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Diffstat (limited to 'net/ipv4/udp.c')
-rw-r--r--net/ipv4/udp.c187
1 files changed, 86 insertions, 101 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 8e42fbbd576..2095abc3cab 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -8,7 +8,7 @@
* Authors: Ross Biro
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
* Arnt Gulbrandsen, <agulbra@nvg.unit.no>
- * Alan Cox, <Alan.Cox@linux.org>
+ * Alan Cox, <alan@lxorguk.ukuu.org.uk>
* Hirokazu Takahashi, <taka@valinux.co.jp>
*
* Fixes:
@@ -108,9 +108,6 @@
* Snmp MIB for the UDP layer
*/
-DEFINE_SNMP_STAT(struct udp_mib, udp_stats_in6) __read_mostly;
-EXPORT_SYMBOL(udp_stats_in6);
-
struct hlist_head udp_hash[UDP_HTABLE_SIZE];
DEFINE_RWLOCK(udp_hash_lock);
@@ -125,14 +122,23 @@ EXPORT_SYMBOL(sysctl_udp_wmem_min);
atomic_t udp_memory_allocated;
EXPORT_SYMBOL(udp_memory_allocated);
-static inline int __udp_lib_lport_inuse(struct net *net, __u16 num,
- const struct hlist_head udptable[])
+static int udp_lib_lport_inuse(struct net *net, __u16 num,
+ const struct hlist_head udptable[],
+ struct sock *sk,
+ int (*saddr_comp)(const struct sock *sk1,
+ const struct sock *sk2))
{
- struct sock *sk;
+ struct sock *sk2;
struct hlist_node *node;
- sk_for_each(sk, node, &udptable[udp_hashfn(net, num)])
- if (net_eq(sock_net(sk), net) && sk->sk_hash == num)
+ sk_for_each(sk2, node, &udptable[udp_hashfn(net, num)])
+ if (net_eq(sock_net(sk2), net) &&
+ sk2 != sk &&
+ sk2->sk_hash == num &&
+ (!sk2->sk_reuse || !sk->sk_reuse) &&
+ (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
+ || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
+ (*saddr_comp)(sk, sk2))
return 1;
return 0;
}
@@ -149,83 +155,37 @@ int udp_lib_get_port(struct sock *sk, unsigned short snum,
const struct sock *sk2 ) )
{
struct hlist_head *udptable = sk->sk_prot->h.udp_hash;
- struct hlist_node *node;
- struct hlist_head *head;
- struct sock *sk2;
int error = 1;
struct net *net = sock_net(sk);
write_lock_bh(&udp_hash_lock);
if (!snum) {
- int i, low, high, remaining;
- unsigned rover, best, best_size_so_far;
+ int low, high, remaining;
+ unsigned rand;
+ unsigned short first;
inet_get_local_port_range(&low, &high);
remaining = (high - low) + 1;
- best_size_so_far = UINT_MAX;
- best = rover = net_random() % remaining + low;
-
- /* 1st pass: look for empty (or shortest) hash chain */
- for (i = 0; i < UDP_HTABLE_SIZE; i++) {
- int size = 0;
-
- head = &udptable[udp_hashfn(net, rover)];
- if (hlist_empty(head))
- goto gotit;
-
- sk_for_each(sk2, node, head) {
- if (++size >= best_size_so_far)
- goto next;
- }
- best_size_so_far = size;
- best = rover;
- next:
- /* fold back if end of range */
- if (++rover > high)
- rover = low + ((rover - low)
- & (UDP_HTABLE_SIZE - 1));
-
-
- }
-
- /* 2nd pass: find hole in shortest hash chain */
- rover = best;
- for (i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++) {
- if (! __udp_lib_lport_inuse(net, rover, udptable))
- goto gotit;
- rover += UDP_HTABLE_SIZE;
- if (rover > high)
- rover = low + ((rover - low)
- & (UDP_HTABLE_SIZE - 1));
+ rand = net_random();
+ snum = first = rand % remaining + low;
+ rand |= 1;
+ while (udp_lib_lport_inuse(net, snum, udptable, sk,
+ saddr_comp)) {
+ do {
+ snum = snum + rand;
+ } while (snum < low || snum > high);
+ if (snum == first)
+ goto fail;
}
-
-
- /* All ports in use! */
+ } else if (udp_lib_lport_inuse(net, snum, udptable, sk, saddr_comp))
goto fail;
-gotit:
- snum = rover;
- } else {
- head = &udptable[udp_hashfn(net, snum)];
-
- sk_for_each(sk2, node, head)
- if (sk2->sk_hash == snum &&
- sk2 != sk &&
- net_eq(sock_net(sk2), net) &&
- (!sk2->sk_reuse || !sk->sk_reuse) &&
- (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
- || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
- (*saddr_comp)(sk, sk2) )
- goto fail;
