/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2008 Apple Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
- *
- * Copyright (c) 1999-2003 Apple Computer, 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. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * 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
* 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
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/protosw.h>
+#include <sys/domain.h>
+#include <kern/locks.h>
#include <kern/cpu_number.h> /* before tcp_seq.h, for tcp_random18() */
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
+#if INET6
+#include <netinet6/tcp6_var.h>
+#endif
#include <netinet/tcpip.h>
#if TCPDEBUG
#include <netinet/tcp_debug.h>
#endif
#include <sys/kdebug.h>
+extern void postevent(struct socket *, struct sockbuf *,
+ int);
#define DBG_FNC_TCP_FAST NETDBG_CODE(DBG_NETTCP, (5 << 8))
#define DBG_FNC_TCP_SLOW NETDBG_CODE(DBG_NETTCP, (5 << 8) | 1)
+static int background_io_trigger = 5;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, background_io_trigger, CTLFLAG_RW,
+ &background_io_trigger, 0, "Background IO Trigger Setting");
+
/*
* NOTE - WARNING
*
static int
sysctl_msec_to_ticks SYSCTL_HANDLER_ARGS
{
+#pragma unused(arg1, arg2)
int error, s, tt;
tt = *(int *)oidp->oid_arg1;
- s = tt * 1000 / hz;
+ s = tt * 1000 / TCP_RETRANSHZ;;
error = sysctl_handle_int(oidp, &s, 0, req);
if (error || !req->newptr)
return (error);
- tt = s * hz / 1000;
+ tt = s * TCP_RETRANSHZ / 1000;
if (tt < 1)
return (EINVAL);
SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPINTVL, keepintvl, CTLTYPE_INT|CTLFLAG_RW,
&tcp_keepintvl, 0, sysctl_msec_to_ticks, "I", "");
-int tcp_delacktime;
-SYSCTL_PROC(_net_inet_tcp, TCPCTL_DELACKTIME, delacktime,
- CTLTYPE_INT|CTLFLAG_RW, &tcp_delacktime, 0, sysctl_msec_to_ticks, "I",
- "Time before a delayed ACK is sent");
-
int tcp_msl;
SYSCTL_PROC(_net_inet_tcp, OID_AUTO, msl, CTLTYPE_INT|CTLFLAG_RW,
&tcp_msl, 0, sysctl_msec_to_ticks, "I", "Maximum segment lifetime");
SYSCTL_INT(_net_inet_tcp, OID_AUTO, always_keepalive, CTLFLAG_RW,
&always_keepalive , 0, "Assume SO_KEEPALIVE on all TCP connections");
+/*
+ * See tcp_syn_backoff[] for interval values between SYN retransmits;
+ * the value set below defines the number of retransmits, before we
+ * disable the timestamp and window scaling options during subsequent
+ * SYN retransmits. Setting it to 0 disables the dropping off of those
+ * two options.
