| Message ID | 20171023202223.42600-1-cpaasch@apple.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [v3,net-next] tcp: Configure TFO without cookie per socket and/or per route | expand |
On Mon, Oct 23, 2017 at 1:22 PM, Christoph Paasch <cpaasch@apple.com> wrote: > > We already allow to enable TFO without a cookie by using the > fastopen-sysctl and setting it to TFO_SERVER_COOKIE_NOT_REQD (or > TFO_CLIENT_NO_COOKIE). > This is safe to do in certain environments where we know that there > isn't a malicous host (aka., data-centers) or when the > application-protocol already provides an authentication mechanism in the > first flight of data. > > A server however might be providing multiple services or talking to both > sides (public Internet and data-center). So, this server would want to > enable cookie-less TFO for certain services and/or for connections that > go to the data-center. > > This patch exposes a socket-option and a per-route attribute to enable such > fine-grained configurations. > > Signed-off-by: Christoph Paasch <cpaasch@apple.com> Reviewed-by: Yuchung Cheng <ycheng@google.com> nice work thanks. > --- > > Notes: > v3: * Fix/Clarify commit-log > * Add helper function tcp_fastopen_no_cookie() > * Set tp->fastopen_no_cookie to "val", not 1 in do_tcp_setsockopt(). > v2: * Rename to fastopen_no_cookie and TCP_FASTOPEN_NO_COOKIE > * Add per-route attribute for fastopen_no_cookie > * Get rid of the capability check > > include/linux/tcp.h | 3 ++- > include/net/tcp.h | 3 ++- > include/uapi/linux/rtnetlink.h | 2 ++ > include/uapi/linux/tcp.h | 1 + > net/ipv4/tcp.c | 12 ++++++++++++ > net/ipv4/tcp_fastopen.c | 20 +++++++++++++++++--- > net/ipv4/tcp_input.c | 2 +- > 7 files changed, 37 insertions(+), 6 deletions(-) > > diff --git a/include/linux/tcp.h b/include/linux/tcp.h > index 1d2c44e09e31..173a7c2f9636 100644 > --- a/include/linux/tcp.h > +++ b/include/linux/tcp.h > @@ -215,7 +215,8 @@ struct tcp_sock { > u8 chrono_type:2, /* current chronograph type */ > rate_app_limited:1, /* rate_{delivered,interval_us} limited? */ > fastopen_connect:1, /* FASTOPEN_CONNECT sockopt */ > - unused:4; > + fastopen_no_cookie:1, /* Allow send/recv SYN+data without a cookie */ > + unused:3; > u8 nonagle : 4,/* Disable Nagle algorithm? */ > thin_lto : 1,/* Use linear timeouts for thin streams */ > unused1 : 1, > diff --git a/include/net/tcp.h b/include/net/tcp.h > index 2c13484704cb..2392f74074e7 100644 > --- a/include/net/tcp.h > +++ b/include/net/tcp.h > @@ -1567,7 +1567,8 @@ int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, > void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); > struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, > struct request_sock *req, > - struct tcp_fastopen_cookie *foc); > + struct tcp_fastopen_cookie *foc, > + const struct dst_entry *dst); > void tcp_fastopen_init_key_once(struct net *net); > bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, > struct tcp_fastopen_cookie *cookie); > diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h > index dab7dad9e01a..fe6679268901 100644 > --- a/include/uapi/linux/rtnetlink.h > +++ b/include/uapi/linux/rtnetlink.h > @@ -430,6 +430,8 @@ enum { > #define RTAX_QUICKACK RTAX_QUICKACK > RTAX_CC_ALGO, > #define RTAX_CC_ALGO RTAX_CC_ALGO > + RTAX_FASTOPEN_NO_COOKIE, > +#define RTAX_FASTOPEN_NO_COOKIE RTAX_FASTOPEN_NO_COOKIE > __RTAX_MAX > }; > > diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h > index 69c7493e42f8..d67e1d40c6d6 100644 > --- a/include/uapi/linux/tcp.h > +++ b/include/uapi/linux/tcp.h > @@ -120,6 +120,7 @@ enum { > #define TCP_ULP 31 /* Attach a ULP to a TCP connection */ > #define TCP_MD5SIG_EXT 32 /* TCP MD5 Signature with extensions */ > #define TCP_FASTOPEN_KEY 33 /* Set the key for Fast Open (cookie) */ > +#define TCP_FASTOPEN_NO_COOKIE 34 /* Enable TFO without a TFO cookie */ > > struct tcp_repair_opt { > __u32 opt_code; > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index 8b1fa4dd4538..02eb2f9cce4f 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -2832,6 +2832,14 @@ static int do_tcp_setsockopt(struct sock *sk, int level, > err = -EOPNOTSUPP; > } > break; > + case TCP_FASTOPEN_NO_COOKIE: > + if (val > 1 || val < 0) > + err = -EINVAL; > + else if (!