#define _IP_VHL
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <kern/zalloc.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
#if INET6
#include <netinet6/in6_pcb.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#endif
#include <netinet/tcp.h>
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcpip.h>
#include <netinet/tcp_cache.h>
#if TCPDEBUG
#include <netinet/tcp_debug.h>
#endif
#include <sys/kdebug.h>
#if IPSEC
#include <netinet6/ipsec.h>
#endif
#include <libkern/OSAtomic.h>
SYSCTL_SKMEM_TCP_INT(OID_AUTO, sack, CTLFLAG_RW | CTLFLAG_LOCKED,
int, tcp_do_sack, 1, "Enable/Disable TCP SACK support");
SYSCTL_SKMEM_TCP_INT(OID_AUTO, sack_maxholes, CTLFLAG_RW | CTLFLAG_LOCKED,
static int, tcp_sack_maxholes, 128,
"Maximum number of TCP SACK holes allowed per connection");
SYSCTL_SKMEM_TCP_INT(OID_AUTO, sack_globalmaxholes,
CTLFLAG_RW | CTLFLAG_LOCKED, static int, tcp_sack_globalmaxholes, 65536,
"Global maximum number of TCP SACK holes");
static SInt32 tcp_sack_globalholes = 0;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, sack_globalholes, CTLFLAG_RD | CTLFLAG_LOCKED,
&tcp_sack_globalholes, 0,
"Global number of TCP SACK holes currently allocated");
static int tcp_detect_reordering = 1;
static int tcp_dsack_ignore_hw_duplicates = 0;
#if (DEVELOPMENT || DEBUG)
SYSCTL_INT(_net_inet_tcp, OID_AUTO, detect_reordering,
CTLFLAG_RW | CTLFLAG_LOCKED,
&tcp_detect_reordering, 0, "");
SYSCTL_INT(_net_inet_tcp, OID_AUTO, ignore_hw_duplicates,
CTLFLAG_RW | CTLFLAG_LOCKED,
&tcp_dsack_ignore_hw_duplicates, 0, "");
#endif
extern struct zone *sack_hole_zone;
#define TCP_VALIDATE_SACK_SEQ_NUMBERS(_tp_, _sb_, _ack_) \
(SEQ_GT((_sb_)->end, (_sb_)->start) && \
SEQ_GT((_sb_)->start, (_tp_)->snd_una) && \
SEQ_GT((_sb_)->start, (_ack_)) && \
SEQ_LT((_sb_)->start, (_tp_)->snd_max) && \
SEQ_GT((_sb_)->end, (_tp_)->snd_una) && \
SEQ_LEQ((_sb_)->end, (_tp_)->snd_max))
void
tcp_update_sack_list(struct tcpcb *tp, tcp_seq rcv_start, tcp_seq rcv_end)
{
struct sackblk head_blk, saved_blks[MAX_SACK_BLKS];
int num_head, num_saved, i;
head_blk.start = rcv_start;
head_blk.end = rcv_end;
num_saved = 0;
for (i = 0; i < tp->rcv_numsacks; i++) {
tcp_seq start = tp->sackblks[i].start;
tcp_seq end = tp->sackblks[i].end;
if (SEQ_GEQ(start, end) || SEQ_LEQ(start, tp->rcv_nxt)) {
} else if (SEQ_LEQ(head_blk.start, end) &&
SEQ_GEQ(head_blk.end, start)) {
if (SEQ_GT(head_blk.start, start))
head_blk.start = start;
if (SEQ_LT(head_blk.end, end))
head_blk.end = end;
} else {
saved_blks[num_saved].start = start;
saved_blks[num_saved].end = end;
num_saved++;
}
}
num_head = 0;
if (SEQ_GT(head_blk.start, tp->rcv_nxt)) {
tp->sackblks[0] = head_blk;
num_head = 1;
if (num_saved >= MAX_SACK_BLKS)
num_saved--;
}
if (num_saved > 0) {
bcopy(saved_blks, &tp->sackblks[num_head],
