diff options
Diffstat (limited to 'net/netfilter')
-rw-r--r-- | net/netfilter/x_tables.c | 199 |
1 files changed, 142 insertions, 57 deletions
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index bfbf521f6ea..5baccfa5a0d 100644 --- 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" |