bsw@1071: /*
bsw@1071:  * minimalistic Lua LDAP interface library
bsw@1071:  *
bsw@1071:  * The library does not set any global variable itself and must thus be
bsw@1071:  * loaded with
bsw@1071:  *
bsw@1071:  *     mldap = require("mldap")
bsw@1071:  *
bsw@1071:  * or a similar statement.
bsw@1071:  *
bsw@1071:  * The library provides two functions, conn = bind{...} and unbind(conn)
bsw@1071:  * to connect to and disconnect from the LDAP server respectively. The
bsw@1071:  * unbind function is also provided as a method of the connection userdata
bsw@1071:  * object (see below).
bsw@1071:  *
bsw@1071:  * The arguments to the bind{...} function are documented in the source code
bsw@1071:  * (see C function mldap_bind). In case of success, the bind function returns
bsw@1071:  * a userdata object that provides two methods: query{...} and unbind(). In
bsw@1071:  * case of error, the bind function returns nil as first return value, an
bsw@1071:  * error string as second return value, and a numeric error code as third
bsw@1071:  * return value. A positive error code is an LDAP resultCode, a negative
bsw@1071:  * error code is an OpenLDAP API error code:
bsw@1071:  *
bsw@1071:  *     connection, error_string, numeric_error_code = mldap.bind{...}
bsw@1071:  *
bsw@1071:  * For translating numeric error codes to an identifying (machine readable)
bsw@1071:  * string identifier, the library provides in addition to the two functions
bsw@1071:  * a table named 'errorcodes', for example:
bsw@1071:  *
bsw@1071:  *     49 == mldap.errorcodes["invalid_credentials"]
bsw@1071:  *
bsw@1071:  * and
bsw@1071:  *
bsw@1071:  *     mldap.errorcodes[49] == "invalid_credentials"
bsw@1071:  *
bsw@1071:  * The arguments and return value of the query{...} method of the connection
bsw@1071:  * userdata object are also documented in the source code below (see
bsw@1071:  * C function mldap_query). Error conditions are reported the same way as the
bsw@1071:  * bind{...} function does.
bsw@1071:  *
bsw@1071:  * To close the connection, either the unbind() function of the library or
bsw@1071:  * the unbind() method can be called; it is allowed to call them multiple
bsw@1071:  * times, and they are also invoked by the garbage collector.
bsw@1071:  *
bsw@1071:  */
bsw@1071: 
bsw@1071: // Lua header inclusions:
bsw@1071: #include <lua.h>
bsw@1071: #include <lauxlib.h>
bsw@1071: 
bsw@1071: // OpenLDAP header inclusions:
bsw@1071: #include <ldap.h>
bsw@1071: 
bsw@1071: // Standard C inclusions:
bsw@1071: #include <stdlib.h>
bsw@1071: #include <stdbool.h>
bsw@1071: #include <unistd.h>
bsw@1071: 
bsw@1071: // Error code translation is included from separate C file:
bsw@1071: #include "mldap_errorcodes.c"
bsw@1071: 
bsw@1071: // Provide compatibility with Lua 5.1:
bsw@1071: #if LUA_VERSION_NUM < 502
bsw@1071: #define luaL_newlib(L, t) lua_newtable((L)); luaL_register(L, NULL, t)
bsw@1071: #define lua_rawlen lua_objlen
bsw@1071: #define lua_len lua_objlen
bsw@1071: #define luaL_setmetatable(L, regkey) \
bsw@1071:   lua_getfield((L), LUA_REGISTRYINDEX, (regkey)); \
bsw@1071:   lua_setmetatable((L), -2);
bsw@1071: #endif
bsw@1071: 
bsw@1071: // prefix for all Lua registry entries of this library:
bsw@1071: #define MLDAP_REGKEY "556aeaf3c864af2e_mldap_"
bsw@1071: 
bsw@1071: 
bsw@1071: static const char *mldap_get_named_string_arg(
bsw@1071:   // gets a named argument of type "string" from a table at the given stack position
bsw@1071: 
bsw@1071:   lua_State *L,         // pointer to lua_State variable
bsw@1071:   int idx,              // stack index of the table containing the named arguments
bsw@1071:   const char *argname,  // name of the argument
