/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2012 Apple Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License"). You may not use this file except in compliance with the
- * License. Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * 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.
*
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * 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 OR NON-INFRINGEMENT. Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * 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_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
* @(#)tcp_output.c 8.4 (Berkeley) 5/24/95
* $FreeBSD: src/sys/netinet/tcp_output.c,v 1.39.2.10 2001/07/07 04:30:38 silby Exp $
*/
+/*
+ * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
+ * support for mandatory and extensible security protections. This notice
+ * is included in support of clause 2.2 (b) of the Apple Public License,
+ * Version 2.0.
+ */
#define _IP_VHL
#include <sys/socketvar.h>
#include <net/route.h>
+#include <net/ntstat.h>
+#include <net/if_var.h>
+#include <net/if.h>
+#include <net/if_types.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
+#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
+#include <mach/sdt.h>
#if INET6
#include <netinet6/in6_pcb.h>
#include <netinet/ip6.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcpip.h>
+#include <netinet/tcp_cc.h>
#if TCPDEBUG
#include <netinet/tcp_debug.h>
#endif
#include <sys/kdebug.h>
+#include <mach/sdt.h>
#if IPSEC
#include <netinet6/ipsec.h>
#endif /*IPSEC*/
+#if CONFIG_MACF_NET
+#include <security/mac_framework.h>
+#endif /* MAC_SOCKET */
+
+#include <netinet/lro_ext.h>
+
#define DBG_LAYER_BEG NETDBG_CODE(DBG_NETTCP, 1)
#define DBG_LAYER_END NETDBG_CODE(DBG_NETTCP, 3)
#define DBG_FNC_TCP_OUTPUT NETDBG_CODE(DBG_NETTCP, (4 << 8) | 1)
-
#ifdef notyet
extern struct mbuf *m_copypack();
#endif
-static int path_mtu_discovery = 1;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, path_mtu_discovery, CTLFLAG_RW,
+int path_mtu_discovery = 1;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, path_mtu_discovery, CTLFLAG_RW | CTLFLAG_LOCKED,
&path_mtu_discovery, 1, "Enable Path MTU Discovery");
int ss_fltsz = 1;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, slowstart_flightsize, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, slowstart_flightsize, CTLFLAG_RW | CTLFLAG_LOCKED,
&ss_fltsz, 1, "Slow start flight size");
-int ss_fltsz_local = 4; /* starts with four segments max */
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, local_slowstart_flightsize, CTLFLAG_RW,
+int ss_fltsz_local = 8; /* starts with eight segments max */
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, local_slowstart_flightsize, CTLFLAG_RW | CTLFLAG_LOCKED,
&ss_fltsz_local, 1, "Slow start flight size for local networks");
-int tcp_do_newreno = 0;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, newreno, CTLFLAG_RW, &tcp_do_newreno,
- 0, "Enable NewReno Algorithms");
+int tcp_do_tso = 1;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, tso, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &tcp_do_tso, 0, "Enable TCP Segmentation Offload");
+
+
+int tcp_ecn_outbound = 0;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, ecn_initiate_out, CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_ecn_outbound,
+ 0, "Initiate ECN for outbound connections");
+
+int tcp_ecn_inbound = 0;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, ecn_negotiate_in, CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_ecn_inbound,
+ 0, "Allow ECN negotiation for inbound connections");
int tcp_packet_chaining = 50;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, packetchain, CTLFLAG_RW, &tcp_packet_chaining,
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, packetchain, CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_packet_chaining,
0, "Enable TCP output packet chaining");
-struct mbuf *m_copym_with_hdrs(struct mbuf*, int, int, int, struct mbuf**, int*);
-static long packchain_newlist = 0;
-static long packchain_looped = 0;
-static long packchain_sent = 0;
+int tcp_output_unlocked = 1;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, socket_unlocked_on_output, CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_output_unlocked,
+ 0, "Unlock TCP when sending packets down to IP");
+
+int tcp_do_rfc3390 = 1;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &tcp_do_rfc3390, 1, "Calculate intial slowstart cwnd depending on MSS");
+
+int tcp_min_iaj_win = MIN_IAJ_WIN;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, min_iaj_win, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &tcp_min_iaj_win, 1, "Minimum recv win based on inter-packet arrival jitter");
+
+int tcp_acc_iaj_react_limit = ACC_IAJ_REACT_LIMIT;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, acc_iaj_react_limit, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &tcp_acc_iaj_react_limit, 1, "Accumulated IAJ when receiver starts to react");
+
+uint32_t tcp_do_autosendbuf = 1;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, doautosndbuf, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &tcp_do_autosendbuf, 1, "Enable send socket buffer auto-tuning");
+
+uint32_t tcp_autosndbuf_inc = 8 * 1024;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, autosndbufinc, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &tcp_autosndbuf_inc, 1, "Increment in send socket bufffer size");
+
+uint32_t tcp_autosndbuf_max = 512 * 1024;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, autosndbufmax, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &tcp_autosndbuf_max, 1, "Maximum send socket buffer size");
+uint32_t tcp_prioritize_acks = 1;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, ack_prioritize, CTLFLAG_RW | CTLFLAG_LOCKED,
+ &tcp_prioritize_acks, 1, "Prioritize pure acks");
+
+static int32_t packchain_newlist = 0;
+static int32_t packchain_looped = 0;
+static int32_t packchain_sent = 0;
/* temporary: for testing */
#if IPSEC
#endif
extern int slowlink_wsize; /* window correction for slow links */
-extern u_long route_generation;
-extern int fw_enable; /* firewall is on: disable packet chaining */
-extern int ipsec_bypass;
+#if IPFIREWALL
+extern int fw_enable; /* firewall check for packet chaining */
+extern int fw_bypass; /* firewall check: disable packet chaining if there is rules */
+#endif /* IPFIREWALL */
extern vm_size_t so_cache_zone_element_size;
+#if RANDOM_IP_ID
+extern int ip_use_randomid;
+#endif /* RANDOM_IP_ID */
+extern u_int32_t dlil_filter_count;
+extern u_int32_t kipf_count;
+extern int tcp_recv_bg;
+extern int maxseg_unacked;
+
+static int tcp_ip_output(struct socket *, struct tcpcb *, struct mbuf *, int,
+ struct mbuf *, int, int, int32_t, boolean_t);
+
+extern uint32_t get_base_rtt(struct tcpcb *tp);
+static struct mbuf* tcp_send_lroacks(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th);
static __inline__ u_int16_t
get_socket_id(struct socket * s)
if (so_cache_zone_element_size == 0) {
return (0);
}
- val = (u_int16_t)(((u_int32_t)s) / so_cache_zone_element_size);
+ val = (u_int16_t)(((uintptr_t)s) / so_cache_zone_element_size);
if (val == 0) {
val = 0xffff;
}
/*
* Tcp output routine: figure out what should be sent and send it.
+ *
+ * Returns: 0 Success
+ * EADDRNOTAVAIL
+ * ENOBUFS
+ * EMSGSIZE
+ * EHOSTUNREACH
+ * ENETDOWN
+ * ip_output_list:ENOMEM
+ * ip_output_list:EADDRNOTAVAIL
+ * ip_output_list:ENETUNREACH
+ * ip_output_list:EHOSTUNREACH
+ * ip_output_list:EACCES
+ * ip_output_list:EMSGSIZE
+ * ip_output_list:ENOBUFS
+ * ip_output_list:??? [ignorable: mostly IPSEC/firewall/DLIL]
+ * ip6_output_list:EINVAL
+ * ip6_output_list:EOPNOTSUPP
+ * ip6_output_list:EHOSTUNREACH
+ * ip6_output_list:EADDRNOTAVAIL
+ * ip6_output_list:ENETUNREACH
+ * ip6_output_list:EMSGSIZE
+ * ip6_output_list:ENOBUFS
+ * ip6_output_list:??? [ignorable: mostly IPSEC/firewall/DLIL]
*/
int
-tcp_output(tp)
- register struct tcpcb *tp;
+tcp_output(struct tcpcb *tp)
{
- register struct socket *so = tp->t_inpcb->inp_socket;
- register long len, win;
- int off, flags, error;
+ struct socket *so = tp->t_inpcb->inp_socket;
+ int32_t len, recwin, sendwin, off;
+ int flags, error;
register struct mbuf *m;
struct ip *ip = NULL;
register struct ipovly *ipov = NULL;
register struct tcphdr *th;
u_char opt[TCP_MAXOLEN];
unsigned ipoptlen, optlen, hdrlen;
- int idle, sendalot, howmuchsent = 0;
- int maxburst = TCP_MAXBURST;
- struct rmxp_tao *taop;
- struct rmxp_tao tao_noncached;
+ int idle, sendalot, lost = 0;
+ int i, sack_rxmit;
+ int tso = 0;
+ int sack_bytes_rxmt;
+ struct sackhole *p;
+#ifdef IPSEC
+ unsigned ipsec_optlen = 0;
+#endif
int last_off = 0;
int m_off;
- struct mbuf *m_last = 0;
- struct mbuf *m_head = 0;
- struct mbuf *packetlist = 0;
- struct mbuf *lastpacket = 0;
+ int idle_time = 0;
+ struct mbuf *m_lastm = NULL;
+ struct mbuf *m_head = NULL;
+ struct mbuf *packetlist = NULL;
+ struct mbuf *tp_inp_options = tp->t_inpcb->inp_depend4.inp4_options;
#if INET6
int isipv6 = tp->t_inpcb->inp_vflag & INP_IPV6 ;
#endif
short packchain_listadd = 0;
u_int16_t socket_id = get_socket_id(so);
-
+ int so_options = so->so_options;
+ struct rtentry *rt;
+ u_int32_t basertt, svc_flags = 0, allocated_len;
+ u_int32_t lro_ackmore = (tp->t_lropktlen != 0) ? 1 : 0;
+ struct mbuf *mnext = NULL;
+ int sackoptlen = 0;
/*
* Determine length of data that should be transmitted,
* If there is some data or critical controls (SYN, RST)
* to send, then transmit; otherwise, investigate further.
*/
- idle = (tp->snd_max == tp->snd_una);
- if (idle && tp->t_rcvtime >= tp->t_rxtcur) {
- /*
- * We have been idle for "a while" and no acks are
- * expected to clock out any data we send --
- * slow start to get ack "clock" running again.
- *
- * Set the slow-start flight size depending on whether
- * this is a local network or not.
- */
- if (
-#if INET6
- (isipv6 && in6_localaddr(&tp->t_inpcb->in6p_faddr)) ||
- (!isipv6 &&
-#endif
- in_localaddr(tp->t_inpcb->inp_faddr)
-#if INET6
- )
-#endif
- )
- tp->snd_cwnd = tp->t_maxseg * ss_fltsz_local;
- else
- tp->snd_cwnd = tp->t_maxseg * ss_fltsz;
- }
+ idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
+ /* Since idle_time is signed integer, the following integer subtraction
+ * will take care of wrap around of tcp_now
+ */
+ idle_time = tcp_now - tp->t_rcvtime;
+ if (idle && idle_time >= TCP_IDLETIMEOUT(tp)) {
+ if (CC_ALGO(tp)->after_idle != NULL)
+ CC_ALGO(tp)->after_idle(tp);
+ DTRACE_TCP5(cc, void, NULL, struct inpcb *, tp->t_inpcb,
+ struct tcpcb *, tp, struct tcphdr *, NULL,
+ int32_t, TCP_CC_IDLE_TIMEOUT);
+ }
+ tp->t_flags &= ~TF_LASTIDLE;
+ if (idle) {
+ if (tp->t_flags & TF_MORETOCOME) {
+ tp->t_flags |= TF_LASTIDLE;
+ idle = 0;
+ }
+ }
again:
KERNEL_DEBUG(DBG_FNC_TCP_OUTPUT | DBG_FUNC_START, 0,0,0,0,0);
#if INET6
if (isipv6) {
-
KERNEL_DEBUG(DBG_LAYER_BEG,
((tp->t_inpcb->inp_fport << 16) | tp->t_inpcb->inp_lport),
(((tp->t_inpcb->in6p_laddr.s6_addr16[0] & 0xffff) << 16) |
(tp->t_inpcb->in6p_faddr.s6_addr16[0] & 0xffff)),
sendalot,0,0);
- }
- else
+ } else
#endif
{
(((tp->t_inpcb->inp_laddr.s_addr & 0xffff) << 16) |
(tp->t_inpcb->inp_faddr.s_addr & 0xffff)),
sendalot,0,0);
+ }
/*
* If the route generation id changed, we need to check that our
* local (source) IP address is still valid. If it isn't either
* return error or silently do nothing (assuming the address will
* come back before the TCP connection times out).
