user/sven/linux.git/net/ipv4/fib_rules.c, branch leds/master

net: ipv4 sysctl option to ignore routes when nexthop link is down

2015-06-24T09:15:54Z

This feature is only enabled with the new per-interface or ipv4 global sysctls called 'ignore_routes_with_linkdown'. net.ipv4.conf.all.ignore_routes_with_linkdown = 0 net.ipv4.conf.default.ignore_routes_with_linkdown = 0 net.ipv4.conf.lo.ignore_routes_with_linkdown = 0 ... When the above sysctls are set, will report to userspace that a route is dead and will no longer resolve to this nexthop when performing a fib lookup. This will signal to userspace that the route will not be selected. The signalling of a RTNH_F_DEAD is only passed to userspace if the sysctl is enabled and link is down. This was done as without it the netlink listeners would have no idea whether or not a nexthop would be selected. The kernel only sets RTNH_F_DEAD internally if the interface has IFF_UP cleared. With the new sysctl set, the following behavior can be observed (interface p8p1 is link-down): default via 10.0.5.2 dev p9p1 10.0.5.0/24 dev p9p1 proto kernel scope link src 10.0.5.15 70.0.0.0/24 dev p7p1 proto kernel scope link src 70.0.0.1 80.0.0.0/24 dev p8p1 proto kernel scope link src 80.0.0.1 dead linkdown 90.0.0.0/24 via 80.0.0.2 dev p8p1 metric 1 dead linkdown 90.0.0.0/24 via 70.0.0.2 dev p7p1 metric 2 90.0.0.1 via 70.0.0.2 dev p7p1 src 70.0.0.1 cache local 80.0.0.1 dev lo src 80.0.0.1 cache 80.0.0.2 via 10.0.5.2 dev p9p1 src 10.0.5.15 cache While the route does remain in the table (so it can be modified if needed rather than being wiped away as it would be if IFF_UP was cleared), the proper next-hop is chosen automatically when the link is down. Now interface p8p1 is linked-up: default via 10.0.5.2 dev p9p1 10.0.5.0/24 dev p9p1 proto kernel scope link src 10.0.5.15 70.0.0.0/24 dev p7p1 proto kernel scope link src 70.0.0.1 80.0.0.0/24 dev p8p1 proto kernel scope link src 80.0.0.1 90.0.0.0/24 via 80.0.0.2 dev p8p1 metric 1 90.0.0.0/24 via 70.0.0.2 dev p7p1 metric 2 192.168.56.0/24 dev p2p1 proto kernel scope link src 192.168.56.2 90.0.0.1 via 80.0.0.2 dev p8p1 src 80.0.0.1 cache local 80.0.0.1 dev lo src 80.0.0.1 cache 80.0.0.2 dev p8p1 src 80.0.0.1 cache and the output changes to what one would expect. If the sysctl is not set, the following output would be expected when p8p1 is down: default via 10.0.5.2 dev p9p1 10.0.5.0/24 dev p9p1 proto kernel scope link src 10.0.5.15 70.0.0.0/24 dev p7p1 proto kernel scope link src 70.0.0.1 80.0.0.0/24 dev p8p1 proto kernel scope link src 80.0.0.1 linkdown 90.0.0.0/24 via 80.0.0.2 dev p8p1 metric 1 linkdown 90.0.0.0/24 via 70.0.0.2 dev p7p1 metric 2 Since the dead flag does not appear, there should be no expectation that the kernel would skip using this route due to link being down. v2: Split kernel changes into 2 patches, this actually makes a behavioral change if the sysctl is set. Also took suggestion from Alex to simplify code by only checking sysctl during fib lookup and suggestion from Scott to add a per-interface sysctl. v3: Code clean-ups to make it more readable and efficient as well as a reverse path check fix. v4: Drop binary sysctl v5: Whitespace fixups from Dave v6: Style changes from Dave and checkpatch suggestions v7: One more checkpatch fixup Signed-off-by: Andy Gospodarek Signed-off-by: Dinesh Dutt Acked-by: Scott Feldman Signed-off-by: David S. Miller

ipv4: coding style: comparison for equality with NULL

2015-04-03T16:11:15Z

The ipv4 code uses a mixture of coding styles. In some instances check for NULL pointer is done as x == NULL and sometimes as !x. !x is preferred according to checkpatch and this patch makes the code consistent by adopting the latter form. No changes detected by objdiff. Signed-off-by: Ian Morris Signed-off-by: David S. Miller

netlink: implement nla_get_in_addr and nla_get_in6_addr

2015-03-31T17:58:35Z

Those are counterparts to nla_put_in_addr and nla_put_in6_addr. Signed-off-by: Jiri Benc Signed-off-by: David S. Miller

