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Diffstat (limited to 'source3/python/py_tdbpack.c')
| -rw-r--r-- | source3/python/py_tdbpack.c | 721 |
1 files changed, 0 insertions, 721 deletions
diff --git a/source3/python/py_tdbpack.c b/source3/python/py_tdbpack.c deleted file mode 100644 index e504f30b86..0000000000 --- a/source3/python/py_tdbpack.c +++ /dev/null @@ -1,721 +0,0 @@ -/* -*- c-file-style: "python"; indent-tabs-mode: nil; -*- - - Python wrapper for Samba tdb pack/unpack functions - Copyright (C) Martin Pool 2002, 2003 - - - NOTE PYTHON STYLE GUIDE - http://www.python.org/peps/pep-0007.html - - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 3 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program. If not, see <http://www.gnu.org/licenses/>. -*/ - -#include "Python.h" - -/* This symbol is used in both config.h and Python.h which causes an - annoying compiler warning. */ - -#ifdef HAVE_FSTAT -#undef HAVE_FSTAT -#endif - -/* This module is supposed to be standalone, however for portability - it would be good to use the FUNCTION_MACRO preprocessor define. */ - -#include "include/config.h" - -#ifdef HAVE_FUNCTION_MACRO -#define FUNCTION_MACRO (__FUNCTION__) -#else -#define FUNCTION_MACRO (__FILE__) -#endif - -static PyObject * pytdbpack_number(char ch, PyObject *val_iter, PyObject *packed_list); -static PyObject * pytdbpack_str(char ch, - PyObject *val_iter, PyObject *packed_list, - const char *encoding); -static PyObject * pytdbpack_buffer(PyObject *val_iter, PyObject *packed_list); - -static PyObject *pytdbunpack_item(char, char **pbuf, int *plen, PyObject *); - -static PyObject *pytdbpack_data(const char *format_str, - PyObject *val_seq, - PyObject *val_list); - -static PyObject * -pytdbunpack_string(char **pbuf, int *plen, const char *encoding); - -static void pack_le_uint32(unsigned long val_long, unsigned char *pbuf); - - -static PyObject *pytdbpack_bad_type(char ch, - const char *expected, - PyObject *val_obj); - -static const char * pytdbpack_docstring = -"Convert between Python values and Samba binary encodings.\n" -"\n" -"This module is conceptually similar to the standard 'struct' module, but it\n" -"uses both a different binary format and a different description string.\n" -"\n" -"Samba's encoding is based on that used inside DCE-RPC and SMB: a\n" -"little-endian, unpadded, non-self-describing binary format. It is intended\n" -"that these functions be as similar as possible to the routines in Samba's\n" -"tdb/tdbutil module, with appropriate adjustments for Python datatypes.\n" -"\n" -"Python strings are used to specify the format of data to be packed or\n" -"unpacked.\n" -"\n" -"String encodings are implied by the database format: they may be either DOS\n" -"codepage (currently hardcoded to 850), or Unix codepage (currently hardcoded\n" -"to be the same as the default Python encoding).\n" -"\n" -"tdbpack format strings:\n" -"\n" -" 'f': NUL-terminated string in codepage iso8859-1\n" -" \n" -" 'P': same as 'f'\n" -"\n" -" 'F': NUL-terminated string in iso-8859-1\n" -"\n" -" 'd': 4 byte little-endian unsigned number\n" -"\n" -" 'w': 2 byte little-endian unsigned number\n" -"\n" -" 'P': \"Pointer\" value -- in the subset of DCERPC used by Samba, this is\n" -" really just an \"exists\" or \"does not exist\" flag. The boolean\n" -" value of the Python object is used.\n" -" \n" -" 'B': 4-byte LE length, followed by that many bytes of binary data.\n" -" Corresponds to a Python integer giving the length, followed by a byte\n" -" string of the appropriate length.\n" -"\n" -" '$': Special flag indicating that the preceding format code should be\n" -" repeated while data remains. This is only supported for unpacking.\n" -"\n" -" Every code corresponds to a single Python object, except 'B' which\n" -" corresponds to two values (length and contents), and '$', which produces\n" -" however many make sense.