kernel/linux.git/include/net/nexthop.h, branch v5.6.11

net: Properly update v4 routes with v6 nexthop

2019-09-05T10:35:58+00:00

When creating a v4 route that uses a v6 nexthop from a nexthop group. Allow the kernel to properly send the nexthop as v6 via the RTA_VIA attribute. Broken behavior: $ ip nexthop add via fe80::9 dev eth0 $ ip nexthop show id 1 via fe80::9 dev eth0 scope link $ ip route add 4.5.6.7/32 nhid 1 $ ip route show default via 10.0.2.2 dev eth0 4.5.6.7 nhid 1 via 254.128.0.0 dev eth0 10.0.2.0/24 dev eth0 proto kernel scope link src 10.0.2.15 $ Fixed behavior: $ ip nexthop add via fe80::9 dev eth0 $ ip nexthop show id 1 via fe80::9 dev eth0 scope link $ ip route add 4.5.6.7/32 nhid 1 $ ip route show default via 10.0.2.2 dev eth0 4.5.6.7 nhid 1 via inet6 fe80::9 dev eth0 10.0.2.0/24 dev eth0 proto kernel scope link src 10.0.2.15 $ v2, v3: Addresses code review comments from David Ahern Fixes: dcb1ecb50edf (“ipv4: Prepare for fib6_nh from a nexthop object”) Signed-off-by: Donald Sharp Reviewed-by: David Ahern Signed-off-by: David S. Miller

nexthop: Fix nexthop_num_path for blackhole nexthops

2019-08-25T21:29:10+00:00

Donald reported this sequence: ip next add id 1 blackhole ip next add id 2 blackhole ip ro add 1.1.1.1/32 nhid 1 ip ro add 1.1.1.2/32 nhid 2 would cause a crash. Backtrace is: [ 151.302790] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 151.304043] CPU: 1 PID: 277 Comm: ip Not tainted 5.3.0-rc5+ #37 [ 151.305078] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/2014 [ 151.306526] RIP: 0010:fib_add_nexthop+0x8b/0x2aa [ 151.307343] Code: 35 f7 81 48 8d 14 01 c7 02 f1 f1 f1 f1 c7 42 04 01 f4 f4 f4 48 89 f2 48 c1 ea 03 65 48 8b 0c 25 28 00 00 00 48 89 4d d0 31 c9 <80> 3c 02 00 74 08 48 89 f7 e8 1a e8 53 ff be 08 00 00 00 4c 89 e7 [ 151.310549] RSP: 0018:ffff888116c27340 EFLAGS: 00010246 [ 151.311469] RAX: dffffc0000000000 RBX: ffff8881154ece00 RCX: 0000000000000000 [ 151.312713] RDX: 0000000000000004 RSI: 0000000000000020 RDI: ffff888115649b40 [ 151.313968] RBP: ffff888116c273d8 R08: ffffed10221e3757 R09: ffff888110f1bab8 [ 151.315212] R10: 0000000000000001 R11: ffff888110f1bab3 R12: ffff888115649b40 [ 151.316456] R13: 0000000000000020 R14: ffff888116c273b0 R15: ffff888115649b40 [ 151.317707] FS: 00007f60b4d8d800(0000) GS:ffff88811ac00000(0000) knlGS:0000000000000000 [ 151.319113] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 151.320119] CR2: 0000555671ffdc00 CR3: 00000001136ba005 CR4: 0000000000020ee0 [ 151.321367] Call Trace: [ 151.321820] ? fib_nexthop_info+0x635/0x635 [ 151.322572] fib_dump_info+0xaa4/0xde0 [ 151.323247] ? fib_create_info+0x2431/0x2431 [ 151.324008] ? napi_alloc_frag+0x2a/0x2a [ 151.324711] rtmsg_fib+0x2c4/0x3be [ 151.325339] fib_table_insert+0xe2f/0xeee ... fib_dump_info incorrectly has nhs = 0 for blackhole nexthops, so it believes the nexthop object is a multipath group (nhs != 1) and ends up down the nexthop_mpath_fill_node() path which is wrong for a blackhole. The blackhole check in nexthop_num_path is leftover from early days of the blackhole implementation which did not initialize the device. In the end the design was simpler (fewer special case checks) to set the device to loopback in nh_info, so the check in nexthop_num_path should have been removed. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Reported-by: Donald Sharp Signed-off-by: David Ahern Signed-off-by: David S. Miller

