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Index: netinet/tcp_input.c
===================================================================
--- netinet/tcp_input.c
+++ netinet/tcp_input.c
@@ -1734,7 +1734,7 @@
tp->snd_nxt == tp->snd_max &&
tiwin && tiwin == tp->snd_wnd &&
((tp->t_flags & (TF_NEEDSYN|TF_NEEDFIN)) == 0) &&
- LIST_EMPTY(&tp->t_segq) &&
+ TAILQ_EMPTY(&tp->t_segq) &&
((to.to_flags & TOF_TS) == 0 ||
TSTMP_GEQ(to.to_tsval, tp->ts_recent)) ) {
@@ -2440,7 +2440,7 @@
* later; if not, do so now to pass queued data to user.
*/
if (tlen == 0 && (thflags & TH_FIN) == 0)
- (void) tcp_reass(tp, (struct tcphdr *)0, 0,
+ (void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
(struct mbuf *)0);
tp->snd_wl1 = th->th_seq - 1;
/* FALLTHROUGH */
@@ -3017,7 +3017,7 @@
* fast retransmit can work).
*/
if (th->th_seq == tp->rcv_nxt &&
- LIST_EMPTY(&tp->t_segq) &&
+ TAILQ_EMPTY(&tp->t_segq) &&
(TCPS_HAVEESTABLISHED(tp->t_state) ||
tfo_syn)) {
if (DELAY_ACK(tp, tlen) || tfo_syn)
@@ -3042,7 +3042,7 @@
* m_adj() doesn't actually frees any mbufs
* when trimming from the head.
*/
- thflags = tcp_reass(tp, th, &tlen, m);
+ thflags = tcp_reass(tp, th, &save_start, &tlen, m);
tp->t_flags |= TF_ACKNOW;
}
if (tlen > 0 && (tp->t_flags & TF_SACK_PERMIT))
Index: netinet/tcp_log_buf.h
===================================================================
--- netinet/tcp_log_buf.h
+++ netinet/tcp_log_buf.h
@@ -217,7 +217,9 @@
BBR_LOG_REDUCE, /* old bbr log reduce for 4.1 and earlier 46*/
TCP_LOG_RTT, /* A rtt (in useconds) is being sampled and applied to the srtt algo 47 */
BBR_LOG_SETTINGS_CHG, /* Settings changed for loss response 48 */
- TCP_LOG_END /* End (keep at end) 49 */
+ BBR_LOG_SRTT_GAIN_EVENT, /* SRTT gaining 49 */
+ TCP_LOG_REASS, /* Reassembly buffer logging 50 */
+ TCP_LOG_END /* End (keep at end) 51 */
};
enum tcp_log_states {
Index: netinet/tcp_reass.c
===================================================================
--- netinet/tcp_reass.c
+++ netinet/tcp_reass.c
@@ -72,6 +72,8 @@
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
+#include <netinet/tcp_log_buf.h>
+#include <netinet/tcp_hpts.h>
#include <netinet6/tcp6_var.h>
#include <netinet/tcpip.h>
#ifdef TCPDEBUG
@@ -78,9 +80,28 @@
#include <netinet/tcp_debug.h>
#endif /* TCPDEBUG */
+#define TCP_R_LOG_ADD 1
+#define TCP_R_LOG_LIMIT_REACHED 2
+#define TCP_R_LOG_APPEND 3
+#define TCP_R_LOG_PREPEND 4
+#define TCP_R_LOG_REPLACE 5
+#define TCP_R_LOG_MERGE_INTO 6
+#define TCP_R_LOG_NEW_ENTRY 7
+#define TCP_R_LOG_READ 8
+#define TCP_R_LOG_ZERO 9
+#define TCP_R_LOG_DUMP 10
+#define TCP_R_LOG_TRIM 11
+
+/* For debugging we want counters and BB logging */
+/*#define TCP_REASS_COUNTERS 1*/
+/*#define TCP_REASS_LOGGING 1 */
+
static SYSCTL_NODE(_net_inet_tcp, OID_AUTO, reass, CTLFLAG_RW, 0,
"TCP Segment Reassembly Queue");
+static SYSCTL_NODE(_net_inet_tcp_reass, OID_AUTO, stats, CTLFLAG_RW, 0,
+ "TCP Segment Reassembly stats");
+
static int tcp_reass_maxseg = 0;
SYSCTL_INT(_net_inet_tcp_reass, OID_AUTO, maxsegments, CTLFLAG_RDTUN,
&tcp_reass_maxseg, 0,
@@ -96,6 +117,58 @@
&tcp_reass_maxqueuelen, 0,
"Maximum number of TCP Segments per Reassembly Queue");
+#ifdef TCP_REASS_COUNTERS
+
+counter_u64_t reass_entry;
+SYSCTL_COUNTER_U64(_net_inet_tcp_reass_stats, OID_AUTO, entry, CTLFLAG_RD,
+ &reass_entry, "A segment entered reassembly ");
+
+counter_u64_t reass_path1;
+SYSCTL_COUNTER_U64(_net_inet_tcp_reass_stats, OID_AUTO, path1, CTLFLAG_RD,
+ &reass_path1, "Took path 1");
+
+counter_u64_t reass_path2;
+SYSCTL_COUNTER_U64(_net_inet_tcp_reass_stats, OID_AUTO, path2, CTLFLAG_RD,
+ &reass_path2, "Took path 2");
+
+counter_u64_t reass_path3;
+SYSCTL_COUNTER_U64(_net_inet_tcp_reass_stats, OID_AUTO, path3, CTLFLAG_RD,
+ &reass_path3, "Took path 3");
+
+counter_u64_t reass_path4;
+SYSCTL_COUNTER_U64(_net_inet_tcp_reass_stats, OID_AUTO, path4, CTLFLAG_RD,
+ &reass_path4, "Took path 4");
+
+counter_u64_t reass_path5;
+SYSCTL_COUNTER_U64(_net_inet_tcp_reass_stats, OID_AUTO, path5, CTLFLAG_RD,
+ &reass_path5, "Took path 5");
+
+counter_u64_t reass_path6;
