L4Re/departure

libfsserver/lib/files/opener_context_resource.cc

157:3b44f61b6303
2021-08-03 Paul Boddie Made the opener resource responsible for creating new resource servers instead of returning pagers for the context to wrap up in servers whose references are then returned.
     1 /*     2  * A context resource offering support for opening files.     3  *     4  * Copyright (C) 2021 Paul Boddie <paul@boddie.org.uk>     5  *     6  * This program is free software; you can redistribute it and/or     7  * modify it under the terms of the GNU General Public License as     8  * published by the Free Software Foundation; either version 2 of     9  * the License, or (at your option) any later version.    10  *    11  * This program is distributed in the hope that it will be useful,    12  * but WITHOUT ANY WARRANTY; without even the implied warranty of    13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    14  * GNU General Public License for more details.    15  *    16  * You should have received a copy of the GNU General Public License    17  * along with this program; if not, write to the Free Software    18  * Foundation, Inc., 51 Franklin Street, Fifth Floor,    19  * Boston, MA  02110-1301, USA    20  */    21     22 #include "opener_context_resource.h"    23 #include "opener_context_object_server.h"    24 #include "opener_resource.h"    25     26 #include <string.h>    27     28     29     30 /* Support for providing access to files. */    31     32 OpenerContextResource::OpenerContextResource(OpenerResource *opener, Memory *memory)    33 : SimplePager(memory), _opener(opener)    34 {    35 }    36     37 int OpenerContextResource::expected_items()    38 {    39     return OpenerContextObject_expected_items;    40 }    41     42 ipc_server_handler_type OpenerContextResource::handler()    43 {    44     return (ipc_server_handler_type) handle_OpenerContextObject;    45 }    46     47     48     49 /* Data access methods. */    50     51 char *OpenerContextResource::get_path()    52 {    53     char *buffer = _region->read();    54     offset_t size = _region->size();    55     56     /* Confine the path to the limit of the buffer. */    57     58     if ((buffer != NULL) && (strnlen(buffer, size) < size))    59         return buffer;    60     else    61         return NULL;    62 }    63     64     65     66 /* Opener context interface methods. */    67     68 long OpenerContextResource::open(flags_t flags, offset_t *size, l4_cap_idx_t *file)    69 {    70     char *path = get_path();    71     72     if (path == NULL)    73         return -L4_EINVAL;    74     75     return _opener->open(path, flags, size, file);    76 }    77     78 // vim: tabstop=4 expandtab shiftwidth=4