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path: root/net/ipv4/route.c
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2012-12-07ipv4/route/rtnl: get mcast attributes when dst is multicastNicolas Dichtel
Commit f1ce3062c538 (ipv4: Remove 'rt_dst' from 'struct rtable') removes the call to ipmr_get_route(), which will get multicast parameters of the route. I revert the part of the patch that remove this call. I think the goal was only to get rid of rt_dst field. The patch is only compiled-tested. My first idea was to remove ipmr_get_route() because rt_fill_info() was the only user, but it seems the previous patch cleans the code a bit too much ;-) Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/wireless/iwlwifi/pcie/tx.c Minor iwlwifi conflict in TX queue disabling between 'net', which removed a bogus warning, and 'net-next' which added some status register poking code. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-22ipv4: do not cache looped multicastsJulian Anastasov
Starting from 3.6 we cache output routes for multicasts only when using route to 224/4. For local receivers we can set RTCF_LOCAL flag depending on the membership but in such case we use maddr and saddr which are not caching keys as before. Additionally, we can not use same place to cache routes that differ in RTCF_LOCAL flag value. Fix it by caching only RTCF_MULTICAST entries without RTCF_LOCAL (send-only, no loopback). As a side effect, we avoid unneeded lookup for fnhe when not caching because multicasts are not redirected and they do not learn PMTU. Thanks to Maxime Bizon for showing the caching problems in __mkroute_output for 3.6 kernels: different RTCF_LOCAL flag in cache can lead to wrong ip_mc_output or ip_output call and the visible problem is that traffic can not reach local receivers via loopback. Reported-by: Maxime Bizon <mbizon@freebox.fr> Tested-by: Maxime Bizon <mbizon@freebox.fr> Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-19net: Don't export sysctls to unprivileged usersEric W. Biederman
In preparation for supporting the creation of network namespaces by unprivileged users, modify all of the per net sysctl exports and refuse to allow them to unprivileged users. This makes it safe for unprivileged users in general to access per net sysctls, and allows sysctls to be exported to unprivileged users on an individual basis as they are deemed safe. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-13xfrm: Fix the gc threshold value for ipv4Steffen Klassert
The xfrm gc threshold value depends on ip_rt_max_size. This value was set to INT_MAX with the routing cache removal patch, so we start doing garbage collecting when we have INT_MAX/2 IPsec routes cached. Fix this by going back to the static threshold of 1024 routes. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2012-10-18ipv4: Fix flushing of cached routing informationsSteffen Klassert
Currently we can not flush cached pmtu/redirect informations via the ipv4_sysctl_rtcache_flush sysctl. We need to check the rt_genid of the old route and reset the nh exeption if the old route is expired when we bind a new route to a nh exeption. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-11ipv4: fix route mark sparse warningstephen hemminger
Sparse complains about RTA_MARK which is should be host order according to include file and usage in iproute. net/ipv4/route.c:2223:46: warning: incorrect type in argument 3 (different base types) net/ipv4/route.c:2223:46: expected restricted __be32 [usertype] value net/ipv4/route.c:2223:46: got unsigned int [unsigned] [usertype] flowic_mark Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-08ipv4: Add FLOWI_FLAG_KNOWN_NHJulian Anastasov
Add flag to request that output route should be returned with known rt_gateway, in case we want to use it as nexthop for neighbour resolving. The returned route can be cached as follows: - in NH exception: because the cached routes are not shared with other destinations - in FIB NH: when using gateway because all destinations for NH share same gateway As last option, to return rt_gateway!=0 we have to set DST_NOCACHE. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-08ipv4: introduce rt_uses_gatewayJulian Anastasov
Add new flag to remember when route is via gateway. We will use it to allow rt_gateway to contain address of directly connected host for the cases when DST_NOCACHE is used or when the NH exception caches per-destination route without DST_NOCACHE flag, i.e. when routes are not used for other destinations. By this way we force the neighbour resolving to work with the routed destination but we can use different address in the packet, feature needed for IPVS-DR where original packet for virtual IP is routed via route to real IP. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-08ipv4: make sure nh_pcpu_rth_output is always allocatedJulian Anastasov
