ccid: ccid-2/3 code cosmetics

This patch collects cosmetics-only changes to separate these from
code changes:
 * update with regard to CodingStyle and whitespace changes,
 * documentation:
   - adding/revising comments,
   - remove CCID-3 RX socket documentation which is either
     duplicate or refers to fields that no longer exist,
 * expand embedded tfrc_tx_info struct inline for consistency,
   removing indirections via #define.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 27 insertions, 26 deletions

diff --git a/net/dccp/ccids/ccid2.c b/net/dccp/ccids/ccid2.c
index 9b3ae9922be1..f564211c3885 100644
--- a/net/dccp/ccids/ccid2.c
+++ b/net/dccp/ccids/ccid2.c
@@ -193,8 +193,8 @@ static void ccid2_hc_tx_rto_expire(unsigned long data)
         hc->tx_ssthresh = hc->tx_cwnd / 2;
         if (hc->tx_ssthresh < 2)
                 hc->tx_ssthresh = 2;
-        hc->tx_cwnd      = 1;
-        hc->tx_pipe      = 0;
+        hc->tx_cwnd     = 1;
+        hc->tx_pipe     = 0;
 
         /* clear state about stuff we sent */
         hc->tx_seqt = hc->tx_seqh;
diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 95f752986497..a666f3febf2b 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -218,9 +218,9 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
 
         /*
          * Determine new allowed sending rate X as per draft rfc3448bis-00, 4.4
+         * RTO is 0 if and only if no feedback has been received yet.
          */
-        if (hc->tx_t_rto == 0 ||        /* no feedback received yet */
-            hc->tx_p == 0) {
+        if (hc->tx_t_rto == 0 || hc->tx_p == 0) {
 
                 /* halve send rate directly */
                 hc->tx_x = max(hc->tx_x / 2,
@@ -256,7 +256,7 @@ static void ccid3_hc_tx_no_feedback_timer(unsigned long data)
          * Set new timeout for the nofeedback timer.
          * See comments in packet_recv() regarding the value of t_RTO.
          */
-        if (unlikely(hc->tx_t_rto == 0))        /* no feedback yet */
+        if (unlikely(hc->tx_t_rto == 0))        /* no feedback received yet */
                 t_nfb = TFRC_INITIAL_TIMEOUT;
         else
                 t_nfb = max(hc->tx_t_rto, 2 * hc->tx_t_ipi);
@@ -372,7 +372,7 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more,
 static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
 {
         struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
-        struct ccid3_options_received *opt_recv;
+        struct ccid3_options_received *opt_recv = &hc->tx_options_received;
         ktime_t now;
         unsigned long t_nfb;
         u32 pinv, r_sample;
@@ -386,7 +386,6 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
             hc->tx_state != TFRC_SSTATE_NO_FBACK)
                 return;
 
-        opt_recv = &hc->tx_options_received;
         now = ktime_get_real();
 
         /* Estimate RTT from history if ACK number is valid */
@@ -489,11 +488,9 @@ static int ccid3_hc_tx_parse_options(struct sock *sk, unsigned char option,
         int rc = 0;
         const struct dccp_sock *dp = dccp_sk(sk);
         struct ccid3_hc_tx_sock *hc = ccid3_hc_tx_sk(sk);
-        struct ccid3_options_received *opt_recv;
+        struct ccid3_options_received *opt_recv = &hc->tx_options_received;
         __be32 opt_val;
 
-        opt_recv = &hc->tx_options_received;
-
         if (opt_recv->ccid3or_seqno != dp->dccps_gsr) {
                 opt_recv->ccid3or_seqno              = dp->dccps_gsr;
                 opt_recv->ccid3or_loss_event_rate    = ~0;
@@ -582,6 +579,7 @@ static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
                                   u32 __user *optval, int __user *optlen)
 {
         const struct ccid3_hc_tx_sock *hc;
+        struct tfrc_tx_info tfrc;
         const void *val;
 
