1 files changed, 127 insertions, 0 deletions
diff --git a/bbot/tftp.cxx b/bbot/tftp.cxx
new file mode 100644
index 0000000..a7398be
--- /dev/null
+++ b/bbot/tftp.cxx
@@ -0,0 +1,127 @@
+// file      : bbot/tftp.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <bbot/tftp>
+
+#include <arpa/inet.h>  // htonl()
+#include <netinet/in.h> // sockaddr_in
+#include <sys/socket.h>
+#include <sys/select.h>
+
+#include <cstring> // memset()
+
+#include <bbot/agent>
+
+using namespace std;
+using namespace butl;
+
+namespace bbot
+{
+  tftp_server::
+  tftp_server (const string& map)
+  {
+    int fd (socket (AF_INET, SOCK_DGRAM, 0));
+
+    if (fd == -1)
+      throw_system_error (errno);
+
+    fd_.reset (fd);
+
+    // Bind to ephemeral port.
+    //
+    sockaddr_in addr;
+    memset (&addr, 0, sizeof (addr));
+    addr.sin_family = AF_INET;
+    addr.sin_addr.s_addr = htonl (INADDR_ANY);
+    addr.sin_port = htons (0);
+
+    if (bind (fd,
+              reinterpret_cast<sockaddr*> (&addr),
+              sizeof (sockaddr_in)) == -1)
+      throw_system_error (errno);
+
+    // Create the map file.
+    //
+    map_ = auto_rmfile (path::temp_path ("bbot-agent-tftp-map"));
+    ofdstream ofs (map_.path ());
+    ofs << map << endl;
+    ofs.close ();
+  }
+
+  uint16_t tftp_server::
+  port () const
+  {
+    sockaddr_in addr;
+    socklen_t size (sizeof (addr));
+
+    if (getsockname (fd_.get (),
+                     reinterpret_cast<sockaddr*> (&addr),
+                     &size) == -1)
+      throw_system_error (errno);
+
+    assert (size == sizeof (addr));
+    return ntohs (addr.sin_port);
+  }
+
+  bool tftp_server::
+  serve (size_t& sec)
+  {
+    tracer trace ("tftp_server::serve");
+
+    int fd (fd_.get ());
+
+    // Note: Linux updates the timeout value which we rely upon.
+    //
+    timeval timeout {static_cast<long> (sec), 0};
+
+    fd_set rd;
+    FD_ZERO (&rd);
+
+    for (;;)
+    {
+      FD_SET (fd, &rd);
+
+      int r (select (fd + 1, &rd, nullptr, nullptr, &timeout));
+
+      if (r == -1)
+      {
+        if (errno == EINTR)
+          continue;
+
+        throw_system_error (errno);
+      }
+      else if (r == 0) // Timeout.
+        return false;
+
+      if (FD_ISSET (fd, &rd))
+      {
+        text << "connection";
+
+        // The inetd "protocol" is to pass the socket as stdin/stdout file
+        // descriptors.
+        //
+        // Notes/issues:
+        //
+        // 1. Writes diagnostics to syslog.
+        //
+        run_io (trace,
+                fddup (fd),
+                fddup (fd),
+                2,
+                "sudo",                     // Required for --secure (chroot).
+                "/usr/sbin/in.tftpd",       // Standard installation location.
+                "--timeout", 1,             // Wait for more requests.
+                "--permissive",             // Use inherited umask.
+                "--create",                 // Allow creating new files (PUT).
+                "--map-file", map_.path (), // Path remapping rules.
+                "--user", uname,            // Run as our effective user.
+                "--secure",                 // Chroot to data directory.
+                "/build/tftp/");
+
+        sec = static_cast<size_t> (timeout.tv_sec);
+        return true;
+      }
+    }
+  }
+}