Hello, In net/core/dev.c I found this lines in function dev_ifsioc: case SIOCADDMULTI: if (!dev->set_multicast_list || ifr->ifr_hwaddr.sa_family != AF_UNSPEC) return -EINVAL; if (!netif_device_present(dev)) return -ENODEV; --> dev_mc_add(dev, ifr->ifr_hwaddr.sa_data, dev->addr_len, 1); --> return 0; case SIOCDELMULTI: if (!dev->set_multicast_list || ifr->ifr_hwaddr.sa_family != AF_UNSPEC) return -EINVAL; if (!netif_device_present(dev)) return -ENODEV; --> dev_mc_delete(dev, ifr->ifr_hwaddr.sa_data, dev->addr_len, 1); --> return 0; As I understand functions dev_mc_add and dev_mc_delete return values including different errors. But this values are not checked in this code. This causes for example returning success when trying to delete a non-exiting muticast address. It could be fixed this way : case SIOCADDMULTI: if (!dev->set_multicast_list || ifr->ifr_hwaddr.sa_family != AF_UNSPEC) return -EINVAL; if (!netif_device_present(dev)) return -ENODEV; --> return dev_mc_add(dev, ifr->ifr_hwaddr.sa_data, dev->addr_len, 1); case SIOCDELMULTI: if (!dev->set_multicast_list || ifr->ifr_hwaddr.sa_family != AF_UNSPEC) return -EINVAL; if (!netif_device_present(dev)) return -ENODEV; --> return dev_mc_delete(dev, ifr->ifr_hwaddr.sa_data, dev->addr_len, 1); There are a few more functions in kernel (with dev_mc_add and dev_mc_delete) where you can find similar code. If the described situation is really error then this fuctions should be fixed too. I used 2.6.2 and 2.4.18 kernels. Thanks for your attention. - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
