| Message ID | 20240520214255.2590923-1-chopps@chopps.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | Add IP-TFS mode to xfrm | expand |
Hi Chris, On Mon, May 20, 2024 at 05:42:38PM -0400, Christian Hopps via Devel wrote: > From: Christian Hopps <chopps@labn.net> > > Summary of Changes > ------------------ > > This patchset adds a new xfrm mode implementing on-demand IP-TFS. IP-TFS > (AggFrag encapsulation) has been standardized in RFC9347. > > Link: https://www.rfc-editor.org/rfc/rfc9347.txt > > This feature supports demand driven (i.e., non-constant send rate) > IP-TFS to take advantage of the AGGFRAG ESP payload encapsulation. This > payload type supports aggregation and fragmentation of the inner IP > packet stream which in turn yields higher small-packet bandwidth as well > as reducing MTU/PMTU issues. Congestion control is unimplementated as > the send rate is demand driven rather than constant. > > In order to allow loading this fucntionality as a module a set of > callbacks xfrm_mode_cbs has been added to xfrm as well. > > Patchset Changes: > ----------------- > > 23 files changed, 3252 insertions(+), 19 deletions(-) > Documentation/networking/xfrm_sysctl.rst | 30 + > include/net/netns/xfrm.h | 6 + > include/net/xfrm.h | 40 + > include/uapi/linux/in.h | 2 + > include/uapi/linux/ip.h | 16 + > include/uapi/linux/ipsec.h | 3 +- > include/uapi/linux/snmp.h | 3 + > include/uapi/linux/xfrm.h | 9 +- > net/ipv4/esp4.c | 3 +- > net/ipv6/esp6.c | 3 +- > net/netfilter/nft_xfrm.c | 3 +- > net/xfrm/Makefile | 1 + > net/xfrm/trace_iptfs.h | 218 +++ > net/xfrm/xfrm_compat.c | 10 +- > net/xfrm/xfrm_device.c | 4 +- > net/xfrm/xfrm_input.c | 14 +- > net/xfrm/xfrm_iptfs.c | 2741 ++++++++++++++++++++++++++++++ > net/xfrm/xfrm_output.c | 6 + > net/xfrm/xfrm_policy.c | 26 +- > net/xfrm/xfrm_proc.c | 3 + > net/xfrm/xfrm_state.c | 60 + > net/xfrm/xfrm_sysctl.c | 38 + > net/xfrm/xfrm_user.c | 32 + > > Patchset Structure: > ------------------- > > The first 8 commits are changes to the xfrm infrastructure to support > the callbacks as well as more generic IP-TFS additions that may be used > outside the actual IP-TFS implementation. > > - iptfs: config: add CONFIG_XFRM_IPTFS > - iptfs: uapi: ip: add ip_tfs_*_hdr packet formats > - iptfs: uapi: IPPROTO_AGGFRAG AGGFRAG in ESP > - iptfs: sysctl: allow configuration of global default values > - iptfs: netlink: add config (netlink) options > - iptfs: xfrm: Add mode_cbs module functionality > - iptfs: xfrm: add generic iptfs defines and functionality > > The last 9+1 commits constitute the IP-TFS implementation constructed in > layers to make review easier. The first 9 commits all apply to a single > file `net/xfrm/xfrm_iptfs.c`, the last commit adds a new tracepoint > header file along with the use of these new tracepoint calls. > > - iptfs: impl: add new iptfs xfrm mode impl > - iptfs: impl: add user packet (tunnel ingress) handling > - iptfs: impl: share page fragments of inner packets > - iptfs: impl: add fragmenting of larger than MTU user packets > - iptfs: impl: add basic receive packet (tunnel egress) handling > - iptfs: impl: handle received fragmented inner packets > - iptfs: impl: add reusing received skb for the tunnel egress packet > - iptfs: impl: add skb-fragment sharing