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udp: no longer use SLAB_DESTROY_BY_RCU

Browse source 
Tom Herbert would like not touching UDP socket refcnt for encapsulated
traffic. For this to happen, we need to use normal RCU rules, with a grace
period before freeing a socket. UDP sockets are not short lived in the
high usage case, so the added cost of call_rcu() should not be a concern.

This actually removes a lot of complexity in UDP stack.

Multicast receives no longer need to hold a bucket spinlock.

Note that ip early demux still needs to take a reference on the socket.

Same remark for functions used by xt_socket and xt_PROXY netfilter modules,
but this might be changed later.

Performance for a single UDP socket receiving flood traffic from
many RX queues/cpus.

Simple udp_rx using simple recvfrom() loop :
438 kpps instead of 374 kpps : 17 % increase of the peak rate.

v2: Addressed Willem de Bruijn feedback in multicast handling
 - keep early demux break in __udp4_lib_demux_lookup()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Cc: Willem de Bruijn <willemb@google.com>
Tested-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2016-04-01 08:52:13 -07:00 • committed by David S. Miller
parent a4298e4522
commit ca065d0cf8
6 changed files with 172 additions and 359 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
include/linux/udp.h
View file

@ -98,11 +98,11 @@ static inline bool udp_get_no_check6_rx(struct sock *sk)
return udp_sk(sk)->no_check6_rx; return udp_sk(sk)->no_check6_rx;
} }
#define udp_portaddr_for_each_entry(__sk, node, list) \ #define udp_portaddr_for_each_entry(__sk, list) \
hlist_nulls_for_each_entry(__sk, node, list, __sk_common.skc_portaddr_node) hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node)
#define udp_portaddr_for_each_entry_rcu(__sk, node, list) \ #define udp_portaddr_for_each_entry_rcu(__sk, list) \
hlist_nulls_for_each_entry_rcu(__sk, node, list, __sk_common.skc_portaddr_node) hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node)
#define IS_UDPLITE(__sk) (udp_sk(__sk)->pcflag) #define IS_UDPLITE(__sk) (udp_sk(__sk)->pcflag)

12
include/net/sock.h
View file

@ -178,7 +178,7 @@ struct sock_common {
int skc_bound_dev_if; int skc_bound_dev_if;
union { union {
struct hlist_node skc_bind_node; struct hlist_node skc_bind_node;
struct hlist_nulls_node skc_portaddr_node; struct hlist_node skc_portaddr_node;
}; };
struct proto *skc_prot; struct proto *skc_prot;
possible_net_t skc_net; possible_net_t skc_net;
@ -670,18 +670,18 @@ static inline void sk_add_bind_node(struct sock *sk,
hlist_for_each_entry(__sk, list, sk_bind_node) hlist_for_each_entry(__sk, list, sk_bind_node)
/** /**
* sk_nulls_for_each_entry_offset - iterate over a list at a given struct offset * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
* @tpos: the type * to use as a loop cursor. * @tpos: the type * to use as a loop cursor.
* @pos: the &struct hlist_node to use as a loop cursor. * @pos: the &struct hlist_node to use as a loop cursor.
* @head: the head for your list. * @head: the head for your list.
* @offset: offset of hlist_node within the struct. * @offset: offset of hlist_node within the struct.
* *
*/ */
#define sk_nulls_for_each_entry_offset(tpos, pos, head, offset) \ #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset) \
for (pos = (head)->first; \ for (pos = rcu_dereference((head)->first); \
(!is_a_nulls(pos)) && \ pos != NULL && \
({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \ ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \
pos = pos->next) pos = rcu_dereference(pos->next))
static inline struct user_namespace *sk_user_ns(struct sock *sk) static inline struct user_namespace *sk_user_ns(struct sock *sk)
{ {

2
include/net/udp.h
View file

@ -59,7 +59,7 @@ struct udp_skb_cb {
* @lock: spinlock protecting changes to head/count * @lock: spinlock protecting changes to head/count
*/ */
struct udp_hslot { struct udp_hslot {
struct hlist_nulls_head head; struct hlist_head head;
int count; int count;
spinlock_t lock; spinlock_t lock;
} __attribute__((aligned(2 * sizeof(long)))); } __attribute__((aligned(2 * sizeof(long))));

