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/*
* module.c - Load "kernel modules"
*
* Written 2001,2002 by Werner Almesberger
* Copyright 2001 EPFL-ICA, Network Robots
* Copyright 2002 Werner Almesberger
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <dlfcn.h>
#include <memutil.h>
#include "tcsim.h"
void *tc_module(char prefix,const char *name); /* extern in ulib */
void *tc_module(char prefix,const char *name)
{
char *symbol,*path;
void *handle,*util;
/*
* dlopen keeps track of what we've loaded, so it's actually safe to call
* it whenever we need that element. Caching the new elements, like
* iproute2/tc does, is of course more efficient.
*/
symbol = alloc_sprintf("%s_util",name);
handle = dlopen(NULL,RTLD_NOW); /* preloaded ? */
if (handle) {
util = dlsym(handle,symbol);
if (util) {
free(symbol);
return util;
}
}
path = alloc_sprintf("%c_%s.so",prefix,name);
handle = dlopen(path,RTLD_NOW);
if (!handle) {
free(path);
free(symbol);
return NULL;
}
util = dlsym(handle,symbol);
if (util) {
free(path);
free(symbol);
return util;
}
errorf("%s does not define %s",path,symbol);
return NULL; /* not reached */
}
void preload_tc_module(const char *path)
{
void *handle;
handle = dlopen(path,RTLD_NOW | RTLD_GLOBAL);
if (!handle) errorf("%s",dlerror());
}
/*
* Buglet: libc seems to have its own init_module, which is found if our @@@
* module doesn't have one. Very irritating ...
*/
void kernel_module(const char *path)
{
void *handle;
int (*init_module)(void);
int error;
handle = dlopen(path,RTLD_NOW);
if (!handle) errorf("%s",dlerror());
init_module = dlsym(handle,"init_module");
if (!init_module) errorf("module %s: symbol init_module not found");
error = init_module();
if (!error) return;
yyerrorf("init_module: %s",strerror(error));
}
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