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2016-05-04tcp: guarantee forward progress in tcp_sendmsg()Eric Dumazet
Under high rx pressure, it is possible tcp_sendmsg() never has a chance to allocate an skb and loop forever as sk_flush_backlog() would always return true. Fix this by calling sk_flush_backlog() only if one skb had been allocated and filled before last backlog check. Fixes: d41a69f1d390 ("tcp: make tcp_sendmsg() aware of socket backlog") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-02tcp: make tcp_sendmsg() aware of socket backlogEric Dumazet
Large sendmsg()/write() hold socket lock for the duration of the call, unless sk->sk_sndbuf limit is hit. This is bad because incoming packets are parked into socket backlog for a long time. Critical decisions like fast retransmit might be delayed. Receivers have to maintain a big out of order queue with additional cpu overhead, and also possible stalls in TX once windows are full. Bidirectional flows are particularly hurt since the backlog can become quite big if the copy from user space triggers IO (page faults) Some applications learnt to use sendmsg() (or sendmmsg()) with small chunks to avoid this issue. Kernel should know better, right ? Add a generic sk_flush_backlog() helper and use it right before a new skb is allocated. Typically we put 64KB of payload per skb (unless MSG_EOR is requested) and checking socket backlog every 64KB gives good results. As a matter of fact, tests with TSO/GSO disabled give very nice results, as we manage to keep a small write queue and smaller perceived rtt. Note that sk_flush_backlog() maintains socket ownership, so is not equivalent to a {release_sock(sk); lock_sock(sk);}, to ensure implicit atomicity rules that sendmsg() was giving to (possibly buggy) applications. In this simple implementation, I chose to not call tcp_release_cb(), but we might consider this later. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-02tcp: do not block bh during prequeue processingEric Dumazet
AFAIK, nothing in current TCP stack absolutely wants BH being disabled once socket is owned by a thread running in process context. As mentioned in my prior patch ("tcp: give prequeue mode some care"), processing a batch of packets might take time, better not block BH at all. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-02tcp: do not assume TCP code is non preemptibleEric Dumazet
We want to to make TCP stack preemptible, as draining prequeue and backlog queues can take lot of time. Many SNMP updates were assuming that BH (and preemption) was disabled. Need to convert some __NET_INC_STATS() calls to NET_INC_STATS() and some __TCP_INC_STATS() to TCP_INC_STATS() Before using this_cpu_ptr(net->ipv4.tcp_sk) in tcp_v4_send_reset() and tcp_v4_send_ack(), we add an explicit preempt disabled section. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-28tcp: Make use of MSG_EOR in tcp_sendmsgMartin KaFai Lau
This patch adds an eor bit to the TCP_SKB_CB. When MSG_EOR is passed to tcp_sendmsg, the eor bit will be set at the skb containing the last byte of the userland's msg. The eor bit will prevent data from appending to that skb in the future. The change in do_tcp_sendpages is to honor the eor set during the previous tcp_sendmsg(MSG_EOR) call. This patch handles the tcp_sendmsg case. The followup patches will handle other skb coalescing and fragment cases. One potential use case is to use MSG_EOR with SOF_TIMESTAMPING_TX_ACK to get a more accurate TCP ack timestamping on application protocol with multiple outgoing response messages (e.g. HTTP2). Packetdrill script for testing: ~~~~~~ +0 `sysctl -q -w net.ipv4.tcp_min_tso_segs=10` +0 `sysctl -q -w net.ipv4.tcp_no_metrics_save=1` +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 +0 bind(3, ..., ...) = 0 +0 listen(3, 1) = 0 0.100 < S 0:0(0) win 32792 <mss 1460,sackOK,nop,nop,nop,wscale 7> 0.100 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 7> 0.200 < . 1:1(0) ack 1 win 257 0.200 accept(3, ..., ...) = 4 +0 setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0 0.200 write(4, ..., 14600) = 14600 0.200 sendto(4, ..., 730, MSG_EOR, ..., ...) = 730 0.200 sendto(4, ..., 730, MSG_EOR, ..., ...) = 730 0.200 > . 1:7301(7300) ack 1 0.200 > P. 7301:14601(7300) ack 1 0.300 < . 1:1(0) ack 14601 win 257 0.300 > P. 14601:15331(730) ack 1 0.300 > P. 15331:16061(730) ack 1 0.400 < . 1:1(0) ack 16061 win 257 0.400 close(4) = 0 0.400 > F. 16061:16061(0) ack 1 0.400 < F. 1:1(0) ack 16062 win 257 0.400 > . 16062:16062(0) ack 2 Signed-off-by: Martin KaFai Lau <kafai@fb.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Soheil Hassas Yeganeh <soheil@google.com> Cc: Willem de Bruijn <willemb@google.com> Cc: Yuchung Cheng <ycheng@google.com> Suggested-by: Eric Dumazet <edumazet@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-28tcp: remove SKBTX_ACK_TSTAMP since it is redundantSoheil Hassas Yeganeh
