Deal with the case where a syncache entry added by the TOE driver is

evicted from the syncache but a later syncache_expand succeeds because
of syncookies.  The TOE driver has to resort to more direct means to
install its hooks in the socket in this case.

4 files changed, 33 insertions, 0 deletions

diff --git a/sys/dev/cxgb/ulp/tom/cxgb_listen.c b/sys/dev/cxgb/ulp/tom/cxgb_listen.c
index c80abf0..8148ae4 100644
--- a/sys/dev/cxgb/ulp/tom/cxgb_listen.c
+++ b/sys/dev/cxgb/ulp/tom/cxgb_listen.c
@@ -41,6 +41,7 @@ __FBSDID("$FreeBSD$");
 #include <netinet/ip.h>
 #include <netinet/in_pcb.h>
 #include <netinet/in_var.h>
+#include <netinet/tcp_timer.h>
 #include <netinet/tcp_var.h>
 #define TCPSTATES
 #include <netinet/tcp_fsm.h>
@@ -759,6 +760,15 @@ reset:
 		goto reset;
 	}
 
+	if (__predict_false(!(synqe->flags & TP_SYNQE_EXPANDED))) {
+		struct inpcb *new_inp = sotoinpcb(so);
+
+		INP_WLOCK(new_inp);
+		tcp_timer_activate(intotcpcb(new_inp), TT_KEEP, 0);
+		t3_offload_socket(tod, synqe, so);
+		INP_WUNLOCK(new_inp);
+	}
+
 	/* Remove the synq entry and release its reference on the lctx */
 	TAILQ_REMOVE(&lctx->synq, synqe, link);
 	inp = release_lctx(td, lctx);
@@ -1136,5 +1146,6 @@ t3_offload_socket(struct toedev *tod, void *arg, struct socket *so)
 	offload_socket(so, toep);
 	make_established(so, cpl->snd_isn, cpl->rcv_isn, cpl->tcp_opt);
 	update_tid(td, toep, synqe->tid);
+	synqe->flags |= TP_SYNQE_EXPANDED;
 }
 #endif
diff --git a/sys/dev/cxgb/ulp/tom/cxgb_toepcb.h b/sys/dev/cxgb/ulp/tom/cxgb_toepcb.h
index d0046c8..d821a01 100644
--- a/sys/dev/cxgb/ulp/tom/cxgb_toepcb.h
+++ b/sys/dev/cxgb/ulp/tom/cxgb_toepcb.h
@@ -44,6 +44,7 @@
 #define TP_IS_A_SYNQ_ENTRY	(1 << 9)
 #define TP_ABORT_RPL_SENT	(1 << 10)
 #define TP_SEND_FIN          	(1 << 11)
+#define TP_SYNQE_EXPANDED	(1 << 12)
 
 struct toepcb {
 	TAILQ_ENTRY(toepcb) link; /* toep_list */
diff --git a/sys/dev/cxgbe/tom/t4_listen.c b/sys/dev/cxgbe/tom/t4_listen.c
index c717a90a..19b9b4b 100644
--- a/sys/dev/cxgbe/tom/t4_listen.c
+++ b/sys/dev/cxgbe/tom/t4_listen.c
@@ -50,6 +50,7 @@ __FBSDID("$FreeBSD$");
 #include <netinet/in.h>
 #include <netinet/in_pcb.h>
 #include <netinet/ip.h>
+#include <netinet/tcp_timer.h>
 #include <netinet/tcp_var.h>
 #define TCPSTATES
 #include <netinet/tcp_fsm.h>
@@ -805,6 +806,7 @@ t4_offload_socket(struct toedev *tod, void *arg, struct socket *so)
 	make_established(toep, cpl->snd_isn, cpl->rcv_isn, cpl->tcp_opt);
 	toep->flags |= TPF_CPL_PENDING;
 	update_tid(sc, synqe->tid, toep);
+	synqe->flags |= TPF_SYNQE_EXPANDED;
 }
 
 static inline void
@@ -1349,6 +1351,24 @@ reset:
 		goto reset;
 	}
 
+	/*
+	 * This is for the unlikely case where the syncache entry that we added
+	 * has been evicted from the syncache, but the syncache_expand above
+	 * works because of syncookies.
+	 *
+	 * XXX: we've held the tcbinfo lock throughout so there's no risk of
+	 * anyone accept'ing a connection before we've installed our hooks, but
+	 * this somewhat defeats the purpose of having a tod_offload_socket :-(
+	 */
+	if (__predict_false(!(synqe->flags & TPF_SYNQE_EXPANDED))) {
+		struct inpcb *new_inp = sotoinpcb(so);
+
+		INP_WLOCK(new_inp);
+		tcp_timer_activate(intotcpcb(new_inp), TT_KEEP, 0);
+		t4_offload_socket(TOEDEV(ifp), synqe, so);
+		INP_WUNLOCK(new_inp);
+	}
+
 	/* Done with the synqe */
 	TAILQ_REMOVE(&lctx->synq, synqe, link);
 	inp = release_lctx(sc, lctx);
diff --git a/sys/dev/cxgbe/tom/t4_tom.h b/sys/dev/cxgbe/tom/t4_tom.h
index f75afd3..2e6bad4 100644
--- a/sys/dev/cxgbe/tom/t4_tom.h
+++ b/sys/dev/cxgbe/tom/t4_tom.h
@@ -66,6 +66,7 @@ enum {
 	TPF_SYNQE	   = (1 << 8),	/* synq_entry, not really a toepcb */
 	TPF_SYNQE_NEEDFREE = (1 << 9),	/* synq_entry was malloc'd separately */
 	TPF_SYNQE_TCPDDP   = (1 << 10),	/* ulp_mode TCPDDP in toepcb */
+	TPF_SYNQE_EXPANDED = (1 << 11),	/* toepcb ready, tid context updated */
 };
 
 enum {