introduce netlink bucket

Hi Davem,

This patch introduces the netlink bucket struct, it joins three arrays into an array of netlink bucket.

===== net/netlink/af_netlink.c 1.57 vs edited =====

@@ -69,13 +69,15 @@
 
 #define nlk_sk(__sk) ((struct netlink_opt *)(__sk)->sk_protinfo)
 
-static struct hlist_head nl_table[MAX_LINKS];
 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
-static unsigned nl_nonroot[MAX_LINKS];
 
+static struct netlink_bucket {
+	struct hlist_head nl_table;
+	unsigned nl_nonroot;
 #ifdef NL_EMULATE_DEV
-static struct socket *netlink_kernel[MAX_LINKS];
+	struct socket *netlink_kernel;
 #endif
+} nl_bucket[MAX_LINKS];
 
 static int netlink_dump(struct sock *sk);
 static void netlink_destroy_callback(struct netlink_callback *cb);

@@ -164,7 +166,7 @@
 	struct hlist_node *node;
 
 	read_lock(&nl_table_lock);
-	sk_for_each(sk, node, &nl_table[protocol]) {
+	sk_for_each(sk, node, &nl_bucket[protocol].nl_table) {
 		if (nlk_sk(sk)->pid == pid) {
 			sock_hold(sk);
 			goto found;

@@ -185,7 +187,7 @@
 	struct hlist_node *node;
 
 	netlink_table_grab();
-	sk_for_each(osk, node, &nl_table[sk->sk_protocol]) {
+	sk_for_each(osk, node, &nl_bucket[sk->sk_protocol].nl_table) {
 		if (nlk_sk(osk)->pid == pid)
 			break;
 	}

@@ -193,7 +195,7 @@
 		err = -EBUSY;
 		if (nlk_sk(sk)->pid == 0) {
 			nlk_sk(sk)->pid = pid;
-			sk_add_node(sk, &nl_table[sk->sk_protocol]);
+			sk_add_node(sk, &nl_bucket[sk->sk_protocol].nl_table);
 			err = 0;
 		}
 	}

@@ -297,7 +299,7 @@
 
 retry:
 	netlink_table_grab();
-	sk_for_each(osk, node, &nl_table[sk->sk_protocol]) {
+	sk_for_each(osk, node, &nl_bucket[sk->sk_protocol].nl_table) {
 		if (nlk_sk(osk)->pid == pid) {
 			/* Bind collision, search negative pid values. */
 			if (pid > 0)

@@ -318,7 +320,7 @@
 
 static inline int netlink_capable(struct socket *sock, unsigned flag) 
 { 
-	return (nl_nonroot[sock->sk->sk_protocol] & flag) ||
+	return (nl_bucket[sock->sk->sk_protocol].nl_nonroot & flag) ||
 	       capable(CAP_NET_ADMIN);
 } 
 

@@ -615,7 +617,7 @@
 
 	netlink_lock_table();
 
-	sk_for_each(sk, node, &nl_table[protocol]) {
+	sk_for_each(sk, node, &nl_bucket[protocol].nl_table) {
 		struct netlink_opt *nlk = nlk_sk(sk);
 
 		if (ssk == sk)

@@ -675,7 +677,7 @@
 	int protocol = ssk->sk_protocol;
 
 	read_lock(&nl_table_lock);
-	sk_for_each(sk, node, &nl_table[protocol]) {
+	sk_for_each(sk, node, &nl_bucket[protocol].nl_table) {
 		struct netlink_opt *nlk = nlk_sk(sk);
 		if (ssk == sk)
 			continue;

@@ -883,7 +885,7 @@
 void netlink_set_nonroot(int protocol, unsigned flags)
 { 
 	if ((unsigned)protocol < MAX_LINKS) 
-		nl_nonroot[protocol] = flags;
+		nl_bucket[protocol].nl_nonroot = flags;
 } 
 
 static void netlink_destroy_callback(struct netlink_callback *cb)

