From 593109802b52e3f89c3a65436bfdba78f8c517c4 Mon Sep 17 00:00:00 2001

From: Greg Hudson <ghudson@mit.edu>

Date: Thu, 23 Jun 2022 16:41:40 -0400

Subject: [PATCH] Simplify plugin loading code

Remove the USE_CFBUNDLE code, which was only used by KfM.  Handle

platform conditionals according to current practice.  Use

k5_dir_filenames() instead of opendir() and remove the Windows

implementation of opendir().

---

 src/util/support/plugins.c | 507 +++++++++++--------------------------

 1 file changed, 150 insertions(+), 357 deletions(-)

diff --git a/src/util/support/plugins.c b/src/util/support/plugins.c

index c6a9a21d57..0850565687 100644

--- a/src/util/support/plugins.c

+++ b/src/util/support/plugins.c

@@ -29,16 +29,6 @@

 #if USE_DLOPEN

 #include <dlfcn.h>

 #endif

-#include <sys/types.h>

-#ifdef HAVE_SYS_STAT_H

-#include <sys/stat.h>

-#endif

-#ifdef HAVE_SYS_PARAM_H

-#include <sys/param.h>

-#endif

-#ifdef HAVE_UNISTD_H

-#include <unistd.h>

-#endif

 #if USE_DLOPEN

 #ifdef RTLD_GROUP

@@ -68,16 +58,6 @@

 #endif

 #endif

-#if USE_DLOPEN && USE_CFBUNDLE

-#include <CoreFoundation/CoreFoundation.h>

-

-/* Currently CoreFoundation only exists on the Mac so we just use

- * pthreads directly to avoid creating empty function calls on other

- * platforms.  If a thread initializer ever gets created in the common

- * plugin code, move this there */

-static pthread_mutex_t krb5int_bundle_mutex = PTHREAD_MUTEX_INITIALIZER;

-#endif

-

 #include <stdarg.h>

 static void Tprintf (const char *fmt, ...)

 {

@@ -90,374 +70,193 @@ static void Tprintf (const char *fmt, ...)

 }

 struct plugin_file_handle {

-#if USE_DLOPEN

+#if defined(USE_DLOPEN)

     void *dlhandle;

-#endif

-#ifdef _WIN32

-    HMODULE hinstPlugin;

-#endif

-#if !defined (USE_DLOPEN) && !defined (_WIN32)

+#elif defined(_WIN32)

+    HMODULE module;

+#else

     char dummy;

 #endif

 };

-#ifdef _WIN32

-struct dirent {

-    long d_ino;                 /* inode (always 1 in WIN32) */

-    off_t d_off;                /* offset to this dirent */

-    unsigned short d_reclen;    /* length of d_name */

-    char d_name[_MAX_FNAME+1];  /* filename (null terminated) */

-};

-

-typedef struct {

-    intptr_t handle;            /* _findfirst/_findnext handle */

-    short offset;               /* offset into directory */

-    short finished;             /* 1 if there are not more files */

-    struct _finddata_t fileinfo;/* from _findfirst/_findnext */

-    char *dir;                  /* the dir we are reading */

-    struct dirent dent;         /* the dirent to return */

-} DIR;

+#if defined(USE_DLOPEN)

-DIR * opendir(const char *dir)

+static long

+open_plugin_dlfcn(struct plugin_file_handle *h, const char *filename,

+                  struct errinfo *ep)

 {

-    DIR *dp;

-    char *filespec;

-    intptr_t handle;

-    int index;

-

-    filespec = malloc(strlen(dir) + 2 + 1);

-    strcpy(filespec, dir);

-    index = strlen(filespec) - 1;

-    if (index >= 0 && (filespec[index] == '/' || filespec[index] == '\\'))

-        filespec[index] = '\0';

-    strcat(filespec, "/*");

-

-    dp = (DIR *)malloc(sizeof(DIR));

-    dp->offset = 0;

-    dp->finished = 0;

-    dp->dir = strdup(dir);

-

-    if ((handle = _findfirst(filespec, &(dp->fileinfo))) < 0) {

-        if (errno == ENOENT)

-            dp->finished = 1;

-        else {

-            free(filespec);

-            free(dp->dir);

-            free(dp);

-            return NULL;

-        }

+    const char *e;

+

+    h->dlhandle = dlopen(filename, PLUGIN_DLOPEN_FLAGS);

