Modules/socketmodule.h

   1 /* Socket module header file */
   2
   3 /* Includes needed for the sockaddr_* symbols below */
   4 #ifndef MS_WINDOWS
   5 #ifdef __VMS
   6 #   include <socket.h>
   7 # else
   8 #   include <sys/socket.h>
   9 # endif
  10 # include <netinet/in.h>
  11 # if !(defined(__BEOS__) || defined(__CYGWIN__) || (defined(PYOS_OS2) && defined(PYCC_VACPP)))
  12 #  include <netinet/tcp.h>
  13 # endif
  14
  15 #else /* MS_WINDOWS */
  16 #if _MSC_VER >= 1300
  17 # include <winsock2.h>
  18 # include <ws2tcpip.h>
  19 # define HAVE_ADDRINFO
  20 # define HAVE_SOCKADDR_STORAGE
  21 # define HAVE_GETADDRINFO
  22 # define HAVE_GETNAMEINFO
  23 # define ENABLE_IPV6
  24 #else
  25 # include <winsock.h>
  26 #endif
  27 #endif
  28
  29 #ifdef HAVE_SYS_UN_H
  30 # include <sys/un.h>
  31 #else
  32 # undef AF_UNIX
  33 #endif
  34
  35 #ifdef HAVE_LINUX_NETLINK_H
  36 # ifdef HAVE_ASM_TYPES_H
  37 #  include <asm/types.h>
  38 # endif
  39 # include <linux/netlink.h>
  40 #else
  41 #  undef AF_NETLINK
  42 #endif
  43
  44 #ifdef HAVE_BLUETOOTH_BLUETOOTH_H
  45 #include <bluetooth/bluetooth.h>
  46 #include <bluetooth/rfcomm.h>
  47 #include <bluetooth/l2cap.h>
  48 #include <bluetooth/sco.h>
  49 #include <bluetooth/hci.h>
  50 #endif
  51
  52 #ifdef HAVE_BLUETOOTH_H
  53 #include <bluetooth.h>
  54 #endif
  55
  56 #ifdef HAVE_NETPACKET_PACKET_H
  57 # include <sys/ioctl.h>
  58 # include <net/if.h>
  59 # include <netpacket/packet.h>
  60 #endif
  61
  62 #ifndef Py__SOCKET_H
  63 #define Py__SOCKET_H
  64 #ifdef __cplusplus
  65 extern "C" {
  66 #endif
  67
  68 /* Python module and C API name */
  69 #define PySocket_MODULE_NAME    "_socket"
  70 #define PySocket_CAPI_NAME      "CAPI"
  71
  72 /* Abstract the socket file descriptor type */
  73 #ifdef MS_WINDOWS
  74 typedef SOCKET SOCKET_T;
  75 #       ifdef MS_WIN64
  76 #               define SIZEOF_SOCKET_T 8
  77 #       else
  78 #               define SIZEOF_SOCKET_T 4
  79 #       endif
  80 #else
  81 typedef int SOCKET_T;
  82 #       define SIZEOF_SOCKET_T SIZEOF_INT
  83 #endif
  84
  85 /* Socket address */
  86 typedef union sock_addr {
  87         struct sockaddr_in in;
  88 #ifdef AF_UNIX
  89         struct sockaddr_un un;
  90 #endif
  91 #ifdef AF_NETLINK
  92         struct sockaddr_nl nl;
  93 #endif
  94 #ifdef ENABLE_IPV6
  95         struct sockaddr_in6 in6;
  96         struct sockaddr_storage storage;
  97 #endif
  98 #ifdef HAVE_BLUETOOTH_BLUETOOTH_H
  99         struct sockaddr_l2 bt_l2;
 100         struct sockaddr_rc bt_rc;
 101         struct sockaddr_sco bt_sco;
 102         struct sockaddr_hci bt_hci;
 103 #endif
 104 #ifdef HAVE_NETPACKET_PACKET_H
 105         struct sockaddr_ll ll;
 106 #endif
 107 } sock_addr_t;
 108
 109 /* The object holding a socket.  It holds some extra information,
 110    like the address family, which is used to decode socket address
 111    arguments properly. */
 112
 113 typedef struct {
 114         PyObject_HEAD
 115         SOCKET_T sock_fd;       /* Socket file descriptor */
 116         int sock_family;        /* Address family, e.g., AF_INET */
 117         int sock_type;          /* Socket type, e.g., SOCK_STREAM */
 118         int sock_proto;         /* Protocol type, usually 0 */
 119         PyObject *(*errorhandler)(void); /* Error handler; checks
 120                                             errno, returns NULL and
 121                                             sets a Python exception */
 122         double sock_timeout;             /* Operation timeout in seconds;
 123                                             0.0 means non-blocking */
 124 } PySocketSockObject;
 125
 126 /* --- C API ----------------------------------------------------*/
 127
 128 /* Short explanation of what this C API export mechanism does
 129    and how it works:
 130
 131     The _ssl module needs access to the type object defined in
 132     the _socket module. Since cross-DLL linking introduces a lot of
 133     problems on many platforms, the "trick" is to wrap the
 134     C API of a module in a struct which then gets exported to
 135     other modules via a PyCObject.