- }
-
inet_sk(sk)->num = snum;
sk->sk_hash = snum;
if (sk_unhashed(sk)) {
- head = &udptable[udp_hashfn(net, snum)];
- sk_add_node(sk, head);
+ sk_add_node(sk, &udptable[udp_hashfn(net, snum)]);
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
}
error = 0;
@@ -302,6 +262,28 @@ static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
return result;
}
+static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
+ __be16 sport, __be16 dport,
+ struct hlist_head udptable[])
+{
+ struct sock *sk;
+ const struct iphdr *iph = ip_hdr(skb);
+
+ if (unlikely(sk = skb_steal_sock(skb)))
+ return sk;
+ else
+ return __udp4_lib_lookup(dev_net(skb->dst->dev), iph->saddr, sport,
+ iph->daddr, dport, inet_iif(skb),
+ udptable);
+}
+
+struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
+ __be32 daddr, __be16 dport, int dif)
+{
+ return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, udp_hash);
+}
+EXPORT_SYMBOL_GPL(udp4_lib_lookup);
+
static inline struct sock *udp_v4_mcast_next(struct sock *sk,
__be16 loc_port, __be32 loc_addr,
__be16 rmt_port, __be32 rmt_addr,
@@ -951,6 +933,27 @@ int udp_disconnect(struct sock *sk, int flags)
return 0;
}
+static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+ int is_udplite = IS_UDPLITE(sk);
+ int rc;
+
+ if ((rc = sock_queue_rcv_skb(sk, skb)) < 0) {
+ /* Note that an ENOMEM error is charged twice */
+ if (rc == -ENOMEM)
+ UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
+ is_udplite);
+ goto drop;
+ }
+
+ return 0;
+
+drop:
+ UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
+ kfree_skb(skb);
+ return -1;
+}
+
/* returns:
* -1: error
* 0: success
@@ -989,9 +992,7 @@ int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
up->encap_rcv != NULL) {
int ret;
- bh_unlock_sock(sk);
ret = (*up->encap_rcv)(sk, skb);
- bh_lock_sock(sk);
if (ret <= 0) {
UDP_INC_STATS_BH(sock_net(sk),
UDP_MIB_INDATAGRAMS,
@@ -1044,17 +1045,16 @@ int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
goto drop;
}
- if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
- /* Note that an ENOMEM error is charged twice */
- if (rc == -ENOMEM) {
- UDP_INC_STATS_BH(sock_net(sk),
- UDP_MIB_RCVBUFERRORS, is_udplite);
- atomic_inc(&sk->sk_drops);
- }
- goto drop;
- }
+ rc = 0;
- return 0;
+ bh_lock_sock(sk);
+ if (!sock_owned_by_user(sk))
+ rc = __udp_queue_rcv_skb(sk, skb);
+ else
+ sk_add_backlog(sk, skb);
+ bh_unlock_sock(sk);
+
+ return rc;
drop:
UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, is_udplite);
@@ -1092,15 +1092,7 @@ static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
skb1 = skb_clone(skb, GFP_ATOMIC);
if (skb1) {
- int ret = 0;
-
- bh_lock_sock(sk);
- if (!sock_owned_by_user(sk))
- ret = udp_queue_rcv_skb(sk, skb1);
- else
- sk_add_backlog(sk, skb1);
- bh_unlock_sock(sk);
-
+ int ret = udp_queue_rcv_skb(sk, skb1);
if (ret > 0)
/* we should probably re-process instead
* of dropping packets here. */
@@ -1191,17 +1183,10 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
return __udp4_lib_mcast_deliver(net, skb, uh,
saddr, daddr, udptable);
- sk = __udp4_lib_lookup(net, saddr, uh->source, daddr,
- uh->dest, inet_iif(skb), udptable);
+ sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable);
if (sk != NULL) {
- int ret = 0;
- bh_lock_sock(sk);
- if (!sock_owned_by_user(sk))
- ret = udp_queue_rcv_skb(sk, skb);
- else
- sk_add_backlog(sk, skb);
- bh_unlock_sock(sk);
+ int ret = udp_queue_rcv_skb(sk, skb);
sock_put(sk);
/* a return value > 0 means to resubmit the input, but
@@ -1494,7 +1479,7 @@ struct proto udp_prot = {
.sendmsg = udp_sendmsg,
.recvmsg = udp_recvmsg,
.sendpage = udp_sendpage,
- .backlog_rcv = udp_queue_rcv_skb,
+ .backlog_rcv = __udp_queue_rcv_skb,
.hash = udp_lib_hash,
.unhash = udp_lib_unhash,
.get_port = udp_v4_get_port,
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-19 14:46:54 +0000