#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/mcache.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/syslog.h>
#include <sys/protosw.h>
#include <kern/zalloc.h>
#include <kern/locks.h>
#include <mach/sdt.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/tcp.h>
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_var.h>
#include <netinet/mptcp_var.h>
#include <netinet/mptcp.h>
#include <netinet/mptcp_seq.h>
#include <netinet/mptcp_opt.h>
#include <netinet/mptcp_timer.h>
int mptcp_enable = 1;
SYSCTL_INT(_net_inet_mptcp, OID_AUTO, enable, CTLFLAG_RW | CTLFLAG_LOCKED,
&mptcp_enable, 0, "Enable Multipath TCP Support");
int mptcp_mpcap_retries = 4;
SYSCTL_INT(_net_inet_mptcp, OID_AUTO, mptcp_cap_retr,
CTLFLAG_RW | CTLFLAG_LOCKED,
&mptcp_mpcap_retries, 0, "Number of MP Capable SYN Retries");
int mptcp_dss_csum = 0;
SYSCTL_INT(_net_inet_mptcp, OID_AUTO, dss_csum, CTLFLAG_RW | CTLFLAG_LOCKED,
&mptcp_dss_csum, 0, "Enable DSS checksum");
int mptcp_fail_thresh = 1;
SYSCTL_INT(_net_inet_mptcp, OID_AUTO, fail, CTLFLAG_RW | CTLFLAG_LOCKED,
&mptcp_fail_thresh, 0, "Failover threshold");
int mptcp_subflow_keeptime = 60 * 14;
SYSCTL_INT(_net_inet_mptcp, OID_AUTO, keepalive, CTLFLAG_RW | CTLFLAG_LOCKED,
&mptcp_subflow_keeptime, 0, "Keepalive in seconds");
int mptcp_rtthist_rtthresh = 600;
SYSCTL_INT(_net_inet_mptcp, OID_AUTO, rtthist_thresh, CTLFLAG_RW | CTLFLAG_LOCKED,
&mptcp_rtthist_rtthresh, 0, "Rtt threshold");
int mptcp_use_rto = 1;
SYSCTL_INT(_net_inet_mptcp, OID_AUTO, userto, CTLFLAG_RW | CTLFLAG_LOCKED,
&mptcp_use_rto, 0, "Disable RTO for subflow selection");
int mptcp_rtothresh = 1500;
SYSCTL_INT(_net_inet_mptcp, OID_AUTO, rto_thresh, CTLFLAG_RW | CTLFLAG_LOCKED,
&mptcp_rtothresh, 0, "RTO threshold");
uint32_t mptcp_probeto = 1000;
SYSCTL_UINT(_net_inet_mptcp, OID_AUTO, probeto, CTLFLAG_RW | CTLFLAG_LOCKED,
&mptcp_probeto, 0, "Disable probing by setting to 0");
uint32_t mptcp_probecnt = 5;
SYSCTL_UINT(_net_inet_mptcp, OID_AUTO, probecnt, CTLFLAG_RW | CTLFLAG_LOCKED,
&mptcp_probecnt, 0, "Number of probe writes");
static uint16_t mptcp_input_csum(struct tcpcb *, struct mbuf *, uint64_t,
uint32_t, uint16_t, uint16_t, uint16_t);
static int
mptcp_reass_present(struct socket *mp_so)
{
struct mptses *mpte = mpsotompte(mp_so);
struct mptcb *mp_tp = mpte->mpte_mptcb;
struct tseg_qent *q;
int dowakeup = 0;
int flags = 0;
if (mp_tp->mpt_state < MPTCPS_ESTABLISHED) {
return flags;
}
q = LIST_FIRST(&mp_tp->mpt_segq);
if (!q || q->tqe_m->m_pkthdr.mp_dsn != mp_tp->mpt_rcvnxt) {
return flags;
}
if (mp_tp->mpt_flags & MPTCPF_REASS_INPROG) {
return flags;
}
mp_tp->mpt_flags |= MPTCPF_REASS_INPROG;
do {
mp_tp->mpt_rcvnxt += q->tqe_len;
LIST_REMOVE(q, tqe_q);
if (mp_so->so_state & SS_CANTRCVMORE) {
m_freem(q->tqe_m);
} else {
flags = !!(q->tqe_m->m_pkthdr.pkt_flags & PKTF_MPTCP_DFIN);
if (sbappendstream_rcvdemux(mp_so, q->tqe_m, 0, 0)) {
dowakeup = 1;
}
}
zfree(tcp_reass_zone, q);
mp_tp->mpt_reassqlen--;
q = LIST_FIRST(&mp_tp->mpt_segq);
} while (q && q->tqe_m->m_pkthdr.mp_dsn == mp_tp->mpt_rcvnxt);
mp_tp->mpt_flags &= ~MPTCPF_REASS_INPROG;
if (dowakeup) {
sorwakeup(mp_so);
}
return flags;
}
static int
mptcp_reass(struct socket *mp_so, struct pkthdr *phdr, int *tlenp, struct mbuf *m)
{
struct mptcb *mp_tp = mpsotomppcb(mp_so)->mpp_pcbe->mpte_mptcb;
u_int64_t mb_dsn = phdr->mp_dsn;
struct tseg_qent *q;
struct tseg_qent *p = NULL;
struct tseg_qent *nq;
struct tseg_qent *te = NULL;
u_int16_t qlimit;
qlimit = min(max(100, mp_so->so_rcv.sb_hiwat >> 10),
(tcp_autorcvbuf_max >> 10));
if (mb_dsn != mp_tp->mpt_rcvnxt &&
(mp_tp->mpt_reassqlen + 1) >= qlimit) {
tcpstat.tcps_mptcp_rcvmemdrop++;
