From 025d93d148d46bedb26905975f5d9c83d280b46e Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Thu, 31 Jan 2008 04:48:54 -0800 Subject: [PATCH] [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 Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/netfilter/x_tables.c | 230 ++++++++++++++++++++++++--------------- 1 file changed, 145 insertions(+), 85 deletions(-) diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index cd78fc853a5d..89e322d3b361 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -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--; - } - return pos ? NULL : head; -} - -static struct list_head *type2list(u_int16_t af, u_int16_t type) -{ - struct list_head *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; - } +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 list; + return seq_list_next(v, &init_net.xt.tables[af], pos); } -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; + struct proc_dir_entry *pde = seq->private; + 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_table_seq_show(struct seq_file *seq, void *v) +{ + struct xt_table *table = list_entry(v, struct xt_table, list); - if (mutex_lock_interruptible(&xt[af].mutex) != 0) - return NULL; + if (strlen(table->name)) + return seq_printf(seq, "%s\n", table->name); + else + return 0; +} - return xt_get_idx(list, seq, *pos); +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_next(struct seq_file *seq, void *v, 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 = seq->private; - u_int16_t af = (unsigned long)pde->data & 0xffff; - u_int16_t type = (unsigned long)pde->data >> 16; - struct list_head *list; + struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private; + u_int16_t af = (unsigned long)pde->data; - if (af >= NPROTO) - return NULL; + mutex_lock(&xt[af].mutex); + return seq_list_start(&xt[af].match, *pos); +} - list = type2list(af, type); - if (!list) - 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; - (*pos)++; - return xt_get_idx(list, seq, *pos); + return seq_list_next(v, &xt[af].match, pos); } -static void xt_tgt_seq_stop(struct seq_file *seq, void *v) +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 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_match_seq_show(struct seq_file *seq, void *v) { - char *name = (char *)v + sizeof(struct list_head); + struct xt_match *match = list_entry(v, struct xt_match, list); - if (strlen(name)) - return seq_printf(seq, "%s\n", name); + if (strlen(match->name)) + return seq_printf(seq, "%s\n", match->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_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_tgt_open(struct inode *inode, struct file *file) +static int xt_match_open(struct inode *inode, struct file *file) { int ret; - ret = seq_open(file, &xt_tgt_seq_ops); + ret = seq_open(file, &xt_match_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_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_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; -- 2.34.1