Use rwlock per inpcb table to protect notify list. The notify

function may sleep, so holding a mutex is not possible.  The same
list entry and rwlock is used for UDP multicast and raw IP delivery.
By adding a write lock, exclusive netlock is no longer necessary
for PCB notify and UDP and raw IP input.
OK mvs@

diff --git a/sys/netinet/in_pcb.c b/sys/netinet/in_pcb.c
index 903a03b..d145fb6 100644 (file)
--- a/sys/netinet/in_pcb.c
+++ b/sys/netinet/in_pcb.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: in_pcb.c,v 1.271 2022/08/21 11:44:53 bluhm Exp $      */
+/*     $OpenBSD: in_pcb.c,v 1.272 2022/08/22 10:37:27 bluhm Exp $      */
 /*     $NetBSD: in_pcb.c,v 1.25 1996/02/13 23:41:53 christos Exp $     */
 
 /*
@@ -175,6 +175,7 @@ void
 in_pcbinit(struct inpcbtable *table, int hashsize)
 {
        mtx_init(&table->inpt_mtx, IPL_SOFTNET);
+       rw_init(&table->inpt_notify, "inpnotify");
        TAILQ_INIT(&table->inpt_queue);
        table->inpt_hashtbl = hashinit(hashsize, M_PCB, M_WAITOK,
            &table->inpt_mask);
@@ -696,8 +697,6 @@ in_pcbnotifyall(struct inpcbtable *table, struct sockaddr *dst, u_int rtable,
        struct in_addr faddr;
        u_int rdomain;
 
-       NET_ASSERT_LOCKED_EXCLUSIVE();
-
        if (dst->sa_family != AF_INET)
                return;
        faddr = satosin(dst)->sin_addr;
@@ -706,8 +705,18 @@ in_pcbnotifyall(struct inpcbtable *table, struct sockaddr *dst, u_int rtable,
        if (notify == NULL)
                return;
 
+       /*
+        * Use a temporary notify list protected by rwlock to run over
+        * selected PCB.  This is necessary as the list of all PCB is
+        * protected by a mutex.  Notify may call ip_output() eventually
+        * which may sleep as pf lock is a rwlock.  Also the SRP
+        * implementation of the routing table might sleep.
+        * The same inp_notify list entry and inpt_notify rwlock are
+        * used for UDP multicast and raw IP delivery.
+        */
        SIMPLEQ_INIT(&inpcblist);
        rdomain = rtable_l2(rtable);
+       rw_enter_write(&table->inpt_notify);
        mtx_enter(&table->inpt_mtx);
        TAILQ_FOREACH(inp, &table->inpt_queue, inp_queue) {
 #ifdef INET6
@@ -729,6 +738,7 @@ in_pcbnotifyall(struct inpcbtable *table, struct sockaddr *dst, u_int rtable,
                (*notify)(inp, errno);
                in_pcbunref(inp);
        }
+       rw_exit_write(&table->inpt_notify);
 }
 
 /*

diff --git a/sys/netinet/in_pcb.h b/sys/netinet/in_pcb.h
index 9d19225..cc262a2 100644 (file)
--- a/sys/netinet/in_pcb.h
+++ b/sys/netinet/in_pcb.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: in_pcb.h,v 1.130 2022/08/21 11:44:53 bluhm Exp $      */
+/*     $OpenBSD: in_pcb.h,v 1.131 2022/08/22 10:37:27 bluhm Exp $      */
 /*     $NetBSD: in_pcb.h,v 1.14 1996/02/13 23:42:00 christos Exp $     */
 
 /*
@@ -66,6 +66,7 @@
 
 #include <sys/queue.h>
 #include <sys/mutex.h>
+#include <sys/rwlock.h>
 #include <sys/refcnt.h>
 #include <netinet/ip6.h>
 #include <netinet6/ip6_var.h>
@@ -79,6 +80,7 @@
  *     I       immutable after creation
  *     N       net lock
  *     t       inpt_mtx                pcb table mutex
+ *     y       inpt_notify             pcb table rwlock for notify
  *     p       inpcb_mtx               pcb mutex
  */
 
