/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2007 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_subr.c 8.2 (Berkeley) 5/24/95
* $FreeBSD: src/sys/netinet/tcp_subr.c,v 1.73.2.22 2001/08/22 00:59:12 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.
+ */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
-#if INET6
#include <sys/domain.h>
-#endif
#include <sys/proc.h>
#include <sys/kauth.h>
#include <sys/socket.h>
#include <sys/random.h>
#include <sys/syslog.h>
#include <kern/locks.h>
-
-
+#include <kern/zalloc.h>
#include <net/route.h>
#include <net/if.h>
#endif
#endif /*IPSEC*/
-#include <sys/md5.h>
+#if CONFIG_MACF_NET
+#include <security/mac_framework.h>
+#endif /* MAC_NET */
+
+#include <libkern/crypto/md5.h>
#include <sys/kdebug.h>
#define DBG_FNC_TCP_CLOSE NETDBG_CODE(DBG_NETTCP, ((5 << 8) | 2))
/* temporary: for testing */
#if IPSEC
extern int ipsec_bypass;
-extern lck_mtx_t *sadb_mutex;
#endif
int tcp_mssdflt = TCP_MSS;
static int tcp_isn_reseed_interval = 0;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
&tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret");
+static int tcp_background_io_enabled = 1;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, background_io_enabled, CTLFLAG_RW,
+ &tcp_background_io_enabled, 0, "Background IO Enabled");
+
+int tcp_TCPTV_MIN = 1;
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, rtt_min, CTLFLAG_RW,
+ &tcp_TCPTV_MIN, 0, "min rtt value allowed");
static void tcp_cleartaocache(void);
static void tcp_notify(struct inpcb *, int);
struct zone *sack_hole_zone;
+extern unsigned int total_mb_cnt;
+extern unsigned int total_cl_cnt;
+extern int sbspace_factor;
+extern int tcp_sockthreshold;
+extern int slowlink_wsize; /* window correction for slow links */
+extern int path_mtu_discovery;
+
+
/*
* Target size of TCP PCB hash tables. Must be a power of two.
*
* variable net.inet.tcp.tcbhashsize
*/
#ifndef TCBHASHSIZE
-#define TCBHASHSIZE 4096
+#define TCBHASHSIZE CONFIG_TCBHASHSIZE
#endif
/*
extern u_long *delack_bitmask;
extern u_long route_generation;
+int get_inpcb_str_size(void);
+int get_tcp_str_size(void);
-int get_inpcb_str_size()
+
+int get_inpcb_str_size(void)
{
return sizeof(struct inpcb);
}
-int get_tcp_str_size()
+int get_tcp_str_size(void)
{
return sizeof(struct tcpcb);
}
tcp_ccgen = 1;
tcp_cleartaocache();
- tcp_delacktime = TCPTV_DELACK;
tcp_keepinit = TCPTV_KEEP_INIT;
tcp_keepidle = TCPTV_KEEP_IDLE;
tcp_keepintvl = TCPTV_KEEPINTVL;
tcp_maxpersistidle = TCPTV_KEEP_IDLE;
tcp_msl = TCPTV_MSL;
read_random(&tcp_now, sizeof(tcp_now));
- tcp_now = tcp_now & 0x7fffffff; /* Starts tcp internal 500ms clock at a random value */
+ tcp_now = tcp_now & 0x3fffffff; /* Starts tcp internal 100ms clock at a random value */
LIST_INIT(&tcb);
for (i=0; i < N_TIME_WAIT_SLOTS; i++) {
LIST_INIT(&time_wait_slots[i]);
}
+
+ timeout(tcp_fasttimo, NULL, hz/TCP_RETRANSHZ);
}
/*
* NOTE: If m != NULL, then ti must point to *inside* the mbuf.
*/
void
-tcp_respond(tp, ipgen, th, m, ack, seq, flags)
- struct tcpcb *tp;
- void *ipgen;
- register struct tcphdr *th;
- register struct mbuf *m;
- tcp_seq ack, seq;
- int flags;
+tcp_respond(
+ struct tcpcb *tp,
+ void *ipgen,
+ register struct tcphdr *th,
+ register struct mbuf *m,
+ tcp_seq ack,
+ tcp_seq seq,
+ int flags,
+#if CONFIG_FORCE_OUT_IFP
+ ifnet_t ifp
+#else
+ __unused ifnet_t ifp
+#endif
+ )
{
register int tlen;
int win = 0;
if (tp) {
if (!(flags & TH_RST)) {
- win = sbspace(&tp->t_inpcb->inp_socket->so_rcv);
+ win = tcp_sbspace(tp);
if (win > (long)TCP_MAXWIN << tp->rcv_scale)
win = (long)TCP_MAXWIN << tp->rcv_scale;
}
}
}
if (m == 0) {
- m = m_gethdr(M_DONTWAIT, MT_HEADER);
+ m = m_gethdr(M_DONTWAIT, MT_HEADER); /* MAC-OK */
if (m == NULL)
return;
tlen = 0;
m->m_len = tlen;
m->m_pkthdr.len = tlen;
m->m_pkthdr.rcvif = 0;
+#if CONFIG_MACF_NET
+ if (tp != NULL && tp->t_inpcb != NULL) {
+ /*
+ * Packet is associated with a socket, so allow the
+ * label of the response to reflect the socket label.
