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| author | Mantas Mikulnas <grawity@gmail.com> | 2017-03-24 12:23:39 +0000 |
|---|---|---|
| committer | Roy Marples <roy@marples.name> | 2017-03-24 12:26:59 +0000 |
| commit | 8f2d1fafd1a28025b2558fc42ad03768b489facd (patch) | |
| tree | 881a78aae6c2183a9124b0b0ab9eca49cb966b3e | |
| parent | b76edfe80bc2435fbe3ff973f3b28d77b83eb114 (diff) | |
| download | parpd-8f2d1fafd1a28025b2558fc42ad03768b489facd.tar.xz | |
Fix inverted check for ARP packet type
Summary:
Currently the BPF filter accepts all ARP packets that _aren't_ requests.
Fixes T110.
Reviewers: roy
Reviewed By: roy
Tags: #parpd
Maniphest Tasks: T110
Differential Revision: https://dev.marples.name/D102
| -rw-r--r-- | bpf-filter.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/bpf-filter.h b/bpf-filter.h index 1d28dbe..9be7a3c 100644 --- a/bpf-filter.h +++ b/bpf-filter.h @@ -62,7 +62,8 @@ static const struct bpf_insn bpf_arp_filter [] = { /* Make sure this is an ARP REQUEST. */ BPF_STMT(BPF_LD + BPF_H + BPF_IND, offsetof(struct arphdr, ar_op)), - BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPOP_REQUEST, 2, 0), + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPOP_REQUEST, 1, 0), + BPF_STMT(BPF_RET + BPF_K, 0), /* Make sure the protocol length matches. */ BPF_STMT(BPF_LD + BPF_B + BPF_IND, offsetof(struct arphdr, ar_pln)), |