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-rw-r--r--sys/net/if.c67
-rw-r--r--sys/net/if_mib.c34
-rw-r--r--sys/net/if_var.h11
3 files changed, 84 insertions, 28 deletions
diff --git a/sys/net/if.c b/sys/net/if.c
index 457b763..4d4b676 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -52,6 +52,7 @@
#include <sys/protosw.h>
#include <sys/kernel.h>
#include <sys/lock.h>
+#include <sys/refcount.h>
#include <sys/rwlock.h>
#include <sys/sockio.h>
#include <sys/syslog.h>
@@ -204,19 +205,35 @@ static struct ifnet *
ifnet_byindex_locked(u_short idx)
{
INIT_VNET_NET(curvnet);
+
+ if (idx > V_if_index)
+ return (NULL);
+ return (V_ifindex_table[idx].ife_ifnet);
+}
+
+struct ifnet *
+ifnet_byindex(u_short idx)
+{
struct ifnet *ifp;
- ifp = V_ifindex_table[idx].ife_ifnet;
+ IFNET_RLOCK();
+ ifp = ifnet_byindex_locked(idx);
+ IFNET_RUNLOCK();
return (ifp);
}
struct ifnet *
-ifnet_byindex(u_short idx)
+ifnet_byindex_ref(u_short idx)
{
struct ifnet *ifp;
IFNET_RLOCK();
ifp = ifnet_byindex_locked(idx);
+ if (ifp == NULL) {
+ IFNET_RUNLOCK();
+ return (NULL);
+ }
+ if_ref(ifp);
IFNET_RUNLOCK();
return (ifp);
}
@@ -490,6 +507,7 @@ if_alloc(u_char type)
if_grow();
ifp->if_type = type;
+ ifp->if_alloctype = type;
if (if_com_alloc[type] != NULL) {
ifp->if_l2com = if_com_alloc[type](type, ifp);
@@ -498,11 +516,12 @@ if_alloc(u_char type)
return (NULL);
}
}
+
+ IF_ADDR_LOCK_INIT(ifp);
+ refcount_init(&ifp->if_refcount, 1); /* Index reference. */
IFNET_WLOCK();
ifnet_setbyindex(ifp->if_index, ifp);
IFNET_WUNLOCK();
- IF_ADDR_LOCK_INIT(ifp);
-
return (ifp);
}
@@ -516,7 +535,7 @@ void
if_free(struct ifnet *ifp)
{
- if_free_type(ifp, ifp->if_type);
+ if_free_type(ifp, ifp->if_alloctype);
}
/*
@@ -529,28 +548,50 @@ if_free_type(struct ifnet *ifp, u_char type)
{
INIT_VNET_NET(curvnet); /* ifp->if_vnet can be NULL here ! */
- if (ifp != ifnet_byindex(ifp->if_index)) {
- if_printf(ifp, "%s: value was not if_alloced, skipping\n",
- __func__);
+ /*
+ * Some drivers modify if_type, so we can't rely on it being the
+ * same in free as it was in alloc. Now that we have if_alloctype,
+ * we should just use that, but drivers expect to pass a type.
+ */
+ KASSERT(ifp->if_alloctype == type,
+ ("if_free_type: type (%d) != alloctype (%d)", type,
+ ifp->if_alloctype));
+
+ if (!refcount_release(&ifp->if_refcount))
return;
- }
IFNET_WLOCK();
+ KASSERT(ifp == ifnet_byindex_locked(ifp->if_index),
+ ("%s: freeing unallocated ifnet", ifp->if_xname));
ifnet_setbyindex(ifp->if_index, NULL);
-
- /* XXX: should be locked with if_findindex() */
while (V_if_index > 0 && ifnet_byindex_locked(V_if_index) == NULL)
V_if_index--;
IFNET_WUNLOCK();
- if (if_com_free[type] != NULL)
- if_com_free[type](ifp->if_l2com, type);
+ if (if_com_free[ifp->if_alloctype] != NULL)
+ if_com_free[ifp->if_alloctype](ifp->if_l2com,
+ ifp->if_alloctype);
IF_ADDR_LOCK_DESTROY(ifp);
free(ifp, M_IFNET);
}
void
+if_ref(struct ifnet *ifp)
+{
+
+ /* We don't assert the ifnet list lock here, but arguably should. */
+ refcount_acquire(&ifp->if_refcount);
+}
+
+void
+if_rele(struct ifnet *ifp)
+{
+
+ if_free(ifp);
+}
+
+void
ifq_attach(struct ifaltq *ifq, struct ifnet *ifp)
{
diff --git a/sys/net/if_mib.c b/sys/net/if_mib.c
index 143095a..9482eb9 100644
--- a/sys/net/if_mib.c
+++ b/sys/net/if_mib.c
@@ -88,16 +88,16 @@ sysctl_ifdata(SYSCTL_HANDLER_ARGS) /* XXX bad syntax! */
if (namelen != 2)
return EINVAL;
-
- if (name[0] <= 0 || name[0] > V_if_index ||
