Add remote device support via bpfd

SPECS/bcc+clang.spec

@@ -79,6 +79,11 @@ Requires: python-bcc
 %description -n bcc-tools
 Command line tools for BPF Compiler Collection (BCC)
 
+%package -n bpfd
+Summary: Proxy daemon for remote target devices
+%description -n bpfd
+Proxy daemon for remote target devices
+
 %files -n python-bcc
 %{python_sitelib}/bcc*
 
@@ -99,3 +104,6 @@ Command line tools for BPF Compiler Collection (BCC)
 /usr/share/bcc/introspection/*
 /usr/share/bcc/tools/*
 /usr/share/bcc/man/*
+
+%files -n bpfd
+/usr/bin/bpfd

SPECS/bcc.spec

@@ -138,6 +138,11 @@ Requires: %{python_bcc} = %{version}-%{release}
 %description -n bcc-tools
 Command line tools for BPF Compiler Collection (BCC)
 
+%package -n bpfd
+Summary: Proxy daemon for remote target devices
+%description -n bpfd
+Proxy daemon for remote target devices
+
 %files -n libbcc
 /usr/lib64/*
 /usr/include/bcc/*
@@ -169,6 +174,9 @@ Command line tools for BPF Compiler Collection (BCC)
 /usr/share/bcc/tools/*
 /usr/share/bcc/man/*
 
+%files -n bpfd
+/usr/bin/bpfd
+
 %post -n libbcc -p /sbin/ldconfig
 
 %postun -n libbcc -p /sbin/ldconfig

debian/bpfd.install

@@ -0,0 +1 @@
+usr/bin/bpfd

debian/control

@@ -55,3 +55,7 @@ Provides: bpfcc-lua
 Conflicts: bpfcc-lua
 Depends: libbcc (= ${binary:Version})
 Description: Standalone tool to run BCC tracers written in Lua
+
+Package: bpfd
+Architecture: all
+Description: Proxy daemon for remote target devices

src/cc/CMakeLists.txt

@@ -102,6 +102,7 @@ if(ENABLE_USDT)
 endif()
 
 add_subdirectory(frontends)
+add_subdirectory(bpfd)
 
 # Link against LLVM libraries
 target_link_libraries(bcc-shared ${bcc_common_libs_for_s})

src/cc/bcc_common.cc

@@ -17,6 +17,14 @@
 #include "bpf_module.h"
 
 extern "C" {
+
+// This stores the appropriate callback function to invoke when there is a
+// need to create a map. This is done so that the Python interface can pass
+// custom callbacks to create maps for situations wherein the map creation
+// functions provided by libbbc are not sufficient (e.g. when there is a need
+// to create maps on remote target devices).
+bpf_create_map_cb_t bpf_create_map_cb;
+
 void * bpf_module_create_b(const char *filename, const char *proto_filename, unsigned flags) {
   auto mod = new ebpf::BPFModule(flags);
   if (mod->load_b(filename, proto_filename) != 0) {
@@ -27,7 +35,9 @@ void * bpf_module_create_b(const char *filename, const char *proto_filename, uns
 }
 
 void * bpf_module_create_c(const char *filename, unsigned flags, const char *cflags[],
-                           int ncflags, bool allow_rlimit) {
+                           int ncflags, bool allow_rlimit, bpf_create_map_cb_t map_cb) {
+  bpf_create_map_cb = map_cb;
+
   auto mod = new ebpf::BPFModule(flags, nullptr, true, "", allow_rlimit);
   if (mod->load_c(filename, cflags, ncflags) != 0) {
     delete mod;
@@ -37,7 +47,9 @@ void * bpf_module_create_c(const char *filename, unsigned flags, const char *cfl
 }
 
