[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>

1 files changed, 32 insertions, 44 deletions

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 2a580eb2579b..41bef0a88ab6 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1124,17 +1124,14 @@ err:
         return fa_head;
 }
 
-static int
-fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
-               struct nlmsghdr *nlhdr, struct netlink_skb_parms *req)
+static int fn_trie_insert(struct fib_table *tb, struct fib_config *cfg)
 {
         struct trie *t = (struct trie *) tb->tb_data;
         struct fib_alias *fa, *new_fa;
         struct list_head *fa_head = NULL;
         struct fib_info *fi;
-        int plen = r->rtm_dst_len;
-        int type = r->rtm_type;
-        u8 tos = r->rtm_tos;
+        int plen = cfg->fc_dst_len;
+        u8 tos = cfg->fc_tos;
         u32 key, mask;
         int err;
         struct leaf *l;
@@ -1142,11 +1139,7 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
         if (plen > 32)
                 return -EINVAL;
 
-        key = 0;
-        if (rta->rta_dst)
-                memcpy(&key, rta->rta_dst, 4);
-
-        key = ntohl(key);
+        key = ntohl(cfg->fc_dst);
 
         pr_debug("Insert table=%u %08x/%d\n", tb->tb_id, key, plen);
 
@@ -1157,10 +1150,11 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
 
         key = key & mask;
 
-        fi = fib_create_info(r, rta, nlhdr, &err);
-
-        if (!fi)
+        fi = fib_create_info(cfg);
+        if (IS_ERR(fi)) {
+                err = PTR_ERR(fi);
                 goto err;
+        }
 
         l = fib_find_node(t, key);
         fa = NULL;
@@ -1185,10 +1179,10 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
                 struct fib_alias *fa_orig;
 
                 err = -EEXIST;
-                if (nlhdr->nlmsg_flags & NLM_F_EXCL)
+                if (cfg->fc_nlflags & NLM_F_EXCL)
                         goto out;
 
-                if (nlhdr->nlmsg_flags & NLM_F_REPLACE) {
+                if (cfg->fc_nlflags & NLM_F_REPLACE) {
                         struct fib_info *fi_drop;
                         u8 state;
 
@@ -1200,8 +1194,8 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
                         fi_drop = fa->fa_info;
                         new_fa->fa_tos = fa->fa_tos;
                         new_fa->fa_info = fi;
-                        new_fa->fa_type = type;
-                        new_fa->fa_scope = r->rtm_scope;
+                        new_fa->fa_type = cfg->fc_type;
+                        new_fa->fa_scope = cfg->fc_scope;
                         state = fa->fa_state;
                         new_fa->fa_state &= ~FA_S_ACCESSED;
 
@@ -1224,17 +1218,17 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
                                 break;
                         if (fa->fa_info->fib_priority != fi->fib_priority)
                                 break;
-                        if (fa->fa_type == type &&
-                            fa->fa_scope == r->rtm_scope &&
+                        if (fa->fa_type == cfg->fc_type &&
+                            fa->fa_scope == cfg->fc_scope &&
                             fa->fa_info == fi) {
                                 goto out;
                         }
                 }
-                if (!(nlhdr->nlmsg_flags & NLM_F_APPEND))
+                if (!(cfg->fc_nlflags & NLM_F_APPEND))
                         fa = fa_orig;
         }
         err = -ENOENT;
-        if (!(nlhdr->nlmsg_flags & NLM_F_CREATE))
+        if (!(cfg->fc_nlflags & NLM_F_CREATE))
                 goto out;
 
         err = -ENOBUFS;
@@ -1244,8 +1238,8 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
 
         new_fa->fa_info = fi;
         new_fa->fa_tos = tos;
-        new_fa->fa_type = type;
-        new_fa->fa_scope = r->rtm_scope;
+        new_fa->fa_type = cfg->fc_type;
+        new_fa->fa_scope = cfg->fc_scope;
         new_fa->fa_state = 0;
         /*
          * Insert new entry to the list.
@@ -1262,7 +1256,8 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
                           (fa ? &fa->fa_list : fa_head));
 
         rt_cache_flush(-1);
-        rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id, nlhdr, req);
+        rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id,
+                  &cfg->fc_nlinfo);
 succeeded:
         return 0;
 
@@ -1548,28 +1543,21 @@ static int trie_leaf_remove(struct trie *t, t_key key)
         return 1;
 }
 
-static int
-fn_trie_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
-                struct nlmsghdr *nlhdr, struct netlink_skb_parms *req)
+static int fn_trie_delete(struct fib_table *tb, struct fib_config *cfg)
 {
         struct trie *t = (struct trie *) tb->tb_data;
         u32 key, mask;
-        int plen = r->rtm_dst_len;
-        u8 tos = r->rtm_tos;
+        int plen = cfg->fc_dst_len;
+        u8 tos = cfg->fc_tos;
         struct fib_alias *fa, *fa_to_delete;
         struct list_head *fa_head;
         struct leaf *l;
         struct leaf_info *li;
 
-
         if (plen > 32)
                 return -EINVAL;
 
-        key = 0;
-        if (rta->rta_dst)
-                memcpy(&key, rta->rta_dst, 4);
-
-        key = ntohl(key);
+        key = ntohl(cfg->fc_dst);
         mask = ntohl(inet_make_mask(plen));
 
         if (key & ~mask)
@@ -1598,13 +1586,12 @@ fn_trie_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
                 if (fa->fa_tos != tos)
                         break;
 
-                if ((!r->rtm_type ||
-                     fa->fa_type == r->rtm_type) &&
-                    (r->rtm_scope == RT_SCOPE_NOWHERE ||
-                     fa->fa_scope == r->rtm_scope) &&
-                    (!r->rtm_protocol ||
-                     fi->fib_protocol == r->rtm_protocol) &&
-                    fib_nh_match(r, nlhdr, rta, fi) == 0) {
+                if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
+                    (cfg->fc_scope == RT_SCOPE_NOWHERE ||
+                     fa->fa_scope == cfg->fc_scope) &&
+                    (!cfg->fc_protocol ||
+                     fi->fib_protocol == cfg->fc_protocol) &&
+                    fib_nh_match(cfg, fi) == 0) {
                         fa_to_delete = fa;
                         break;
                 }
@@ -1614,7 +1601,8 @@ fn_trie_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
                 return -ESRCH;
 
         fa = fa_to_delete;
-        rtmsg_fib(RTM_DELROUTE, htonl(key), fa, plen, tb->tb_id, nlhdr, req);
+        rtmsg_fib(RTM_DELROUTE, htonl(key), fa, plen, tb->tb_id,
+                  &cfg->fc_nlinfo);
 
         l = fib_find_node(t, key);
         li = find_leaf_info(l, plen);