/*
- * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2011 Andre Noll <maan@systemlinux.org>
*
* Licensed under the GPL v2. For licencing details see COPYING.
*/
/** \file acl.c Access control lists for paraslash senders. */
+#include <regex.h>
+
#include "para.h"
#include "error.h"
#include "string.h"
struct list_head node;
};
-
/**
* Return true if addr_1 matches addr_2 in the first `netmask' bits.
*/
return (htonl(addr_1) & mask) == (htonl(addr_2) & mask);
}
-int acl_lookup(int fd, struct list_head *acl)
+/**
+ * Find out whether the peer name of a given fd belongs to an acl.
+ *
+ * \param fd File descriptor.
+ * \param acl The access control list.
+ *
+ * \return One if \a fd belongs to \a acl, zero otherwise.
+ */
+static int acl_lookup(int fd, struct list_head *acl)
{
struct access_info *ai, *tmp;
struct sockaddr_storage ss;
return 0;
}
-void acl_add_entry(struct list_head *acl, struct in_addr addr,
- int netmask)
+/**
+ * Add an entry to an access control list.
+ *
+ * \param acl The access control list.
+ * \param addr The address to add.
+ * \param netmask The netmask to use for this entry.
+ */
+static void acl_add_entry(struct list_head *acl, char *addr, int netmask)
{
struct access_info *ai = para_malloc(sizeof(struct access_info));
- ai->addr = addr;
+
+ inet_pton(AF_INET, addr, &ai->addr);
ai->netmask = netmask;
- PARA_INFO_LOG("adding %s/%i to access list\n", inet_ntoa(ai->addr),
- ai->netmask);
+ PARA_INFO_LOG("adding %s/%i to access list\n", addr, ai->netmask);
para_list_add(&ai->node, acl);
}
-
-void acl_del_entry(struct list_head *acl, struct in_addr addr,
- int netmask)
+/**
+ * Delete an entry from an access control list.
+ *
+ * \param acl The access control list.
+ * \param addr The address to delete.
+ * \param netmask The netmask of the entry to be removed from the list.
+ */
+static void acl_del_entry(struct list_head *acl, char *addr, unsigned netmask)
{
struct access_info *ai, *tmp;
+ struct in_addr to_delete;
+
+ inet_pton(AF_INET, addr, &to_delete);
list_for_each_entry_safe(ai, tmp, acl, node) {
- char *nad = para_strdup(inet_ntoa(ai->addr));
- if (!strcmp(nad, inet_ntoa(addr)) &&
- ai->netmask == netmask) {
+
+ if (v4_addr_match(to_delete.s_addr, ai->addr.s_addr,
+ PARA_MIN(netmask, ai->netmask))) {
PARA_NOTICE_LOG("removing %s/%i from access list\n",
- nad, ai->netmask);
+ addr, ai->netmask);
list_del(&ai->node);
free(ai);
}
- free(nad);
}
}
+/**
+ * Compute a string containing the contents of an acl.
+ *
+ * \param acl The access control list.
+ *
+ * \return A string containing the contents of \a acl, or \p NULL
+ * if \a acl is empty.
+ */
char *acl_get_contents(struct list_head *acl)
{
struct access_info *ai, *tmp_ai;
return ret;
}
+/**
+ * Initialize an access control list.
+ *
+ * \param acl The list to initialize.
+ * \param acl_info An array of strings of the form ip/netmask.
+ * \param num The number of strings in \a acl_info.
+ */
void acl_init(struct list_head *acl, char * const *acl_info, int num)
{
- int i;
+ char addr[16];
+ int mask, i;
INIT_LIST_HEAD(acl);
- for (i = 0; i < num; i++) {
- char *arg = para_strdup(acl_info[i]);
- char *p = strchr(arg, '/');
- struct in_addr addr;
- int netmask;
-
- if (!p)
- goto err;
- *p = '\0';
- if (!inet_pton(AF_INET, arg, &addr))
- goto err;
- netmask = atoi(++p);
- if (netmask < 0 || netmask > 32)
- goto err;
+ for (i = 0; i < num; i++)
+ if (parse_cidr(acl_info[i], addr, sizeof(addr), &mask) == NULL)
+ PARA_CRIT_LOG("ACL syntax error: %s, ignoring\n",
+ acl_info[i]);
+ else
+ acl_add_entry(acl, addr, mask);
+}
+
+/**
+ * Check whether the peer name of a given fd is allowed by an acl.
+ *
+ * \param fd File descriptor.
+ * \param acl The access control list.
+ * \param default_deny Whether \a acl is a whitelist.
+ *
+ * \return Positive if the peer of \a fd is permitted by \a acl, \p -E_ACL_PERM
+ * otherwise.
+ */
+int acl_check_access(int fd, struct list_head *acl, int default_deny)
+{
+ int match = acl_lookup(fd, acl);
+
+ return (!match || default_deny) && (match || !default_deny)?
+ 1 : -E_ACL_PERM;
+}
+
+/**
+ * Permit access for a range of IP addresses.
+ *
+ * \param addr The address to permit.
+ * \param netmask The netmask of the entry to be permitted.
+ * \param acl The access control list.
+ * \param default_deny Whether \a acl is a whitelist.
+ */
+void acl_allow(char *addr, int netmask,
+ struct list_head *acl, int default_deny)
+{
+ if (default_deny)
acl_add_entry(acl, addr, netmask);
- goto success;
-err:
- PARA_CRIT_LOG("syntax error: %s\n", acl_info[i]);
-success:
- free(arg);
- continue;
- }
+ else
+ acl_del_entry(acl, addr, netmask);
}
+/**
+ * Deny access for a range of IP addresses.
+ *
+ * \param addr The address to deny.
+ * \param netmask The netmask of the entry to be denied.
+ * \param acl The access control list.
+ * \param default_deny Whether \a acl is a whitelist.
+ */
+void acl_deny(char *addr, int netmask,
+ struct list_head *acl, int default_deny)
+{
+ acl_allow(addr, netmask, acl, !default_deny);
+}