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-rw-r--r--sys/kern/subr_witness.c7
-rw-r--r--sys/netinet/igmp.c20
-rw-r--r--sys/netinet/in.c28
-rw-r--r--sys/netinet/in_var.h14
-rw-r--r--sys/netinet/ip_input.c2
-rw-r--r--sys/netinet/ip_output.c3
6 files changed, 56 insertions, 18 deletions
diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c
index 082c8b8..190f96e 100644
--- a/sys/kern/subr_witness.c
+++ b/sys/kern/subr_witness.c
@@ -286,6 +286,13 @@ static struct witness_order_list_entry order_lists[] = {
{ "ifaddr", &lock_class_mtx_sleep },
{ NULL, NULL },
/*
+ * Multicast - protocol locks before interface locks.
+ */
+ { "in_multi_mtx", &lock_class_mtx_sleep },
+ { "igmp_mtx", &lock_class_mtx_sleep },
+ { "if_addr_mtx", &lock_class_mtx_sleep },
+ { NULL, NULL },
+ /*
* UNIX Domain Sockets
*/
{ "unp", &lock_class_mtx_sleep },
diff --git a/sys/netinet/igmp.c b/sys/netinet/igmp.c
index 2c68e3c..8612a23 100644
--- a/sys/netinet/igmp.c
+++ b/sys/netinet/igmp.c
@@ -286,6 +286,7 @@ igmp_input(register struct mbuf *m, int off)
* - Use the value specified in the query message as
* the maximum timeout.
*/
+ IN_MULTI_LOCK();
IN_FIRST_MULTI(step, inm);
while (inm != NULL) {
if (inm->inm_ifp == ifp &&
@@ -301,6 +302,7 @@ igmp_input(register struct mbuf *m, int off)
}
IN_NEXT_MULTI(step, inm);
}
+ IN_MULTI_UNLOCK();
break;
@@ -343,14 +345,15 @@ igmp_input(register struct mbuf *m, int off)
* If we belong to the group being reported, stop
* our timer for that group.
*/
+ IN_MULTI_LOCK();
IN_LOOKUP_MULTI(igmp->igmp_group, ifp, inm);
-
if (inm != NULL) {
inm->inm_timer = 0;
++igmpstat.igps_rcv_ourreports;
inm->inm_state = IGMP_OTHERMEMBER;
}
+ IN_MULTI_UNLOCK();
break;
}
@@ -365,7 +368,8 @@ igmp_input(register struct mbuf *m, int off)
void
igmp_joingroup(struct in_multi *inm)
{
- int s = splnet();
+
+ IN_MULTI_LOCK_ASSERT();
if (inm->inm_addr.s_addr == igmp_all_hosts_group
|| inm->inm_ifp->if_flags & IFF_LOOPBACK) {
@@ -384,13 +388,14 @@ igmp_joingroup(struct in_multi *inm)
}
/* XXX handling of failure case? */
}
- splx(s);
}
void
igmp_leavegroup(struct in_multi *inm)
{
+ IN_MULTI_LOCK_ASSERT();
+
if (inm->inm_state == IGMP_IREPORTEDLAST &&
inm->inm_addr.s_addr != igmp_all_hosts_group &&
!(inm->inm_ifp->if_flags & IFF_LOOPBACK) &&
@@ -403,7 +408,6 @@ igmp_fasttimo(void)
{
register struct in_multi *inm;
struct in_multistep step;
- int s;
/*
* Quick check to see if any work needs to be done, in order
@@ -413,7 +417,7 @@ igmp_fasttimo(void)
if (!igmp_timers_are_running)
return;
- s = splnet();
+ IN_MULTI_LOCK();