sizeof(struct sackblk) * num_saved);
}
tp->rcv_numsacks = num_head + num_saved;
if ((tp->t_flags & TF_STRETCHACK) != 0 && tp->rcv_numsacks > 0)
tcp_reset_stretch_ack(tp);
#if TRAFFIC_MGT
if (tp->acc_iaj > 0 && tp->rcv_numsacks > 0)
reset_acc_iaj(tp);
#endif
}
void
tcp_clean_sackreport( struct tcpcb *tp)
{
tp->rcv_numsacks = 0;
bzero(&tp->sackblks[0], sizeof (struct sackblk) * MAX_SACK_BLKS);
}
static struct sackhole *
tcp_sackhole_alloc(struct tcpcb *tp, tcp_seq start, tcp_seq end)
{
struct sackhole *hole;
if (tp->snd_numholes >= tcp_sack_maxholes ||
tcp_sack_globalholes >= tcp_sack_globalmaxholes) {
tcpstat.tcps_sack_sboverflow++;
return NULL;
}
hole = (struct sackhole *)zalloc(sack_hole_zone);
if (hole == NULL)
return NULL;
hole->start = start;
hole->end = end;
hole->rxmit = start;
tp->snd_numholes++;
OSIncrementAtomic(&tcp_sack_globalholes);
return hole;
}
static void
tcp_sackhole_free(struct tcpcb *tp, struct sackhole *hole)
{
zfree(sack_hole_zone, hole);
tp->snd_numholes--;
OSDecrementAtomic(&tcp_sack_globalholes);
}
static struct sackhole *
tcp_sackhole_insert(struct tcpcb *tp, tcp_seq start, tcp_seq end,
struct sackhole *after)
{
struct sackhole *hole;
hole = tcp_sackhole_alloc(tp, start, end);
if (hole == NULL)
return NULL;
hole->rxmit_start = tcp_now;
if (after != NULL)
TAILQ_INSERT_AFTER(&tp->snd_holes, after, hole, scblink);
else
TAILQ_INSERT_TAIL(&tp->snd_holes, hole, scblink);
if (tp->sackhint.nexthole == NULL)
tp->sackhint.nexthole = hole;
return(hole);
}
static void
tcp_sackhole_remove(struct tcpcb *tp, struct sackhole *hole)
{
if (tp->sackhint.nexthole == hole)
tp->sackhint.nexthole = TAILQ_NEXT(hole, scblink);
TAILQ_REMOVE(&tp->snd_holes, hole, scblink);
tcp_sackhole_free(tp, hole);
}
static void
tcp_sack_detect_reordering(struct tcpcb *tp, struct sackhole *s,
tcp_seq sacked_seq, tcp_seq snd_fack)
{
int32_t rext = 0, reordered = 0;
if (SEQ_GT(s->end, snd_fack))
return;
if (tp->t_rxtshift > 0)
return;
if (SEQ_LT(s->rxmit, sacked_seq)) {
reordered = 1;
tcpstat.tcps_avoid_rxmt++;
}
if (reordered) {
if (tcp_detect_reordering == 1 &&
!(tp->t_flagsext & TF_PKTS_REORDERED)) {
tp->t_flagsext |= TF_PKTS_REORDERED;
tcpstat.tcps_detect_reordering++;
}
tcpstat.tcps_reordered_pkts++;
tp->t_reordered_pkts++;
if (TCP_ECN_ENABLED(tp)) {
INP_INC_IFNET_STAT(tp->t_inpcb, ecn_fallback_reorder);
tcpstat.tcps_ecn_fallback_reorder++;
tcp_heuristic_ecn_aggressive(tp);
}
VERIFY(SEQ_GEQ(snd_fack, s->rxmit));
if (s->rxmit_start > 0) {
rext = timer_diff(tcp_now, 0, s->rxmit_start, 0);
if (rext < 0)
return;
tp->t_reorderwin = max(tp->t_reorderwin, rext);
tp->t_reorderwin = min(tp->t_reorderwin,
(tp->t_srtt >> (TCP_RTT_SHIFT - 1)));
tp->t_reorderwin = max(tp->t_reorderwin, 10);
}
}
}
void
tcp_sack_doack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th,
u_int32_t *newbytes_acked)
