netfilter: nf_log: use an array of loggers instead of list
Now that legacy ulog targets are not available anymore in the tree, we
can have up to two possible loggers:
1) The plain text logging via kernel logging ring.
2) The nfnetlink_log infrastructure which delivers log messages
to userspace.
This patch replaces the list of loggers by an array of two pointers
per family for each possible logger and it also introduces a new field
to the nf_logger structure which indicates the position in the logger
array (based on the logger type).
This prepares a follow up patch that consolidates the nf_log_packet()
interface by allowing to specify the logger as parameter.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/include/net/netfilter/nf_log.h b/include/net/netfilter/nf_log.h
index 99eac12..06b4c6b 100644
--- a/include/net/netfilter/nf_log.h
+++ b/include/net/netfilter/nf_log.h
@@ -12,8 +12,11 @@
#define NF_LOG_UID 0x08 /* Log UID owning local socket */
#define NF_LOG_MASK 0x0f
-#define NF_LOG_TYPE_LOG 0x01
-#define NF_LOG_TYPE_ULOG 0x02
+enum nf_log_type {
+ NF_LOG_TYPE_LOG = 0,
+ NF_LOG_TYPE_ULOG,
+ NF_LOG_TYPE_MAX
+};
struct nf_loginfo {
u_int8_t type;
@@ -40,10 +43,10 @@
const char *prefix);
struct nf_logger {
- struct module *me;
- nf_logfn *logfn;
- char *name;
- struct list_head list[NFPROTO_NUMPROTO];
+ char *name;
+ enum nf_log_type type;
+ nf_logfn *logfn;
+ struct module *me;
};
/* Function to register/unregister log function. */
diff --git a/net/bridge/netfilter/ebt_log.c b/net/bridge/netfilter/ebt_log.c
index 5322a36..0577477 100644
--- a/net/bridge/netfilter/ebt_log.c
+++ b/net/bridge/netfilter/ebt_log.c
@@ -207,6 +207,7 @@
static struct nf_logger ebt_log_logger __read_mostly = {
.name = "ebt_log",
+ .type = NF_LOG_TYPE_LOG,
.logfn = &ebt_log_packet,
.me = THIS_MODULE,
};
diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index 85296d4..7a29a3a 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -16,16 +16,22 @@
#define NF_LOG_PREFIXLEN 128
#define NFLOGGER_NAME_LEN 64
-static struct list_head nf_loggers_l[NFPROTO_NUMPROTO] __read_mostly;
+static struct nf_logger __rcu *loggers[NFPROTO_NUMPROTO][NF_LOG_TYPE_MAX] __read_mostly;
static DEFINE_MUTEX(nf_log_mutex);
static struct nf_logger *__find_logger(int pf, const char *str_logger)
{
- struct nf_logger *t;
+ struct nf_logger *log;
+ int i;
- list_for_each_entry(t, &nf_loggers_l[pf], list[pf]) {
- if (!strnicmp(str_logger, t->name, strlen(t->name)))
- return t;
+ for (i = 0; i < NF_LOG_TYPE_MAX; i++) {
+ if (loggers[pf][i] == NULL)
+ continue;
+
+ log = rcu_dereference_protected(loggers[pf][i],
+ lockdep_is_held(&nf_log_mutex));
+ if (!strnicmp(str_logger, log->name, strlen(log->name)))
+ return log;
}
return NULL;
@@ -73,17 +79,14 @@
if (pf >= ARRAY_SIZE(init_net.nf.nf_loggers))
return -EINVAL;
- for (i = 0; i < ARRAY_SIZE(logger->list); i++)
- INIT_LIST_HEAD(&logger->list[i]);
-
mutex_lock(&nf_log_mutex);
if (pf == NFPROTO_UNSPEC) {
for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
- list_add_tail(&(logger->list[i]), &(nf_loggers_l[i]));
+ rcu_assign_pointer(loggers[i][logger->type], logger);
} else {
/* register at end of list to honor first register win */
- list_add_tail(&logger->list[pf], &nf_loggers_l[pf]);
+ rcu_assign_pointer(loggers[pf][logger->type], logger);
}
mutex_unlock(&nf_log_mutex);
@@ -98,7 +101,7 @@
mutex_lock(&nf_log_mutex);
for (i = 0; i < NFPROTO_NUMPROTO; i++)
- list_del(&logger->list[i]);
+ RCU_INIT_POINTER(loggers[i][logger->type], NULL);
mutex_unlock(&nf_log_mutex);
}
EXPORT_SYMBOL(nf_log_unregister);
@@ -188,8 +191,7 @@
{
loff_t *pos = v;
const struct nf_logger *logger;
- struct nf_logger *t;
- int ret;
+ int i, ret;
struct net *net = seq_file_net(s);
logger = rcu_dereference_protected(net->nf.nf_loggers[*pos],
@@ -203,11 +205,16 @@
if (ret < 0)
return ret;
- list_for_each_entry(t, &nf_loggers_l[*pos], list[*pos]) {
- ret = seq_printf(s, "%s", t->name);
+ for (i = 0; i < NF_LOG_TYPE_MAX; i++) {
+ if (loggers[*pos][i] == NULL)
+ continue;
+
+ logger = rcu_dereference_protected(loggers[*pos][i],
+ lockdep_is_held(&nf_log_mutex));
+ ret = seq_printf(s, "%s", logger->name);
if (ret < 0)
return ret;
- if (&t->list[*pos] != nf_loggers_l[*pos].prev) {
+ if (i == 0 && loggers[*pos][i + 1] != NULL) {
ret = seq_printf(s, ",");
if (ret < 0)
return ret;
@@ -389,14 +396,5 @@
int __init netfilter_log_init(void)
{
- int i, ret;
-
- ret = register_pernet_subsys(&nf_log_net_ops);
- if (ret < 0)
- return ret;
-
- for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
- INIT_LIST_HEAD(&(nf_loggers_l[i]));
-
- return 0;
+ return register_pernet_subsys(&nf_log_net_ops);
}
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index d292c8d..160bb8e 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -773,6 +773,7 @@
static struct nf_logger nfulnl_logger __read_mostly = {
.name = "nfnetlink_log",
+ .type = NF_LOG_TYPE_ULOG,
.logfn = &nfulnl_log_packet,
.me = THIS_MODULE,
};
diff --git a/net/netfilter/xt_LOG.c b/net/netfilter/xt_LOG.c
index 5ab2484..e668d97 100644
--- a/net/netfilter/xt_LOG.c
+++ b/net/netfilter/xt_LOG.c
@@ -896,6 +896,7 @@
static struct nf_logger ipt_log_logger __read_mostly = {
.name = "ipt_LOG",
+ .type = NF_LOG_TYPE_LOG,
.logfn = &ipt_log_packet,
.me = THIS_MODULE,
};
@@ -903,6 +904,7 @@
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
static struct nf_logger ip6t_log_logger __read_mostly = {
.name = "ip6t_LOG",
+ .type = NF_LOG_TYPE_LOG,
.logfn = &ip6t_log_packet,
.me = THIS_MODULE,
};