Commit 025d93d1 authored by Alexey Dobriyan's avatar Alexey Dobriyan Committed by David S. Miller
Browse files

[NETFILTER]: x_tables: semi-rewrite of /proc/net/foo_tables_* 



There are many small but still wrong things with /proc/net/*_tables_*
so I decided to do overhaul simultaneously making it more suitable for
per-netns /proc/net/*_tables_* implementation.

Fix
a) xt_get_idx() duplicating now standard seq_list_start/seq_list_next
   iterators
b) tables/matches/targets list was chosen again and again on every ->next
c) multiple useless "af >= NPROTO" checks -- we simple don't supply invalid
   AFs there and registration function should BUG_ON instead.

   Regardless, the one in ->next() is the most useless -- ->next doesn't
   run at all if ->start fails.
d) Don't use mutex_lock_interruptible() -- it can fail and ->stop is
   executed even if ->start failed, so unlock without lock is possible.

As side effect, streamline code by splitting xt_tgt_ops into xt_target_ops,
xt_matches_ops, xt_tables_ops.

xt_tables_ops hooks will be changed by per-netns code. Code of
xt_matches_ops, xt_target_ops is identical except the list chosen for
iterating, but I think consolidating code for two files not worth it
given "<< 16" hacks needed for it.

[Patrick: removed unused enum in x_tables.c]

Signed-off-by: default avatarAlexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 09e410de

net/netfilter/x_tables.c

+145 −85
Original line number Diff line number Diff line
@@ -58,12 +58,6 @@ static struct xt_af *xt; 
#define duprintf(format, args...)

#endif



enum {

	TABLE,

	TARGET,

	MATCH,

};



static const char *xt_prefix[NPROTO] = {

	[AF_INET]	= "ip",

	[AF_INET6]	= "ip6",
@@ -726,124 +720,190 @@ void *xt_unregister_table(struct xt_table *table) 
EXPORT_SYMBOL_GPL(xt_unregister_table);



#ifdef CONFIG_PROC_FS

static struct list_head *xt_get_idx(struct list_head *list, struct seq_file *seq, loff_t pos)

static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)

{

	struct list_head *head = list->next;

	struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;

	u_int16_t af = (unsigned long)pde->data;



	if (!head || list_empty(list))

		return NULL;

	mutex_lock(&xt[af].mutex);

	return seq_list_start(&init_net.xt.tables[af], *pos);

}



	while (pos && (head = head->next)) {

		if (head == list)

			return NULL;

		pos--;

static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)

{

	struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;

	u_int16_t af = (unsigned long)pde->data;



	return seq_list_next(v, &init_net.xt.tables[af], pos);

}

	return pos ? NULL : head;



static void xt_table_seq_stop(struct seq_file *seq, void *v)

{

	struct proc_dir_entry *pde = seq->private;

	u_int16_t af = (unsigned long)pde->data;



	mutex_unlock(&xt[af].mutex);

}



static struct list_head *type2list(u_int16_t af, u_int16_t type)

static int xt_table_seq_show(struct seq_file *seq, void *v)

{

	struct list_head *list;

	struct xt_table *table = list_entry(v, struct xt_table, list);



	switch (type) {

	case TARGET:

		list = &xt[af].target;

		break;

	case MATCH:

		list = &xt[af].match;

		break;

	case TABLE:

		list = &init_net.xt.tables[af];

		break;

	default:

		list = NULL;

		break;

	if (strlen(table->name))

		return seq_printf(seq, "%s\n", table->name);

	else

		return 0;

}



	return list;

static const struct seq_operations xt_table_seq_ops = {

	.start	= xt_table_seq_start,

	.next	= xt_table_seq_next,

	.stop	= xt_table_seq_stop,

	.show	= xt_table_seq_show,

};



static int xt_table_open(struct inode *inode, struct file *file)

{

	int ret;



	ret = seq_open(file, &xt_table_seq_ops);

	if (!ret) {

		struct seq_file *seq = file->private_data;



		seq->private = PDE(inode);

	}

	return ret;

}



static void *xt_tgt_seq_start(struct seq_file *seq, loff_t *pos)

static const struct file_operations xt_table_ops = {

	.owner	 = THIS_MODULE,

	.open	 = xt_table_open,

	.read	 = seq_read,

	.llseek	 = seq_lseek,

	.release = seq_release,

};



static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)

{

	struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;

	u_int16_t af = (unsigned long)pde->data & 0xffff;

	u_int16_t type = (unsigned long)pde->data >> 16;

	struct list_head *list;



	if (af >= NPROTO)

		return NULL;

	u_int16_t af = (unsigned long)pde->data;



	list = type2list(af, type);

	if (!list)

		return NULL;

	mutex_lock(&xt[af].mutex);

	return seq_list_start(&xt[af].match, *pos);

}



	if (mutex_lock_interruptible(&xt[af].mutex) != 0)

		return NULL;

static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *pos)

{

	struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;

	u_int16_t af = (unsigned long)pde->data;



	return xt_get_idx(list, seq, *pos);

	return seq_list_next(v, &xt[af].match, pos);

}



static void *xt_tgt_seq_next(struct seq_file *seq, void *v, loff_t *pos)

static void xt_match_seq_stop(struct seq_file *seq, void *v)

