| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/module.h> |
| #include <linux/proc_fs.h> |
| #include <linux/skbuff.h> |
| #include <linux/netfilter.h> |
| #include <linux/seq_file.h> |
| #include <net/protocol.h> |
| #include <net/netfilter/nf_log.h> |
| |
| #include "nf_internals.h" |
| |
| /* Internal logging interface, which relies on the real |
| LOG target modules */ |
| |
| #define NF_LOG_PREFIXLEN 128 |
| |
| static const struct nf_logger *nf_loggers[NFPROTO_NUMPROTO] __read_mostly; |
| static struct list_head nf_loggers_l[NFPROTO_NUMPROTO] __read_mostly; |
| static DEFINE_MUTEX(nf_log_mutex); |
| |
| static struct nf_logger *__find_logger(int pf, const char *str_logger) |
| { |
| struct nf_logger *t; |
| |
| list_for_each_entry(t, &nf_loggers_l[pf], list[pf]) { |
| if (!strnicmp(str_logger, t->name, strlen(t->name))) |
| return t; |
| } |
| |
| return NULL; |
| } |
| |
| /* return EEXIST if the same logger is registred, 0 on success. */ |
| int nf_log_register(u_int8_t pf, struct nf_logger *logger) |
| { |
| const struct nf_logger *llog; |
| |
| if (pf >= ARRAY_SIZE(nf_loggers)) |
| return -EINVAL; |
| |
| mutex_lock(&nf_log_mutex); |
| |
| if (pf == NFPROTO_UNSPEC) { |
| int i; |
| for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) |
| list_add_tail(&(logger->list[i]), &(nf_loggers_l[i])); |
| } else { |
| /* register at end of list to honor first register win */ |
| list_add_tail(&logger->list[pf], &nf_loggers_l[pf]); |
| llog = rcu_dereference(nf_loggers[pf]); |
| if (llog == NULL) |
| rcu_assign_pointer(nf_loggers[pf], logger); |
| } |
| |
| mutex_unlock(&nf_log_mutex); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(nf_log_register); |
| |
| void nf_log_unregister(struct nf_logger *logger) |
| { |
| const struct nf_logger *c_logger; |
| int i; |
| |
| mutex_lock(&nf_log_mutex); |
| for (i = 0; i < ARRAY_SIZE(nf_loggers); i++) { |
| c_logger = rcu_dereference(nf_loggers[i]); |
| if (c_logger == logger) |
| rcu_assign_pointer(nf_loggers[i], NULL); |
| list_del(&logger->list[i]); |
| } |
| mutex_unlock(&nf_log_mutex); |
| |
| synchronize_rcu(); |
| } |
| EXPORT_SYMBOL(nf_log_unregister); |
| |
| int nf_log_bind_pf(u_int8_t pf, const struct nf_logger *logger) |
| { |
| mutex_lock(&nf_log_mutex); |
| if (__find_logger(pf, logger->name) == NULL) { |
| mutex_unlock(&nf_log_mutex); |
| return -ENOENT; |
| } |
| rcu_assign_pointer(nf_loggers[pf], logger); |
| mutex_unlock(&nf_log_mutex); |
| return 0; |
| } |
| EXPORT_SYMBOL(nf_log_bind_pf); |
| |
| void nf_log_unbind_pf(u_int8_t pf) |
| { |
| mutex_lock(&nf_log_mutex); |
| rcu_assign_pointer(nf_loggers[pf], NULL); |
| mutex_unlock(&nf_log_mutex); |
| } |
| EXPORT_SYMBOL(nf_log_unbind_pf); |
| |
| void nf_log_packet(u_int8_t pf, |
| unsigned int hooknum, |
| const struct sk_buff *skb, |
| const struct net_device *in, |
| const struct net_device *out, |
| const struct nf_loginfo *loginfo, |
| const char *fmt, ...) |
| { |
| va_list args; |
| char prefix[NF_LOG_PREFIXLEN]; |
| const struct nf_logger *logger; |
| |
| rcu_read_lock(); |
| logger = rcu_dereference(nf_loggers[pf]); |
| if (logger) { |
| va_start(args, fmt); |
| vsnprintf(prefix, sizeof(prefix), fmt, args); |
| va_end(args); |
| logger->logfn(pf, hooknum, skb, in, out, loginfo, prefix); |
| } |
| rcu_read_unlock(); |
| } |
| EXPORT_SYMBOL(nf_log_packet); |
| |
| #ifdef CONFIG_PROC_FS |
| static void *seq_start(struct seq_file *seq, loff_t *pos) |
| __acquires(RCU) |
| { |
| rcu_read_lock(); |
| |
| if (*pos >= ARRAY_SIZE(nf_loggers)) |
| return NULL; |
| |
| return pos; |
| } |
| |
| static void *seq_next(struct seq_file *s, void *v, loff_t *pos) |
| { |
| (*pos)++; |
| |
| if (*pos >= ARRAY_SIZE(nf_loggers)) |
| return NULL; |
| |
| return pos; |
| } |
| |
| static void seq_stop(struct seq_file *s, void *v) |
| __releases(RCU) |
| { |
| rcu_read_unlock(); |
| } |
| |
| static int seq_show(struct seq_file *s, void *v) |
| { |
| loff_t *pos = v; |
| const struct nf_logger *logger; |
| struct nf_logger *t; |
| int ret; |
| |
| logger = rcu_dereference(nf_loggers[*pos]); |
| |
| if (!logger) |
| ret = seq_printf(s, "%2lld NONE (", *pos); |
| else |
| ret = seq_printf(s, "%2lld %s (", *pos, logger->name); |
| |
| if (ret < 0) |
| return ret; |
| |
| mutex_lock(&nf_log_mutex); |
| list_for_each_entry(t, &nf_loggers_l[*pos], list[*pos]) { |
| ret = seq_printf(s, "%s", t->name); |
| if (ret < 0) { |
| mutex_unlock(&nf_log_mutex); |
| return ret; |
| } |
| if (&t->list[*pos] != nf_loggers_l[*pos].prev) { |
| ret = seq_printf(s, ","); |
| if (ret < 0) { |
| mutex_unlock(&nf_log_mutex); |
| return ret; |
| } |
| } |
| } |
| mutex_unlock(&nf_log_mutex); |
| |
| return seq_printf(s, ")\n"); |
| } |
| |
| static const struct seq_operations nflog_seq_ops = { |
| .start = seq_start, |
| .next = seq_next, |
| .stop = seq_stop, |
| .show = seq_show, |
| }; |
| |
| static int nflog_open(struct inode *inode, struct file *file) |
| { |
| return seq_open(file, &nflog_seq_ops); |
| } |
| |
| static const struct file_operations nflog_file_ops = { |
| .owner = THIS_MODULE, |
| .open = nflog_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release, |
| }; |
| |
| #endif /* PROC_FS */ |
| |
| |
| int __init netfilter_log_init(void) |
| { |
| int i; |
| #ifdef CONFIG_PROC_FS |
| if (!proc_create("nf_log", S_IRUGO, |
| proc_net_netfilter, &nflog_file_ops)) |
| return -1; |
| #endif |
| |
| for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) |
| INIT_LIST_HEAD(&(nf_loggers_l[i])); |
| |
| return 0; |
| } |