{
struct sackhole *cur, *temp;
struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1], *sblkp;
int i, j, num_sack_blks;
tcp_seq old_snd_fack = 0, th_ack = th->th_ack;
num_sack_blks = 0;
if (SEQ_LT(tp->snd_una, th_ack) && !TAILQ_EMPTY(&tp->snd_holes)) {
sack_blocks[num_sack_blks].start = tp->snd_una;
sack_blocks[num_sack_blks++].end = th_ack;
}
for (i = 0; i < to->to_nsacks; i++) {
bcopy((to->to_sacks + i * TCPOLEN_SACK),
&sack, sizeof(sack));
sack.start = ntohl(sack.start);
sack.end = ntohl(sack.end);
if (TCP_VALIDATE_SACK_SEQ_NUMBERS(tp, &sack, th_ack))
sack_blocks[num_sack_blks++] = sack;
}
if (num_sack_blks == 0)
return;
VERIFY(num_sack_blks <= (TCP_MAX_SACK + 1));
for (i = 0; i < num_sack_blks; i++) {
for (j = i + 1; j < num_sack_blks; j++) {
if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
sack = sack_blocks[i];
sack_blocks[i] = sack_blocks[j];
sack_blocks[j] = sack;
}
}
}
if (TAILQ_EMPTY(&tp->snd_holes)) {
tp->snd_fack = SEQ_MAX(tp->snd_una, th_ack);
*newbytes_acked += (tp->snd_fack - tp->snd_una);
}
old_snd_fack = tp->snd_fack;
sblkp = &sack_blocks[num_sack_blks - 1];
if (SEQ_LT(tp->snd_fack, sblkp->start)) {
temp = tcp_sackhole_insert(tp, tp->snd_fack,sblkp->start,NULL);
if (temp != NULL) {
tp->snd_fack = sblkp->end;
*newbytes_acked += (sblkp->end - sblkp->start);
sblkp--;
} else {
while (sblkp >= sack_blocks &&
SEQ_LT(tp->snd_fack, sblkp->start))
sblkp--;
if (sblkp >= sack_blocks &&
SEQ_LT(tp->snd_fack, sblkp->end)) {
*newbytes_acked += (sblkp->end - tp->snd_fack);
tp->snd_fack = sblkp->end;
}
}
} else if (SEQ_LT(tp->snd_fack, sblkp->end)) {
*newbytes_acked += (sblkp->end - tp->snd_fack);
tp->snd_fack = sblkp->end;
}
cur = TAILQ_LAST(&tp->snd_holes, sackhole_head);
while (sblkp >= sack_blocks && cur != NULL) {
if (SEQ_GEQ(sblkp->start, cur->end)) {
sblkp--;
continue;
}
if (SEQ_LEQ(sblkp->end, cur->start)) {
cur = TAILQ_PREV(cur, sackhole_head, scblink);
continue;
}
tp->sackhint.sack_bytes_rexmit -= (cur->rxmit - cur->start);
if (SEQ_LEQ(sblkp->start, cur->start)) {
if (SEQ_GEQ(sblkp->end, cur->end)) {
*newbytes_acked += (cur->end - cur->start);
tcp_sack_detect_reordering(tp, cur,
cur->end, old_snd_fack);
temp = cur;
cur = TAILQ_PREV(cur, sackhole_head, scblink);
tcp_sackhole_remove(tp, temp);
continue;
} else {
*newbytes_acked += (sblkp->end - cur->start);
tcp_sack_detect_reordering(tp, cur,
sblkp->end, old_snd_fack);
cur->start = sblkp->end;
cur->rxmit = SEQ_MAX(cur->rxmit, cur->start);
}
} else {
if (SEQ_GEQ(sblkp->end, cur->end)) {
*newbytes_acked += (cur->end - sblkp->start);
tcp_sack_detect_reordering(tp, cur,
cur->end, old_snd_fack);
cur->end = sblkp->start;
cur->rxmit = SEQ_MIN(cur->rxmit, cur->end);
} else {
*newbytes_acked += (sblkp->end - sblkp->start);
tcp_sack_detect_reordering(tp, cur,
sblkp->end, old_snd_fack);