+    if (h->dlhandle == NULL) {

+        e = dlerror();

+        if (e == NULL)

+            e = _("unknown failure");

+        Tprintf("dlopen(%s): %s\n", filename, e);

+        k5_set_error(ep, ENOENT, _("unable to load plugin [%s]: %s"),

+                     filename, e);

+        return ENOENT;

     }

-

-    dp->handle = handle;

-    free(filespec);

-

-    return dp;

+    return 0;

 }

+#define open_plugin open_plugin_dlfcn

-struct dirent * readdir(DIR *dp)

+static long

+get_sym_dlfcn(struct plugin_file_handle *h, const char *csymname,

+              void **sym_out, struct errinfo *ep)

 {

-    if (!dp || dp->finished) return NULL;

-

-    if (dp->offset != 0) {

-        if (_findnext(dp->handle, &(dp->fileinfo)) < 0) {

-            dp->finished = 1;

-            return NULL;

-        }

+    const char *e;

+

+    if (h->dlhandle == NULL)

+        return ENOENT;

+    *sym_out = dlsym(h->dlhandle, csymname);

+    if (*sym_out == NULL) {

+        e = dlerror();

+        if (e == NULL)

+            e = _("unknown failure");

+        Tprintf("dlsym(%s): %s\n", csymname, e);

+        k5_set_error(ep, ENOENT, "%s", e);

+        return ENOENT;

     }

-    dp->offset++;

-

-    strncpy(dp->dent.d_name, dp->fileinfo.name, _MAX_FNAME);

-    dp->dent.d_ino = 1;

-    dp->dent.d_reclen = (unsigned short)strlen(dp->dent.d_name);

-    dp->dent.d_off = dp->offset;

-

-    return &(dp->dent);

-}

-

-int closedir(DIR *dp)

-{

-    if (!dp) return 0;

-    _findclose(dp->handle);

-    free(dp->dir);

-    free(dp);

-

     return 0;

 }

-#endif

+#define get_sym get_sym_dlfcn

-long KRB5_CALLCONV

-krb5int_open_plugin (const char *filepath, struct plugin_file_handle **h, struct errinfo *ep)

+static void

+close_plugin_dlfcn(struct plugin_file_handle *h)

 {

-    long err = 0;

-    struct plugin_file_handle *htmp = NULL;

-    int got_plugin = 0;

-#if defined(USE_CFBUNDLE) || defined(_WIN32)

-    struct stat statbuf;

-

-    if (!err) {

-        if (stat (filepath, &statbuf) < 0) {

-            err = errno;

-            Tprintf ("stat(%s): %s\n", filepath, strerror (err));

-            k5_set_error(ep, err, _("unable to find plugin [%s]: %s"),

-                         filepath, strerror(err));

-        }

-    }

-#endif

-

-    if (!err) {

-        htmp = calloc (1, sizeof (*htmp)); /* calloc initializes ptrs to NULL */

-        if (htmp == NULL) { err = ENOMEM; }

-    }

-

-#if USE_DLOPEN

-    if (!err

-#if USE_CFBUNDLE

-                 && ((statbuf.st_mode & S_IFMT) == S_IFREG

-                 || (statbuf.st_mode & S_IFMT) == S_IFDIR)

-#endif /* USE_CFBUNDLE */

-        ) {

-        void *handle = NULL;

-

-#if USE_CFBUNDLE

-        char executablepath[MAXPATHLEN];

-

-        if ((statbuf.st_mode & S_IFMT) == S_IFDIR) {

-            int lock_err = 0;

-            CFStringRef pluginString = NULL;

-            CFURLRef pluginURL = NULL;

-            CFBundleRef pluginBundle = NULL;

-            CFURLRef executableURL = NULL;

-

-            /* Lock around CoreFoundation calls since objects are refcounted

-             * and the refcounts are not thread-safe.  Using pthreads directly

-             * because this code is Mac-specific */

-            lock_err = pthread_mutex_lock(&krb5int_bundle_mutex);

-            if (lock_err) { err = lock_err; }

-

-            if (!err) {

-                pluginString = CFStringCreateWithCString (kCFAllocatorDefault,

-                                                          filepath,

-                                                          kCFStringEncodingASCII);

