diff options
Diffstat (limited to 'lib/module.c')
| -rw-r--r-- | lib/module.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/lib/module.c b/lib/module.c new file mode 100644 index 0000000..af7d20c --- /dev/null +++ b/lib/module.c @@ -0,0 +1,204 @@ +// SPDX-License-Identifier: ISC +/* + * Copyright (c) 2015-16 David Lamparter, for NetDEF, Inc. + */ + +#include "config.h" + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <unistd.h> +#include <limits.h> +#include <dlfcn.h> + +#include "module.h" +#include "memory.h" +#include "lib/version.h" +#include "printfrr.h" + +DEFINE_MTYPE_STATIC(LIB, MODULE_LOADNAME, "Module loading name"); +DEFINE_MTYPE_STATIC(LIB, MODULE_LOADARGS, "Module loading arguments"); +DEFINE_MTYPE_STATIC(LIB, MODULE_LOAD_ERR, "Module loading error"); + +static struct frrmod_info frrmod_default_info = { + .name = "libfrr", + .version = FRR_VERSION, + .description = "libfrr core module", +}; +union _frrmod_runtime_u frrmod_default = { + .r = + { + .info = &frrmod_default_info, + .finished_loading = 1, + }, +}; + +XREF_SETUP(); + +// if defined(HAVE_SYS_WEAK_ALIAS_ATTRIBUTE) +// union _frrmod_runtime_u _frrmod_this_module +// __attribute__((weak, alias("frrmod_default"))); +// elif defined(HAVE_SYS_WEAK_ALIAS_PRAGMA) +#pragma weak _frrmod_this_module = frrmod_default +// else +// error need weak symbol support +// endif + +struct frrmod_runtime *frrmod_list = &frrmod_default.r; +static struct frrmod_runtime **frrmod_last = &frrmod_default.r.next; +static const char *execname = NULL; + +void frrmod_init(struct frrmod_runtime *modinfo) +{ + modinfo->finished_loading = true; + *frrmod_last = modinfo; + frrmod_last = &modinfo->next; + + execname = modinfo->info->name; +} + +/* + * If caller wants error strings, it should define non-NULL pFerrlog + * which will be called with 0-terminated error messages. These + * messages will NOT contain newlines, and the (*pFerrlog)() function + * could be called multiple times for a single call to frrmod_load(). + * + * The (*pFerrlog)() function may copy these strings if needed, but + * should expect them to be freed by frrmod_load() before frrmod_load() + * returns. + * + * frrmod_load() is coded such that (*pFerrlog)() will be called only + * in the case where frrmod_load() returns an error. + */ +struct frrmod_runtime *frrmod_load(const char *spec, const char *dir, + void (*pFerrlog)(const void *, const char *), + const void *pErrlogCookie) +{ + void *handle = NULL; + char name[PATH_MAX], fullpath[PATH_MAX * 2], *args; + struct frrmod_runtime *rtinfo, **rtinfop; + const struct frrmod_info *info; + +#define FRRMOD_LOAD_N_ERRSTR 10 + char *aErr[FRRMOD_LOAD_N_ERRSTR]; + unsigned int iErr = 0; + + memset(aErr, 0, sizeof(aErr)); + +#define ERR_RECORD(...) \ + do { \ + if (pFerrlog && (iErr < FRRMOD_LOAD_N_ERRSTR)) { \ + aErr[iErr++] = asprintfrr(MTYPE_MODULE_LOAD_ERR, \ + __VA_ARGS__); \ + } \ + } while (0) + +#define ERR_REPORT \ + do { \ + if (pFerrlog) { \ + unsigned int i; \ + \ + for (i = 0; i < iErr; ++i) { \ + (*pFerrlog)(pErrlogCookie, aErr[i]); \ + } \ + } \ + } while (0) + +#define ERR_FREE \ + do { \ + unsigned int i; \ + \ + for (i = 0; i < iErr; ++i) { \ + XFREE(MTYPE_MODULE_LOAD_ERR, aErr[i]); \ + aErr[i] = 0; \ + } \ + iErr = 0; \ + } while (0) + + snprintf(name, sizeof(name), "%s", spec); + args = strchr(name, ':'); + if (args) + *args++ = '\0'; + + if (!strchr(name, '/')) { + if (execname) { + snprintf(fullpath, sizeof(fullpath), "%s/%s_%s.so", dir, + execname, name); + handle = dlopen(fullpath, RTLD_NOW | RTLD_GLOBAL); + if (!handle) + ERR_RECORD("loader error: dlopen(%s): %s", + fullpath, dlerror()); + } + if (!handle) { + snprintf(fullpath, sizeof(fullpath), "%s/%s.so", dir, + name); + handle = dlopen(fullpath, RTLD_NOW | RTLD_GLOBAL); + if (!handle) + ERR_RECORD("loader error: dlopen(%s): %s", + fullpath, dlerror()); + } + } + if (!handle) { + snprintf(fullpath, sizeof(fullpath), "%s", name); + handle = dlopen(fullpath, RTLD_NOW | RTLD_GLOBAL); + if (!handle) + ERR_RECORD("loader error: dlopen(%s): %s", fullpath, + dlerror()); + } + if (!handle) { + ERR_REPORT; + ERR_FREE; + return NULL; + } + + /* previous dlopen() errors are no longer relevant */ + ERR_FREE; + + rtinfop = dlsym(handle, "frr_module"); + if (!rtinfop) { + dlclose(handle); + ERR_RECORD("\"%s\" is not an FRR module: %s", name, dlerror()); + ERR_REPORT; + ERR_FREE; + return NULL; + } + rtinfo = *rtinfop; + rtinfo->load_name = XSTRDUP(MTYPE_MODULE_LOADNAME, name); + rtinfo->dl_handle = handle; + if (args) + rtinfo->load_args = XSTRDUP(MTYPE_MODULE_LOADARGS, args); + info = rtinfo->info; + + if (rtinfo->finished_loading) { + dlclose(handle); + ERR_RECORD("module \"%s\" already loaded", name); + goto out_fail; + } + + if (info->init && info->init()) { + dlclose(handle); + ERR_RECORD("module \"%s\" initialisation failed", name); + goto out_fail; + } + + rtinfo->finished_loading = true; + + *frrmod_last = rtinfo; + frrmod_last = &rtinfo->next; + ERR_FREE; + return rtinfo; + +out_fail: + XFREE(MTYPE_MODULE_LOADARGS, rtinfo->load_args); + XFREE(MTYPE_MODULE_LOADNAME, rtinfo->load_name); + ERR_REPORT; + ERR_FREE; + return NULL; +} + +#if 0 +void frrmod_unload(struct frrmod_runtime *module) +{ +} +#endif |