m_freem(m);
*tlenp = 0;
return 0;
}
te = (struct tseg_qent *) zalloc(tcp_reass_zone);
if (te == NULL) {
tcpstat.tcps_mptcp_rcvmemdrop++;
m_freem(m);
return 0;
}
mp_tp->mpt_reassqlen++;
LIST_FOREACH(q, &mp_tp->mpt_segq, tqe_q) {
if (MPTCP_SEQ_GT(q->tqe_m->m_pkthdr.mp_dsn, mb_dsn)) {
break;
}
p = q;
}
if (p != NULL) {
int64_t i;
i = p->tqe_m->m_pkthdr.mp_dsn + p->tqe_len - mb_dsn;
if (i > 0) {
if (i >= *tlenp) {
tcpstat.tcps_mptcp_rcvduppack++;
m_freem(m);
zfree(tcp_reass_zone, te);
te = NULL;
mp_tp->mpt_reassqlen--;
goto out;
}
m_adj(m, i);
*tlenp -= i;
phdr->mp_dsn += i;
}
}
tcpstat.tcps_mp_oodata++;
while (q) {
int64_t i = (mb_dsn + *tlenp) - q->tqe_m->m_pkthdr.mp_dsn;
if (i <= 0) {
break;
}
if (i < q->tqe_len) {
q->tqe_m->m_pkthdr.mp_dsn += i;
q->tqe_len -= i;
m_adj(q->tqe_m, i);
break;
}
nq = LIST_NEXT(q, tqe_q);
LIST_REMOVE(q, tqe_q);
m_freem(q->tqe_m);
zfree(tcp_reass_zone, q);
mp_tp->mpt_reassqlen--;
q = nq;
}
te->tqe_m = m;
te->tqe_th = NULL;
te->tqe_len = *tlenp;
if (p == NULL) {
LIST_INSERT_HEAD(&mp_tp->mpt_segq, te, tqe_q);
} else {
LIST_INSERT_AFTER(p, te, tqe_q);
}
out:
return mptcp_reass_present(mp_so);
}
void
mptcp_input(struct mptses *mpte, struct mbuf *m)
{
struct socket *mp_so;
struct mptcb *mp_tp = NULL;
int count = 0, wakeup = 0;
struct mbuf *save = NULL, *prev = NULL;
struct mbuf *freelist = NULL, *tail = NULL;
VERIFY(m->m_flags & M_PKTHDR);
mp_so = mptetoso(mpte);
mp_tp = mpte->mpte_mptcb;
socket_lock_assert_owned(mp_so);
DTRACE_MPTCP(input);
mp_tp->mpt_rcvwnd = mptcp_sbspace(mp_tp);
count = mp_so->so_rcv.sb_cc;
if (mp_tp->mpt_flags & MPTCPF_FALLBACK_TO_TCP) {
struct mbuf *iter;
int mb_dfin = 0;
fallback:
mptcp_sbrcv_grow(mp_tp);
iter = m;
while (iter) {
if ((iter->m_flags & M_PKTHDR) &&
(iter->m_pkthdr.pkt_flags & PKTF_MPTCP_DFIN)) {
mb_dfin = 1;
}
if ((iter->m_flags & M_PKTHDR) && m_pktlen(iter) == 0) {
if (prev == NULL) {
m = iter->m_next;
m_free(iter);
iter = m;
} else {
prev->m_next = iter->m_next;
m_free(iter);
iter = prev->m_next;
}
VERIFY(iter == NULL || iter->m_flags & M_PKTHDR);
} else {
prev = iter;
iter = iter->m_next;
}
}
if (sbappendstream_rcvdemux(mp_so, m, 0, 0)) {
sorwakeup(mp_so);
}
DTRACE_MPTCP5(receive__degraded, struct mbuf *, m,
struct socket *, mp_so,
struct sockbuf *, &mp_so->so_rcv,
struct sockbuf *, &mp_so->so_snd,
struct mptses *, mpte);
count = mp_so->so_rcv.sb_cc - count;
mp_tp->mpt_rcvnxt += count;
if (mb_dfin) {
mptcp_close_fsm(mp_tp, MPCE_RECV_DATA_FIN);
socantrcvmore(mp_so);
}
return;
}
do {
u_int64_t mb_dsn;
int32_t mb_datalen;
int64_t todrop;
int mb_dfin = 0;
VERIFY(m->m_flags & M_PKTHDR);
if (!(m->m_pkthdr.pkt_flags & PKTF_MPTCP)) {
goto fallback;
}
save = m->m_next;
while (save && (!(save->m_flags & M_PKTHDR) ||
!(save->m_pkthdr.pkt_flags & PKTF_MPTCP))) {
prev = save;
save = save->m_next;
}
if (prev) {
prev->m_next = NULL;
} else {
m->m_next = NULL;
}
mb_dsn = m->m_pkthdr.mp_dsn;
mb_datalen = m->m_pkthdr.mp_rlen;
todrop = (mb_dsn + mb_datalen) - (mp_tp->mpt_rcvnxt + mp_tp->mpt_rcvwnd);
if (todrop > 0) {
tcpstat.tcps_mptcp_rcvpackafterwin++;
os_log_info(mptcp_log_handle, "%s - %lx: dropping dsn %u dlen %u rcvnxt %u rcvwnd %u todrop %lld\n",
__func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte),
(uint32_t)mb_dsn, mb_datalen, (uint32_t)mp_tp->mpt_rcvnxt,
mp_tp->mpt_rcvwnd, todrop);
if (todrop >= mb_datalen) {
if (freelist == NULL) {
freelist = m;
} else {
tail->m_next = m;
}
if (prev != NULL) {
tail = prev;
} else {
tail = m;
}
m = save;
prev = save = NULL;
continue;
} else {
m_adj(m, -todrop);
mb_datalen -= todrop;
m->m_pkthdr.mp_rlen -= todrop;
}
m->m_pkthdr.pkt_flags &= ~PKTF_MPTCP_DFIN;
}
