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[UDP]: Revert 2-pass hashing changes.
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This reverts changesets:

6aaf47f
b7b5f48
de34ed9
fc03841

There are still some correctness issues recently
discovered which do not have a known fix that doesn't
involve doing a full hash table scan on port bind.

So revert for now.

Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller committed Jun 7, 2007
1 parent 3c0d2f3 commit df2bc45
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Showing 8 changed files with 78 additions and 212 deletions.
9 changes: 1 addition & 8 deletions include/net/udp.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -119,16 +119,9 @@ static inline void udp_lib_close(struct sock *sk, long timeout)
}


struct udp_get_port_ops {
int (*saddr_cmp)(const struct sock *sk1, const struct sock *sk2);
int (*saddr_any)(const struct sock *sk);
unsigned int (*hash_port_and_rcv_saddr)(__u16 port,
const struct sock *sk);
};

/* net/ipv4/udp.c */
extern int udp_get_port(struct sock *sk, unsigned short snum,
const struct udp_get_port_ops *ops);
int (*saddr_cmp)(const struct sock *, const struct sock *));
extern void udp_err(struct sk_buff *, u32);

extern int udp_sendmsg(struct kiocb *iocb, struct sock *sk,
Expand Down
2 changes: 1 addition & 1 deletion include/net/udplite.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -120,5 +120,5 @@ static inline __wsum udplite_csum_outgoing(struct sock *sk, struct sk_buff *skb)

extern void udplite4_register(void);
extern int udplite_get_port(struct sock *sk, unsigned short snum,
const struct udp_get_port_ops *ops);
int (*scmp)(const struct sock *, const struct sock *));
#endif /* _UDPLITE_H */
241 changes: 68 additions & 173 deletions net/ipv4/udp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -114,36 +114,14 @@ DEFINE_RWLOCK(udp_hash_lock);

static int udp_port_rover;

/*
* Note about this hash function :
* Typical use is probably daddr = 0, only dport is going to vary hash
*/
static inline unsigned int udp_hash_port(__u16 port)
{
return port;
}

static inline int __udp_lib_port_inuse(unsigned int hash, int port,
const struct sock *this_sk,
struct hlist_head udptable[],
const struct udp_get_port_ops *ops)
static inline int __udp_lib_lport_inuse(__u16 num, struct hlist_head udptable[])
{
struct sock *sk;
struct hlist_node *node;
struct inet_sock *inet;

sk_for_each(sk, node, &udptable[hash & (UDP_HTABLE_SIZE - 1)]) {
if (sk->sk_hash != hash)
continue;
inet = inet_sk(sk);
if (inet->num != port)
continue;
if (this_sk) {
if (ops->saddr_cmp(sk, this_sk))
return 1;
} else if (ops->saddr_any(sk))
sk_for_each(sk, node, &udptable[num & (UDP_HTABLE_SIZE - 1)])
if (sk->sk_hash == num)
return 1;
}
return 0;
}

Expand All @@ -154,16 +132,16 @@ static inline int __udp_lib_port_inuse(unsigned int hash, int port,
* @snum: port number to look up
* @udptable: hash list table, must be of UDP_HTABLE_SIZE
* @port_rover: pointer to record of last unallocated port
* @ops: AF-dependent address operations
* @saddr_comp: AF-dependent comparison of bound local IP addresses
*/
int __udp_lib_get_port(struct sock *sk, unsigned short snum,
struct hlist_head udptable[], int *port_rover,
const struct udp_get_port_ops *ops)
int (*saddr_comp)(const struct sock *sk1,
const struct sock *sk2 ) )
{
struct hlist_node *node;
struct hlist_head *head;
struct sock *sk2;
unsigned int hash;
int error = 1;

write_lock_bh(&udp_hash_lock);
Expand All @@ -178,8 +156,7 @@ int __udp_lib_get_port(struct sock *sk, unsigned short snum,
for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
int size;

