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-rw-r--r--plugins/sudoers/alias.c377
1 files changed, 377 insertions, 0 deletions
diff --git a/plugins/sudoers/alias.c b/plugins/sudoers/alias.c
new file mode 100644
index 0000000..d435400
--- /dev/null
+++ b/plugins/sudoers/alias.c
@@ -0,0 +1,377 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2004-2005, 2007-2019
+ * 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
+ */
+
+/*
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "sudoers.h"
+#include "redblack.h"
+#include <gram.h>
+
+/*
+ * Comparison function for the red-black tree.
+ * Aliases are sorted by name with the type used as a tie-breaker.
+ */
+static int
+alias_compare(const void *v1, const void *v2)
+{
+ const struct alias *a1 = (const struct alias *)v1;
+ const struct alias *a2 = (const struct alias *)v2;
+ int res;
+ debug_decl(alias_compare, SUDOERS_DEBUG_ALIAS);
+
+ if (a1 == NULL)
+ res = -1;
+ else if (a2 == NULL)
+ res = 1;
+ else if ((res = strcmp(a1->name, a2->name)) == 0)
+ res = a1->type - a2->type;
+ debug_return_int(res);
+}
+
+/*
+ * Search the tree for an alias with the specified name and type.
+ * Returns a pointer to the alias structure or NULL if not found.
+ * Caller is responsible for calling alias_put() on the returned
+ * alias to mark it as unused.
+ */
+struct alias *
+alias_get(struct sudoers_parse_tree *parse_tree, const char *name, int type)
+{
+ struct alias key;
+ struct rbnode *node;
+ struct alias *a = NULL;
+ debug_decl(alias_get, SUDOERS_DEBUG_ALIAS);
+
+ if (parse_tree->aliases == NULL)
+ debug_return_ptr(NULL);
+
+ key.name = (char *)name;
+ key.type = type;
+ if ((node = rbfind(parse_tree->aliases, &key)) != NULL) {
+ /*
+ * Check whether this alias is already in use.
+ * If so, we've detected a loop. If not, set the flag,
+ * which the caller should clear with a call to alias_put().
+ */
+ a = node->data;
+ if (a->used) {
+ errno = ELOOP;
+ debug_return_ptr(NULL);
+ }
+ a->used = true;
+ } else {
+ errno = ENOENT;
+ }
+ debug_return_ptr(a);
+}
+
+/*
+ * Clear the "used" flag in an alias once the caller is done with it.
+ */
+void
+alias_put(struct alias *a)
+{
+ debug_decl(alias_put, SUDOERS_DEBUG_ALIAS);
+ a->used = false;
+ debug_return;
+}
+
+/*
+ * Add an alias to the aliases redblack tree.
+ * Note that "file" must be a reference-counted string.
+ * Returns true on success and false on failure, setting errno.
+ */
+bool
+alias_add(struct sudoers_parse_tree *parse_tree, char *name, int type,
+ char *file, int line, int column, struct member *members)
+{
+ struct alias *a;
+ debug_decl(alias_add, SUDOERS_DEBUG_ALIAS);
+
+ if (parse_tree->aliases == NULL) {
+ if ((parse_tree->aliases = alloc_aliases()) == NULL)
+ debug_return_bool(false);
+ }
+
+ a = calloc(1, sizeof(*a));
+ if (a == NULL)
+ debug_return_bool(false);
+
+ /* Only set elements used by alias_compare() in case there is a dupe. */
+ a->name = name;
+ a->type = type;
+ switch (rbinsert(parse_tree->aliases, a, NULL)) {
+ case 1:
+ free(a);
+ errno = EEXIST;
+ debug_return_bool(false);
+ case -1:
+ free(a);
+ debug_return_bool(false);
+ }
+
+ /*
+ * It is now safe to fill in the rest of the alias. We do this last
+ * since it modifies "file" (adds a ref) and "members" (tailq conversion).
