@@ -193,6 +193,20 @@ SOF_TIMESTAMPING_OPT_ID:
among all possibly concurrently outstanding timestamp requests for
that socket.
+ The process can optionally override the default generated ID, by
+ passing a specific ID with control message SCM_TS_OPT_ID (not
+ supported for TCP sockets)::
+
+ struct msghdr *msg;
+ ...
+ cmsg = CMSG_FIRSTHDR(msg);
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = SCM_TS_OPT_ID;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(__u32));
+ *((__u32 *) CMSG_DATA(cmsg)) = opt_id;
+ err = sendmsg(fd, msg, 0);
+
+
SOF_TIMESTAMPING_OPT_ID_TCP:
Pass this modifier along with SOF_TIMESTAMPING_OPT_ID for new TCP
timestamping applications. SOF_TIMESTAMPING_OPT_ID defines how the
@@ -140,6 +140,8 @@
#define SO_PASSPIDFD 76
#define SO_PEERPIDFD 77
+#define SCM_TS_OPT_ID 78
+
#if !defined(__KERNEL__)
#if __BITS_PER_LONG == 64
@@ -151,6 +151,8 @@
#define SO_PASSPIDFD 76
#define SO_PEERPIDFD 77
+#define SCM_TS_OPT_ID 78
+
#if !defined(__KERNEL__)
#if __BITS_PER_LONG == 64
@@ -132,6 +132,8 @@
#define SO_PASSPIDFD 0x404A
#define SO_PEERPIDFD 0x404B
+#define SCM_TS_OPT_ID 0x404C
+
#if !defined(__KERNEL__)
#if __BITS_PER_LONG == 64
@@ -133,6 +133,8 @@
#define SO_PASSPIDFD 0x0055
#define SO_PEERPIDFD 0x0056
+#define SCM_TS_OPT_ID 0x0057
+
#if !defined(__KERNEL__)
@@ -174,6 +174,7 @@ struct inet_cork {
__s16 tos;
char priority;
__u16 gso_size;
+ u32 ts_opt_id;
u64 transmit_time;
u32 mark;
};
@@ -241,7 +242,8 @@ struct inet_sock {
struct inet_cork_full cork;
};
-#define IPCORK_OPT 1 /* ip-options has been held in ipcork.opt */
+#define IPCORK_OPT 1 /* ip-options has been held in ipcork.opt */
+#define IPCORK_TS_OPT_ID 2 /* ts_opt_id field is valid, overriding sk_tskey */
enum {
INET_FLAGS_PKTINFO = 0,
@@ -952,6 +952,12 @@ enum sock_flags {
};
#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
+#define SOCKCM_FLAG_TS_OPT_ID BIT(31)
+/*
+ * The highest bit of sk_tsflags is reserved for kernel-internal
+ * SOCKCM_FLAG_TS_OPT_ID. This check is to control that SOF_TIMESTAMPING*
+ * values do not reach this reserved area
+ */
static inline void sock_copy_flags(struct sock *nsk, const struct sock *osk)
{
@@ -1794,6 +1800,7 @@ struct sockcm_cookie {
u64 transmit_time;
u32 mark;
u32 tsflags;
+ u32 ts_opt_id;
};
static inline void sockcm_init(struct sockcm_cookie *sockc,
@@ -135,6 +135,8 @@
#define SO_PASSPIDFD 76
#define SO_PEERPIDFD 77
+#define SCM_TS_OPT_ID 78
+
#if !defined(__KERNEL__)
#if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__))
@@ -2831,6 +2831,9 @@ int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
{
u32 tsflags;
+ BUILD_BUG_ON_MSG(SOF_TIMESTAMPING_LAST == (1 << 31),
+ "SOF_TIMESTAMPING* cannot use BIT(31) because it's reserved for SOCKCM_FLAG_TS_OPT_ID");
+
switch (cmsg->cmsg_type) {
case SO_MARK:
if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
@@ -2859,6 +2862,17 @@ int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
return -EINVAL;
sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
break;
+ case SCM_TS_OPT_ID:
+ if (sk_is_tcp(sk))
+ return -EINVAL;
+ tsflags = READ_ONCE(sk->sk_tsflags);
+ if (!(tsflags & SOF_TIMESTAMPING_OPT_ID))
+ return -EINVAL;
+ if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
+ return -EINVAL;
+ sockc->ts_opt_id = *(u32 *)CMSG_DATA(cmsg);
+ sockc->tsflags |= SOCKCM_FLAG_TS_OPT_ID;
+ break;
/* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
case SCM_RIGHTS:
case SCM_CREDENTIALS:
@@ -973,7 +973,7 @@ static int __ip_append_data(struct sock *sk,
unsigned int maxfraglen, fragheaderlen, maxnonfragsize;
int csummode = CHECKSUM_NONE;
struct rtable *rt = dst_rtable(cork->dst);
- bool paged, hold_tskey, extra_uref = false;
+ bool paged, hold_tskey = false, extra_uref = false;
unsigned int wmem_alloc_delta = 0;
u32 tskey = 0;
@@ -1049,10 +1049,15 @@ static int __ip_append_data(struct sock *sk,
cork->length += length;
- hold_tskey = cork->tx_flags & SKBTX_ANY_TSTAMP &&
- READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID;
- if (hold_tskey)
- tskey = atomic_inc_return(&sk->sk_tskey) - 1;
+ if (cork->tx_flags & SKBTX_ANY_TSTAMP &&
+ READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID) {
+ if (cork->flags & IPCORK_TS_OPT_ID) {
+ tskey = cork->ts_opt_id;
+ } else {
+ tskey = atomic_inc_return(&sk->sk_tskey) - 1;
+ hold_tskey = true;
+ }
+ }
/* So, what's going on in the loop below?
