feat: support bind wan and lan in the same interface

This commit is contained in:
mzz2017
2023-02-08 14:36:16 +08:00
parent 00d42d1a6f
commit 3c139765d2
3 changed files with 219 additions and 206 deletions

View File

@ -198,15 +198,31 @@ retryLoadBpf:
_ = core.Close()
}
}()
// Bind to links. Binding should be advance of dialerGroups to avoid un-routable old connection.
for _, ifname := range lanInterface {
if err = core.bindLan(ifname); err != nil {
return nil, fmt.Errorf("bindLan: %v: %w", ifname, err)
/// Bind to links. Binding should be advance of dialerGroups to avoid un-routable old connection.
// Add clsact qdisc
for _, ifname := range common.Deduplicate(append(append([]string{}, lanInterface...), wanInterface...)) {
_ = core.addQdisc(ifname)
}
// Bind to LAN
if len(lanInterface) > 0 {
if err = core.setupRoutingPolicy(); err != nil {
return nil, err
}
for _, ifname := range lanInterface {
if err = core.bindLan(ifname); err != nil {
return nil, fmt.Errorf("bindLan: %v: %w", ifname, err)
}
}
}
for _, ifname := range wanInterface {
if err = core.bindWan(ifname); err != nil {
return nil, fmt.Errorf("bindWan: %v: %w", ifname, err)
// Bind to WAN
if len(wanInterface) > 0 {
if err = core.setupSkPidMonitor(); err != nil {
return nil, err
}
for _, ifname := range wanInterface {
if err = core.bindWan(ifname); err != nil {
return nil, fmt.Errorf("bindWan: %v: %w", ifname, err)
}
}
}

View File

@ -12,15 +12,14 @@ import (
ciliumLink "github.com/cilium/ebpf/link"
"github.com/safchain/ethtool"
"github.com/sirupsen/logrus"
"github.com/v2rayA/dae/common"
"github.com/v2rayA/dae/common/consts"
internal "github.com/v2rayA/dae/pkg/ebpf_internal"
"github.com/vishvananda/netlink"
"golang.org/x/sys/unix"
"net/netip"
"os"
"os/exec"
"regexp"
"strings"
)
type ControlPlaneCore struct {
@ -47,39 +46,6 @@ func (c *ControlPlaneCore) Close() (err error) {
}
func getIfParamsFromLink(link netlink.Link) (ifParams bpfIfParams, err error) {
// TODO: We should monitor IP change of the link.
ipnets, err := netlink.AddrList(link, netlink.FAMILY_ALL)
if err != nil {
return bpfIfParams{}, err
}
if len(ipnets) == 0 {
return bpfIfParams{}, fmt.Errorf("interface %v has no ip", link.Attrs().Name)
}
// Get first Ip4 and Ip6.
for _, ipnet := range ipnets {
ip, ok := netip.AddrFromSlice(ipnet.IP)
if !ok {
continue
}
if ip.IsLinkLocalUnicast() || ip.IsLinkLocalMulticast() {
continue
}
if (ip.Is6() && ifParams.HasIp6) ||
(ip.Is4() && ifParams.HasIp4) {
continue
}
ip6format := ip.As16()
if ip.Is4() {
ifParams.HasIp4 = true
ifParams.Ip4 = common.Ipv6ByteSliceToUint32Array(ip6format[:])
} else {
ifParams.HasIp6 = true
ifParams.Ip6 = common.Ipv6ByteSliceToUint32Array(ip6format[:])
}
if ifParams.HasIp4 && ifParams.HasIp6 {
break
}
}
// Get link offload features.
et, err := ethtool.NewEthtool()
if err != nil {
@ -111,60 +77,11 @@ func getIfParamsFromLink(link netlink.Link) (ifParams bpfIfParams, err error) {
return ifParams, nil
}
func (c *ControlPlaneCore) bindLan(ifname string) error {
c.log.Infof("Bind to LAN: %v", ifname)
func (c *ControlPlaneCore) addQdisc(ifname string) error {
link, err := netlink.LinkByName(ifname)
if err != nil {
return err
}
/// Insert ip rule / ip route.
