remove unused option --keep

1. remove --keep option
2. update README

Signed-off-by: Leon Huayra <hffilwlqm@gmail.com>

README.md

@@ -25,8 +25,7 @@ Flags:
       --icmpid uint16      trace icmp id
   -H, --ipaddr string      ip address
       --iptables           output iptables path
-      --keep               keep trace packet all lifetime (DEPRECATED: not implemented yet)
-  -N, --netns uint32       trace this Network Namespace only
+  -N, --netns uint32       trace this netns inode only
       --noroute            do not output route path
   -p, --pid uint32         trace this PID only
   -P, --port uint16        udp or tcp port

config.go

@@ -21,7 +21,6 @@ type Config struct {
 	CallStack  bool
 	Iptables   bool
 	NoRoute    bool
-	Keep       bool
 	Time       bool
 	Timestamp  bool
 	Gops       string
@@ -38,17 +37,14 @@ func init() {
 	fs.Uint64VarP(&cfg.CatchCount, "catch-count", "c", 1000, "catch and print count")
 	fs.Uint16VarP(&cfg.Port, "port", "P", 0, "udp or tcp port")
 	fs.Uint32VarP(&cfg.Pid, "pid", "p", 0, "trace this PID only")
-	fs.Uint32VarP(&cfg.NetNS, "netns", "N", 0, "trace this Network Namespace only")
+	fs.Uint32VarP(&cfg.NetNS, "netns", "N", 0, "trace this netns inode only")
 	fs.BoolVar(&cfg.DropStack, "dropstack", false, "output kernel stack trace when drop packet")
 	fs.BoolVar(&cfg.CallStack, "callstack", false, "output kernel stack trace")
 	fs.BoolVar(&cfg.Iptables, "iptables", false, "output iptables path")
 	fs.BoolVar(&cfg.NoRoute, "noroute", false, "do not output route path")
-	fs.BoolVar(&cfg.Keep, "keep", false, "keep trace packet all lifetime")
 	fs.BoolVarP(&cfg.Time, "time", "T", true, "show HH:MM:SS timestamp")
 	fs.BoolVarP(&cfg.Timestamp, "timestamp", "t", false, "show timestamp in seconds at us resolution")
 	fs.StringVar(&cfg.Gops, "gops", "", "gops address")
-
-	fs.Lookup("keep").Deprecated = "not implemented yet"
 }
 
 func (c *Config) parse() error {

ebpf.go

@@ -96,8 +96,8 @@ type BpfConfig struct {
 	IcmpID    uint16
 	DropStack uint8
 	CallStack uint8
-	Keep      uint8
 	Proto     uint8
+	pad       uint8
 }
 
 const sizeOfBpfConfig = int(unsafe.Sizeof(BpfConfig{}))
@@ -127,7 +127,6 @@ func (p *bpfProgram) storeConfig() error {
 		IcmpID:    (cfg.IcmpID >> 8) & (cfg.IcmpID << 8),
 		DropStack: bool2uint8(cfg.DropStack),
 		CallStack: bool2uint8(cfg.CallStack),
-		Keep:      bool2uint8(cfg.Keep),
 		Proto:     cfg.proto,
 	}
 

ebpf/headers/skbtracer.h

@@ -53,8 +53,8 @@ struct config {
     u16 icmpid;
     u8 dropstack;
     u8 callstack;
-    u8 keep;
     u8 proto;
+    u8 pad;
 };
 
 BPF_MAP_DEF(skbtracer_cfg) = {
@@ -478,8 +478,8 @@ INLINE bool filter_netns(struct config *cfg, struct sk_buff *skb) {
 }
 
 INLINE bool filter_pid(struct config *cfg) {
-    u32 tgid = bpf_get_current_pid_tgid() >> 32;
-    return cfg->pid != 0 && cfg->pid != tgid;
+    u32 pid = bpf_get_current_pid_tgid() >> 32;
+    return cfg->pid != 0 && cfg->pid != pid;
 }
 
 INLINE bool filter_dropstack(struct config *cfg) {