if (MPTCP_SEQ_LT(mb_dsn, mp_tp->mpt_rcvnxt)) {
if (MPTCP_SEQ_LEQ((mb_dsn + mb_datalen),
mp_tp->mpt_rcvnxt)) {
if (freelist == NULL) {
freelist = m;
} else {
tail->m_next = m;
}
if (prev != NULL) {
tail = prev;
} else {
tail = m;
}
m = save;
prev = save = NULL;
continue;
} else {
m_adj(m, (mp_tp->mpt_rcvnxt - mb_dsn));
mb_datalen -= (mp_tp->mpt_rcvnxt - mb_dsn);
mb_dsn = mp_tp->mpt_rcvnxt;
m->m_pkthdr.mp_rlen = mb_datalen;
m->m_pkthdr.mp_dsn = mb_dsn;
}
}
if (MPTCP_SEQ_GT(mb_dsn, mp_tp->mpt_rcvnxt) ||
!LIST_EMPTY(&mp_tp->mpt_segq)) {
mb_dfin = mptcp_reass(mp_so, &m->m_pkthdr, &mb_datalen, m);
goto next;
}
mb_dfin = !!(m->m_pkthdr.pkt_flags & PKTF_MPTCP_DFIN);
mptcp_sbrcv_grow(mp_tp);
if (sbappendstream_rcvdemux(mp_so, m, 0, 0)) {
wakeup = 1;
}
DTRACE_MPTCP6(receive, struct mbuf *, m, struct socket *, mp_so,
struct sockbuf *, &mp_so->so_rcv,
struct sockbuf *, &mp_so->so_snd,
struct mptses *, mpte,
struct mptcb *, mp_tp);
count = mp_so->so_rcv.sb_cc - count;
tcpstat.tcps_mp_rcvtotal++;
tcpstat.tcps_mp_rcvbytes += count;
mp_tp->mpt_rcvnxt += count;
next:
if (mb_dfin) {
mptcp_close_fsm(mp_tp, MPCE_RECV_DATA_FIN);
socantrcvmore(mp_so);
}
m = save;
prev = save = NULL;
count = mp_so->so_rcv.sb_cc;
} while (m);
if (freelist) {
m_freem(freelist);
}
if (wakeup) {
sorwakeup(mp_so);
}
}
boolean_t
mptcp_can_send_more(struct mptcb *mp_tp, boolean_t ignore_reinject)
{
struct socket *mp_so = mptetoso(mp_tp->mpt_mpte);
if (!ignore_reinject && mp_tp->mpt_mpte->mpte_reinjectq) {
return TRUE;
}
if (!(mp_so->so_flags1 & SOF1_PRECONNECT_DATA) && MPTCP_SEQ_GEQ(mp_tp->mpt_sndnxt, mp_tp->mpt_sndmax)) {
return FALSE;
}
if (MPTCP_SEQ_LEQ(mp_tp->mpt_snduna + mp_tp->mpt_sndwnd, mp_tp->mpt_sndnxt)) {
return FALSE;
}
if (mp_tp->mpt_sndnxt + 1 == mp_tp->mpt_sndmax && mp_tp->mpt_state > MPTCPS_CLOSE_WAIT) {
return FALSE;
}
if (mp_tp->mpt_state >= MPTCPS_FIN_WAIT_2) {
return FALSE;
}
return TRUE;
}
int
mptcp_output(struct mptses *mpte)
{
struct mptcb *mp_tp;
struct mptsub *mpts;
struct mptsub *mpts_tried = NULL;
struct socket *mp_so;
struct mptsub *preferred_mpts = NULL;
uint64_t old_snd_nxt;
int error = 0;
mp_so = mptetoso(mpte);
socket_lock_assert_owned(mp_so);
mp_tp = mpte->mpte_mptcb;
VERIFY(!(mpte->mpte_mppcb->mpp_flags & MPP_WUPCALL));
mpte->mpte_mppcb->mpp_flags |= MPP_WUPCALL;
old_snd_nxt = mp_tp->mpt_sndnxt;
while (mptcp_can_send_more(mp_tp, FALSE)) {
mpts = mptcp_get_subflow(mpte, &preferred_mpts);
if (mpts == NULL) {
mptcplog((LOG_INFO, "%s: no subflow\n", __func__),
MPTCP_SENDER_DBG, MPTCP_LOGLVL_LOG);
break;
}
if (mpts_tried != NULL &&
(mpts == mpts_tried || (mpts->mpts_flags & MPTSF_FAILINGOVER))) {
mpts_tried->mpts_flags &= ~MPTSF_FAILINGOVER;
mpts_tried->mpts_flags |= MPTSF_ACTIVE;
mptcp_start_timer(mpte, MPTT_REXMT);
break;
}
if (tcp_do_autosendbuf == 1 &&
(mp_so->so_snd.sb_flags & (SB_AUTOSIZE | SB_TRIM)) == SB_AUTOSIZE &&
tcp_cansbgrow(&mp_so->so_snd)) {
if ((mp_tp->mpt_sndwnd / 4 * 5) >= mp_so->so_snd.sb_hiwat &&
mp_so->so_snd.sb_cc >= (mp_so->so_snd.sb_hiwat / 8 * 7)) {
if (sbreserve(&mp_so->so_snd,
min(mp_so->so_snd.sb_hiwat + tcp_autosndbuf_inc,
tcp_autosndbuf_max)) == 1) {
mp_so->so_snd.sb_idealsize = mp_so->so_snd.sb_hiwat;
}
}
}
DTRACE_MPTCP3(output, struct mptses *, mpte, struct mptsub *, mpts,
struct socket *, mp_so);
error = mptcp_subflow_output(mpte, mpts, 0);
if (error) {
mpts->mpts_flags |= MPTSF_FAILINGOVER;
mpts->mpts_flags &= ~MPTSF_ACTIVE;
mpts_tried = mpts;
if (error != ECANCELED) {
os_log_error(mptcp_log_handle, "%s - %lx: Error = %d mpts_flags %#x\n",
__func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte),
error, mpts->mpts_flags);
}
break;
}
mpts->mpts_flags |= MPTSF_ACTIVE;