*
@@ -1327,6 +1332,10 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
cork->transmit_time = ipc->sockc.transmit_time;
cork->tx_flags = 0;
sock_tx_timestamp(sk, ipc->sockc.tsflags, &cork->tx_flags);
+ if (ipc->sockc.tsflags & SOCKCM_FLAG_TS_OPT_ID) {
+ cork->flags |= IPCORK_TS_OPT_ID;
+ cork->ts_opt_id = ipc->sockc.ts_opt_id;
+ }
return 0;
}
@@ -1402,7 +1402,10 @@ static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
cork->base.tx_flags = 0;
cork->base.mark = ipc6->sockc.mark;
sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags);
-
+ if (ipc6->sockc.tsflags & SOCKCM_FLAG_TS_OPT_ID) {
+ cork->base.flags |= IPCORK_TS_OPT_ID;
+ cork->base.ts_opt_id = ipc6->sockc.ts_opt_id;
+ }
cork->base.length = 0;
cork->base.transmit_time = ipc6->sockc.transmit_time;
@@ -1433,7 +1436,7 @@ static int __ip6_append_data(struct sock *sk,
bool zc = false;
u32 tskey = 0;
struct rt6_info *rt = dst_rt6_info(cork->dst);
- bool paged, hold_tskey, extra_uref = false;
+ bool paged, hold_tskey = false, extra_uref = false;
struct ipv6_txoptions *opt = v6_cork->opt;
int csummode = CHECKSUM_NONE;
unsigned int maxnonfragsize, headersize;
@@ -1543,10 +1546,15 @@ static int __ip6_append_data(struct sock *sk,
flags &= ~MSG_SPLICE_PAGES;
}
- hold_tskey = cork->tx_flags & SKBTX_ANY_TSTAMP &&
- READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID;
- if (hold_tskey)
- tskey = atomic_inc_return(&sk->sk_tskey) - 1;
+ if (cork->tx_flags & SKBTX_ANY_TSTAMP &&
+ READ_ONCE(sk->sk_tsflags) & SOF_TIMESTAMPING_OPT_ID) {
+ if (cork->flags & IPCORK_TS_OPT_ID) {
+ tskey = cork->ts_opt_id;
+ } else {
+ tskey = atomic_inc_return(&sk->sk_tskey) - 1;
+ hold_tskey = true;
+ }
+ }
/*
* Let's try using as much space as possible.
SOF_TIMESTAMPING_OPT_ID socket option flag gives a way to correlate TX timestamps and packets sent via socket. Unfortunately, there is no way to reliably predict socket timestamp ID value in case of error returned by sendmsg. For UDP sockets it's impossible because of lockless nature of UDP transmit, several threads may send packets in parallel. In case of RAW sockets MSG_MORE option makes things complicated. More details are in the conversation [1]. This patch adds new control message type to give user-space software an opportunity to control the mapping between packets and values by providing ID with each sendmsg for UDP sockets. The documentation is also added in this patch. [1] https://lore.kernel.org/netdev/CALCETrU0jB+kg0mhV6A8mrHfTE1D1pr1SD_B9Eaa9aDPfgHdtA@mail.gmail.com/ Signed-off-by: Vadim Fedorenko <vadfed@meta.com> --- Documentation/networking/timestamping.rst | 14 ++++++++++++++ arch/alpha/include/uapi/asm/socket.h | 2 ++ arch/mips/include/uapi/asm/socket.h | 2 ++ arch/parisc/include/uapi/asm/socket.h | 2 ++ arch/sparc/include/uapi/asm/socket.h | 2 ++ include/net/inet_sock.h | 4 +++- include/net/sock.h | 7 +++++++ include/uapi/asm-generic/socket.h | 2 ++ net/core/sock.c | 14 ++++++++++++++ net/ipv4/ip_output.c | 19 ++++++++++++++----- net/ipv6/ip6_output.c | 20 ++++++++++++++------ 11 files changed, 76 insertions(+), 12 deletions(-)