diff options
| author | Damien Bergamini <damien@cvs.openbsd.org> | 2008-04-17 18:05:34 +0000 |
|---|---|---|
| committer | Damien Bergamini <damien@cvs.openbsd.org> | 2008-04-17 18:05:34 +0000 |
| commit | 58bd3d5d1f8766fb6f7af3e51dc4bf9ea504389a (patch) | |
| tree | 1cadf8d2b7f151678024452de190319bf925f7b9 | |
| parent | 7d4b1c6f2891eacf9056f14e8d50e8cc4aba0bc0 (diff) | |
call ieee80211_crc_init() only once, when the first 802.11 device
attaches instead of at every attach.
discussed with deraadt@
| -rw-r--r-- | sys/net80211/ieee80211_crypto.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/sys/net80211/ieee80211_crypto.c b/sys/net80211/ieee80211_crypto.c index 7147980a019..99ecfd68a5f 100644 --- a/sys/net80211/ieee80211_crypto.c +++ b/sys/net80211/ieee80211_crypto.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ieee80211_crypto.c,v 1.37 2008/04/16 18:32:15 damien Exp $ */ +/* $OpenBSD: ieee80211_crypto.c,v 1.38 2008/04/17 18:05:33 damien Exp $ */ /*- * Copyright (c) 2008 Damien Bergamini <damien.bergamini@free.fr> @@ -64,7 +64,7 @@ void ieee80211_derive_gtk(const u_int8_t *, size_t, const u_int8_t *, void ieee80211_crypto_attach(struct ifnet *ifp) { - ieee80211_crc_init(); /* XXX only once? */ + ieee80211_crc_init(); } void @@ -220,19 +220,24 @@ ieee80211_decrypt(struct ieee80211com *ic, struct mbuf *m0, } /* - * CRC 32 -- routine from RFC 2083 + * CRC (Cyclic Redundancy Check) (routine from RFC 2083). */ -/* Table of CRCs of all 8-bit messages */ +/* Table of CRCs of all 8-bit messages. */ static u_int32_t ieee80211_crc_table[256]; /* Make the table for a fast CRC. */ void ieee80211_crc_init(void) { + /* Flag: has the table been computed? Initially false. */ + static int crc_table_computed = 0; u_int32_t c; int n, k; + if (crc_table_computed) + return; + for (n = 0; n < 256; n++) { c = (u_int32_t)n; for (k = 0; k < 8; k++) { @@ -243,12 +248,13 @@ ieee80211_crc_init(void) } ieee80211_crc_table[n] = c; } + crc_table_computed = 1; } /* * Update a running CRC with the bytes buf[0..len-1]--the CRC * should be initialized to all 1's, and the transmitted value - * is the 1's complement of the final running CRC + * is the 1's complement of the final running CRC. */ u_int32_t ieee80211_crc_update(u_int32_t crc, const u_int8_t *buf, int len) |