Adding upstream version 0.2.0.

Signed-off-by: Daniel Baumann <daniel@debian.org>

examples/writer.c

@@ -0,0 +1,84 @@
+#include <dnswire/writer.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "create_dnstap.c"
+
+int main(int argc, const char* argv[])
+{
+    if (argc < 2) {
+        fprintf(stderr, "usage: writer <file>\n");
+        return 1;
+    }
+
+    /*
+     * We start by opening the output file for writing.
+     */
+
+    FILE* fp = fopen(argv[1], "w");
+    if (!fp) {
+        fprintf(stderr, "Unable to open %s: %s\n", argv[1], strerror(errno));
+        return 1;
+    }
+
+    /*
+     * We first initialize the writer and check that it can allocate the
+     * buffers it needs.
+     */
+
+    struct dnswire_writer writer;
+
+    if (dnswire_writer_init(&writer) != dnswire_ok) {
+        fprintf(stderr, "Unable to initialize dnswire writer\n");
+        return 1;
+    }
+
+    /*
+     * Now we create a DNSTAP message.
+     */
+
+    struct dnstap d = create_dnstap("writer");
+
+    /*
+     * We set the DNSTAP message the writer should write.
+     */
+
+    dnswire_writer_set_dnstap(writer, &d);
+
+    /*
+     * We now loop and wait for the DNSTAP message to be written.
+     */
+
+    int done = 0;
+
+    while (!done) {
+        switch (dnswire_writer_fwrite(&writer, fp)) {
+        case dnswire_ok:
+            /*
+             * The DNSTAP message was written successfully, we can now set
+             * a new DNSTAP message for the writer or stop the stream.
+             *
+             * This stops the stream, loop again until it's stopped.
+             */
+            dnswire_writer_stop(&writer);
+            break;
+        case dnswire_again:
+            break;
+        case dnswire_endofdata:
+            /*
+             * The stream is stopped, we're done!
+             */
+            done = 1;
+            break;
+        default:
+            fprintf(stderr, "dnswire_writer_fwrite() error\n");
+            done = 1;
+        }
+    }
+
+    dnswire_writer_destroy(writer);
+    fclose(fp);
+    return 0;
+}