+SYSCTL_COUNTER_U64(_net_inet_tcp_reass_stats, OID_AUTO, path6, CTLFLAG_RD,
+ &reass_path6, "Took path 6");
+
+counter_u64_t reass_path7;
+SYSCTL_COUNTER_U64(_net_inet_tcp_reass_stats, OID_AUTO, path7, CTLFLAG_RD,
+ &reass_path7, "Took path 7");
+
+counter_u64_t reass_fullwalk;
+SYSCTL_COUNTER_U64(_net_inet_tcp_reass_stats, OID_AUTO, fullwalk, CTLFLAG_RD,
+ &reass_fullwalk, "Took a full walk ");
+
+counter_u64_t reass_nospace;
+SYSCTL_COUNTER_U64(_net_inet_tcp_reass_stats, OID_AUTO, nospace, CTLFLAG_RD,
+ &reass_nospace, "Had no mbuf capacity ");
+
+counter_u64_t merge_fwd;
+SYSCTL_COUNTER_U64(_net_inet_tcp_reass_stats, OID_AUTO, merge_fwd, CTLFLAG_RD,
+ &merge_fwd, "Ran merge fwd");
+
+counter_u64_t merge_into;
+SYSCTL_COUNTER_U64(_net_inet_tcp_reass_stats, OID_AUTO, merge_into, CTLFLAG_RD,
+ &merge_into, "Ran merge into");
+
+#endif
+
/* Initialize TCP reassembly queue */
static void
tcp_reass_zone_change(void *tag)
@@ -107,6 +180,73 @@
tcp_reass_maxseg);
}
+#ifdef TCP_REASS_LOGGING
+
+static void
+tcp_log_reassm(struct tcpcb *tp, struct tseg_qent *q, struct tseg_qent *p,
+ tcp_seq seq, int len, uint8_t action, int instance)
+{
+ uint32_t cts;
+ struct timeval tv;
+ if (tp->t_logstate != TCP_LOG_STATE_OFF) {
+ union tcp_log_stackspecific log;
+
+ cts = tcp_get_usecs(&tv);
+ log.u_bbr.flex1 = seq;
+ log.u_bbr.cur_del_rate = (uint64_t)q;
+ log.u_bbr.delRate = (uint64_t)p;
+ if (q != NULL) {
+ log.u_bbr.flex2 = q->tqe_start;
+ log.u_bbr.flex3 = q->tqe_len;
+ log.u_bbr.flex4 = q->tqe_mbuf_cnt;
+ }
+ if (p != NULL) {
+ log.u_bbr.flex5 = p->tqe_start;
+ log.u_bbr.pkts_out = p->tqe_len;
+ log.u_bbr.epoch = p->tqe_mbuf_cnt;
+ }
+ log.u_bbr.flex6 = tp->t_segqmbuflen;
+ log.u_bbr.flex7 = instance;
+ log.u_bbr.flex8 = action;
+ log.u_bbr.timeStamp = cts;
+ TCP_LOG_EVENTP(tp, NULL,
+ &tp->t_inpcb->inp_socket->so_rcv,
+ &tp->t_inpcb->inp_socket->so_snd,
+ TCP_LOG_REASS, 0,
+ len, &log, false, &tv);
+ }
+}
+
+static void
+tcp_reass_log_dump(struct tcpcb *tp)
+{
+ struct tseg_qent *q;
+
+ if (tp->t_logstate != TCP_LOG_STATE_OFF) {
+ TAILQ_FOREACH(q, &tp->t_segq, tqe_q) {
+ tcp_log_reassm(tp, q, NULL, q->tqe_start, q->tqe_len, TCP_R_LOG_DUMP, 0);
+ }
+ };
+}
+
+static void
+tcp_reass_log_new_in(struct tcpcb *tp, tcp_seq seq, int len, struct mbuf *m,
+ int logval,
+ struct tseg_qent *q)
+{
+ int cnt;
+ struct mbuf *t;
+ cnt = 0;
+ t = m;
+ while (t) {
+ cnt += t->m_len;
+ t = t->m_next;
+ }
+ tcp_log_reassm(tp, q, NULL, seq, len, logval, cnt);
+}
+
+#endif
+
void
tcp_reass_global_init(void)
{
@@ -119,8 +259,23 @@
/* Set the zone limit and read back the effective value. */
tcp_reass_maxseg = uma_zone_set_max(tcp_reass_zone,
tcp_reass_maxseg);
+#ifdef TCP_REASS_COUNTERS
+ reass_path1 = counter_u64_alloc(M_WAITOK);
+ reass_path2 = counter_u64_alloc(M_WAITOK);
+ reass_path3 = counter_u64_alloc(M_WAITOK);
+ reass_path4 = counter_u64_alloc(M_WAITOK);
+ reass_path5 = counter_u64_alloc(M_WAITOK);
+ reass_path6 = counter_u64_alloc(M_WAITOK);
+ reass_path7 = counter_u64_alloc(M_WAITOK);
+ reass_fullwalk = counter_u64_alloc(M_WAITOK);
+ reass_nospace = counter_u64_alloc(M_WAITOK);
+ reass_entry = counter_u64_alloc(M_WAITOK);
+ merge_fwd = counter_u64_alloc(M_WAITOK);
+ merge_into = counter_u64_alloc(M_WAITOK);
+#endif
EVENTHANDLER_REGISTER(nmbclusters_change,
tcp_reass_zone_change, NULL, EVENTHANDLER_PRI_ANY);
+
}
void
@@ -130,32 +285,250 @@
INP_WLOCK_ASSERT(tp->t_inpcb);
- while ((qe = LIST_FIRST(&tp->t_segq)) != NULL) {
- LIST_REMOVE(qe, tqe_q);
+ while ((qe = TAILQ_FIRST(&tp->t_segq)) != NULL) {
+ TAILQ_REMOVE(&tp->t_segq, qe, tqe_q);
m_freem(qe->tqe_m);
uma_zfree(tcp_reass_zone, qe);
tp->t_segqlen--;
}
-
+ tp->t_segqmbuflen = 0;
KASSERT((tp->t_segqlen == 0),
("TCP reass queue %p segment count is %d instead of 0 after flush.",
tp, tp->t_segqlen));
}
+static int
+tcp_reass_setuplast(struct tseg_qent *q)
+{
+ /*
+ * We enter with q->tqe_last set
+ * to a mbuf, but we are not sure it is
+ * the last. We run though and move it
+ * to the last mbuf. Keeping track
+ * of the mbuf sizing which we
+ * return aftre setting up last.
