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.
Signed-off-by: Eric Leblond <eric@xxxxxx>
---
include/linux/sysctl.h | 1 +
net/netfilter/nf_log.c | 91 +++++++++++++++++++++++++++++++++++++++++++++--
2 files changed, 88 insertions(+), 4 deletions(-)
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 39d471d..aa11b1c 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -335,6 +335,7 @@ enum
NET_NF_CONNTRACK_FRAG6_LOW_THRESH=30,
NET_NF_CONNTRACK_FRAG6_HIGH_THRESH=31,
NET_NF_CONNTRACK_CHECKSUM=32,
+ NET_NF_LOG=33,
};
/* /proc/sys/net/ipv4 */
diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index fc1deca..d4b5259 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -14,23 +14,34 @@
LOG target modules */
#define NF_LOG_PREFIXLEN 128
-#define NFLOGGER_NAME_LEN 12
+#define NFLOGGER_NAME_LEN 24
static const struct nf_logger *nf_loggers[NFPROTO_NUMPROTO] __read_mostly;
static struct list_head nf_loggers_l[NFPROTO_NUMPROTO] __read_mostly;
static DEFINE_SPINLOCK(nf_log_lock);
-static struct nf_logger *__find_logger(int pf, const char *str_logger)
+static struct nf_logger *__find_logger_n(int pf, const char *str_logger, size_t len)
{
struct nf_logger *t;
- list_for_each_entry(t, &nf_loggers_l[pf], list[pf])
- if (!strnicmp(str_logger, t->name, NFLOGGER_NAME_LEN))
+ if (len > NFLOGGER_NAME_LEN)
+ return NULL;
+
+ list_for_each_entry(t, &nf_loggers_l[pf], list[pf]) {
+ if ((len != NFLOGGER_NAME_LEN) && (strlen(t->name) != len))
+ continue;
+ if (!strnicmp(str_logger, t->name, len))
return t;
+ }
return NULL;
}
+static struct nf_logger *__find_logger(int pf, const char *str_logger)
+{
+ return __find_logger_n(pf, str_logger, NFLOGGER_NAME_LEN);
+}
+
/* return EEXIST if the same logger is registred, 0 on success. */
int nf_log_register(u_int8_t pf, struct nf_logger *logger)
{
@@ -221,16 +232,88 @@ 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 = NET_NF_LOG, },
+ { }
+};
+
+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;
+ char ln_name[NFLOGGER_NAME_LEN];
+
+ rcu_read_lock();
+ if (write) {
+ logger = __find_logger_n(table->ctl_name, buffer, *lenp -1);
+ if (logger == NULL) {
+ rcu_read_unlock();
+ return -EINVAL;
+ }
+ r = nf_log_bind_pf(table->ctl_name, logger);
+ } else {
+ logger = rcu_dereference(nf_loggers[table->ctl_name]);
+ if (! logger)
+ table->data = "NONE";
+ else {
+ memcpy(ln_name, logger->name, NFLOGGER_NAME_LEN);
+ table->data = ln_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 = i;
+ 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_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)
{
int i;
+
#ifdef CONFIG_PROC_FS
if (!proc_create("nf_log", S_IRUGO,
proc_net_netfilter, &nflog_file_ops))
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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