bsw@1071:   int mandatory         // if not 0, then the argument is mandatory and an error is raised if it isn't found
bsw@1071: 
bsw@1071:   // leaves the string as new element on top of the stack
bsw@1071: ) {
bsw@1071: 
bsw@1071:   // pushes the table entry with the given argument name on top of the stack:
bsw@1071:   lua_getfield(L, idx, argname);
bsw@1071: 
bsw@1071:   // check, if the entry is nil or false:
bsw@1071:   if (!lua_toboolean(L, -1)) {
bsw@1071: 
bsw@1071:     // throw error, if named argument is mandatory:
bsw@1071:     if (mandatory) return luaL_error(L, "Named argument '%s' missing", argname), NULL;
bsw@1071: 
bsw@1071:     // return NULL pointer, if named argument is not mandatory:
bsw@1071:     return NULL;
bsw@1071: 
bsw@1071:   }
bsw@1071: 
bsw@1071:   // throw error, if the value of the argument is not string:
bsw@1071:   if (lua_type(L, -1) != LUA_TSTRING) return luaL_error(L, "Named argument '%s' is not a string", argname), NULL;
bsw@1071: 
bsw@1071:   // return a pointer to the string, leaving the string on top of the stack to avoid garbage collection:
bsw@1071:   return lua_tostring(L, -1);
bsw@1071: 
bsw@1071:   // leaves one element on the stack
bsw@1071: }
bsw@1071: 
bsw@1071: 
bsw@1071: static int mldap_get_named_number_arg(
bsw@1071:   // gets a named argument of type "number" from a table at the given stack position
bsw@1071: 
bsw@1071:   lua_State *L,             // pointer to lua_State variable
bsw@1071:   int idx,                  // stack index of the table containing the named arguments
bsw@1071:   const char *argname,      // name of the argument
bsw@1071:   int mandatory,            // if not 0, then the argument is mandatory and an error is raised if it isn't found
bsw@1071:   lua_Number default_value  // default value to return, if the argument is not mandatory and nil or false
bsw@1071: 
bsw@1071:   // opposed to 'mldap_get_named_string_arg', this function leaves no element on the stack
bsw@1071: ) {
bsw@1071: 
bsw@1071:   lua_Number value;  // value to return
bsw@1071: 
bsw@1071:   // pushes the table entry with the given argument name on top of the stack:
bsw@1071:   lua_getfield(L, idx, argname);
bsw@1071: 
bsw@1071:   // check, if the entry is nil or false:
bsw@1071:   if (lua_isnil(L, -1)) {
bsw@1071: 
bsw@1071:     // throw error, if named argument is mandatory:
bsw@1071:     if (mandatory) return luaL_error(L, "Named argument '%s' missing", argname), 0;
bsw@1071: 
bsw@1071:     // set default value as return value, if named argument is not mandatory:
bsw@1071:     value = default_value;
bsw@1071: 
bsw@1071:   } else {
bsw@1071: 
bsw@1071:     // throw error, if the value of the argument is not a number:
bsw@1071:     if (lua_type(L, -1) != LUA_TNUMBER) return luaL_error(L, "Named argument '%s' is not a number", argname), 0;
bsw@1071: 
bsw@1071:     // set return value to the number:
bsw@1071:     value = lua_tonumber(L, -1);
bsw@1071: 
bsw@1071:   }
bsw@1071: 
bsw@1071:   // remove unnecessary element from stack (not needed to avoid garbage collection):
bsw@1071:   return value;
bsw@1071: 
bsw@1071:   // leaves no new elements on the stack
bsw@1071: }
bsw@1071: 
bsw@1071: 
bsw@1071: static int mldap_scope(
bsw@1071:   // converts a string ("base", "onelevel", "subtree", "children") to an integer representing the LDAP scope
bsw@1071:   // and throws an error for any unknown string
bsw@1071: 
bsw@1071:   lua_State *L,             // pointer to lua_State variable (needed to throw errors)
bsw@1071:   const char *scope_string  // string that is either ("base", "onelevel", "subtree", "children")
bsw@1071: 