*/
+ rt = tp->t_inpcb->inp_route.ro_rt;
+ if (rt != NULL && (!(rt->rt_flags & RTF_UP) ||
+ rt->generation_id != route_generation)) {
+ struct ifnet *ifp;
+ struct in_ifaddr *ia = NULL;
+ struct in6_ifaddr *ia6 = NULL;
+ int found_srcaddr = 0;
+
+ /* disable multipages at the socket */
+ somultipages(so, FALSE);
+
+ /* Disable TSO for the socket until we know more */
+ tp->t_flags &= ~TF_TSO;
+
+ if (isipv6) {
+ ia6 = ifa_foraddr6(&tp->t_inpcb->in6p_laddr);
+ if (ia6 != NULL)
+ found_srcaddr = 1;
+ } else {
+ ia = ifa_foraddr(tp->t_inpcb->inp_laddr.s_addr);
+ if (ia != NULL)
+ found_srcaddr = 1;
+ }
- if ((tp->t_inpcb->inp_route.ro_rt != NULL &&
- (tp->t_inpcb->inp_route.ro_rt->generation_id != route_generation)) || (tp->t_inpcb->inp_route.ro_rt == NULL)) {
/* check that the source address is still valid */
- if (ifa_foraddr(tp->t_inpcb->inp_laddr.s_addr) == 0) {
+ if (found_srcaddr == 0) {
+
+ soevent(so,
+ (SO_FILT_HINT_LOCKED | SO_FILT_HINT_NOSRCADDR));
+
if (tp->t_state >= TCPS_CLOSE_WAIT) {
- tcp_close(tp);
+ tcp_drop(tp, EADDRNOTAVAIL);
return(EADDRNOTAVAIL);
}
/* set Retransmit timer if it wasn't set
* reset Persist timer and shift register as the
- * adversed peer window may not be valid anymore
+ * advertised peer window may not be valid anymore
*/
if (!tp->t_timer[TCPT_REXMT]) {
- tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
+ tp->t_timer[TCPT_REXMT] = OFFSET_FROM_START(tp, tp->t_rxtcur);
if (tp->t_timer[TCPT_PERSIST]) {
tp->t_timer[TCPT_PERSIST] = 0;
tp->t_rxtshift = 0;
+ tp->t_persist_stop = 0;
+ tp->rxt_start = 0;
}
}
- if (packetlist) {
- error = ip_output_list(packetlist, packchain_listadd, tp->t_inpcb->inp_options, &tp->t_inpcb->inp_route,
- (so->so_options & SO_DONTROUTE), 0);
- tp->t_lastchain = 0;
- }
- if (so->so_flags & SOF_NOADDRAVAIL)
+ if (tp->t_pktlist_head != NULL)
+ m_freem_list(tp->t_pktlist_head);
+ TCP_PKTLIST_CLEAR(tp);
+
+ /* drop connection if source address isn't available */
+ if (so->so_flags & SOF_NOADDRAVAIL) {
+ tcp_drop(tp, EADDRNOTAVAIL);
return(EADDRNOTAVAIL);
- else
- return(0); /* silently ignore and keep data in socket */
+ }
+ else {
+ tcp_check_timer_state(tp);
+ return(0); /* silently ignore, keep data in socket: address may be back */
+ }
+ }
+ if (ia != NULL)
+ IFA_REMREF(&ia->ia_ifa);
+
+ if (ia6 != NULL)
+ IFA_REMREF(&ia6->ia_ifa);
+
+ /*
+ * Address is still valid; check for multipages capability
+ * again in case the outgoing interface has changed.
+ */
+ RT_LOCK(rt);
+ if ((ifp = rt->rt_ifp) != NULL) {
+ somultipages(so, (ifp->if_hwassist & IFNET_MULTIPAGES));
+ tcp_set_tso(tp, ifp);
}
- }
+ if (rt->rt_flags & RTF_UP)
+ rt->generation_id = route_generation;
+ /*
+ * See if we should do MTU discovery. Don't do it if:
+ * 1) it is disabled via the sysctl
+ * 2) the route isn't up
+ * 3) the MTU is locked (if it is, then discovery has been
+ * disabled)
+ */
+
+ if (!path_mtu_discovery || ((rt != NULL) &&
+ (!(rt->rt_flags & RTF_UP) || (rt->rt_rmx.rmx_locks & RTV_MTU))))
+ tp->t_flags &= ~TF_PMTUD;
+ else
+ tp->t_flags |= TF_PMTUD;
+
+ RT_UNLOCK(rt);
}
+
+ /*
+ * If we've recently taken a timeout, snd_max will be greater than
+ * snd_nxt. There may be SACK information that allows us to avoid
+ * resending already delivered data. Adjust snd_nxt accordingly.
+ */
+ if (tp->sack_enable && SEQ_LT(tp->snd_nxt, tp->snd_max))
+ tcp_sack_adjust(tp);
sendalot = 0;
off = tp->snd_nxt - tp->snd_una;
- win = min(tp->snd_wnd, tp->snd_cwnd);
+ sendwin = min(tp->snd_wnd, tp->snd_cwnd);
+
if (tp->t_flags & TF_SLOWLINK && slowlink_wsize > 0)
- win = min(win, slowlink_wsize);
+ sendwin = min(sendwin, slowlink_wsize);
flags = tcp_outflags[tp->t_state];
+ /*
+ * Send any SACK-generated retransmissions. If we're explicitly trying
+ * to send out new data (when sendalot is 1), bypass this function.
+ * If we retransmit in fast recovery mode, decrement snd_cwnd, since
+ * we're replacing a (future) new transmission with a retransmission
+ * now, and we previously incremented snd_cwnd in tcp_input().
+ */
+ /*
+ * Still in sack recovery , reset rxmit flag to zero.
+ */
+ sack_rxmit = 0;
+ sack_bytes_rxmt = 0;
+ len = 0;
+ p = NULL;
+ if (tp->sack_enable && IN_FASTRECOVERY(tp) &&
+ (p = tcp_sack_output(tp, &sack_bytes_rxmt))) {
+ int32_t cwin;
+
+ cwin = min(tp->snd_wnd, tp->snd_cwnd) - sack_bytes_rxmt;
+ if (cwin < 0)
+ cwin = 0;
+ /* Do not retransmit SACK segments beyond snd_recover */
+ if (SEQ_GT(p->end, tp->snd_recover)) {
+ /*
+ * (At least) part of sack hole extends beyond
+ * snd_recover. Check to see if we can rexmit data
+ * for this hole.
+ */
+ if (SEQ_GEQ(p->rxmit, tp->snd_recover)) {
+ /*
+ * Can't rexmit any more data for this hole.
+ * That data will be rexmitted in the next
+ * sack recovery episode, when snd_recover
+ * moves past p->rxmit.
+ */
+ p = NULL;
+ goto after_sack_rexmit;
+ } else
+ /* Can rexmit part of the current hole */
+ len = ((int32_t)min(cwin,
+ tp->snd_recover - p->rxmit));
+ } else {
+ len = ((int32_t)min(cwin, p->end - p->rxmit));
+ }
+ if (len > 0) {
+ off = p->rxmit - tp->snd_una; /* update off only if we really transmit SACK data */
+ sack_rxmit = 1;
+ sendalot = 1;
+ tcpstat.tcps_sack_rexmits++;
+ tcpstat.tcps_sack_rexmit_bytes +=
+ min(len, tp->t_maxseg);
+ if (nstat_collect) {
+ nstat_route_tx(tp->t_inpcb->inp_route.ro_rt, 1,
+ min(len, tp->t_maxseg), NSTAT_TX_FLAG_RETRANSMIT);
+ locked_add_64(&tp->t_inpcb->inp_stat->txpackets, 1);
+ locked_add_64(&tp->t_inpcb->inp_stat->txbytes,
+ min(len, tp->t_maxseg));
+ tp->t_stat.txretransmitbytes += min(len, tp->t_maxseg);
+ }
+ } else {
+ len = 0;
+ }
+ }
+after_sack_rexmit:
/*
* Get standard flags, and add SYN or FIN if requested by 'hidden'
* state flags.
* and go to transmit state.
*/
if (tp->t_force) {
- if (win == 0) {
+ if (sendwin == 0) {
/*
* If we still have some data to send, then
* clear the FIN bit. Usually this would
*/
if (off < so->so_snd.sb_cc)
flags &= ~TH_FIN;
- win = 1;
+ sendwin = 1;
} else {
tp->t_timer[TCPT_PERSIST] = 0;
tp->t_rxtshift = 0;
+ tp->rxt_start = 0;
+ tp->t_persist_stop = 0;
}
}
- len = (long)ulmin(so->so_snd.sb_cc, win) - off;
-
- if ((taop = tcp_gettaocache(tp->t_inpcb)) == NULL) {
- taop = &tao_noncached;
- bzero(taop, sizeof(*taop));
+ /*
+ * If snd_nxt == snd_max and we have transmitted a FIN, the
+ * offset will be > 0 even if so_snd.sb_cc is 0, resulting in
+ * a negative length. This can also occur when TCP opens up
+ * its congestion window while receiving additional duplicate
+ * acks after fast-retransmit because TCP will reset snd_nxt
+ * to snd_max after the fast-retransmit.
+ *
+ * In the normal retransmit-FIN-only case, however, snd_nxt will
+ * be set to snd_una, the offset will be 0, and the length may
+ * wind up 0.
+ *
+ * If sack_rxmit is true we are retransmitting from the scoreboard
+ * in which case len is already set.
+ */
+ if (sack_rxmit == 0) {
+ if (sack_bytes_rxmt == 0)
+ len = min(so->so_snd.sb_cc, sendwin) - off;
+ else {
+ int32_t cwin;
+
+ /*
+ * We are inside of a SACK recovery episode and are
+ * sending new data, having retransmitted all the
+ * data possible in the scoreboard.
+ */
+ len = min(so->so_snd.sb_cc, tp->snd_wnd)
+ - off;
+ /*
+ * Don't remove this (len > 0) check !
+ * We explicitly check for len > 0 here (although it
+ * isn't really necessary), to work around a gcc
+ * optimization issue - to force gcc to compute
+ * len above. Without this check, the computation
+ * of len is bungled by the optimizer.
+ */
+ if (len > 0) {
+ cwin = tp->snd_cwnd -
+ (tp->snd_nxt - tp->sack_newdata) -
+ sack_bytes_rxmt;
+ if (cwin < 0)
+ cwin = 0;
+ len = imin(len, cwin);
+ }
+ else
+ len = 0;
+ }
}
/*
if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una)) {
flags &= ~TH_SYN;
off--, len++;
- if (len > 0 && tp->t_state == TCPS_SYN_SENT &&
- taop->tao_ccsent == 0) {
- if (packetlist) {
- error = ip_output_list(packetlist, packchain_listadd, tp->t_inpcb->inp_options, &tp->t_inpcb->inp_route,
- (so->so_options & SO_DONTROUTE), 0);
- tp->t_lastchain = 0;
+ if (len > 0 && tp->t_state == TCPS_SYN_SENT) {
+ while (tp->t_inpcb->inp_sndinprog_cnt == 0 &&
+ tp->t_pktlist_head != NULL) {
+ packetlist = tp->t_pktlist_head;
+ packchain_listadd = tp->t_lastchain;
+ packchain_sent++;
+ TCP_PKTLIST_CLEAR(tp);
+
+ error = tcp_ip_output(so, tp, packetlist,
+ packchain_listadd, tp_inp_options,
+ (so_options & SO_DONTROUTE),
+ (sack_rxmit | (sack_bytes_rxmt != 0)), 0,
+#ifdef INET6
+ isipv6);
+#else
+ 0);
+#endif
+
+
+ }
+ /*
+ * tcp was closed while we were in ip,
+ * resume close
+ */
+ if (tp->t_inpcb->inp_sndinprog_cnt == 0 &&
+ (tp->t_flags & TF_CLOSING)) {
+ tp->t_flags &= ~TF_CLOSING;
+ (void) tcp_close(tp);
+ } else {
+ tcp_check_timer_state(tp);
}
- KERNEL_DEBUG(DBG_FNC_TCP_OUTPUT | DBG_FUNC_END, 0,0,0,0,0);
- return 0;
+ KERNEL_DEBUG(DBG_FNC_TCP_OUTPUT | DBG_FUNC_END,
+ 0,0,0,0,0);
+ return(0);
}
}
/*
- * Be careful not to send data and/or FIN on SYN segments
- * in cases when no CC option will be sent.