- ifnet_byindex(name[0]) == NULL)
- return ENOENT;
-
- ifp = ifnet_byindex(name[0]);
+ if (name[0] <= 0)
+ return (ENOENT);
+ ifp = ifnet_byindex_ref(name[0]);
+ if (ifp == NULL)
+ return (ENOENT);
switch(name[1]) {
default:
- return ENOENT;
+ error = ENOENT;
+ goto out;
case IFDATA_GENERAL:
bzero(&ifmd, sizeof(ifmd));
@@ -114,11 +114,11 @@ sysctl_ifdata(SYSCTL_HANDLER_ARGS) /* XXX bad syntax! */
error = SYSCTL_OUT(req, &ifmd, sizeof ifmd);
if (error || !req->newptr)
- return error;
+ goto out;
error = SYSCTL_IN(req, &ifmd, sizeof ifmd);
if (error)
- return error;
+ goto out;
#define DONTCOPY(fld) ifmd.ifmd_data.ifi_##fld = ifp->if_data.ifi_##fld
DONTCOPY(type);
@@ -139,18 +139,20 @@ sysctl_ifdata(SYSCTL_HANDLER_ARGS) /* XXX bad syntax! */
case IFDATA_LINKSPECIFIC:
error = SYSCTL_OUT(req, ifp->if_linkmib, ifp->if_linkmiblen);
if (error || !req->newptr)
- return error;
+ goto out;
error = SYSCTL_IN(req, ifp->if_linkmib, ifp->if_linkmiblen);
if (error)
- return error;
+ goto out;
break;
case IFDATA_DRIVERNAME:
/* 20 is enough for 64bit ints */
dlen = strlen(ifp->if_dname) + 20 + 1;
- if ((dbuf = malloc(dlen, M_TEMP, M_NOWAIT)) == NULL)
- return (ENOMEM);
+ if ((dbuf = malloc(dlen, M_TEMP, M_NOWAIT)) == NULL) {
+ error = ENOMEM;
+ goto out;
+ }
if (ifp->if_dunit == IF_DUNIT_NONE)
strcpy(dbuf, ifp->if_dname);
else
@@ -160,9 +162,11 @@ sysctl_ifdata(SYSCTL_HANDLER_ARGS) /* XXX bad syntax! */
if (error == 0 && req->newptr != NULL)
error = EPERM;
free(dbuf, M_TEMP);
- return (error);
+ goto out;
}
- return 0;
+out:
+ if_rele(ifp);
+ return error;
}
SYSCTL_NODE(_net_link_generic, IFMIB_IFDATA, ifdata, CTLFLAG_RW,
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index 4b7447d..26b2747 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -121,6 +121,7 @@ struct ifnet {
char if_xname[IFNAMSIZ]; /* external name (name + unit) */
const char *if_dname; /* driver name */
int if_dunit; /* unit or IF_DUNIT_NONE */
+ u_int if_refcount; /* reference count */
struct ifaddrhead if_addrhead; /* linked list of addresses per if */
/*
* if_addrhead is the list of all addresses associated to
@@ -190,12 +191,14 @@ struct ifnet {
/* protected by if_addr_mtx */
void *if_pf_kif;
void *if_lagg; /* lagg glue */
+ u_char if_alloctype; /* if_type at time of allocation */
/*
* Spare fields are added so that we can modify sensitive data
* structures without changing the kernel binary interface, and must
* be used with care where binary compatibility is required.
*/
+ char if_cspare[3];
void *if_pspare[8];
int if_ispare[4];
};
@@ -721,7 +724,13 @@ struct ifindex_entry {
struct cdev *ife_dev;
};
+/*
+ * Look up an ifnet given its index; the _ref variant also acquires a
+ * reference that must be freed using if_rele(). It is almost always a bug
+ * to call ifnet_byindex() instead if ifnet_byindex_ref().
+ */
struct ifnet *ifnet_byindex(u_short idx);
+struct ifnet *ifnet_byindex_ref(u_short idx);
/*
* Given the index, ifaddr_byindex() returns the one and only
@@ -758,6 +767,8 @@ void if_initname(struct ifnet *, const char *, int);
void if_link_state_change(struct ifnet *, int);
int if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
void if_qflush(struct ifnet *);
+void if_ref(struct ifnet *);
+void if_rele(struct ifnet *);
int if_setlladdr(struct ifnet *, const u_char *, int);
void if_up(struct ifnet *);
/*void ifinit(void);*/ /* declared in systm.h for main() */
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