The SKBTX_ACK_TSTAMP flag is set in skb_shinfo->tx_flags when the timestamp of the TCP acknowledgement should be reported on error queue. Since accessing skb_shinfo is likely to incur a cache-line miss at the time of receiving the ack, the txstamp_ack bit was added in tcp_skb_cb, which is set iff the SKBTX_ACK_TSTAMP flag is set for an skb. This makes SKBTX_ACK_TSTAMP flag redundant. Remove the SKBTX_ACK_TSTAMP and instead use the txstamp_ack bit everywhere. Note that this frees one bit in shinfo->tx_flags. Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Suggested-by: Willem de Bruijn <willemb@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-28tcp: remove an unnecessary check in tcp_tx_timestampSoheil Hassas Yeganeh
Remove the redundant check for sk->sk_tsflags in tcp_tx_timestamp. tcp_tx_timestamp() receives the tsflags as a parameter. As a result the "sk->sk_tsflags || tsflags" is redundant, since tsflags already includes sk->sk_tsflags plus overrides from control messages. Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-28net: rename NET_{ADD|INC}_STATS_BH()Eric Dumazet
Rename NET_INC_STATS_BH() to __NET_INC_STATS() and NET_ADD_STATS_BH() to __NET_ADD_STATS() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-28net: tcp: rename TCP_INC_STATS_BHEric Dumazet
Rename TCP_INC_STATS_BH() to __TCP_INC_STATS() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-28net: snmp: kill various STATS_USER() helpersEric Dumazet
In the old days (before linux-3.0), SNMP counters were duplicated, one for user context, and one for BH context. After commit 8f0ea0fe3a03 ("snmp: reduce percpu needs by 50%") we have a single copy, and what really matters is preemption being enabled or disabled, since we use this_cpu_inc() or __this_cpu_inc() respectively. We therefore kill SNMP_INC_STATS_USER(), SNMP_ADD_STATS_USER(), NET_INC_STATS_USER(), NET_ADD_STATS_USER(), SCTP_INC_STATS_USER(), SNMP_INC_STATS64_USER(), SNMP_ADD_STATS64_USER(), TCP_ADD_STATS_USER(), UDP_INC_STATS_USER(), UDP6_INC_STATS_USER(), and XFRM_INC_STATS_USER() Following patches will rename __BH helpers to make clear their usage is not tied to BH being disabled. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-04sock: enable timestamping using control messagesSoheil Hassas Yeganeh
Currently, SOL_TIMESTAMPING can only be enabled using setsockopt. This is very costly when users want to sample writes to gather tx timestamps. Add support for enabling SO_TIMESTAMPING via control messages by using tsflags added in `struct sockcm_cookie` (added in the previous patches in this series) to set the tx_flags of the last skb created in a sendmsg. With this patch, the timestamp recording bits in tx_flags of the skbuff is overridden if SO_TIMESTAMPING is passed in a cmsg. Please note that this is only effective for overriding the recording timestamps flags. Users should enable timestamp reporting (e.g., SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_OPT_ID) using socket options and then should ask for SOF_TIMESTAMPING_TX_* using control messages per sendmsg to sample timestamps for each write. Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-04tcp: use one bit in TCP_SKB_CB to mark ACK timestampsSoheil Hassas Yeganeh
Currently, to avoid a cache line miss for accessing skb_shinfo, tcp_ack_tstamp skips socket that do not have SOF_TIMESTAMPING_TX_ACK bit set in sk_tsflags. This is implemented based on an implicit assumption that the SOF_TIMESTAMPING_TX_ACK is set via socket options for the duration that ACK timestamps are needed. To implement per-write timestamps, this check should be removed and replaced with a per-packet alternative that quickly skips packets missing ACK timestamps marks without a cache-line miss. To enable per-packet marking without a cache line miss, use one bit in TCP_SKB_CB to mark a whether a SKB might need a ack tx timestamp or not. Further checks in tcp_ack_tstamp are not modified and work as before. Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: "Highlights: 1) Support more Realtek wireless chips, from Jes Sorenson. 2) New BPF types for per-cpu hash and arrap maps, from Alexei Starovoitov. 3) Make several TCP sysctls per-namespace, from Nikolay Borisov. 