c > @@ -25,6 +25,9 @@ > #define ICMP_TOOBIG_SIZE 98 > #define ICMP_TOOBIG_PAYLOAD_SIZE 92 > [...]
