net: socket infrastructure for SO_TIMESTAMPING

The overlap with the old SO_TIMESTAMP[NS] options is handled so
that time stamping in software (net_enable_timestamp()) is
enabled when SO_TIMESTAMP[NS] and/or SO_TIMESTAMPING_RX_SOFTWARE
is set.  It's disabled if all of these are off.

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 186 insertions, 42 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index ded6854e3e4a..cc9d5bcb06f7 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -158,7 +158,7 @@ struct sock_common {
   *     @sk_allocation: allocation mode
   *     @sk_sndbuf: size of send buffer in bytes
   *     @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
-  *                %SO_OOBINLINE settings
+  *                %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
   *     @sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets
   *     @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
   *     @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
@@ -488,6 +488,13 @@ enum sock_flags {
         SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
         SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
         SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
+        SOCK_TIMESTAMPING_TX_HARDWARE,  /* %SOF_TIMESTAMPING_TX_HARDWARE */
+        SOCK_TIMESTAMPING_TX_SOFTWARE,  /* %SOF_TIMESTAMPING_TX_SOFTWARE */
+        SOCK_TIMESTAMPING_RX_HARDWARE,  /* %SOF_TIMESTAMPING_RX_HARDWARE */
+        SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
+        SOCK_TIMESTAMPING_SOFTWARE,     /* %SOF_TIMESTAMPING_SOFTWARE */
+        SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */
+        SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */
 };
 
 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
@@ -1346,14 +1353,45 @@ static __inline__ void
 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
 {
         ktime_t kt = skb->tstamp;
+        struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
 
-        if (sock_flag(sk, SOCK_RCVTSTAMP))
+        /*
+         * generate control messages if
+         * - receive time stamping in software requested (SOCK_RCVTSTAMP
+         *   or SOCK_TIMESTAMPING_RX_SOFTWARE)
+         * - software time stamp available and wanted
+         *   (SOCK_TIMESTAMPING_SOFTWARE)
+         * - hardware time stamps available and wanted
+         *   (SOCK_TIMESTAMPING_SYS_HARDWARE or
+         *   SOCK_TIMESTAMPING_RAW_HARDWARE)
+         */
+        if (sock_flag(sk, SOCK_RCVTSTAMP) ||
+            sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE) ||
+            (kt.tv64 && sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) ||
+            (hwtstamps->hwtstamp.tv64 &&
+             sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE)) ||
+            (hwtstamps->syststamp.tv64 &&
+             sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE)))
                 __sock_recv_timestamp(msg, sk, skb);
         else
                 sk->sk_stamp = kt;
 }
 
 /**
+ * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
+ * @msg:        outgoing packet
+ * @sk:         socket sending this packet
+ * @shtx:       filled with instructions for time stamping
+ *
+ * Currently only depends on SOCK_TIMESTAMPING* flags. Returns error code if
+ * parameters are invalid.
+ */
+extern int sock_tx_timestamp(struct msghdr *msg,
+                             struct sock *sk,
+                             union skb_shared_tx *shtx);
+
+
+/**
  * sk_eat_skb - Release a skb if it is no longer needed
  * @sk: socket to eat this skb from
  * @skb: socket buffer to eat
@@ -1421,7 +1459,7 @@ static inline struct sock *skb_steal_sock(struct sk_buff *skb)
         return NULL;
 }
 
-extern void sock_enable_timestamp(struct sock *sk);
+extern void sock_enable_timestamp(struct sock *sk, int flag);
 extern int sock_get_timestamp(struct sock *, struct timeval __user *);
 extern int sock_get_timestampns(struct sock *, struct timespec __user *);
 
diff --git a/net/compat.c b/net/compat.c
index a3a2ba0fac08..8d739053afe4 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -216,7 +216,7 @@ Efault:
 int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *data)
 {
         struct compat_timeval ctv;
-        struct compat_timespec cts;
+        struct compat_timespec cts[3];
         struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
         struct compat_cmsghdr cmhdr;
         int cmlen;
@@ -233,12 +233,17 @@ int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *dat
                 data = &ctv;
                 len = sizeof(ctv);
         }
-        if (level == SOL_SOCKET && type == SCM_TIMESTAMPNS) {
+        if (level == SOL_SOCKET &&
+            (type == SCM_TIMESTAMPNS || type == SCM_TIMESTAMPING)) {
+                int count = type == SCM_TIMESTAMPNS ? 1 : 3;
+                int i;
                 struct timespec *ts = (struct timespec *)data;
-                cts.tv_sec = ts->tv_sec;
-                cts.tv_nsec = ts->tv_nsec;
+                for (i = 0; i < count; i++) {
+                        cts[i].tv_sec = ts[i].tv_sec;
+                        cts[i].tv_nsec = ts[i].tv_nsec;
+                }
                 data = &cts;
-                len = sizeof(cts);
+                len = sizeof(cts[0]) * count;
         }
 