@@ -1034,7 +1036,7 @@
 		return -ENOBUFS;
 	nlk_sk(sk)->handler = function;
 	write_lock_bh(&nl_emu_lock);
-	netlink_kernel[unit] = sk->sk_socket;
+	nl_bucket[unit].netlink_kernel = sk->sk_socket;
 	write_unlock_bh(&nl_emu_lock);
 	return 0;
 }

@@ -1044,8 +1046,8 @@
 	struct socket *sock;
 
 	write_lock_bh(&nl_emu_lock);
-	sock = netlink_kernel[unit];
-	netlink_kernel[unit] = NULL;
+	sock = nl_bucket[unit].netlink_kernel;
+	nl_bucket[unit].netlink_kernel = NULL;
 	write_unlock_bh(&nl_emu_lock);
 
 	sock_release(sock);

@@ -1056,7 +1058,7 @@
 	struct socket *sock;
 
 	read_lock(&nl_emu_lock);
-	sock = netlink_kernel[unit];
+	sock = nl_bucket[unit].netlink_kernel;
 	if (sock) {
 		struct sock *sk = sock->sk;
 		memset(skb->cb, 0, sizeof(skb->cb));

@@ -1083,7 +1085,7 @@
 	loff_t off = 0;
 
 	for (i=0; i<MAX_LINKS; i++) {
-		sk_for_each(s, node, &nl_table[i]) {
+		sk_for_each(s, node, &nl_bucket[i].nl_table) {
 			if (off == pos) {
 				seq->private = (void *) i;
 				return s;

@@ -1114,7 +1116,7 @@
 		long i = (long)seq->private;
 
 		while (++i < MAX_LINKS) {
-			s = sk_head(&nl_table[i]);
+			s = sk_head(&nl_bucket[i].nl_table);
 			if (s) {
 				seq->private = (void *) i;
 				break;

Please hold onto any work involving netlink itself, there are some pending patches in that area right now.

Thanks,

Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

uh just curious, what kind of patches?

Pablo

Herbert and I have a pending patch which changes the code over to use hash lookups for the "find socket by PID" netlink code.

Here is the work Herbert and I were talking about. It kind of makes your patch taken care of already :-)

Herbert, this is what I actually checked into my tree. If you could cook up a 2.4.x version, that would be really great.

# This is a BitKeeper generated diff -Nru style patch. #
# ChangeSet
# 2004/11/03 15:34:53-08:00 [email protected]
# [NETLINK]: Hash sockets by pid if not multicast.
#
# Collaborative work between David S. Miller and
# Herbert Xu.
#
# Signed-off-by: Herbert Xu <[email protected]>
# Signed-off-by: David S. Miller <[email protected]>
#

# net/netlink/af_netlink.c
#   2004/11/03 15:33:45-08:00 [email protected] +374 -109
#   [NETLINK]: Hash sockets by pid if not multicast.
# 
diff -Nru a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
--- a/net/netlink/af_netlink.c	2004-11-03 15:35:38 -08:00
+++ b/net/netlink/af_netlink.c	2004-11-03 15:35:38 -08:00
@@ -44,6 +44,12 @@
 #include <linux/smp_lock.h>
 #include <linux/notifier.h>
 #include <linux/security.h>
+#include <linux/jhash.h>
+#include <linux/jiffies.h>
+#include <linux/random.h>
+#include <linux/bitops.h>
+#include <linux/mm.h>
+#include <linux/types.h>
 #include <net/sock.h>
 #include <net/scm.h>

@@ -56,9 +62,9 @@
struct netlink_opt
{
u32 pid;
- unsigned groups;
+ unsigned int groups;
u32 dst_pid;
- unsigned dst_groups;
+ unsigned int dst_groups;
unsigned long state;
int (*handler)(int unit, struct sk_buff *skb);
wait_queue_head_t wait;
@@ -69,9 +75,28 @@

#define nlk_sk(__sk) ((struct netlink_opt *)(__sk)->sk_protinfo)