4) Allow the use of SO_REUSEPORT in order to do per-thread processing of incoming TCP/UDP connections. The muxing can be done using a BPF program which hashes the incoming packet. From Craig Gallek. 5) Add a multiplexer for TCP streams, to provide a messaged based interface. BPF programs can be used to determine the message boundaries. From Tom Herbert. 6) Add 802.1AE MACSEC support, from Sabrina Dubroca. 7) Avoid factorial complexity when taking down an inetdev interface with lots of configured addresses. We were doing things like traversing the entire address less for each address removed, and flushing the entire netfilter conntrack table for every address as well. 8) Add and use SKB bulk free infrastructure, from Jesper Brouer. 9) Allow offloading u32 classifiers to hardware, and implement for ixgbe, from John Fastabend. 10) Allow configuring IRQ coalescing parameters on a per-queue basis, from Kan Liang. 11) Extend ethtool so that larger link mode masks can be supported. From David Decotigny. 12) Introduce devlink, which can be used to configure port link types (ethernet vs Infiniband, etc.), port splitting, and switch device level attributes as a whole. From Jiri Pirko. 13) Hardware offload support for flower classifiers, from Amir Vadai. 14) Add "Local Checksum Offload". Basically, for a tunneled packet the checksum of the outer header is 'constant' (because with the checksum field filled into the inner protocol header, the payload of the outer frame checksums to 'zero'), and we can take advantage of that in various ways. From Edward Cree" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1548 commits) bonding: fix bond_get_stats() net: bcmgenet: fix dma api length mismatch net/mlx4_core: Fix backward compatibility on VFs phy: mdio-thunder: Fix some Kconfig typos lan78xx: add ndo_get_stats64 lan78xx: handle statistics counter rollover RDS: TCP: Remove unused constant RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket net: smc911x: convert pxa dma to dmaengine team: remove duplicate set of flag IFF_MULTICAST bonding: remove duplicate set of flag IFF_MULTICAST net: fix a comment typo ethernet: micrel: fix some error codes ip_tunnels, bpf: define IP_TUNNEL_OPTS_MAX and use it bpf, dst: add and use dst_tclassid helper bpf: make skb->tc_classid also readable net: mvneta: bm: clarify dependencies cls_bpf: reset class and reuse major in da ldmvsw: Checkpatch sunvnet.c and sunvnet_common.c ldmvsw: Add ldmvsw.c driver code ...
2016-03-17Merge branch 'linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto update from Herbert Xu: "Here is the crypto update for 4.6: API: - Convert remaining crypto_hash users to shash or ahash, also convert blkcipher/ablkcipher users to skcipher. - Remove crypto_hash interface. - Remove crypto_pcomp interface. - Add crypto engine for async cipher drivers. - Add akcipher documentation. - Add skcipher documentation. Algorithms: - Rename crypto/crc32 to avoid name clash with lib/crc32. - Fix bug in keywrap where we zero the wrong pointer. Drivers: - Support T5/M5, T7/M7 SPARC CPUs in n2 hwrng driver. - Add PIC32 hwrng driver. - Support BCM6368 in bcm63xx hwrng driver. - Pack structs for 32-bit compat users in qat. - Use crypto engine in omap-aes. - Add support for sama5d2x SoCs in atmel-sha. - Make atmel-sha available again. - Make sahara hashing available again. - Make ccp hashing available again. - Make sha1-mb available again. - Add support for multiple devices in ccp. - Improve DMA performance in caam. - Add hashing support to rockchip" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (116 commits) crypto: qat - remove redundant arbiter configuration crypto: ux500 - fix checks of error code returned by devm_ioremap_resource() crypto: atmel - fix checks of error code returned by devm_ioremap_resource() crypto: qat - Change the definition of icp_qat_uof_regtype hwrng: exynos - use __maybe_unused to hide pm functions crypto: ccp - Add abstraction for device-specific calls crypto: ccp - CCP versioning support crypto: ccp - Support for multiple CCPs crypto: ccp - Remove check for x86 family and model crypto: ccp - memset request context to zero during import lib/mpi: use "static inline" instead of "extern inline" lib/mpi: avoid assembler warning hwrng: bcm63xx - fix non device tree compatibility crypto: testmgr - allow rfc3686 aes-ctr variants in fips mode. crypto: qat - The AE id should be less than the maximal AE number lib/mpi: Endianness fix crypto: rockchip - add hash support for crypto engine in rk3288 crypto: xts - fix compile errors crypto: doc - add skcipher API documentation crypto: doc - update AEAD AD handling ...