-                if (pluginString == NULL) { err = ENOMEM; }

-            }

-

-            if (!err) {

-                pluginURL = CFURLCreateWithFileSystemPath (kCFAllocatorDefault,

-                                                           pluginString,

-                                                           kCFURLPOSIXPathStyle,

-                                                           true);

-                if (pluginURL == NULL) { err = ENOMEM; }

-            }

-

-            if (!err) {

-                pluginBundle = CFBundleCreate (kCFAllocatorDefault, pluginURL);

-                if (pluginBundle == NULL) { err = ENOENT; } /* XXX need better error */

-            }

-

-            if (!err) {

-                executableURL = CFBundleCopyExecutableURL (pluginBundle);

-                if (executableURL == NULL) { err = ENOMEM; }

-            }

-

-            if (!err) {

-                if (!CFURLGetFileSystemRepresentation (executableURL,

-                                                       true, /* absolute */

-                                                       (UInt8 *)executablepath,

-                                                       sizeof (executablepath))) {

-                    err = ENOMEM;

-                }

-            }

-

-            if (!err) {

-                /* override the path the caller passed in */

-                filepath = executablepath;

-            }

-

-            if (executableURL    != NULL) { CFRelease (executableURL); }

-            if (pluginBundle     != NULL) { CFRelease (pluginBundle); }

-            if (pluginURL        != NULL) { CFRelease (pluginURL); }

-            if (pluginString     != NULL) { CFRelease (pluginString); }

-

-            /* unlock after CFRelease calls since they modify refcounts */

-            if (!lock_err) { pthread_mutex_unlock (&krb5int_bundle_mutex); }

-        }

-#endif /* USE_CFBUNDLE */

-

-        if (!err) {

-            handle = dlopen(filepath, PLUGIN_DLOPEN_FLAGS);

-            if (handle == NULL) {

-                const char *e = dlerror();

-                if (e == NULL)

-                    e = _("unknown failure");

-                Tprintf ("dlopen(%s): %s\n", filepath, e);

-                err = ENOENT; /* XXX */

-                k5_set_error(ep, err, _("unable to load plugin [%s]: %s"),

-                             filepath, e);

-            }

-        }

+    if (h->dlhandle != NULL)

+        dlclose(h->dlhandle);

+}

+#define close_plugin close_plugin_dlfcn

-        if (!err) {

-            got_plugin = 1;

-            htmp->dlhandle = handle;

-            handle = NULL;

-        }

+#elif defined(_WIN32)

-        if (handle != NULL) { dlclose (handle); }

+static long

+open_plugin_win32(struct plugin_file_handle *h, const char *filename,

+                  struct errinfo *ep)

+{

+    h->module = LoadLibrary(filename);

+    if (h == NULL) {

+        Tprintf("Unable to load dll: %s\n", filename);

+        k5_set_error(ep, ENOENT, _("unable to load DLL [%s]"), filename);

+        return ENOENT;

     }

-#endif /* USE_DLOPEN */

-

-#ifdef _WIN32

-    if (!err && (statbuf.st_mode & S_IFMT) == S_IFREG) {

-        HMODULE handle = NULL;

+    return 0;

+}

+#define open_plugin open_plugin_win32

-        handle = LoadLibrary(filepath);

-        if (handle == NULL) {

-            Tprintf ("Unable to load dll: %s\n", filepath);

-            err = ENOENT; /* XXX */

-            k5_set_error(ep, err, _("unable to load DLL [%s]"), filepath);

-        }

+static long

+get_sym_win32(struct plugin_file_handle *h, const char *csymname,

+              void **sym_out, struct errinfo *ep)

+{

+    LPVOID lpMsgBuf;

+    DWORD dw;

-        if (!err) {

-            got_plugin = 1;

-            htmp->hinstPlugin = handle;

-            handle = NULL;

+    if (h->module == NULL)

+        return ENOENT;

+    *sym_out = GetProcAddress(h->module, csymname);

+    if (*sym_out == NULL) {

+        Tprintf("GetProcAddress(%s): %i\n", csymname, GetLastError());

+        dw = GetLastError();

+        if (FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |

+                          FORMAT_MESSAGE_FROM_SYSTEM,

+                          NULL, dw, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),

+                          (LPTSTR)&lpMsgBuf, 0, NULL)) {

+            k5_set_error(ep, ENOENT, _("unable to get DLL Symbol: %s"),

+                         (char *)lpMsgBuf);

+            LocalFree(lpMsgBuf);

