--- /dev/null
+/*
+ * Copyright (c) 2012-2013 Apple Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+
+#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/thread_act.h>
+#include <mach/sdt.h>
+
+#include <dev/random/randomdev.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_dbg = 0;
+SYSCTL_INT(_net_inet_mptcp, OID_AUTO, debug, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &mptcp_dbg, 0, "Enable Multipath TCP Debugging");
+
+/* Number of times to try negotiating MPTCP on SYN retransmissions */
+int mptcp_mpcap_retries = MPTCP_CAPABLE_RETRIES;
+SYSCTL_INT(_net_inet_mptcp, OID_AUTO, mptcp_cap_retr,
+ CTLFLAG_RW | CTLFLAG_LOCKED,
+ &mptcp_mpcap_retries, 0, "Number of MP Capable SYN Retries");
+
+/*
+ * By default, DSS checksum is turned off, revisit if we ever do
+ * MPTCP for non SSL Traffic.
+ */
+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");
+
+/*
+ * When mptcp_fail_thresh number of retransmissions are sent, subflow failover
+ * is attempted on a different path.
+ */
+int mptcp_fail_thresh = 1;
+SYSCTL_INT(_net_inet_mptcp, OID_AUTO, fail, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &mptcp_fail_thresh, 0, "Failover threshold");
+
+
+/*
+ * MPTCP subflows have TCP keepalives set to ON
+ */
+int mptcp_subflow_keeptime = 60;
+SYSCTL_INT(_net_inet_mptcp, OID_AUTO, keepalive, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &mptcp_subflow_keeptime, 0, "Keepalive in seconds");
+
+/*
+ * MP_PRIO option.
+ */
+int mptcp_mpprio_enable = 1;
+SYSCTL_INT(_net_inet_mptcp, OID_AUTO, mpprio, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &mptcp_mpprio_enable, 0, "Enable MP_PRIO option");
+
+/*
+ * REMOVE_ADDR option.
+ */
+int mptcp_remaddr_enable = 1;
+SYSCTL_INT(_net_inet_mptcp, OID_AUTO, remaddr, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &mptcp_remaddr_enable, 0, "Enable REMOVE_ADDR option");
+
+/*
+ * MPTCP input, called when data has been read from a subflow socket.
+ */
+void
+mptcp_input(struct mptses *mpte, struct mbuf *m)
+{
+ struct socket *mp_so;
+ struct mptcb *mp_tp = NULL;
+ u_int64_t mb_dsn;
+ u_int32_t mb_datalen;
+ int count = 0;
+ struct mbuf *save = NULL;
+ struct mbuf *freelist = NULL, *tail = NULL;
+
+ VERIFY(m->m_flags & M_PKTHDR);
+
+ MPTE_LOCK_ASSERT_HELD(mpte); /* same as MP socket lock */
+ mp_so = mpte->mpte_mppcb->mpp_socket;
+
+ DTRACE_MPTCP(input);
+
+ /*
+ * Each mbuf contains MPTCP Data Sequence Map
+ * Process the data for reassembly, delivery to MPTCP socket
+ * client, etc.
+ *
+ */
+ count = mp_so->so_rcv.sb_cc;
+
+ VERIFY(m != NULL);
+ /*
+ * In the degraded fallback case, data is accepted without DSS map
+ */
+ if (!(m->m_pkthdr.pkt_flags & PKTF_MPTCP)) {
+ /* XXX need a check that this is indeed degraded */
+ if (sbappendstream(&mp_so->so_rcv, m))
+ 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;
+ mptcplog3((LOG_DEBUG, "%s: fread %d bytes\n", __func__, count));
+ return;
+ }
+
+ mp_tp = mpte->mpte_mptcb;
+ VERIFY(mp_tp != NULL);
+
+ MPT_LOCK(mp_tp);
+ do {
+ save = m->m_next;
+ m->m_next = NULL;
+
+ mb_dsn = m->m_pkthdr.mp_dsn;
+ mb_datalen = m->m_pkthdr.mp_rlen;
+
+ if (MPTCP_SEQ_GT(mb_dsn, mp_tp->mpt_rcvatmark)) {
+ tcpstat.tcps_mp_oodata++;
+ MPT_UNLOCK(mp_tp);
+ m_freem(m);
+ return;
+ /*
+ * Reassembly queue support here in future. Per spec,
+ * senders must implement retransmission timer to
+ * retransmit unacked data. Dropping out of order
+ * gives a slight hit on performance but allows us to
+ * deploy MPTCP and protects us against in-window DoS
+ * attacks that attempt to use up memory by sending
+ * out of order data. When doing load sharing across
+ * subflows, out of order support is a must.
