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2020-12-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
xdp_return_frame_bulk() needs to pass a xdp_buff to __xdp_return(). strlcpy got converted to strscpy but here it makes no functional difference, so just keep the right code. Conflicts: net/netfilter/nf_tables_api.c Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-09tcp: Retain ECT bits for tos reflectionWei Wang
For DCTCP, we have to retain the ECT bits set by the congestion control algorithm on the socket when reflecting syn TOS in syn-ack, in order to make ECN work properly. Fixes: ac8f1710c12b ("tcp: reflect tos value received in SYN to the socket") Reported-by: Alexander Duyck <alexanderduyck@fb.com> Signed-off-by: Wei Wang <weiwan@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-03tcp: merge 'init_req' and 'route_req' functionsFlorian Westphal
The Multipath-TCP standard (RFC 8684) says that an MPTCP host should send a TCP reset if the token in a MP_JOIN request is unknown. At this time we don't do this, the 3whs completes and the 'new subflow' is reset afterwards. There are two ways to allow MPTCP to send the reset. 1. override 'send_synack' callback and emit the rst from there. The drawback is that the request socket gets inserted into the listeners queue just to get removed again right away. 2. Send the reset from the 'route_req' function instead. This avoids the 'add&remove request socket', but route_req lacks the skb that is required to send the TCP reset. Instead of just adding the skb to that function for MPTCP sake alone, Paolo suggested to merge init_req and route_req functions. This saves one indirection from syn processing path and provides the skb to the merged function at the same time. 'send reset on unknown mptcp join token' is added in next patch. Suggested-by: Paolo Abeni <pabeni@redhat.com> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Trivial conflict in CAN, keep the net-next + the byteswap wrapper. Conflicts: drivers/net/can/usb/gs_usb.c Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-24tcp: Set ECT0 bit in tos/tclass for synack when BPF needs ECNAlexander Duyck
When a BPF program is used to select between a type of TCP congestion control algorithm that uses either ECN or not there is a case where the synack for the frame was coming up without the ECT0 bit set. A bit of research found that this was due to the final socket being configured to dctcp while the listener socket was staying in cubic. To reproduce it all that is needed is to monitor TCP traffic while running the sample bpf program "samples/bpf/tcp_cong_kern.c". What is observed, assuming tcp_dctcp module is loaded or compiled in and the traffic matches the rules in the sample file, is that for all frames with the exception of the synack the ECT0 bit is set. To address that it is necessary to make one additional call to tcp_bpf_ca_needs_ecn using the request socket and then use the output of that to set the ECT0 bit for the tos/tclass of the packet. Fixes: 91b5b21c7c16 ("bpf: Add support for changing congestion control") Signed-off-by: Alexander Duyck <alexanderduyck@fb.com> Link: https://lore.kernel.org/r/160593039663.2604.1374502006916871573.stgit@localhost.localdomain Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-23tcp: fix race condition when creating child sockets from syncookiesRicardo Dias
When the TCP stack is in SYN flood mode, the server child socket is created from the SYN cookie received in a TCP packet with the ACK flag set. The child socket is created when the server receives the first TCP packet with a valid SYN cookie from the client. Usually, this packet corresponds to the final step of the TCP 3-way handshake, the ACK packet. But is also possible to receive a valid SYN cookie from the first TCP data packet sent by the client, and thus create a child socket from that SYN cookie. Since a client socket is ready to send data as soon as it receives the SYN+ACK packet from the server, the client can send the ACK packet (sent by the TCP stack code), and the first data packet (sent by the userspace program) almost at the same time, and thus the server will equally receive the two TCP packets with valid SYN cookies almost at the same instant. When such event happens, the TCP stack code has a race condition that occurs between the momement a lookup is done to the established connections