+ */
+static int tcp_broken_peer_syn_rxmit_thres = 7;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, broken_peer_syn_rxmit_thres, CTLFLAG_RW,
+ &tcp_broken_peer_syn_rxmit_thres, 0, "Number of retransmitted SYNs before "
+ "TCP disables rfc1323 and rfc1644 during the rest of attempts");
+
+int tcp_pmtud_black_hole_detect = 1 ;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, pmtud_blackhole_detection, CTLFLAG_RW,
+ &tcp_pmtud_black_hole_detect, 0, "Path MTU Discovery Black Hole Detection");
+
+int tcp_pmtud_black_hole_mss = 1200 ;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, pmtud_blackhole_mss, CTLFLAG_RW,
+ &tcp_pmtud_black_hole_mss, 0, "Path MTU Discovery Black Hole Detection lowered MSS");
+
static int tcp_keepcnt = TCPTV_KEEPCNT;
+static int tcp_gc_done = FALSE; /* perfromed garbage collection of "used" sockets */
/* max idle probes */
int tcp_maxpersistidle;
/* max idle time in persist */
struct inpcbhead time_wait_slots[N_TIME_WAIT_SLOTS];
int cur_tw_slot = 0;
-u_long *delack_bitmask;
+u_int32_t *delack_bitmask;
+void add_to_time_wait_locked(struct tcpcb *tp);
+void add_to_time_wait(struct tcpcb *tp) ;
-void add_to_time_wait(tp)
- struct tcpcb *tp;
+static void tcp_garbage_collect(struct inpcb *, int);
+
+void add_to_time_wait_locked(struct tcpcb *tp)
{
int tw_slot;
+ struct inpcbinfo *pcbinfo = &tcbinfo;
+
+ /* pcb list should be locked when we get here */
+ lck_rw_assert(pcbinfo->mtx, LCK_RW_ASSERT_EXCLUSIVE);
LIST_REMOVE(tp->t_inpcb, inp_list);
- if (tp->t_timer[TCPT_2MSL] == 0)
+ if (tp->t_timer[TCPT_2MSL] <= 0)
tp->t_timer[TCPT_2MSL] = 1;
- tp->t_rcvtime += tp->t_timer[TCPT_2MSL] & (N_TIME_WAIT_SLOTS - 1);
+ /*
+ * Because we're pulling this pcb out of the main TCP pcb list,
+ * we need to recalculate the TCPT_2MSL timer value for tcp_slowtimo
+ * higher timer granularity.
+ */
+
+ tp->t_timer[TCPT_2MSL] = (tp->t_timer[TCPT_2MSL] / TCP_RETRANSHZ) * PR_SLOWHZ;
+ tp->t_rcvtime = (tp->t_rcvtime / TCP_RETRANSHZ) * PR_SLOWHZ;
+
+ tp->t_rcvtime += tp->t_timer[TCPT_2MSL] & (N_TIME_WAIT_SLOTS - 1);
+
tw_slot = (tp->t_timer[TCPT_2MSL] & (N_TIME_WAIT_SLOTS - 1)) + cur_tw_slot;
if (tw_slot >= N_TIME_WAIT_SLOTS)
tw_slot -= N_TIME_WAIT_SLOTS;
LIST_INSERT_HEAD(&time_wait_slots[tw_slot], tp->t_inpcb, inp_list);
}
+void add_to_time_wait(struct tcpcb *tp)
+{
+ struct inpcbinfo *pcbinfo = &tcbinfo;
+
+ if (!lck_rw_try_lock_exclusive(pcbinfo->mtx)) {
+ tcp_unlock(tp->t_inpcb->inp_socket, 0, 0);
+ lck_rw_lock_exclusive(pcbinfo->mtx);
+ tcp_lock(tp->t_inpcb->inp_socket, 0, 0);
+ }
+ add_to_time_wait_locked(tp);
+ lck_rw_done(pcbinfo->mtx);
+}
* Fast timeout routine for processing delayed acks
*/
void
-tcp_fasttimo()
+tcp_fasttimo(void *arg)
{
- register struct inpcb *inp;
+#pragma unused(arg)
+ struct inpcb *inp;
register struct tcpcb *tp;
+ struct socket *so;
+#if TCPDEBUG
+ int ostate;
+#endif
- register u_long i,j;
- register u_long temp_mask;
- register u_long elem_base = 0;
- struct inpcbhead *head;
- int s = splnet();
+ struct inpcbinfo *pcbinfo = &tcbinfo;
- static
- int delack_checked = 0;
+ int delack_done = 0;
KERNEL_DEBUG(DBG_FNC_TCP_FAST | DBG_FUNC_START, 0,0,0,0,0);
- if (!tcp_delack_enabled)
