[PATCH 0/2] Adding SO_PEEK_OFF for TCPv6

[PATCH 0/2] Adding SO_PEEK_OFF for TCPv6

[jmaloy]

From: Jon Maloy <jmaloy@redhat.com>

Adding SO_PEEK_OFF for TCPv6 and selftest for both TCPv4 and TCPv6.

Jon Maloy (2):
  tcp: add SO_PEEK_OFF socket option tor TCPv6
  selftests: add selftest for tcp SO_PEEK_OFF support

 net/ipv6/af_inet6.c                           |   1 +
 tools/testing/selftests/net/Makefile          |   1 +
 tools/testing/selftests/net/tcp_so_peek_off.c | 181 ++++++++++++++++++
 3 files changed, 183 insertions(+)
 create mode 100644 tools/testing/selftests/net/tcp_so_peek_off.c

-- 
2.45.2

[PATCH 1/2] tcp: add SO_PEEK_OFF socket option tor TCPv6

[jmaloy]

From: Jon Maloy <jmaloy@redhat.com>

When we added the SO_PEEK_OFF socket option to TCP we forgot
to add it even for TCP on IPv6.

We do that here.

Fixes: 05ea491641d3 ("tcp: add support for SO_PEEK_OFF socket option")
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Tested-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
---
 net/ipv6/af_inet6.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 90d2c7e3f5e9..ba69b86f1c7d 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -708,6 +708,7 @@ const struct proto_ops inet6_stream_ops = {
 	.splice_eof	   = inet_splice_eof,
 	.sendmsg_locked    = tcp_sendmsg_locked,
 	.splice_read	   = tcp_splice_read,
+	.set_peek_off      = sk_set_peek_off,
 	.read_sock	   = tcp_read_sock,
 	.read_skb	   = tcp_read_skb,
 	.peek_len	   = tcp_peek_len,
-- 
@@ -708,6 +708,7 @@ const struct proto_ops inet6_stream_ops = {
 	.splice_eof	   = inet_splice_eof,
 	.sendmsg_locked    = tcp_sendmsg_locked,
 	.splice_read	   = tcp_splice_read,
+	.set_peek_off      = sk_set_peek_off,
 	.read_sock	   = tcp_read_sock,
 	.read_skb	   = tcp_read_skb,
 	.peek_len	   = tcp_peek_len,
-- 
2.45.2

[PATCH 2/2] selftests: add selftest for tcp SO_PEEK_OFF support

[jmaloy]

From: Jon Maloy <jmaloy@redhat.com>

We add a selftest to check that the new feature added in
commit 05ea491641d3 ("tcp: add support for SO_PEEK_OFF socket option")
works correctly.

Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Tested-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
---
 tools/testing/selftests/net/Makefile          |   1 +
 tools/testing/selftests/net/tcp_so_peek_off.c | 181 ++++++++++++++++++
 2 files changed, 182 insertions(+)
 create mode 100644 tools/testing/selftests/net/tcp_so_peek_off.c

diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index 8eaffd7a641c..1179e3261bef 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -80,6 +80,7 @@ TEST_PROGS += io_uring_zerocopy_tx.sh
 TEST_GEN_FILES += bind_bhash
 TEST_GEN_PROGS += sk_bind_sendto_listen
 TEST_GEN_PROGS += sk_connect_zero_addr
+TEST_GEN_PROGS += tcp_so_peek_off
 TEST_PROGS += test_ingress_egress_chaining.sh
 TEST_GEN_PROGS += so_incoming_cpu
 TEST_PROGS += sctp_vrf.sh
diff --git a/tools/testing/selftests/net/tcp_so_peek_off.c b/tools/testing/selftests/net/tcp_so_peek_off.c
new file mode 100644
index 000000000000..8379ea02e3d7
--- /dev/null
+++ b/tools/testing/selftests/net/tcp_so_peek_off.c
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include "../kselftest.h"
+
+static char *afstr(int af)
+{
+	return af == AF_INET ? "TCP/IPv4" : "TCP/IPv6";
+}
+
+int tcp_peek_offset_probe(sa_family_t af)
+{
+	int optv = 0;
+	int ret = 0;
+	int s;
+
+	s = socket(af, SOCK_STREAM | SOCK_CLOEXEC, IPPROTO_TCP);
+	if (s < 0) {
+		ksft_perror("Temporary TCP socket creation failed");
+	} else {
+		if (!setsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &optv, sizeof(int)))
+			ret = 1;
+		else
+			printf("%s does not support SO_PEEK_OFF\n", afstr(af));
+		close(s);
+	}
+	return ret;
+}
+
+static void tcp_peek_offset_set(int s, int offset)
+{
+	if (setsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &offset, sizeof(offset)))
+		ksft_perror("Failed to set SO_PEEK_OFF value\n");
+}
+
+static int tcp_peek_offset_get(int s)
+{
+	int offset;
+	socklen_t len = sizeof(offset);
+
+	if (getsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &offset, &len))
+		ksft_perror("Failed to get SO_PEEK_OFF value\n");
+	return offset;
+}
+
+static int tcp_peek_offset_test(sa_family_t af)
+{
+	union {
+		struct sockaddr sa;
+		struct sockaddr_in a4;
+		struct sockaddr_in6 a6;
+	} a;
+	int res = 0;
+	int s[2] = {0, 0};
+	int recv_sock = 0;
+	int offset = 0;
+	ssize_t len;
+	char buf;
+
+	memset(&a, 0, sizeof(a));
+	a.sa.sa_family = af;
+
+	s[0] = socket(af, SOCK_STREAM, IPPROTO_TCP);
+	s[1] = socket(af, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
+
+	if (s[0] < 0 || s[1] < 0) {
+		ksft_perror("Temporary probe socket creation failed\n");
+		goto out;
+	}
+	if (bind(s[0], &a.sa, sizeof(a)) < 0) {
+		ksft_perror("Temporary probe socket bind() failed\n");
+		goto out;
+	}
+	if (getsockname(s[0], &a.sa, &((socklen_t) { sizeof(a) })) < 0) {
+		ksft_perror("Temporary probe socket getsockname() failed\n");
+		goto out;
+	}
+	if (listen(s[0], 0) < 0) {
+		ksft_perror("Temporary probe socket listen() failed\n");
+		goto out;
+	}
+	if (connect(s[1], &a.sa, sizeof(a)) >= 0 || errno != EINPROGRESS) {
+		ksft_perror("Temporary probe socket connect() failed\n");
+		goto out;
+	}
+	recv_sock = accept(s[0], NULL, NULL);
+	if (recv_sock <= 0) {
+		ksft_perror("Temporary probe socket accept() failed\n");
+		goto out;
+	}
+
+	/* Some basic tests of getting/setting offset */
+	offset = tcp_peek_offset_get(recv_sock);
+	if (offset != -1) {
+		ksft_perror("Initial value of socket offset not -1\n");
+		goto out;
+	}
+	tcp_peek_offset_set(recv_sock, 0);
+	offset = tcp_peek_offset_get(recv_sock);
+	if (offset != 0) {
+		ksft_perror("Failed to set socket offset to 0\n");
+		goto out;
+	}
+
+	/* Transfer a message */
+	if (send(s[1], (char *)("ab"), 2, 0) <= 0 || errno != EINPROGRESS) {
+		ksft_perror("Temporary probe socket send() failed\n");
+		goto out;
+	}
+	/* Read first byte */
+	len = recv(recv_sock, &buf, 1, MSG_PEEK);
+	if (len != 1 || buf != 'a') {
+		ksft_perror("Failed to read first byte of message\n");
+		goto out;
+	}
+	offset = tcp_peek_offset_get(recv_sock);
+	if (offset != 1) {
+		ksft_perror("Offset not forwarded correctly at first byte\n");
+		goto out;
+	}
+	/* Try to read beyond last byte */
+	len = recv(recv_sock, &buf, 2, MSG_PEEK);
+	if (len != 1 || buf != 'b') {
+		ksft_perror("Failed to read last byte of message\n");
+		goto out;
+	}
+	offset = tcp_peek_offset_get(recv_sock);
+	if (offset != 2) {
+		ksft_perror("Offset not forwarded correctly at last byte\n");
+		goto out;
+	}
+	/* Flush message */
+	len = recv(recv_sock, NULL, 2, MSG_TRUNC);
+	if (len != 2) {
+		ksft_perror("Failed to flush message\n");
+		goto out;
+	}
+	offset = tcp_peek_offset_get(recv_sock);
+	if (offset != 0) {
+		ksft_perror("Offset not reverted correctly after flush\n");
+		goto out;
+	}
+
+	printf("%s with MSG_PEEK_OFF works correctly\n", afstr(af));
+	res = 1;
+out:
+	close(recv_sock);
+	close(s[1]);
+	close(s[0]);
+	return res;
+}
+
+int main(void)
+{
