netfilter: make proc/net/ip* print names from foreign NFPROTO

When extensions were moved to the NFPROTO_UNSPEC wildcard in
ab4f21e6fb1c09b13c4c3cb8357babe8223471bd, they disappeared from the
procfs files.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index bfbf521f6ea5a4bba99387781d9033cba0ff30a1..5baccfa5a0deb53657424ffd9b6c78713b57a8a1 100644 (file)
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -827,59 +827,143 @@ static const struct file_operations xt_table_ops = {
        .release = seq_release_net,
 };
 
-static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
+/*
+ * Traverse state for ip{,6}_{tables,matches} for helping crossing
+ * the multi-AF mutexes.
+ */
+struct nf_mttg_trav {
+       struct list_head *head, *curr;
+       uint8_t class, nfproto;
+};
+
+enum {
+       MTTG_TRAV_INIT,
+       MTTG_TRAV_NFP_UNSPEC,
+       MTTG_TRAV_NFP_SPEC,
+       MTTG_TRAV_DONE,
+};
+
+static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos,
+    bool is_target)
 {
-       struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
-       u_int16_t af = (unsigned long)pde->data;
+       static const uint8_t next_class[] = {
+               [MTTG_TRAV_NFP_UNSPEC] = MTTG_TRAV_NFP_SPEC,
+               [MTTG_TRAV_NFP_SPEC]   = MTTG_TRAV_DONE,
+       };
+       struct nf_mttg_trav *trav = seq->private;
+
+       switch (trav->class) {
+       case MTTG_TRAV_INIT:
+               trav->class = MTTG_TRAV_NFP_UNSPEC;
+               mutex_lock(&xt[NFPROTO_UNSPEC].mutex);
+               trav->head = trav->curr = is_target ?
+                       &xt[NFPROTO_UNSPEC].target : &xt[NFPROTO_UNSPEC].match;
+               break;
+       case MTTG_TRAV_NFP_UNSPEC:
+               trav->curr = trav->curr->next;
+               if (trav->curr != trav->head)
+                       break;
+               mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
+               mutex_lock(&xt[trav->nfproto].mutex);
+               trav->head = trav->curr = is_target ?
+                       &xt[trav->nfproto].target : &xt[trav->nfproto].match;
+               trav->class = next_class[trav->class];
+               break;
+       case MTTG_TRAV_NFP_SPEC:
+               trav->curr = trav->curr->next;
+               if (trav->curr != trav->head)
+                       break;
+               /* fallthru, _stop will unlock */
+       default:
+               return NULL;
+       }
 
-       mutex_lock(&xt[af].mutex);
-       return seq_list_start(&xt[af].match, *pos);
+       if (ppos != NULL)
+               ++*ppos;
+       return trav;
 }
 
-static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
+    bool is_target)
 {
-       struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
-       u_int16_t af = (unsigned long)pde->data;
+       struct nf_mttg_trav *trav = seq->private;
+       unsigned int j;
 
-       return seq_list_next(v, &xt[af].match, pos);
+       trav->class = MTTG_TRAV_INIT;
+       for (j = 0; j < *pos; ++j)
+               if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
+                       return NULL;
+       return trav;
 }
 
-static void xt_match_seq_stop(struct seq_file *seq, void *v)
+static void xt_mttg_seq_stop(struct seq_file *seq, void *v)
 {
-       struct proc_dir_entry *pde = seq->private;
-       u_int16_t af = (unsigned long)pde->data;
+       struct nf_mttg_trav *trav = seq->private;
+
+       switch (trav->class) {
+       case MTTG_TRAV_NFP_UNSPEC:
+               mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
+               break;
+       case MTTG_TRAV_NFP_SPEC:
+               mutex_unlock(&xt[trav->nfproto].mutex);
+               break;
+       }
+}
 
-       mutex_unlock(&xt[af].mutex);
+static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
+{
+       return xt_mttg_seq_start(seq, pos, false);
 }
 
