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-rw-r--r--net/ipv4/udp.c271
1 files changed, 167 insertions, 104 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 98c1fd09be88..cf5ab0581eba 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -81,6 +81,8 @@
#include <asm/uaccess.h>
#include <asm/ioctls.h>
#include <linux/bootmem.h>
+#include <linux/highmem.h>
+#include <linux/swap.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/module.h>
@@ -104,12 +106,8 @@
#include <net/xfrm.h>
#include "udp_impl.h"
-/*
- * Snmp MIB for the UDP layer
- */
-
-struct hlist_head udp_hash[UDP_HTABLE_SIZE];
-DEFINE_RWLOCK(udp_hash_lock);
+struct udp_table udp_table;
+EXPORT_SYMBOL(udp_table);
int sysctl_udp_mem[3] __read_mostly;
int sysctl_udp_rmem_min __read_mostly;
@@ -123,15 +121,15 @@ atomic_t udp_memory_allocated;
EXPORT_SYMBOL(udp_memory_allocated);
static int udp_lib_lport_inuse(struct net *net, __u16 num,
- const struct hlist_head udptable[],
+ const struct udp_hslot *hslot,
struct sock *sk,
int (*saddr_comp)(const struct sock *sk1,
const struct sock *sk2))
{
struct sock *sk2;
- struct hlist_node *node;
+ struct hlist_nulls_node *node;
- sk_for_each(sk2, node, &udptable[udp_hashfn(net, num)])
+ sk_nulls_for_each(sk2, node, &hslot->head)
if (net_eq(sock_net(sk2), net) &&
sk2 != sk &&
sk2->sk_hash == num &&
@@ -154,12 +152,11 @@ int udp_lib_get_port(struct sock *sk, unsigned short snum,
int (*saddr_comp)(const struct sock *sk1,
const struct sock *sk2 ) )
{
- struct hlist_head *udptable = sk->sk_prot->h.udp_hash;
+ struct udp_hslot *hslot;
+ struct udp_table *udptable = sk->sk_prot->h.udp_table;
int error = 1;
struct net *net = sock_net(sk);
- write_lock_bh(&udp_hash_lock);
-
if (!snum) {
int low, high, remaining;
unsigned rand;
@@ -171,26 +168,34 @@ int udp_lib_get_port(struct sock *sk, unsigned short snum,
rand = net_random();
snum = first = rand % remaining + low;
rand |= 1;
- while (udp_lib_lport_inuse(net, snum, udptable, sk,
- saddr_comp)) {
+ for (;;) {
+ hslot = &udptable->hash[udp_hashfn(net, snum)];
+ spin_lock_bh(&hslot->lock);
+ if (!udp_lib_lport_inuse(net, snum, hslot, sk, saddr_comp))
+ break;
+ spin_unlock_bh(&hslot->lock);
do {
snum = snum + rand;
} while (snum < low || snum > high);
if (snum == first)
goto fail;
}
- } else if (udp_lib_lport_inuse(net, snum, udptable, sk, saddr_comp))
- goto fail;
-
+ } else {
+ hslot = &udptable->hash[udp_hashfn(net, snum)];
+ spin_lock_bh(&hslot->lock);
+ if (udp_lib_lport_inuse(net, snum, hslot, sk, saddr_comp))
+ goto fail_unlock;
+ }
inet_sk(sk)->num = snum;
sk->sk_hash = snum;
if (sk_unhashed(sk)) {
- sk_add_node(sk, &udptable[udp_hashfn(net, snum)]);
+ sk_nulls_add_node_rcu(sk, &hslot->head);
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
}
error = 0;
+fail_unlock:
+ spin_unlock_bh(&hslot->lock);
fail:
- write_unlock_bh(&udp_hash_lock);
return error;
}
@@ -208,63 +213,91 @@ int udp_v4_get_port(struct sock *sk, unsigned short snum)
return udp_lib_get_port(sk, snum, ipv4_rcv_saddr_equal);
}
+static inline int compute_score(struct sock *sk, struct net *net, __be32 saddr,
+ unsigned short hnum,
+ __be16 sport, __be32 daddr, __be16 dport, int dif)
+{
+ int score = -1;
+
+ if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum &&
+ !ipv6_only_sock(sk)) {
+ struct inet_sock *inet = inet_sk(sk);
+
+ score = (sk->sk_family == PF_INET ? 1 : 0);