hashtable to check for the existence of a connection for the same client, and the moment that the child socket is added to the established connections hashtable. As a consequence, this race condition can lead to a situation where we add two child sockets to the established connections hashtable and deliver two sockets to the userspace program to the same client. This patch fixes the race condition by checking if an existing child socket exists for the same client when we are adding the second child socket to the established connections socket. If an existing child socket exists, we drop the packet and discard the second child socket to the same client. Signed-off-by: Ricardo Dias <rdias@singlestore.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20201120111133.GA67501@rdias-suse-pc.lan Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-20tcp: Allow full IP tos/IPv6 tclass to be reflected in L3 headerAlexander Duyck
An issue was recently found where DCTCP SYN/ACK packets did not have the ECT bit set in the L3 header. A bit of code review found that the recent change referenced below had gone though and added a mask that prevented the ECN bits from being populated in the L3 header. This patch addresses that by rolling back the mask so that it is only applied to the flags coming from the incoming TCP request instead of applying it to the socket tos/tclass field. Doing this the ECT bits were restored in the SYN/ACK packets in my testing. One thing that is not addressed by this patch set is the fact that tcp_reflect_tos appears to be incompatible with ECN based congestion avoidance algorithms. At a minimum the feature should likely be documented which it currently isn't. Fixes: ac8f1710c12b ("tcp: reflect tos value received in SYN to the socket") Signed-off-by: Alexander Duyck <alexanderduyck@fb.com> Acked-by: Wei Wang <weiwan@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-14tcp: uninline tcp_stream_memory_free()Eric Dumazet
Both IPv4 and IPv6 needs it via a function pointer. Following patch will avoid the indirect call. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Small conflict around locking in rxrpc_process_event() - channel_lock moved to bundle in next, while state lock needs _bh() from net. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-06tcp: fix receive window update in tcp_add_backlog()Eric Dumazet
We got reports from GKE customers flows being reset by netfilter conntrack unless nf_conntrack_tcp_be_liberal is set to 1. Traces seemed to suggest ACK packet being dropped by the packet capture, or more likely that ACK were received in the wrong order. wscale=7, SYN and SYNACK not shown here. This ACK allows the sender to send 1871*128 bytes from seq 51359321 : New right edge of the window -> 51359321+1871*128=51598809 09:17:23.389210 IP A > B: Flags [.], ack 51359321, win 1871, options [nop,nop,TS val 10 ecr 999], length 0 09:17:23.389212 IP B > A: Flags [.], seq 51422681:51424089, ack 1577, win 268, options [nop,nop,TS val 999 ecr 10], length 1408 09:17:23.389214 IP A > B: Flags [.], ack 51422681, win 1376, options [nop,nop,TS val 10 ecr 999], length 0 09:17:23.389253 IP B > A: Flags [.], seq 51424089:51488857, ack 1577, win 268, options [nop,nop,TS val 999 ecr 10], length 64768 09:17:23.389272 IP A > B: Flags [.], ack 51488857, win 859, options [nop,nop,TS val 10 ecr 999], length 0 09:17:23.389275 IP B > A: Flags [.], seq 51488857:51521241, ack 1577, win 268, options [nop,nop,TS val 999 ecr 10], length 32384 Receiver now allows to send 606*128=77568 from seq 51521241 : New right edge of the window -> 51521241+606*128=51598809 09:17:23.389296 IP A > B: Flags [.], ack 51521241, win 606, options [nop,nop,TS val 10 ecr 999], length 0 09:17:23.389308 IP B > A: Flags [.], seq 51521241:51553625, ack 1577, win 268, options [nop,nop,TS val 999 ecr 10], length 32384 It seems the sender exceeds RWIN allowance, since 51611353 > 51598809 09:17:23.389346 IP B > A: Flags [.], seq 51553625:51611353, ack 1577, win 268, options [nop,nop,TS val 999 ecr 10], length 57728 09:17:23.389356 IP B > A: Flags [.], seq 51611353:51618393, ack 1577, win 268, options [nop,nop,TS val 999 ecr 10], length 7040 09:17:23.389367 IP A > B: Flags [.], ack 51611353, win 0, options [nop,nop,TS val 10 ecr 999], length 0 netfilter conntrack is not happy and sends RST 09:17:23.389389 IP A > B: Flags [R], seq 92176528, win 0, length 0 