Avoid checking nh_pcpu_rth_output in fast path, abort fib_info creation on alloc_percpu failure. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-08ipv4: fix sending of redirectsJulian Anastasov
After "Cache input routes in fib_info nexthops" (commit d2d68ba9fe) and "Elide fib_validate_source() completely when possible" (commit 7a9bc9b81a) we can not send ICMP redirects. It seems we should not cache the RTCF_DOREDIRECT flag in nh_rth_input because the same fib_info can be used for traffic that is not redirected, eg. from other input devices or from sources that are not in same subnet. As result, we have to disable the caching of RTCF_DOREDIRECT flag and to force source validation for the case when forwarding traffic to the input device. If traffic comes from directly connected source we allow redirection as it was done before both changes. Avoid setting RTCF_DOREDIRECT if IN_DEV_TX_REDIRECTS is disabled, this can avoid source address validation and to help caching the routes. After the change "Adjust semantics of rt->rt_gateway" (commit f8126f1d51) we should make sure our ICMP_REDIR_HOST messages contain daddr instead of 0.0.0.0 when target is directly connected. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-08ipv4: Don't report stale pmtu values to userspaceSteffen Klassert
We report cached pmtu values even if they are already expired. Change this to not report these values after they are expired and fix a race in the expire time calculation, as suggested by Eric Dumazet. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-08ipv4: Don't create nh exeption when the device mtu is smaller than the ↵Steffen Klassert
reported pmtu When a local tool like tracepath tries to send packets bigger than the device mtu, we create a nh exeption and set the pmtu to device mtu. The device mtu does not expire, so check if the device mtu is smaller than the reported pmtu and don't crerate a nh exeption in that case. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-08ipv4: Always invalidate or update the route on pmtu eventsSteffen Klassert
Some protocols, like IPsec still cache routes. So we need to invalidate the old route on pmtu events to avoid the reuse of stale routes. We also need to update the mtu and expire time of the route if we already use a nh exception route, otherwise we ignore newly learned pmtu values after the first expiration. With this patch we always invalidate or update the route on pmtu events. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/team/team.c drivers/net/usb/qmi_wwan.c net/batman-adv/bat_iv_ogm.c net/ipv4/fib_frontend.c net/ipv4/route.c net/l2tp/l2tp_netlink.c The team, fib_frontend, route, and l2tp_netlink conflicts were simply overlapping changes. qmi_wwan and bat_iv_ogm were of the "use HEAD" variety. With help from Antonio Quartulli. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-18netns: move net->ipv4.rt_genid to net->rt_genidNicolas Dichtel
This commit prepares the use of rt_genid by both IPv4 and IPv6. Initialization is left in IPv4 part. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-18net: rt_cache_flush() cleanupEric Dumazet
We dont use jhash anymore since route cache removal, so we can get rid of get_random_bytes() calls for rt_genid changes. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-18ipv4/route: arg delay is useless in rt_cache_flush()Nicolas Dichtel
Since route cache deletion (89aef8921bfbac22f), delay is no more used. Remove it. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-10netlink: Rename pid to portid to avoid confusionEric W. Biederman
It is a frequent mistake to confuse the netlink port identifier with a process identifier. Try to reduce this confusion by renaming fields that hold port identifiers portid instead of pid. I have carefully avoided changing the structures exported to userspace to avoid changing the userspace API. I have successfully built an allyesconfig kernel with this change. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-07net: rt_cache_flush() cleanupEric Dumazet
We dont use jhash anymore since route cache removal, so we can get rid of get_random_bytes() calls for rt_genid changes. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-07ipv4/route: arg delay is useless in rt_cache_flush()Nicolas Dichtel
Since route cache deletion (89aef8921bfbac22f), delay is no more used. Remove it. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-31ipv4: Minor logic clean-up in ipv4_mtuAlexander Duyck