mpts->mpts_probesoon = mpts->mpts_probecnt = 0;
if (mptcp_probeto && mpts != preferred_mpts && preferred_mpts != NULL) {
if (preferred_mpts->mpts_probesoon) {
if ((tcp_now - preferred_mpts->mpts_probesoon) > mptcp_probeto) {
mptcp_subflow_output(mpte, preferred_mpts, MPTCP_SUBOUT_PROBING);
if (preferred_mpts->mpts_probecnt >= mptcp_probecnt) {
preferred_mpts->mpts_probesoon = 0;
preferred_mpts->mpts_probecnt = 0;
}
}
} else {
preferred_mpts->mpts_probesoon = tcp_now;
preferred_mpts->mpts_probecnt = 0;
}
}
if (mpte->mpte_active_sub == NULL) {
mpte->mpte_active_sub = mpts;
} else if (mpte->mpte_active_sub != mpts) {
mpte->mpte_active_sub->mpts_flags &= ~MPTSF_ACTIVE;
mpte->mpte_active_sub = mpts;
mptcpstats_inc_switch(mpte, mpts);
}
}
if (mp_tp->mpt_state > MPTCPS_CLOSE_WAIT) {
if (mp_tp->mpt_sndnxt + 1 == mp_tp->mpt_sndmax &&
mp_tp->mpt_snduna == mp_tp->mpt_sndnxt) {
mptcp_finish_usrclosed(mpte);
}
}
mptcp_handle_deferred_upcalls(mpte->mpte_mppcb, MPP_WUPCALL);
return 0;
}
static struct mptsub *
mptcp_choose_subflow(struct mptsub *mpts, struct mptsub *curbest, int *currtt)
{
struct tcpcb *tp = sototcpcb(mpts->mpts_socket);
if (tp->t_srtt && *currtt > tp->t_srtt &&
(curbest == NULL || tp->t_rxtshift == 0 ||
sototcpcb(curbest->mpts_socket)->t_rxtshift)) {
*currtt = tp->t_srtt;
return mpts;
}
if (curbest &&
sototcpcb(curbest->mpts_socket)->t_rxtshift &&
tp->t_rxtshift == 0) {
*currtt = tp->t_srtt;
return mpts;
}
return curbest != NULL ? curbest : mpts;
}
static struct mptsub *
mptcp_return_subflow(struct mptsub *mpts)
{
if (mpts && mptcp_subflow_cwnd_space(mpts->mpts_socket) <= 0) {
return NULL;
}
return mpts;
}
static boolean_t
mptcp_subflow_is_slow(struct mptses *mpte, struct mptsub *mpts)
{
struct tcpcb *tp = sototcpcb(mpts->mpts_socket);
int fail_thresh = mptcp_fail_thresh;
if (mpte->mpte_svctype == MPTCP_SVCTYPE_HANDOVER) {
fail_thresh *= 2;
}
return tp->t_rxtshift >= fail_thresh &&
(mptetoso(mpte)->so_snd.sb_cc || mpte->mpte_reinjectq);
}
struct mptsub *
mptcp_get_subflow(struct mptses *mpte, struct mptsub **preferred)
{
struct tcpcb *besttp, *secondtp;
struct inpcb *bestinp, *secondinp;
struct mptsub *mpts;
struct mptsub *best = NULL;
struct mptsub *second_best = NULL;
int exp_rtt = INT_MAX, cheap_rtt = INT_MAX;
TAILQ_FOREACH(mpts, &mpte->mpte_subflows, mpts_entry) {
struct socket *so = mpts->mpts_socket;
struct tcpcb *tp = sototcpcb(so);
struct inpcb *inp = sotoinpcb(so);
mptcplog((LOG_DEBUG, "%s mpts %u mpts_flags %#x, suspended %u sostate %#x tpstate %u cellular %d rtt %u rxtshift %u cheap %u exp %u cwnd %d\n",
__func__, mpts->mpts_connid, mpts->mpts_flags,
INP_WAIT_FOR_IF_FEEDBACK(inp), so->so_state, tp->t_state,
inp->inp_last_outifp ? IFNET_IS_CELLULAR(inp->inp_last_outifp) : -1,
tp->t_srtt, tp->t_rxtshift, cheap_rtt, exp_rtt,
mptcp_subflow_cwnd_space(so)),
MPTCP_SOCKET_DBG, MPTCP_LOGLVL_VERBOSE);
if (inp->inp_last_outifp == NULL) {
continue;
}
if (INP_WAIT_FOR_IF_FEEDBACK(inp)) {
continue;
}
if (mpts->mpts_flags & MPTSF_MP_DEGRADED) {
best = mpts;
break;
}
if (so->so_flags1 & SOF1_PRECONNECT_DATA) {
return mptcp_return_subflow(mpts);
}
if (!(mpts->mpts_flags & MPTSF_MP_CAPABLE)) {
continue;
}
if ((so->so_state & SS_ISDISCONNECTED) ||
!(so->so_state & SS_ISCONNECTED) ||
!TCPS_HAVEESTABLISHED(tp->t_state) ||
tp->t_state > TCPS_CLOSE_WAIT) {
continue;
}
if (IFNET_IS_CELLULAR(inp->inp_last_outifp)) {
second_best = mptcp_choose_subflow(mpts, second_best,
&exp_rtt);
} else {
best = mptcp_choose_subflow(mpts, best, &cheap_rtt);
}
}
if (best == NULL) {
return mptcp_return_subflow(second_best);
}
if (second_best == NULL) {
return mptcp_return_subflow(best);
}