-static struct hlist_head nl_table[MAX_LINKS];
+struct nl_pid_hash {
+ struct hlist_head *table;
+ unsigned long rehash_time;
+
+ unsigned int mask;
+ unsigned int shift;
+
+ unsigned int entries;
+ unsigned int max_shift;
+
+ u32 rnd;
+};
+
+struct netlink_table {
+ struct nl_pid_hash hash;
+ struct hlist_head mc_list;
+};
+
+static struct netlink_table *nl_table;
+
static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
-static unsigned nl_nonroot[MAX_LINKS];
+static unsigned int nl_nonroot[MAX_LINKS];

#ifdef NL_EMULATE_DEV
static struct socket *netlink_kernel[MAX_LINKS];
@@ -85,6 +110,11 @@

static struct notifier_block *netlink_chain;

+static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid) +{
+ return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
+}
+
static void netlink_sock_destruct(struct sock *sk)
{
skb_queue_purge(&sk->sk_receive_queue);
@@ -153,11 +183,14 @@

static __inline__ struct sock *netlink_lookup(int protocol, u32 pid) {
+ struct nl_pid_hash *hash = &nl_table[protocol].hash;
+ struct hlist_head *head;
struct sock *sk;
struct hlist_node *node;

read_lock(&nl_table_lock);
- sk_for_each(sk, node, &nl_table[protocol]) {
+ head = nl_pid_hashfn(hash, pid);
+ sk_for_each(sk, node, head) {
if (nlk_sk(sk)->pid == pid) {
sock_hold(sk);
goto found;
@@ -169,27 +202,118 @@
return sk;
}

+static inline struct hlist_head *nl_pid_hash_alloc(size_t size) +{
+ if (size <= PAGE_SIZE)
+ return kmalloc(size, GFP_ATOMIC);
+ else
+ return (struct hlist_head *)
+ __get_free_pages(GFP_ATOMIC, get_order(size));
+}
+
+static inline void nl_pid_hash_free(struct hlist_head *table, size_t size) +{
+ if (size <= PAGE_SIZE)
+ kfree(table);
+ else
+ free_pages((unsigned long)table, get_order(size));
+}
+
+static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) +{
+ unsigned int omask, mask, shift;
+ size_t osize, size;
+ struct hlist_head *otable, *table;
+ int i;
+
+ omask = mask = hash->mask;
+ osize = size = (mask + 1) * sizeof(*table);
+ shift = hash->shift;
+
+ if (grow) {
+ if (++shift > hash->max_shift)
+ return 0;
+ mask = mask * 2 + 1;
+ size *= 2;
+ }
+
+ table = nl_pid_hash_alloc(size);
+ if (!table)
+ return 0;
+
+ memset(table, 0, size);
+ otable = hash->table;
+ hash->table = table;
+ hash->mask = mask;
+ hash->shift = shift;
+ get_random_bytes(&hash->rnd, sizeof(hash->rnd));
+
+ for (i = 0; i <= omask; i++) {
+ struct sock *sk;
+ struct hlist_node *node, *tmp;
+
+ sk_for_each_safe(sk, node, tmp, &otable[i])
+ __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
+ }
+
+ nl_pid_hash_free(otable, osize);
+ hash->rehash_time = jiffies + 10 * 60 * HZ;
+ return 1;
+}
+
+static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) +{
+ int avg = hash->entries >> hash->shift;
+
+ if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
+ return 1;
+
+ if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
+ nl_pid_hash_rehash(hash, 0);
+ return 1;
+ }
+
+ return 0;
+}
+
static struct proto_ops netlink_ops;

static int netlink_insert(struct sock *sk, u32 pid) {
+ struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
+ struct hlist_head *head;
int err = -EADDRINUSE;
struct sock *osk;
struct hlist_node *node;
+ int len;

