Merge branch 'tstamp-next'

Willem de Bruijn says:

====================
timestamping updates

The main goal for this patchset is to allow correlating timestamps
with the egress interface. Also introduce a warning, as discussed
previously, and update the tests to verify the new feature.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Documentation/networking/timestamping.txt

@@ -122,7 +122,7 @@ SOF_TIMESTAMPING_RAW_HARDWARE:
 
 1.3.3 Timestamp Options
 
-The interface supports one option
+The interface supports the options
 
 SOF_TIMESTAMPING_OPT_ID:
 
@@ -130,19 +130,36 @@ SOF_TIMESTAMPING_OPT_ID:
   have multiple concurrent timestamping requests outstanding. Packets
   can be reordered in the transmit path, for instance in the packet
   scheduler. In that case timestamps will be queued onto the error
-  queue out of order from the original send() calls. This option
-  embeds a counter that is incremented at send() time, to order
-  timestamps within a flow.
+  queue out of order from the original send() calls. It is not always
+  possible to uniquely match timestamps to the original send() calls
+  based on timestamp order or payload inspection alone, then.
+
+  This option associates each packet at send() with a unique
+  identifier and returns that along with the timestamp. The identifier
+  is derived from a per-socket u32 counter (that wraps). For datagram
+  sockets, the counter increments with each sent packet. For stream
+  sockets, it increments with every byte.
+
+  The counter starts at zero. It is initialized the first time that
+  the socket option is enabled. It is reset each time the option is
+  enabled after having been disabled. Resetting the counter does not
+  change the identifiers of existing packets in the system.
 
   This option is implemented only for transmit timestamps. There, the
   timestamp is always looped along with a struct sock_extended_err.
   The option modifies field ee_data to pass an id that is unique
   among all possibly concurrently outstanding timestamp requests for
-  that socket. In practice, it is a monotonically increasing u32
-  (that wraps).
+  that socket.
+
+
+SOF_TIMESTAMPING_OPT_CMSG:
 
-  In datagram sockets, the counter increments on each send call. In
-  stream sockets, it increments with every byte.
+  Support recv() cmsg for all timestamped packets. Control messages
+  are already supported unconditionally on all packets with receive
+  timestamps and on IPv6 packets with transmit timestamp. This option
+  extends them to IPv4 packets with transmit timestamp. One use case
+  is to correlate packets with their egress device, by enabling socket
+  option IP_PKTINFO simultaneously.
 
 
 1.4 Bytestream Timestamps

Documentation/networking/timestamping/txtimestamp.c

@@ -46,6 +46,7 @@
 #include <netpacket/packet.h>
 #include <poll.h>
 #include <stdarg.h>
+#include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -58,6 +59,14 @@
 #include <time.h>
 #include <unistd.h>
 
+/* ugly hack to work around netinet/in.h and linux/ipv6.h conflicts */
+#ifndef in6_pktinfo
+struct in6_pktinfo {
+	struct in6_addr	ipi6_addr;
+	int		ipi6_ifindex;
+};
+#endif
+
 /* command line parameters */
 static int cfg_proto = SOCK_STREAM;
 static int cfg_ipproto = IPPROTO_TCP;
@@ -65,6 +74,8 @@ static int cfg_num_pkts = 4;
 static int do_ipv4 = 1;
 static int do_ipv6 = 1;
 static int cfg_payload_len = 10;
+static bool cfg_show_payload;
+static bool cfg_do_pktinfo;
 static uint16_t dest_port = 9000;
 
 static struct sockaddr_in daddr;
@@ -131,6 +142,30 @@ static void print_timestamp(struct scm_timestamping *tss, int tstype,
 	__print_timestamp(tsname, &tss->ts[0], tskey, payload_len);
 }
 
