BMC/Intel-BMC/linux.git/net/ipv4/fib_trie.c, branch dev

ipv4: off-by-one in continuation handling in /proc/net/route

2015-08-14T04:16:29+00:00

When generating /proc/net/route we emit a header followed by a line for each route. When a short read is performed we will restart this process based on the open file descriptor. When calculating the start point we fail to take into account that the 0th entry is the header. This leads us to skip the first entry when doing a continuation read. This can be easily seen with the comparison below: while read l; do echo "$l"; done A cat /proc/net/route >B diff -bu A B | grep '^[+-]' On my example machine I have approximatly 10KB of route output. There we see the very first non-title element is lost in the while read case, and an entry around the 8K mark in the cat case: +wlan0 00000000 02021EAC 0003 0 0 400 00000000 0 0 0 -tun1 00C0AC0A 00000000 0001 0 0 950 00C0FFFF 0 0 0 Fix up the off-by-one when reaquiring position on continuation. Fixes: 8be33e955cb9 ("fib_trie: Fib walk rcu should take a tnode and key instead of a trie and a leaf") BugLink: http://bugs.launchpad.net/bugs/1483440 Acked-by: Alexander Duyck Signed-off-by: Andy Whitcroft Signed-off-by: David S. Miller

fib_trie: Drop unnecessary calls to leaf_pull_suffix

2015-07-27T21:29:11+00:00

It was reported that update_suffix was taking a long time on systems where a large number of leaves were attached to a single node. As it turns out fib_table_flush was calling update_suffix for each leaf that didn't have all of the aliases stripped from it. As a result, on this large node removing one leaf would result in us calling update_suffix for every other leaf on the node. The fix is to just remove the calls to leaf_pull_suffix since they are redundant as we already have a call in resize that will go through and update the suffix length for the node before we exit out of fib_table_flush or fib_table_flush_external. Reported-by: David Ahern Signed-off-by: Alexander Duyck Tested-by: David Ahern Signed-off-by: David S. Miller

ipv4: consider TOS in fib_select_default

2015-07-25T05:46:11+00:00

fib_select_default considers alternative routes only when res->fi is for the first alias in res->fa_head. In the common case this can happen only when the initial lookup matches the first alias with highest TOS value. This prevents the alternative routes to require specific TOS. This patch solves the problem as follows: - routes that require specific TOS should be returned by fib_select_default only when TOS matches, as already done in fib_table_lookup. This rule implies that depending on the TOS we can have many different lists of alternative gateways and we have to keep the last used gateway (fa_default) in first alias for the TOS instead of using single tb_default value. - as the aliases are ordered by many keys (TOS desc, fib_priority asc), we restrict the possible results to routes with matching TOS and lowest metric (fib_priority) and routes that match any TOS, again with lowest metric. For example, packet with TOS 8 can not use gw3 (not lowest metric), gw4 (different TOS) and gw6 (not lowest metric), all other gateways can be used: tos 8 via gw1 metric 2 <--- res->fa_head and res->fi tos 8 via gw2 metric 2 tos 8 via gw3 metric 3 tos 4 via gw4 tos 0 via gw5 tos 0 via gw6 metric 1 Reported-by: Hagen Paul Pfeifer Signed-off-by: Julian Anastasov Signed-off-by: David S. Miller

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

2015-06-24T09:15:54+00:00

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: include NLM_F_APPEND flag in append route notifications

2015-06-21T17:23:04+00:00

This patch adds NLM_F_APPEND flag to struct nlmsg_hdr->nlmsg_flags in newroute notifications if the route add was an append. (This is similar to how NLM_F_REPLACE is already part of new route replace notifications today) This helps userspace determine if the route add operation was an append. Signed-off-by: Roopa Prabhu Acked-by: Scott Feldman Signed-off-by: David S. Miller

fib_trie: coding style: Use pointer after check

2015-06-08T06:45:40+00:00

As Alexander Duyck pointed out that: struct tnode { ... struct key_vector kv[1]; } The kv[1] member of struct tnode is an arry that refernced by a null pointer will not crash the system, like this: struct tnode *p = NULL; struct key_vector *kv = p->kv; As such p->kv doesn't actually dereference anything, it is simply a means for getting the offset to the array from the pointer p. This patch make the code more regular to avoid making people feel odd when they look at the code. Signed-off-by: Firo Yang Signed-off-by: David S. Miller

ipv4: Fix fib_trie.c build, missing linux/vmalloc.h include.

2015-05-27T04:19:03+00:00

We used to get this indirectly I supposed, but no longer do. Either way, an explicit include should have been done in the first place. net/ipv4/fib_trie.c: In function '__node_free_rcu': >> net/ipv4/fib_trie.c:293:3: error: implicit declaration of function 'vfree' [-Werror=implicit-function-declaration] vfree(n); ^ net/ipv4/fib_trie.c: In function 'tnode_alloc': >> net/ipv4/fib_trie.c:312:3: error: implicit declaration of function 'vzalloc' [-Werror=implicit-function-declaration] return vzalloc(size); ^ >> net/ipv4/fib_trie.c:312:3: warning: return makes pointer from integer without a cast cc1: some warnings being treated as errors Reported-by: kbuild test robot Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2015-05-23T05:22:35+00:00

Conflicts: drivers/net/ethernet/cadence/macb.c drivers/net/phy/phy.c include/linux/skbuff.h net/ipv4/tcp.c net/switchdev/switchdev.c Switchdev was a case of RTNH_H_{EXTERNAL --> OFFLOAD} renaming overlapping with net-next changes of various sorts. phy.c was a case of two changes, one adding a local variable to a function whilst the second was removing one. tcp.c overlapped a deadlock fix with the addition of new tcp_info statistic values. macb.c involved the addition of two zyncq device entries. skbuff.h involved adding back ipv4_daddr to nf_bridge_info whilst net-next changes put two other existing members of that struct into a union. Signed-off-by: David S. Miller

ipv4: fill in table id when replacing a route

2015-05-22T18:33:17+00:00

When replacing an IPv4 route, tb_id member of the new fib_alias structure is not set in the replace code path so that the new route is ignored. Fixes: 0ddcf43d5d4a ("ipv4: FIB Local/MAIN table collapse") Signed-off-by: Michal Kubecek Acked-by: Alexander Duyck Signed-off-by: David S. Miller

rename RTNH_F_EXTERNAL to RTNH_F_OFFLOAD

2015-05-15T02:45:39+00:00

RTNH_F_EXTERNAL today is printed as "offload" in iproute2 output. This patch renames the flag to be consistent with what the user sees. Signed-off-by: Roopa Prabhu Signed-off-by: David S. Miller