rgw: Fix incorrect content length and range for zero sized objects du…

…ring range requests

Fixes: http://tracker.ceph.com/issues/16388

Signed-off-by: Pavan Rallabhandi <PRallabhandi@walmartlabs.com>

src/rgw/rgw_rados.cc

@@ -8662,6 +8662,12 @@ int RGWRados::Object::Read::prepare(int64_t *pofs, int64_t *pend)
     }
   }
 
+  // for range requests with obj size 0
+  if (!astate->size) {
+    end = astate->size - 1;
+    return -ERANGE;
+  }
+
   if (pofs)
     *pofs = ofs;
   if (pend)

src/rgw/rgw_rest.cc

@@ -655,7 +655,9 @@ void end_header(struct req_state* s, RGWOp* op, const char *content_type,
       s->formatter->close_section();
     }
     s->formatter->output_footer();
-    dump_content_length(s, s->formatter->get_len());
+    if (s->obj_size) {
+      dump_content_length(s, s->formatter->get_len());
+    }
   } else {
     if (proposed_content_length != NO_CONTENT_LENGTH) {
       dump_content_length(s, proposed_content_length);
@@ -769,8 +771,13 @@ void dump_range(struct req_state *s, uint64_t ofs, uint64_t end,
 
   /* dumping range into temp buffer first, as libfcgi will fail to digest
    * %lld */
-  snprintf(range_buf, sizeof(range_buf), "%lld-%lld/%lld", (long long)ofs,
-	   (long long)end, (long long)total);
+
+  if (!total) {
+    snprintf(range_buf, sizeof(range_buf), "*/%lld", (long long)total);
+  } else {
+    snprintf(range_buf, sizeof(range_buf), "%lld-%lld/%lld", (long long)ofs,
+		(long long)end, (long long)total);
+  }
   int r = STREAM_IO(s)->print("Content-Range: bytes %s\r\n", range_buf);
   if (r < 0) {
     ldout(s->cct, 0) << "ERROR: s->cio->print() returned err=" << r << dendl;

src/rgw/rgw_rest_swift.cc

@@ -1205,17 +1205,20 @@ int RGWGetObj_ObjStore_SWIFT::send_response_data(bufferlist& bl,
 
   set_req_state_err(s, (partial_content && !op_ret) ? STATUS_PARTIAL_CONTENT
 		    : op_ret);
+
   dump_errno(s);
-  if (s->err.is_err()) {
-    end_header(s, NULL);
-    return 0;
-  }
 
   if (range_str) {
     dump_range(s, ofs, end, s->obj_size);
   }
 
   dump_content_length(s, total_len);
+
+  if (s->err.is_err()) {
+    end_header(s, NULL);
+    return 0;
+  }
+
   dump_last_modified(s, lastmod);
   {
     utime_t ut(lastmod);