slightly generic acl code

git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@8385 ec53bebd-3082-4978-b11e-865c3cabbd6b

lib/krb5/acl.c

@@ -0,0 +1,189 @@
+/*
+ * Copyright (c) 2000 Kungliga Tekniska H<>gskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "krb5_locl.h"
+#include <fnmatch.h>
+
+RCSID("$Id$");
+
+struct acl_field {
+    enum { acl_string, acl_fnmatch, acl_retval } type;
+    union {
+	const char *cstr;
+	char **retv;
+    } u;
+    struct acl_field *next, **last;
+};
+
+static void
+acl_free_list(struct acl_field *acl)
+{
+    struct acl_field *next;
+    while(acl != NULL) {
+	next = acl->next;
+	free(acl);
+	acl = next;
+    }
+}
+
+static krb5_error_code
+acl_parse_format(krb5_context context,
+		 struct acl_field **acl_ret,
+		 const char *format,
+		 va_list ap)
+{
+    const char *p;
+    struct acl_field *acl = NULL, *tmp;
+
+    for(p = format; *p != '\0'; p++) {
+	tmp = malloc(sizeof(*tmp));
+	if(tmp == NULL) {
+	    acl_free_list(acl);
+	    return ENOMEM;
+	}
+	if(*p == 's') {
+	    tmp->type = acl_string;
+	    tmp->u.cstr = va_arg(ap, const char*);
+	} else if(*p == 'f') {
+	    tmp->type = acl_fnmatch;
+	    tmp->u.cstr = va_arg(ap, const char*);
+	} else if(*p == 'r') {
+	    tmp->type = acl_retval;
+	    tmp->u.retv = va_arg(ap, char **);
+	}
+	tmp->next = NULL;
+	if(acl == NULL)
+	    acl = tmp;
+	else
+	    *acl->last = tmp;
+	acl->last = &tmp->next;
+    }
+    *acl_ret = acl;
+    return 0;
+}
+
+static krb5_boolean
+acl_match_field(krb5_context context,
+		const char *string,
+		struct acl_field *field)
+{
+    if(field->type == acl_string) {
+	return !strcmp(string, field->u.cstr);
+    } else if(field->type == acl_fnmatch) {
+	return !fnmatch(string, field->u.cstr, 0);
+    } else if(field->type == acl_retval) {
+	*field->u.retv = strdup(string);
+	return TRUE;
+    }
+    return FALSE;
+}
+
+static krb5_boolean
+acl_match_acl(krb5_context context,
+	      struct acl_field *acl,
+	      const char *string)
+{
+    char buf[256];
+    for(;strsep_copy(&string, " \t", buf, sizeof(buf)) != -1; 
+	acl = acl->next) {
+	if(buf[0] == '\0')
+	    continue; /* skip ws */
+	if(!acl_match_field(context, buf, acl)) {
+	    return FALSE;
+	}
+    }
+    return TRUE;
+}
+
+
+krb5_error_code
+krb5_acl_match_string(krb5_context context,
+		      const char *acl_string,
+		      const char *format,
+		      ...)
+{
+    krb5_error_code ret;
+    struct acl_field *acl;
+
+    va_list ap;
+    va_start(ap, format);
+    ret = acl_parse_format(context, &acl, format, ap);
+    va_end(ap);
+    if(ret)
+	return ret;
+
+    ret = acl_match_acl(context, acl, acl_string);
+
+    acl_free_list(acl);
+    return ret ? 0 : EACCES;
+}
+	       
+krb5_error_code
+krb5_acl_match_file(krb5_context context,
+		    const char *file,
+		    const char *format,
+		    ...)
+{
+    krb5_error_code ret;
+    struct acl_field *acl;
+    char buf[256];
+    va_list ap;
+    FILE *f;
+
+    f = fopen(file, "r");
+    if(f == NULL)
+	return errno;
+
+    va_start(ap, format);
+    ret = acl_parse_format(context, &acl, format, ap);
+    va_end(ap);
+    if(ret) {
+	fclose(f);
+	return ret;
+    }
+
+    ret = EACCES; /* XXX */
+    while(fgets(buf, sizeof(buf), f)) {
+	if(buf[0] == '#')
+	    continue;
+	if(acl_match_acl(context, acl, buf)) {
+	    ret = 0;
+	    goto out;
+	}
+    }
+
+  out:
+    fclose(f);
+    acl_free_list(acl);
+    return ret;
+}