+	int res4, res6;
+
+	res4 = tcp_peek_offset_probe(AF_INET);
+	res6 = tcp_peek_offset_probe(AF_INET6);
+
+	if (!res4 && !res6)
+		return KSFT_SKIP;
+
+	if (res4)
+		res4 = tcp_peek_offset_test(AF_INET);
+
+	if (res6)
+		res6 = tcp_peek_offset_test(AF_INET6);
+
+	if (!res4 || !res6)
+		return KSFT_FAIL;
+
+	return KSFT_PASS;
+}
+
-- 
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include "../kselftest.h"
+
+static char *afstr(int af)
+{
+	return af == AF_INET ? "TCP/IPv4" : "TCP/IPv6";
+}
+
+int tcp_peek_offset_probe(sa_family_t af)
+{
+	int optv = 0;
+	int ret = 0;
+	int s;
+
+	s = socket(af, SOCK_STREAM | SOCK_CLOEXEC, IPPROTO_TCP);
+	if (s < 0) {
+		ksft_perror("Temporary TCP socket creation failed");
+	} else {
+		if (!setsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &optv, sizeof(int)))
+			ret = 1;
+		else
+			printf("%s does not support SO_PEEK_OFF\n", afstr(af));
+		close(s);
+	}
+	return ret;
+}
+
+static void tcp_peek_offset_set(int s, int offset)
+{
+	if (setsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &offset, sizeof(offset)))
+		ksft_perror("Failed to set SO_PEEK_OFF value\n");
+}
+
+static int tcp_peek_offset_get(int s)
+{
+	int offset;
+	socklen_t len = sizeof(offset);
+
+	if (getsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &offset, &len))
+		ksft_perror("Failed to get SO_PEEK_OFF value\n");
+	return offset;
+}
+
+static int tcp_peek_offset_test(sa_family_t af)
+{
+	union {
+		struct sockaddr sa;
+		struct sockaddr_in a4;
+		struct sockaddr_in6 a6;
+	} a;
+	int res = 0;
+	int s[2] = {0, 0};
+	int recv_sock = 0;
+	int offset = 0;
+	ssize_t len;
+	char buf;
+
+	memset(&a, 0, sizeof(a));
+	a.sa.sa_family = af;
+
+	s[0] = socket(af, SOCK_STREAM, IPPROTO_TCP);
+	s[1] = socket(af, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
+
+	if (s[0] < 0 || s[1] < 0) {
+		ksft_perror("Temporary probe socket creation failed\n");
+		goto out;
+	}
+	if (bind(s[0], &a.sa, sizeof(a)) < 0) {
+		ksft_perror("Temporary probe socket bind() failed\n");
+		goto out;
+	}
+	if (getsockname(s[0], &a.sa, &((socklen_t) { sizeof(a) })) < 0) {
+		ksft_perror("Temporary probe socket getsockname() failed\n");
+		goto out;
+	}
+	if (listen(s[0], 0) < 0) {
+		ksft_perror("Temporary probe socket listen() failed\n");
+		goto out;
+	}
+	if (connect(s[1], &a.sa, sizeof(a)) >= 0 || errno != EINPROGRESS) {
+		ksft_perror("Temporary probe socket connect() failed\n");
+		goto out;
+	}
+	recv_sock = accept(s[0], NULL, NULL);
+	if (recv_sock <= 0) {
+		ksft_perror("Temporary probe socket accept() failed\n");
+		goto out;
+	}
+
+	/* Some basic tests of getting/setting offset */
+	offset = tcp_peek_offset_get(recv_sock);
+	if (offset != -1) {
+		ksft_perror("Initial value of socket offset not -1\n");
+		goto out;
+	}
+	tcp_peek_offset_set(recv_sock, 0);
+	offset = tcp_peek_offset_get(recv_sock);
+	if (offset != 0) {
+		ksft_perror("Failed to set socket offset to 0\n");
+		goto out;
+	}
+
+	/* Transfer a message */
+	if (send(s[1], (char *)("ab"), 2, 0) <= 0 || errno != EINPROGRESS) {
+		ksft_perror("Temporary probe socket send() failed\n");
+		goto out;
+	}
+	/* Read first byte */
+	len = recv(recv_sock, &buf, 1, MSG_PEEK);
+	if (len != 1 || buf != 'a') {
+		ksft_perror("Failed to read first byte of message\n");
+		goto out;
+	}
+	offset = tcp_peek_offset_get(recv_sock);
+	if (offset != 1) {
+		ksft_perror("Offset not forwarded correctly at first byte\n");
+		goto out;
+	}
+	/* Try to read beyond last byte */
+	len = recv(recv_sock, &buf, 2, MSG_PEEK);
+	if (len != 1 || buf != 'b') {
+		ksft_perror("Failed to read last byte of message\n");
+		goto out;
+	}
+	offset = tcp_peek_offset_get(recv_sock);
+	if (offset != 2) {
+		ksft_perror("Offset not forwarded correctly at last byte\n");
+		goto out;
+	}
+	/* Flush message */
+	len = recv(recv_sock, NULL, 2, MSG_TRUNC);
+	if (len != 2) {
+		ksft_perror("Failed to flush message\n");
+		goto out;
+	}
+	offset = tcp_peek_offset_get(recv_sock);
+	if (offset != 0) {
+		ksft_perror("Offset not reverted correctly after flush\n");
+		goto out;
+	}
+
+	printf("%s with MSG_PEEK_OFF works correctly\n", afstr(af));
+	res = 1;
+out:
+	close(recv_sock);
+	close(s[1]);
+	close(s[0]);
+	return res;
+}
+
+int main(void)
+{
+	int res4, res6;
+
+	res4 = tcp_peek_offset_probe(AF_INET);
+	res6 = tcp_peek_offset_probe(AF_INET6);
+
+	if (!res4 && !res6)
+		return KSFT_SKIP;
+
+	if (res4)
+		res4 = tcp_peek_offset_test(AF_INET);
+
+	if (res6)
+		res6 = tcp_peek_offset_test(AF_INET6);
+
+	if (!res4 || !res6)
+		return KSFT_FAIL;
+
+	return KSFT_PASS;
+}
+
-- 
2.45.2

