[DCCP] Introduce dccp_timestamp

To start the timestamps with 0.0ms, easing the integer maths in the CCIDs, this
probably will be reworked to use the to be introduced struct timeval_offset
infrastructure out of skb_get_timestamp, etc.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

8 files changed, 60 insertions, 39 deletions

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index 145aafafe4e2..348e6fb262c3 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -169,7 +169,7 @@ static void ccid3_hc_tx_update_x(struct sock *sk)
         } else {
                 struct timeval now;
 
-                do_gettimeofday(&now);
+                dccp_timestamp(sk, &now);
                 if (timeval_delta(&now, &hctx->ccid3hctx_t_ld) >=
                     hctx->ccid3hctx_rtt) {
                         hctx->ccid3hctx_x = max_t(u32, min_t(u32, hctx->ccid3hctx_x_recv,
@@ -317,7 +317,7 @@ static int ccid3_hc_tx_send_packet(struct sock *sk,
                 dccp_tx_hist_add_entry(&hctx->ccid3hctx_hist, new_packet);
         }
 
-        do_gettimeofday(&now);
+        dccp_timestamp(sk, &now);
 
         switch (hctx->ccid3hctx_state) {
         case TFRC_SSTATE_NO_SENT:
@@ -382,7 +382,7 @@ static void ccid3_hc_tx_packet_sent(struct sock *sk, int more, int len)
                 return;
         }
 
-        do_gettimeofday(&now);
+        dccp_timestamp(sk, &now);
 
         /* check if we have sent a data packet */
         if (len > 0) {
@@ -461,6 +461,7 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
         struct ccid3_hc_tx_sock *hctx = dp->dccps_hc_tx_ccid_private;
         struct ccid3_options_received *opt_recv;
         struct dccp_tx_hist_entry *packet;
+        struct timeval now;
         unsigned long next_tmout; 
         u32 t_elapsed;
         u32 pinv;
@@ -508,7 +509,8 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb)
                 }
 
                 /* Update RTT */
-                r_sample = timeval_now_delta(&packet->dccphtx_tstamp);
+                dccp_timestamp(sk, &now);
+                r_sample = timeval_delta(&now, &packet->dccphtx_tstamp);
                 if (unlikely(r_sample <= t_elapsed))
                         LIMIT_NETDEBUG(KERN_WARNING
                                        "%s: r_sample=%uus, t_elapsed=%uus\n",
@@ -774,7 +776,7 @@ static void ccid3_hc_rx_send_feedback(struct sock *sk)
 
         ccid3_pr_debug("%s, sk=%p\n", dccp_role(sk), sk);
 
-        do_gettimeofday(&now);
+        dccp_timestamp(sk, &now);
 
         switch (hcrx->ccid3hcrx_state) {
         case TFRC_RSTATE_NO_DATA:
@@ -903,10 +905,9 @@ found:
         if (rtt == 0)
                 rtt = 1;
 
-        delta = timeval_now_delta(&hcrx->ccid3hcrx_tstamp_last_feedback);
-        x_recv = hcrx->ccid3hcrx_bytes_recv * USEC_PER_SEC;
-        if (likely(delta > 1))
-                x_recv /= delta;
+        dccp_timestamp(sk, &tstamp);
+        delta = timeval_delta(&tstamp, &hcrx->ccid3hcrx_tstamp_last_feedback);
+        x_recv = usecs_div(hcrx->ccid3hcrx_bytes_recv, delta);
 
         tmp1 = (u64)x_recv * (u64)rtt;
         do_div(tmp1,10000000);
@@ -981,7 +982,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
                 if (opt_recv->dccpor_timestamp_echo == 0)
                         break;
                 p_prev = hcrx->ccid3hcrx_rtt;
-                do_gettimeofday(&now);
+                dccp_timestamp(sk, &now);
                 timeval_sub_usecs(&now, opt_recv->dccpor_timestamp_echo * 10);
                 r_sample = timeval_usecs(&now);
                 t_elapsed = opt_recv->dccpor_elapsed_time * 10;
@@ -1013,7 +1014,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
                 return;
         }
 