+ */
+ /* a->used = false; */
+ a->file = sudo_rcstr_addref(file);
+ a->line = line;
+ a->column = column;
+ HLTQ_TO_TAILQ(&a->members, members, entries);
+ debug_return_bool(true);
+}
+
+/*
+ * Closure to adapt 2-arg rbapply() to 3-arg alias_apply().
+ */
+struct alias_apply_closure {
+ struct sudoers_parse_tree *parse_tree;
+ int (*func)(struct sudoers_parse_tree *, struct alias *, void *);
+ void *cookie;
+};
+
+/* Adapt rbapply() to alias_apply() calling convention. */
+static int
+alias_apply_func(void *v1, void *v2)
+{
+ struct alias *a = v1;
+ struct alias_apply_closure *closure = v2;
+
+ return closure->func(closure->parse_tree, a, closure->cookie);
+}
+
+/*
+ * Apply a function to each alias entry and pass in a cookie.
+ */
+void
+alias_apply(struct sudoers_parse_tree *parse_tree,
+ int (*func)(struct sudoers_parse_tree *, struct alias *, void *),
+ void *cookie)
+{
+ struct alias_apply_closure closure;
+ debug_decl(alias_apply, SUDOERS_DEBUG_ALIAS);
+
+ if (parse_tree->aliases != NULL) {
+ closure.parse_tree = parse_tree;
+ closure.func = func;
+ closure.cookie = cookie;
+ rbapply(parse_tree->aliases, alias_apply_func, &closure, inorder);
+ }
+
+ debug_return;
+}
+
+/*
+ * Returns true if there are no aliases in the parse_tree, else false.
+ */
+bool
+no_aliases(struct sudoers_parse_tree *parse_tree)
+{
+ debug_decl(no_aliases, SUDOERS_DEBUG_ALIAS);
+ debug_return_bool(parse_tree->aliases == NULL ||
+ rbisempty(parse_tree->aliases));
+}
+
+/*
+ * Free memory used by an alias struct and its members.
+ */
+void
+alias_free(void *v)
+{
+ struct alias *a = (struct alias *)v;
+ debug_decl(alias_free, SUDOERS_DEBUG_ALIAS);
+
+ if (a != NULL) {
+ free(a->name);
+ sudo_rcstr_delref(a->file);
+ free_members(&a->members);
+ free(a);
+ }
+
+ debug_return;
+}
+
+/*
+ * Find the named alias, remove it from the tree and return it.
+ */
+struct alias *
+alias_remove(struct sudoers_parse_tree *parse_tree, const char *name, int type)
+{
+ struct rbnode *node;
+ struct alias key;
+ debug_decl(alias_remove, SUDOERS_DEBUG_ALIAS);
+
+ if (parse_tree->aliases != NULL) {
+ key.name = (char *)name;
+ key.type = type;
+ if ((node = rbfind(parse_tree->aliases, &key)) != NULL)
+ debug_return_ptr(rbdelete(parse_tree->aliases, node));
+ }
+ errno = ENOENT;
+ debug_return_ptr(NULL);
+}
+
+struct rbtree *
+alloc_aliases(void)
+{
+ debug_decl(alloc_aliases, SUDOERS_DEBUG_ALIAS);
+
+ debug_return_ptr(rbcreate(alias_compare));
+}
+
+void
+free_aliases(struct rbtree *aliases)
+{
+ debug_decl(free_aliases, SUDOERS_DEBUG_ALIAS);
+
+ if (aliases != NULL)
+ rbdestroy(aliases, alias_free);
+}
+
+const char *
+alias_type_to_string(int alias_type)
+{
+ return alias_type == HOSTALIAS ? "Host_Alias" :
+ alias_type == CMNDALIAS ? "Cmnd_Alias" :
+ alias_type == USERALIAS ? "User_Alias" :
+ alias_type == RUNASALIAS ? "Runas_Alias" :
+ "Invalid_Alias";
+}
+
+/*
+ * Remove the alias of the specified type as well as any other aliases
+ * referenced by that alias. Stores removed aliases in a freelist.
