Module Name: src
Committed By: dyoung
Date: Thu Aug 13 00:34:05 UTC 2009
Modified Files:
src/sys/netinet6: in6.c in6_ifattach.c in6_ifattach.h
Log Message:
Postpone to a workqueue adding link-local and loopback IPv6 addresses
to an interface. This keeps the kernel from entering ifp->if_ioctl
recursively, which can deadlock if if_ioctl takes locks. This will
fix deadlocks & LOCKDEBUG errors in agr(4) (kern/39940) and in
gre(4).
To generate a diff of this commit:
cvs rdiff -u -r1.151 -r1.152 src/sys/netinet6/in6.c
cvs rdiff -u -r1.82 -r1.83 src/sys/netinet6/in6_ifattach.c
cvs rdiff -u -r1.11 -r1.12 src/sys/netinet6/in6_ifattach.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/netinet6/in6.c
diff -u src/sys/netinet6/in6.c:1.151 src/sys/netinet6/in6.c:1.152
--- src/sys/netinet6/in6.c:1.151 Tue May 12 23:01:26 2009
+++ src/sys/netinet6/in6.c Thu Aug 13 00:34:04 2009
@@ -1,4 +1,4 @@
-/* $NetBSD: in6.c,v 1.151 2009/05/12 23:01:26 elad Exp $ */
+/* $NetBSD: in6.c,v 1.152 2009/08/13 00:34:04 dyoung Exp $ */
/* $KAME: in6.c,v 1.198 2001/07/18 09:12:38 itojun Exp $ */
/*
@@ -62,7 +62,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: in6.c,v 1.151 2009/05/12 23:01:26 elad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: in6.c,v 1.152 2009/08/13 00:34:04 dyoung Exp $");
#include "opt_inet.h"
#include "opt_pfil_hooks.h"
@@ -76,6 +76,7 @@
#include <sys/socketvar.h>
#include <sys/sockio.h>
#include <sys/systm.h>
+#include <sys/once.h>
#include <sys/proc.h>
#include <sys/time.h>
#include <sys/kernel.h>
@@ -2230,8 +2231,11 @@
void *
in6_domifattach(struct ifnet *ifp)
{
+ static ONCE_DECL(ifwqest);
struct in6_ifextra *ext;
+ RUN_ONCE(&ifwqest, in6_ifaddrs_wq_establish);
+
ext = malloc(sizeof(*ext), M_IFADDR, M_WAITOK|M_ZERO);
ext->in6_ifstat = malloc(sizeof(struct in6_ifstat),
Index: src/sys/netinet6/in6_ifattach.c
diff -u src/sys/netinet6/in6_ifattach.c:1.82 src/sys/netinet6/in6_ifattach.c:1.83
--- src/sys/netinet6/in6_ifattach.c:1.82 Thu Jul 30 17:28:36 2009
+++ src/sys/netinet6/in6_ifattach.c Thu Aug 13 00:34:04 2009
@@ -1,4 +1,4 @@
-/* $NetBSD: in6_ifattach.c,v 1.82 2009/07/30 17:28:36 dyoung Exp $ */
+/* $NetBSD: in6_ifattach.c,v 1.83 2009/08/13 00:34:04 dyoung Exp $ */
/* $KAME: in6_ifattach.c,v 1.124 2001/07/18 08:32:51 jinmei Exp $ */
/*
@@ -31,10 +31,11 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: in6_ifattach.c,v 1.82 2009/07/30 17:28:36 dyoung Exp $");
+__KERNEL_RCSID(0, "$NetBSD: in6_ifattach.c,v 1.83 2009/08/13 00:34:04 dyoung Exp $");
#include <sys/param.h>
#include <sys/systm.h>
+#include <sys/kmem.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/sockio.h>
@@ -42,6 +43,7 @@
#include <sys/syslog.h>
#include <sys/md5.h>
#include <sys/socketvar.h>
+#include <sys/workqueue.h>
#include <net/if.h>
#include <net/if_dl.h>
@@ -60,12 +62,41 @@
#include <net/net_osdep.h>
+/* Record of an interface to add a link-local and possibly a loopback
+ * IPv6 address to, processed on a workqueue(9) by in6_ifaddrs_worker.
+ */
+struct in6_ifaddr_work {
+ struct work iw_work;
+ struct ifindexgen {
+ int ig_idx; /* Interface index */
+ int ig_gen; /* Interface index generation */
+ } iw_idxgen, /* Identify of the interface
+ * to receive a link-local and
+ * possibly a loopback address.
+ */
+ iw_alt_idxgen; /* Optional identity of a second
+ * interface. If iw_alt_present
+ * is true, this field
+ * identifies a second interface
+ * whose EUI64 we use to derive
+ * the link-local address for
+ * the interface indicated by
+ * iw_idxgen.
+ */
+ bool iw_alt_present; /* iff true, iw_alt_idxgen is valid. */
+};
+
unsigned long in6_maxmtu = 0;
int ip6_auto_linklocal = 1; /* enable by default */
callout_t in6_tmpaddrtimer_ch;
+static struct workqueue *in6_ifaddrs_wq = NULL;
+
+static void in6_ifaddrs_schedule(struct ifnet *, struct ifnet *);
+static void in6_ifaddrs_init(struct ifnet *, struct ifnet *);
+static void in6_ifaddrs_worker(struct work *, void *);
#if 0
static int get_hostid_ifid(struct ifnet *, struct in6_addr *);
@@ -751,8 +782,6 @@
void
in6_ifattach(struct ifnet *ifp, struct ifnet *altifp)
{
- struct in6_ifaddr *ia;
- struct in6_addr in6;
/* some of the interfaces are inherently not IPv6 capable */
switch (ifp->if_type) {
@@ -811,6 +840,26 @@
return;
}
+ /* Assign addresses to ifp in another thread in order to
+ * avoid re-entering ifp->if_ioctl().
