source/net/resolve.cpp

   1 #include "platform_api.h"
   2 #include <msp/core/systemerror.h>
   3 #include <msp/strings/format.h>
   4 #include "sockaddr_private.h"
   5 #include "socket.h"
   6 #include "resolve.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() ? 0 : host.c_str());
  44         const char *cserv = (serv.empty() ? 0 : serv.c_str());
  45         int flags = 0;
  46         if(host=="*")
  47         {
  48                 flags = AI_PASSIVE;
  49                 chost = 0;
  50         }
  51
  52         addrinfo hints = { flags, family_to_sys(family), 0, 0, 0, 0, 0, 0 };
  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(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                                 RefPtr<runtime_error> err = task->error;
 137                                 task->error = 0;
 138                                 thread.pop_complete_task();
 139                                 throw *err;
 140                         }
 141                         signal_resolve_failed.emit(task->tag, *task->error);
 142                 }
 143                 thread.pop_complete_task();
 144         }
 145 }
 146
 147
 148 Resolver::WorkerThread::WorkerThread():
 149         Thread("Resolver"),
 150         sem(1)
 151 {
 152         launch();
 153 }
 154
 155 Resolver::WorkerThread::~WorkerThread()
 156 {
 157         done = true;
 158         sem.signal();
 159         join();
 160 }
 161
 162 void Resolver::WorkerThread::add_task(const Task &t)
 163 {
 164         MutexLock lock(queue_mutex);
 165         bool was_starved = (queue.empty() || queue.back().is_complete());
 166         queue.push_back(t);
 167         if(was_starved)
 168                 sem.signal();
 169 }
 170
 171 Resolver::Task *Resolver::WorkerThread::get_complete_task()
 172 {
 173         MutexLock lock(queue_mutex);
 174         if(!queue.empty() && queue.front().is_complete())
 175                 return &queue.front();
 176         else
 177                 return 0;
 178 }
 179
 180 void Resolver::WorkerThread::pop_complete_task()
 181 {
 182         MutexLock lock(queue_mutex);
 183         if(!queue.empty() && queue.front().is_complete())
 184         {
 185                 delete queue.front().addr;
 186                 delete queue.front().error;
 187                 queue.pop_front();
 188         }
 189 }
 190
 191 void Resolver::WorkerThread::main()
 192 {
 193         bool wait = true;
 194         while(!done)
 195         {
 196                 if(wait)
 197                         sem.wait();
 198                 wait = false;
 199
 200                 Task *task = 0;
 201                 {
 202                         MutexLock lock(queue_mutex);
 203                         for(auto i=queue.begin(); (!task && i!=queue.end()); ++i)
 204                                 if(!i->is_complete())
 205                                         task = &*i;
 206                 }
 207
 208                 if(task)
 209                 {
 210                         try
 211                         {
 212                                 SockAddr *addr = Net::resolve(task->host, task->serv, task->family);
 213                                 {
 214                                         MutexLock lock(queue_mutex);
 215                                         task->addr = addr;
 216                                 }
 217                         }
 218                         catch(const runtime_error &e)
 219                         {
 220                                 MutexLock lock(queue_mutex);
 221                                 task->error = new runtime_error(e);
 222                         }
 223                         notify_pipe.put(1);
 224                 }
 225                 else
 226                         wait = true;
 227         }
 228 }
 229
 230 } // namespace Net
 231 } // namespace Msp