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) > + err = -EINVAL; > + else > + tp->fastopen_no_cookie = val; > + break; > case TCP_TIMESTAMP: > if (!tp->repair) > err = -EPERM; > @@ -3252,6 +3260,10 @@ static int do_tcp_getsockopt(struct sock *sk, int level, > val = tp->fastopen_connect; > break; > > + case TCP_FASTOPEN_NO_COOKIE: > + val = tp->fastopen_no_cookie; > + break; > + > case TCP_TIMESTAMP: > val = tcp_time_stamp_raw() + tp->tsoffset; > break; > diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c > index 21075ce19cb6..e0a4b56644aa 100644 > --- a/net/ipv4/tcp_fastopen.c > +++ b/net/ipv4/tcp_fastopen.c > @@ -310,13 +310,23 @@ static bool tcp_fastopen_queue_check(struct sock *sk) > return true; > } > > +static bool tcp_fastopen_no_cookie(const struct sock *sk, > + const struct dst_entry *dst, > + int flag) > +{ > + return (sock_net(sk)->ipv4.sysctl_tcp_fastopen & flag) || > + tcp_sk(sk)->fastopen_no_cookie || > + (dst && dst_metric(dst, RTAX_FASTOPEN_NO_COOKIE)); > +} > + > /* Returns true if we should perform Fast Open on the SYN. The cookie (foc) > * may be updated and return the client in the SYN-ACK later. E.g., Fast Open > * cookie request (foc->len == 0). > */ > struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, > struct request_sock *req, > - struct tcp_fastopen_cookie *foc) > + struct tcp_fastopen_cookie *foc, > + const struct dst_entry *dst) > { > bool syn_data = TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq + 1; > int tcp_fastopen = sock_net(sk)->ipv4.sysctl_tcp_fastopen; > @@ -333,7 +343,8 @@ struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, > return NULL; > } > > - if (syn_data && (tcp_fastopen & TFO_SERVER_COOKIE_NOT_REQD)) > + if (syn_data && > + tcp_fastopen_no_cookie(sk, dst, TFO_SERVER_COOKIE_NOT_REQD)) > goto fastopen; > > if (foc->len >= 0 && /* Client presents or requests a cookie */ > @@ -370,6 +381,7 @@ bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, > struct tcp_fastopen_cookie *cookie) > { > unsigned long last_syn_loss = 0; > + const struct dst_entry *dst; > int syn_loss = 0; > > tcp_fastopen_cache_get(sk, mss, cookie, &syn_loss, &last_syn_loss); > @@ -387,7 +399,9 @@ bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, > return false; > } > > - if (sock_net(sk)->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_NO_COOKIE) { > + dst = __sk_dst_get(sk); > + > + if (tcp_fastopen_no_cookie(sk, dst, TFO_CLIENT_NO_COOKIE)) { > cookie->len = -1; > return true; > } > diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c > index ab3f12898245..714ba553e545 100644 > --- a/net/ipv4/tcp_input.c > +++ b/net/ipv4/tcp_input.c > @@ -6329,7 +6329,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, > tcp_openreq_init_rwin(req, sk, dst); > if (!want_cookie) { > tcp_reqsk_record_syn(sk, req, skb); > - fastopen_sk = tcp_try_fastopen(sk, skb, req, &foc); > + fastopen_sk = tcp_try_fastopen(sk, skb, req, &foc, dst); > } > if (fastopen_sk) { > af_ops->send_synack(fastopen_sk, dst, &fl, req, > -- > 2.14.1 >
diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 1d2c44e09e31..173a7c2f9636 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -215,7 +215,8 @@ struct tcp_sock { u8 chrono_type:2, /* current chronograph type */ rate_app_limited:1, /* rate_{delivered,interval_us} limited? */ fastopen_connect:1, /* FASTOPEN_CONNECT sockopt */ - unused:4; + fastopen_no_cookie:1, /* Allow send/recv SYN+data without a cookie */ + unused:3; u8 nonagle : 4,/* Disable Nagle algorithm? */ thin_lto : 1,/* Use linear timeouts for thin streams */ unused1 : 1, diff --git a/include/net/tcp.h b/include/net/tcp.h index 2c13484704cb..2392f74074e7 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1567,7 +1567,8 @@ int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, struct request_sock *req, - struct tcp_fastopen_cookie *foc); + struct tcp_fastopen_cookie *foc, + const struct dst_entry *dst); void tcp_fastopen_init_key_once(struct net *net); bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, struct tcp_fastopen_cookie *cookie); diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h index dab7dad9e01a..fe6679268901 100644 --- a/include/uapi/linux/rtnetlink.h +++ b/include/uapi/linux/rtnetlink.h @@ -430,6 +430,8 @@ enum { #define RTAX_QUICKACK RTAX_QUICKACK RTAX_CC_ALGO, #define RTAX_CC_ALGO RTAX_CC_ALGO + RTAX_FASTOPEN_NO_COOKIE, +#define RTAX_FASTOPEN_NO_COOKIE RTAX_FASTOPEN_NO_COOKIE __RTAX_MAX }; diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h index 69c7493e42f8..d67e1d40c6d6 100644 --- a/include/uapi/linux/tcp.h +++ b/include/uapi/linux/tcp.h @@ -120,6 +120,7 @@ enum { #define TCP_ULP 31 /* Attach a ULP to a TCP connection */ #define TCP_MD5SIG_EXT 32 /* TCP MD5 Signature with extensions */ #define TCP_FASTOPEN_KEY 33 /* Set the key for Fast Open (cookie) */ +#define TCP_FASTOPEN_NO_COOKIE 34 /* Enable TFO without a TFO cookie */ struct tcp_repair_opt { __u32 opt_code; diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 8b1fa4dd4538..02eb2f9cce4f 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2832,6 +2832,14 @@ static int do_tcp_setsockopt(struct sock *sk, int level, err = -EOPNOTSUPP; } break; + case TCP_FASTOPEN_NO_COOKIE: + if (val > 1 || val < 0) + err = -EINVAL; + else if (!