/* * This file is part of the sigrok project. * * Copyright (C) 2010 Uwe Hermann * * 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 2 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, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include "config.h" #include /* First, so we avoid a _POSIX_C_SOURCE warning. */ #include #include #include /* Re-define some string functions for Python >= 3.0. */ #if PY_VERSION_HEX >= 0x03000000 #define PyString_AsString PyBytes_AsString #define PyString_FromString PyBytes_FromString #define PyString_Check PyBytes_Check #endif /* The list of protocol decoders. */ static GSList *list_pds = NULL; /* * Here's a quick overview of Python/C API reference counting. * * Check the Python/C API docs for what type of reference a function returns. * * - If it returns a "new reference", you're responsible to Py_XDECREF() it. * * - If it returns a "borrowed reference", you MUST NOT Py_XDECREF() it. * * - If a function "steals" a reference, you no longer are responsible for * Py_XDECREF()ing it (someone else will do it for you at some point). */ static int srd_load_decoder(const char *name, struct srd_decoder **dec); /** * Initialize libsigrokdecode. * * @return SRD_OK upon success, a (negative) error code otherwise. */ int srd_init(void) { DIR *dir; struct dirent *dp; char *decodername; struct srd_decoder *dec; int ret; /* Py_Initialize() returns void and usually cannot fail. */ Py_Initialize(); /* Add search directory for the protocol decoders. */ /* FIXME: Check error code. */ /* FIXME: What happens if this function is called multiple times? */ PyRun_SimpleString("import sys;" "sys.path.append(r'" DECODERS_DIR "');"); if (!(dir = opendir(DECODERS_DIR))) return SRD_ERR_DECODERS_DIR; while ((dp = readdir(dir)) != NULL) { if (!g_str_has_suffix(dp->d_name, ".py")) continue; /* Decoder name == filename (without .py suffix). */ decodername = g_strndup(dp->d_name, strlen(dp->d_name) - 3); /* TODO: Error handling. */ dec = malloc(sizeof(struct srd_decoder)); /* Load the decoder. */ ret = srd_load_decoder(decodername, &dec); /* Append it to the list of supported/loaded decoders. */ list_pds = g_slist_append(list_pds, dec); } closedir(dir); return SRD_OK; } /** * Returns the list of supported/loaded protocol decoders. * * This is a GSList containing the names of the decoders as strings. * * @return List of decoders, NULL if none are supported or loaded. */ GSList *srd_list_decoders(void) { return list_pds; } /** * Get the decoder with the specified ID. * * @param id The ID string of the decoder to return. * @return The decoder with the specified ID, or NULL if not found. */ struct srd_decoder *srd_get_decoder_by_id(const char *id) { GSList *l; struct srd_decoder *dec; for (l = srd_list_decoders(); l; l = l->next) { dec = l->data; if (!strcmp(dec->id, id)) return dec; } return NULL; } /** * Helper function to handle Python strings. * * TODO: @param entries. * * @return SRD_OK upon success, a (negative) error code otherwise. * The 'outstr' argument points to a malloc()ed string upon success. */ static int h_str(PyObject *py_res, PyObject *py_func, PyObject *py_mod, const char *key, char **outstr) { PyObject *py_str; char *str; int ret; py_str = PyMapping_GetItemString(py_res, (char *)key); if (!py_str || !PyString_Check(py_str)) { ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ goto err_h_decref_func; } /* * PyString_AsString()'s returned string refers to an internal buffer * (not a copy), i.e. the data must not be modified, and the memory * must not be free()'d. */ if (!(str = PyString_AsString(py_str))) { ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ goto err_h_decref_str; } if (!(*outstr = g_strdup(str))) { ret = SRD_ERR_MALLOC; goto err_h_decref_str; } Py_XDECREF(py_str); return SRD_OK; err_h_decref_str: Py_XDECREF(py_str); err_h_decref_func: Py_XDECREF(py_func); Py_XDECREF(py_mod); if (PyErr_Occurred()) PyErr_Print(); /* Returns void. */ return ret; } /** * TODO * * @param name TODO * * @return SRD_OK upon success, a (negative) error code otherwise. */ static int srd_load_decoder(const char *name, struct srd_decoder **dec) { struct srd_decoder *d; PyObject *py_mod, *py_func, *py_res /* , *py_tuple */; int r; /* "Import" the Python module. */ if (!(py_mod = PyImport_ImportModule(name))) { /* NEWREF */ PyErr_Print(); /* Returns void. */ return SRD_ERR_PYTHON; /* TODO: More specific error? */ } /* Get the 'register' function name as Python callable object. */ py_func = PyObject_GetAttrString(py_mod, "register"); /* NEWREF */ if (!py_func || !PyCallable_Check(py_func)) { if (PyErr_Occurred()) PyErr_Print(); /* Returns void. */ Py_XDECREF(py_mod); return SRD_ERR_PYTHON; /* TODO: More specific error? */ } /* Call the 'register' function without arguments, get the result. */ if (!