7e9c6eeb13
The netfilter subsystem only supports a handful of protocols (much less than PF_*) and even non-PF protocols like ARP and pseudo-protocols like PF_BRIDGE. By creating NFPROTO_*, we can earn a few memory savings on arrays that previously were always PF_MAX-sized and keep the pseudo-protocols to ourselves. Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: Patrick McHardy <kaber@trash.net>
173 lines
3.5 KiB
C
173 lines
3.5 KiB
C
#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/proc_fs.h>
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#include <linux/skbuff.h>
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#include <linux/netfilter.h>
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#include <linux/seq_file.h>
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#include <net/protocol.h>
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#include <net/netfilter/nf_log.h>
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#include "nf_internals.h"
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/* Internal logging interface, which relies on the real
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LOG target modules */
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#define NF_LOG_PREFIXLEN 128
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static const struct nf_logger *nf_loggers[NFPROTO_NUMPROTO] __read_mostly;
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static DEFINE_MUTEX(nf_log_mutex);
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/* return EBUSY if somebody else is registered, EEXIST if the same logger
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* is registred, 0 on success. */
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int nf_log_register(u_int8_t pf, const struct nf_logger *logger)
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{
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int ret;
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if (pf >= ARRAY_SIZE(nf_loggers))
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return -EINVAL;
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/* Any setup of logging members must be done before
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* substituting pointer. */
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ret = mutex_lock_interruptible(&nf_log_mutex);
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if (ret < 0)
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return ret;
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if (!nf_loggers[pf])
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rcu_assign_pointer(nf_loggers[pf], logger);
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else if (nf_loggers[pf] == logger)
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ret = -EEXIST;
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else
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ret = -EBUSY;
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mutex_unlock(&nf_log_mutex);
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return ret;
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}
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EXPORT_SYMBOL(nf_log_register);
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void nf_log_unregister_pf(u_int8_t pf)
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{
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if (pf >= ARRAY_SIZE(nf_loggers))
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return;
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mutex_lock(&nf_log_mutex);
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rcu_assign_pointer(nf_loggers[pf], NULL);
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mutex_unlock(&nf_log_mutex);
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/* Give time to concurrent readers. */
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synchronize_rcu();
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}
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EXPORT_SYMBOL(nf_log_unregister_pf);
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void nf_log_unregister(const struct nf_logger *logger)
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{
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int i;
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mutex_lock(&nf_log_mutex);
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for (i = 0; i < ARRAY_SIZE(nf_loggers); i++) {
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if (nf_loggers[i] == logger)
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rcu_assign_pointer(nf_loggers[i], NULL);
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}
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mutex_unlock(&nf_log_mutex);
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synchronize_rcu();
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}
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EXPORT_SYMBOL(nf_log_unregister);
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void nf_log_packet(u_int8_t pf,
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unsigned int hooknum,
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const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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const struct nf_loginfo *loginfo,
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const char *fmt, ...)
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{
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va_list args;
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char prefix[NF_LOG_PREFIXLEN];
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const struct nf_logger *logger;
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rcu_read_lock();
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logger = rcu_dereference(nf_loggers[pf]);
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if (logger) {
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va_start(args, fmt);
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vsnprintf(prefix, sizeof(prefix), fmt, args);
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va_end(args);
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logger->logfn(pf, hooknum, skb, in, out, loginfo, prefix);
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}
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rcu_read_unlock();
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}
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EXPORT_SYMBOL(nf_log_packet);
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#ifdef CONFIG_PROC_FS
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static void *seq_start(struct seq_file *seq, loff_t *pos)
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__acquires(RCU)
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{
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rcu_read_lock();
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if (*pos >= ARRAY_SIZE(nf_loggers))
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return NULL;
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return pos;
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}
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static void *seq_next(struct seq_file *s, void *v, loff_t *pos)
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{
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(*pos)++;
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if (*pos >= ARRAY_SIZE(nf_loggers))
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return NULL;
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return pos;
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}
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static void seq_stop(struct seq_file *s, void *v)
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__releases(RCU)
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{
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rcu_read_unlock();
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}
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static int seq_show(struct seq_file *s, void *v)
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{
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loff_t *pos = v;
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const struct nf_logger *logger;
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logger = rcu_dereference(nf_loggers[*pos]);
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if (!logger)
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return seq_printf(s, "%2lld NONE\n", *pos);
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return seq_printf(s, "%2lld %s\n", *pos, logger->name);
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}
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static const struct seq_operations nflog_seq_ops = {
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.start = seq_start,
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.next = seq_next,
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.stop = seq_stop,
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.show = seq_show,
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};
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static int nflog_open(struct inode *inode, struct file *file)
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{
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return seq_open(file, &nflog_seq_ops);
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}
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static const struct file_operations nflog_file_ops = {
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.owner = THIS_MODULE,
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.open = nflog_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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#endif /* PROC_FS */
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int __init netfilter_log_init(void)
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{
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#ifdef CONFIG_PROC_FS
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if (!proc_create("nf_log", S_IRUGO,
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proc_net_netfilter, &nflog_file_ops))
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return -1;
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#endif
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return 0;
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}
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