+ */
+ }
+
+ if (MPTCP_SEQ_LT(mb_dsn, mp_tp->mpt_rcvatmark)) {
+ VERIFY(m->m_pkthdr.pkt_flags & PKTF_MPTCP);
+ VERIFY(m->m_flags & M_PKTHDR);
+ VERIFY(m->m_len >= (int)mb_datalen);
+ VERIFY(m->m_pkthdr.len >= (int)mb_datalen);
+ if (MPTCP_SEQ_LEQ((mb_dsn + mb_datalen),
+ mp_tp->mpt_rcvatmark)) {
+ if (freelist == NULL)
+ freelist = tail = m;
+ else {
+ tail->m_next = m;
+ tail = m;
+ }
+ m = save;
+ continue;
+ } else {
+ m_adj(m, (mp_tp->mpt_rcvatmark - mb_dsn));
+ }
+ mptcplog((LOG_INFO, "%s: %llu %d 2 \n", __func__,
+ mp_tp->mpt_rcvatmark, m->m_pkthdr.len));
+ }
+
+ MPT_UNLOCK(mp_tp);
+ if (sbappendstream(&mp_so->so_rcv, m)) {
+ sorwakeup(mp_so);
+ }
+ 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);
+ MPT_LOCK(mp_tp);
+ count = mp_so->so_rcv.sb_cc - count;
+ tcpstat.tcps_mp_rcvtotal++;
+ tcpstat.tcps_mp_rcvbytes += count;
+ mptcplog3((LOG_DEBUG, "%s: read %d bytes\n", __func__, count));
+ /*
+ * The data received at the MPTCP layer will never exceed the
+ * receive window because anything to the right of the
+ * receive window will be trimmed at the subflow level.
+ */
+ mp_tp->mpt_rcvwnd = mptcp_sbspace(mp_tp);
+ mp_tp->mpt_rcvatmark += count;
+ m = save;
+ count = mp_so->so_rcv.sb_cc;
+ } while (m);
+ MPT_UNLOCK(mp_tp);
+
+ if (freelist)
+ m_freem(freelist);
+}
+
+/*
+ * MPTCP output.
+ */
+int
+mptcp_output(struct mptses *mpte)
+{
+ struct mptsub *mpts;
+ struct mptsub *mpts_tried = NULL;
+ struct socket *mp_so;
+ int error = 0;
+
+ MPTE_LOCK_ASSERT_HELD(mpte); /* same as MP socket lock */
+ mp_so = mpte->mpte_mppcb->mpp_socket;
+ if (mp_so->so_state & SS_CANTSENDMORE) {
+ return (EPIPE);
+ }
+
+try_again:
+ /* get the "best" subflow to be used for transmission */
+ mpts = mptcp_get_subflow(mpte, NULL);
+ if (mpts == NULL) {
+ mptcplog((LOG_ERR, "%s: mp_so 0x%llx has no usable subflow\n",
+ __func__, (u_int64_t)VM_KERNEL_ADDRPERM(mp_so)));
+ goto out;
+ }
+
+ mptcplog3((LOG_INFO, "%s: mp_so 0x%llx cid %d \n", __func__,
+ (uint64_t)VM_KERNEL_ADDRPERM(mp_so), mpts->mpts_connid));
+
+ /* In case there's just one flow, we reattempt later */
+ MPTS_LOCK(mpts);
+ if ((mpts_tried != NULL) && ((mpts == mpts_tried) ||
+ (mpts->mpts_flags & MPTSF_FAILINGOVER))) {
+ MPTS_UNLOCK(mpts);
+ MPTS_LOCK(mpts_tried);
+ mpts_tried->mpts_flags &= ~MPTSF_FAILINGOVER;
+ mpts_tried->mpts_flags |= MPTSF_ACTIVE;
+ MPTS_UNLOCK(mpts_tried);
+ MPT_LOCK(mpte->mpte_mptcb);
+ mptcp_start_timer(mpte->mpte_mptcb, MPTT_REXMT);
+ MPT_UNLOCK(mpte->mpte_mptcb);
+ mptcplog((LOG_INFO, "%s: mp_so 0x%llx retry later\n",
+ __func__, (u_int64_t)VM_KERNEL_ADDRPERM(mp_so)));