+ */
+ struct mbuf *m;
+ int cnt=0;
+
+ m = q->tqe_last;
+ cnt += MSIZE;
+ if (m->m_flags & M_EXT)
+ cnt += m->m_ext.ext_size;
+ while (m->m_next != NULL) {
+ m = m->m_next;
+ cnt += MSIZE;
+ if (m->m_flags & M_EXT)
+ cnt += m->m_ext.ext_size;
+ }
+ /* M is now the last */
+ q->tqe_last = m;
+ return(cnt);
+}
+
+
+static int
+tcp_reass_append(struct tcpcb *tp, struct tseg_qent *last, struct mbuf *m, struct tcphdr *th,
+ int *tlenp, int in)
+{
+ int added;
+
+#ifdef TCP_REASS_LOGGING
+ tcp_log_reassm(tp, last, NULL, th->th_seq, *tlenp, TCP_R_LOG_APPEND, in);
+#endif
+ last->tqe_len += *tlenp;
+ last->tqe_m->m_pkthdr.len += *tlenp;
+ /* Preserve the FIN bit if its there */
+ last->tqe_flags |= (th->th_flags & TH_FIN);
+ last->tqe_last->m_next = m;
+ last->tqe_last = m;
+ added = tcp_reass_setuplast(last);
+ last->tqe_mbuf_cnt += added;
+#ifdef TCP_REASS_LOGGING
+ tcp_reass_log_new_in(tp, last->tqe_start, added, last->tqe_m,
+ TCP_R_LOG_APPEND,
+ last);
+#endif
+ return(added);
+}
+
+static int
+tcp_reass_prepend(struct tcpcb *tp, struct tseg_qent *first, struct mbuf *m, struct tcphdr *th,
+ int *tlenp, int in)
+{
+ struct mbuf *tm;
+ int i, added;
+
+#ifdef TCP_REASS_LOGGING
+ tcp_log_reassm(tp, first, NULL, th->th_seq, *tlenp, TCP_R_LOG_PREPEND, in);
+#endif
+ if (SEQ_GT((th->th_seq + *tlenp), first->tqe_start)) {
+ /* The new data overlaps into the old */
+ i = (th->th_seq + *tlenp) - first->tqe_start;
+#ifdef TCP_REASS_LOGGING
+ tcp_log_reassm(tp, first, NULL, 0, i, TCP_R_LOG_TRIM, 1);
+#endif
+ m_adj(first->tqe_m, i);
+ first->tqe_len -= i;
+ first->tqe_start += i;
+ }
+ /* We must find the last of this chain */
+ tm = m;
+ added = MSIZE;
+ if (tm->m_flags & M_EXT)
+ added += tm->m_ext.ext_size;
+ while (tm->m_next != NULL) {
+ /* Find the last one */
+ tm = tm->m_next;
+ added += MSIZE;
+ if (tm->m_flags & M_EXT)
+ added += tm->m_ext.ext_size;
+ }
+ /* Ok now setup our chain to point to the old first */
+ tm->m_next = first->tqe_m;
+ first->tqe_m = m;
+ first->tqe_len += *tlenp;
+ first->tqe_start = th->th_seq;
+ first->tqe_m->m_pkthdr.len = first->tqe_len;
+ first->tqe_mbuf_cnt += added;
+#ifdef TCP_REASS_LOGGING
+ tcp_reass_log_new_in(tp, first->tqe_start, added, first->tqe_m,
+ TCP_R_LOG_PREPEND,
+ first);
+#endif
+ return(added);
+}
+
+static void
+tcp_reas_replace(struct tcpcb *tp, struct tseg_qent *q, struct mbuf *m, tcp_seq seq, int len)
+{
+ /*
+ * Free the data in q, and replace
+ * it with the new segment.
+ */
+#ifdef TCP_REASS_LOGGING
+ tcp_log_reassm(tp, q, NULL, seq, len, TCP_R_LOG_REPLACE, 0);
+#endif
+ m_freem(q->tqe_m);
+ KASSERT(tp->t_segqmbuflen >= q->tqe_mbuf_cnt,
+ ("Tp:%p seg queue goes negative", tp));
+ tp->t_segqmbuflen -= q->tqe_mbuf_cnt;
+ q->tqe_m = m;
+ q->tqe_mbuf_cnt = MSIZE;
+ if (m->m_flags & M_EXT)
+ q->tqe_mbuf_cnt += m->m_ext.ext_size;
+ q->tqe_start = seq;
+ q->tqe_len = len;
+ q->tqe_m->m_pkthdr.len = q->tqe_len;
+ q->tqe_last = m;
+ tp->t_segqmbuflen += tcp_reass_setuplast(q);
+}
+
+static void
+tcp_reas_merge_into(struct tcpcb *tp, struct tseg_qent *ent, struct tseg_qent *q)
+{
+ /*
+ * Merge q int ent and free q from the list.
