Make the routing socket more MP save by using a SRPL list for the pcb list.

Still needs the big kernel lock but this is another step in the right direction.
With and OK mpi@

1 files changed, 65 insertions, 56 deletions

diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index 6a516bf00cd..35bdd09d143 100644
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rtsock.c,v 1.259 2017/12/18 09:40:17 mpi Exp $	*/
+/*	$OpenBSD: rtsock.c,v 1.260 2018/02/08 22:24:41 claudio Exp $	*/
 /*	$NetBSD: rtsock.c,v 1.18 1996/03/29 00:32:10 cgd Exp $	*/
 
 /*
@@ -70,6 +70,7 @@
 #include <sys/socketvar.h>
 #include <sys/domain.h>
 #include <sys/protosw.h>
+#include <sys/srp.h>
 
 #include <net/if.h>
 #include <net/if_dl.h>
@@ -94,7 +95,6 @@
 #include <sys/kernel.h>
 #include <sys/timeout.h>
 
-struct sockaddr		route_dst = { 2, PF_ROUTE, };
 struct sockaddr		route_src = { 2, PF_ROUTE, };
 
 struct walkarg {
@@ -103,6 +103,8 @@ struct walkarg {
 };
 
 void	route_prinit(void);
+void	route_ref(void *, void *);
+void	route_unref(void *, void *);
 int	route_output(struct mbuf *, struct socket *, struct sockaddr *,
 	    struct mbuf *);
 int	route_ctloutput(int, struct socket *, int, int, struct mbuf *);
@@ -133,7 +135,8 @@ int		 sysctl_rtable_rtstat(void *, size_t *, void *);
 
 struct routecb {
 	struct rawcb		rcb;
-	LIST_ENTRY(routecb)	rcb_list;
+	SRPL_ENTRY(routecb)	rcb_list;
+	struct refcnt		refcnt;
 	struct timeout		timeout;
 	unsigned int		msgfilter;
 	unsigned int		flags;
@@ -142,11 +145,10 @@ struct routecb {
 #define	sotoroutecb(so)	((struct routecb *)(so)->so_pcb)
 
 struct route_cb {
-	LIST_HEAD(, routecb)	rcb;
-	int			ip_count;
-	int			ip6_count;
-	int			mpls_count;
-	int			any_count;
+	SRPL_HEAD(, routecb)	rcb;
+	struct srpl_rc		rcb_rc;
+	struct rwlock		rcb_lk;
+	unsigned int		any_count;
 };
 
 struct route_cb route_cb;
@@ -165,9 +167,26 @@ struct route_cb route_cb;
 void
 route_prinit(void)
 {
-	LIST_INIT(&route_cb.rcb);
+	srpl_rc_init(&route_cb.rcb_rc, route_ref, route_unref, NULL);
+	rw_init(&route_cb.rcb_lk, "rtsock");
+	SRPL_INIT(&route_cb.rcb);
 }
 
+void
+route_ref(void *null, void *v)
+{
+	struct routecb *rop = v;
+
+	refcnt_take(&rop->refcnt);
+}
+
+void
+route_unref(void *null, void *v)
+{
+	struct routecb *rop = v;
+
+	refcnt_rele_wake(&rop->refcnt);
+}
 
 int
 route_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam,
@@ -218,9 +237,10 @@ route_attach(struct socket *so, int proto)
 	 */
 	rop = malloc(sizeof(struct routecb), M_PCB, M_WAITOK|M_ZERO);
 	rp = &rop->rcb;
-	so->so_pcb = rp;
+	so->so_pcb = rop;
 	/* Init the timeout structure */
-	timeout_set(&rop->timeout, route_senddesync, rp);
+	timeout_set(&rop->timeout, route_senddesync, rop);
+	refcnt_init(&rop->refcnt);
 
 	if (curproc == NULL)
 		error = EACCES;
@@ -230,31 +250,24 @@ route_attach(struct socket *so, int proto)
 		free(rop, M_PCB, sizeof(struct routecb));
 		return (error);
 	}
+
 	rp->rcb_socket = so;
 	rp->rcb_proto.sp_family = so->so_proto->pr_domain->dom_family;
 	rp->rcb_proto.sp_protocol = proto;
 
 	rop->rtableid = curproc->p_p->ps_rtableid;
-	switch (rp->rcb_proto.sp_protocol) {
-	case AF_INET:
-		route_cb.ip_count++;
-		break;
-	case AF_INET6:
-		route_cb.ip6_count++;
-		break;
-#ifdef MPLS
-	case AF_MPLS:
-		route_cb.mpls_count++;
-		break;
-#endif
-	}
 
 	soisconnected(so);
 	so->so_options |= SO_USELOOPBACK;
 
 	rp->rcb_faddr = &route_src;
+
+	rw_enter(&route_cb.rcb_lk, RW_WRITE);
+
+	SRPL_INSERT_HEAD_LOCKED(&route_cb.rcb_rc, &route_cb.rcb, rop, rcb_list);
 	route_cb.any_count++;
-	LIST_INSERT_HEAD(&route_cb.rcb, rop, rcb_list);
+
+	rw_exit(&route_cb.rcb_lk);
 
 	return (0);
 }
@@ -263,7 +276,6 @@ int
 route_detach(struct socket *so)
 {
 	struct routecb	*rop;
-	int		 af;
 
 	soassertlocked(so);
 
@@ -271,18 +283,17 @@ route_detach(struct socket *so)
 	if (rop == NULL)
 		return (EINVAL);
 