netlink_table_grab();
- sk_for_each(osk, node, &nl_table[sk->sk_protocol]) {
+ head = nl_pid_hashfn(hash, pid);
+ len = 0;
+ sk_for_each(osk, node, head) {
if (nlk_sk(osk)->pid == pid)
break;
+ len++;
}
- if (!node) {
- err = -EBUSY;
- if (nlk_sk(sk)->pid == 0) {
- nlk_sk(sk)->pid = pid;
- sk_add_node(sk, &nl_table[sk->sk_protocol]);
- err = 0;
- }
- }
+ if (node)
+ goto err;
+
+ err = -EBUSY;
+ if (nlk_sk(sk)->pid)
+ goto err;
+
+ err = -ENOMEM;
+ if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
+ goto err;
+
+ if (len && nl_pid_hash_dilute(hash, len))
+ head = nl_pid_hashfn(hash, pid);
+ hash->entries++;
+ nlk_sk(sk)->pid = pid;
+ sk_add_node(sk, head);
+ err = 0;
+
+err:
netlink_table_ungrab();
return err;
}
@@ -197,7 +321,10 @@
static void netlink_remove(struct sock *sk)
{
netlink_table_grab();
+ nl_table[sk->sk_protocol].hash.entries--;
sk_del_node_init(sk);
+ if (nlk_sk(sk)->groups)
+ __sk_del_bind_node(sk);
netlink_table_ungrab();
}

@@ -282,19 +409,25 @@
static int netlink_autobind(struct socket *sock)
{
struct sock *sk = sock->sk;
+ struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
+ struct hlist_head *head;
struct sock *osk;
struct hlist_node *node;
s32 pid = current->pid;
int err;
+ static s32 rover = -4097;

retry:
+ cond_resched();
netlink_table_grab();
- sk_for_each(osk, node, &nl_table[sk->sk_protocol]) {
+ head = nl_pid_hashfn(hash, pid);
+ sk_for_each(osk, node, head) {
if (nlk_sk(osk)->pid == pid) {
/* Bind collision, search negative pid values. */ if (pid > 0)
- pid = -4096;
- pid--;
+ pid = rover;
+ else if (--pid > 0)
+ pid = -4097;
netlink_table_ungrab();
goto retry;
}
@@ -308,7 +441,7 @@
return 0;
}

-static inline int netlink_capable(struct socket *sock, unsigned flag) +static inline int netlink_capable(struct socket *sock, unsigned int flag)
{
return (nl_nonroot[sock->sk->sk_protocol] & flag) ||
capable(CAP_NET_ADMIN);
@@ -331,21 +464,19 @@
if (nlk->pid) {
if (nladdr->nl_pid != nlk->pid)
return -EINVAL;
- nlk->groups = nladdr->nl_groups;
- return 0;
+ } else {
+ err = nladdr->nl_pid ?
+ netlink_insert(sk, nladdr->nl_pid) :
+ netlink_autobind(sock);
+ if (err)
+ return err;
}

- if (nladdr->nl_pid == 0) {
- err = netlink_autobind(sock);
- if (err == 0)
- nlk->groups = nladdr->nl_groups;
- return err;
- }
+ nlk->groups = nladdr->nl_groups;
+ if (nladdr->nl_groups)
+ sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);

- err = netlink_insert(sk, nladdr->nl_pid);
- if (err == 0)
- nlk->groups = nladdr->nl_groups;
- return err;
+ return 0;
}

static int netlink_connect(struct socket *sock, struct sockaddr *addr,
@@ -590,16 +721,76 @@
return -1;
}

+struct netlink_broadcast_data {
+ struct sock *exclude_sk;
+ u32 pid;
+ u32 group;
+ int failure;
+ int congested;
+ int delivered;
+ int allocation;
+ struct sk_buff *skb, *skb2;
+};
+
+static inline int do_one_broadcast(struct sock *sk,
+ struct netlink_broadcast_data *p)
+{
+ struct netlink_opt *nlk = nlk_sk(sk);
+ int val;
+
+ if (p->exclude_sk == sk)
+ goto out;
+
+ if (nlk->pid == p->pid || !(nlk->groups & p->group))
+ goto out;
+
+ if (p->failure) {
+ netlink_overrun(sk);
+ goto out;
+ }
+
+ sock_hold(sk);
+ if (p->skb2 == NULL) {
+ if (atomic_read(&p->skb->users) != 1) {
+ p->skb2 = skb_clone(p->skb, p->allocation);
+ } else {
+ p->skb2 = p->skb;
+ atomic_inc(&p->skb->users);
+ }
+ }
+ if (p->skb2 == NULL) {
+ netlink_overrun(sk);
+ /* Clone failed. Notify ALL listeners. */
+ p->failure = 1;
+ } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
+ netlink_overrun(sk);
+ } else {
+ p->congested |= val;
+ p->delivered = 1;
+ p->skb2 = NULL;
+ }
+ sock_put(sk);
+
+out:
+ return 0;
+}
+
int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
u32 group, int allocation)
{
- struct sock *sk;
+ struct netlink_broadcast_data info;
struct hlist_node *node;
- struct sk_buff *skb2 = NULL;
- int protocol = ssk->sk_protocol;
- int failure = 0, delivered = 0;
- int congested = 0;
- int val;
+ struct sock *sk;
+
+ info.exclude_sk = ssk;
+ info.pid = pid;
+ info.group = group;
+ info.failure = 0;
+ info.congested = 0;
+ info.delivered = 0;
+ info.allocation = allocation;
+ info.skb = skb;
+ info.skb2 = NULL;

