cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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sendmsg6_prog.c (1508B)

      1// SPDX-License-Identifier: GPL-2.0
      2// Copyright (c) 2018 Facebook
      3
      4#include <linux/stddef.h>
      5#include <linux/bpf.h>
      6#include <sys/socket.h>
      7
      8#include <bpf/bpf_helpers.h>
      9#include <bpf/bpf_endian.h>
     10
     11#include <bpf_sockopt_helpers.h>
     12
     13#define SRC_REWRITE_IP6_0	0
     14#define SRC_REWRITE_IP6_1	0
     15#define SRC_REWRITE_IP6_2	0
     16#define SRC_REWRITE_IP6_3	6
     17
     18#define DST_REWRITE_IP6_0	0
     19#define DST_REWRITE_IP6_1	0
     20#define DST_REWRITE_IP6_2	0
     21#define DST_REWRITE_IP6_3	1
     22
     23#define DST_REWRITE_PORT6	6666
     24
     25SEC("cgroup/sendmsg6")
     26int sendmsg_v6_prog(struct bpf_sock_addr *ctx)
     27{
     28	if (ctx->type != SOCK_DGRAM)
     29		return 0;
     30
     31	if (!get_set_sk_priority(ctx))
     32		return 0;
     33
     34	/* Rewrite source. */
     35	if (ctx->msg_src_ip6[3] == bpf_htonl(1) ||
     36	    ctx->msg_src_ip6[3] == bpf_htonl(0)) {
     37		ctx->msg_src_ip6[0] = bpf_htonl(SRC_REWRITE_IP6_0);
     38		ctx->msg_src_ip6[1] = bpf_htonl(SRC_REWRITE_IP6_1);
     39		ctx->msg_src_ip6[2] = bpf_htonl(SRC_REWRITE_IP6_2);
     40		ctx->msg_src_ip6[3] = bpf_htonl(SRC_REWRITE_IP6_3);
     41	} else {
     42		/* Unexpected source. Reject sendmsg. */
     43		return 0;
     44	}
     45
     46	/* Rewrite destination. */
     47	if (ctx->user_ip6[0] == bpf_htonl(0xFACEB00C)) {
     48		ctx->user_ip6[0] = bpf_htonl(DST_REWRITE_IP6_0);
     49		ctx->user_ip6[1] = bpf_htonl(DST_REWRITE_IP6_1);
     50		ctx->user_ip6[2] = bpf_htonl(DST_REWRITE_IP6_2);
     51		ctx->user_ip6[3] = bpf_htonl(DST_REWRITE_IP6_3);
     52
     53		ctx->user_port = bpf_htons(DST_REWRITE_PORT6);
     54	} else {
     55		/* Unexpected destination. Reject sendmsg. */
     56		return 0;
     57	}
     58
     59	return 1;
     60}
     61
     62char _license[] SEC("license") = "GPL";