+ */
+#ifdef TCP_REASS_LOGGING
+ tcp_log_reassm(tp, q, ent, 0, 0, TCP_R_LOG_MERGE_INTO, 0);
+#endif
+#ifdef TCP_REASS_COUNTERS
+ counter_u64_add(merge_into, 1);
+#endif
+ ent->tqe_last->m_next = q->tqe_m;
+ ent->tqe_last = q->tqe_last;
+ ent->tqe_len += q->tqe_len;
+ ent->tqe_mbuf_cnt += q->tqe_mbuf_cnt;
+ ent->tqe_m->m_pkthdr.len += q->tqe_len;
+ ent->tqe_flags |= (q->tqe_flags & TH_FIN);
+ TAILQ_REMOVE(&tp->t_segq, q, tqe_q);
+ uma_zfree(tcp_reass_zone, q);
+ tp->t_segqlen--;
+
+}
+
+static void
+tcp_reas_merge_forward(struct tcpcb *tp, struct tseg_qent *ent)
+{
+ struct tseg_qent *q, *qtmp;
+ int i;
+ tcp_seq max;
+ /*
+ * Given an entry merge forward anyplace
+ * that ent overlaps forward.
+ */
+
+ max = ent->tqe_start + ent->tqe_len;
+ q = TAILQ_NEXT(ent, tqe_q);
+ if (q == NULL) {
+ /* Nothing left */
+ return;
+ }
+ TAILQ_FOREACH_FROM_SAFE(q, &tp->t_segq, tqe_q, qtmp) {
+ if (SEQ_GT(q->tqe_start, max)) {
+ /* Beyond q */
+ break;
+ }
+ /* We have some or all that are overlapping */
+ if (SEQ_GEQ(max, (q->tqe_start + q->tqe_len))) {
+ /* It consumes it all */
+ tp->t_segqmbuflen -= q->tqe_mbuf_cnt;
+ m_freem(q->tqe_m);
+ TAILQ_REMOVE(&tp->t_segq, q, tqe_q);
+ uma_zfree(tcp_reass_zone, q);
+ tp->t_segqlen--;
+ continue;
+ }
+ /*
+ * Trim the q entry to dovetail to this one
+ * and then merge q into ent updating max
+ * in the process.
+ */
+ i = max - q->tqe_start;
+#ifdef TCP_REASS_LOGGING
+ tcp_log_reassm(tp, q, NULL, 0, i, TCP_R_LOG_TRIM, 2);
+#endif
+ m_adj(q->tqe_m, i);
+ q->tqe_len -= i;
+ q->tqe_start += i;
+ tcp_reas_merge_into(tp, ent, q);
+ max = ent->tqe_start + ent->tqe_len;
+ }
+#ifdef TCP_REASS_COUNTERS
+ counter_u64_add(merge_fwd, 1);
+#endif
+}
+
+static int
+tcp_reass_overhead_of_chain(struct mbuf *m)
+{
+ int len = 0;
+
+ if (m->m_flags & M_EXT)
+ len += m->m_ext.ext_size;
+ while (m->m_next != NULL) {
+ m = m->m_next;
+ len += MSIZE;
+ if (m->m_flags & M_EXT)
+ len += m->m_ext.ext_size;
+ }
+ return(len);
+}
+
int
-tcp_reass(struct tcpcb *tp, struct tcphdr *th, int *tlenp, struct mbuf *m)
+tcp_reass(struct tcpcb *tp, struct tcphdr *th, tcp_seq *seq_start, int *tlenp, struct mbuf *m)
{
- struct tseg_qent *q;
+ struct tseg_qent *q, *last, *first;
struct tseg_qent *p = NULL;
- struct tseg_qent *nq;
+ struct tseg_qent *nq = NULL;
struct tseg_qent *te = NULL;
+ struct sockbuf *sb;
struct socket *so = tp->t_inpcb->inp_socket;
char *s = NULL;
- int flags;
- struct tseg_qent tqs;
+ int flags, i, len, lenof;
INP_WLOCK_ASSERT(tp->t_inpcb);
-
/*
* XXX: tcp_reass() is rather inefficient with its data structures
* and should be rewritten (see NetBSD for optimizations).
@@ -167,8 +540,264 @@
*/
if (th == NULL)
goto present;
+ KASSERT(SEQ_GEQ(th->th_seq, tp->rcv_nxt),
+ ("Attempt to add old entry to reassembly queue (th=%p, tp=%p)",
+ th, tp));
+#ifdef TCP_REASS_LOGGING
+ tcp_reass_log_new_in(tp, th->th_seq, *tlenp, m, TCP_R_LOG_ADD, NULL);
+#endif
+ /*
+ * Will it fit?
+ */
+#ifdef TCP_REASS_COUNTERS
+ counter_u64_add(reass_entry, 1);
+#endif
+ len = tcp_reass_overhead_of_chain(m);
+ sb = &tp->t_inpcb->inp_socket->so_snd;
+ if ((sb->sb_mbcnt + tp->t_segqmbuflen + len) > sb->sb_mbmax) {
+ /* No room */
+#ifdef TCP_REASS_COUNTERS
+ counter_u64_add(reass_nospace, 1);
+#endif
+#ifdef TCP_REASS_LOGGING
+ tcp_log_reassm(tp, NULL, NULL, th->th_seq, len, TCP_R_LOG_LIMIT_REACHED, 0);
+#endif
+ m_freem(m);
+ *tlenp = 0;
+#ifdef TCP_REASS_LOGGING
+ tcp_reass_log_dump(tp);
+#endif
+ return (0);
+ }
+ /*
+ * First lets deal with two common cases, the
+ * segment appends to the back of our collected
+ * segments. Or the segment is the next in line.
