| Message ID | 20210930113844.1829373-1-razor@blackwall.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | ip: nexthop: cache nexthops and print routes' nh info | expand |
Hello: This series was applied to iproute2/iproute2-next.git (refs/heads/main): On Thu, 30 Sep 2021 14:38:32 +0300 you wrote: > From: Nikolay Aleksandrov <nikolay@nvidia.com> > > Hi, > This set tries to help with an old ask that we've had for some time > which is to print nexthop information while monitoring or dumping routes. > The core problem is that people cannot follow nexthop changes while > monitoring route changes, by the time they check the nexthop it could be > deleted or updated to something else. In order to help them out I've > added a nexthop cache which is populated (only used if -d / show_details > is specified) while decoding routes and kept up to date while monitoring. > The nexthop information is printed on its own line starting with the > "nh_info" attribute and its embedded inside it if printing JSON. To > cache the nexthop entries I parse them into structures, in order to > reuse most of the code the print helpers have been altered so they rely > on prepared structures. Nexthops are now always parsed into a structure, > even if they won't be cached, that structure is later used to print the > nexthop and destroyed if not going to be cached. New nexthops (not found > in the cache) are retrieved from the kernel using a private netlink > socket so they don't disrupt an ongoing dump, similar to how interfaces > are retrieved and cached. > > [...] Here is the summary with links: - [iproute2-next,01/12] ip: print_rta_if takes ifindex as device argument instead of attribute https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=f72789965eff - [iproute2-next,02/12] ip: export print_rta_gateway version which outputs prepared gateway string https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=371e889da771 - [iproute2-next,03/12] ip: nexthop: add resilient group structure https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=cfb0a8729ea4 - [iproute2-next,04/12] ip: nexthop: split print_nh_res_group into parse and print parts https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=60a7515b89ff - [iproute2-next,05/12] ip: nexthop: add nh entry structure https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=7ec1cee630e3 - [iproute2-next,06/12] ip: nexthop: parse attributes into nh entry structure before printing https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=945c26db686b - [iproute2-next,07/12] ip: nexthop: factor out print_nexthop's nh entry printing https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=a2ca43121501 - [iproute2-next,08/12] ip: nexthop: factor out ipnh_get_id rtnl talk into a helper https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=53d7c43bd385 - [iproute2-next,09/12] ip: nexthop: add cache helpers https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=60a970303288 - [iproute2-next,10/12] ip: nexthop: add a helper which retrieves and prints cached nh entry https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=cb3d18c29e20 - [iproute2-next,11/12] ip: route: print and cache detailed nexthop information when requested https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=5d5dc549ce7d - [iproute2-next,12/12] ip: nexthop: add print_cache_nexthop which prints and manages the nh cache https://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git/commit/?id=7ca868a7aa26 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
From: Nikolay Aleksandrov <nikolay@nvidia.com> Hi, This set tries to help with an old ask that we've had for some time which is to print nexthop information while monitoring or dumping routes. The core problem is that people cannot follow nexthop changes while monitoring route changes, by the time they check the nexthop it could be deleted or updated to something else. In order to help them out I've added a nexthop cache which is populated (only used if -d / show_details is specified) while decoding routes and kept up to date while monitoring. The nexthop information is printed on its own line starting with the "nh_info" attribute and its embedded inside it if printing JSON. To cache the nexthop entries I parse them into structures, in order to reuse most of the code the print helpers have been altered so they rely on prepared structures. Nexthops are now always parsed into a structure, even if they won't be cached, that structure is later used to print the nexthop and destroyed if not going to be cached. New nexthops (not found in the cache) are retrieved from the kernel using a private netlink socket so they don't disrupt an ongoing dump, similar to how interfaces are retrieved and cached. I have tested the set with the kernel forwarding selftests and also by