var output []byte
if output, err = exec.Command("sh", "-c", `
ip rule add fwmark 0x80000000/0x80000000 table 2023
ip route add local default dev lo table 2023
ip -6 rule add fwmark 0x80000000/0x80000000 table 2023
ip -6 route add local default dev lo table 2023
`).CombinedOutput(); err != nil {
return fmt.Errorf("%w: %v", err, string(bytes.TrimSpace(output)))
}
c.deferFuncs = append(c.deferFuncs, func() error {
return exec.Command("sh", "-c", `
ip rule del fwmark 0x80000000/0x80000000 table 2023
ip route del local default dev lo table 2023
ip -6 rule del fwmark 0x80000000/0x80000000 table 2023
ip -6 route del local default dev lo table 2023
`).Run()
})
/// Insert an elem into IfindexParamsMap.
ifParams, err := getIfParamsFromLink(link)
if err != nil {
return err
}
if err = ifParams.CheckVersionRequirement(c.kernelVersion); err != nil {
return err
}
if err := c.bpf.IfindexParamsMap.Update(uint32(link.Attrs().Index), ifParams, ebpf.UpdateAny); err != nil {
return fmt.Errorf("update IfindexIpsMap: %w", err)
}
// FIXME: not only this link ip.
if ifParams.HasIp4 {
if err := c.bpf.HostIpLpm.Update(_bpfLpmKey{
PrefixLen: 128,
Data: ifParams.Ip4,
}, uint32(1), ebpf.UpdateAny); err != nil {
return fmt.Errorf("update IfindexIpsMap: %w", err)
}
}
if ifParams.HasIp6 {
if err := c.bpf.HostIpLpm.Update(_bpfLpmKey{
PrefixLen: 128,
Data: ifParams.Ip6,
}, uint32(1), ebpf.UpdateAny); err != nil {
return fmt.Errorf("update IfindexIpsMap: %w", err)
}
}
// Insert qdisc and filters.
qdisc := &netlink.GenericQdisc{
QdiscAttrs: netlink.QdiscAttrs{
LinkIndex: link.Attrs().Index,
@ -174,48 +91,66 @@ func (c *ControlPlaneCore) bindLan(ifname string) error {
QdiscType: "clsact",
}
if err := netlink.QdiscAdd(qdisc); err != nil {
if os.IsExist(err) {
_ = netlink.QdiscDel(qdisc)
err = netlink.QdiscAdd(qdisc)
}
if err != nil {
return fmt.Errorf("cannot add clsact qdisc: %w", err)
}
}
c.deferFuncs = append(c.deferFuncs, func() error {
if err := netlink.QdiscDel(qdisc); err != nil {
return fmt.Errorf("QdiscDel: %w", err)
}
return nil
})
filterIngress := &netlink.BpfFilter{
FilterAttrs: netlink.FilterAttrs{
LinkIndex: link.Attrs().Index,
Parent: netlink.HANDLE_MIN_INGRESS,
Handle: netlink.MakeHandle(0, 1),
Protocol: unix.ETH_P_ALL,
Priority: 0,
},
Fd: c.bpf.bpfPrograms.TproxyLanIngress.FD(),
Name: consts.AppName + "_ingress",
DirectAction: true,
}
if err := netlink.FilterAdd(filterIngress); err != nil {
return fmt.Errorf("cannot attach ebpf object to filter ingress: %w", err)
return fmt.Errorf("cannot add clsact qdisc: %w", err)
}
return nil
}
func (c *ControlPlaneCore) bindWan(ifname string) error {
c.log.Infof("Bind to WAN: %v", ifname)
func (c *ControlPlaneCore) delQdisc(ifname string) error {
link, err := netlink.LinkByName(ifname)
if err != nil {
return err
}
if link.Attrs().Index == consts.LoopbackIfIndex {
return fmt.Errorf("cannot bind to loopback interface")
qdisc := &netlink.GenericQdisc{
QdiscAttrs: netlink.QdiscAttrs{
LinkIndex: link.Attrs().Index,
Handle: netlink.MakeHandle(0xffff, 0),
Parent: netlink.HANDLE_CLSACT,
},
QdiscType: "clsact",
}
if err := netlink.QdiscDel(qdisc); err != nil {
if !os.IsExist(err) {
return fmt.Errorf("cannot add clsact qdisc: %w", err)
}
}
return nil
}
func (c *ControlPlaneCore) setupRoutingPolicy() (err error) {
/// Insert ip rule / ip route.