+ */
+ last = TAILQ_LAST_FAST(&tp->t_segq, tseg_qent, tqe_q);
+ if (last) {
+ if ((SEQ_GEQ(th->th_seq, last->tqe_start)) &&
+ (SEQ_GEQ((last->tqe_start + last->tqe_len), th->th_seq))) {
+ /* Common case, trailing segment is added */
+#ifdef TCP_REASS_COUNTERS
+ counter_u64_add(reass_path1, 1);
+#endif
+ if (SEQ_GT((last->tqe_start + last->tqe_len), th->th_seq)) {
+ i = (last->tqe_start + last->tqe_len) - th->th_seq;
+ if (i < *tlenp) {
+#ifdef TCP_REASS_LOGGING
+ tcp_log_reassm(tp, last, NULL, 0, i, TCP_R_LOG_TRIM, 3);
+#endif
+ m_adj(m, i);
+ *tlenp -= i;
+ th->th_seq += i;
+ } else {
+ /* Complete overlap */
+ TCPSTAT_INC(tcps_rcvduppack);
+ TCPSTAT_ADD(tcps_rcvdupbyte, *tlenp);
+ m_freem(m);
+ goto present;
+ }
+ }
+ lenof = tcp_reass_append(tp, last, m, th, tlenp, 1);
+ tp->t_segqmbuflen += lenof;
+ *seq_start = last->tqe_start;
+ *tlenp = last->tqe_len;
+ goto present;
+ } else if (SEQ_GEQ(th->th_seq, (last->tqe_start + last->tqe_len))) {
+ /*
+ * Second common case, we missed
+ * another one and have something more
+ * for the end.
+ */
+#ifdef TCP_REASS_COUNTERS
+ counter_u64_add(reass_path2, 1);
+#endif
+ p = last;
+ q = NULL;
+ goto new_entry;
+ }
+ } else if (last == NULL) {
+ /* First one in */
+ q = NULL;
+ goto new_entry;
+ }
+ first = TAILQ_FIRST(&tp->t_segq);
+ if (first &&
+ (SEQ_LT(th->th_seq, first->tqe_start)) &&
+ ((th->th_seq + *tlenp) == first->tqe_start)) {
+ /*
+ * The head of the queue is prepended by this and
+ * it may be the one I want most.
+ */
+ struct mbuf *foobar;
+#ifdef TCP_REASS_COUNTERS
+ counter_u64_add(reass_path3, 1);
+#endif
+ if (SEQ_LT(th->th_seq, tp->rcv_nxt)) {
+ /*
+ * The resend was even before
+ * what we have. We need to trim it.
+ */
+ i = tp->rcv_nxt - th->th_seq;
+#ifdef TCP_REASS_LOGGING
+ tcp_log_reassm(tp, first, NULL, 0, i, TCP_R_LOG_TRIM, 4);
+#endif
+ m_adj(first->tqe_m, i);
+ first->tqe_len -= i;
+ *tlenp -= i;
+ first->tqe_m->m_pkthdr.len -= i;
+ first->tqe_start = tp->rcv_nxt;
+ }
+ foobar = first->tqe_m;
+ lenof = tcp_reass_prepend(tp, first, m, th, tlenp, 1);
+ if (foobar == first->tqe_m) {
+ panic("First stayed same m:%p foobar:%p first->tqe_m:%p tp:%p first:%p",
+ m, foobar, first->tqe_m, tp, first);
+ } else if (first->tqe_m != m) {
+ panic("First did not change to m:%p foobar:%p first->tqe_m:%p tp:%p first:%p",
+ m, foobar, first->tqe_m, tp, first);
+ }
+ tp->t_segqmbuflen += lenof;
+ *seq_start = first->tqe_start;
+ *tlenp = first->tqe_len;
+ goto present;
+ } else if (first == last) {
+ /* Second one in */
+ if (SEQ_GT(th->th_seq, first->tqe_start)) {
+ /* first is behind us (p) */
+ p = first;
+ q = NULL;
+ goto new_entry;
+ } else {
+ /* first is ahead of us (q) */
+ p = NULL;
+ q = first;
+ goto new_entry;
+ }
+ }
/*
+ * Find a segment which begins after this one does.
+ */
+#ifdef TCP_REASS_COUNTERS
+ counter_u64_add(reass_fullwalk, 1);
+#endif
+ TAILQ_FOREACH(q, &tp->t_segq, tqe_q) {
+ if (SEQ_GT(q->tqe_start, th->th_seq))
+ break;
+ p = q;
+ }
+ /*
+ * If there is a preceding segment, it may provide some of
+ * our data already. If so, drop the data from the incoming
+ * segment. If it provides all of our data, drop the
+ * entire mbuf.
+ */
+ if (p != NULL) {
+ int i;
+ /* conversion to int (in i) handles seq wraparound */
+ i = p->tqe_start + p->tqe_len - th->th_seq;
+ if (i >= 0) {
+ if (i >= *tlenp) {
+ TCPSTAT_INC(tcps_rcvduppack);
+ TCPSTAT_ADD(tcps_rcvdupbyte, *tlenp);
+ m_freem(m);
+ /*
+ * Try to present any queued data
+ * at the left window edge to the user.