+ * Be careful not to send data and/or FIN on SYN segments.
* This measure is needed to prevent interoperability problems
* with not fully conformant TCP implementations.
*/
- if ((flags & TH_SYN) &&
- ((tp->t_flags & TF_NOOPT) || !(tp->t_flags & TF_REQ_CC) ||
- ((flags & TH_ACK) && !(tp->t_flags & TF_RCVD_CC)))) {
+ if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
len = 0;
flags &= ~TH_FIN;
}
- if (len < 0) {
+ /* The check here used to be (len < 0). Some times len is zero when
+ * the congestion window is closed and we need to check if persist timer
+ * has to be set in that case. But don't set persist until connection
+ * is established.
+ */
+ if (len <= 0 && !(flags & TH_SYN)) {
/*
* If FIN has been sent but not acked,
* but we haven't been called to retransmit,
- * len will be -1. Otherwise, window shrank
+ * len will be < 0. Otherwise, window shrank
* after we sent into it. If window shrank to 0,
* cancel pending retransmit, pull snd_nxt back
* to (closed) window, and set the persist timer
* close completely, just wait for an ACK.
*/
len = 0;
- if (win == 0) {
+ if (sendwin == 0) {
tp->t_timer[TCPT_REXMT] = 0;
tp->t_rxtshift = 0;
+ tp->rxt_start = 0;
tp->snd_nxt = tp->snd_una;
if (tp->t_timer[TCPT_PERSIST] == 0)
tcp_setpersist(tp);
}
}
+
+ /* Automatic sizing of send socket buffer. Increase the send socket buffer
+ * size if all of the following criteria are met
+ * 1. the receiver has enough buffer space for this data
+ * 2. send buffer is filled to 7/8th with data (so we actually
+ * have data to make use of it);
+ * 3. our send window (slow start and congestion controlled) is
+ * larger than sent but unacknowledged data in send buffer.
+ */
+ basertt = get_base_rtt(tp);
+ if (tcp_do_autosendbuf == 1 &&
+ !INP_WAIT_FOR_IF_FEEDBACK(tp->t_inpcb) && !IN_FASTRECOVERY(tp) &&
+ (so->so_snd.sb_flags & (SB_AUTOSIZE | SB_TRIM)) == SB_AUTOSIZE &&
+ tcp_cansbgrow(&so->so_snd)) {
+ if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
+ so->so_snd.sb_cc >= (so->so_snd.sb_hiwat / 8 * 7) &&
+ sendwin >= (so->so_snd.sb_cc -
+ (tp->snd_nxt - tp->snd_una))) {
+ /* Also increase the send buffer only if the
+ * round-trip time is not increasing because we do
+ * not want to contribute to latency by filling buffers.
+ * We also do not want to hold onto application's
+ * old data for too long. Interactive applications would
+ * rather discard old data.
+ */
+ if (tp->t_rttcur <=
+ (basertt + 25)) {
+ if (sbreserve(&so->so_snd,
+ min(so->so_snd.sb_hiwat + tcp_autosndbuf_inc,
+ tcp_autosndbuf_max)) == 1) {
+ so->so_snd.sb_idealsize = so->so_snd.sb_hiwat;
+ }
+ } else {
+ so->so_snd.sb_idealsize =
+ max(tcp_sendspace, so->so_snd.sb_hiwat -
+ (2 * tcp_autosndbuf_inc));
+ so->so_snd.sb_flags |= SB_TRIM;
+ }
+ }
+ }
+
+ /*
+ * Truncate to the maximum segment length or enable TCP Segmentation
+ * Offloading (if supported by hardware) and ensure that FIN is removed
+ * if the length no longer contains the last data byte.
+ *
+ * TSO may only be used if we are in a pure bulk sending state. The
+ * presence of TCP-MD5, SACK retransmits, SACK advertizements, ipfw rules
+ * and IP options prevent using TSO. With TSO the TCP header is the same
+ * (except for the sequence number) for all generated packets. This
+ * makes it impossible to transmit any options which vary per generated
+ * segment or packet.
+ *
+ * The length of TSO bursts is limited to TCP_MAXWIN. That limit and
+ * removal of FIN (if not already catched here) are handled later after
+ * the exact length of the TCP options are known.
+ */
+#if IPSEC
+ /*
+ * Pre-calculate here as we save another lookup into the darknesses
+ * of IPsec that way and can actually decide if TSO is ok.
+ */
+ if (ipsec_bypass == 0)
+ ipsec_optlen = ipsec_hdrsiz_tcp(tp);
+#endif
+
if (len > tp->t_maxseg) {
- len = tp->t_maxseg;
- howmuchsent += len;
- sendalot = 1;
+ if ((tp->t_flags & TF_TSO) && tcp_do_tso &&
+#if RANDOM_IP_ID
+ ip_use_randomid &&
+#endif /* RANDOM_IP_ID */
+ kipf_count == 0 && dlil_filter_count == 0 &&
+ tp->rcv_numsacks == 0 && sack_rxmit == 0 && sack_bytes_rxmt == 0 &&
+ tp->t_inpcb->inp_options == NULL &&
+ tp->t_inpcb->in6p_options == NULL
+#if IPSEC
+ && ipsec_optlen == 0
+#endif
+#if IPFIREWALL
+ && (fw_enable == 0 || fw_bypass)
+#endif
+ ) {
+ tso = 1;
+ sendalot = 0;
+ } else {
+ len = tp->t_maxseg;
+ sendalot = 1;
+ tso = 0;
+ }
+ }
+ if (sack_rxmit) {
+ if (SEQ_LT(p->rxmit + len, tp->snd_una + so->so_snd.sb_cc))
+ flags &= ~TH_FIN;
+ } else {
+ if (SEQ_LT(tp->snd_nxt + len, tp->snd_una + so->so_snd.sb_cc))
+ flags &= ~TH_FIN;
}
- if (SEQ_LT(tp->snd_nxt + len, tp->snd_una + so->so_snd.sb_cc))
- flags &= ~TH_FIN;
- if (tp->t_flags & TF_SLOWLINK && slowlink_wsize > 0 ) /* Clips window size for slow links */
- win = min(sbspace(&so->so_rcv), slowlink_wsize);
- else
- win = sbspace(&so->so_rcv);
+ recwin = tcp_sbspace(tp);
/*
- * Sender silly window avoidance. If connection is idle
- * and can send all data, a maximum segment,
- * at least a maximum default-size segment do it,
- * or are forced, do it; otherwise don't bother.
- * If peer's buffer is tiny, then send
- * when window is at least half open.
- * If retransmitting (possibly after persist timer forced us
- * to send into a small window), then must resend.
+ * Sender silly window avoidance. We transmit under the following
+ * conditions when len is non-zero:
+ *
+ * - we've timed out (e.g. persist timer)
+ * - we need to retransmit
+ * - We have a full segment (or more with TSO)
+ * - This is the last buffer in a write()/send() and we are
+ * either idle or running NODELAY
+ * - we have more then 1/2 the maximum send window's worth of
+ * data (receiver may be limited the window size)
*/
if (len) {
- if (len == tp->t_maxseg)
- goto send;
- if (!(tp->t_flags & TF_MORETOCOME) &&
- (idle || tp->t_flags & TF_NODELAY) &&
- (tp->t_flags & TF_NOPUSH) == 0 &&
- len + off >= so->so_snd.sb_cc)
+ if (tp->t_force) {
+ tp->t_flags &= ~TF_MAXSEGSNT;
goto send;
- if (tp->t_force)
- goto send;
- if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0)
+ }
+ if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
+ if (len >= tp->t_maxseg)
+ tp->t_flags |= TF_MAXSEGSNT;
+ else
+ tp->t_flags &= ~TF_MAXSEGSNT;
goto send;
- if (SEQ_LT(tp->snd_nxt, tp->snd_max))
+ }
+ if (sack_rxmit)
goto send;
+
+ /*
+ * Send new data on the connection only if it is
+ * not flow controlled
+ */
+ if (!INP_WAIT_FOR_IF_FEEDBACK(tp->t_inpcb) ||
+ tp->t_state != TCPS_ESTABLISHED) {
+ if (len >= tp->t_maxseg) {
+ tp->t_flags |= TF_MAXSEGSNT;
+ goto send;
+ }
+ if (!(tp->t_flags & TF_MORETOCOME) &&
+ (idle || tp->t_flags & TF_NODELAY || tp->t_flags & TF_MAXSEGSNT) &&
+ (tp->t_flags & TF_NOPUSH) == 0 &&
+ len + off >= so->so_snd.sb_cc) {
+ tp->t_flags &= ~TF_MAXSEGSNT;
+ goto send;
+ }
+ if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
+ tp->t_flags &= ~TF_MAXSEGSNT;
+ goto send;
+ }
+ } else {
+ tcpstat.tcps_fcholdpacket++;
+ }
}
/*
* Compare available window to amount of window
* known to peer (as advertised window less
* next expected input). If the difference is at least two
- * max size segments, or at least 50% of the maximum possible
+ * max size segments, or at least 25% of the maximum possible
* window, then want to send a window update to peer.
+ * Skip this if the connection is in T/TCP half-open state.
*/
- if (win > 0) {
+ if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN)) {
/*
* "adv" is the amount we can increase the window,
* taking into account that we are limited by
* TCP_MAXWIN << tp->rcv_scale.
*/
- long adv = min(win, (long)TCP_MAXWIN << tp->rcv_scale) -
+ int32_t adv = imin(recwin, (int)TCP_MAXWIN << tp->rcv_scale) -
(tp->rcv_adv - tp->rcv_nxt);
- if (adv >= (long) (2 * tp->t_maxseg))
- goto send;
- if (2 * adv >= (long) so->so_rcv.sb_hiwat)
- goto send;
+ if (adv >= (int32_t) (2 * tp->t_maxseg)) {
+ /* Update only if the resulting scaled value of the window changed, or
+ * if there is a change in the sequence since the last ack.
+ * This avoids what appears as dupe ACKS (see rdar://5640997)
+ *
+ * If streaming is detected avoid sending too many window updates.
+ * We will depend on the delack timer to send a window update
+ * when needed.
+ */
+ if ((tp->t_flags & TF_STRETCHACK) == 0 &&
+ (tp->last_ack_sent != tp->rcv_nxt ||
+ ((recwin + adv) >> tp->rcv_scale) > recwin)) {
+ goto send;
+ }
+
+ /* Make sure that the delayed ack timer is set if we
+ * delayed sending a window update because of streaming
+ * detection.
+ */
+ if ((tp->t_flags & TF_STRETCHACK) != 0 &&
+ (tp->t_flags & TF_DELACK) == 0) {
+ tp->t_flags |= TF_DELACK;
+ tp->t_timer[TCPT_DELACK] = OFFSET_FROM_START(tp, tcp_delack);
+ }
+ }
+ if (4 * adv >= (int32_t) so->so_rcv.sb_hiwat)
+ goto send;
}
/*
- * Send if we owe peer an ACK.