         cmlen = CMSG_COMPAT_LEN(len);
@@ -455,7 +460,7 @@ int compat_sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
         struct timeval tv;
 
         if (!sock_flag(sk, SOCK_TIMESTAMP))
-                sock_enable_timestamp(sk);
+                sock_enable_timestamp(sk, SOCK_TIMESTAMP);
         tv = ktime_to_timeval(sk->sk_stamp);
         if (tv.tv_sec == -1)
                 return err;
@@ -479,7 +484,7 @@ int compat_sock_get_timestampns(struct sock *sk, struct timespec __user *usersta
         struct timespec ts;
 
         if (!sock_flag(sk, SOCK_TIMESTAMP))
-                sock_enable_timestamp(sk);
+                sock_enable_timestamp(sk, SOCK_TIMESTAMP);
         ts = ktime_to_timespec(sk->sk_stamp);
         if (ts.tv_sec == -1)
                 return err;
diff --git a/net/core/sock.c b/net/core/sock.c
index 4c64be4f8765..40887e76652c 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -120,6 +120,7 @@
 #include <net/net_namespace.h>
 #include <net/request_sock.h>
 #include <net/sock.h>
+#include <linux/net_tstamp.h>
 #include <net/xfrm.h>
 #include <linux/ipsec.h>
 
@@ -255,11 +256,14 @@ static void sock_warn_obsolete_bsdism(const char *name)
         }
 }
 
-static void sock_disable_timestamp(struct sock *sk)
+static void sock_disable_timestamp(struct sock *sk, int flag)
 {
-        if (sock_flag(sk, SOCK_TIMESTAMP)) {
-                sock_reset_flag(sk, SOCK_TIMESTAMP);
-                net_disable_timestamp();
+        if (sock_flag(sk, flag)) {
+                sock_reset_flag(sk, flag);
+                if (!sock_flag(sk, SOCK_TIMESTAMP) &&
+                    !sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE)) {
+                        net_disable_timestamp();
+                }
         }
 }
 
@@ -614,13 +618,38 @@ set_rcvbuf:
                         else
                                 sock_set_flag(sk, SOCK_RCVTSTAMPNS);
                         sock_set_flag(sk, SOCK_RCVTSTAMP);
-                        sock_enable_timestamp(sk);
+                        sock_enable_timestamp(sk, SOCK_TIMESTAMP);
                 } else {
                         sock_reset_flag(sk, SOCK_RCVTSTAMP);
                         sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
                 }
                 break;
 
+        case SO_TIMESTAMPING:
+                if (val & ~SOF_TIMESTAMPING_MASK) {
+                        ret = EINVAL;
+                        break;
+                }
+                sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
+                                  val & SOF_TIMESTAMPING_TX_HARDWARE);
+                sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
+                                  val & SOF_TIMESTAMPING_TX_SOFTWARE);
+                sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
+                                  val & SOF_TIMESTAMPING_RX_HARDWARE);
+                if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
+                        sock_enable_timestamp(sk,
+                                              SOCK_TIMESTAMPING_RX_SOFTWARE);
+                else
+                        sock_disable_timestamp(sk,
+                                               SOCK_TIMESTAMPING_RX_SOFTWARE);
+                sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
+                                  val & SOF_TIMESTAMPING_SOFTWARE);
+                sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
+                                  val & SOF_TIMESTAMPING_SYS_HARDWARE);
+                sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
+                                  val & SOF_TIMESTAMPING_RAW_HARDWARE);
+                break;
+
         case SO_RCVLOWAT:
                 if (val < 0)
                         val = INT_MAX;
@@ -768,6 +797,24 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
                 v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
                 break;
 
+        case SO_TIMESTAMPING:
+                v.val = 0;
+                if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
+                        v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
+                if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
+                        v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
+                if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
+                        v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
+                if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
+                        v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
+                if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
+                        v.val |= SOF_TIMESTAMPING_SOFTWARE;
+                if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
+                        v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
+                if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
+                        v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
+                break;
+
         case SO_RCVTIMEO:
                 lv=sizeof(struct timeval);
                 if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
@@ -969,7 +1016,8 @@ void sk_free(struct sock *sk)
                 rcu_assign_pointer(sk->sk_filter, NULL);
         }
 
-        sock_disable_timestamp(sk);
+        sock_disable_timestamp(sk, SOCK_TIMESTAMP);
+        sock_disable_timestamp(sk, SOCK_TIMESTAMPING_RX_SOFTWARE);
 
         if (atomic_read(&sk->sk_omem_alloc))
                 printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
@@ -1787,7 +1835,7 @@ int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
 {
         struct timeval tv;
         if (!sock_flag(sk, SOCK_TIMESTAMP))
-                sock_enable_timestamp(sk);
+                sock_enable_timestamp(sk, SOCK_TIMESTAMP);
         tv = ktime_to_timeval(sk->sk_stamp);
         if (tv.tv_sec == -1)
                 return -ENOENT;
@@ -1803,7 +1851,7 @@ int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
 {
         struct timespec ts;
         if (!sock_flag(sk, SOCK_TIMESTAMP))
-                sock_enable_timestamp(sk);
+                sock_enable_timestamp(sk, SOCK_TIMESTAMP);
         ts = ktime_to_timespec(sk->sk_stamp);
         if (ts.tv_sec == -1)
                 return -ENOENT;
@@ -1815,11 +1863,20 @@ int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
 }
 EXPORT_SYMBOL(sock_get_timestampns);
 