(py_res = PyObject_CallFunction(py_func, NULL))) { /* NEWREF */ PyErr_Print(); /* Returns void. */ Py_XDECREF(py_func); Py_XDECREF(py_mod); return SRD_ERR_PYTHON; /* TODO: More specific error? */ } if (!(d = malloc(sizeof(struct srd_decoder)))) return SRD_ERR_MALLOC; if ((r = h_str(py_res, py_func, py_mod, "id", &(d->id))) < 0) return r; if ((r = h_str(py_res, py_func, py_mod, "name", &(d->name))) < 0) return r; if ((r = h_str(py_res, py_func, py_mod, "longname", &(d->longname))) < 0) return r; if ((r = h_str(py_res, py_func, py_mod, "desc", &(d->desc))) < 0) return r; if ((r = h_str(py_res, py_func, py_mod, "longdesc", &(d->longdesc))) < 0) return r; if ((r = h_str(py_res, py_func, py_mod, "author", &(d->author))) < 0) return r; if ((r = h_str(py_res, py_func, py_mod, "email", &(d->email))) < 0) return r; if ((r = h_str(py_res, py_func, py_mod, "license", &(d->license))) < 0) return r; d->py_mod = py_mod; Py_XDECREF(py_res); Py_XDECREF(py_func); /* Get the 'decode' function name as Python callable object. */ py_func = PyObject_GetAttrString(py_mod, "decode"); /* NEWREF */ if (!py_func || !PyCallable_Check(py_func)) { if (PyErr_Occurred()) PyErr_Print(); /* Returns void. */ Py_XDECREF(py_mod); return SRD_ERR_PYTHON; /* TODO: More specific error? */ } d->py_func = py_func; /* TODO: Handle func, inputformats, outputformats. */ /* Note: They must at least be set to NULL, will segfault otherwise. */ d->func = NULL; d->inputformats = NULL; d->outputformats = NULL; *dec = d; return SRD_OK; } /** * Run the specified decoder function. * * @param dec TODO * @param inbuf TODO * @param inbuflen TODO * @param outbuf TODO * @param outbuflen TODO * * @return SRD_OK upon success, a (negative) error code otherwise. */ int srd_run_decoder(struct srd_decoder *dec, uint8_t *inbuf, uint64_t inbuflen, uint8_t **outbuf, uint64_t *outbuflen) { PyObject *py_mod, *py_func, *py_args, *py_value, *py_res; int r, ret; /* TODO: Use #defines for the return codes. */ /* Return an error upon unusable input. */ if (dec == NULL) return SRD_ERR_ARGS; /* TODO: More specific error? */ if (inbuf == NULL) return SRD_ERR_ARGS; /* TODO: More specific error? */ if (inbuflen == 0) /* No point in working on empty buffers. */ return SRD_ERR_ARGS; /* TODO: More specific error? */ if (outbuf == NULL) return SRD_ERR_ARGS; /* TODO: More specific error? */ if (outbuflen == NULL) return SRD_ERR_ARGS; /* TODO: More specific error? */ /* TODO: Error handling. */ py_mod = dec->py_mod; Py_XINCREF(py_mod); py_func = dec->py_func; Py_XINCREF(py_func); /* Create a Python tuple of size 1. */ if (!(py_args = PyTuple_New(1))) { /* NEWREF */ ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ goto err_run_decref_func; } /* Get the input buffer as Python "string" (byte array). */ /* TODO: int vs. uint64_t for 'inbuflen'? */ if (!(py_value = Py_BuildValue("s#", inbuf, inbuflen))) { /* NEWREF */ ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ goto err_run_decref_args; } /* * IMPORTANT: PyTuple_SetItem() "steals" a reference to py_value! * That means we are no longer responsible for Py_XDECREF()'ing it. * It will automatically be free'd when the 'py_args' tuple is free'd. */ if (PyTuple_SetItem(py_args, 0, py_value) != 0) { /* STEAL */ ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ Py_XDECREF(py_value); /* TODO: Ref. stolen upon error? */ goto err_run_decref_args; } if (!(py_res = PyObject_CallObject(py_func, py_args))) { /* NEWREF */ ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ goto err_run_decref_args; } if ((r = PyObject_AsCharBuffer(py_res, (const char **)outbuf, (Py_ssize_t *)outbuflen))) { ret = SRD_ERR_PYTHON; /* TODO: More specific error? */ Py_XDECREF(py_res); goto err_run_decref_args; } ret = SRD_OK; Py_XDECREF(py_res); err_run_decref_args: Py_XDECREF(py_args); err_run_decref_func: Py_XDECREF(py_func); Py_XDECREF(py_mod); if (PyErr_Occurred()) PyErr_Print(); /* Returns void. */ return ret; } /** * TODO */ static int srd_unload_decoder(struct srd_decoder *dec) { g_free(dec->id); g_free(dec->name); g_free(dec->desc); g_free(dec->func); /* TODO: Free everything in inputformats and outputformats. */ if (dec->inputformats != NULL) g_slist_free(dec->inputformats); if (dec->outputformats != NULL) g_slist_free(dec->outputformats); Py_XDECREF(dec->py_func); Py_XDECREF(dec->py_mod); return SRD_OK; } /** * TODO */ static int srd_unload_all_decoders(void) { GSList *l; struct srd_decoder *dec; for (l = srd_list_decoders(); l; l = l->next) { dec = l->data; /* TODO: Error handling. */ srd_unload_decoder(dec); } return SRD_OK; } /** * Shutdown libsigrokdecode. * * @return SRD_OK upon success, a (negative) error code otherwise. */ int srd_exit(void) { /* Unload/free all decoders, and then the list of decoders itself. */ /* TODO: Error handling. */ srd_unload_all_decoders(); g_slist_free(list_pds); /* Py_Finalize() returns void, any finalization errors are ignored. */ Py_Finalize(); return SRD_OK; }