Hello, I wanted to raise this one too, if it's of any interest for the community.
François Le Lundi, Mai 17, 2021 11:44 CEST, François Legal via Xenomai <xenomai@xenomai.org> a écrit: > This patch enables retrieving, in realtime application, of RTNET enabled > adapters packet timestamps. > It uses the linux semantic SO_TIMESTAMPNS, and the linux code to put the > timestamp in the control_msg structure. > > I tested this patch with af_packet sockets only. UDP & TCP might be a little > bit trickier as many fragment/segments get reassembled in a single recvmsg. I > believe the linux code I used to put the timestamps in the control structure > should be OK though. > > Signed-off-by: François LEGAL <de...@thom.fr.eu.org> > --- > kernel/drivers/net/stack/Kconfig | 8 +++ > .../drivers/net/stack/include/rtnet_socket.h | 7 +++ > kernel/drivers/net/stack/ipv4/tcp/tcp.c | 8 +++ > kernel/drivers/net/stack/ipv4/udp/udp.c | 7 +++ > kernel/drivers/net/stack/packet/af_packet.c | 7 +++ > kernel/drivers/net/stack/socket.c | 59 +++++++++++++++++++ 6 > files changed, 96 insertions(+) > > diff --git a/kernel/drivers/net/stack/Kconfig > b/kernel/drivers/net/stack/Kconfig > index 830cec5ad..f8ee0f1ad 100644 > --- a/kernel/drivers/net/stack/Kconfig > +++ b/kernel/drivers/net/stack/Kconfig > @@ -12,6 +12,14 @@ config XENO_DRIVERS_NET_RX_FIFO_SIZE > of two! Effectively, only CONFIG_RTNET_RX_FIFO_SIZE-1 slots will > be usable. > > +config XENO_DRIVERS_NET_PACKET_TIMESTAMP > + bool "Enable packet timestamping (SO_TIMESTAMPNS)" > + depends on XENO_DRIVERS_NET > + ---help--- > + Enable userland access to low level packet timestamps using > SO_TIMESTAMPNS > + ioctl on socket. Timestamp are then returned in recvmsg calls in > msg_control > + structure inside msghdr structure. > + > config XENO_DRIVERS_NET_ETH_P_ALL > depends on XENO_DRIVERS_NET > bool "Support for ETH_P_ALL" > diff --git a/kernel/drivers/net/stack/include/rtnet_socket.h > b/kernel/drivers/net/stack/include/rtnet_socket.h > index d2caab649..dc488a58a 100644 > --- a/kernel/drivers/net/stack/include/rtnet_socket.h > +++ b/kernel/drivers/net/stack/include/rtnet_socket.h > @@ -29,6 +29,7 @@ > > #include <asm/atomic.h> > #include <linux/list.h> > +#include <net/sock.h> > > #include <rtdev.h> > #include <rtdm/net.h> > @@ -77,6 +78,12 @@ struct rtsocket { > } prot; > }; > > +#ifdef CONFIG_XENO_DRIVERS_NET_PACKET_TIMESTAMP > +#define SOCKET_FLAG_TIMESTAMP SOCK_RCVTSTAMPNS > +int rtnet_put_cmsg(struct rtdm_fd *fd, struct user_msghdr *msg, int level, > + int type, int len, void *data); > +#endif > + > static inline struct rtdm_fd *rt_socket_fd(struct rtsocket *sock) > { > return rtdm_private_to_fd(sock); > diff --git a/kernel/drivers/net/stack/ipv4/tcp/tcp.c > b/kernel/drivers/net/stack/ipv4/tcp/tcp.c > index d8c189c88..c8b21c521 100644 > --- a/kernel/drivers/net/stack/ipv4/tcp/tcp.c > +++ b/kernel/drivers/net/stack/ipv4/tcp/tcp.c > @@ -2027,6 +2027,14 @@ static ssize_t rt_tcp_read(struct rtdm_fd *fd, void > *buf, size_t nbyte) > kfree_rtskb(first_skb); /* or store the data? */ > return -EFAULT; > } > + > +#ifdef CONFIG_XENO_DRIVERS_NET_PACKET_TIMESTAMP > + if (test_bit(SOCKET_FLAG_TIMESTAMP, &sock->flags)) > + rtnet_put_cmsg(fd, msg, SOL_SOCKET, SCM_TIMESTAMPNS, > + sizeof(nanosecs_abs_t), > + (void *) &skb->time_stamp); > +#endif /* CONFIG_XENO_DRIVERS_NET_PACKET_TIMESTAMP */ > + > rtdm_lock_get_irqsave(&ts->socket_lock, context); > if (ts->sync.window) { > ts->sync.window += block_size; > diff --git a/kernel/drivers/net/stack/ipv4/udp/udp.c > b/kernel/drivers/net/stack/ipv4/udp/udp.c > index 546b35855..ac6448027 100644 > --- a/kernel/drivers/net/stack/ipv4/udp/udp.c > +++ b/kernel/drivers/net/stack/ipv4/udp/udp.c > @@ -463,6 +463,13 @@ ssize_t rt_udp_recvmsg(struct rtdm_fd *fd, struct > user_msghdr *msg, > do { > rtskb_trim(skb, data_len); > > +#ifdef CONFIG_XENO_DRIVERS_NET_PACKET_TIMESTAMP > + if (test_bit(SOCKET_FLAG_TIMESTAMP, &sock->flags)) > + rtnet_put_cmsg(fd, msg, SOL_SOCKET, SCM_TIMESTAMPNS, > + sizeof(nanosecs_abs_t), > + (void *) &skb->time_stamp); > +#endif /* CONFIG_XENO_DRIVERS_NET_PACKET_TIMESTAMP */ > + > block_size = skb->len; > copied += block_size; > data_len -= block_size; > diff --git a/kernel/drivers/net/stack/packet/af_packet.c > b/kernel/drivers/net/stack/packet/af_packet.c > index cc7487303..10e8113fe 100644 > --- a/kernel/drivers/net/stack/packet/af_packet.c > +++ b/kernel/drivers/net/stack/packet/af_packet.c > @@ -364,6 +364,13 @@ static ssize_t rt_packet_recvmsg(struct rtdm_fd *fd, > struct user_msghdr *msg, > if (rtdm_fd_to_context(fd)->device->driver->socket_type != SOCK_DGRAM) > rtskb_push(rtskb, rtskb->data - rtskb->mac.raw); > > +#ifdef CONFIG_XENO_DRIVERS_NET_PACKET_TIMESTAMP > + if (test_bit(SOCKET_FLAG_TIMESTAMP, &sock->flags)) > + rtnet_put_cmsg(fd, msg, SOL_SOCKET, SCM_TIMESTAMPNS, > + sizeof(nanosecs_abs_t), > + (void *) &rtskb->time_stamp); > +#endif /* CONFIG_XENO_DRIVERS_NET_PACKET_TIMESTAMP */ > + > /* The data must not be longer than the available buffer size */ > copy_len = rtskb->len; > len = rtdm_get_iov_flatlen(iov, msg->msg_iovlen); > diff --git a/kernel/drivers/net/stack/socket.c > b/kernel/drivers/net/stack/socket.c > index f030663be..5a9702975 100644 > --- a/kernel/drivers/net/stack/socket.c > +++ b/kernel/drivers/net/stack/socket.c > @@ -273,6 +273,15 @@ int rt_socket_if_ioctl(struct rtdm_fd *fd, int request, > void __user *arg) > return rtnet_put_arg(fd, &u_ifc->ifc_len, &size, sizeof(size)); > } > > +#ifdef CONFIG_XENO_DRIVERS_NET_PACKET_TIMESTAMP > + if (request == SO_TIMESTAMPNS) { > + struct rtsocket *sock = rtdm_fd_to_private(fd); > + > + set_bit(SOCKET_FLAG_TIMESTAMP, &sock->flags); > + return 0; > + } > +#endif > + > u_ifr = arg; > ifr = rtnet_get_arg(fd, &_ifr, u_ifr, sizeof(_ifr)); > if (IS_ERR(ifr)) > @@ -393,3 +402,53 @@ int rtnet_put_arg(struct rtdm_fd *fd, void *dst, const > void *src, size_t len) > return rtdm_copy_to_user(fd, dst, src, len); > } > EXPORT_SYMBOL_GPL(rtnet_put_arg); > + > +#ifdef CONFIG_XENO_DRIVERS_NET_PACKET_TIMESTAMP > +int rtnet_put_cmsg(struct rtdm_fd *fd, struct user_msghdr *msg, int level, > + int type, int len, void *data) > +{ > + struct cmsghdr __user *cm = msg->msg_control; > + struct cmsghdr cmhdr; > + int cmlen = CMSG_LEN(len); > + int err; > + > + if (MSG_CMSG_COMPAT & msg->msg_flags) > + return 0; /* XXX: return error? check spec. */ > + > + if ((cm == NULL) || (msg->msg_controllen < sizeof(*cm))) { > + msg->msg_flags |= MSG_CTRUNC; > + return 0; /* XXX: return error? check spec. */ > + } > + if (msg->msg_controllen < cmlen) { > + msg->msg_flags |= MSG_CTRUNC; > + cmlen = msg->msg_controllen; > + } > + cmhdr.cmsg_level = level; > + cmhdr.cmsg_type = type; > + cmhdr.cmsg_len = cmlen; > + > + err = -EFAULT; > + > + if (!rtdm_fd_is_user(fd)) { > + memcpy(cm, &cmhdr, sizeof(struct cmsghdr)); > + memcpy(CMSG_DATA(cm), data, cmlen - sizeof(struct cmsghdr)); > + err = 0; > + } else { > + if (rtdm_copy_to_user(fd, cm, &cmhdr, sizeof(struct cmsghdr)))+ > goto out; > + if (rtdm_copy_to_user(fd, CMSG_DATA(cm), data, > + cmlen - sizeof(struct cmsghdr))) > + goto out; > + cmlen = CMSG_SPACE(len); > + if (msg->msg_controllen < cmlen) > + cmlen = msg->msg_controllen; > + msg->msg_control += cmlen; > + msg->msg_controllen -= cmlen; > + err = 0; > + } > +out: > + return err; > +} > +EXPORT_SYMBOL(rtdm_put_cmsg); > + > +#endif /* CONFIG_XENO_DRIVERS_NET_PACKET_TIMESTAMP */ > -- > 2.20.1 > >