+ goto out;
+ }
+
+ DTRACE_MPTCP3(output, struct mptses *, mpte, struct mptsub *, mpts,
+ struct socket *, mp_so);
+ error = mptcp_subflow_output(mpte, mpts);
+ if (error) {
+ /* can be a temporary loss of source address or other error */
+ mpts->mpts_flags |= MPTSF_FAILINGOVER;
+ mpts->mpts_flags &= ~MPTSF_ACTIVE;
+ mpts_tried = mpts;
+ MPTS_UNLOCK(mpts);
+ mptcplog((LOG_INFO, "%s: error = %d \n", __func__, error));
+ goto try_again;
+ }
+ /* The model is to have only one active flow at a time */
+ mpts->mpts_flags |= MPTSF_ACTIVE;
+ MPTS_UNLOCK(mpts);
+ if (mpte->mpte_active_sub == NULL) {
+ mpte->mpte_active_sub = mpts;
+ } else if (mpte->mpte_active_sub != mpts) {
+ MPTS_LOCK(mpte->mpte_active_sub);
+ mpte->mpte_active_sub->mpts_flags &= ~MPTSF_ACTIVE;
+ MPTS_UNLOCK(mpte->mpte_active_sub);
+ mpte->mpte_active_sub = mpts;
+ }
+out:
+ /* subflow errors should not be percolated back up */
+ return (0);
+}
+
+/*
+ * Return the most eligible subflow to be used for sending data.
+ * This function also serves to check if any alternate subflow is available
+ * or not.
+ */
+struct mptsub *
+mptcp_get_subflow(struct mptses *mpte, struct mptsub *ignore)
+{
+ struct mptsub *mpts;
+ struct mptsub *fallback = NULL;
+ struct socket *so = NULL;
+
+ MPTE_LOCK_ASSERT_HELD(mpte); /* same as MP socket lock */
+
+ TAILQ_FOREACH(mpts, &mpte->mpte_subflows, mpts_entry) {
+ MPTS_LOCK_SPIN(mpts);
+
+ if ((ignore) && (mpts == ignore)) {
+ MPTS_UNLOCK(mpts);
+ continue;
+ }
+
+ /* There can only be one subflow in degraded state */
+ if (mpts->mpts_flags & MPTSF_MP_DEGRADED) {
+ MPTS_UNLOCK(mpts);
+ break;
+ }
+
+ if (!(mpts->mpts_flags & MPTSF_MP_CAPABLE)) {
+ MPTS_UNLOCK(mpts);
+ continue;
+ }
+
+ if (mpts->mpts_flags & MPTSF_SUSPENDED) {
+ MPTS_UNLOCK(mpts);
+ continue;
+ }
+
+ if (mpts->mpts_flags & MPTSF_FAILINGOVER) {
+ so = mpts->mpts_socket;
+ if ((so) && (!(so->so_flags & SOF_PCBCLEARING))) {
+ socket_lock(so, 1);
+ if (so->so_snd.sb_cc == 0) {
+ mpts->mpts_flags &= ~MPTSF_FAILINGOVER;
+ so->so_flags &= ~SOF_MP_TRYFAILOVER;
+ fallback = mpts;
+ socket_unlock(so, 1);
+ } else {
+ fallback = mpts;
+ socket_unlock(so, 1);
+ MPTS_UNLOCK(mpts);
+ continue;
+ }
+ } else {
+ MPTS_UNLOCK(mpts);
+ continue;
+ }
+ }
+
+ if (mpts->mpts_flags & MPTSF_PREFERRED) {
+ MPTS_UNLOCK(mpts);
+ break;
+ }
+
+ /* When there are no preferred flows, use first one in list */
+ if (fallback == NULL)
+ fallback = mpts;
+
+ MPTS_UNLOCK(mpts);
+ }
+ /*
+ * If there is no preferred or backup subflow, and there is no active
+ * subflow use the last usable subflow.