- return;
-
- for (i=0; i < (tcbinfo.hashsize / 32); i++) {
- if (delack_bitmask[i]) {
- temp_mask = 1;
- for (j=0; j < 32; j++) {
- if (temp_mask & delack_bitmask[i]) {
- head = &tcbinfo.hashbase[elem_base + j];
- for (inp=head->lh_first; inp != 0; inp = inp->inp_hash.le_next) {
- delack_checked++;
- if ((tp = (struct tcpcb *)inp->inp_ppcb) && (tp->t_flags & TF_DELACK)) {
- tp->t_flags &= ~TF_DELACK;
- tp->t_flags |= TF_ACKNOW;
- tcpstat.tcps_delack++;
- (void) tcp_output(tp);
- }
- }
- }
- temp_mask <<= 1;
- }
- delack_bitmask[i] = 0;
- }
- elem_base += 32;
+
+ lck_rw_lock_shared(pcbinfo->mtx);
+
+ /* Walk the list of valid tcpcbs and send ACKS on the ones with DELACK bit set */
+
+ LIST_FOREACH(inp, &tcb, inp_list) {
+
+ so = inp->inp_socket;
+
+ if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) == WNT_STOPUSING)
+ continue;
+
+ tcp_lock(so, 1, 0);
+
+ if ((in_pcb_checkstate(inp, WNT_RELEASE,1) == WNT_STOPUSING) && so->so_usecount == 1) {
+ tcp_unlock(so, 1, 0);
+ continue;
+ }
+
+ tp = intotcpcb(inp);
+
+ if (tp == 0 || tp->t_state == TCPS_LISTEN) {
+ tcp_unlock(so, 1, 0);
+ continue;
+ }
+
+
+ /* Only run the retransmit timer in that case */
+ if (tp->t_timer[0] && --tp->t_timer[0] == 0) {
+ tp = tcp_timers(tp, 0);
+ if (tp == NULL)
+ goto tpgone;
+ }
+
+ /* TCP pcb timers following the tcp_now clock rate */
+
+ tp->t_rcvtime++;
+ tp->t_starttime++;
+ if (tp->t_rtttime)
+ tp->t_rtttime++;
+
+ /*
+ * Process delayed acks (if enabled) according to PR_FASTHZ, not the retrans timer
+ */
+
+ if (tcp_delack_enabled && (tcp_now % (TCP_RETRANSHZ/PR_FASTHZ)) && tp->t_flags & TF_DELACK) {
+ delack_done++;
+ tp->t_flags &= ~TF_DELACK;
+ tp->t_flags |= TF_ACKNOW;
+ tcpstat.tcps_delack++;
+ tp->t_unacksegs = 0;
+ (void) tcp_output(tp);
+ }
+tpgone:
+ tcp_unlock(so, 1, 0);
}
- KERNEL_DEBUG(DBG_FNC_TCP_FAST | DBG_FUNC_END, delack_checked,tcpstat.tcps_delack,0,0,0);
- splx(s);
+ KERNEL_DEBUG(DBG_FNC_TCP_FAST | DBG_FUNC_END, delack_done, 0, tcpstat.tcps_delack,0,0);
+ lck_rw_done(pcbinfo->mtx);
+ tcp_now++;
+ timeout(tcp_fasttimo, 0, hz/TCP_RETRANSHZ);
}
-/*
- * Tcp protocol timeout routine called every 500 ms.
- * Updates the timers in all active tcb's and
- * causes finite state machine actions if timers expire.
- */
+static void
+tcp_garbage_collect(struct inpcb *inp, int istimewait)
+{
+ struct socket *so;
+ struct tcpcb *tp;
+
+ so = inp->inp_socket;
+ tp = intotcpcb(inp);
+
+ /*
+ * Skip if still in use or busy; it would have been more efficient
+ * if we were to test so_usecount against 0, but this isn't possible
+ * due to the current implementation of tcp_dropdropablreq() where
+ * overflow sockets that are eligible for garbage collection have
+ * their usecounts set to 1.
+ */
+ if (so->so_usecount > 1 || !lck_mtx_try_lock_spin(inp->inpcb_mtx))
+ return;
+
+ /* Check again under the lock */
+ if (so->so_usecount > 1) {
+ lck_mtx_unlock(inp->inpcb_mtx);
+ return;
+ }
+
+ /*
+ * Overflowed socket dropped from the listening queue? Do this
+ * only if we are called to clean up the time wait slots, since
+ * tcp_dropdropablreq() considers a socket to have been fully
+ * dropped after add_to_time_wait() is finished.
