xnu-2782.1.97.tar.gz

[apple/xnu.git] / bsd / netinet / mptcp_opt.c

diff --git a/bsd/netinet/mptcp_opt.c b/bsd/netinet/mptcp_opt.c
index a4ea96ef644fb54478181a5c40709b4dbbc8e879..173e56075bd7f96d25cf80e77e93c87ac1b556dd 100644 (file)
--- a/bsd/netinet/mptcp_opt.c
+++ b/bsd/netinet/mptcp_opt.c
@@ -1,5 +1,5 @@
 /*
 /*

- * Copyright (c) 2012-2013 Apple Inc. All rights reserved.
+ * Copyright (c) 2012-2014 Apple Inc. All rights reserved.

  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  *
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  *


@@ -53,6 +53,15 @@
 
 #include <mach/sdt.h>
 
 
 #include <mach/sdt.h>
 

+/*
+ * SYSCTL for enforcing 64 bit dsn
+ */
+int32_t force_64bit_dsn = 0; 
+SYSCTL_INT(_net_inet_mptcp, OID_AUTO, force_64bit_dsn, 
+    CTLFLAG_RW|CTLFLAG_LOCKED, &force_64bit_dsn, 0,
+    "Force MPTCP 64bit dsn");
+
+

 static int mptcp_validate_join_hmac(struct tcpcb *, u_char*, int);
 static int mptcp_snd_mpprio(struct tcpcb *tp, u_char *cp, int optlen);
 
 static int mptcp_validate_join_hmac(struct tcpcb *, u_char*, int);
 static int mptcp_snd_mpprio(struct tcpcb *tp, u_char *cp, int optlen);
 


@@ -160,6 +169,17 @@ mptcp_setup_join_subflow_syn_opts(struct socket *so, int flags, u_char *opt,
 
        if ((flags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
                struct mptcp_mpjoin_opt_rsp mpjoin_rsp;
 
        if ((flags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
                struct mptcp_mpjoin_opt_rsp mpjoin_rsp;

+               struct mptcb *mp_tp = tptomptp(tp);
+
+               if (mp_tp == NULL)
+                       return (optlen);
+
+               MPT_LOCK(mp_tp);
+               if (mptcp_get_localkey(mp_tp) == 0) {
+                       MPT_UNLOCK(mp_tp);
+                       return (optlen);
+               }
+               MPT_UNLOCK(mp_tp);

                bzero(&mpjoin_rsp, sizeof (mpjoin_rsp));
                mpjoin_rsp.mmjo_kind = TCPOPT_MULTIPATH;
                mpjoin_rsp.mmjo_len = sizeof (mpjoin_rsp);
                bzero(&mpjoin_rsp, sizeof (mpjoin_rsp));
                mpjoin_rsp.mmjo_kind = TCPOPT_MULTIPATH;
                mpjoin_rsp.mmjo_len = sizeof (mpjoin_rsp);


@@ -170,7 +190,7 @@ mptcp_setup_join_subflow_syn_opts(struct socket *so, int flags, u_char *opt,
                mptcp_get_rands(tp->t_local_aid, tptomptp(tp),
                    &mpjoin_rsp.mmjo_rand, NULL);
                mpjoin_rsp.mmjo_mac = mptcp_get_trunced_hmac(tp->t_local_aid,
                mptcp_get_rands(tp->t_local_aid, tptomptp(tp),
                    &mpjoin_rsp.mmjo_rand, NULL);
                mpjoin_rsp.mmjo_mac = mptcp_get_trunced_hmac(tp->t_local_aid,

-                   tptomptp(tp));
+                   mp_tp);

                memcpy(opt + optlen, &mpjoin_rsp, mpjoin_rsp.mmjo_len);
                optlen += mpjoin_rsp.mmjo_len;
        } else {
                memcpy(opt + optlen, &mpjoin_rsp, mpjoin_rsp.mmjo_len);
                optlen += mpjoin_rsp.mmjo_len;
        } else {


@@ -192,6 +212,14 @@ mptcp_setup_join_subflow_syn_opts(struct socket *so, int flags, u_char *opt,
                    &mpjoin_req.mmjo_rand, NULL);
                memcpy(opt + optlen, &mpjoin_req, mpjoin_req.mmjo_len);
                optlen += mpjoin_req.mmjo_len;
                    &mpjoin_req.mmjo_rand, NULL);
                memcpy(opt + optlen, &mpjoin_req, mpjoin_req.mmjo_len);
                optlen += mpjoin_req.mmjo_len;

