Added golang JSON deserializer example.

Signed-off-by: Toni Uhlig <matzeton@googlemail.com>

2 files changed, 113 insertions, 3 deletions

diff --git a/Makefile b/Makefile
index bbea5e99d..b3d942d1f 100644
--- a/Makefile
+++ b/Makefile
@@ -2,6 +2,9 @@ CC = gcc
 PROJECT_CFLAGS += -Wall -Wextra $(EXTRA_CFLAGS) -I.
 LIBS += -pthread -lpcap -lm
 
+GOCC = go
+GOFLAGS = -ldflags='-s -w'
+
 ifneq ($(PKG_CONFIG_BIN),)
 ifneq ($(PKG_CONFIG_PREFIX),)
 PC_CFLAGS=$(shell PKG_CONFIG_PATH=$(shell realpath $(PKG_CONFIG_PREFIX)) $(PKG_CONFIG_BIN) --define-prefix=$(shell realpath $(PKG_CONFIG_PREFIX)) --cflags libndpi)
@@ -67,7 +70,7 @@ RM = rm -f
 
 all: help nDPId nDPIsrvd
 
-examples: examples/c-json-stdout/c-json-stdout
+examples: examples/c-json-stdout/c-json-stdout examples/go-dashboard/go-dashboard
 
 nDPId: nDPId.c utils.c
 	$(CC) $(PROJECT_CFLAGS) $(CFLAGS) $(PC_CFLAGS) $^ -o $@ $(LDFLAGS) $(PC_LDFLAGS) $(LIBS)
@@ -75,15 +78,20 @@ nDPId: nDPId.c utils.c
 nDPIsrvd: nDPIsrvd.c utils.c
 	$(CC) $(PROJECT_CFLAGS) $(CFLAGS) $^ -o $@ $(LDFLAGS) $(LIBS)
 
-examples/c-json-stdout/c-json-stdout:
+examples/c-json-stdout/c-json-stdout: examples/c-json-stdout/c-json-stdout.c
 ifneq ($(DISABLE_JSMN),yes)
 	$(CC) $(PROJECT_CFLAGS) $(CFLAGS) -DJSMN_STATIC=1 -DJSMN_STRICT=1 -DUSE_JSON=1 $@.c -o $@ $(LDFLAGS) $(LIBS)
 else
 	$(CC) $(PROJECT_CFLAGS) $(CFLAGS) $@.c -o $@ $(LDFLAGS) $(LIBS)
 endif
 
+examples/go-dashboard/go-dashboard: examples/go-dashboard/main.go
+ifneq ($(GOCC),)
+	$(GOCC) build -o examples/go-dashboard/go-dashboard $(GOFLAGS) examples/go-dashboard/main.go
+endif
+
 clean:
-	$(RM) -f nDPId nDPIsrvd examples/c-json-stdout/c-json-stdout
+	$(RM) -f nDPId nDPIsrvd examples/c-json-stdout/c-json-stdout examples/go-dashboard/go-dashboard
 