@@ -103,7 +105,7 @@ struct inpcb {
        LIST_ENTRY(inpcb) inp_hash;             /* [t] local and foreign hash */
        LIST_ENTRY(inpcb) inp_lhash;            /* [t] local port hash */
        TAILQ_ENTRY(inpcb) inp_queue;           /* [t] inet PCB queue */
-       SIMPLEQ_ENTRY(inpcb) inp_notify;        /* [N] notify or udp append */
+       SIMPLEQ_ENTRY(inpcb) inp_notify;        /* [y] notify or udp append */
        struct    inpcbtable *inp_table;        /* [I] inet queue/hash table */
        union     inpaddru inp_faddru;          /* Foreign address. */
        union     inpaddru inp_laddru;          /* Local address. */
@@ -166,6 +168,7 @@ LIST_HEAD(inpcbhead, inpcb);
 
 struct inpcbtable {
        struct mutex inpt_mtx;                  /* protect queue and hash */
+       struct rwlock inpt_notify;              /* protect inp_notify list */
        TAILQ_HEAD(inpthead, inpcb) inpt_queue; /* [t] inet PCB queue */
        struct  inpcbhead *inpt_hashtbl;        /* [t] local and foreign hash */
        struct  inpcbhead *inpt_lhashtbl;       /* [t] local port hash */

diff --git a/sys/netinet/raw_ip.c b/sys/netinet/raw_ip.c
index 66c096b..b5368df 100644 (file)
--- a/sys/netinet/raw_ip.c
+++ b/sys/netinet/raw_ip.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: raw_ip.c,v 1.134 2022/08/22 08:08:46 mvs Exp $        */
+/*     $OpenBSD: raw_ip.c,v 1.135 2022/08/22 10:37:27 bluhm Exp $      */
 /*     $NetBSD: raw_ip.c,v 1.25 1996/02/18 18:58:33 christos Exp $     */
 
 /*
@@ -160,8 +160,8 @@ rip_input(struct mbuf **mp, int *offp, int proto, int af)
                }
        }
 #endif
-       NET_ASSERT_LOCKED_EXCLUSIVE();
        SIMPLEQ_INIT(&inpcblist);
+       rw_enter_write(&rawcbtable.inpt_notify);
        mtx_enter(&rawcbtable.inpt_mtx);
        TAILQ_FOREACH(inp, &rawcbtable.inpt_queue, inp_queue) {
                if (inp->inp_socket->so_state & SS_CANTRCVMORE)
@@ -189,6 +189,8 @@ rip_input(struct mbuf **mp, int *offp, int proto, int af)
        mtx_leave(&rawcbtable.inpt_mtx);
 
        if (SIMPLEQ_EMPTY(&inpcblist)) {
+               rw_exit_write(&rawcbtable.inpt_notify);
+
                if (ip->ip_p != IPPROTO_ICMP)
                        icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PROTOCOL,
                            0, 0);
@@ -199,6 +201,8 @@ rip_input(struct mbuf **mp, int *offp, int proto, int af)
                counters[ips_noproto]++;
                counters[ips_delivered]--;
                counters_leave(&ref, ipcounters);
+
+               return IPPROTO_DONE;
        }
 
        while ((inp = SIMPLEQ_FIRST(&inpcblist)) != NULL) {
@@ -224,6 +228,8 @@ rip_input(struct mbuf **mp, int *offp, int proto, int af)
                }
                in_pcbunref(inp);
        }
+       rw_exit_write(&rawcbtable.inpt_notify);
+
        return IPPROTO_DONE;
 }
 

diff --git a/sys/netinet/udp_usrreq.c b/sys/netinet/udp_usrreq.c
index e813571..5a0ade0 100644 (file)
--- a/sys/netinet/udp_usrreq.c
+++ b/sys/netinet/udp_usrreq.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: udp_usrreq.c,v 1.286 2022/08/22 08:08:46 mvs Exp $    */
+/*     $OpenBSD: udp_usrreq.c,v 1.287 2022/08/22 10:37:27 bluhm Exp $  */
 /*     $NetBSD: udp_usrreq.c,v 1.28 1996/03/16 23:54:03 christos Exp $ */
 
 /*
@@ -372,8 +372,8 @@ udp_input(struct mbuf **mp, int *offp, int proto, int af)
                 * Locate pcb(s) for datagram.
                 * (Algorithm copied from raw_intr().)
                 */
-               NET_ASSERT_LOCKED_EXCLUSIVE();
                SIMPLEQ_INIT(&inpcblist);
+               rw_enter_write(&udbtable.inpt_notify);
                mtx_enter(&udbtable.inpt_mtx);
                TAILQ_FOREACH(inp, &udbtable.inpt_queue, inp_queue) {
                        if (inp->inp_socket->so_state & SS_CANTRCVMORE)
@@ -446,6 +446,8 @@ udp_input(struct mbuf **mp, int *offp, int proto, int af)
                mtx_leave(&udbtable.inpt_mtx);
 