+ if (inet->rcv_saddr) {
+ if (inet->rcv_saddr != daddr)
+ return -1;
+ score += 2;
+ }
+ if (inet->daddr) {
+ if (inet->daddr != saddr)
+ return -1;
+ score += 2;
+ }
+ if (inet->dport) {
+ if (inet->dport != sport)
+ return -1;
+ score += 2;
+ }
+ if (sk->sk_bound_dev_if) {
+ if (sk->sk_bound_dev_if != dif)
+ return -1;
+ score += 2;
+ }
+ }
+ return score;
+}
+
/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
* harder than this. -DaveM
*/
static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
__be16 sport, __be32 daddr, __be16 dport,
- int dif, struct hlist_head udptable[])
+ int dif, struct udp_table *udptable)
{
- struct sock *sk, *result = NULL;
- struct hlist_node *node;
+ struct sock *sk, *result;
+ struct hlist_nulls_node *node;
unsigned short hnum = ntohs(dport);
- int badness = -1;
-
- read_lock(&udp_hash_lock);
- sk_for_each(sk, node, &udptable[udp_hashfn(net, hnum)]) {
- struct inet_sock *inet = inet_sk(sk);
-
- if (net_eq(sock_net(sk), net) && sk->sk_hash == hnum &&
- !ipv6_only_sock(sk)) {
- int score = (sk->sk_family == PF_INET ? 1 : 0);
- if (inet->rcv_saddr) {
- if (inet->rcv_saddr != daddr)
- continue;
- score+=2;
- }
- if (inet->daddr) {
- if (inet->daddr != saddr)
- continue;
- score+=2;
- }
- if (inet->dport) {
- if (inet->dport != sport)
- continue;
- score+=2;
- }
- if (sk->sk_bound_dev_if) {
- if (sk->sk_bound_dev_if != dif)
- continue;
- score+=2;
- }
- if (score == 9) {
- result = sk;
- break;
- } else if (score > badness) {
- result = sk;
- badness = score;
- }
+ unsigned int hash = udp_hashfn(net, hnum);
+ struct udp_hslot *hslot = &udptable->hash[hash];
+ int score, badness;
+
+ rcu_read_lock();
+begin:
+ result = NULL;
+ badness = -1;
+ sk_nulls_for_each_rcu(sk, node, &hslot->head) {
+ score = compute_score(sk, net, saddr, hnum, sport,
+ daddr, dport, dif);
+ if (score > badness) {
+ result = sk;
+ badness = score;
}
}
- if (result)
- sock_hold(result);
- read_unlock(&udp_hash_lock);
+ /*
+ * if the nulls value we got at the end of this lookup is
+ * not the expected one, we must restart lookup.
+ * We probably met an item that was moved to another chain.
+ */
+ if (get_nulls_value(node) != hash)
+ goto begin;
+
+ if (result) {
+ if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
+ result = NULL;
+ else if (unlikely(compute_score(result, net, saddr, hnum, sport,
+ daddr, dport, dif) < badness)) {
+ sock_put(result);
+ goto begin;
+ }
+ }
+ rcu_read_unlock();
return result;
}
static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
__be16 sport, __be16 dport,
- struct hlist_head udptable[])
+ struct udp_table *udptable)
{
struct sock *sk;
const struct iphdr *iph = ip_hdr(skb);
@@ -280,7 +313,7 @@ static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
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);
+ return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table);
}
EXPORT_SYMBOL_GPL(udp4_lib_lookup);
@@ -289,11 +322,11 @@ static inline struct sock *udp_v4_mcast_next(struct net *net, struct sock *sk,
__be16 rmt_port, __be32 rmt_addr,
int dif)
{
- struct hlist_node *node;
+ struct hlist_nulls_node *node;
struct sock *s = sk;
unsigned short hnum = ntohs(loc_port);
- sk_for_each_from(s, node) {
+ sk_nulls_for_each_from(s, node) {
struct inet_sock *inet = inet_sk(s);
if (!net_eq(sock_net(s), net) ||
@@ -324,7 +357,7 @@ found:
* to find the appropriate port.