293
net/ipv4/udp.c
View file

@ -143,10 +143,9 @@ static int udp_lib_lport_inuse(struct net *net, __u16 num,
unsigned int log) unsigned int log)
{ {
struct sock *sk2; struct sock *sk2;
struct hlist_nulls_node *node;
kuid_t uid = sock_i_uid(sk); kuid_t uid = sock_i_uid(sk);
sk_nulls_for_each(sk2, node, &hslot->head) { sk_for_each(sk2, &hslot->head) {
if (net_eq(sock_net(sk2), net) && if (net_eq(sock_net(sk2), net) &&
sk2 != sk && sk2 != sk &&
(bitmap || udp_sk(sk2)->udp_port_hash == num) && (bitmap || udp_sk(sk2)->udp_port_hash == num) &&
@ -177,12 +176,11 @@ static int udp_lib_lport_inuse2(struct net *net, __u16 num,
bool match_wildcard)) bool match_wildcard))
{ {
struct sock *sk2; struct sock *sk2;
struct hlist_nulls_node *node;
kuid_t uid = sock_i_uid(sk); kuid_t uid = sock_i_uid(sk);
int res = 0; int res = 0;
spin_lock(&hslot2->lock); spin_lock(&hslot2->lock);
udp_portaddr_for_each_entry(sk2, node, &hslot2->head) { udp_portaddr_for_each_entry(sk2, &hslot2->head) {
if (net_eq(sock_net(sk2), net) && if (net_eq(sock_net(sk2), net) &&
sk2 != sk && sk2 != sk &&
(udp_sk(sk2)->udp_port_hash == num) && (udp_sk(sk2)->udp_port_hash == num) &&
@ -207,11 +205,10 @@ static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot,
bool match_wildcard)) bool match_wildcard))
{ {
struct net *net = sock_net(sk); struct net *net = sock_net(sk);
struct hlist_nulls_node *node;
kuid_t uid = sock_i_uid(sk); kuid_t uid = sock_i_uid(sk);
struct sock *sk2; struct sock *sk2;
sk_nulls_for_each(sk2, node, &hslot->head) { sk_for_each(sk2, &hslot->head) {
if (net_eq(sock_net(sk2), net) && if (net_eq(sock_net(sk2), net) &&
sk2 != sk && sk2 != sk &&
sk2->sk_family == sk->sk_family && sk2->sk_family == sk->sk_family &&
@ -333,17 +330,18 @@ found:
goto fail_unlock; goto fail_unlock;
} }
sk_nulls_add_node_rcu(sk, &hslot->head); sk_add_node_rcu(sk, &hslot->head);
hslot->count++; hslot->count++;
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash); hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);
spin_lock(&hslot2->lock); spin_lock(&hslot2->lock);
hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
&hslot2->head); &hslot2->head);
hslot2->count++; hslot2->count++;
spin_unlock(&hslot2->lock); spin_unlock(&hslot2->lock);
} }
sock_set_flag(sk, SOCK_RCU_FREE);
error = 0; error = 0;
fail_unlock: fail_unlock:
spin_unlock_bh(&hslot->lock); spin_unlock_bh(&hslot->lock);
@ -497,37 +495,27 @@ static struct sock *udp4_lib_lookup2(struct net *net,
struct sk_buff *skb) struct sk_buff *skb)
{ {
struct sock *sk, *result; struct sock *sk, *result;
struct hlist_nulls_node *node;
int score, badness, matches = 0, reuseport = 0; int score, badness, matches = 0, reuseport = 0;
bool select_ok = true;
u32 hash = 0; u32 hash = 0;
begin:
result = NULL; result = NULL;
badness = 0; badness = 0;
udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
score = compute_score2(sk, net, saddr, sport, score = compute_score2(sk, net, saddr, sport,
daddr, hnum, dif); daddr, hnum, dif);
if (score > badness) { if (score > badness) {
result = sk;
badness = score;
reuseport = sk->sk_reuseport; reuseport = sk->sk_reuseport;
if (reuseport) { if (reuseport) {
hash = udp_ehashfn(net, daddr, hnum, hash = udp_ehashfn(net, daddr, hnum,
saddr, sport); saddr, sport);
if (select_ok) { result = reuseport_select_sock(sk, hash, skb,
struct sock *sk2;
sk2 = reuseport_select_sock(sk, hash, skb,
sizeof(struct udphdr)); sizeof(struct udphdr));
if (sk2) { if (result)
result = sk2; return result;
select_ok = false;
goto found;
}
}
matches = 1; matches = 1;
} }
badness = score;
result = sk;
} else if (score == badness && reuseport) { } else if (score == badness && reuseport) {
matches++; matches++;
if (reciprocal_scale(hash, matches) == 0) if (reciprocal_scale(hash, matches) == 0)
@ -535,23 +523,6 @@ begin:
hash = next_pseudo_random32(hash); hash = next_pseudo_random32(hash);
} }
} }
/*
* 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) != slot2)
goto begin;
if (result) {
found:
if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
result = NULL;
else if (unlikely(compute_score2(result, net, saddr, sport,
daddr, hnum, dif) < badness)) {
sock_put(result);
goto begin;
}
}
return result; return result;
} }
@ -563,15 +534,12 @@ struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
int dif, struct udp_table *udptable, struct sk_buff *skb) int dif, struct udp_table *udptable, struct sk_buff *skb)
{ {
struct sock *sk, *result; struct sock *sk, *result;
struct hlist_nulls_node *node;
unsigned short hnum = ntohs(dport); unsigned short hnum = ntohs(dport);
unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
int score, badness, matches = 0, reuseport = 0; int score, badness, matches = 0, reuseport = 0;
bool select_ok = true;
u32 hash = 0; u32 hash = 0;