+ * Send if we owe the peer an ACK, RST, SYN, or urgent data. ACKNOW
+ * is also a catch-all for the retransmit timer timeout case.
*/
if (tp->t_flags & TF_ACKNOW)
goto send;
goto send;
/*
* If our state indicates that FIN should be sent
- * and we have not yet done so, or we're retransmitting the FIN,
- * then we need to send.
+ * and we have not yet done so, then we need to send.
*/
if (flags & TH_FIN &&
((tp->t_flags & TF_SENTFIN) == 0 || tp->snd_nxt == tp->snd_una))
goto send;
-
+ /*
+ * In SACK, it is possible for tcp_output to fail to send a segment
+ * after the retransmission timer has been turned off. Make sure
+ * that the retransmission timer is set.
+ */
+ if (tp->sack_enable && (tp->t_state >= TCPS_ESTABLISHED) &&
+ SEQ_GT(tp->snd_max, tp->snd_una) &&
+ tp->t_timer[TCPT_REXMT] == 0 &&
+ tp->t_timer[TCPT_PERSIST] == 0) {
+ tp->t_timer[TCPT_REXMT] = OFFSET_FROM_START(tp, tp->t_rxtcur);
+ goto just_return;
+ }
/*
* TCP window updates are not reliable, rather a polling protocol
* using ``persist'' packets is used to insure receipt of window
if (so->so_snd.sb_cc && tp->t_timer[TCPT_REXMT] == 0 &&
tp->t_timer[TCPT_PERSIST] == 0) {
tp->t_rxtshift = 0;
+ tp->rxt_start = 0;
tcp_setpersist(tp);
}
-
+just_return:
/*
* If there is no reason to send a segment, just return.
* but if there is some packets left in the packet list, send them now.
*/
- if (packetlist) {
- error = ip_output_list(packetlist, packchain_listadd, tp->t_inpcb->inp_options, &tp->t_inpcb->inp_route,
- (so->so_options & SO_DONTROUTE), 0);
+ while (tp->t_inpcb->inp_sndinprog_cnt == 0 &&
+ tp->t_pktlist_head != NULL) {
+ packetlist = tp->t_pktlist_head;
+ packchain_listadd = tp->t_lastchain;
+ packchain_sent++;
+ TCP_PKTLIST_CLEAR(tp);
+
+ error = tcp_ip_output(so, tp, packetlist, packchain_listadd,
+ tp_inp_options, (so_options & SO_DONTROUTE),
+ (sack_rxmit | (sack_bytes_rxmt != 0)), recwin,
+#ifdef INET6
+ isipv6);
+#else
+ 0);
+#endif
+ }
+ /* tcp was closed while we were in ip; resume close */
+ if (tp->t_inpcb->inp_sndinprog_cnt == 0 &&
+ (tp->t_flags & TF_CLOSING)) {
+ tp->t_flags &= ~TF_CLOSING;
+ (void) tcp_close(tp);
+ } else {
+ tcp_check_timer_state(tp);
}
KERNEL_DEBUG(DBG_FNC_TCP_OUTPUT | DBG_FUNC_END, 0,0,0,0,0);
return (0);
hdrlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
else
#endif
- hdrlen = sizeof (struct tcpiphdr);
+ hdrlen = sizeof (struct tcpiphdr);
if (flags & TH_SYN) {
tp->snd_nxt = tp->iss;
if ((tp->t_flags & TF_NOOPT) == 0) {
if ((tp->t_flags & TF_REQ_SCALE) &&
((flags & TH_ACK) == 0 ||
(tp->t_flags & TF_RCVD_SCALE))) {
- *((u_int32_t *)(opt + optlen)) = htonl(
+ *((u_int32_t *)(void *)(opt + optlen)) = htonl(
TCPOPT_NOP << 24 |
TCPOPT_WINDOW << 16 |
TCPOLEN_WINDOW << 8 |
optlen += 4;
}
}
+
}
+
+ /*
+ RFC 3168 states that:
+ - If you ever sent an ECN-setup SYN/SYN-ACK you must be prepared
+ to handle the TCP ECE flag, even if you also later send a
+ non-ECN-setup SYN/SYN-ACK.
+ - If you ever send a non-ECN-setup SYN/SYN-ACK, you must not set
+ the ip ECT flag.
+
+ It is not clear how the ECE flag would ever be set if you never
+ set the IP ECT flag on outbound packets. All the same, we use
+ the TE_SETUPSENT to indicate that we have committed to handling
+ the TCP ECE flag correctly. We use the TE_SENDIPECT to indicate
+ whether or not we should set the IP ECT flag on outbound packets.
+ */
+ /*
+ * For a SYN-ACK, send an ECN setup SYN-ACK
+ */
+ if (tcp_ecn_inbound && (flags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
+ if ((tp->ecn_flags & TE_SETUPRECEIVED) != 0) {
+ if ((tp->ecn_flags & TE_SETUPSENT) == 0) {
+ /* Setting TH_ECE makes this an ECN-setup SYN-ACK */
+ flags |= TH_ECE;
+
+ /*
+ * Record that we sent the ECN-setup and default to
+ * setting IP ECT.
+ */
+ tp->ecn_flags |= (TE_SETUPSENT | TE_SENDIPECT);
+ }
+ else {
+ /*
+ * We sent an ECN-setup SYN-ACK but it was dropped.
+ * Fallback to non-ECN-setup SYN-ACK and clear flag
+ * that to indicate we should not send data with IP ECT set.
+ *
+ * Pretend we didn't receive an ECN-setup SYN.
+ */
+ tp->ecn_flags &= ~TE_SETUPRECEIVED;
+ }
+ }
+ }
+ else if (tcp_ecn_outbound && (flags & (TH_SYN | TH_ACK)) == TH_SYN) {
+ if ((tp->ecn_flags & TE_SETUPSENT) == 0) {
+ /* Setting TH_ECE and TH_CWR makes this an ECN-setup SYN */
+ flags |= (TH_ECE | TH_CWR);
+
+ /*
+ * Record that we sent the ECN-setup and default to
+ * setting IP ECT.
+ */
+ tp->ecn_flags |= (TE_SETUPSENT | TE_SENDIPECT);
+ }
+ else {
+ /*
+ * We sent an ECN-setup SYN but it was dropped.
+ * Fall back to no ECN and clear flag indicating
+ * we should send data with IP ECT set.
+ */
+ tp->ecn_flags &= ~TE_SENDIPECT;
+ }
+ }
+
+ /*
+ * Check if we should set the TCP CWR flag.
+ * CWR flag is sent when we reduced the congestion window because
+ * we received a TCP ECE or we performed a fast retransmit. We
+ * never set the CWR flag on retransmitted packets. We only set
+ * the CWR flag on data packets. Pure acks don't have this set.
+ */
+ if ((tp->ecn_flags & TE_SENDCWR) != 0 && len != 0 &&
+ !SEQ_LT(tp->snd_nxt, tp->snd_max) && !sack_rxmit) {
+ flags |= TH_CWR;
+ tp->ecn_flags &= ~TE_SENDCWR;
+ }
+
+ /*
+ * Check if we should set the TCP ECE flag.
+ */
+ if ((tp->ecn_flags & TE_SENDECE) != 0 && len == 0) {
+ flags |= TH_ECE;
+ }
/*
* Send a timestamp and echo-reply if this is a SYN and our side
(flags & TH_RST) == 0 &&
((flags & TH_ACK) == 0 ||
(tp->t_flags & TF_RCVD_TSTMP))) {
- u_int32_t *lp = (u_int32_t *)(opt + optlen);
+ u_int32_t *lp = (u_int32_t *)(void *)(opt + optlen);
/* Form timestamp option as shown in appendix A of RFC 1323. */
*lp++ = htonl(TCPOPT_TSTAMP_HDR);
optlen += TCPOLEN_TSTAMP_APPA;
}
- /*
- * Send `CC-family' options if our side wants to use them (TF_REQ_CC),
- * options are allowed (!TF_NOOPT) and it's not a RST.
- */
- if ((tp->t_flags & (TF_REQ_CC|TF_NOOPT)) == TF_REQ_CC &&
- (flags & TH_RST) == 0) {
- switch (flags & (TH_SYN|TH_ACK)) {
- /*
- * This is a normal ACK, send CC if we received CC before
- * from our peer.
+ /* Note the timestamp for receive buffer autosizing */
+ if (tp->rfbuf_ts == 0 && (so->so_rcv.sb_flags & SB_AUTOSIZE))
+ tp->rfbuf_ts = tcp_now;
+
+ if (tp->sack_enable && ((tp->t_flags & TF_NOOPT) == 0)) {
+ /*
+ * Tack on the SACK permitted option *last*.
+ * And do padding of options after tacking this on.
+ * This is because of MSS, TS, WinScale and Signatures are
+ * all present, we have just 2 bytes left for the SACK
+ * permitted option, which is just enough.
*/
- case TH_ACK:
- if (!(tp->t_flags & TF_RCVD_CC))
- break;
- /*FALLTHROUGH*/
-
/*
- * We can only get here in T/TCP's SYN_SENT* state, when
- * we're a sending a non-SYN segment without waiting for
- * the ACK of our SYN. A check above assures that we only
- * do this if our peer understands T/TCP.
+ * If this is the first SYN of connection (not a SYN
+ * ACK), include SACK permitted option. If this is a
+ * SYN ACK, include SACK permitted option if peer has
+ * already done so. This is only for active connect,
+ * since the syncache takes care of the passive connect.
*/
- case 0:
- opt[optlen++] = TCPOPT_NOP;
- opt[optlen++] = TCPOPT_NOP;
- opt[optlen++] = TCPOPT_CC;
- opt[optlen++] = TCPOLEN_CC;
- *(u_int32_t *)&opt[optlen] = htonl(tp->cc_send);
-
- optlen += 4;
- break;
+ if ((flags & TH_SYN) &&
+ (!(flags & TH_ACK) || (tp->t_flags & TF_SACK_PERMIT))) {
+ u_char *bp;
+ bp = (u_char *)opt + optlen;
+
+ *bp++ = TCPOPT_SACK_PERMITTED;
+ *bp++ = TCPOLEN_SACK_PERMITTED;
+ optlen += TCPOLEN_SACK_PERMITTED;
+ }
/*
- * This is our initial SYN, check whether we have to use
- * CC or CC.new.
+ * Send SACKs if necessary. This should be the last
+ * option processed. Only as many SACKs are sent as
+ * are permitted by the maximum options size.
+ *
+ * In general, SACK blocks consume 8*n+2 bytes.
+ * So a full size SACK blocks option is 34 bytes
+ * (to generate 4 SACK blocks). At a minimum,
+ * we need 10 bytes (to generate 1 SACK block).
+ * If TCP Timestamps (12 bytes) and TCP Signatures
+ * (18 bytes) are both present, we'll just have
+ * 10 bytes for SACK options 40 - (12 + 18).
*/
- case TH_SYN:
- opt[optlen++] = TCPOPT_NOP;
- opt[optlen++] = TCPOPT_NOP;
- opt[optlen++] = tp->t_flags & TF_SENDCCNEW ?
- TCPOPT_CCNEW : TCPOPT_CC;
- opt[optlen++] = TCPOLEN_CC;
- *(u_int32_t *)&opt[optlen] = htonl(tp->cc_send);
- optlen += 4;
- break;
+ if (TCPS_HAVEESTABLISHED(tp->t_state) &&
+ (tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0 &&
+ MAX_TCPOPTLEN - optlen - 2 >= TCPOLEN_SACK) {
+ int nsack, padlen;
+ u_char *bp = (u_char *)opt + optlen;
+ u_int32_t *lp;
- /*
- * This is a SYN,ACK; send CC and CC.echo if we received
- * CC from our peer.
