diff options
author | Martin KaFai Lau <kafai@fb.com> | 2014-10-20 13:42:43 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-10-24 00:14:39 -0400 |
commit | a3c00e46efdb4009369971c97203ea67f7630fe4 (patch) | |
tree | 98789f21ff6f3fd596ec49933fc69d5d0979be44 /net/ipv6/route.c | |
parent | 105970f6087ae240b00deaff85773ed9bf381145 (diff) | |
download | op-kernel-dev-a3c00e46efdb4009369971c97203ea67f7630fe4.zip op-kernel-dev-a3c00e46efdb4009369971c97203ea67f7630fe4.tar.gz |
ipv6: Remove BACKTRACK macro
It is the prep work to reduce the number of calls to fib6_lookup().
The BACKTRACK macro could be hard-to-read and error-prone due to
its side effects (mainly goto).
This patch is to:
1. Replace BACKTRACK macro with a function (fib6_backtrack) with the following
return values:
* If it is backtrack-able, returns next fn for retry.
* If it reaches the root, returns NULL.
2. The caller needs to decide if a backtrack is needed (by testing
rt == net->ipv6.ip6_null_entry).
3. Rename the goto labels in ip6_pol_route() to make the next few
patches easier to read.
Cc: David Miller <davem@davemloft.net>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/route.c')
-rw-r--r-- | net/ipv6/route.c | 70 |
1 files changed, 40 insertions, 30 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index a318dd89..f1ab2f4 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -772,23 +772,22 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, } #endif -#define BACKTRACK(__net, saddr) \ -do { \ - if (rt == __net->ipv6.ip6_null_entry) { \ - struct fib6_node *pn; \ - while (1) { \ - if (fn->fn_flags & RTN_TL_ROOT) \ - goto out; \ - pn = fn->parent; \ - if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn) \ - fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr); \ - else \ - fn = pn; \ - if (fn->fn_flags & RTN_RTINFO) \ - goto restart; \ - } \ - } \ -} while (0) +static struct fib6_node* fib6_backtrack(struct fib6_node *fn, + struct in6_addr *saddr) +{ + struct fib6_node *pn; + while (1) { + if (fn->fn_flags & RTN_TL_ROOT) + return NULL; + pn = fn->parent; + if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn) + fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr); + else + fn = pn; + if (fn->fn_flags & RTN_RTINFO) + return fn; + } +} static struct rt6_info *ip6_pol_route_lookup(struct net *net, struct fib6_table *table, @@ -804,8 +803,11 @@ restart: rt = rt6_device_match(net, rt, &fl6->saddr, fl6->flowi6_oif, flags); if (rt->rt6i_nsiblings && fl6->flowi6_oif == 0) rt = rt6_multipath_select(rt, fl6, fl6->flowi6_oif, flags); - BACKTRACK(net, &fl6->saddr); -out: + if (rt == net->ipv6.ip6_null_entry) { + fn = fib6_backtrack(fn, &fl6->saddr); + if (fn) + goto restart; + } dst_use(&rt->dst, jiffies); read_unlock_bh(&table->tb6_lock); return rt; @@ -924,19 +926,25 @@ static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, strict |= flags & RT6_LOOKUP_F_IFACE; -relookup: +redo_fib6_lookup_lock: read_lock_bh(&table->tb6_lock); -restart_2: +redo_fib6_lookup: fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); -restart: +redo_rt6_select: rt = rt6_select(fn, oif, strict | reachable); if (rt->rt6i_nsiblings) rt = rt6_multipath_select(rt, fl6, oif, strict | reachable); - BACKTRACK(net, &fl6->saddr); - if (rt == net->ipv6.ip6_null_entry || - rt->rt6i_flags & RTF_CACHE) + if (rt == net->ipv6.ip6_null_entry) { + fn = fib6_backtrack(fn, &fl6->saddr); + if (fn) + goto redo_rt6_select; + else + goto out; + } + + if (rt->rt6i_flags & RTF_CACHE) goto out; dst_hold(&rt->dst); @@ -967,12 +975,12 @@ restart: * released someone could insert this route. Relookup. */ ip6_rt_put(rt); - goto relookup; + goto redo_fib6_lookup_lock; out: if (reachable) { reachable = 0; - goto restart_2; + goto redo_fib6_lookup; } dst_hold(&rt->dst); read_unlock_bh(&table->tb6_lock); @@ -1235,10 +1243,12 @@ restart: rt = net->ipv6.ip6_null_entry; else if (rt->dst.error) { rt = net->ipv6.ip6_null_entry; - goto out; + } else if (rt == net->ipv6.ip6_null_entry) { + fn = fib6_backtrack(fn, &fl6->saddr); + if (fn) + goto restart; } - BACKTRACK(net, &fl6->saddr); -out: + dst_hold(&rt->dst); read_unlock_bh(&table->tb6_lock); |