b0da853703
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 <herbert@gondor.apana.org.au>. Since ECN can always be enabled with TSO, the SOCK_NO_LARGESEND sock flag is completely removed. Signed-off-by: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
130 lines
3.2 KiB
C
130 lines
3.2 KiB
C
#ifndef _NET_TCP_ECN_H_
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#define _NET_TCP_ECN_H_ 1
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#include <net/inet_ecn.h>
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#include <net/request_sock.h>
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#define TCP_HP_BITS (~(TCP_RESERVED_BITS|TCP_FLAG_PSH))
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#define TCP_ECN_OK 1
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#define TCP_ECN_QUEUE_CWR 2
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#define TCP_ECN_DEMAND_CWR 4
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static inline void TCP_ECN_queue_cwr(struct tcp_sock *tp)
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{
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if (tp->ecn_flags&TCP_ECN_OK)
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tp->ecn_flags |= TCP_ECN_QUEUE_CWR;
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}
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/* Output functions */
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static inline void TCP_ECN_send_synack(struct tcp_sock *tp,
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struct sk_buff *skb)
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{
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TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_CWR;
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if (!(tp->ecn_flags&TCP_ECN_OK))
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TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_ECE;
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}
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static inline void TCP_ECN_send_syn(struct sock *sk, struct tcp_sock *tp,
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struct sk_buff *skb)
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{
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tp->ecn_flags = 0;
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if (sysctl_tcp_ecn) {
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TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ECE|TCPCB_FLAG_CWR;
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tp->ecn_flags = TCP_ECN_OK;
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}
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}
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static __inline__ void
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TCP_ECN_make_synack(struct request_sock *req, struct tcphdr *th)
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{
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if (inet_rsk(req)->ecn_ok)
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th->ece = 1;
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}
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static inline void TCP_ECN_send(struct sock *sk, struct tcp_sock *tp,
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struct sk_buff *skb, int tcp_header_len)
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{
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if (tp->ecn_flags & TCP_ECN_OK) {
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/* Not-retransmitted data segment: set ECT and inject CWR. */
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if (skb->len != tcp_header_len &&
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!before(TCP_SKB_CB(skb)->seq, tp->snd_nxt)) {
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INET_ECN_xmit(sk);
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if (tp->ecn_flags&TCP_ECN_QUEUE_CWR) {
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tp->ecn_flags &= ~TCP_ECN_QUEUE_CWR;
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skb->h.th->cwr = 1;
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if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
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skb_shinfo(skb)->gso_type |=
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SKB_GSO_TCPV4_ECN;
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}
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} else {
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/* ACK or retransmitted segment: clear ECT|CE */
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INET_ECN_dontxmit(sk);
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}
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if (tp->ecn_flags & TCP_ECN_DEMAND_CWR)
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skb->h.th->ece = 1;
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}
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}
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/* Input functions */
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static inline void TCP_ECN_accept_cwr(struct tcp_sock *tp, struct sk_buff *skb)
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{
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if (skb->h.th->cwr)
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tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
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}
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static inline void TCP_ECN_withdraw_cwr(struct tcp_sock *tp)
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{
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tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
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}
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static inline void TCP_ECN_check_ce(struct tcp_sock *tp, struct sk_buff *skb)
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{
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if (tp->ecn_flags&TCP_ECN_OK) {
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if (INET_ECN_is_ce(TCP_SKB_CB(skb)->flags))
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tp->ecn_flags |= TCP_ECN_DEMAND_CWR;
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/* Funny extension: if ECT is not set on a segment,
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* it is surely retransmit. It is not in ECN RFC,
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* but Linux follows this rule. */
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else if (INET_ECN_is_not_ect((TCP_SKB_CB(skb)->flags)))
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tcp_enter_quickack_mode((struct sock *)tp);
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}
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}
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static inline void TCP_ECN_rcv_synack(struct tcp_sock *tp, struct tcphdr *th)
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{
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if ((tp->ecn_flags&TCP_ECN_OK) && (!th->ece || th->cwr))
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tp->ecn_flags &= ~TCP_ECN_OK;
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}
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static inline void TCP_ECN_rcv_syn(struct tcp_sock *tp, struct tcphdr *th)
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{
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if ((tp->ecn_flags&TCP_ECN_OK) && (!th->ece || !th->cwr))
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tp->ecn_flags &= ~TCP_ECN_OK;
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}
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static inline int TCP_ECN_rcv_ecn_echo(struct tcp_sock *tp, struct tcphdr *th)
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{
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if (th->ece && !th->syn && (tp->ecn_flags&TCP_ECN_OK))
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return 1;
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return 0;
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}
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static inline void TCP_ECN_openreq_child(struct tcp_sock *tp,
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struct request_sock *req)
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{
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tp->ecn_flags = inet_rsk(req)->ecn_ok ? TCP_ECN_OK : 0;
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}
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static __inline__ void
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TCP_ECN_create_request(struct request_sock *req, struct tcphdr *th)
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{
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if (sysctl_tcp_ecn && th->ece && th->cwr)
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inet_rsk(req)->ecn_ok = 1;
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}
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#endif
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