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2020-09-10tcp: Only init congestion control if not initialized alreadyNeal Cardwell3-2/+6
Change tcp_init_transfer() to only initialize congestion control if it has not been initialized already. With this new approach, we can arrange things so that if the EBPF code sets the congestion control by calling setsockopt(TCP_CONGESTION) then tcp_init_transfer() will not re-initialize the CC module. This is an approach that has the following beneficial properties: (1) This allows CC module customizations made by the EBPF called in tcp_init_transfer() to persist, and not be wiped out by a later call to tcp_init_congestion_control() in tcp_init_transfer(). (2) Does not flip the order of EBPF and CC init, to avoid causing bugs for existing code upstream that depends on the current order. (3) Does not cause 2 initializations for for CC in the case where the EBPF called in tcp_init_transfer() wants to set the CC to a new CC algorithm. (4) Allows follow-on simplifications to the code in net/core/filter.c and net/ipv4/tcp_cong.c, which currently both have some complexity to special-case CC initialization to avoid double CC initialization if EBPF sets the CC. Signed-off-by: Neal Cardwell <[email protected]> Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Yuchung Cheng <[email protected]> Acked-by: Kevin Yang <[email protected]> Cc: Lawrence Brakmo <[email protected]>
2020-09-10tcp: reflect tos value received in SYN to the socketWei Wang2-1/+18
This commit adds a new TCP feature to reflect the tos value received in SYN, and send it out on the SYN-ACK, and eventually set the tos value of the established socket with this reflected tos value. This provides a way to set the traffic class/QoS level for all traffic in the same connection to be the same as the incoming SYN request. It could be useful in data centers to provide equivalent QoS according to the incoming request. This feature is guarded by /proc/sys/net/ipv4/tcp_reflect_tos, and is by default turned off. Signed-off-by: Wei Wang <[email protected]> Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-09-10ip: pass tos into ip_build_and_send_pkt()Wei Wang2-3/+5
This commit adds tos as a new passed in parameter to ip_build_and_send_pkt() which will be used in the later commit. This is a pure restructure and does not have any functional change. Signed-off-by: Wei Wang <[email protected]> Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-09-10tcp: record received TOS value in the request socketWei Wang2-3/+4
A new field is added to the request sock to record the TOS value received on the listening socket during 3WHS: When not under syn flood, it is recording the TOS value sent in SYN. When under syn flood, it is recording the TOS value sent in the ACK. This is a preparation patch in order to do TOS reflection in the later commit. Signed-off-by: Wei Wang <[email protected]> Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-09-10ipmr: Use full VIF ID in netlink cache reportsPaul Davey1-1/+1
Insert the full 16 bit VIF ID into ipmr Netlink cache reports. The VIF_ID attribute has 32 bits of space so can store the full VIF ID extracted from the high and low byte fields in the igmpmsg. Signed-off-by: Paul Davey <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-09-10ipmr: Add high byte of VIF ID to igmpmsgPaul Davey1-2/+6
Use the unused3 byte in struct igmpmsg to hold the high 8 bits of the VIF ID. If using more than 255 IPv4 multicast interfaces it is necessary to have access to a VIF ID for cache reports that is wider than 8 bits, the VIF ID present in the igmpmsg reports sent to mroute_sk was only 8 bits wide in the igmpmsg header. Adding the high 8 bits of the 16 bit VIF ID in the unused byte allows use of more than 255 IPv4 multicast interfaces. Signed-off-by: Paul Davey <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-09-10ipmr: Add route table ID to netlink cache reportsPaul Davey1-1/+3
Insert the multicast route table ID as a Netlink attribute to Netlink cache report notifications. When multiple route tables are in use it is necessary to have a way to determine which route table a given cache report belongs to when receiving the cache report. Signed-off-by: Paul Davey <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-09-08ip: fix tos reflection in ack and reset packetsWei Wang1-1/+2
Currently, in tcp_v4_reqsk_send_ack() and tcp_v4_send_reset(), we echo the TOS value of the received packets in the response. However, we do not want to echo the lower 2 ECN bits in accordance with RFC 3168 6.1.5 robustness principles. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Wei Wang <[email protected]> Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-09-08cipso: fix 'audit_secid' kernel-doc warning in cipso_ipv4.cWang Hai1-1/+1
Fixes the following W=1 kernel build warning(s): net/ipv4/cipso_ipv4.c:510: warning: Excess function parameter 'audit_secid' description in 'cipso_v4_doi_remove' Reported-by: Hulk Robot <[email protected]> Signed-off-by: Wang Hai <[email protected]> Acked-by: Paul Moore <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-09-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski3-4/+5
We got slightly different patches removing a double word in a comment in net/ipv4/raw.c - picked the version from net. Simple conflict in drivers/net/ethernet/ibm/ibmvnic.c. Use cached values instead of VNIC login response buffer (following what commit 507ebe6444a4 ("ibmvnic: Fix use-after-free of VNIC login response buffer") did). Signed-off-by: Jakub Kicinski <[email protected]>