+ */
+ mac_mbuf_label_associate_inpcb(tp->t_inpcb, m);
+ } else {
+ /*
+ * Packet is not associated with a socket, so possibly
+ * update the label in place.
+ */
+ mac_netinet_tcp_reply(m);
+ }
+#endif
nth->th_seq = htonl(seq);
nth->th_ack = htonl(ack);
nth->th_x2 = 0;
} else
#endif /* INET6 */
{
- (void) ip_output_list(m, 0, NULL, ro, ipflags, NULL);
+#if CONFIG_FORCE_OUT_IFP
+ ifp = (tp && tp->t_inpcb) ? tp->t_inpcb->pdp_ifp :
+ (ifp && (ifp->if_flags & IFF_POINTOPOINT) != 0) ? ifp : NULL;
+#endif
+ (void) ip_output_list(m, 0, NULL, ro, ipflags, NULL, ifp);
if (ro == &sro && ro->ro_rt) {
rtfree(ro->ro_rt);
ro->ro_rt = NULL;
*/
tp->t_srtt = TCPTV_SRTTBASE;
tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
- tp->t_rttmin = TCPTV_MIN;
+ tp->t_rttmin = tcp_TCPTV_MIN;
tp->t_rxtcur = TCPTV_RTOBASE;
tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
+ tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
tp->t_rcvtime = 0;
+ tp->t_bw_rtttime = 0;
/*
* IPv4 TTL initialization is necessary for an IPv6 socket as well,
* because the socket may be bound to an IPv6 wildcard address,
break;
}
+ /*
+ * If another thread for this tcp is currently in ip (indicated by
+ * the TF_SENDINPROG flag), defer the cleanup until after it returns
+ * back to tcp. This is done to serialize the close until after all
+ * pending output is finished, in order to avoid having the PCB be
+ * detached and the cached route cleaned, only for ip to cache the
+ * route back into the PCB again. Note that we've cleared all the
+ * timers at this point. Set TF_CLOSING to indicate to tcp_output()
+ * that is should call us again once it returns from ip; at that
+ * point both flags should be cleared and we can proceed further
+ * with the cleanup.
+ */
+ if (tp->t_flags & (TF_CLOSING|TF_SENDINPROG)) {
+ tp->t_flags |= TF_CLOSING;
+ return (NULL);
+ }
+ lck_mtx_lock(rt_mtx);
/*
* If we got enough samples through the srtt filter,
* save the rtt and rttvar in the routing entry.
*/
if (tp->t_rttupdated >= 16) {
register u_long i = 0;
+
#if INET6
if (isipv6) {
struct sockaddr_in6 *sin6;
if ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0) {
i = tp->t_srtt *
- (RTM_RTTUNIT / (PR_SLOWHZ * TCP_RTT_SCALE));
+ (RTM_RTTUNIT / (TCP_RETRANSHZ * TCP_RTT_SCALE));
if (rt->rt_rmx.rmx_rtt && i)
/*
* filter this update to half the old & half
}
if ((rt->rt_rmx.rmx_locks & RTV_RTTVAR) == 0) {
i = tp->t_rttvar *
- (RTM_RTTUNIT / (PR_SLOWHZ * TCP_RTTVAR_SCALE));
+ (RTM_RTTUNIT / (TCP_RETRANSHZ * TCP_RTTVAR_SCALE));
if (rt->rt_rmx.rmx_rttvar && i)
rt->rt_rmx.rmx_rttvar =
(rt->rt_rmx.rmx_rttvar + i) / 2;
* mark route for deletion if no information is
* cached.