         /* Listen socks doesn't have a private CCID block */
@@ -591,10 +589,17 @@ static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
         hc = ccid3_hc_tx_sk(sk);
         switch (optname) {
         case DCCP_SOCKOPT_CCID_TX_INFO:
-                if (len < sizeof(hc->tx_tfrc))
+                if (len < sizeof(tfrc))
                         return -EINVAL;
-                len = sizeof(hc->tx_tfrc);
-                val = &hc->tx_tfrc;
+                tfrc.tfrctx_x      = hc->tx_x;
+                tfrc.tfrctx_x_recv = hc->tx_x_recv;
+                tfrc.tfrctx_x_calc = hc->tx_x_calc;
+                tfrc.tfrctx_rtt    = hc->tx_rtt;
+                tfrc.tfrctx_p      = hc->tx_p;
+                tfrc.tfrctx_rto    = hc->tx_t_rto;
+                tfrc.tfrctx_ipi    = hc->tx_t_ipi;
+                len = sizeof(tfrc);
+                val = &tfrc;
                 break;
         default:
                 return -ENOPROTOOPT;
@@ -749,10 +754,11 @@ static u32 ccid3_first_li(struct sock *sk)
         x_recv = scaled_div32(hc->rx_bytes_recv, delta);
         if (x_recv == 0) {              /* would also trigger divide-by-zero */
                 DCCP_WARN("X_recv==0\n");
-                if ((x_recv = hc->rx_x_recv) == 0) {
+                if (hc->rx_x_recv == 0) {
                         DCCP_BUG("stored value of X_recv is zero");
                         return ~0U;
                 }
+                x_recv = hc->rx_x_recv;
         }
 
         fval = scaled_div(hc->rx_s, hc->rx_rtt);
diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h
index 032635776653..b1864243be07 100644
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -95,14 +95,13 @@ enum ccid3_hc_tx_states {
  * @tx_options_received:  Parsed set of retrieved options
  */
 struct ccid3_hc_tx_sock {
-        struct tfrc_tx_info             tx_tfrc;
-#define tx_x                            tx_tfrc.tfrctx_x
-#define tx_x_recv                       tx_tfrc.tfrctx_x_recv
-#define tx_x_calc                       tx_tfrc.tfrctx_x_calc
-#define tx_rtt                          tx_tfrc.tfrctx_rtt
-#define tx_p                            tx_tfrc.tfrctx_p
-#define tx_t_rto                        tx_tfrc.tfrctx_rto
-#define tx_t_ipi                        tx_tfrc.tfrctx_ipi
+        u64                             tx_x;
+        u64                             tx_x_recv;
+        u32                             tx_x_calc;
+        u32                             tx_rtt;
+        u32                             tx_p;
+        u32                             tx_t_rto;
+        u32                             tx_t_ipi;
         u16                             tx_s;
         enum ccid3_hc_tx_states         tx_state:8;
         u8                              tx_last_win_count;
@@ -131,16 +130,12 @@ enum ccid3_hc_rx_states {
 
 /**
  * struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
- * @rx_x_recv:               Receiver estimate of send rate (RFC 3448 4.3)
- * @rx_rtt:                  Receiver estimate of rtt (non-standard)
- * @rx_p:                    Current loss event rate (RFC 3448 5.4)
  * @rx_last_counter:         Tracks window counter (RFC 4342, 8.1)
  * @rx_state:                Receiver state, one of %ccid3_hc_rx_states
  * @rx_bytes_recv:           Total sum of DCCP payload bytes
  * @rx_x_recv:               Receiver estimate of send rate (RFC 3448, sec. 4.3)
  * @rx_rtt:                  Receiver estimate of RTT
  * @rx_tstamp_last_feedback: Time at which last feedback was sent
- * @rx_tstamp_last_ack:      Time at which last feedback was sent
  * @rx_hist:                 Packet history (loss detection + RTT sampling)
  * @rx_li_hist:              Loss Interval database
  * @rx_s:                    Received packet size in bytes