09:17:23.389488 IP B > A: Flags [R], seq 174478967, win 0, length 0 Now imagine ACK were delivered out of order and tcp_add_backlog() sets window based on wrong packet. New right edge of the window -> 51521241+859*128=51631193 Normally TCP stack handles OOO packets just fine, but it turns out tcp_add_backlog() does not. It can update the window field of the aggregated packet even if the ACK sequence of the last received packet is too old. Many thanks to Alexandre Ferrieux for independently reporting the issue and suggesting a fix. Fixes: 4f693b55c3d2 ("tcp: implement coalescing on backlog queue") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Alexandre Ferrieux <alexandre.ferrieux@orange.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10tcp: reflect tos value received in SYN to the socketWei Wang
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 <weiwan@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10ip: pass tos into ip_build_and_send_pkt()Wei Wang
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 <weiwan@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
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 <davem@davemloft.net>
2020-08-24net: ipv4: delete repeated wordsRandy Dunlap
Drop duplicate words in comments in net/ipv4/. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-24bpf: tcp: Add bpf_skops_hdr_opt_len() and bpf_skops_write_hdr_opt()Martin KaFai Lau
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 <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/bpf/20200820190052.2885316-1-kafai@fb.com
2020-07-25bpf: Refactor to provide aux info to bpf_iter_init_seq_priv_tYonghong Song
This patch refactored target bpf_iter_init_seq_priv_t callback function to accept additional information. This will be needed in later patches for map element targets since a particular map should be passed to traverse elements for that particular map. In the future, other information may be passed to target as well, e.g., pid, cgroup id, etc. to customize the iterator. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184110.590156-1-yhs@fb.com
2020-07-25bpf: Refactor bpf_iter_reg to have separate seq_info memberYonghong Song
There is no functionality change for this patch. Struct bpf_iter_reg is used to register a bpf_iter target, which includes information for both prog_load, link_create and seq_file creation. This patch puts fields related seq_file creation into a different structure. This will be useful for map elements iterator where one iterator covers different map types and different map types may have different seq_ops, init/fini private_data function and private_data size. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184109.590030-1-yhs@fb.com
2020-07-24net/tcp: switch ->md5_parse to sockptr_tChristoph Hellwig
Pass a sockptr_t to prepare for set_fs-less handling of the kernel pointer from bpf-cgroup. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-07-21 The following pull-request contains BPF updates for your *net-next* tree. We've added 46 non-merge commits during the last 6 day(s) which contain a total of 68 files changed, 4929 insertions(+), 526 deletions(-). The main changes are: 1) Run BPF program on socket lookup, from Jakub. 2) Introduce cpumap, from Lorenzo. 3) s390 JIT fixes, from Ilya. 4) teach riscv JIT to emit compressed insns, from Luke. 5) use build time computed BTF ids in bpf iter, from Yonghong. ==================== Purely independent overlapping changes in both filter.h and xdp.h Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-21bpf: net: Use precomputed btf_id for bpf iteratorsYonghong Song
One additional field btf_id is added to struct bpf_ctx_arg_aux to store the precomputed btf_ids. The btf_id is computed at build time with BTF_ID_LIST or BTF_ID_LIST_GLOBAL macro definitions. All existing bpf iterators are changed to used pre-compute btf_ids. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200720163403.1393551-1-yhs@fb.com
2020-07-19net/ipv6: remove compat_ipv6_{get,set}sockoptChristoph Hellwig
Handle the few cases that need special treatment in-line using in_compat_syscall(). This also removes all the now unused compat_{get,set}sockopt methods. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19net/ipv4: remove compat_ip_{get,set}sockoptChristoph Hellwig
Handle the few cases that need special treatment in-line using in_compat_syscall(). Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