+ * Also handle the case of connections getting closed by the peer while in the queue as
+ * seen with rdar://6422317
+ *
+ */
+ if (so->so_usecount == 1 &&
+ ((istimewait && (so->so_flags & SOF_OVERFLOW)) ||
+ ((tp != NULL) && (tp->t_state == TCPS_CLOSED) && (so->so_head != NULL)
+ && ((so->so_state & (SS_INCOMP|SS_CANTSENDMORE|SS_CANTRCVMORE)) ==
+ (SS_INCOMP|SS_CANTSENDMORE|SS_CANTRCVMORE))))) {
+
+ if (inp->inp_state != INPCB_STATE_DEAD) {
+ /* Become a regular mutex */
+ lck_mtx_convert_spin(inp->inpcb_mtx);
+#if INET6
+ if (INP_CHECK_SOCKAF(so, AF_INET6))
+ in6_pcbdetach(inp);
+ else
+#endif /* INET6 */
+ in_pcbdetach(inp);
+ }
+ so->so_usecount--;
+ lck_mtx_unlock(inp->inpcb_mtx);
+ return;
+ } else if (inp->inp_wantcnt != WNT_STOPUSING) {
+ lck_mtx_unlock(inp->inpcb_mtx);
+ return;
+ }
+
+ /*
+ * We get here because the PCB is no longer searchable (WNT_STOPUSING);
+ * detach (if needed) and dispose if it is dead (usecount is 0). This
+ * covers all cases, including overflow sockets and those that are
+ * considered as "embryonic", i.e. created by sonewconn() in TCP input
+ * path, and have not yet been committed. For the former, we reduce
+ * the usecount to 0 as done by the code above. For the latter, the
+ * usecount would have reduced to 0 as part calling soabort() when the
+ * socket is dropped at the end of tcp_input().
+ */
+ if (so->so_usecount == 0) {
+ /* Become a regular mutex */
+ lck_mtx_convert_spin(inp->inpcb_mtx);
+ if (inp->inp_state != INPCB_STATE_DEAD) {
+#if INET6
+ if (INP_CHECK_SOCKAF(so, AF_INET6))
+ in6_pcbdetach(inp);
+ else
+#endif /* INET6 */
+ in_pcbdetach(inp);
+ }
+ in_pcbdispose(inp);
+ } else {
+ lck_mtx_unlock(inp->inpcb_mtx);
+ }
+}
+
+static int bg_cnt = 0;
+#define BG_COUNTER_MAX 3
+
void
-tcp_slowtimo()
+tcp_slowtimo(void)
{
- register struct inpcb *ip, *ipnxt;
- register struct tcpcb *tp;
- register int i;
- int s;
+ struct inpcb *inp, *nxt;
+ struct tcpcb *tp;
+ struct socket *so;
+ int i;
#if TCPDEBUG
int ostate;
#endif
-#if KDEBUG
- static int tws_checked;
+
+#if KDEBUG
+ static int tws_checked = 0;
#endif
+ struct inpcbinfo *pcbinfo = &tcbinfo;
+
KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_START, 0,0,0,0,0);
- s = splnet();
tcp_maxidle = tcp_keepcnt * tcp_keepintvl;
- ip = tcb.lh_first;
- if (ip == NULL) {
- splx(s);
- return;
- }
- /*
- * Search through tcb's and update active timers.