In ipv4_mtu there is some logic where we are testing for a non-zero value and a timer expiration, then setting the value to zero, and then testing if the value is zero we set it to a value based on the dst. Instead of bothering with the extra steps it is easier to just cleanup the logic so that we set it to the dst based value if it is zero or if the timer has expired. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
2012-08-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Merge the 'net' tree to get the recent set of netfilter bug fixes in order to assist with some merge hassles Pablo is going to have to deal with for upcoming changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-30ipv4: must use rcu protection while calling fib_lookupEric Dumazet
Following lockdep splat was reported by Pavel Roskin : [ 1570.586223] =============================== [ 1570.586225] [ INFO: suspicious RCU usage. ] [ 1570.586228] 3.6.0-rc3-wl-main #98 Not tainted [ 1570.586229] ------------------------------- [ 1570.586231] /home/proski/src/linux/net/ipv4/route.c:645 suspicious rcu_dereference_check() usage! [ 1570.586233] [ 1570.586233] other info that might help us debug this: [ 1570.586233] [ 1570.586236] [ 1570.586236] rcu_scheduler_active = 1, debug_locks = 0 [ 1570.586238] 2 locks held by Chrome_IOThread/4467: [ 1570.586240] #0: (slock-AF_INET){+.-...}, at: [<ffffffff814f2c0c>] release_sock+0x2c/0xa0 [ 1570.586253] #1: (fnhe_lock){+.-...}, at: [<ffffffff815302fc>] update_or_create_fnhe+0x2c/0x270 [ 1570.586260] [ 1570.586260] stack backtrace: [ 1570.586263] Pid: 4467, comm: Chrome_IOThread Not tainted 3.6.0-rc3-wl-main #98 [ 1570.586265] Call Trace: [ 1570.586271] [<ffffffff810976ed>] lockdep_rcu_suspicious+0xfd/0x130 [ 1570.586275] [<ffffffff8153042c>] update_or_create_fnhe+0x15c/0x270 [ 1570.586278] [<ffffffff815305b3>] __ip_rt_update_pmtu+0x73/0xb0 [ 1570.586282] [<ffffffff81530619>] ip_rt_update_pmtu+0x29/0x90 [ 1570.586285] [<ffffffff815411dc>] inet_csk_update_pmtu+0x2c/0x80 [ 1570.586290] [<ffffffff81558d1e>] tcp_v4_mtu_reduced+0x2e/0xc0 [ 1570.586293] [<ffffffff81553bc4>] tcp_release_cb+0xa4/0xb0 [ 1570.586296] [<ffffffff814f2c35>] release_sock+0x55/0xa0 [ 1570.586300] [<ffffffff815442ef>] tcp_sendmsg+0x4af/0xf50 [ 1570.586305] [<ffffffff8156fc60>] inet_sendmsg+0x120/0x230 [ 1570.586308] [<ffffffff8156fb40>] ? inet_sk_rebuild_header+0x40/0x40 [ 1570.586312] [<ffffffff814f4bdd>] ? sock_update_classid+0xbd/0x3b0 [ 1570.586315] [<ffffffff814f4c50>] ? sock_update_classid+0x130/0x3b0 [ 1570.586320] [<ffffffff814ec435>] do_sock_write+0xc5/0xe0 [ 1570.586323] [<ffffffff814ec4a3>] sock_aio_write+0x53/0x80 [ 1570.586328] [<ffffffff8114bc83>] do_sync_write+0xa3/0xe0 [ 1570.586332] [<ffffffff8114c5a5>] vfs_write+0x165/0x180 [ 1570.586335] [<ffffffff8114c805>] sys_write+0x45/0x90 [ 1570.586340] [<ffffffff815d2722>] system_call_fastpath+0x16/0x1b Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Pavel Roskin <proski@gnu.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-24ipv4: take rt_uncached_lock only if neededEric Dumazet
Multicast traffic allocates dst with DST_NOCACHE, but dst is not inserted into rt_uncached_list. This slowdown multicast workloads on SMP because rt_uncached_lock is contended. Change the test before taking the lock to actually check the dst was inserted into rt_uncached_list. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-23ipv4: properly update pmtuEric Dumazet
Sylvain Munault reported following info : - TCP connection get "stuck" with data in send queue when doing "large" transfers ( like typing 'ps ax' on a ssh connection ) - Only happens on path where the PMTU is lower than the MTU of the interface - Is not present right after boot, it only appears 10-20min after boot or so. (and that's inside the _same_ TCP connection, it works fine at first and then in the same ssh session, it'll get stuck) - Definitely seems related to fragments somehow since I see a router sending ICMP message saying fragmentation is needed. - Exact same setup works fine with kernel 3.5.1 Problem happens when the 10 minutes (ip_rt_mtu_expires) expiration period is over. ip_rt_update_pmtu() calls dst_set_expires() to rearm a new expiration, but dst_set_expires() does nothing because dst.expires is already set. It seems we want to set the expires field to a new value, regardless of prior one. With help from Julian Anastasov. Reported-by: Sylvain Munaut <s.munaut@whatever-company.com> Signed-off-by: Eric Dumazet <edumazet@google.com> CC: Julian Anastasov <ja@ssi.bg> Tested-by: Sylvain Munaut <s.munaut@whatever-company.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2012-08-14ipv4: Cache local output routesYan, Zheng