+ */
+ in6_ifaddrs_schedule(ifp, altifp);
+}
+
+/* in6_ifaddrs_init
+ *
+ * Add a link-local address to ifp, and if ifp is a loopback address,
+ * add a loopback address to it, too.
+ *
+ * If altifp is not NULL, derive the link-local address of ifp from the
+ * EUI64 of altifp.
+ */
+void
+in6_ifaddrs_init(struct ifnet *ifp, struct ifnet *altifp)
+{
+ struct in6_addr in6;
+ struct in6_ifaddr *ia;
+
/*
* assign loopback address for loopback interface.
* XXX multiple loopback interface case.
@@ -835,6 +884,95 @@
}
}
+/* getifp: helper for in6_ifaddrs_worker().
+ *
+ * Lookup an ifnet by ifindexgen, a pair consisting of an interface
+ * index (if_index) and an interface-index generation number.
+ */
+static struct ifnet *
+getifp(struct ifindexgen *ig)
+{
+ int ifindex = ig->ig_idx;
+ uint64_t ifindex_gen = ig->ig_gen;
+ struct ifnet *ifp;
+
+ if (ifindex2ifnet == NULL)
+ printf("%s: no ifindices in use\n", __func__);
+ else if (ifindex >= if_indexlim) {
+ printf("%s: ifindex %d >= limit %d\n", __func__, ifindex,
+ if_indexlim);
+ } else if ((ifp = ifindex2ifnet[ifindex]) == NULL)
+ printf("%s: ifindex %d not in use\n", __func__, ifindex);
+ else if (ifp->if_index_gen != ifindex_gen)
+ printf("%s: ifindex %d recycled\n", __func__, ifindex);
+ else
+ return ifp;
+ return NULL;
+}
+
+static void
+in6_ifaddrs_worker(struct work *wk, void *arg)
+{
+ struct in6_ifaddr_work *iw = (struct in6_ifaddr_work *)wk;
+ struct ifnet *altifp = NULL, *ifp;
+
+ if ((ifp = getifp(&iw->iw_idxgen)) != NULL &&
+ (!iw->iw_alt_present ||
+ (altifp = getifp(&iw->iw_alt_idxgen)) != NULL))
+ in6_ifaddrs_init(ifp, altifp);
+
+ kmem_free(iw, sizeof(*iw));
+}
+
+int
+in6_ifaddrs_wq_establish(void)
+{
+ int rc;
+
+ rc = workqueue_create(&in6_ifaddrs_wq, "in6ifaddr", in6_ifaddrs_worker,
+ NULL, PRI_KERNEL, IPL_NET, 0);
+
+ if (rc != 0) {
+ printf("%s: could not create inet6 ifaddrs workqueue.\n",
+ __func__);
+ }
+ return rc;
+}
+
+/* in6_ifaddrs_schedule
+ *
+ * Schedule ifp for a kernel thread to add addresses.
+ *
+ * The kernel thread will assign a link-local address to ifp, and if ifp
+ * is a loopback address, add a loopback address to it, too.
+ *
+ * If altifp is not NULL, derive the link-local address of ifp from the
+ * EUI64 of altifp.
+ */
+void
+in6_ifaddrs_schedule(struct ifnet *ifp, struct ifnet *altifp)
+{
+ struct in6_ifaddr_work *iw;
+ struct ifindexgen *ig, *alt_ig;
+
+ iw = kmem_zalloc(sizeof(*iw), KM_SLEEP);
+
+ ig = &iw->iw_idxgen;
+ alt_ig = &iw->iw_alt_idxgen;
+
+ KASSERT(ifp->if_index < if_indexlim);
+ ig->ig_idx = ifp->if_index;
+ ig->ig_gen = ifp->if_index_gen;
+ if (altifp != NULL) {
+ KASSERT(altifp->if_index < if_indexlim);
+ alt_ig->ig_idx = altifp->if_index;
+ alt_ig->ig_gen = altifp->if_index_gen;
+ iw->iw_alt_present = true;
+ }
+
+ workqueue_enqueue(in6_ifaddrs_wq, &iw->iw_work, NULL);
+}
+
/*
* NOTE: in6_ifdetach() does not support loopback if at this moment.
* We don't need this function in bsdi, because interfaces are never removed
Index: src/sys/netinet6/in6_ifattach.h
diff -u src/sys/netinet6/in6_ifattach.h:1.11 src/sys/netinet6/in6_ifattach.h:1.12
--- src/sys/netinet6/in6_ifattach.h:1.11 Thu Nov 1 20:33:57 2007
+++ src/sys/netinet6/in6_ifattach.h Thu Aug 13 00:34:05 2009
@@ -1,4 +1,4 @@
-/* $NetBSD: in6_ifattach.h,v 1.11 2007/11/01 20:33:57 dyoung Exp $ */
+/* $NetBSD: in6_ifattach.h,v 1.12 2009/08/13 00:34:05 dyoung Exp $ */
/* $KAME: in6_ifattach.h,v 1.8 2000/04/12 03:51:30 itojun Exp $ */
/*
@@ -40,6 +40,7 @@
void in6_tmpaddrtimer(void *);
int in6_get_hw_ifid(struct ifnet *, struct in6_addr *);
int in6_nigroup(struct ifnet *, const char *, int, struct sockaddr_in6 *);
+int in6_ifaddrs_wq_establish(void);
#endif /* _KERNEL */
#endif /* !_NETINET6_IN6_IFATTACH_H_ */