2016-03-14tcp: Add RFC4898 tcpEStatsPerfDataSegsOut/InMartin KaFai Lau
Per RFC4898, they count segments sent/received containing a positive length data segment (that includes retransmission segments carrying data). Unlike tcpi_segs_out/in, tcpi_data_segs_out/in excludes segments carrying no data (e.g. pure ack). The patch also updates the segs_in in tcp_fastopen_add_skb() so that segs_in >= data_segs_in property is kept. Together with retransmission data, tcpi_data_segs_out gives a better signal on the rxmit rate. v6: Rebase on the latest net-next v5: Eric pointed out that checking skb->len is still needed in tcp_fastopen_add_skb() because skb can carry a FIN without data. Hence, instead of open coding segs_in and data_segs_in, tcp_segs_in() helper is used. Comment is added to the fastopen case to explain why segs_in has to be reset and tcp_segs_in() has to be called before __skb_pull(). v4: Add comment to the changes in tcp_fastopen_add_skb() and also add remark on this case in the commit message. v3: Add const modifier to the skb parameter in tcp_segs_in() v2: Rework based on recent fix by Eric: commit a9d99ce28ed3 ("tcp: fix tcpi_segs_in after connection establishment") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Cc: Chris Rapier <rapier@psc.edu> Cc: Eric Dumazet <edumazet@google.com> Cc: Marcelo Ricardo Leitner <mleitner@redhat.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-09tcp: Add tcp_inq to get available receive bytes on socketTom Herbert
Create a common kernel function to get the number of bytes available on a TCP socket. This is based on code in INQ getsockopt and we now call the function for that getsockopt. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/phy/bcm7xxx.c drivers/net/phy/marvell.c drivers/net/vxlan.c All three conflicts were cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-18tcp: correctly crypto_alloc_hash return checkInsu Yun
crypto_alloc_hash never returns NULL Signed-off-by: Insu Yun <wuninsu@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-17tcp: add tcpi_min_rtt and tcpi_notsent_bytes to tcp_infoEric Dumazet
tcpi_min_rtt reports the minimal rtt observed by TCP stack for the flow, in usec unit. Might be ~0U if not yet known. tcpi_notsent_bytes reports the amount of bytes in the write queue that were not yet sent. This is done in a single patch to not add a temporary 32bit padding hole in tcp_info. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-09net:Add sysctl_max_skb_fragsHans Westgaard Ry
Devices may have limits on the number of fragments in an skb they support. Current codebase uses a constant as maximum for number of fragments one skb can hold and use. When enabling scatter/gather and running traffic with many small messages the codebase uses the maximum number of fragments and may thereby violate the max for certain devices. The patch introduces a global variable as max number of fragments. Signed-off-by: Hans Westgaard Ry <hans.westgaard.ry@oracle.com> Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07ipv4: Namespaceify tcp_fin_timeout sysctl knobNikolay Borisov
Signed-off-by: Nikolay Borisov <kernel@kyup.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07ipv4: Namespaceify tcp reordering sysctl knobNikolay Borisov
Signed-off-by: Nikolay Borisov <kernel@kyup.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-07ipv4: Namespaceify tcp syn retries sysctl knobNikolay Borisov
Signed-off-by: Nikolay Borisov <kernel@kyup.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tcp: do not enqueue skb with SYN flagEric Dumazet
If we remove the SYN flag from the skbs that tcp_fastopen_add_skb() places in socket receive queue, then we can remove the test that tcp_recvmsg() has to perform in fast path. All we have to do is to adjust SEQ in the slow path. For the moment, we place an unlikely() and output a message if we find an skb having SYN flag set. Goal would be to get rid of the test completely. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-29tcp: beware of alignments in tcp_get_info()Eric Dumazet
With some combinations of user provided flags in netlink command, it is possible to call tcp_get_info() with a buffer that is not 8-bytes aligned. It does matter on some arches, so we need to use put_unaligned() to store the u64 fields. Current iproute2 package does not trigger this particular issue. Fixes: 0df48c26d841 ("tcp: add tcpi_bytes_acked to tcp_info") Fixes: 977cb0ecf82e ("tcp: add pacing_rate information into tcp_info") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-27tcp: Use ahashHerbert Xu
This patch replaces uses of the long obsolete hash interface with ahash. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: David S. Miller <davem@davemloft.net>
2016-01-15net: tcp_memcontrol: protect all tcp_memcontrol calls by jump-labelJohannes Weiner
Move the jump-label from sock_update_memcg() and sock_release_memcg() to the callsite, and so eliminate those function calls when socket accounting is not enabled. This also eliminates the need for dummy functions because the calls will be optimized away if the Kconfig options are not enabled. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-22net: tcp: deal with listen sockets properly in tcp_abort.Lorenzo Colitti