- */
- case (TH_SYN|TH_ACK):
- if (tp->t_flags & TF_RCVD_CC) {
- opt[optlen++] = TCPOPT_NOP;
- opt[optlen++] = TCPOPT_NOP;
- opt[optlen++] = TCPOPT_CC;
- opt[optlen++] = TCPOLEN_CC;
- *(u_int32_t *)&opt[optlen] =
- htonl(tp->cc_send);
- optlen += 4;
- opt[optlen++] = TCPOPT_NOP;
- opt[optlen++] = TCPOPT_NOP;
- opt[optlen++] = TCPOPT_CCECHO;
- opt[optlen++] = TCPOLEN_CC;
- *(u_int32_t *)&opt[optlen] =
- htonl(tp->cc_recv);
- optlen += 4;
+ nsack = (MAX_TCPOPTLEN - optlen - 2) / TCPOLEN_SACK;
+ nsack = min(nsack, tp->rcv_numsacks);
+ sackoptlen = (2 + nsack * TCPOLEN_SACK);
+
+ /*
+ * First we need to pad options so that the
+ * SACK blocks can start at a 4-byte boundary
+ * (sack option and length are at a 2 byte offset).
+ */
+ padlen = (MAX_TCPOPTLEN - optlen - sackoptlen) % 4;
+ optlen += padlen;
+ while (padlen-- > 0)
+ *bp++ = TCPOPT_NOP;
+
+ tcpstat.tcps_sack_send_blocks++;
+ *bp++ = TCPOPT_SACK;
+ *bp++ = sackoptlen;
+ lp = (u_int32_t *)(void *)bp;
+ for (i = 0; i < nsack; i++) {
+ struct sackblk sack = tp->sackblks[i];
+ *lp++ = htonl(sack.start);
+ *lp++ = htonl(sack.end);
}
- break;
+ optlen += sackoptlen;
}
- }
+ }
+
+ /* Pad TCP options to a 4 byte boundary */
+ if (optlen < MAX_TCPOPTLEN && (optlen % sizeof(u_int32_t))) {
+ int pad = sizeof(u_int32_t) - (optlen % sizeof(u_int32_t));
+ u_char *bp = (u_char *)opt + optlen;
+
+ optlen += pad;
+ while (pad) {
+ *bp++ = TCPOPT_EOL;
+ pad--;
+ }
+ }
+
+ hdrlen += optlen;
- hdrlen += optlen;
#if INET6
if (isipv6)
ipoptlen = ip6_optlen(tp->t_inpcb);
else
#endif
{
- if (tp->t_inpcb->inp_options) {
- ipoptlen = tp->t_inpcb->inp_options->m_len -
+ if (tp_inp_options) {
+ ipoptlen = tp_inp_options->m_len -
offsetof(struct ipoption, ipopt_list);
- } else {
+ } else
ipoptlen = 0;
- }
}
#if IPSEC
- if (ipsec_bypass == 0)
- ipoptlen += ipsec_hdrsiz_tcp(tp);
+ ipoptlen += ipsec_optlen;
#endif
/*
* bump the packet length beyond the t_maxopd length.
* Clear the FIN bit because we cut off the tail of
* the segment.
+ *
+ * When doing TSO limit a burst to TCP_MAXWIN minus the
+ * IP, TCP and Options length to keep ip->ip_len from
+ * overflowing. Prevent the last segment from being
+ * fractional thus making them all equal sized and set
+ * the flag to continue sending. TSO is disabled when
+ * IP options or IPSEC are present.
*/
if (len + optlen + ipoptlen > tp->t_maxopd) {
/*
* If there is still more to send, don't close the connection.
*/
flags &= ~TH_FIN;
- len = tp->t_maxopd - optlen - ipoptlen;
- howmuchsent += len;
- sendalot = 1;
+ if (tso) {
+ int32_t tso_maxlen;
+
+ tso_maxlen = tp->tso_max_segment_size ? tp->tso_max_segment_size : TCP_MAXWIN;
+
+ if (len > tso_maxlen - hdrlen - optlen) {
+ len = tso_maxlen - hdrlen - optlen;
+ len = len - (len % (tp->t_maxopd - optlen));
+ sendalot = 1;
+ } else if (tp->t_flags & TF_NEEDFIN)
+ sendalot = 1;
+ } else {
+ len = tp->t_maxopd - optlen - ipoptlen;
+ sendalot = 1;
+ }
}
-/*#ifdef DIAGNOSTIC*/
-#if INET6
if (max_linkhdr + hdrlen > MCLBYTES)
panic("tcphdr too big");
-#else
- if (max_linkhdr + hdrlen > MHLEN)
- panic("tcphdr too big");
-#endif
-/*#endif*/
+ /* Check if there is enough data in the send socket
+ * buffer to start measuring bw
+ */
+ if ((tp->t_flagsext & TF_MEASURESNDBW) != 0 &&
+ (tp->t_bwmeas != NULL) &&
+ (tp->t_flagsext & TF_BWMEAS_INPROGRESS) == 0 &&
+ (so->so_snd.sb_cc - (tp->snd_max - tp->snd_una)) >=
+ tp->t_bwmeas->bw_minsize) {
+ tp->t_bwmeas->bw_size = min((so->so_snd.sb_cc - (tp->snd_max - tp->snd_una)),
+ tp->t_bwmeas->bw_maxsize);
+ tp->t_flagsext |= TF_BWMEAS_INPROGRESS;
+ tp->t_bwmeas->bw_start = tp->snd_max;
+ tp->t_bwmeas->bw_ts = tcp_now;
+ }
+
+ VERIFY(tp->t_inpcb->inp_flowhash != 0);
+
/*
* Grab a header mbuf, attaching a copy of data to
* be transmitted, and initialize the header from
if (len) {
if (tp->t_force && len == 1)
tcpstat.tcps_sndprobe++;
- else if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
+ else if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
tcpstat.tcps_sndrexmitpack++;
tcpstat.tcps_sndrexmitbyte += len;
+ if (nstat_collect) {
+ nstat_route_tx(tp->t_inpcb->inp_route.ro_rt, 1,
+ len, NSTAT_TX_FLAG_RETRANSMIT);
+ locked_add_64(&tp->t_inpcb->inp_stat->txpackets, 1);
+ locked_add_64(&tp->t_inpcb->inp_stat->txbytes, len);
+ tp->t_stat.txretransmitbytes += len;
+ }
} else {
tcpstat.tcps_sndpack++;
tcpstat.tcps_sndbyte += len;
- }
-#ifdef notyet
- if ((m = m_copypack(so->so_snd.sb_mb, off,
- (int)len, max_linkhdr + hdrlen)) == 0) {
- error = ENOBUFS;
- goto out;
+ if (nstat_collect) {
+ locked_add_64(&tp->t_inpcb->inp_stat->txpackets, 1);
+ locked_add_64(&tp->t_inpcb->inp_stat->txbytes, len);
+ }
}
- /*
- * m_copypack left space for our hdr; use it.
- */
- m->m_len += hdrlen;
- m->m_data -= hdrlen;
-#else
/*
* try to use the new interface that allocates all
* the necessary mbuf hdrs under 1 mbuf lock and
* data area (no cluster attached)
*/
m = NULL;
-#if INET6
+
+ /* minimum length we are going to allocate */
+ allocated_len = MHLEN;
if (MHLEN < hdrlen + max_linkhdr) {
- MGETHDR(m, M_DONTWAIT, MT_HEADER);
+ MGETHDR(m, M_DONTWAIT, MT_HEADER);
if (m == NULL) {
- error = ENOBUFS;
+ error = ENOBUFS;
goto out;
}
MCLGET(m, M_DONTWAIT);
}
m->m_data += max_linkhdr;
m->m_len = hdrlen;
+ allocated_len = MCLBYTES;
}
-#endif
- if (len <= MHLEN - hdrlen - max_linkhdr) {
+ if (len <= allocated_len - hdrlen - max_linkhdr) {
if (m == NULL) {
- MGETHDR(m, M_DONTWAIT, MT_HEADER);
+ VERIFY(allocated_len <= MHLEN);
+ MGETHDR(m, M_DONTWAIT, MT_HEADER);
if (m == NULL) {
- error = ENOBUFS;
+ error = ENOBUFS;
goto out;
}
m->m_data += max_linkhdr;
m->m_len = hdrlen;
}
/* makes sure we still have data left to be sent at this point */
- if (so->so_snd.sb_mb == NULL || off == -1) {
+ if (so->so_snd.sb_mb == NULL || off < 0) {
if (m != NULL) m_freem(m);
error = 0; /* should we return an error? */
goto out;
* m_copym_with_hdrs to avoid rescanning from the beginning of the socket buffer mbuf list.
* setting the mbuf pointer to NULL is sufficient to disable the hint mechanism.
*/
- if (m_head != so->so_snd.sb_mb || last_off != off)
- m_last = NULL;
+ if (m_head != so->so_snd.sb_mb || sack_rxmit || last_off != off)
+ m_lastm = NULL;
last_off = off + len;
m_head = so->so_snd.sb_mb;
* m_copym_with_hdrs will always return the last mbuf pointer and the offset into it that
* it acted on to fullfill the current request, whether a valid 'hint' was passed in or not
*/
- if ((m = m_copym_with_hdrs(so->so_snd.sb_mb, off, (int) len, M_DONTWAIT, &m_last, &m_off)) == NULL) {
+ if ((m = m_copym_with_hdrs(so->so_snd.sb_mb, off, len, M_DONTWAIT, &m_lastm, &m_off)) == NULL) {
error = ENOBUFS;
goto out;
}
m->m_len = hdrlen;
}
}
-#endif
/*
* If we're sending everything we've got, set PUSH.
* (This will keep happy those implementations which only
else
tcpstat.tcps_sndwinup++;
- MGETHDR(m, M_DONTWAIT, MT_HEADER);
+ MGETHDR(m, M_DONTWAIT, MT_HEADER); /* MAC-OK */
if (m == NULL) {
error = ENOBUFS;
goto out;
}
-#if INET6
- if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
- MHLEN >= hdrlen) {
- MH_ALIGN(m, hdrlen);
- } else
-#endif
+ if (MHLEN < (hdrlen + max_linkhdr)) {
+ MCLGET(m, M_DONTWAIT);
+ if ((m->m_flags & M_EXT) == 0) {
+ m_freem(m);
+ error = ENOBUFS;
+ goto out;
+ }
+ }
m->m_data += max_linkhdr;
m->m_len = hdrlen;
}
m->m_pkthdr.rcvif = 0;
+#if CONFIG_MACF_NET
+ mac_mbuf_label_associate_inpcb(tp->t_inpcb, m);
+#endif
#if INET6
if (isipv6) {
ip6 = mtod(m, struct ip6_hdr *);
- th = (struct tcphdr *)(ip6 + 1);
+ th = (struct tcphdr *)(void *)(ip6 + 1);
tcp_fillheaders(tp, ip6, th);
+ if ((tp->ecn_flags & TE_SENDIPECT) != 0 && len &&
+ !SEQ_LT(tp->snd_nxt, tp->snd_max) && !sack_rxmit) {
+ ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20);
+ }
+ svc_flags |= PKT_SCF_IPV6;
} else
#endif /* INET6 */
{
ip = mtod(m, struct ip *);
ipov = (struct ipovly *)ip;
- th = (struct tcphdr *)(ip + 1);
+ th = (struct tcphdr *)(void *)(ip + 1);
/* this picks up the pseudo header (w/o the length) */
tcp_fillheaders(tp, ip, th);
+ if ((tp->ecn_flags & TE_SENDIPECT) != 0 && len &&
+ !SEQ_LT(tp->snd_nxt, tp->snd_max) && !sack_rxmit) {
+ ip->ip_tos = IPTOS_ECN_ECT0;
+ }
}
/*
* window for use in delaying messages about window sizes.
* If resending a FIN, be sure not to use a new sequence number.
*/
- if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
+ if (flags & TH_FIN && (tp->t_flags & TF_SENTFIN) &&
tp->snd_nxt == tp->snd_max)
tp->snd_nxt--;
/*
* case, since we know we aren't doing a retransmission.
* (retransmit and persist are mutually exclusive...)
