source/net/resolve.cpp

   1 #include "resolve.h"
   2 #include <msp/core/systemerror.h>
   3 #include <msp/strings/format.h>
   4 #include "platform_api.h"
   5 #include "sockaddr_private.h"
   6 #include "socket.h"
   7
   8 using namespace std;
   9
  10 namespace {
  11
  12 void parse_host_serv(const string &str, string &host, string &serv)
  13 {
  14         if(str[0]=='[')
  15         {
  16                 string::size_type bracket = str.find(']');
  17                 host = str.substr(1, bracket-1);
  18                 string::size_type colon = str.find(':', bracket);
  19                 if(colon!=string::npos)
  20                         serv = str.substr(colon+1);
  21         }
  22         else
  23         {
  24                 string::size_type colon = str.find(':');
  25                 if(colon!=string::npos)
  26                 {
  27                         host = str.substr(0, colon);
  28                         serv = str.substr(colon+1);
  29                 }
  30                 else
  31                         host = str;
  32         }
  33 }
  34
  35 }
  36
  37
  38 namespace Msp {
  39 namespace Net {
  40
  41 SockAddr *resolve(const string &host, const string &serv, Family family)
  42 {
  43         const char *chost = (host.empty() ? nullptr : host.c_str());
  44         const char *cserv = (serv.empty() ? nullptr : serv.c_str());
  45         int flags = 0;
  46         if(host=="*")
  47         {
  48                 flags = AI_PASSIVE;
  49                 chost = nullptr;
  50         }
  51
  52         addrinfo hints = { flags, family_to_sys(family), 0, 0, 0, nullptr, nullptr, nullptr };
  53         addrinfo *res;
  54
  55         int err = getaddrinfo(chost, cserv, &hints, &res);
  56         if(err==0)
  57         {
  58                 SockAddr::SysAddr sa;
  59                 sa.size = res->ai_addrlen;
  60                 const char *sptr = reinterpret_cast<const char *>(res->ai_addr);
  61                 char *dptr = reinterpret_cast<char *>(&sa.addr);
  62                 copy(sptr, sptr+res->ai_addrlen, dptr);
  63                 SockAddr *addr = SockAddr::new_from_sys(sa);
  64                 freeaddrinfo(res);
  65                 return addr;
  66         }
  67         else
  68 #ifdef _WIN32
  69                 throw system_error("getaddrinfo", WSAGetLastError());
  70 #else
  71                 throw system_error("getaddrinfo", gai_strerror(err));
  72 #endif
  73 }
  74
  75 SockAddr *resolve(const string &str, Family family)
  76 {
  77         string host, serv;
  78         parse_host_serv(str, host, serv);
  79
  80         return resolve(host, serv, family);
  81 }
  82
  83
  84 Resolver::Resolver()
  85 {
  86         thread.get_notify_pipe().signal_data_available.connect(sigc::mem_fun(this, &Resolver::task_done));
  87 }
  88
  89 void Resolver::use_event_dispatcher(IO::EventDispatcher *ed)
  90 {
  91         if(event_disp)
  92                 event_disp->remove(thread.get_notify_pipe());
  93         event_disp = ed;
  94         if(event_disp)
  95                 event_disp->add(thread.get_notify_pipe());
  96 }
  97
  98 unsigned Resolver::resolve(const string &host, const string &serv, Family family)
  99 {
 100         Task task;
 101         task.tag = next_tag++;
 102         task.host = host;
 103         task.serv = serv;
 104         task.family = family;
 105         thread.add_task(move(task));
 106         return task.tag;
 107 }
 108
 109 unsigned Resolver::resolve(const string &str, Family family)
 110 {
 111         string host, serv;
 112         parse_host_serv(str, host, serv);
 113
 114         return resolve(host, serv, family);
 115 }
 116
 117 void Resolver::tick()
 118 {
 119         if(IO::poll(thread.get_notify_pipe(), IO::P_INPUT, Time::zero))
 120                 task_done();
 121 }
 122
 123 void Resolver::task_done()
 124 {
 125         char buf[64];
 126         thread.get_notify_pipe().read(buf, sizeof(buf));
 127
 128         while(Task *task = thread.get_complete_task())
 129         {
 130                 if(task->addr)
 131                         signal_address_resolved.emit(task->tag, *task->addr);
 132                 else if(task->error)
 133                 {
 134                         if(signal_resolve_failed.empty())
 135                         {
 136                                 unique_ptr<runtime_error> err = move(task->error);
 137                                 thread.pop_complete_task();
 138                                 throw *err;
 139                         }
 140                         signal_resolve_failed.emit(task->tag, *task->error);
 141                 }
 142                 thread.pop_complete_task();
 143         }
 144 }
 145
 146
 147 Resolver::WorkerThread::WorkerThread():
 148         Thread("Resolver"),
 149         sem(1)
 150 {
 151         launch();
 152 }
 153
 154 Resolver::WorkerThread::~WorkerThread()
 155 {
 156         done = true;
 157         sem.signal();
 158         join();
 159 }
 160
 161 void Resolver::WorkerThread::add_task(Task &&t)
 162 {
 163         MutexLock lock(queue_mutex);
 164         bool was_starved = (queue.empty() || queue.back().is_complete());
 165         queue.push_back(move(t));
 166         if(was_starved)
 167                 sem.signal();
 168 }
 169
 170 Resolver::Task *Resolver::WorkerThread::get_complete_task()
 171 {
 172         MutexLock lock(queue_mutex);
 173         if(!queue.empty() && queue.front().is_complete())
 174                 return &queue.front();
 175         else
 176                 return nullptr;
 177 }
 178
 179 void Resolver::WorkerThread::pop_complete_task()
 180 {
 181         MutexLock lock(queue_mutex);
 182         if(!queue.empty() && queue.front().is_complete())
 183                 queue.pop_front();
 184 }
 185
 186 void Resolver::WorkerThread::main()
 187 {
 188         bool wait = true;
 189         while(!done)
 190         {
 191                 if(wait)
 192                         sem.wait();
 193                 wait = false;
 194
 195                 Task *task = nullptr;
 196                 {
 197                         MutexLock lock(queue_mutex);
 198                         for(auto i=queue.begin(); (!task && i!=queue.end()); ++i)
 199                                 if(!i->is_complete())
 200                                         task = &*i;
 201                 }
 202
 203                 if(task)
 204                 {
 205                         try
 206                         {
 207                                 unique_ptr<SockAddr> addr(Net::resolve(task->host, task->serv, task->family));
 208                                 {
 209                                         MutexLock lock(queue_mutex);
 210                                         task->addr = move(addr);
 211                                 }
 212                         }
 213                         catch(const runtime_error &e)
 214                         {
 215                                 MutexLock lock(queue_mutex);
 216                                 task->error = make_unique<runtime_error>(e);
 217                         }
 218                         notify_pipe.put(1);
 219                 }
 220                 else
 221                         wait = true;
 222         }
 223 }
 224
 225 } // namespace Net
 226 } // namespace Msp