linux/include/net/ip_fib.h, branch v5.0

net: ipv4: Fix memory leak in network namespace dismantle

2019-01-15T21:33:44Z

IPv4 routing tables are flushed in two cases: 1. In response to events in the netdev and inetaddr notification chains 2. When a network namespace is being dismantled In both cases only routes associated with a dead nexthop group are flushed. However, a nexthop group will only be marked as dead in case it is populated with actual nexthops using a nexthop device. This is not the case when the route in question is an error route (e.g., 'blackhole', 'unreachable'). Therefore, when a network namespace is being dismantled such routes are not flushed and leaked [1]. To reproduce: # ip netns add blue # ip -n blue route add unreachable 192.0.2.0/24 # ip netns del blue Fix this by not skipping error routes that are not marked with RTNH_F_DEAD when flushing the routing tables. To prevent the flushing of such routes in case #1, add a parameter to fib_table_flush() that indicates if the table is flushed as part of namespace dismantle or not. Note that this problem does not exist in IPv6 since error routes are associated with the loopback device. [1] unreferenced object 0xffff888066650338 (size 56): comm "ip", pid 1206, jiffies 4294786063 (age 26.235s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 b0 1c 62 61 80 88 ff ff ..........ba.... e8 8b a1 64 80 88 ff ff 00 07 00 08 fe 00 00 00 ...d............ backtrace: [<00000000856ed27d>] inet_rtm_newroute+0x129/0x220 [<00000000fcdfc00a>] rtnetlink_rcv_msg+0x397/0xa20 [<00000000cb85801a>] netlink_rcv_skb+0x132/0x380 [<00000000ebc991d2>] netlink_unicast+0x4c0/0x690 [<0000000014f62875>] netlink_sendmsg+0x929/0xe10 [<00000000bac9d967>] sock_sendmsg+0xc8/0x110 [<00000000223e6485>] ___sys_sendmsg+0x77a/0x8f0 [<000000002e94f880>] __sys_sendmsg+0xf7/0x250 [<00000000ccb1fa72>] do_syscall_64+0x14d/0x610 [<00000000ffbe3dae>] entry_SYSCALL_64_after_hwframe+0x49/0xbe [<000000003a8b605b>] 0xffffffffffffffff unreferenced object 0xffff888061621c88 (size 48): comm "ip", pid 1206, jiffies 4294786063 (age 26.235s) hex dump (first 32 bytes): 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk 6b 6b 6b 6b 6b 6b 6b 6b d8 8e 26 5f 80 88 ff ff kkkkkkkk..&_.... backtrace: [<00000000733609e3>] fib_table_insert+0x978/0x1500 [<00000000856ed27d>] inet_rtm_newroute+0x129/0x220 [<00000000fcdfc00a>] rtnetlink_rcv_msg+0x397/0xa20 [<00000000cb85801a>] netlink_rcv_skb+0x132/0x380 [<00000000ebc991d2>] netlink_unicast+0x4c0/0x690 [<0000000014f62875>] netlink_sendmsg+0x929/0xe10 [<00000000bac9d967>] sock_sendmsg+0xc8/0x110 [<00000000223e6485>] ___sys_sendmsg+0x77a/0x8f0 [<000000002e94f880>] __sys_sendmsg+0xf7/0x250 [<00000000ccb1fa72>] do_syscall_64+0x14d/0x610 [<00000000ffbe3dae>] entry_SYSCALL_64_after_hwframe+0x49/0xbe [<000000003a8b605b>] 0xffffffffffffffff Fixes: 8cced9eff1d4 ("[NETNS]: Enable routing configuration in non-initial namespace.") Signed-off-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller

net: Don't return invalid table id error when dumping all families

2018-10-24T21:06:25Z

When doing a route dump across all address families, do not error out if the table does not exist. This allows a route dump for AF_UNSPEC with a table id that may only exist for some of the families. Do return the table does not exist error if dumping routes for a specific family and the table does not exist. Signed-off-by: David Ahern Signed-off-by: David S. Miller

