Files
TripleCross/src/user/include/modules/xdp.h

75 lines
2.3 KiB
C

#ifndef __MOD_XDP_H
#define __MOD_XDP_H
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include <linux/if_link.h>
#include "common.h"
#include <sys/resource.h>
#include "kit.skel.h"
int attach_xdp_receive(struct kit_bpf *skel, __u32 ifindex, __u32 flags){
//Attach BPF program to network interface
//New way of doing it: it allows for future addition of multiple
//XDP programs attached to same interface if needed
//Also done this way to modularize attaching the different tracepoints
//of the rootkit
/** @ref Test suite by readhat ebpf devs on XDP
* https://git.zx2c4.com/linux/plain/tools/testing/selftests/bpf/prog_tests/xdp_link.c
*/
struct bpf_prog_info prog_info;
__u32 bpf_prog_info_size = sizeof(prog_info);
__u32 xdp_prog_fd = bpf_program__fd(skel->progs.xdp_receive);
__u32 xdp_prog_id_old = 0;
__u32 xdp_prog_id_new;
__u32 err;
DECLARE_LIBBPF_OPTS(bpf_xdp_set_link_opts, opts, .old_fd = -1);
memset(&prog_info, 0, bpf_prog_info_size);
err = bpf_obj_get_info_by_fd(xdp_prog_fd, &prog_info, &bpf_prog_info_size);
if(err<0){
fprintf(stderr, "Failed to setup xdp link\n");
return -1;
}
xdp_prog_id_new = prog_info.id;
//Check whether there exists previously loaded XDP program
err = bpf_get_link_xdp_id(ifindex, &xdp_prog_id_old, 0);
if(err<0 || (xdp_prog_id_old!=0 && xdp_prog_id_old!=xdp_prog_id_new)){
fprintf(stderr, "Xdp program found id--> old:%u != new:%u\n", xdp_prog_id_old, xdp_prog_id_new);
fprintf(stderr,"This should not happen, since our xdp program is removed automatically between calls\nRun `ip link set dev lo xdpgeneric off` to detach whichever program is running");
//TODO automatically force the reattach
return -1;
}
// Attach loaded xdp program
skel->links.xdp_receive = bpf_program__attach_xdp(skel->progs.xdp_receive, ifindex);
err = libbpf_get_error(skel->links.xdp_receive);
if (err<0) {
fprintf(stderr, "Failed to attach XDP program\n");
return -1;
}
return 0;
}
int attach_xdp_all(struct kit_bpf *skel, __u32 ifindex, __u32 flags){
return attach_xdp_receive(skel, ifindex, flags);
}
int detach_xdp_receive(struct kit_bpf *skel){
int err = detach_link_generic(skel->links.xdp_receive);
if(err<0){
fprintf(stderr, "Failed to detach XDP program\n");
return -1;
}
return 0;
}
int detach_xdp_all(struct kit_bpf *skel){
return detach_xdp_receive(skel);
}
#endif