rcu_read_lock();
if (hslot->count > 10) { if (hslot->count > 10) {
hash2 = udp4_portaddr_hash(net, daddr, hnum); hash2 = udp4_portaddr_hash(net, daddr, hnum);
slot2 = hash2 & udptable->mask; slot2 = hash2 & udptable->mask;
@ -593,35 +561,27 @@ struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr,
htonl(INADDR_ANY), hnum, dif, htonl(INADDR_ANY), hnum, dif,
hslot2, slot2, skb); hslot2, slot2, skb);
} }
rcu_read_unlock();
return result; return result;
} }
begin: begin:
result = NULL; result = NULL;
badness = 0; badness = 0;
sk_nulls_for_each_rcu(sk, node, &hslot->head) { sk_for_each_rcu(sk, &hslot->head) {
score = compute_score(sk, net, saddr, hnum, sport, score = compute_score(sk, net, saddr, hnum, sport,
daddr, dport, dif); daddr, dport, dif);
if (score > badness) { if (score > badness) {
result = sk;
badness = score;
reuseport = sk->sk_reuseport; reuseport = sk->sk_reuseport;
if (reuseport) { if (reuseport) {
hash = udp_ehashfn(net, daddr, hnum, hash = udp_ehashfn(net, daddr, hnum,
saddr, sport); saddr, sport);
if (select_ok) { result = reuseport_select_sock(sk, hash, skb,
struct sock *sk2;
sk2 = reuseport_select_sock(sk, hash, skb,
sizeof(struct udphdr)); sizeof(struct udphdr));
if (sk2) { if (result)
result = sk2; return result;
select_ok = false;
goto found;
}
}
matches = 1; matches = 1;
} }
result = sk;
badness = score;
} else if (score == badness && reuseport) { } else if (score == badness && reuseport) {
matches++; matches++;
if (reciprocal_scale(hash, matches) == 0) if (reciprocal_scale(hash, matches) == 0)
@ -629,25 +589,6 @@ begin:
hash = next_pseudo_random32(hash); hash = next_pseudo_random32(hash);
} }
} }
/*
* 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) != slot)
goto begin;
if (result) {
found:
if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
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; return result;
} }
EXPORT_SYMBOL_GPL(__udp4_lib_lookup); EXPORT_SYMBOL_GPL(__udp4_lib_lookup);
@ -663,13 +604,24 @@ static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
udptable, skb); udptable, skb);
} }
/* Must be called under rcu_read_lock().
* Does increment socket refcount.
*/
#if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \
IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY)
struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport, struct sock *udp4_lib_lookup(struct net *net, __be32 saddr, __be16 sport,
__be32 daddr, __be16 dport, int dif) __be32 daddr, __be16 dport, int dif)
{ {
return __udp4_lib_lookup(net, saddr, sport, daddr, dport, dif, struct sock *sk;
&udp_table, NULL);
sk = __udp4_lib_lookup(net, saddr, sport, daddr, dport,
dif, &udp_table, NULL);
if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))
sk = NULL;
return sk;
} }
EXPORT_SYMBOL_GPL(udp4_lib_lookup); EXPORT_SYMBOL_GPL(udp4_lib_lookup);
#endif
static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk, static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
__be16 loc_port, __be32 loc_addr, __be16 loc_port, __be32 loc_addr,
@ -771,7 +723,7 @@ void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable)
sk->sk_err = err; sk->sk_err = err;
sk->sk_error_report(sk); sk->sk_error_report(sk);
out: out:
sock_put(sk); return;
} }
void udp_err(struct sk_buff *skb, u32 info) void udp_err(struct sk_buff *skb, u32 info)
@ -1474,13 +1426,13 @@ void udp_lib_unhash(struct sock *sk)
spin_lock_bh(&hslot->lock); spin_lock_bh(&hslot->lock);
if (rcu_access_pointer(sk->sk_reuseport_cb)) if (rcu_access_pointer(sk->sk_reuseport_cb))
reuseport_detach_sock(sk); reuseport_detach_sock(sk);
if (sk_nulls_del_node_init_rcu(sk)) { if (sk_del_node_init_rcu(sk)) {
hslot->count--; hslot->count--;
inet_sk(sk)->inet_num = 0; inet_sk(sk)->inet_num = 0;
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
spin_lock(&hslot2->lock); spin_lock(&hslot2->lock);
hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
hslot2->count--; hslot2->count--;
spin_unlock(&hslot2->lock); spin_unlock(&hslot2->lock);
} }
@ -1513,12 +1465,12 @@ void udp_lib_rehash(struct sock *sk, u16 newhash)
if (hslot2 != nhslot2) { if (hslot2 != nhslot2) {
spin_lock(&hslot2->lock); spin_lock(&hslot2->lock);
hlist_nulls_del_init_rcu(&udp_sk(sk)->udp_portaddr_node); hlist_del_init_rcu(&udp_sk(sk)->udp_portaddr_node);
hslot2->count--; hslot2->count--;
spin_unlock(&hslot2->lock); spin_unlock(&hslot2->lock);
spin_lock(&nhslot2->lock); spin_lock(&nhslot2->lock);
hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node, hlist_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,
&nhslot2->head); &nhslot2->head);
nhslot2->count++; nhslot2->count++;
spin_unlock(&nhslot2->lock); spin_unlock(&nhslot2->lock);
@ -1697,35 +1649,6 @@ drop:
return -1; return -1;
} }
static void flush_stack(struct sock **stack, unsigned int count,