2020-09-03ip: expose inet sockopts through inet_diagWei Wang1-0/+17
Expose all exisiting inet sockopt bits through inet_diag for debug purpose. Corresponding changes in iproute2 ss will be submitted to output all these values. Signed-off-by: Wei Wang <[email protected]> Signed-off-by: Eric Dumazet <[email protected]> Signed-off-by: Mahesh Bandewar <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-09-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller8-52/+314
Daniel Borkmann says: ==================== pull-request: bpf-next 2020-09-01 The following pull-request contains BPF updates for your *net-next* tree. There are two small conflicts when pulling, resolve as follows: 1) Merge conflict in tools/lib/bpf/libbpf.c between 88a82120282b ("libbpf: Factor out common ELF operations and improve logging") in bpf-next and 1e891e513e16 ("libbpf: Fix map index used in error message") in net-next. Resolve by taking the hunk in bpf-next: [...] scn = elf_sec_by_idx(obj, obj->efile.btf_maps_shndx); data = elf_sec_data(obj, scn); if (!scn || !data) { pr_warn("elf: failed to get %s map definitions for %s\n", MAPS_ELF_SEC, obj->path); return -EINVAL; } [...] 2) Merge conflict in drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c between 9647c57b11e5 ("xsk: i40e: ice: ixgbe: mlx5: Test for dma_need_sync earlier for better performance") in bpf-next and e20f0dbf204f ("net/mlx5e: RX, Add a prefetch command for small L1_CACHE_BYTES") in net-next. Resolve the two locations by retaining net_prefetch() and taking xsk_buff_dma_sync_for_cpu() from bpf-next. Should look like: [...] xdp_set_data_meta_invalid(xdp); xsk_buff_dma_sync_for_cpu(xdp, rq->xsk_pool); net_prefetch(xdp->data); [...] We've added 133 non-merge commits during the last 14 day(s) which contain a total of 246 files changed, 13832 insertions(+), 3105 deletions(-). The main changes are: 1) Initial support for sleepable BPF programs along with bpf_copy_from_user() helper for tracing to reliably access user memory, from Alexei Starovoitov. 2) Add BPF infra for writing and parsing TCP header options, from Martin KaFai Lau. 3) bpf_d_path() helper for returning full path for given 'struct path', from Jiri Olsa. 4) AF_XDP support for shared umems between devices and queues, from Magnus Karlsson. 5) Initial prep work for full BPF-to-BPF call support in libbpf, from Andrii Nakryiko. 6) Generalize bpf_sk_storage map & add local storage for inodes, from KP Singh. 7) Implement sockmap/hash updates from BPF context, from Lorenz Bauer. 8) BPF xor verification for scalar types & add BPF link iterator, from Yonghong Song. 9) Use target's prog type for BPF_PROG_TYPE_EXT prog verification, from Udip Pant. 10) Rework BPF tracing samples to use libbpf loader, from Daniel T. Lee. 11) Fix xdpsock sample to really cycle through all buffers, from Weqaar Janjua. 12) Improve type safety for tun/veth XDP frame handling, from Maciej Żenczykowski. 13) Various smaller cleanups and improvements all over the place. ==================== Signed-off-by: David S. Miller <[email protected]>
2020-08-31net: ipv4: remove unused arg exact_dif in compute_scoreMiaohe Lin1-4/+2
The arg exact_dif is not used anymore, remove it. inet_exact_dif_match() is no longer needed after the above is removed, so remove it too. Signed-off-by: Miaohe Lin <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-31net: clean up codestyleMiaohe Lin4-9/+11
This is a pure codestyle cleanup patch. No functional change intended. Signed-off-by: Miaohe Lin <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-31net: Use helper macro IP_MAX_MTU in __ip_append_data()Miaohe Lin1-1/+1
What 0xFFFF means here is actually the max mtu of a ip packet. Use help macro IP_MAX_MTU here. Signed-off-by: Miaohe Lin <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-28netfilter: delete repeated wordsRandy Dunlap1-1/+1
Drop duplicated words in net/netfilter/ and net/ipv4/netfilter/. Signed-off-by: Randy Dunlap <[email protected]> Reviewed-by: Florian Westphal <[email protected]> Signed-off-by: Pablo Neira Ayuso <[email protected]>
2020-08-27net: Fix some commentsMiaohe Lin1-1/+1
Fix some comments, including wrong function name, duplicated word and so on. Signed-off-by: Miaohe Lin <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-26ipv4: nexthop: Correctly update nexthop group when replacing a nexthopIdo Schimmel1-0/+32
Each nexthop group contains an indication if it has IPv4 nexthops ('has_v4'). Its purpose is to prevent IPv6 routes from using groups with IPv4 nexthops. However, the indication is not updated when a nexthop is replaced. This results in the kernel wrongly rejecting IPv6 routes from pointing to groups that only contain IPv6 nexthops. Example: # ip nexthop replace id 1 via 192.0.2.2 dev dummy10 # ip nexthop replace id 10 group 1 # ip nexthop replace id 1 via 2001:db8:1::2 dev dummy10 # ip route replace 2001:db8:10::/64 nhid 10 Error: IPv6 routes can not use an IPv4 nexthop. Solve this by iterating over all the nexthop groups that the replaced nexthop is a member of and potentially update their IPv4 indication according to the new set of member nexthops. Avoid wasting cycles by only performing the update in case an IPv4 nexthop is replaced by an IPv6 nexthop. Signed-off-by: Ido Schimmel <[email protected]> Reviewed-by: David Ahern <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-26ipv4: nexthop: Correctly update nexthop group when removing a nexthopIdo Schimmel1-1/+7