hash = ops->hash_port_and_rcv_saddr(result, sk);
head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
head = &udptable[result & (UDP_HTABLE_SIZE - 1)];
if (hlist_empty(head)) {
if (result > sysctl_local_port_range[1])
result = sysctl_local_port_range[0] +
Expand All @@ -204,57 +181,29 @@ int __udp_lib_get_port(struct sock *sk, unsigned short snum,
result = sysctl_local_port_range[0]
+ ((result - sysctl_local_port_range[0]) &
(UDP_HTABLE_SIZE - 1));
hash = udp_hash_port(result);
if (__udp_lib_port_inuse(hash, result,
NULL, udptable, ops))
continue;
if (ops->saddr_any(sk))
break;

hash = ops->hash_port_and_rcv_saddr(result, sk);
if (! __udp_lib_port_inuse(hash, result,
sk, udptable, ops))
if (! __udp_lib_lport_inuse(result, udptable))
break;
}
if (i >= (1 << 16) / UDP_HTABLE_SIZE)
goto fail;
gotit:
*port_rover = snum = result;
} else {
hash = udp_hash_port(snum);
head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
head = &udptable[snum & (UDP_HTABLE_SIZE - 1)];

sk_for_each(sk2, node, head)
if (sk2->sk_hash == hash &&
sk2 != sk &&
inet_sk(sk2)->num == snum &&
(!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) &&
ops->saddr_cmp(sk, sk2))
if (sk2->sk_hash == snum &&
sk2 != sk &&
(!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;

if (!ops->saddr_any(sk)) {
hash = ops->hash_port_and_rcv_saddr(snum, sk);
head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];

sk_for_each(sk2, node, head)
if (sk2->sk_hash == hash &&
sk2 != sk &&
inet_sk(sk2)->num == snum &&
(!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) &&
ops->saddr_cmp(sk, sk2))
goto fail;
}
}
inet_sk(sk)->num = snum;
sk->sk_hash = hash;
sk->sk_hash = snum;
if (sk_unhashed(sk)) {
head = &udptable[hash & (UDP_HTABLE_SIZE - 1)];
head = &udptable[snum & (UDP_HTABLE_SIZE - 1)];
sk_add_node(sk, head);
sock_prot_inc_use(sk->sk_prot);
}
Expand All @@ -265,12 +214,12 @@ int __udp_lib_get_port(struct sock *sk, unsigned short snum,
}

int udp_get_port(struct sock *sk, unsigned short snum,
const struct udp_get_port_ops *ops)
int (*scmp)(const struct sock *, const struct sock *))
{
return __udp_lib_get_port(sk, snum, udp_hash, &udp_port_rover, ops);
return __udp_lib_get_port(sk, snum, udp_hash, &udp_port_rover, scmp);
}

static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
{
struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);

Expand All @@ -279,33 +228,9 @@ static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
inet1->rcv_saddr == inet2->rcv_saddr ));
}

static int ipv4_rcv_saddr_any(const struct sock *sk)
{
return !inet_sk(sk)->rcv_saddr;
}

static inline unsigned int ipv4_hash_port_and_addr(__u16 port, __be32 addr)
{
addr ^= addr >> 16;
addr ^= addr >> 8;
return port ^ addr;
}

static unsigned int ipv4_hash_port_and_rcv_saddr(__u16 port,
const struct sock *sk)
{
return ipv4_hash_port_and_addr(port, inet_sk(sk)->rcv_saddr);
}

const struct udp_get_port_ops udp_ipv4_ops = {
.saddr_cmp = ipv4_rcv_saddr_equal,
.saddr_any = ipv4_rcv_saddr_any,
.hash_port_and_rcv_saddr = ipv4_hash_port_and_rcv_saddr,
};

static inline int udp_v4_get_port(struct sock *sk, unsigned short snum)
{
return udp_get_port(sk, snum, &udp_ipv4_ops);
return udp_get_port(sk, snum, ipv4_rcv_saddr_equal);
}

