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-rw-r--r--net/mctp/device.c89
1 files changed, 74 insertions, 15 deletions
diff --git a/net/mctp/device.c b/net/mctp/device.c
index 8799ee77e7b7..99a3bda8852f 100644
--- a/net/mctp/device.c
+++ b/net/mctp/device.c
@@ -6,6 +6,7 @@
* Copyright (c) 2021 Google
*/
+#include <linux/if_arp.h>
#include <linux/if_link.h>
#include <linux/mctp.h>
#include <linux/netdevice.h>
@@ -24,25 +25,48 @@ struct mctp_dump_cb {
size_t a_idx;
};
-/* unlocked: caller must hold rcu_read_lock */
+/* unlocked: caller must hold rcu_read_lock.
+ * Returned mctp_dev has its refcount incremented, or NULL if unset.
+ */
struct mctp_dev *__mctp_dev_get(const struct net_device *dev)
{
- return rcu_dereference(dev->mctp_ptr);
+ struct mctp_dev *mdev = rcu_dereference(dev->mctp_ptr);
+
+ /* RCU guarantees that any mdev is still live.
+ * Zero refcount implies a pending free, return NULL.
+ */
+ if (mdev)
+ if (!refcount_inc_not_zero(&mdev->refs))
+ return NULL;
+ return mdev;
}
+/* Returned mctp_dev does not have refcount incremented. The returned pointer
+ * remains live while rtnl_lock is held, as that prevents mctp_unregister()
+ */
struct mctp_dev *mctp_dev_get_rtnl(const struct net_device *dev)
{
return rtnl_dereference(dev->mctp_ptr);
}
-static int mctp_fill_addrinfo(struct sk_buff *skb, struct netlink_callback *cb,
- struct mctp_dev *mdev, mctp_eid_t eid)
+static int mctp_addrinfo_size(void)
+{
+ return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
+ + nla_total_size(1) // IFA_LOCAL
+ + nla_total_size(1) // IFA_ADDRESS
+ ;
+}
+
+/* flag should be NLM_F_MULTI for dump calls */
+static int mctp_fill_addrinfo(struct sk_buff *skb,
+ struct mctp_dev *mdev, mctp_eid_t eid,
+ int msg_type, u32 portid, u32 seq, int flag)
{
struct ifaddrmsg *hdr;
struct nlmsghdr *nlh;
- nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
- RTM_NEWADDR, sizeof(*hdr), NLM_F_MULTI);
+ nlh = nlmsg_put(skb, portid, seq,
+ msg_type, sizeof(*hdr), flag);
if (!nlh)
return -EMSGSIZE;
@@ -72,10 +96,14 @@ static int mctp_dump_dev_addrinfo(struct mctp_dev *mdev, struct sk_buff *skb,
struct netlink_callback *cb)
{
struct mctp_dump_cb *mcb = (void *)cb->ctx;
+ u32 portid, seq;
int rc = 0;
+ portid = NETLINK_CB(cb->skb).portid;
+ seq = cb->nlh->nlmsg_seq;
for (; mcb->a_idx < mdev->num_addrs; mcb->a_idx++) {
- rc = mctp_fill_addrinfo(skb, cb, mdev, mdev->addrs[mcb->a_idx]);
+ rc = mctp_fill_addrinfo(skb, mdev, mdev->addrs[mcb->a_idx],
+ RTM_NEWADDR, portid, seq, NLM_F_MULTI);
if (rc < 0)
break;
}
@@ -92,7 +120,7 @@ static int mctp_dump_addrinfo(struct sk_buff *skb, struct netlink_callback *cb)
struct ifaddrmsg *hdr;
struct mctp_dev *mdev;
int ifindex;
- int idx, rc;
+ int idx = 0, rc;
hdr = nlmsg_data(cb->nlh);
// filter by ifindex if requested
@@ -109,6 +137,7 @@ static int mctp_dump_addrinfo(struct sk_buff *skb, struct netlink_callback *cb)
if (mdev) {
rc = mctp_dump_dev_addrinfo(mdev,
skb, cb);
+ mctp_dev_put(mdev);
// Error indicates full buffer, this
// callback will get retried.