Each nexthop group contains an indication if it has IPv4 nexthops ('has_v4'). Its purpose is to prevent IPv6 routes from using groups with IPv4 nexthops. However, the indication is not updated when a nexthop is removed. This results in the kernel wrongly rejecting IPv6 routes from pointing to groups that only contain IPv6 nexthops. Example: # ip nexthop replace id 1 via 192.0.2.2 dev dummy10 # ip nexthop replace id 2 via 2001:db8:1::2 dev dummy10 # ip nexthop replace id 10 group 1/2 # ip nexthop del id 1 # ip route replace 2001:db8:10::/64 nhid 10 Error: IPv6 routes can not use an IPv4 nexthop. Solve this by updating the indication according to the new set of member nexthops. Signed-off-by: Ido Schimmel <[email protected]> Reviewed-by: David Ahern <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-26ipv4: nexthop: Remove unnecessary rtnl_dereference()Ido Schimmel1-1/+1
The pointer is not RCU protected, so remove the unnecessary rtnl_dereference(). This suppresses the following warning: net/ipv4/nexthop.c:1101:24: error: incompatible types in comparison expression (different address spaces): net/ipv4/nexthop.c:1101:24: struct rb_node [noderef] __rcu * net/ipv4/nexthop.c:1101:24: struct rb_node * Signed-off-by: Ido Schimmel <[email protected]> Reviewed-by: David Ahern <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-26ipv4: nexthop: Use nla_put_be32() for NHA_GATEWAYIdo Schimmel1-1/+1
The code correctly uses nla_get_be32() to get the payload of the attribute, but incorrectly uses nla_put_u32() to add the attribute to the payload. This results in the following warning: net/ipv4/nexthop.c:279:59: warning: incorrect type in argument 3 (different base types) net/ipv4/nexthop.c:279:59: expected unsigned int [usertype] value net/ipv4/nexthop.c:279:59: got restricted __be32 [usertype] ipv4 Suppress the warning by using nla_put_be32(). Signed-off-by: Ido Schimmel <[email protected]> Reviewed-by: David Ahern <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-26ipv4: nexthop: Reduce allocation size of 'struct nh_group'Ido Schimmel1-4/+1
The struct looks as follows: struct nh_group { struct nh_group *spare; /* spare group for removals */ u16 num_nh; bool mpath; bool fdb_nh; bool has_v4; struct nh_grp_entry nh_entries[]; }; But its offset within 'struct nexthop' is also taken into account to determine the allocation size. Instead, use struct_size() to allocate only the required number of bytes. Signed-off-by: Ido Schimmel <[email protected]> Reviewed-by: David Ahern <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-26ipv4: Silence suspicious RCU usage warningIdo Schimmel1-1/+2
fib_info_notify_update() is always called with RTNL held, but not from an RCU read-side critical section. This leads to the following warning [1] when the FIB table list is traversed with hlist_for_each_entry_rcu(), but without a proper lockdep expression. Since modification of the list is protected by RTNL, silence the warning by adding a lockdep expression which verifies RTNL is held. [1] ============================= WARNING: suspicious RCU usage 5.9.0-rc1-custom-14233-g2f26e122d62f #129 Not tainted ----------------------------- net/ipv4/fib_trie.c:2124 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by ip/834: #0: ffffffff85a3b6b0 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0 stack backtrace: CPU: 0 PID: 834 Comm: ip Not tainted 5.9.0-rc1-custom-14233-g2f26e122d62f #129 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack+0x100/0x184 lockdep_rcu_suspicious+0x143/0x14d fib_info_notify_update+0x8d1/0xa60 __nexthop_replace_notify+0xd2/0x290 rtm_new_nexthop+0x35e2/0x5946 rtnetlink_rcv_msg+0x4f7/0xbd0 netlink_rcv_skb+0x17a/0x480 rtnetlink_rcv+0x22/0x30 netlink_unicast+0x5ae/0x890 netlink_sendmsg+0x98a/0xf40 ____sys_sendmsg+0x879/0xa00 ___sys_sendmsg+0x122/0x190 __sys_sendmsg+0x103/0x1d0 __x64_sys_sendmsg+0x7d/0xb0 do_syscall_64+0x32/0x50 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fde28c3be57 Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10 RSP: 002b:00007ffc09330028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fde28c3be57 RDX: 0000000000000000 RSI: 00007ffc09330090 RDI: 0000000000000003 RBP: 000000005f45f911 R08: 0000000000000001 R09: 00007ffc0933012c R10: 0000000000000076 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffc09330290 R14: 00007ffc09330eee R15: 00005610e48ed020 Fixes: 1bff1a0c9bbd ("ipv4: Add function to send route updates") Signed-off-by: Ido Schimmel <[email protected]> Reviewed-by: David Ahern <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-25net: clean up codestyle for net/ipv4Miaohe Lin3-20/+23
This is a pure codestyle cleanup patch. Also add a blank line after declarations as warned by checkpatch.pl. Signed-off-by: Miaohe Lin <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-25net: Remove duplicated midx check against 0Miaohe Lin1-3/+2
Check midx against 0 is always equal to check midx against sk_bound_dev_if when sk_bound_dev_if is known not equal to 0 in these case. Signed-off-by: Miaohe Lin <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-25net: Avoid unnecessary inet_addr_type() call when addr is INADDR_ANYMiaohe Lin1-2/+2