igmp_timers_are_running = 0;
IN_FIRST_MULTI(step, inm);
while (inm != NULL) {
@@ -427,13 +431,12 @@ igmp_fasttimo(void)
}
IN_NEXT_MULTI(step, inm);
}
- splx(s);
+ IN_MULTI_UNLOCK();
}
void
igmp_slowtimo(void)
{
- int s = splnet();
struct router_info *rti;
IGMP_PRINTF("[igmp.c,_slowtimo] -- > entering \n");
@@ -447,7 +450,6 @@ igmp_slowtimo(void)
}
mtx_unlock(&igmp_mtx);
IGMP_PRINTF("[igmp.c,_slowtimo] -- > exiting \n");
- splx(s);
}
static void
@@ -458,6 +460,8 @@ igmp_sendpkt(struct in_multi *inm, int type, unsigned long addr)
struct ip *ip;
struct ip_moptions imo;
+ IN_MULTI_LOCK_ASSERT();
+
MGETHDR(m, M_DONTWAIT, MT_HEADER);
if (m == NULL)
return;
diff --git a/sys/netinet/in.c b/sys/netinet/in.c
index fcc1809..3f9d369 100644
--- a/sys/netinet/in.c
+++ b/sys/netinet/in.c
@@ -68,7 +68,16 @@ static int subnetsarelocal = 0;
SYSCTL_INT(_net_inet_ip, OID_AUTO, subnets_are_local, CTLFLAG_RW,
&subnetsarelocal, 0, "Treat all subnets as directly connected");
+/*
+ * The IPv4 multicast list (in_multihead and associated structures) are
+ * protected by the global in_multi_mtx. See in_var.h for more details. For
+ * now, in_multi_mtx is marked as recursible due to IGMP's calling back into
+ * ip_output() to send IGMP packets while holding the lock; this probably is
+ * not quite desirable.
+ */
struct in_multihead in_multihead; /* XXX BSS initialization */
+struct mtx in_multi_mtx;
+MTX_SYSINIT(in_multi_mtx, &in_multi_mtx, "in_multi_mtx", MTX_DEF | MTX_RECURSE);
extern struct inpcbinfo ripcbinfo;
extern struct inpcbinfo udbinfo;
@@ -949,8 +958,8 @@ in_addmulti(ap, ifp)
int error;
struct sockaddr_in sin;
struct ifmultiaddr *ifma;
- int s = splnet();
+ IN_MULTI_LOCK();
/*
* Call generic routine to add membership or increment
* refcount. It wants addresses in the form of a sockaddr,
@@ -962,7 +971,7 @@ in_addmulti(ap, ifp)
sin.sin_addr = *ap;
error = if_addmulti(ifp, (struct sockaddr *)&sin, &ifma);
if (error) {
- splx(s);
+ IN_MULTI_UNLOCK();
return 0;
}
@@ -971,16 +980,14 @@ in_addmulti(ap, ifp)
* a new record. Otherwise, we are done.
*/
if (ifma->ifma_protospec != NULL) {
- splx(s);
+ IN_MULTI_UNLOCK();
return ifma->ifma_protospec;
}
- /* XXX - if_addmulti uses M_WAITOK. Can this really be called
- at interrupt time? If so, need to fix if_addmulti. XXX */
inm = (struct in_multi *)malloc(sizeof(*inm), M_IPMADDR,
M_NOWAIT | M_ZERO);
if (inm == NULL) {
- splx(s);
+ IN_MULTI_UNLOCK();
return (NULL);
}
@@ -994,7 +1001,7 @@ in_addmulti(ap, ifp)
* Let IGMP know that we have joined a new IP multicast group.