+ */
+static bool
+alias_remove_recursive(struct sudoers_parse_tree *parse_tree, char *name,
+ int type, struct rbtree *freelist)
+{
+ struct member *m;
+ struct alias *a;
+ bool ret = true;
+ debug_decl(alias_remove_recursive, SUDOERS_DEBUG_ALIAS);
+
+ if ((a = alias_remove(parse_tree, name, type)) != NULL) {
+ TAILQ_FOREACH(m, &a->members, entries) {
+ if (m->type == ALIAS) {
+ if (!alias_remove_recursive(parse_tree, m->name, type, freelist))
+ ret = false;
+ }
+ }
+ if (rbinsert(freelist, a, NULL) != 0)
+ ret = false;
+ }
+ debug_return_bool(ret);
+}
+
+static int
+alias_find_used_members(struct sudoers_parse_tree *parse_tree,
+ struct member_list *members, int atype, struct rbtree *used_aliases)
+{
+ struct member *m;
+ int errors = 0;
+ debug_decl(alias_find_used_members, SUDOERS_DEBUG_ALIAS);
+
+ if (members != NULL) {
+ TAILQ_FOREACH(m, members, entries) {
+ if (m->type != ALIAS)
+ continue;
+ if (!alias_remove_recursive(parse_tree, m->name, atype, used_aliases))
+ errors++;
+ }
+ }
+
+ debug_return_int(errors);
+}
+
+/*
+ * Move all aliases referenced by userspecs to used_aliases.
+ */
+bool
+alias_find_used(struct sudoers_parse_tree *parse_tree, struct rbtree *used_aliases)
+{
+ struct privilege *priv;
+ struct userspec *us;
+ struct cmndspec *cs;
+ struct defaults *d;
+ struct member *m;
+ int errors = 0;
+ debug_decl(alias_find_used, SUDOERS_DEBUG_ALIAS);
+
+ /* Move referenced aliases to used_aliases. */
+ TAILQ_FOREACH(us, &parse_tree->userspecs, entries) {
+ errors += alias_find_used_members(parse_tree, &us->users,
+ USERALIAS, used_aliases);
+ TAILQ_FOREACH(priv, &us->privileges, entries) {
+ errors += alias_find_used_members(parse_tree, &priv->hostlist,
+ HOSTALIAS, used_aliases);
+ TAILQ_FOREACH(cs, &priv->cmndlist, entries) {
+ errors += alias_find_used_members(parse_tree, cs->runasuserlist,
+ RUNASALIAS, used_aliases);
+ errors += alias_find_used_members(parse_tree, cs->runasgrouplist,
+ RUNASALIAS, used_aliases);
+ if ((m = cs->cmnd)->type == ALIAS) {
+ if (!alias_remove_recursive(parse_tree, m->name, CMNDALIAS,
+ used_aliases))
+ errors++;
+ }
+ }
+ }
+ }
+ TAILQ_FOREACH(d, &parse_tree->defaults, entries) {
+ switch (d->type) {
+ case DEFAULTS_HOST:
+ errors += alias_find_used_members(parse_tree,
+ &d->binding->members, HOSTALIAS, used_aliases);
+ break;
+ case DEFAULTS_USER:
+ errors += alias_find_used_members(parse_tree,
+ &d->binding->members, USERALIAS, used_aliases);
+ break;
+ case DEFAULTS_RUNAS:
+ errors += alias_find_used_members(parse_tree,
+ &d->binding->members, RUNASALIAS, used_aliases);
+ break;
+ case DEFAULTS_CMND:
+ errors += alias_find_used_members(parse_tree,
+ &d->binding->members, CMNDALIAS, used_aliases);
+ break;
+ default:
+ break;
+ }
+ }
+
+ debug_return_int(errors ? false : true);
+}
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