temp = tcp_sackhole_insert(tp, sblkp->end,
cur->end, cur);
if (temp != NULL) {
if (SEQ_GT(cur->rxmit, temp->rxmit)) {
temp->rxmit = cur->rxmit;
tp->sackhint.sack_bytes_rexmit
+= (temp->rxmit
- temp->start);
}
cur->end = sblkp->start;
cur->rxmit = SEQ_MIN(cur->rxmit,
cur->end);
temp->rxmit_start = cur->rxmit_start;
}
}
}
tp->sackhint.sack_bytes_rexmit += (cur->rxmit - cur->start);
if (SEQ_LEQ(sblkp->start, cur->start))
cur = TAILQ_PREV(cur, sackhole_head, scblink);
else
sblkp--;
}
}
void
tcp_free_sackholes(struct tcpcb *tp)
{
struct sackhole *q;
while ((q = TAILQ_FIRST(&tp->snd_holes)) != NULL)
tcp_sackhole_remove(tp, q);
tp->sackhint.sack_bytes_rexmit = 0;
tp->sackhint.nexthole = NULL;
tp->sack_newdata = 0;
}
void
tcp_sack_partialack(struct tcpcb *tp, struct tcphdr *th)
{
int num_segs = 1;
tp->t_timer[TCPT_REXMT] = 0;
tp->t_rtttime = 0;
if (((BYTES_ACKED(th, tp)) / tp->t_maxseg) > 2)
num_segs = 2;
tp->snd_cwnd = (tp->sackhint.sack_bytes_rexmit +
(tp->snd_nxt - tp->sack_newdata) +
num_segs * tp->t_maxseg);
if (tp->snd_cwnd > tp->snd_ssthresh)
tp->snd_cwnd = tp->snd_ssthresh;
if (SEQ_LT(tp->snd_fack, tp->snd_recover) &&
tp->snd_fack == th->th_ack && TAILQ_EMPTY(&tp->snd_holes)) {
struct sackhole *temp;
temp = tcp_sackhole_insert(tp, tp->snd_fack,
tp->snd_recover, NULL);
if (temp != NULL)
tp->snd_fack = tp->snd_recover;
}
(void) tcp_output(tp);
}
static struct sackhole *
tcp_sack_output_debug(struct tcpcb *tp, int *sack_bytes_rexmt)
{
struct sackhole *p;
*sack_bytes_rexmt = 0;
TAILQ_FOREACH(p, &tp->snd_holes, scblink) {
if (SEQ_LT(p->rxmit, p->end)) {
if (SEQ_LT(p->rxmit, tp->snd_una)) {
continue;
}
*sack_bytes_rexmt += (p->rxmit - p->start);
break;
}
*sack_bytes_rexmt += (p->rxmit - p->start);
}
return (p);
}
struct sackhole *
tcp_sack_output(struct tcpcb *tp, int *sack_bytes_rexmt)
{
struct sackhole *hole = NULL, *dbg_hole = NULL;
int dbg_bytes_rexmt;
dbg_hole = tcp_sack_output_debug(tp, &dbg_bytes_rexmt);
*sack_bytes_rexmt = tp->sackhint.sack_bytes_rexmit;
hole = tp->sackhint.nexthole;
if (hole == NULL || SEQ_LT(hole->rxmit, hole->end))
goto out;
while ((hole = TAILQ_NEXT(hole, scblink)) != NULL) {
if (SEQ_LT(hole->rxmit, hole->end)) {
tp->sackhint.nexthole = hole;
break;
}
}
out:
if (dbg_hole != hole) {
printf("%s: Computed sack hole not the same as cached value\n", __func__);
hole = dbg_hole;
}
if (*sack_bytes_rexmt != dbg_bytes_rexmt) {
printf("%s: Computed sack_bytes_retransmitted (%d) not "
"the same as cached value (%d)\n",
__func__, dbg_bytes_rexmt, *sack_bytes_rexmt);
*sack_bytes_rexmt = dbg_bytes_rexmt;
}
return (hole);
}
void
tcp_sack_adjust(struct tcpcb *tp)
{
struct sackhole *p, *cur = TAILQ_FIRST(&tp->snd_holes);
if (cur == NULL)
return;
if (SEQ_GEQ(tp->snd_nxt, tp->snd_fack))
return;
while ((p = TAILQ_NEXT(cur, scblink)) != NULL) {