We can avoid unnecessary inet_addr_type() call by check addr against INADDR_ANY first. Signed-off-by: Miaohe Lin <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-25net: Set ping saddr after we successfully get the ping portMiaohe Lin1-16/+3
We can defer set ping saddr until we successfully get the ping port. So we can avoid clear saddr when failed. Since ping_clear_saddr() is not used anymore now, remove it. Signed-off-by: Miaohe Lin <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-25net: gain ipv4 mtu when mtu is not lockedMiaohe Lin1-1/+2
When mtu is locked, we should not obtain ipv4 mtu as we return immediately in this case and leave acquired ipv4 mtu unused. Signed-off-by: Miaohe Lin <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-24net: Use helper macro RT_TOS() in __icmp_send()Miaohe Lin1-2/+2
Use helper macro RT_TOS() to get tos in __icmp_send(). Signed-off-by: Miaohe Lin <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-24net: Avoid access icmp_err_convert when icmp code is ICMP_FRAG_NEEDEDMiaohe Lin1-2/+3
There is no need to fetch errno and fatal info from icmp_err_convert when icmp code is ICMP_FRAG_NEEDED. Signed-off-by: Miaohe Lin <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-24net: ipv4: delete repeated wordsRandy Dunlap5-6/+6
Drop duplicate words in comments in net/ipv4/. Signed-off-by: Randy Dunlap <[email protected]> Cc: "David S. Miller" <[email protected]> Cc: Jakub Kicinski <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-24io_uring: allow tcp ancillary data for __sys_recvmsg_sock()Luke Hsiao1-0/+1
For TCP tx zero-copy, the kernel notifies the process of completions by queuing completion notifications on the socket error queue. This patch allows reading these notifications via recvmsg to support TCP tx zero-copy. Ancillary data was originally disallowed due to privilege escalation via io_uring's offloading of sendmsg() onto a kernel thread with kernel credentials (https://crbug.com/project-zero/1975). So, we must ensure that the socket type is one where the ancillary data types that are delivered on recvmsg are plain data (no file descriptors or values that are translated based on the identity of the calling process). This was tested by using io_uring to call recvmsg on the MSG_ERRQUEUE with tx zero-copy enabled. Before this patch, we received -EINVALID from this specific code path. After this patch, we could read tcp tx zero-copy completion notifications from the MSG_ERRQUEUE. Signed-off-by: Soheil Hassas Yeganeh <[email protected]> Signed-off-by: Arjun Roy <[email protected]> Acked-by: Eric Dumazet <[email protected]> Reviewed-by: Jann Horn <[email protected]> Reviewed-by: Jens Axboe <[email protected]> Signed-off-by: Luke Hsiao <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-24tcp: bpf: Optionally store mac header in TCP_SAVE_SYNMartin KaFai Lau2-2/+15
This patch is adapted from Eric's patch in an earlier discussion [1]. The TCP_SAVE_SYN currently only stores the network header and tcp header. This patch allows it to optionally store the mac header also if the setsockopt's optval is 2. It requires one more bit for the "save_syn" bit field in tcp_sock. This patch achieves this by moving the syn_smc bit next to the is_mptcp. The syn_smc is currently used with the TCP experimental option. Since syn_smc is only used when CONFIG_SMC is enabled, this patch also puts the "IS_ENABLED(CONFIG_SMC)" around it like the is_mptcp did with "IS_ENABLED(CONFIG_MPTCP)". The mac_hdrlen is also stored in the "struct saved_syn" to allow a quick offset from the bpf prog if it chooses to start getting from the network header or the tcp header. [1]: https://lore.kernel.org/netdev/CANn89iLJNWh6bkH7DNhy_kmcAexuUCccqERqe7z2QsvPhGrYPQ@mail.gmail.com/ Suggested-by: Eric Dumazet <[email protected]> Signed-off-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-08-24bpf: tcp: Allow bpf prog to write and parse TCP header optionMartin KaFai Lau3-16/+109
[ Note: The TCP changes here is mainly to implement the bpf pieces into the bpf_skops_*() functions introduced in the earlier patches. ] The earlier effort in BPF-TCP-CC allows the TCP Congestion Control algorithm to be written in BPF. It opens up opportunities to allow a faster turnaround time in testing/releasing new congestion control ideas to production environment. The same flexibility can be extended to writing TCP header option. It is not uncommon that people want to test new TCP header option to improve the TCP performance. Another use case is for data-center that has a more controlled environment and has more flexibility in putting header options for internal only use. For example, we want to test the idea in putting maximum delay ACK in TCP header option which is similar to a draft RFC proposal [1]. This patch introduces the necessary BPF API and use them in the TCP stack to allow BPF_PROG_TYPE_SOCK_OPS program to parse and write TCP header options. It currently supports most of the TCP packet except RST. Supported TCP header option: ─────────────────────────── This patch allows the bpf-prog to write any option kind. Different bpf-progs can write its own option by calling the new helper bpf_store_hdr_opt(). The helper will ensure there is no duplicated option in the header. By allowing bpf-prog to write any option kind, this gives a lot of flexibility to the bpf-prog. Different bpf-prog can write its own option kind. It could also allow the bpf-prog to support a recently standardized option on an older kernel. Sockops Callback Flags: ────────────────────── The