diff options
Diffstat (limited to 'tools/testing/selftests/bpf/sendmsg6_prog.c')
| -rw-r--r-- | tools/testing/selftests/bpf/sendmsg6_prog.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/sendmsg6_prog.c b/tools/testing/selftests/bpf/sendmsg6_prog.c new file mode 100644 index 0000000000000..5aeaa284fc474 --- /dev/null +++ b/tools/testing/selftests/bpf/sendmsg6_prog.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018 Facebook + +#include <linux/stddef.h> +#include <linux/bpf.h> +#include <sys/socket.h> + +#include "bpf_helpers.h" +#include "bpf_endian.h" + +#define SRC_REWRITE_IP6_0 0 +#define SRC_REWRITE_IP6_1 0 +#define SRC_REWRITE_IP6_2 0 +#define SRC_REWRITE_IP6_3 6 + +#define DST_REWRITE_IP6_0 0 +#define DST_REWRITE_IP6_1 0 +#define DST_REWRITE_IP6_2 0 +#define DST_REWRITE_IP6_3 1 + +#define DST_REWRITE_PORT6 6666 + +int _version SEC("version") = 1; + +SEC("cgroup/sendmsg6") +int sendmsg_v6_prog(struct bpf_sock_addr *ctx) +{ + if (ctx->type != SOCK_DGRAM) + return 0; + + /* Rewrite source. */ + if (ctx->msg_src_ip6[3] == bpf_htonl(1) || + ctx->msg_src_ip6[3] == bpf_htonl(0)) { + ctx->msg_src_ip6[0] = bpf_htonl(SRC_REWRITE_IP6_0); + ctx->msg_src_ip6[1] = bpf_htonl(SRC_REWRITE_IP6_1); + ctx->msg_src_ip6[2] = bpf_htonl(SRC_REWRITE_IP6_2); + ctx->msg_src_ip6[3] = bpf_htonl(SRC_REWRITE_IP6_3); + } else { + /* Unexpected source. Reject sendmsg. */ + return 0; + } + + /* Rewrite destination. */ + if ((ctx->user_ip6[0] & 0xFFFF) == bpf_htons(0xFACE) && + ctx->user_ip6[0] >> 16 == bpf_htons(0xB00C)) { + ctx->user_ip6[0] = bpf_htonl(DST_REWRITE_IP6_0); + ctx->user_ip6[1] = bpf_htonl(DST_REWRITE_IP6_1); + ctx->user_ip6[2] = bpf_htonl(DST_REWRITE_IP6_2); + ctx->user_ip6[3] = bpf_htonl(DST_REWRITE_IP6_3); + + ctx->user_port = bpf_htons(DST_REWRITE_PORT6); + } else { + /* Unexpected destination. Reject sendmsg. */ + return 0; + } + + return 1; +} + +char _license[] SEC("license") = "GPL"; |