\n"; - -static char const pytdbpack_doc[] = -"pack(format, values) -> buffer\n" -"Pack Python objects into Samba binary format according to format string.\n" -"\n" -"arguments:\n" -" format -- string of tdbpack format characters\n" -" values -- sequence of value objects corresponding 1:1 to format characters\n" -"\n" -"returns:\n" -" buffer -- string containing packed data\n" -"\n" -"raises:\n" -" IndexError -- if there are too few values for the format\n" -" ValueError -- if any of the format characters is illegal\n" -" TypeError -- if the format is not a string, or values is not a sequence,\n" -" or any of the values is of the wrong type for the corresponding\n" -" format character\n" -"\n" -"notes:\n" -" For historical reasons, it is not an error to pass more values than are consumed\n" -" by the format.\n"; - - -static char const pytdbunpack_doc[] = -"unpack(format, buffer) -> (values, rest)\n" -"Unpack Samba binary data according to format string.\n" -"\n" -"arguments:\n" -" format -- string of tdbpack characters\n" -" buffer -- string of packed binary data\n" -"\n" -"returns:\n" -" 2-tuple of:\n" -" values -- sequence of values corresponding 1:1 to format characters\n" -" rest -- string containing data that was not decoded, or '' if the\n" -" whole string was consumed\n" -"\n" -"raises:\n" -" IndexError -- if there is insufficient data in the buffer for the\n" -" format (or if the data is corrupt and contains a variable-length\n" -" field extending past the end)\n" -" ValueError -- if any of the format characters is illegal\n" -"\n" -"notes:\n" -" Because unconsumed data is returned, you can feed it back in to the\n" -" unpacker to extract further fields. Alternatively, if you wish to modify\n" -" some fields near the start of the data, you may be able to save time by\n" -" only unpacking and repacking the necessary part.\n"; - - -const char *pytdb_dos_encoding = "cp850"; - -/* NULL, meaning that the Samba default encoding *must* be the same as the - Python default encoding. */ -const char *pytdb_unix_encoding = NULL; - - -/* - * Pack objects to bytes. - * - * All objects are first individually encoded onto a list, and then the list - * of strings is concatenated. This is faster than concatenating strings, - * and reasonably simple to code. - */ -static PyObject * -pytdbpack(PyObject *self, - PyObject *args) -{ - char *format_str; - PyObject *val_seq, *val_iter = NULL, - *packed_list = NULL, *packed_str = NULL, - *empty_str = NULL; - - /* TODO: Test passing wrong types or too many arguments */ - if (!PyArg_ParseTuple(args, "sO", &format_str, &val_seq)) - return NULL; - - if (!(val_iter = PyObject_GetIter(val_seq))) - goto out; - - /* Create list to hold strings until we're done, then join them all. */ - if (!(packed_list = PyList_New(0))) - goto out; - - if (!pytdbpack_data(format_str, val_iter, packed_list)) - goto out; - - /* this function is not officially documented but it works */ - if (!(empty_str = PyString_InternFromString(""))) - goto out; - - packed_str = _PyString_Join(empty_str, packed_list); - - out: - Py_XDECREF(empty_str); - Py_XDECREF(val_iter); - Py_XDECREF(packed_list); - - return packed_str; -} - - -/* - Pack data according to FORMAT_STR from the elements of VAL_SEQ into - PACKED_BUF. - - The string has already been checked out, so we know that VAL_SEQ is large - enough to hold the packed data, and that there are enough value items. - (However, their types may not have been thoroughly checked yet.) - - In addition, val_seq is a Python Fast sequence. - - Returns NULL for error (with exception set), or None. -*/ -PyObject * -pytdbpack_data(const char *format_str, - PyObject *val_iter, - PyObject *packed_list) -{ - int format_i, val_i = 0; - - for (format_i = 0, val_i = 0; format_str[format_i]; format_i++) { - char ch = format_str[format_i]; - - switch (ch) { - /* dispatch to the appropriate packer for this type, - which should pull things off the iterator, and - append them to the packed_list */ - case 'w': - case 'd': - case 'p': - if (!