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-rw-r--r--src/hooks.c251
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diff --git a/src/hooks.c b/src/hooks.c
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+++ b/src/hooks.c
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+/*
+ * Copyright (c) 2012-2016 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif /* HAVE_STRINGS_H */
+#include <unistd.h>
+#include <errno.h>
+
+#include "sudo.h"
+#include "sudo_plugin.h"
+#include "sudo_plugin_int.h"
+
+/* Singly linked hook list. */
+struct sudo_hook_entry {
+ SLIST_ENTRY(sudo_hook_entry) entries;
+ union {
+ sudo_hook_fn_t generic_fn;
+ sudo_hook_fn_setenv_t setenv_fn;
+ sudo_hook_fn_unsetenv_t unsetenv_fn;
+ sudo_hook_fn_getenv_t getenv_fn;
+ sudo_hook_fn_putenv_t putenv_fn;
+ } u;
+ void *closure;
+};
+SLIST_HEAD(sudo_hook_list, sudo_hook_entry);
+
+/* Each hook type gets own hook list. */
+static struct sudo_hook_list sudo_hook_setenv_list =
+ SLIST_HEAD_INITIALIZER(sudo_hook_setenv_list);
+static struct sudo_hook_list sudo_hook_unsetenv_list =
+ SLIST_HEAD_INITIALIZER(sudo_hook_unsetenv_list);
+static struct sudo_hook_list sudo_hook_getenv_list =
+ SLIST_HEAD_INITIALIZER(sudo_hook_getenv_list);
+static struct sudo_hook_list sudo_hook_putenv_list =
+ SLIST_HEAD_INITIALIZER(sudo_hook_putenv_list);
+
+/* NOTE: must not anything that might call setenv() */
+int
+process_hooks_setenv(const char *name, const char *value, int overwrite)
+{
+ struct sudo_hook_entry *hook;
+ int rc = SUDO_HOOK_RET_NEXT;
+
+ /* First process the hooks. */
+ SLIST_FOREACH(hook, &sudo_hook_setenv_list, entries) {
+ rc = hook->u.setenv_fn(name, value, overwrite, hook->closure);
+ if (rc == SUDO_HOOK_RET_STOP || rc == SUDO_HOOK_RET_ERROR)
+ break;
+ }
+ return rc;
+}
+
+/* NOTE: must not anything that might call putenv() */
+int
+process_hooks_putenv(char *string)
+{
+ struct sudo_hook_entry *hook;
+ int rc = SUDO_HOOK_RET_NEXT;
+
+ /* First process the hooks. */
+ SLIST_FOREACH(hook, &sudo_hook_putenv_list, entries) {
+ rc = hook->u.putenv_fn(string, hook->closure);
+ if (rc == SUDO_HOOK_RET_STOP || rc == SUDO_HOOK_RET_ERROR)
+ break;
+ }
+ return rc;
+}
+
+/* NOTE: must not anything that might call getenv() */
+int
+process_hooks_getenv(const char *name, char **value)
+{
+ struct sudo_hook_entry *hook;
+ char *val = NULL;
+ int rc = SUDO_HOOK_RET_NEXT;
+
+ /* First process the hooks. */
+ SLIST_FOREACH(hook, &sudo_hook_getenv_list, entries) {
+ rc = hook->u.getenv_fn(name, &val, hook->closure);
+ if (rc == SUDO_HOOK_RET_STOP || rc == SUDO_HOOK_RET_ERROR)
+ break;
+ }
+ if (val != NULL)
+ *value = val;
+ return rc;
+}
+
+/* NOTE: must not anything that might call unsetenv() */
+int
+process_hooks_unsetenv(const char *name)
+{
+ struct sudo_hook_entry *hook;
+ int rc = SUDO_HOOK_RET_NEXT;
+
+ /* First process the hooks. */
+ SLIST_FOREACH(hook, &sudo_hook_unsetenv_list, entries) {
+ rc = hook->u.unsetenv_fn(name, hook->closure);
+ if (rc == SUDO_HOOK_RET_STOP || rc == SUDO_HOOK_RET_ERROR)