When closing a listen socket, tcp_abort currently calls tcp_done without clearing the request queue. If the socket has a child socket that is established but not yet accepted, the child socket is then left without a parent, causing a leak. Fix this by setting the socket state to TCP_CLOSE and calling inet_csk_listen_stop with the socket lock held, like tcp_close does. Tested using net_test. With this patch, calling SOCK_DESTROY on a listen socket that has an established but not yet accepted child socket results in the parent and the child being closed, such that they no longer appear in sock_diag dumps. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Lorenzo Colitti <lorenzo@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-18tcp: diag: add support for request sockets to tcp_abort()Eric Dumazet
Adding support for SYN_RECV request sockets to tcp_abort() is quite easy after our tcp listener rewrite. Note that we also need to better handle listeners, or we might leak not yet accepted children, because of a missing inet_csk_listen_stop() call. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Lorenzo Colitti <lorenzo@google.com> Tested-by: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-16net: diag: Support destroying TCP sockets.Lorenzo Colitti
This implements SOCK_DESTROY for TCP sockets. It causes all blocking calls on the socket to fail fast with ECONNABORTED and causes a protocol close of the socket. It informs the other end of the connection by sending a RST, i.e., initiating a TCP ABORT as per RFC 793. ECONNABORTED was chosen for consistency with FreeBSD. Signed-off-by: Lorenzo Colitti <lorenzo@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-15tcp: Fix conditions to determine checksum offloadTom Herbert
In tcp_send_sendpage and tcp_sendmsg we check the route capabilities to determine if checksum offload can be performed. This check currently does not take the IP protocol into account for devices that advertise only one of NETIF_F_IPV6_CSUM or NETIF_F_IP_CSUM. This patch adds a function to check capabilities for checksum offload with a socket called sk_check_csum_caps. This function checks for specific IPv4 or IPv6 offload support based on the family of the socket. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-15net: Rename NETIF_F_ALL_CSUM to NETIF_F_CSUM_MASKTom Herbert
The name NETIF_F_ALL_CSUM is a misnomer. This does not correspond to the set of features for offloading all checksums. This is a mask of the checksum offload related features bits. It is incorrect to set both NETIF_F_HW_CSUM and NETIF_F_IP_CSUM or NETIF_F_IPV6 at the same time for features of a device. This patch: - Changes instances of NETIF_F_ALL_CSUM to NETIF_F_CSUM_MASK (where NETIF_F_ALL_CSUM is being used as a mask). - Changes bonding, sfc/efx, ipvlan, macvlan, vlan, and team drivers to use NEITF_F_HW_CSUM in features list instead of NETIF_F_ALL_CSUM. Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-01net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATAEric Dumazet
This patch is a cleanup to make following patch easier to review. Goal is to move SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA from (struct socket)->flags to a (struct socket_wq)->flags to benefit from RCU protection in sock_wake_async() To ease backports, we rename both constants. Two new helpers, sk_set_bit(int nr, struct sock *sk) and sk_clear_bit(int net, struct sock *sk) are added so that following patch can change their implementation. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-15tcp: ensure proper barriers in lockless contextsEric Dumazet
Some functions access TCP sockets without holding a lock and might output non consistent data, depending on compiler and or architecture. tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ... Introduce sk_state_load() and sk_state_store() to fix the issues, and more clearly document where this lack of locking is happening. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-21tcp: track min RTT using windowed min-filterYuchung Cheng
Kathleen Nichols' algorithm for tracking the minimum RTT of a data stream over some measurement window. It uses constant space and constant time per update. Yet it almost always delivers the same minimum as an implementation that has to keep all the data in the window. The measurement window is tunable via sysctl.net.ipv4.tcp_min_rtt_wlen with a default value of 5 minutes. The algorithm keeps track of the best, 2nd best & 3rd best min values, maintaining an invariant that the measurement time of the n'th best >= n-1'th best. It also makes sure that the three values are widely separated in the time window since that bounds the worse case error when that data is monotonically increasing over the window. Upon getting a new min, we can forget everything earlier because it has no value - the new min is less than everything else in the window by definition and it's the most recent. So we restart fresh on every new min and overwrites the 2nd & 3rd choices. The same property holds for the 2nd & 3rd best. Therefore we have to maintain two invariants to maximize the information in the samples, one on values (1st.v <= 2nd.v <= 3rd.v) and the other on times (now-win <=1st.t <= 2nd.t <= 3rd.t <= now). These invariants determine the structure of the code The RTT input to the windowed filter is the minimum RTT measured from ACK or SACK, or as the last resort from TCP timestamps. The accessor tcp_min_rtt() returns the minimum RTT seen in the window. ~0U indicates it is not available. The minimum is 1usec even if the true RTT is below that. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-07net: ipv4: tcp.c Fixed an assignment coding style issueYuvaraja Mariappan
Fixed an assignment coding style issue Signed-off-by: Yuvaraja Mariappan <ymariappan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29tcp: prepare fastopen code for upcoming listener changesEric Dumazet
While auditing TCP stack for upcoming 'lockless' listener changes, I found I had to change fastopen_init_queue() to properly init the object before publishing it. Otherwise an other cpu could try to lock the spinlock before it gets properly initialized. Instead of adding appropriate barriers, just remove dynamic memory allocations : - Structure is 28 bytes on 64bit arches. Using additional 8 bytes for holding a pointer seems overkill. - Two listeners can share same cache line and performance would suffer. If we really want to save few bytes, we would instead dynamically allocate whole struct request_sock_queue in the future. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-25tcp: fix slow start after idle vs TSO/GSOEric Dumazet
slow start after idle might reduce cwnd, but we perform this after first packet was cooked and sent. With TSO/GSO, it means that we might send a full TSO packet even if cwnd should have been reduced to IW10. Moving the SSAI check in skb_entail() makes sense, because we slightly reduce number of times this check is done, especially for large send() and TCP Small queue callbacks from softirq context. As Neal pointed out, we also need to perform the check if/when receive window opens. Tested: Following packetdrill test demonstrates the problem // Test of slow start after idle `sysctl -q net.ipv4.tcp_slow_start_after_idle=1` 0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 +0 bind(3, ..., ...) = 0 +0 listen(3, 1) = 0 +0 < S 0:0(0) win 65535 <mss 1000,sackOK,nop,nop,nop,wscale 7> +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 6> +.100 < . 1:1(0) ack 1 win 511 +0 accept(3, ..., ...) = 4 +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [200000], 4) = 0 +0 write(4, ..., 26000) = 26000 +0 > . 1:5001(5000) ack 1 +0 > . 5001:10001(5000) ack 1 +0 %{ assert tcpi_snd_cwnd == 10 }% +.100 < . 1:1(0) ack 10001 win 511 +0 %{ assert tcpi_snd_cwnd == 20, tcpi_snd_cwnd }% +0 > . 10001:20001(10000) ack 1 +0 > P. 20001:26001(6000) ack 1 +.100 < . 1:1(0) ack 26001 win 511 +0 %{ assert tcpi_snd_cwnd == 36, tcpi_snd_cwnd }% +4 write(4, ..., 20000) = 20000 // If slow start after idle works properly, we should send 5 MSS here (cwnd/2) +0 > . 26001:31001(5000) ack 1 +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }% +0 > . 31001:36001(5000) ack 1 Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-27tcp: fix recv with flags MSG_WAITALL | MSG_PEEKSabrina Dubroca
Currently, tcp_recvmsg enters a busy loop in sk_wait_data if called with flags = MSG_WAITALL | MSG_PEEK. sk_wait_data waits for sk_receive_queue not empty, but in this case, the receive queue is not empty, but does not contain any skb that we can use. Add a "last skb seen on receive queue" argument to sk_wait_data, so that it sleeps until the receive queue has new skbs. Link: https://bugzilla.kernel.org/show_bug.cgi?id=99461 Link: https://sourceware.org/bugzilla/show_bug.cgi?id=18493 Link: https://bugzilla.redhat.com/show_bug.cgi?id=1205258 Reported-by: Enrico Scholz <rh-bugzilla@ensc.de> Reported-by: Dan Searle <dan@censornet.com> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/ethernet/mellanox/mlx4/main.c net/packet/af_packet.c Both conflicts were cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-23tcp: Do not call tcp_fastopen_reset_cipher from interrupt contextChristoph Paasch