bpf program will only be called to parse/write tcp header option if the following newly added callback flags are enabled in tp->bpf_sock_ops_cb_flags: BPF_SOCK_OPS_PARSE_UNKNOWN_HDR_OPT_CB_FLAG BPF_SOCK_OPS_PARSE_ALL_HDR_OPT_CB_FLAG BPF_SOCK_OPS_WRITE_HDR_OPT_CB_FLAG A few words on the PARSE CB flags. When the above PARSE CB flags are turned on, the bpf-prog will be called on packets received at a sk that has at least reached the ESTABLISHED state. The parsing of the SYN-SYNACK-ACK will be discussed in the "3 Way HandShake" section. The default is off for all of the above new CB flags, i.e. the bpf prog will not be called to parse or write bpf hdr option. There are details comment on these new cb flags in the UAPI bpf.h. sock_ops->skb_data and bpf_load_hdr_opt() ───────────────────────────────────────── sock_ops->skb_data and sock_ops->skb_data_end covers the whole TCP header and its options. They are read only. The new bpf_load_hdr_opt() helps to read a particular option "kind" from the skb_data. Please refer to the comment in UAPI bpf.h. It has details on what skb_data contains under different sock_ops->op. 3 Way HandShake ─────────────── The bpf-prog can learn if it is sending SYN or SYNACK by reading the sock_ops->skb_tcp_flags. * Passive side When writing SYNACK (i.e. sock_ops->op == BPF_SOCK_OPS_WRITE_HDR_OPT_CB), the received SYN skb will be available to the bpf prog. The bpf prog can use the SYN skb (which may carry the header option sent from the remote bpf prog) to decide what bpf header option should be written to the outgoing SYNACK skb. The SYN packet can be obtained by getsockopt(TCP_BPF_SYN*). More on this later. Also, the bpf prog can learn if it is in syncookie mode (by checking sock_ops->args[0] == BPF_WRITE_HDR_TCP_SYNACK_COOKIE). The bpf prog can store the received SYN pkt by using the existing bpf_setsockopt(TCP_SAVE_SYN). The example in a later patch does it. [ Note that the fullsock here is a listen sk, bpf_sk_storage is not very useful here since the listen sk will be shared by many concurrent connection requests. Extending bpf_sk_storage support to request_sock will add weight to the minisock and it is not necessary better than storing the whole ~100 bytes SYN pkt. ] When the connection is established, the bpf prog will be called in the existing PASSIVE_ESTABLISHED_CB callback. At that time, the bpf prog can get the header option from the saved syn and then apply the needed operation to the newly established socket. The later patch will use the max delay ack specified in the SYN header and set the RTO of this newly established connection as an example. The received ACK (that concludes the 3WHS) will also be available to the bpf prog during PASSIVE_ESTABLISHED_CB through the sock_ops->skb_data. It could be useful in syncookie scenario. More on this later. There is an existing getsockopt "TCP_SAVED_SYN" to return the whole saved syn pkt which includes the IP[46] header and the TCP header. A few "TCP_BPF_SYN*" getsockopt has been added to allow specifying where to start getting from, e.g. starting from TCP header, or from IP[46] header. The new getsockopt(TCP_BPF_SYN*) will also know where it can get the SYN's packet from: - (a) the just received syn (available when the bpf prog is writing SYNACK) and it is the only way to get SYN during syncookie mode. or - (b) the saved syn (available in PASSIVE_ESTABLISHED_CB and also other existing CB). The bpf prog does not need to know where the SYN pkt is coming from. The getsockopt(TCP_BPF_SYN*) will hide this details. Similarly, a flags "BPF_LOAD_HDR_OPT_TCP_SYN" is also added to bpf_load_hdr_opt() to read a particular header option from the SYN packet. * Fastopen Fastopen should work the same as the regular non fastopen case. This is a test in a later patch. * Syncookie For syncookie, the later example patch asks the active side's bpf prog to resend the header options in ACK. The server can use bpf_load_hdr_opt() to look at the options in this received ACK during PASSIVE_ESTABLISHED_CB. * Active side The bpf prog will get a chance to write the bpf header option in the SYN packet during WRITE_HDR_OPT_CB. The received SYNACK pkt will also be available to the bpf prog during the existing ACTIVE_ESTABLISHED_CB callback through the sock_ops->skb_data and bpf_load_hdr_opt(). * Turn off header CB flags after 3WHS If the bpf prog does not need to write/parse header options beyond the 3WHS, the bpf prog can clear the bpf_sock_ops_cb_flags to avoid being called for header options. Or the bpf-prog can select to leave the UNKNOWN_HDR_OPT_CB_FLAG on so that the kernel will only call it when there is option that the kernel cannot handle. [1]: draft-wang-tcpm-low-latency-opt-00 https://tools.ietf.org/html/draft-wang-tcpm-low-latency-opt-00 Signed-off-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-08-24bpf: tcp: Add bpf_skops_hdr_opt_len() and bpf_skops_write_hdr_opt()Martin KaFai Lau3-17/+98