besttp = sototcpcb(best->mpts_socket);
bestinp = sotoinpcb(best->mpts_socket);
secondtp = sototcpcb(second_best->mpts_socket);
secondinp = sotoinpcb(second_best->mpts_socket);
if (preferred != NULL) {
*preferred = mptcp_return_subflow(best);
}
if (mpte->mpte_svctype == MPTCP_SVCTYPE_HANDOVER) {
if (!IFNET_IS_CELLULAR(bestinp->inp_last_outifp) &&
mptcp_is_wifi_unusable_for_session(mpte) != 0 && mptcp_subflow_is_slow(mpte, best)) {
return mptcp_return_subflow(second_best);
}
return mptcp_return_subflow(best);
} else if (mpte->mpte_svctype == MPTCP_SVCTYPE_INTERACTIVE) {
int rtt_thresh = mptcp_rtthist_rtthresh << TCP_RTT_SHIFT;
int rto_thresh = mptcp_rtothresh;
if (!IFNET_IS_CELLULAR(bestinp->inp_last_outifp) &&
mptcp_is_wifi_unusable_for_session(mpte) != 0) {
rtt_thresh /= 2;
rto_thresh /= 2;
}
if (besttp->t_srtt && secondtp->t_srtt &&
besttp->t_srtt >= rtt_thresh &&
secondtp->t_srtt < rtt_thresh) {
tcpstat.tcps_mp_sel_rtt++;
mptcplog((LOG_DEBUG, "%s: best cid %d at rtt %d, second cid %d at rtt %d\n", __func__,
best->mpts_connid, besttp->t_srtt >> TCP_RTT_SHIFT,
second_best->mpts_connid,
secondtp->t_srtt >> TCP_RTT_SHIFT),
MPTCP_SENDER_DBG, MPTCP_LOGLVL_LOG);
return mptcp_return_subflow(second_best);
}
if (mptcp_subflow_is_slow(mpte, best) &&
secondtp->t_rxtshift == 0) {
return mptcp_return_subflow(second_best);
}
if (besttp->t_rxtcur && secondtp->t_rxtcur &&
besttp->t_rxtcur >= rto_thresh &&
secondtp->t_rxtcur < rto_thresh) {
tcpstat.tcps_mp_sel_rto++;
mptcplog((LOG_DEBUG, "%s: best cid %d at rto %d, second cid %d at rto %d\n", __func__,
best->mpts_connid, besttp->t_rxtcur,
second_best->mpts_connid, secondtp->t_rxtcur),
MPTCP_SENDER_DBG, MPTCP_LOGLVL_LOG);
return mptcp_return_subflow(second_best);
}
return mptcp_return_subflow(best);
} else if (mpte->mpte_svctype >= MPTCP_SVCTYPE_AGGREGATE) {
struct mptsub *tmp;
if (besttp->t_srtt > secondtp->t_srtt) {
tmp = best;
best = second_best;
besttp = secondtp;
bestinp = secondinp;
second_best = tmp;
secondtp = sototcpcb(second_best->mpts_socket);
secondinp = sotoinpcb(second_best->mpts_socket);
}
if (mptcp_subflow_cwnd_space(bestinp->inp_socket) <= 0) {
return mptcp_return_subflow(second_best);
}
return mptcp_return_subflow(best);
} else {
panic("Unknown service-type configured for MPTCP");
}
return NULL;
}
static const char *
mptcp_event_to_str(uint32_t event)
{
const char *c = "UNDEFINED";
switch (event) {
case MPCE_CLOSE:
c = "MPCE_CLOSE";
break;
case MPCE_RECV_DATA_ACK:
c = "MPCE_RECV_DATA_ACK";
break;
case MPCE_RECV_DATA_FIN:
c = "MPCE_RECV_DATA_FIN";
break;
}
return c;
}
static const char *
mptcp_state_to_str(mptcp_state_t state)
{
const char *c = "UNDEFINED";
switch (state) {
case MPTCPS_CLOSED:
c = "MPTCPS_CLOSED";
break;
case MPTCPS_LISTEN:
c = "MPTCPS_LISTEN";
break;
case MPTCPS_ESTABLISHED:
c = "MPTCPS_ESTABLISHED";
break;
case MPTCPS_CLOSE_WAIT:
c = "MPTCPS_CLOSE_WAIT";
break;
case MPTCPS_FIN_WAIT_1:
c = "MPTCPS_FIN_WAIT_1";
break;
case MPTCPS_CLOSING:
c = "MPTCPS_CLOSING";
break;
case MPTCPS_LAST_ACK:
c = "MPTCPS_LAST_ACK";
break;
case MPTCPS_FIN_WAIT_2:
c = "MPTCPS_FIN_WAIT_2";
break;
case MPTCPS_TIME_WAIT:
c = "MPTCPS_TIME_WAIT";
break;
case MPTCPS_TERMINATE:
c = "MPTCPS_TERMINATE";
break;
}
return c;
}
void
mptcp_close_fsm(struct mptcb *mp_tp, uint32_t event)
{
struct socket *mp_so = mptetoso(mp_tp->mpt_mpte);
socket_lock_assert_owned(mp_so);
mptcp_state_t old_state = mp_tp->mpt_state;
DTRACE_MPTCP2(state__change, struct mptcb *, mp_tp,
uint32_t, event);
switch (mp_tp->mpt_state) {
case MPTCPS_CLOSED:
case MPTCPS_LISTEN:
mp_tp->mpt_state = MPTCPS_TERMINATE;
break;
case MPTCPS_ESTABLISHED:
if (event == MPCE_CLOSE) {