if (rc < 0)
@@ -127,6 +156,32 @@ out:
return skb->len;
}
+static void mctp_addr_notify(struct mctp_dev *mdev, mctp_eid_t eid, int msg_type,
+ struct sk_buff *req_skb, struct nlmsghdr *req_nlh)
+{
+ u32 portid = NETLINK_CB(req_skb).portid;
+ struct net *net = dev_net(mdev->dev);
+ struct sk_buff *skb;
+ int rc = -ENOBUFS;
+
+ skb = nlmsg_new(mctp_addrinfo_size(), GFP_KERNEL);
+ if (!skb)
+ goto out;
+
+ rc = mctp_fill_addrinfo(skb, mdev, eid, msg_type,
+ portid, req_nlh->nlmsg_seq, 0);
+ if (rc < 0) {
+ WARN_ON_ONCE(rc == -EMSGSIZE);
+ goto out;
+ }
+
+ rtnl_notify(skb, net, portid, RTNLGRP_MCTP_IFADDR, req_nlh, GFP_KERNEL);
+ return;
+out:
+ kfree_skb(skb);
+ rtnl_set_sk_err(net, RTNLGRP_MCTP_IFADDR, rc);
+}
+
static const struct nla_policy ifa_mctp_policy[IFA_MAX + 1] = {
[IFA_ADDRESS] = { .type = NLA_U8 },
[IFA_LOCAL] = { .type = NLA_U8 },
@@ -168,7 +223,7 @@ static int mctp_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh,
if (!mdev)
return -ENODEV;
- if (!mctp_address_ok(addr->s_addr))
+ if (!mctp_address_unicast(addr->s_addr))
return -EINVAL;
/* Prevent duplicates. Under RTNL so don't need to lock for reading */
@@ -189,6 +244,7 @@ static int mctp_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh,
kfree(tmp_addrs);
+ mctp_addr_notify(mdev, addr->s_addr, RTM_NEWADDR, skb, nlh);
mctp_route_add_local(mdev, addr->s_addr);
return 0;
@@ -244,6 +300,8 @@ static int mctp_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh,
mdev->num_addrs--;
spin_unlock_irqrestore(&mdev->addrs_lock, flags);
+ mctp_addr_notify(mdev, addr->s_addr, RTM_DELADDR, skb, nlh);
+
return 0;
}
@@ -254,7 +312,8 @@ void mctp_dev_hold(struct mctp_dev *mdev)
void mctp_dev_put(struct mctp_dev *mdev)
{
- if (refcount_dec_and_test(&mdev->refs)) {
+ if (mdev && refcount_dec_and_test(&mdev->refs)) {
+ kfree(mdev->addrs);
dev_put(mdev->dev);
kfree_rcu(mdev, rcu);
}
@@ -326,6 +385,7 @@ static size_t mctp_get_link_af_size(const struct net_device *dev,
if (!mdev)
return 0;
ret = nla_total_size(4); /* IFLA_MCTP_NET */
+ mctp_dev_put(mdev);
return ret;
}
@@ -369,10 +429,10 @@ static void mctp_unregister(struct net_device *dev)
struct mctp_dev *mdev;
mdev = mctp_dev_get_rtnl(dev);
- if (mctp_known(dev) != (bool)mdev) {
+ if (mdev && !mctp_known(dev)) {
// Sanity check, should match what was set in mctp_register
- netdev_warn(dev, "%s: mdev pointer %d but type (%d) match is %d",
- __func__, (bool)mdev, mctp_known(dev), dev->type);
+ netdev_warn(dev, "%s: BUG mctp_ptr set for unknown type %d",
+ __func__, dev->type);
return;
}
if (!mdev)
@@ -382,7 +442,6 @@ static void mctp_unregister(struct net_device *dev)
mctp_route_remove_dev(mdev);
mctp_neigh_remove_dev(mdev);
- kfree(mdev->addrs);
mctp_dev_put(mdev);
}
@@ -396,7 +455,7 @@ static int mctp_register(struct net_device *dev)
if (mdev) {
if (!mctp_known(dev))
- netdev_warn(dev, "%s: mctp_dev set for unknown type %d",
+ netdev_warn(dev, "%s: BUG mctp_ptr set for unknown type %d",
__func__, dev->type);
return 0;
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.