// TODO: Refactor me with netlink.
var output []byte
cleanFunc := func() error {
return exec.Command("sh", "-c", `
ip rule del fwmark 0x80000000/0x80000000 table 2023
ip route del local default dev lo table 2023
ip -6 rule del fwmark 0x80000000/0x80000000 table 2023
ip -6 route del local default dev lo table 2023
`).Run()
}
tryAgain:
if output, err = exec.Command("sh", "-c", `
ip rule add fwmark 0x80000000/0x80000000 table 2023
ip route add local default dev lo table 2023
ip -6 rule add fwmark 0x80000000/0x80000000 table 2023
ip -6 route add local default dev lo table 2023
`).CombinedOutput(); err != nil {
if strings.Contains(string(output), "File exists") {
_ = cleanFunc()
goto tryAgain
}
return fmt.Errorf("%w: %v", err, string(bytes.TrimSpace(output)))
}
c.deferFuncs = append(c.deferFuncs, cleanFunc)
return nil
}
func (c *ControlPlaneCore) bindLan(ifname string) error {
c.log.Infof("Bind to LAN: %v", ifname)
link, err := netlink.LinkByName(ifname)
if err != nil {
return err
}
/// Insert an elem into IfindexParamsMap.
ifParams, err := getIfParamsFromLink(link)
@ -229,6 +164,35 @@ func (c *ControlPlaneCore) bindWan(ifname string) error {
return fmt.Errorf("update IfindexIpsMap: %w", err)
}
// Insert filters.
filterIngress := &netlink.BpfFilter{
FilterAttrs: netlink.FilterAttrs{
LinkIndex: link.Attrs().Index,
Parent: netlink.HANDLE_MIN_INGRESS,
Handle: netlink.MakeHandle(0x2023, 2),
Protocol: unix.ETH_P_ALL,
// Priority should be behind of WAN's
Priority: 2,
},
Fd: c.bpf.bpfPrograms.TproxyLanIngress.FD(),
Name: consts.AppName + "_lan_ingress",
DirectAction: true,
}
// Remove and add.
_ = netlink.FilterDel(filterIngress)
if err := netlink.FilterAdd(filterIngress); err != nil {
return fmt.Errorf("cannot attach ebpf object to filter ingress: %w", err)
}
c.deferFuncs = append(c.deferFuncs, func() error {
if err := netlink.FilterDel(filterIngress); err != nil {
return fmt.Errorf("FilterDel(%v:%v): %w", ifname, filterIngress.Name, err)
}
return nil
})
return nil
}
func (c *ControlPlaneCore) setupSkPidMonitor() error {
/// Set-up SrcPidMapper.
/// Attach programs to support pname routing.
// Get the first-mounted cgroupv2 path.
@ -266,65 +230,77 @@ func (c *ControlPlaneCore) bindWan(ifname string) error {
return nil
})
}
return nil
}
func (c *ControlPlaneCore) bindWan(ifname string) error {
c.log.Infof("Bind to WAN: %v", ifname)
link, err := netlink.LinkByName(ifname)
if err != nil {
return err
}
if link.Attrs().Index == consts.LoopbackIfIndex {
return fmt.Errorf("cannot bind to loopback interface")
}
/// Insert an elem into IfindexParamsMap.
ifParams, err := getIfParamsFromLink(link)
if err != nil {
return err
}
if err = ifParams.CheckVersionRequirement(c.kernelVersion); err != nil {
return err
}
if err := c.bpf.IfindexParamsMap.Update(uint32(link.Attrs().Index), ifParams, ebpf.UpdateAny); err != nil {
return fmt.Errorf("update IfindexIpsMap: %w", err)
}
/// Set-up WAN ingress/egress TC programs.
