[PATCHv2 net-next 02/12] sctp: add asoc intl_enable negotiation during 4 shakehands

[Xin Long]

asoc intl_enable will be set when local sp strm_interleave is set
and there's I-DATA chunk in init and init_ack extensions, as said
in section 2.2.1 of RFC8260.

asoc intl_enable indicates all data will be sent as I-DATA chunks.

Signed-off-by: Xin Long <lucien....@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leit...@gmail.com>
Acked-by: Neil Horman <nhor...@tuxdriver.com>
---
 include/linux/sctp.h     |  3 +++
 net/sctp/sm_make_chunk.c | 18 ++++++++++++++++--
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/include/linux/sctp.h b/include/linux/sctp.h
index da803df..6d2bd64 100644
--- a/include/linux/sctp.h
+++ b/include/linux/sctp.h
@@ -102,6 +102,9 @@ enum sctp_cid {
        /* AUTH Extension Section 4.1 */
        SCTP_CID_AUTH                   = 0x0F,
 
+       /* sctp ndata 5.1. I-DATA */
+       SCTP_CID_I_DATA                 = 0x40,
+
        /* PR-SCTP Sec 3.2 */
        SCTP_CID_FWD_TSN                = 0xC0,
 
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 9bf575f..da33c85 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -228,7 +228,7 @@ struct sctp_chunk *sctp_make_init(const struct 
sctp_association *asoc,
        struct sctp_inithdr init;
        union sctp_params addrs;
        struct sctp_sock *sp;
-       __u8 extensions[4];
+       __u8 extensions[5];
        size_t chunksize;
        __be16 types[2];
        int num_ext = 0;
@@ -278,6 +278,11 @@ struct sctp_chunk *sctp_make_init(const struct 
sctp_association *asoc,
        if (sp->adaptation_ind)
                chunksize += sizeof(aiparam);
 
+       if (sp->strm_interleave) {
+               extensions[num_ext] = SCTP_CID_I_DATA;
+               num_ext += 1;
+       }
+
        chunksize += vparam_len;
 
        /* Account for AUTH related parameters */
@@ -392,7 +397,7 @@ struct sctp_chunk *sctp_make_init_ack(const struct 
sctp_association *asoc,
        struct sctp_inithdr initack;
        union sctp_params addrs;
        struct sctp_sock *sp;
-       __u8 extensions[4];
+       __u8 extensions[5];
        size_t chunksize;
        int num_ext = 0;
        int cookie_len;
@@ -442,6 +447,11 @@ struct sctp_chunk *sctp_make_init_ack(const struct 
sctp_association *asoc,
        if (sp->adaptation_ind)
                chunksize += sizeof(aiparam);
 
+       if (asoc->intl_enable) {
+               extensions[num_ext] = SCTP_CID_I_DATA;
+               num_ext += 1;
+       }
+
        if (asoc->peer.auth_capable) {
                auth_random = (struct sctp_paramhdr *)asoc->c.auth_random;
                chunksize += ntohs(auth_random->length);
@@ -2032,6 +2042,10 @@ static void sctp_process_ext_param(struct 
sctp_association *asoc,
                        if (net->sctp.addip_enable)
                                asoc->peer.asconf_capable = 1;
                        break;
+               case SCTP_CID_I_DATA:
+                       if (sctp_sk(asoc->base.sk)->strm_interleave)
+                               asoc->intl_enable = 1;
+                       break;
                default:
                        break;
                }
-- 
2.1.0