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#include "plugins.h"
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <assert.h>
#include <dlfcn.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
struct ptx__plugin_manager_tag
{
ptx_plugin_t *pl_head, *pl_tail;
};
struct ptx__plugin_handle_tag
{
/* what plugin manager is this plugin known to? */
ptx_plugin_manager_t *manager;
/* handle to library */
void *modp;
const struct ptx_plugin_desc *desc;
/* plugin list entries */
ptx_plugin_t *prev;
ptx_plugin_t *next;
int path_fd;
/* plugin filename */
char fname[1];
};
ptx_plugin_manager_t *ptx_plugin_manager_new(void)
{
ptx_plugin_manager_t *mgr = malloc(sizeof(ptx_plugin_manager_t));
if (!mgr) return NULL;
/* do init */
mgr->pl_head = mgr->pl_tail = NULL;
return mgr;
}
/* inform the plugin that it is about to be unloaded. It should clean up its resources. */
static void deinit_plugin(ptx_plugin_t *plugin);
/* unload/cleanup/free the plugin. */
static void free_plugin(ptx_plugin_t *plugin);
void ptx_plugin_manager_free(ptx_plugin_manager_t *mgr)
{
if (!mgr) return;
/* do cleanup */
for (ptx_plugin_t *plugin = mgr->pl_head, *next; plugin; plugin = next) {
next = plugin->next;
deinit_plugin(plugin);
free_plugin(plugin);
}
free(mgr);
return;
}
static ptx_plugin_t *load_plugin(ptx_plugin_manager_t *manager, const char *plugin_file, const char *plugin_fname)
{
/* define and initialize all variables to be cleaned up here! */
size_t fnamelen = strlen(plugin_fname);
ptx_plugin_t *plugin = NULL;
void *mod_dl = NULL;
const struct ptx_plugin_desc *pl_desc;
plugin = calloc(1, sizeof(ptx_plugin_t) + fnamelen);
if (!plugin) {
fprintf(stderr, "(plugin) malloc (loading %s): %s\n", plugin_file, strerror(errno));
/* FIXME: maybe abort() for these sorts of issues? */
goto cleanup;
}
plugin->manager = manager;
memcpy(plugin->fname, plugin_fname, fnamelen); /* NUL-termination achieved thanks to calloc */
mod_dl = dlopen(plugin_file, RTLD_NOW | RTLD_LOCAL);
if (!mod_dl) {
fprintf(stderr, "(plugin) dlopen: failed to load %s: %s\n", plugin_fname, dlerror());
goto cleanup;
}
plugin->modp = mod_dl;
pl_desc = dlsym(mod_dl, PTX_STR(PTX__INTERNAL_PLUGIN_DESC_SYM));
if (!pl_desc) {
fprintf(stderr, "(plugin) dlsym(descriptor): failed to load %s: %s\n", plugin_fname, dlerror());
goto cleanup;
}
plugin->desc = pl_desc;
return plugin;
cleanup:
if (mod_dl) dlclose(mod_dl);
free(plugin);
return NULL;
}
#define PATHBUF_LEN (32)
int ptx_plugin_manager_load_dir(ptx_plugin_manager_t *mgr, const char *dirname)
{
struct dirent *ent;
char pl_pathbuf[PATHBUF_LEN] = { 0 };
struct stat st;
DIR *dir = opendir(dirname);
if (!dir) {
fprintf(stderr, "Failed to load plugins from %s (opendir): %s\n", dirname, strerror(errno));
return -1;
}
int pl_dir_fd = dirfd(dir);
assert(pl_dir_fd >= 0);
while ((errno = 0, ent = readdir(dir))) {
int pl_fd = openat(pl_dir_fd, ent->d_name, O_PATH);
if (pl_fd < 0) {
fprintf(stderr, "(plugin) openat: failed to open %s/%s: %s\n", dirname, ent->d_name, strerror(errno));
continue;
}
if (fstat(pl_fd, &st) < 0) {
fprintf(stderr, "(plugin) fstat: failed to stat %s/%s: %s\n", dirname, ent->d_name, strerror(errno));
goto cleanup_iter;
}
if (!S_ISREG(st.st_mode)) {
goto cleanup_iter; /* not a file. skip silently */
}
int rlen = snprintf(pl_pathbuf, PATHBUF_LEN, "/proc/self/fd/%d", pl_fd);
assert(rlen < PATHBUF_LEN);
assert(pl_pathbuf[PATHBUF_LEN-1] == '\0');
ptx_plugin_t *plugin = load_plugin(mgr, pl_pathbuf, ent->d_name);
if (!plugin) goto cleanup_iter; /* error has been reported by load_plugin already. */
plugin->path_fd = pl_fd;
if (mgr->pl_head) {
assert(mgr->pl_tail);
mgr->pl_tail->next = plugin;
plugin->prev = mgr->pl_tail;
plugin->next = NULL;
mgr->pl_tail = plugin;
} else {
assert(!mgr->pl_tail);
plugin->prev = plugin->next = NULL;
mgr->pl_head = mgr->pl_tail = plugin;
}
continue;
cleanup_iter:
close(pl_fd);
}
int errno_save = errno;
closedir(dir);
if (errno_save != 0) {
fprintf(stderr, "Error reading entries from %s (readdir): %s\n", dirname, strerror(errno));
return -1;
}
return 0;
}
static void deinit_plugin(ptx_plugin_t *plugin)
{
/* TODO */
UNUSED(plugin);
}
static void free_plugin(ptx_plugin_t *plugin)
{
dlclose(plugin->modp);
close(plugin->path_fd);
free(plugin);
}
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