func MapWalk()

in pkg/clihelper/show.go [84:237]
139 lines of code
30 McCabe index (conditional complexity)

func MapWalk(mapID int) error {
	if mapID <= 0 {
		return fmt.Errorf("Invalid mapID")
	}

	mapFD, err := goebpfutils.GetMapFDFromID(mapID)
	if err != nil {
		return err
	}

	mapInfo, err := goebpfmaps.GetBPFmapInfo(mapFD)
	if err != nil {
		return err
	}
	unix.Close(mapFD)

	if mapInfo.Type != constdef.BPF_MAP_TYPE_LPM_TRIE.Index() && mapInfo.Type != constdef.BPF_MAP_TYPE_LRU_HASH.Index() && mapInfo.Type != constdef.BPF_MAP_TYPE_HASH.Index() {
		return fmt.Errorf("Unsupported map type, should be - LPM trie (egress/ingress maps) or LRU hash (Conntrack table)")
	}

	if mapInfo.Type == constdef.BPF_MAP_TYPE_LPM_TRIE.Index() {
		iterKey := utils.BPFTrieKey{}
		iterNextKey := utils.BPFTrieKey{}

		err = goebpfmaps.GetFirstMapEntryByID(uintptr(unsafe.Pointer(&iterKey)), mapID)
		if err != nil {
			if errors.Is(err, unix.ENOENT) {
				fmt.Println("No Entries found, Empty map")
				return nil
			}
			return fmt.Errorf("Unable to get First key: %v", err)
		} else {
			for {

				iterValue := [24]utils.BPFTrieVal{}
				err = goebpfmaps.GetMapEntryByID(uintptr(unsafe.Pointer(&iterKey)), uintptr(unsafe.Pointer(&iterValue)), mapID)
				if err != nil {
					return fmt.Errorf("Unable to get map entry: %v", err)
				} else {
					retrievedKey := fmt.Sprintf("Key : IP/Prefixlen - %s/%d ", utils.ConvIntToIPv4(iterKey.IP).String(), iterKey.PrefixLen)
					fmt.Println(retrievedKey)
					for i := 0; i < len(iterValue); i++ {
						if iterValue[i].Protocol == 0 {
							continue
						}
						fmt.Println("-------------------")
						fmt.Println("Value Entry : ", i)
						fmt.Println("Protocol - ", utils.GetProtocol(int(iterValue[i].Protocol)))
						fmt.Println("StartPort - ", iterValue[i].StartPort)
						fmt.Println("Endport - ", iterValue[i].EndPort)
						fmt.Println("-------------------")
					}
					fmt.Println("*******************************")
				}

				err = goebpfmaps.GetNextMapEntryByID(uintptr(unsafe.Pointer(&iterKey)), uintptr(unsafe.Pointer(&iterNextKey)), mapID)
				if errors.Is(err, unix.ENOENT) {
					fmt.Println("Done reading all entries")
					break
				}
				if err != nil {
					fmt.Println("Failed to get next entry Done searching")
					break
				}
				iterKey = iterNextKey
			}
		}
	}

	if mapInfo.Type == constdef.BPF_MAP_TYPE_LRU_HASH.Index() {
		iterKey := utils.ConntrackKey{}
		iterNextKey := utils.ConntrackKey{}
		err = goebpfmaps.GetFirstMapEntryByID(uintptr(unsafe.Pointer(&iterKey)), mapID)
		if err != nil {
			if errors.Is(err, unix.ENOENT) {
				fmt.Println("No Entries found, Empty map")
				return nil
			}
			return fmt.Errorf("Unable to get First key: %v", err)
		} else {
			for {
				iterValue := utils.ConntrackVal{}
				err = goebpfmaps.GetMapEntryByID(uintptr(unsafe.Pointer(&iterKey)), uintptr(unsafe.Pointer(&iterValue)), mapID)
				if err != nil {
					return fmt.Errorf("Unable to get map entry: %v", err)
				} else {
					retrievedKey := fmt.Sprintf("Conntrack Key : Source IP - %s Source port - %d Dest IP - %s Dest port - %d Protocol - %d Owner IP - %s", utils.ConvIntToIPv4(iterKey.Source_ip).String(), iterKey.Source_port, utils.ConvIntToIPv4(iterKey.Dest_ip).String(), iterKey.Dest_port, iterKey.Protocol, utils.ConvIntToIPv4(iterKey.Owner_ip).String())
					fmt.Println(retrievedKey)
					fmt.Println("Value : ")
					fmt.Println("Conntrack Val - ", iterValue.Value)
					fmt.Println("*******************************")
				}

				err = goebpfmaps.GetNextMapEntryByID(uintptr(unsafe.Pointer(&iterKey)), uintptr(unsafe.Pointer(&iterNextKey)), mapID)
				if errors.Is(err, unix.ENOENT) {
					fmt.Println("Done reading all entries")
					break
				}
				if err != nil {
					fmt.Println("Failed to get next entry Done searching")
					break
				}
				iterKey = iterNextKey
			}
		}
	}

	if mapInfo.Type == constdef.BPF_MAP_TYPE_HASH.Index() {
		var key, nextKey uint32
		// Get the first entry
		err = goebpfmaps.GetFirstMapEntryByID(
			uintptr(unsafe.Pointer(&key)),
			mapID)
		if err != nil {
			if errors.Is(err, unix.ENOENT) {
				fmt.Println("No entries found, empty HASH map (pod_state_map?)")
				return nil
			}
			return fmt.Errorf("unable to get first key (HASH): %v", err)
		}

		for {
			var val PodState
			err = goebpfmaps.GetMapEntryByID(
				uintptr(unsafe.Pointer(&key)),
				uintptr(unsafe.Pointer(&val)),
				mapID)
			if err != nil {
				return fmt.Errorf("unable to get HASH entry for key=%d: %v", key, err)
			}

			fmt.Println("Key : ", key)
			fmt.Println("State - ", val.State)
			fmt.Println("*******************************")

			err = goebpfmaps.GetNextMapEntryByID(
				uintptr(unsafe.Pointer(&key)),
				uintptr(unsafe.Pointer(&nextKey)),
				mapID)
			if errors.Is(err, unix.ENOENT) {
				fmt.Println("Done reading all entries in BPF_MAP_TYPE_HASH")
				break
			}
			if err != nil {
				fmt.Println("Failed to get next entry, done searching")
				break
			}
			key = nextKey
		}
		return nil
	}

	return nil
}