Revert "Fix base64"

This reverts commit d9fa4df.

Author: simonemainardi

.gitignore

@@ -1,6 +1,6 @@
-**/*.o
-**/*.a
+*.o
+*.a
 ebpflow.ebpf.enc
 ebpftest
 toolebpflow
-autom4te.cache/
+autom4te.cache/

Makefile.in

@@ -29,15 +29,12 @@ all: ebpflowexport
 container_info.o: container_info.cpp container_info.h
 	g++ -c $(CFLAGS) container_info.cpp -o container_info.o
 
-libb64.a:
-	make -C ./libs/b64/src && mv ./libs/b64/src/libb64.a ./libb64.a && make -C ./libs/b64/src clean
-
 libebpfflow.a: ebpf_flow.cpp ebpf_flow.h container_info.o ebpflow.ebpf.enc
-	g++ -c $(CFLAGS) ebpf_flow.cpp -I./libs/ -o ebpf_flow.o
+	g++ -c $(CFLAGS) ebpf_flow.cpp -o ebpf_flow.o
 	ar rvs $@ ebpf_flow.o container_info.o
 
-ebpflowexport: ebpflowexport.cpp libebpfflow.a Makefile libb64.a
-	g++ $(CFLAGS) ebpflowexport.cpp -o $@ libebpfflow.a libb64.a $(LIBS)
+ebpflowexport: ebpflowexport.cpp libebpfflow.a Makefile
+	g++ $(CFLAGS) ebpflowexport.cpp -o $@ libebpfflow.a $(LIBS)
 
 ebpflow.ebpf.enc: ebpflow_header.ebpf ebpf_types.h ebpflow_code.ebpf Makefile
 	echo -n "const char * ebpf_code = R\"(" > ebpflow.ebpf.enc
@@ -48,4 +45,4 @@ go_ebpflowexport: ebpflowexport.go Makefile libebpfflow.a
 	go build -o go_ebpflowexport ebpflowexport.go
 
 clean:
-	/bin/rm -f *~ container_info.a libebpfflow.a *.o ebpflow.ebpf.enc libb64.a
+	/bin/rm -f *~ container_info.a libebpfflow.a *.o ebpflow.ebpf.enc

ebpf_flow.cpp

@@ -34,14 +34,52 @@
 #include <unistd.h>
 #include <linux/version.h>
 
-#define BUFFERSIZE 1024
-#include <b64/decode.h>
 #include "ebpflow.ebpf.enc"
 
 static ContainerInfo cinfo;
 
 /* ******************************************* */
 
+std::string b64decode(const void* data, const size_t len) {
+  unsigned char* p = (unsigned char*)data;
+  int pad = len > 0 && (len % 4 || p[len - 1] == '=');
+  const size_t L = ((len + 3) / 4 - pad) * 4;
+  std::string str(L / 4 * 3 + pad, '\0');
+  const int B64index[256] = {
+    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,
+    0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 62, 63, 62, 62, 63, 52, 53, 54, 55,
+    56, 57, 58, 59, 60, 61,  0,  0,  0,  0,  0,  0,  0,  0,  1,  2,  3,  4,  5,  6,
+    7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,  0,
+    0,  0,  0, 63,  0, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51 };
+
+  for(size_t i = 0, j = 0; i < L; i += 4) {
+    int n = B64index[p[i]] << 18 |
+      B64index[p[i + 1]] << 12 |
+      B64index[p[i + 2]] << 6 |
+      B64index[p[i + 3]];
+    str[j++] = n >> 16;
+    str[j++] = n >> 8 & 0xFF;
+    str[j++] = n & 0xFF;
+  }
+
+  if(pad) {
+    int n = B64index[p[L]] << 18 | B64index[p[L + 1]] << 12;
+    str[str.size() - 1] = n >> 16;
+
+    if(len > L + 2 && p[L + 2] != '=') {
+      n |= B64index[p[L + 2]] << 6;
+      str.push_back(n >> 8 & 0xFF);
+    }
+  }
+
+  return str;
+}
+
+/* ******************************************* */
+/* ******************************************* */
+
 static int attachEBPFTracepoint(ebpf::BPF *bpf,
 				const char *tracepoint, const char *probe_func) {
   ebpf::StatusTuple rc = bpf->attach_tracepoint(tracepoint, probe_func);
@@ -79,13 +117,7 @@ extern "C" {
   void* init_ebpf_flow(void *priv_ptr, eBPFHandler ebpfHandler,
 		       ebpfRetCode *rc, u_int16_t flags) {
     ebpf::BPF *bpf = NULL;
-    // Decoding ebpf b64 (http://libb64.sourceforge.net)
-    std::stringstream ebpf_b64_s(ebpf_code);
-    std::stringstream code_s;
-    base64::decoder E;
-    E.decode(ebpf_b64_s, code_s);
-    std::string code = code_s.str().c_str();
-
+    std::string code = b64decode(ebpf_code, strlen(ebpf_code));
     ebpf::StatusTuple open_res(0);
 
     // Default value is 0