core: allow configuring the network stack

build.mk

@@ -11,7 +11,7 @@ opt.release = -O2 -flto
 sanitize = $(sanitize.$(mode))
 opt = $(opt.$(mode))
 
-libs = -laio -ltcmalloc
+libs = -laio -ltcmalloc -lboost_program_options
 
 LDFLAGS = $(libs)
 

core/reactor.cc

@@ -3,6 +3,7 @@
  */
 
 #include "reactor.hh"
+#include "print.hh"
 #include <cassert>
 #include <unistd.h>
 #include <fcntl.h>
@@ -48,6 +49,12 @@ reactor::reactor()
     receive_signal(SIGINT).then([this] { _stopped = true; });
 }
 
+void reactor::configure(boost::program_options::variables_map vm) {
+    _networking_stack = vm.count("network-stack")
+        ? networking_stack_registry::create(sstring(vm["network-stack"].as<std::string>()))
+        : networking_stack_registry::create();
+}
+
 future<> reactor::get_epoll_future(pollable_fd_state& pfd,
         promise<> pollable_fd_state::*pr, int event) {
     if (pfd.events_known & event) {
@@ -476,6 +483,19 @@ networking_stack_registry::create(sstring name) {
     return _map()[name]();
 }
 
+boost::program_options::options_description
+reactor::get_options_description() {
+    namespace bpo = boost::program_options;
+    bpo::options_description opts("Core options");
+    auto net_stack_names = networking_stack_registry::list();
+    opts.add_options()
+        ("network-stack", bpo::value<std::string>(),
+                sprint("select networking stack (valid values: %s)",
+                        format_separated(net_stack_names.begin(), net_stack_names.end(), ", ")).c_str())
+        ;
+    return opts;
+}
+
 networking_stack_registrator<posix_networking_stack> nsr_posix{"posix", true};
 
 reactor the_reactor;

core/reactor.hh

@@ -26,6 +26,7 @@
 #include <atomic>
 #include <boost/lockfree/queue.hpp>
 #include <boost/optional.hpp>
+#include <boost/program_options.hpp>
 #include "util/eclipse.hh"
 #include "future.hh"
 #include "posix.hh"
@@ -354,10 +355,13 @@ private:
     void abort_on_error(int ret);
     void complete_timers();
 public:
+    static boost::program_options::options_description get_options_description();
     reactor();
     reactor(const reactor&) = delete;
     void operator=(const reactor&) = delete;
 
+    void configure(boost::program_options::variables_map config);
+
     server_socket listen(socket_address sa, listen_options opts = {});
 
     pollable_fd posix_listen(socket_address sa, listen_options opts = {});