kernel/linux.git/drivers/net/gtp.c, branch v6.18.22

ipv4: Convert ->flowi4_tos to dscp_t.

2025-08-27T00:34:31+00:00

Convert the ->flowic_tos field of struct flowi_common from __u8 to dscp_t, rename it ->flowic_dscp and propagate these changes to struct flowi and struct flowi4. We've had several bugs in the past where ECN bits could interfere with IPv4 routing, because these bits were not properly cleared when setting ->flowi4_tos. These bugs should be fixed now and the dscp_t type has been introduced to ensure that variables carrying DSCP values don't accidentally have any ECN bits set. Several variables and structure fields have been converted to dscp_t already, but the main IPv4 routing structure, struct flowi4, is still using a __u8. To avoid any future regression, this patch converts it to dscp_t. There are many users to convert at once. Fortunately, around half of ->flowi4_tos users already have a dscp_t value at hand, which they currently convert to __u8 using inet_dscp_to_dsfield(). For all of these users, we just need to drop that conversion. But, although we try to do the __u8 <-> dscp_t conversions at the boundaries of the network or of user space, some places still store TOS/DSCP variables as __u8 in core networking code. Those can hardly be converted either because the data structure is part of UAPI or because the same variable or field is also used for handling ECN in other parts of the code. In all of these cases where we don't have a dscp_t variable at hand, we need to use inet_dsfield_to_dscp() when interacting with ->flowi4_dscp. Changes since v1: * Fix space alignment in __bpf_redirect_neigh_v4() (Ido). Signed-off-by: Guillaume Nault Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/29acecb45e911d17446b9a3dbdb1ab7b821ea371.1756128932.git.gnault@redhat.com Signed-off-by: Jakub Kicinski

net: ipv6: Add a flags argument to ip6tunnel_xmit(), udp_tunnel6_xmit_skb()

2025-06-18T01:18:45+00:00

ip6tunnel_xmit() erases the contents of the SKB control block. In order to be able to set particular IP6CB flags on the SKB, add a corresponding parameter, and propagate it to udp_tunnel6_xmit_skb() as well. In one of the following patches, VXLAN driver will use this facility to mark packets as subject to IPv6 multicast routing. Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Reviewed-by: Nikolay Aleksandrov Link: https://patch.msgid.link/acb4f9f3e40c3a931236c3af08a720b017fbfbfb.1750113335.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski

net: ipv4: Add a flags argument to iptunnel_xmit(), udp_tunnel_xmit_skb()

2025-06-18T01:18:44+00:00

iptunnel_xmit() erases the contents of the SKB control block. In order to be able to set particular IPCB flags on the SKB, add a corresponding parameter, and propagate it to udp_tunnel_xmit_skb() as well. In one of the following patches, VXLAN driver will use this facility to mark packets as subject to IP multicast routing. Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Reviewed-by: Nikolay Aleksandrov Acked-by: Antonio Quartulli Link: https://patch.msgid.link/89c9daf9f2dc088b6b92ccebcc929f51742de91f.1750113335.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski

gtp: Convert gtp_net_exit_batch_rtnl() to ->exit_rtnl().

2025-04-15T00:08:44+00:00

gtp_net_exit_batch_rtnl() iterates the dying netns list and performs the same operations for each. Let's use ->exit_rtnl(). Signed-off-by: Kuniyuki Iwashima Reviewed-by: Sabrina Dubroca Link: https://patch.msgid.link/20250411205258.63164-12-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

net: Use link/peer netns in newlink() of rtnl_link_ops

2025-02-21T23:28:02+00:00

Add two helper functions - rtnl_newlink_link_net() and rtnl_newlink_peer_net() for netns fallback logic. Peer netns falls back to link netns, and link netns falls back to source netns. Convert the use of params->net in netdevice drivers to one of the helper functions for clarity. Signed-off-by: Xiao Liang Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250219125039.18024-4-shaw.leon@gmail.com Signed-off-by: Jakub Kicinski