tcp_fastopen_reset_cipher really cannot be called from interrupt context. It allocates the tcp_fastopen_context with GFP_KERNEL and calls crypto_alloc_cipher, which allocates all kind of stuff with GFP_KERNEL. Thus, we might sleep when the key-generation is triggered by an incoming TFO cookie-request which would then happen in interrupt- context, as shown by enabling CONFIG_DEBUG_ATOMIC_SLEEP: [ 36.001813] BUG: sleeping function called from invalid context at mm/slub.c:1266 [ 36.003624] in_atomic(): 1, irqs_disabled(): 0, pid: 1016, name: packetdrill [ 36.004859] CPU: 1 PID: 1016 Comm: packetdrill Not tainted 4.1.0-rc7 #14 [ 36.006085] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [ 36.008250] 00000000000004f2 ffff88007f8838a8 ffffffff8171d53a ffff880075a084a8 [ 36.009630] ffff880075a08000 ffff88007f8838c8 ffffffff810967d3 ffff88007f883928 [ 36.011076] 0000000000000000 ffff88007f8838f8 ffffffff81096892 ffff88007f89be00 [ 36.012494] Call Trace: [ 36.012953] <IRQ> [<ffffffff8171d53a>] dump_stack+0x4f/0x6d [ 36.014085] [<ffffffff810967d3>] ___might_sleep+0x103/0x170 [ 36.015117] [<ffffffff81096892>] __might_sleep+0x52/0x90 [ 36.016117] [<ffffffff8118e887>] kmem_cache_alloc_trace+0x47/0x190 [ 36.017266] [<ffffffff81680d82>] ? tcp_fastopen_reset_cipher+0x42/0x130 [ 36.018485] [<ffffffff81680d82>] tcp_fastopen_reset_cipher+0x42/0x130 [ 36.019679] [<ffffffff81680f01>] tcp_fastopen_init_key_once+0x61/0x70 [ 36.020884] [<ffffffff81680f2c>] __tcp_fastopen_cookie_gen+0x1c/0x60 [ 36.022058] [<ffffffff816814ff>] tcp_try_fastopen+0x58f/0x730 [ 36.023118] [<ffffffff81671788>] tcp_conn_request+0x3e8/0x7b0 [ 36.024185] [<ffffffff810e3872>] ? __module_text_address+0x12/0x60 [ 36.025327] [<ffffffff8167b2e1>] tcp_v4_conn_request+0x51/0x60 [ 36.026410] [<ffffffff816727e0>] tcp_rcv_state_process+0x190/0xda0 [ 36.027556] [<ffffffff81661f97>] ? __inet_lookup_established+0x47/0x170 [ 36.028784] [<ffffffff8167c2ad>] tcp_v4_do_rcv+0x16d/0x3d0 [ 36.029832] [<ffffffff812e6806>] ? security_sock_rcv_skb+0x16/0x20 [ 36.030936] [<ffffffff8167cc8a>] tcp_v4_rcv+0x77a/0x7b0 [ 36.031875] [<ffffffff816af8c3>] ? iptable_filter_hook+0x33/0x70 [ 36.032953] [<ffffffff81657d22>] ip_local_deliver_finish+0x92/0x1f0 [ 36.034065] [<ffffffff81657f1a>] ip_local_deliver+0x9a/0xb0 [ 36.035069] [<ffffffff81657c90>] ? ip_rcv+0x3d0/0x3d0 [ 36.035963] [<ffffffff81657569>] ip_rcv_finish+0x119/0x330 [ 36.036950] [<ffffffff81657ba7>] ip_rcv+0x2e7/0x3d0 [ 36.037847] [<ffffffff81610652>] __netif_receive_skb_core+0x552/0x930 [ 36.038994] [<ffffffff81610a57>] __netif_receive_skb+0x27/0x70 [ 36.040033] [<ffffffff81610b72>] process_backlog+0xd2/0x1f0 [ 36.041025] [<ffffffff81611482>] net_rx_action+0x122/0x310 [ 36.042007] [<ffffffff81076743>] __do_softirq+0x103/0x2f0 [ 36.042978] [<ffffffff81723e3c>] do_softirq_own_stack+0x1c/0x30 This patch moves the call to tcp_fastopen_init_key_once to the places where a listener socket creates its TFO-state, which always happens in user-context (either from the setsockopt, or implicitly during the listen()-call) Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Fixes: 222e83d2e0ae ("tcp: switch tcp_fastopen key generation to net_get_random_once") Signed-off-by: Christoph Paasch <cpaasch@apple.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-16sock_diag: implement a get_info handler for inetCraig Gallek
This get_info handler will simply dispatch to the appropriate existing inet protocol handler. This patch also includes a new netlink attribute (INET_DIAG_PROTOCOL). This attribute is currently only used for multicast messages. Without this attribute, there is no way of knowing the IP protocol used by the socket information being broadcast. This attribute is not necessary in the 'dump' variant of this protocol (though it could easily be added) because dump requests are issued for specific family/protocol pairs. Tested: ss -E (note, the -E option has not yet been merged into the upstream version of ss). Signed-off-by: Craig Gallek <kraig@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-25net: make skb_splice_bits more configureableHannes Frederic Sowa
Prepare skb_splice_bits to be able to deal with AF_UNIX sockets. AF_UNIX sockets don't use lock_sock/release_sock and thus we have to use a callback to make the locking and unlocking configureable. Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/ethernet/cadence/macb.c drivers/net/phy/phy.c include/linux/skbuff.h net/ipv4/tcp.c net/switchdev/switchdev.c Switchdev was a case of RTNH_H_{EXTERNAL --> OFFLOAD} renaming overlapping with net-next changes of various sorts. phy.c was a case of two changes, one adding a local variable to a function whilst the second was removing one. tcp.c overlapped a deadlock fix with the addition of new tcp_info statistic values. macb.c involved the addition of two zyncq device entries. skbuff.h involved adding back ipv4_daddr to nf_bridge_info whilst net-next changes put two other existing members of that struct into a union. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-22tcp: fix a potential deadlock in tcp_get_info()Eric Dumazet