*/
- if ((tp->t_flags & TF_LQ_OVERFLOW) && tcp_lq_overflow &&
+ if ((so->so_flags & SOF_OVERFLOW) && tcp_lq_overflow &&
((rt->rt_rmx.rmx_locks & RTV_RTT) == 0)){
if (rt->rt_rmx.rmx_rtt == 0)
rt->rt_flags |= RTF_DELCLONE;
}
no_valid_rt:
/* free the reassembly queue, if any */
+ lck_mtx_unlock(rt_mtx);
+
(void) tcp_freeq(tp);
tcp_free_sackholes(tp);
+ /* Free the packet list */
+ if (tp->t_pktlist_head != NULL)
+ m_freem_list(tp->t_pktlist_head);
+ TCP_PKTLIST_CLEAR(tp);
+
#ifdef __APPLE__
if (so->cached_in_sock_layer)
inp->inp_saved_ppcb = (caddr_t) tp;
void
tcp_drain()
{
-/*
- * ###LD 05/19/04 locking issue, tcpdrain is disabled, deadlock situation with tcbinfo.mtx
- */
if (do_tcpdrain)
{
struct inpcb *inpb;
* where we're really low on mbufs, this is potentially
* usefull.
*/
- lck_rw_lock_exclusive(tcbinfo.mtx);
+ if (!lck_rw_try_lock_exclusive(tcbinfo.mtx)) /* do it next time if the lock is in use */
+ return;
+
for (inpb = LIST_FIRST(tcbinfo.listhead); inpb;
inpb = LIST_NEXT(inpb, inp_list)) {
if ((tcpb = intotcpcb(inpb))) {
static int
tcp_pcblist SYSCTL_HANDLER_ARGS
{
+#pragma unused(oidp, arg1, arg2)
int error, i, n;
struct inpcb *inp, **inp_list;
inp_gen_t gencnt;
struct xinpgen xig;
+ int slot;
/*
* The process of preparing the TCB list is too time-consuming and
lck_rw_done(tcbinfo.mtx);
return error;
}
- /*
- * We are done if there is no pcb
- */
- if (n == 0) {
- lck_rw_done(tcbinfo.mtx);
- return 0;
+ /*
+ * We are done if there is no pcb
+ */
+ if (n == 0) {
+ lck_rw_done(tcbinfo.mtx);
+ return 0;
}
inp_list = _MALLOC(n * sizeof *inp_list, M_TEMP, M_WAITOK);
#endif
inp_list[i++] = inp;
}
+
+ for (slot = 0; slot < N_TIME_WAIT_SLOTS; slot++) {
+ struct inpcb *inpnxt;
+
+ for (inp = time_wait_slots[slot].lh_first; inp && i < n; inp = inpnxt) {
+ inpnxt = inp->inp_list.le_next;
+ if (inp->inp_gencnt <= gencnt && inp->inp_state != INPCB_STATE_DEAD)
+ inp_list[i++] = inp;
+ }
+ }
+
n = i;
error = 0;
#define ISN_BYTES_PER_SECOND 1048576
-u_char isn_secret[32];
-int isn_last_reseed;
-MD5_CTX isn_ctx;
+//PWC - md5 routines cause alignment exceptions. Need to figure out why. For now use lame incremental
+// isn. how's that for not easily guessable!?
+
+int pwc_bogus;
tcp_seq
tcp_new_isn(tp)
u_int32_t md5_buffer[4];
tcp_seq new_isn;
struct timeval timenow;
+ u_char isn_secret[32];
+ int isn_last_reseed = 0;
+ MD5_CTX isn_ctx;
/* Use arc4random for SYN-ACKs when not in exact RFC1948 mode. */
if (((tp->t_state == TCPS_LISTEN) || (tp->t_state == TCPS_TIME_WAIT))
{
struct tcpcb *tp = intotcpcb(inp);
- if (tp)
+ if (tp) {
tp->snd_cwnd = tp->t_maxseg;
+ tp->t_bytes_acked = 0;
+ }
}
/*
#endif /* INET6 */
if (tp) {
+ lck_mtx_lock(rt_mtx);
#if INET6
if (isipv6)
rt = tcp_rtlookup6(inp);
isipv6 ? tcp_v6mssdflt :
#endif /* INET6 */
tcp_mssdflt;
+ lck_mtx_unlock(rt_mtx);
return;
}
taop = rmx_taop(rt->rt_rmx);
#endif /* INET6 */
;
+ lck_mtx_unlock(rt_mtx);
if (offered)
mss = min(mss, offered);
/*
{
struct route *ro;
struct rtentry *rt;
+ struct tcpcb *tp;
ro = &inp->inp_route;
if (ro == NULL)
return (NULL);
rt = ro->ro_rt;
+
+ lck_mtx_assert(rt_mtx, LCK_MTX_ASSERT_OWNED);
