1 | /** |
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2 | * NDG python embedded bbftp daemon module. |
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3 | * |
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4 | * @author Stephen Pascoe |
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5 | * |
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6 | * Copyright (C) 2006 CCLRC & NERC |
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7 | * |
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8 | * This software may be distributed under the terms of the Q Public Licence, version 1.0 or later. |
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9 | * |
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10 | */ |
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11 | |
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12 | #include <Python.h> |
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13 | |
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14 | extern char **environ; |
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15 | /* |
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16 | * variables and prototypes from bbftpd source |
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17 | */ |
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18 | |
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19 | extern int be_daemon; |
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20 | extern int newcontrolport; |
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21 | |
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22 | int bbftpd_main(int argc, char **argv, char **envp); |
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23 | int ndg_message_send(char *buffer, int buffertosendlength, char *logmessage) ; |
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24 | int ndg_message_recv(char **buffer, int *length, char *logmessage) ; |
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25 | |
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26 | /* |
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27 | * Static variables. |
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28 | */ |
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29 | static PyObject *authContext = NULL; |
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30 | static PyObject *authzContext = NULL; |
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31 | |
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32 | /*--------------------------------------------------------------------------------------------------- |
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33 | * The following functions interact with bbftpd_private_user. They are placed here to separate |
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34 | * python and bbftp APIs. |
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35 | * |
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36 | */ |
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37 | |
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38 | /** |
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39 | * Make a callback bbftpd->python to handle authentication. |
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40 | * |
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41 | * @param[out] logmessage filled with an error message on failure |
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42 | * @return 0 on success, -1 on failure |
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43 | */ |
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44 | int bbftpd_private_auth_callback(char *logmessage) { |
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45 | |
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46 | if (authzContext != NULL) { |
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47 | sprintf(logmessage, "bbftpd_private_auth_callback: authzContext already present"); |
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48 | return -1; |
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49 | } |
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50 | |
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51 | if (authContext == NULL) { |
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52 | sprintf(logmessage, "bbftpd_private_auth_callback: no authContext set"); |
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53 | return -1; |
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54 | } |
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55 | |
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56 | if ((authzContext = PyObject_CallMethod(authContext, "authorise", "")) == NULL) { |
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57 | //!TODO: should probably read the exception object to fill logmessage. |
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58 | sprintf(logmessage, "bbftpd_private_auth_callback: authContext.authorise() failed"); |
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59 | return -1; |
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60 | } |
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61 | |
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62 | /* If authContext.authorise() returned None then authorisation failed. */ |
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63 | if (authzContext == Py_None) { |
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64 | sprintf(logmessage, "bbftpd_private_auth_callback: python authorisation failed"); |
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65 | return -1; |
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66 | } |
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67 | |
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68 | return 0; |
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69 | } |
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70 | |
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71 | /** |
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72 | * retrieve the username from authzContext. |
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73 | * |
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74 | * @param[out] logmessage filled with an error message on failure |
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75 | * @return pointer to the username or NULL on failure |
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76 | */ |
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77 | char *bbftpd_private_auth_getusername(char *logmessage) { |
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78 | char *username; |
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79 | PyObject *str_obj; |
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80 | |
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81 | if (authzContext == NULL) { |
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82 | sprintf(logmessage, "bbftpd_private_auth_getusername: no authzContext set"); |
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83 | return NULL; |
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84 | } |
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85 | |
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86 | if ((str_obj = PyObject_GetAttrString(authzContext, "username")) == NULL) { |
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87 | sprintf(logmessage, "bbftpd_private_auth_getusername: authzContext.username lookup failed"); |
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88 | return NULL; |
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89 | } |
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90 | |
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91 | if ((username = PyString_AsString(str_obj)) == NULL) { |
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92 | Py_DECREF(str_obj); |
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93 | sprintf(logmessage, "bbftpd_private_auth_getusername: authzContext.username not a string"); |
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94 | return NULL; |
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95 | } |
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96 | |
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97 | return username; |
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98 | } |
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99 | |
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100 | /*------------------------------------------------------------------------------------------------- |
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101 | * Functions exported to python |
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102 | * |
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103 | */ |
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104 | |
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105 | /* send(string) */ |
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106 | static PyObject *bbftpd_send(PyObject *self, PyObject *args) { |
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107 | char *buffer, logmessage[1024]; |
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108 | int len; |
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109 | |
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110 | if (!PyArg_ParseTuple(args, "s#", &buffer, &len)) { |
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111 | return NULL; |
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112 | } |
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113 | |
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114 | if (authContext == NULL) { |
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115 | PyErr_SetString(PyExc_RuntimeError, "Must be called within a bbftpd callback"); |
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116 | return NULL; |
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117 | } |
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118 | |
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119 | if (ndg_message_send(buffer, len, logmessage) == -1) { |
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120 | PyErr_SetString(PyExc_IOError, logmessage); |
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121 | return NULL; |
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122 | } |
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123 | |
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124 | Py_RETURN_NONE; |
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125 | } |