- */
- for (; ip != NULL; ip = ipnxt) {
- ipnxt = ip->inp_list.le_next;
- tp = intotcpcb(ip);
- if (tp == 0 || tp->t_state == TCPS_LISTEN)
+ lck_rw_lock_shared(pcbinfo->mtx);
+
+ bg_cnt++;
+
+ LIST_FOREACH(inp, &tcb, inp_list) {
+
+ so = inp->inp_socket;
+
+ if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) == WNT_STOPUSING)
continue;
- /*
- * Bogus state when port owned by SharedIP with loopback as the
- * only configured interface: BlueBox does not filters loopback
- */
- if (tp->t_state == TCP_NSTATES)
- continue;
- for (i = 0; i < TCPT_NTIMERS; i++) {
- if (tp->t_timer[i] && --tp->t_timer[i] == 0) {
+ tcp_lock(so, 1, 0);
+
+ if ((in_pcb_checkstate(inp, WNT_RELEASE,1) == WNT_STOPUSING) && so->so_usecount == 1) {
+ tcp_unlock(so, 1, 0);
+ continue;
+ }
+ tp = intotcpcb(inp);
+ if (tp == 0 || tp->t_state == TCPS_LISTEN) {
+ tcp_unlock(so, 1, 0);
+ continue;
+ }
+
+ tp = intotcpcb(inp);
+
+ if (tp == 0 || tp->t_state == TCPS_LISTEN)
+ goto tpgone;
+
+#if TRAFFIC_MGT
+ if (so->so_traffic_mgt_flags & TRAFFIC_MGT_SO_BACKGROUND &&
+ bg_cnt > BG_COUNTER_MAX) {
+ u_int32_t curr_recvtotal = tcpstat.tcps_rcvtotal;
+ u_int32_t curr_bg_recvtotal = tcpstat.tcps_bg_rcvtotal;
+ u_int32_t bg_recvdiff = curr_bg_recvtotal - tp->bg_recv_snapshot;
+ u_int32_t tot_recvdiff = curr_recvtotal - tp->tot_recv_snapshot;
+ u_int32_t fg_recv_change = tot_recvdiff - bg_recvdiff;
+ u_int32_t recv_change;
+
+ if (!(so->so_traffic_mgt_flags & TRAFFIC_MGT_SO_BG_SUPPRESSED)) {
+ if (tot_recvdiff)
+ recv_change = (fg_recv_change * 100) / tot_recvdiff;
+ else
+ recv_change = 0;
+
+ if (recv_change > background_io_trigger) {
+ so->so_traffic_mgt_flags |= TRAFFIC_MGT_SO_BG_SUPPRESSED;
+ }
+
+ tp->tot_recv_snapshot = curr_recvtotal;
+ tp->bg_recv_snapshot = curr_bg_recvtotal;
+ }
+ else { // SUPPRESSED
+ // this allows for bg traffic to subside before we start measuring total traffic change
+ if (tot_recvdiff)
+ recv_change = (bg_recvdiff * 100) / tot_recvdiff;
+ else
+ recv_change = 0;
+
+ if (recv_change < background_io_trigger) {
+ // Draconian for now: if there is any change at all, keep suppressed
+ if (!tot_recvdiff) {
+ so->so_traffic_mgt_flags &= ~TRAFFIC_MGT_SO_BG_SUPPRESSED;
+ tp->t_unacksegs = 0;
+ (void) tcp_output(tp); // open window
+ }
+ }
+
+ tp->tot_recv_snapshot = curr_recvtotal;
+ tp->bg_recv_snapshot = curr_bg_recvtotal;
+ }
+ }
+#endif /* TRAFFIC_MGT */
+
+ for (i = 1; i < TCPT_NTIMERS; i++) {
+ if (tp->t_timer[i] != 0) {
+ tp->t_timer[i] -= TCP_RETRANSHZ/PR_SLOWHZ;
+ if (tp->t_timer[i] <= 0) {
#if TCPDEBUG
- ostate = tp->t_state;
+ ostate = tp->t_state;
#endif
- tp = tcp_timers(tp, i);
- if (tp == NULL)
- goto tpgone;
+
+ tp->t_timer[i] = 0; /* account for granularity change between tcp_now and slowtimo */
+ tp = tcp_timers(tp, i);
+ if (tp == NULL)
+ goto tpgone;
#if TCPDEBUG
- if (tp->t_inpcb->inp_socket->so_options
- & SO_DEBUG)
- tcp_trace(TA_USER, ostate, tp,
- (void *)0,
- (struct tcphdr *)0,
- PRU_SLOWTIMO);
+ if (tp->t_inpcb->inp_socket->so_options
+ & SO_DEBUG)
+ tcp_trace(TA_USER, ostate, tp,
+ (void *)0,
+ (struct tcphdr *)0,
+ PRU_SLOWTIMO);