-        packet = dccp_rx_hist_entry_new(ccid3_rx_hist, opt_recv->dccpor_ndp,
+        packet = dccp_rx_hist_entry_new(ccid3_rx_hist, sk, opt_recv->dccpor_ndp,
                                         skb, SLAB_ATOMIC);
         if (packet == NULL) {
                 ccid3_pr_debug("%s, sk=%p, Not enough mem to add rx packet "
@@ -1045,7 +1046,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
                 if (ins != 0)
                         break;
 
-                do_gettimeofday(&now);
+                dccp_timestamp(sk, &now);
                 if (timeval_delta(&now, &hcrx->ccid3hcrx_tstamp_last_ack) >=
                     hcrx->ccid3hcrx_rtt) {
                         hcrx->ccid3hcrx_tstamp_last_ack = now;
@@ -1100,7 +1101,7 @@ static int ccid3_hc_rx_init(struct sock *sk)
         hcrx->ccid3hcrx_state = TFRC_RSTATE_NO_DATA;
         INIT_LIST_HEAD(&hcrx->ccid3hcrx_hist);
         INIT_LIST_HEAD(&hcrx->ccid3hcrx_li_hist);
-        do_gettimeofday(&hcrx->ccid3hcrx_tstamp_last_ack);
+        dccp_timestamp(sk, &hcrx->ccid3hcrx_tstamp_last_ack);
         hcrx->ccid3hcrx_tstamp_last_feedback = hcrx->ccid3hcrx_tstamp_last_ack;
         hcrx->ccid3hcrx_rtt = 5000; /* XXX 5ms for now... */
         return 0;
diff --git a/net/dccp/ccids/ccid3.h b/net/dccp/ccids/ccid3.h
index ee8cbace6630..58be6125b695 100644
--- a/net/dccp/ccids/ccid3.h
+++ b/net/dccp/ccids/ccid3.h
@@ -115,7 +115,7 @@ struct ccid3_hc_rx_sock {
         u64                     ccid3hcrx_seqno_last_counter:48,
                                 ccid3hcrx_state:8,
                                 ccid3hcrx_last_counter:4;
-        unsigned long           ccid3hcrx_rtt;
+        u32                     ccid3hcrx_rtt;
         u32                     ccid3hcrx_p;
         u32                     ccid3hcrx_bytes_recv;
         struct timeval          ccid3hcrx_tstamp_last_feedback;
diff --git a/net/dccp/ccids/lib/packet_history.h b/net/dccp/ccids/lib/packet_history.h
index fb90a91aa93d..b375ebdb7dcf 100644
--- a/net/dccp/ccids/lib/packet_history.h
+++ b/net/dccp/ccids/lib/packet_history.h
@@ -134,6 +134,7 @@ static inline struct dccp_tx_hist_entry *
 
 static inline struct dccp_rx_hist_entry *
                      dccp_rx_hist_entry_new(struct dccp_rx_hist *hist,
+                                            const struct sock *sk, 
                                             const u32 ndp, 
                                             const struct sk_buff *skb,
                                             const unsigned int __nocast prio)
@@ -148,7 +149,7 @@ static inline struct dccp_rx_hist_entry *
                 entry->dccphrx_ccval = dh->dccph_ccval;
                 entry->dccphrx_type  = dh->dccph_type;
                 entry->dccphrx_ndp   = ndp;
-                do_gettimeofday(&(entry->dccphrx_tstamp));
+                dccp_timestamp(sk, &entry->dccphrx_tstamp);
         }
 
         return entry;
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index 33456c0d5937..95c4630b3b18 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -426,10 +426,13 @@ extern struct dccp_ackpkts *
                 dccp_ackpkts_alloc(unsigned int len,
                                   const unsigned int __nocast priority);
 extern void dccp_ackpkts_free(struct dccp_ackpkts *ap);
-extern int dccp_ackpkts_add(struct dccp_ackpkts *ap, u64 ackno, u8 state);
+extern int dccp_ackpkts_add(struct dccp_ackpkts *ap, const struct sock *sk,
+                            u64 ackno, u8 state);
 extern void dccp_ackpkts_check_rcv_ackno(struct dccp_ackpkts *ap,
                                          struct sock *sk, u64 ackno);
 