struct sk_buff *skb, unsigned int final)
{
unsigned int i;
struct sk_buff *skb1 = NULL;
struct sock *sk;
for (i = 0; i < count; i++) {
sk = stack[i];
if (likely(!skb1))
skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
if (!skb1) {
atomic_inc(&sk->sk_drops);
UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
IS_UDPLITE(sk));
UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
IS_UDPLITE(sk));
}
if (skb1 && udp_queue_rcv_skb(sk, skb1) <= 0)
skb1 = NULL;
sock_put(sk);
}
if (unlikely(skb1))
kfree_skb(skb1);
}
/* For TCP sockets, sk_rx_dst is protected by socket lock /* For TCP sockets, sk_rx_dst is protected by socket lock
* For UDP, we use xchg() to guard against concurrent changes. * For UDP, we use xchg() to guard against concurrent changes.
*/ */
@ -1749,14 +1672,14 @@ static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
struct udp_table *udptable, struct udp_table *udptable,
int proto) int proto)
{ {
struct sock *sk, *stack[256 / sizeof(struct sock *)]; struct sock *sk, *first = NULL;
struct hlist_nulls_node *node;
unsigned short hnum = ntohs(uh->dest); unsigned short hnum = ntohs(uh->dest);
struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
int dif = skb->dev->ifindex;
unsigned int count = 0, offset = offsetof(typeof(*sk), sk_nulls_node);
unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
bool inner_flushed = false; unsigned int offset = offsetof(typeof(*sk), sk_node);
int dif = skb->dev->ifindex;
struct hlist_node *node;
struct sk_buff *nskb;
if (use_hash2) { if (use_hash2) {
hash2_any = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum) & hash2_any = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum) &
@ -1767,23 +1690,28 @@ start_lookup:
offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
} }
spin_lock(&hslot->lock); sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
sk_nulls_for_each_entry_offset(sk, node, &hslot->head, offset) { if (!__udp_is_mcast_sock(net, sk, uh->dest, daddr,
if (__udp_is_mcast_sock(net, sk, uh->source, saddr, dif, hnum))
uh->dest, daddr, continue;
uh->source, saddr,
dif, hnum)) {
if (unlikely(count == ARRAY_SIZE(stack))) {
flush_stack(stack, count, skb, ~0);
inner_flushed = true;
count = 0;
}
stack[count++] = sk;
sock_hold(sk);
}
}
spin_unlock(&hslot->lock); if (!first) {
first = sk;
continue;
}
nskb = skb_clone(skb, GFP_ATOMIC);
if (unlikely(!nskb)) {
atomic_inc(&sk->sk_drops);
UDP_INC_STATS_BH(net, UDP_MIB_RCVBUFERRORS,
IS_UDPLITE(sk));
UDP_INC_STATS_BH(net, UDP_MIB_INERRORS,
IS_UDPLITE(sk));
continue;
}
if (udp_queue_rcv_skb(sk, nskb) > 0)
consume_skb(nskb);
}
/* Also lookup *:port if we are using hash2 and haven't done so yet. */ /* Also lookup *:port if we are using hash2 and haven't done so yet. */
if (use_hash2 && hash2 != hash2_any) { if (use_hash2 && hash2 != hash2_any) {
@ -1791,16 +1719,13 @@ start_lookup:
goto start_lookup; goto start_lookup;
} }
/* if (first) {
* do the slow work with no lock held if (udp_queue_rcv_skb(first, skb) > 0)
*/ consume_skb(skb);
if (count) {
flush_stack(stack, count, skb, count - 1);
} else { } else {
if (!inner_flushed) kfree_skb(skb);
UDP_INC_STATS_BH(net, UDP_MIB_IGNOREDMULTI, UDP_INC_STATS_BH(net, UDP_MIB_IGNOREDMULTI,
proto == IPPROTO_UDPLITE); proto == IPPROTO_UDPLITE);
consume_skb(skb);
} }
return 0; return 0;
} }
@ -1897,7 +1822,6 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
inet_compute_pseudo); inet_compute_pseudo);
ret = udp_queue_rcv_skb(sk, skb); ret = udp_queue_rcv_skb(sk, skb);
sock_put(sk);
/* a return value > 0 means to resubmit the input, but /* a return value > 0 means to resubmit the input, but
* it wants the return to be -protocol, or 0 * it wants the return to be -protocol, or 0
@ -1958,49 +1882,24 @@ static struct sock *__udp4_lib_mcast_demux_lookup(struct net *net,
int dif) int dif)
{ {
struct sock *sk, *result; struct sock *sk, *result;
struct hlist_nulls_node *node;
unsigned short hnum = ntohs(loc_port); unsigned short hnum = ntohs(loc_port);
unsigned int count, slot = udp_hashfn(net, hnum, udp_table.mask); unsigned int slot = udp_hashfn(net, hnum, udp_table.mask);
struct udp_hslot *hslot = &udp_table.hash[slot]; struct udp_hslot *hslot = &udp_table.hash[slot];
/* Do not bother scanning a too big list */ /* Do not bother scanning a too big list */
if (hslot->count > 10) if (hslot->count > 10)
return NULL; return NULL;
rcu_read_lock();
begin:
count = 0;
result = NULL; result = NULL;
sk_nulls_for_each_rcu(sk, node, &hslot->head) { sk_for_each_rcu(sk, &hslot->head) {
if (__udp_is_mcast_sock(net, sk, if (__udp_is_mcast_sock(net, sk, loc_port, loc_addr,
loc_port, loc_addr, rmt_port, rmt_addr, dif, hnum)) {
rmt_port, rmt_addr, if (result)
dif, hnum)) { return NULL;
result = sk; result = sk;
++count;
} }
} }
/*