#endif
+ }
}
}
- tp->t_rcvtime++;
- tp->t_starttime++;
- if (tp->t_rtttime)
- tp->t_rtttime++;
tpgone:
- ;
+ tcp_unlock(so, 1, 0);
}
+
+ if (bg_cnt > 3)
+ bg_cnt = 0;
-#if KDEBUG
- tws_checked = 0;
-#endif
- KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_NONE, tws_checked,0,0,0,0);
+ /* Second part of tcp_slowtimo: garbage collect socket/tcpcb
+ * We need to acquire the list lock exclusively to do this
+ */
+
+ if (lck_rw_lock_shared_to_exclusive(pcbinfo->mtx) == FALSE) {
+ if (tcp_gc_done == TRUE) { /* don't sweat it this time. cleanup was done last time */
+ tcp_gc_done = FALSE;
+ KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_END, tws_checked, cur_tw_slot,0,0,0);
+ return; /* Upgrade failed and lost lock - give up this time. */
+ }
+ lck_rw_lock_exclusive(pcbinfo->mtx); /* Upgrade failed, lost lock now take it again exclusive */
+ }
+ tcp_gc_done = TRUE;
/*
* Process the items in the current time-wait slot
*/
+#if KDEBUG
+ tws_checked = 0;
+#endif
+ KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_NONE, tws_checked,0,0,0,0);
- for (ip = time_wait_slots[cur_tw_slot].lh_first; ip; ip = ipnxt)
- {
+ LIST_FOREACH(inp, &time_wait_slots[cur_tw_slot], inp_list) {
#if KDEBUG
tws_checked++;
#endif
- ipnxt = ip->inp_list.le_next;
- tp = intotcpcb(ip);
- if (tp == NULL) { /* tp already closed, remove from list */
- LIST_REMOVE(ip, inp_list);
- continue;
- }
+
+ if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) == WNT_STOPUSING)
+ continue;
+
+ tcp_lock(inp->inp_socket, 1, 0);
+
+ if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING)
+ goto twunlock;
+
+ tp = intotcpcb(inp);
+ if (tp == NULL) /* tp already closed, remove from list */
+ goto twunlock;
+
if (tp->t_timer[TCPT_2MSL] >= N_TIME_WAIT_SLOTS) {
tp->t_timer[TCPT_2MSL] -= N_TIME_WAIT_SLOTS;
tp->t_rcvtime += N_TIME_WAIT_SLOTS;
else
tp->t_timer[TCPT_2MSL] = 0;
- if (tp->t_timer[TCPT_2MSL] == 0)
- tp = tcp_timers(tp, TCPT_2MSL);
+ if (tp->t_timer[TCPT_2MSL] == 0) {
+
+ /* That pcb is ready for a close */
+ tcp_free_sackholes(tp);
+ tp = tcp_close(tp);
+ }
+twunlock:
+ tcp_unlock(inp->inp_socket, 1, 0);
+ }
+
+
+ LIST_FOREACH_SAFE(inp, &tcb, inp_list, nxt) {
+ tcp_garbage_collect(inp, 0);
+ }
+
+ /* Now cleanup the time wait ones */
+ LIST_FOREACH_SAFE(inp, &time_wait_slots[cur_tw_slot], inp_list, nxt) {
+ tcp_garbage_collect(inp, 1);
}
if (++cur_tw_slot >= N_TIME_WAIT_SLOTS)
cur_tw_slot = 0;
- tcp_now++; /* for timestamps */
- splx(s);
+
+ lck_rw_done(pcbinfo->mtx);
KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_END, tws_checked, cur_tw_slot,0,0,0);
}
register int rexmt;
struct socket *so_tmp;
struct tcptemp *t_template;
+ int optlen = 0;
#if TCPDEBUG
int ostate;
int isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV4) == 0;
#endif /* INET6 */
+ so_tmp = tp->t_inpcb->inp_socket;
switch (timer) {
/*
* 2 MSL timeout in shutdown went off. If we're closed but
* still waiting for peer to close and connection has been idle
- * too long, or if 2MSL time is up from TIME_WAIT, delete connection
- * control block. Otherwise, check again in a bit.
