git: d1ce01214a55 - main - TCP LRO: disable mbuf queuing when packet filter hooks are in place

The branch main has been updated by tuexen:

URL: https://cgit.FreeBSD.org/src/commit/?id=d1ce01214a5540db8a7e09fdf46b7ea2d06ffc48

commit d1ce01214a5540db8a7e09fdf46b7ea2d06ffc48
Author:     Michael Tuexen <tuexen@FreeBSD.org>
AuthorDate: 2024-03-08 09:03:43 +0000
Commit:     Michael Tuexen <tuexen@FreeBSD.org>
CommitDate: 2024-03-08 09:03:43 +0000

    TCP LRO: disable mbuf queuing when packet filter hooks are in place
    
    When doing mbuf queueing, the packet filter hooks in ether_demux(),
    ip_input(), and ip6_input() are by-passed. This means that the packet
    filters don't process incoming packets, which might result in
    connection failures. For example bypassing the TCP sequence number
    validation will result in dropping valid packets.
    Please note that this patch is only disabling mbuf queueing, not LRO.
    
    Reported by:            Herbert J. Skuhra
    Reviewed by:            glebius, rrs, rscheff
    MFC after:              1 week
    Sponsored by:           Netflix, Inc.
    Differential Revision:  https://reviews.freebsd.org/D43769
---
 sys/netinet/tcp_lro_hpts.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/sys/netinet/tcp_lro_hpts.c b/sys/netinet/tcp_lro_hpts.c
index 84944c8db1ce..9c0d4be91d53 100644
--- a/sys/netinet/tcp_lro_hpts.c
+++ b/sys/netinet/tcp_lro_hpts.c
@@ -47,6 +47,7 @@
 #include <net/if_types.h>
 #include <net/infiniband.h>
 #include <net/if_lagg.h>
+#include <net/pfil.h>
 
 #include <netinet/in.h>
 #include <netinet/ip6.h>
@@ -54,6 +55,7 @@
 #include <netinet/ip_var.h>
 #include <netinet/in_pcb.h>
 #include <netinet6/in6_pcb.h>
+#include <netinet6/ip6_var.h>
 #include <netinet/tcp.h>
 #include <netinet/tcp_lro.h>
 #include <netinet/tcp_var.h>
@@ -424,7 +426,7 @@ tcp_lro_lookup(struct ifnet *ifp, struct lro_parser *pa)
 {
 	struct inpcb *inp;
 
-	CURVNET_SET(ifp->if_vnet);
+	CURVNET_ASSERT_SET();
 	switch (pa->data.lro_type) {
 #ifdef INET6
 	case LRO_TYPE_IPV6_TCP:
@@ -449,10 +451,8 @@ tcp_lro_lookup(struct ifnet *ifp, struct lro_parser *pa)
 		break;
 #endif
 	default:
-		CURVNET_RESTORE();
 		return (NULL);
 	}
-	CURVNET_RESTORE();
 
 	return (intotcpcb(inp));
 }
@@ -488,9 +488,28 @@ _tcp_lro_flush_tcphpts(struct lro_ctrl *lc, struct lro_entry *le)
 	    IN6_IS_ADDR_UNSPECIFIED(&le->inner.data.s_addr.v6)))
 		return (TCP_LRO_CANNOT);
 #endif
+
+	CURVNET_SET(lc->ifp->if_vnet);
+	/*
+	 * Ensure that there are no packet filter hooks which would normally
+	 * being triggered in ether_demux(), ip_input(), or ip6_input().
+	 */
+	if (
+#ifdef INET
+	    PFIL_HOOKED_IN(V_inet_pfil_head) ||
+#endif
+#ifdef INET6
+	    PFIL_HOOKED_IN(V_inet6_pfil_head) ||
+#endif
+	    PFIL_HOOKED_IN(V_link_pfil_head)) {
+		CURVNET_RESTORE();
+		return (TCP_LRO_CANNOT);
+	}
+
 	/* Lookup inp, if any.  Returns locked TCP inpcb. */
 	tp = tcp_lro_lookup(lc->ifp,
 	    (le->inner.data.lro_type == LRO_TYPE_NONE) ? &le->outer : &le->inner);
+	CURVNET_RESTORE();
 	if (tp == NULL)
 		return (TCP_LRO_CANNOT);