*/
igmp_joingroup(inm);
- splx(s);
+ IN_MULTI_UNLOCK();
return (inm);
}
@@ -1005,10 +1012,11 @@ void
in_delmulti(inm)
register struct in_multi *inm;
{
- struct ifmultiaddr *ifma = inm->inm_ifma;
+ struct ifmultiaddr *ifma;
struct in_multi my_inm;
- int s = splnet();
+ IN_MULTI_LOCK();
+ ifma = inm->inm_ifma;
my_inm.inm_ifp = NULL ; /* don't send the leave msg */
if (ifma->ifma_refcount == 1) {
/*
@@ -1026,5 +1034,5 @@ in_delmulti(inm)
if_delmulti(ifma->ifma_ifp, ifma->ifma_addr);
if (my_inm.inm_ifp != NULL)
igmp_leavegroup(&my_inm);
- splx(s);
+ IN_MULTI_UNLOCK();
}
diff --git a/sys/netinet/in_var.h b/sys/netinet/in_var.h
index 95a4558..5792a0b 100644
--- a/sys/netinet/in_var.h
+++ b/sys/netinet/in_var.h
@@ -167,6 +167,17 @@ SYSCTL_DECL(_net_inet_raw);
extern LIST_HEAD(in_multihead, in_multi) in_multihead;
/*
+ * Lock macros for IPv4 layer multicast address lists. IPv4 lock goes
+ * before link layer multicast locks in the lock order. In most cases,
+ * consumers of IN_*_MULTI() macros should acquire the locks before
+ * calling them; users of the in_{add,del}multi() functions should not.
+ */
+extern struct mtx in_multi_mtx;
+#define IN_MULTI_LOCK() mtx_lock(&in_multi_mtx)
+#define IN_MULTI_UNLOCK() mtx_unlock(&in_multi_mtx)
+#define IN_MULTI_LOCK_ASSERT() mtx_assert(&in_multi_mtx, MA_OWNED)
+
+/*
* Structure used by macros below to remember position when stepping through
* all of the in_multi records.
*/
@@ -185,6 +196,7 @@ struct in_multistep {
do { \
struct ifmultiaddr *ifma; \
\
+ IN_MULTI_LOCK_ASSERT(); \
IF_ADDR_LOCK(ifp); \
TAILQ_FOREACH(ifma, &((ifp)->if_multiaddrs), ifma_link) { \
if (ifma->ifma_addr->sa_family == AF_INET \
@@ -207,6 +219,7 @@ do { \
/* struct in_multistep step; */ \
/* struct in_multi *inm; */ \
do { \
+ IN_MULTI_LOCK_ASSERT(); \
if (((inm) = (step).i_inm) != NULL) \
(step).i_inm = LIST_NEXT((step).i_inm, inm_link); \
} while(0)
@@ -215,6 +228,7 @@ do { \
/* struct in_multistep step; */ \
/* struct in_multi *inm; */ \
do { \
+ IN_MULTI_LOCK_ASSERT(); \
(step).i_inm = LIST_FIRST(&in_multihead); \
IN_NEXT_MULTI((step), (inm)); \
} while(0)
diff --git a/sys/netinet/ip_input.c b/sys/netinet/ip_input.c
index ff4b4be..eb42a4d 100644
--- a/sys/netinet/ip_input.c
+++ b/sys/netinet/ip_input.c
@@ -607,7 +607,9 @@ passin:
* See if we belong to the destination multicast group on the
* arrival interface.
*/
+ IN_MULTI_LOCK();
IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
+ IN_MULTI_UNLOCK();
if (inm == NULL) {
ipstat.ips_notmember++;
m_freem(m);
diff --git a/sys/netinet/ip_output.c b/sys/netinet/ip_output.c
index 0241479..0a43b2d 100644
--- a/sys/netinet/ip_output.c
+++ b/sys/netinet/ip_output.c
@@ -291,9 +291,11 @@ again:
ip->ip_src = IA_SIN(ia)->sin_addr;
}
+ IN_MULTI_LOCK();
IN_LOOKUP_MULTI(ip->ip_dst, ifp, inm);
if (inm != NULL &&
(imo == NULL || imo->imo_multicast_loop)) {
+ IN_MULTI_UNLOCK();
/*
* If we belong to the destination multicast group
* on the outgoing interface, and the caller did not
@@ -302,6 +304,7 @@ again:
ip_mloopback(ifp, m, dst, hlen);
}
else {
+ IN_MULTI_UNLOCK();
/*
* If we are acting as a multicast router, perform
* multicast forwarding as if the packet had just
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