                if (SIMPLEQ_EMPTY(&inpcblist)) {
+                       rw_exit_write(&udbtable.inpt_notify);
+
                        /*
                         * No matching pcb found; discard datagram.
                         * (No need to send an ICMP Port Unreachable
@@ -469,6 +471,8 @@ udp_input(struct mbuf **mp, int *offp, int proto, int af)
                        }
                        in_pcbunref(inp);
                }
+               rw_exit_write(&udbtable.inpt_notify);
+
                return IPPROTO_DONE;
        }
        /*

diff --git a/sys/netinet6/in6_pcb.c b/sys/netinet6/in6_pcb.c
index 43a6e73..471a961 100644 (file)
--- a/sys/netinet6/in6_pcb.c
+++ b/sys/netinet6/in6_pcb.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: in6_pcb.c,v 1.119 2022/08/08 12:06:31 bluhm Exp $     */
+/*     $OpenBSD: in6_pcb.c,v 1.120 2022/08/22 10:37:27 bluhm Exp $     */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -387,8 +387,6 @@ in6_pcbnotify(struct inpcbtable *table, struct sockaddr_in6 *dst,
        u_int32_t flowinfo;
        u_int rdomain;
 
-       NET_ASSERT_LOCKED_EXCLUSIVE();
-
        if ((unsigned)cmd >= PRC_NCMDS)
                return;
 
@@ -430,6 +428,7 @@ in6_pcbnotify(struct inpcbtable *table, struct sockaddr_in6 *dst,
 
        SIMPLEQ_INIT(&inpcblist);
        rdomain = rtable_l2(rtable);
+       rw_enter_write(&table->inpt_notify);
        mtx_enter(&table->inpt_mtx);
        TAILQ_FOREACH(inp, &table->inpt_queue, inp_queue) {
                if ((inp->inp_flags & INP_IPV6) == 0)
@@ -513,6 +512,7 @@ in6_pcbnotify(struct inpcbtable *table, struct sockaddr_in6 *dst,
                (*notify)(inp, errno);
                in_pcbunref(inp);
        }
+       rw_exit_write(&table->inpt_notify);
 }
 
 struct inpcb *

diff --git a/sys/netinet6/raw_ip6.c b/sys/netinet6/raw_ip6.c
index 3809f77..29af83a 100644 (file)
--- a/sys/netinet6/raw_ip6.c
+++ b/sys/netinet6/raw_ip6.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: raw_ip6.c,v 1.154 2022/08/22 08:08:46 mvs Exp $       */
+/*     $OpenBSD: raw_ip6.c,v 1.155 2022/08/22 10:37:27 bluhm Exp $     */
 /*     $KAME: raw_ip6.c,v 1.69 2001/03/04 15:55:44 itojun Exp $        */
 
 /*
@@ -172,8 +172,8 @@ rip6_input(struct mbuf **mp, int *offp, int proto, int af)
                }
        }
 #endif
-       NET_ASSERT_LOCKED_EXCLUSIVE();
        SIMPLEQ_INIT(&inpcblist);
+       rw_enter_write(&rawin6pcbtable.inpt_notify);
        mtx_enter(&rawin6pcbtable.inpt_mtx);
        TAILQ_FOREACH(in6p, &rawin6pcbtable.inpt_queue, inp_queue) {
                if (in6p->inp_socket->so_state & SS_CANTRCVMORE)
@@ -224,6 +224,8 @@ rip6_input(struct mbuf **mp, int *offp, int proto, int af)
                struct counters_ref ref;
                uint64_t *counters;
 
+               rw_exit_write(&rawin6pcbtable.inpt_notify);
+
                if (proto != IPPROTO_ICMPV6) {
                        rip6stat_inc(rip6s_nosock);
                        if (m->m_flags & M_MCAST)
@@ -240,6 +242,8 @@ rip6_input(struct mbuf **mp, int *offp, int proto, int af)
                counters = counters_enter(&ref, ip6counters);
                counters[ip6s_delivered]--;
                counters_leave(&ref, ip6counters);
+
+               return IPPROTO_DONE;
        }
 
        while ((in6p = SIMPLEQ_FIRST(&inpcblist)) != NULL) {
@@ -267,6 +271,8 @@ rip6_input(struct mbuf **mp, int *offp, int proto, int af)
                }
                in_pcbunref(in6p);
        }
+       rw_exit_write(&rawin6pcbtable.inpt_notify);
+
        return IPPROTO_DONE;
 }