tcp: rename tcp_skb_cb flags

Rename struct tcp_skb_cb "flags" to "tcp_flags" to ease code review and
maintenance.

Its content is a combination of FIN/SYN/RST/PSH/ACK/URG/ECE/CWR flags

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 28a9997..0113d30 100644 (file)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -636,7 +636,7 @@ struct tcp_skb_cb {
        __u32           seq;            /* Starting sequence number     */
        __u32           end_seq;        /* SEQ + FIN + SYN + datalen    */
        __u32           when;           /* used to compute rtt's        */
-       __u8            flags;          /* TCP header flags.            */
+       __u8            tcp_flags;      /* TCP header flags. (tcp[13])  */
        __u8            sacked;         /* State flags for SACK/FACK.   */
 #define TCPCB_SACKED_ACKED     0x01    /* SKB ACK'd by a SACK block    */
 #define TCPCB_SACKED_RETRANS   0x02    /* SKB retransmitted            */

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index cc0d5de..131c45f 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -524,7 +524,7 @@ EXPORT_SYMBOL(tcp_ioctl);
 
 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
 {
-       TCP_SKB_CB(skb)->flags |= TCPHDR_PSH;
+       TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
        tp->pushed_seq = tp->write_seq;
 }
 
@@ -540,7 +540,7 @@ static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
 
        skb->csum    = 0;
        tcb->seq     = tcb->end_seq = tp->write_seq;
-       tcb->flags   = TCPHDR_ACK;
+       tcb->tcp_flags = TCPHDR_ACK;
        tcb->sacked  = 0;
        skb_header_release(skb);
        tcp_add_write_queue_tail(sk, skb);
@@ -830,7 +830,7 @@ new_segment:
                skb_shinfo(skb)->gso_segs = 0;
 
                if (!copied)
-                       TCP_SKB_CB(skb)->flags &= ~TCPHDR_PSH;
+                       TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
 
                copied += copy;
                poffset += copy;
@@ -1074,7 +1074,7 @@ new_segment:
                        }
 
                        if (!copied)
-                               TCP_SKB_CB(skb)->flags &= ~TCPHDR_PSH;
+                               TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
 
                        tp->write_seq += copy;
                        TCP_SKB_CB(skb)->end_seq += copy;

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 7008fcc..143221e 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1449,7 +1449,7 @@ static int tcp_shifted_skb(struct sock *sk, struct sk_buff *skb,
                tp->lost_cnt_hint -= tcp_skb_pcount(prev);
        }
 
-       TCP_SKB_CB(skb)->flags |= TCP_SKB_CB(prev)->flags;
+       TCP_SKB_CB(skb)->tcp_flags |= TCP_SKB_CB(prev)->tcp_flags;
        if (skb == tcp_highest_sack(sk))
                tcp_advance_highest_sack(sk, skb);
 
@@ -3348,7 +3348,7 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets,
                 * connection startup slow start one packet too
                 * quickly.  This is severely frowned upon behavior.
                 */
-               if (!(scb->flags & TCPHDR_SYN)) {
+               if (!(scb->tcp_flags & TCPHDR_SYN)) {
                        flag |= FLAG_DATA_ACKED;
                } else {
                        flag |= FLAG_SYN_ACKED;

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 081dcd6..dde6b57 100644 (file)
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -297,9 +297,9 @@ static u16 tcp_select_window(struct sock *sk)
 /* Packet ECN state for a SYN-ACK */
 static inline void TCP_ECN_send_synack(struct tcp_sock *tp, struct sk_buff *skb)
 {
-       TCP_SKB_CB(skb)->flags &= ~TCPHDR_CWR;
+       TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_CWR;
        if (!(tp->ecn_flags & TCP_ECN_OK))
-               TCP_SKB_CB(skb)->flags &= ~TCPHDR_ECE;
+               TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_ECE;
 }
 
 /* Packet ECN state for a SYN.  */
@@ -309,7 +309,7 @@ static inline void TCP_ECN_send_syn(struct sock *sk, struct sk_buff *skb)
 
        tp->ecn_flags = 0;
        if (sysctl_tcp_ecn == 1) {
-               TCP_SKB_CB(skb)->flags |= TCPHDR_ECE | TCPHDR_CWR;
+               TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_ECE | TCPHDR_CWR;
                tp->ecn_flags = TCP_ECN_OK;
        }
 }
@@ -356,7 +356,7 @@ static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags)
        skb->ip_summed = CHECKSUM_PARTIAL;
        skb->csum = 0;
 
-       TCP_SKB_CB(skb)->flags = flags;
+       TCP_SKB_CB(skb)->tcp_flags = flags;
        TCP_SKB_CB(skb)->sacked = 0;
 
        skb_shinfo(skb)->gso_segs = 1;
@@ -826,7 +826,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
        tcb = TCP_SKB_CB(skb);
        memset(&opts, 0, sizeof(opts));
 
