rgw: Swift API: X-Trans-Id header is wrongly formatted

src/rgw/rgw_common.h

@@ -1057,6 +1057,8 @@ struct req_state {
 
    string req_id;
 
+   string trans_id;
+
    req_info info;
 
    req_state(CephContext *_cct, class RGWEnv *e);

src/rgw/rgw_main.cc

@@ -555,8 +555,9 @@ static int process_request(RGWRados *store, RGWREST *rest, RGWRequest *req, RGWC
   s->obj_ctx = &rados_ctx;
 
   s->req_id = store->unique_id(req->id);
+  s->trans_id = store->unique_trans_id(req->id);
 
-  req->log(s, "initializing");
+  req->log_format(s, "initializing for trans_id = %s", s->trans_id.c_str());
 
   RGWOp *op = NULL;
   int init_error = 0;

src/rgw/rgw_rados.cc

@@ -1520,6 +1520,8 @@ int RGWRados::init_complete()
   if (ret < 0)
     return ret;
 
+  init_unique_trans_id_deps();
+
   ret = region_map.read(cct, this);
   if (ret < 0) {
     if (ret != -ENOENT) {

src/rgw/rgw_rados.h

@@ -1244,6 +1244,7 @@ class RGWRados
 
   string region_name;
   string zone_name;
+  string trans_id_suffix;
 
   RGWQuotaHandler *quota_handler;
 
@@ -2063,6 +2064,34 @@ class RGWRados
     return s;
   }
 
+  void init_unique_trans_id_deps() {
+    char buf[16 + 2 + 1]; /* uint64_t needs 16, 2 hyphens add further 2 */
+
+    snprintf(buf, sizeof(buf), "-%llx-", (unsigned long long)instance_id());
+    url_encode(string(buf) + zone.name, trans_id_suffix);
+  }
+
+  /* In order to preserve compability with Swift API, transaction ID
+   * should contain at least 32 characters satisfying following spec:
+   *  - first 21 chars must be in range [0-9a-f]. Swift uses this
+   *    space for storing fragment of UUID obtained through a call to
+   *    uuid4() function of Python's uuid module;
+   *  - char no. 22 must be a hyphen;
+   *  - at least 10 next characters constitute hex-formatted timestamp
+   *    padded with zeroes if necessary. All bytes must be in [0-9a-f]
+   *    range;
+   *  - last, optional part of transaction ID is any url-encoded string
+   *    without restriction on length. */
+  string unique_trans_id(const uint64_t unique_num) {
+    char buf[41]; /* 2 + 21 + 1 + 16 (timestamp can consume up to 16) + 1 */
+    time_t timestamp = time(NULL);
+
+    snprintf(buf, sizeof(buf), "tx%021llx-%010llx",
+             (unsigned long long)unique_num,
+             (unsigned long long)timestamp);
+
+    return string(buf) + trans_id_suffix;
+  }
 
   void get_log_pool_name(string& name) {
     name = zone.log_pool.name;

src/rgw/rgw_rest.cc

@@ -492,10 +492,22 @@ void dump_start(struct req_state *s)
   }
 }
 
+void dump_trans_id(req_state *s)
+{
+  if (s->prot_flags & RGW_REST_SWIFT) {
+    s->cio->print("X-Trans-Id: %s\r\n", s->trans_id.c_str());
+  }
+  else {
+    s->cio->print("x-amz-request-id: %s\r\n", s->trans_id.c_str());
+  }
+}
+
 void end_header(struct req_state *s, RGWOp *op, const char *content_type, const int64_t proposed_content_length)
 {
   string ctype;
 
+  dump_trans_id(s);
+
   if (op) {
     dump_access_control(s, op);
   }