[IPv4]: FIB configuration using struct fib_config

Introduces struct fib_config replacing the ugly struct kern_rta
prone to ordering issues. Avoids creating faked netlink messages
for auto generated routes or requests via ioctl.

A new interface net/nexthop.h is added to help navigate through
nexthop configuration arrays.

A new struct nl_info will be used to carry the necessary netlink
information to be used for notifications later on.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 71 insertions, 27 deletions

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 8e9ba563d342..42ed96fab3f5 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -20,25 +20,32 @@
 #include <linux/seq_file.h>
 #include <net/fib_rules.h>
 
-/* WARNING: The ordering of these elements must match ordering
- *          of RTA_* rtnetlink attribute numbers.
- */
-struct kern_rta {
-        void            *rta_dst;
-        void            *rta_src;
-        int             *rta_iif;
-        int             *rta_oif;
-        void            *rta_gw;
-        u32             *rta_priority;
-        void            *rta_prefsrc;
-        struct rtattr   *rta_mx;
-        struct rtattr   *rta_mp;
-        unsigned char   *rta_protoinfo;
-        u32             *rta_flow;
-        struct rta_cacheinfo *rta_ci;
-        struct rta_session *rta_sess;
-        u32             *rta_mp_alg;
-};
+struct fib_config {
+        u8                      fc_family;
+        u8                      fc_dst_len;
+        u8                      fc_src_len;
+        u8                      fc_tos;
+        u8                      fc_protocol;
+        u8                      fc_scope;
+        u8                      fc_type;
+        /* 1 byte unused */
+        u32                     fc_table;
+        u32                     fc_dst;
+        u32                     fc_src;
+        u32                     fc_gw;
+        int                     fc_oif;
+        u32                     fc_flags;
+        u32                     fc_priority;
+        u32                     fc_prefsrc;
+        struct nlattr           *fc_mx;
+        struct rtnexthop        *fc_mp;
+        int                     fc_mx_len;
+        int                     fc_mp_len;
+        u32                     fc_flow;
+        u32                     fc_mp_alg;
+        u32                     fc_nlflags;
+        struct nl_info          fc_nlinfo;
+ };
 
 struct fib_info;
 
@@ -154,12 +161,8 @@ struct fib_table {
         u32             tb_id;
         unsigned        tb_stamp;
         int             (*tb_lookup)(struct fib_table *tb, const struct flowi *flp, struct fib_result *res);
-        int             (*tb_insert)(struct fib_table *table, struct rtmsg *r,
-                                     struct kern_rta *rta, struct nlmsghdr *n,
-                                     struct netlink_skb_parms *req);
-        int             (*tb_delete)(struct fib_table *table, struct rtmsg *r,
-                                     struct kern_rta *rta, struct nlmsghdr *n,
-                                     struct netlink_skb_parms *req);
+        int             (*tb_insert)(struct fib_table *, struct fib_config *);
+        int             (*tb_delete)(struct fib_table *, struct fib_config *);
         int             (*tb_dump)(struct fib_table *table, struct sk_buff *skb,
                                      struct netlink_callback *cb);
         int             (*tb_flush)(struct fib_table *table);
@@ -228,8 +231,6 @@ struct rtentry;
 extern int ip_fib_check_default(u32 gw, struct net_device *dev);
 extern int fib_sync_down(u32 local, struct net_device *dev, int force);
 extern int fib_sync_up(struct net_device *dev);
-extern int fib_convert_rtentry(int cmd, struct nlmsghdr *nl, struct rtmsg *rtm,
-                               struct kern_rta *rta, struct rtentry *r);
 extern u32  __fib_res_prefsrc(struct fib_result *res);
 
 /* Exported by fib_hash.c */
diff --git a/include/net/netlink.h b/include/net/netlink.h
index bf593eb59e1b..47044da167c5 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -192,6 +192,16 @@ struct nla_policy {
         u16             minlen;
 };
 
+/**
+ * struct nl_info - netlink source information
+ * @nlh: Netlink message header of original request
+ * @pid: Netlink PID of requesting application
+ */
+struct nl_info {
+        struct nlmsghdr         *nlh;
+        u32                     pid;
+};
+
 extern void             netlink_run_queue(struct sock *sk, unsigned int *qlen,
                                           int (*cb)(struct sk_buff *,
                                                     struct nlmsghdr *, int *));
diff --git a/include/net/nexthop.h b/include/net/nexthop.h
new file mode 100644
index 000000000000..3334dbfa5aa4
--- /dev/null
+++ b/include/net/nexthop.h
@@ -0,0 +1,33 @@
+#ifndef __NET_NEXTHOP_H
+#define __NET_NEXTHOP_H
+
+#include <linux/rtnetlink.h>
+#include <net/netlink.h>
+
+static inline int rtnh_ok(const struct rtnexthop *rtnh, int remaining)
+{
+        return remaining >= sizeof(*rtnh) &&
+               rtnh->rtnh_len >= sizeof(*rtnh) &&
+               rtnh->rtnh_len <= remaining;
+}
+
+static inline struct rtnexthop *rtnh_next(const struct rtnexthop *rtnh,
+                                         int *remaining)
+{
+        int totlen = NLA_ALIGN(rtnh->rtnh_len);
+
+        *remaining -= totlen;
+        return (struct rtnexthop *) ((char *) rtnh + totlen);
+}
+
+static inline struct nlattr *rtnh_attrs(const struct rtnexthop *rtnh)
+{
+        return (struct nlattr *) ((char *) rtnh + NLA_ALIGN(sizeof(*rtnh)));
+}
+
+static inline int rtnh_attrlen(const struct rtnexthop *rtnh)
+{
+        return rtnh->rtnh_len - NLA_ALIGN(sizeof(*rtnh));
+}
+
+#endif