From e4bec827feda76d5e7417a2696a75424834d564f Mon Sep 17 00:00:00 2001 From: David S. Miller Date: Fri, 22 Sep 2006 15:17:35 -0700 Subject: [IPSEC] esp: Defer output IV initialization to first use. First of all, if the xfrm_state only gets used for input packets this entropy is a complete waste. Secondly, it is often the case that a configuration loads many rules (perhaps even dynamically) and they don't all necessarily ever get used. This get_random_bytes() call was showing up in the profiles for xfrm_state inserts which is how I noticed this. Signed-off-by: David S. Miller --- net/ipv4/esp4.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index e87377e1d6b6..13b29360d102 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -95,8 +95,13 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) esph->seq_no = htonl(++x->replay.oseq); xfrm_aevent_doreplay(x); - if (esp->conf.ivlen) + if (esp->conf.ivlen) { + if (unlikely(!esp->conf.ivinitted)) { + get_random_bytes(esp->conf.ivec, esp->conf.ivlen); + esp->conf.ivinitted = 1; + } crypto_blkcipher_set_iv(tfm, esp->conf.ivec, esp->conf.ivlen); + } do { struct scatterlist *sg = &esp->sgbuf[0]; @@ -378,7 +383,7 @@ static int esp_init_state(struct xfrm_state *x) esp->conf.ivec = kmalloc(esp->conf.ivlen, GFP_KERNEL); if (unlikely(esp->conf.ivec == NULL)) goto error; - get_random_bytes(esp->conf.ivec, esp->conf.ivlen); + esp->conf.ivinitted = 0; } if (crypto_blkcipher_setkey(tfm, esp->conf.key, esp->conf.key_len)) goto error; -- cgit v1.2.3