uhd: Add fuzzy serial number checking

We have integer 32-bit serial numbers for MPM devices, for example
"1234abcd". For serial numbers which have less than eight digits,
e.g. "123abcd", a user may feel inclined to prefix this number with
a 0 when they are searching for devices, e.g. "0123abcd". This change
makes it so that specifying "0123abcd" will match a device with serial
number "123ABCD".

4 files changed, 55 insertions, 1 deletions

diff --git a/host/lib/include/uhdlib/utils/serial_number.hpp b/host/lib/include/uhdlib/utils/serial_number.hpp
new file mode 100644
index 000000000..230f9657d
--- /dev/null
+++ b/host/lib/include/uhdlib/utils/serial_number.hpp
@@ -0,0 +1,29 @@
+//
+// Copyright 2020 Ettus Research, a National Instruments Brand
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+#ifndef INCLUDED_UHDLIB_UTILS_SERIAL_NUMBER_HPP
+#    define INCLUDED_UHDLIB_UTILS_SERIAL_NUMBER_HPP
+
+#include <string>
+
+namespace uhd { namespace utils {
+
+/*! Convenience function to determine whether two serial numbers refer to the
+ * same device. Serial numbers are case-insensitive and ignore leading zeros,
+ * so e.g. the strings "0123abcd" and "123ABCD" are considered the same serial
+ * number.
+ *
+ * Serial numbers cannot be longer than 8 characters or have characters outside
+ * the range 0-9a-fA-F.
+ *
+ * \param serial_a The first serial number to compare
+ * \param serial_b The second serial number to compare
+ */
+bool serial_numbers_match(const std::string& serial_a, const std::string& serial_b);
+
+}}
+
+#endif /* INCLUDED_UHDLIB_UTILS_SERIAL_NUMBER_HPP */
diff --git a/host/lib/usrp/mpmd/mpmd_find.cpp b/host/lib/usrp/mpmd/mpmd_find.cpp
index 501b250b0..c04615587 100644
--- a/host/lib/usrp/mpmd/mpmd_find.cpp
+++ b/host/lib/usrp/mpmd/mpmd_find.cpp
@@ -9,6 +9,7 @@
 #include "mpmd_devices.hpp"
 #include "mpmd_impl.hpp"
 #include "mpmd_link_if_mgr.hpp"
+#include <uhdlib/utils/serial_number.hpp>
 #include <uhd/transport/if_addrs.hpp>
 #include <uhd/transport/udp_simple.hpp>
 #include <uhd/types/device_addr.hpp>
@@ -110,7 +111,7 @@ device_addrs_t mpmd_find_with_addr(
         }
         // filter the discovered device below by matching optional keys
         if ((not hint_.has_key("name") or hint_["name"] == new_addr["name"])
-            and (not hint_.has_key("serial") or hint_["serial"] == new_addr["serial"])
+            and (not hint_.has_key("serial") or uhd::serial_numbers_match(hint_["serial"], new_addr["serial"]))
             and (not hint_.has_key("type") or hint_["type"] == new_addr["type"]
                     or hint_["type"] == MPM_CATCHALL_DEVICE_TYPE)
             and (not hint_.has_key("product")
diff --git a/host/lib/utils/CMakeLists.txt b/host/lib/utils/CMakeLists.txt
index 5d1d22e9b..aa06e2c45 100644
--- a/host/lib/utils/CMakeLists.txt
+++ b/host/lib/utils/CMakeLists.txt
@@ -214,6 +214,7 @@ LIBUHD_APPEND_SOURCES(
     ${CMAKE_CURRENT_SOURCE_DIR}/pathslib.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/platform.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/prefs.cpp
+    ${CMAKE_CURRENT_SOURCE_DIR}/serial_number.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/static.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/system_time.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/tasks.cpp
diff --git a/host/lib/utils/serial_number.cpp b/host/lib/utils/serial_number.cpp
new file mode 100644
index 000000000..7fd0863d6
--- /dev/null
+++ b/host/lib/utils/serial_number.cpp
@@ -0,0 +1,23 @@
+//
+// Copyright 2020 Ettus Research, a National Instruments Brand
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+
+#include <uhdlib/utils/serial_number.hpp>
+#include <stdexcept>
+#include <string>
+
+namespace uhd
+{
+   bool serial_numbers_match(const std::string& serial_a, const std::string& serial_b)
+   {
+      try {
+         const uint32_t a = std::stoi(serial_a, 0, 16);
+         const uint32_t b = std::stoi(serial_b, 0, 16);
+         return a == b;
+      } catch (std::out_of_range& e) {
+         return false;
+      }
+   }
+}