(packed_list = pytdbpack_number(ch, val_iter, packed_list))) - return NULL; - break; - - case 'f': - case 'P': - if (!(packed_list = pytdbpack_str(ch, val_iter, packed_list, pytdb_unix_encoding))) - return NULL; - break; - - case 'B': - if (!(packed_list = pytdbpack_buffer(val_iter, packed_list))) - return NULL; - break; - - default: - PyErr_Format(PyExc_ValueError, - "%s: format character '%c' is not supported", - FUNCTION_MACRO, ch); - return NULL; - } - } - - return packed_list; -} - - -static PyObject * -pytdbpack_number(char ch, PyObject *val_iter, PyObject *packed_list) -{ - unsigned long val_long; - PyObject *val_obj = NULL, *long_obj = NULL, *result_obj = NULL; - PyObject *new_list = NULL; - unsigned char pack_buf[4]; - - if (!(val_obj = PyIter_Next(val_iter))) - goto out; - - if (!(long_obj = PyNumber_Long(val_obj))) { - pytdbpack_bad_type(ch, "Number", val_obj); - goto out; - } - - val_long = PyLong_AsUnsignedLong(long_obj); - pack_le_uint32(val_long, pack_buf); - - /* pack as 32-bit; if just packing a 'w' 16-bit word then only take - the first two bytes. */ - - if (!(result_obj = PyString_FromStringAndSize(pack_buf, ch == 'w' ? 2 : 4))) - goto out; - - if (PyList_Append(packed_list, result_obj) != -1) - new_list = packed_list; - - out: - Py_XDECREF(val_obj); - Py_XDECREF(long_obj); - Py_XDECREF(result_obj); - - return new_list; -} - - -/* - * Take one string from the iterator val_iter, convert it to 8-bit, and return - * it. - * - * If the input is neither a string nor Unicode, an exception is raised. - * - * If the input is Unicode, then it is converted to the appropriate encoding. - * - * If the input is a String, and encoding is not null, then it is converted to - * Unicode using the default decoding method, and then converted to the - * encoding. If the encoding is NULL, then the string is written out as-is -- - * this is used when the default Python encoding is the same as the Samba - * encoding. - * - * I hope this approach avoids being too fragile w.r.t. being passed either - * Unicode or String objects. - */ -static PyObject * -pytdbpack_str(char ch, - PyObject *val_iter, PyObject *packed_list, const char *encoding) -{ - PyObject *val_obj = NULL; - PyObject *unicode_obj = NULL; - PyObject *coded_str = NULL; - PyObject *nul_str = NULL; - PyObject *new_list = NULL; - - if (!(val_obj = PyIter_Next(val_iter))) - goto out; - - if (PyUnicode_Check(val_obj)) { - if (!(coded_str = PyUnicode_AsEncodedString(val_obj, encoding, NULL))) - goto out; - } - else if (PyString_Check(val_obj) && !encoding) { - /* For efficiency, we assume that the Python interpreter has - the same default string encoding as Samba's native string - encoding. On the PSA, both are always 8859-1. */ - coded_str = val_obj; - Py_INCREF(coded_str); - } - else if (PyString_Check(val_obj)) { - /* String, but needs to be converted */ - if (!(unicode_obj = PyString_AsDecodedObject(val_obj, NULL, NULL))) - goto out; - if (!(coded_str = PyUnicode_AsEncodedString(unicode_obj, encoding, NULL))) - goto out; - } - else { - pytdbpack_bad_type(ch, "String or Unicode", val_obj); - goto out; - } - - if (!nul_str) - /* this is constant and often-used; hold it forever */ - if (!