code > - iptfs: impl: handle reordering of received packets > - iptfs: impl: add tracepoint functionality > > Patchset History: > ----------------- > > RFCv1 (11/10/2023) > > RFCv1 -> RFCv2 (11/12/2023) > > Updates based on feedback from Simon Horman, Antony, > Michael Richardson, and kernel test robot. > > RFCv2 -> v1 (2/19/2024) > > Updates based on feedback from Sabrina Dubroca, kernel test robot > > v1 -> v2 (5/19/2024) > > Updates based on feedback from Sabrina Dubroca, Simon Horman, Antony. > > o Add handling of new netlink SA direction attribute (Antony). > o Split single patch/commit of xfrm_iptfs.c (the actual IP-TFS impl) > into 9+1 distinct layered functionality commits for aiding review. > - xfrm: fix return check on clone() callback > - xfrm: add sa_len() callback in xfrm_mode_cbs for copy to user > - iptfs: remove unneeded skb free count variable > - iptfs: remove unused variable and "breadcrumb" for future code. > - iptfs: use do_div() to avoid "__udivd13 missing" link failure. > - iptfs: remove some BUG_ON() assertions questioned in review. > -- I ran a couple of tests and it hit KSAN BUG. I was sending large ping while MTU is 1500. north login: shed systemd-user-sessions.service - Permit User Sessions. north login: [ 78.594770] ================================================================== [ 78.595825] BUG: KASAN: null-ptr-deref in iptfs_output_collect+0x263/0x57b [ 78.596658] Read of size 8 at addr 0000000000000108 by task ping/493 [ 78.597435] ng rpc-statd-notify.service - Notify NFS peers of a restart... [ 78.597651] CPU: 0 PID: 493 Comm: ping Not tainted 6.9.0-rc2-00697-g489ca863e24f-dirty #11 [ 78.598645] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 78.599747] Call Trace:tty@ttyS2.service - Serial Getty on ttyS2. [ 78.600070] <TASK>l-getty@ttyS3.service - Serial Getty on ttyS3. [ 78.600354] dump_stack_lvl+0x2a/0x3bogin Prompts. [ 78.600817] kasan_report+0x84/0xa6rvice - Hostname Service... [ 78.601262] ? iptfs_output_collect+0x263/0x57bl server. [ 78.601825] iptfs_output_collect+0x263/0x57bogin Management. [ 78.602374] ip_send_skb+0x25/0x57vice - Notify NFS peers of a restart. [ 78.602807] raw_sendmsg+0xee8/0x1011t - Multi-User System. [ 78.603269] ? native_flush_tlb_one_user+0xd/0xe5e Service. [ 78.603850] ? raw_hash_sk+0x21b/0x21b [ 78.604331] ? kernel_init_pages+0x42/0x51 [ 78.604845] ? prep_new_page+0x44/0x51Re…line ext4 Metadata Check Snapshots. [ 78.605318] ? get_page_from_freelist+0x72b/0x915 Interface. [ 78.605903] ? signal_pending_state+0x77/0x77cord Runlevel Change in UTMP... [ 78.606462] ? __might_resched+0x8a/0x240e - Record Runlevel Change in UTMP. [ 78.606966] ? __might_sleep+0x25/0xa0 [ 78.607440] ? first_zones_zonelist+0x2c/0x43 [ 78.607985] ? __rcu_read_lock+0x2d/0x3a [ 78.608479] ? __pte_offset_map+0x32/0xa4 [ 78.608979] ? __might_resched+0x8a/0x240 [ 78.609478] ? __might_sleep+0x25/0xa0 [ 78.609949] ? inet_send_prepare+0x54/0x54 [ 78.610464] ? sock_sendmsg_nosec+0x42/0x6c [ 78.610984] sock_sendmsg_nosec+0x42/0x6c [ 78.611485] __sys_sendto+0x15d/0x1cc [ 78.611947] ? __x64_sys_getpeername+0x44/0x44 [ 78.612498] ? __handle_mm_fault+0x679/0xae4 [ 78.613033] ? find_vma+0x6b/0x8b [ 78.613457] ? find_vma_intersection+0x8a/0x8a [ 78.614006] ? __handle_irq_event_percpu+0x180/0x197 [ 78.614617] ? handle_mm_fault+0x38/0x154 [ 78.615114] ? handle_mm_fault+0xeb/0x154 [ 78.615620] ? preempt_latency_start+0x29/0x34 [ 78.616169] ? preempt_count_sub+0x14/0xb3 [ 78.616678] ? up_read+0x4b/0x5c [ 78.617094] __x64_sys_sendto+0x76/0x82 [ 78.617577] do_syscall_64+0x6b/0xd7 [ 78.618043] entry_SYSCALL_64_after_hwframe+0x46/0x4e [ 78.618667] RIP: 0033:0x7fed3de99a73 [ 78.619118] Code: 8b 15 a9 83 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 80 3d 71 0b 0d 00 00 41 89 ca 74 14 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 75 c3 0f 1f 40 00 55 48 83 ec 30 44 89 4c 24 [ 78.621291] RSP: 002b:00007ffff6bdf478 EFLAGS: 00000202 ORIG_RAX: 000000000000002c [ 78.622205] RAX: ffffffffffffffda RBX: 000055c538159340 RCX: 00007fed3de99a73 [ 78.623056] RDX: 00000000000007d8 RSI: 000055c53815f3c0 RDI: 0000000000000003 [ 78.623908] RBP: 000055c53815f3c0 R08: 000055c53815b5c0 R09: 0000000000000010 [ 78.624765] R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000007d8 [ 78.625619] R13: 00007ffff6be0b60 R14: 0000001d00000001 R15: 000055c53815c680 [ 78.626480] </TASK> [ 78.626773] ================================================================== [ 78.627656] Disabling lock debugging due to kernel taint [ 78.628305] BUG: kernel NULL pointer dereference, address: 0000000000000108 [ 78.629136] #PF: supervisor read access in kernel mode [ 78.629766] #PF: error_code(0x0000) - not-present page [ 78.630402] PGD 0 P4D 0 [ 78.630739] Oops: 0000 [#1] PREEMPT DEBUG_PAGEALLOC KASAN [ 78.631398] CPU: 0 PID: 493 Comm: ping Tainted: G B 6.9.0-rc2-00697-g489ca863e24f-dirty #11 [ 78.632548] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 78.633649] RIP: 0010:iptfs_output_collect+0x263/0x57b [ 78.634283] Code: 73 70 0f 84 25 01 00 00 45 39 f4 0f 83 1c 01 00 00 48 8d 7b 10 e8 27 37 62 ff 4c 8b 73 10 49 8d be 08 01 00 00 e8 17 37 62 ff <4d> 8b b6 08 01 00 00 49 8d be b0 01 00 00 e8 04 37 62 ff 49 8b 86 [ 78.636444] RSP: 0018:ffffc90000d679c8 EFLAGS: 00010296 [ 78.637076] RAX: 0000000000000001 RBX: ffff888110ffbc80 RCX: fffffbfff07623ad [ 78.637923] RDX: fffffbfff07623ad RSI: fffffbfff07623ad RDI: ffffffff83b11d60 [ 78.638792] RBP: ffff88810e3a1400 R08: 0000000000000008 R09: 0000000000000001 [ 78.639645] R10: ffffffff83b11d67 R11: fffffbfff07623ac R12: 00000000000005a2 [ 78.640498] R13: 0000000000000000 R14: 0000000000000000 R15: ffff88810e9a3401 [ 78.641359] FS: 00007fed3dbddc40(0000) GS:ffffffff82cb2000(0000) knlGS:0000000000000000 [ 78.642324] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 78.643022] CR2: 0000000000000108 CR3: 0000000110e84000 CR4: 0000000000350ef0 [ 78.643882] Call Trace: [ 78.644204] <TASK> [ 78.644487] ? __die_body+0x1a/0x56 [ 78.644929] ? page_fault_oops+0x45f/0x4cd [ 78.645441] ? dump_pagetable+0x1db/0x1db [ 78.645942] ? vprintk_emit+0x163/0x171 [ 78.646425] ? iptfs_output_collect+0x263/0x57b [ 78.646986] ? _printk+0xb2/0xe1 [ 78.647401] ? find_first_fitting_seq+0x193/0x193 [ 78.647982] ? iptfs_output_collect+0x263/0x57b [ 78.648541] ? do_user_addr_fault+0x14f/0x56c [ 78.649084] ? exc_page_fault+0xa5/0xbe [ 78.649566] ? asm_exc_page_fault+0x22/0x30 [ 78.650100] ? iptfs_output_collect+0x263/0x57b [ 78.650660] ? iptfs_output_collect+0x263/0x57b [ 78.651221] ip_send_skb+0x25/0x57 [ 