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#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>
#include "portability.h"
#ifdef _WIN32
#define dlclose FreeLibrary
#define dlsym GetProcAddress
#define dlerror() "Failed"
#define dlopen(lib,ig) LoadLibrary(lib)
#else
#include <dlfcn.h>
#endif
#include "plugin.h"
static size_t plugins = 0;
static void** plugin_handle = NULL;
static int plugin_attach(char* path, char* file){
plugin_init init = NULL;
void* handle = NULL;
char* lib = NULL;
#ifdef _WIN32
char* path_separator = "\\";
#else
char* path_separator = "/";
#endif
if(!path || !file || !strlen(path)){
fprintf(stderr, "Invalid plugin loader path\n");
return 1;
}
lib = calloc(strlen(path) + strlen(file) + 2, sizeof(char));
if(!lib){
fprintf(stderr, "Failed to allocate memory\n");
return 1;
}
snprintf(lib, strlen(path) + strlen(file) + 2, "%s%s%s",
path,
(path[strlen(path) - 1] == path_separator[0]) ? "" : path_separator,
file);
handle = dlopen(lib, RTLD_NOW);
if(!handle){
#ifdef _WIN32
char* error = NULL;
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &error, 0, NULL);
fprintf(stderr, "Failed to load plugin %s, check that all supporting libraries are present: %s\n", lib, error);
LocalFree(error);
#else
fprintf(stderr, "Failed to load plugin %s: %s\n", lib, dlerror());
#endif
free(lib);
return 0;
}
init = (plugin_init) dlsym(handle, "init");
if(init){
if(init()){
fprintf(stderr, "Plugin %s failed to initialize\n", lib);
dlclose(handle);
free(lib);
return 1;
}
}
else{
dlclose(handle);
free(lib);
return 0;
}
free(lib);
plugin_handle = realloc(plugin_handle, (plugins + 1) * sizeof(void*));
if(!plugin_handle){
fprintf(stderr, "Failed to allocate memory\n");
dlclose(handle);
return 1;
}
plugin_handle[plugins] = handle;
plugins++;
return 0;
}
int plugins_load(char* path){
int rv = -1;
#ifdef _WIN32
char* search_expression = calloc(strlen(path) + strlen("*.dll") + 1, sizeof(char));
if(!search_expression){
fprintf(stderr, "Failed to allocate memory\n");
return -1;
}
snprintf(search_expression, strlen(path) + strlen("*.dll"), "%s*.dll", path);
WIN32_FIND_DATA result;
HANDLE hSearch = FindFirstFile(search_expression, &result);
if(hSearch == INVALID_HANDLE_VALUE){
LPVOID lpMsgBuf = NULL;
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &lpMsgBuf, 0, NULL);
fprintf(stderr, "Failed to search for backend plugin files in %s: %s\n", path, lpMsgBuf);
LocalFree(lpMsgBuf);
return -1;
}
do {
if(plugin_attach(path, result.cFileName)){
goto load_done;
}
} while(FindNextFile(hSearch, &result));
rv = 0;
load_done:
free(search_expression);
FindClose(hSearch);
return rv;
#else
struct dirent* entry;
struct stat file_stat;
DIR* directory = opendir(path);
if(!directory){
fprintf(stderr, "Failed to open plugin search path %s: %s\n", path, strerror(errno));
return 1;
}
for(entry = readdir(directory); entry; entry = readdir(directory)){
if(strlen(entry->d_name) < 4 || strncmp(".so", entry->d_name + (strlen(entry->d_name) - 3), 3)){
continue;
}
if(fstatat(dirfd(directory), entry->d_name, &file_stat, 0) < 0){
fprintf(stderr, "Failed to stat %s: %s\n", entry->d_name, strerror(errno));
continue;
}
if(!S_ISREG(file_stat.st_mode)){
continue;
}
if(plugin_attach(path, entry->d_name)){
goto load_done;
}
}
rv = 0;
load_done:
if(closedir(directory) < 0){
fprintf(stderr, "Failed to close plugin directory %s: %s\n", path, strerror(errno));
return -1;
}
return rv;
#endif
}
int plugins_close(){
size_t u;
for(u = 0; u < plugins; u++){
#ifdef _WIN32
char* error = NULL;
//FreeLibrary returns the inverse of dlclose
if(!FreeLibrary(plugin_handle[u])){
FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &error, 0, NULL);
fprintf(stderr, "Failed to unload plugin: %s\n", error);
LocalFree(error);
}
#else
if(dlclose(plugin_handle[u])){
fprintf(stderr, "Failed to unload plugin: %s\n", dlerror());
}
#endif
}
free(plugin_handle);
plugins = 0;
return 0;
}
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