         }

-

-        if (handle != NULL)

-            FreeLibrary(handle);

-    }

-#endif

-

-    if (!err && !got_plugin) {

-        err = ENOENT;  /* no plugin or no way to load plugins */

-        k5_set_error(ep, err, _("plugin unavailable: %s"), strerror(err));

+        return ENOENT;

     }

+    return 0;

+}

+#define get_sym get_sym_win32

-    if (!err) {

-        *h = htmp;

-        htmp = NULL;  /* h takes ownership */

-    }

+static void

+close_plugin_win32(struct plugin_file_handle *h)

+{

+    if (h->module != NULL)

+        FreeLibrary(h->module);

+}

+#define close_plugin close_plugin_win32

-    free(htmp);

+#else

-    return err;

+static long

+open_plugin_dummy(struct plugin_file_handle *h, const char *filename,

+                  struct errinfo *ep)

+{

+    k5_set_error(ep, ENOENT, _("plugin loading unavailable"));

+    return ENOENT;

 }

+#define open_plugin open_plugin_dummy

 static long

-krb5int_get_plugin_sym (struct plugin_file_handle *h,

-                        const char *csymname, int isfunc, void **ptr,

-                        struct errinfo *ep)

+get_sym_dummy(struct plugin_file_handle *h, const char *csymname,

+              void **sym_out, struct errinfo *ep)

 {

-    long err = 0;

-    void *sym = NULL;

+    return ENOENT;

+}

+#define get_sym get_sym_dummy

+

+static void

+close_plugin_dummy(struct plugin_file_handle *h)

+{

+}

+#define close_plugin close_plugin_dummy

-#if USE_DLOPEN

-    if (!err && !sym && (h->dlhandle != NULL)) {

-        /* XXX Do we need to add a leading "_" to the symbol name on any

-           modern platforms?  */

-        sym = dlsym (h->dlhandle, csymname);

-        if (sym == NULL) {

-            const char *e = dlerror (); /* XXX copy and save away */

-            if (e == NULL)

-                e = "unknown failure";

-            Tprintf ("dlsym(%s): %s\n", csymname, e);

-            err = ENOENT; /* XXX */

-            k5_set_error(ep, err, "%s", e);

-        }

-    }

 #endif

-#ifdef _WIN32

-    LPVOID lpMsgBuf;

-    DWORD dw;

+long KRB5_CALLCONV

+krb5int_open_plugin(const char *filename,

+                    struct plugin_file_handle **handle_out, struct errinfo *ep)

+{

+    long ret;

+    struct plugin_file_handle *h;

-    if (!err && !sym && (h->hinstPlugin != NULL)) {

-        sym = GetProcAddress(h->hinstPlugin, csymname);

-        if (sym == NULL) {

-            const char *e = "unable to get dll symbol"; /* XXX copy and save away */

-            Tprintf ("GetProcAddress(%s): %i\n", csymname, GetLastError());

-            err = ENOENT; /* XXX */

-            k5_set_error(ep, err, "%s", e);

-

-            dw = GetLastError();

-            if (FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |

-                              FORMAT_MESSAGE_FROM_SYSTEM,

-                              NULL,

-                              dw,

-                              MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),

-                              (LPTSTR) &lpMsgBuf,

-                              0, NULL )) {

-

-                fprintf (stderr, "unable to get dll symbol, %s\n", (LPCTSTR)lpMsgBuf);

-                LocalFree(lpMsgBuf);

-            }

-        }

-    }

-#endif

+    *handle_out = NULL;

-    if (!err && (sym == NULL)) {

-        err = ENOENT;  /* unimplemented */

-    }

+    h = calloc(1, sizeof(*h));

+    if (h == NULL)

+        return ENOMEM;

-    if (!err) {

-        *ptr = sym;

+    ret = open_plugin(h, filename, ep);

+    if (ret) {

+        free(h);

+        return ret;

     }

-    return err;

+    *handle_out = h;

+    return 0;

 }

 long KRB5_CALLCONV

-krb5int_get_plugin_data (struct plugin_file_handle *h, const char *csymname,

-                         void **ptr, struct errinfo *ep)

+krb5int_get_plugin_data(struct plugin_file_handle *h, const char *csymname,

+                        void **sym_out, struct errinfo *ep)

 {

-    return krb5int_get_plugin_sym (h, csymname, 0, ptr, ep);

