diff options
Diffstat (limited to '')
-rw-r--r-- | tools/testing/selftests/bpf/progs/connect_force_port4.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/connect_force_port4.c b/tools/testing/selftests/bpf/progs/connect_force_port4.c new file mode 100644 index 000000000..739630867 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/connect_force_port4.c @@ -0,0 +1,83 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <string.h> +#include <stdbool.h> + +#include <linux/bpf.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <sys/socket.h> + +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_endian.h> + +char _license[] SEC("license") = "GPL"; +int _version SEC("version") = 1; + +struct svc_addr { + __be32 addr; + __be16 port; +}; + +struct { + __uint(type, BPF_MAP_TYPE_SK_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, int); + __type(value, struct svc_addr); +} service_mapping SEC(".maps"); + +SEC("cgroup/connect4") +int connect4(struct bpf_sock_addr *ctx) +{ + struct sockaddr_in sa = {}; + struct svc_addr *orig; + + /* Force local address to 127.0.0.1:22222. */ + sa.sin_family = AF_INET; + sa.sin_port = bpf_htons(22222); + sa.sin_addr.s_addr = bpf_htonl(0x7f000001); + + if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0) + return 0; + + /* Rewire service 1.2.3.4:60000 to backend 127.0.0.1:60123. */ + if (ctx->user_port == bpf_htons(60000)) { + orig = bpf_sk_storage_get(&service_mapping, ctx->sk, 0, + BPF_SK_STORAGE_GET_F_CREATE); + if (!orig) + return 0; + + orig->addr = ctx->user_ip4; + orig->port = ctx->user_port; + + ctx->user_ip4 = bpf_htonl(0x7f000001); + ctx->user_port = bpf_htons(60123); + } + return 1; +} + +SEC("cgroup/getsockname4") +int getsockname4(struct bpf_sock_addr *ctx) +{ + /* Expose local server as 1.2.3.4:60000 to client. */ + if (ctx->user_port == bpf_htons(60123)) { + ctx->user_ip4 = bpf_htonl(0x01020304); + ctx->user_port = bpf_htons(60000); + } + return 1; +} + +SEC("cgroup/getpeername4") +int getpeername4(struct bpf_sock_addr *ctx) +{ + struct svc_addr *orig; + + /* Expose service 1.2.3.4:60000 as peer instead of backend. */ + if (ctx->user_port == bpf_htons(60123)) { + orig = bpf_sk_storage_get(&service_mapping, ctx->sk, 0, 0); + if (orig) { + ctx->user_ip4 = orig->addr; + ctx->user_port = orig->port; + } + } + return 1; +} |