Commit caacf05e5ad1abf causes big drop of UDP loop back performance. The cause of the regression is that we do not cache the local output routes. Each time we send a datagram from unconnected UDP socket, the kernel allocates a dst_entry and adds it to the rt_uncached_list. It creates lock contention on the rt_uncached_lock. Reported-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-09net: Loopback ifindex is constant nowPavel Emelyanov
As pointed out, there are places, that access net->loopback_dev->ifindex and after ifindex generation is made per-net this value becomes constant equals 1. So go ahead and introduce the LOOPBACK_IFINDEX constant and use it where appropriate. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-04ipv4: Introduce IN_DEV_NET_ROUTE_LOCALNETEric Dumazet
performance profiles show a high cost in the IN_DEV_ROUTE_LOCALNET() call done in ip_route_input_slow(), because of multiple dereferences, even if cache lines are clean and available in cpu caches. Since we already have the 'net' pointer, introduce IN_DEV_NET_ROUTE_LOCALNET() macro avoiding two dereferences (dev_net(in_dev->dev)) Also change the tests to use IN_DEV_NET_ROUTE_LOCALNET() only if saddr or/and daddr are loopback addresse. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-02ipv4: route.c cleanupEric Dumazet
Remove unused includes after IP cache removal Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-31ipv4: Properly purge netdev references on uncached routes.David S. Miller
When a device is unregistered, we have to purge all of the references to it that may exist in the entire system. If a route is uncached, we currently have no way of accomplishing this. So create a global list that is scanned when a network device goes down. This mirrors the logic in net/core/dst.c's dst_ifdown(). Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-31ipv4: Cache routes in nexthop exception entries.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-31ipv4: percpu nh_rth_output cacheEric Dumazet
Input path is mostly run under RCU and doesnt touch dst refcnt But output path on forwarding or UDP workloads hits badly dst refcount, and we have lot of false sharing, for example in ipv4_mtu() when reading rt->rt_pmtu Using a percpu cache for nh_rth_output gives a nice performance increase at a small cost. 24 udpflood test on my 24 cpu machine (dummy0 output device) (each process sends 1.000.000 udp frames, 24 processes are started) before : 5.24 s after : 2.06 s For reference, time on linux-3.5 : 6.60 s Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-31ipv4: Restore old dst_free() behavior.Eric Dumazet
commit 404e0a8b6a55 (net: ipv4: fix RCU races on dst refcounts) tried to solve a race but added a problem at device/fib dismantle time : We really want to call dst_free() as soon as possible, even if sockets still have dst in their cache. dst_release() calls in free_fib_info_rcu() are not welcomed. Root of the problem was that now we also cache output routes (in nh_rth_output), we must use call_rcu() instead of call_rcu_bh() in rt_free(), because output route lookups are done in process context. Based on feedback and initial patch from David Miller (adding another call_rcu_bh() call in fib, but it appears it was not the right fix) I left the inet_sk_rx_dst_set() helper and added __rcu attributes to nh_rth_output and nh_rth_input to better document what is going on in this code. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-30net: ipv4: fix RCU races on dst refcountsEric Dumazet
commit c6cffba4ffa2 (ipv4: Fix input route performance regression.) added various fatal races with dst refcounts. crashes happen on tcp workloads if routes are added/deleted at the same time. The dst_free() calls from free_fib_info_rcu() are clearly racy. We need instead regular dst refcounting (dst_release()) and make sure dst_release() is aware of RCU grace periods : Add DST_RCU_FREE flag so that dst_release() respects an RCU grace period before dst destruction for cached dst Introduce a new inet_sk_rx_dst_set() helper, using atomic_inc_not_zero() to make sure we dont increase a zero refcount (On a dst currently waiting an rcu grace period before destruction) rt_cache_route() must take a reference on the new cached route, and release it if was not able to install it. With this patch, my machines survive various benchmarks. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-26ipv4: Fix input route performance regression.David S. Miller
With the routing cache removal we lost the "noref" code paths on input, and this can kill some routing workloads. Reinstate the noref path when we hit a cached route in the FIB nexthops. With help from Eric Dumazet. Reported-by: Alexander Duyck <alexander.duyck@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-25ipv4: rt_cache_valid must check expired routesEric Dumazet
