Hi,
On Thursday 31 May 2007 02:21, Julian Anastasov wrote:
> > I've posted a few patches making omitting this check possible
> > selectively back in March. Do those changes look acceptable?
> >
> > http://marc.info/?l=linux-netdev&m=117310979823297&w=3
> Also, i'm not sure if FLOWI_FLAG_TRANSPARENT should cause
> different values for flags to be cached many times. Users without this
> flag get EINVAL when fl4_src is not configured, other failures are not
> cached too. And as fl4_src is considered in both cases (both kinds of
> callers get same path on success) we don't need changes except in
> ip_route_output_slow()? By this way I hope we can avoid any possible
> forking of cache entries just by different flags.
Indeed, for output it probably does not matter, I've removed the flags
check from the flow index compare routine.
> Then we can use some more generic name, only for the flowi flag,
> eg. FLOWI_FLAG_ANYSRC or something better?
You're right, _TRANSPARENT was a bad idea. I'm not very good at
choosing names.
So what about this one?
Loosen source address check on IPv4 output
From: KOVACS Krisztian <[EMAIL PROTECTED]>
ip_route_output() contains a check to make sure that no flows with
non-local source IP addresses are routed. This obviously makes using
such addresses impossible.
This patch introduces a flowi flag which makes omitting this check
possible. The new flag provides a way of handling transparent and
non-transparent connections differently.
Signed-off-by: KOVACS Krisztian <[EMAIL PROTECTED]>
---
include/net/flow.h | 1 +
net/ipv4/route.c | 47 +++++++++++++++++++++++++----------------------
2 files changed, 26 insertions(+), 22 deletions(-)
diff --git a/include/net/flow.h b/include/net/flow.h
index f3cc1f8..1bfc0dc 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -49,6 +49,7 @@ struct flowi {
__u8 proto;
__u8 flags;
#define FLOWI_FLAG_MULTIPATHOLDROUTE 0x01
+#define FLOWI_FLAG_ANYSRC 0x02
union {
struct {
__be16 sport;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 8603cfb..88d0a79 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2396,7 +2396,7 @@ static int ip_route_output_slow(struct rtable **rp, const
struct flowi *oldflp)
/* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
dev_out = ip_dev_find(oldflp->fl4_src);
- if (dev_out == NULL)
+ if (dev_out == NULL && !(oldflp->flags & FLOWI_FLAG_ANYSRC))
goto out;
/* I removed check for oif == dev_out->oif here.
@@ -2407,29 +2407,32 @@ static int ip_route_output_slow(struct rtable **rp,
const struct flowi *oldflp)
of another iface. --ANK
*/
- if (oldflp->oif == 0
- && (MULTICAST(oldflp->fl4_dst) || oldflp->fl4_dst ==
htonl(0xFFFFFFFF))) {
- /* Special hack: user can direct multicasts
- and limited broadcast via necessary interface
- without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
- This hack is not just for fun, it allows
- vic,vat and friends to work.
- They bind socket to loopback, set ttl to zero
- and expect that it will work.
- From the viewpoint of routing cache they are broken,
- because we are not allowed to build multicast path
- with loopback source addr (look, routing cache
- cannot know, that ttl is zero, so that packet
- will not leave this host and route is valid).
- Luckily, this hack is good workaround.
- */
+ if (dev_out) {
+ if (oldflp->oif == 0
+ && (MULTICAST(oldflp->fl4_dst)
+ || oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
+ /* Special hack: user can direct multicasts
+ and limited broadcast via necessary interface
+ without fiddling with IP_MULTICAST_IF or
IP_PKTINFO.
+ This hack is not just for fun, it allows
+ vic,vat and friends to work.
+ They bind socket to loopback, set ttl to zero
+ and expect that it will work.
+ From the viewpoint of routing cache they are
broken,
+ because we are not allowed to build
multicast path
+ with loopback source addr (look, routing
cache
+ cannot know, that ttl is zero, so that packet
+ will not leave this host and route is valid).
+ Luckily, this hack is good workaround.
+ */
+
+ fl.oif = dev_out->ifindex;
+ goto make_route;
+ }
- fl.oif = dev_out->ifindex;
- goto make_route;
- }
- if (dev_out)
dev_put(dev_out);
- dev_out = NULL;
+ dev_out = NULL;
+ }
}
-
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