if (SEQ_LT(tp->snd_nxt, cur->end))
return;
if (SEQ_GEQ(tp->snd_nxt, p->start))
cur = p;
else {
tp->snd_nxt = p->start;
return;
}
}
if (SEQ_LT(tp->snd_nxt, cur->end))
return;
tp->snd_nxt = tp->snd_fack;
return;
}
boolean_t
tcp_sack_byte_islost(struct tcpcb *tp)
{
u_int32_t unacked_bytes, sndhole_bytes = 0;
struct sackhole *sndhole;
if (!SACK_ENABLED(tp) || IN_FASTRECOVERY(tp) ||
TAILQ_EMPTY(&tp->snd_holes) ||
(tp->t_flagsext & TF_PKTS_REORDERED))
return (FALSE);
unacked_bytes = tp->snd_max - tp->snd_una;
TAILQ_FOREACH(sndhole, &tp->snd_holes, scblink) {
sndhole_bytes += (sndhole->end - sndhole->start);
}
VERIFY(unacked_bytes >= sndhole_bytes);
return ((unacked_bytes - sndhole_bytes) >
((tcprexmtthresh - 1) * tp->t_maxseg));
}
boolean_t
tcp_sack_process_dsack(struct tcpcb *tp, struct tcpopt *to,
struct tcphdr *th)
{
struct sackblk first_sack, second_sack;
struct tcp_rxt_seg *rxseg;
bcopy(to->to_sacks, &first_sack, sizeof(first_sack));
first_sack.start = ntohl(first_sack.start);
first_sack.end = ntohl(first_sack.end);
if (to->to_nsacks > 1) {
bcopy((to->to_sacks + TCPOLEN_SACK), &second_sack,
sizeof(second_sack));
second_sack.start = ntohl(second_sack.start);
second_sack.end = ntohl(second_sack.end);
}
if (SEQ_LT(first_sack.start, th->th_ack) &&
SEQ_LEQ(first_sack.end, th->th_ack)) {
if (!(TCP_DSACK_SEQ_IN_WINDOW(tp, first_sack.start, th->th_ack) &&
TCP_DSACK_SEQ_IN_WINDOW(tp, first_sack.end, th->th_ack))) {
to->to_nsacks--;
to->to_sacks += TCPOLEN_SACK;
tcpstat.tcps_dsack_recvd_old++;
return (TRUE);
}
} else if (to->to_nsacks > 1 &&
SEQ_LEQ(second_sack.start, first_sack.start) &&
SEQ_GEQ(second_sack.end, first_sack.end)) {
if (!TCP_VALIDATE_SACK_SEQ_NUMBERS(tp, &second_sack,
th->th_ack)) {
to->to_nsacks--;
to->to_sacks += TCPOLEN_SACK;
tcpstat.tcps_dsack_recvd_old++;
return (TRUE);
}
} else {
return (FALSE);
}
to->to_nsacks--;
to->to_sacks += TCPOLEN_SACK;
tcpstat.tcps_dsack_recvd++;
tp->t_dsack_recvd++;
if (tp->t_flagsext & TF_DISABLE_DSACK)
return (TRUE);
if ((tp->t_flagsext & TF_SENT_TLPROBE) &&
first_sack.end == tp->t_tlphighrxt) {
if ((rxseg = tcp_rxtseg_find(tp, first_sack.start,
(first_sack.end - 1))) != NULL)
rxseg->rx_flags |= TCP_RXT_DSACK_FOR_TLP;
}
if (((tp->t_rxtshift == 1 && first_sack.start == tp->snd_una) ||
((tp->t_flagsext & TF_SENT_TLPROBE) &&
first_sack.end == tp->t_tlphighrxt)) &&
TAILQ_EMPTY(&tp->snd_holes) &&
SEQ_GT(th->th_ack, tp->snd_una)) {
tcpstat.tcps_dsack_ackloss++;
return (TRUE);
} else if ((rxseg = tcp_rxtseg_find(tp, first_sack.start,
(first_sack.end - 1))) == NULL) {
if (!tcp_dsack_ignore_hw_duplicates) {
tp->t_flagsext |= TF_DISABLE_DSACK;
tcpstat.tcps_dsack_disable++;
}
} else {
if (rxseg->rx_count == 1)
rxseg->rx_flags |= TCP_RXT_SPURIOUS;
else
rxseg->rx_flags &= ~TCP_RXT_SPURIOUS;
}
return (TRUE);
}