Hi,
On Mon, May 26, 2025 at 04:59:02PM +0800, Lance Yang wrote:
> diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
> index 2f666751c7e7..cdc27424f84a 100644
> --- a/net/netfilter/nf_conntrack_standalone.c
> +++ b/net/netfilter/nf_conntrack_standalone.c
> @@ -14,6 +14,7 @@
> #include <linux/sysctl.h>
> #endif
>
> +#include <net/netfilter/nf_log.h>
> #include <net/netfilter/nf_conntrack.h>
> #include <net/netfilter/nf_conntrack_core.h>
> #include <net/netfilter/nf_conntrack_l4proto.h>
> @@ -543,6 +544,29 @@ nf_conntrack_hash_sysctl(const struct ctl_table *table, int write,
> return ret;
> }
>
> +static int
> +nf_conntrack_log_invalid_sysctl(const struct ctl_table *table, int write,
> + void *buffer, size_t *lenp, loff_t *ppos)
> +{
> + int ret, i;
> +
> + ret = proc_dou8vec_minmax(table, write, buffer, lenp, ppos);
> + if (ret < 0 || !write)
> + return ret;
> +
> + if (*(u8 *)table->data == 0)
> + return ret;
What is this table->data check for? I don't find any similar idiom
like this in the existing proc_dou8vec_minmax() callers.
> +
> + /* Load nf_log_syslog only if no logger is currently registered */
> + for (i = 0; i < NFPROTO_NUMPROTO; i++) {
> + if (nf_log_is_registered(i))
> + return ret;
> + }
> + request_module("%s", "nf_log_syslog");
> +
> + return ret;
> +}
> +
> static struct ctl_table_header *nf_ct_netfilter_header;
>
> enum nf_ct_sysctl_index {
> @@ -649,7 +673,7 @@ static struct ctl_table nf_ct_sysctl_table[] = {
> .data = &init_net.ct.sysctl_log_invalid,
> .maxlen = sizeof(u8),
> .mode = 0644,
> - .proc_handler = proc_dou8vec_minmax,
> + .proc_handler = nf_conntrack_log_invalid_sysctl,
> },
> [NF_SYSCTL_CT_EXPECT_MAX] = {
> .procname = "nf_conntrack_expect_max",
> diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
> index 6dd0de33eebd..c7dd5019a89d 100644
> --- a/net/netfilter/nf_log.c
> +++ b/net/netfilter/nf_log.c
> @@ -125,6 +125,33 @@ void nf_log_unregister(struct nf_logger *logger)
> }
> EXPORT_SYMBOL(nf_log_unregister);
>
> +/**
> + * nf_log_is_registered - Check if any logger is registered for a given
> + * protocol family.
> + *
> + * @pf: Protocol family
> + *
> + * Returns: true if at least one logger is active for @pf, false otherwise.
> + */
> +bool nf_log_is_registered(u_int8_t pf)
> +{
> + int i;
> +
> + /* Out of bounds. */
No need for this comment, please remove it.
> + if (pf >= NFPROTO_NUMPROTO) {
> + WARN_ON_ONCE(1);
> + return false;
> + }
