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[UDP]: Unify UDPv4 and UDPv6 ->get_port()
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This patch creates one common function which is called by
udp_v4_get_port() and udp_v6_get_port(). As a result,
  * duplicated code is removed
  * udp_port_rover and local port lookup can now be removed from udp.h
  * further savings follow since the same function will be used by UDP-Litev4
    and UDP-Litev6

In contrast to the patch sent in response to Yoshifujis comments
(fixed by this variant), the code below also removes the
EXPORT_SYMBOL(udp_port_rover), since udp_port_rover can now remain
local to net/ipv4/udp.c.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Gerrit Renker authored and David S. Miller committed Sep 22, 2006
1 parent 6a28ec8 commit 25030a7
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Showing 3 changed files with 64 additions and 126 deletions.
18 changes: 2 additions & 16 deletions include/net/udp.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,25 +30,9 @@

#define UDP_HTABLE_SIZE 128

/* udp.c: This needs to be shared by v4 and v6 because the lookup
* and hashing code needs to work with different AF's yet
* the port space is shared.
*/
extern struct hlist_head udp_hash[UDP_HTABLE_SIZE];
extern rwlock_t udp_hash_lock;

extern int udp_port_rover;

static inline int udp_lport_inuse(u16 num)
{
struct sock *sk;
struct hlist_node *node;

sk_for_each(sk, node, &udp_hash[num & (UDP_HTABLE_SIZE - 1)])
if (inet_sk(sk)->num == num)
return 1;
return 0;
}

/* Note: this must match 'valbool' in sock_setsockopt */
#define UDP_CSUM_NOXMIT 1
Expand All @@ -63,6 +47,8 @@ extern struct proto udp_prot;

struct sk_buff;

extern int udp_get_port(struct sock *sk, unsigned short snum,
int (*saddr_cmp)(struct sock *, struct sock *));
extern void udp_err(struct sk_buff *, u32);

extern int udp_sendmsg(struct kiocb *iocb, struct sock *sk,
Expand Down
96 changes: 60 additions & 36 deletions net/ipv4/udp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -118,14 +118,34 @@ DEFINE_SNMP_STAT(struct udp_mib, udp_statistics) __read_mostly;
struct hlist_head udp_hash[UDP_HTABLE_SIZE];
DEFINE_RWLOCK(udp_hash_lock);

/* Shared by v4/v6 udp. */
/* Shared by v4/v6 udp_get_port */
int udp_port_rover;

static int udp_v4_get_port(struct sock *sk, unsigned short snum)
static inline int udp_lport_inuse(u16 num)
{
struct sock *sk;
struct hlist_node *node;

sk_for_each(sk, node, &udp_hash[num & (UDP_HTABLE_SIZE - 1)])
if (inet_sk(sk)->num == num)
return 1;
return 0;
}

/**
* udp_get_port - common port lookup for IPv4 and IPv6
*
* @sk: socket struct in question
* @snum: port number to look up
* @saddr_comp: AF-dependent comparison of bound local IP addresses
*/
int udp_get_port(struct sock *sk, unsigned short snum,
int (*saddr_cmp)(struct sock *sk1, struct sock *sk2))
{
struct hlist_node *node;
struct hlist_head *head;
struct sock *sk2;
struct inet_sock *inet = inet_sk(sk);
int error = 1;

write_lock_bh(&udp_hash_lock);
if (snum == 0) {
Expand All @@ -137,24 +157,22 @@ static int udp_v4_get_port(struct sock *sk, unsigned short snum)
best_size_so_far = 32767;
best = result = udp_port_rover;
for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
struct hlist_head *list;
int size;

list = &udp_hash[result & (UDP_HTABLE_SIZE - 1)];
if (hlist_empty(list)) {
head = &udp_hash[result & (UDP_HTABLE_SIZE - 1)];
if (hlist_empty(head)) {
if (result > sysctl_local_port_range[1])
result = sysctl_local_port_range[0] +
((result - sysctl_local_port_range[0]) &
(UDP_HTABLE_SIZE - 1));
goto gotit;
}
size = 0;
sk_for_each(sk2, node, list)
if (++size >= best_size_so_far)
goto next;
best_size_so_far = size;
best = result;
next:;
sk_for_each(sk2, node, head)
if (++size < best_size_so_far) {
best_size_so_far = size;
best = result;
}
}
result = best;
for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result += UDP_HTABLE_SIZE) {
Expand All @@ -170,38 +188,44 @@ static int udp_v4_get_port(struct sock *sk, unsigned short snum)
gotit:
udp_port_rover = snum = result;
} else {
sk_for_each(sk2, node,
&udp_hash[snum & (UDP_HTABLE_SIZE - 1)]) {
struct inet_sock *inet2 = inet_sk(sk2);