commit d2d68ba9fe8 (ipv4: Cache input routes in fib_info nexthops.) introduced rt_cache_valid() helper. It unfortunately doesn't check if route is expired before caching it. I noticed sk_setup_caps() was constantly called on a tcp workload. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-23ipv4: Change rt->rt_iif encoding.David S. Miller
On input packet processing, rt->rt_iif will be zero if we should use skb->dev->ifindex. Since we access rt->rt_iif consistently via inet_iif(), that is the only spot whose interpretation have to adjust. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-23ipv4: Prepare for change of rt->rt_iif encoding.David S. Miller
Use inet_iif() consistently, and for TCP record the input interface of cached RX dst in inet sock. rt->rt_iif is going to be encoded differently, so that we can legitimately cache input routes in the FIB info more aggressively. When the input interface is "use SKB device index" the rt->rt_iif will be set to zero. This forces us to move the TCP RX dst cache installation into the ipv4 specific code, and as well it should since doing the route caching for ipv6 is pointless at the moment since it is not inspected in the ipv6 input paths yet. Also, remove the unlikely on dst->obsolete, all ipv4 dsts have obsolete set to a non-zero value to force invocation of the check callback. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-23ipv4: Remove all RTCF_DIRECTSRC handliing.David S. Miller
The last and final kernel user, ICMP address replies, has been removed. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20ipv4: Kill rt->fiDavid S. Miller
It's not really needed. We only grabbed a reference to the fib_info for the sake of fib_info local metrics. However, fib_info objects are freed using RCU, as are therefore their private metrics (if any). We would have triggered a route cache flush if we eliminated a reference to a fib_info object in the routing tables. Therefore, any existing cached routes will first check and see that they have been invalidated before an errant reference to these metric values would occur. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20ipv4: Turn rt->rt_route_iif into rt->rt_is_input.David S. Miller
That is this value's only use, as a boolean to indicate whether a route is an input route or not. So implement it that way, using a u16 gap present in the struct already. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20ipv4: Kill rt->rt_oifDavid S. Miller
Never actually used. It was being set on output routes to the original OIF specified in the flow key used for the lookup. Adjust the only user, ipmr_rt_fib_lookup(), for greater correctness of the flowi4_oif and flowi4_iif values, thanks to feedback from Julian Anastasov. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20ipv4: Dirty less cache lines in route caching paths.David S. Miller
Don't bother incrementing dst->__use and setting dst->lastuse, they are completely pointless and just slow things down. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20ipv4: Kill FLOWI_FLAG_RT_NOCACHE and associated code.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20ipv4: Cache input routes in fib_info nexthops.David S. Miller
Caching input routes is slightly simpler than output routes, since we don't need to be concerned with nexthop exceptions. (locally destined, and routed packets, never trigger PMTU events or redirects that will be processed by us). However, we have to elide caching for the DIRECTSRC and non-zero itag cases. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20ipv4: Cache output routes in fib_info nexthops.David S. Miller
If we have an output route that lacks nexthop exceptions, we can cache it in the FIB info nexthop. Such routes will have DST_HOST cleared because such routes refer to a family of destinations, rather than just one. The sequence of the handling of exceptions during route lookup is adjusted to make the logic work properly. Before we allocate the route, we lookup the exception. Then we know if we will cache this route or not, and therefore whether DST_HOST should be set on the allocated route. Then we use DST_HOST to key off whether we should store the resulting route, during rt_set_nexthop(), in the FIB nexthop cache. With help from Eric Dumazet. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20ipv4: Kill routes during PMTU/redirect updates.David S. Miller
Mark them obsolete so there will be a re-lookup to fetch the FIB nexthop exception info. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20net: Document dst->obsolete better.David S. Miller
Add a big comment explaining how the field works, and use defines instead of magic constants for the values assigned to it. Suggested by Joe Perches. Signed-off-by: David S. Miller <davem@davemloft.net>