+/* TODO: convert to check_and_print payload once API is stable */
+static void print_payload(char *data, int len)
+{
+	int i;
+
+	if (len > 70)
+		len = 70;
+
+	fprintf(stderr, "payload: ");
+	for (i = 0; i < len; i++)
+		fprintf(stderr, "%02hhx ", data[i]);
+	fprintf(stderr, "\n");
+}
+
+static void print_pktinfo(int family, int ifindex, void *saddr, void *daddr)
+{
+	char sa[INET6_ADDRSTRLEN], da[INET6_ADDRSTRLEN];
+
+	fprintf(stderr, "         pktinfo: ifindex=%u src=%s dst=%s\n",
+		ifindex,
+		saddr ? inet_ntop(family, saddr, sa, sizeof(sa)) : "unknown",
+		daddr ? inet_ntop(family, daddr, da, sizeof(da)) : "unknown");
+}
+
 static void __poll(int fd)
 {
 	struct pollfd pollfd;
@@ -156,10 +191,9 @@ static void __recv_errmsg_cmsg(struct msghdr *msg, int payload_len)
 		    cm->cmsg_type == SCM_TIMESTAMPING) {
 			tss = (void *) CMSG_DATA(cm);
 		} else if ((cm->cmsg_level == SOL_IP &&
-		     cm->cmsg_type == IP_RECVERR) ||
-		    (cm->cmsg_level == SOL_IPV6 &&
-		     cm->cmsg_type == IPV6_RECVERR)) {
-
+			    cm->cmsg_type == IP_RECVERR) ||
+			   (cm->cmsg_level == SOL_IPV6 &&
+			    cm->cmsg_type == IPV6_RECVERR)) {
 			serr = (void *) CMSG_DATA(cm);
 			if (serr->ee_errno != ENOMSG ||
 			    serr->ee_origin != SO_EE_ORIGIN_TIMESTAMPING) {
@@ -168,6 +202,16 @@ static void __recv_errmsg_cmsg(struct msghdr *msg, int payload_len)
 						serr->ee_origin);
 				serr = NULL;
 			}
+		} else if (cm->cmsg_level == SOL_IP &&
+			   cm->cmsg_type == IP_PKTINFO) {
+			struct in_pktinfo *info = (void *) CMSG_DATA(cm);
+			print_pktinfo(AF_INET, info->ipi_ifindex,
+				      &info->ipi_spec_dst, &info->ipi_addr);
+		} else if (cm->cmsg_level == SOL_IPV6 &&
+			   cm->cmsg_type == IPV6_PKTINFO) {
+			struct in6_pktinfo *info6 = (void *) CMSG_DATA(cm);
+			print_pktinfo(AF_INET6, info6->ipi6_ifindex,
+				      NULL, &info6->ipi6_addr);
 		} else
 			fprintf(stderr, "unknown cmsg %d,%d\n",
 					cm->cmsg_level, cm->cmsg_type);
@@ -206,7 +250,11 @@ static int recv_errmsg(int fd)
 	if (ret == -1 && errno != EAGAIN)
 		error(1, errno, "recvmsg");
 
-	__recv_errmsg_cmsg(&msg, ret);
+	if (ret > 0) {
+		__recv_errmsg_cmsg(&msg, ret);
+		if (cfg_show_payload)
+			print_payload(data, cfg_payload_len);
+	}
 
 	free(data);
 	return ret == -1;
@@ -215,9 +263,9 @@ static int recv_errmsg(int fd)
 static void do_test(int family, unsigned int opt)
 {
 	char *buf;
-	int fd, i, val, total_len;
+	int fd, i, val = 1, total_len;
 
-	if (family == IPPROTO_IPV6 && cfg_proto != SOCK_STREAM) {
+	if (family == AF_INET6 && cfg_proto != SOCK_STREAM) {
 		/* due to lack of checksum generation code */
 		fprintf(stderr, "test: skipping datagram over IPv6\n");
 		return;
@@ -239,7 +287,6 @@ static void do_test(int family, unsigned int opt)
 		error(1, errno, "socket");
 
 	if (cfg_proto == SOCK_STREAM) {
-		val = 1;
 		if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY,
 			       (char*) &val, sizeof(val)))
 			error(1, 0, "setsockopt no nagle");
@@ -253,7 +300,20 @@ static void do_test(int family, unsigned int opt)
 		}
 	}
 
+	if (cfg_do_pktinfo) {
+		if (family == AF_INET6) {
+			if (setsockopt(fd, SOL_IPV6, IPV6_RECVPKTINFO,
+				       &val, sizeof(val)))
+				error(1, errno, "setsockopt pktinfo ipv6");
+		} else {
+			if (setsockopt(fd, SOL_IP, IP_PKTINFO,
+				       &val, sizeof(val)))
+				error(1, errno, "setsockopt pktinfo ipv4");
+		}
+	}
+
 	opt |= SOF_TIMESTAMPING_SOFTWARE |
+	       SOF_TIMESTAMPING_OPT_CMSG |
 	       SOF_TIMESTAMPING_OPT_ID;
 	if (setsockopt(fd, SOL_SOCKET, SO_TIMESTAMPING,
 		       (char *) &opt, sizeof(opt)))
@@ -262,8 +322,6 @@ static void do_test(int family, unsigned int opt)
 	for (i = 0; i < cfg_num_pkts; i++) {
 		memset(&ts_prev, 0, sizeof(ts_prev));
 		memset(buf, 'a' + i, total_len);
-		buf[total_len - 2] = '\n';
-		buf[total_len - 1] = '\0';
 
 		if (cfg_proto == SOCK_RAW) {
 			struct udphdr *udph;
@@ -324,11 +382,13 @@ static void __attribute__((noreturn)) usage(const char *filepath)
 			"  -4:   only IPv4\n"
 			"  -6:   only IPv6\n"
 			"  -h:   show this message\n"
+			"  -I:   request PKTINFO\n"
 			"  -l N: send N bytes at a time\n"
 			"  -r:   use raw\n"
 			"  -R:   use raw (IP_HDRINCL)\n"
 			"  -p N: connect to port N\n"
-			"  -u:   use udp\n",
+			"  -u:   use udp\n"
+			"  -x:   show payload (up to 70 bytes)\n",
 			filepath);
 	exit(1);
 }
@@ -338,7 +398,7 @@ static void parse_opt(int argc, char **argv)
 	int proto_count = 0;
 	char c;
 