 void * bpf_module_create_c_from_string(const char *text, unsigned flags, const char *cflags[],
-                                       int ncflags, bool allow_rlimit) {
+                                       int ncflags, bool allow_rlimit, bpf_create_map_cb_t map_cb) {
+  bpf_create_map_cb = map_cb;
+
   auto mod = new ebpf::BPFModule(flags, nullptr, true, "", allow_rlimit);
   if (mod->load_string(text, cflags, ncflags) != 0) {
     delete mod;

src/cc/bcc_common.h

@@ -25,11 +25,14 @@
 extern "C" {
 #endif
 
+typedef int (*bpf_create_map_cb_t)(void *data, bool allow_rlimit);
+extern bpf_create_map_cb_t bpf_create_map_cb;
+
 void * bpf_module_create_b(const char *filename, const char *proto_filename, unsigned flags);
 void * bpf_module_create_c(const char *filename, unsigned flags, const char *cflags[], int ncflags,
-                           bool allow_rlimit);
+                           bool allow_rlimit, bpf_create_map_cb_t map_cb);
 void * bpf_module_create_c_from_string(const char *text, unsigned flags, const char *cflags[],
-                                       int ncflags, bool allow_rlimit);
+                                       int ncflags, bool allow_rlimit, bpf_create_map_cb_t map_cb);
 void bpf_module_destroy(void *program);
 char * bpf_module_license(void *program);
 unsigned bpf_module_kern_version(void *program);

src/cc/bpf_module.cc

@@ -43,6 +43,7 @@
 #include "exported_files.h"
 #include "libbpf.h"
 #include "bcc_btf.h"
+#include "bcc_common.h"
 #include "libbpf/src/bpf.h"
 
 namespace ebpf {
@@ -340,7 +341,10 @@ int BPFModule::load_maps(sec_map_def &sections) {
       attr.btf_value_type_id = map_tids[map_name].second;
     }
 
-    fd = bcc_create_map_xattr(&attr, allow_rlimit_);
+    if (bpf_create_map_cb)
+      fd = bpf_create_map_cb(&attr, allow_rlimit_);
+    else
+      fd = bcc_create_map_xattr(&attr, allow_rlimit_);
     if (fd < 0) {
       fprintf(stderr, "could not open bpf map: %s, error: %s\n",
               map_name, strerror(errno));

src/cc/bpfd/CMakeLists.txt

@@ -0,0 +1,30 @@
+# Copyright (c) Jazel Canseco, 2018
+# Copyright (c) Adrian Ratiu, 2019
+# Licensed under the Apache License, Version 2.0 (the "License")
+
+cmake_minimum_required(VERSION 2.8.7)
+
+if(NOT CMAKE_BUILD_TYPE)
+  set(CMAKE_BUILD_TYPE Release)
+endif()
+
+set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_CURRENT_SOURCE_DIR}/../../../cmake)
+
+find_package(LibElf REQUIRED)
+find_package(ZLIB REQUIRED)
+
+include_directories(${CMAKE_CURRENT_SOURCE_DIR}/..
+                    ${CMAKE_CURRENT_SOURCE_DIR}/../libbpf/include
+                    ${CMAKE_CURRENT_SOURCE_DIR}/../libbpf/include/uapi)
+
+add_library(bcc-bpfd-static STATIC ../common.cc ../bcc_syms.cc ../ns_guard.cc ../bcc_proc.c
+                                   ../libbpf.c ../perf_reader.c ../bcc_elf.c ../bcc_perf_map.c)
+
+file(GLOB libbpf_sources "../libbpf/src/*.c")
+add_library(bpf-bpfd-static STATIC ../libbpf.c ${libbpf_sources})
+
+add_executable(bpfd bpfd.c base64.c remote_perf_reader.c utils.c cmd_parsers.c)
+target_link_libraries(bpfd bpf-bpfd-static bcc-bpfd-static)
+target_link_libraries(bpfd ${LIBELF_LIBRARIES} ${ZLIB_LIBRARIES})
+
+install(TARGETS bpfd RUNTIME DESTINATION bin)