{

	struct proc_dir_entry *pde = seq->private;

	u_int16_t af = (unsigned long)pde->data & 0xffff;

	u_int16_t type = (unsigned long)pde->data >> 16;

	struct list_head *list;

	u_int16_t af = (unsigned long)pde->data;



	if (af >= NPROTO)

		return NULL;

	mutex_unlock(&xt[af].mutex);

}



	list = type2list(af, type);

	if (!list)

		return NULL;

static int xt_match_seq_show(struct seq_file *seq, void *v)

{

	struct xt_match *match = list_entry(v, struct xt_match, list);



	if (strlen(match->name))

		return seq_printf(seq, "%s\n", match->name);

	else

		return 0;

}



static const struct seq_operations xt_match_seq_ops = {

	.start	= xt_match_seq_start,

	.next	= xt_match_seq_next,

	.stop	= xt_match_seq_stop,

	.show	= xt_match_seq_show,

};



static int xt_match_open(struct inode *inode, struct file *file)

{

	int ret;



	ret = seq_open(file, &xt_match_seq_ops);

	if (!ret) {

		struct seq_file *seq = file->private_data;



	(*pos)++;

	return xt_get_idx(list, seq, *pos);

		seq->private = PDE(inode);

	}

	return ret;

}



static const struct file_operations xt_match_ops = {

	.owner	 = THIS_MODULE,

	.open	 = xt_match_open,

	.read	 = seq_read,

	.llseek	 = seq_lseek,

	.release = seq_release,

};



static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)

{

	struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;

	u_int16_t af = (unsigned long)pde->data;



	mutex_lock(&xt[af].mutex);

	return seq_list_start(&xt[af].target, *pos);

}



static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *pos)

{

	struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;

	u_int16_t af = (unsigned long)pde->data;



static void xt_tgt_seq_stop(struct seq_file *seq, void *v)

	return seq_list_next(v, &xt[af].target, pos);

}



static void xt_target_seq_stop(struct seq_file *seq, void *v)

{

	struct proc_dir_entry *pde = seq->private;

	u_int16_t af = (unsigned long)pde->data & 0xffff;

	u_int16_t af = (unsigned long)pde->data;



	mutex_unlock(&xt[af].mutex);

}



static int xt_name_seq_show(struct seq_file *seq, void *v)

static int xt_target_seq_show(struct seq_file *seq, void *v)

{

	char *name = (char *)v + sizeof(struct list_head);

	struct xt_target *target = list_entry(v, struct xt_target, list);



	if (strlen(name))

		return seq_printf(seq, "%s\n", name);

	if (strlen(target->name))

		return seq_printf(seq, "%s\n", target->name);

	else

		return 0;

}



static const struct seq_operations xt_tgt_seq_ops = {

	.start	= xt_tgt_seq_start,

	.next	= xt_tgt_seq_next,

	.stop	= xt_tgt_seq_stop,

	.show	= xt_name_seq_show,

static const struct seq_operations xt_target_seq_ops = {

	.start	= xt_target_seq_start,

	.next	= xt_target_seq_next,

	.stop	= xt_target_seq_stop,

	.show	= xt_target_seq_show,

};



static int xt_tgt_open(struct inode *inode, struct file *file)

static int xt_target_open(struct inode *inode, struct file *file)

{

	int ret;



	ret = seq_open(file, &xt_tgt_seq_ops);

	ret = seq_open(file, &xt_target_seq_ops);

	if (!ret) {

		struct seq_file *seq = file->private_data;

		struct proc_dir_entry *pde = PDE(inode);



		seq->private = pde;

		seq->private = PDE(inode);

	}



	return ret;

}



static const struct file_operations xt_file_ops = {

static const struct file_operations xt_target_ops = {

	.owner	 = THIS_MODULE,

	.open	 = xt_tgt_open,

	.open	 = xt_target_open,

	.read	 = seq_read,

	.llseek	 = seq_lseek,

	.release = seq_release,
@@ -869,25 +929,25 @@ int xt_proto_init(int af) 
#ifdef CONFIG_PROC_FS

	strlcpy(buf, xt_prefix[af], sizeof(buf));

	strlcat(buf, FORMAT_TABLES, sizeof(buf));

	proc = proc_net_fops_create(&init_net, buf, 0440, &xt_file_ops);

	proc = proc_net_fops_create(&init_net, buf, 0440, &xt_table_ops);

	if (!proc)

		goto out;

	proc->data = (void *) ((unsigned long) af | (TABLE << 16));

	proc->data = (void *)(unsigned long)af;





	strlcpy(buf, xt_prefix[af], sizeof(buf));

	strlcat(buf, FORMAT_MATCHES, sizeof(buf));

	proc = proc_net_fops_create(&init_net, buf, 0440, &xt_file_ops);

	proc = proc_net_fops_create(&init_net, buf, 0440, &xt_match_ops);

	if (!proc)

		goto out_remove_tables;

	proc->data = (void *) ((unsigned long) af | (MATCH << 16));

	proc->data = (void *)(unsigned long)af;



	strlcpy(buf, xt_prefix[af], sizeof(buf));

	strlcat(buf, FORMAT_TARGETS, sizeof(buf));

	proc = proc_net_fops_create(&init_net, buf, 0440, &xt_file_ops);

	proc = proc_net_fops_create(&init_net, buf, 0440, &xt_target_ops);

	if (!proc)

		goto out_remove_matches;

	proc->data = (void *) ((unsigned long) af | (TARGET << 16));

	proc->data = (void *)(unsigned long)af;

#endif



	return 0;

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