+
if (rt == NULL || !(rt->rt_flags & RTF_UP) || rt->generation_id != route_generation) {
/* No route yet, so try to acquire one */
if (inp->inp_faddr.s_addr != INADDR_ANY) {
ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
inp->inp_faddr;
- rtalloc(ro);
+ rtalloc_ign_locked(ro, 0UL);
rt = ro->ro_rt;
}
}
+ if (rt != NULL && rt->rt_ifp != NULL)
+ somultipages(inp->inp_socket,
+ (rt->rt_ifp->if_hwassist & IFNET_MULTIPAGES));
+
+ /*
+ * Update MTU discovery determination. 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)
+ */
+
+ tp = intotcpcb(inp);
+
+ 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;
+
return rt;
}
{
struct route_in6 *ro6;
struct rtentry *rt;
+ struct tcpcb *tp;
+
+ lck_mtx_assert(rt_mtx, LCK_MTX_ASSERT_OWNED);
ro6 = &inp->in6p_route;
rt = ro6->ro_rt;
dst6->sin6_family = AF_INET6;
dst6->sin6_len = sizeof(*dst6);
dst6->sin6_addr = inp->in6p_faddr;
- rtalloc((struct route *)ro6);
+ rtalloc_ign_locked((struct route *)ro6, 0UL);
rt = ro6->ro_rt;
}
}
+ if (rt != NULL && rt->rt_ifp != NULL)
+ somultipages(inp->inp_socket,
+ (rt->rt_ifp->if_hwassist & IFNET_MULTIPAGES));
+ /*
+ * Update path MTU Discovery determination
+ * while looking up the route:
+ * 1) we have a valid route to the destination
+ * 2) the MTU is not locked (if it is, then discovery has been
+ * disabled)
+ */
+
+
+ tp = intotcpcb(inp);
+
+ /*
+ * Update MTU discovery determination. 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;
+
return rt;
}
#endif /* INET6 */
if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
return 0;
- MGETHDR(m, M_DONTWAIT, MT_DATA);
+ MGETHDR(m, M_DONTWAIT, MT_DATA); /* MAC-OK */
if (!m)
return 0;
- lck_mtx_lock(sadb_mutex);
#if INET6
if ((inp->inp_vflag & INP_IPV6) != 0) {
ip6 = mtod(m, struct ip6_hdr *);
tcp_fillheaders(tp, ip, th);
hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
}
- lck_mtx_unlock(sadb_mutex);
m_free(m);
return hdrsiz;
}
struct inpcb *inp;
{
struct rtentry *rt;
+ struct rmxp_tao *taop;
+ lck_mtx_lock(rt_mtx);
#if INET6
if ((inp->inp_vflag & INP_IPV6) != 0)
rt = tcp_rtlookup6(inp);
/* Make sure this is a host route and is up. */
if (rt == NULL ||
- (rt->rt_flags & (RTF_UP|RTF_HOST)) != (RTF_UP|RTF_HOST))
+ (rt->rt_flags & (RTF_UP|RTF_HOST)) != (RTF_UP|RTF_HOST)) {
+ lck_mtx_unlock(rt_mtx);
return NULL;
-
- return rmx_taop(rt->rt_rmx);
+ }
+
+ taop = rmx_taop(rt->rt_rmx);
+ lck_mtx_unlock(rt_mtx);
+ return (taop);
}
/*
lck_mtx_lock(((struct inpcb *)so->so_pcb)->inpcb_mtx);
}
else {
- panic("tcp_lock: so=%x NO PCB! lr=%x\n", so, lr_saved);
+ panic("tcp_lock: so=%p NO PCB! lr=%x\n", so, lr_saved);
lck_mtx_lock(so->so_proto->pr_domain->dom_mtx);
}
if (so->so_usecount < 0)
- panic("tcp_lock: so=%x so_pcb=%x lr=%x ref=%x\n",
+ panic("tcp_lock: so=%p so_pcb=%p lr=%x ref=%x\n",
so, so->so_pcb, lr_saved, so->so_usecount);
if (refcount)
so->so_usecount++;
- so->lock_lr[so->next_lock_lr] = (u_int32_t *)lr_saved;
+ so->lock_lr[so->next_lock_lr] = (u_int32_t)lr_saved;
so->next_lock_lr = (so->next_lock_lr+1) % SO_LCKDBG_MAX;
return (0);
}
else lr_saved = lr;
#ifdef MORE_TCPLOCK_DEBUG