(nul_str = PyString_FromStringAndSize("", 1))) - goto out; - - if ((PyList_Append(packed_list, coded_str) != -1) - && (PyList_Append(packed_list, nul_str) != -1)) - new_list = packed_list; - - out: - Py_XDECREF(val_obj); - Py_XDECREF(unicode_obj); - Py_XDECREF(coded_str); - - return new_list; -} - - -/* - * Pack (LENGTH, BUFFER) pair onto the list. - * - * The buffer must already be a String, not Unicode, because it contains 8-bit - * untranslated data. In some cases it will actually be UTF_16_LE data. - */ -static PyObject * -pytdbpack_buffer(PyObject *val_iter, PyObject *packed_list) -{ - PyObject *val_obj; - PyObject *new_list = NULL; - - /* pull off integer and stick onto list */ - if (!(packed_list = pytdbpack_number('d', val_iter, packed_list))) - return NULL; - - /* this assumes that the string is the right length; the old code did - the same. */ - if (!(val_obj = PyIter_Next(val_iter))) - return NULL; - - if (!PyString_Check(val_obj)) { - pytdbpack_bad_type('B', "String", val_obj); - goto out; - } - - if (PyList_Append(packed_list, val_obj) != -1) - new_list = packed_list; - - out: - Py_XDECREF(val_obj); - return new_list; -} - - -static PyObject *pytdbpack_bad_type(char ch, - const char *expected, - PyObject *val_obj) -{ - PyObject *r = PyObject_Repr(val_obj); - if (!r) - return NULL; - PyErr_Format(PyExc_TypeError, - "tdbpack: format '%c' requires %s, not %s", - ch, expected, PyString_AS_STRING(r)); - Py_DECREF(r); - return val_obj; -} - - -/* - XXX: glib and Samba have quicker macro for doing the endianness conversions, - but I don't know of one in plain libc, and it's probably not a big deal. I - realize this is kind of dumb because we'll almost always be on x86, but - being safe is important. -*/ -static void pack_le_uint32(unsigned long val_long, unsigned char *pbuf) -{ - pbuf[0] = val_long & 0xff; - pbuf[1] = (val_long >> 8) & 0xff; - pbuf[2] = (val_long >> 16) & 0xff; - pbuf[3] = (val_long >> 24) & 0xff; -} - - -#if 0 /* not used */ -static void pack_bytes(long len, const char *from, - unsigned char **pbuf) -{ - memcpy(*pbuf, from, len); - (*pbuf) += len; -} -#endif - - -static PyObject * -pytdbunpack(PyObject *self, - PyObject *args) -{ - char *format_str, *packed_str, *ppacked; - PyObject *val_list = NULL, *ret_tuple = NULL; - PyObject *rest_string = NULL; - int format_len, packed_len; - char last_format = '#'; /* invalid */ - int i; - - /* get arguments */ - if (!PyArg_ParseTuple(args, "ss#", &format_str, &packed_str, &packed_len)) - return NULL; - - format_len = strlen(format_str); - - /* Allocate list to hold results. Initially empty, and we append - results as we go along. */ - val_list = PyList_New(0); - if (!val_list) - goto failed; - ret_tuple = PyTuple_New(2); - if (!ret_tuple) - goto failed; - - /* For every object, unpack. */ - for (ppacked = packed_str, i = 0; i < format_len && format_str[i] != '$'; i++) { - last_format = format_str[i]; - /* packed_len is reduced in place */ - if (!pytdbunpack_item(format_str[i], &ppacked, &packed_len, val_list)) - goto failed; - } - - /* If the last character was '$', keep going until out of space */ - if (format_str[i] == '$') { - if (i == 0) { - PyErr_Format(PyExc_ValueError, - "%s: '$' may not be first character in format", - FUNCTION_MACRO); - return NULL; - } - while (packed_len > 0) - if (!pytdbunpack_item(last_format, &ppacked, &packed_len, val_list)) - goto failed; - } - - /* save leftovers for next time */ - rest_string = PyString_FromStringAndSize(ppacked, packed_len); - if (!rest_string) - goto failed; - - /* return (values, rest) tuple; give up references to them */ - PyTuple_SET_ITEM(ret_tuple, 0, val_list); - val_list = NULL; - PyTuple_SET_ITEM(ret_tuple, 1, rest_string); - val_list = NULL; - return ret_tuple; - - failed: - /* handle failure: deallocate anything. XDECREF forms handle NULL - pointers for objects that haven't been allocated yet. */ - Py_XDECREF(val_list); - Py_XDECREF(ret_tuple); - Py_XDECREF(rest_string); - return NULL; -} - - -static void -pytdbunpack_err_too_short(void) -{ - PyErr_Format(PyExc_IndexError, - "%s: data too short for unpack