Re: [PATCH 2/2] selftests: add selftest for tcp SO_PEEK_OFF support

[Jason Xing]

Hello Jon,

On Sat, Aug 24, 2024 at 5:19 AM <jmaloy@redhat.com> wrote:
>
> From: Jon Maloy <jmaloy@redhat.com>
>
> We add a selftest to check that the new feature added in
> commit 05ea491641d3 ("tcp: add support for SO_PEEK_OFF socket option")
> works correctly.
>
> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
> Tested-by: Stefano Brivio <sbrivio@redhat.com>
> Signed-off-by: Jon Maloy <jmaloy@redhat.com>

Thanks for working on this. Sorry that I just noticed I missed your
previous reply :(

> ---
>  tools/testing/selftests/net/Makefile          |   1 +
>  tools/testing/selftests/net/tcp_so_peek_off.c | 181 ++++++++++++++++++
>  2 files changed, 182 insertions(+)
>  create mode 100644 tools/testing/selftests/net/tcp_so_peek_off.c
>
> diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
> index 8eaffd7a641c..1179e3261bef 100644
> --- a/tools/testing/selftests/net/Makefile
> +++ b/tools/testing/selftests/net/Makefile
> @@ -80,6 +80,7 @@ TEST_PROGS += io_uring_zerocopy_tx.sh
>  TEST_GEN_FILES += bind_bhash
>  TEST_GEN_PROGS += sk_bind_sendto_listen
>  TEST_GEN_PROGS += sk_connect_zero_addr
> +TEST_GEN_PROGS += tcp_so_peek_off
>  TEST_PROGS += test_ingress_egress_chaining.sh
>  TEST_GEN_PROGS += so_incoming_cpu
>  TEST_PROGS += sctp_vrf.sh
> diff --git a/tools/testing/selftests/net/tcp_so_peek_off.c b/tools/testing/selftests/net/tcp_so_peek_off.c
> new file mode 100644
> index 000000000000..8379ea02e3d7
> --- /dev/null
> +++ b/tools/testing/selftests/net/tcp_so_peek_off.c
> @@ -0,0 +1,181 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <errno.h>
> +#include <sys/types.h>
> +#include <netinet/in.h>
> +#include <arpa/inet.h>
> +#include "../kselftest.h"
> +
> +static char *afstr(int af)
> +{
> +       return af == AF_INET ? "TCP/IPv4" : "TCP/IPv6";
> +}
> +
> +int tcp_peek_offset_probe(sa_family_t af)
> +{
> +       int optv = 0;
> +       int ret = 0;
> +       int s;
> +
> +       s = socket(af, SOCK_STREAM | SOCK_CLOEXEC, IPPROTO_TCP);
> +       if (s < 0) {
> +               ksft_perror("Temporary TCP socket creation failed");
> +       } else {
> +               if (!setsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &optv, sizeof(int)))
> +                       ret = 1;
> +               else
> +                       printf("%s does not support SO_PEEK_OFF\n", afstr(af));
> +               close(s);
> +       }
> +       return ret;
> +}
> +
> +static void tcp_peek_offset_set(int s, int offset)
> +{
> +       if (setsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &offset, sizeof(offset)))
> +               ksft_perror("Failed to set SO_PEEK_OFF value\n");
> +}
> +
> +static int tcp_peek_offset_get(int s)
> +{
> +       int offset;
> +       socklen_t len = sizeof(offset);
> +
> +       if (getsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &offset, &len))
> +               ksft_perror("Failed to get SO_PEEK_OFF value\n");
> +       return offset;
> +}
> +
> +static int tcp_peek_offset_test(sa_family_t af)
> +{
> +       union {
> +               struct sockaddr sa;
> +               struct sockaddr_in a4;
> +               struct sockaddr_in6 a6;
> +       } a;
> +       int res = 0;
> +       int s[2] = {0, 0};
> +       int recv_sock = 0;
> +       int offset = 0;
> +       ssize_t len;
> +       char buf;
> +
> +       memset(&a, 0, sizeof(a));
> +       a.sa.sa_family = af;
> +
> +       s[0] = socket(af, SOCK_STREAM, IPPROTO_TCP);
> +       s[1] = socket(af, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
> +
> +       if (s[0] < 0 || s[1] < 0) {
> +               ksft_perror("Temporary probe socket creation failed\n");
> +               goto out;

Nit: I wonder if we can use more proper test statements to avoid such
hiding failure[1] when closing a invalid file descriptor, even though
it doesn't harm the test itself?

