sd-netlink: introduce sd_netlink_attach_filter()

yuwata · yuwata · commit dc317a9aed3e · 2021-10-19T20:41:09.000+09:00
diff --git a/src/libsystemd/sd-netlink/sd-netlink.c b/src/libsystemd/sd-netlink/sd-netlink.c
@@ -1023,3 +1023,18 @@ int sd_netlink_add_match(
         return netlink_add_match_internal(rtnl, ret_slot, groups, n_groups, type, 0, callback,
                                           destroy_callback, userdata, description);
 }
+
+int sd_netlink_attach_filter(sd_netlink *nl, size_t len, struct sock_filter *filter) {
+        assert_return(nl, -EINVAL);
+        assert_return(len == 0 || filter, -EINVAL);
+
+        if (setsockopt(nl->fd, SOL_SOCKET,
+                       len == 0 ? SO_DETACH_FILTER : SO_ATTACH_FILTER,
+                       &(struct sock_fprog) {
+                               .len = len,
+                               .filter = filter,
+                       }, sizeof(struct sock_fprog)) < 0)
+                return -errno;
+
+        return 0;
+}
diff --git a/src/systemd/sd-netlink.h b/src/systemd/sd-netlink.h
@@ -21,6 +21,7 @@
 #include <inttypes.h>
 #include <net/ethernet.h>
 #include <netinet/in.h>
+#include <linux/filter.h>
 #include <linux/neighbour.h>
 #include <linux/rtnetlink.h>
 
@@ -68,6 +69,7 @@ int sd_netlink_add_match(sd_netlink *nl, sd_netlink_slot **ret_slot, uint16_t ma
 
 int sd_netlink_attach_event(sd_netlink *nl, sd_event *e, int64_t priority);
 int sd_netlink_detach_event(sd_netlink *nl);
+int sd_netlink_attach_filter(sd_netlink *nl, size_t len, struct sock_filter *filter);
 
 /* message */
 int sd_netlink_message_append_string(sd_netlink_message *m, unsigned short type, const char *data);
