mptcp: send out checksum for MP_CAPABLE with data

If the checksum is enabled, send out the data checksum with the
MP_CAPABLE suboption with data.

In mptcp_established_options_mp, save the data checksum in
opts->ext_copy.csum. In mptcp_write_options, adjust the option length and
send it out with the MP_CAPABLE suboption.

Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Geliang Tang 2021-06-17 16:46:10 -07:00 committed by David S. Miller
parent 06fe1719aa
commit c94b1f96dc

View File

@ -439,6 +439,7 @@ static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb,
struct mptcp_sock *msk = mptcp_sk(subflow->conn);
struct mptcp_ext *mpext;
unsigned int data_len;
u8 len;
/* When skb is not available, we better over-estimate the emitted
* options len. A full DSS option (28 bytes) is longer than
@ -474,10 +475,16 @@ static bool mptcp_established_options_mp(struct sock *sk, struct sk_buff *skb,
* packets that start the first subflow of an MPTCP connection,
* as well as the first packet that carries data
*/
if (data_len > 0)
*size = ALIGN(TCPOLEN_MPTCP_MPC_ACK_DATA, 4);
else
if (data_len > 0) {
len = TCPOLEN_MPTCP_MPC_ACK_DATA;
if (opts->csum_reqd) {
opts->ext_copy.csum = mpext->csum;
len += TCPOLEN_MPTCP_DSS_CHECKSUM;
}
*size = ALIGN(len, 4);
} else {
*size = TCPOLEN_MPTCP_MPC_ACK;
}
pr_debug("subflow=%p, local_key=%llu, remote_key=%llu map_len=%d",
subflow, subflow->local_key, subflow->remote_key,
@ -1122,6 +1129,25 @@ static void mptcp_set_rwin(const struct tcp_sock *tp)
WRITE_ONCE(msk->rcv_wnd_sent, ack_seq);
}
static u16 mptcp_make_csum(const struct mptcp_ext *mpext)
{
struct csum_pseudo_header header;
__wsum csum;
/* cfr RFC 8684 3.3.1.:
* the data sequence number used in the pseudo-header is
* always the 64-bit value, irrespective of what length is used in the
* DSS option itself.
*/
header.data_seq = cpu_to_be64(mpext->data_seq);
header.subflow_seq = htonl(mpext->subflow_seq);
header.data_len = htons(mpext->data_len);
header.csum = 0;
csum = csum_partial(&header, sizeof(header), ~csum_unfold(mpext->csum));
return (__force u16)csum_fold(csum);
}
void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
struct mptcp_out_options *opts)
{
@ -1129,14 +1155,17 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
OPTION_MPTCP_MPC_ACK) & opts->suboptions) {
u8 len, flag = MPTCP_CAP_HMAC_SHA256;
if (OPTION_MPTCP_MPC_SYN & opts->suboptions)
if (OPTION_MPTCP_MPC_SYN & opts->suboptions) {
len = TCPOLEN_MPTCP_MPC_SYN;
else if (OPTION_MPTCP_MPC_SYNACK & opts->suboptions)
} else if (OPTION_MPTCP_MPC_SYNACK & opts->suboptions) {
len = TCPOLEN_MPTCP_MPC_SYNACK;
else if (opts->ext_copy.data_len)
} else if (opts->ext_copy.data_len) {
len = TCPOLEN_MPTCP_MPC_ACK_DATA;
else
if (opts->csum_reqd)
len += TCPOLEN_MPTCP_DSS_CHECKSUM;
} else {
len = TCPOLEN_MPTCP_MPC_ACK;
}
if (opts->csum_reqd)
flag |= MPTCP_CAP_CHECKSUM_REQD;
@ -1159,8 +1188,13 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
if (!opts->ext_copy.data_len)
goto mp_capable_done;
put_unaligned_be32(opts->ext_copy.data_len << 16 |
TCPOPT_NOP << 8 | TCPOPT_NOP, ptr);
if (opts->csum_reqd) {
put_unaligned_be32(opts->ext_copy.data_len << 16 |
mptcp_make_csum(&opts->ext_copy), ptr);
} else {
put_unaligned_be32(opts->ext_copy.data_len << 16 |
TCPOPT_NOP << 8 | TCPOPT_NOP, ptr);
}
ptr += 1;
}