*/
-void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[])
+void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
{
struct inet_sock *inet;
struct iphdr *iph = (struct iphdr*)skb->data;
@@ -393,7 +426,7 @@ out:
void udp_err(struct sk_buff *skb, u32 info)
{
- __udp4_lib_err(skb, info, udp_hash);
+ __udp4_lib_err(skb, info, &udp_table);
}
/*
@@ -686,7 +719,7 @@ do_append_data:
up->len += ulen;
getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag;
err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
- sizeof(struct udphdr), &ipc, rt,
+ sizeof(struct udphdr), &ipc, &rt,
corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
if (err)
udp_flush_pending_frames(sk);
@@ -935,6 +968,23 @@ int udp_disconnect(struct sock *sk, int flags)
return 0;
}
+void udp_lib_unhash(struct sock *sk)
+{
+ if (sk_hashed(sk)) {
+ struct udp_table *udptable = sk->sk_prot->h.udp_table;
+ unsigned int hash = udp_hashfn(sock_net(sk), sk->sk_hash);
+ struct udp_hslot *hslot = &udptable->hash[hash];
+
+ spin_lock_bh(&hslot->lock);
+ if (sk_nulls_del_node_init_rcu(sk)) {
+ inet_sk(sk)->num = 0;
+ sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
+ }
+ spin_unlock_bh(&hslot->lock);
+ }
+}
+EXPORT_SYMBOL(udp_lib_unhash);
+
static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
int is_udplite = IS_UDPLITE(sk);
@@ -1073,13 +1123,14 @@ drop:
static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
struct udphdr *uh,
__be32 saddr, __be32 daddr,
- struct hlist_head udptable[])
+ struct udp_table *udptable)
{
struct sock *sk;
+ struct udp_hslot *hslot = &udptable->hash[udp_hashfn(net, ntohs(uh->dest))];
int dif;
- read_lock(&udp_hash_lock);
- sk = sk_head(&udptable[udp_hashfn(net, ntohs(uh->dest))]);
+ spin_lock(&hslot->lock);
+ sk = sk_nulls_head(&hslot->head);
dif = skb->dev->ifindex;
sk = udp_v4_mcast_next(net, sk, uh->dest, daddr, uh->source, saddr, dif);
if (sk) {
@@ -1088,7 +1139,7 @@ static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
do {
struct sk_buff *skb1 = skb;
- sknext = udp_v4_mcast_next(net, sk_next(sk), uh->dest,
+ sknext = udp_v4_mcast_next(net, sk_nulls_next(sk), uh->dest,
daddr, uh->source, saddr,
dif);
if (sknext)
@@ -1105,7 +1156,7 @@ static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
} while (sknext);
} else
kfree_skb(skb);
- read_unlock(&udp_hash_lock);
+ spin_unlock(&hslot->lock);
return 0;
}
@@ -1151,7 +1202,7 @@ static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
* All we need to do is get the socket, and then do a checksum.
*/
-int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
+int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
int proto)
{
struct sock *sk;
@@ -1219,13 +1270,13 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
return 0;
short_packet:
- LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From " NIPQUAD_FMT ":%u %d/%d to " NIPQUAD_FMT ":%u\n",
+ LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %pI4:%u %d/%d to %pI4:%u\n",
proto == IPPROTO_UDPLITE ? "-Lite" : "",
- NIPQUAD(saddr),
+ &saddr,
ntohs(uh->source),
ulen,
skb->len,
- NIPQUAD(daddr),
+ &daddr,
ntohs(uh->dest));
goto drop;
@@ -1234,11 +1285,11 @@ csum_error:
* RFC1122: OK. Discards the bad packet silently (as far as
* the network is concerned, anyway) as per 4.1.3.4 (MUST).
