manager: use built-in xdp prog

Signed-off-by: Ric Li <[email protected]>

manager/gen_skel.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+cp $1/manager.xdp.c .
+
+clang -g -O2 -target bpf -c manager.xdp.c -o manager.xdp.o
+llvm-strip -g manager.xdp.o
+bpftool gen skeleton manager.xdp.o > xdp.skel.h

manager/manager.xdp.c

@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+ * Copyright(c) 2023 Intel Corporation
+ */
+
+//clang-format off
+#include <linux/bpf.h>
+//clang-format off
+
+#include <bpf/bpf_helpers.h>
+#include <xdp/parsing_helpers.h>
+#include <xdp/xdp_helpers.h>
+
+char LICENSE[] SEC("license") = "Dual BSD/GPL";
+
+struct {
+  __uint(type, BPF_MAP_TYPE_ARRAY);
+  __uint(max_entries, 65536);
+  __type(key, int);
+  __type(value, int);
+} udp4_dp_filter SEC(".maps");
+
+#define DEFAULT_QUEUE_IDS 64
+
+struct {
+  __uint(type, BPF_MAP_TYPE_XSKMAP);
+  __uint(key_size, sizeof(int));
+  __uint(value_size, sizeof(int));
+  __uint(max_entries, DEFAULT_QUEUE_IDS);
+} xsks_map SEC(".maps");
+
+volatile int refcnt = 1;
+
+static int __always_inline lookup_udp4_dp(int dp) {
+  int* value;
+
+  value = bpf_map_lookup_elem(&udp4_dp_filter, &dp);
+  if (value && *value != 0) return 1;
+  return 0;
+}
+
+SEC("xdp")
+int xsk_def_prog(struct xdp_md* ctx) {
+  if (!refcnt) return XDP_PASS;
+
+  void* data_end = (void*)(long)ctx->data_end;
+  void* data = (void*)(long)ctx->data;
+
+  struct hdr_cursor nh;
+  struct ethhdr* eth;
+  int eth_type;
+
+  nh.pos = data;
+  eth_type = parse_ethhdr(&nh, data_end, &eth);
+  if (eth_type != bpf_htons(ETH_P_IP)) return XDP_PASS;
+
+  struct iphdr* iphdr;
+  int ip_type;
+  ip_type = parse_iphdr(&nh, data_end, &iphdr);
+  if (ip_type != IPPROTO_UDP) return XDP_PASS;
+
+  struct udphdr* udphdr;
+  int ret;
+  ret = parse_udphdr(&nh, data_end, &udphdr);
+  if (ret < 0) return XDP_PASS;
+
+  int dst_port = bpf_ntohs(udphdr->dest);
+  if (lookup_udp4_dp(dst_port) == 0) return XDP_PASS;
+
+  return bpf_redirect_map(&xsks_map, ctx->rx_queue_index, XDP_PASS);
+}

manager/meson.build

@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # Copyright 2023 Intel Corporation
 
-project('mtl_manager', 'cpp', default_options: ['buildtype=release', 'cpp_std=c++17'])
+project('mtl_manager', 'cpp', default_options: ['buildtype=release', 'cpp_std=c++17'], version: '0.2.0')
 
 exec_env = host_machine.system()
 set_variable('is_windows', exec_env == 'windows')
@@ -15,8 +15,6 @@ message('BUILD Environment: ' + exec_env)
 
 cpp_c = meson.get_compiler('cpp')
 
-sources = ['mtl_manager.cpp']
-
 cpp_args = ['-std=c++17', '-Wall']
 link_cpp_args = ['-lstdc++fs']
 
@@ -41,6 +39,15 @@ else
   message('libxdp and libbpf not found, no af_xdp backend')
 endif
 
+# Generate XDP prog code
+gen_skel = find_program('gen_skel.sh')
+sekl = custom_target('skeleton',
+  output : ['xdp.skel.h'],
+  input : ['manager.xdp.c'],
+  command : [gen_skel] + meson.current_source_dir())
+
+sources = ['mtl_manager.cpp', sekl]
+
 executable('MtlManager', sources,
   cpp_args: cpp_args,
   link_args: link_cpp_args,

manager/mtl_interface.hpp

@@ -9,6 +9,8 @@
 #include <bpf/libbpf.h>
 #include <xdp/libxdp.h>
 #include <xdp/xsk.h>
+
+#include "xdp.skel.h"
 #endif
 
 #include <net/if.h>
@@ -136,34 +138,39 @@ int mtl_interface::clear_flow_rules() {
 
 #ifdef MTL_HAS_XDP_BACKEND
 int mtl_interface::load_xdp() {
-  /* get xdp prog path from env or use manager default path */
-  std::string xdp_prog_path;
-  char* xdp_prog_path_env = getenv("MTL_XDP_PROG_PATH");
-  if (xdp_prog_path_env != nullptr) {
-    xdp_prog_path = xdp_prog_path_env;
-  } else {
-    xdp_prog_path = "/tmp/imtl/xdp_prog.o";
-  }
+  /* get customized xdp prog path from env */
+  std::string xdp_prog_path = getenv("MTL_XDP_PROG_PATH");
 
   if (!std::filesystem::is_regular_file(xdp_prog_path)) {
     log(log_level::WARNING,
-        "Fallback to use libxdp default prog for " + xdp_prog_path + " is not valid.");
+        "Fallback to use built-in prog for " + xdp_prog_path + " is not valid.");
   } else {
     xdp_prog = xdp_program__open_file(xdp_prog_path.c_str(), NULL, NULL);
     if (libxdp_get_error(xdp_prog)) {
-      log(log_level::WARNING,
-          "Fallback to use libxdp default prog for " + xdp_prog_path + " cannot load.");
+      log(log_level::WARNING, "Fallback to use built-in prog prog for " + xdp_prog_path +
+                                  " cannot be loaded.");
       xdp_prog = nullptr;
-    } else {
-      if (xdp_program__attach(xdp_prog, ifindex, XDP_MODE_NATIVE, 0) < 0) {
-        log(log_level::WARNING,
-            "Failed to attach XDP program with native mode, try skb mode.");
-        if (xdp_program__attach(xdp_prog, ifindex, XDP_MODE_SKB, 0) < 0) {
-          log(log_level::ERROR, "Failed to attach XDP program " + xdp_prog_path);
-          xdp_program__close(xdp_prog);
-          return -1;
-        }
-      }
+    }
+  }
+
+  if (xdp_prog == nullptr) {
+    /* load built-in xdp prog from skeleton */
+    xdp_prog_path = "<built-in>";
+    struct manager_xdp* skel = manager_xdp__open();
+    if (!skel) {
+      log(log_level::ERROR, "Failed to open built-in xdp prog skeleton");
+      return -1;
+    }
+    xdp_prog = xdp_program__from_bpf_obj(skel->obj, "xdp");
+  }
+
+  if (xdp_program__attach(xdp_prog, ifindex, XDP_MODE_NATIVE, 0) < 0) {
+    log(log_level::WARNING,
+        "Failed to attach XDP program with native mode, try skb mode.");
+    if (xdp_program__attach(xdp_prog, ifindex, XDP_MODE_SKB, 0) < 0) {
+      log(log_level::ERROR, "Failed to attach XDP program " + xdp_prog_path);
+      xdp_program__close(xdp_prog);
+      return -1;
     }
   }
 
@@ -183,7 +190,6 @@ int mtl_interface::load_xdp() {
     return -1;
   }
 
-  if (xdp_prog == nullptr) xdp_prog_path = "<libxdp_default>";
   log(log_level::INFO, "Loaded xdp prog " + xdp_prog_path);
   return 0;
 }