/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
Expand All @@ -317,77 +242,63 @@ static struct sock *__udp4_lib_lookup(__be32 saddr, __be16 sport,
{
struct sock *sk, *result = NULL;
struct hlist_node *node;
unsigned int hash, hashwild;
int score, best = -1, hport = ntohs(dport);

hash = ipv4_hash_port_and_addr(hport, daddr);
hashwild = udp_hash_port(hport);
unsigned short hnum = ntohs(dport);
int badness = -1;

read_lock(&udp_hash_lock);

lookup:

sk_for_each(sk, node, &udptable[hash & (UDP_HTABLE_SIZE - 1)]) {
sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) {
struct inet_sock *inet = inet_sk(sk);

if (sk->sk_hash != hash || ipv6_only_sock(sk) ||
inet->num != hport)
continue;

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;
goto found;
} else if (score > best) {
result = sk;
best = score;
if (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;
}
}
}

if (hash != hashwild) {
hash = hashwild;
goto lookup;
}
found:
if (result)
sock_hold(result);
read_unlock(&udp_hash_lock);
return result;
}

static inline struct sock *udp_v4_mcast_next(struct sock *sk, unsigned int hnum,
int hport, __be32 loc_addr,
static inline struct sock *udp_v4_mcast_next(struct sock *sk,
__be16 loc_port, __be32 loc_addr,
__be16 rmt_port, __be32 rmt_addr,
int dif)
{
struct hlist_node *node;
struct sock *s = sk;
unsigned short hnum = ntohs(loc_port);

sk_for_each_from(s, node) {
struct inet_sock *inet = inet_sk(s);

if (s->sk_hash != hnum ||
inet->num != hport ||
(inet->daddr && inet->daddr != rmt_addr) ||
(inet->dport != rmt_port && inet->dport) ||
(inet->rcv_saddr && inet->rcv_saddr != loc_addr) ||
Expand Down Expand Up @@ -1221,45 +1132,29 @@ static int __udp4_lib_mcast_deliver(struct sk_buff *skb,
__be32 saddr, __be32 daddr,
struct hlist_head udptable[])
{
struct sock *sk, *skw, *sknext;
struct sock *sk;
int dif;
int hport = ntohs(uh->dest);
unsigned int hash = ipv4_hash_port_and_addr(hport, daddr);
unsigned int hashwild = udp_hash_port(hport);

dif = skb->dev->ifindex;

read_lock(&udp_hash_lock);

sk = sk_head(&udptable[hash & (UDP_HTABLE_SIZE - 1)]);
skw = sk_head(&udptable[hashwild & (UDP_HTABLE_SIZE - 1)]);

sk = udp_v4_mcast_next(sk, hash, hport, daddr, uh->source, saddr, dif);
if (!sk) {
hash = hashwild;
sk = udp_v4_mcast_next(skw, hash, hport, daddr, uh->source,
saddr, dif);
}
sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
dif = skb->dev->ifindex;
sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
if (sk) {
struct sock *sknext = NULL;

do {
struct sk_buff *skb1 = skb;
sknext = udp_v4_mcast_next(sk_next(sk), hash, hport,
daddr, uh->source, saddr, dif);
if (!sknext && hash != hashwild) {
hash = hashwild;
sknext = udp_v4_mcast_next(skw, hash, hport,
daddr, uh->source, saddr, dif);
}

sknext = udp_v4_mcast_next(sk_next(sk), uh->dest, daddr,
uh->source, saddr, dif);
if (sknext)
skb1 = skb_clone(skb, GFP_ATOMIC);

if (skb1) {
int ret = udp_queue_rcv_skb(sk, skb1);
if (ret > 0)
/*
* we should probably re-process
* instead of dropping packets here.
*/
/* we should probably re-process instead
* of dropping packets here. */
kfree_skb(skb1);
}
sk = sknext;
Expand Down Expand Up @@ -1346,7 +1241,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udptable);

sk = __udp4_lib_lookup(saddr, uh->source, daddr, uh->dest,
skb->dev->ifindex, udptable);
skb->dev->ifindex, udptable );

if (sk != NULL) {
int ret = udp_queue_rcv_skb(sk, skb);
Expand Down
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