4 files changed, 46 insertions, 18 deletions

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 975dbeb60ab0..52d74760fb68 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -421,6 +421,10 @@ int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
         dev = dev_get_by_name(net, driver_name);
         if (!dev)
                 return -ENODEV;
+        if (tipc_mtu_bad(dev, 0)) {
+                dev_put(dev);
+                return -EINVAL;
+        }
 
         /* Associate TIPC bearer with L2 bearer */
         rcu_assign_pointer(b->media_ptr, dev);
@@ -610,8 +614,6 @@ static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
         if (!b)
                 return NOTIFY_DONE;
 
-        b->mtu = dev->mtu;
-
         switch (evt) {
         case NETDEV_CHANGE:
                 if (netif_carrier_ok(dev))
@@ -624,6 +626,11 @@ static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
                 tipc_reset_bearer(net, b);
                 break;
         case NETDEV_CHANGEMTU:
+                if (tipc_mtu_bad(dev, 0)) {
+                        bearer_disable(net, b);
+                        break;
+                }
+                b->mtu = dev->mtu;
                 tipc_reset_bearer(net, b);
                 break;
         case NETDEV_CHANGEADDR:
diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h
index 78892e2f53e3..278ff7f616f9 100644
--- a/net/tipc/bearer.h
+++ b/net/tipc/bearer.h
@@ -39,6 +39,7 @@
 
 #include "netlink.h"
 #include "core.h"
+#include "msg.h"
 #include <net/genetlink.h>
 
 #define MAX_MEDIA       3
@@ -59,6 +60,9 @@
 #define TIPC_MEDIA_TYPE_IB      2
 #define TIPC_MEDIA_TYPE_UDP     3
 
+/* minimum bearer MTU */
+#define TIPC_MIN_BEARER_MTU     (MAX_H_SIZE + INT_H_SIZE)
+
 /**
  * struct tipc_media_addr - destination address used by TIPC bearers
  * @value: address info (format defined by media)
@@ -215,4 +219,13 @@ void tipc_bearer_xmit(struct net *net, u32 bearer_id,
 void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
                          struct sk_buff_head *xmitq);
 
+/* check if device MTU is too low for tipc headers */
+static inline bool tipc_mtu_bad(struct net_device *dev, unsigned int reserve)
+{
+        if (dev->mtu >= TIPC_MIN_BEARER_MTU + reserve)
+                return false;
+        netdev_warn(dev, "MTU too low for tipc bearer\n");
+        return true;
+}
+
 #endif  /* _TIPC_BEARER_H */
diff --git a/net/tipc/link.c b/net/tipc/link.c
index ecc12411155e..bda89bf9f4ff 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -47,8 +47,8 @@
 #include <linux/pkt_sched.h>
 
 struct tipc_stats {
-        u32 sent_info;          /* used in counting # sent packets */
-        u32 recv_info;          /* used in counting # recv'd packets */
+        u32 sent_pkts;
+        u32 recv_pkts;
         u32 sent_states;
         u32 recv_states;
         u32 sent_probes;
@@ -857,7 +857,6 @@ void tipc_link_reset(struct tipc_link *l)
         l->acked = 0;
         l->silent_intv_cnt = 0;
         l->rst_cnt = 0;
-        l->stats.recv_info = 0;
         l->stale_count = 0;
         l->bc_peer_is_up = false;
         memset(&l->mon_state, 0, sizeof(l->mon_state));
@@ -888,6 +887,7 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
         struct sk_buff_head *transmq = &l->transmq;
         struct sk_buff_head *backlogq = &l->backlogq;
         struct sk_buff *skb, *_skb, *bskb;
+        int pkt_cnt = skb_queue_len(list);
 
         /* Match msg importance against this and all higher backlog limits: */
         if (!skb_queue_empty(backlogq)) {
@@ -901,6 +901,11 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
                 return -EMSGSIZE;
         }
 
+        if (pkt_cnt > 1) {
+                l->stats.sent_fragmented++;
+                l->stats.sent_fragments += pkt_cnt;
+        }
+
         /* Prepare each packet for sending, and add to relevant queue: */
         while (skb_queue_len(list)) {
                 skb = skb_peek(list);
@@ -920,6 +925,7 @@ int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
                         __skb_queue_tail(xmitq, _skb);
                         TIPC_SKB_CB(skb)->ackers = l->ackers;
                         l->rcv_unacked = 0;
+                        l->stats.sent_pkts++;
                         seqno++;
                         continue;
                 }
@@ -968,6 +974,7 @@ void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
                 msg_set_ack(hdr, ack);
                 msg_set_bcast_ack(hdr, bc_ack);
                 l->rcv_unacked = 0;
+                l->stats.sent_pkts++;
                 seqno++;
         }
         l->snd_nxt = seqno;
@@ -1260,7 +1267,7 @@ int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
 
                 /* Deliver packet */
                 l->rcv_nxt++;
-                l->stats.recv_info++;
+                l->stats.recv_pkts++;
                 if (!tipc_data_input(l, skb, l->inputq))
                         rc |= tipc_link_input(l, skb, l->inputq);
                 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
@@ -1800,10 +1807,6 @@ void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
 void tipc_link_reset_stats(struct tipc_link *l)
 {
         memset(&l->stats, 0, sizeof(l->stats));
-        if (!link_is_bc_sndlink(l)) {
-                l->stats.sent_info = l->snd_nxt;
-                l->stats.recv_info = l->rcv_nxt;
-        }
 }
 
 static void link_print(struct tipc_link *l, const char *str)
@@ -1867,12 +1870,12 @@ static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
         };
 
         struct nla_map map[] = {
-                {TIPC_NLA_STATS_RX_INFO, s->recv_info},
+                {TIPC_NLA_STATS_RX_INFO, 0},
                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
-                {TIPC_NLA_STATS_TX_INFO, s->sent_info},
+                {TIPC_NLA_STATS_TX_INFO, 0},
                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
@@ -1947,9 +1950,9 @@ int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
                 goto attr_msg_full;
         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
                 goto attr_msg_full;
-        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
+        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->stats.recv_pkts))
                 goto attr_msg_full;
-        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
+        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->stats.sent_pkts))
                 goto attr_msg_full;
 
         if (tipc_link_is_up(link))
@@ -2004,12 +2007,12 @@ static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
         };
 
         struct nla_map map[] = {
-                {TIPC_NLA_STATS_RX_INFO, stats->recv_info},
+                {TIPC_NLA_STATS_RX_INFO, stats->recv_pkts},
                 {TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
                 {TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
                 {TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
                 {TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
-                {TIPC_NLA_STATS_TX_INFO, stats->sent_info},
+                {TIPC_NLA_STATS_TX_INFO, stats->sent_pkts},
                 {TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
                 {TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
                 {TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
@@ -2076,9 +2079,9 @@ int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg)
                 goto attr_msg_full;
         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
                 goto attr_msg_full;
-        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, bcl->rcv_nxt))
+        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, 0))
                 goto attr_msg_full;
-        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, bcl->snd_nxt))
+        if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, 0))
                 goto attr_msg_full;
 
         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index 78cab9c5a445..b58dc95f3d35 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -697,6 +697,11 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
                 udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
                 udp_conf.use_udp_checksums = false;
                 ub->ifindex = dev->ifindex;
+                if (tipc_mtu_bad(dev, sizeof(struct iphdr) +
+                                      sizeof(struct udphdr))) {
+                        err = -EINVAL;
+                        goto err;
+                }
                 b->mtu = dev->mtu - sizeof(struct iphdr)
                         - sizeof(struct udphdr);
 #if IS_ENABLED(CONFIG_IPV6)