[1]: "EBADF (Bad file descriptor)"

> +       }
> +       if (bind(s[0], &a.sa, sizeof(a)) < 0) {
> +               ksft_perror("Temporary probe socket bind() failed\n");
> +               goto out;
> +       }
> +       if (getsockname(s[0], &a.sa, &((socklen_t) { sizeof(a) })) < 0) {
> +               ksft_perror("Temporary probe socket getsockname() failed\n");
> +               goto out;
> +       }
> +       if (listen(s[0], 0) < 0) {
> +               ksft_perror("Temporary probe socket listen() failed\n");
> +               goto out;
> +       }
> +       if (connect(s[1], &a.sa, sizeof(a)) >= 0 || errno != EINPROGRESS) {
> +               ksft_perror("Temporary probe socket connect() failed\n");
> +               goto out;
> +       }
> +       recv_sock = accept(s[0], NULL, NULL);
> +       if (recv_sock <= 0) {
> +               ksft_perror("Temporary probe socket accept() failed\n");
> +               goto out;

Same here.

> +       }
> +
> +       /* Some basic tests of getting/setting offset */
> +       offset = tcp_peek_offset_get(recv_sock);
> +       if (offset != -1) {
> +               ksft_perror("Initial value of socket offset not -1\n");
> +               goto out;
> +       }
> +       tcp_peek_offset_set(recv_sock, 0);
> +       offset = tcp_peek_offset_get(recv_sock);
> +       if (offset != 0) {
> +               ksft_perror("Failed to set socket offset to 0\n");
> +               goto out;
> +       }
> +
> +       /* Transfer a message */
> +       if (send(s[1], (char *)("ab"), 2, 0) <= 0 || errno != EINPROGRESS) {
> +               ksft_perror("Temporary probe socket send() failed\n");
> +               goto out;
> +       }
> +       /* Read first byte */
> +       len = recv(recv_sock, &buf, 1, MSG_PEEK);
> +       if (len != 1 || buf != 'a') {
> +               ksft_perror("Failed to read first byte of message\n");
> +               goto out;
> +       }
> +       offset = tcp_peek_offset_get(recv_sock);
> +       if (offset != 1) {
> +               ksft_perror("Offset not forwarded correctly at first byte\n");
> +               goto out;
> +       }
> +       /* Try to read beyond last byte */
> +       len = recv(recv_sock, &buf, 2, MSG_PEEK);
> +       if (len != 1 || buf != 'b') {
> +               ksft_perror("Failed to read last byte of message\n");
> +               goto out;
> +       }
> +       offset = tcp_peek_offset_get(recv_sock);
> +       if (offset != 2) {
> +               ksft_perror("Offset not forwarded correctly at last byte\n");
> +               goto out;
> +       }
> +       /* Flush message */
> +       len = recv(recv_sock, NULL, 2, MSG_TRUNC);
> +       if (len != 2) {
> +               ksft_perror("Failed to flush message\n");
> +               goto out;
> +       }
> +       offset = tcp_peek_offset_get(recv_sock);
> +       if (offset != 0) {
> +               ksft_perror("Offset not reverted correctly after flush\n");
> +               goto out;
> +       }
> +
> +       printf("%s with MSG_PEEK_OFF works correctly\n", afstr(af));
> +       res = 1;
> +out:
> +       close(recv_sock);
> +       close(s[1]);
> +       close(s[0]);
> +       return res;
> +}
> +
> +int main(void)
> +{
> +       int res4, res6;
> +
> +       res4 = tcp_peek_offset_probe(AF_INET);
> +       res6 = tcp_peek_offset_probe(AF_INET6);
> +
> +       if (!res4 && !res6)
> +               return KSFT_SKIP;
> +
> +       if (res4)
> +               res4 = tcp_peek_offset_test(AF_INET);
> +
> +       if (res6)
> +               res6 = tcp_peek_offset_test(AF_INET6);
> +
> +       if (!res4 || !res6)

What if res6 is NULL after checking tcp_peek_offset_probe() while res4
is always working correctly, then we will get notified with a
KSFT_FAIL failure instead of KSFT_SKIP.

The thing could happen because you reuse the same return value for v4/v6 mode.

Thanks,
Jason

> +               return KSFT_FAIL;
> +
> +       return KSFT_PASS;
> +}
> +
> --
> 2.45.2
>
>

Re: [PATCH 1/2] tcp: add SO_PEEK_OFF socket option tor TCPv6

[Jason Xing]

On Sat, Aug 24, 2024 at 5:19 AM <jmaloy@redhat.com> wrote:
>
> From: Jon Maloy <jmaloy@redhat.com>
>
> When we added the SO_PEEK_OFF socket option to TCP we forgot
> to add it even for TCP on IPv6.