+ * too long, or if 2MSL time is up from TIME_WAIT or FIN_WAIT_2,
+ * delete connection control block.
+ * Otherwise, (this case shouldn't happen) check again in a bit
+ * we keep the socket in the main list in that case.
*/
case TCPT_2MSL:
+ tcp_free_sackholes(tp);
if (tp->t_state != TCPS_TIME_WAIT &&
- tp->t_rcvtime <= tcp_maxidle) {
- tp->t_timer[TCPT_2MSL] = tcp_keepintvl;
- add_to_time_wait(tp);
+ tp->t_state != TCPS_FIN_WAIT_2 &&
+ tp->t_rcvtime < tcp_maxidle) {
+ tp->t_timer[TCPT_2MSL] = (u_int32_t)tcp_keepintvl;
}
- else
+ else {
tp = tcp_close(tp);
+ return(tp);
+ }
break;
/*
* to a longer retransmit interval and retransmit one segment.
*/
case TCPT_REXMT:
+ tcp_free_sackholes(tp);
if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) {
tp->t_rxtshift = TCP_MAXRXTSHIFT;
tcpstat.tcps_timeoutdrop++;
- so_tmp = tp->t_inpcb->inp_socket;
tp = tcp_drop(tp, tp->t_softerror ?
tp->t_softerror : ETIMEDOUT);
postevent(so_tmp, 0, EV_TIMEOUT);
*/
tp->snd_cwnd_prev = tp->snd_cwnd;
tp->snd_ssthresh_prev = tp->snd_ssthresh;
- tp->t_badrxtwin = tcp_now + (tp->t_srtt >> (TCP_RTT_SHIFT + 1));
+ tp->snd_recover_prev = tp->snd_recover;
+ if (IN_FASTRECOVERY(tp))
+ tp->t_flags |= TF_WASFRECOVERY;
+ else
+ tp->t_flags &= ~TF_WASFRECOVERY;
+ tp->t_badrxtwin = tcp_now + (tp->t_srtt >> (TCP_RTT_SHIFT));
}
tcpstat.tcps_rexmttimeo++;
if (tp->t_state == TCPS_SYN_SENT)
tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
/*
- * Disable rfc1323 and rfc1644 if we havn't got any response to
- * our third SYN to work-around some broken terminal servers
- * (most of which have hopefully been retired) that have bad VJ
- * header compression code which trashes TCP segments containing
- * unknown-to-them TCP options.
+ * Check for potential Path MTU Discovery Black Hole
*/
- if ((tp->t_state == TCPS_SYN_SENT) && (tp->t_rxtshift == 3))
- tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_REQ_CC);
+
+ if (tcp_pmtud_black_hole_detect && (tp->t_state == TCPS_ESTABLISHED)) {
+ if (((tp->t_flags & (TF_PMTUD|TF_MAXSEGSNT)) == (TF_PMTUD|TF_MAXSEGSNT)) && (tp->t_rxtshift == 2)) {
+ /*
+ * Enter Path MTU Black-hole Detection mechanism:
+ * - Disable Path MTU Discovery (IP "DF" bit).
+ * - Reduce MTU to lower value than what we negociated with peer.
+ */
+
+ tp->t_flags &= ~TF_PMTUD; /* Disable Path MTU Discovery for now */
+ tp->t_flags |= TF_BLACKHOLE; /* Record that we may have found a black hole */
+ optlen = tp->t_maxopd - tp->t_maxseg;
+ tp->t_pmtud_saved_maxopd = tp->t_maxopd; /* Keep track of previous MSS */
+ if (tp->t_maxopd > tcp_pmtud_black_hole_mss)
+ tp->t_maxopd = tcp_pmtud_black_hole_mss; /* Reduce the MSS to intermediary value */
+ else {
+ tp->t_maxopd = /* use the default MSS */
+#if INET6
+ isipv6 ? tcp_v6mssdflt :
+#endif /* INET6 */
+ tcp_mssdflt;
+ }
+ tp->t_maxseg = tp->t_maxopd - optlen;
+ }
+ /*
+ * If further retransmissions are still unsuccessful with a lowered MTU,
+ * maybe this isn't a Black Hole and we restore the previous MSS and
+ * blackhole detection flags.