+ * This is needed after the 3-WHS
+ * completes. Note this probably
+ * will not work and we will return.
+ */
+ goto present;
+ }
+ if (i > 0) {
+#ifdef TCP_REASS_LOGGING
+ tcp_log_reassm(tp, p, NULL, 0, i, TCP_R_LOG_TRIM, 5);
+#endif
+ m_adj(m, i);
+ *tlenp -= i;
+ th->th_seq += i;
+ }
+ }
+ }
+ if (q &&
+ SEQ_GT((th->th_seq + *tlenp), q->tqe_start)) {
+ /*
+ * The new data runs over the
+ * top of previously sack'd data. It
+ * may be partially overlapping, or
+ * it may overlap the entire segment.
+ */
+ if (SEQ_GEQ((th->th_seq + *tlenp), (q->tqe_start + q->tqe_len))) {
+ /* It consumes it all */
+#ifdef TCP_REASS_COUNTERS
+ counter_u64_add(reass_path4, 1);
+#endif
+ tcp_reas_replace(tp, q, m, th->th_seq, *tlenp);
+ /* Now does it go further than that? */
+ tcp_reas_merge_forward(tp, q);
+ } else {
+ /*
+ * We just need to prepend the data
+ * to this. It does not overrun
+ * the end.
+ */
+#ifdef TCP_REASS_COUNTERS
+ counter_u64_add(reass_path5, 1);
+#endif
+ lenof = tcp_reass_prepend(tp, q, m, th, tlenp, 2);
+ tp->t_segqmbuflen += lenof;
+ }
+ /*
+ * Now if there is a previous we may be
+ * able to merge them.
+ */
+ if ((p) &&
+ ((p->tqe_start + p->tqe_len) == q->tqe_start)) {
+ /*
+ * For the sack update below we need to update
+ * q to point to p.
+ */
+#ifdef TCP_REASS_COUNTERS
+ counter_u64_add(reass_path6, 1);
+#endif
+ tcp_reas_merge_into(tp, p, q);
+ q = p;
+ }
+ *seq_start = q->tqe_start;
+ *tlenp = q->tqe_len;
+ goto present;
+ }
+ if (p &&
+ (th->th_seq == (p->tqe_start + p->tqe_len))) {
+ /*
+ * If dovetails in with this one
+ * append it.
+ */
+#ifdef TCP_REASS_COUNTERS
+ counter_u64_add(reass_path7, 1);
+#endif
+ lenof = tcp_reass_append(tp, p, m, th, tlenp, 2);
+ tp->t_segqmbuflen += lenof;
+ /*
+ * Does it now dovetail with next if there is
+ * one?
+ */
+ if (q &&
+ ((p->tqe_start + p->tqe_len) == q->tqe_start)) {
+ /* Yep we can coalesce further */
+ tcp_reas_merge_into(tp, p, q);
+ }
+ *seq_start = p->tqe_start;
+ *tlenp = p->tqe_len;
+ goto present;
+ }
+ /*
+ * When we reach here we can't combine it
+ * with any existing segment.
+ *
* Limit the number of segments that can be queued to reduce the
* potential for mbuf exhaustion. For best performance, we want to be
* able to queue a full window's worth of segments. The size of the
@@ -188,9 +817,10 @@
* Investigate why and re-evaluate the below limit after the behaviour
* is understood.
*/
- if ((th->th_seq != tp->rcv_nxt || !TCPS_HAVEESTABLISHED(tp->t_state)) &&
+new_entry:
+ if ((!TCPS_HAVEESTABLISHED(tp->t_state)) &&
tp->t_segqlen >= min((so->so_rcv.sb_hiwat / tp->t_maxseg) + 1,
- tcp_reass_maxqueuelen)) {
+ tcp_reass_maxqueuelen)) {
TCPSTAT_INC(tcps_rcvreassfull);
*tlenp = 0;
if ((s = tcp_log_addrs(&tp->t_inpcb->inp_inc, th, NULL, NULL))) {
@@ -199,122 +829,48 @@
free(s, M_TCPLOG);
}
m_freem(m);
+#ifdef TCP_REASS_LOGGING
+ tcp_reass_log_dump(tp);
+#endif
return (0);
}
-
/*
* Allocate a new queue entry. If we can't, or hit the zone limit
* just drop the pkt.
- *
- * Use a temporary structure on the stack for the missing segment
- * when the zone is exhausted. Otherwise we may get stuck.
*/
te = uma_zalloc(tcp_reass_zone, M_NOWAIT);
if (te == NULL) {
- if (th->th_seq != tp->rcv_nxt || !TCPS_HAVEESTABLISHED(tp->t_state)) {
- TCPSTAT_INC(tcps_rcvmemdrop);
- m_freem(m);
- *tlenp = 0;
- if ((s = tcp_log_addrs(&tp->t_inpcb->inp_inc, th, NULL,
- NULL))) {
- log(LOG_DEBUG, "%s; %s: global zone limit "
- "reached, segment dropped\n", s, __func__);
- free(s, M_TCPLOG);
- }
- return (0);
- } else {
- bzero(&tqs, sizeof(struct tseg_qent));
- te = &tqs;
- if ((s = tcp_log_addrs(&tp->t_inpcb->inp_inc, th, NULL,
- NULL))) {
- log(LOG_DEBUG,
- "%s; %s: global zone limit reached, using "
- "stack for missing segment\n", s, __func__);
- free(s, M_TCPLOG);
- }
+ TCPSTAT_INC(tcps_rcvmemdrop);
+ m_freem(m);
+ *tlenp = 0;
+ if ((s = tcp_log_addrs(&tp->t_inpcb->inp_inc, th, NULL,
+ NULL))) {
+ log(LOG_DEBUG, "%s; %s: global zone limit "
+ "reached, segment dropped\n", s, __func__);
+ free(s, M_TCPLOG);
}
+ return (0);
}
tp->t_segqlen++;
-
- /*
- * Find a segment which begins after this one does.
