From: Michael Chan Date: Thu, 29 Jun 2006 19:30:00 +0000 (-0700) Subject: [NET]: Add ECN support for TSO X-Git-Tag: v2.6.18-rc1~321^2~16 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b0da8537037f337103348f239ad901477e907aa8;p=linux-2.6 [NET]: Add ECN support for TSO In the current TSO implementation, NETIF_F_TSO and ECN cannot be turned on together in a TCP connection. The problem is that most hardware that supports TSO does not handle CWR correctly if it is set in the TSO packet. Correct handling requires CWR to be set in the first packet only if it is set in the TSO header. This patch adds the ability to turn on NETIF_F_TSO and ECN using GSO if necessary to handle TSO packets with CWR set. Hardware that handles CWR correctly can turn on NETIF_F_TSO_ECN in the dev-> features flag. All TSO packets with CWR set will have the SKB_GSO_TCPV4_ECN set. If the output device does not have the NETIF_F_TSO_ECN feature set, GSO will split the packet up correctly with CWR only set in the first segment. With help from Herbert Xu . Since ECN can always be enabled with TSO, the SOCK_NO_LARGESEND sock flag is completely removed. Signed-off-by: Michael Chan Signed-off-by: David S. Miller --- diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index efd1e2af0b..aa2d3c12c4 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -316,6 +316,7 @@ struct net_device #define NETIF_F_TSO (SKB_GSO_TCPV4 << NETIF_F_GSO_SHIFT) #define NETIF_F_UFO (SKB_GSO_UDPV4 << NETIF_F_GSO_SHIFT) #define NETIF_F_GSO_ROBUST (SKB_GSO_DODGY << NETIF_F_GSO_SHIFT) +#define NETIF_F_TSO_ECN (SKB_GSO_TCPV4_ECN << NETIF_F_GSO_SHIFT) #define NETIF_F_GEN_CSUM (NETIF_F_NO_CSUM | NETIF_F_HW_CSUM) #define NETIF_F_ALL_CSUM (NETIF_F_IP_CSUM | NETIF_F_GEN_CSUM) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 5fb72da7da..e74c294929 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -175,6 +175,9 @@ enum { /* This indicates the skb is from an untrusted source. */ SKB_GSO_DODGY = 1 << 2, + + /* This indicates the tcp segment has CWR set. */ + SKB_GSO_TCPV4_ECN = 1 << 3, }; /** diff --git a/include/net/sock.h b/include/net/sock.h index 2d8d6adf16..7136bae48c 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -383,7 +383,6 @@ enum sock_flags { SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */ SOCK_DBG, /* %SO_DEBUG setting */ SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */ - SOCK_NO_LARGESEND, /* whether to sent large segments or not */ SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */ SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */ }; @@ -1033,7 +1032,7 @@ static inline void sk_setup_caps(struct sock *sk, struct dst_entry *dst) if (sk->sk_route_caps & NETIF_F_GSO) sk->sk_route_caps |= NETIF_F_TSO; if (sk->sk_route_caps & NETIF_F_TSO) { - if (sock_flag(sk, SOCK_NO_LARGESEND) || dst->header_len) + if (dst->header_len) sk->sk_route_caps &= ~NETIF_F_TSO; else sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM; diff --git a/include/net/tcp_ecn.h b/include/net/tcp_ecn.h index c6b8439744..7bb366f709 100644 --- a/include/net/tcp_ecn.h +++ b/include/net/tcp_ecn.h @@ -31,10 +31,9 @@ static inline void TCP_ECN_send_syn(struct sock *sk, struct tcp_sock *tp, struct sk_buff *skb) { tp->ecn_flags = 0; - if (sysctl_tcp_ecn && !(sk->sk_route_caps & NETIF_F_TSO)) { + if (sysctl_tcp_ecn) { TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ECE|TCPCB_FLAG_CWR; tp->ecn_flags = TCP_ECN_OK; - sock_set_flag(sk, SOCK_NO_LARGESEND); } } @@ -56,6 +55,9 @@ static inline void TCP_ECN_send(struct sock *sk, struct tcp_sock *tp, if (tp->ecn_flags&TCP_ECN_QUEUE_CWR) { tp->ecn_flags &= ~TCP_ECN_QUEUE_CWR; skb->h.th->cwr = 1; + if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) + skb_shinfo(skb)->gso_type |= + SKB_GSO_TCPV4_ECN; } } else { /* ACK or retransmitted segment: clear ECT|CE */ diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 94fe5b1f9d..7fa0b4a8a3 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4178,8 +4178,6 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, */ TCP_ECN_rcv_synack(tp, th); - if (tp->ecn_flags&TCP_ECN_OK) - sock_set_flag(sk, SOCK_NO_LARGESEND); tp->snd_wl1 = TCP_SKB_CB(skb)->seq; tcp_ack(sk, skb, FLAG_SLOWPATH); @@ -4322,8 +4320,6 @@ discard: tp->max_window = tp->snd_wnd; TCP_ECN_rcv_syn(tp, th); - if (tp->ecn_flags&TCP_ECN_OK) - sock_set_flag(sk, SOCK_NO_LARGESEND); tcp_mtup_init(sk); tcp_sync_mss(sk, icsk->icsk_pmtu_cookie); diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 2b9b7f6c7f..54b2ef7d3e 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -440,8 +440,6 @@ struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req, newicsk->icsk_ack.last_seg_size = skb->len - newtp->tcp_header_len; newtp->rx_opt.mss_clamp = req->mss; TCP_ECN_openreq_child(newtp, req); - if (newtp->ecn_flags&TCP_ECN_OK) - sock_set_flag(newsk, SOCK_NO_LARGESEND); TCP_INC_STATS_BH(TCP_MIB_PASSIVEOPENS); } diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index bdd71db8bf..5a7cb4a9c8 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2044,8 +2044,6 @@ struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst, memset(th, 0, sizeof(struct tcphdr)); th->syn = 1; th->ack = 1; - if (dst->dev->features&NETIF_F_TSO) - ireq->ecn_ok = 0; TCP_ECN_make_synack(req, th); th->source = inet_sk(sk)->sport; th->dest = ireq->rmt_port;