+ */
+ if (mpts == NULL) {
+ return (fallback);
+ }
+
+ return (mpts);
+}
+
+void
+mptcp_close_fsm(struct mptcb *mp_tp, uint32_t event)
+{
+ MPT_LOCK_ASSERT_HELD(mp_tp);
+
+ 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_CLOSED;
+ break;
+
+ case MPTCPS_ESTABLISHED:
+ if (event == MPCE_CLOSE)
+ mp_tp->mpt_state = MPTCPS_FIN_WAIT_1;
+ else if (event == MPCE_RECV_DATA_FIN)
+ mp_tp->mpt_state = MPTCPS_CLOSE_WAIT;
+ break;
+
+ case MPTCPS_CLOSE_WAIT:
+ if (event == MPCE_CLOSE)
+ mp_tp->mpt_state = MPTCPS_LAST_ACK;
+ 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_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)
+ mp_tp->mpt_state = MPTCPS_CLOSED;
+ break;
+
+ case MPTCPS_FIN_WAIT_2:
+ if (event == MPCE_RECV_DATA_FIN)
+ mp_tp->mpt_state = MPTCPS_TIME_WAIT;
+ break;
+
+ case MPTCPS_TIME_WAIT:
+ break;
+
+ case MPTCPS_FASTCLOSE_WAIT:
+ if (event == MPCE_CLOSE)
+ mp_tp->mpt_state = MPTCPS_CLOSED;
+ break;
+
+ default:
+ VERIFY(0);
+ /* NOTREACHED */
+ }
+ DTRACE_MPTCP2(state__change, struct mptcb *, mp_tp,
+ uint32_t, event);
+ mptcplog((LOG_INFO, "%s: state = %d\n",
+ __func__, mp_tp->mpt_state));
+}
+
+/*
+ * Update the mptcb send state variables, but the actual sbdrop occurs
+ * in MPTCP layer
+ */
+void
+mptcp_data_ack_rcvd(struct mptcb *mp_tp, struct tcpcb *tp, u_int64_t full_dack)
+{
+ u_int64_t acked = 0;
+
+ acked = full_dack - mp_tp->mpt_snduna;
+
+ if (acked) {
+ mp_tp->mpt_snduna += acked;
+ }
+ if ((full_dack == mp_tp->mpt_sndmax) &&
+ (mp_tp->mpt_state >= MPTCPS_FIN_WAIT_1)) {
+ mptcp_close_fsm(mp_tp, MPCE_RECV_DATA_ACK);
+ tp->t_mpflags &= ~TMPF_SEND_DFIN;
+ }
+}
+
+/* If you change this function, match up mptcp_update_rcv_state_f */
+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);
+
+ /* XXX for autosndbuf grow sb here */
+ MPT_LOCK(mp_tp);
+ MPTCP_EXTEND_DSN(mp_tp->mpt_rcvnxt, dss_info->mdss_dsn, full_dsn);
+ MPT_UNLOCK(mp_tp);
+ 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) {
+ mptcplog((LOG_INFO, "%s: Received infinite mapping.",
+ __func__));
+ if ((mp_tp->mpt_flags & MPTCPF_CHECKSUM) && (csum != 0)) {
+ mptcplog((LOG_ERR, "%s: Bad checksum value %x \n",
+ __func__, csum));
+ }
+ mptcp_notify_mpfail(tp->t_inpcb->inp_socket);
+ return;
+ }
+ MPT_LOCK(mp_tp);
+ if (mptcp_dbg >= MP_VERBOSE_DEBUG_1)
+ printf("%s: seqn = %x len = %x full = %llx rcvnxt = %llu \n",
+ __func__, seqn, mdss_data_len, full_dsn,
+ mp_tp->mpt_rcvnxt);
+
+ /* Process a Data FIN packet , handled in mptcp_do_fin_opt */
+ if ((seqn == 0) && (mdss_data_len == 1)) {
+ mptcplog((LOG_INFO, "%s: Data FIN DSS opt state = %d \n",
+ __func__, mp_tp->mpt_state));
+ MPT_UNLOCK(mp_tp);
+ return;
+ }
+ MPT_UNLOCK(mp_tp);
+ 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;
+}
+
+
+void
+mptcp_update_rcv_state_f(struct mptcp_dss_ack_opt *dss_info, struct tcpcb *tp,
+ uint16_t csum)
+{
+ u_int64_t full_dsn = 0;
+ struct mptcb *mp_tp = tptomptp(tp);
+
+ NTOHL(dss_info->mdss_dsn);
+ NTOHL(dss_info->mdss_subflow_seqn);
+ NTOHS(dss_info->mdss_data_len);
+ MPT_LOCK(mp_tp);
+ MPTCP_EXTEND_DSN(mp_tp->mpt_rcvnxt, dss_info->mdss_dsn, full_dsn);
+ MPT_UNLOCK(mp_tp);
+ 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_g(struct mptcp_dss64_ack32_opt *dss_info,
+ struct tcpcb *tp, uint16_t csum)
+{
+ u_int64_t dsn = mptcp_ntoh64(dss_info->mdss_dsn);
+ struct mptcb *mp_tp = tptomptp(tp);
+
+ NTOHL(dss_info->mdss_subflow_seqn);
+ NTOHS(dss_info->mdss_data_len);
+ mptcp_update_rcv_state_meat(mp_tp, tp,
+ dsn,
+ dss_info->mdss_subflow_seqn,
+ dss_info->mdss_data_len,
+ csum);
+}
+
+/*
+ * MPTCP Checksum support
+ * The checksum is calculated whenever the MPTCP DSS option is included
+ * in the TCP packet. The checksum includes the sum of the MPTCP psuedo
+ * header and the actual data indicated by the length specified in the
+ * DSS option.