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) + err = -EINVAL; + else + tp->fastopen_no_cookie = val; + break; case TCP_TIMESTAMP: if (!tp->repair) err = -EPERM; @@ -3252,6 +3260,10 @@ static int do_tcp_getsockopt(struct sock *sk, int level, val = tp->fastopen_connect; break; + case TCP_FASTOPEN_NO_COOKIE: + val = tp->fastopen_no_cookie; + break; + case TCP_TIMESTAMP: val = tcp_time_stamp_raw() + tp->tsoffset; break; diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index 21075ce19cb6..e0a4b56644aa 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -310,13 +310,23 @@ static bool tcp_fastopen_queue_check(struct sock *sk) return true; } +static bool tcp_fastopen_no_cookie(const struct sock *sk, + const struct dst_entry *dst, + int flag) +{ + return (sock_net(sk)->ipv4.sysctl_tcp_fastopen & flag) || + tcp_sk(sk)->fastopen_no_cookie || + (dst && dst_metric(dst, RTAX_FASTOPEN_NO_COOKIE)); +} + /* Returns true if we should perform Fast Open on the SYN. The cookie (foc) * may be updated and return the client in the SYN-ACK later. E.g., Fast Open * cookie request (foc->len == 0). */ struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, struct request_sock *req, - struct tcp_fastopen_cookie *foc) + struct tcp_fastopen_cookie *foc, + const struct dst_entry *dst) { bool syn_data = TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq + 1; int tcp_fastopen = sock_net(sk)->ipv4.sysctl_tcp_fastopen; @@ -333,7 +343,8 @@ struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, return NULL; } - if (syn_data && (tcp_fastopen & TFO_SERVER_COOKIE_NOT_REQD)) + if (syn_data && + tcp_fastopen_no_cookie(sk, dst, TFO_SERVER_COOKIE_NOT_REQD)) goto fastopen; if (foc->len >= 0 && /* Client presents or requests a cookie */ @@ -370,6 +381,7 @@ bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, struct tcp_fastopen_cookie *cookie) { unsigned long last_syn_loss = 0; + const struct dst_entry *dst; int syn_loss = 0; tcp_fastopen_cache_get(sk, mss, cookie, &syn_loss, &last_syn_loss); @@ -387,7 +399,9 @@ bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, return false; } - if (sock_net(sk)->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_NO_COOKIE) { + dst = __sk_dst_get(sk); + + if (tcp_fastopen_no_cookie(sk, dst, TFO_CLIENT_NO_COOKIE)) { cookie->len = -1; return true; } diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index ab3f12898245..714ba553e545 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6329,7 +6329,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, tcp_openreq_init_rwin(req, sk, dst); if (!want_cookie) { tcp_reqsk_record_syn(sk, req, skb); - fastopen_sk = tcp_try_fastopen(sk, skb, req, &foc); + fastopen_sk = tcp_try_fastopen(sk, skb, req, &foc, dst); } if (fastopen_sk) { af_ops->send_synack(fastopen_sk, dst, &fl, req,
We already allow to enable TFO without a cookie by using the fastopen-sysctl and setting it to TFO_SERVER_COOKIE_NOT_REQD (or TFO_CLIENT_NO_COOKIE). This is safe to do in certain environments where we know that there isn't a malicous host (aka., data-centers) or when the application-protocol already provides an authentication mechanism in the first flight of data. A server however might be providing multiple services or talking to both sides (public Internet and data-center). So, this server would want to enable cookie-less TFO for certain services and/or for connections that go to the data-center. This patch exposes a socket-option and a per-route attribute to enable such fine-grained configurations. Signed-off-by: Christoph Paasch <cpaasch@apple.com> --- Notes: v3: * Fix/Clarify commit-log * Add helper function tcp_fastopen_no_cookie() * Set tp->fastopen_no_cookie to "val", not 1 in do_tcp_setsockopt(). v2: * Rename to fastopen_no_cookie and TCP_FASTOPEN_NO_COOKIE * Add per-route attribute for fastopen_no_cookie * Get rid of the capability check include/linux/tcp.h | 3 ++- include/net/tcp.h | 3 ++- include/uapi/linux/rtnetlink.h | 2 ++ include/uapi/linux/tcp.h | 1 + net/ipv4/tcp.c | 12 ++++++++++++ net/ipv4/tcp_fastopen.c | 20 +++++++++++++++++--- net/ipv4/tcp_input.c | 2 +- 7 files changed, 37 insertions(+), 6 deletions(-)