dpdk: Add support for DPDK 18.11 API

Substituting old values to restore API breakage from DPDK 18.11 to DPDK 19.
It is recommended at this point that users upgrade to more recent DPDK LTS
versions, but the DPDK 18.11 API is functional with UHD.

Signed-off-by: mattprost <matt.prost@ni.com>

5 files changed, 44 insertions, 3 deletions

diff --git a/host/cmake/Modules/FindDPDK.cmake b/host/cmake/Modules/FindDPDK.cmake
index 4f1426dfd..90240e61d 100644
--- a/host/cmake/Modules/FindDPDK.cmake
+++ b/host/cmake/Modules/FindDPDK.cmake
@@ -39,7 +39,7 @@ else()
 endif()
 
 find_package(PkgConfig)
-PKG_CHECK_MODULES(PC_DPDK QUIET libdpdk>=19.11)
+PKG_CHECK_MODULES(PC_DPDK QUIET libdpdk>=18.11)
 
 find_path (DPDK_VERSION_INCLUDE_DIR rte_version.h
     HINTS ${PC_DPDK_INCLUDE_DIRS}
diff --git a/host/docs/dpdk.dox b/host/docs/dpdk.dox
index 0b86c78ba..a48ce42d3 100644
--- a/host/docs/dpdk.dox
+++ b/host/docs/dpdk.dox
@@ -26,7 +26,8 @@ computer.
 \subsection dpdk_installation DPDK Installation Instructions
 
 As a new and developing technology, the DPDK APIs are unstable. UHD requires
-version 19.11, 20.11 or 21.11.
+version 18.11(deprecated), 19.11, 20.11 or 21.11. Adjacent non-LTS releases of
+DPDK may work, but are not recommended.
 
 On Ubuntu 20.04, Fedora 33-36, or Debian Bullseye/Buster (via backports),
 DPDK is available in your distribution's repositories. For example, on Debian
diff --git a/host/lib/CMakeLists.txt b/host/lib/CMakeLists.txt
index 094827d2a..5aee65d38 100644
--- a/host/lib/CMakeLists.txt
+++ b/host/lib/CMakeLists.txt
@@ -60,7 +60,7 @@ endmacro(INCLUDE_SUBDIRECTORY)
 message(STATUS "")
 # Dependencies
 find_package(LIBUSB)
-find_package(DPDK 19.11...21.11)
+find_package(DPDK 18.11...21.11)
 LIBUHD_REGISTER_COMPONENT("USB" ENABLE_USB ON "ENABLE_LIBUHD;LIBUSB_FOUND" OFF OFF)
 # Devices
 LIBUHD_REGISTER_COMPONENT("B100" ENABLE_B100 ON "ENABLE_LIBUHD;ENABLE_USB" OFF OFF)
diff --git a/host/lib/include/uhdlib/transport/dpdk/common.hpp b/host/lib/include/uhdlib/transport/dpdk/common.hpp
index c1302335a..4c5ba02e9 100644
--- a/host/lib/include/uhdlib/transport/dpdk/common.hpp
+++ b/host/lib/include/uhdlib/transport/dpdk/common.hpp
@@ -26,6 +26,38 @@
 
 /* NOTE: There are changes to all the network standard fields in 19.x */
 
+/*
+ * Substituting old values to support DPDK 18.11 with the API changes in DPDK 19.
+ * There were no functional changes in the DPDK calls utilized by UHD between
+ * these two API versions.
+ */
+#if RTE_VER_YEAR < 19 || (RTE_VER_YEAR == 19 && RTE_VER_MONTH < 8)
+// 18.11 data types
+#define rte_ether_addr ether_addr
+#define rte_ether_hdr  ether_hdr
+#define rte_arp_hdr    arp_hdr
+#define arp_hardware   arp_hrd
+#define arp_protocol   arp_pro
+#define arp_hlen       arp_hln
+#define arp_plen       arp_pln
+#define arp_opcode     arp_op
+#define rte_ipv4_hdr   ipv4_hdr
+#define rte_udp_hdr    udp_hdr
+// 18.11 constants
+#define RTE_ETHER_TYPE_IPV4  ETHER_TYPE_IPv4
+#define RTE_ETHER_TYPE_ARP   ETHER_TYPE_ARP
+#define RTE_ETHER_ADDR_LEN   ETHER_ADDR_LEN
+#define RTE_ETHER_CRC_LEN    ETHER_CRC_LEN
+#define RTE_ETHER_HDR_LEN    ETHER_HDR_LEN
+#define RTE_IPV4_HDR_DF_FLAG IPV4_HDR_DF_FLAG
+#define RTE_ARP_HRD_ETHER    ARP_HRD_ETHER
+#define RTE_ARP_OP_REPLY     ARP_OP_REPLY
+#define RTE_ARP_OP_REQUEST   ARP_OP_REQUEST
+// 18.11 functions
+#define rte_ether_addr_copy    ether_addr_copy
+#define rte_ether_format_addr  ether_format_addr
+#define rte_is_zero_ether_addr is_zero_ether_addr
+#endif
 
 namespace uhd { namespace transport {
 
diff --git a/host/lib/transport/uhd-dpdk/dpdk_common.cpp b/host/lib/transport/uhd-dpdk/dpdk_common.cpp
index 55bf57cdc..0f0a00e51 100644
--- a/host/lib/transport/uhd-dpdk/dpdk_common.cpp
+++ b/host/lib/transport/uhd-dpdk/dpdk_common.cpp
@@ -413,6 +413,14 @@ void dpdk_ctx::init(const device_addr_t& user_args)
     unsigned int i;
     std::lock_guard<std::mutex> lock(_init_mutex);
     if (!_init_done) {
+#if RTE_VER_YEAR < 19 || (RTE_VER_YEAR == 19 && RTE_VER_MONTH < 11)
+        UHD_LOG_WARNING("DPDK",
+            "Deprecated DPDK version "
+                << RTE_VER_YEAR << "." << RTE_VER_MONTH
+                << " detected. Consider upgrading DPDK. Recommended versions are 19.11, "
+                   "20.11, and 21.11.");
+#endif
+
         /* Gather global config, build args for EAL, and init UHD-DPDK */
         const device_addr_t dpdk_args = uhd::prefs::get_dpdk_args(user_args);
         UHD_LOG_TRACE("DPDK", "Configuration:" << std::endl << dpdk_args.to_pp_string());