xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mptcp: Handle MP_CAPABLE options for outgoing connections

Browse Source 
Add hooks to tcp_output.c to add MP_CAPABLE to an outgoing SYN request,
to capture the MP_CAPABLE in the received SYN-ACK, to add MP_CAPABLE to
the final ACK of the three-way handshake.

Use the .sk_rx_dst_set() handler in the subflow proto to capture when the
responding SYN-ACK is received and notify the MPTCP connection layer.

Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Peter Krystad
2020-01-21 16:56:18 -08:00
committed by David S. Miller
parent 2303f994b3
commit cec37a6e41
9 changed files with 663 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

44
net/ipv4/tcp_output.c
View File

@@ -597,6 +597,22 @@ static void smc_set_option_cond(const struct tcp_sock *tp,
#endif
}
static void mptcp_set_option_cond(const struct request_sock *req,
struct tcp_out_options *opts,
unsigned int *remaining)
{
if (rsk_is_mptcp(req)) {
unsigned int size;
if (mptcp_synack_options(req, &size, &opts->mptcp)) {
if (*remaining >= size) {
opts->options |= OPTION_MPTCP;
*remaining -= size;
}
}
}
}
/* Compute TCP options for SYN packets. This is not the final
* network wire format yet.
*/
@@ -666,6 +682,15 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
smc_set_option(tp, opts, &remaining);
if (sk_is_mptcp(sk)) {
unsigned int size;
if (mptcp_syn_options(sk, &size, &opts->mptcp)) {
opts->options |= OPTION_MPTCP;
remaining -= size;
}
}
return MAX_TCP_OPTION_SPACE - remaining;
}
@@ -727,6 +752,8 @@ static unsigned int tcp_synack_options(const struct sock *sk,
}
}
mptcp_set_option_cond(req, opts, &remaining);
smc_set_option_cond(tcp_sk(sk), ireq, opts, &remaining);
return MAX_TCP_OPTION_SPACE - remaining;
@@ -764,6 +791,23 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb
size += TCPOLEN_TSTAMP_ALIGNED;
}
/* MPTCP options have precedence over SACK for the limited TCP
* option space because a MPTCP connection would be forced to
* fall back to regular TCP if a required multipath option is
* missing. SACK still gets a chance to use whatever space is
* left.
*/
if (sk_is_mptcp(sk)) {
unsigned int remaining = MAX_TCP_OPTION_SPACE - size;
unsigned int opt_size = 0;
if (mptcp_established_options(sk, skb, &opt_size, remaining,
&opts->mptcp)) {
opts->options |= OPTION_MPTCP;
size += opt_size;
}
}
eff_sacks = tp->rx_opt.num_sacks + tp->rx_opt.dsack;
if (unlikely(eff_sacks)) {
const unsigned int remaining = MAX_TCP_OPTION_SPACE - size;