+               /* send an event up, if Fast Join is requested */
+               if (mptcp_zerortt_fastjoin && 
+                   (so->so_flags & SOF_MPTCP_FASTJOIN)) {
+                       soevent(so,
+                           (SO_FILT_HINT_LOCKED | SO_FILT_HINT_MPFASTJ));
+                       if (mptcp_dbg >= MP_ERR_DEBUG)
+                               printf("%s: fast join request\n", __func__);
+               }

        }
        return (optlen);
 }
        }
        return (optlen);
 }


@@ -216,6 +244,7 @@ mptcp_setup_join_ack_opts(struct tcpcb *tp, u_char *opt, unsigned optlen)
            sizeof (join_rsp2.mmjo_mac));
        memcpy(opt + optlen, &join_rsp2, join_rsp2.mmjo_len);
        new_optlen = optlen + join_rsp2.mmjo_len;
            sizeof (join_rsp2.mmjo_mac));
        memcpy(opt + optlen, &join_rsp2, join_rsp2.mmjo_len);
        new_optlen = optlen + join_rsp2.mmjo_len;

+       tp->t_mpflags |= TMPF_FASTJOINBY2_SEND;

        return (new_optlen);
 }
 
        return (new_optlen);
 }
 


@@ -316,8 +345,7 @@ mptcp_send_infinite_mapping(struct tcpcb *tp, u_char *opt, unsigned int optlen)
        if (mp_tp->mpt_flags & MPTCPF_RECVD_MPFAIL) {
                infin_opt.mdss_dsn = (u_int32_t)
                    MPTCP_DATASEQ_LOW32(mp_tp->mpt_dsn_at_csum_fail);
        if (mp_tp->mpt_flags & MPTCPF_RECVD_MPFAIL) {
                infin_opt.mdss_dsn = (u_int32_t)
                    MPTCP_DATASEQ_LOW32(mp_tp->mpt_dsn_at_csum_fail);

-               error = mptcp_get_map_for_dsn(so, mp_tp->mpt_dsn_at_csum_fail,
-                   &infin_opt.mdss_subflow_seqn);
+               infin_opt.mdss_subflow_seqn = mp_tp->mpt_ssn_at_csum_fail;

        } else {
                infin_opt.mdss_dsn = (u_int32_t)
                    MPTCP_DATASEQ_LOW32(mp_tp->mpt_snduna);
        } else {
                infin_opt.mdss_dsn = (u_int32_t)
                    MPTCP_DATASEQ_LOW32(mp_tp->mpt_snduna);


@@ -407,7 +435,7 @@ unsigned int
 mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
     unsigned int optlen, int flags, int datalen,
     unsigned int **dss_lenp, u_int8_t **finp, u_int64_t *dss_valp,
 mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
     unsigned int optlen, int flags, int datalen,
     unsigned int **dss_lenp, u_int8_t **finp, u_int64_t *dss_valp,

-    u_int32_t **sseqp)
+    u_int32_t **sseqp, boolean_t *p_mptcp_acknow)

 {
        struct inpcb *inp = (struct inpcb *)tp->t_inpcb;
        struct socket *so = inp->inp_socket;
 {
        struct inpcb *inp = (struct inpcb *)tp->t_inpcb;
        struct socket *so = inp->inp_socket;


@@ -415,22 +443,25 @@ mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
        boolean_t do_csum = FALSE;
        boolean_t send_64bit_dsn = FALSE;
        boolean_t send_64bit_ack = FALSE;
        boolean_t do_csum = FALSE;
        boolean_t send_64bit_dsn = FALSE;
        boolean_t send_64bit_ack = FALSE;

+       u_int32_t old_mpt_flags = tp->t_mpflags &
+               (TMPF_SND_MPPRIO | TMPF_SND_REM_ADDR | TMPF_SND_MPFAIL);

 
 