The bpf prog needs to parse the SYN header to learn what options have been sent by the peer's bpf-prog before writing its options into SYNACK. This patch adds a "syn_skb" arg to tcp_make_synack() and send_synack(). This syn_skb will eventually be made available (as read-only) to the bpf prog. This will be the only SYN packet available to the bpf prog during syncookie. For other regular cases, the bpf prog can also use the saved_syn. When writing options, the bpf prog will first be called to tell the kernel its required number of bytes. It is done by the new bpf_skops_hdr_opt_len(). The bpf prog will only be called when the new BPF_SOCK_OPS_WRITE_HDR_OPT_CB_FLAG is set in tp->bpf_sock_ops_cb_flags. When the bpf prog returns, the kernel will know how many bytes are needed and then update the "*remaining" arg accordingly. 4 byte alignment will be included in the "*remaining" before this function returns. The 4 byte aligned number of bytes will also be stored into the opts->bpf_opt_len. "bpf_opt_len" is a newly added member to the struct tcp_out_options. Then the new bpf_skops_write_hdr_opt() will call the bpf prog to write the header options. The bpf prog is only called if it has reserved spaces before (opts->bpf_opt_len > 0). The bpf prog is the last one getting a chance to reserve header space and writing the header option. These two functions are half implemented to highlight the changes in TCP stack. The actual codes preparing the bpf running context and invoking the bpf prog will be added in the later patch with other necessary bpf pieces. Signed-off-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-08-24bpf: tcp: Add bpf_skops_parse_hdr()Martin KaFai Lau1-0/+36
The patch adds a function bpf_skops_parse_hdr(). It will call the bpf prog to parse the TCP header received at a tcp_sock that has at least reached the ESTABLISHED state. For the packets received during the 3WHS (SYN, SYNACK and ACK), the received skb will be available to the bpf prog during the callback in bpf_skops_established() introduced in the previous patch and in the bpf_skops_write_hdr_opt() that will be added in the next patch. Calling bpf prog to parse header is controlled by two new flags in tp->bpf_sock_ops_cb_flags: BPF_SOCK_OPS_PARSE_UNKNOWN_HDR_OPT_CB_FLAG and BPF_SOCK_OPS_PARSE_ALL_HDR_OPT_CB_FLAG. When BPF_SOCK_OPS_PARSE_UNKNOWN_HDR_OPT_CB_FLAG is set, the bpf prog will only be called when there is unknown option in the TCP header. When BPF_SOCK_OPS_PARSE_ALL_HDR_OPT_CB_FLAG is set, the bpf prog will be called on all received TCP header. This function is half implemented to highlight the changes in TCP stack. The actual codes preparing the bpf running context and invoking the bpf prog will be added in the later patch with other necessary bpf pieces. Signed-off-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-08-24bpf: tcp: Add bpf_skops_established()Martin KaFai Lau2-5/+29
In tcp_init_transfer(), it currently calls the bpf prog to give it a chance to handle the just "ESTABLISHED" event (e.g. do setsockopt on the newly established sk). Right now, it is done by calling the general purpose tcp_call_bpf(). In the later patch, it also needs to pass the just-received skb which concludes the 3 way handshake. E.g. the SYNACK received at the active side. The bpf prog can then learn some specific header options written by the peer's bpf-prog and potentially do setsockopt on the newly established sk. Thus, instead of reusing the general purpose tcp_call_bpf(), a new function bpf_skops_established() is added to allow passing the "skb" to the bpf prog. The actual skb passing from bpf_skops_established() to the bpf prog will happen together in a later patch which has the necessary bpf pieces. A "skb" arg is also added to tcp_init_transfer() such that it can then be passed to bpf_skops_established(). Calling the new bpf_skops_established() instead of tcp_call_bpf() should be a noop in this patch. Signed-off-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: John Fastabend <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-08-24tcp: Add saw_unknown to struct tcp_options_receivedMartin KaFai Lau1-6/+16
In a later patch, the bpf prog only wants to be called to handle a header option if that particular header option cannot be handled by the kernel. This unknown option could be written by the peer's bpf-prog. It could also be a new standard option that the running kernel does not support it while a bpf-prog can handle it. This patch adds a "saw_unknown" bit to "struct tcp_options_received" and it uses an existing one byte hole to do that. "saw_unknown" will be set in tcp_parse_options() if it sees an option that the kernel cannot handle. Signed-off-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Acked-by: John Fastabend <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-08-24tcp: bpf: Add TCP_BPF_RTO_MIN for bpf_setsockoptMartin KaFai Lau1-0/+2
This patch adds bpf_setsockopt(TCP_BPF_RTO_MIN) to allow bpf prog to set the min rto of a connection. It could be used together with the earlier patch which has added bpf_setsockopt(TCP_BPF_DELACK_MAX). A later selftest patch will communicate the max delay ack in a bpf tcp header option and then the receiving side can use bpf_setsockopt(TCP_BPF_RTO_MIN) to set a shorter rto. Signed-off-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Acked-by: John Fastabend <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-08-24tcp: bpf: Add TCP_BPF_DELACK_MAX setsockoptMartin KaFai Lau2-0/+4
This change is mostly from an internal patch and adapts it from sysctl config to the bpf_setsockopt setup. The bpf_prog can set the max delay ack by using bpf_setsockopt(TCP_BPF_DELACK_MAX). This max delay ack can be communicated to its peer through bpf header option. The receiving peer can then use this max delay ack and set a potentially lower rto by using bpf_setsockopt(TCP_BPF_RTO_MIN) which will be introduced in the next patch. Another later selftest patch will also use it like the above to show how to write and parse bpf tcp header option. Signed-off-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Acked-by: John Fastabend <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-08-24tcp: Use a struct to represent a saved_synMartin KaFai Lau2-11/+14