if (inet2->num == snum &&
sk2 != sk &&
!ipv6_only_sock(sk2) &&
(!sk2->sk_bound_dev_if ||
!sk->sk_bound_dev_if ||
sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
(!inet2->rcv_saddr ||
!inet->rcv_saddr ||
inet2->rcv_saddr == inet->rcv_saddr) &&
(!sk2->sk_reuse || !sk->sk_reuse))
head = &udp_hash[snum & (UDP_HTABLE_SIZE - 1)];

sk_for_each(sk2, node, head)
if (inet_sk(sk2)->num == 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_cmp)(sk, sk2) )
goto fail;
}
}
inet->num = snum;
inet_sk(sk)->num = snum;
if (sk_unhashed(sk)) {
struct hlist_head *h = &udp_hash[snum & (UDP_HTABLE_SIZE - 1)];

sk_add_node(sk, h);
head = &udp_hash[snum & (UDP_HTABLE_SIZE - 1)];
sk_add_node(sk, head);
sock_prot_inc_use(sk->sk_prot);
}
write_unlock_bh(&udp_hash_lock);
return 0;

error = 0;
fail:
write_unlock_bh(&udp_hash_lock);
return 1;
return error;
}

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

return ( !ipv6_only_sock(sk2) &&
(!inet1->rcv_saddr || !inet2->rcv_saddr ||
inet1->rcv_saddr == inet2->rcv_saddr ));
}

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


static void udp_v4_hash(struct sock *sk)
{
BUG();
Expand Down Expand Up @@ -1596,7 +1620,7 @@ EXPORT_SYMBOL(udp_disconnect);
EXPORT_SYMBOL(udp_hash);
EXPORT_SYMBOL(udp_hash_lock);
EXPORT_SYMBOL(udp_ioctl);
EXPORT_SYMBOL(udp_port_rover);
EXPORT_SYMBOL(udp_get_port);
EXPORT_SYMBOL(udp_prot);
EXPORT_SYMBOL(udp_sendmsg);
EXPORT_SYMBOL(udp_poll);
Expand Down
76 changes: 2 additions & 74 deletions net/ipv6/udp.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -61,81 +61,9 @@

DEFINE_SNMP_STAT(struct udp_mib, udp_stats_in6) __read_mostly;

/* Grrr, addr_type already calculated by caller, but I don't want
* to add some silly "cookie" argument to this method just for that.
*/
static int udp_v6_get_port(struct sock *sk, unsigned short snum)
static inline int udp_v6_get_port(struct sock *sk, unsigned short snum)
{
struct sock *sk2;
struct hlist_node *node;

write_lock_bh(&udp_hash_lock);
if (snum == 0) {
int best_size_so_far, best, result, i;

if (udp_port_rover > sysctl_local_port_range[1] ||
udp_port_rover < sysctl_local_port_range[0])
udp_port_rover = sysctl_local_port_range[0];
best_size_so_far = 32767;
best = result = udp_port_rover;
for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
int size;
struct hlist_head *list;

list = &udp_hash[result & (UDP_HTABLE_SIZE - 1)];
if (hlist_empty(list)) {
if (result > sysctl_local_port_range[1])
result = sysctl_local_port_range[0] +
((result - sysctl_local_port_range[0]) &
(UDP_HTABLE_SIZE - 1));
goto gotit;
}
size = 0;
sk_for_each(sk2, node, list)
if (++size >= best_size_so_far)
goto next;
best_size_so_far = size;
best = result;
next:;
}
result = best;
for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result += UDP_HTABLE_SIZE) {
if (result > sysctl_local_port_range[1])
result = sysctl_local_port_range[0]
+ ((result - sysctl_local_port_range[0]) &
(UDP_HTABLE_SIZE - 1));
if (!udp_lport_inuse(result))
break;
}
if (i >= (1 << 16) / UDP_HTABLE_SIZE)
goto fail;
gotit:
udp_port_rover = snum = result;
} else {
sk_for_each(sk2, node,
&udp_hash[snum & (UDP_HTABLE_SIZE - 1)]) {
if (inet_sk(sk2)->num == snum &&
sk2 != sk &&
(!sk2->sk_bound_dev_if ||
!sk->sk_bound_dev_if ||
sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
(!sk2->sk_reuse || !sk->sk_reuse) &&
ipv6_rcv_saddr_equal(sk, sk2))
goto fail;
}
}

inet_sk(sk)->num = snum;
if (sk_unhashed(sk)) {
sk_add_node(sk, &udp_hash[snum & (UDP_HTABLE_SIZE - 1)]);
sock_prot_inc_use(sk->sk_prot);
}
write_unlock_bh(&udp_hash_lock);
return 0;

fail:
write_unlock_bh(&udp_hash_lock);
return 1;
return udp_get_port(sk, snum, ipv6_rcv_saddr_equal);
}

static void udp_v6_hash(struct sock *sk)
Expand Down

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