*/
- LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From " NIPQUAD_FMT ":%u to " NIPQUAD_FMT ":%u ulen %d\n",
+ LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %pI4:%u to %pI4:%u ulen %d\n",
proto == IPPROTO_UDPLITE ? "-Lite" : "",
- NIPQUAD(saddr),
+ &saddr,
ntohs(uh->source),
- NIPQUAD(daddr),
+ &daddr,
ntohs(uh->dest),
ulen);
drop:
@@ -1249,7 +1300,7 @@ drop:
int udp_rcv(struct sk_buff *skb)
{
- return __udp4_lib_rcv(skb, udp_hash, IPPROTO_UDP);
+ return __udp4_lib_rcv(skb, &udp_table, IPPROTO_UDP);
}
void udp_destroy_sock(struct sock *sk)
@@ -1491,7 +1542,8 @@ struct proto udp_prot = {
.sysctl_wmem = &sysctl_udp_wmem_min,
.sysctl_rmem = &sysctl_udp_rmem_min,
.obj_size = sizeof(struct udp_sock),
- .h.udp_hash = udp_hash,
+ .slab_flags = SLAB_DESTROY_BY_RCU,
+ .h.udp_table = &udp_table,
#ifdef CONFIG_COMPAT
.compat_setsockopt = compat_udp_setsockopt,
.compat_getsockopt = compat_udp_getsockopt,
@@ -1501,20 +1553,23 @@ struct proto udp_prot = {
/* ------------------------------------------------------------------------ */
#ifdef CONFIG_PROC_FS
-static struct sock *udp_get_first(struct seq_file *seq)
+static struct sock *udp_get_first(struct seq_file *seq, int start)
{
struct sock *sk;
struct udp_iter_state *state = seq->private;
struct net *net = seq_file_net(seq);
- for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
- struct hlist_node *node;
- sk_for_each(sk, node, state->hashtable + state->bucket) {
+ for (state->bucket = start; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
+ struct hlist_nulls_node *node;
+ struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
+ spin_lock_bh(&hslot->lock);
+ sk_nulls_for_each(sk, node, &hslot->head) {
if (!net_eq(sock_net(sk), net))
continue;
if (sk->sk_family == state->family)
goto found;
}
+ spin_unlock_bh(&hslot->lock);
}
sk = NULL;
found:
@@ -1527,21 +1582,19 @@ static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
struct net *net = seq_file_net(seq);
do {
- sk = sk_next(sk);
-try_again:
- ;
+ sk = sk_nulls_next(sk);
} while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
- if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
- sk = sk_head(state->hashtable + state->bucket);
- goto try_again;
+ if (!sk) {
+ spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
+ return udp_get_first(seq, state->bucket + 1);
}
return sk;
}
static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
{
- struct sock *sk = udp_get_first(seq);
+ struct sock *sk = udp_get_first(seq, 0);
if (sk)
while (pos && (sk = udp_get_next(seq, sk)) != NULL)
@@ -1550,9 +1603,7 @@ static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
}
static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
- __acquires(udp_hash_lock)
{
- read_lock(&udp_hash_lock);
return *pos ? udp_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
}
@@ -1570,9 +1621,11 @@ static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
}
static void udp_seq_stop(struct seq_file *seq, void *v)
- __releases(udp_hash_lock)
{
- read_unlock(&udp_hash_lock);
+ struct udp_iter_state *state = seq->private;
+
+ if (state->bucket < UDP_HTABLE_SIZE)
+ spin_unlock_bh(&state->udp_table->hash[state->bucket].lock);
}
static int udp_seq_open(struct inode *inode, struct file *file)
@@ -1588,7 +1641,7 @@ static int udp_seq_open(struct inode *inode, struct file *file)
s = ((struct seq_file *)file->private_data)->private;
s->family = afinfo->family;
- s->hashtable = afinfo->hashtable;
+ s->udp_table = afinfo->udp_table;
return err;
}
@@ -1660,7 +1713,7 @@ int udp4_seq_show(struct seq_file *seq, void *v)
static struct udp_seq_afinfo udp4_seq_afinfo = {
.name = "udp",
.family = AF_INET,
- .hashtable = udp_hash,
+ .udp_table = &udp_table,
.seq_fops = {
.owner = THIS_MODULE,
},
@@ -1695,16 +1748,28 @@ void udp4_proc_exit(void)
}
#endif /* CONFIG_PROC_FS */
+void __init udp_table_init(struct udp_table *table)
+{
+ int i;
+
+ for (i = 0; i < UDP_HTABLE_SIZE; i++) {
+ INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
+ spin_lock_init(&table->hash[i].lock);
+ }
+}
+
void __init udp_init(void)
{
- unsigned long limit;
+ unsigned long nr_pages, limit;
+ udp_table_init(&udp_table);
/* 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);
+ nr_pages = totalram_pages - totalhigh_pages;
+ limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
+ limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
limit = max(limit, 128UL);
sysctl_udp_mem[0] = limit / 4 * 3;
sysctl_udp_mem[1] = limit;
@@ -1715,8 +1780,6 @@ void __init udp_init(void)
}
EXPORT_SYMBOL(udp_disconnect);
-EXPORT_SYMBOL(udp_hash);
-EXPORT_SYMBOL(udp_hash_lock);
EXPORT_SYMBOL(udp_ioctl);
EXPORT_SYMBOL(udp_prot);
EXPORT_SYMBOL(udp_sendmsg);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 03:16:45 +0100