The TCP_SAVE_SYN has both the network header and tcp header. The total length of the saved syn packet is currently stored in the first 4 bytes (u32) of an array and the actual packet data is stored after that. A later patch will add a bpf helper that allows to get the tcp header alone from the saved syn without the network header. It will be more convenient to have a direct offset to a specific header instead of re-parsing it. This requires to separately store the network hdrlen. The total header length (i.e. network + tcp) is still needed for the current usage in getsockopt. Although this total length can be obtained by looking into the tcphdr and then get the (th->doff << 2), this patch chooses to directly store the tcp hdrlen in the second four bytes of this newly created "struct saved_syn". By using a new struct, it can give a readable name to each individual header length. Signed-off-by: Martin KaFai Lau <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Reviewed-by: Eric Dumazet <[email protected]> Acked-by: John Fastabend <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-08-22net: nexthop: don't allow empty NHA_GROUPNikolay Aleksandrov1-1/+4
Currently the nexthop code will use an empty NHA_GROUP attribute, but it requires at least 1 entry in order to function properly. Otherwise we end up derefencing null or random pointers all over the place due to not having any nh_grp_entry members allocated, nexthop code relies on having at least the first member present. Empty NHA_GROUP doesn't make any sense so just disallow it. Also add a WARN_ON for any future users of nexthop_create_group(). BUG: kernel NULL pointer dereference, address: 0000000000000080 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP CPU: 0 PID: 558 Comm: ip Not tainted 5.9.0-rc1+ #93 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014 RIP: 0010:fib_check_nexthop+0x4a/0xaa Code: 0f 84 83 00 00 00 48 c7 02 80 03 f7 81 c3 40 80 fe fe 75 12 b8 ea ff ff ff 48 85 d2 74 6b 48 c7 02 40 03 f7 81 c3 48 8b 40 10 <48> 8b 80 80 00 00 00 eb 36 80 78 1a 00 74 12 b8 ea ff ff ff 48 85 RSP: 0018:ffff88807983ba00 EFLAGS: 00010213 RAX: 0000000000000000 RBX: ffff88807983bc00 RCX: 0000000000000000 RDX: ffff88807983bc00 RSI: 0000000000000000 RDI: ffff88807bdd0a80 RBP: ffff88807983baf8 R08: 0000000000000dc0 R09: 000000000000040a R10: 0000000000000000 R11: ffff88807bdd0ae8 R12: 0000000000000000 R13: 0000000000000000 R14: ffff88807bea3100 R15: 0000000000000001 FS: 00007f10db393700(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000080 CR3: 000000007bd0f004 CR4: 00000000003706f0 Call Trace: fib_create_info+0x64d/0xaf7 fib_table_insert+0xf6/0x581 ? __vma_adjust+0x3b6/0x4d4 inet_rtm_newroute+0x56/0x70 rtnetlink_rcv_msg+0x1e3/0x20d ? rtnl_calcit.isra.0+0xb8/0xb8 netlink_rcv_skb+0x5b/0xac netlink_unicast+0xfa/0x17b netlink_sendmsg+0x334/0x353 sock_sendmsg_nosec+0xf/0x3f ____sys_sendmsg+0x1a0/0x1fc ? copy_msghdr_from_user+0x4c/0x61 ___sys_sendmsg+0x63/0x84 ? handle_mm_fault+0xa39/0x11b5 ? sockfd_lookup_light+0x72/0x9a __sys_sendmsg+0x50/0x6e do_syscall_64+0x54/0xbe entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f10dacc0bb7 Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb cd 66 0f 1f 44 00 00 8b 05 9a 4b 2b 00 85 c0 75 2e 48 63 ff 48 63 d2 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 b1 f2 2a 00 f7 d8 64 89 02 48 RSP: 002b:00007ffcbe628bf8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ffcbe628f80 RCX: 00007f10dacc0bb7 RDX: 0000000000000000 RSI: 00007ffcbe628c60 RDI: 0000000000000003 RBP: 000000005f41099c R08: 0000000000000001 R09: 0000000000000008 R10: 00000000000005e9 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffcbe628d70 R15: 0000563a86c6e440 Modules linked in: CR2: 0000000000000080 CC: David Ahern <[email protected]> Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Reported-by: [email protected] Signed-off-by: Nikolay Aleksandrov <[email protected]> Reviewed-by: David Ahern <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-21net: sk_msg: Simplify sk_psock initializationLorenz Bauer2-13/+9
Initializing psock->sk_proto and other saved callbacks is only done in sk_psock_update_proto, after sk_psock_init has returned. The logic for this is difficult to follow, and needlessly complex. Instead, initialize psock->sk_proto whenever we allocate a new psock. Additionally, assert the following invariants: * The SK has no ULP: ULP does it's own finagling of sk->sk_prot * sk_user_data is unused: we need it to store sk_psock Protect our access to sk_user_data with sk_callback_lock, which is what other users like reuseport arrays, etc. do. The result is that an sk_psock is always fully initialized, and that psock->sk_proto is always the "original" struct proto. The latter allows us to use psock->sk_proto when initializing IPv6 TCP / UDP callbacks for sockmap. Signed-off-by: Lorenz Bauer <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: John Fastabend <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-08-20csum_partial_copy_nocheck(): drop the last argumentAl Viro3-3/+3