 help:
 	@echo '------------------------------------'
@@ -96,6 +104,8 @@ help:
 	@echo 'LDFLAGS          = $(LDFLAGS)'
 	@echo 'PROJECT_CFLAGS	= $(PROJECT_CFLAGS)'
 	@echo 'LIBS             = $(LIBS)'
+	@echo 'GOCC             = $(GOCC)'
+	@echo 'GOFLAGS          = $(GOFLAGS)'
 	@echo 'CUSTOM_LIBNDPI   = $(CUSTOM_LIBNDPI)'
 	@echo 'NDPI_WITH_GCRYPT = $(NDPI_WITH_GCRYPT)'
 	@echo 'NDPI_WITH_PCRE   = $(NDPI_WITH_PCRE)'
diff --git a/examples/go-dashboard/main.go b/examples/go-dashboard/main.go
new file mode 100644
index 000000000..b9dcd314d
--- /dev/null
+++ b/examples/go-dashboard/main.go
@@ -0,0 +1,100 @@
+package main
+
+import (
+	"bufio"
+	"encoding/json"
+	"io"
+	"log"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var (
+	WarningLogger *log.Logger
+	InfoLogger    *log.Logger
+	ErrorLogger   *log.Logger
+
+	NETWORK_BUFFER_MAX_SIZE uint16 = 9216
+	nDPIsrvd_JSON_BYTES     uint16 = 4
+)
+
+func main() {
+	InfoLogger = log.New(os.Stderr, "INFO: ", log.Ldate|log.Ltime|log.Lshortfile)
+	WarningLogger = log.New(os.Stderr, "WARNING: ", log.Ldate|log.Ltime|log.Lshortfile)
+	ErrorLogger = log.New(os.Stderr, "ERROR: ", log.Ldate|log.Ltime|log.Lshortfile)
+
+	conn, _ := net.Dial("tcp", "127.0.0.1:7000")
+
+	buf := make([]byte, NETWORK_BUFFER_MAX_SIZE)
+	var jsonStr string
+	var jsonStrLen uint16 = 0
+	var jsonLen uint16 = 0
+
+	rd := bufio.NewReaderSize(conn, int(NETWORK_BUFFER_MAX_SIZE))
+	for {
+		nread, err := rd.Read(buf)
+
+		if err != nil {
+			if err != io.EOF {
+				ErrorLogger.Printf("Read Error: %v\n", err)
+				break
+			}
+		}
+
+		if nread == 0 || err == io.EOF {
+			WarningLogger.Printf("Disconnect from Server\n")
+			break
+		}
+
+		jsonStr += string(buf[:nread])
+		jsonStrLen += uint16(nread)
+
+		for {
+			if jsonStrLen < nDPIsrvd_JSON_BYTES+1 {
+				break
+			}
+
+			if jsonStr[nDPIsrvd_JSON_BYTES] != '{' {
+				ErrorLogger.Printf("BUG: JSON invalid opening character at position %d: '%s' (%x)\n",
+					nDPIsrvd_JSON_BYTES,
+					string(jsonStr[:nDPIsrvd_JSON_BYTES]), jsonStr[nDPIsrvd_JSON_BYTES])
+				os.Exit(1)
+			}
+
+			if jsonLen == 0 {
+				var tmp uint64
+				if tmp, err = strconv.ParseUint(strings.TrimLeft(jsonStr[:4], "0"), 10, 16); err != nil {
+					ErrorLogger.Printf("BUG: Could not parse length of a JSON string: %v\n", err)
+					os.Exit(1)
+				} else {
+					jsonLen = uint16(tmp)
+				}
+			}
+
+			if jsonStrLen < jsonLen+nDPIsrvd_JSON_BYTES {
+				break
+			}
+
+			if jsonStr[jsonLen+nDPIsrvd_JSON_BYTES-1] != '}' {
+				ErrorLogger.Printf("BUG: JSON invalid closing character at position %d: '%s'\n",
+					jsonLen+nDPIsrvd_JSON_BYTES,
+					string(jsonStr[jsonLen+nDPIsrvd_JSON_BYTES-1]))
+				os.Exit(1)
+			}
+
+			jsonMap := make(map[string]interface{})
+			err := json.Unmarshal([]byte(jsonStr[nDPIsrvd_JSON_BYTES:nDPIsrvd_JSON_BYTES+jsonLen]), &jsonMap)
+			if err != nil {
+				ErrorLogger.Printf("BUG: JSON error: %v\n", err)
+				os.Exit(1)
+			}
+			InfoLogger.Printf("JSON map: %v\n-------------------------------------------------------\n", jsonMap)
+
+			jsonStr = jsonStr[jsonLen+nDPIsrvd_JSON_BYTES:]
+			jsonStrLen -= (jsonLen + nDPIsrvd_JSON_BYTES)
+			jsonLen = 0
+		}
+	}
+}