-       if (mptcp_enable == 0) {
+       if ((mptcp_enable == 0) ||
+           (mp_tp == NULL) ||
+           (mp_tp->mpt_flags & MPTCPF_PEEL_OFF) ||
+           (tp->t_state == TCPS_CLOSED)) {

                /* do nothing */
                /* do nothing */

-               return (optlen);
-       }
-
-       if (mp_tp == NULL) {
-               return (optlen);
+               goto ret_optlen;

        }
 
        }
 

-       if (mp_tp->mpt_flags & MPTCPF_CHECKSUM)
+       if (mp_tp->mpt_flags & MPTCPF_CHECKSUM) {

                do_csum = TRUE;
                do_csum = TRUE;

+       }

 
        /* tcp_output handles the SYN path separately */
 
        /* tcp_output handles the SYN path separately */

-       if (flags & TH_SYN)
-               return (optlen);
+       if (flags & TH_SYN) {
+               goto ret_optlen;
+       }

 
        if ((MAX_TCPOPTLEN - optlen) <
            sizeof (struct mptcp_mpcapable_opt_common)) {
 
        if ((MAX_TCPOPTLEN - optlen) <
            sizeof (struct mptcp_mpcapable_opt_common)) {


@@ -440,13 +471,13 @@ mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
                            "len %d\n", __func__, optlen, flags, tp->t_mpflags,
                            datalen);
                }
                            "len %d\n", __func__, optlen, flags, tp->t_mpflags,
                            datalen);
                }

-               return (optlen);
+               goto ret_optlen;

        }
 
        if (tp->t_mpflags & TMPF_FASTCLOSE) {
                optlen = mptcp_send_fastclose(tp, opt, optlen, flags);
                VERIFY(datalen == 0);
        }
 
        if (tp->t_mpflags & TMPF_FASTCLOSE) {
                optlen = mptcp_send_fastclose(tp, opt, optlen, flags);
                VERIFY(datalen == 0);

-               return (optlen);
+               goto ret_optlen;

        }
 
        if (tp->t_mpflags & TMPF_TCP_FALLBACK) {
        }
 
        if (tp->t_mpflags & TMPF_TCP_FALLBACK) {


@@ -454,12 +485,20 @@ mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
                        optlen = mptcp_send_mpfail(tp, opt, optlen);
                else if (!(tp->t_mpflags & TMPF_INFIN_SENT))
                        optlen = mptcp_send_infinite_mapping(tp, opt, optlen);
                        optlen = mptcp_send_mpfail(tp, opt, optlen);
                else if (!(tp->t_mpflags & TMPF_INFIN_SENT))
                        optlen = mptcp_send_infinite_mapping(tp, opt, optlen);

-               return (optlen);
+               goto ret_optlen;

        }
 
        if (tp->t_mpflags & TMPF_SND_MPPRIO) {
                optlen = mptcp_snd_mpprio(tp, opt, optlen);
        }
 
        if (tp->t_mpflags & TMPF_SND_MPPRIO) {
                optlen = mptcp_snd_mpprio(tp, opt, optlen);

-               return (optlen);
+               goto ret_optlen;
+       }
+
+       if (((tp->t_mpflags & TMPF_FASTJOINBY2_SEND) ||
+           (tp->t_mpflags & TMPF_FASTJOIN_SEND )) &&
+           (datalen > 0)) {
+               tp->t_mpflags &= ~TMPF_FASTJOINBY2_SEND;
+               tp->t_mpflags &= ~TMPF_FASTJOIN_SEND;
+               goto fastjoin_send;

        }
 
        if ((tp->t_mpflags & TMPF_PREESTABLISHED) &&
        }
 
        if ((tp->t_mpflags & TMPF_PREESTABLISHED) &&


@@ -468,7 +507,7 @@ mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
                struct mptcp_mpcapable_opt_rsp1 mptcp_opt;
                if ((MAX_TCPOPTLEN - optlen) <
                    sizeof (struct mptcp_mpcapable_opt_rsp1))
                struct mptcp_mpcapable_opt_rsp1 mptcp_opt;
                if ((MAX_TCPOPTLEN - optlen) <
                    sizeof (struct mptcp_mpcapable_opt_rsp1))