- printf("tcp_unlock: so=%x sopcb=%x lock=%x ref=%x lr=%x\n",
+ printf("tcp_unlock: so=%p sopcb=%x lock=%x ref=%x lr=%x\n",
so, so->so_pcb, ((struct inpcb *)so->so_pcb)->inpcb_mtx, so->so_usecount, lr_saved);
#endif
if (refcount)
so->so_usecount--;
if (so->so_usecount < 0)
- panic("tcp_unlock: so=%x usecount=%x\n", so, so->so_usecount);
+ panic("tcp_unlock: so=%p usecount=%x\n", so, so->so_usecount);
if (so->so_pcb == NULL)
- panic("tcp_unlock: so=%x NO PCB usecount=%x lr=%x\n", so, so->so_usecount, lr_saved);
+ panic("tcp_unlock: so=%p NO PCB usecount=%x lr=%x\n", so, so->so_usecount, lr_saved);
else {
lck_mtx_assert(((struct inpcb *)so->so_pcb)->inpcb_mtx, LCK_MTX_ASSERT_OWNED);
- so->unlock_lr[so->next_unlock_lr] = (u_int *)lr_saved;
+ so->unlock_lr[so->next_unlock_lr] = (u_int32_t)lr_saved;
so->next_unlock_lr = (so->next_unlock_lr+1) % SO_LCKDBG_MAX;
lck_mtx_unlock(((struct inpcb *)so->so_pcb)->inpcb_mtx);
}
}
lck_mtx_t *
-tcp_getlock(so, locktype)
- struct socket *so;
- int locktype;
+tcp_getlock(
+ struct socket *so,
+ __unused int locktype)
{
struct inpcb *inp = sotoinpcb(so);
if (so->so_pcb) {
if (so->so_usecount < 0)
- panic("tcp_getlock: so=%x usecount=%x\n", so, so->so_usecount);
+ panic("tcp_getlock: so=%p usecount=%x\n", so, so->so_usecount);
return(inp->inpcb_mtx);
}
else {
- panic("tcp_getlock: so=%x NULL so_pcb\n", so);
+ panic("tcp_getlock: so=%p NULL so_pcb\n", so);
return (so->so_proto->pr_domain->dom_mtx);
}
}
+long
+tcp_sbspace(struct tcpcb *tp)
+{
+ struct sockbuf *sb = &tp->t_inpcb->inp_socket->so_rcv;
+ long space, newspace;
+
+ space = ((long) lmin((sb->sb_hiwat - sb->sb_cc),
+ (sb->sb_mbmax - sb->sb_mbcnt)));
+
+#if TRAFFIC_MGT
+ if (tp->t_inpcb->inp_socket->so_traffic_mgt_flags & TRAFFIC_MGT_SO_BACKGROUND) {
+ if (tcp_background_io_enabled &&
+ tp->t_inpcb->inp_socket->so_traffic_mgt_flags & TRAFFIC_MGT_SO_BG_SUPPRESSED) {
+ tp->t_flags |= TF_RXWIN0SENT;
+ return 0; /* Triggers TCP window closing by responding there is no space */
+ }
+ }
+#endif /* TRAFFIC_MGT */
+
+ /* Avoid inscreasing window size if the current window
+ * is already very low, we could be in "persist" mode and
+ * we could break some apps (see rdar://5409343)
+ */
+
+ if (space < tp->t_maxseg)
+ return space;
+
+ /* Clip window size for slower link */
+
+ if (((tp->t_flags & TF_SLOWLINK) != 0) && slowlink_wsize > 0 )
+ return lmin(space, slowlink_wsize);
+
+ /*
+ * Check for ressources constraints before over-ajusting the amount of space we can
+ * advertise in the TCP window size updates.
+ */
+
+ if (sbspace_factor && (tp->t_inpcb->inp_pcbinfo->ipi_count < tcp_sockthreshold) &&
+ (total_mb_cnt / 8) < (mbstat.m_clusters / sbspace_factor)) {
+ if (space < (long)(sb->sb_maxused - sb->sb_cc)) {/* make sure we don't constrain the window if we have enough ressources */
+ space = (long) lmax((sb->sb_maxused - sb->sb_cc), tp->rcv_maxbyps);
+ }
+ newspace = (long) lmax(((long)sb->sb_maxused - sb->sb_cc), (long)tp->rcv_maxbyps);
+
+ if (newspace > space)
+ space = newspace;
+ }
+ return space;
+}
+/* DSEP Review Done pl-20051213-v02 @3253,@3391,@3400 */
projects / apple / xnu.git / blobdiff