*/
- if (len || (flags & (TH_SYN|TH_FIN)) || tp->t_timer[TCPT_PERSIST])
- th->th_seq = htonl(tp->snd_nxt);
- else
- th->th_seq = htonl(tp->snd_max);
+ if (sack_rxmit == 0) {
+ if (len || (flags & (TH_SYN|TH_FIN)) || tp->t_timer[TCPT_PERSIST])
+ th->th_seq = htonl(tp->snd_nxt);
+ else
+ th->th_seq = htonl(tp->snd_max);
+ } else {
+ th->th_seq = htonl(p->rxmit);
+ p->rxmit += len;
+ tp->sackhint.sack_bytes_rexmit += len;
+ }
th->th_ack = htonl(tp->rcv_nxt);
+ tp->last_ack_sent = tp->rcv_nxt;
+
if (optlen) {
bcopy(opt, th + 1, optlen);
th->th_off = (sizeof (struct tcphdr) + optlen) >> 2;
* Calculate receive window. Don't shrink window,
* but avoid silly window syndrome.
*/
- if (win < (long)(so->so_rcv.sb_hiwat / 4) && win < (long)tp->t_maxseg)
- win = 0;
- if (win < (long)(tp->rcv_adv - tp->rcv_nxt))
- win = (long)(tp->rcv_adv - tp->rcv_nxt);
+ if (recwin < (int32_t)(so->so_rcv.sb_hiwat / 4) && recwin < (int)tp->t_maxseg)
+ recwin = 0;
+ if (recwin < (int32_t)(tp->rcv_adv - tp->rcv_nxt))
+ recwin = (int32_t)(tp->rcv_adv - tp->rcv_nxt);
if (tp->t_flags & TF_SLOWLINK && slowlink_wsize > 0) {
- if (win > (long)slowlink_wsize)
- win = slowlink_wsize;
- th->th_win = htons((u_short) (win>>tp->rcv_scale));
+ if (recwin > (int32_t)slowlink_wsize)
+ recwin = slowlink_wsize;
}
- else {
- if (win > (long)TCP_MAXWIN << tp->rcv_scale)
- win = (long)TCP_MAXWIN << tp->rcv_scale;
- th->th_win = htons((u_short) (win>>tp->rcv_scale));
+#if TRAFFIC_MGT
+ if (tcp_recv_bg == 1 || IS_TCP_RECV_BG(so)) {
+ if (tp->acc_iaj > tcp_acc_iaj_react_limit) {
+ uint32_t min_iaj_win = tcp_min_iaj_win * tp->t_maxseg;
+ if (tp->iaj_rwintop == 0 ||
+ SEQ_LT(tp->iaj_rwintop, tp->rcv_adv))
+ tp->iaj_rwintop = tp->rcv_adv;
+ if (SEQ_LT(tp->iaj_rwintop, tp->rcv_nxt + min_iaj_win))
+ tp->iaj_rwintop = tp->rcv_nxt + min_iaj_win;
+ recwin = min(tp->iaj_rwintop - tp->rcv_nxt, recwin);
+ }
}
+#endif /* TRAFFIC_MGT */
- /*
- * Adjust the RXWIN0SENT flag - indicate that we have advertised
- * a 0 window. This may cause the remote transmitter to stall. This
- * flag tells soreceive() to disable delayed acknowledgements when
- * draining the buffer. This can occur if the receiver is attempting
- * to read more data then can be buffered prior to transmitting on
- * the connection.
- */
- if (win == 0)
- tp->t_flags |= TF_RXWIN0SENT;
- else
- tp->t_flags &= ~TF_RXWIN0SENT;
+ if (recwin > (int32_t)(TCP_MAXWIN << tp->rcv_scale))
+ recwin = (int32_t)(TCP_MAXWIN << tp->rcv_scale);
+ th->th_win = htons((u_short) (recwin>>tp->rcv_scale));
+ /*
+ * Adjust the RXWIN0SENT flag - indicate that we have advertised
+ * a 0 window. This may cause the remote transmitter to stall. This
+ * flag tells soreceive() to disable delayed acknowledgements when
+ * draining the buffer. This can occur if the receiver is attempting
+ * to read more data then can be buffered prior to transmitting on
+ * the connection.
+ */
+ if (th->th_win == 0)
+ tp->t_flags |= TF_RXWIN0SENT;
+ else
+ tp->t_flags &= ~TF_RXWIN0SENT;
if (SEQ_GT(tp->snd_up, tp->snd_nxt)) {
th->th_urp = htons((u_short)(tp->snd_up - tp->snd_nxt));
th->th_flags |= TH_URG;
*/
m->m_pkthdr.len = hdrlen + len; /* in6_cksum() need this */
#if INET6
- if (isipv6)
+ if (isipv6) {
/*
* ip6_plen is not need to be filled now, and will be filled
* in ip6_output.
*/
- th->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(struct ip6_hdr),
- sizeof(struct tcphdr) + optlen + len);
+ m->m_pkthdr.csum_flags = CSUM_TCPIPV6;
+ m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
+ if (len + optlen)
+ th->th_sum = in_addword(th->th_sum,
+ htons((u_short)(optlen + len)));
+ }
else
#endif /* INET6 */
{
if (len + optlen)
th->th_sum = in_addword(th->th_sum,
htons((u_short)(optlen + len)));
+ }
- /* IP version must be set here for ipv4/ipv6 checking later */
- KASSERT(ip->ip_v == IPVERSION,
- ("%s: IP version incorrect: %d", __FUNCTION__, ip->ip_v));
- }
+ /*
+ * Enable TSO and specify the size of the segments.
+ * The TCP pseudo header checksum is always provided.
+ */
+ if (tso) {
+#if INET6
+ if (isipv6)
+ m->m_pkthdr.csum_flags = CSUM_TSO_IPV6;
+ else
+#endif /* INET6 */
+ m->m_pkthdr.csum_flags = CSUM_TSO_IPV4;
+
+ m->m_pkthdr.tso_segsz = tp->t_maxopd - optlen;
+ }
+ else
+ m->m_pkthdr.tso_segsz = 0;
/*
* In transmit state, time the transmission and arrange for
tp->t_flags |= TF_SENTFIN;
}
}
+ if (sack_rxmit)
+ goto timer;
tp->snd_nxt += len;
if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
tp->snd_max = tp->snd_nxt;
* not currently timing anything.
*/
if (tp->t_rtttime == 0) {
- tp->t_rtttime = 1;
+ tp->t_rtttime = tcp_now;
tp->t_rtseq = startseq;
tcpstat.tcps_segstimed++;
}
* Initialize shift counter which is used for backoff
* of retransmit time.
*/
+timer:
if (tp->t_timer[TCPT_REXMT] == 0 &&
- tp->snd_nxt != tp->snd_una) {
- tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
+ ((sack_rxmit && tp->snd_nxt != tp->snd_max) ||
+ tp->snd_nxt != tp->snd_una)) {
if (tp->t_timer[TCPT_PERSIST]) {
tp->t_timer[TCPT_PERSIST] = 0;
tp->t_rxtshift = 0;
+ tp->rxt_start = 0;
+ tp->t_persist_stop = 0;
}
+ tp->t_timer[TCPT_REXMT] = OFFSET_FROM_START(tp, tp->t_rxtcur);
}
- } else
- if (SEQ_GT(tp->snd_nxt + len, tp->snd_max))
+ } else {
+ /*
+ * Persist case, update snd_max but since we are in
+ * persist mode (no window) we do not update snd_nxt.
+ */
+ int xlen = len;
+ if (flags & TH_SYN)
+ ++xlen;
+ if (flags & TH_FIN) {
+ ++xlen;
+ tp->t_flags |= TF_SENTFIN;
+ }
+ if (SEQ_GT(tp->snd_nxt + xlen, tp->snd_max))
tp->snd_max = tp->snd_nxt + len;
+ }
#if TCPDEBUG
/*
* Trace.
*/
- if (so->so_options & SO_DEBUG)
+ if (so_options & SO_DEBUG)
tcp_trace(TA_OUTPUT, tp->t_state, tp, mtod(m, void *), th, 0);
#endif
* to handle ttl and tos; we could keep them in
* the template, but need a way to checksum without them.
*/
+#ifdef INET6
/*
* m->m_pkthdr.len should have been set before cksum calcuration,
* because in6_cksum() need it.
*/
-#if INET6
if (isipv6) {
/*
* we separately set hoplimit for every segment, since the
: NULL);
/* TODO: IPv6 IP6TOS_ECT bit on */
-#if IPSEC
- if (ipsec_bypass == 0 && ipsec_setsocket(m, so) != 0) {
- m_freem(m);
- error = ENOBUFS;
- goto out;
- }
-#endif /*IPSEC*/
- m->m_pkthdr.socket_id = socket_id;
- error = ip6_output(m,
- tp->t_inpcb->in6p_outputopts,
- &tp->t_inpcb->in6p_route,
- (so->so_options & SO_DONTROUTE), NULL, NULL, 0);
+ KERNEL_DEBUG(DBG_LAYER_BEG,
+ ((tp->t_inpcb->inp_fport << 16) | tp->t_inpcb->inp_lport),
+ (((tp->t_inpcb->in6p_laddr.s6_addr16[0] & 0xffff) << 16) |
+ (tp->t_inpcb->in6p_faddr.s6_addr16[0] & 0xffff)),
+ sendalot,0,0);
} else
#endif /* INET6 */
- {
- struct rtentry *rt;
- ip->ip_len = m->m_pkthdr.len;
-#if INET6
- if (isipv6)
- ip->ip_ttl = in6_selecthlim(tp->t_inpcb,
- tp->t_inpcb->in6p_route.ro_rt ?
- tp->t_inpcb->in6p_route.ro_rt->rt_ifp
- : NULL);
- else
-#endif /* INET6 */
- ip->ip_ttl = tp->t_inpcb->inp_ip_ttl; /* XXX */
- ip->ip_tos = tp->t_inpcb->inp_ip_tos; /* XXX */
-
-
-#if INET6
- if (isipv6) {
- KERNEL_DEBUG(DBG_LAYER_BEG,
- ((tp->t_inpcb->inp_fport << 16) | tp->t_inpcb->inp_lport),
- (((tp->t_inpcb->in6p_laddr.s6_addr16[0] & 0xffff) << 16) |
- (tp->t_inpcb->in6p_faddr.s6_addr16[0] & 0xffff)),
- 0,0,0);
- }
- else
-#endif
{
- KERNEL_DEBUG(DBG_LAYER_BEG,
- ((tp->t_inpcb->inp_fport << 16) | tp->t_inpcb->inp_lport),
- (((tp->t_inpcb->inp_laddr.s_addr & 0xffff) << 16) |
- (tp->t_inpcb->inp_faddr.s_addr & 0xffff)),
- 0,0,0);
- }
+ ip->ip_len = m->m_pkthdr.len;
+ ip->ip_ttl = tp->t_inpcb->inp_ip_ttl; /* XXX */
+ ip->ip_tos |= (tp->t_inpcb->inp_ip_tos & ~IPTOS_ECN_MASK);/* XXX */
+ KERNEL_DEBUG(DBG_LAYER_BEG,
+ ((tp->t_inpcb->inp_fport << 16) | tp->t_inpcb->inp_lport),
+ (((tp->t_inpcb->inp_laddr.s_addr & 0xffff) << 16) |
+ (tp->t_inpcb->inp_faddr.s_addr & 0xffff)),
+ 0,0,0);
+ }
/*
- * See if we should do MTU discovery. We do it only if the following
- * are true:
- * 1) we have a valid route to the destination
- * 2) the MTU is not locked (if it is, then discovery has been
- * disabled)
+ * See if we should do MTU discovery.