-       if (unlikely(tcb->flags & TCPHDR_SYN))
+       if (unlikely(tcb->tcp_flags & TCPHDR_SYN))
                tcp_options_size = tcp_syn_options(sk, skb, &opts, &md5);
        else
                tcp_options_size = tcp_established_options(sk, skb, &opts,
@@ -850,9 +850,9 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
        th->seq                 = htonl(tcb->seq);
        th->ack_seq             = htonl(tp->rcv_nxt);
        *(((__be16 *)th) + 6)   = htons(((tcp_header_size >> 2) << 12) |
-                                       tcb->flags);
+                                       tcb->tcp_flags);
 
-       if (unlikely(tcb->flags & TCPHDR_SYN)) {
+       if (unlikely(tcb->tcp_flags & TCPHDR_SYN)) {
                /* RFC1323: The window in SYN & SYN/ACK segments
                 * is never scaled.
                 */
@@ -875,7 +875,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
        }
 
        tcp_options_write((__be32 *)(th + 1), tp, &opts);
-       if (likely((tcb->flags & TCPHDR_SYN) == 0))
+       if (likely((tcb->tcp_flags & TCPHDR_SYN) == 0))
                TCP_ECN_send(sk, skb, tcp_header_size);
 
 #ifdef CONFIG_TCP_MD5SIG
@@ -889,7 +889,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
 
        icsk->icsk_af_ops->send_check(sk, skb);
 
-       if (likely(tcb->flags & TCPHDR_ACK))
+       if (likely(tcb->tcp_flags & TCPHDR_ACK))
                tcp_event_ack_sent(sk, tcp_skb_pcount(skb));
 
        if (skb->len != tcp_header_size)
@@ -1032,9 +1032,9 @@ int tcp_fragment(struct sock *sk, struct sk_buff *skb, u32 len,
        TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(buff)->seq;
 
        /* PSH and FIN should only be set in the second packet. */
-       flags = TCP_SKB_CB(skb)->flags;
-       TCP_SKB_CB(skb)->flags = flags & ~(TCPHDR_FIN | TCPHDR_PSH);
-       TCP_SKB_CB(buff)->flags = flags;
+       flags = TCP_SKB_CB(skb)->tcp_flags;
+       TCP_SKB_CB(skb)->tcp_flags = flags & ~(TCPHDR_FIN | TCPHDR_PSH);
+       TCP_SKB_CB(buff)->tcp_flags = flags;
        TCP_SKB_CB(buff)->sacked = TCP_SKB_CB(skb)->sacked;
 
        if (!skb_shinfo(skb)->nr_frags && skb->ip_summed != CHECKSUM_PARTIAL) {
@@ -1340,7 +1340,8 @@ static inline unsigned int tcp_cwnd_test(struct tcp_sock *tp,
        u32 in_flight, cwnd;
 
        /* Don't be strict about the congestion window for the final FIN.  */
-       if ((TCP_SKB_CB(skb)->flags & TCPHDR_FIN) && tcp_skb_pcount(skb) == 1)
+       if ((TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) &&
+           tcp_skb_pcount(skb) == 1)
                return 1;
 
        in_flight = tcp_packets_in_flight(tp);
@@ -1409,7 +1410,7 @@ static inline int tcp_nagle_test(struct tcp_sock *tp, struct sk_buff *skb,
         * Nagle can be ignored during F-RTO too (see RFC4138).
         */
        if (tcp_urg_mode(tp) || (tp->frto_counter == 2) ||
-           (TCP_SKB_CB(skb)->flags & TCPHDR_FIN))
+           (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN))
                return 1;
 
        if (!tcp_nagle_check(tp, skb, cur_mss, nonagle))
@@ -1497,9 +1498,9 @@ static int tso_fragment(struct sock *sk, struct sk_buff *skb, unsigned int len,
        TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(buff)->seq;
 
        /* PSH and FIN should only be set in the second packet. */
-       flags = TCP_SKB_CB(skb)->flags;
-       TCP_SKB_CB(skb)->flags = flags & ~(TCPHDR_FIN | TCPHDR_PSH);
-       TCP_SKB_CB(buff)->flags = flags;
+       flags = TCP_SKB_CB(skb)->tcp_flags;
+       TCP_SKB_CB(skb)->tcp_flags = flags & ~(TCPHDR_FIN | TCPHDR_PSH);
+       TCP_SKB_CB(buff)->tcp_flags = flags;
 
        /* This packet was never sent out yet, so no SACK bits. */
        TCP_SKB_CB(buff)->sacked = 0;
@@ -1530,7 +1531,7 @@ static int tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
        u32 send_win, cong_win, limit, in_flight;
        int win_divisor;
 
-       if (TCP_SKB_CB(skb)->flags & TCPHDR_FIN)
+       if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
                goto send_now;
 
        if (icsk->icsk_ca_state != TCP_CA_Open)
@@ -1657,7 +1658,7 @@ static int tcp_mtu_probe(struct sock *sk)
 
        TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(skb)->seq;
        TCP_SKB_CB(nskb)->end_seq = TCP_SKB_CB(skb)->seq + probe_size;
-       TCP_SKB_CB(nskb)->flags = TCPHDR_ACK;
+       TCP_SKB_CB(nskb)->tcp_flags = TCPHDR_ACK;
        TCP_SKB_CB(nskb)->sacked = 0;
        nskb->csum = 0;
        nskb->ip_summed = skb->ip_summed;
@@ -1677,11 +1678,11 @@ static int tcp_mtu_probe(struct sock *sk)
                if (skb->len <= copy) {
                        /* We've eaten all the data from this skb.
                         * Throw it away. */
-                       TCP_SKB_CB(nskb)->flags |= TCP_SKB_CB(skb)->flags;
+                       TCP_SKB_CB(nskb)->tcp_flags |= TCP_SKB_CB(skb)->tcp_flags;
                        tcp_unlink_write_queue(skb, sk);
                        sk_wmem_free_skb(sk, skb);
                } else {
-                       TCP_SKB_CB(nskb)->flags |= TCP_SKB_CB(skb)->flags &
+                       TCP_SKB_CB(nskb)->tcp_flags |= TCP_SKB_CB(skb)->tcp_flags &
                                                   ~(TCPHDR_FIN|TCPHDR_PSH);
                        if (!skb_shinfo(skb)->nr_frags) {
                                skb_pull(skb, copy);
@@ -1987,7 +1988,7 @@ static void tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb)
        TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(next_skb)->end_seq;
 
        /* Merge over control information. This moves PSH/FIN etc. over */
-       TCP_SKB_CB(skb)->flags |= TCP_SKB_CB(next_skb)->flags;
+       TCP_SKB_CB(skb)->tcp_flags |= TCP_SKB_CB(next_skb)->tcp_flags;
 
        /* All done, get rid of second SKB and account for it so
         * packet counting does not break.
@@ -2035,7 +2036,7 @@ static void tcp_retrans_try_collapse(struct sock *sk, struct sk_buff *to,
 
        if (!sysctl_tcp_retrans_collapse)
                return;
-       if (TCP_SKB_CB(skb)->flags & TCPHDR_SYN)
+       if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)
                return;
 
        tcp_for_write_queue_from_safe(skb, tmp, sk) {
@@ -2127,12 +2128,12 @@ int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
         * since it is cheap to do so and saves bytes on the network.
         */
        if (skb->len > 0 &&
-           (TCP_SKB_CB(skb)->flags & TCPHDR_FIN) &&
+           (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) &&
            tp->snd_una == (TCP_SKB_CB(skb)->end_seq - 1)) {
                if (!pskb_trim(skb, 0)) {
                        /* Reuse, even though it does some unnecessary work */
                        tcp_init_nondata_skb(skb, TCP_SKB_CB(skb)->end_seq - 1,
-                                            TCP_SKB_CB(skb)->flags);
+                                            TCP_SKB_CB(skb)->tcp_flags);
                        skb->ip_summed = CHECKSUM_NONE;
                }
        }
@@ -2322,7 +2323,7 @@ void tcp_send_fin(struct sock *sk)
        mss_now = tcp_current_mss(sk);
 
        if (tcp_send_head(sk) != NULL) {
-               TCP_SKB_CB(skb)->flags |= TCPHDR_FIN;
+               TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_FIN;
                TCP_SKB_CB(skb)->end_seq++;
                tp->write_seq++;
        } else {
@@ -2384,11 +2385,11 @@ int tcp_send_synack(struct sock *sk)
        struct sk_buff *skb;
 
        skb = tcp_write_queue_head(sk);
-       if (skb == NULL || !(TCP_SKB_CB(skb)->flags & TCPHDR_SYN)) {
+       if (skb == NULL || !(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
                printk(KERN_DEBUG "tcp_send_synack: wrong queue state\n");
                return -EFAULT;
        }
-       if (!(TCP_SKB_CB(skb)->flags & TCPHDR_ACK)) {
+       if (!(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_ACK)) {
                if (skb_cloned(skb)) {
                        struct sk_buff *nskb = skb_copy(skb, GFP_ATOMIC);
                        if (nskb == NULL)
@@ -2402,7 +2403,7 @@ int tcp_send_synack(struct sock *sk)
                        skb = nskb;
                }
 
-               TCP_SKB_CB(skb)->flags |= TCPHDR_ACK;
+               TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_ACK;
                TCP_ECN_send_synack(tcp_sk(sk), skb);
        }
        TCP_SKB_CB(skb)->when = tcp_time_stamp;
@@ -2799,13 +2800,13 @@ int tcp_write_wakeup(struct sock *sk)
                if (seg_size < TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq ||
                    skb->len > mss) {
                        seg_size = min(seg_size, mss);
-                       TCP_SKB_CB(skb)->flags |= TCPHDR_PSH;
+                       TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
                        if (tcp_fragment(sk, skb, seg_size, mss))
                                return -1;
                } else if (!tcp_skb_pcount(skb))
                        tcp_set_skb_tso_segs(sk, skb, mss);
 
-               TCP_SKB_CB(skb)->flags |= TCPHDR_PSH;
+               TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
                TCP_SKB_CB(skb)->when = tcp_time_stamp;
                err = tcp_transmit_skb(sk, skb, 1, GFP_ATOMIC);
                if (!err)