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126 | |
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127 | /* recv(length) -> string */ |
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128 | static PyObject *bbftpd_recv(PyObject *self, PyObject *args) { |
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129 | char *buffer, logmessage[1024]; |
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130 | int len; |
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131 | PyObject *ret; |
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132 | |
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133 | if (!PyArg_ParseTuple(args, "")) { |
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134 | return NULL; |
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135 | } |
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136 | |
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137 | if (authContext == NULL) { |
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138 | PyErr_SetString(PyExc_RuntimeError, "Must be called within a bbftpd callback"); |
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139 | return NULL; |
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140 | } |
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141 | |
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142 | if (ndg_message_recv(&buffer, &len, logmessage) == -1) { |
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143 | PyErr_SetString(PyExc_IOError, logmessage); |
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144 | free(buffer); |
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145 | return NULL; |
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146 | } |
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147 | |
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148 | ret = Py_BuildValue("s#", buffer, len); |
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149 | free(buffer); |
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150 | return ret; |
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151 | } |
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152 | |
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153 | |
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154 | |
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155 | /** |
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156 | * Main entry point for the python module. |
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157 | */ |
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158 | static PyObject *bbftpd_run(PyObject *self, PyObject *args) { |
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159 | int argc, i; |
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160 | char **argv, **arg_p; |
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161 | int pid; |
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162 | char preargs[2][20] = { "bbftpd_embedded", "-b" }; |
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163 | PyObject *daemon_args, *item; |
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164 | |
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165 | if (!PyArg_ParseTuple(args, "OO", &authContext, &daemon_args)) { |
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166 | return NULL; |
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167 | } |
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168 | Py_INCREF(authContext); |
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169 | Py_INCREF(daemon_args); |
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170 | |
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171 | /* |
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172 | * Convert arguments into a standard argv sequence. |
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173 | */ |
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174 | argc = PySequence_Size(daemon_args); |
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175 | if ((argv = (char**)malloc((argc + 2)*sizeof(char*))) == NULL) { |
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176 | PyErr_SetString(PyExc_MemoryError, "malloc failed"); |
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177 | Py_DECREF(daemon_args); |
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178 | return NULL; |
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179 | } |
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180 | |
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181 | // Add fixed arguments to daemon's argv |
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182 | arg_p = argv; |
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183 | *arg_p = preargs[0]; arg_p++; |
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184 | *arg_p = preargs[1]; arg_p++; |
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185 | |
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186 | for (i=0; i<argc; i++) { |
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187 | if ((item = PySequence_GetItem(daemon_args, i)) == NULL) { |
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188 | Py_DECREF(authContext); |
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189 | Py_DECREF(daemon_args); |
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190 | return NULL; |
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191 | } |
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192 | if ((*arg_p = PyString_AsString(item)) == NULL) { |
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193 | free(argv); |
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194 | Py_DECREF(item); |
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195 | Py_DECREF(authContext); |
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196 | Py_DECREF(daemon_args); |
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197 | return NULL; |
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198 | } |
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199 | arg_p++; |
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200 | Py_DECREF(item); |
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201 | } |
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202 | |
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203 | /* |
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204 | * We must reset some global variables so that bbftpd_run can be executed multiple times. |
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205 | */ |
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206 | be_daemon = 0; |
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207 | |
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208 | pid = bbftpd_main(argc+2, argv, environ); |
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209 | |
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210 | free(argv); |
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211 | Py_DECREF(authContext); authContext = NULL; |
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212 | Py_DECREF(daemon_args); |
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213 | |
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214 | return Py_BuildValue("i", pid); |
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215 | } |
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216 | |
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217 | static PyMethodDef BbftpdMethods[] = { |
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218 | { |
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219 | "run", bbftpd_run, METH_VARARGS, |
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220 | "Execute the bbftpd server.\n" |
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221 | "\n" |
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222 | "Forks an embedded bbftpd process as if it were executed\n" |
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223 | "with the command line $ bbftpd -b <args>." |
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224 | "\n" |
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225 | "@param args: command line arguments to pass to the server\n" |
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226 | "@return: the PID of the server process\n" |
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227 | }, |
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228 | { |
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229 | "send", bbftpd_send, METH_VARARGS, |
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230 | "Send an authentication message to the client.\n" |
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231 | "\n" |
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232 | "Equivilent to bbftpd_private_send() C call.\n" |
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233 | "\n" |
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234 | "@param buffer: A string containing the message\n" |
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235 | "@raise IOError: if bbftpd_private_send() call fails\n" |
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236 | }, |
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237 | { |
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238 | "recv", bbftpd_recv, METH_VARARGS, |
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239 | "Receive an authentication message from the client.\n" |
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240 | "\n" |
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241 | "Equivilent to bbftpd_private_recv() C call.\n" |
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242 | "\n" |
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243 | "@param len: The length of message to expect\n" |
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244 | "@return: A string containing the message\n" |
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245 | "@raise IOError: if bbftpd_private_recv() call fails\n" |
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246 | }, |
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247 | {NULL, NULL, 0, NULL} |
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248 | }; |
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249 | |
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250 | PyMODINIT_FUNC initbbftpd(void) { |
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251 | (void) Py_InitModule("bbftpd", BbftpdMethods); |
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252 | } |
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253 | |
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