diff options
| author | sam <sam@FreeBSD.org> | 2003-10-13 03:42:53 +0000 |
|---|---|---|
| committer | sam <sam@FreeBSD.org> | 2003-10-13 03:42:53 +0000 |
| commit | 725572efdacc819dce829edb301e4edc87502fe0 (patch) | |
| tree | 57237d2e3dbd4376c95c96d422866b4f367fe21a /sys/dev/ath | |
| parent | 04745ccf4c58682033e85ca6acd947ebc25e8bc4 (diff) | |
| download | FreeBSD-src-725572efdacc819dce829edb301e4edc87502fe0.zip FreeBSD-src-725572efdacc819dce829edb301e4edc87502fe0.tar.gz | |
Reduce per-packet overhead when using WEP by using an advancing IV
seeded with arc4random rather than calling arc4random for each
packet. Note this is the same algorithm used to select the IV when
doing WEP on the host.
Diffstat (limited to 'sys/dev/ath')
| -rw-r--r-- | sys/dev/ath/if_ath.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/sys/dev/ath/if_ath.c b/sys/dev/ath/if_ath.c index 1369f93..e5c6fb0 100644 --- a/sys/dev/ath/if_ath.c +++ b/sys/dev/ath/if_ath.c @@ -1735,7 +1735,14 @@ ath_tx_start(struct ath_softc *sc, struct ieee80211_node *ni, struct ath_buf *bf * So we use pseudo random IV for now, though it is not the * right way. */ - iv = arc4random(); + iv = ic->ic_iv; + /* + * Skip 'bad' IVs from Fluhrer/Mantin/Shamir: + * (B, 255, N) with 3 <= B < 8 + */ + if (iv >= 0x03ff00 && (iv & 0xf8ff00) == 0x00ff00) + iv += 0x000100; + ic->ic_iv = iv + 1; for (i = 0; i < IEEE80211_WEP_IVLEN; i++) { ivp[i] = iv; iv >>= 8; |