-void sock_enable_timestamp(struct sock *sk)
+void sock_enable_timestamp(struct sock *sk, int flag)
 {
-        if (!sock_flag(sk, SOCK_TIMESTAMP)) {
-                sock_set_flag(sk, SOCK_TIMESTAMP);
-                net_enable_timestamp();
+        if (!sock_flag(sk, flag)) {
+                sock_set_flag(sk, flag);
+                /*
+                 * we just set one of the two flags which require net
+                 * time stamping, but time stamping might have been on
+                 * already because of the other one
+                 */
+                if (!sock_flag(sk,
+                                flag == SOCK_TIMESTAMP ?
+                                SOCK_TIMESTAMPING_RX_SOFTWARE :
+                                SOCK_TIMESTAMP))
+                        net_enable_timestamp();
         }
 }
 
diff --git a/net/socket.c b/net/socket.c
index 35dd7371752a..47a3dc074eb0 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -545,6 +545,18 @@ void sock_release(struct socket *sock)
         sock->file = NULL;
 }
 
+int sock_tx_timestamp(struct msghdr *msg, struct sock *sk,
+                      union skb_shared_tx *shtx)
+{
+        shtx->flags = 0;
+        if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
+                shtx->hardware = 1;
+        if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
+                shtx->software = 1;
+        return 0;
+}
+EXPORT_SYMBOL(sock_tx_timestamp);
+
 static inline int __sock_sendmsg(struct kiocb *iocb, struct socket *sock,
                                  struct msghdr *msg, size_t size)
 {
@@ -595,33 +607,65 @@ int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
         return result;
 }
 
+static int ktime2ts(ktime_t kt, struct timespec *ts)
+{
+        if (kt.tv64) {
+                *ts = ktime_to_timespec(kt);
+                return 1;
+        } else {
+                return 0;
+        }
+}
+
 /*
  * called from sock_recv_timestamp() if sock_flag(sk, SOCK_RCVTSTAMP)
  */
 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
         struct sk_buff *skb)
 {
-        ktime_t kt = skb->tstamp;
-
-        if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
-                struct timeval tv;
-                /* Race occurred between timestamp enabling and packet
-                   receiving.  Fill in the current time for now. */
-                if (kt.tv64 == 0)
-                        kt = ktime_get_real();
-                skb->tstamp = kt;
-                tv = ktime_to_timeval(kt);
-                put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP, sizeof(tv), &tv);
-        } else {
-                struct timespec ts;
-                /* Race occurred between timestamp enabling and packet
-                   receiving.  Fill in the current time for now. */
-                if (kt.tv64 == 0)
-                        kt = ktime_get_real();
-                skb->tstamp = kt;
-                ts = ktime_to_timespec(kt);
-                put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPNS, sizeof(ts), &ts);
+        int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP);
+        struct timespec ts[3];
+        int empty = 1;
+        struct skb_shared_hwtstamps *shhwtstamps =
+                skb_hwtstamps(skb);
+
+        /* Race occurred between timestamp enabling and packet
+           receiving.  Fill in the current time for now. */
+        if (need_software_tstamp && skb->tstamp.tv64 == 0)
+                __net_timestamp(skb);
+
+        if (need_software_tstamp) {
+                if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
+                        struct timeval tv;
+                        skb_get_timestamp(skb, &tv);
+                        put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP,
+                                 sizeof(tv), &tv);
+                } else {
+                        struct timespec ts;
+                        skb_get_timestampns(skb, &ts);
+                        put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPNS,
+                                 sizeof(ts), &ts);
+                }
+        }
+
+
+        memset(ts, 0, sizeof(ts));
+        if (skb->tstamp.tv64 &&
+            sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) {
+                skb_get_timestampns(skb, ts + 0);
+                empty = 0;
+        }
+        if (shhwtstamps) {
+                if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE) &&
+                    ktime2ts(shhwtstamps->syststamp, ts + 1))
+                        empty = 0;
+                if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE) &&
+                    ktime2ts(shhwtstamps->hwtstamp, ts + 2))
+                        empty = 0;
         }
+        if (!empty)
+                put_cmsg(msg, SOL_SOCKET,
+                         SCM_TIMESTAMPING, sizeof(ts), &ts);
 }
 
 EXPORT_SYMBOL_GPL(__sock_recv_timestamp);