-	while ((c = getopt(argc, argv, "46hl:p:rRu")) != -1) {
+	while ((c = getopt(argc, argv, "46hIl:p:rRux")) != -1) {
 		switch (c) {
 		case '4':
 			do_ipv6 = 0;
@@ -346,6 +406,9 @@ static void parse_opt(int argc, char **argv)
 		case '6':
 			do_ipv4 = 0;
 			break;
+		case 'I':
+			cfg_do_pktinfo = true;
+			break;
 		case 'r':
 			proto_count++;
 			cfg_proto = SOCK_RAW;
@@ -367,6 +430,9 @@ static void parse_opt(int argc, char **argv)
 		case 'p':
 			dest_port = strtoul(optarg, NULL, 10);
 			break;
+		case 'x':
+			cfg_show_payload = true;
+			break;
 		case 'h':
 		default:
 			usage(argv[0]);

include/uapi/linux/net_tstamp.h

@@ -23,8 +23,9 @@ enum {
 	SOF_TIMESTAMPING_OPT_ID = (1<<7),
 	SOF_TIMESTAMPING_TX_SCHED = (1<<8),
 	SOF_TIMESTAMPING_TX_ACK = (1<<9),
+	SOF_TIMESTAMPING_OPT_CMSG = (1<<10),
 
-	SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_TX_ACK,
+	SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_CMSG,
 	SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) |
 				 SOF_TIMESTAMPING_LAST
 };

net/ipv4/ip_sockglue.c

@@ -399,6 +399,22 @@ void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 inf
 		kfree_skb(skb);
 }
 
+static bool ipv4_pktinfo_prepare_errqueue(const struct sock *sk,
+					  const struct sk_buff *skb,
+					  int ee_origin)
+{
+	struct in_pktinfo *info = PKTINFO_SKB_CB(skb);
+
+	if ((ee_origin != SO_EE_ORIGIN_TIMESTAMPING) ||
+	    (!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_CMSG)) ||
+	    (!skb->dev))
+		return false;
+
+	info->ipi_spec_dst.s_addr = ip_hdr(skb)->saddr;
+	info->ipi_ifindex = skb->dev->ifindex;
+	return true;
+}
+
 /*
  *	Handle MSG_ERRQUEUE
  */
@@ -414,6 +430,8 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 	int err;
 	int copied;
 
+	WARN_ON_ONCE(sk->sk_family == AF_INET6);
+
 	err = -EAGAIN;
 	skb = sock_dequeue_err_skb(sk);
 	if (skb == NULL)
@@ -444,7 +462,9 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 	sin = &errhdr.offender;
 	sin->sin_family = AF_UNSPEC;
-	if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP) {
+
+	if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
+	    ipv4_pktinfo_prepare_errqueue(sk, skb, serr->ee.ee_origin)) {
 		struct inet_sock *inet = inet_sk(sk);
 
 		sin->sin_family = AF_INET;
@@ -1049,7 +1069,7 @@ static int do_ip_setsockopt(struct sock *sk, int level,
 }
 
 /**
- * ipv4_pktinfo_prepare - transfert some info from rtable to skb
+ * ipv4_pktinfo_prepare - transfer some info from rtable to skb
  * @sk: socket
  * @skb: buffer
  *

net/ipv6/datagram.c

@@ -325,6 +325,16 @@ void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 	kfree_skb(skb);
 }
 
+static void ip6_datagram_prepare_pktinfo_errqueue(struct sk_buff *skb)
+{
+	int ifindex = skb->dev ? skb->dev->ifindex : -1;
+
+	if (skb->protocol == htons(ETH_P_IPV6))
+		IP6CB(skb)->iif = ifindex;
+	else
+		PKTINFO_SKB_CB(skb)->ipi_ifindex = ifindex;
+}
+
 /*
  *	Handle MSG_ERRQUEUE
  */
@@ -388,8 +398,12 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 		sin->sin6_family = AF_INET6;
 		sin->sin6_flowinfo = 0;
 		sin->sin6_port = 0;
-		if (np->rxopt.all)
+		if (np->rxopt.all) {
+			if (serr->ee.ee_origin != SO_EE_ORIGIN_ICMP &&
+			    serr->ee.ee_origin != SO_EE_ORIGIN_ICMP6)
+				ip6_datagram_prepare_pktinfo_errqueue(skb);
 			ip6_datagram_recv_common_ctl(sk, msg, skb);
+		}
 		if (skb->protocol == htons(ETH_P_IPV6)) {
 			sin->sin6_addr = ipv6_hdr(skb)->saddr;
 			if (np->rxopt.all)
@@ -491,7 +505,10 @@ void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 			ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 					       &src_info.ipi6_addr);
 		}
-		put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info);
+
+		if (src_info.ipi6_ifindex >= 0)
+			put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
+				 sizeof(src_info), &src_info);
 	}
 }