-static int xt_match_seq_show(struct seq_file *seq, void *v)
+static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
 {
-       struct xt_match *match = list_entry(v, struct xt_match, list);
+       return xt_mttg_seq_next(seq, v, ppos, false);
+}
 
-       if (strlen(match->name))
-               return seq_printf(seq, "%s\n", match->name);
-       else
-               return 0;
+static int xt_match_seq_show(struct seq_file *seq, void *v)
+{
+       const struct nf_mttg_trav *trav = seq->private;
+       const struct xt_match *match;
+
+       switch (trav->class) {
+       case MTTG_TRAV_NFP_UNSPEC:
+       case MTTG_TRAV_NFP_SPEC:
+               if (trav->curr == trav->head)
+                       return 0;
+               match = list_entry(trav->curr, struct xt_match, list);
+               return (*match->name == '\0') ? 0 :
+                      seq_printf(seq, "%s\n", match->name);
+       }
+       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,
+       .stop   = xt_mttg_seq_stop,
        .show   = xt_match_seq_show,
 };
 
 static int xt_match_open(struct inode *inode, struct file *file)
 {
+       struct seq_file *seq;
+       struct nf_mttg_trav *trav;
        int ret;
 
-       ret = seq_open(file, &xt_match_seq_ops);
-       if (!ret) {
-               struct seq_file *seq = file->private_data;
+       trav = kmalloc(sizeof(*trav), GFP_KERNEL);
+       if (trav == NULL)
+               return -ENOMEM;
 
-               seq->private = PDE(inode);
+       ret = seq_open(file, &xt_match_seq_ops);
+       if (ret < 0) {
+               kfree(trav);
+               return ret;
        }
-       return ret;
+
+       seq = file->private_data;
+       seq->private = trav;
+       trav->nfproto = (unsigned long)PDE(inode)->data;
+       return 0;
 }
 
 static const struct file_operations xt_match_ops = {
@@ -887,62 +971,63 @@ static const struct file_operations xt_match_ops = {
        .open    = xt_match_open,
        .read    = seq_read,
        .llseek  = seq_lseek,
-       .release = seq_release,
+       .release = seq_release_private,
 };
 
 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);
+       return xt_mttg_seq_start(seq, pos, true);
 }
 
-static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
 {
-       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);
+       return xt_mttg_seq_next(seq, v, ppos, true);
 }
 
 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;
+       const struct nf_mttg_trav *trav = seq->private;
+       const struct xt_target *target;
+
+       switch (trav->class) {
+       case MTTG_TRAV_NFP_UNSPEC:
+       case MTTG_TRAV_NFP_SPEC:
+               if (trav->curr == trav->head)
+                       return 0;
+               target = list_entry(trav->curr, struct xt_target, list);
+               return (*target->name == '\0') ? 0 :
+                      seq_printf(seq, "%s\n", target->name);
+       }
+       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,
+       .stop   = xt_mttg_seq_stop,
        .show   = xt_target_seq_show,
 };
 
 static int xt_target_open(struct inode *inode, struct file *file)
 {
+       struct seq_file *seq;
+       struct nf_mttg_trav *trav;
        int ret;
 
-       ret = seq_open(file, &xt_target_seq_ops);
-       if (!ret) {
-               struct seq_file *seq = file->private_data;
+       trav = kmalloc(sizeof(*trav), GFP_KERNEL);
+       if (trav == NULL)
+               return -ENOMEM;
 
-               seq->private = PDE(inode);
+       ret = seq_open(file, &xt_target_seq_ops);
+       if (ret < 0) {
+               kfree(trav);
+               return ret;
        }
-       return ret;
+
+       seq = file->private_data;
+       seq->private = trav;
+       trav->nfproto = (unsigned long)PDE(inode)->data;
+       return 0;
 }
 
 static const struct file_operations xt_target_ops = {
@@ -950,7 +1035,7 @@ static const struct file_operations xt_target_ops = {
        .open    = xt_target_open,
        .read    = seq_read,
        .llseek  = seq_lseek,
-       .release = seq_release,
+       .release = seq_release_private,
 };
 
 #define FORMAT_TABLES  "_tables_names"