 136
 137     The code in socketmodule.c defines this struct (which currently
 138     only contains the type object reference, but could very
 139     well also include other C APIs needed by other modules)
 140     and exports it as PyCObject via the module dictionary
 141     under the name "CAPI".
 142
 143     Other modules can now include the socketmodule.h file
 144     which defines the needed C APIs to import and set up
 145     a static copy of this struct in the importing module.
 146
 147     After initialization, the importing module can then
 148     access the C APIs from the _socket module by simply
 149     referring to the static struct, e.g.
 150
 151     Load _socket module and its C API; this sets up the global
 152     PySocketModule:
 153
 154         if (PySocketModule_ImportModuleAndAPI())
 155             return;
 156
 157
 158     Now use the C API as if it were defined in the using
 159     module:
 160
 161         if (!PyArg_ParseTuple(args, "O!|zz:ssl",
 162
 163                               PySocketModule.Sock_Type,
 164
 165                               (PyObject*)&Sock,
 166                               &key_file, &cert_file))
 167             return NULL;
 168
 169     Support could easily be extended to export more C APIs/symbols
 170     this way. Currently, only the type object is exported,
 171     other candidates would be socket constructors and socket
 172     access functions.
 173
 174 */
 175
 176 /* C API for usage by other Python modules */
 177 typedef struct {
 178         PyTypeObject *Sock_Type;
 179         PyObject *error;
 180 } PySocketModule_APIObject;
 181
 182 /* XXX The net effect of the following appears to be to define a function
 183    XXX named PySocketModule_APIObject in _ssl.c.  It's unclear why it isn't
 184    XXX defined there directly.
 185
 186    >>> It's defined here because other modules might also want to use
 187    >>> the C API.
 188
 189 */
 190 #ifndef PySocket_BUILDING_SOCKET
 191
 192 /* --- C API ----------------------------------------------------*/
 193
 194 /* Interfacestructure to C API for other modules.
 195    Call PySocketModule_ImportModuleAndAPI() to initialize this
 196    structure. After that usage is simple:
 197
 198    if (!PyArg_ParseTuple(args, "O!|zz:ssl",
 199                          &PySocketModule.Sock_Type, (PyObject*)&Sock,
 200                          &key_file, &cert_file))
 201          return NULL;
 202    ...
 203 */
 204
 205 static
 206 PySocketModule_APIObject PySocketModule;
 207
 208 /* You *must* call this before using any of the functions in
 209    PySocketModule and check its outcome; otherwise all accesses will
 210    result in a segfault. Returns 0 on success. */
 211
 212 #ifndef DPRINTF
 213 # define DPRINTF if (0) printf
 214 #endif
 215
 216 static
 217 int PySocketModule_ImportModuleAndAPI(void)
 218 {
 219         PyObject *mod = 0, *v = 0;
 220         char *apimodule = PySocket_MODULE_NAME;
 221         char *apiname = PySocket_CAPI_NAME;
 222         void *api;
 223
 224         DPRINTF("Importing the %s C API...\n", apimodule);
 225         mod = PyImport_ImportModule(apimodule);
 226         if (mod == NULL)
 227                 goto onError;
 228         DPRINTF(" %s package found\n", apimodule);
 229         v = PyObject_GetAttrString(mod, apiname);
 230         if (v == NULL)
 231                 goto onError;
 232         Py_DECREF(mod);
 233         DPRINTF(" API object %s found\n", apiname);
 234         api = PyCObject_AsVoidPtr(v);
 235         if (api == NULL)
 236                 goto onError;
 237         Py_DECREF(v);
 238         memcpy(&PySocketModule, api, sizeof(PySocketModule));
 239         DPRINTF(" API object loaded and initialized.\n");
 240         return 0;
 241
 242  onError:
 243         DPRINTF(" not found.\n");
 244         Py_XDECREF(mod);
 245         Py_XDECREF(v);
 246         return -1;
 247 }
 248
 249 #endif /* !PySocket_BUILDING_SOCKET */
 250
 251 #ifdef __cplusplus
 252 }
 253 #endif
 254 #endif /* !Py__SOCKET_H */