cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

tcbpf1_kern.c (2619B)

      1#define KBUILD_MODNAME "foo"
      2#include <uapi/linux/bpf.h>
      3#include <uapi/linux/if_ether.h>
      4#include <uapi/linux/if_packet.h>
      5#include <uapi/linux/ip.h>
      6#include <uapi/linux/in.h>
      7#include <uapi/linux/tcp.h>
      8#include <uapi/linux/filter.h>
      9#include <uapi/linux/pkt_cls.h>
     10#include <bpf/bpf_helpers.h>
     11#include "bpf_legacy.h"
     12
     13/* compiler workaround */
     14#define _htonl __builtin_bswap32
     15
     16static inline void set_dst_mac(struct __sk_buff *skb, char *mac)
     17{
     18	bpf_skb_store_bytes(skb, 0, mac, ETH_ALEN, 1);
     19}
     20
     21#define IP_CSUM_OFF (ETH_HLEN + offsetof(struct iphdr, check))
     22#define TOS_OFF (ETH_HLEN + offsetof(struct iphdr, tos))
     23
     24static inline void set_ip_tos(struct __sk_buff *skb, __u8 new_tos)
     25{
     26	__u8 old_tos = load_byte(skb, TOS_OFF);
     27
     28	bpf_l3_csum_replace(skb, IP_CSUM_OFF, htons(old_tos), htons(new_tos), 2);
     29	bpf_skb_store_bytes(skb, TOS_OFF, &new_tos, sizeof(new_tos), 0);
     30}
     31
     32#define TCP_CSUM_OFF (ETH_HLEN + sizeof(struct iphdr) + offsetof(struct tcphdr, check))
     33#define IP_SRC_OFF (ETH_HLEN + offsetof(struct iphdr, saddr))
     34
     35#define IS_PSEUDO 0x10
     36
     37static inline void set_tcp_ip_src(struct __sk_buff *skb, __u32 new_ip)
     38{
     39	__u32 old_ip = _htonl(load_word(skb, IP_SRC_OFF));
     40
     41	bpf_l4_csum_replace(skb, TCP_CSUM_OFF, old_ip, new_ip, IS_PSEUDO | sizeof(new_ip));
     42	bpf_l3_csum_replace(skb, IP_CSUM_OFF, old_ip, new_ip, sizeof(new_ip));
     43	bpf_skb_store_bytes(skb, IP_SRC_OFF, &new_ip, sizeof(new_ip), 0);
     44}
     45
     46#define TCP_DPORT_OFF (ETH_HLEN + sizeof(struct iphdr) + offsetof(struct tcphdr, dest))
     47static inline void set_tcp_dest_port(struct __sk_buff *skb, __u16 new_port)
     48{
     49	__u16 old_port = htons(load_half(skb, TCP_DPORT_OFF));
     50
     51	bpf_l4_csum_replace(skb, TCP_CSUM_OFF, old_port, new_port, sizeof(new_port));
     52	bpf_skb_store_bytes(skb, TCP_DPORT_OFF, &new_port, sizeof(new_port), 0);
     53}
     54
     55SEC("classifier")
     56int bpf_prog1(struct __sk_buff *skb)
     57{
     58	__u8 proto = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
     59	long *value;
     60
     61	if (proto == IPPROTO_TCP) {
     62		set_ip_tos(skb, 8);
     63		set_tcp_ip_src(skb, 0xA010101);
     64		set_tcp_dest_port(skb, 5001);
     65	}
     66
     67	return 0;
     68}
     69SEC("redirect_xmit")
     70int _redirect_xmit(struct __sk_buff *skb)
     71{
     72	return bpf_redirect(skb->ifindex + 1, 0);
     73}
     74SEC("redirect_recv")
     75int _redirect_recv(struct __sk_buff *skb)
     76{
     77	return bpf_redirect(skb->ifindex + 1, 1);
     78}
     79SEC("clone_redirect_xmit")
     80int _clone_redirect_xmit(struct __sk_buff *skb)
     81{
     82	bpf_clone_redirect(skb, skb->ifindex + 1, 0);
     83	return TC_ACT_SHOT;
     84}
     85SEC("clone_redirect_recv")
     86int _clone_redirect_recv(struct __sk_buff *skb)
     87{
     88	bpf_clone_redirect(skb, skb->ifindex + 1, 1);
     89	return TC_ACT_SHOT;
     90}
     91char _license[] SEC("license") = "GPL";