This patchs adds support of modification of the used logger via sysctl.
It can be used to change the logger to module that can not use the bind
operation (ipt_LOG and ipt_ULOG). For this purpose, it creates a
directory /proc/sys/net/netfilter/nf_log which contains a file
per-protocol. The content of the file is the name current logger (NONE if
not set) and a logger can be setup by simply echoing its name to the file.
By echoing "NONE" to a /proc/sys/net/netfilter/nf_log/PROTO file, the
logger corresponding to this PROTO is set to NULL.
Signed-off-by: Eric Leblond <eric@xxxxxx>
---
net/netfilter/nf_log.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 76 insertions(+), 0 deletions(-)
diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index efda4ba..87f1d49 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -14,6 +14,7 @@
LOG target modules */
#define NF_LOG_PREFIXLEN 128
+#define NFLOGGER_NAME_LEN 64
static const struct nf_logger *nf_loggers[NFPROTO_NUMPROTO] __read_mostly;
static struct list_head nf_loggers_l[NFPROTO_NUMPROTO] __read_mostly;
@@ -209,6 +210,78 @@ static const struct file_operations nflog_file_ops = {
#endif /* PROC_FS */
+#ifdef CONFIG_SYSCTL
+struct ctl_path nf_log_sysctl_path[] = {
+ { .procname = "net", .ctl_name = CTL_NET, },
+ { .procname = "netfilter", .ctl_name = NET_NETFILTER, },
+ { .procname = "nf_log", .ctl_name = CTL_UNNUMBERED, },
+ { }
+};
+
+static struct ctl_table nf_log_sysctl_table[NFPROTO_NUMPROTO+1];
+static struct ctl_table_header *nf_log_dir_header;
+
+static int nf_log_proc_dostring(ctl_table *table, int write, struct file *filp,
+ void *buffer, size_t *lenp, loff_t *ppos)
+{
+ const struct nf_logger *logger;
+ int r = 0;
+ int tindex = (unsigned long) table->extra1;
+
+ if (write) {
+ if (!strnicmp(buffer, "NONE", *lenp - 1)) {
+ return nf_log_unbind_pf(tindex);
+ }
+ mutex_lock(&nf_log_mutex);
+ logger = __find_logger(tindex, buffer);
+ if (logger == NULL) {
+ mutex_unlock(&nf_log_mutex);
+ return -EINVAL;
+ }
+ rcu_assign_pointer(nf_loggers[tindex], logger);
+ mutex_unlock(&nf_log_mutex);
+ } else {
+ rcu_read_lock();
+ logger = rcu_dereference(nf_loggers[tindex]);
+ if (! logger)
+ table->data = "NONE";
+ else
+ table->data = logger->name;
+ r = proc_dostring(table, write, filp, buffer, lenp, ppos);
+ rcu_read_unlock();
+ }
+
+ return r;
+}
+
+static int netfilter_log_sysctl_init(void)
+{
+ int i;
+
+ for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++) {
+ char *pr_name = kmalloc(3, GFP_KERNEL);
+ /* FIXME free at deinit but there is currently no deinit */
+ snprintf(pr_name, 3, "%d", i);
+ nf_log_sysctl_table[i].ctl_name = CTL_UNNUMBERED;
+ nf_log_sysctl_table[i].procname = pr_name;
+ nf_log_sysctl_table[i].data = NULL;
+ nf_log_sysctl_table[i].maxlen = NFLOGGER_NAME_LEN * sizeof(char);
+ nf_log_sysctl_table[i].mode = 0644;
+ nf_log_sysctl_table[i].proc_handler = nf_log_proc_dostring;
+ nf_log_sysctl_table[i].extra1 = (void *)(unsigned long) i;
+ }
+
+ nf_log_dir_header = register_sysctl_paths(nf_log_sysctl_path,
+ nf_log_sysctl_table);
+
+ return 0;
+}
+#else
+static int netfilter_log_sysctl_init(void)
+{
+ return 0;
+}
+#endif /* CONFIG_SYSCTL */
int __init netfilter_log_init(void)
{
@@ -219,6 +292,9 @@ int __init netfilter_log_init(void)
return -1;
#endif
+ if (netfilter_log_sysctl_init() < 0)
+ return -1;
+
for (i = NFPROTO_UNSPEC; i < NFPROTO_NUMPROTO; i++)
INIT_LIST_HEAD(&(nf_loggers_l[i]));
--
1.5.6.3
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