* 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) != slot)
goto begin;
if (result) {
if (count != 1 ||
unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
result = NULL;
else if (unlikely(!__udp_is_mcast_sock(net, result,
loc_port, loc_addr,
rmt_port, rmt_addr,
dif, hnum))) {
sock_put(result);
result = NULL;
}
}
rcu_read_unlock();
return result; return result;
} }
@ -2013,37 +1912,22 @@ static struct sock *__udp4_lib_demux_lookup(struct net *net,
__be16 rmt_port, __be32 rmt_addr, __be16 rmt_port, __be32 rmt_addr,
int dif) int dif)
{ {
struct sock *sk, *result;
struct hlist_nulls_node *node;
unsigned short hnum = ntohs(loc_port); unsigned short hnum = ntohs(loc_port);
unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum); unsigned int hash2 = udp4_portaddr_hash(net, loc_addr, hnum);
unsigned int slot2 = hash2 & udp_table.mask; unsigned int slot2 = hash2 & udp_table.mask;
struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; struct udp_hslot *hslot2 = &udp_table.hash2[slot2];
INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr); INET_ADDR_COOKIE(acookie, rmt_addr, loc_addr);
const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum);
struct sock *sk;
rcu_read_lock(); udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
result = NULL; if (INET_MATCH(sk, net, acookie, rmt_addr,
udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { loc_addr, ports, dif))
if (INET_MATCH(sk, net, acookie, return sk;
rmt_addr, loc_addr, ports, dif))
result = sk;
/* Only check first socket in chain */ /* Only check first socket in chain */
break; break;
} }
return NULL;
if (result) {
if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
result = NULL;
else if (unlikely(!INET_MATCH(sk, net, acookie,
rmt_addr, loc_addr,
ports, dif))) {
sock_put(result);
result = NULL;
}
}
rcu_read_unlock();
return result;
} }
void udp_v4_early_demux(struct sk_buff *skb) void udp_v4_early_demux(struct sk_buff *skb)
@ -2051,7 +1935,7 @@ void udp_v4_early_demux(struct sk_buff *skb)
struct net *net = dev_net(skb->dev); struct net *net = dev_net(skb->dev);
const struct iphdr *iph; const struct iphdr *iph;
const struct udphdr *uh; const struct udphdr *uh;
struct sock *sk; struct sock *sk = NULL;
struct dst_entry *dst; struct dst_entry *dst;
int dif = skb->dev->ifindex; int dif = skb->dev->ifindex;
int ours; int ours;
@ -2083,11 +1967,9 @@ void udp_v4_early_demux(struct sk_buff *skb)
} else if (skb->pkt_type == PACKET_HOST) { } else if (skb->pkt_type == PACKET_HOST) {
sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr, sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
uh->source, iph->saddr, dif); uh->source, iph->saddr, dif);
} else {
return;
} }
if (!sk) if (!sk || !atomic_inc_not_zero_hint(&sk->sk_refcnt, 2))
return; return;
skb->sk = sk; skb->sk = sk;
@ -2387,14 +2269,13 @@ static struct sock *udp_get_first(struct seq_file *seq, int start)
for (state->bucket = start; state->bucket <= state->udp_table->mask; for (state->bucket = start; state->bucket <= state->udp_table->mask;
++state->bucket) { ++state->bucket) {
struct hlist_nulls_node *node;
struct udp_hslot *hslot = &state->udp_table->hash[state->bucket]; struct udp_hslot *hslot = &state->udp_table->hash[state->bucket];
if (hlist_nulls_empty(&hslot->head)) if (hlist_empty(&hslot->head))
continue; continue;
spin_lock_bh(&hslot->lock); spin_lock_bh(&hslot->lock);
sk_nulls_for_each(sk, node, &hslot->head) { sk_for_each(sk, &hslot->head) {
if (!net_eq(sock_net(sk), net)) if (!net_eq(sock_net(sk), net))
continue; continue;
if (sk->sk_family == state->family) if (sk->sk_family == state->family)
@ -2413,7 +2294,7 @@ static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
struct net *net = seq_file_net(seq); struct net *net = seq_file_net(seq);
do { do {
sk = sk_nulls_next(sk); sk = sk_next(sk);
} while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family)); } while (sk && (!net_eq(sock_net(sk), net) || sk->sk_family != state->family));
if (!sk) { if (!sk) {
@ -2622,12 +2503,12 @@ void __init udp_table_init(struct udp_table *table, const char *name)
table->hash2 = table->hash + (table->mask + 1); table->hash2 = table->hash + (table->mask + 1);
for (i = 0; i <= table->mask; i++) { for (i = 0; i <= table->mask; i++) {
INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i); INIT_HLIST_HEAD(&table->hash[i].head);
table->hash[i].count = 0; table->hash[i].count = 0;
spin_lock_init(&table->hash[i].lock); spin_lock_init(&table->hash[i].lock);
} }
for (i = 0; i <= table->mask; i++) { for (i = 0; i <= table->mask; i++) {
INIT_HLIST_NULLS_HEAD(&table->hash2[i].head, i); INIT_HLIST_HEAD(&table->hash2[i].head);
table->hash2[i].count = 0; table->hash2[i].count = 0;
spin_lock_init(&table->hash2[i].lock); spin_lock_init(&table->hash2[i].lock);
} }