+ break;
+ }
+ return rc;
+}
+
+/* Hook registration internals. */
+static int
+register_hook_internal(struct sudo_hook_list *head,
+ int (*hook_fn)(), void *closure)
+{
+ struct sudo_hook_entry *hook;
+ debug_decl(register_hook_internal, SUDO_DEBUG_HOOKS)
+
+ if ((hook = calloc(1, sizeof(*hook))) == NULL) {
+ sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+ "unable to allocate memory");
+ debug_return_int(-1);
+ }
+ hook->u.generic_fn = hook_fn;
+ hook->closure = closure;
+ SLIST_INSERT_HEAD(head, hook, entries);
+
+ debug_return_int(0);
+}
+
+/* Register the specified hook. */
+int
+register_hook(struct sudo_hook *hook)
+{
+ int ret;
+ debug_decl(register_hook, SUDO_DEBUG_HOOKS)
+
+ if (SUDO_API_VERSION_GET_MAJOR(hook->hook_version) != SUDO_HOOK_VERSION_MAJOR) {
+ /* Major versions must match. */
+ errno = EINVAL;
+ ret = -1;
+ } else {
+ switch (hook->hook_type) {
+ case SUDO_HOOK_GETENV:
+ ret = register_hook_internal(&sudo_hook_getenv_list,
+ hook->hook_fn, hook->closure);
+ break;
+ case SUDO_HOOK_PUTENV:
+ ret = register_hook_internal(&sudo_hook_putenv_list,
+ hook->hook_fn, hook->closure);
+ break;
+ case SUDO_HOOK_SETENV:
+ ret = register_hook_internal(&sudo_hook_setenv_list,
+ hook->hook_fn, hook->closure);
+ break;
+ case SUDO_HOOK_UNSETENV:
+ ret = register_hook_internal(&sudo_hook_unsetenv_list,
+ hook->hook_fn, hook->closure);
+ break;
+ default:
+ /* XXX - use define for unknown value */
+ errno = ENOTSUP;
+ ret = 1;
+ break;
+ }
+ }
+
+ debug_return_int(ret);
+}
+
+/* Hook deregistration internals. */
+static void
+deregister_hook_internal(struct sudo_hook_list *head,
+ int (*hook_fn)(), void *closure)
+{
+ struct sudo_hook_entry *hook, *prev = NULL;
+ debug_decl(deregister_hook_internal, SUDO_DEBUG_HOOKS)
+
+ SLIST_FOREACH(hook, head, entries) {
+ if (hook->u.generic_fn == hook_fn && hook->closure == closure) {
+ /* Remove from list and free. */
+ if (prev == NULL)
+ SLIST_REMOVE_HEAD(head, entries);
+ else
+ SLIST_REMOVE_AFTER(prev, entries);
+ free(hook);
+ break;
+ }
+ prev = hook;
+ }
+
+ debug_return;
+}
+
+/* Deregister the specified hook. */
+int
+deregister_hook(struct sudo_hook *hook)
+{
+ int ret = 0;
+ debug_decl(deregister_hook, SUDO_DEBUG_HOOKS)
+
+ if (SUDO_API_VERSION_GET_MAJOR(hook->hook_version) != SUDO_HOOK_VERSION_MAJOR) {
+ /* Major versions must match. */
+ ret = -1;
+ } else {
+ switch (hook->hook_type) {
+ case SUDO_HOOK_GETENV:
+ deregister_hook_internal(&sudo_hook_getenv_list, hook->hook_fn,
+ hook->closure);
+ break;
+ case SUDO_HOOK_PUTENV:
+ deregister_hook_internal(&sudo_hook_putenv_list, hook->hook_fn,
+ hook->closure);
+ break;
+ case SUDO_HOOK_SETENV:
+ deregister_hook_internal(&sudo_hook_setenv_list, hook->hook_fn,
+ hook->closure);
+ break;
+ case SUDO_HOOK_UNSETENV:
+ deregister_hook_internal(&sudo_hook_unsetenv_list, hook->hook_fn,
+ hook->closure);
+ break;
+ default:
+ /* XXX - use define for unknown value */
+ ret = 1;
+ break;
+ }
+ }
+
+ debug_return_int(ret);
+}
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