Rework source layout in preparation for modular sudo.

plugins/sudoers/alias.c

@@ -0,0 +1,202 @@
+/*
+ * Copyright (c) 2004-2005m, 2007-2009
+ *	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>
+#else
+# ifdef HAVE_STRINGS_H
+#  include <strings.h>
+# endif
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif /* HAVE_UNISTD_H */
+
+#include "sudo.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(v1, v2)
+    const void *v1, *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(name, type)
+    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(name, type, members)
+    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)) {
+	alias_free(a);
+	snprintf(errbuf, sizeof(errbuf), "Alias `%s' already defined", name);
+	return(errbuf);
+    }
+    return(NULL);
+}
+
+/*
+ * Apply a function to each alias entry and pass in a cookie.
+ */
+void
+alias_apply(func, cookie)
+    int (*func) __P((void *, void *));
+    void *cookie;
+{
+    rbapply(aliases, func, cookie, inorder);
+}
+
+/*
+ * Returns TRUE if there are no aliases, else FALSE.
+ */
+int
+no_aliases()
+{
+    return(rbisempty(aliases));
+}
+
+/*
+ * Free memory used by an alias struct and its members.
+ */
+void
+alias_free(v)
+    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(name, type)
+    char *name;
+    int type;
+{
+    struct rbnode *node;
+    struct alias key, *a;
+
+    key.name = name;
+    key.type = type;
+    if ((node = rbfind(aliases, &key)) == NULL)
+	return(NULL);
+    a = rbdelete(aliases, node);
+    return(a);
+}
+
+void
+init_aliases()
+{
+    if (aliases != NULL)
+	rbdestroy(aliases, alias_free);
+    aliases = rbcreate(alias_compare);
+}