18
net/ipv4/udp_diag.c
View file

@ -36,10 +36,11 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
const struct inet_diag_req_v2 *req) const struct inet_diag_req_v2 *req)
{ {
int err = -EINVAL; int err = -EINVAL;
struct sock *sk; struct sock *sk = NULL;
struct sk_buff *rep; struct sk_buff *rep;
struct net *net = sock_net(in_skb->sk); struct net *net = sock_net(in_skb->sk);
rcu_read_lock();
if (req->sdiag_family == AF_INET) if (req->sdiag_family == AF_INET)
sk = __udp4_lib_lookup(net, sk = __udp4_lib_lookup(net,
req->id.idiag_src[0], req->id.idiag_sport, req->id.idiag_src[0], req->id.idiag_sport,
@ -54,9 +55,9 @@ static int udp_dump_one(struct udp_table *tbl, struct sk_buff *in_skb,
req->id.idiag_dport, req->id.idiag_dport,
req->id.idiag_if, tbl, NULL); req->id.idiag_if, tbl, NULL);
#endif #endif
else if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))
goto out_nosk; sk = NULL;
rcu_read_unlock();
err = -ENOENT; err = -ENOENT;
if (!sk) if (!sk)
goto out_nosk; goto out_nosk;
@ -96,24 +97,23 @@ static void udp_dump(struct udp_table *table, struct sk_buff *skb,
struct netlink_callback *cb, struct netlink_callback *cb,
const struct inet_diag_req_v2 *r, struct nlattr *bc) const struct inet_diag_req_v2 *r, struct nlattr *bc)
{ {
int num, s_num, slot, s_slot;
struct net *net = sock_net(skb->sk); struct net *net = sock_net(skb->sk);
int num, s_num, slot, s_slot;
s_slot = cb->args[0]; s_slot = cb->args[0];
num = s_num = cb->args[1]; num = s_num = cb->args[1];
for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) { for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) {
struct sock *sk;
struct hlist_nulls_node *node;
struct udp_hslot *hslot = &table->hash[slot]; struct udp_hslot *hslot = &table->hash[slot];
struct sock *sk;
num = 0; num = 0;
if (hlist_nulls_empty(&hslot->head)) if (hlist_empty(&hslot->head))
continue; continue;
spin_lock_bh(&hslot->lock); spin_lock_bh(&hslot->lock);
sk_nulls_for_each(sk, node, &hslot->head) { sk_for_each(sk, &hslot->head) {
struct inet_sock *inet = inet_sk(sk); struct inet_sock *inet = inet_sk(sk);
if (!net_eq(sock_net(sk), net)) if (!net_eq(sock_net(sk), net))