netlink_trim(skb, allocation);

@@ -607,77 +798,65 @@

netlink_lock_table();

- sk_for_each(sk, node, &nl_table[protocol]) {
- struct netlink_opt *nlk = nlk_sk(sk);
-
- if (ssk == sk)
- continue;
-
- if (nlk->pid == pid || !(nlk->groups & group))
- continue;
-
- if (failure) {
- netlink_overrun(sk);
- continue;
- }
-
- sock_hold(sk);
- if (skb2 == NULL) {
- if (atomic_read(&skb->users) != 1) {
- skb2 = skb_clone(skb, allocation);
- } else {
- skb2 = skb;
- atomic_inc(&skb->users);
- }
- }
- if (skb2 == NULL) {
- netlink_overrun(sk);
- /* Clone failed. Notify ALL listeners. */
- failure = 1;
- } else if ((val = netlink_broadcast_deliver(sk, skb2)) < 0) {
- netlink_overrun(sk);
- } else {
- congested |= val;
- delivered = 1;
- skb2 = NULL;
- }
- sock_put(sk);
- }
+ sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
+ do_one_broadcast(sk, &info);

netlink_unlock_table();

- if (skb2)
- kfree_skb(skb2);
+ if (info.skb2)
+ kfree_skb(info.skb2);
kfree_skb(skb);

- if (delivered) {
- if (congested && (allocation & __GFP_WAIT))
+ if (info.delivered) {
+ if (info.congested && (allocation & __GFP_WAIT))
yield();
return 0;
}
- if (failure)
+ if (info.failure)
return -ENOBUFS;
return -ESRCH;
}

+struct netlink_set_err_data {
+ struct sock *exclude_sk;
+ u32 pid;
+ u32 group;
+ int code;
+};
+
+static inline int do_one_set_err(struct sock *sk,
+ struct netlink_set_err_data *p)
+{
+ struct netlink_opt *nlk = nlk_sk(sk);
+
+ if (sk == p->exclude_sk)
+ goto out;
+
+ if (nlk->pid == p->pid || !(nlk->groups & p->group))
+ goto out;
+
+ sk->sk_err = p->code;
+ sk->sk_error_report(sk);
+out:
+ return 0;
+}
+
void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) {
- struct sock *sk;
+ struct netlink_set_err_data info;
struct hlist_node *node;
- int protocol = ssk->sk_protocol;
+ struct sock *sk;
+
+ info.exclude_sk = ssk;
+ info.pid = pid;
+ info.group = group;
+ info.code = code;

read_lock(&nl_table_lock);
- sk_for_each(sk, node, &nl_table[protocol]) {
- struct netlink_opt *nlk = nlk_sk(sk);
- if (ssk == sk)
- continue;

- if (nlk->pid == pid || !(nlk->groups & group))
- continue;
+ sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
+ do_one_set_err(sk, &info);

- sk->sk_err = code;
- sk->sk_error_report(sk);
- }
read_unlock(&nl_table_lock);
}

@@ -853,6 +1032,9 @@
struct socket *sock;
struct sock *sk;

+ if (!nl_table)
+ return NULL;
+
if (unit<0 || unit>=MAX_LINKS)
return NULL;

