> > Classic BPF filters using a variable offset into the packet, such as
> > "tcp[tcpflags] & tcp-syn != 0" or "tcp[0:4] = ...", read the wrong bytes.
> >
> > The indirect loads ldb/ld [x + k] were handled in the same case as the
> > arithmetic instructions, which take the source register from
> > BPF_SRC(code), that is bit 0x08. In a load opcode that bit is part of
> > the size field, not a K/X selector, so BPF_LD|BPF_IND|BPF_B (0x50) and
> > BPF_LD|BPF_IND|BPF_W (0x40) both yield BPF_K and the index register
> > becomes R0 (A) instead of R7 (X). The halfword form works only because
> > BPF_H and BPF_X are both 0x08.
> >
> > Give the indirect loads their own case next to the absolute loads and
> > emit X as the index register. The interpreter and the JITs already
> > take the index from src_reg, so this fixes all engines.
> >
> > Bugzilla ID: 2085
> > Fixes: 2eccf6afbea9 ("bpf: add function to convert classic BPF to DPDK BPF")
> > Cc: [email protected]
> >
> > Signed-off-by: Stephen Hemminger <[email protected]>
>
> Acked-by: Konstantin Ananyev <[email protected]>
Applied, thanks.