78.651652] raw_sendmsg+0xee8/0x1011 [ 78.652113] ? native_flush_tlb_one_user+0xd/0xe5 [ 78.652693] ? raw_hash_sk+0x21b/0x21b [ 78.653166] ? kernel_init_pages+0x42/0x51 [ 78.653683] ? prep_new_page+0x44/0x51 [ 78.654160] ? get_page_from_freelist+0x72b/0x915 [ 78.654739] ? signal_pending_state+0x77/0x77 [ 78.655284] ? __might_resched+0x8a/0x240 [ 78.655784] ? __might_sleep+0x25/0xa0 [ 78.656255] ? first_zones_zonelist+0x2c/0x43 [ 78.656798] ? __rcu_read_lock+0x2d/0x3a [ 78.657289] ? __pte_offset_map+0x32/0xa4 [ 78.657788] ? __might_resched+0x8a/0x240 [ 78.658291] ? __might_sleep+0x25/0xa0 [ 78.658763] ? inet_send_prepare+0x54/0x54 [ 78.659272] ? sock_sendmsg_nosec+0x42/0x6c [ 78.659791] sock_sendmsg_nosec+0x42/0x6c [ 78.660293] __sys_sendto+0x15d/0x1cc [ 78.660755] ? __x64_sys_getpeername+0x44/0x44 [ 78.661304] ? __handle_mm_fault+0x679/0xae4 [ 78.661838] ? find_vma+0x6b/0x8b [ 78.662272] ? find_vma_intersection+0x8a/0x8a [ 78.662828] ? __handle_irq_event_percpu+0x180/0x197 [ 78.663436] ? handle_mm_fault+0x38/0x154 [ 78.663935] ? handle_mm_fault+0xeb/0x154 [ 78.664435] ? preempt_latency_start+0x29/0x34 [ 78.664987] ? preempt_count_sub+0x14/0xb3 [ 78.665498] ? up_read+0x4b/0x5c [ 78.665911] __x64_sys_sendto+0x76/0x82 [ 78.666398] do_syscall_64+0x6b/0xd7 [ 78.666849] entry_SYSCALL_64_after_hwframe+0x46/0x4e [ 78.667466] RIP: 0033:0x7fed3de99a73 [ 78.667918] Code: 8b 15 a9 83 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 80 3d 71 0b 0d 00 00 41 89 ca 74 14 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 75 c3 0f 1f 40 00 55 48 83 ec 30 44 89 4c 24 [ 78.670097] RSP: 002b:00007ffff6bdf478 EFLAGS: 00000202 ORIG_RAX: 000000000000002c [ 78.671002] RAX: ffffffffffffffda RBX: 000055c538159340 RCX: 00007fed3de99a73 [ 78.671858] RDX: 00000000000007d8 RSI: 000055c53815f3c0 RDI: 0000000000000003 [ 78.672708] RBP: 000055c53815f3c0 R08: 000055c53815b5c0 R09: 0000000000000010 [ 78.673564] R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000007d8 [ 78.674430] R13: 00007ffff6be0b60 R14: 0000001d00000001 R15: 000055c53815c680 [ 78.675287] </TASK> [ 78.675580] Modules linked in: [ 78.675975] CR2: 0000000000000108 [ 78.676396] ---[ end trace 0000000000000000 ]--- [ 78.676966] RIP: 0010:iptfs_output_collect+0x263/0x57b [ 78.677596] Code: 73 70 0f 84 25 01 00 00 45 39 f4 0f 83 1c 01 00 00 48 8d 7b 10 e8 27 37 62 ff 4c 8b 73 10 49 8d be 08 01 00 00 e8 17 37 62 ff <4d> 8b b6 08 01 00 00 49 8d be b0 01 00 00 e8 04 37 62 ff 49 8b 86 [ 78.679768] RSP: 0018:ffffc90000d679c8 EFLAGS: 00010296 [ 78.680410] RAX: 0000000000000001 RBX: ffff888110ffbc80 RCX: fffffbfff07623ad [ 78.681264] RDX: fffffbfff07623ad RSI: fffffbfff07623ad RDI: ffffffff83b11d60 [ 78.682136] RBP: ffff88810e3a1400 R08: 0000000000000008 R09: 0000000000000001 [ 78.682997] R10: ffffffff83b11d67 R11: fffffbfff07623ac R12: 00000000000005a2 [ 78.683853] R13: 0000000000000000 R14: 0000000000000000 R15: ffff88810e9a3401 [ 78.684710] FS: 00007fed3dbddc40(0000) GS:ffffffff82cb2000(0000) knlGS:0000000000000000 [ 78.685675] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 78.686387] CR2: 0000000000000108 CR3: 0000000110e84000 CR4: 0000000000350ef0 [ 78.687246] Kernel panic - not syncing: Fatal exception in interrupt [ 78.688014] Kernel Offset: disabled [ 78.688460] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- ping -s 2000 -n -q -W 1 -c 2 -I 192.0.3.254 192.0.2.254 (gdb) list *iptfs_output_collect+0x263 0xffffffff81d5076f is in iptfs_output_collect (./include/net/net_namespace.h:383). 