+ */
+ else {
+
+ if ((tp->t_flags & TF_BLACKHOLE) && (tp->t_rxtshift > 4)) {
+ tp->t_flags |= TF_PMTUD;
+ tp->t_flags &= ~TF_BLACKHOLE;
+ optlen = tp->t_maxopd - tp->t_maxseg;
+ tp->t_maxopd = tp->t_pmtud_saved_maxopd;
+ tp->t_maxseg = tp->t_maxopd - optlen;
+ }
+ }
+ }
+
+
+ /*
+ * Disable rfc1323 and rfc1644 if we haven't got any response to
+ * our SYN (after we reach the threshold) to work-around some
+ * broken terminal servers (most of which have hopefully been
+ * retired) that have bad VJ header compression code which
+ * trashes TCP segments containing unknown-to-them TCP options.
+ */
+ if ((tp->t_state == TCPS_SYN_SENT) &&
+ (tp->t_rxtshift == tcp_broken_peer_syn_rxmit_thres))
+ tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_REQ_CC);
/*
* If losing, let the lower level know and try for
* a better route. Also, if we backed off this far,
* growth is 2 mss. We don't allow the threshhold
* to go below this.)
*/
- {
- u_int win = min(tp->snd_wnd, tp->snd_cwnd) / 2 / tp->t_maxseg;
- if (win < 2)
- win = 2;
- tp->snd_cwnd = tp->t_maxseg;
- tp->snd_ssthresh = win * tp->t_maxseg;
- tp->t_dupacks = 0;
+ if (tp->t_state >= TCPS_ESTABLISHED) {
+ u_int win = min(tp->snd_wnd, tp->snd_cwnd) / 2 / tp->t_maxseg;
+ if (win < 2)
+ win = 2;
+ tp->snd_cwnd = tp->t_maxseg;
+ tp->snd_ssthresh = win * tp->t_maxseg;
+ tp->t_bytes_acked = 0;
+ tp->t_dupacks = 0;
+ tp->t_unacksegs = 0;
}
+ EXIT_FASTRECOVERY(tp);
(void) tcp_output(tp);
break;
}
tcp_setpersist(tp);
tp->t_force = 1;
+ tp->t_unacksegs = 0;
(void) tcp_output(tp);
tp->t_force = 0;
break;
goto dropit;
if ((always_keepalive ||
tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) &&
- tp->t_state <= TCPS_CLOSING) {
- if (tp->t_rcvtime >= TCP_KEEPIDLE(tp) + tcp_maxidle)
+ (tp->t_state <= TCPS_CLOSING || tp->t_state == TCPS_FIN_WAIT_2)) {
+ if (tp->t_rcvtime >= TCP_KEEPIDLE(tp) + (u_int32_t)tcp_maxidle)
goto dropit;
/*
* Send a packet designed to force a response
tcpstat.tcps_keepprobe++;
t_template = tcp_maketemplate(tp);
if (t_template) {
+ unsigned int ifscope;
+
+ if (tp->t_inpcb->inp_flags & INP_BOUND_IF)
+ ifscope = tp->t_inpcb->inp_boundif;
+ else
+ ifscope = IFSCOPE_NONE;
+
tcp_respond(tp, t_template->tt_ipgen,
&t_template->tt_t, (struct mbuf *)NULL,
- tp->rcv_nxt, tp->snd_una - 1, 0);
+ tp->rcv_nxt, tp->snd_una - 1, 0, ifscope);
(void) m_free(dtom(t_template));
}
tp->t_timer[TCPT_KEEP] = tcp_keepintvl;
#endif
dropit:
tcpstat.tcps_keepdrops++;
- so_tmp = tp->t_inpcb->inp_socket;
tp = tcp_drop(tp, ETIMEDOUT);
postevent(so_tmp, 0, EV_TIMEOUT);
break;
projects / apple / xnu.git / blobdiff