198
net/ipv6/udp.c
View file

@ -213,37 +213,28 @@ static struct sock *udp6_lib_lookup2(struct net *net,
struct sk_buff *skb) struct sk_buff *skb)
{ {
struct sock *sk, *result; struct sock *sk, *result;
struct hlist_nulls_node *node;
int score, badness, matches = 0, reuseport = 0; int score, badness, matches = 0, reuseport = 0;
bool select_ok = true;
u32 hash = 0; u32 hash = 0;
begin:
result = NULL; result = NULL;
badness = -1; badness = -1;
udp_portaddr_for_each_entry_rcu(sk, node, &hslot2->head) { udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
score = compute_score2(sk, net, saddr, sport, score = compute_score2(sk, net, saddr, sport,
daddr, hnum, dif); daddr, hnum, dif);
if (score > badness) { if (score > badness) {
result = sk;
badness = score;
reuseport = sk->sk_reuseport; reuseport = sk->sk_reuseport;
if (reuseport) { if (reuseport) {
hash = udp6_ehashfn(net, daddr, hnum, hash = udp6_ehashfn(net, daddr, hnum,
saddr, sport); saddr, sport);
if (select_ok) {
struct sock *sk2;
sk2 = reuseport_select_sock(sk, hash, skb, result = reuseport_select_sock(sk, hash, skb,
sizeof(struct udphdr)); sizeof(struct udphdr));
if (sk2) { if (result)
result = sk2; return result;
select_ok = false;
goto found;
}
}
matches = 1; matches = 1;
} }
result = sk;
badness = score;
} else if (score == badness && reuseport) { } else if (score == badness && reuseport) {
matches++; matches++;
if (reciprocal_scale(hash, matches) == 0) if (reciprocal_scale(hash, matches) == 0)
@ -251,27 +242,10 @@ begin:
hash = next_pseudo_random32(hash); hash = next_pseudo_random32(hash);
} }
} }
/*
* 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) != slot2)
goto begin;
if (result) {
found:
if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
result = NULL;
else if (unlikely(compute_score2(result, net, saddr, sport,
daddr, hnum, dif) < badness)) {
sock_put(result);
goto begin;
}
}
return result; return result;
} }
/* rcu_read_lock() must be held */
struct sock *__udp6_lib_lookup(struct net *net, struct sock *__udp6_lib_lookup(struct net *net,
const struct in6_addr *saddr, __be16 sport, const struct in6_addr *saddr, __be16 sport,
const struct in6_addr *daddr, __be16 dport, const struct in6_addr *daddr, __be16 dport,
@ -279,15 +253,12 @@ struct sock *__udp6_lib_lookup(struct net *net,
struct sk_buff *skb) struct sk_buff *skb)
{ {
struct sock *sk, *result; struct sock *sk, *result;
struct hlist_nulls_node *node;
unsigned short hnum = ntohs(dport); unsigned short hnum = ntohs(dport);
unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask);
struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; struct udp_hslot *hslot2, *hslot = &udptable->hash[slot];
int score, badness, matches = 0, reuseport = 0; int score, badness, matches = 0, reuseport = 0;
bool select_ok = true;
u32 hash = 0; u32 hash = 0;
rcu_read_lock();
if (hslot->count > 10) { if (hslot->count > 10) {
hash2 = udp6_portaddr_hash(net, daddr, hnum); hash2 = udp6_portaddr_hash(net, daddr, hnum);
slot2 = hash2 & udptable->mask; slot2 = hash2 & udptable->mask;
@ -309,34 +280,26 @@ struct sock *__udp6_lib_lookup(struct net *net,
&in6addr_any, hnum, dif, &in6addr_any, hnum, dif,
hslot2, slot2, skb); hslot2, slot2, skb);
} }
rcu_read_unlock();
return result; return result;
} }
begin: begin:
result = NULL; result = NULL;
badness = -1; badness = -1;
sk_nulls_for_each_rcu(sk, node, &hslot->head) { sk_for_each_rcu(sk, &hslot->head) {
score = compute_score(sk, net, hnum, saddr, sport, daddr, dport, dif); score = compute_score(sk, net, hnum, saddr, sport, daddr, dport, dif);
if (score > badness) { if (score > badness) {
result = sk;
badness = score;
reuseport = sk->sk_reuseport; reuseport = sk->sk_reuseport;
if (reuseport) { if (reuseport) {
hash = udp6_ehashfn(net, daddr, hnum, hash = udp6_ehashfn(net, daddr, hnum,
saddr, sport); saddr, sport);
if (select_ok) { result = reuseport_select_sock(sk, hash, skb,
struct sock *sk2;
sk2 = reuseport_select_sock(sk, hash, skb,
sizeof(struct udphdr)); sizeof(struct udphdr));
if (sk2) { if (result)
result = sk2; return result;
select_ok = false;
goto found;
}
}
matches = 1; matches = 1;
} }
result = sk;
badness = score;
} else if (score == badness && reuseport) { } else if (score == badness && reuseport) {
matches++; matches++;
if (reciprocal_scale(hash, matches) == 0) if (reciprocal_scale(hash, matches) == 0)
@ -344,25 +307,6 @@ begin:
hash = next_pseudo_random32(hash); hash = next_pseudo_random32(hash);
} }
} }
/*
* 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) != slot)
goto begin;
if (result) {
found:
if (unlikely(!atomic_inc_not_zero_hint(&result->sk_refcnt, 2)))
result = NULL;
else if (unlikely(compute_score(result, net, hnum, saddr, sport,
daddr, dport, dif) < badness)) {
sock_put(result);
goto begin;
}
}
rcu_read_unlock();
return result; return result;
} }
EXPORT_SYMBOL_GPL(__udp6_lib_lookup); EXPORT_SYMBOL_GPL(__udp6_lib_lookup);
@ -382,12 +326,24 @@ static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
udptable, skb); udptable, skb);
} }
/* Must be called under rcu_read_lock().
* Does increment socket refcount.
*/
#if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \
IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY)
struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport,
const struct in6_addr *daddr, __be16 dport, int dif) const struct in6_addr *daddr, __be16 dport, int dif)
{ {
return __udp6_lib_lookup(net, saddr, sport, daddr, dport, dif, &udp_table, NULL); struct sock *sk;
sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport,
