bpf/progs/connect4_dropper.c

0001 // SPDX-License-Identifier: GPL-2.0
0002
0003 #include <string.h>
0004
0005 #include <linux/stddef.h>
0006 #include <linux/bpf.h>
0007
0008 #include <sys/socket.h>
0009
0010 #include <bpf/bpf_helpers.h>
0011 #include <bpf/bpf_endian.h>
0012
0013 #define VERDICT_REJECT  0
0014 #define VERDICT_PROCEED 1
0015
0016 SEC("cgroup/connect4")
0017 int connect_v4_dropper(struct bpf_sock_addr *ctx)
0018 {
0019     if (ctx->type != SOCK_STREAM)
0020         return VERDICT_PROCEED;
0021     if (ctx->user_port == bpf_htons(60120))
0022         return VERDICT_REJECT;
0023     return VERDICT_PROCEED;
0024 }
0025
0026 char _license[] SEC("license") = "GPL";