nexthops: Add ipv6 helper to walk all fib6_nh in a nexthop struct

2019-06-10T17:44:56+00:00

IPv6 has traditionally had a single fib6_nh per fib6_info. With nexthops we can have multiple fib6_nh associated with a fib6_info. Add a nexthop helper to invoke a callback for each fib6_nh in a 'struct nexthop'. If the callback returns non-0, the loop is stopped and the return value passed to the caller. Signed-off-by: David Ahern Signed-off-by: David S. Miller

nexthop: off by one in nexthop_mpath_select()

2019-06-09T20:37:25+00:00

The nhg->nh_entries[] array is allocated in nexthop_grp_alloc() and it has nhg->num_nh elements so this check should be >= instead of >. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: Dan Carpenter Reviewed-by: David Ahern Signed-off-by: David S. Miller

ipv6: Plumb support for nexthop object in a fib6_info

2019-06-05T02:26:50+00:00

Add struct nexthop and nh_list list_head to fib6_info. nh_list is the fib6_info side of the nexthop <-> fib_info relationship. Since a fib6_info referencing a nexthop object can not have 'sibling' entries (the old way of doing multipath routes), the nh_list is a union with fib6_siblings. Add f6i_list list_head to 'struct nexthop' to track fib6_info entries using a nexthop instance. Update __remove_nexthop_fib to walk f6_list and delete fib entries using the nexthop. Add a few nexthop helpers for use when a nexthop is added to fib6_info: - nexthop_fib6_nh - return first fib6_nh in a nexthop object - fib6_info_nh_dev moved to nexthop.h and updated to use nexthop_fib6_nh if the fib6_info references a nexthop object - nexthop_path_fib6_result - similar to ipv4, select a path within a multipath nexthop object. If the nexthop is a blackhole, set fib6_result type to RTN_BLACKHOLE, and set the REJECT flag Update the fib6_info references to check for nh and take a different path as needed: - rt6_qualify_for_ecmp - if a fib entry uses a nexthop object it can NOT be coalesced with other fib entries into a multipath route - rt6_duplicate_nexthop - use nexthop_cmp if either fib6_info references a nexthop - addrconf (host routes), RA's and info entries (anything configured via ndisc) does not use nexthop objects - fib6_info_destroy_rcu - put reference to nexthop object - fib6_purge_rt - drop fib6_info from f6i_list - fib6_select_path - update to use the new nexthop_path_fib6_result when fib entry uses a nexthop object - rt6_device_match - update to catch use of nexthop object as a blackhole and set fib6_type and flags. - ip6_route_info_create - don't add space for fib6_nh if fib entry is going to reference a nexthop object, take a reference to nexthop object, disallow use of source routing - rt6_nlmsg_size - add space for RTA_NH_ID - add rt6_fill_node_nexthop to add nexthop data on a dump As with ipv4, most of the changes push existing code into the else branch of whether the fib entry uses a nexthop object. Update the nexthop code to walk f6i_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern Signed-off-by: David S. Miller

