From: Jonas Gorski jonas.gorski@bisdn.de
commit 2aa71b4b294ee2c3041d085404cea914be9b3225 upstream.
Fix handling IPv4 routes referencing a nexthop via its id by replacing calls to fib_info_nh() with fib_info_nhc().
Trying to add an IPv4 route referencing a nextop via nhid:
$ ip link set up swp5 $ ip a a 10.0.0.1/24 dev swp5 $ ip nexthop add dev swp5 id 20 via 10.0.0.2 $ ip route add 10.0.1.0/24 nhid 20
triggers warnings when trying to handle the route:
[ 528.805763] ------------[ cut here ]------------ [ 528.810437] WARNING: CPU: 3 PID: 53 at include/net/nexthop.h:468 __prestera_fi_is_direct+0x2c/0x68 [prestera] [ 528.820434] Modules linked in: prestera_pci act_gact act_police sch_ingress cls_u32 cls_flower prestera arm64_delta_tn48m_dn_led(O) arm64_delta_tn48m_dn_cpld(O) [last unloaded: prestera_pci] [ 528.837485] CPU: 3 PID: 53 Comm: kworker/u8:3 Tainted: G O 6.4.5 #1 [ 528.845178] Hardware name: delta,tn48m-dn (DT) [ 528.849641] Workqueue: prestera_ordered __prestera_router_fib_event_work [prestera] [ 528.857352] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 528.864347] pc : __prestera_fi_is_direct+0x2c/0x68 [prestera] [ 528.870135] lr : prestera_k_arb_fib_evt+0xb20/0xd50 [prestera] [ 528.876007] sp : ffff80000b20bc90 [ 528.879336] x29: ffff80000b20bc90 x28: 0000000000000000 x27: ffff0001374d3a48 [ 528.886510] x26: ffff000105604000 x25: ffff000134af8a28 x24: ffff0001374d3800 [ 528.893683] x23: ffff000101c89148 x22: ffff000101c89000 x21: ffff000101c89200 [ 528.900855] x20: ffff00013641fda0 x19: ffff800009d01088 x18: 0000000000000059 [ 528.908027] x17: 0000000000000277 x16: 0000000000000000 x15: 0000000000000000 [ 528.915198] x14: 0000000000000003 x13: 00000000000fe400 x12: 0000000000000000 [ 528.922371] x11: 0000000000000002 x10: 0000000000000aa0 x9 : ffff8000013d2020 [ 528.929543] x8 : 0000000000000018 x7 : 000000007b1703f8 x6 : 000000001ca72f86 [ 528.936715] x5 : 0000000033399ea7 x4 : 0000000000000000 x3 : ffff0001374d3acc [ 528.943886] x2 : 0000000000000000 x1 : ffff00010200de00 x0 : ffff000134ae3f80 [ 528.951058] Call trace: [ 528.953516] __prestera_fi_is_direct+0x2c/0x68 [prestera] [ 528.958952] __prestera_router_fib_event_work+0x100/0x158 [prestera] [ 528.965348] process_one_work+0x208/0x488 [ 528.969387] worker_thread+0x4c/0x430 [ 528.973068] kthread+0x120/0x138 [ 528.976313] ret_from_fork+0x10/0x20 [ 528.979909] ---[ end trace 0000000000000000 ]--- [ 528.984998] ------------[ cut here ]------------ [ 528.989645] WARNING: CPU: 3 PID: 53 at include/net/nexthop.h:468 __prestera_fi_is_direct+0x2c/0x68 [prestera] [ 528.999628] Modules linked in: prestera_pci act_gact act_police sch_ingress cls_u32 cls_flower prestera arm64_delta_tn48m_dn_led(O) arm64_delta_tn48m_dn_cpld(O) [last unloaded: prestera_pci] [ 529.016676] CPU: 3 PID: 53 Comm: kworker/u8:3 Tainted: G W O 6.4.5 #1 [ 529.024368] Hardware name: delta,tn48m-dn (DT) [ 529.028830] Workqueue: prestera_ordered __prestera_router_fib_event_work [prestera] [ 529.036539] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 529.043533] pc : __prestera_fi_is_direct+0x2c/0x68 [prestera] [ 529.049318] lr : __prestera_k_arb_fc_apply+0x280/0x2f8 [prestera] [ 529.055452] sp : ffff80000b20bc60 [ 529.058781] x29: ffff80000b20bc60 x28: 0000000000000000 x27: ffff0001374d3a48 [ 529.065953] x26: ffff000105604000 x25: ffff000134af8a28 x24: ffff0001374d3800 [ 529.073126] x23: ffff000101c89148 x22: ffff000101c89148 x21: ffff00013641fda0 [ 529.080299] x20: ffff000101c89000 x19: ffff000101c89020 x18: 0000000000000059 [ 529.087471] x17: 0000000000000277 x16: 0000000000000000 x15: 0000000000000000 [ 