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| /*
* Test Procedure :
*
* i. Create "libsum.so" from sum.c (kept in same folder).
*
* gcc -o libgetsum.so -shared -fPIC getsum.c -D_GNU_SOURCE
*
* ii. Create "libgetsum.so" from sum.c (kept in same folder).
*
* gcc -o libsum.so -shared -fPIC sum.c -D_GNU_SOURCE
*
* iii. Create "flags" binary from flags.c file
*
* gcc -o flags flags.c -ldl -D_GNU_SOURCE
*
*/
/*
* Verification Method:
*
* [libsum.so] : Loaded successfully
* [dlsym()] : Executed successfully
* sum(0,0) : 1
* Error relocating /home/vishal/libgetsum.so: sum: symbol not found
* [libsum.so] : Closed successfully
* [libsum.so] : Loaded again successfully
* [libgetsum.so] : Loaded again successfully
* [dlsym()] : Executed successfully
* getsum(4, 5) : 11
* [dlsym()] : Executed successfully
* func() : Executed Successfully From [libgetsum.so]
* [dladdr()] : Executed successfully
* Function : funcXYZ
* Shared Lib : /home/vishal/libgetsum.so
*
*/
#include
#include
#include
#include
/*Please Provide Absolute Path Of Both Libs */
#define LIB_1 "Absolute_path_to_libsum.so"
#define LIB_2 "Absolute_path_to_libgetsum.so"
int main(int argc, char **argv)
{
/*------------------- PASS 1 : Loading Shared Lib 1 -----------------*/
void *lib1 = dlopen(LIB_1, RTLD_LAZY | RTLD_LOCAL | RTLD_NODELETE );
if (!lib1) {
dprintf(1, "[libsum.so] : Error in finding the library : PASS 1\n");
fputs(dlerror(), stderr);
exit(1);
}
else{
dprintf(1, "[libsum.so] : Loaded successfully \n");
}
/*---------------------------------------------------------------------*/
/*------------------ PASS 2 : Finding Symbol & Execute it--------------*/
int (*sum)(int , int) = (int (*)(int , int))dlsym(lib1, "sum");
char *error = dlerror();
if (error != NULL) {
dprintf(1, "[dlsym()] : Error : PASS 2\n");
fputs(error, stderr);
exit(1);
}
else{
dprintf(1,"[dlsym()] : Executed successfully\n");
printf("sum(0,0) : %d \n", (*sum)(0, 0));
}
/*---------------------------------------------------------------------*/
/*------------------ PASS 3 : Loading Shared Lib 2 -------------------*/
void *lib2 = dlopen(LIB_2, RTLD_NOW);
if (!lib2) {
fputs(dlerror(), stderr);
if( dlclose(lib1) == 0 ){ /* Closing Shared Lib 1 */
dprintf(1, "\n[libsum.so] : Closed successfully \n");
}
else{
dprintf(1, "\n[libsum.so] : Error in closing : PASS 3 \n");
}
}
else{
dprintf(1, "[libgetsum.so] : Loaded successfully \n");
}
/*---------------------------------------------------------------------*/
/*----------------- PASS 4 : Loading Shared Lib 1 Again ---------------*/
lib1 = dlopen(LIB_1, RTLD_NOW | RTLD_NOLOAD | RTLD_GLOBAL );
if (!lib1) {
dprintf(1, "[libsum.so] : Error in finding the library : PASS 4\n");
fputs(dlerror(), stderr);
exit(1);
}
else{
dprintf(1, "[libsum.so] : Loaded again successfully \n");
}
/*---------------------------------------------------------------------*/
/*----------------- PASS 5 : Loading Shared Lib 2 Again ---------------*/
lib2 = dlopen(LIB_2, RTLD_NOW | RTLD_GLOBAL );
if (!lib2) {
dprintf(1, "[libgetsum.so] : Error in finding the library : PASS 5\n");
fputs(dlerror(), stderr);
exit(1);
}
else{
dprintf(1, "[libgetsum.so] : Loaded again successfully \n");
}
/*---------------------------------------------------------------------*/
/*------------------ PASS 6 : Finding Symbol & Execute it--------------*/
int (*getsum)(int , int) = (int (*)(int , int))dlsym(RTLD_DEFAULT, "getsum");
error = dlerror();
if (error != NULL) {
dprintf(1, "[dlsym()] : Error : PASS 6\n");
fputs(error, stderr);
exit(1);
}
else{
dprintf(1,"[dlsym()] : Executed successfully\n");
printf("getsum(4, 5) : %d\n", (*getsum)(4, 5));
}
/*---------------------------------------------------------------------*/
/*------------------ PASS 7 : Finding Symbol & Execute it--------------*/
void (*func)(void) = (void (*)(void))dlsym( lib2, "funcXYZ");
error = dlerror();
if (error != NULL) {
dprintf(1, "[dlsym()] : Error : PASS 7\n");
fputs(error, stderr);
exit(1);
}
else{
dprintf(1,"[dlsym()] : Executed successfully\n");
printf("func() : ");
(*func)();
}
/*---------------------------------------------------------------------*/
/*------------- PASS 8 : Resolving Function Name By Address -----------*/
Dl_info DlInfo;
if( dladdr(func, &DlInfo) != 0 ){
dprintf(1, "[dladdr()] : Executed successfully \n");
dprintf(1, "Function : %s \n", DlInfo.dli_sname);
dprintf(1, "Shared Lib : %s \n", DlInfo.dli_fname);
}
else{
dprintf(1, "[dladdr()] : Error : PASS 8\n");
exit(1);
}
/*---------------------------------------------------------------------*/
dlclose(lib1);
dlclose(lib2);
return 0;
}
|