bsw@1071:   // does not affect or use the Lua stack at all
bsw@1071: ) {
bsw@1071: 
bsw@1071:   // return integer according to string value:
bsw@1071:   if (!strcmp(scope_string, "base"))     return LDAP_SCOPE_BASE;
bsw@1071:   if (!strcmp(scope_string, "onelevel")) return LDAP_SCOPE_ONELEVEL;
bsw@1071:   if (!strcmp(scope_string, "subtree"))  return LDAP_SCOPE_SUBTREE;
bsw@1071:   if (!strcmp(scope_string, "children")) return LDAP_SCOPE_CHILDREN;
bsw@1071: 
bsw@1071:   // throw error for unknown string values:
bsw@1071:   return luaL_error(L, "Invalid LDAP scope: '%s'", scope_string), 0;
bsw@1071: 
bsw@1071: }
bsw@1071: 
bsw@1071: 
bsw@1071: static int mldap_bind(lua_State *L) {
bsw@1071:   // Lua C function that takes named arguments as a table
bsw@1071:   // and returns a userdata object, representing the LDAP connection
bsw@1071:   // or returns nil, an error string, and an error code (integer) on error
bsw@1071: 
bsw@1071:   // named arguments:
bsw@1071:   // "uri"      (string)  server URI to connect to
bsw@1071:   // "who"      (string)  DN to bind as
bsw@1071:   // "password" (string)  password for DN to bind as
bsw@1071:   // "timeout"  (number)  timeout in seconds
bsw@1071: 
bsw@1071:   static const int ldap_version = LDAP_VERSION3;  // providing a pointer (&ldap_version) to set LDAP protocol version 3
bsw@1071:   const char *uri;           // C string for "uri" argument
bsw@1071:   const char *who;           // C string for "who" argument
bsw@1071:   struct berval cred;        // credentials ("password") are stored as struct berval
bsw@1071:   lua_Number timeout_float;  // float (lua_Number) for timeout
bsw@1071:   struct timeval timeout;    // timeout is stored as struct timeval
bsw@1071:   int ldap_error;            // LDAP error code (as returned by libldap calls)
bsw@1071:   LDAP *ldp;                 // pointer to an opaque OpenLDAP structure representing the connection
bsw@1071:   LDAP **ldp_ptr;            // pointer to a Lua userdata structure (that only contains the 'ldp' pointer)
bsw@1071: 
bsw@1071:   // throw error if first argument is not a table:
bsw@1071:   if (lua_type(L, 1) != LUA_TTABLE) {
bsw@1071:     luaL_error(L, "Argument to function 'bind' is not a table.");
bsw@1071:   }
bsw@1071: 
bsw@1071:   // extract arguments:
bsw@1071:   uri = mldap_get_named_string_arg(L, 1, "uri", true);
bsw@1071:   who = mldap_get_named_string_arg(L, 1, "who", false);
bsw@1071:   cred.bv_val = mldap_get_named_string_arg(L, 1, "password", false);
bsw@1071:   if (cred.bv_val) cred.bv_len = strlen(cred.bv_val);
bsw@1071:   else cred.bv_len = 0;
bsw@1071:   timeout_float = mldap_get_named_number_arg(L, 1, "timeout", false, -1);
bsw@1071:   timeout.tv_sec = timeout_float;
bsw@1071:   timeout.tv_usec = (timeout_float - timeout.tv_sec) * 1000000;
bsw@1071: 
bsw@1071:   // initialize OpenLDAP structure and provide URI for connection:
bsw@1071:   ldap_error = ldap_initialize(&ldp, uri);
bsw@1071:   // on error, jump to label "mldap_queryconn_error1", as no ldap_unbind_ext_s() is needed:
bsw@1071:   if (ldap_error != LDAP_SUCCESS) goto mldap_queryconn_error1;
bsw@1071: 
bsw@1071:   // set LDAP protocol version 3:
bsw@1071:   ldap_error = ldap_set_option(ldp, LDAP_OPT_PROTOCOL_VERSION, &ldap_version);
bsw@1071:   // on error, jump to label "mldap_queryconn_error2", as ldap_unbind_ext_s() must be called:
bsw@1071:   if (ldap_error != LDAP_SUCCESS) goto mldap_queryconn_error2;
bsw@1071: 
bsw@1071:   // set timeout for asynchronous OpenLDAP library calls:
bsw@1071:   ldap_error = ldap_set_option(ldp, LDAP_OPT_TIMEOUT, &timeout);
bsw@1071:   // on error, jump to label "mldap_queryconn_error2", as ldap_unbind_ext_s() must be called:
bsw@1071:   if (ldap_error != LDAP_SUCCESS) goto mldap_queryconn_error2;
bsw@1071: 
bsw@1071:   // connect to LDAP server:
bsw@1071:   ldap_error = ldap_sasl_bind_s(
bsw@1071:     ldp,               // pointer to opaque OpenLDAP structure representing the connection
bsw@1071:     who,               // DN to bind as
bsw@1071:     LDAP_SASL_SIMPLE,  // SASL mechanism "simple" for password authentication
bsw@1071:     &cred,             // password as struct berval
bsw@1071:     NULL,              // no server controls
bsw@1071:     NULL,              // no client controls
bsw@1071:     NULL               // do not store server credentials
bsw@1071:   );
bsw@1071: 
bsw@1071:   // error handling:
bsw@1071:   if (ldap_error != LDAP_SUCCESS) {
bsw@1071: 
bsw@1071:     // error label to jump to, if a call of ldap_unbind_ext_s() is required:
bsw@1071:     mldap_queryconn_error2:
bsw@1071: 
bsw@1071:     // close connection and free resources:
bsw@1071:     ldap_unbind_ext_s(ldp, NULL, NULL);
bsw@1071: 
bsw@1071:     // error label to jump to, if no call of ldap_unbind_ext_s() is required:
bsw@1071:     mldap_queryconn_error1:
bsw@1071: 
bsw@1071:     // return three values:
bsw@1071:     lua_pushnil(L);                                  // return nil as first value
bsw@1071:     lua_pushstring(L, ldap_err2string(ldap_error));  // return error string as second value
bsw@1071:     lua_pushinteger(L, ldap_error);                  // return error code (integer) as third value
bsw@1071:     return 3;
bsw@1071: 
bsw@1071:   }
bsw@1071: 
bsw@1071:   // create new Lua userdata object (that will contain the 'ldp' pointer) on top of stack:
bsw@1071:   ldp_ptr = lua_newuserdata(L, sizeof(LDAP *));
bsw@1071: 
bsw@1071:   // set metatable of Lua userdata object:
bsw@1071:   luaL_setmetatable(L, MLDAP_REGKEY "connection_metatable");
bsw@1071: 
bsw@1071:   // write contents of Lua userdata object (the 'ldp' pointer):
bsw@1071:   *ldp_ptr = ldp;
bsw@1071: 
bsw@1071:   // return Lua userdata object from top of stack:
bsw@1071:   return 1;
bsw@1071: 
bsw@1071: }
bsw@1071: 
bsw@1071: 
bsw@1071: static int mldap_search(lua_State *L) {
bsw@1071:   // Lua C function used as "search" method of Lua userdata object representing the LDAP connection
bsw@1071:   // that takes a Lua userdata object (the LDAP connection) as first argument,
bsw@1071:   // a table with named arguments as second argument,
bsw@1071:   // and returns a result table on success (see below)
bsw@1071:   // or returns nil, an error string, and an error code (integer) on error
bsw@1071: 
bsw@1071:   // named arguments:
bsw@1071:   // "base"  (string)   DN of the entry at which to start the search
bsw@1071:   // "scope" (string)   scope of the search, one of:
bsw@1071:   //                      "base" to search the object itself
bsw@1071:   //                      "onelevel" to search the object's immediate children
bsw@1071:   //                      "subtree" to search the object and all its descendants
bsw@1071:   //                      "children" to search all of the descendants
bsw@1071:   // "filter" (string)  string representation of the filter to apply in the search
bsw@1071:   //                    (conforming to RFC 4515 as extended in RFC 4526)
bsw@1071:   // "attrs"  (table)   list of attribute descriptions (each a string) to return from matching entries
bsw@1071: 
bsw@1071:   // structure of result table:
bsw@1071:   // {
bsw@1071:   //   { dn      = <distinguished name (DN)>,
bsw@1071:   //     <attr1> = { <value1>, <value2>, ... },
bsw@1071:   //     <attr2> = { <value1>, <value2>, ... },
bsw@1071:   //     ...
