Added gethostbyname_ex(), which returns the same kind of data as

gethostbyaddr().  (Plain gethostbyname() returns only the IP address.)
This moves the code shared by gethostbyaddr() and gethostbyname_ex()
to a subroutine.

Original patch by Dan Stromberg; some tweaks by GvR.

diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 0eb3fd539257c0ef81419a356530790c1b208de4..58b2c987aff4c4ab0d282ef2e18daa109ceea59c 100644 (file)
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -1314,49 +1314,18 @@ static char gethostbyname_doc[] =
 Return the IP address (a string of the form '255.255.255.255') for a host.";
 
 
-/* Python interface to gethostbyaddr(IP). */
+/* Convenience function common to gethostbyname_ex and gethostbyaddr */
 
-/*ARGSUSED*/
 static PyObject *
-BUILD_FUNC_DEF_2(PySocket_gethostbyaddr,PyObject *,self, PyObject *, args)
-{
-        struct sockaddr_in addr;
-       char *ip_num;
+gethost_common(h, addr)
        struct hostent *h;
+       struct sockaddr_in *addr;
+{
        char **pch;
        PyObject *rtn_tuple = (PyObject *)NULL;
        PyObject *name_list = (PyObject *)NULL;
        PyObject *addr_list = (PyObject *)NULL;
        PyObject *tmp;
-#ifdef HAVE_GETHOSTBYNAME_R
-       struct hostent hp_allocated;
-       char buf[16384];
-       int buf_len = (sizeof buf) - 1;
-       int errnop;
-#endif /* HAVE_GETHOSTBYNAME_R */
-
-       if (!PyArg_Parse(args, "s", &ip_num))
-               return NULL;
-       if (setipaddr(ip_num, &addr) < 0)
-               return NULL;
-       Py_BEGIN_ALLOW_THREADS
-#ifdef HAVE_GETHOSTBYNAME_R
-       h = gethostbyaddr_r((char *)&addr.sin_addr,
-                           sizeof(addr.sin_addr),
-                           AF_INET, 
-                           &hp_allocated, buf, buf_len, &errnop);
-#else /* not HAVE_GETHOSTBYNAME_R */
-#if defined(WITH_THREAD) && !defined(MS_WINDOWS)
-       acquire_lock(gethostbyname_lock,1);
-#endif
-       h = gethostbyaddr((char *)&addr.sin_addr,
-                         sizeof(addr.sin_addr),
-                         AF_INET);
-#if defined(WITH_THREAD) && !defined(MS_WINDOWS)
-       release_lock(gethostbyname_lock);
-#endif
-#endif /* HAVE_GETHOSTBYNAME_R */
-       Py_END_ALLOW_THREADS
        if (h == NULL) {
 #ifdef HAVE_HSTRERROR
                /* Let's get real error message to return */
@@ -1383,8 +1352,8 @@ BUILD_FUNC_DEF_2(PySocket_gethostbyaddr,PyObject *,self, PyObject *, args)
        }
        for (pch = h->h_addr_list; *pch != NULL; pch++) {
                int status;
-               memcpy((char *) &addr.sin_addr, *pch, h->h_length);
-               tmp = makeipaddr(&addr);
+               memcpy((char *) &addr->sin_addr, *pch, h->h_length);
+               tmp = makeipaddr(addr);
                if (tmp == NULL)
                        goto err;
                status = PyList_Append(addr_list, tmp);
@@ -1399,6 +1368,98 @@ BUILD_FUNC_DEF_2(PySocket_gethostbyaddr,PyObject *,self, PyObject *, args)
        return rtn_tuple;
 }
 