rtnetlink: Pack newlink() params into struct

2025-02-21T23:28:02+00:00

There are 4 net namespaces involved when creating links: - source netns - where the netlink socket resides, - target netns - where to put the device being created, - link netns - netns associated with the device (backend), - peer netns - netns of peer device. Currently, two nets are passed to newlink() callback - "src_net" parameter and "dev_net" (implicitly in net_device). They are set as follows, depending on netlink attributes in the request. +------------+-------------------+---------+---------+ | peer netns | IFLA_LINK_NETNSID | src_net | dev_net | +------------+-------------------+---------+---------+ | | absent | source | target | | absent +-------------------+---------+---------+ | | present | link | link | +------------+-------------------+---------+---------+ | | absent | peer | target | | present +-------------------+---------+---------+ | | present | peer | link | +------------+-------------------+---------+---------+ When IFLA_LINK_NETNSID is present, the device is created in link netns first and then moved to target netns. This has some side effects, including extra ifindex allocation, ifname validation and link events. These could be avoided if we create it in target netns from the beginning. On the other hand, the meaning of src_net parameter is ambiguous. It varies depending on how parameters are passed. It is the effective link (or peer netns) by design, but some drivers ignore it and use dev_net instead. To provide more netns context for drivers, this patch packs existing newlink() parameters, along with the source netns, link netns and peer netns, into a struct. The old "src_net" is renamed to "net" to avoid confusion with real source netns, and will be deprecated later. The use of src_net are converted to params->net trivially. Signed-off-by: Xiao Liang Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250219125039.18024-3-shaw.leon@gmail.com Signed-off-by: Jakub Kicinski

gtp: Suppress list corruption splat in gtp_net_exit_batch_rtnl().

2025-02-20T02:49:28+00:00

Brad Spengler reported the list_del() corruption splat in gtp_net_exit_batch_rtnl(). [0] Commit eb28fd76c0a0 ("gtp: Destroy device along with udp socket's netns dismantle.") added the for_each_netdev() loop in gtp_net_exit_batch_rtnl() to destroy devices in each netns as done in geneve and ip tunnels. However, this could trigger ->dellink() twice for the same device during ->exit_batch_rtnl(). Say we have two netns A & B and gtp device B that resides in netns B but whose UDP socket is in netns A. 1. cleanup_net() processes netns A and then B. 2. gtp_net_exit_batch_rtnl() finds the device B while iterating netns A's gn->gtp_dev_list and calls ->dellink(). [ device B is not yet unlinked from netns B as unregister_netdevice_many() has not been called. ] 3. gtp_net_exit_batch_rtnl() finds the device B while iterating netns B's for_each_netdev() and calls ->dellink(). gtp_dellink() cleans up the device's hash table, unlinks the dev from gn->gtp_dev_list, and calls unregister_netdevice_queue(). Basically, calling gtp_dellink() multiple times is fine unless CONFIG_DEBUG_LIST is enabled. Let's remove for_each_netdev() in gtp_net_exit_batch_rtnl() and delegate the destruction to default_device_exit_batch() as done in bareudp. [0]: list_del corruption, ffff8880aaa62c00->next (autoslab_size_M_dev_P_net_core_dev_11127_8_1328_8_S_4096_A_64_n_139+0xc00/0x1000 [slab object]) is LIST_POISON1 (ffffffffffffff02) (prev is 0xffffffffffffff04) kernel BUG at lib/list_debug.c:58! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 UID: 0 PID: 1804 Comm: kworker/u8:7 Tainted: G T 6.12.13-grsec-full-20250211091339 #1 Tainted: [T]=RANDSTRUCT Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: netns cleanup_net RIP: 0010:[] __list_del_entry_valid_or_report+0x141/0x200 lib/list_debug.c:58 Code: c2 76 91 31 c0 e8 9f b1 f7 fc 0f 0b 4d 89 f0 48 c7 c1 02 ff ff ff 48 89 ea 48 89 ee 48 c7 c7 e0 c2 76 91 31 c0 e8 7f b1 f7 fc <0f> 0b 4d 89 e8 48 c7 c1 04 ff ff ff 48 89 ea 48 89 ee 48 c7 c7 60 RSP: 0018:fffffe8040b4fbd0 EFLAGS: 00010283 RAX: 00000000000000cc RBX: dffffc0000000000 RCX: ffffffff818c4054 RDX: ffffffff84947381 RSI: ffffffff818d1512 RDI: 0000000000000000 RBP: ffff8880aaa62c00 R08: 0000000000000001 R09: fffffbd008169f32 R10: fffffe8040b4f997 R11: 0000000000000001 R12: a1988d84f24943e4 R13: ffffffffffffff02 R14: ffffffffffffff04 R15: ffff8880aaa62c08 RBX: kasan shadow of 0x0 RCX: __wake_up_klogd.part.0+0x74/0xe0 kernel/printk/printk.c:4554 RDX: __list_del_entry_valid_or_report+0x141/0x200 lib/list_debug.c:58 RSI: vprintk+0x72/0x100 kernel/printk/printk_safe.c:71 RBP: autoslab_size_M_dev_P_net_core_dev_11127_8_1328_8_S_4096_A_64_n_139+0xc00/0x1000 [slab object] RSP: process kstack fffffe8040b4fbd0+0x7bd0/0x8000 [kworker/u8:7+netns 1804 ] R09: kasan shadow of process kstack fffffe8040b4f990+0x7990/0x8000 [kworker/u8:7+netns 1804 ] R10: process kstack fffffe8040b4f997+0x7997/0x8000 [kworker/u8:7+netns 1804 ] R15: autoslab_size_M_dev_P_net_core_dev_11127_8_1328_8_S_4096_A_64_n_139+0xc08/0x1000 [slab object] FS: 0000000000000000(0000) GS:ffff888116000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000748f5372c000 CR3: 0000000015408000 CR4: 00000000003406f0 shadow CR4: 00000000003406f0 Stack: 0000000000000000 ffffffff8a0c35e7 ffffffff8a0c3603 ffff8880aaa62c00 ffff8880aaa62c00 0000000000000004 ffff88811145311c 0000000000000005 0000000000000001 ffff8880aaa62000 fffffe8040b4fd40 ffffffff8a0c360d Call Trace: [] __list_del_entry_valid include/linux/list.h:131 [inline] fffffe8040b4fc28 [] __list_del_entry include/linux/list.h:248 [inline] fffffe8040b4fc28 [] list_del include/linux/list.h:262 [inline] fffffe8040b4fc28 [] gtp_dellink+0x16d/0x360 drivers/net/gtp.c:1557 fffffe8040b4fc28 [] gtp_net_exit_batch_rtnl+0x124/0x2c0 drivers/net/gtp.c:2495 fffffe8040b4fc88 [] cleanup_net+0x5a4/0xbe0 net/core/net_namespace.c:635 fffffe8040b4fcd0 [] process_one_work+0xbd7/0x2160 kernel/workqueue.c:3326 fffffe8040b4fd88 [] process_scheduled_works kernel/workqueue.c:3407 [inline] fffffe8040b4fec0 [] worker_thread+0x6b5/0xfa0 kernel/workqueue.c:3488 fffffe8040b4fec0 [] kthread+0x360/0x4c0 kernel/kthread.c:397 fffffe8040b4ff78 [] ret_from_fork+0x74/0xe0 arch/x86/kernel/process.c:172 fffffe8040b4ffb8 [] ret_from_fork_asm+0x29/0xc0 arch/x86/entry/entry_64.S:399 fffffe8040b4ffe8 Modules linked in: Fixes: eb28fd76c0a0 ("gtp: Destroy device along with udp socket's netns dismantle.") Reported-by: Brad Spengler Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250217203705.40342-2-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

