[NET]: Fix fib_rules compatibility breakage

[net-next-2.6.git] / net / core / fib_rules.c

diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 6b0e63cacd93347be11dcf085b2c3774ef4c2534..d011819a805805480d14fd0d00832f2b794d9082 100644 (file)
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -107,6 +107,22 @@ out:
 
 EXPORT_SYMBOL_GPL(fib_rules_unregister);
 
+static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
+                         struct flowi *fl, int flags)
+{
+       int ret = 0;
+
+       if (rule->ifindex && (rule->ifindex != fl->iif))
+               goto out;
+
+       if ((rule->mark ^ fl->mark) & rule->mark_mask)
+               goto out;
+
+       ret = ops->match(rule, fl, flags);
+out:
+       return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
+}
+
 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
                     int flags, struct fib_lookup_arg *arg)
 {
@@ -116,10 +132,7 @@ int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
        rcu_read_lock();
 
        list_for_each_entry_rcu(rule, ops->rules_list, list) {
-               if (rule->ifindex && (rule->ifindex != fl->iif))
-                       continue;
-
-               if (!ops->match(rule, fl, flags))
+               if (!fib_rule_match(rule, ops, fl, flags))
                        continue;
 
                err = ops->action(rule, fl, flags, arg);
@@ -139,6 +152,28 @@ out:
 
 EXPORT_SYMBOL_GPL(fib_rules_lookup);
 
+static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb,
+                           struct fib_rules_ops *ops)
+{
+       int err = -EINVAL;
+
+       if (frh->src_len)
+               if (tb[FRA_SRC] == NULL ||
+                   frh->src_len > (ops->addr_size * 8) ||
+                   nla_len(tb[FRA_SRC]) != ops->addr_size)
+                       goto errout;
+
+       if (frh->dst_len)
+               if (tb[FRA_DST] == NULL ||
+                   frh->dst_len > (ops->addr_size * 8) ||
+                   nla_len(tb[FRA_DST]) != ops->addr_size)
+                       goto errout;
+
+       err = 0;
+errout:
+       return err;
+}
+
 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 {
        struct fib_rule_hdr *frh = nlmsg_data(nlh);
@@ -160,6 +195,10 @@ int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
        if (err < 0)
                goto errout;
 
+       err = validate_rulemsg(frh, tb, ops);
+       if (err < 0)
+               goto errout;
+
        rule = kzalloc(ops->rule_size, GFP_KERNEL);
        if (rule == NULL) {
                err = -ENOMEM;
@@ -179,6 +218,18 @@ int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
                        rule->ifindex = dev->ifindex;
        }
 
+       if (tb[FRA_FWMARK]) {
+               rule->mark = nla_get_u32(tb[FRA_FWMARK]);
+               if (rule->mark)
+                       /* compatibility: if the mark value is non-zero all bits
+                        * are compared unless a mask is explicitly specified.
+                        */
+                       rule->mark_mask = 0xFFFFFFFF;
+       }
+
+       if (tb[FRA_FWMASK])
+               rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
+
        rule->action = frh->action;
        rule->flags = frh->flags;
        rule->table = frh_get_table(frh, tb);
@@ -235,6 +286,10 @@ int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
        if (err < 0)
                goto errout;
 
+       err = validate_rulemsg(frh, tb, ops);
+       if (err < 0)
+               goto errout;
+
        list_for_each_entry(rule, ops->rules_list, list) {
                if (frh->action && (frh->action != rule->action))
                        continue;
@@ -250,6 +305,14 @@ int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
                    nla_strcmp(tb[FRA_IFNAME], rule->ifname))
                        continue;
 
+               if (tb[FRA_FWMARK] &&
+                   (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
+                       continue;
+
+               if (tb[FRA_FWMASK] &&
+                   (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
+                       continue;
+
                if (!ops->compare(rule, frh, tb))
                        continue;
 
@@ -273,6 +336,22 @@ errout:
        return err;
 }
 
+static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
+                                        struct fib_rule *rule)
+{
+       size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
+                        + nla_total_size(IFNAMSIZ) /* FRA_IFNAME */
+                        + nla_total_size(4) /* FRA_PRIORITY */
+                        + nla_total_size(4) /* FRA_TABLE */
+                        + nla_total_size(4) /* FRA_FWMARK */
+                        + nla_total_size(4); /* FRA_FWMASK */
+
+       if (ops->nlmsg_payload)
+               payload += ops->nlmsg_payload(rule);
+
+       return payload;
+}
+
 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
                            u32 pid, u32 seq, int type, int flags,
                            struct fib_rules_ops *ops)
@@ -282,7 +361,7 @@ static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
 
        nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
        if (nlh == NULL)
-               return -1;
+               return -EMSGSIZE;
 
        frh = nlmsg_data(nlh);
        frh->table = rule->table;
@@ -298,13 +377,20 @@ static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
        if (rule->pref)
                NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref);
 
+       if (rule->mark)
+               NLA_PUT_U32(skb, FRA_FWMARK, rule->mark);
+
+       if (rule->mark_mask || rule->mark)
+               NLA_PUT_U32(skb, FRA_FWMASK, rule->mark_mask);
+
        if (ops->fill(rule, skb, nlh, frh) < 0)
                goto nla_put_failure;
 
        return nlmsg_end(skb, nlh);
 
 nla_put_failure:
-       return nlmsg_cancel(skb, nlh);
+       nlmsg_cancel(skb, nlh);
+       return -EMSGSIZE;
 }
 
 int fib_rules_dump(struct sk_buff *skb, struct netlink_callback *cb, int family)
@@ -318,7 +404,7 @@ int fib_rules_dump(struct sk_buff *skb, struct netlink_callback *cb, int family)
                return -EAFNOSUPPORT;
 
        rcu_read_lock();
-       list_for_each_entry(rule, ops->rules_list, list) {
+       list_for_each_entry_rcu(rule, ops->rules_list, list) {
                if (idx < cb->args[0])
                        goto skip;
 
@@ -345,16 +431,17 @@ static void notify_rule_change(int event, struct fib_rule *rule,
        struct sk_buff *skb;
        int err = -ENOBUFS;
 
-       skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+       skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
        if (skb == NULL)
                goto errout;
 
        err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
        if (err < 0) {
+               /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
+               WARN_ON(err == -EMSGSIZE);
                kfree_skb(skb);
                goto errout;
        }
-
        err = rtnl_notify(skb, pid, ops->nlgroup, nlh, GFP_KERNEL);
 errout:
        if (err < 0)