All conflicts seemed rather trivial, with some guidance from Saeed Mameed on the tc_ct.c one. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-01tcp: md5: refine tcp_md5_do_add()/tcp_md5_hash_key() barriersEric Dumazet
My prior fix went a bit too far, according to Herbert and Mathieu. Since we accept that concurrent TCP MD5 lookups might see inconsistent keys, we can use READ_ONCE()/WRITE_ONCE() instead of smp_rmb()/smp_wmb() Clearing all key->key[] is needed to avoid possible KMSAN reports, if key->keylen is increased. Since tcp_md5_do_add() is not fast path, using __GFP_ZERO to clear all struct tcp_md5sig_key is simpler. data_race() was added in linux-5.8 and will prevent KCSAN reports, this can safely be removed in stable backports, if data_race() is not yet backported. v2: use data_race() both in tcp_md5_hash_key() and tcp_md5_do_add() Fixes: 6a2febec338d ("tcp: md5: add missing memory barriers in tcp_md5_do_add()/tcp_md5_hash_key()") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Marco Elver <elver@google.com> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-30tcp: md5: add missing memory barriers in tcp_md5_do_add()/tcp_md5_hash_key()Eric Dumazet
MD5 keys are read with RCU protection, and tcp_md5_do_add() might update in-place a prior key. Normally, typical RCU updates would allocate a new piece of memory. In this case only key->key and key->keylen might be updated, and we do not care if an incoming packet could see the old key, the new one, or some intermediate value, since changing the key on a live flow is known to be problematic anyway. We only want to make sure that in the case key->keylen is changed, cpus in tcp_md5_hash_key() wont try to use uninitialized data, or crash because key->keylen was read twice to feed sg_init_one() and ahash_request_set_crypt() Fixes: 9ea88a153001 ("tcp: md5: check md5 signature without socket lock") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-24net: bpf: Implement bpf iterator for tcpYonghong Song
The bpf iterator for tcp is implemented. Both tcp4 and tcp6 sockets will be traversed. It is up to bpf program to filter for tcp4 or tcp6 only, or both families of sockets. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200623230805.3987959-1-yhs@fb.com
2020-06-24net: bpf: Add bpf_seq_afinfo in tcp_iter_stateYonghong Song
A new field bpf_seq_afinfo is added to tcp_iter_state to provide bpf tcp iterator afinfo. There are two reasons on why we did this. First, the current way to get afinfo from PDE_DATA does not work for bpf iterator as its seq_file inode does not conform to /proc/net/{tcp,tcp6} inode structures. More specifically, anonymous bpf iterator will use an anonymous inode which is shared in the system and we cannot change inode private data structure at all. Second, bpf iterator for tcp/tcp6 wants to traverse all tcp and tcp6 sockets in one pass and bpf program can control whether they want to skip one sk_family or not. Having a different afinfo with family AF_UNSPEC make it easier to understand in the code. This patch does not change /proc/net/{tcp,tcp6} behavior as the bpf_seq_afinfo will be NULL for these two proc files. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200623230804.3987829-1-yhs@fb.com
2020-05-28tcp: ipv6: support RFC 6069 (TCP-LD)Eric Dumazet
Make tcp_ld_RTO_revert() helper available to IPv6, and implement RFC 6069 : Quoting this RFC : 3. Connectivity Disruption Indication For Internet Protocol version 6 (IPv6) [RFC2460], the counterpart of the ICMP destination unreachable message of code 0 (net unreachable) and of code 1 (host unreachable) is the ICMPv6 destination unreachable message of code 0 (no route to destination) [RFC4443]. As with IPv4, a router should generate an ICMPv6 destination unreachable message of code 0 in response to a packet that cannot be delivered to its destination address because it lacks a matching entry in its routing table. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-27tcp: rename tcp_v4_err() skb parameterEric Dumazet
This essentially reverts 4d1a2d9ec1c1 ("Revert Backoff [v3]: Rename skb to icmp_skb in tcp_v4_err()") Now we have tcp_ld_RTO_revert() helper, we can use the usual name for sk_buff parameter, so that tcp_v4_err() and tcp_v6_err() use similar names. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-27tcp: add tcp_ld_RTO_revert() helperEric Dumazet
