diff options
author | David S. Miller | 2013-10-19 19:45:46 -0400 |
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committer | David S. Miller | 2013-10-19 19:45:46 -0400 |
commit | 7dcade390860712551a4feb080911d5002226188 (patch) | |
tree | 68768a3e760a90b2b13a8e7a83d573c0e63a4a35 /include/linux/net.h | |
parent | 53481da372851a5506deb5247302f75459b472b4 (diff) | |
parent | e34c9a69970d8664a36b46e6445a7cc879111cfd (diff) |
Merge branch 'net_get_random_once'
Hannes Frederic Sowa says:
====================
This series implements support for delaying the initialization of secret
keys, e.g. used for hashing, for as long as possible. This functionality
is implemented by a new macro, net_get_random_bytes.
I already used it to protect the socket hashes, the syncookie secret
(most important) and the tcp_fastopen secrets.
Changelog:
v2) Use static_keys in net_get_random_once to have as minimal impact to
the fast-path as possible.
v3) added patch "static_key: WARN on usage before jump_label_init was called":
Patch "x86/jump_label: expect default_nop if static_key gets enabled
on boot-up" relaxes the checks for using static_key primitives before
jump_label_init. So tighten them first.
v4) Update changelog on the patch "static_key: WARN on usage before
jump_label_init was called"
Included patches:
ipv4: split inet_ehashfn to hash functions per compilation unit
ipv6: split inet6_ehashfn to hash functions per compilation unit
static_key: WARN on usage before jump_label_init was called
x86/jump_label: expect default_nop if static_key gets enabled on boot-up
net: introduce new macro net_get_random_once
inet: split syncookie keys for ipv4 and ipv6 and initialize with net_get_random_once
inet: convert inet_ehash_secret and ipv6_hash_secret to net_get_random_once
tcp: switch tcp_fastopen key generation to net_get_random_once
net: switch net_secret key generation to net_get_random_once
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/net.h')
-rw-r--r-- | include/linux/net.h | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/net.h b/include/linux/net.h index ca9ec8540905..a489705f6fa3 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -239,6 +239,31 @@ do { \ #define net_random() prandom_u32() #define net_srandom(seed) prandom_seed((__force u32)(seed)) +bool __net_get_random_once(void *buf, int nbytes, bool *done, + struct static_key *done_key); + +#ifdef HAVE_JUMP_LABEL +#define ___NET_RANDOM_STATIC_KEY_INIT ((struct static_key) \ + { .enabled = ATOMIC_INIT(0), .entries = (void *)1 }) +#else /* !HAVE_JUMP_LABEL */ +#define ___NET_RANDOM_STATIC_KEY_INIT STATIC_KEY_INIT_FALSE +#endif /* HAVE_JUMP_LABEL */ + +/* BE CAREFUL: this function is not interrupt safe */ +#define net_get_random_once(buf, nbytes) \ + ({ \ + bool ___ret = false; \ + static bool ___done = false; \ + static struct static_key ___done_key = \ + ___NET_RANDOM_STATIC_KEY_INIT; \ + if (!static_key_true(&___done_key)) \ + ___ret = __net_get_random_once(buf, \ + nbytes, \ + &___done, \ + &___done_key); \ + ___ret; \ + }) + int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, size_t num, size_t len); int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, |