--- /dev/null
+/*
+ * Copyright (c) 2004-2005, 2007-2011
+ * Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * 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.
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <config.h>
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <stdio.h>
+#ifdef STDC_HEADERS
+# include <stdlib.h>
+# include <stddef.h>
+#else
+# ifdef HAVE_STDLIB_H
+# include <stdlib.h>
+# endif
+#endif /* STDC_HEADERS */
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif /* HAVE_UNISTD_H */
+
+#include "sudoers.h"
+#include "parse.h"
+#include "redblack.h"
+#include <gram.h>
+
+/*
+ * Globals
+ */
+struct rbtree *aliases;
+unsigned int alias_seqno;
+
+/*
+ * Comparison function for the red-black tree.
+ * Aliases are sorted by name with the type used as a tie-breaker.
+ */
+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;
+
+ if (v1 == NULL)
+ res = -1;
+ else if (v2 == NULL)
+ res = 1;
+ else if ((res = strcmp(a1->name, a2->name)) == 0)
+ res = a1->type - a2->type;
+ return 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.
+ */
+struct alias *
+alias_find(char *name, int type)
+{
+ struct alias key;
+ struct rbnode *node;
+ struct alias *a = NULL;
+
+ key.name = name;
+ key.type = type;
+ if ((node = rbfind(aliases, &key)) != NULL) {
+ /*
+ * Compare the global sequence number with the one stored
+ * in the alias. If they match then we've seen this alias
+ * before and found a loop.
+ */
+ a = node->data;
+ if (a->seqno == alias_seqno)
+ return NULL;
+ a->seqno = alias_seqno;
+ }
+ return a;
+}
+
+/*
+ * Add an alias to the aliases redblack tree.
+ * Returns NULL on success and an error string on failure.
+ */
+char *
+alias_add(char *name, int type, struct member *members)
+{
+ static char errbuf[512];
+ struct alias *a;
+
+ a = emalloc(sizeof(*a));
+ a->name = name;
+ a->type = type;
+ a->seqno = 0;
+ list2tq(&a->members, members);
+ if (rbinsert(aliases, a)) {
+ snprintf(errbuf, sizeof(errbuf), "Alias `%s' already defined", name);
+ alias_free(a);
+ return errbuf;
+ }
+ return NULL;
+}
+
+/*
+ * Apply a function to each alias entry and pass in a cookie.
+ */
+void
+alias_apply(int (*func)(void *, void *), void *cookie)
+{
+ rbapply(aliases, func, cookie, inorder);
+}
+
+/*
+ * Returns TRUE if there are no aliases, else FALSE.
+ */
+int
+no_aliases(void)
+{
+ return rbisempty(aliases);
+}
+
+/*
+ * Free memory used by an alias struct and its members.
+ */
+void
+alias_free(void *v)
+{
+ struct alias *a = (struct alias *)v;
+ struct member *m;
+ struct sudo_command *c;
+ void *next;
+
+ efree(a->name);
+ for (m = a->members.first; m != NULL; m = next) {
+ next = m->next;
+ if (m->type == COMMAND) {
+ c = (struct sudo_command *) m->name;
+ efree(c->cmnd);
+ efree(c->args);
+ }
+ efree(m->name);
+ efree(m);
+ }
+ efree(a);
+}
+
+/*
+ * Find the named alias, remove it from the tree and return it.
+ */
+struct alias *
+alias_remove(char *name, int type)
+{
+ struct rbnode *node;
+ struct alias key;
+
+ key.name = name;
+ key.type = type;
+ if ((node = rbfind(aliases, &key)) == NULL)
+ return NULL;
+ return rbdelete(aliases, node);
+}
+
+void
+init_aliases(void)
+{
+ if (aliases != NULL)
+ rbdestroy(aliases, alias_free);
+ aliases = rbcreate(alias_compare);
+}