[PATCH net-next 4/5] tcp: Allow getsockopt of listener's keypool

[Christoph Paasch]

Allow to get the full list of the listener's keypool through a
getsockopt.

Signed-off-by: Christoph Paasch <cpaa...@apple.com>
---
 net/ipv4/tcp.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 27e2f6837062..cdb317392138 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3420,21 +3420,24 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
                return 0;
 
        case TCP_FASTOPEN_KEY: {
-               __u8 key[TCP_FASTOPEN_KEY_LENGTH];
+               __u8 key[TCP_FASTOPEN_KEY_LENGTH * TCP_FASTOPEN_CTXT_LEN];
                struct tcp_fastopen_context *ctx;
+               unsigned int key_len = 0;
 
                if (get_user(len, optlen))
                        return -EFAULT;
 
                rcu_read_lock();
                ctx = rcu_dereference(icsk->icsk_accept_queue.fastopenq.ctx);
-               if (ctx)
-                       memcpy(key, ctx->key, sizeof(key));
-               else
-                       len = 0;
+               while (ctx) {
+                       memcpy(&key[key_len], ctx->key, 
TCP_FASTOPEN_KEY_LENGTH);
+
+                       key_len += TCP_FASTOPEN_KEY_LENGTH;
+                       ctx = rcu_dereference(ctx->next);
+               }
                rcu_read_unlock();
 
-               len = min_t(unsigned int, len, sizeof(key));
+               len = min_t(unsigned int, len, key_len);
                if (put_user(len, optlen))
                        return -EFAULT;
                if (copy_to_user(optval, key, len))
-- 
2.16.2