It's always 0. Note that we theoretically could use ~0U as well - result will be the same modulo 0xffff, _if_ the damn thing did the right thing for any value of initial sum; later we'll make use of that when convenient. However, unlike csum_and_copy_..._user(), there are instances that did not work for arbitrary initial sums; c6x is one such. Signed-off-by: Al Viro <[email protected]>
2020-08-20icmp_push_reply(): reorder adding the checksum upAl Viro1-4/+4
do csum_partial_copy_nocheck() on the first fragment, then add the rest to it. Equivalent transformation. That was the only caller of csum_partial_copy_nocheck() that might pass it non-zero as the last argument. Signed-off-by: Al Viro <[email protected]>
2020-08-20skb_copy_and_csum_bits(): don't bother with the last argumentAl Viro2-3/+3
it's always 0 Signed-off-by: Al Viro <[email protected]>
2020-08-19net: Use generic ns_common::countChristian Brauner2-3/+3
Switch over network namespaces to use the newly introduced common lifetime counter. Network namespaces have an additional counter named "passive". This counter does not guarantee that the network namespace is not already de-initialized and so isn't concerned with the actual lifetime of the network namespace; only the "count" counter is. So the latter is moved into struct ns_common. Currently every namespace type has its own lifetime counter which is stored in the specific namespace struct. The lifetime counters are used identically for all namespaces types. Namespaces may of course have additional unrelated counters and these are not altered. This introduces a common lifetime counter into struct ns_common. The ns_common struct encompasses information that all namespaces share. That should include the lifetime counter since its common for all of them. It also allows us to unify the type of the counters across all namespaces. Most of them use refcount_t but one uses atomic_t and at least one uses kref. Especially the last one doesn't make much sense since it's just a wrapper around refcount_t since 2016 and actually complicates cleanup operations by having to use container_of() to cast the correct namespace struct out of struct ns_common. Having the lifetime counter for the namespaces in one place reduces maintenance cost. Not just because after switching all namespaces over we will have removed more code than we added but also because the logic is more easily understandable and we indicate to the user that the basic lifetime requirements for all namespaces are currently identical. Signed-off-by: Kirill Tkhai <[email protected]> Reviewed-by: Kees Cook <[email protected]> Acked-by: Christian Brauner <[email protected]> [[email protected]: rewrite commit] Link: https://lore.kernel.org/r/159644977635.604812.1319877322927063560.stgit@localhost.localdomain Signed-off-by: Christian Brauner <[email protected]>
2020-08-18net: ipv4: remove duplicate "the the" phrase in Kconfig textColin Ian King1-7/+7
The Kconfig help text contains the phrase "the the" in the help text. Fix this and reformat the block of help text. Signed-off-by: Colin Ian King <[email protected]> Signed-off-by: David S. Miller <[email protected]>
2020-08-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds6-76/+91
Pull networking fixes from David Miller: "Some merge window fallout, some longer term fixes: 1) Handle headroom properly in lapbether and x25_asy drivers, from Xie He. 2) Fetch MAC address from correct r8152 device node, from Thierry Reding. 3) In the sw kTLS path we should allow MSG_CMSG_COMPAT in sendmsg, from Rouven Czerwinski. 4) Correct fdputs in socket layer, from Miaohe Lin. 5) Revert troublesome sockptr_t optimization, from Christoph Hellwig. 6) Fix TCP TFO key reading on big endian, from Jason Baron. 7) Missing CAP_NET_RAW check in nfc, from Qingyu Li. 8) Fix inet fastreuse optimization with tproxy sockets, from Tim Froidcoeur. 9) Fix 64-bit divide in new SFC driver, from Edward Cree. 10) Add a tracepoint for prandom_u32 so that we can more easily perform usage analysis. From Eric Dumazet. 11) Fix rwlock imbalance in AF_PACKET, from John Ogness" * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (49 commits) net: openvswitch: introduce common code for flushing flows af_packet: TPACKET_V3: fix fill status rwlock imbalance random32: add a tracepoint for prandom_u32() Revert "ipv4: tunnel: fix compilation on ARCH=um" net: accept an empty mask in /sys/class/net/*/queues/rx-*/rps_cpus net: ethernet: stmmac: Disable hardware multicast filter net: stmmac: dwmac1000: provide multicast filter fallback ipv4: tunnel: fix compilation on ARCH=um vsock: fix potential null pointer dereference in vsock_poll() sfc: fix ef100 design-param checking net: initialize fastreuse on inet_inherit_port net: refactor bind_bucket fastreuse into helper net: phy: marvell10g: fix null pointer dereference net: Fix potential memory leak in proto_register() net: qcom/emac: add missed clk_disable_unprepare in error path of emac_clks_phase1_init ionic_lif: Use devm_kcalloc() in ionic_qcq_alloc() net/nfc/rawsock.c: add CAP_NET_RAW check. hinic: fix strncpy output truncated compile warnings drivers/net/wan/x25_asy: Added needed_headroom and a skb->len check net/tls: Fix kmap usage ...
2020-08-12Revert "ipv4: tunnel: fix compilation on ARCH=um"David S. Miller1-1/+0
This reverts commit 06a7a37be55e29961c9ba2abec4d07c8e0e21861. The bug was already fixed, this added a dup include. Reported-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]>