378 } 379 380 static inline struct net *read_pnet(const possible_net_t *pnet) 381 { 382 #ifdef CONFIG_NET_NS 383 return rcu_dereference_protected(pnet->net, true); 384 #else 385 return &init_net; 386 #endif 387 } I suspect actual crash is from the line 1756 instead, (gdb) list *iptfs_output_collect+0x256 0xffffffff81d50762 is in iptfs_output_collect (net/xfrm/xfrm_iptfs.c:1756). 1751 return 0; 1752 1753 /* We only send ICMP too big if the user has configured us as 1754 * dont-fragment. 1755 */ 1756 XFRM_INC_STATS(dev_net(skb->dev), LINUX_MIB_XFRMOUTERROR); 1757 1758 if (sk) { 1759 xfrm_local_error(skb, pmtu); 1760 } else if (ip_hdr(skb)->version == 4) { Later I ran with gdb iptfs_is_too_big which is called twice and second time it crash. Here is gdb bt. Just before the crash #0 iptfs_is_too_big (pmtu=1442, skb=0xffff88810dbea3c0, sk=0xffff888104d4ed40) at net/xfrm/xfrm_iptfs.c:1756 #1 iptfs_output_collect (net=<optimized out>, sk=0xffff888104d4ed40, skb=0xffff88810dbea3c0) at net/xfrm/xfrm_iptfs.c:1847 #2 0xffffffff81c8a3cb in ip_send_skb (net=0xffffffff83e57f20 <init_net>, skb=0xffff88810dbea3c0) at net/ipv4/ip_output.c:1492 #3 0xffffffff81c8a439 in ip_push_pending_frames (sk=sk@entry=0xffff888104d4ed40, fl4=fl4@entry=0xffffc90000e3fb90) at net/ipv4/ip_output.c:1512 #4 0xffffffff81ccf3cf in raw_sendmsg (sk=0xffff888104d4ed40, msg=0xffffc90000e3fd80, len=<optimized out>) at net/ipv4/raw.c:654 #5 0xffffffff81b096ea in sock_sendmsg_nosec (sock=sock@entry=0xffff888115136040, msg=msg@entry=0xffffc90000e3fd80) at net/socket.c:730 #6 0xffffffff81b0c327 in __sock_sendmsg (msg=0xffffc90000e3fd80, sock=0xffff888115136040) at net/socket.c:745 #7 __sys_sendto (fd=<optimized out>, buff=buff@entry=0x558edefb73c0, len=len@entry=2008, flags=flags@entry=0, addr=addr@entry=0x558edefb35c0, addr_len=addr_len@entry=16) at net/socket.c:2191 #8 0xffffffff81b0c40c in __do_sys_sendto (addr_len=16, addr=0x558edefb35c0, flags=0, len=2008, buff=0x558edefb73c0, fd=<optimized out>) at net/socket.c:2203 #9 __se_sys_sendto (addr_len=16, addr=94072114722240, flags=0, len=2008, buff=94072114738112, fd=<optimized out>) at net/socket.c:2199 gdb) list 1751 return 0; 1752 1753 /* We only send ICMP too big if the user has configured us as 1754 * dont-fragment. 1755 */ 1756 XFRM_INC_STATS(dev_net(skb->dev), LINUX_MIB_XFRMOUTERROR); 1757 1758 if (sk) { 1759 xfrm_local_error(skb, pmtu); 1760 } else if (ip_hdr(skb)->version == 4) { -antony
From: Christian Hopps <chopps@labn.net> Summary of Changes ------------------ This patchset adds a new xfrm mode implementing on-demand IP-TFS. IP-TFS (AggFrag encapsulation) has been standardized in RFC9347. Link: https://www.rfc-editor.org/rfc/rfc9347.txt This feature supports demand driven (i.e., non-constant send rate) IP-TFS to take advantage of the AGGFRAG ESP payload encapsulation. This payload type supports aggregation and fragmentation of the inner IP packet stream which in turn yields higher small-packet bandwidth as well as reducing MTU/PMTU issues. Congestion control is unimplementated as the send rate is demand