net: Enable kernel side filtering of route dumps

2018-10-16T07:14:07Z

Update parsing of route dump request to enable kernel side filtering. Allow filtering results by protocol (e.g., which routing daemon installed the route), route type (e.g., unicast), table id and nexthop device. These amount to the low hanging fruit, yet a huge improvement, for dumping routes. ip_valid_fib_dump_req is called with RTNL held, so __dev_get_by_index can be used to look up the device index without taking a reference. From there filter->dev is only used during dump loops with the lock still held. Set NLM_F_DUMP_FILTERED in the answer_flags so the user knows the results have been filtered should no entries be returned. Signed-off-by: David Ahern Signed-off-by: David S. Miller

net/ipv4: Plumb support for filtering route dumps

2018-10-16T07:13:12Z

Implement kernel side filtering of routes by table id, egress device index, protocol and route type. If the table id is given in the filter, lookup the table and call fib_table_dump directly for it. Signed-off-by: David Ahern Signed-off-by: David S. Miller

net: Add struct for fib dump filter

2018-10-16T07:13:12Z

Add struct fib_dump_filter for options on limiting which routes are returned in a dump request. The current list is table id, protocol, route type, rtm_flags and nexthop device index. struct net is needed to lookup the net_device from the index. Declare the filter for each route dump handler and plumb the new arguments from dump handlers to ip_valid_fib_dump_req. Signed-off-by: David Ahern Signed-off-by: David S. Miller

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

2018-10-13T04:38:46Z

Conflicts were easy to resolve using immediate context mostly, except the cls_u32.c one where I simply too the entire HEAD chunk. Signed-off-by: David S. Miller

net: ipv4: update fnhe_pmtu when first hop's MTU changes

2018-10-11T05:44:46Z

Since commit 5aad1de5ea2c ("ipv4: use separate genid for next hop exceptions"), exceptions get deprecated separately from cached routes. In particular, administrative changes don't clear PMTU anymore. As Stefano described in commit e9fa1495d738 ("ipv6: Reflect MTU changes on PMTU of exceptions for MTU-less routes"), the PMTU discovered before the local MTU change can become stale: - if the local MTU is now lower than the PMTU, that PMTU is now incorrect - if the local MTU was the lowest value in the path, and is increased, we might discover a higher PMTU Similarly to what commit e9fa1495d738 did for IPv6, update PMTU in those cases. If the exception was locked, the discovered PMTU was smaller than the minimal accepted PMTU. In that case, if the new local MTU is smaller than the current PMTU, let PMTU discovery figure out if locking of the exception is still needed. To do this, we need to know the old link MTU in the NETDEV_CHANGEMTU notifier. By the time the notifier is called, dev->mtu has been changed. This patch adds the old MTU as additional information in the notifier structure, and a new call_netdevice_notifiers_u32() function. Fixes: 5aad1de5ea2c ("ipv4: use separate genid for next hop exceptions") Signed-off-by: Sabrina Dubroca Reviewed-by: Stefano Brivio Reviewed-by: David Ahern Signed-off-by: David S. Miller

rtnetlink: Update fib dumps for strict data checking

2018-10-08T17:39:05Z

Add helper to check netlink message for route dumps. If the strict flag is set the dump request is expected to have an rtmsg struct as the header. All elements of the struct are expected to be 0 with the exception of rtm_flags (which is used by both ipv4 and ipv6 dumps) and no attributes can be appended. rtm_flags can only have RTM_F_CLONED and RTM_F_PREFIX set. Update inet_dump_fib, inet6_dump_fib, mpls_dump_routes, ipmr_rtm_dumproute, and ip6mr_rtm_dumproute to call this helper if strict data checking is enabled. Signed-off-by: David Ahern Signed-off-by: David S. Miller

net/ipv4: Move device validation to helper

2018-09-21T03:01:52Z

Move the device matching check in __fib_validate_source to a helper and export it for use by netfilter modules. Code move only; no functional change intended. Signed-off-by: David Ahern Signed-off-by: David S. Miller

net/ipv4: Add helper to return path MTU based on fib result

2018-05-22T08:51:09Z

Determine path MTU from a FIB lookup result. Logic is a distillation of ip_dst_mtu_maybe_forward. Signed-off-by: David Ahern Signed-off-by: Daniel Borkmann