format", FUNCTION_MACRO); -} - - -static PyObject * -pytdbunpack_uint32(char **pbuf, int *plen) -{ - unsigned long v; - unsigned char *b; - - if (*plen < 4) { - pytdbunpack_err_too_short(); - return NULL; - } - - b = *pbuf; - v = b[0] | b[1]<<8 | b[2]<<16 | b[3]<<24; - - (*pbuf) += 4; - (*plen) -= 4; - - return PyLong_FromUnsignedLong(v); -} - - -static PyObject *pytdbunpack_int16(char **pbuf, int *plen) -{ - long v; - unsigned char *b; - - if (*plen < 2) { - pytdbunpack_err_too_short(); - return NULL; - } - - b = *pbuf; - v = b[0] | b[1]<<8; - - (*pbuf) += 2; - (*plen) -= 2; - - return PyInt_FromLong(v); -} - - -static PyObject * -pytdbunpack_string(char **pbuf, int *plen, const char *encoding) -{ - int len; - char *nul_ptr, *start; - - start = *pbuf; - - nul_ptr = memchr(start, '\0', *plen); - if (!nul_ptr) { - pytdbunpack_err_too_short(); - return NULL; - } - - len = nul_ptr - start; - - *pbuf += len + 1; /* skip \0 */ - *plen -= len + 1; - - return PyString_Decode(start, len, encoding, NULL); -} - - -static PyObject * -pytdbunpack_buffer(char **pbuf, int *plen, PyObject *val_list) -{ - /* first get 32-bit len */ - long slen; - unsigned char *b; - unsigned char *start; - PyObject *str_obj = NULL, *len_obj = NULL; - - if (*plen < 4) { - pytdbunpack_err_too_short(); - return NULL; - } - - b = *pbuf; - slen = b[0] | b[1]<<8 | b[2]<<16 | b[3]<<24; - - if (slen < 0) { /* surely you jest */ - PyErr_Format(PyExc_ValueError, - "%s: buffer seems to have negative length", FUNCTION_MACRO); - return NULL; - } - - (*pbuf) += 4; - (*plen) -= 4; - start = *pbuf; - - if (*plen < slen) { - PyErr_Format(PyExc_IndexError, - "%s: not enough data to unpack buffer: " - "need %d bytes, have %d", FUNCTION_MACRO, - (int) slen, *plen); - return NULL; - } - - (*pbuf) += slen; - (*plen) -= slen; - - if (!(len_obj = PyInt_FromLong(slen))) - goto failed; - - if (PyList_Append(val_list, len_obj) == -1) - goto failed; - - if (!(str_obj = PyString_FromStringAndSize(start, slen))) - goto failed; - - if (PyList_Append(val_list, str_obj) == -1) - goto failed; - - Py_DECREF(len_obj); - Py_DECREF(str_obj); - - return val_list; - - failed: - Py_XDECREF(len_obj); /* handles NULL */ - Py_XDECREF(str_obj); - return NULL; -} - - -/* Unpack a single field from packed data, according to format character CH. - Remaining data is at *PBUF, of *PLEN. - - *PBUF is advanced, and *PLEN reduced to reflect the amount of data that has - been consumed. - - Returns a reference to None, or NULL for failure. -*/ -static PyObject *pytdbunpack_item(char ch, - char **pbuf, - int *plen, - PyObject *val_list) -{ - PyObject *unpacked; - - if (ch == 'w') { /* 16-bit int */ - unpacked = pytdbunpack_int16(pbuf, plen); - } - else if (ch == 'd' || ch == 'p') { /* 32-bit int */ - /* pointers can just come through as integers */ - unpacked = pytdbunpack_uint32(pbuf, plen); - } - else if (ch == 'f' || ch == 'P') { /* nul-term string */ - unpacked = pytdbunpack_string(pbuf, plen, pytdb_unix_encoding); - } - else if (ch == 'B') { /* length, buffer */ - return pytdbunpack_buffer(pbuf, plen, val_list); - } - else { - PyErr_Format(PyExc_ValueError, - "%s: format character '%c' is not supported", - FUNCTION_MACRO, ch); - - return NULL; - } - - /* otherwise OK */ - if (!unpacked) - return NULL; - - if (PyList_Append(val_list, unpacked) == -1) - val_list = NULL; - - /* PyList_Append takes a new reference to the inserted object. - Therefore, we no longer need the original reference. */ - Py_DECREF(unpacked); - - return val_list; -} - - - - - - -static PyMethodDef pytdbpack_methods[] = { - { "pack", pytdbpack, METH_VARARGS, (char *) pytdbpack_doc }, - { "unpack", pytdbunpack, METH_VARARGS, (char *) pytdbunpack_doc }, -}; - -DL_EXPORT(void) -inittdbpack(void) -{ - Py_InitModule3("tdbpack", pytdbpack_methods, - (char *) pytdbpack_docstring); -} |