From 1d610d4d31a8ed36d57f88108331edc7585570b7 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 1 Apr 2021 16:11:11 +0200 Subject: [PATCH] netfilter: x_tables: move known table lists to net_generic infra Will reduce struct net size by 208 bytes. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/x_tables.c | 46 ++++++++++++++++++++++++++++------------ 1 file changed, 33 insertions(+), 13 deletions(-) diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index 6bd31a7a27fc..8e23ef2673e4 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include @@ -38,6 +39,10 @@ MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module"); #define XT_PCPU_BLOCK_SIZE 4096 #define XT_MAX_TABLE_SIZE (512 * 1024 * 1024) +struct xt_pernet { + struct list_head tables[NFPROTO_NUMPROTO]; +}; + struct compat_delta { unsigned int offset; /* offset in kernel */ int delta; /* delta in 32bit user land */ @@ -55,7 +60,8 @@ struct xt_af { #endif }; -static struct xt_af *xt; +static unsigned int xt_pernet_id __read_mostly; +static struct xt_af *xt __read_mostly; static const char *const xt_prefix[NFPROTO_NUMPROTO] = { [NFPROTO_UNSPEC] = "x", @@ -1203,10 +1209,11 @@ EXPORT_SYMBOL(xt_free_table_info); struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af, const char *name) { + struct xt_pernet *xt_net = net_generic(net, xt_pernet_id); struct xt_table *t, *found = NULL; mutex_lock(&xt[af].mutex); - list_for_each_entry(t, &net->xt.tables[af], list) + list_for_each_entry(t, &xt_net->tables[af], list) if (strcmp(t->name, name) == 0 && try_module_get(t->me)) return t; @@ -1214,7 +1221,8 @@ struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af, goto out; /* Table doesn't exist in this netns, re-try init */ - list_for_each_entry(t, &init_net.xt.tables[af], list) { + xt_net = net_generic(&init_net, xt_pernet_id); + list_for_each_entry(t, &xt_net->tables[af], list) { int err; if (strcmp(t->name, name)) @@ -1237,8 +1245,9 @@ struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af, if (!found) goto out; + xt_net = net_generic(net, xt_pernet_id); /* and once again: */ - list_for_each_entry(t, &net->xt.tables[af], list) + list_for_each_entry(t, &xt_net->tables[af], list) if (strcmp(t->name, name) == 0) return t; @@ -1423,9 +1432,10 @@ struct xt_table *xt_register_table(struct net *net, struct xt_table_info *bootstrap, struct xt_table_info *newinfo) { - int ret; + struct xt_pernet *xt_net = net_generic(net, xt_pernet_id); struct xt_table_info *private; struct xt_table *t, *table; + int ret; /* Don't add one object to multiple lists. */ table = kmemdup(input_table, sizeof(struct xt_table), GFP_KERNEL); @@ -1436,7 +1446,7 @@ struct xt_table *xt_register_table(struct net *net, mutex_lock(&xt[table->af].mutex); /* Don't autoload: we'd eat our tail... */ - list_for_each_entry(t, &net->xt.tables[table->af], list) { + list_for_each_entry(t, &xt_net->tables[table->af], list) { if (strcmp(t->name, table->name) == 0) { ret = -EEXIST; goto unlock; @@ -1455,7 +1465,7 @@ struct xt_table *xt_register_table(struct net *net, /* save number of initial entries */ private->initial_entries = private->number; - list_add(&table->list, &net->xt.tables[table->af]); + list_add(&table->list, &xt_net->tables[table->af]); mutex_unlock(&xt[table->af].mutex); return table; @@ -1486,19 +1496,25 @@ EXPORT_SYMBOL_GPL(xt_unregister_table); #ifdef CONFIG_PROC_FS static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos) { + u8 af = (unsigned long)PDE_DATA(file_inode(seq->file)); struct net *net = seq_file_net(seq); - u_int8_t af = (unsigned long)PDE_DATA(file_inode(seq->file)); + struct xt_pernet *xt_net; + + xt_net = net_generic(net, xt_pernet_id); mutex_lock(&xt[af].mutex); - return seq_list_start(&net->xt.tables[af], *pos); + return seq_list_start(&xt_net->tables[af], *pos); } static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos) { + u8 af = (unsigned long)PDE_DATA(file_inode(seq->file)); struct net *net = seq_file_net(seq); - u_int8_t af = (unsigned long)PDE_DATA(file_inode(seq->file)); + struct xt_pernet *xt_net; - return seq_list_next(v, &net->xt.tables[af], pos); + xt_net = net_generic(net, xt_pernet_id); + + return seq_list_next(v, &xt_net->tables[af], pos); } static void xt_table_seq_stop(struct seq_file *seq, void *v) @@ -1864,24 +1880,28 @@ EXPORT_SYMBOL_GPL(xt_percpu_counter_free); static int __net_init xt_net_init(struct net *net) { + struct xt_pernet *xt_net = net_generic(net, xt_pernet_id); int i; for (i = 0; i < NFPROTO_NUMPROTO; i++) - INIT_LIST_HEAD(&net->xt.tables[i]); + INIT_LIST_HEAD(&xt_net->tables[i]); return 0; } static void __net_exit xt_net_exit(struct net *net) { + struct xt_pernet *xt_net = net_generic(net, xt_pernet_id); int i; for (i = 0; i < NFPROTO_NUMPROTO; i++) - WARN_ON_ONCE(!list_empty(&net->xt.tables[i])); + WARN_ON_ONCE(!list_empty(&xt_net->tables[i])); } static struct pernet_operations xt_net_ops = { .init = xt_net_init, .exit = xt_net_exit, + .id = &xt_pernet_id, + .size = sizeof(struct xt_pernet), }; static int __init xt_init(void)