// Insert qdisc.
qdisc := &netlink.GenericQdisc{
QdiscAttrs: netlink.QdiscAttrs{
LinkIndex: link.Attrs().Index,
Handle: netlink.MakeHandle(0xffff, 0),
Parent: netlink.HANDLE_CLSACT,
},
QdiscType: "clsact",
}
if err := netlink.QdiscAdd(qdisc); err != nil {
if os.IsExist(err) {
_ = netlink.QdiscDel(qdisc)
err = netlink.QdiscAdd(qdisc)
}
if err != nil {
return fmt.Errorf("cannot add clsact qdisc: %w", err)
}
}
c.deferFuncs = append(c.deferFuncs, func() error {
if err := netlink.QdiscDel(qdisc); err != nil {
return fmt.Errorf("QdiscDel: %w", err)
}
return nil
})
// Insert TC filters
filterEgress := &netlink.BpfFilter{
FilterAttrs: netlink.FilterAttrs{
LinkIndex: link.Attrs().Index,
Parent: netlink.HANDLE_MIN_EGRESS,
Handle: netlink.MakeHandle(0, 1),
Handle: netlink.MakeHandle(0x2023, 1),
Protocol: unix.ETH_P_ALL,
Priority: 0,
Priority: 1,
},
Fd: c.bpf.bpfPrograms.TproxyWanEgress.FD(),
Name: consts.AppName + "_egress",
Name: consts.AppName + "_wan_egress",
DirectAction: true,
}
// Remove and add.
_ = netlink.FilterDel(filterEgress)
if err := netlink.FilterAdd(filterEgress); err != nil {
return fmt.Errorf("cannot attach ebpf object to filter egress: %w", err)
}
c.deferFuncs = append(c.deferFuncs, func() error {
if err := netlink.FilterDel(filterEgress); err != nil && !os.IsNotExist(err) {
return fmt.Errorf("FilterDel(%v:%v): %w", ifname, filterEgress.Name, err)
}
return nil
})
filterIngress := &netlink.BpfFilter{
FilterAttrs: netlink.FilterAttrs{
LinkIndex: link.Attrs().Index,
Parent: netlink.HANDLE_MIN_INGRESS,
Handle: netlink.MakeHandle(0, 1),
Handle: netlink.MakeHandle(0x2023, 1),
Protocol: unix.ETH_P_ALL,
Priority: 0,
Priority: 1,
},
Fd: c.bpf.bpfPrograms.TproxyWanIngress.FD(),
Name: consts.AppName + "_ingress",
Name: consts.AppName + "_wan_ingress",
DirectAction: true,
}
// Remove and add.
_ = netlink.FilterDel(filterIngress)
if err := netlink.FilterAdd(filterIngress); err != nil {
return fmt.Errorf("cannot attach ebpf object to filter ingress: %w", err)
}
c.deferFuncs = append(c.deferFuncs, func() error {
if err := netlink.FilterDel(filterIngress); err != nil {
return fmt.Errorf("FilterDel(%v:%v): %w", ifname, filterIngress.Name, err)
}
return nil
})
return nil
}

View File

@ -11,10 +11,9 @@
#include "headers/socket_defs.h"
#include "headers/vmlinux.h"
// #include <bpf/bpf_core_read.h>
#include "headers/bpf_core_read.h"
#include "headers/bpf_endian.h"
#include "headers/bpf_helpers.h"
#include "headers/bpf_core_read.h"
// #define __DEBUG_ROUTING
// #define __PRINT_ROUTING_RESULT
@ -190,11 +189,6 @@ struct {
// Interface Ips:
struct if_params {
__be32 ip4[4];
__be32 ip6[4];
bool has_ip4;
bool has_ip6;
bool rx_cksm_offload;
bool tx_l4_cksm_ip4_offload;
bool tx_l4_cksm_ip6_offload;
@ -220,7 +214,7 @@ struct map_lpm_type {
__uint(max_entries, MAX_LPM_SIZE);
__uint(key_size, sizeof(struct lpm_key));
__uint(value_size, sizeof(__u32));
} unused_lpm_type SEC(".maps"), host_ip_lpm SEC(".maps");
} unused_lpm_type SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
__uint(key_size, sizeof(__u32));
@ -1193,12 +1187,12 @@ int tproxy_lan_ingress(struct __sk_buff *skb) {
ip rule add fwmark 0x80000000/0x80000000 table 2023
ip route add local default dev lo table 2023
ip -6 rule add fwmark 0x80000000/0x80000000 table 2023
ip -6 route add local ::/0 dev lo table 2023
ip -6 route add local default dev lo table 2023
ip rule del fwmark 0x80000000/0x80000000 table 2023
ip route del local default dev lo table 2023
ip -6 rule del fwmark 0x80000000/0x80000000 table 2023
ip -6 route del local ::/0 dev lo table 2023
ip -6 route del local default dev lo table 2023
*/
// Socket lookup and assign skb to existing socket connection.
struct bpf_sock_tuple tuple = {0};
@ -1446,13 +1440,28 @@ int tproxy_wan_egress(struct __sk_buff *skb) {
return TC_ACT_OK;
}
__be16 sport;
if (l4proto == IPPROTO_TCP) {
sport = tcph.source;
} else if (l4proto == IPPROTO_UDP) {
sport = udph.source;
// Backup for further use.