+extern void dccp_timestamp(const struct sock *sk, struct timeval *tv);
+
 static inline suseconds_t timeval_usecs(const struct timeval *tv)
 {
         return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
@@ -468,17 +471,6 @@ static inline void timeval_sub_usecs(struct timeval *tv,
         }
 }
 
-/*
- * Returns the difference in usecs between timeval
- * passed in and current time
- */
-static inline suseconds_t timeval_now_delta(const struct timeval *tv)
-{
-        struct timeval now;
-        do_gettimeofday(&now);
-        return timeval_delta(&now, tv);
-}
-
 #ifdef CONFIG_IP_DCCP_DEBUG
 extern void dccp_ackvector_print(const u64 ackno,
                                  const unsigned char *vector, int len);
diff --git a/net/dccp/input.c b/net/dccp/input.c
index ef29cef1dafe..c60bc3433f5e 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -170,7 +170,7 @@ int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
         if (dp->dccps_options.dccpo_send_ack_vector) {
                 struct dccp_ackpkts *ap = dp->dccps_hc_rx_ackpkts;
 
-                if (dccp_ackpkts_add(dp->dccps_hc_rx_ackpkts,
+                if (dccp_ackpkts_add(dp->dccps_hc_rx_ackpkts, sk,
                                      DCCP_SKB_CB(skb)->dccpd_seq,
                                      DCCP_ACKPKTS_STATE_RECEIVED)) {
                         LIMIT_NETDEBUG(KERN_WARNING "DCCP: acknowledgeable "
@@ -498,7 +498,7 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
                  * DCCP_ACKPKTS_STATE_ECN_MARKED
                  */
                 if (dp->dccps_options.dccpo_send_ack_vector) {
-                        if (dccp_ackpkts_add(dp->dccps_hc_rx_ackpkts,
+                        if (dccp_ackpkts_add(dp->dccps_hc_rx_ackpkts, sk,
                                              DCCP_SKB_CB(skb)->dccpd_seq,
                                              DCCP_ACKPKTS_STATE_RECEIVED))
                                 goto discard;
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 3fc75dbee4b8..fee9a8c3777b 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -1243,6 +1243,7 @@ static int dccp_v4_init_sock(struct sock *sk)
         static int dccp_ctl_socket_init = 1;
 
         dccp_options_init(&dp->dccps_options);
+        do_gettimeofday(&dp->dccps_epoch);
 
         if (dp->dccps_options.dccpo_send_ack_vector) {
                 dp->dccps_hc_rx_ackpkts =
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index ce5dff4ac22e..18461bc04cbe 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -96,6 +96,7 @@ struct sock *dccp_create_openreq_child(struct sock *sk,
                 newdp->dccps_hc_rx_ackpkts = NULL;
                 newdp->dccps_role = DCCP_ROLE_SERVER;
                 newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
+                do_gettimeofday(&newdp->dccps_epoch);
 
                 if (newdp->dccps_options.dccpo_send_ack_vector) {
                         newdp->dccps_hc_rx_ackpkts =
diff --git a/net/dccp/options.c b/net/dccp/options.c
index 34b230a00875..d4c4242d8dd7 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -140,7 +140,7 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
                         opt_recv->dccpor_timestamp = ntohl(*(u32 *)value);
 
