X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=acl.c;h=a3e161db3278c3db1e7b82d1836cbaa16e8897ec;hp=3a30bd453306cfc65c0dc0605af9e9015b88f1d6;hb=926c584394c29354752458b06f7226f0da0dd35e;hpb=0f6df2322c12b1cc20dea08bb6c397465d4f5b46

diff --git a/acl.c b/acl.c
index 3a30bd45..a3e161db 100644
--- a/acl.c
+++ b/acl.c
@@ -24,7 +24,6 @@ struct access_info {
 	struct list_head node;
 };
 
-
 /**
  * Return true if addr_1 matches addr_2 in the first `netmask' bits.
  */
@@ -37,7 +36,15 @@ static int v4_addr_match(uint32_t addr_1, uint32_t addr_2, uint8_t netmask)
 	return (htonl(addr_1) & mask) == (htonl(addr_2) & mask);
 }
 
-int host_in_acl(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;
@@ -59,7 +66,14 @@ no_match:
 	return 0;
 }
 
-void add_acl_entry(struct list_head *acl, struct in_addr addr,
+/**
+ * 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, struct in_addr addr,
 		int netmask)
 {
 	struct access_info *ai = para_malloc(sizeof(struct access_info));
@@ -70,8 +84,14 @@ void add_acl_entry(struct list_head *acl, struct in_addr addr,
 	para_list_add(&ai->node, acl);
 }
 
-
-void del_acl_entry(struct list_head *acl, struct in_addr addr,
+/**
+ * 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, struct in_addr addr,
 		int netmask)
 {
 	struct access_info *ai, *tmp;
@@ -89,7 +109,15 @@ void del_acl_entry(struct list_head *acl, struct in_addr addr,
 	}
 }
 
-char *get_acl_contents(struct list_head *acl)
+/**
+ * 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;
 	char *ret = NULL;
@@ -103,7 +131,14 @@ char *get_acl_contents(struct list_head *acl)
 	return ret;
 }
 
-void init_acl(struct list_head *acl, char * const *acl_info, int num)
+/**
+ * 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;
 
@@ -122,7 +157,7 @@ void init_acl(struct list_head *acl, char * const *acl_info, int num)
 		netmask = atoi(++p);
 		if (netmask < 0 || netmask > 32)
 			goto err;
-		add_acl_entry(acl, addr, netmask);
+		acl_add_entry(acl, addr, netmask);
 		goto success;
 err:
 		PARA_CRIT_LOG("syntax error: %s\n", acl_info[i]);
@@ -132,3 +167,51 @@ success:
 	}
 }
 
+/**
+ * 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(struct in_addr addr, int netmask,
+		struct list_head *acl, int default_deny)
+{
+	if (default_deny)
+		acl_add_entry(acl, addr, netmask);
+	else
+		acl_del_entry(acl, addr, netmask);
+}
+
+/**
+ * Deny 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_deny(struct in_addr addr, int netmask,
+		struct list_head *acl, int default_deny)
+{
+	acl_allow(addr, netmask, acl, !default_deny);
+}