Taking socket spinlock in tcp_get_info() can deadlock, as inet_diag_dump_icsk() holds the &hashinfo->ehash_locks[i], while packet processing can use the reverse locking order. We could avoid this locking for TCP_LISTEN states, but lockdep would certainly get confused as all TCP sockets share same lockdep classes. [ 523.722504] ====================================================== [ 523.728706] [ INFO: possible circular locking dependency detected ] [ 523.734990] 4.1.0-dbg-DEV #1676 Not tainted [ 523.739202] ------------------------------------------------------- [ 523.745474] ss/18032 is trying to acquire lock: [ 523.750002] (slock-AF_INET){+.-...}, at: [<ffffffff81669d44>] tcp_get_info+0x2c4/0x360 [ 523.758129] [ 523.758129] but task is already holding lock: [ 523.763968] (&(&hashinfo->ehash_locks[i])->rlock){+.-...}, at: [<ffffffff816bcb75>] inet_diag_dump_icsk+0x1d5/0x6c0 [ 523.774661] [ 523.774661] which lock already depends on the new lock. [ 523.774661] [ 523.782850] [ 523.782850] the existing dependency chain (in reverse order) is: [ 523.790326] -> #1 (&(&hashinfo->ehash_locks[i])->rlock){+.-...}: [ 523.796599] [<ffffffff811126bb>] lock_acquire+0xbb/0x270 [ 523.802565] [<ffffffff816f5868>] _raw_spin_lock+0x38/0x50 [ 523.808628] [<ffffffff81665af8>] __inet_hash_nolisten+0x78/0x110 [ 523.815273] [<ffffffff816819db>] tcp_v4_syn_recv_sock+0x24b/0x350 [ 523.822067] [<ffffffff81684d41>] tcp_check_req+0x3c1/0x500 [ 523.828199] [<ffffffff81682d09>] tcp_v4_do_rcv+0x239/0x3d0 [ 523.834331] [<ffffffff816842fe>] tcp_v4_rcv+0xa8e/0xc10 [ 523.840202] [<ffffffff81658fa3>] ip_local_deliver_finish+0x133/0x3e0 [ 523.847214] [<ffffffff81659a9a>] ip_local_deliver+0xaa/0xc0 [ 523.853440] [<ffffffff816593b8>] ip_rcv_finish+0x168/0x5c0 [ 523.859624] [<ffffffff81659db7>] ip_rcv+0x307/0x420 Lets use u64_sync infrastructure instead. As a bonus, 64bit arches get optimized, as these are nop for them. Fixes: 0df48c26d841 ("tcp: add tcpi_bytes_acked to tcp_info") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-22tcp: add tcpi_segs_in and tcpi_segs_out to tcp_infoMarcelo Ricardo Leitner
This patch tracks the total number of inbound and outbound segments on a TCP socket. One may use this number to have an idea on connection quality when compared against the retransmissions. RFC4898 named these : tcpEStatsPerfSegsIn and tcpEStatsPerfSegsOut These are a 32bit field each and can be fetched both from TCP_INFO getsockopt() if one has a handle on a TCP socket, or from inet_diag netlink facility (iproute2/ss patch will follow) Note that tp->segs_out was placed near tp->snd_nxt for good data locality and minimal performance impact, while tp->segs_in was placed near tp->bytes_received for the same reason. Join work with Eric Dumazet. Note that received SYN are accounted on the listener, but sent SYNACK are not accounted. Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-21tcp: ensure epoll edge trigger wakeup when write queue is emptyJason Baron
We currently rely on the setting of SOCK_NOSPACE in the write() path to ensure that we wake up any epoll edge trigger waiters when acks return to free space in the write queue. However, if we fail to allocate even a single skb in the write queue, we could end up waiting indefinitely. Fix this by explicitly issuing a wakeup when we detect the condition of an empty write queue and a return value of -EAGAIN. This allows userspace to re-try as we expect this to be a temporary failure. I've tested this approach by artificially making sk_stream_alloc_skb() return NULL periodically. In that case, epoll edge trigger waiters will hang indefinitely in epoll_wait() without this patch. Signed-off-by: Jason Baron <jbaron@akamai.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-21tcp: add a force_schedule argument to sk_stream_alloc_skb()Eric Dumazet
In commit 8e4d980ac215 ("tcp: fix behavior for epoll edge trigger") we fixed a possible hang of TCP sockets under memory pressure, by allowing sk_stream_alloc_skb() to use sk_forced_mem_schedule() if no packet is in socket write queue. It turns out there are other cases where we want to force memory schedule : tcp_fragment() & tso_fragment() need to split a big TSO packet into two smaller ones. If we block here because of TCP memory pressure, we can effectively block TCP socket from sending new data. If no further ACK is coming, this hang would be definitive, and socket has no chance to effectively reduce its memory usage. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-19tcp: Return error instead of partial read for saved syn headersEric B Munson
Currently the getsockopt() requesting the cached contents of the syn packet headers will fail silently if the caller uses a buffer that is too small to contain the requested data. Rather than fail silently and discard the headers, getsockopt() should return an error and report the required size to hold the data. Signed-off-by: Eric B Munson <emunson@akamai.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: James Morris <jmorris@namei.org> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Patrick McHardy <kaber@trash.net> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-18tcp: halves tcp_mem[] limitsEric Dumazet
Allowing tcp to use ~19% of physical memory is way too much, and allowed bugs to be hidden. Add to this that some drivers use a full page per incoming frame, so real cost can be twice the advertized one. Reduce tcp_mem by 50 % as a first step to sanity. tcp_mem[0,1,2] defaults are now 4.68%, 6.25%, 9.37% of physical memory. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>