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

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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: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexey Dobriyan 2008-01-31 04:48:54 -08:00 committed by David S. Miller
parent 09e410def6
commit 025d93d148
1 changed files with 157 additions and 97 deletions
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254
net/netfilter/x_tables.c
View File

@ -58,12 +58,6 @@ static struct xt_af *xt;
#define duprintf(format, args...) #define duprintf(format, args...)
#endif #endif
enum {
TABLE,
TARGET,
MATCH,
};
static const char *xt_prefix[NPROTO] = { static const char *xt_prefix[NPROTO] = {
[AF_INET] = "ip", [AF_INET] = "ip",
[AF_INET6] = "ip6", [AF_INET6] = "ip6",
@ -726,124 +720,190 @@ void *xt_unregister_table(struct xt_table *table)
EXPORT_SYMBOL_GPL(xt_unregister_table); EXPORT_SYMBOL_GPL(xt_unregister_table);
#ifdef CONFIG_PROC_FS #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)) mutex_lock(&xt[af].mutex);
return NULL; return seq_list_start(&init_net.xt.tables[af], *pos);
while (pos && (head = head->next)) {
if (head == list)
return NULL;
pos--;
}
return pos ? NULL : head;
} }
static struct list_head *type2list(u_int16_t af, u_int16_t type) static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{ {
struct list_head *list; struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
u_int16_t af = (unsigned long)pde->data;
switch (type) { return seq_list_next(v, &init_net.xt.tables[af], pos);
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;
}
return list;
} }
static void *xt_tgt_seq_start(struct seq_file *seq, loff_t *pos) static void xt_table_seq_stop(struct seq_file *seq, void *v)
{
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;
list = type2list(af, type);
if (!list)
return NULL;
if (mutex_lock_interruptible(&xt[af].mutex) != 0)
return NULL;
return xt_get_idx(list, seq, *pos);
}
static void *xt_tgt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{ {
struct proc_dir_entry *pde = seq->private; struct proc_dir_entry *pde = seq->private;
u_int16_t af = (unsigned long)pde->data & 0xffff; u_int16_t af = (unsigned long)pde->data;
u_int16_t type = (unsigned long)pde->data >> 16;
struct list_head *list;
if (af >= NPROTO)
return NULL;
list = type2list(af, type);
if (!list)
return NULL;
(*pos)++;
return xt_get_idx(list, seq, *pos);
}
static void xt_tgt_seq_stop(struct seq_file *seq, void *v)
{
struct proc_dir_entry *pde = seq->private;
u_int16_t af = (unsigned long)pde->data & 0xffff;
mutex_unlock(&xt[af].mutex); mutex_unlock(&xt[af].mutex);
} }
static int xt_name_seq_show(struct seq_file *seq, void *v) static int xt_table_seq_show(struct seq_file *seq, void *v)
{ {
char *name = (char *)v + sizeof(struct list_head); struct xt_table *table = list_entry(v, struct xt_table, list);
if (strlen(name)) if (strlen(table->name))
return seq_printf(seq, "%s\n", name); return seq_printf(seq, "%s\n", table->name);
else else
return 0; return 0;
} }
static const struct seq_operations xt_tgt_seq_ops = { static const struct seq_operations xt_table_seq_ops = {
.start = xt_tgt_seq_start, .start = xt_table_seq_start,
.next = xt_tgt_seq_next, .next = xt_table_seq_next,
.stop = xt_tgt_seq_stop, .stop = xt_table_seq_stop,
.show = xt_name_seq_show, .show = xt_table_seq_show,
}; };
static int xt_tgt_open(struct inode *inode, struct file *file) static int xt_table_open(struct inode *inode, struct file *file)
{ {
int ret; int ret;
ret = seq_open(file, &xt_tgt_seq_ops); ret = seq_open(file, &xt_table_seq_ops);
if (!ret) { if (!ret) {
struct seq_file *seq = file->private_data; struct seq_file *seq = file->private_data;
struct proc_dir_entry *pde = PDE(inode);
seq->private = pde; seq->private = PDE(inode);
} }
return ret; return ret;
} }
static const struct file_operations xt_file_ops = { static const struct file_operations xt_table_ops = {
.owner = THIS_MODULE, .owner = THIS_MODULE,
.open = xt_tgt_open, .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;
mutex_lock(&xt[af].mutex);
return seq_list_start(&xt[af].match, *pos);
}
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 seq_list_next(v, &xt[af].match, 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;
mutex_unlock(&xt[af].mutex);
}
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;
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;
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;
mutex_unlock(&xt[af].mutex);
}
static int xt_target_seq_show(struct seq_file *seq, void *v)
{
struct xt_target *target = list_entry(v, struct xt_target, list);
if (strlen(target->name))
return seq_printf(seq, "%s\n", target->name);
else
return 0;
}
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_target_open(struct inode *inode, struct file *file)
{
int ret;
ret = seq_open(file, &xt_target_seq_ops);
if (!ret) {
struct seq_file *seq = file->private_data;
seq->private = PDE(inode);
}
return ret;
}
static const struct file_operations xt_target_ops = {
.owner = THIS_MODULE,
.open = xt_target_open,
.read = seq_read, .read = seq_read,
.llseek = seq_lseek, .llseek = seq_lseek,
.release = seq_release, .release = seq_release,
@ -869,25 +929,25 @@ int xt_proto_init(int af)
#ifdef CONFIG_PROC_FS #ifdef CONFIG_PROC_FS
strlcpy(buf, xt_prefix[af], sizeof(buf)); strlcpy(buf, xt_prefix[af], sizeof(buf));
strlcat(buf, FORMAT_TABLES, 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) if (!proc)
goto out; goto out;
proc->data = (void *) ((unsigned long) af | (TABLE << 16)); proc->data = (void *)(unsigned long)af;
strlcpy(buf, xt_prefix[af], sizeof(buf)); strlcpy(buf, xt_prefix[af], sizeof(buf));
strlcat(buf, FORMAT_MATCHES, 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) if (!proc)
goto out_remove_tables; 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)); strlcpy(buf, xt_prefix[af], sizeof(buf));
strlcat(buf, FORMAT_TARGETS, 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) if (!proc)
goto out_remove_matches; goto out_remove_matches;
proc->data = (void *) ((unsigned long) af | (TARGET << 16)); proc->data = (void *)(unsigned long)af;
#endif #endif
return 0; return 0;