ipv4: Plumb support for nexthop object in a fib_info

2019-06-05T02:26:49+00:00

Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the fib_info side of the nexthop <-> fib_info relationship. Add fi_list list_head to 'struct nexthop' to track fib_info entries using a nexthop instance. Add __remove_nexthop_fib and add it to __remove_nexthop to walk the new list_head and mark those fib entries as dead when the nexthop is deleted. Add a few nexthop helpers for use when a nexthop is added to fib_info: - nexthop_cmp to determine if 2 nexthops are the same - nexthop_path_fib_result to select a path for a multipath 'struct nexthop' - nexthop_fib_nhc to select a specific fib_nh_common within a multipath 'struct nexthop' Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop case. Update the fib_info functions to check for fi->nh and take a different path as needed: - free_fib_info_rcu - put the nexthop object reference - fib_release_info - remove the fib_info from the nexthop's fi_list - nh_comp - use nexthop_cmp when either fib_info references a nexthop object - fib_info_hashfn - use the nexthop id for the hashing vs the oif of each fib_nh in a fib_info - fib_nlmsg_size - add space for the RTA_NH_ID attribute - fib_create_info - verify nexthop reference can be taken, verify nexthop spec is valid for fib entry, and add fib_info to fi_list for a nexthop - fib_select_multipath - use the new nexthop_path_fib_result to select a path when nexthop objects are used - fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat it the same as a fib entry using 'blackhole' The bulk of the changes are in fib_semantics.c and most of that is moving the existing change_nexthops into an else branch. Update the nexthop code to walk fi_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern Signed-off-by: David S. Miller

ipv4: Use accessors for fib_info nexthop data

2019-06-05T02:26:49+00:00

Use helpers to access fib_nh and fib_nhs fields of a fib_info. Drop the fib_dev macro which is an alias for the first nexthop. Replacements: fi->fib_dev --> fib_info_nh(fi, 0)->fib_nh_dev fi->fib_nh --> fib_info_nh(fi, 0) fi->fib_nh[i] --> fib_info_nh(fi, i) fi->fib_nhs --> fib_info_num_path(fi) where fib_info_nh(fi, i) returns fi->fib_nh[nhsel] and fib_info_num_path returns fi->fib_nhs. Move the existing fib_info_nhc to nexthop.h and define the new ones there. A later patch adds a check if a fib_info uses a nexthop object, and defining the helpers in nexthop.h avoid circular header dependencies. After this all remaining open coded references to fi->fib_nhs and fi->fib_nh are in: - fib_create_info and helpers used to lookup an existing fib_info entry, and - the netdev event functions fib_sync_down_dev and fib_sync_up. The latter two will not be reused for nexthops, and the fib_create_info will be updated to handle a nexthop in a fib_info. Signed-off-by: David Ahern Signed-off-by: David S. Miller

nexthop: Add support for nexthop groups

2019-05-29T04:37:30+00:00

Allow the creation of nexthop groups which reference other nexthop objects to create multipath routes: +--------------+ +------------+ +--------------+ | | nh nh_grp --->| nh_grp_entry |-+ +------------+ +---------|----+ ^ | | +------------+ +----------------+ +--->| nh, weight | nh_parent +------------+ A group entry points to a nexthop with a weight for that hop within the group. The nexthop has a list_head, grp_list, for tracking which groups it is a member of and the group entry has a reference back to the parent. The grp_list is used when a nexthop is deleted - to efficiently remove it from groups using it. If a nexthop group spec is given, no other attributes can be set. Each nexthop id in a group spec must already exist. Similar to single nexthops, the specification of a nexthop group can be updated so that data is managed with rcu locking. Add path selection function to account for multiple paths and add ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is in a good state. Update NETDEV event handling to rebalance multipath nexthop groups if a nexthop is deleted due to a link event (down or unregister). When a nexthop is removed any groups using it are updated. Groups using a nexthop a tracked via a grp_list. Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the request. Signed-off-by: David Ahern Signed-off-by: David S. Miller

nexthop: Add support for lwt encaps

2019-05-29T04:37:30+00:00

Add support for NHA_ENCAP and NHA_ENCAP_TYPE. Leverages the existing code for lwtunnel within fib_nh_common, so the only change needed is handling the attributes in the nexthop code. Signed-off-by: David Ahern Signed-off-by: David S. Miller

nexthop: Add support for IPv6 gateways

2019-05-29T04:37:30+00:00

Handle IPv6 gateway in a nexthop spec. If nh_family is set to AF_INET6, NHA_GATEWAY is expected to be an IPv6 address. Add ipv6 option to gw in nh_config to hold the address, add fib6_nh to nh_info to leverage the ipv6 initialization and cleanup code. Update nh_fill_node to dump the v6 address. Signed-off-by: David Ahern Signed-off-by: David S. Miller