+ * Look at the flag updated on the following criterias:
+ * 1) Path MTU discovery is authorized by the sysctl
+ * 2) The route isn't set yet (unlikely but could happen)
+ * 3) The route is up
+ * 4) the MTU is not locked (if it is, then discovery has been
+ * disabled for that route)
*/
- if (path_mtu_discovery
- && (rt = tp->t_inpcb->inp_route.ro_rt)
- && rt->rt_flags & RTF_UP
- && !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
- ip->ip_off |= IP_DF;
- }
+#ifdef INET6
+ if (!isipv6)
+#endif
+ if (path_mtu_discovery && (tp->t_flags & TF_PMTUD))
+ ip->ip_off |= IP_DF;
+
#if IPSEC
if (ipsec_bypass == 0)
ipsec_setsocket(m, so);
/*
* The socket is kept locked while sending out packets in ip_output, even if packet chaining is not active.
*/
-
+ lost = 0;
m->m_pkthdr.socket_id = socket_id;
- if (packetlist) {
- m->m_nextpkt = NULL;
- lastpacket->m_nextpkt = m;
- lastpacket = m;
- packchain_listadd++;
+
+ /*
+ * Embed the flow hash in pkt hdr and mark the packet as
+ * capable of flow controlling
+ */
+ m->m_pkthdr.m_flowhash = tp->t_inpcb->inp_flowhash;
+ m->m_pkthdr.m_fhflags |=
+ (PF_TAG_TCP | PF_TAG_FLOWHASH | PF_TAG_FLOWADV);
+
+ m->m_nextpkt = NULL;
+
+ if (tp->t_inpcb->inp_last_outifp != NULL &&
+ tp->t_inpcb->inp_last_outifp != lo_ifp) {
+ /* Hint to prioritize this packet if
+ * 1. if the packet has no data
+ * 2. the interface supports transmit-start model and did
+ * not disable ACK prioritization.
+ * 3. Only ACK flag is set.
+ * 4. there is no outstanding data on this connection.
+ */
+ if (tcp_prioritize_acks != 0 && len == 0 &&
+ (tp->t_inpcb->inp_last_outifp->if_eflags &
+ (IFEF_TXSTART | IFEF_NOACKPRI)) == IFEF_TXSTART &&
+ th->th_flags == TH_ACK && tp->snd_una == tp->snd_max &&
+ tp->t_timer[TCPT_REXMT] == 0) {
+ svc_flags |= PKT_SCF_TCP_ACK;
+ }
+ set_packet_service_class(m, so, MBUF_SC_UNSPEC, svc_flags);
}
- else {
- m->m_nextpkt = NULL;
+
+ tp->t_pktlist_sentlen += len;
+ tp->t_lastchain++;
+
+#ifdef INET6
+ if (isipv6) {
+ DTRACE_TCP5(send, struct mbuf *, m, struct inpcb *, tp->t_inpcb,
+ struct ip6 *, ip6, struct tcpcb *, tp, struct tcphdr *,
+ th);
+ } else
+#endif
+ {
+ DTRACE_TCP5(send, struct mbuf *, m, struct inpcb *, tp->t_inpcb,
+ struct ip *, ip, struct tcpcb *, tp, struct tcphdr *, th);
+ }
+
+ if (tp->t_pktlist_head != NULL) {
+ tp->t_pktlist_tail->m_nextpkt = m;
+ tp->t_pktlist_tail = m;
+ } else {
packchain_newlist++;
- packetlist = lastpacket = m;
- packchain_listadd=0;
+ tp->t_pktlist_head = tp->t_pktlist_tail = m;
}
- if ((ipsec_bypass == 0) || fw_enable || sendalot == 0 || (tp->t_state != TCPS_ESTABLISHED) ||
- (tp->snd_cwnd <= (tp->snd_wnd / 4)) ||
- (tp->t_flags & (TH_PUSH | TF_ACKNOW)) || tp->t_force != 0 ||
- packchain_listadd >= tcp_packet_chaining) {
- lastpacket->m_nextpkt = 0;
- error = ip_output_list(packetlist, packchain_listadd, tp->t_inpcb->inp_options, &tp->t_inpcb->inp_route,
- (so->so_options & SO_DONTROUTE), 0);
- tp->t_lastchain = packchain_listadd;
- packchain_sent++;
- packetlist = NULL;
- if (error == 0)
- howmuchsent = 0;
+ if ((lro_ackmore) && (!sackoptlen) && (!tp->t_timer[TCPT_PERSIST]) &&
+ ((th->th_flags & TH_ACK) == TH_ACK) && (!len) &&
+ (tp->t_state == TCPS_ESTABLISHED)) {
+ /* For a pure ACK, see if you need to send more of them */
+ mnext = tcp_send_lroacks(tp, m, th);
+ if (mnext) {
+ tp->t_pktlist_tail->m_nextpkt = mnext;
+ if (mnext->m_nextpkt == NULL) {
+ tp->t_pktlist_tail = mnext;
+ tp->t_lastchain++;
+ } else {
+ struct mbuf *tail, *next;
+ next = mnext->m_nextpkt;
+ tail = next->m_nextpkt;
+ while (tail) {
+ next = tail;
+ tail = tail->m_nextpkt;
+ tp->t_lastchain++;
+ }
+ tp->t_pktlist_tail = next;
+ }
+ }
}
- else {
+
+ if (sendalot == 0 || (tp->t_state != TCPS_ESTABLISHED) ||
+ (tp->snd_cwnd <= (tp->snd_wnd / 8)) ||
+ (tp->t_flags & (TH_PUSH | TF_ACKNOW)) || tp->t_force != 0 ||
+ tp->t_lastchain >= tcp_packet_chaining) {
+ error = 0;
+ while (tp->t_inpcb->inp_sndinprog_cnt == 0 &&
+ tp->t_pktlist_head != NULL) {
+ packetlist = tp->t_pktlist_head;
+ packchain_listadd = tp->t_lastchain;
+ packchain_sent++;
+ lost = tp->t_pktlist_sentlen;
+ TCP_PKTLIST_CLEAR(tp);
+
+ error = tcp_ip_output(so, tp, packetlist,
+ packchain_listadd, tp_inp_options,
+ (so_options & SO_DONTROUTE),
+ (sack_rxmit | (sack_bytes_rxmt != 0)), recwin,
+#ifdef INET6
+ isipv6);
+#else
+ 0);
+#endif
+
+ if (error) {
+ /*
+ * Take into account the rest of unsent
+ * packets in the packet list for this tcp
+ * into "lost", since we're about to free
+ * the whole list below.
+ */
+ lost += tp->t_pktlist_sentlen;
+ break;
+ } else {
+ lost = 0;
+ }
+ }
+ /* tcp was closed while we were in ip; resume close */
+ if (tp->t_inpcb->inp_sndinprog_cnt == 0 &&
+ (tp->t_flags & TF_CLOSING)) {
+ tp->t_flags &= ~TF_CLOSING;
+ (void) tcp_close(tp);
+ return (0);
+ }
+ } else {
error = 0;
packchain_looped++;
tcpstat.tcps_sndtotal++;
- if (win > 0 && SEQ_GT(tp->rcv_nxt+win, tp->rcv_adv))
- tp->rcv_adv = tp->rcv_nxt + win;
- tp->last_ack_sent = tp->rcv_nxt;
- tp->t_flags &= ~(TF_ACKNOW|TF_DELACK);
+
goto again;
}
- }
if (error) {
-
/*
- * We know that the packet was lost, so back out the
- * sequence number advance, if any.
+ * Assume that the packets were lost, so back out the
+ * sequence number advance, if any. Note that the "lost"
+ * variable represents the amount of user data sent during
+ * the recent call to ip_output_list() plus the amount of
+ * user data in the packet list for this tcp at the moment.
*/
- if (tp->t_force == 0 || !tp->t_timer[TCPT_PERSIST]) {
+ if (tp->t_force == 0 || tp->t_timer[TCPT_PERSIST] == 0) {
/*
* No need to check for TH_FIN here because
* the TF_SENTFIN flag handles that case.
*/
- if ((flags & TH_SYN) == 0)
- tp->snd_nxt -= howmuchsent;
+ if ((flags & TH_SYN) == 0) {
+ if (sack_rxmit) {
+ p->rxmit -= lost;
+ tp->sackhint.sack_bytes_rexmit -= lost;
+ } else
+ tp->snd_nxt -= lost;
+ }
}
- howmuchsent = 0;
out:
+ if (tp->t_pktlist_head != NULL)
+ m_freem_list(tp->t_pktlist_head);
+ TCP_PKTLIST_CLEAR(tp);
+
if (error == ENOBUFS) {
- if (!tp->t_timer[TCPT_REXMT] &&
- !tp->t_timer[TCPT_PERSIST])
- tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
- tcp_quench(tp->t_inpcb, 0);
- if (packetlist)
- m_freem_list(packetlist);
- tp->t_lastchain = 0;
+ if (!tp->t_timer[TCPT_REXMT] &&
+ !tp->t_timer[TCPT_PERSIST])
+ tp->t_timer[TCPT_REXMT] =
+ OFFSET_FROM_START(tp, tp->t_rxtcur);
+
+ tp->snd_cwnd = tp->t_maxseg;
+ tp->t_bytes_acked = 0;
+
+ tcp_check_timer_state(tp);
KERNEL_DEBUG(DBG_FNC_TCP_OUTPUT | DBG_FUNC_END, 0,0,0,0,0);
+
+ DTRACE_TCP5(cc, void, NULL, struct inpcb *, tp->t_inpcb,
+ struct tcpcb *, tp, struct tcphdr *, NULL,
+ int32_t, TCP_CC_OUTPUT_ERROR);
return (0);
}
if (error == EMSGSIZE) {
* for us. tcp_mtudisc() will, as its last action,
* initiate retransmission, so it is important to
* not do so here.
+ *
+ * If TSO was active we either got an interface
+ * without TSO capabilits or TSO was turned off.
+ * Disable it for this connection as too and
+ * immediatly retry with MSS sized segments generated
+ * by this function.
*/
+ if (tso)
+ tp->t_flags &= ~TF_TSO;
+
tcp_mtudisc(tp->t_inpcb, 0);
- if (packetlist)
- m_freem_list(packetlist);
- tp->t_lastchain = 0;
+ tcp_check_timer_state(tp);
+
KERNEL_DEBUG(DBG_FNC_TCP_OUTPUT | DBG_FUNC_END, 0,0,0,0,0);
return 0;
}
if ((error == EHOSTUNREACH || error == ENETDOWN)
&& TCPS_HAVERCVDSYN(tp->t_state)) {
tp->t_softerror = error;
- if (packetlist)
- m_freem_list(packetlist);
- tp->t_lastchain = 0;
+ tcp_check_timer_state(tp);
KERNEL_DEBUG(DBG_FNC_TCP_OUTPUT | DBG_FUNC_END, 0,0,0,0,0);
return (0);
}
- if (packetlist)
- m_freem_list(packetlist);
- tp->t_lastchain = 0;
+ tcp_check_timer_state(tp);
KERNEL_DEBUG(DBG_FNC_TCP_OUTPUT | DBG_FUNC_END, 0,0,0,0,0);
return (error);
}
-sentit:
+
tcpstat.tcps_sndtotal++;
+ KERNEL_DEBUG(DBG_FNC_TCP_OUTPUT | DBG_FUNC_END,0,0,0,0,0);
+ if (sendalot)
+ goto again;
+
+ tcp_check_timer_state(tp);
+ return (0);
+}
+
+static int
+tcp_ip_output(struct socket *so, struct tcpcb *tp, struct mbuf *pkt,
+ int cnt, struct mbuf *opt, int flags, int sack_in_progress, int recwin,
+ boolean_t isipv6)
+{
+ int error = 0;
+ boolean_t chain;
+ boolean_t unlocked = FALSE;
+ struct inpcb *inp = tp->t_inpcb;
+ struct ip_out_args ipoa =
+ { IFSCOPE_NONE, { 0 }, IPOAF_SELECT_SRCIF | IPOAF_BOUND_SRCADDR };
+ struct route ro;
+ struct ifnet *outif = NULL;
+#ifdef INET6
+ struct ip6_out_args ip6oa =
+ { IFSCOPE_NONE, { 0 }, IP6OAF_SELECT_SRCIF | IP6OAF_BOUND_SRCADDR };
+ struct route_in6 ro6;
+ struct flowadv *adv =
+ (isipv6 ? &ip6oa.ip6oa_flowadv : &ipoa.ipoa_flowadv);
+#else
+ struct flowadv *adv = &ipoa.ipoa_flowadv;
+#endif /* !INET6 */
+
+ /* If socket was bound to an ifindex, tell ip_output about it */
+ if (inp->inp_flags & INP_BOUND_IF) {
+#ifdef INET6
+ if (isipv6) {
+ ip6oa.ip6oa_boundif = inp->inp_boundifp->if_index;
+ ip6oa.ip6oa_flags |= IP6OAF_BOUND_IF;
+ } else
+#endif
+ {
+ ipoa.ipoa_boundif = inp->inp_boundifp->if_index;
+ ipoa.ipoa_flags |= IPOAF_BOUND_IF;
+ }
+ }
+
+ if (inp->inp_flags & INP_NO_IFT_CELLULAR) {
+#ifdef INET6
+ if (isipv6)
+ ip6oa.ip6oa_flags |= IP6OAF_NO_CELLULAR;
+ else
+#endif
+ ipoa.ipoa_flags |= IPOAF_NO_CELLULAR;
+ }
+#ifdef INET6
+ if (isipv6)
+ flags |= IPV6_OUTARGS;
+ else
+#endif
+ flags |= IP_OUTARGS;
+
+ /* Copy the cached route and take an extra reference */
+#ifdef INET6
+ if (isipv6)
+ in6p_route_copyout(inp, &ro6);
+ else
+#endif
+ inp_route_copyout(inp, &ro);
+
/*
* Data sent (as far as we can tell).