__be16 ipv4_tot_len = 0;
struct tuples tuples = {0};
tuples.l4proto = l4proto;
if (ipversion == 4) {
tuples.src.ip[2] = bpf_htonl(0x0000ffff);
tuples.src.ip[3] = iph.saddr;
tuples.dst.ip[2] = bpf_htonl(0x0000ffff);
tuples.dst.ip[3] = iph.daddr;
ipv4_tot_len = iph.tot_len;
} else {
return TC_ACT_OK;
__builtin_memcpy(tuples.dst.ip, &ipv6h.daddr, IPV6_BYTE_LENGTH);
__builtin_memcpy(tuples.src.ip, &ipv6h.saddr, IPV6_BYTE_LENGTH);
}
if (l4proto == IPPROTO_TCP) {
tuples.src.port = tcph.source;
tuples.dst.port = tcph.dest;
} else {
tuples.src.port = udph.source;
tuples.dst.port = udph.dest;
}
// We should know if this packet is from tproxy.
@ -1462,29 +1471,41 @@ int tproxy_wan_egress(struct __sk_buff *skb) {
if (!tproxy_port) {
return TC_ACT_OK;
}
bool tproxy_response = *tproxy_port == sport;
// Backup for further use.
__be16 ipv4_tot_len = 0;
// Parse saddr and daddr as ipv6 format.
__be32 saddr[4];
__be32 daddr[4];
if (ipversion == 4) {
saddr[0] = 0;
saddr[1] = 0;
saddr[2] = bpf_htonl(0x0000ffff);
saddr[3] = iph.saddr;
daddr[0] = 0;
daddr[1] = 0;
daddr[2] = bpf_htonl(0x0000ffff);
daddr[3] = iph.daddr;
ipv4_tot_len = iph.tot_len;
} else {
__builtin_memcpy(daddr, &ipv6h.daddr, IPV6_BYTE_LENGTH);
__builtin_memcpy(saddr, &ipv6h.saddr, IPV6_BYTE_LENGTH);
bool tproxy_response = *tproxy_port == tuples.src.port;
// Double check to avoid bind wan and lan to one interface.
if (tproxy_response && l4proto == IPPROTO_TCP) {
// If it is a TCP first handshake, it is not a tproxy response.
if (tcph.syn && !tcph.syn) {
tproxy_response = false;
// Abnormal.
return TC_ACT_SHOT;
} else {
// If there is an existing socket on localhost, it is not a tproxy
// response.
struct bpf_sock_tuple tuple = {0};
__u32 tuple_size;
if (ipversion == 4) {
tuple.ipv4.daddr = tuples.dst.ip[3];
tuple.ipv4.saddr = tuples.src.ip[3];
tuple.ipv4.dport = tuples.dst.port;
tuple.ipv4.sport = tuples.src.port;
tuple_size = sizeof(tuple.ipv4);
} else {
__builtin_memcpy(tuple.ipv6.daddr, tuples.dst.ip, IPV6_BYTE_LENGTH);
__builtin_memcpy(tuple.ipv6.saddr, tuples.src.ip, IPV6_BYTE_LENGTH);
tuple.ipv6.dport = tuples.dst.port;
tuple.ipv6.sport = tuples.src.port;
tuple_size = sizeof(tuple.ipv6);
}
struct bpf_sock *sk =
bpf_skc_lookup_tcp(skb, &tuple, tuple_size, BPF_F_CURRENT_NETNS, 0);
if (sk) {
// Not a tproxy response.
tproxy_response = false;
bpf_sk_release(sk);
return TC_ACT_OK;
}
}
}
if (tproxy_response) {
@ -1511,7 +1532,7 @@ int tproxy_wan_egress(struct __sk_buff *skb) {
__builtin_memset(&key_src, 0, sizeof(key_src));
// Use daddr as key in WAN because tproxy (control plane) also lookups the
// map element using income client ip (that is daddr).