- */
- LIST_FOREACH(q, &tp->t_segq, tqe_q) {
- if (SEQ_GT(q->tqe_th->th_seq, th->th_seq))
- break;
- p = q;
- }
-
- /*
- * If there is a preceding segment, it may provide some of
- * our data already. If so, drop the data from the incoming
- * segment. If it provides all of our data, drop us.
- */
- if (p != NULL) {
- int i;
- /* conversion to int (in i) handles seq wraparound */
- i = p->tqe_th->th_seq + p->tqe_len - th->th_seq;
- if (i > 0) {
- if (i >= *tlenp) {
- TCPSTAT_INC(tcps_rcvduppack);
- TCPSTAT_ADD(tcps_rcvdupbyte, *tlenp);
- m_freem(m);
- if (te != &tqs)
- uma_zfree(tcp_reass_zone, te);
- tp->t_segqlen--;
- /*
- * Try to present any queued data
- * at the left window edge to the user.
- * This is needed after the 3-WHS
- * completes.
- */
- goto present; /* ??? */
- }
- m_adj(m, i);
- *tlenp -= i;
- th->th_seq += i;
- }
- }
tp->t_rcvoopack++;
TCPSTAT_INC(tcps_rcvoopack);
TCPSTAT_ADD(tcps_rcvoobyte, *tlenp);
-
- /*
- * While we overlap succeeding segments trim them or,
- * if they are completely covered, dequeue them.
- */
- while (q) {
- int i = (th->th_seq + *tlenp) - q->tqe_th->th_seq;
- if (i <= 0)
- break;
- if (i < q->tqe_len) {
- q->tqe_th->th_seq += i;
- q->tqe_len -= i;
- m_adj(q->tqe_m, i);
- break;
- }
-
- nq = LIST_NEXT(q, tqe_q);
- LIST_REMOVE(q, tqe_q);
- m_freem(q->tqe_m);
- uma_zfree(tcp_reass_zone, q);
- tp->t_segqlen--;
- q = nq;
- }
-
/* Insert the new segment queue entry into place. */
te->tqe_m = m;
- te->tqe_th = th;
+ te->tqe_flags = th->th_flags;
te->tqe_len = *tlenp;
-
+ te->tqe_start = th->th_seq;
+ te->tqe_last = m;
+ te->tqe_mbuf_cnt = tcp_reass_setuplast(te);
+ tp->t_segqmbuflen += te->tqe_mbuf_cnt;
if (p == NULL) {
- LIST_INSERT_HEAD(&tp->t_segq, te, tqe_q);
+ TAILQ_INSERT_HEAD(&tp->t_segq, te, tqe_q);
} else {
- KASSERT(te != &tqs, ("%s: temporary stack based entry not "
- "first element in queue", __func__));
- LIST_INSERT_AFTER(p, te, tqe_q);
+ TAILQ_INSERT_AFTER(&tp->t_segq, p, te, tqe_q);
}
-
+#ifdef TCP_REASS_LOGGING
+ tcp_reass_log_new_in(tp, th->th_seq, *tlenp, m, TCP_R_LOG_NEW_ENTRY, te);
+#endif
present:
/*
* Present data to user, advancing rcv_nxt through
@@ -322,24 +878,55 @@
*/
if (!TCPS_HAVEESTABLISHED(tp->t_state))
return (0);
- q = LIST_FIRST(&tp->t_segq);
- if (!q || q->tqe_th->th_seq != tp->rcv_nxt)
+ q = TAILQ_FIRST(&tp->t_segq);
+ KASSERT(q == NULL || SEQ_GEQ(q->tqe_start, tp->rcv_nxt),
+ ("Reassembly queue for %p has stale entry at head", tp));
+ if (!q || q->tqe_start != tp->rcv_nxt) {
+#ifdef TCP_REASS_LOGGING
+ tcp_reass_log_dump(tp);
+#endif
return (0);
+ }
SOCKBUF_LOCK(&so->so_rcv);
do {
tp->rcv_nxt += q->tqe_len;
- flags = q->tqe_th->th_flags & TH_FIN;
- nq = LIST_NEXT(q, tqe_q);
- LIST_REMOVE(q, tqe_q);
- if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
+ flags = q->tqe_flags & TH_FIN;
+ nq = TAILQ_NEXT(q, tqe_q);
+ TAILQ_REMOVE(&tp->t_segq, q, tqe_q);
+ if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
m_freem(q->tqe_m);
- else
+ } else {
+#ifdef TCP_REASS_LOGGING
+ tcp_reass_log_new_in(tp, q->tqe_start, q->tqe_len, q->tqe_m, TCP_R_LOG_READ, q);
+ tcp_log_reassm(tp, q, NULL, th->th_seq, *tlenp, TCP_R_LOG_READ, 1);
+#endif
sbappendstream_locked(&so->so_rcv, q->tqe_m, 0);
- if (q != &tqs)
- uma_zfree(tcp_reass_zone, q);
+ }
+#ifdef TCP_REASS_LOGGING
+ tcp_log_reassm(tp, q, NULL, th->th_seq, *tlenp, TCP_R_LOG_READ, 2);
+#endif
+ KASSERT(tp->t_segqmbuflen >= q->tqe_mbuf_cnt,
+ ("tp:%p seg queue goes negative", tp));
+ tp->t_segqmbuflen -= q->tqe_mbuf_cnt;
+ uma_zfree(tcp_reass_zone, q);
tp->t_segqlen--;
q = nq;
- } while (q && q->tqe_th->th_seq == tp->rcv_nxt);
+ } while (q && q->tqe_start == tp->rcv_nxt);
+ if (TAILQ_EMPTY(&tp->t_segq) &&
+ (tp->t_segqmbuflen != 0)) {
+#ifdef INVARIANTS
+ panic("tp:%p segq:%p len:%d queue empty",
+ tp, &tp->t_segq, tp->t_segqmbuflen);
+#else
+#ifdef TCP_REASS_LOGGING
+ tcp_log_reassm(tp, NULL, NULL, th->th_seq, *tlenp, TCP_R_LOG_ZERO, 0);
+#endif
+ tp->t_segqmbuflen = 0;
+#endif
+ }
+#ifdef TCP_REASS_LOGGING
+ tcp_reass_log_dump(tp);
+#endif
sorwakeup_locked(so);
return (flags);
}
Index: netinet/tcp_stacks/rack.c
===================================================================
--- netinet/tcp_stacks/rack.c
+++ netinet/tcp_stacks/rack.c
@@ -4780,7 +4780,7 @@
* segments are out of order (so fast retransmit can work).