Even though you said "we forgot", I'm not sure if this patch series
belongs to net-next material...

>
> We do that here.
>
> Fixes: 05ea491641d3 ("tcp: add support for SO_PEEK_OFF socket option")
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
> Tested-by: Stefano Brivio <sbrivio@redhat.com>
> Signed-off-by: Jon Maloy <jmaloy@redhat.com>

Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>

You seem to forget to carry Eric's Reviewed-by tag, please see the link :)
https://lore.kernel.org/all/CANn89iJmdGdAN1OZEfoM2LNVOewkYDuPXObRoNWhGyn93P=8OQ@mail.gmail.com/

Thanks,
Jason

Re: [PATCH 1/2] tcp: add SO_PEEK_OFF socket option tor TCPv6

[Eric Dumazet]

On Fri, Aug 23, 2024 at 11:19 PM <jmaloy@redhat.com> wrote:
>
> From: Jon Maloy <jmaloy@redhat.com>
>
> When we added the SO_PEEK_OFF socket option to TCP we forgot
> to add it even for TCP on IPv6.
>
> We do that here.
>
> Fixes: 05ea491641d3 ("tcp: add support for SO_PEEK_OFF socket option")
> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
> Tested-by: Stefano Brivio <sbrivio@redhat.com>
> Signed-off-by: Jon Maloy <jmaloy@redhat.com>

Reviewed-by: Eric Dumazet <edumazet@google.com>

Thanks.

Re: [PATCH 2/2] selftests: add selftest for tcp SO_PEEK_OFF support

[Jon Maloy]

