Commit c860e997 authored by Yuchung Cheng's avatar Yuchung Cheng Committed by David S. Miller

tcp: fix Fast Open key endianness

Fast Open key could be stored in different endian based on the CPU.
Previously hosts in different endianness in a server farm using
the same key config (sysctl value) would produce different cookies.
This patch fixes it by always storing it as little endian to keep
same API for LE hosts.
Reported-by: default avatarDaniele Iamartino <danielei@google.com>
Signed-off-by: default avatarYuchung Cheng <ycheng@google.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarNeal Cardwell <ncardwell@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0933cc29
......@@ -265,8 +265,9 @@ static int proc_tcp_fastopen_key(struct ctl_table *table, int write,
ipv4.sysctl_tcp_fastopen);
struct ctl_table tbl = { .maxlen = (TCP_FASTOPEN_KEY_LENGTH * 2 + 10) };
struct tcp_fastopen_context *ctxt;
int ret;
u32 user_key[4]; /* 16 bytes, matching TCP_FASTOPEN_KEY_LENGTH */
__le32 key[4];
int ret, i;
tbl.data = kmalloc(tbl.maxlen, GFP_KERNEL);
if (!tbl.data)
......@@ -275,11 +276,14 @@ static int proc_tcp_fastopen_key(struct ctl_table *table, int write,
rcu_read_lock();
ctxt = rcu_dereference(net->ipv4.tcp_fastopen_ctx);
if (ctxt)
memcpy(user_key, ctxt->key, TCP_FASTOPEN_KEY_LENGTH);
memcpy(key, ctxt->key, TCP_FASTOPEN_KEY_LENGTH);
else
memset(user_key, 0, sizeof(user_key));
memset(key, 0, sizeof(key));
rcu_read_unlock();
for (i = 0; i < ARRAY_SIZE(key); i++)
user_key[i] = le32_to_cpu(key[i]);
snprintf(tbl.data, tbl.maxlen, "%08x-%08x-%08x-%08x",
user_key[0], user_key[1], user_key[2], user_key[3]);
ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
......@@ -290,7 +294,11 @@ static int proc_tcp_fastopen_key(struct ctl_table *table, int write,
ret = -EINVAL;
goto bad_key;
}
tcp_fastopen_reset_cipher(net, NULL, user_key,
for (i = 0; i < ARRAY_SIZE(user_key); i++)
key[i] = cpu_to_le32(user_key[i]);
tcp_fastopen_reset_cipher(net, NULL, key,
TCP_FASTOPEN_KEY_LENGTH);
}
......
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