+
+/* Python interface to gethostbyname_ex(name). */
+
+/*ARGSUSED*/
+static PyObject *
+BUILD_FUNC_DEF_2(PySocket_gethostbyname_ex,PyObject *,self, PyObject *,args)
+{
+       char *name;
+       struct hostent *h;
+       struct sockaddr_in addr;
+       PyObject *addr_list = (PyObject *)NULL;
+       char **pch;
+       PyObject *tmp;
+#ifdef HAVE_GETHOSTBYNAME_R
+       struct hostent hp_allocated;
+       char buf[16384];
+       int buf_len = (sizeof buf) - 1;
+       int errnop;
+#endif /* HAVE_GETHOSTBYNAME_R */
+       if (!PyArg_Parse(args, "s", &name))
+               return NULL;
+       if (setipaddr(name, &addr) < 0)
+               return NULL;
+       Py_BEGIN_ALLOW_THREADS
+#ifdef HAVE_GETHOSTBYNAME_R
+       h = gethostbyname_r(name, &hp_allocated, buf, buf_len, &errnop);
+#else /* not HAVE_GETHOSTBYNAME_R */
+#if defined(WITH_THREAD) && !defined(MS_WINDOWS)
+       acquire_lock(gethostbyname_lock,1);
+#endif
+       h = gethostbyname(name);
+#if defined(WITH_THREAD) && !defined(MS_WINDOWS)
+       release_lock(gethostbyname_lock);
+#endif
+#endif /* HAVE_GETHOSTBYNAME_R */
+       Py_END_ALLOW_THREADS
+       return gethost_common(h,&addr);
+}
+
+static char ghbn_ex_doc[] =
+"gethostbyname_ex(host) -> (name, aliaslist, addresslist)\n\
+\n\
+Return the true host name, a list of aliases, and a list of IP addresses,\n\
+for a host.  The host argument is a string giving a host name or IP number.";
+
+
+/* Python interface to gethostbyaddr(IP). */
+
+/*ARGSUSED*/
+static PyObject *
+BUILD_FUNC_DEF_2(PySocket_gethostbyaddr,PyObject *,self, PyObject *, args)
+{
+        struct sockaddr_in addr;
+       char *ip_num;
+       struct hostent *h;
+       char **pch;
+       PyObject *rtn_tuple = (PyObject *)NULL;
+       PyObject *name_list = (PyObject *)NULL;
+       PyObject *addr_list = (PyObject *)NULL;
+       PyObject *tmp;
+#ifdef HAVE_GETHOSTBYNAME_R
+       struct hostent hp_allocated;
+       char buf[16384];
+       int buf_len = (sizeof buf) - 1;
+       int errnop;
+#endif /* HAVE_GETHOSTBYNAME_R */
+
+       if (!PyArg_Parse(args, "s", &ip_num))
+               return NULL;
+       if (setipaddr(ip_num, &addr) < 0)
+               return NULL;
+       Py_BEGIN_ALLOW_THREADS
+#ifdef HAVE_GETHOSTBYNAME_R
+       h = gethostbyaddr_r((char *)&addr.sin_addr,
+                           sizeof(addr.sin_addr),
+                           AF_INET, 
+                           &hp_allocated, buf, buf_len, &errnop);
+#else /* not HAVE_GETHOSTBYNAME_R */
+#if defined(WITH_THREAD) && !defined(MS_WINDOWS)
+       acquire_lock(gethostbyname_lock,1);
+#endif
+       h = gethostbyaddr((char *)&addr.sin_addr,
+                         sizeof(addr.sin_addr),
+                         AF_INET);
+#if defined(WITH_THREAD) && !defined(MS_WINDOWS)
+       release_lock(gethostbyname_lock);
+#endif
+#endif /* HAVE_GETHOSTBYNAME_R */
+       Py_END_ALLOW_THREADS
+       return gethost_common(h,&addr);
+}
+
 static char gethostbyaddr_doc[] =
 "gethostbyaddr(host) -> (name, aliaslist, addresslist)\n\
 \n\
@@ -1623,6 +1684,7 @@ Convert a 32-bit integer from host to network byte order.";
 
 static PyMethodDef PySocket_methods[] = {
        {"gethostbyname",       PySocket_gethostbyname, 0, gethostbyname_doc},
+       {"gethostbyname_ex",    PySocket_gethostbyname_ex, 0, ghbn_ex_doc},
        {"gethostbyaddr",       PySocket_gethostbyaddr, 0, gethostbyaddr_doc},
        {"gethostname",         PySocket_gethostname, 0, gethostname_doc},
        {"getservbyname",       PySocket_getservbyname, 0, getservbyname_doc},