+    return get_sym(h, csymname, sym_out, ep);

 }

 long KRB5_CALLCONV

-krb5int_get_plugin_func (struct plugin_file_handle *h, const char *csymname,

-                         void (**ptr)(), struct errinfo *ep)

+krb5int_get_plugin_func(struct plugin_file_handle *h, const char *csymname,

+                        void (**sym_out)(), struct errinfo *ep)

 {

     void *dptr = NULL;

-    long err = krb5int_get_plugin_sym (h, csymname, 1, &dptr, ep);

-    if (!err) {

-        /* Cast function pointers to avoid code duplication */

-        *ptr = (void (*)()) dptr;

-    }

-    return err;

+    long ret = get_sym(h, csymname, &dptr, ep);

+

+    if (!ret)

+        *sym_out = (void (*)())dptr;

+    return ret;

 }

 void KRB5_CALLCONV

 krb5int_close_plugin (struct plugin_file_handle *h)

 {

-#if USE_DLOPEN

-    if (h->dlhandle != NULL) { dlclose(h->dlhandle); }

-#endif

-#ifdef _WIN32

-    if (h->hinstPlugin != NULL) { FreeLibrary(h->hinstPlugin); }

-#endif

-    free (h);

+    close_plugin(h);

+    free(h);

 }

-/* autoconf docs suggest using this preference order */

-#if HAVE_DIRENT_H || USE_DIRENT_H

-#include <dirent.h>

-#define NAMELEN(D) strlen((D)->d_name)

-#else

-#ifndef _WIN32

-#define dirent direct

-#define NAMELEN(D) ((D)->d->namlen)

-#else

-#define NAMELEN(D) strlen((D)->d_name)

-#endif

-#if HAVE_SYS_NDIR_H

-# include <sys/ndir.h>

-#elif HAVE_SYS_DIR_H

-# include <sys/dir.h>

-#elif HAVE_NDIR_H

-# include <ndir.h>

-#endif

-#endif

-

 static long

 krb5int_plugin_file_handle_array_init (struct plugin_file_handle ***harray)

 {

@@ -619,42 +418,36 @@ krb5int_open_plugin_dirs (const char * const *dirnames,

                 if (handle   != NULL) { krb5int_close_plugin (handle); }

             }

         } else {

-            /* load all plugins in each directory */

-            DIR *dir = opendir (dirnames[i]);

+            char **fnames = NULL;

+            int j;

-            while (dir != NULL && !err) {

-                struct dirent *d = NULL;

+            err = k5_dir_filenames(dirnames[i], &fnames);

+            for (j = 0; !err && fnames[j] != NULL; j++) {

                 char *filepath = NULL;

                 struct plugin_file_handle *handle = NULL;

-                d = readdir (dir);

-                if (d == NULL) { break; }

-

-                if ((strcmp (d->d_name, ".") == 0) ||

-                    (strcmp (d->d_name, "..") == 0)) {

+                if (strcmp(fnames[j], ".") == 0 ||

+                    strcmp(fnames[j], "..") == 0)

                     continue;

-                }

-                if (!err) {

-                    int len = NAMELEN (d);

-                    if (asprintf(&filepath, "%s/%*s", dirnames[i], len, d->d_name) < 0) {

-                        filepath = NULL;

-                        err = ENOMEM;

-                    }

+                if (asprintf(&filepath, "%s/%s", dirnames[i], fnames[j]) < 0) {

+                    filepath = NULL;

+                    err = ENOMEM;

                 }

-                if (!err) {

-                    if (krb5int_open_plugin (filepath, &handle, ep) == 0) {

-                        err = krb5int_plugin_file_handle_array_add (&h, &count, handle);

-                        if (!err) { handle = NULL; }  /* h takes ownership */

-                    }

+                if (!err && krb5int_open_plugin(filepath, &handle, ep) == 0) {

+                    err = krb5int_plugin_file_handle_array_add(&h, &count,

+                                                               handle);

+                    if (!err)

+                        handle = NULL;  /* h takes ownership */

                 }

                 free(filepath);

-                if (handle    != NULL) { krb5int_close_plugin (handle); }

+                if (handle != NULL)

+                    krb5int_close_plugin(handle);

             }

-            if (dir != NULL) { closedir (dir); }

+            k5_free_filenames(fnames);

         }

     }

-- 

2.38.1