stressing it with nexthop create/update/delete in loops while monitoring. Comments are very welcome as usual. :) Changes since RFC: - reordered parse/print splits, in order to do that I have to parse resilient groups first, then add nh entry parsing so code has been reordered as well and patch order has changed, but there have been no functional changes (as before refactoring of old code is done in the first 8 patches and then patches 9-12 add the new cache and use it) - re-run all tests above Patch breakdown: Patches 1-2: update current route helpers to take parsed arguments so we can directly pass them from the nh_entry structure later Patch 3: adds new nha_res_grp structure which describes a resilient nexhtop group Patch 4: splits print_nh_res_group into a parse and print parts which use the new nha_res_grp structure Patch 5: adds new nh_entry structure which describes a nexthop Patch 6: factors out print_nexthop's attribute parsing into nh_entry structure used before printing Patch 7: factors out print_nexthop's nh_entry structure printing Patch 8: factors out ipnh_get's rtnl talk part and allows to use a different rt handle for the communication Patch 9: adds nexthop cache and helpers to manage it, it uses the new __ipnh_get to retrieve nexthops Patch 10: adds a new helper print_cache_nexthop_id that prints nexthop information from its id, if the nexthop is not found in the cache it fetches it Patch 11: the new print_cache_nexthop_id helper is used when printing routes with show_details (-d) to output detailed nexthop information, the format after nh_info is the same as ip nexthop show Patch 12: changes print_nexthop into print_cache_nexthop which always outputs the nexthop information and can also update the cache (based on process_cache argument), it's used to keep the cache up to date while monitoring Example outputs (monitor): [NEXTHOP]id 101 via 169.254.2.22 dev veth2 scope link proto unspec [NEXTHOP]id 102 via 169.254.3.23 dev veth4 scope link proto unspec [NEXTHOP]id 103 group 101/102 type resilient buckets 512 idle_timer 0 unbalanced_timer 0 unbalanced_time 0 scope global proto unspec [ROUTE]unicast 192.0.2.0/24 nhid 203 table 4 proto boot scope global nh_info id 203 group 201/202 type resilient buckets 512 idle_timer 0 unbalanced_timer 0 unbalanced_time 0 scope global proto unspec nexthop via 169.254.2.12 dev veth3 weight 1 nexthop via 169.254.3.13 dev veth5 weight 1 [NEXTHOP]id 204 via fe80:2::12 dev veth3 scope link proto unspec [NEXTHOP]id 205 via fe80:3::13 dev veth5 scope link proto unspec [NEXTHOP]id 206 group 204/205 type resilient buckets 512 idle_timer 0 unbalanced_timer 0 unbalanced_time 0 scope global proto unspec [ROUTE]unicast 2001:db8:1::/64 nhid 206 table 4 proto boot scope global metric 1024 pref medium nh_info id 206 group 204/205 type resilient buckets 512 idle_timer 0 unbalanced_timer 0 unbalanced_time 0 scope global proto unspec nexthop via fe80:2::12 dev veth3 weight 1 nexthop via fe80:3::13 dev veth5 weight 1 [NEXTHOP]id 2 encap mpls 200/300 via 10.1.1.1 dev ens20 scope link proto unspec onlink [ROUTE]unicast 2.3.4.10 nhid 2 table main proto boot scope global nh_info id 2 encap mpls 200/300 via 10.1.1.1 dev ens20 scope link proto unspec onlink JSON: { "type": "unicast", "dst": "198.51.100.0/24", "nhid": 103, "table": "3", "protocol": "boot", "scope": "global", "flags": [ ], "nh_info": { "id": 103, "group": [ { "id": 101, "weight": 11 },{ "id": 102, "weight": 45 } ], "type": "resilient", "resilient_args": { "buckets": 512, "idle_timer": 0, "unbalanced_timer": 0, "unbalanced_time": 0 }, "scope": "global", "protocol": "unspec", "flags": [ ] }, "nexthops": [ { "gateway": "169.254.2.22", "dev": "veth2", "weight": 11, "flags": [ ] },{ "gateway": "169.254.3.23", "dev": "veth4", "weight": 45, "flags": [ ] } ] } Thank you, Nik Nikolay Aleksandrov (12): ip: print_rta_if takes ifindex as device argument instead of attribute ip: export print_rta_gateway version which outputs prepared gateway string ip: nexthop: add resilient group structure ip: nexthop: split print_nh_res_group into parse and print parts ip: nexthop: add nh entry structure ip: nexthop: parse attributes into nh entry structure before printing ip: nexthop: factor out print_nexthop's nh entry printing ip: nexthop: factor out ipnh_get_id rtnl talk into a helper ip: nexthop: add cache helpers ip: nexthop: add a helper which retrieves and prints cached nh entry ip: route: print and cache detailed nexthop information when requested ip: nexthop: add print_cache_nexthop which prints and manages the nh cache ip/ip_common.h | 4 +- ip/ipmonitor.c | 3 +- ip/ipnexthop.c | 459 +++++++++++++++++++++++++++++++++++++++---------- ip/iproute.c | 32 ++-- ip/nh_common.h | 53 ++++++ 5 files changed, 448 insertions(+), 103 deletions(-) create mode 100644 ip/nh_common.h