[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 <[EMAIL PROTECTED]>
---
include/net/esp.h | 5 +++--
net/ipv4/esp4.c | 10 +++++++---
net/ipv6/esp6.c | 9 +++++++--
3 files changed, 17 insertions(+), 7 deletions(-)
diff --git a/include/net/esp.h b/include/net/esp.h
index 90cd94f..636163c 100644
--- a/include/net/esp.h
+++ b/include/net/esp.h
@@ -14,13 +14,14 @@ struct esp_data
struct {
u8 *key; /* Key */
int key_len; /* Key length */
- u8 *ivec; /* ivec buffer */
+ int padlen; /* 0..255 */
/* ivlen is offset from enc_data, where encrypted data start.
* It is logically different of crypto_tfm_alg_ivsize(tfm).
* We assume that it is either zero (no ivec), or
* >= crypto_tfm_alg_ivsize(tfm). */
int ivlen;
- int padlen; /* 0..255 */
+ int ivinitted;
+ u8 *ivec; /* ivec buffer */
struct crypto_tfm *tfm; /* crypto handle */
} conf;
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index fc2f8ce..1ceda9f 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -91,9 +91,13 @@ static int esp_output(struct xfrm_state
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_cipher_set_iv(tfm, esp->conf.ivec,
crypto_tfm_alg_ivsize(tfm));
-
+ }
do {
struct scatterlist *sg = &esp->sgbuf[0];
@@ -363,7 +367,7 @@ static int esp_init_state(struct xfrm_st
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_cipher_setkey(esp->conf.tfm, esp->conf.key,
esp->conf.key_len))
goto error;
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index a278d5e..efa6155 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -95,8 +95,13 @@ static int esp6_output(struct xfrm_state
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_cipher_set_iv(tfm, esp->conf.ivec,
crypto_tfm_alg_ivsize(tfm));
+ }
do {
struct scatterlist *sg = &esp->sgbuf[0];
@@ -339,7 +344,7 @@ static int esp6_init_state(struct xfrm_s
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_cipher_setkey(esp->conf.tfm, esp->conf.key,
esp->conf.key_len))
goto error;
--
1.4.2.rc2.g3e042
-
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