-                       return (optlen);
+                       goto ret_optlen;

                bzero(&mptcp_opt, sizeof (struct mptcp_mpcapable_opt_rsp1));
                mptcp_opt.mmc_common.mmco_kind = TCPOPT_MULTIPATH;
                mptcp_opt.mmc_common.mmco_len =
                bzero(&mptcp_opt, sizeof (struct mptcp_mpcapable_opt_rsp1));
                mptcp_opt.mmc_common.mmco_kind = TCPOPT_MULTIPATH;
                mptcp_opt.mmc_common.mmco_len =


@@ -498,7 +537,7 @@ mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
                if (mptcp_dbg >= MP_ERR_DEBUG) {
                        printf("MPTCP SUCCESS %s: established.\n", __func__);
                }
                if (mptcp_dbg >= MP_ERR_DEBUG) {
                        printf("MPTCP SUCCESS %s: established.\n", __func__);
                }

-               return (optlen);
+               goto ret_optlen;

        } else if (tp->t_mpflags & TMPF_MPTCP_TRUE) {
                if (tp->t_mpflags & TMPF_SND_REM_ADDR) {
                        int rem_opt_len = sizeof (struct mptcp_remaddr_opt);
        } else if (tp->t_mpflags & TMPF_MPTCP_TRUE) {
                if (tp->t_mpflags & TMPF_SND_REM_ADDR) {
                        int rem_opt_len = sizeof (struct mptcp_remaddr_opt);


@@ -506,7 +545,7 @@ mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
                                mptcp_send_remaddr_opt(tp,
                                    (struct mptcp_remaddr_opt *)(opt + optlen));
                                optlen += rem_opt_len;
                                mptcp_send_remaddr_opt(tp,
                                    (struct mptcp_remaddr_opt *)(opt + optlen));
                                optlen += rem_opt_len;

-                               return (optlen);
+                               goto ret_optlen;

                        } else {
                                tp->t_mpflags &= ~TMPF_SND_REM_ADDR;
                        }
                        } else {
                                tp->t_mpflags &= ~TMPF_SND_REM_ADDR;
                        }


@@ -518,6 +557,12 @@ mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
            (!(tp->t_mpflags & TMPF_RECVD_JOIN)) &&
            (tp->t_mpflags & TMPF_SENT_JOIN) &&
            (!(tp->t_mpflags & TMPF_MPTCP_TRUE))) {
            (!(tp->t_mpflags & TMPF_RECVD_JOIN)) &&
            (tp->t_mpflags & TMPF_SENT_JOIN) &&
            (!(tp->t_mpflags & TMPF_MPTCP_TRUE))) {

+               MPT_LOCK(mp_tp);
+               if (mptcp_get_localkey(mp_tp) == 0) {
+                       MPT_UNLOCK(mp_tp);
+                       goto ret_optlen;
+               }
+               MPT_UNLOCK(mp_tp);

                /* Do the ACK part */
                optlen = mptcp_setup_join_ack_opts(tp, opt, optlen);
                if (!tp->t_mpuna) {
                /* Do the ACK part */
                optlen = mptcp_setup_join_ack_opts(tp, opt, optlen);
                if (!tp->t_mpuna) {


@@ -526,16 +571,19 @@ mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
                /* Start a timer to retransmit the ACK */
                tp->t_timer[TCPT_JACK_RXMT] =
                            OFFSET_FROM_START(tp, tcp_jack_rxmt);
                /* Start a timer to retransmit the ACK */
                tp->t_timer[TCPT_JACK_RXMT] =
                            OFFSET_FROM_START(tp, tcp_jack_rxmt);

-               return (optlen);
+               goto ret_optlen;

        }
 
        if (!(tp->t_mpflags & TMPF_MPTCP_TRUE))
        }
 
        if (!(tp->t_mpflags & TMPF_MPTCP_TRUE))

-               return (optlen);
-
-       /* From here on, all options are sent only if MPTCP_TRUE */
+               goto ret_optlen;
+fastjoin_send:
+       /* 
+        * From here on, all options are sent only if MPTCP_TRUE 
+        * or when data is sent early on as in Fast Join
+        */

 
        MPT_LOCK(mp_tp);
 
        MPT_LOCK(mp_tp);

