windows/winnpc.c

   1 /*
   2  * Windows support module which deals with being a named-pipe client.
   3  */
   4
   5 #include <stdio.h>
   6 #include <assert.h>
   7
   8 #define DEFINE_PLUG_METHOD_MACROS
   9 #include "tree234.h"
  10 #include "putty.h"
  11 #include "network.h"
  12 #include "proxy.h"
  13 #include "ssh.h"
  14
  15 #if !defined NO_SECURITY
  16
  17 #include "winsecur.h"
  18
  19 Socket make_handle_socket(HANDLE send_H, HANDLE recv_H, HANDLE stderr_H,
  20                           Plug plug, int overlapped);
  21
  22 Socket new_named_pipe_client(const char *pipename, Plug plug)
  23 {
  24     HANDLE pipehandle;
  25     PSID usersid, pipeowner;
  26     PSECURITY_DESCRIPTOR psd;
  27     char *err;
  28     Socket ret;
  29
  30     assert(strncmp(pipename, "\\\\.\\pipe\\", 9) == 0);
  31     assert(strchr(pipename + 9, '\\') == NULL);
  32
  33     while (1) {
  34         pipehandle = CreateFile(pipename, GENERIC_READ | GENERIC_WRITE,
  35                                 0, NULL, OPEN_EXISTING,
  36                                 FILE_FLAG_OVERLAPPED, NULL);
  37
  38         if (pipehandle != INVALID_HANDLE_VALUE)
  39             break;
  40
  41         if (GetLastError() != ERROR_PIPE_BUSY) {
  42             err = dupprintf("Unable to open named pipe '%s': %s",
  43                             pipename, win_strerror(GetLastError()));
  44             ret = new_error_socket(err, plug);
  45             sfree(err);
  46             return ret;
  47         }
  48
  49         /*
  50          * If we got ERROR_PIPE_BUSY, wait for the server to
  51          * create a new pipe instance. (Since the server is
  52          * expected to be winnps.c, which will do that immediately
  53          * after a previous connection is accepted, that shouldn't
  54          * take excessively long.)
  55          */
  56         if (!WaitNamedPipe(pipename, NMPWAIT_USE_DEFAULT_WAIT)) {
  57             err = dupprintf("Error waiting for named pipe '%s': %s",
  58                             pipename, win_strerror(GetLastError()));
  59             ret = new_error_socket(err, plug);
  60             sfree(err);
  61             return ret;
  62         }
  63     }
  64
  65     if ((usersid = get_user_sid()) == NULL) {
  66         CloseHandle(pipehandle);
  67         err = dupprintf("Unable to get user SID");
  68         ret = new_error_socket(err, plug);
  69         sfree(err);
  70         return ret;
  71     }
  72
  73     if (p_GetSecurityInfo(pipehandle, SE_KERNEL_OBJECT,
  74                           OWNER_SECURITY_INFORMATION,
  75                           &pipeowner, NULL, NULL, NULL,
  76                           &psd) != ERROR_SUCCESS) {
  77         err = dupprintf("Unable to get named pipe security information: %s",
  78                         win_strerror(GetLastError()));
  79         ret = new_error_socket(err, plug);
  80         sfree(err);
  81         CloseHandle(pipehandle);
  82         return ret;
  83     }
  84
  85     if (!EqualSid(pipeowner, usersid)) {
  86         err = dupprintf("Owner of named pipe '%s' is not us", pipename);
  87         ret = new_error_socket(err, plug);
  88         sfree(err);
  89         CloseHandle(pipehandle);
  90         LocalFree(psd);
  91         return ret;
  92     }
  93
  94     LocalFree(psd);
  95
  96     return make_handle_socket(pipehandle, pipehandle, NULL, plug, TRUE);
  97 }
  98
  99 #endif /* !defined NO_SECURITY */