@@ -875,9 +1057,9 @@
return sk;
}

-void netlink_set_nonroot(int protocol, unsigned flags) +void netlink_set_nonroot(int protocol, unsigned int flags)
{
- if ((unsigned)protocol < MAX_LINKS)
+ if ((unsigned int)protocol < MAX_LINKS)
nl_nonroot[protocol] = flags;
}

@@ -1070,20 +1252,31 @@
#endif

#ifdef CONFIG_PROC_FS
+struct nl_seq_iter {
+ int link;
+ int hash_idx;
+};
+
static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) {
- long i;
+ struct nl_seq_iter *iter = seq->private;
+ int i, j;
struct sock *s;
struct hlist_node *node;
loff_t off = 0;

for (i=0; i<MAX_LINKS; i++) {
- sk_for_each(s, node, &nl_table[i]) {
- if (off == pos) {
- seq->private = (void *) i;
- return s;
+ struct nl_pid_hash *hash = &nl_table[i].hash;
+
+ for (j = 0; j <= hash->mask; j++) {
+ sk_for_each(s, node, &hash->table[j]) {
+ if (off == pos) {
+ iter->link = i;
+ iter->hash_idx = j;
+ return s;
+ }
+ ++off;
}
- ++off;
}
}
return NULL;
@@ -1098,6 +1291,8 @@
static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) {
struct sock *s;
+ struct nl_seq_iter *iter;
+ int i, j;

++*pos;

@@ -1105,18 +1300,29 @@
return netlink_seq_socket_idx(seq, 0);

s = sk_next(v);
- if (!s) {
- long i = (long)seq->private;
+ if (s)
+ return s;
+
+ iter = seq->private;
+ i = iter->link;
+ j = iter->hash_idx + 1;

- while (++i < MAX_LINKS) {
- s = sk_head(&nl_table[i]);
+ do {
+ struct nl_pid_hash *hash = &nl_table[i].hash;
+
+ for (; j <= hash->mask; j++) {
+ s = sk_head(&hash->table[j]);
if (s) {
- seq->private = (void *) i;
- break;
+ iter->link = i;
+ iter->hash_idx = j;
+ return s;
}
}
- }
- return s;
+
+ j = 0;
+ } while (++i < MAX_LINKS);
+
+ return NULL;
}

static void netlink_seq_stop(struct seq_file *seq, void *v)
@@ -1160,7 +1366,24 @@

static int netlink_seq_open(struct inode *inode, struct file *file) {
- return seq_open(file, &netlink_seq_ops);
+ struct seq_file *seq;
+ struct nl_seq_iter *iter;
+ int err;
+
+ iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter)
+ return -ENOMEM;
+
+ err = seq_open(file, &netlink_seq_ops);
+ if (err) {
+ kfree(iter);
+ return err;
+ }
+
+ memset(iter, 0, sizeof(*iter));
+ seq = file->private_data;
+ seq->private = iter;
+ return 0;
}

static struct file_operations netlink_seq_fops = {
@@ -1168,7 +1391,7 @@
.open = netlink_seq_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = seq_release,
+ .release = seq_release_private,
};

#endif
@@ -1210,14 +1433,54 @@
.owner = THIS_MODULE, /* for consistency 8) */
};

+extern void netlink_skb_parms_too_large(void);
+
static int __init netlink_proto_init(void)
{
struct sk_buff *dummy_skb;
+ int i;
+ unsigned long max;
+ unsigned int order;
+
+ if (sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb))
+ netlink_skb_parms_too_large();
+
+ nl_table = kmalloc(sizeof(*nl_table) * MAX_LINKS, GFP_KERNEL);
+ if (!nl_table) {
+enomem:
+ printk(KERN_CRIT "netlink_init: Cannot allocate nl_table\n");
+ return -ENOMEM;
+ }
+
+ memset(nl_table, 0, sizeof(*nl_table) * MAX_LINKS);