529.094642] x14: 0000000000000003 x13: 00000000000fe400 x12: 0000000000000000 [ 529.101814] x11: 0000000000000002 x10: 0000000000000aa0 x9 : ffff8000013cee80 [ 529.108985] x8 : 0000000000000018 x7 : 000000007b1703f8 x6 : 0000000000000018 [ 529.116157] x5 : 00000000d3497eb6 x4 : ffff000105604081 x3 : 000000008e979557 [ 529.123329] x2 : 0000000000000000 x1 : ffff00010200de00 x0 : ffff000134ae3f80 [ 529.130501] Call trace: [ 529.132958] __prestera_fi_is_direct+0x2c/0x68 [prestera] [ 529.138394] prestera_k_arb_fib_evt+0x6b8/0xd50 [prestera] [ 529.143918] __prestera_router_fib_event_work+0x100/0x158 [prestera] [ 529.150313] process_one_work+0x208/0x488 [ 529.154348] worker_thread+0x4c/0x430 [ 529.158030] kthread+0x120/0x138 [ 529.161274] ret_from_fork+0x10/0x20 [ 529.164867] ---[ end trace 0000000000000000 ]---
and results in a non offloaded route:
$ ip route 10.0.0.0/24 dev swp5 proto kernel scope link src 10.0.0.1 rt_trap 10.0.1.0/24 nhid 20 via 10.0.0.2 dev swp5 rt_trap
When creating a route referencing a nexthop via its ID, the nexthop will be stored in a separate nh pointer instead of the array of nexthops in the fib_info struct. This causes issues since fib_info_nh() only handles the nexthops array, but not the separate nh pointer, and will loudly WARN about it.
In contrast fib_info_nhc() handles both, but returns a fib_nh_common pointer instead of a fib_nh pointer. Luckily we only ever access fields from the fib_nh_common parts, so we can just replace all instances of fib_info_nh() with fib_info_nhc() and access the fields via their fib_nh_common names.
This allows handling IPv4 routes with an external nexthop, and they now get offloaded as expected:
$ ip route 10.0.0.0/24 dev swp5 proto kernel scope link src 10.0.0.1 rt_trap 10.0.1.0/24 nhid 20 via 10.0.0.2 dev swp5 offload rt_offload
Fixes: 396b80cb5cc8 ("net: marvell: prestera: Add neighbour cache accounting") Signed-off-by: Jonas Gorski jonas.gorski@bisdn.de Acked-by: Elad Nachman enachman@marvell.com Link: https://lore.kernel.org/r/20230804101220.247515-1-jonas.gorski@bisdn.de Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/marvell/prestera/prestera_router.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
--- a/drivers/net/ethernet/marvell/prestera/prestera_router.c +++ b/drivers/net/ethernet/marvell/prestera/prestera_router.c @@ -166,11 +166,11 @@ prestera_util_neigh2nc_key(struct preste
static bool __prestera_fi_is_direct(struct fib_info *fi) { - struct fib_nh *fib_nh; + struct fib_nh_common *fib_nhc;
if (fib_info_num_path(fi) == 1) { - fib_nh = fib_info_nh(fi, 0); - if (fib_nh->fib_nh_gw_family == AF_UNSPEC) + fib_nhc = fib_info_nhc(fi, 0); + if (fib_nhc->nhc_gw_family == AF_UNSPEC) return true; }
@@ -261,7 +261,7 @@ static bool __prestera_util_kern_n_is_reachable_v4(u32 tb_id, __be32 *addr, struct net_device *dev) { - struct fib_nh *fib_nh; + struct fib_nh_common *fib_nhc; struct fib_result res; bool reachable;
@@ -269,8 +269,8 @@ __prestera_util_kern_n_is_reachable_v4(u
if (!prestera_util_kern_get_route(&res, tb_id, addr)) if (prestera_fi_is_direct(res.fi)) { - fib_nh = fib_info_nh(res.fi, 0); - if (dev == fib_nh->fib_nh_dev) + fib_nhc = fib_info_nhc(res.fi, 0); + if (dev == fib_nhc->nhc_dev) reachable = true; }
@@ -324,7 +324,7 @@ prestera_kern_fib_info_nhc(struct fib_no if (info->family == AF_INET) { fen4_info = container_of(info, struct fib_entry_notifier_info, info); - return &fib_info_nh(fen4_info->fi, n)->nh_common; + return fib_info_nhc(fen4_info->fi, n); } else if (info->family == AF_INET6) { fen6_info = container_of(info, struct fib6_entry_notifier_info, info);