__builtin_memcpy(key_src.ip, daddr, IPV6_BYTE_LENGTH);
__builtin_memcpy(key_src.ip, tuples.dst.ip, IPV6_BYTE_LENGTH);
key_src.port = tcph.source;
__u8 outbound;
if (unlikely(tcp_state_syn)) {
@ -1538,7 +1559,8 @@ int tproxy_wan_egress(struct __sk_buff *skb) {
bpf_htonl((ethh.h_source[2] << 24) + (ethh.h_source[3] << 16) +
(ethh.h_source[4] << 8) + (ethh.h_source[5])),
};
if ((ret = routing(flag, &tcph, saddr, daddr, mac)) < 0) {
if ((ret = routing(flag, &tcph, tuples.src.ip, tuples.dst.ip, mac)) <
0) {
bpf_printk("shot routing: %d", ret);
return TC_ACT_SHOT;
}
@ -1572,7 +1594,7 @@ int tproxy_wan_egress(struct __sk_buff *skb) {
if (unlikely(tcp_state_syn)) {
struct ip_port_outbound value_dst;
__builtin_memset(&value_dst, 0, sizeof(value_dst));
__builtin_memcpy(value_dst.ip, daddr, IPV6_BYTE_LENGTH);
__builtin_memcpy(value_dst.ip, tuples.dst.ip, IPV6_BYTE_LENGTH);
value_dst.port = tcph.dest;
value_dst.outbound = outbound;
// bpf_printk("UPDATE: %pI6:%u", key_src.ip, bpf_ntohs(key_src.port));
@ -1595,7 +1617,7 @@ int tproxy_wan_egress(struct __sk_buff *skb) {
// Backup for further use.
struct ip_port_outbound new_hdr;
__builtin_memset(&new_hdr, 0, sizeof(new_hdr));
__builtin_memcpy(new_hdr.ip, daddr, IPV6_BYTE_LENGTH);
__builtin_memcpy(new_hdr.ip, tuples.dst.ip, IPV6_BYTE_LENGTH);
new_hdr.port = udph.dest;
// Routing. It decides if we redirect traffic to control plane.
@ -1620,7 +1642,7 @@ int tproxy_wan_egress(struct __sk_buff *skb) {
bpf_htonl((ethh.h_source[2] << 24) + (ethh.h_source[3] << 16) +
(ethh.h_source[4] << 8) + (ethh.h_source[5])),
};
if ((ret = routing(flag, &udph, saddr, daddr, mac)) < 0) {
if ((ret = routing(flag, &udph, tuples.src.ip, tuples.dst.ip, mac)) < 0) {
bpf_printk("shot routing: %d", ret);
return TC_ACT_SHOT;
}
@ -1700,7 +1722,7 @@ int tproxy_wan_ingress(struct __sk_buff *skb) {
// Tproxy related.
__u16 tproxy_typ = bpf_ntohs(*(__u16 *)&ethh.h_source[4]);
if (*(__u32 *)&ethh.h_source[0] != bpf_htonl(0x02000203) || tproxy_typ > 1) {
return TC_ACT_OK;
return TC_ACT_PIPE;
}
bool tproxy_response = tproxy_typ == 1;
@ -1773,7 +1795,6 @@ int tproxy_wan_ingress(struct __sk_buff *skb) {
if (!original_dst) {
bpf_printk("[%X]Bad Connection: to: %pI6:%u", bpf_ntohl(tcph.seq),
key_dst.ip, bpf_ntohs(key_dst.port));
// Do not impact previous connections.
return TC_ACT_SHOT;
}
@ -1933,7 +1954,7 @@ static int __always_inline update_map_elem_by_cookie(const __u64 cookie) {
buf[to_read] = 0;
}
if ((ret = bpf_core_read_user(&buf, to_read,
(const void *)(arg_start + j)))) {
(const void *)(arg_start + j)))) {
bpf_printk("failed to read process name: %d", ret);
return ret;
}
@ -1950,7 +1971,7 @@ static int __always_inline update_map_elem_by_cookie(const __u64 cookie) {
length_cpy = TASK_COMM_LEN;
}
if ((ret = bpf_core_read_user(&val.pname, length_cpy,
(const void *)(arg_start + last_slash)))) {
(const void *)(arg_start + last_slash)))) {
bpf_printk("failed to read process name: %d", ret);
return ret;
}