On 2024-08-23 19:44, Jason Xing wrote:
> Hello Jon,
>
> On Sat, Aug 24, 2024 at 5:19 AM <jmaloy@redhat.com> wrote:
>> From: Jon Maloy <jmaloy@redhat.com>
>>
>> We add a selftest to check that the new feature added in
>> commit 05ea491641d3 ("tcp: add support for SO_PEEK_OFF socket option")
>> works correctly.
>>
>> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
>> Tested-by: Stefano Brivio <sbrivio@redhat.com>
>> Signed-off-by: Jon Maloy <jmaloy@redhat.com>
> Thanks for working on this. Sorry that I just noticed I missed your
> previous reply :(
There is still the ditto UDP selftest to be done ;-)
>> ---
>>   tools/testing/selftests/net/Makefile          |   1 +
>>   tools/testing/selftests/net/tcp_so_peek_off.c | 181 ++++++++++++++++++
>>   2 files changed, 182 insertions(+)
>>   create mode 100644 tools/testing/selftests/net/tcp_so_peek_off.c
>>
>> diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
>> index 8eaffd7a641c..1179e3261bef 100644
>> --- a/tools/testing/selftests/net/Makefile
>> +++ b/tools/testing/selftests/net/Makefile
>> @@ -80,6 +80,7 @@ TEST_PROGS += io_uring_zerocopy_tx.sh
>>   TEST_GEN_FILES += bind_bhash
>>   TEST_GEN_PROGS += sk_bind_sendto_listen
>>   TEST_GEN_PROGS += sk_connect_zero_addr
>> +TEST_GEN_PROGS += tcp_so_peek_off
>>   TEST_PROGS += test_ingress_egress_chaining.sh
>>   TEST_GEN_PROGS += so_incoming_cpu
>>   TEST_PROGS += sctp_vrf.sh
>> diff --git a/tools/testing/selftests/net/tcp_so_peek_off.c b/tools/testing/selftests/net/tcp_so_peek_off.c
>> new file mode 100644
>> index 000000000000..8379ea02e3d7
>> --- /dev/null
>> +++ b/tools/testing/selftests/net/tcp_so_peek_off.c
>> @@ -0,0 +1,181 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +
>> +#include <stdio.h>
>> +#include <stdlib.h>
>> +#include <string.h>
>> +#include <unistd.h>
>> +#include <errno.h>
>> +#include <sys/types.h>
>> +#include <netinet/in.h>
>> +#include <arpa/inet.h>
>> +#include "../kselftest.h"
>> +
>> +static char *afstr(int af)
>> +{
>> +       return af == AF_INET ? "TCP/IPv4" : "TCP/IPv6";
>> +}
>> +
>> +int tcp_peek_offset_probe(sa_family_t af)
>> +{
>> +       int optv = 0;
>> +       int ret = 0;
>> +       int s;
>> +
>> +       s = socket(af, SOCK_STREAM | SOCK_CLOEXEC, IPPROTO_TCP);
>> +       if (s < 0) {
>> +               ksft_perror("Temporary TCP socket creation failed");
>> +       } else {
>> +               if (!setsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &optv, sizeof(int)))
>> +                       ret = 1;
>> +               else
>> +                       printf("%s does not support SO_PEEK_OFF\n", afstr(af));
>> +               close(s);
>> +       }
>> +       return ret;
>> +}
>> +
>> +static void tcp_peek_offset_set(int s, int offset)
>> +{
>> +       if (setsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &offset, sizeof(offset)))
>> +               ksft_perror("Failed to set SO_PEEK_OFF value\n");
>> +}
>> +
>> +static int tcp_peek_offset_get(int s)
>> +{
>> +       int offset;
>> +       socklen_t len = sizeof(offset);
>> +
>> +       if (getsockopt(s, SOL_SOCKET, SO_PEEK_OFF, &offset, &len))
>> +               ksft_perror("Failed to get SO_PEEK_OFF value\n");
>> +       return offset;
>> +}
>> +
>> +static int tcp_peek_offset_test(sa_family_t af)
>> +{
>> +       union {
>> +               struct sockaddr sa;
>> +               struct sockaddr_in a4;
>> +               struct sockaddr_in6 a6;
>> +       } a;
>> +       int res = 0;
>> +       int s[2] = {0, 0};
>> +       int recv_sock = 0;
>> +       int offset = 0;
>> +       ssize_t len;
>> +       char buf;
>> +
>> +       memset(&a, 0, sizeof(a));
>> +       a.sa.sa_family = af;
>> +
>> +       s[0] = socket(af, SOCK_STREAM, IPPROTO_TCP);
>> +       s[1] = socket(af, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
>> +
>> +       if (s[0] < 0 || s[1] < 0) {
>> +               ksft_perror("Temporary probe socket creation failed\n");
>> +               goto out;
> Nit: I wonder if we can use more proper test statements to avoid such
> hiding failure[1] when closing a invalid file descriptor, even though
> it doesn't harm the test itself?
>
> [1]: "EBADF (Bad file descriptor)"
Fixed that in v2.
>> +       }
>> +       if (bind(s[0], &a.sa, sizeof(a)) < 0) {
>> +               ksft_perror("Temporary probe socket bind() failed\n");
>> +               goto out;
>> +       }
>> +       if (getsockname(s[0], &a.sa, &((socklen_t) { sizeof(a) })) < 0) {
>> +               ksft_perror("Temporary probe socket getsockname() failed\n");
>> +               goto out;
>> +       }
>> +       if (listen(s[0], 0) < 0) {
>> +               ksft_perror("Temporary probe socket listen() failed\n");
>> +               goto out;
>> +       }
>> +       if (connect(s[1], &a.sa, sizeof(a)) >= 0 || errno != EINPROGRESS) {
>> +               ksft_perror("Temporary probe socket connect() failed\n");
>> +               goto out;
>> +       }
>> +       recv_sock = accept(s[0], NULL, NULL);
>> +       if (recv_sock <= 0) {
>> +               ksft_perror("Temporary probe socket accept() failed\n");
>> +               goto out;
> Same here.
Fixed.
>> +       }
>> +
>> +       /* Some basic tests of getting/setting offset */
>> +       offset = tcp_peek_offset_get(recv_sock);
>> +       if (offset != -1) {
>> +               ksft_perror("Initial value of socket offset not -1\n");
>> +               goto out;
>> +       }
>> +       tcp_peek_offset_set(recv_sock, 0);
>> +       offset = tcp_peek_offset_get(recv_sock);
>> +       if (offset != 0) {
>> +               ksft_perror("Failed to set socket offset to 0\n");
>> +               goto out;
>> +       }
>> +
>> +       /* Transfer a message */
>> +       if (send(s[1], (char *)("ab"), 2, 0) <= 0 || errno != EINPROGRESS) {
>> +               ksft_perror("Temporary probe socket send() failed\n");
>> +               goto out;
>> +       }
>> +       /* Read first byte */
>> +       len = recv(recv_sock, &buf, 1, MSG_PEEK);
>> +       if (len != 1 || buf != 'a') {
>> +               ksft_perror("Failed to read first byte of message\n");
>> +               goto out;
>> +       }
>> +       offset = tcp_peek_offset_get(recv_sock);
>> +       if (offset != 1) {
>> +               ksft_perror("Offset not forwarded correctly at first byte\n");
>> +               goto out;
>> +       }
>> +       /* Try to read beyond last byte */
>> +       len = recv(recv_sock, &buf, 2, MSG_PEEK);
>> +       if (len != 1 || buf != 'b') {
>> +               ksft_perror("Failed to read last byte of message\n");
>> +               goto out;
>> +       }
>> +       offset = tcp_peek_offset_get(recv_sock);
>> +       if (offset != 2) {
>> +               ksft_perror("Offset not forwarded correctly at last byte\n");
>> +               goto out;
>> +       }
>> +       /* Flush message */
>> +       len = recv(recv_sock, NULL, 2, MSG_TRUNC);
>> +       if (len != 2) {
>> +               ksft_perror("Failed to flush message\n");
>> +               goto out;
>> +       }
>> +       offset = tcp_peek_offset_get(recv_sock);
>> +       if (offset != 0) {
>> +               ksft_perror("Offset not reverted correctly after flush\n");
>> +               goto out;
>> +       }
>> +
>> +       printf("%s with MSG_PEEK_OFF works correctly\n", afstr(af));
>> +       res = 1;
>> +out:
>> +       close(recv_sock);
>> +       close(s[1]);
>> +       close(s[0]);
>> +       return res;
>> +}
>> +
>> +int main(void)
>> +{
>> +       int res4, res6;
>> +
>> +       res4 = tcp_peek_offset_probe(AF_INET);
>> +       res6 = tcp_peek_offset_probe(AF_INET6);
>> +
>> +       if (!res4 && !res6)
>> +               return KSFT_SKIP;
>> +
>> +       if (res4)
>> +               res4 = tcp_peek_offset_test(AF_INET);
>> +
>> +       if (res6)
>> +               res6 = tcp_peek_offset_test(AF_INET6);
>> +
>> +       if (!res4 || !res6)
> What if res6 is NULL after checking tcp_peek_offset_probe() while res4
> is always working correctly, then we will get notified with a
> KSFT_FAIL failure instead of KSFT_SKIP.
This is intentional. If IPv4 is supported, and IPv6 is not, that is a 
failure.