-       if (mp_tp->mpt_flags & MPTCPF_SND_64BITDSN) {
+       if ((mp_tp->mpt_flags & MPTCPF_SND_64BITDSN) || force_64bit_dsn) {

                send_64bit_dsn = TRUE;
        }
        if (mp_tp->mpt_flags & MPTCPF_SND_64BITACK) {
                send_64bit_dsn = TRUE;
        }
        if (mp_tp->mpt_flags & MPTCPF_SND_64BITACK) {


@@ -550,7 +598,7 @@ mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
                            __func__,                                   \
                            len, optlen);                               \
                }                                                       \
                            __func__,                                   \
                            len, optlen);                               \
                }                                                       \

-               return (optlen);                                        \
+               goto ret_optlen;                                        \

        }                                                               \
 }
 
        }                                                               \
 }
 


@@ -615,7 +663,7 @@ mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
 
                if ((dsn_ack_opt.mdss_data_len == 0) ||
                    (dsn_ack_opt.mdss_dsn == 0)) {
 
                if ((dsn_ack_opt.mdss_data_len == 0) ||
                    (dsn_ack_opt.mdss_dsn == 0)) {

-                       return (optlen);
+                       goto ret_optlen;

                }
 
                if (tp->t_mpflags & TMPF_SEND_DFIN) {
                }
 
                if (tp->t_mpflags & TMPF_SEND_DFIN) {


@@ -650,7 +698,7 @@ mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
                            mptcp_ntoh64(dsn_ack_opt.mdss_ack));
                }
                tp->t_mpflags &= ~TMPF_MPTCP_ACKNOW;
                            mptcp_ntoh64(dsn_ack_opt.mdss_ack));
                }
                tp->t_mpflags &= ~TMPF_MPTCP_ACKNOW;

-               return (optlen);
+               goto ret_optlen;

        }
 
        if ((tp->t_mpflags & TMPF_SEND_DSN) &&
        }
 
        if ((tp->t_mpflags & TMPF_SEND_DSN) &&


@@ -680,7 +728,7 @@ mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
 
                if ((dsn_opt.mdss_data_len == 0) ||
                    (dsn_opt.mdss_dsn == 0)) {
 
                if ((dsn_opt.mdss_data_len == 0) ||
                    (dsn_opt.mdss_dsn == 0)) {

-                       return (optlen);
+                       goto ret_optlen;

                }
 
                if (tp->t_mpflags & TMPF_SEND_DFIN) {
                }
 
                if (tp->t_mpflags & TMPF_SEND_DFIN) {


@@ -706,7 +754,7 @@ mptcp_setup_opts(struct tcpcb *tp, int32_t off, u_char *opt,
                            ntohs(dsn_opt.mdss_data_len));
                }
                tp->t_mpflags &= ~TMPF_MPTCP_ACKNOW;
                            ntohs(dsn_opt.mdss_data_len));
                }
                tp->t_mpflags &= ~TMPF_MPTCP_ACKNOW;

-               return (optlen);
+               goto ret_optlen;

        }
 
        /* 32-bit Data ACK option */
        }
 
        /* 32-bit Data ACK option */


@@ -735,7 +783,7 @@ do_ack32_only:
                optlen += len;
                VERIFY(optlen <= MAX_TCPOPTLEN);
                tp->t_mpflags &= ~TMPF_MPTCP_ACKNOW;
                optlen += len;
                VERIFY(optlen <= MAX_TCPOPTLEN);
                tp->t_mpflags &= ~TMPF_MPTCP_ACKNOW;

-               return (optlen);
+               goto ret_optlen;

        }
 
        /* 64-bit Data ACK option */
        }
 
        /* 64-bit Data ACK option */


@@ -767,7 +815,7 @@ do_ack64_only:
                optlen += len;
                VERIFY(optlen <= MAX_TCPOPTLEN);
                tp->t_mpflags &= ~TMPF_MPTCP_ACKNOW;
                optlen += len;
                VERIFY(optlen <= MAX_TCPOPTLEN);
                tp->t_mpflags &= ~TMPF_MPTCP_ACKNOW;

-               return (optlen);
+               goto ret_optlen;

        }
 
        /* 32-bit DSS+Data ACK option */
        }
 
        /* 32-bit DSS+Data ACK option */


@@ -828,7 +876,7 @@ do_ack64_only:
                if (optlen > MAX_TCPOPTLEN)
                        panic("optlen too large");
                tp->t_mpflags &= ~TMPF_MPTCP_ACKNOW;
                if (optlen > MAX_TCPOPTLEN)
                        panic("optlen too large");
                tp->t_mpflags &= ~TMPF_MPTCP_ACKNOW;