bsw@1071:   //   },
bsw@1071:   //   { dn      = <distinguished name (DN)>,
bsw@1071:   //     <attr1> = { <value1>, <value2>, ... },
bsw@1071:   //     <attr2> = { <value1>, <value2>, ... },
bsw@1071:   //     ...
bsw@1071:   //   },
bsw@1071:   //   ...
bsw@1071:   // }
bsw@1071: 
bsw@1071:   const char *base;          // C string for "base" argument
bsw@1071:   const char *scope_string;  // C string for "scope" argument
bsw@1071:   int scope;                 // integer representing the scope
bsw@1071:   const char *filter;        // C string for "filter" argument
bsw@1071:   size_t nattrs;             // number of attributes in "attrs" argument
bsw@1071:   char **attrs;              // C string array of "attrs" argument
bsw@1071:   size_t attr_idx;           // index variable for building the C string array of "attrs"
bsw@1071:   int ldap_error;            // LDAP error code (as returned by libldap calls)
bsw@1071:   LDAP **ldp_ptr;            // pointer to a pointer to the OpenLDAP structure representing the connection
bsw@1071:   LDAPMessage *res;          // pointer to the result of ldap_search_ext_s() call
bsw@1071:   LDAPMessage *ent;          // pointer to an entry in the result of ldap_search_ext_s() call
bsw@1071:   int i;                     // integer to fill the Lua table returned as result
bsw@1071: 
bsw@1071:   // truncate the Lua stack to 2 elements:
bsw@1071:   lua_settop(L, 2);
bsw@1071: 
bsw@1071:   // check if the first argument is a Lua userdata object with the correct metatable
bsw@1071:   // and get a C pointer to that userdata object:
bsw@1071:   ldp_ptr = luaL_checkudata(L, 1, MLDAP_REGKEY "connection_metatable");
bsw@1071: 
bsw@1071:   // throw an error, if the connection has already been closed:
bsw@1071:   if (!*ldp_ptr) {
bsw@1071:     return luaL_error(L, "LDAP connection has already been closed");
bsw@1071:   }
bsw@1071: 
bsw@1071:   // check if the second argument is a table, and throw an error if it's not a table:
bsw@1071:   if (lua_type(L, 2) != LUA_TTABLE) {
bsw@1071:     luaL_error(L, "Argument to function 'bind' is not a table.");
bsw@1071:   }
bsw@1071: 
bsw@1071:   // extract named arguments (requires memory allocation for 'attrs'):
bsw@1071:   base = mldap_get_named_string_arg(L, 2, "base", true);  // pushed to 3
bsw@1071:   scope_string = mldap_get_named_string_arg(L, 2, "scope", true);  // pushed to 4
bsw@1071:   scope = mldap_scope(L, scope_string);
bsw@1071:   lua_pop(L, 1);  // removes stack element 4
bsw@1071:   filter = mldap_get_named_string_arg(L, 2, "filter", false);  // pushed to 4
bsw@1071:   lua_getfield(L, 2, "attrs");  // pushed to 5
bsw@1071:   nattrs = lua_len(L, -1);
bsw@1071:   attrs = calloc(nattrs + 1, sizeof(char *));  // memory allocation, +1 for terminating NULL
bsw@1071:   if (!attrs) return luaL_error(L, "Memory allocation error in C function 'mldap_queryconn'");
bsw@1071:   for (attr_idx=0; attr_idx<nattrs; attr_idx++) {
bsw@1071:     lua_pushinteger(L, attr_idx+1);
bsw@1071:     lua_gettable(L, 5);  // pushed onto variable stack position
bsw@1071:     if (lua_type(L, -1) != LUA_TSTRING) {
