static int receive_filter(VirtIONet *n, const uint8_t *buf, int size) { static const uint8_t bcast[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; static const uint8_t vlan[] = {0x81, 0x00}; uint8_t *ptr = (uint8_t *)buf; int i; if (n->promisc) return 1; if (!memcmp(&ptr[12], vlan, sizeof(vlan))) { int vid = be16_to_cpup((uint16_t *)(ptr + 14)) & 0xfff; if (!(n->vlans[vid >> 5] & (1U << (vid & 0x1f)))) return 0; } if ((ptr[0] & 1) && n->allmulti) return 1; if (!memcmp(ptr, bcast, sizeof(bcast))) return 1; if (!memcmp(ptr, n->mac, ETH_ALEN)) return 1; for (i = 0; i < n->mac_table.in_use; i++) { if (!memcmp(ptr, &n->mac_table.macs[i * ETH_ALEN], ETH_ALEN)) return 1; } return 0; }