-               return (optlen);
+               goto ret_optlen;

        }
 
        /* 32-bit DSS + 64-bit DACK option */
        }
 
        /* 32-bit DSS + 64-bit DACK option */


@@ -887,7 +935,7 @@ do_ack64_only:
                if (optlen > MAX_TCPOPTLEN)
                        panic("optlen too large");
                tp->t_mpflags &= ~TMPF_MPTCP_ACKNOW;
                if (optlen > MAX_TCPOPTLEN)
                        panic("optlen too large");
                tp->t_mpflags &= ~TMPF_MPTCP_ACKNOW;

-               return (optlen);
+               goto ret_optlen;

        }
 
        if (tp->t_mpflags & TMPF_SEND_DFIN) {
        }
 
        if (tp->t_mpflags & TMPF_SEND_DFIN) {


@@ -902,14 +950,18 @@ do_ack64_only:
                bzero(&dss_ack_opt, sizeof (dss_ack_opt));
 
                MPT_LOCK(mp_tp);
                bzero(&dss_ack_opt, sizeof (dss_ack_opt));
 
                MPT_LOCK(mp_tp);

-               /* Data FIN occupies one sequence space */
-               if ((mp_tp->mpt_sndnxt + 1) != mp_tp->mpt_sndmax) {
+               /*
+                * Data FIN occupies one sequence space.
+                * Don't send it if it has been Acked.
+                */
+               if (((mp_tp->mpt_sndnxt + 1) != mp_tp->mpt_sndmax) ||
+                   (mp_tp->mpt_snduna == mp_tp->mpt_sndmax)) {

                        MPT_UNLOCK(mp_tp);
                        if (mptcp_dbg == MP_VERBOSE_DEBUG_2)
                                printf("%s: Fin state %d %llu %llu\n", __func__,
                                    mp_tp->mpt_state, mp_tp->mpt_sndnxt,
                                    mp_tp->mpt_sndmax);
                        MPT_UNLOCK(mp_tp);
                        if (mptcp_dbg == MP_VERBOSE_DEBUG_2)
                                printf("%s: Fin state %d %llu %llu\n", __func__,
                                    mp_tp->mpt_state, mp_tp->mpt_sndnxt,
                                    mp_tp->mpt_sndmax);

-                       return (optlen);
+                       goto ret_optlen;

                }
 
                dss_ack_opt.mdss_copt.mdss_kind = TCPOPT_MULTIPATH;
                }
 
                dss_ack_opt.mdss_copt.mdss_kind = TCPOPT_MULTIPATH;


@@ -934,7 +986,34 @@ do_ack64_only:
                optlen += len;
        }
 
                optlen += len;
        }
 

-       return (optlen);
+ret_optlen:
+       if (TRUE == *p_mptcp_acknow ) {
+               VERIFY(old_mpt_flags != 0);
+               u_int32_t new_mpt_flags = tp->t_mpflags &
+                   (TMPF_SND_MPPRIO | TMPF_SND_REM_ADDR | TMPF_SND_MPFAIL);
+
+               /*
+                * If none of the above mpflags were acted on by
+                * this routine, reset these flags and set p_mptcp_acknow
+                * to false.
+                * XXX The reset value of p_mptcp_acknow can be used 
+                * to communicate tcp_output to NOT send a pure ack without any
+                * MPTCP options as it will be treated as a dup ack.
+                * Since the instances of mptcp_setup_opts not acting on
+                * these options are mostly corner cases and sending a dup
+                * ack here would only have an impact if the system
+                * has sent consecutive dup acks before this false one,
+                * we haven't modified the logic in tcp_output to avoid
+                * that.
+                */
+               if (old_mpt_flags == new_mpt_flags) { 
+                       tp->t_mpflags &= ~(TMPF_SND_MPPRIO
+                           | TMPF_SND_REM_ADDR | TMPF_SND_MPFAIL);
+                       *p_mptcp_acknow = FALSE;
+               }
+       }
+
+       return optlen;