mp_tp->mpt_state = MPTCPS_FIN_WAIT_1;
mp_tp->mpt_sndmax += 1;
} else if (event == MPCE_RECV_DATA_FIN) {
mp_tp->mpt_rcvnxt += 1;
mp_tp->mpt_state = MPTCPS_CLOSE_WAIT;
}
break;
case MPTCPS_CLOSE_WAIT:
if (event == MPCE_CLOSE) {
mp_tp->mpt_state = MPTCPS_LAST_ACK;
mp_tp->mpt_sndmax += 1;
}
break;
case MPTCPS_FIN_WAIT_1:
if (event == MPCE_RECV_DATA_ACK) {
mp_tp->mpt_state = MPTCPS_FIN_WAIT_2;
} else if (event == MPCE_RECV_DATA_FIN) {
mp_tp->mpt_rcvnxt += 1;
mp_tp->mpt_state = MPTCPS_CLOSING;
}
break;
case MPTCPS_CLOSING:
if (event == MPCE_RECV_DATA_ACK) {
mp_tp->mpt_state = MPTCPS_TIME_WAIT;
}
break;
case MPTCPS_LAST_ACK:
if (event == MPCE_RECV_DATA_ACK) {
mptcp_close(mp_tp->mpt_mpte, mp_tp);
}
break;
case MPTCPS_FIN_WAIT_2:
if (event == MPCE_RECV_DATA_FIN) {
mp_tp->mpt_rcvnxt += 1;
mp_tp->mpt_state = MPTCPS_TIME_WAIT;
}
break;
case MPTCPS_TIME_WAIT:
case MPTCPS_TERMINATE:
break;
default:
VERIFY(0);
}
DTRACE_MPTCP2(state__change, struct mptcb *, mp_tp,
uint32_t, event);
mptcplog((LOG_INFO, "%s: %s to %s on event %s\n", __func__,
mptcp_state_to_str(old_state),
mptcp_state_to_str(mp_tp->mpt_state),
mptcp_event_to_str(event)),
MPTCP_STATE_DBG, MPTCP_LOGLVL_LOG);
}
void
mptcp_update_dss_rcv_state(struct mptcp_dsn_opt *dss_info, struct tcpcb *tp,
uint16_t csum)
{
struct mptcb *mp_tp = tptomptp(tp);
u_int64_t full_dsn = 0;
NTOHL(dss_info->mdss_dsn);
NTOHL(dss_info->mdss_subflow_seqn);
NTOHS(dss_info->mdss_data_len);
MPTCP_EXTEND_DSN(mp_tp->mpt_rcvnxt, dss_info->mdss_dsn, full_dsn);
mptcp_update_rcv_state_meat(mp_tp, tp,
full_dsn, dss_info->mdss_subflow_seqn, dss_info->mdss_data_len,
csum);
}
void
mptcp_update_rcv_state_meat(struct mptcb *mp_tp, struct tcpcb *tp,
u_int64_t full_dsn, u_int32_t seqn, u_int16_t mdss_data_len,
uint16_t csum)
{
if (mdss_data_len == 0) {
os_log_error(mptcp_log_handle, "%s - %lx: Infinite Mapping.\n",
__func__, (unsigned long)VM_KERNEL_ADDRPERM(mp_tp->mpt_mpte));
if ((mp_tp->mpt_flags & MPTCPF_CHECKSUM) && (csum != 0)) {
os_log_error(mptcp_log_handle, "%s - %lx: Bad checksum %x \n",
__func__, (unsigned long)VM_KERNEL_ADDRPERM(mp_tp->mpt_mpte), csum);
}
mptcp_notify_mpfail(tp->t_inpcb->inp_socket);
return;
}
mptcp_notify_mpready(tp->t_inpcb->inp_socket);
tp->t_rcv_map.mpt_dsn = full_dsn;
tp->t_rcv_map.mpt_sseq = seqn;
tp->t_rcv_map.mpt_len = mdss_data_len;
tp->t_rcv_map.mpt_csum = csum;
tp->t_mpflags |= TMPF_EMBED_DSN;
}
static int
mptcp_validate_dss_map(struct socket *so, struct tcpcb *tp, struct mbuf *m,
int hdrlen)
{
u_int32_t datalen;
if (!(m->m_pkthdr.pkt_flags & PKTF_MPTCP)) {
return 0;
}
datalen = m->m_pkthdr.mp_rlen;
if (m->m_pkthdr.len > ((int) datalen + hdrlen)) {
os_log_error(mptcp_log_handle, "%s - %lx: mbuf len %d, MPTCP expected %d",
__func__, (unsigned long)VM_KERNEL_ADDRPERM(tptomptp(tp)->mpt_mpte), m->m_pkthdr.len, datalen);
} else {
return 0;
}
tp->t_mpflags |= TMPF_SND_MPFAIL;
mptcp_notify_mpfail(so);
m_freem(m);
return -1;
}
int
mptcp_input_preproc(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
int drop_hdrlen)
{
mptcp_insert_rmap(tp, m, th);
if (mptcp_validate_dss_map(tp->t_inpcb->inp_socket, tp, m,
drop_hdrlen) != 0) {
return -1;
}
return 0;
}
int
mptcp_validate_csum(struct tcpcb *tp, struct mbuf *m, uint64_t dsn,
uint32_t sseq, uint16_t dlen, uint16_t csum, uint16_t dfin)
{
uint16_t mptcp_csum;
mptcp_csum = mptcp_input_csum(tp, m, dsn, sseq, dlen, csum, dfin);
if (mptcp_csum) {
tp->t_mpflags |= TMPF_SND_MPFAIL;
mptcp_notify_mpfail(tp->t_inpcb->inp_socket);
m_freem(m);
tcpstat.tcps_mp_badcsum++;
return -1;
}
return 0;
}
static uint16_t
mptcp_input_csum(struct tcpcb *tp, struct mbuf *m, uint64_t dsn, uint32_t sseq,
uint16_t dlen, uint16_t csum, uint16_t dfin)