driven rather than constant. In order to allow loading this fucntionality as a module a set of callbacks xfrm_mode_cbs has been added to xfrm as well. Patchset Changes: ----------------- 23 files changed, 3252 insertions(+), 19 deletions(-) Documentation/networking/xfrm_sysctl.rst | 30 + include/net/netns/xfrm.h | 6 + include/net/xfrm.h | 40 + include/uapi/linux/in.h | 2 + include/uapi/linux/ip.h | 16 + include/uapi/linux/ipsec.h | 3 +- include/uapi/linux/snmp.h | 3 + include/uapi/linux/xfrm.h | 9 +- net/ipv4/esp4.c | 3 +- net/ipv6/esp6.c | 3 +- net/netfilter/nft_xfrm.c | 3 +- net/xfrm/Makefile | 1 + net/xfrm/trace_iptfs.h | 218 +++ net/xfrm/xfrm_compat.c | 10 +- net/xfrm/xfrm_device.c | 4 +- net/xfrm/xfrm_input.c | 14 +- net/xfrm/xfrm_iptfs.c | 2741 ++++++++++++++++++++++++++++++ net/xfrm/xfrm_output.c | 6 + net/xfrm/xfrm_policy.c | 26 +- net/xfrm/xfrm_proc.c | 3 + net/xfrm/xfrm_state.c | 60 + net/xfrm/xfrm_sysctl.c | 38 + net/xfrm/xfrm_user.c | 32 + Patchset Structure: ------------------- The first 8 commits are changes to the xfrm infrastructure to support the callbacks as well as more generic IP-TFS additions that may be used outside the actual IP-TFS implementation. - iptfs: config: add CONFIG_XFRM_IPTFS - iptfs: uapi: ip: add ip_tfs_*_hdr packet formats - iptfs: uapi: IPPROTO_AGGFRAG AGGFRAG in ESP - iptfs: sysctl: allow configuration of global default values - iptfs: netlink: add config (netlink) options - iptfs: xfrm: Add mode_cbs module functionality - iptfs: xfrm: add generic iptfs defines and functionality The last 9+1 commits constitute the IP-TFS implementation constructed in layers to make review easier. The first 9 commits all apply to a single file `net/xfrm/xfrm_iptfs.c`, the last commit adds a new tracepoint header file along with the use of these new tracepoint calls. - iptfs: impl: add new iptfs xfrm mode impl - iptfs: impl: add user packet (tunnel ingress) handling - iptfs: impl: share page fragments of inner packets - iptfs: impl: add fragmenting of larger than MTU user packets - iptfs: impl: add basic receive packet (tunnel egress) handling - iptfs: impl: handle received fragmented inner packets - iptfs: impl: add reusing received skb for the tunnel egress packet - iptfs: impl: add skb-fragment sharing code - iptfs: impl: handle reordering of received packets - iptfs: impl: add tracepoint functionality Patchset History: ----------------- RFCv1 (11/10/2023) RFCv1 -> RFCv2 (11/12/2023) Updates based on feedback from Simon Horman, Antony, Michael Richardson, and kernel test robot. RFCv2 -> v1 (2/19/2024) Updates based on feedback from Sabrina Dubroca, kernel test robot v1 -> v2 (5/19/2024) Updates based on feedback from Sabrina Dubroca, Simon Horman, Antony. o Add handling of new netlink SA direction attribute (Antony). o Split single patch/commit of xfrm_iptfs.c (the actual IP-TFS impl) into 9+1 distinct layered functionality commits for aiding review. - xfrm: fix return check on clone() callback - xfrm: add sa_len() callback in xfrm_mode_cbs for copy to user - iptfs: remove unneeded skb free count variable - iptfs: remove unused variable and "breadcrumb" for future code. - iptfs: use do_div() to avoid "__udivd13 missing" link failure. - iptfs: remove some BUG_ON() assertions questioned in review.