4 files changed, 45 insertions, 0 deletions

diff --git a/include/linux/sctp.h b/include/linux/sctp.h
index 38e2cf66195f..b36c76635f18 100644
--- a/include/linux/sctp.h
+++ b/include/linux/sctp.h
@@ -110,6 +110,7 @@ enum sctp_cid {
 
         /* Use hex, as defined in ADDIP sec. 3.1 */
         SCTP_CID_ASCONF                 = 0xC1,
+        SCTP_CID_I_FWD_TSN              = 0xC2,
         SCTP_CID_ASCONF_ACK             = 0x80,
         SCTP_CID_RECONF                 = 0x82,
 }; /* enum */
@@ -616,6 +617,22 @@ struct sctp_fwdtsn_chunk {
         struct sctp_fwdtsn_hdr fwdtsn_hdr;
 };
 
+struct sctp_ifwdtsn_skip {
+        __be16 stream;
+        __u8 reserved;
+        __u8 flags;
+        __be32 mid;
+};
+
+struct sctp_ifwdtsn_hdr {
+        __be32 new_cum_tsn;
+        struct sctp_ifwdtsn_skip skip[0];
+};
+
+struct sctp_ifwdtsn_chunk {
+        struct sctp_chunkhdr chunk_hdr;
+        struct sctp_ifwdtsn_hdr fwdtsn_hdr;
+};
 
 /* ADDIP
  * Section 3.1.1 Address Configuration Change Chunk (ASCONF)
diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h
index 0993b4953b3a..2883c43c5258 100644
--- a/include/net/sctp/sm.h
+++ b/include/net/sctp/sm.h
@@ -199,6 +199,9 @@ struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
                                  const struct sctp_chunk *chunk);
 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
                                    __u8 flags, int paylen, gfp_t gfp);
+struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
+                                     __u32 new_cum_tsn, size_t nstreams,
+                                     struct sctp_ifwdtsn_skip *skiplist);
 struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
                                             const struct sctp_sndrcvinfo *sinfo,
                                             int len, __u8 flags, gfp_t gfp);
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 8ef638d966f1..a5c3cf41e693 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -599,6 +599,7 @@ struct sctp_chunk {
                 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
                 struct sctp_authhdr *auth_hdr;
                 struct sctp_idatahdr *idata_hdr;
+                struct sctp_ifwdtsn_hdr *ifwdtsn_hdr;
         } subh;
 
         __u8 *chunk_end;
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 23a7313d7972..b9b269cf615e 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -3536,6 +3536,30 @@ struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
         return retval;
 }
 
+struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
+                                     __u32 new_cum_tsn, size_t nstreams,
+                                     struct sctp_ifwdtsn_skip *skiplist)
+{
+        struct sctp_chunk *retval = NULL;
+        struct sctp_ifwdtsn_hdr ftsn_hdr;
+        size_t hint;
+
+        hint = (nstreams + 1) * sizeof(__u32);
+
+        retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint,
+                                   GFP_ATOMIC);
+        if (!retval)
+                return NULL;
+
+        ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
+        retval->subh.ifwdtsn_hdr =
+                sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
+
+        sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist);
+
+        return retval;
+}
+
 /* RE-CONFIG 3.1 (RE-CONFIG chunk)
  *   0                   1                   2                   3
  *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1