[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, 44 insertions, 50 deletions

diff --git a/net/ipv4/fib_hash.c b/net/ipv4/fib_hash.c
index b5bee1a71e5c..357557549ce5 100644
--- a/net/ipv4/fib_hash.c
+++ b/net/ipv4/fib_hash.c
@@ -379,42 +379,39 @@ static struct fib_node *fib_find_node(struct fn_zone *fz, u32 key)
         return NULL;
 }
 
-static int
-fn_hash_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
-               struct nlmsghdr *n, struct netlink_skb_parms *req)
+static int fn_hash_insert(struct fib_table *tb, struct fib_config *cfg)
 {
         struct fn_hash *table = (struct fn_hash *) tb->tb_data;
         struct fib_node *new_f, *f;
         struct fib_alias *fa, *new_fa;
         struct fn_zone *fz;
         struct fib_info *fi;
-        int z = r->rtm_dst_len;
-        int type = r->rtm_type;
-        u8 tos = r->rtm_tos;
+        u8 tos = cfg->fc_tos;
         u32 key;
         int err;
 
-        if (z > 32)
+        if (cfg->fc_dst_len > 32)
                 return -EINVAL;
-        fz = table->fn_zones[z];
-        if (!fz && !(fz = fn_new_zone(table, z)))
+
+        fz = table->fn_zones[cfg->fc_dst_len];
+        if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len)))
                 return -ENOBUFS;
 
         key = 0;
-        if (rta->rta_dst) {
-                u32 dst;
-                memcpy(&dst, rta->rta_dst, 4);
-                if (dst & ~FZ_MASK(fz))
+        if (cfg->fc_dst) {
+                if (cfg->fc_dst & ~FZ_MASK(fz))
                         return -EINVAL;
-                key = fz_key(dst, fz);
+                key = fz_key(cfg->fc_dst, fz);
         }
 
-        if  ((fi = fib_create_info(r, rta, n, &err)) == NULL)
-                return err;
+        fi = fib_create_info(cfg);
+        if (IS_ERR(fi))
+                return PTR_ERR(fi);
 
         if (fz->fz_nent > (fz->fz_divisor<<1) &&
             fz->fz_divisor < FZ_MAX_DIVISOR &&
-            (z==32 || (1<<z) > fz->fz_divisor))
+            (cfg->fc_dst_len == 32 ||
+             (1 << cfg->fc_dst_len) > fz->fz_divisor))
                 fn_rehash_zone(fz);
 
         f = fib_find_node(fz, key);
@@ -440,18 +437,18 @@ fn_hash_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
                 struct fib_alias *fa_orig;
 
                 err = -EEXIST;
-                if (n->nlmsg_flags & NLM_F_EXCL)
+                if (cfg->fc_nlflags & NLM_F_EXCL)
                         goto out;
 
-                if (n->nlmsg_flags & NLM_F_REPLACE) {
+                if (cfg->fc_nlflags & NLM_F_REPLACE) {
                         struct fib_info *fi_drop;
                         u8 state;
 
                         write_lock_bh(&fib_hash_lock);
                         fi_drop = fa->fa_info;
                         fa->fa_info = fi;
-                        fa->fa_type = type;
-                        fa->fa_scope = r->rtm_scope;
+                        fa->fa_type = cfg->fc_type;
+                        fa->fa_scope = cfg->fc_scope;
                         state = fa->fa_state;
                         fa->fa_state &= ~FA_S_ACCESSED;
                         fib_hash_genid++;
@@ -474,17 +471,17 @@ fn_hash_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 (!(n->nlmsg_flags & NLM_F_APPEND))
+                if (!(cfg->fc_nlflags & NLM_F_APPEND))
                         fa = fa_orig;
         }
 
         err = -ENOENT;
-        if (!(n->nlmsg_flags&NLM_F_CREATE))
+        if (!(cfg->fc_nlflags & NLM_F_CREATE))
                 goto out;
 
         err = -ENOBUFS;
@@ -506,8 +503,8 @@ fn_hash_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;
 
         /*
@@ -526,7 +523,8 @@ fn_hash_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
                 fz->fz_nent++;
         rt_cache_flush(-1);
 
-        rtmsg_fib(RTM_NEWROUTE, key, new_fa, z, tb->tb_id, n, req);
+        rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id,
+                  &cfg->fc_nlinfo);
         return 0;
 
 out_free_new_fa:
@@ -537,30 +535,25 @@ out:
 }
 
 
-static int
-fn_hash_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
-               struct nlmsghdr *n, struct netlink_skb_parms *req)
+static int fn_hash_delete(struct fib_table *tb, struct fib_config *cfg)
 {
         struct fn_hash *table = (struct fn_hash*)tb->tb_data;
         struct fib_node *f;
         struct fib_alias *fa, *fa_to_delete;
-        int z = r->rtm_dst_len;
         struct fn_zone *fz;
         u32 key;
-        u8 tos = r->rtm_tos;
 
-        if (z > 32)
+        if (cfg->fc_dst_len > 32)
                 return -EINVAL;
-        if ((fz  = table->fn_zones[z]) == NULL)
+
+        if ((fz  = table->fn_zones[cfg->fc_dst_len]) == NULL)
                 return -ESRCH;
 
         key = 0;
-        if (rta->rta_dst) {
-                u32 dst;
-                memcpy(&dst, rta->rta_dst, 4);
-                if (dst & ~FZ_MASK(fz))
+        if (cfg->fc_dst) {
+                if (cfg->fc_dst & ~FZ_MASK(fz))
                         return -EINVAL;
-                key = fz_key(dst, fz);
+                key = fz_key(cfg->fc_dst, fz);
         }
 
         f = fib_find_node(fz, key);
@@ -568,7 +561,7 @@ fn_hash_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
         if (!f)
                 fa = NULL;
         else
-                fa = fib_find_alias(&f->fn_alias, tos, 0);
+                fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0);
         if (!fa)
                 return -ESRCH;
 
@@ -577,16 +570,16 @@ fn_hash_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
         list_for_each_entry_continue(fa, &f->fn_alias, fa_list) {
                 struct fib_info *fi = fa->fa_info;
 
-                if (fa->fa_tos != tos)
+                if (fa->fa_tos != cfg->fc_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, n, 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;
                 }
@@ -596,7 +589,8 @@ fn_hash_delete(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
                 int kill_fn;
 
                 fa = fa_to_delete;
-                rtmsg_fib(RTM_DELROUTE, key, fa, z, tb->tb_id, n, req);
+                rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len,
+                          tb->tb_id, &cfg->fc_nlinfo);
 
                 kill_fn = 0;
                 write_lock_bh(&fib_hash_lock);