This patch modifies nf_log to use a linked list of loggers for each
protocol. This list of loggers is read and write protected with a
mutex.
This patch separates registration and binding. To be used as
logging module, a module has to register calling nf_log_register()
and to bind to a protocol it has to call nf_log_bind_pf().
This patch also converts the logging modules to the new API. For nfnetlink_log,
it simply switchs call to register functions to call to bind function and
adds a call to nf_log_register() during init. For other modules, it just
remove a const flag from the logger structure and replace it with a
__read_mostly.
Signed-off-by: Eric Leblond <eric@xxxxxx>
---
include/net/netfilter/nf_log.h | 11 ++++-
net/ipv4/netfilter/ipt_LOG.c | 2 +-
net/ipv4/netfilter/ipt_ULOG.c | 2 +-
net/ipv6/netfilter/ip6t_LOG.c | 2 +-
net/netfilter/nf_log.c | 91 ++++++++++++++++++++++++++++++++-------
net/netfilter/nfnetlink_log.c | 11 ++++-
6 files changed, 93 insertions(+), 26 deletions(-)
diff --git a/include/net/netfilter/nf_log.h b/include/net/netfilter/nf_log.h
index 7182c06..ccaa43a 100644
--- a/include/net/netfilter/nf_log.h
+++ b/include/net/netfilter/nf_log.h
@@ -1,6 +1,8 @@
#ifndef _NF_LOG_H
#define _NF_LOG_H
+#include <linux/netfilter.h>
+
/* those NF_LOG_* defines and struct nf_loginfo are legacy definitios that will
* disappear once iptables is replaced with pkttables. Please DO NOT use them
* for any new code! */
@@ -40,12 +42,15 @@ struct nf_logger {
struct module *me;
nf_logfn *logfn;
char *name;
+ struct list_head list[NFPROTO_NUMPROTO];
};
/* Function to register/unregister log function. */
-int nf_log_register(u_int8_t pf, const struct nf_logger *logger);
-void nf_log_unregister(const struct nf_logger *logger);
-void nf_log_unregister_pf(u_int8_t pf);
+int nf_log_register(u_int8_t pf, struct nf_logger *logger);
+void nf_log_unregister(struct nf_logger *logger);
+
+int nf_log_bind_pf(u_int8_t pf, const struct nf_logger *logger);
+int nf_log_unbind_pf(u_int8_t pf);
/* Calls the registered backend logging function */
void nf_log_packet(u_int8_t pf,
diff --git a/net/ipv4/netfilter/ipt_LOG.c b/net/ipv4/netfilter/ipt_LOG.c
index 27a78fb..acc44c6 100644
--- a/net/ipv4/netfilter/ipt_LOG.c
+++ b/net/ipv4/netfilter/ipt_LOG.c
@@ -464,7 +464,7 @@ static struct xt_target log_tg_reg __read_mostly = {
.me = THIS_MODULE,
};
-static const struct nf_logger ipt_log_logger ={
+static struct nf_logger ipt_log_logger __read_mostly = {
.name = "ipt_LOG",
.logfn = &ipt_log_packet,
.me = THIS_MODULE,
diff --git a/net/ipv4/netfilter/ipt_ULOG.c b/net/ipv4/netfilter/ipt_ULOG.c
index 18a2826..d32cc4b 100644
--- a/net/ipv4/netfilter/ipt_ULOG.c
+++ b/net/ipv4/netfilter/ipt_ULOG.c
@@ -379,7 +379,7 @@ static struct xt_target ulog_tg_reg __read_mostly = {
.me = THIS_MODULE,
};
-static struct nf_logger ipt_ulog_logger = {
+static struct nf_logger ipt_ulog_logger __read_mostly = {
.name = "ipt_ULOG",
.logfn = ipt_logfn,
.me = THIS_MODULE,
diff --git a/net/ipv6/netfilter/ip6t_LOG.c b/net/ipv6/netfilter/ip6t_LOG.c
index 37adf5a..7018cac 100644
--- a/net/ipv6/netfilter/ip6t_LOG.c
+++ b/net/ipv6/netfilter/ip6t_LOG.c
@@ -477,7 +477,7 @@ static struct xt_target log_tg6_reg __read_mostly = {
.me = THIS_MODULE,
};
-static const struct nf_logger ip6t_logger = {
+static struct nf_logger ip6t_logger __read_mostly = {
.name = "ip6t_LOG",
.logfn = &ip6t_log_packet,
.me = THIS_MODULE,
diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index fa8ae5d..50d34db 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -16,31 +16,55 @@
