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>

1 files changed, 32 insertions, 31 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 081dcd6fd0c4..dde6b5768316 100644
--- 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)