netlink: implement nla_put_in_addr and nla_put_in6_addr

2015-03-31T17:58:35Z

IP addresses are often stored in netlink attributes. Add generic functions to do that. For nla_put_in_addr, it would be nicer to pass struct in_addr but this is not used universally throughout the kernel, in way too many places __be32 is used to store IPv4 address. Signed-off-by: Jiri Benc Signed-off-by: David S. Miller

ipv4: FIB Local/MAIN table collapse

2015-03-11T20:22:14Z

This patch is meant to collapse local and main into one by converting tb_data from an array to a pointer. Doing this allows us to point the local table into the main while maintaining the same variables in the table. As such the tb_data was converted from an array to a pointer, and a new array called data is added in order to still provide an object for tb_data to point to. In order to track the origin of the fib aliases a tb_id value was added in a hole that existed on 64b systems. Using this we can also reverse the merge in the event that custom FIB rules are enabled. With this patch I am seeing an improvement of 20ns to 30ns for routing lookups as long as custom rules are not enabled, with custom rules enabled we fall back to split tables and the original behavior. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller

switchdev: don't support custom ip rules, for now

2015-03-06T05:24:58Z

Keep switchdev FIB offload model simple for now and don't allow custom ip rules. Signed-off-by: Scott Feldman Signed-off-by: David S. Miller

fib_trie: Push rcu_read_lock/unlock to callers

2014-12-31T23:25:54Z

This change is to start cleaning up some of the rcu_read_lock/unlock handling. I realized while reviewing the code there are several spots that I don't believe are being handled correctly or are masking warnings by locally calling rcu_read_lock/unlock instead of calling them at the correct level. A common example is a call to fib_get_table followed by fib_table_lookup. The rcu_read_lock/unlock ought to wrap both but there are several spots where they were not wrapped. Signed-off-by: Alexander Duyck Signed-off-by: David S. Miller

ipv4: Fix incorrect error code when adding an unreachable route

2014-11-16T19:11:45Z

Trying to add an unreachable route incorrectly returns -ESRCH if if custom FIB rules are present: [root@localhost ~]# ip route add 74.125.31.199 dev eth0 via 1.2.3.4 RTNETLINK answers: Network is unreachable [root@localhost ~]# ip rule add to 55.66.77.88 table 200 [root@localhost ~]# ip route add 74.125.31.199 dev eth0 via 1.2.3.4 RTNETLINK answers: No such process [root@localhost ~]# Commit 83886b6b636173b206f475929e58fac75c6f2446 ("[NET]: Change "not found" return value for rule lookup") changed fib_rules_lookup() to use -ESRCH as a "not found" code internally, but for user space it should be translated into -ENETUNREACH. Handle the translation centrally in ipv4-specific fib_lookup(), leaving the DECnet case alone. On a related note, commit b7a71b51ee37d919e4098cd961d59a883fd272d8 ("ipv4: removed redundant conditional") removed a similar translation from ip_route_input_slow() prematurely AIUI. Fixes: b7a71b51ee37 ("ipv4: removed redundant conditional") Signed-off-by: Panu Matilainen Signed-off-by: David S. Miller

inet: fix NULL pointer Oops in fib(6)_rule_suppress

2013-12-10T22:54:23Z

This changes ensures that the routing entry investigated by the suppress function actually does point to a device struct before following that pointer, fixing a possible kernel oops situation when verifying the interface group associated with a routing table entry. According to Daniel Golle, this Oops can be triggered by a user process trying to establish an outgoing IPv6 connection while having no real IPv6 connectivity set up (only autoassigned link-local addresses). Fixes: 6ef94cfafba15 ("fib_rules: add route suppression based on ifgroup") Reported-by: Daniel Golle Tested-by: Daniel Golle Signed-off-by: Stefan Tomanek Signed-off-by: David S. Miller

fib_rules: fix suppressor names and default values

2013-08-03T17:40:23Z

This change brings the suppressor attribute names into line; it also changes the data types to provide a more consistent interface. While -1 indicates that the suppressor is not enabled, values >= 0 for suppress_prefixlen or suppress_ifgroup reject routing decisions violating the constraint. This changes the previously presented behaviour of suppress_prefixlen, where a prefix length _less_ than the attribute value was rejected. After this change, a prefix length less than *or* equal to the value is considered a violation of the rule constraint. It also changes the default values for default and newly added rules (disabling any suppression for those). Signed-off-by: Stefan Tomanek Signed-off-by: David S. Miller