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| author | David S. Miller <davem@davemloft.net> | 2010-12-13 23:52:14 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-12-13 23:52:14 +0300 |
| commit | 0dbaee3b37e118a96bb7b8eb0d9bbaeeb46264be (patch) | |
| tree | 37000c5d7e663e4ae9800a7bcde9934984b8bae9 /include/net | |
| parent | cc6f02dd490dac4ad821d5077b934c9b37037cd0 (diff) | |
| download | linux-0dbaee3b37e118a96bb7b8eb0d9bbaeeb46264be.tar.xz | |
net: Abstract default ADVMSS behind an accessor.
Make all RTAX_ADVMSS metric accesses go through a new helper function,
dst_metric_advmss().
Leave the actual default metric as "zero" in the real metric slot,
and compute the actual default value dynamically via a new dst_ops
AF specific callback.
For stacked IPSEC routes, we use the advmss of the path which
preserves existing behavior.
Unlike ipv4/ipv6, DecNET ties the advmss to the mtu and thus updates
advmss on pmtu updates. This inconsistency in advmss handling
results in more raw metric accesses than I wish we ended up with.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/dst.h | 14 | ||||
| -rw-r--r-- | include/net/dst_ops.h | 1 |
2 files changed, 14 insertions, 1 deletions
diff --git a/include/net/dst.h b/include/net/dst.h index 755ac6c1aa03..03a1c3d52d80 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -112,10 +112,22 @@ dst_metric_raw(const struct dst_entry *dst, const int metric) static inline u32 dst_metric(const struct dst_entry *dst, const int metric) { - WARN_ON_ONCE(metric == RTAX_HOPLIMIT); + WARN_ON_ONCE(metric == RTAX_HOPLIMIT || + metric == RTAX_ADVMSS); return dst_metric_raw(dst, metric); } +static inline u32 +dst_metric_advmss(const struct dst_entry *dst) +{ + u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS); + + if (!advmss) + advmss = dst->ops->default_advmss(dst); + + return advmss; +} + static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val) { dst->_metrics[metric-1] = val; diff --git a/include/net/dst_ops.h b/include/net/dst_ops.h index 51665b3461b8..15fb7af08c42 100644 --- a/include/net/dst_ops.h +++ b/include/net/dst_ops.h @@ -16,6 +16,7 @@ struct dst_ops { int (*gc)(struct dst_ops *ops); struct dst_entry * (*check)(struct dst_entry *, __u32 cookie); + unsigned int (*default_advmss)(const struct dst_entry *); void (*destroy)(struct dst_entry *); void (*ifdown)(struct dst_entry *, struct net_device *dev, int how); |