- if (sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)) {
- printk(KERN_CRIT "netlink_init: panic\n");
- return -1;
+ if (num_physpages >= (128 * 1024))
+ max = num_physpages >> (21 - PAGE_SHIFT);
+ else
+ max = num_physpages >> (23 - PAGE_SHIFT);
+
+ order = get_bitmask_order(max) - 1 + PAGE_SHIFT;
+ max = (1UL << order) / sizeof(struct hlist_head);
+ order = get_bitmask_order(max > UINT_MAX ? UINT_MAX : max) - 1;
+
+ for (i = 0; i < MAX_LINKS; i++) {
+ struct nl_pid_hash *hash = &nl_table[i].hash;
+
+ hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table));
+ if (!hash->table) {
+ while (i-- > 0)
+ nl_pid_hash_free(nl_table[i].hash.table,
+ 1 * sizeof(*hash->table));
+ kfree(nl_table);
+ goto enomem;
+ }
+ memset(hash->table, 0, 1 * sizeof(*hash->table));
+ hash->max_shift = order;
+ hash->shift = 0;
+ hash->mask = 0;
+ hash->rehash_time = jiffies;
}
+
sock_register(&netlink_family_ops);
#ifdef CONFIG_PROC_FS
proc_net_fops_create("netlink", 0, &netlink_seq_fops);
@@ -1231,6 +1494,8 @@

 {
        sock_unregister(PF_NETLINK);
        proc_net_remove("netlink");

+ kfree(nl_table);
+ nl_table = NULL;
}

core_initcall(netlink_proto_init);

Move netlink_kernel and nl_nonroot arrays to nl_table structure. Do you like it?

--
Pablo

===== net/netlink/af_netlink.c 1.62 vs edited =====

@@ -91,16 +91,15 @@
 struct netlink_table {
 	struct nl_pid_hash hash;
 	struct hlist_head mc_list;
+	unsigned int nl_nonroot;
+#ifdef NL_EMULATE_DEV
+	struct socket *netlink_kernel;
+#endif
 };
 
 static struct netlink_table *nl_table;
 
 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
-static unsigned int nl_nonroot[MAX_LINKS];
-
-#ifdef NL_EMULATE_DEV
-static struct socket *netlink_kernel[MAX_LINKS];
-#endif
 
 static int netlink_dump(struct sock *sk);
 static void netlink_destroy_callback(struct netlink_callback *cb);

@@ -442,7 +441,7 @@
 
 static inline int netlink_capable(struct socket *sock, unsigned int flag) 
 { 
-	return (nl_nonroot[sock->sk->sk_protocol] & flag) ||
+	return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
 	       capable(CAP_NET_ADMIN);
 } 
 

@@ -1066,7 +1065,7 @@
 void netlink_set_nonroot(int protocol, unsigned int flags)
 { 
 	if ((unsigned int)protocol < MAX_LINKS) 
-		nl_nonroot[protocol] = flags;
+		nl_table[protocol].nl_nonroot = flags;
 } 
 
 static void netlink_destroy_callback(struct netlink_callback *cb)

@@ -1217,7 +1216,7 @@
 		return -ENOBUFS;
 	nlk_sk(sk)->handler = function;
 	write_lock_bh(&nl_emu_lock);
-	netlink_kernel[unit] = sk->sk_socket;
+	nl_table[unit].netlink_kernel = sk->sk_socket;
 	write_unlock_bh(&nl_emu_lock);
 	return 0;
 }

@@ -1227,8 +1226,8 @@
 	struct socket *sock;
 
 	write_lock_bh(&nl_emu_lock);
-	sock = netlink_kernel[unit];
-	netlink_kernel[unit] = NULL;
+	sock = nl_table[unit].netlink_kernel;
+	nl_table[unit].netlink_kernel = NULL;
 	write_unlock_bh(&nl_emu_lock);
 
 	sock_release(sock);

@@ -1239,7 +1238,7 @@
 	struct socket *sock;
 
 	read_lock(&nl_emu_lock);
-	sock = netlink_kernel[unit];
+	sock = nl_table[unit].netlink_kernel;
 	if (sock) {
 		struct sock *sk = sock->sk;
 		memset(skb->cb, 0, sizeof(skb->cb));