RFC 6069 logic has been implemented for IPv4 only so far, right in the middle of tcp_v4_err() and was error prone. Move this code to one helper, to make tcp_v4_err() more readable and to eventually expand RFC 6069 to IPv6 in the future. Also perform sock_owned_by_user() check a bit sooner. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Tested-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26tcp: tcp_v4_err() icmp skb is named icmp_skbEric Dumazet
I missed the fact that tcp_v4_err() differs from tcp_v6_err(). After commit 4d1a2d9ec1c1 ("Rename skb to icmp_skb in tcp_v4_err()") the skb argument has been renamed to icmp_skb only in one function. I will in a future patch reconciliate these functions to avoid this kind of confusion. Fixes: 45af29ca761c ("tcp: allow traceroute -Mtcp for unpriv users") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-25tcp: allow traceroute -Mtcp for unpriv usersEric Dumazet
Unpriv users can use traceroute over plain UDP sockets, but not TCP ones. $ traceroute -Mtcp 8.8.8.8 You do not have enough privileges to use this traceroute method. $ traceroute -n -Mudp 8.8.8.8 traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets 1 192.168.86.1 3.631 ms 3.512 ms 3.405 ms 2 10.1.10.1 4.183 ms 4.125 ms 4.072 ms 3 96.120.88.125 20.621 ms 19.462 ms 20.553 ms 4 96.110.177.65 24.271 ms 25.351 ms 25.250 ms 5 69.139.199.197 44.492 ms 43.075 ms 44.346 ms 6 68.86.143.93 27.969 ms 25.184 ms 25.092 ms 7 96.112.146.18 25.323 ms 96.112.146.22 25.583 ms 96.112.146.26 24.502 ms 8 72.14.239.204 24.405 ms 74.125.37.224 16.326 ms 17.194 ms 9 209.85.251.9 18.154 ms 209.85.247.55 14.449 ms 209.85.251.9 26.296 ms^C We can easily support traceroute over TCP, by queueing an error message into socket error queue. Note that applications need to set IP_RECVERR/IPV6_RECVERR option to enable this feature, and that the error message is only queued while in SYN_SNT state. socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3 setsockopt(3, SOL_IPV6, IPV6_RECVERR, [1], 4) = 0 setsockopt(3, SOL_SOCKET, SO_TIMESTAMP_OLD, [1], 4) = 0 setsockopt(3, SOL_IPV6, IPV6_UNICAST_HOPS, [5], 4) = 0 connect(3, {sa_family=AF_INET6, sin6_port=htons(8787), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "2002:a05:6608:297::", &sin6_addr), sin6_scope_id=0}, 28) = -1 EHOSTUNREACH (No route to host) recvmsg(3, {msg_name={sa_family=AF_INET6, sin6_port=htons(8787), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "2002:a05:6608:297::", &sin6_addr), sin6_scope_id=0}, msg_namelen=1024->28, msg_iov=[{iov_base="`\r\337\320\0004\6\1&\7\370\260\200\231\16\27\0\0\0\0\0\0\0\0 \2\n\5f\10\2\227"..., iov_len=1024}], msg_iovlen=1, msg_control=[{cmsg_len=32, cmsg_level=SOL_SOCKET, cmsg_type=SO_TIMESTAMP_OLD, cmsg_data={tv_sec=1590340680, tv_usec=272424}}, {cmsg_len=60, cmsg_level=SOL_IPV6, cmsg_type=IPV6_RECVERR}], msg_controllen=96, msg_flags=MSG_ERRQUEUE}, MSG_ERRQUEUE) = 144 Suggested-by: Maciej Żenczykowski <maze@google.com Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Reviewed-by: Maciej Żenczykowski <maze@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30tcp: add hrtimer slack to sack compressionEric Dumazet
Add a sysctl to control hrtimer slack, default of 100 usec. This gives the opportunity to reduce system overhead, and help very short RTT flows. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-12inet: Use fallthrough;Joe Perches
Convert the various uses of fallthrough comments to fallthrough; Done via script Link: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe@perches.com/ And by hand: net/ipv6/ip6_fib.c has a fallthrough comment outside of an #ifdef block that causes gcc to emit a warning if converted in-place. So move the new fallthrough; inside the containing #ifdef/#endif too. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24tcp: ipv4: Pass lockdep expression to RCU listsAmol Grover
md5sig->head maybe traversed using hlist_for_each_entry_rcu outside an RCU read-side critical section but under the protection of socket lock. Hence, add corresponding lockdep expression to silence false-positive warnings, and harden RCU lists. Signed-off-by: Amol Grover <frextrite@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-01-22 The following pull-request contains BPF updates for your *net-next* tree. We've added 92 non-merge commits during the last 16 day(s) which contain a total of 320 files changed, 7532 insertions(+), 1448 deletions(-). The main changes are: 1) function by function verification and program extensions from Alexei. 2) massive cleanup of selftests/bpf from Toke and Andrii. 3) batched bpf map operations from Brian and Yonghong. 4) tcp congestion control in bpf from Martin. 5) bulking for non-map xdp_redirect form Toke. 6) bpf_send_signal_thread helper from Yonghong. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-09tcp: Export TCP functions and ops structMat Martineau