gtp: Prepare ip4_route_output_gtp() to .flowi4_tos conversion.

2025-01-18T03:01:33+00:00

Use inet_sk_dscp() to get the socket DSCP value as dscp_t, instead of ip_sock_rt_tos() which returns a __u8. This will ease the conversion of fl4->flowi4_tos to dscp_t, which now just becomes a matter of dropping the inet_dscp_to_dsfield() call. Signed-off-by: Guillaume Nault Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/06bdb310a075355ff059cd32da2efc29a63981c9.1737034675.git.gnault@redhat.com Signed-off-by: Jakub Kicinski

gtp: Destroy device along with udp socket's netns dismantle.

2025-01-14T10:20:04+00:00

gtp_newlink() links the device to a list in dev_net(dev) instead of src_net, where a udp tunnel socket is created. Even when src_net is removed, the device stays alive on dev_net(dev). Then, removing src_net triggers the splat below. [0] In this example, gtp0 is created in ns2, and the udp socket is created in ns1. ip netns add ns1 ip netns add ns2 ip -n ns1 link add netns ns2 name gtp0 type gtp role sgsn ip netns del ns1 Let's link the device to the socket's netns instead. Now, gtp_net_exit_batch_rtnl() needs another netdev iteration to remove all gtp devices in the netns. [0]: ref_tracker: net notrefcnt@000000003d6e7d05 has 1/2 users at sk_alloc (./include/net/net_namespace.h:345 net/core/sock.c:2236) inet_create (net/ipv4/af_inet.c:326 net/ipv4/af_inet.c:252) __sock_create (net/socket.c:1558) udp_sock_create4 (net/ipv4/udp_tunnel_core.c:18) gtp_create_sock (./include/net/udp_tunnel.h:59 drivers/net/gtp.c:1423) gtp_create_sockets (drivers/net/gtp.c:1447) gtp_newlink (drivers/net/gtp.c:1507) rtnl_newlink (net/core/rtnetlink.c:3786 net/core/rtnetlink.c:3897 net/core/rtnetlink.c:4012) rtnetlink_rcv_msg (net/core/rtnetlink.c:6922) netlink_rcv_skb (net/netlink/af_netlink.c:2542) netlink_unicast (net/netlink/af_netlink.c:1321 net/netlink/af_netlink.c:1347) netlink_sendmsg (net/netlink/af_netlink.c:1891) ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2583) ___sys_sendmsg (net/socket.c:2639) __sys_sendmsg (net/socket.c:2669) do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) WARNING: CPU: 1 PID: 60 at lib/ref_tracker.c:179 ref_tracker_dir_exit (lib/ref_tracker.c:179) Modules linked in: CPU: 1 UID: 0 PID: 60 Comm: kworker/u16:2 Not tainted 6.13.0-rc5-00147-g4c1224501e9d #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Workqueue: netns cleanup_net RIP: 0010:ref_tracker_dir_exit (lib/ref_tracker.c:179) Code: 00 00 00 fc ff df 4d 8b 26 49 bd 00 01 00 00 00 00 ad de 4c 39 f5 0f 85 df 00 00 00 48 8b 74 24 08 48 89 df e8 a5 cc 12 02 90 <0f> 0b 90 48 8d 6b 44 be 04 00 00 00 48 89 ef e8 80 de 67 ff 48 89 RSP: 0018:ff11000009a07b60 EFLAGS: 00010286 RAX: 0000000000002bd3 RBX: ff1100000f4e1aa0 RCX: 1ffffffff0e40ac6 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8423ee3c RBP: ff1100000f4e1af0 R08: 0000000000000001 R09: fffffbfff0e395ae R10: 0000000000000001 R11: 0000000000036001 R12: ff1100000f4e1af0 R13: dead000000000100 R14: ff1100000f4e1af0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ff1100006ce80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9b2464bd98 CR3: 0000000005286005 CR4: 0000000000771ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ? __warn (kernel/panic.c:748) ? ref_tracker_dir_exit (lib/ref_tracker.c:179) ? report_bug (lib/bug.c:201 lib/bug.c:219) ? handle_bug (arch/x86/kernel/traps.c:285) ? exc_invalid_op (arch/x86/kernel/traps.c:309 (discriminator 1)) ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621) ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:97 ./arch/x86/include/asm/irqflags.h:155 ./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) ? ref_tracker_dir_exit (lib/ref_tracker.c:179) ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:158) ? kfree (mm/slub.c:4613 mm/slub.c:4761) net_free (net/core/net_namespace.c:476 net/core/net_namespace.c:467) cleanup_net (net/core/net_namespace.c:664 (discriminator 3)) process_one_work (kernel/workqueue.c:3229) worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391) kthread (kernel/kthread.c:389) ret_from_fork (arch/x86/kernel/process.c:147) ret_from_fork_asm (arch/x86/entry/entry_64.S:257) Fixes: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Reported-by: Xiao Liang Closes: https://lore.kernel.org/netdev/20250104125732.17335-1-shaw.leon@gmail.com/ Signed-off-by: Kuniyuki Iwashima Signed-off-by: Paolo Abeni

gtp: Use for_each_netdev_rcu() in gtp_genl_dump_pdp().

2025-01-14T10:20:04+00:00

gtp_newlink() links the gtp device to a list in dev_net(dev). However, even after the gtp device is moved to another netns, it stays on the list but should be invisible. Let's use for_each_netdev_rcu() for netdev traversal in gtp_genl_dump_pdp(). Note that gtp_dev_list is no longer used under RCU, so list helpers are converted to the non-RCU variant. Fixes: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Reported-by: Xiao Liang Closes: https://lore.kernel.org/netdev/CABAhCOQdBL6h9M2C+kd+bGivRJ9Q72JUxW+-gur0nub_=PmFPA@mail.gmail.com/ Signed-off-by: Kuniyuki Iwashima Signed-off-by: Paolo Abeni