48 lines
1.0 KiB
C
48 lines
1.0 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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#include "vmlinux.h"
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_tracing.h>
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#include <bpf/bpf_core_read.h>
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#include "bpf_misc.h"
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static struct sockaddr_in old;
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static int handle_sys_connect_common(struct sockaddr_in *uservaddr)
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{
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struct sockaddr_in new;
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bpf_probe_read_user(&old, sizeof(old), uservaddr);
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__builtin_memset(&new, 0xab, sizeof(new));
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bpf_probe_write_user(uservaddr, &new, sizeof(new));
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return 0;
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}
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SEC("ksyscall/connect")
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int BPF_KSYSCALL(handle_sys_connect, int fd, struct sockaddr_in *uservaddr,
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int addrlen)
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{
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return handle_sys_connect_common(uservaddr);
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}
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#if defined(bpf_target_s390)
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#ifndef SYS_CONNECT
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#define SYS_CONNECT 3
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#endif
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SEC("ksyscall/socketcall")
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int BPF_KSYSCALL(handle_sys_socketcall, int call, unsigned long *args)
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{
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if (call == SYS_CONNECT) {
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struct sockaddr_in *uservaddr;
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bpf_probe_read_user(&uservaddr, sizeof(uservaddr), &args[1]);
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return handle_sys_connect_common(uservaddr);
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}
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return 0;
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}
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#endif
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char _license[] SEC("license") = "GPL";
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