*/
if (th->th_seq == tp->rcv_nxt &&
- LIST_EMPTY(&tp->t_segq) &&
+ TAILQ_EMPTY(&tp->t_segq) &&
(TCPS_HAVEESTABLISHED(tp->t_state) ||
tfo_syn)) {
if (DELAY_ACK(tp, tlen) || tfo_syn) {
@@ -4808,7 +4808,7 @@
* m_adj() doesn't actually frees any mbufs when
* trimming from the head.
*/
- thflags = tcp_reass(tp, th, &tlen, m);
+ thflags = tcp_reass(tp, th, &save_start, &tlen, m);
tp->t_flags |= TF_ACKNOW;
}
if (tlen > 0)
@@ -5509,7 +5509,7 @@
* not, do so now to pass queued data to user.
*/
if (tlen == 0 && (thflags & TH_FIN) == 0)
- (void)tcp_reass(tp, (struct tcphdr *)0, 0,
+ (void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
(struct mbuf *)0);
tp->snd_wl1 = th->th_seq - 1;
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
@@ -5574,7 +5574,7 @@
*/
if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
__predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_URG | TH_ACK)) == TH_ACK) &&
- __predict_true(LIST_EMPTY(&tp->t_segq)) &&
+ __predict_true(TAILQ_EMPTY(&tp->t_segq)) &&
__predict_true(th->th_seq == tp->rcv_nxt)) {
struct tcp_rack *rack;
Index: netinet/tcp_subr.c
===================================================================
--- netinet/tcp_subr.c
+++ netinet/tcp_subr.c
@@ -1622,7 +1622,7 @@
tp->t_vnet = inp->inp_vnet;
#endif
tp->t_timers = &tm->tt;
- /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */
+ TAILQ_INIT(&tp->t_segq);
tp->t_maxseg =
#ifdef INET6
isipv6 ? V_tcp_v6mssdflt :
Index: netinet/tcp_usrreq.c
===================================================================
--- netinet/tcp_usrreq.c
+++ netinet/tcp_usrreq.c
@@ -2521,7 +2521,7 @@
db_print_indent(indent);
db_printf("t_segq first: %p t_segqlen: %d t_dupacks: %d\n",
- LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
+ TAILQ_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
db_print_indent(indent);
db_printf("tt_rexmt: %p tt_persist: %p tt_keep: %p\n",
Index: netinet/tcp_var.h
===================================================================
--- netinet/tcp_var.h
+++ netinet/tcp_var.h
@@ -46,12 +46,15 @@
#if defined(_KERNEL) || defined(_WANT_TCPCB)
/* TCP segment queue entry */
struct tseg_qent {
- LIST_ENTRY(tseg_qent) tqe_q;
+ TAILQ_ENTRY(tseg_qent) tqe_q;
+ struct mbuf *tqe_m; /* mbuf contains packet */
+ struct mbuf *tqe_last; /* last mbuf in chain */
+ tcp_seq tqe_start; /* TCP Sequence number start */
int tqe_len; /* TCP segment data length */
- struct tcphdr *tqe_th; /* a pointer to tcp header */
- struct mbuf *tqe_m; /* mbuf contains packet */
+ uint32_t tqe_flags; /* The flags from the th->th_flags */
+ uint32_t tqe_mbuf_cnt; /* Count of mbuf overhead */
};
-LIST_HEAD(tsegqe_head, tseg_qent);
+TAILQ_HEAD(tsegqe_head, tseg_qent);
struct sackblk {
tcp_seq start; /* start seq no. of sack block */
@@ -131,6 +134,7 @@
/* Cache line 3 */
tcp_seq rcv_up; /* receive urgent pointer */
int t_segqlen; /* segment reassembly queue length */
+ uint32_t t_segqmbuflen; /* Count of bytes mbufs on all entries */
struct tsegqe_head t_segq; /* segment reassembly queue */
struct mbuf *t_in_pkt;
struct mbuf *t_tail_pkt;
@@ -837,7 +841,7 @@
const void *);
char *tcp_log_vain(struct in_conninfo *, struct tcphdr *, void *,
const void *);
-int tcp_reass(struct tcpcb *, struct tcphdr *, int *, struct mbuf *);
+int tcp_reass(struct tcpcb *, struct tcphdr *, tcp_seq *, int *, struct mbuf *);
void tcp_reass_global_init(void);
void tcp_reass_flush(struct tcpcb *);
void tcp_dooptions(struct tcpopt *, u_char *, int, int);

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