summaryrefslogtreecommitdiffstats
path: root/net/ipv4/tcp_fastopen.c
Commit message (Collapse)AuthorAgeFilesLines
...
* inet: fix request sock refcountingEric Dumazet2015-03-171-0/+1
| | | | | | | | | | | | | | | | | While testing last patch series, I found req sock refcounting was wrong. We must set skc_refcnt to 1 for all request socks added in hashes, but also on request sockets created by FastOpen or syncookies. It is tricky because we need to defer this initialization so that future RCU lookups do not try to take a refcount on a not yet fully initialized request socket. Also get rid of ireq_refcnt alias. Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: 13854e5a6046 ("inet: add proper refcounting to request sock") Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: rename struct tcp_request_sock listenerEric Dumazet2015-03-171-6/+1
| | | | | | | | | The listener field in struct tcp_request_sock is a pointer back to the listener. We now have req->rsk_listener, so TCP only needs one boolean and not a full pointer. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: add proper refcounting to request sockEric Dumazet2015-03-161-1/+1
| | | | | | | | | | | | | | | | reqsk_put() is the generic function that should be used to release a refcount (and automatically call reqsk_free()) reqsk_free() might be called if refcount is known to be 0 or undefined. refcnt is set to one in inet_csk_reqsk_queue_add() As request socks are not yet in global ehash table, I added temporary debugging checks in reqsk_put() and reqsk_free() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: cleanup static functionsEric Dumazet2015-02-281-1/+0
| | | | | | | | | tcp_fastopen_create_child() is static and should not be exported. tcp4_gso_segment() and tcp6_gso_segment() should be static. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: make sure skb is not shared before using skb_get()Eric Dumazet2015-02-131-8/+24
| | | | | | | | | | | | | | | IPv6 can keep a copy of SYN message using skb_get() in tcp_v6_conn_request() so that caller wont free the skb when calling kfree_skb() later. Therefore TCP fast open has to clone the skb it is queuing in child->sk_receive_queue, as all skbs consumed from receive_queue are freed using __kfree_skb() (ie assuming skb->users == 1) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Fixes: 5b7ed0892f2af ("tcp: move fastopen functions to tcp_fastopen.c") Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: don't include Fast Open option in SYN-ACK on pure SYN-dataYuchung Cheng2015-02-091-5/+8
| | | | | | | | | | | | | | | | If a server has enabled Fast Open and it receives a pure SYN-data packet (without a Fast Open option), it won't accept the data but it incorrectly returns a SYN-ACK with a Fast Open cookie and also increments the SNMP stat LINUX_MIB_TCPFASTOPENPASSIVEFAIL. This patch makes the server include a Fast Open cookie in SYN-ACK only if the SYN has some Fast Open option (i.e., when client requests or presents a cookie). Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: remove unnecessary assignment.Li RongQing2014-09-291-1/+1
| | | | | | | This variable i is overwritten to 0 by following code Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: remove unnecessary tcp_sk assignment.Dave Jones2014-06-161-1/+1
| | | | | | | | This variable is overwritten by the child socket assignment before it ever gets used. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: IPv6 support for fastopen serverDaniel Lee2014-05-131-14/+43
| | | | | | | | | | | | | | After all the preparatory works, supporting IPv6 in Fast Open is now easy. We pretty much just mirror v4 code. The only difference is how we generate the Fast Open cookie for IPv6 sockets. Since Fast Open cookie is 128 bits and we use AES 128, we use CBC-MAC to encrypt both the source and destination IPv6 addresses since the cookie is a MAC tag. Signed-off-by: Daniel Lee <longinus00@gmail.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Jerry Chu <hkchu@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: use tcp_v4_send_synack on first SYN-ACKYuchung Cheng2014-05-131-36/+31
| | | | | | | | | | | | | | | | | | | | To avoid large code duplication in IPv6, we need to first simplify the complicate SYN-ACK sending code in tcp_v4_conn_request(). To use tcp_v4(6)_send_synack() to send all SYN-ACKs, we need to initialize the mini socket's receive window before trying to create the child socket and/or building the SYN-ACK packet. So we move that initialization from tcp_make_synack() to tcp_v4_conn_request() as a new function tcp_openreq_init_req_rwin(). After this refactoring the SYN-ACK sending code is simpler and easier to implement Fast Open for IPv6. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Daniel Lee <longinus00@gmail.com> Signed-off-by: Jerry Chu <hkchu@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: simplify fast open cookie processingYuchung Cheng2014-05-131-43/+28
