diff options
Diffstat (limited to 'src/ebpf/xdp_drop_ebpf.c')
-rw-r--r-- | src/ebpf/xdp_drop_ebpf.c | 97 |
1 files changed, 0 insertions, 97 deletions
diff --git a/src/ebpf/xdp_drop_ebpf.c b/src/ebpf/xdp_drop_ebpf.c deleted file mode 100644 index a08edf58d..000000000 --- a/src/ebpf/xdp_drop_ebpf.c +++ /dev/null @@ -1,97 +0,0 @@ -#include <linux/bpf.h> -#include <linux/if_ether.h> -#include <linux/in.h> -#include <linux/ip.h> -#include <linux/ipv6.h> -#include <linux/udp.h> - -#include <stdint.h> - -/* IP flags. */ -#define IP_CE 0x8000 /* Flag: "Congestion" */ -#define IP_DF 0x4000 /* Flag: "Don't Fragment" */ -#define IP_MF 0x2000 /* Flag: "More Fragments" */ -#define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ - -#define SEC(NAME) __attribute__((section(NAME), used)) - -#define htons(x) ((__be16)___constant_swab16((x))) -#define htonl(x) ((__be32)___constant_swab32((x))) - -struct vlan_hdr { - __be16 h_vlan_TCI; - __be16 h_vlan_encapsulated_proto; -}; - -SEC("prog") -int xdp_drop(struct xdp_md *ctx) { - void *data_end = (void *)(long)ctx->data_end; - void *data = (void *)(long)ctx->data; - struct ethhdr *eth = data; - - uint64_t nh_off = sizeof(*eth); - if (data + nh_off > data_end) { - return XDP_PASS; - } - - uint16_t h_proto = eth->h_proto; - int i; - - /* Handle double VLAN tagged packet. See https://en.wikipedia.org/wiki/IEEE_802.1ad */ - for (i = 0; i < 2; i++) { - if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) { - struct vlan_hdr *vhdr; - - vhdr = data + nh_off; - nh_off += sizeof(struct vlan_hdr); - if (data + nh_off > data_end) { - return XDP_PASS; - } - h_proto = vhdr->h_vlan_encapsulated_proto; - } - } - - if (h_proto == htons(ETH_P_IP)) { - struct iphdr *iph = data + nh_off; - struct udphdr *udph = data + nh_off + sizeof(struct iphdr); - - uint32_t hostid = iph->daddr >> 24; - - if (udph + 1 > (struct udphdr *)data_end) { - return XDP_PASS; - } - if (hostid == 0 || hostid == 255) { - return XDP_DROP; - } - if (iph->frag_off & htons(IP_MF | IP_OFFSET)) { - return XDP_DROP; - } - if (iph->protocol == IPPROTO_UDP) { - __be16 dport = htons(udph->dest); - __be16 sport = htons(udph->source); - - if (dport == 53 || sport == 53) { - return XDP_DROP; - } - } - } else if (h_proto == htons(ETH_P_IPV6)) { - struct ipv6hdr *ip6h = data + nh_off; - struct udphdr *udph = data + nh_off + sizeof(struct ipv6hdr); - - if (udph + 1 > (struct udphdr *)data_end) { - return XDP_PASS; - } - if (ip6h->nexthdr == IPPROTO_UDP) { - __be16 dport = htons(udph->dest); - __be16 sport = htons(udph->source); - - if (dport == 53 || sport == 53) { - return XDP_DROP; - } - } - } - - return XDP_PASS; -} - -char _license[] SEC("license") = "GPL"; |