bsw@1071:       free(attrs);
bsw@1071:       return luaL_error(L, "Element in attribute list is not a string");
bsw@1071:     }
bsw@1071:     attrs[i] = lua_tostring(L, -1);
bsw@1071:   }
bsw@1071:   // attrs[nattrs] = NULL;  // unnecessary due to calloc
bsw@1071: 
bsw@1071:   // execute LDAP search and store pointer to the result in 'res':
bsw@1071:   ldap_error = ldap_search_ext_s(
bsw@1071:     *ldp_ptr,  // pointer to the opaque OpenLDAP structure representing the connection
bsw@1071:     base,      // DN of the entry at which to start the search
bsw@1071:     scope,     // scope of the search
bsw@1071:     filter,    // string representation of the filter to apply in the search
bsw@1071:     attrs,     // array of attribute descriptions (array of strings)
bsw@1071:     0,         // do not only request attribute descriptions but also values
bsw@1071:     NULL,      // no server controls
bsw@1071:     NULL,      // no client controls
bsw@1071:     NULL,      // do not set another timeout
bsw@1071:     0,         // no sizelimit
bsw@1071:     &res       // store result in 'res'
bsw@1071:   );
bsw@1071: 
bsw@1071:   // free data structures that have been allocated for the 'attrs' array:
bsw@1071:   free(attrs);
bsw@1071: 
bsw@1071:   // return nil, an error string, and an error code (integer) in case of error:
bsw@1071:   if (ldap_error != LDAP_SUCCESS) {
bsw@1071:     lua_pushnil(L);
bsw@1071:     lua_pushstring(L, ldap_err2string(ldap_error));
bsw@1071:     lua_pushinteger(L, ldap_error);
bsw@1071:     return 3;
bsw@1071:   }
bsw@1071: 
bsw@1071:   // clear Lua stack:
bsw@1071:   lua_settop(L, 0);
bsw@1071: 
bsw@1071:   // create result table for all entries at stack position 1:
bsw@1071:   lua_newtable(L);
bsw@1071: 
bsw@1071:   // use ldap_first_entry() and ldap_next_entry() functions
bsw@1071:   // to iterate through all entries in the result 'res'
bsw@1071:   // and count 'i' from 1 up:
bsw@1071:   for (
bsw@1071:     ent=ldap_first_entry(*ldp_ptr, res), i=1;
bsw@1071:     ent;
bsw@1071:     ent=ldap_next_entry(*ldp_ptr, ent), i++
bsw@1071:   ) {
bsw@1071: 
bsw@1071:     char *attr;       // name of attribute
bsw@1071:     BerElement *ber;  // structure to iterate through attributes
bsw@1071:     char *dn;         // LDAP entry name (distinguished name)
bsw@1071: 
bsw@1071:     // create result table for one entry at stack position 2:
bsw@1071:     lua_newtable(L);
bsw@1071: 
bsw@1071:     // use ldap_first_attribute() and ldap_next_attribute()
bsw@1071:     // as well as 'BerElement *ber' to iterate through all attributes
bsw@1071:     // ('ber' must be free'd with ber_free(ber, 0) call later):
bsw@1071:     for (
bsw@1071:       attr=ldap_first_attribute(*ldp_ptr, ent, &ber);
bsw@1071:       attr;
bsw@1071:       attr=ldap_next_attribute(*ldp_ptr, ent, ber)
bsw@1071:     ) {
bsw@1071: 
bsw@1071:       struct berval **vals;  // pointer to (first element of) array of values
bsw@1071:       struct berval **val;   // pointer to a value represented as 'struct berval' structure
bsw@1071:       int j;                 // integer to fill a Lua table