{
struct mptcb *mp_tp = tptomptp(tp);
uint16_t real_len = dlen - dfin;
uint32_t sum = 0;
if (mp_tp == NULL) {
return 0;
}
if (!(mp_tp->mpt_flags & MPTCPF_CHECKSUM)) {
return 0;
}
if (tp->t_mpflags & TMPF_TCP_FALLBACK) {
return 0;
}
if ((int)m_length2(m, NULL) < real_len) {
return 0xffff;
}
if (real_len != 0) {
sum = m_sum16(m, 0, real_len);
}
sum += in_pseudo64(htonll(dsn), htonl(sseq), htons(dlen) + csum);
ADDCARRY(sum);
DTRACE_MPTCP3(checksum__result, struct tcpcb *, tp, struct mbuf *, m,
uint32_t, sum);
mptcplog((LOG_DEBUG, "%s: sum = %x \n", __func__, sum),
MPTCP_RECEIVER_DBG, MPTCP_LOGLVL_VERBOSE);
return ~sum & 0xffff;
}
uint32_t
mptcp_output_csum(struct mbuf *m, uint64_t dss_val, uint32_t sseq, uint16_t dlen)
{
uint32_t sum = 0;
if (dlen) {
sum = m_sum16(m, 0, dlen);
}
dss_val = mptcp_hton64(dss_val);
sseq = htonl(sseq);
dlen = htons(dlen);
sum += in_pseudo64(dss_val, sseq, dlen);
ADDCARRY(sum);
sum = ~sum & 0xffff;
DTRACE_MPTCP2(checksum__result, struct mbuf *, m, uint32_t, sum);
mptcplog((LOG_DEBUG, "%s: sum = %x \n", __func__, sum),
MPTCP_SENDER_DBG, MPTCP_LOGLVL_VERBOSE);
return sum;
}
boolean_t
mptcp_no_rto_spike(struct socket *so)
{
struct tcpcb *tp = intotcpcb(sotoinpcb(so));
int32_t spike = 0;
if (tp->t_rxtcur > mptcp_rtothresh) {
spike = tp->t_rxtcur - mptcp_rtothresh;
mptcplog((LOG_DEBUG, "%s: spike = %d rto = %d best = %d cur = %d\n",
__func__, spike,
tp->t_rxtcur, tp->t_rttbest >> TCP_RTT_SHIFT,
tp->t_rttcur),
(MPTCP_SOCKET_DBG | MPTCP_SENDER_DBG), MPTCP_LOGLVL_LOG);
}
if (spike > 0) {
return FALSE;
} else {
return TRUE;
}
}
void
mptcp_handle_deferred_upcalls(struct mppcb *mpp, uint32_t flag)
{
VERIFY(mpp->mpp_flags & flag);
mpp->mpp_flags &= ~flag;
if (mptcp_should_defer_upcall(mpp)) {
return;
}
if (mpp->mpp_flags & MPP_SHOULD_WORKLOOP) {
mpp->mpp_flags &= ~MPP_SHOULD_WORKLOOP;
mptcp_subflow_workloop(mpp->mpp_pcbe);
}
if (mpp->mpp_flags & MPP_SHOULD_RWAKEUP) {
mpp->mpp_flags &= ~MPP_SHOULD_RWAKEUP;
sorwakeup(mpp->mpp_socket);
}
if (mpp->mpp_flags & MPP_SHOULD_WWAKEUP) {
mpp->mpp_flags &= ~MPP_SHOULD_WWAKEUP;
sowwakeup(mpp->mpp_socket);
}
}
void
mptcp_ask_for_nat64(struct ifnet *ifp)
{
in6_post_msg(ifp, KEV_INET6_REQUEST_NAT64_PREFIX, NULL, NULL);
os_log_info(mptcp_log_handle,
"%s: asked for NAT64-prefix on %s\n", __func__,
ifp->if_name);
}
static void
mptcp_reset_itfinfo(struct mpt_itf_info *info)
{
memset(info, 0, sizeof(*info));
}
void
mptcp_session_necp_cb(void *handle, int action, uint32_t interface_index,
uint32_t necp_flags, __unused bool *viable)
{
boolean_t has_v4 = !!(necp_flags & NECP_CLIENT_RESULT_FLAG_HAS_IPV4);
boolean_t has_v6 = !!(necp_flags & NECP_CLIENT_RESULT_FLAG_HAS_IPV6);
boolean_t has_nat64 = !!(necp_flags & NECP_CLIENT_RESULT_FLAG_HAS_NAT64);
boolean_t low_power = !!(necp_flags & NECP_CLIENT_RESULT_FLAG_INTERFACE_LOW_POWER);
struct mppcb *mp = (struct mppcb *)handle;
struct mptses *mpte = mptompte(mp);
struct socket *mp_so;
struct mptcb *mp_tp;
int locked = 0;
uint32_t i, ifindex;
ifindex = interface_index;
VERIFY(ifindex != IFSCOPE_NONE);
if (mp->mpp_socket->so_usecount == 0) {
return;
}
mp_so = mptetoso(mpte);
if (action != NECP_CLIENT_CBACTION_INITIAL) {
socket_lock(mp_so, 1);
locked = 1;
if (mp->mpp_socket->so_usecount == 0) {
goto out;
}
}
socket_lock_assert_owned(mp_so);
mp_tp = mpte->mpte_mptcb;
os_log_info(mptcp_log_handle, "%s - %lx: action: %u ifindex %u usecount %u mpt_flags %#x state %u v4 %u v6 %u nat64 %u power %u\n",
__func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte), action, ifindex,
mp->mpp_socket->so_usecount, mp_tp->mpt_flags, mp_tp->mpt_state,
has_v4, has_v6, has_nat64, low_power);
