[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: 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
David S. Miller
parent
09e410def6
commit
025d93d148
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@ -58,12 +58,6 @@ static struct xt_af *xt;
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#define duprintf(format, args...)
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#endif
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enum {
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TABLE,
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TARGET,
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MATCH,
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};
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static const char *xt_prefix[NPROTO] = {
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[AF_INET] = "ip",
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[AF_INET6] = "ip6",
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@ -726,124 +720,190 @@ void *xt_unregister_table(struct xt_table *table)
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EXPORT_SYMBOL_GPL(xt_unregister_table);
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#ifdef CONFIG_PROC_FS
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static struct list_head *xt_get_idx(struct list_head *list, struct seq_file *seq, loff_t pos)
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static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)
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{
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struct list_head *head = list->next;
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struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
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u_int16_t af = (unsigned long)pde->data;
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if (!head || list_empty(list))
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return NULL;
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while (pos && (head = head->next)) {
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if (head == list)
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return NULL;
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pos--;
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}
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return pos ? NULL : head;
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mutex_lock(&xt[af].mutex);
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return seq_list_start(&init_net.xt.tables[af], *pos);
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}
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static struct list_head *type2list(u_int16_t af, u_int16_t type)
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static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
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{
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struct list_head *list;
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struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
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u_int16_t af = (unsigned long)pde->data;
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switch (type) {
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case TARGET:
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list = &xt[af].target;
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break;
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case MATCH:
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list = &xt[af].match;
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break;
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case TABLE:
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list = &init_net.xt.tables[af];
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break;
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default:
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list = NULL;
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break;
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}
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return list;
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return seq_list_next(v, &init_net.xt.tables[af], pos);
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}
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static void *xt_tgt_seq_start(struct seq_file *seq, loff_t *pos)
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{
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struct proc_dir_entry *pde = (struct proc_dir_entry *) seq->private;
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u_int16_t af = (unsigned long)pde->data & 0xffff;
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u_int16_t type = (unsigned long)pde->data >> 16;
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struct list_head *list;
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if (af >= NPROTO)
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return NULL;
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list = type2list(af, type);
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if (!list)
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return NULL;
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if (mutex_lock_interruptible(&xt[af].mutex) != 0)
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return NULL;
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return xt_get_idx(list, seq, *pos);
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}
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static void *xt_tgt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
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static void xt_table_seq_stop(struct seq_file *seq, void *v)
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{
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struct proc_dir_entry *pde = seq->private;
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u_int16_t af = (unsigned long)pde->data & 0xffff;
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u_int16_t type = (unsigned long)pde->data >> 16;
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struct list_head *list;
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if (af >= NPROTO)
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return NULL;
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list = type2list(af, type);
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if (!list)
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return NULL;
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(*pos)++;
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return xt_get_idx(list, seq, *pos);
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}
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static void xt_tgt_seq_stop(struct seq_file *seq, void *v)
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{
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struct proc_dir_entry *pde = seq->private;
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u_int16_t af = (unsigned long)pde->data & 0xffff;
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u_int16_t af = (unsigned long)pde->data;
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mutex_unlock(&xt[af].mutex);
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}
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static int xt_name_seq_show(struct seq_file *seq, void *v)
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static int xt_table_seq_show(struct seq_file *seq, void *v)
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{
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char *name = (char *)v + sizeof(struct list_head);
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struct xt_table *table = list_entry(v, struct xt_table, list);
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if (strlen(name))
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return seq_printf(seq, "%s\n", name);
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if (strlen(table->name))
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return seq_printf(seq, "%s\n", table->name);
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else
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return 0;
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}
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static const struct seq_operations xt_tgt_seq_ops = {
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.start = xt_tgt_seq_start,
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.next = xt_tgt_seq_next,
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.stop = xt_tgt_seq_stop,
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.show = xt_name_seq_show,
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static const struct seq_operations xt_table_seq_ops = {
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.start = xt_table_seq_start,
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.next = xt_table_seq_next,
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.stop = xt_table_seq_stop,
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.show = xt_table_seq_show,
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};
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static int xt_tgt_open(struct inode *inode, struct file *file)
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static int xt_table_open(struct inode *inode, struct file *file)
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{
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int ret;
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ret = seq_open(file, &xt_tgt_seq_ops);
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ret = seq_open(file, &xt_table_seq_ops);
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if (!ret) {
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struct seq_file *seq = file->private_data;
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struct proc_dir_entry *pde = PDE(inode);
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seq->private = pde;
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seq->private = PDE(inode);
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}
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return ret;
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}
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static const struct file_operations xt_file_ops = {
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static const struct file_operations xt_table_ops = {