 }
 
 /*
 }
 
 /*


@@ -1232,7 +1311,7 @@ mptcp_do_mpjoin_opt(struct tcpcb *tp, u_char *cp, struct tcphdr *th, int optlen)
            (tp->t_mpflags & TMPF_PREESTABLISHED)) {
                struct mptcp_mpjoin_opt_rsp2 *join_rsp2 =
                    (struct mptcp_mpjoin_opt_rsp2 *)cp;
            (tp->t_mpflags & TMPF_PREESTABLISHED)) {
                struct mptcp_mpjoin_opt_rsp2 *join_rsp2 =
                    (struct mptcp_mpjoin_opt_rsp2 *)cp;

-
+               

                if (optlen != sizeof (struct mptcp_mpjoin_opt_rsp2)) {
                        if (mptcp_dbg >= MP_ERR_DEBUG) {
                                printf("ACK: unexpected optlen = %d mp option "
                if (optlen != sizeof (struct mptcp_mpjoin_opt_rsp2)) {
                        if (mptcp_dbg >= MP_ERR_DEBUG) {
                                printf("ACK: unexpected optlen = %d mp option "


@@ -1322,8 +1401,7 @@ mptcp_do_dss_opt_ack_meat(u_int64_t full_dack, struct tcpcb *tp)
        if (MPTCP_SEQ_LEQ(full_dack, mp_tp->mpt_sndmax) &&
            MPTCP_SEQ_GEQ(full_dack, mp_tp->mpt_snduna)) {
                mptcp_data_ack_rcvd(mp_tp, tp, full_dack);
        if (MPTCP_SEQ_LEQ(full_dack, mp_tp->mpt_sndmax) &&
            MPTCP_SEQ_GEQ(full_dack, mp_tp->mpt_snduna)) {
                mptcp_data_ack_rcvd(mp_tp, tp, full_dack);

-               if ((mp_tp->mpt_state == MPTCPS_CLOSED) ||
-                   (mp_tp->mpt_state > MPTCPS_FIN_WAIT_2))
+               if (mp_tp->mpt_state > MPTCPS_FIN_WAIT_2)

                        close_notify = 1;
                MPT_UNLOCK(mp_tp);
                mptcp_notify_mpready(tp->t_inpcb->inp_socket);
                        close_notify = 1;
                MPT_UNLOCK(mp_tp);
                mptcp_notify_mpready(tp->t_inpcb->inp_socket);


@@ -1609,9 +1687,15 @@ mptcp_do_fin_opt(struct tcpcb *tp)
        if (!(tp->t_mpflags & TMPF_RECV_DFIN)) {
                if (mp_tp != NULL) {
                        MPT_LOCK(mp_tp);
        if (!(tp->t_mpflags & TMPF_RECV_DFIN)) {
                if (mp_tp != NULL) {
                        MPT_LOCK(mp_tp);

-                       mp_tp->mpt_rcvnxt += 1;

                        mptcp_close_fsm(mp_tp, MPCE_RECV_DATA_FIN);
                        MPT_UNLOCK(mp_tp);
                        mptcp_close_fsm(mp_tp, MPCE_RECV_DATA_FIN);
                        MPT_UNLOCK(mp_tp);

+
+                       if (tp->t_inpcb->inp_socket != NULL) {
+                               soevent(tp->t_inpcb->inp_socket,
+                                   SO_FILT_HINT_LOCKED |
+                                   SO_FILT_HINT_MPCANTRCVMORE);
+                       }
+

                }
                tp->t_mpflags |= TMPF_RECV_DFIN;
        }
                }
                tp->t_mpflags |= TMPF_RECV_DFIN;
        }


@@ -1633,7 +1717,9 @@ mptcp_do_dss_opt(struct tcpcb *tp, u_char *cp, struct tcphdr *th, int optlen)
        if (!mp_tp)
                return;
 
        if (!mp_tp)
                return;
 