bsw@1071: 
bsw@1071:       // push the attribute name to Lua stack position 3:
bsw@1071:       lua_pushstring(L, attr);
bsw@1071: 
bsw@1071:       // create a new table for the attribute's values on Lua stack position 4:
bsw@1071:       lua_newtable(L);
bsw@1071: 
bsw@1071:       // call ldap_get_values_len() to obtain the values
bsw@1071:       // (required to be free'd later with ldap_value_free_len()):
bsw@1071:       vals = ldap_get_values_len(*ldp_ptr, ent, attr);
bsw@1071: 
bsw@1071:       // iterate through values and count 'j' from 1 up:
bsw@1071:       for (val=vals, j=1; *val; val++, j++) {
bsw@1071: 
bsw@1071:         // push value to Lua stack position 5:
bsw@1071:         lua_pushlstring(L, (*val)->bv_val, (*val)->bv_len);
bsw@1071: 
bsw@1071:         // pop value from Lua stack position 5
bsw@1071:         // and store it in table on Lua stack position 4:
bsw@1071:         lua_rawseti(L, 4, j);
bsw@1071: 
bsw@1071:       }
bsw@1071: 
bsw@1071:       // free data structure of values:
bsw@1071:       ldap_value_free_len(vals);
bsw@1071: 
bsw@1071:       // pop attribute name from Lua stack position 3
bsw@1071:       // and pop value table from Lua stack position 4
bsw@1071:       // and store them in result table for entry at Lua stack position 2:
bsw@1071:       lua_settable(L, 2);
bsw@1071: 
bsw@1071:     }
bsw@1071: 
bsw@1071:     // free 'BerElement *ber' stucture that has been used to iterate through all attributes
bsw@1071:     // (second argument is zero due to manpage of ldap_first_attribute()):
bsw@1071:     ber_free(ber, 0);
bsw@1071: 
bsw@1071:     // store distinguished name (DN) on Lua stack position 3
bsw@1071:     // (aquired memory is free'd with ldap_memfree()):
bsw@1071:     dn = ldap_get_dn(*ldp_ptr, ent);
bsw@1071:     lua_pushstring(L, dn);
bsw@1071:     ldap_memfree(dn);
bsw@1071: 
bsw@1071:     // pop distinguished name (DN) from Lua stack position 3
bsw@1071:     // and store it in field "dn" of entry result table at stack position 2
bsw@1071:     lua_setfield(L, 2, "dn");
bsw@1071: 
bsw@1071:     // pop entry result table from Lua stack position 2
bsw@1071:     // and store it in table at stack position 1:
bsw@1071:     lua_rawseti(L, 1, i);
bsw@1071:     
bsw@1071:   }
bsw@1071: 
bsw@1071:   // return result table from top of Lua stack (stack position 1):
bsw@1071:   return 1;
bsw@1071: 
bsw@1071: }
bsw@1071: 
bsw@1071: static int mldap_unbind(lua_State *L) {
bsw@1071:   // Lua C function used as "unbind" function of module and "unbind" method of Lua userdata object
bsw@1071:   // closing the LDAP connection (if still open)
bsw@1071:   // returning nothing
bsw@1071: 
bsw@1071:   LDAP **ldp_ptr;  // pointer to a pointer to the OpenLDAP structure representing the connection
bsw@1071: 
bsw@1071:   // check if the first argument is a Lua userdata object with the correct metatable
bsw@1071:   // and get a C pointer to that userdata object:
bsw@1071:   ldp_ptr = luaL_checkudata(L, 1, MLDAP_REGKEY "connection_metatable");
bsw@1071: 
bsw@1071:   // check if the Lua userdata object still contains a pointer:
bsw@1071:   if (*ldp_ptr) {
bsw@1071: 
bsw@1071:     // if it does, then call ldap_unbind_ext_s():
bsw@1071:     ldap_unbind_ext_s(
bsw@1071:       *ldp_ptr,  // pointer to the opaque OpenLDAP structure representing the connection
bsw@1071:       NULL,      // no server controls
bsw@1071:       NULL       // no client controls
bsw@1071:     );
bsw@1071: 
bsw@1071:     // store NULL pointer in Lua userdata to mark connection as closed
bsw@1071:     *ldp_ptr = NULL;
bsw@1071:   }
bsw@1071: 
bsw@1071:   // returning nothing:
bsw@1071:   return 0;
bsw@1071: 
bsw@1071: }
bsw@1071: 
bsw@1071: 
bsw@1071: // registration information for library functions:
bsw@1071: static const struct luaL_Reg mldap_module_functions[] = {
bsw@1071:   {"bind", mldap_bind},
bsw@1071:   {"unbind", mldap_unbind},
bsw@1071:   {NULL, NULL}
bsw@1071: };
bsw@1071: 
bsw@1071: 
bsw@1071: // registration information for methods of connection object: 
bsw@1071: static const struct luaL_Reg mldap_connection_methods[] = {
bsw@1071:   {"search", mldap_search},
bsw@1071:   {"unbind", mldap_unbind},
bsw@1071:   {NULL, NULL}
bsw@1071: };
bsw@1071: 
bsw@1071: 
bsw@1071: // registration information for connection metatable: 
bsw@1071: static const struct luaL_Reg mldap_connection_metamethods[] = {
bsw@1071:   {"__gc", mldap_unbind},
bsw@1071:   {NULL, NULL}
bsw@1071: };
bsw@1071: 
bsw@1071: 
bsw@1071: // luaopen function to initialize/register library:
bsw@1071: int luaopen_mldap(lua_State *L) {
bsw@1071: 
bsw@1071:   // clear Lua stack:
bsw@1071:   lua_settop(L, 0);
bsw@1071: 
bsw@1071:   // create table with library functions on Lua stack position 1:
bsw@1071:   luaL_newlib(L, mldap_module_functions);
bsw@1071: 
bsw@1071:   // create metatable for connection objects on Lua stack position 2:
bsw@1071:   luaL_newlib(L, mldap_connection_metamethods);
bsw@1071: 
bsw@1071:   // create table with methods for connection object on Lua stack position 3:
bsw@1071:   luaL_newlib(L, mldap_connection_methods);
bsw@1071: 
bsw@1071:   // pop table with methods for connection object from Lua stack position 3
bsw@1071:   // and store it as "__index" in metatable:
bsw@1071:   lua_setfield(L, 2, "__index");
bsw@1071: 
bsw@1071:   // pop table with metatable for connection objects from Lua stack position 2
bsw@1071:   // and store it in the Lua registry:
bsw@1071:   lua_setfield(L, LUA_REGISTRYINDEX, MLDAP_REGKEY "connection_metatable");
bsw@1071: 
bsw@1071:   // create table for error code mappings on Lua stack position 2:
bsw@1071:   lua_newtable(L);
bsw@1071: 
bsw@1071:   // fill table for error code mappings
bsw@1071:   // that maps integer error codes to error code strings
bsw@1071:   // and vice versa:
bsw@1071:   mldap_set_errorcodes(L);
bsw@1071: 
bsw@1071:   // pop table for error code mappings from Lua stack position 2
bsw@1071:   // and store it as "errorcodes" in table with library functions:
bsw@1071:   lua_setfield(L, 1, "errorcodes");
bsw@1071: 
bsw@1071:   // return table with library functions from top of Lua stack:
bsw@1071:   return 1;
bsw@1071: 
bsw@1071: }