Regards
///jon

> The thing could happen because you reuse the same return value for v4/v6 mode.
>
> Thanks,
> Jason
>
>> +               return KSFT_FAIL;
>> +
>> +       return KSFT_PASS;
>> +}
>> +
>> --
>> 2.45.2
>>
>>

Re: [PATCH 1/2] tcp: add SO_PEEK_OFF socket option tor TCPv6

[Jon Maloy]

On 2024-08-23 19:51, Jason Xing wrote:
> On Sat, Aug 24, 2024 at 5:19 AM <jmaloy@redhat.com> wrote:
>> From: Jon Maloy <jmaloy@redhat.com>
>>
>> When we added the SO_PEEK_OFF socket option to TCP we forgot
>> to add it even for TCP on IPv6.
> Even though you said "we forgot", I'm not sure if this patch series
> belongs to net-next material...
I agree regarding the fix.
The selftest is new however, and belongs in net-next because of that.
Since I made it one series I decided for net-next, but I leave it to the 
discretion of Jakub and the maintainer of the linux-kselftest system to 
decide where they go.

///jon

>
>> We do that here.
>>
>> Fixes: 05ea491641d3 ("tcp: add support for SO_PEEK_OFF socket option")
>> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
>> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
>> Tested-by: Stefano Brivio <sbrivio@redhat.com>
>> Signed-off-by: Jon Maloy <jmaloy@redhat.com>
> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
>
> You seem to forget to carry Eric's Reviewed-by tag, please see the link :)
> https://lore.kernel.org/all/CANn89iJmdGdAN1OZEfoM2LNVOewkYDuPXObRoNWhGyn93P=8OQ@mail.gmail.com/
>
> Thanks,
> Jason
>

Re: [PATCH 2/2] selftests: add selftest for tcp SO_PEEK_OFF support

[Jason Xing]

Hello Jon,

On Tue, Aug 27, 2024 at 3:58 AM Jon Maloy <jmaloy@redhat.com> wrote:
>
>
>
> On 2024-08-23 19:44, Jason Xing wrote:
> > Hello Jon,
> >
> > On Sat, Aug 24, 2024 at 5:19 AM <jmaloy@redhat.com> wrote:
> >> From: Jon Maloy <jmaloy@redhat.com>
> >>
> >> We add a selftest to check that the new feature added in
> >> commit 05ea491641d3 ("tcp: add support for SO_PEEK_OFF socket option")
> >> works correctly.
> >>
> >> Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
> >> Tested-by: Stefano Brivio <sbrivio@redhat.com>
> >> Signed-off-by: Jon Maloy <jmaloy@redhat.com>
> > Thanks for working on this. Sorry that I just noticed I missed your
> > previous reply :(
> There is still the ditto UDP selftest to be done ;-)

The reason why I didn't respond at that time is because I was unsure
if I had enough time to finish it. Now it's time.

After digging into this, there will be a lot of duplicated code if I
write a new one named like "udp_so_peek_off". I think adjusting your
tcp_so_peek_off.c to complete the UDP part is just fine. Of course,
tcp_so_peek_off.c will be renamed :)

I will post one later to see if it's reasonable...

Thanks,
Jason