MPTCP will make use of tcp_send_mss() and tcp_push() when sending data to specific TCP subflows. tcp_request_sock_ipvX_ops and ipvX_specific will be referenced during TCP subflow creation. Co-developed-by: Peter Krystad <peter.krystad@linux.intel.com> Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-09bpf: tcp: Support tcp_congestion_ops in bpfMartin KaFai Lau
This patch makes "struct tcp_congestion_ops" to be the first user of BPF STRUCT_OPS. It allows implementing a tcp_congestion_ops in bpf. The BPF implemented tcp_congestion_ops can be used like regular kernel tcp-cc through sysctl and setsockopt. e.g. [root@arch-fb-vm1 bpf]# sysctl -a | egrep congestion net.ipv4.tcp_allowed_congestion_control = reno cubic bpf_cubic net.ipv4.tcp_available_congestion_control = reno bic cubic bpf_cubic net.ipv4.tcp_congestion_control = bpf_cubic There has been attempt to move the TCP CC to the user space (e.g. CCP in TCP). The common arguments are faster turn around, get away from long-tail kernel versions in production...etc, which are legit points. BPF has been the continuous effort to join both kernel and userspace upsides together (e.g. XDP to gain the performance advantage without bypassing the kernel). The recent BPF advancements (in particular BTF-aware verifier, BPF trampoline, BPF CO-RE...) made implementing kernel struct ops (e.g. tcp cc) possible in BPF. It allows a faster turnaround for testing algorithm in the production while leveraging the existing (and continue growing) BPF feature/framework instead of building one specifically for userspace TCP CC. This patch allows write access to a few fields in tcp-sock (in bpf_tcp_ca_btf_struct_access()). The optional "get_info" is unsupported now. It can be added later. One possible way is to output the info with a btf-id to describe the content. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200109003508.3856115-1-kafai@fb.com
2020-01-02net: Add device index to tcp_md5sigDavid Ahern
Add support for userspace to specify a device index to limit the scope of an entry via the TCP_MD5SIG_EXT setsockopt. The existing __tcpm_pad is renamed to tcpm_ifindex and the new field is only checked if the new TCP_MD5SIG_FLAG_IFINDEX is set in tcpm_flags. For now, the device index must point to an L3 master device (e.g., VRF). The API and error handling are setup to allow the constraint to be relaxed in the future to any device index. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-02tcp: Add l3index to tcp_md5sig_key and md5 functionsDavid Ahern
Add l3index to tcp_md5sig_key to represent the L3 domain of a key, and add l3index to tcp_md5_do_add and tcp_md5_do_del to fill in the key. With the key now based on an l3index, add the new parameter to the lookup functions and consider the l3index when looking for a match. The l3index comes from the skb when processing ingress packets leveraging the helpers created for socket lookups, tcp_v4_sdif and inet_iif (and the v6 variants). When the sdif index is set it means the packet ingressed a device that is part of an L3 domain and inet_iif points to the VRF device. For egress, the L3 domain is determined from the socket binding and sk_bound_dev_if. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-02ipv4/tcp: Pass dif and sdif to tcp_v4_inbound_md5_hashDavid Ahern
The original ingress device index is saved to the cb space of the skb and the cb is moved during tcp processing. Since tcp_v4_inbound_md5_hash can be called before and after the cb move, pass dif and sdif to it so the caller can save both prior to the cb move. Both are used by a later patch. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-02ipv4/tcp: Use local variable for tcp_md5_addrDavid Ahern
