Merge branch 'pu/happy-eyeballs2a'

Happy Eyeballs are coming, yay!

1 files changed, 184 insertions, 56 deletions

diff --git a/methods/connect.cc b/methods/connect.cc
index 1354fe97b..334a1d3f3 100644
--- a/methods/connect.cc
+++ b/methods/connect.cc
@@ -23,6 +23,7 @@
 #include <gnutls/gnutls.h>
 #include <gnutls/x509.h>
 
+#include <list>
 #include <set>
 #include <sstream>
 #include <string>
@@ -35,6 +36,7 @@
 #include <netdb.h>
 #include <arpa/inet.h>
 #include <netinet/in.h>
+#include <sys/select.h>
 #include <sys/socket.h>
 
 #include "aptmethod.h"
@@ -112,16 +114,54 @@ std::unique_ptr<MethodFd> MethodFd::FromFd(int iFd)
 // DoConnect - Attempt a connect operation				/*{{{*/
 // ---------------------------------------------------------------------
 /* This helper function attempts a connection to a single address. */
-static ResultState DoConnect(struct addrinfo *Addr, std::string const &Host,
-			     unsigned long TimeOut, std::unique_ptr<MethodFd> &Fd, aptMethod *Owner)
+struct Connection
 {
-   // Show a status indicator
+   struct addrinfo *Addr;
+   std::string Host;
+   aptMethod *Owner;
+   std::unique_ptr<FdFd> Fd;
    char Name[NI_MAXHOST];
    char Service[NI_MAXSERV];
-   Fd.reset(new FdFd());
 
-   Name[0] = 0;   
-   Service[0] = 0;
+   Connection(struct addrinfo *Addr, std::string const &Host, aptMethod *Owner) : Addr(Addr), Host(Host), Owner(Owner), Fd(new FdFd()), Name{0}, Service{0}
+   {
+   }
+
+   // Allow moving values, but not connections.
+   Connection(Connection &&Conn) = default;
+   Connection(const Connection &Conn) = delete;
+   Connection &operator=(const Connection &) = delete;
+   Connection &operator=(Connection &&Conn) = default;
+
+   ~Connection()
+   {
+      if (Fd != nullptr)
+      {
+	 Fd->Close();
+      }
+   }
+
+   std::unique_ptr<MethodFd> Take()
+   {
+      /* Store the IP we are using.. If something goes
+      wrong this will get tacked onto the end of the error message */
+      std::stringstream ss;
+      ioprintf(ss, _("[IP: %s %s]"), Name, Service);
+      Owner->SetIP(ss.str());
+      Owner->Status(_("Connected to %s (%s)"), Host.c_str(), Name);
+      _error->Discard();
+      Owner->SetFailReason("");
+      LastUsed = Addr;
+      return std::move(Fd);
+   }
+
+   ResultState DoConnect();
+
+   ResultState CheckError();
+};
+
+ResultState Connection::DoConnect()
+{
    getnameinfo(Addr->ai_addr,Addr->ai_addrlen,
 	       Name,sizeof(Name),Service,sizeof(Service),
 	       NI_NUMERICHOST|NI_NUMERICSERV);
@@ -130,15 +170,6 @@ static ResultState DoConnect(struct addrinfo *Addr, std::string const &Host,
    // if that addr did timeout before, we do not try it again
    if(bad_addr.find(std::string(Name)) != bad_addr.end())
       return ResultState::TRANSIENT_ERROR;
-
-   /* If this is an IP rotation store the IP we are using.. If something goes
-      wrong this will get tacked onto the end of the error message */
-   if (LastHostAddr->ai_next != 0)
-   {
-      std::stringstream ss;
-      ioprintf(ss, _("[IP: %s %s]"),Name,Service);
-      Owner->SetIP(ss.str());
-   }
       
    // Get a socket
    if ((static_cast<FdFd *>(Fd.get())->fd = socket(Addr->ai_family, Addr->ai_socktype,
@@ -159,18 +190,11 @@ static ResultState DoConnect(struct addrinfo *Addr, std::string const &Host,
       return ResultState::TRANSIENT_ERROR;
    }
 
-   /* This implements a timeout for connect by opening the connection
-      nonblocking */
-   if (WaitFd(Fd->Fd(), true, TimeOut) == false)
-   {
-      bad_addr.insert(bad_addr.begin(), std::string(Name));
-      Owner->SetFailReason("Timeout");
-      _error->Error(_("Could not connect to %s:%s (%s), "
-		      "connection timed out"),
-		    Host.c_str(), Service, Name);
-      return ResultState::TRANSIENT_ERROR;
-   }
+   return ResultState::SUCCESSFUL;
+}
 