                         dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
-                        do_gettimeofday(&dp->dccps_timestamp_time);
+                        dccp_timestamp(sk, &dp->dccps_timestamp_time);
 
                         dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
                                       debug_prefix, opt_recv->dccpor_timestamp,
@@ -361,9 +361,13 @@ static void dccp_insert_option_ack_vector(struct sock *sk, struct sk_buff *skb)
 #endif
         struct dccp_ackpkts *ap = dp->dccps_hc_rx_ackpkts;
         int len = ap->dccpap_buf_vector_len + 2;
-        const u32 elapsed_time = timeval_now_delta(&ap->dccpap_time) / 10;
+        struct timeval now;
+        u32 elapsed_time;
         unsigned char *to, *from;
 
+        dccp_timestamp(sk, &now);
+        elapsed_time = timeval_delta(&now, &ap->dccpap_time) / 10;
+
         if (elapsed_time != 0)
                 dccp_insert_option_elapsed_time(sk, skb, elapsed_time);
 
@@ -428,13 +432,29 @@ static void dccp_insert_option_ack_vector(struct sock *sk, struct sk_buff *skb)
                       (unsigned long long) ap->dccpap_ack_ackno);
 }
 
+void dccp_timestamp(const struct sock *sk, struct timeval *tv)
+{
+        const struct dccp_sock *dp = dccp_sk(sk);
+
+        do_gettimeofday(tv);
+        tv->tv_sec  -= dp->dccps_epoch.tv_sec;
+        tv->tv_usec -= dp->dccps_epoch.tv_usec;
+
+        while (tv->tv_usec < 0) {
+                tv->tv_sec--;
+                tv->tv_usec += USEC_PER_SEC;
+        }
+}
+
+EXPORT_SYMBOL_GPL(dccp_timestamp);
+
 void dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
 {
         struct timeval tv;
         u32 now;
         
-        do_gettimeofday(&tv);
-        now = (tv.tv_sec * USEC_PER_SEC + tv.tv_usec) / 10;
+        dccp_timestamp(sk, &tv);
+        now = timeval_usecs(&tv) / 10;
         /* yes this will overflow but that is the point as we want a
          * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
 
@@ -452,13 +472,17 @@ static void dccp_insert_option_timestamp_echo(struct sock *sk,
         const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
                                         "CLIENT TX opt: " : "server TX opt: ";
 #endif
+        struct timeval now;
         u32 tstamp_echo;
-        const u32 elapsed_time =
-                        timeval_now_delta(&dp->dccps_timestamp_time) / 10;
-        const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
-        const int len = 6 + elapsed_time_len;
+        u32 elapsed_time;
+        int len, elapsed_time_len;
         unsigned char *to;
 
+        dccp_timestamp(sk, &now);
+        elapsed_time = timeval_delta(&now, &dp->dccps_timestamp_time) / 10;
+        elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
+        len = 6 + elapsed_time_len;
+
         if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
                 LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small to insert "
                                          "timestamp echo!\n");
@@ -623,7 +647,8 @@ static inline int dccp_ackpkts_set_buf_head_state(struct dccp_ackpkts *ap,
 /*
  * Implements the draft-ietf-dccp-spec-11.txt Appendix A
  */
-int dccp_ackpkts_add(struct dccp_ackpkts *ap, u64 ackno, u8 state)
+int dccp_ackpkts_add(struct dccp_ackpkts *ap, const struct sock *sk,
+                     u64 ackno, u8 state)
 {
         /*
          * Check at the right places if the buffer is full, if it is, tell the
@@ -704,7 +729,7 @@ int dccp_ackpkts_add(struct dccp_ackpkts *ap, u64 ackno, u8 state)
         }
 
         ap->dccpap_buf_ackno = ackno;
-        do_gettimeofday(&ap->dccpap_time);
+        dccp_timestamp(sk, &ap->dccpap_time);
 out:
         dccp_pr_debug("");
         dccp_ackpkts_print(ap);