| | | | | | | | | | | | | | | | | Consolidate various cookie checking and generation code to simplify the fast open processing. The main goal is to reduce code duplication in tcp_v4_conn_request() for IPv6 support. Removes two experimental sysctl flags TFO_SERVER_ALWAYS and TFO_SERVER_COOKIE_NOT_CHKD used primarily for developmental debugging purposes. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Daniel Lee <longinus00@gmail.com> Signed-off-by: Jerry Chu <hkchu@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: move fastopen functions to tcp_fastopen.cYuchung Cheng2014-05-131-0/+190
| | | | | | | | | | | | Move common TFO functions that will be used by both v4 and v6 to tcp_fastopen.c. Create a helper tcp_fastopen_queue_check(). Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Daniel Lee <longinus00@gmail.com> Signed-off-by: Jerry Chu <hkchu@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: enable sockets to use MSG_FASTOPEN by defaultYuchung Cheng2013-11-041-1/+1
| | | | | | | | | | | | | Applications have started to use Fast Open (e.g., Chrome browser has such an optional flag) and the feature has gone through several generations of kernels since 3.7 with many real network tests. It's time to enable this flag by default for applications to test more conveniently and extensively. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: switch tcp_fastopen key generation to net_get_random_onceHannes Frederic Sowa2013-10-191-11/+16
| | | | | | | | | | | | | | Changed key initialization of tcp_fastopen cookies to net_get_random_once. If the user sets a custom key net_get_random_once must be called at least once to ensure we don't overwrite the user provided key when the first cookie is generated later on. Cc: Yuchung Cheng <ycheng@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: add server ip to encrypt cookie in fast openYuchung Cheng2013-08-101-7/+6
| | | | | | | | | | | | Encrypt the cookie with both server and client IPv4 addresses, such that multi-homed server will grant different cookies based on both the source and destination IPs. No client change is needed since cookie is opaque to the client. Signed-off-by: Yuchung Cheng <ycheng@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: TCP Fast Open Server - header & support functionsJerry Chu2012-08-311-1/+82
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds all the necessary data structure and support functions to implement TFO server side. It also documents a number of flags for the sysctl_tcp_fastopen knob, and adds a few Linux extension MIBs. In addition, it includes the following: 1. a new TCP_FASTOPEN socket option an application must call to supply a max backlog allowed in order to enable TFO on its listener. 2. A number of key data structures: "fastopen_rsk" in tcp_sock - for a big socket to access its request_sock for retransmission and ack processing purpose. It is non-NULL iff 3WHS not completed. "fastopenq" in request_sock_queue - points to a per Fast Open listener data structure "fastopen_queue" to keep track of qlen (# of outstanding Fast Open requests) and max_qlen, among other things. "listener" in tcp_request_sock - to point to the original listener for book-keeping purpose, i.e., to maintain qlen against max_qlen as part of defense against IP spoofing attack. 3. various data structure and functions, many in tcp_fastopen.c, to support server side Fast Open cookie operations, including /proc/sys/net/ipv4/tcp_fastopen_key to allow manual rekeying. Signed-off-by: H.K. Jerry Chu <hkchu@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net-tcp: Fast Open baseYuchung Cheng2012-07-191-0/+11
This patch impelements the common code for both the client and server. 1. TCP Fast Open option processing. Since Fast Open does not have an option number assigned by IANA yet, it shares the experiment option code 254 by implementing draft-ietf-tcpm-experimental-options with a 16 bits magic number 0xF989. This enables global experiments without clashing the scarce(2) experimental options available for TCP. When the draft status becomes standard (maybe), the client should switch to the new option number assigned while the server supports both numbers for transistion. 2. The new sysctl tcp_fastopen 3. A place holder init function Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>