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authorGeliang Tang <geliangtang@gmail.com>2021-06-18 02:46:10 +0300
committerDavid S. Miller <davem@davemloft.net>2021-06-18 21:40:11 +0300
commitc94b1f96dcfb2e5bd072b10f3429ccf28778ad58 (patch)
tree78c823a069f457d3521baeb95ea192c43e4828d6 /net
parent06fe1719aa501e3b574b1b2b3a7ad2ddac5fb9cb (diff)
downloadlinux-c94b1f96dcfb2e5bd072b10f3429ccf28778ad58.tar.xz
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>
Diffstat (limited to 'net')
-rw-r--r--net/mptcp/options.c52
1 files changed, 43 insertions, 9 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index bb3a1f3b6e99..b4da08db1221 100644
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -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;
}