#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);
-/* return EBUSY if somebody else is registered, EEXIST if the same logger
- * is registred, 0 on success. */
-int nf_log_register(u_int8_t pf, const struct nf_logger *logger)
+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)
{
int ret;
+ const struct nf_logger *llog;
if (pf >= ARRAY_SIZE(nf_loggers))
return -EINVAL;
- /* Any setup of logging members must be done before
- * substituting pointer. */
- ret = mutex_lock_interruptible(&nf_log_mutex);
- if (ret < 0)
- return ret;
+ mutex_lock(&nf_log_mutex);
- if (!nf_loggers[pf])
- rcu_assign_pointer(nf_loggers[pf], logger);
- else if (nf_loggers[pf] == logger)
- ret = -EEXIST;
- else
- ret = -EBUSY;
+ ret = -EEXIST;
+ if (pf == NFPROTO_UNSPEC) {
+ int i;
+ for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
+ if (__find_logger(i, logger->name) == NULL) {
+ ret = 0;
+ list_add_tail(&(logger->list[i]),
+ &(nf_loggers_l[i]));
+ }
+ } else {
+ if (__find_logger(pf, logger->name) == NULL) {
+ ret = 0;
+ /* 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 ret;
}
EXPORT_SYMBOL(nf_log_register);
@@ -58,14 +82,20 @@ void nf_log_unregister_pf(u_int8_t pf)
}
EXPORT_SYMBOL(nf_log_unregister_pf);
-void nf_log_unregister(const struct nf_logger *logger)
+void nf_log_unregister(struct nf_logger *logger)
{
int i;
+ struct nf_logger *llog;
mutex_lock(&nf_log_mutex);
for (i = 0; i < ARRAY_SIZE(nf_loggers); i++) {
- if (nf_loggers[i] == logger)
- rcu_assign_pointer(nf_loggers[i], NULL);
+ llog = __find_logger(i, logger->name);
+ if (llog) {
+ const struct nf_logger *c_logger = rcu_dereference(nf_loggers[i]);
+ if (c_logger == llog)
+ rcu_assign_pointer(nf_loggers[i], NULL);
+ list_del(&(logger->list[i]));
+ }
}
mutex_unlock(&nf_log_mutex);
@@ -73,6 +103,28 @@ void nf_log_unregister(const struct nf_logger *logger)
}
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 -1;
+ }
+ rcu_assign_pointer(nf_loggers[pf], logger);
+ mutex_unlock(&nf_log_mutex);
+ return 0;
+}
+EXPORT_SYMBOL(nf_log_bind_pf);
+
+int 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);
+ return 0;
+}
+EXPORT_SYMBOL(nf_log_unbind_pf);
+
void nf_log_packet(u_int8_t pf,
unsigned int hooknum,
const struct sk_buff *skb,
@@ -163,10 +215,15 @@ static const struct file_operations nflog_file_ops = {
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;
}
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index c712e9f..42e7de9 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -693,7 +693,7 @@ nfulnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb,
return -ENOTSUPP;
}
-static const struct nf_logger nfulnl_logger = {
+static struct nf_logger nfulnl_logger __read_mostly = {
.name = "nfnetlink_log",
.logfn = &nfulnl_log_packet,
.me = THIS_MODULE,
@@ -725,9 +725,9 @@ nfulnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
/* Commands without queue context */
switch (cmd->command) {
case NFULNL_CFG_CMD_PF_BIND:
- return nf_log_register(pf, &nfulnl_logger);
+ return nf_log_bind_pf(pf, &nfulnl_logger);
case NFULNL_CFG_CMD_PF_UNBIND:
- nf_log_unregister_pf(pf);
+ nf_log_unbind_pf(pf);
return 0;
}
}
@@ -952,6 +952,11 @@ static int __init nfnetlink_log_init(void)
goto cleanup_netlink_notifier;
}
+ if ((status = nf_log_register(NFPROTO_UNSPEC, &nfulnl_logger)) < 0) {
+ printk(KERN_ERR "log: failed to register logger\n");
+ goto cleanup_netlink_notifier;
+ }
+
#ifdef CONFIG_PROC_FS
if (!proc_create("nfnetlink_log", 0440,
proc_net_netfilter, &nful_file_ops))
--
1.5.6.3
--
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