if (mp_tp->mpt_flags & MPTCPF_FALLBACK_TO_TCP) {
goto out;
}
if (low_power) {
action = NECP_CLIENT_CBACTION_NONVIABLE;
}
if (action == NECP_CLIENT_CBACTION_NONVIABLE) {
for (i = 0; i < mpte->mpte_itfinfo_size; i++) {
if (mpte->mpte_itfinfo[i].ifindex == IFSCOPE_NONE) {
continue;
}
if (mpte->mpte_itfinfo[i].ifindex == ifindex) {
mptcp_reset_itfinfo(&mpte->mpte_itfinfo[i]);
}
}
mptcp_sched_create_subflows(mpte);
} else if (action == NECP_CLIENT_CBACTION_VIABLE ||
action == NECP_CLIENT_CBACTION_INITIAL) {
int found_slot = 0, slot_index = -1;
struct sockaddr *dst;
struct ifnet *ifp;
ifnet_head_lock_shared();
ifp = ifindex2ifnet[ifindex];
ifnet_head_done();
if (ifp == NULL) {
goto out;
}
if (IFNET_IS_COMPANION_LINK(ifp)) {
goto out;
}
if (IFNET_IS_EXPENSIVE(ifp) &&
(mp_so->so_restrictions & SO_RESTRICT_DENY_EXPENSIVE)) {
goto out;
}
if (IFNET_IS_CONSTRAINED(ifp) &&
(mp_so->so_restrictions & SO_RESTRICT_DENY_CONSTRAINED)) {
goto out;
}
if (IFNET_IS_CELLULAR(ifp) &&
(mp_so->so_restrictions & SO_RESTRICT_DENY_CELLULAR)) {
goto out;
}
if (IS_INTF_CLAT46(ifp)) {
has_v4 = FALSE;
}
for (i = 0; i < mpte->mpte_itfinfo_size; i++) {
if (mpte->mpte_itfinfo[i].ifindex == 0) {
found_slot = 1;
slot_index = i;
}
if (mpte->mpte_itfinfo[i].ifindex == ifindex &&
(mpte->mpte_itfinfo[i].has_v4_conn != has_v4 ||
mpte->mpte_itfinfo[i].has_v6_conn != has_v6 ||
mpte->mpte_itfinfo[i].has_nat64_conn != has_nat64)) {
found_slot = 1;
slot_index = i;
break;
}
if (mpte->mpte_itfinfo[i].ifindex == ifindex) {
goto out;
}
}
dst = mptcp_get_session_dst(mpte, has_v6, has_v4);
if (dst && (dst->sa_family == AF_INET || dst->sa_family == 0) &&
has_v6 && !has_nat64 && !has_v4) {
if (found_slot) {
mpte->mpte_itfinfo[slot_index].has_v4_conn = has_v4;
mpte->mpte_itfinfo[slot_index].has_v6_conn = has_v6;
mpte->mpte_itfinfo[slot_index].has_nat64_conn = has_nat64;
}
mptcp_ask_for_nat64(ifp);
goto out;
}
if (found_slot == 0) {
int new_size = mpte->mpte_itfinfo_size * 2;
struct mpt_itf_info *info = _MALLOC(sizeof(*info) * new_size, M_TEMP, M_ZERO);
if (info == NULL) {
os_log_error(mptcp_log_handle, "%s - %lx: malloc failed for %u\n",
__func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte), new_size);
goto out;
}
memcpy(info, mpte->mpte_itfinfo, mpte->mpte_itfinfo_size * sizeof(*info));
if (mpte->mpte_itfinfo_size > MPTE_ITFINFO_SIZE) {
_FREE(mpte->mpte_itfinfo, M_TEMP);
}
slot_index = mpte->mpte_itfinfo_size;
mpte->mpte_itfinfo = info;
mpte->mpte_itfinfo_size = new_size;
}
VERIFY(slot_index >= 0 && slot_index < (int)mpte->mpte_itfinfo_size);
mpte->mpte_itfinfo[slot_index].ifindex = ifindex;
mpte->mpte_itfinfo[slot_index].has_v4_conn = has_v4;
mpte->mpte_itfinfo[slot_index].has_v6_conn = has_v6;
mpte->mpte_itfinfo[slot_index].has_nat64_conn = has_nat64;
mptcp_sched_create_subflows(mpte);
}
out:
if (locked) {
socket_unlock(mp_so, 1);
}
}
void
mptcp_set_restrictions(struct socket *mp_so)
{
struct mptses *mpte = mpsotompte(mp_so);
uint32_t i;
socket_lock_assert_owned(mp_so);
ifnet_head_lock_shared();
for (i = 0; i < mpte->mpte_itfinfo_size; i++) {
struct mpt_itf_info *info = &mpte->mpte_itfinfo[i];
uint32_t ifindex = info->ifindex;
struct ifnet *ifp;
if (ifindex == IFSCOPE_NONE) {
continue;
}
ifp = ifindex2ifnet[ifindex];
if (ifp == NULL) {
continue;
}
if (IFNET_IS_EXPENSIVE(ifp) &&
(mp_so->so_restrictions & SO_RESTRICT_DENY_EXPENSIVE)) {
info->ifindex = IFSCOPE_NONE;
}
if (IFNET_IS_CONSTRAINED(ifp) &&
(mp_so->so_restrictions & SO_RESTRICT_DENY_CONSTRAINED)) {
info->ifindex = IFSCOPE_NONE;
}
if (IFNET_IS_CELLULAR(ifp) &&
(mp_so->so_restrictions & SO_RESTRICT_DENY_CELLULAR)) {
info->ifindex = IFSCOPE_NONE;
}
}
ifnet_head_done();
}