log_xxd_always(): Use a variable-length array

The debug message buffer is no more with a fixed size (around 600 bytes
of buffer to log) but uses a variable-length array.

It is now possible to log extended APDU of 64kB.

The variable-length array feature is available in GCC in C90 mode and is
mandatory in C99 standard.

git-svn-id: svn:https://anonscm.debian.org/svn/pcsclite/trunk/PCSC@5901 0ce88b0d-b2fd-0310-8134-9614164e65ea

src/debuglog.c

@@ -79,10 +79,9 @@ INTERNAL void DebugLogCategory(const int category, const unsigned char *buffer,
 #else
 
 /**
- * Max string size when dumping a 256 bytes longs APDU
- * Should be bigger than 256*3+30
+ * Max string size dumping a maxmium of 2 lines of 80 characters
  */
-#define DEBUG_BUF_SIZE 2048
+#define DEBUG_BUF_SIZE 160
 
 static char LogMsgType = DEBUGLOG_NO_DEBUG;
 static char LogCategory = DEBUG_CATEGORY_NOTHING;
@@ -177,27 +176,21 @@ static void log_line(const int priority, const char *DebugBuffer)
 static void log_xxd_always(const int priority, const char *msg,
  const unsigned char *buffer, const int len)
 {
- char DebugBuffer[DEBUG_BUF_SIZE];
+ char DebugBuffer[len*3 + strlen(msg) +1];
  int i;
  char *c;
- char *debug_buf_end;
-
- debug_buf_end = DebugBuffer + sizeof DebugBuffer - 5;
+ size_t l;
 
- strlcpy(DebugBuffer, msg, sizeof(DebugBuffer));
- c = DebugBuffer + strlen(DebugBuffer);
+ l = strlcpy(DebugBuffer, msg, sizeof(DebugBuffer));
+ c = DebugBuffer + l;
 
- for (i = 0; (i < len) && (c < debug_buf_end); ++i)
+ for (i = 0; (i < len); ++i)
  {
  /* 2 hex characters, 1 space, 1 NUL : total 4 characters */
  snprintf(c, 4, "%02X ", buffer[i]);
  c += 3;
  }
 
- /* the buffer is too small so end it with "..." */
- if ((c >= debug_buf_end) && (i < len))
- c[-3] = c[-2] = c[-1] = '.';
-
  log_line(priority, DebugBuffer);
 } /* log_xxd_always */