rtnetlink: Compute and store minimum ifinfo dump size
The message size allocated for rtnl ifinfo dumps was limited to
a single page. This is not enough for additional interface info
available with devices that support SR-IOV and caused a bug in
which VF info would not be displayed if more than approximately
40 VFs were created per interface.
Implement a new function pointer for the rtnl_register service that will
calculate the amount of data required for the ifinfo dump and allocate
enough data to satisfy the request.
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index abd936d..a798fc6 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -56,9 +56,11 @@
struct rtnl_link {
rtnl_doit_func doit;
rtnl_dumpit_func dumpit;
+ rtnl_calcit_func calcit;
};
static DEFINE_MUTEX(rtnl_mutex);
+static u16 min_ifinfo_dump_size;
void rtnl_lock(void)
{
@@ -144,12 +146,28 @@
return tab ? tab[msgindex].dumpit : NULL;
}
+static rtnl_calcit_func rtnl_get_calcit(int protocol, int msgindex)
+{
+ struct rtnl_link *tab;
+
+ if (protocol <= RTNL_FAMILY_MAX)
+ tab = rtnl_msg_handlers[protocol];
+ else
+ tab = NULL;
+
+ if (tab == NULL || tab[msgindex].calcit == NULL)
+ tab = rtnl_msg_handlers[PF_UNSPEC];
+
+ return tab ? tab[msgindex].calcit : NULL;
+}
+
/**
* __rtnl_register - Register a rtnetlink message type
* @protocol: Protocol family or PF_UNSPEC
* @msgtype: rtnetlink message type
* @doit: Function pointer called for each request message
* @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message
+ * @calcit: Function pointer to calc size of dump message
*
* Registers the specified function pointers (at least one of them has
* to be non-NULL) to be called whenever a request message for the
@@ -162,7 +180,8 @@
* Returns 0 on success or a negative error code.
*/
int __rtnl_register(int protocol, int msgtype,
- rtnl_doit_func doit, rtnl_dumpit_func dumpit)
+ rtnl_doit_func doit, rtnl_dumpit_func dumpit,
+ rtnl_calcit_func calcit)
{
struct rtnl_link *tab;
int msgindex;
@@ -185,6 +204,9 @@
if (dumpit)
tab[msgindex].dumpit = dumpit;
+ if (calcit)
+ tab[msgindex].calcit = calcit;
+
return 0;
}
EXPORT_SYMBOL_GPL(__rtnl_register);
@@ -199,9 +221,10 @@
* of memory implies no sense in continuing.
*/
void rtnl_register(int protocol, int msgtype,
- rtnl_doit_func doit, rtnl_dumpit_func dumpit)
+ rtnl_doit_func doit, rtnl_dumpit_func dumpit,
+ rtnl_calcit_func calcit)
{
- if (__rtnl_register(protocol, msgtype, doit, dumpit) < 0)
+ if (__rtnl_register(protocol, msgtype, doit, dumpit, calcit) < 0)
panic("Unable to register rtnetlink message handler, "
"protocol = %d, message type = %d\n",
protocol, msgtype);
@@ -1818,6 +1841,11 @@
return err;
}
+static u16 rtnl_calcit(struct sk_buff *skb)
+{
+ return min_ifinfo_dump_size;
+}
+
static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
{
int idx;
@@ -1847,11 +1875,14 @@
struct net *net = dev_net(dev);
struct sk_buff *skb;
int err = -ENOBUFS;
+ size_t if_info_size;
- skb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
+ skb = nlmsg_new((if_info_size = if_nlmsg_size(dev)), GFP_KERNEL);
if (skb == NULL)
goto errout;
+ min_ifinfo_dump_size = max_t(u16, if_info_size, min_ifinfo_dump_size);
+
err = rtnl_fill_ifinfo(skb, dev, type, 0, 0, change, 0);
if (err < 0) {
/* -EMSGSIZE implies BUG in if_nlmsg_size() */
@@ -1902,14 +1933,20 @@
if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
struct sock *rtnl;
rtnl_dumpit_func dumpit;
+ rtnl_calcit_func calcit;
+ u16 min_dump_alloc = 0;
dumpit = rtnl_get_dumpit(family, type);
if (dumpit == NULL)
return -EOPNOTSUPP;
+ calcit = rtnl_get_calcit(family, type);
+ if (calcit)
+ min_dump_alloc = calcit(skb);
__rtnl_unlock();
rtnl = net->rtnl;
- err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
+ err = netlink_dump_start(rtnl, skb, nlh, dumpit,
+ NULL, min_dump_alloc);
rtnl_lock();
return err;
}
@@ -2019,12 +2056,13 @@
netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
register_netdevice_notifier(&rtnetlink_dev_notifier);
- rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink, rtnl_dump_ifinfo);
- rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL);
- rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL);
- rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL);
+ rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink,
+ rtnl_dump_ifinfo, rtnl_calcit);
+ rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL, NULL);
+ rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL, NULL);
+ rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL, NULL);
- rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all);
- rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all);
+ rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all, NULL);
+ rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all, NULL);
}