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.owner = THIS_MODULE,
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.open = xt_tgt_open,
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.open = xt_table_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release,
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};
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static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
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{
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struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
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u_int16_t af = (unsigned long)pde->data;
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mutex_lock(&xt[af].mutex);
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return seq_list_start(&xt[af].match, *pos);
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}
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static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *pos)
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{
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struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
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u_int16_t af = (unsigned long)pde->data;
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return seq_list_next(v, &xt[af].match, pos);
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}
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static void xt_match_seq_stop(struct seq_file *seq, void *v)
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{
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struct proc_dir_entry *pde = seq->private;
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u_int16_t af = (unsigned long)pde->data;
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mutex_unlock(&xt[af].mutex);
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}
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static int xt_match_seq_show(struct seq_file *seq, void *v)
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{
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struct xt_match *match = list_entry(v, struct xt_match, list);
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if (strlen(match->name))
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return seq_printf(seq, "%s\n", match->name);
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else
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return 0;
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}
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static const struct seq_operations xt_match_seq_ops = {
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.start = xt_match_seq_start,
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.next = xt_match_seq_next,
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.stop = xt_match_seq_stop,
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.show = xt_match_seq_show,
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};
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static int xt_match_open(struct inode *inode, struct file *file)
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{
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int ret;
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ret = seq_open(file, &xt_match_seq_ops);
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if (!ret) {
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struct seq_file *seq = file->private_data;
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seq->private = PDE(inode);
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}
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return ret;
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}
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static const struct file_operations xt_match_ops = {
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.owner = THIS_MODULE,
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.open = xt_match_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release,
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};
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static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)
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{
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struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
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u_int16_t af = (unsigned long)pde->data;
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mutex_lock(&xt[af].mutex);
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return seq_list_start(&xt[af].target, *pos);
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}
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static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *pos)
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{
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struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
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u_int16_t af = (unsigned long)pde->data;
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return seq_list_next(v, &xt[af].target, pos);
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}
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static void xt_target_seq_stop(struct seq_file *seq, void *v)
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{
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struct proc_dir_entry *pde = seq->private;
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u_int16_t af = (unsigned long)pde->data;
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mutex_unlock(&xt[af].mutex);
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}
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static int xt_target_seq_show(struct seq_file *seq, void *v)
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{
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struct xt_target *target = list_entry(v, struct xt_target, list);
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if (strlen(target->name))
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return seq_printf(seq, "%s\n", target->name);
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else
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return 0;
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}
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static const struct seq_operations xt_target_seq_ops = {
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.start = xt_target_seq_start,
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.next = xt_target_seq_next,
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.stop = xt_target_seq_stop,
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.show = xt_target_seq_show,
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};
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static int xt_target_open(struct inode *inode, struct file *file)
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{
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int ret;
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ret = seq_open(file, &xt_target_seq_ops);
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if (!ret) {
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struct seq_file *seq = file->private_data;
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seq->private = PDE(inode);
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}
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return ret;
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}
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static const struct file_operations xt_target_ops = {
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.owner = THIS_MODULE,
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.open = xt_target_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = seq_release,
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@ -869,25 +929,25 @@ int xt_proto_init(int af)
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#ifdef CONFIG_PROC_FS
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strlcpy(buf, xt_prefix[af], sizeof(buf));
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strlcat(buf, FORMAT_TABLES, sizeof(buf));
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proc = proc_net_fops_create(&init_net, buf, 0440, &xt_file_ops);
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proc = proc_net_fops_create(&init_net, buf, 0440, &xt_table_ops);
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if (!proc)
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goto out;
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proc->data = (void *) ((unsigned long) af | (TABLE << 16));
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proc->data = (void *)(unsigned long)af;
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strlcpy(buf, xt_prefix[af], sizeof(buf));
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strlcat(buf, FORMAT_MATCHES, sizeof(buf));
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proc = proc_net_fops_create(&init_net, buf, 0440, &xt_file_ops);
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proc = proc_net_fops_create(&init_net, buf, 0440, &xt_match_ops);
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if (!proc)
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goto out_remove_tables;
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proc->data = (void *) ((unsigned long) af | (MATCH << 16));
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proc->data = (void *)(unsigned long)af;
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strlcpy(buf, xt_prefix[af], sizeof(buf));
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strlcat(buf, FORMAT_TARGETS, sizeof(buf));
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proc = proc_net_fops_create(&init_net, buf, 0440, &xt_file_ops);
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proc = proc_net_fops_create(&init_net, buf, 0440, &xt_target_ops);
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if (!proc)
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goto out_remove_matches;
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proc->data = (void *) ((unsigned long) af | (TARGET << 16));
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proc->data = (void *)(unsigned long)af;
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#endif
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return 0;
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