lib/module.h

   1 // SPDX-License-Identifier: ISC
   2 /*
   3  * Copyright (c) 2015-16  David Lamparter, for NetDEF, Inc.
   4  */
   5
   6 #ifndef _FRR_MODULE_H
   7 #define _FRR_MODULE_H
   8
   9 #include <stdint.h>
  10 #include <stdbool.h>
  11
  12 #include "compiler.h"
  13 #include "xref.h"
  14
  15 #ifdef __cplusplus
  16 extern "C" {
  17 #endif
  18
  19 struct frrmod_runtime;
  20
  21 struct frrmod_info {
  22         /* single-line few-word title */
  23         const char *name;
  24         /* human-readable version number, should not contain spaces */
  25         const char *version;
  26         /* one-paragraph description */
  27         const char *description;
  28
  29         int (*init)(void);
  30 };
  31
  32 /* primary entry point structure to be present in loadable module under
  33  * "_frrmod_this_module" dlsym() name
  34  *
  35  * note space for future extensions is reserved below, so other modules
  36  * (e.g. memory management, hooks) can add fields
  37  *
  38  * const members/info are in frrmod_info.
  39  */
  40 struct frrmod_runtime {
  41         struct frrmod_runtime *next;
  42
  43         const struct frrmod_info *info;
  44         void *dl_handle;
  45         bool finished_loading;
  46
  47         char *load_name;
  48         char *load_args;
  49 };
  50
  51 /* space-reserving foo */
  52 struct _frrmod_runtime_size {
  53         struct frrmod_runtime r;
  54         /* this will barf if frrmod_runtime exceeds 1024 bytes ... */
  55         uint8_t space[1024 - sizeof(struct frrmod_runtime)];
  56 };
  57 union _frrmod_runtime_u {
  58         struct frrmod_runtime r;
  59         struct _frrmod_runtime_size s;
  60 };
  61
  62 extern union _frrmod_runtime_u _frrmod_this_module;
  63 #define THIS_MODULE (&_frrmod_this_module.r)
  64
  65 #define FRR_COREMOD_SETUP(...)                                                 \
  66         static const struct frrmod_info _frrmod_info = {__VA_ARGS__};          \
  67         DSO_LOCAL union _frrmod_runtime_u _frrmod_this_module = {{             \
  68                 NULL,                                                          \
  69                 &_frrmod_info,                                                 \
  70         }};                                                                    \
  71         XREF_SETUP();                                                          \
  72         MACRO_REQUIRE_SEMICOLON() /* end */
  73
  74 #define FRR_MODULE_SETUP(...)                                                  \
  75         FRR_COREMOD_SETUP(__VA_ARGS__);                                        \
  76         DSO_SELF struct frrmod_runtime *frr_module = &_frrmod_this_module.r;   \
  77         MACRO_REQUIRE_SEMICOLON() /* end */
  78
  79 extern struct frrmod_runtime *frrmod_list;
  80
  81 extern void frrmod_init(struct frrmod_runtime *modinfo);
  82 extern struct frrmod_runtime *frrmod_load(const char *spec, const char *dir,
  83                                           void (*pFerrlog)(const void *,
  84                                                            const char *),
  85                                           const void *pErrlogCookie);
  86 #if 0
  87 /* not implemented yet */
  88 extern void frrmod_unload(struct frrmod_runtime *module);
  89 #endif
  90
  91 #ifdef __cplusplus
  92 }
  93 #endif
  94
  95 #endif /* _FRR_MODULE_H */