Extract the typecast to (union tcp_md5_addr *) to a local variable rather than the current long, inline declaration with function calls. No functional change intended. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Mere overlapping changes in the conflicts here. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-13tcp/dccp: fix possible race __inet_lookup_established()Eric Dumazet
Michal Kubecek and Firo Yang did a very nice analysis of crashes happening in __inet_lookup_established(). Since a TCP socket can go from TCP_ESTABLISH to TCP_LISTEN (via a close()/socket()/listen() cycle) without a RCU grace period, I should not have changed listeners linkage in their hash table. They must use the nulls protocol (Documentation/RCU/rculist_nulls.txt), so that a lookup can detect a socket in a hash list was moved in another one. Since we added code in commit d296ba60d8e2 ("soreuseport: Resolve merge conflict for v4/v6 ordering fix"), we have to add hlist_nulls_add_tail_rcu() helper. Fixes: 3b24d854cb35 ("tcp/dccp: do not touch listener sk_refcnt under synflood") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Michal Kubecek <mkubecek@suse.cz> Reported-by: Firo Yang <firo.yang@suse.com> Reviewed-by: Michal Kubecek <mkubecek@suse.cz> Link: https://lore.kernel.org/netdev/20191120083919.GH27852@unicorn.suse.cz/ Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-12-09net-tcp: Disable TCP ssthresh metrics cache by defaultKevin(Yudong) Yang
This patch introduces a sysctl knob "net.ipv4.tcp_no_ssthresh_metrics_save" that disables TCP ssthresh metrics cache by default. Other parts of TCP metrics cache, e.g. rtt, cwnd, remain unchanged. As modern networks becoming more and more dynamic, TCP metrics cache today often causes more harm than benefits. For example, the same IP address is often shared by different subscribers behind NAT in residential networks. Even if the IP address is not shared by different users, caching the slow-start threshold of a previous short flow using loss-based congestion control (e.g. cubic) often causes the future longer flows of the same network path to exit slow-start prematurely with abysmal throughput. Caching ssthresh is very risky and can lead to terrible performance. Therefore it makes sense to make disabling ssthresh caching by default and opt-in for specific networks by the administrators. This practice also has worked well for several years of deployment with CUBIC congestion control at Google. Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Kevin(Yudong) Yang <yyd@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-06net: annotate lockless accesses to sk->sk_ack_backlogEric Dumazet
sk->sk_ack_backlog can be read without any lock being held. We need to use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing and/or potential KCSAN warnings. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
The only slightly tricky merge conflict was the netdevsim because the mutex locking fix overlapped a lot of driver reload reorganization. The rest were (relatively) trivial in nature. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-01inet: stop leaking jiffies on the wireEric Dumazet
Historically linux tried to stick to RFC 791, 1122, 2003 for IPv4 ID field generation. RFC 6864 made clear that no matter how hard we try, we can not ensure unicity of IP ID within maximum lifetime for all datagrams with a given source address/destination address/protocol tuple. Linux uses a per socket inet generator (inet_id), initialized at connection startup with a XOR of 'jiffies' and other fields that appear clear on the wire. Thiemo Nagel pointed that this strategy is a privacy concern as this provides 16 bits of entropy to fingerprint devices. Let's switch to a random starting point, this is just as good as far as RFC 6864 is concerned and does not leak anything critical. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Thiemo Nagel <tnagel@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-31tcp: increase tcp_max_syn_backlog max valueEric Dumazet
tcp_max_syn_backlog default value depends on memory size and TCP ehash size. Before this patch, the max value was 2048 [1], which is considered too small nowadays. Increase it to 4096 to match the recent SOMAXCONN change. [1] This is with TCP ehash size being capped to 524288 buckets. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Yue Cao <ycao009@ucr.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Several cases of overlapping changes which were for the most part trivially resolvable. Signed-off-by: David S. Miller <davem@davemloft.net>