+ */
+
+uint16_t
+mptcp_input_csum(struct tcpcb *tp, struct mbuf *m, int off)
+{
+ struct mptcb *mp_tp = tptomptp(tp);
+ uint32_t sum = 0;
+ uint64_t dsn;
+ uint32_t sseq;
+ uint16_t len;
+ uint16_t csum;
+
+ if (mp_tp == NULL)
+ return (0);
+
+ if (!(mp_tp->mpt_flags & MPTCPF_CHECKSUM))
+ return (0);
+
+ if (!(tp->t_mpflags & TMPF_EMBED_DSN))
+ return (0);
+
+ if (tp->t_mpflags & TMPF_TCP_FALLBACK)
+ return (0);
+
+ /*
+ * The remote side may send a packet with fewer bytes than the
+ * claimed DSS checksum length.
+ */
+ if ((int)m_length2(m, NULL) < (off + tp->t_rcv_map.mpt_len))
+ return (0xffff);
+
+ if (tp->t_rcv_map.mpt_len != 0)
+ sum = m_sum16(m, off, tp->t_rcv_map.mpt_len);
+
+ dsn = mptcp_hton64(tp->t_rcv_map.mpt_dsn);
+ sseq = htonl(tp->t_rcv_map.mpt_sseq);
+ len = htons(tp->t_rcv_map.mpt_len);
+ csum = tp->t_rcv_map.mpt_csum;
+ sum += in_pseudo64(dsn, sseq, (len + csum));
+ ADDCARRY(sum);
+ DTRACE_MPTCP3(checksum__result, struct tcpcb *, tp, struct mbuf *, m,
+ uint32_t, sum);
+ mptcplog((LOG_INFO, "%s: sum = %x \n", __func__, sum));
+ return (~sum & 0xffff);
+}
+
+void
+mptcp_output_csum(struct tcpcb *tp, struct mbuf *m, int32_t len,
+ unsigned hdrlen, u_int64_t dss_val, u_int32_t *sseqp)
+{
+ struct mptcb *mp_tp = tptomptp(tp);
+ u_int32_t sum = 0;
+ uint32_t sseq;
+ uint16_t dss_len;
+ uint16_t csum = 0;
+ uint16_t *csump = NULL;
+
+ if (mp_tp == NULL)
+ return;
+
+ if (!(mp_tp->mpt_flags & MPTCPF_CHECKSUM))
+ return;
+
+ if (sseqp == NULL)
+ return;
+
+ if (len)
+ sum = m_sum16(m, hdrlen, len);
+
+ dss_val = mptcp_hton64(dss_val);
+ sseq = *sseqp;
+ dss_len = *(uint16_t *)(void *)((u_char*)sseqp + sizeof (u_int32_t));
+ sum += in_pseudo64(dss_val, sseq, (dss_len + csum));
+
+ ADDCARRY(sum);
+ sum = ~sum & 0xffff;
+ csump = (uint16_t *)(void *)((u_char*)sseqp + sizeof (u_int32_t) +
+ sizeof (uint16_t));
+ DTRACE_MPTCP3(checksum__result, struct tcpcb *, tp, struct mbuf *, m,
+ uint32_t, sum);
+ *csump = sum;
+ mptcplog3((LOG_INFO, "%s: sum = %x \n", __func__, sum));
+}
projects / apple / xnu.git / blobdiff