1 files changed, 55 insertions, 2 deletions

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 1ce6b60b7f93..353284360751 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -82,6 +82,7 @@
 #include <asm/system.h>
 #include <asm/uaccess.h>
 #include <asm/ioctls.h>
+#include <linux/bootmem.h>
 #include <linux/types.h>
 #include <linux/fcntl.h>
 #include <linux/module.h>
@@ -118,6 +119,17 @@ EXPORT_SYMBOL(udp_stats_in6);
 struct hlist_head udp_hash[UDP_HTABLE_SIZE];
 DEFINE_RWLOCK(udp_hash_lock);
 
+int sysctl_udp_mem[3] __read_mostly;
+int sysctl_udp_rmem_min __read_mostly;
+int sysctl_udp_wmem_min __read_mostly;
+
+EXPORT_SYMBOL(sysctl_udp_mem);
+EXPORT_SYMBOL(sysctl_udp_rmem_min);
+EXPORT_SYMBOL(sysctl_udp_wmem_min);
+
+atomic_t udp_memory_allocated;
+EXPORT_SYMBOL(udp_memory_allocated);
+
 static inline int __udp_lib_lport_inuse(__u16 num,
                                         const struct hlist_head udptable[])
 {
@@ -901,13 +913,17 @@ try_again:
                 err = ulen;
 
 out_free:
+        lock_sock(sk);
         skb_free_datagram(sk, skb);
+        release_sock(sk);
 out:
         return err;
 
 csum_copy_err:
+        lock_sock(sk);
         if (!skb_kill_datagram(sk, skb, flags))
                 UDP_INC_STATS_USER(UDP_MIB_INERRORS, is_udplite);
+        release_sock(sk);
 
         if (noblock)
                 return -EAGAIN;
@@ -1072,7 +1088,15 @@ static int __udp4_lib_mcast_deliver(struct sk_buff *skb,
                                 skb1 = skb_clone(skb, GFP_ATOMIC);
 
                         if (skb1) {
-                                int ret = udp_queue_rcv_skb(sk, skb1);
+                                int ret = 0;
+
+                                bh_lock_sock_nested(sk);
+                                if (!sock_owned_by_user(sk))
+                                        ret = udp_queue_rcv_skb(sk, skb1);
+                                else
+                                        sk_add_backlog(sk, skb1);
+                                bh_unlock_sock(sk);
+
                                 if (ret > 0)
                                         /* we should probably re-process instead
                                          * of dropping packets here. */
@@ -1165,7 +1189,13 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
                                inet_iif(skb), udptable);
 
         if (sk != NULL) {
-                int ret = udp_queue_rcv_skb(sk, skb);
+                int ret = 0;
+                bh_lock_sock_nested(sk);
+                if (!sock_owned_by_user(sk))
+                        ret = udp_queue_rcv_skb(sk, skb);
+                else
+                        sk_add_backlog(sk, skb);
+                bh_unlock_sock(sk);
                 sock_put(sk);
 
                 /* a return value > 0 means to resubmit the input, but
@@ -1460,6 +1490,10 @@ struct proto udp_prot = {
         .hash              = udp_lib_hash,
         .unhash            = udp_lib_unhash,
         .get_port          = udp_v4_get_port,
+        .memory_allocated  = &udp_memory_allocated,
+        .sysctl_mem        = sysctl_udp_mem,
+        .sysctl_wmem       = &sysctl_udp_wmem_min,
+        .sysctl_rmem       = &sysctl_udp_rmem_min,
         .obj_size          = sizeof(struct udp_sock),
 #ifdef CONFIG_COMPAT
         .compat_setsockopt = compat_udp_setsockopt,
@@ -1655,6 +1689,25 @@ void udp4_proc_exit(void)
 }
 #endif /* CONFIG_PROC_FS */
 
+void __init udp_init(void)
+{
+        unsigned long limit;
+
+        /* Set the pressure threshold up by the same strategy of TCP. It is a
+         * fraction of global memory that is up to 1/2 at 256 MB, decreasing
+         * toward zero with the amount of memory, with a floor of 128 pages.
+         */
+        limit = min(nr_all_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
+        limit = (limit * (nr_all_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
+        limit = max(limit, 128UL);
+        sysctl_udp_mem[0] = limit / 4 * 3;
+        sysctl_udp_mem[1] = limit;
+        sysctl_udp_mem[2] = sysctl_udp_mem[0] * 2;
+
+        sysctl_udp_rmem_min = SK_MEM_QUANTUM;
+        sysctl_udp_wmem_min = SK_MEM_QUANTUM;
+}
+
 EXPORT_SYMBOL(udp_disconnect);
 EXPORT_SYMBOL(udp_hash);
 EXPORT_SYMBOL(udp_hash_lock);