* If this advertises a larger window than any other segment,
* then remember the size of the advertised window.
- * Any pending ACK has now been sent.
+ * Make sure ACK/DELACK conditions are cleared before
+ * we unlock the socket.
*/
- if (win > 0 && SEQ_GT(tp->rcv_nxt+win, tp->rcv_adv))
- tp->rcv_adv = tp->rcv_nxt + win;
+ if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
+ tp->rcv_adv = tp->rcv_nxt + recwin;
tp->last_ack_sent = tp->rcv_nxt;
- tp->t_flags &= ~(TF_ACKNOW|TF_DELACK);
+ tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
+ tp->t_timer[TCPT_DELACK] = 0;
+ tp->t_unacksegs = 0;
- KERNEL_DEBUG(DBG_FNC_TCP_OUTPUT | DBG_FUNC_END,0,0,0,0,0);
- if (sendalot && (!tcp_do_newreno || --maxburst))
- goto again;
- return (0);
+ /* Increment the count of outstanding send operations */
+ inp->inp_sndinprog_cnt++;
+
+ /*
+ * If allowed, unlock TCP socket while in IP
+ * but only if the connection is established and
+ * in a normal mode where reentrancy on the tcpcb won't be
+ * an issue:
+ * - there is no SACK episode
+ * - we're not in Fast Recovery mode
+ * - if we're not sending from an upcall.
+ */
+ if (tcp_output_unlocked && !so->so_upcallusecount &&
+ (tp->t_state == TCPS_ESTABLISHED) && (sack_in_progress == 0) &&
+ ((tp->t_flags & TF_FASTRECOVERY) == 0)) {
+
+ unlocked = TRUE;
+ socket_unlock(so, 0);
+ }
+
+ /*
+ * Don't send down a chain of packets when:
+ * - TCP chaining is disabled
+ * - there is an IPsec rule set
+ * - there is a non default rule set for the firewall
+ */
+
+ chain = tcp_packet_chaining > 1
+#if IPSEC
+ && ipsec_bypass
+#endif
+#if IPFIREWALL
+ && (fw_enable == 0 || fw_bypass)
+#endif
+ ; // I'm important, not extraneous
+
+
+ while (pkt != NULL) {
+ struct mbuf *npkt = pkt->m_nextpkt;
+
+ if (!chain) {
+ pkt->m_nextpkt = NULL;
+ /*
+ * If we are not chaining, make sure to set the packet
+ * list count to 0 so that IP takes the right path;
+ * this is important for cases such as IPSec where a
+ * single mbuf might result in multiple mbufs as part
+ * of the encapsulation. If a non-zero count is passed
+ * down to IP, the head of the chain might change and
+ * we could end up skipping it (thus generating bogus
+ * packets). Fixing it in IP would be desirable, but
+ * for now this would do it.
+ */
+ cnt = 0;
+ }
+#ifdef INET6
+ if (isipv6)
+ error = ip6_output_list(pkt, cnt,
+ inp->in6p_outputopts, &ro6, flags, NULL, NULL,
+ &ip6oa);
+ else
+#endif
+ error = ip_output_list(pkt, cnt, opt, &ro, flags, NULL,
+ &ipoa);
+
+ if (chain || error) {
+ /*
+ * If we sent down a chain then we are done since
+ * the callee had taken care of everything; else
+ * we need to free the rest of the chain ourselves.
+ */
+ if (!chain)
+ m_freem_list(npkt);
+ break;
+ }
+ pkt = npkt;
+ }
+
+ if (unlocked)
+ socket_lock(so, 0);
+
+ /*
+ * Enter flow controlled state if the connection is established
+ * and is not in recovery.
+ *
+ * A connection will enter suspended state even if it is in
+ * recovery.
+ */
+ if (((adv->code == FADV_FLOW_CONTROLLED && !IN_FASTRECOVERY(tp)) ||
+ adv->code == FADV_SUSPENDED) &&
+ !(tp->t_flags & TF_CLOSING) &&
+ tp->t_state == TCPS_ESTABLISHED) {
+ int rc;
+ rc = inp_set_fc_state(inp, adv->code);
+
+ if (rc == 1)
+ DTRACE_TCP5(cc, void, NULL, struct inpcb *, inp,
+ struct tcpcb *, tp, struct tcphdr *, NULL,
+ int32_t, ((adv->code == FADV_FLOW_CONTROLLED) ?
+ TCP_CC_FLOW_CONTROL : TCP_CC_SUSPEND));
+ }
+
+ /*
+ * When an interface queue gets suspended, some of the
+ * packets are dropped. Return ENOBUFS, to update the
+ * pcb state.
+ */
+ if (adv->code == FADV_SUSPENDED)
+ error = ENOBUFS;
+
+ VERIFY(inp->inp_sndinprog_cnt > 0);
+ if ( --inp->inp_sndinprog_cnt == 0)
+ inp->inp_flags &= ~(INP_FC_FEEDBACK);
+
+#ifdef INET6
+ if (isipv6) {
+ if (ro6.ro_rt != NULL && (outif = ro6.ro_rt->rt_ifp) !=
+ inp->in6p_last_outifp)
+ inp->in6p_last_outifp = outif;
+ } else
+#endif
+ if (ro.ro_rt != NULL && (outif = ro.ro_rt->rt_ifp) !=
+ inp->inp_last_outifp)
+ inp->inp_last_outifp = outif;
+
+ if ((inp->inp_flags & INP_NO_IFT_CELLULAR) && outif != NULL &&
+ outif->if_type == IFT_CELLULAR)
+ soevent(inp->inp_socket,
+ (SO_FILT_HINT_LOCKED|SO_FILT_HINT_IFDENIED));
+
+ /* Synchronize cached PCB route & options */
+#ifdef INET6
+ if (isipv6)
+ in6p_route_copyin(inp, &ro6);
+ else
+#endif
+ inp_route_copyin(inp, &ro);
+
+ if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift == 0 &&
+ tp->t_inpcb->inp_route.ro_rt != NULL) {
+ /* If we found the route and there is an rtt on it
+ * reset the retransmit timer
+ */
+ tcp_getrt_rtt(tp, tp->t_inpcb->in6p_route.ro_rt);
+ tp->t_timer[TCPT_REXMT] = OFFSET_FROM_START(tp, tp->t_rxtcur);
+ }
+ return (error);
}
void
{
int t = ((tp->t_srtt >> 2) + tp->t_rttvar) >> 1;
- if (tp->t_timer[TCPT_REXMT])
- panic("tcp_setpersist: retransmit pending");
+ /* If a PERSIST_TIMER option was set we will limit the
+ * time the persist timer will be active for that connection
+ * in order to avoid DOS by using zero window probes.
+ * see rdar://5805356
+ */
+
+ if ((tp->t_persist_timeout != 0) &&
+ (tp->t_timer[TCPT_PERSIST] == 0) &&
+ (tp->t_persist_stop == 0)) {
+ tp->t_persist_stop = tcp_now + tp->t_persist_timeout;
+ }
+
/*
* Start/restart persistance timer.
*/
TCPT_RANGESET(tp->t_timer[TCPT_PERSIST],
t * tcp_backoff[tp->t_rxtshift],
- TCPTV_PERSMIN, TCPTV_PERSMAX);
+ TCPTV_PERSMIN, TCPTV_PERSMAX, 0);
+ tp->t_timer[TCPT_PERSIST] = OFFSET_FROM_START(tp, tp->t_timer[TCPT_PERSIST]);
+
if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
tp->t_rxtshift++;
}
+
+/*
+ * Send as many acks as data coalesced. Every other packet when stretch
+ * ACK is not enabled. Every 8 packets, if stretch ACK is enabled.
+ */
+static struct mbuf*
+tcp_send_lroacks(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th)
+{
+ struct mbuf *mnext = NULL, *ack_chain = NULL, *tail = NULL;
+ int count = 0;
+ tcp_seq org_ack = ntohl(th->th_ack);
+ tcp_seq prev_ack = 0;
+ int tack_offset = 28; /* XXX IPv6 not supported */
+ int ack_size = (tp->t_flags & TF_STRETCHACK) ?
+ (maxseg_unacked * tp->t_maxseg) : (tp->t_maxseg << 1);
+ int segs_acked = (tp->t_flags & TF_STRETCHACK) ? maxseg_unacked : 2;
+ struct mbuf *prev_ack_pkt = NULL;
+ struct socket *so = tp->t_inpcb->inp_socket;
+
+ count = tp->t_lropktlen/tp->t_maxseg;
+
+ prev_ack = (org_ack - tp->t_lropktlen) + ack_size;
+ if (prev_ack < org_ack) {
+ ack_chain = m_dup(m, M_DONTWAIT);
+ if (ack_chain) {
+ th->th_ack = htonl(prev_ack);
+ tail = ack_chain;
+ count -= segs_acked; /* accounts for prev_ack packet */
+ count = (count <= segs_acked) ? 0 : count - segs_acked;
+ tcpstat.tcps_sndacks++;
+ so_tc_update_stats(m, so, m_get_service_class(m));
+ } else {
+ return NULL;
+ }
+ }
+ else {
+ tp->t_lropktlen = 0;
+ return NULL;
+ }
+
+ prev_ack_pkt = ack_chain;
+
+ while (count > 0) {
+ if ((prev_ack + ack_size) < org_ack) {
+ prev_ack += ack_size;
+ } else {
+ /*
+ * The last ACK sent must have the ACK number that TCP
+ * thinks is the last sent ACK number.
+ */
+ prev_ack = org_ack;
+ }
+ mnext = m_dup(prev_ack_pkt, M_DONTWAIT);
+ if (mnext) {
+ HTONL(prev_ack);
+ bcopy(&prev_ack, mtod(prev_ack_pkt, caddr_t) + tack_offset, 4);
+ NTOHL(prev_ack);
+ tail->m_nextpkt = mnext;
+ tail = mnext;
+ count -= segs_acked;
+ tcpstat.tcps_sndacks++;
+ so_tc_update_stats(m, so, m_get_service_class(m));
+ if (lrodebug == 5) {
+ printf("%s: lropktlen = %d count = %d, th_ack = %x \n",
+ __func__, tp->t_lropktlen, count,
+ th->th_ack);
+ }
+ } else {
+ if (lrodebug == 5) {
+ printf("%s: failed to alloc mbuf.\n", __func__);
+ }
+ break;
+ }
+ prev_ack_pkt = mnext;
+ }
+ tp->t_lropktlen = 0;
+ return ack_chain;
+}
projects / apple / xnu.git / blobdiff