rgw: Swift API returns 400 Bad Request on too long container names.

Fixes: http://tracker.ceph.com/issues/17935
Signed-off-by: Radoslaw Zarzynski <rzarzynski@mirantis.com>

src/rgw/rgw_common.cc

@@ -118,6 +118,7 @@ rgw_http_errors rgw_http_s3_errors({
 rgw_http_errors rgw_http_swift_errors({
     { EACCES, {403, "AccessDenied" }},
     { EPERM, {401, "AccessDenied" }},
+    { ENAMETOOLONG, {400, "Metadata name too long" }},
     { ERR_USER_SUSPENDED, {401, "UserSuspended" }},
     { ERR_INVALID_UTF8, {412, "Invalid UTF8" }},
     { ERR_BAD_URL, {412, "Bad URL" }},

src/rgw/rgw_rest_swift.cc

@@ -2,6 +2,7 @@
 // vim: ts=8 sw=2 smarttab
 
 #include <boost/algorithm/string/predicate.hpp>
+#include <boost/format.hpp>
 #include <boost/optional.hpp>
 #include <boost/utility/in_place_factory.hpp>
 
@@ -2591,11 +2592,22 @@ int RGWHandler_REST_SWIFT::postauth_init()
 
 int RGWHandler_REST_SWIFT::validate_bucket_name(const string& bucket)
 {
-  int ret = RGWHandler_REST::validate_bucket_name(bucket);
-  if (ret < 0)
-    return ret;
+  const size_t len = bucket.size();
+
+  if (len > MAX_BUCKET_NAME_LEN) {
+    /* Bucket Name too long. Generate custom error message and bind it
+     * to an R-value reference. */
+    const auto msg = boost::str(
+      boost::format("Container name length of %lld longer than %lld")
+        % len % int(MAX_BUCKET_NAME_LEN));
+    set_req_state_err(s, ERR_INVALID_BUCKET_NAME, msg);
+    return -ERR_INVALID_BUCKET_NAME;
+  }
 
-  int len = bucket.size();
+  const auto ret = RGWHandler_REST::validate_bucket_name(bucket);
+  if (ret < 0) {
+    return ret;
+  }
 
   if (len == 0)
     return 0;
@@ -2608,7 +2620,7 @@ int RGWHandler_REST_SWIFT::validate_bucket_name(const string& bucket)
 
   const char *s = bucket.c_str();
 
-  for (int i = 0; i < len; ++i, ++s) {
+  for (size_t i = 0; i < len; ++i, ++s) {
     if (*(unsigned char *)s == 0xff)
       return -ERR_INVALID_BUCKET_NAME;
   }

src/rgw/rgw_rest_swift.h

@@ -381,7 +381,7 @@ class RGWHandler_REST_SWIFT : public RGWHandler_REST {
   }
   ~RGWHandler_REST_SWIFT() override = default;
 
-  static int validate_bucket_name(const string& bucket);
+  int validate_bucket_name(const string& bucket);
 
   int init(RGWRados *store, struct req_state *s, rgw::io::BasicClient *cio) override;
   int authorize() override;