-       if (tp->t_mpflags & TMPF_MPTCP_TRUE) {
+       /* We may get Data ACKs just during fallback, so don't ignore those */
+       if ((tp->t_mpflags & TMPF_MPTCP_TRUE) ||
+           (tp->t_mpflags & TMPF_TCP_FALLBACK)) {

                struct mptcp_dss_copt *dss_rsp = (struct mptcp_dss_copt *)cp;
 
                if (dss_rsp->mdss_subtype == MPO_DSS) {
                struct mptcp_dss_copt *dss_rsp = (struct mptcp_dss_copt *)cp;
 
                if (dss_rsp->mdss_subtype == MPO_DSS) {


@@ -1711,8 +1797,20 @@ mptcp_do_mpfail_opt(struct tcpcb *tp, u_char *cp, struct tcphdr *th)
 {
        struct mptcb *mp_tp = NULL;
        struct mptcp_mpfail_opt *fail_opt = (struct mptcp_mpfail_opt *)cp;
 {
        struct mptcb *mp_tp = NULL;
        struct mptcp_mpfail_opt *fail_opt = (struct mptcp_mpfail_opt *)cp;

+       u_int32_t mdss_subflow_seqn = 0;
+       int error = 0;

 
 

-       if ((th->th_flags != TH_ACK) || (th->th_flags != TH_RST))
+       /*
+        * mpfail could make us more vulnerable to attacks. Hence accept
+        * only those that are the next expected sequence number.
+        */
+       if (th->th_seq != tp->rcv_nxt) {
+               tcpstat.tcps_invalid_opt++;
+               return;
+       }
+
+       /* A packet without RST, must atleast have the ACK bit set */
+       if ((th->th_flags != TH_ACK) && (th->th_flags != TH_RST))

                return;
 
        if (fail_opt->mfail_len != sizeof (struct mptcp_mpfail_opt))
                return;
 
        if (fail_opt->mfail_len != sizeof (struct mptcp_mpfail_opt))


@@ -1721,11 +1819,15 @@ mptcp_do_mpfail_opt(struct tcpcb *tp, u_char *cp, struct tcphdr *th)
        mp_tp = (struct mptcb *)tp->t_mptcb;
        if (mp_tp == NULL)
                return;
        mp_tp = (struct mptcb *)tp->t_mptcb;
        if (mp_tp == NULL)
                return;

-

        MPT_LOCK(mp_tp);
        mp_tp->mpt_flags |= MPTCPF_RECVD_MPFAIL;
        mp_tp->mpt_dsn_at_csum_fail = mptcp_hton64(fail_opt->mfail_dsn);
        MPT_UNLOCK(mp_tp);
        MPT_LOCK(mp_tp);
        mp_tp->mpt_flags |= MPTCPF_RECVD_MPFAIL;
        mp_tp->mpt_dsn_at_csum_fail = mptcp_hton64(fail_opt->mfail_dsn);
        MPT_UNLOCK(mp_tp);

+       error = mptcp_get_map_for_dsn(tp->t_inpcb->inp_socket, 
+           mp_tp->mpt_dsn_at_csum_fail, &mdss_subflow_seqn);
+       if (error == 0) {
+               mp_tp->mpt_ssn_at_csum_fail = mdss_subflow_seqn;
+       }

 
        mptcp_notify_mpfail(tp->t_inpcb->inp_socket);
 }
 
        mptcp_notify_mpfail(tp->t_inpcb->inp_socket);
 }


@@ -1816,9 +1918,9 @@ mptcp_send_remaddr_opt(struct tcpcb *tp, struct mptcp_remaddr_opt *opt)
                printf("%s: local id %d remove id %d \n", __func__,
                    tp->t_local_aid, tp->t_rem_aid);
 
                printf("%s: local id %d remove id %d \n", __func__,
                    tp->t_local_aid, tp->t_rem_aid);
 

-       bzero(opt, sizeof (opt));
+       bzero(opt, sizeof (*opt));

        opt->mr_kind = TCPOPT_MULTIPATH;
        opt->mr_kind = TCPOPT_MULTIPATH;

-       opt->mr_len = sizeof (opt);
+       opt->mr_len = sizeof (*opt);

        opt->mr_subtype = MPO_REMOVE_ADDR;
        opt->mr_addr_id = tp->t_rem_aid;
        tp->t_mpflags &= ~TMPF_SND_REM_ADDR;
        opt->mr_subtype = MPO_REMOVE_ADDR;
        opt->mr_addr_id = tp->t_rem_aid;
        tp->t_mpflags &= ~TMPF_SND_REM_ADDR;