+ResultState Connection::CheckError()
+{
    // Check the socket for an error condition
    unsigned int Err;
    unsigned int Len = sizeof(Err);
@@ -198,6 +222,126 @@ static ResultState DoConnect(struct addrinfo *Addr, std::string const &Host,
    return ResultState::SUCCESSFUL;
 }
 									/*}}}*/
+// Order the given host names returned by getaddrinfo()			/*{{{*/
+static std::vector<struct addrinfo *> OrderAddresses(struct addrinfo *CurHost)
+{
+   std::vector<struct addrinfo *> preferredAddrs;
+   std::vector<struct addrinfo *> otherAddrs;
+   std::vector<struct addrinfo *> allAddrs;
+
+   // Partition addresses into preferred and other address families
+   while (CurHost != 0)
+   {
+      if (preferredAddrs.empty() || CurHost->ai_family == preferredAddrs[0]->ai_family)
+	 preferredAddrs.push_back(CurHost);
+      else
+	 otherAddrs.push_back(CurHost);
+
+      // Ignore UNIX domain sockets
+      do
+      {
+	 CurHost = CurHost->ai_next;
+      } while (CurHost != 0 && CurHost->ai_family == AF_UNIX);
+
+      /* If we reached the end of the search list then wrap around to the
+	 start */
+      if (CurHost == 0 && LastUsed != 0)
+	 CurHost = LastHostAddr;
+
+      // Reached the end of the search cycle
+      if (CurHost == LastUsed)
+	 break;
+   }
+
+   // Build a new address vector alternating between preferred and other
+   for (auto prefIter = preferredAddrs.cbegin(), otherIter = otherAddrs.cbegin();
+	prefIter != preferredAddrs.end() || otherIter != otherAddrs.end();)
+   {
+      if (prefIter != preferredAddrs.end())
+	 allAddrs.push_back(*prefIter++);
+      if (otherIter != otherAddrs.end())
+	 allAddrs.push_back(*otherIter++);
+   }
+
+   return std::move(allAddrs);
+}
+									/*}}}*/
+// Check for errors and report them					/*{{{*/
+static ResultState WaitAndCheckErrors(std::list<Connection> &Conns, std::unique_ptr<MethodFd> &Fd, long TimeoutMsec, bool ReportTimeout)
+{
+   // The last error detected
+   ResultState Result = ResultState::TRANSIENT_ERROR;
+
+   struct timeval tv = {
+      // Split our millisecond timeout into seconds and microseconds
+      .tv_sec = TimeoutMsec / 1000,
+      .tv_usec = (TimeoutMsec % 1000) * 1000,
+   };
+
+   // We will return once we have no more connections, a time out, or
+   // a success.
+   while (!Conns.empty())
+   {
+      fd_set Set;
+      int nfds = -1;
+
+      FD_ZERO(&Set);
+
+      for (auto &Conn : Conns)
+      {
+	 int fd = Conn.Fd->Fd();
+	 FD_SET(fd, &Set);
+	 nfds = std::max(nfds, fd);
+      }
+
+      {
+	 int Res;
+	 do
+	 {
+	    Res = select(nfds + 1, 0, &Set, 0, (TimeoutMsec != 0 ? &tv : 0));
+	 } while (Res < 0 && errno == EINTR);
+
+	 if (Res == 0)
+	 {
+	    if (ReportTimeout)
+	    {
+	       for (auto &Conn : Conns)
+	       {
+		  Conn.Owner->SetFailReason("Timeout");
+		  _error->Error(_("Could not connect to %s:%s (%s), "
+				  "connection timed out"),
+				Conn.Host.c_str(), Conn.Service, Conn.Name);
+	       }
+	    }
+	    return ResultState::TRANSIENT_ERROR;
+	 }
+      }
+
+      // iterate over connections, remove failed ones, and return if
+      // there was a successful one.
+      for (auto ConnI = Conns.begin(); ConnI != Conns.end();)
+      {
+	 if (!FD_ISSET(ConnI->Fd->Fd(), &Set))
+	 {
+	    ConnI++;
+	    continue;
+	 }
+
+	 Result = ConnI->CheckError();
+	 if (Result == ResultState::SUCCESSFUL)
+	 {
+	    Fd = ConnI->Take();
+	    return Result;
+	 }
+
+	 // Connection failed. Erase it and continue to next position
+	 ConnI = Conns.erase(ConnI);
+      }
+   }
+
+   return Result;
+}
+									/*}}}*/
 // Connect to a given Hostname						/*{{{*/
 static ResultState ConnectToHostname(std::string const &Host, int const Port,
 				     const char *const Service, int DefPort, std::unique_ptr<MethodFd> &Fd,
@@ -301,39 +445,23 @@ static ResultState ConnectToHostname(std::string const &Host, int const Port,
    }
 
    // When we have an IP rotation stay with the last IP.
-   struct addrinfo *CurHost = LastHostAddr;
-   if (LastUsed != 0)
-       CurHost = LastUsed;
-   
-   while (CurHost != 0)
+   auto Addresses = OrderAddresses(LastUsed != nullptr ? LastUsed : LastHostAddr);
+   std::list<Connection> Conns;
+
+   for (auto Addr : Addresses)
    {
-      auto const result = DoConnect(CurHost, Host, TimeOut, Fd, Owner);
-      if (result == ResultState::SUCCESSFUL)
-      {
-	 LastUsed = CurHost;
-	 return result;
-      }
-      Fd->Close();
+      Connection Conn(Addr, Host, Owner);
+      if (Conn.DoConnect() != ResultState::SUCCESSFUL)
+	 continue;
 
-      // Ignore UNIX domain sockets
-      do
-      {
-	 CurHost = CurHost->ai_next;
-      }
-      while (CurHost != 0 && CurHost->ai_family == AF_UNIX);
+      Conns.push_back(std::move(Conn));
 
-      /* If we reached the end of the search list then wrap around to the
-         start */
-      if (CurHost == 0 && LastUsed != 0)
-	 CurHost = LastHostAddr;
-      
-      // Reached the end of the search cycle
-      if (CurHost == LastUsed)
-	 break;
-      
-      if (CurHost != 0)
-	 _error->Discard();
-   }   
+      if (WaitAndCheckErrors(Conns, Fd, Owner->ConfigFindI("ConnectionAttemptDelayMsec", 250), false) == ResultState::SUCCESSFUL)
+	 return ResultState::SUCCESSFUL;
+   }
+
+   if (WaitAndCheckErrors(Conns, Fd, TimeOut * 1000, true) == ResultState::SUCCESSFUL)
+      return ResultState::SUCCESSFUL;
 
    if (_error->PendingError() == true)
       return ResultState::FATAL_ERROR;