+	rw_enter(&route_cb.rcb_lk, RW_WRITE);
+
 	timeout_del(&rop->timeout);
-	af = rop->rcb.rcb_proto.sp_protocol;
-	if (af == AF_INET)
-		route_cb.ip_count--;
-	else if (af == AF_INET6)
-		route_cb.ip6_count--;
-#ifdef MPLS
-	else if (af == AF_MPLS)
-		route_cb.mpls_count--;
-#endif
 	route_cb.any_count--;
-	LIST_REMOVE(rop, rcb_list);
+
+	SRPL_REMOVE_LOCKED(&route_cb.rcb_rc, &route_cb.rcb,
+	    rop, routecb, rcb_list);
+
+	rw_exit(&route_cb.rcb_lk);
+	/* wait for all references to drop */
+	refcnt_finalize(&rop->refcnt, "rtsockrefs");
 
 	so->so_pcb = NULL;
 	sofree(so);
@@ -348,12 +359,10 @@ route_ctloutput(int op, struct socket *so, int level, int optname,
 void
 route_senddesync(void *data)
 {
-	struct rawcb	*rp;
 	struct routecb	*rop;
 	struct mbuf	*desync_mbuf;
 
-	rp = (struct rawcb *)data;
-	rop = (struct routecb *)rp;
+	rop = (struct routecb *)data;
 
 	/* If we are in a DESYNC state, try to send a RTM_DESYNC packet */
 	if ((rop->flags & ROUTECB_FLAG_DESYNC) == 0)
@@ -365,11 +374,11 @@ route_senddesync(void *data)
 	 */
 	desync_mbuf = rtm_msg1(RTM_DESYNC, NULL);
 	if (desync_mbuf != NULL) {
-		struct socket *so = rp->rcb_socket;
+		struct socket *so = rop->rcb.rcb_socket;
 		if (sbappendaddr(so, &so->so_rcv, &route_src,
 		    desync_mbuf, NULL) != 0) {
 			rop->flags &= ~ROUTECB_FLAG_DESYNC;
-			sorwakeup(rp->rcb_socket);
+			sorwakeup(rop->rcb.rcb_socket);
 			return;
 		}
 		m_freem(desync_mbuf);
@@ -381,26 +390,22 @@ route_senddesync(void *data)
 void
 route_input(struct mbuf *m0, struct socket *so, sa_family_t sa_family)
 {
-	struct rawcb *rp;
 	struct routecb *rop;
+	struct rawcb *rp;
 	struct rt_msghdr *rtm;
 	struct mbuf *m = m0;
-	int sockets = 0;
 	struct socket *last = NULL;
-	struct sockaddr *sosrc, *sodst;
+	struct srp_ref sr;
 
 	KERNEL_ASSERT_LOCKED();
 
-	sosrc = &route_src;
-	sodst = &route_dst;
-
 	/* ensure that we can access the rtm_type via mtod() */
 	if (m->m_len < offsetof(struct rt_msghdr, rtm_type) + 1) {
 		m_freem(m);
 		return;
 	}
 
-	LIST_FOREACH(rop, &route_cb.rcb, rcb_list) {
+	SRPL_FOREACH(rop, &sr, &route_cb.rcb, rcb_list) {
 		rp = &rop->rcb;
 		if (!(rp->rcb_socket->so_state & SS_ISCONNECTED))
 			continue;
@@ -459,8 +464,8 @@ route_input(struct mbuf *m0, struct socket *so, sa_family_t sa_family)
 			struct mbuf *n;
 			if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) {
 				if (sbspace(last, &last->so_rcv) < (2*MSIZE) ||
-				    sbappendaddr(last, &last->so_rcv, sosrc,
-				    n, (struct mbuf *)NULL) == 0) {
+				    sbappendaddr(last, &last->so_rcv,
+				    &route_src, n, (struct mbuf *)NULL) == 0) {
 					/*
 					 * Flag socket as desync'ed and
 					 * flush required
@@ -468,31 +473,35 @@ route_input(struct mbuf *m0, struct socket *so, sa_family_t sa_family)
 					sotoroutecb(last)->flags |=
 					    ROUTECB_FLAG_DESYNC |
 					    ROUTECB_FLAG_FLUSH;
-					route_senddesync(sotorawcb(last));
+					route_senddesync(sotoroutecb(last));
 					m_freem(n);
 				} else {
 					sorwakeup(last);
-					sockets++;
 				}
 			}
+			refcnt_rele_wake(&sotoroutecb(last)->refcnt);
 		}
-		last = rp->rcb_socket;
+		/* keep a reference for last */
+		refcnt_take(&rop->refcnt);
+		last = rop->rcb.rcb_socket;
 	}
 	if (last) {
 		if (sbspace(last, &last->so_rcv) < (2 * MSIZE) ||
-		    sbappendaddr(last, &last->so_rcv, sosrc,
+		    sbappendaddr(last, &last->so_rcv, &route_src,
 		    m, (struct mbuf *)NULL) == 0) {
 			/* Flag socket as desync'ed and flush required */
 			sotoroutecb(last)->flags |=
 			    ROUTECB_FLAG_DESYNC | ROUTECB_FLAG_FLUSH;
-			route_senddesync(sotorawcb(last));
+			route_senddesync(sotoroutecb(last));
 			m_freem(m);
 		} else {
 			sorwakeup(last);
-			sockets++;
 		}
+		refcnt_rele_wake(&sotoroutecb(last)->refcnt);
 	} else
 		m_freem(m);
+
+	SRPL_LEAVE(&sr);
 }
 
 struct rt_msghdr *