dif, &udp_table, NULL);
if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))
sk = NULL;
return sk;
} }
EXPORT_SYMBOL_GPL(udp6_lib_lookup); EXPORT_SYMBOL_GPL(udp6_lib_lookup);
#endif
/* /*
* This should be easy, if there is something there we * This should be easy, if there is something there we
@ -585,7 +541,7 @@ void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
sk->sk_err = err; sk->sk_err = err;
sk->sk_error_report(sk); sk->sk_error_report(sk);
out: out:
sock_put(sk); return;
} }
static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
@ -747,33 +703,6 @@ static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk,
return true; return true;
} }
static void flush_stack(struct sock **stack, unsigned int count,
struct sk_buff *skb, unsigned int final)
{
struct sk_buff *skb1 = NULL;
struct sock *sk;
unsigned int i;
for (i = 0; i < count; i++) {
sk = stack[i];
if (likely(!skb1))
skb1 = (i == final) ? skb : skb_clone(skb, GFP_ATOMIC);
if (!skb1) {
atomic_inc(&sk->sk_drops);
UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_RCVBUFERRORS,
IS_UDPLITE(sk));
UDP6_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
IS_UDPLITE(sk));
}
if (skb1 && udpv6_queue_rcv_skb(sk, skb1) <= 0)
skb1 = NULL;
sock_put(sk);
}
if (unlikely(skb1))
kfree_skb(skb1);
}
static void udp6_csum_zero_error(struct sk_buff *skb) static void udp6_csum_zero_error(struct sk_buff *skb)
{ {
/* RFC 2460 section 8.1 says that we SHOULD log /* RFC 2460 section 8.1 says that we SHOULD log
@ -792,15 +721,15 @@ static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb,
const struct in6_addr *saddr, const struct in6_addr *daddr, const struct in6_addr *saddr, const struct in6_addr *daddr,
struct udp_table *udptable, int proto) struct udp_table *udptable, int proto)
{ {
struct sock *sk, *stack[256 / sizeof(struct sock *)]; struct sock *sk, *first = NULL;
const struct udphdr *uh = udp_hdr(skb); const struct udphdr *uh = udp_hdr(skb);
struct hlist_nulls_node *node;
unsigned short hnum = ntohs(uh->dest); unsigned short hnum = ntohs(uh->dest);
struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum);
int dif = inet6_iif(skb); unsigned int offset = offsetof(typeof(*sk), sk_node);
unsigned int count = 0, offset = offsetof(typeof(*sk), sk_nulls_node);
unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10);
bool inner_flushed = false; int dif = inet6_iif(skb);
struct hlist_node *node;
struct sk_buff *nskb;
if (use_hash2) { if (use_hash2) {
hash2_any = udp6_portaddr_hash(net, &in6addr_any, hnum) & hash2_any = udp6_portaddr_hash(net, &in6addr_any, hnum) &
@ -811,27 +740,32 @@ start_lookup:
offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node);
} }
spin_lock(&hslot->lock); sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) {
sk_nulls_for_each_entry_offset(sk, node, &hslot->head, offset) { if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr,
if (__udp_v6_is_mcast_sock(net, sk, uh->source, saddr, dif, hnum))
uh->dest, daddr, continue;
uh->source, saddr, /* If zero checksum and no_check is not on for
dif, hnum) && * the socket then skip it.
/* If zero checksum and no_check is not on for */
* the socket then skip it. if (!uh->check && !udp_sk(sk)->no_check6_rx)
*/ continue;
(uh->check || udp_sk(sk)->no_check6_rx)) { if (!first) {
if (unlikely(count == ARRAY_SIZE(stack))) { first = sk;
flush_stack(stack, count, skb, ~0); continue;
inner_flushed = true; }
count = 0; nskb = skb_clone(skb, GFP_ATOMIC);
} if (unlikely(!nskb)) {
stack[count++] = sk; atomic_inc(&sk->sk_drops);
sock_hold(sk); UDP6_INC_STATS_BH(net, UDP_MIB_RCVBUFERRORS,
IS_UDPLITE(sk));
UDP6_INC_STATS_BH(net, UDP_MIB_INERRORS,
IS_UDPLITE(sk));
continue;
} }
}
spin_unlock(&hslot->lock); if (udpv6_queue_rcv_skb(sk, nskb) > 0)
consume_skb(nskb);
}
/* Also lookup *:port if we are using hash2 and haven't done so yet. */ /* Also lookup *:port if we are using hash2 and haven't done so yet. */
if (use_hash2 && hash2 != hash2_any) { if (use_hash2 && hash2 != hash2_any) {
@ -839,13 +773,13 @@ start_lookup:
goto start_lookup; goto start_lookup;
} }
if (count) { if (first) {
flush_stack(stack, count, skb, count - 1); if (udpv6_queue_rcv_skb(first, skb) > 0)
consume_skb(skb);
} else { } else {
if (!inner_flushed) kfree_skb(skb);
UDP6_INC_STATS_BH(net, UDP_MIB_IGNOREDMULTI, UDP6_INC_STATS_BH(net, UDP_MIB_IGNOREDMULTI,
proto == IPPROTO_UDPLITE); proto == IPPROTO_UDPLITE);
consume_skb(skb);
} }
return 0; return 0;
} }
@ -853,10 +787,10 @@ start_lookup:
int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
int proto) int proto)
{ {
struct net *net = dev_net(skb->dev);
struct sock *sk;
struct udphdr *uh;
const struct in6_addr *saddr, *daddr; const struct in6_addr *saddr, *daddr;
struct net *net = dev_net(skb->dev);
struct udphdr *uh;
struct sock *sk;
u32 ulen = 0; u32 ulen = 0;
if (!pskb_may_pull(skb, sizeof(struct udphdr))) if (!pskb_may_pull(skb, sizeof(struct udphdr)))
@ -910,7 +844,6 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
int ret; int ret;
if (!uh->check && !udp_sk(sk)->no_check6_rx) { if (!uh->check && !udp_sk(sk)->no_check6_rx) {
sock_put(sk);
udp6_csum_zero_error(skb); udp6_csum_zero_error(skb);
goto csum_error; goto csum_error;
} }
@ -920,7 +853,6 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
ip6_compute_pseudo); ip6_compute_pseudo);
ret = udpv6_queue_rcv_skb(sk, skb); ret = udpv6_queue_rcv_skb(sk, skb);
sock_put(sk);
/* a return value > 0 means to resubmit the input */ /* a return value > 0 means to resubmit the input */
if (ret > 0) if (ret > 0)