@@ -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
new file mode 100644
@@ -0,0 +1,184 @@
+// 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 socket creation failed\n");
+ goto out;
+ }
+ if (bind(s[0], &a.sa, sizeof(a)) < 0) {
+ ksft_perror("Temporary socket bind() failed\n");
+ goto out;
+ }
+ if (getsockname(s[0], &a.sa, &((socklen_t) { sizeof(a) })) < 0) {
+ ksft_perror("Temporary socket getsockname() failed\n");
+ goto out;
+ }
+ if (listen(s[0], 0) < 0) {
+ ksft_perror("Temporary socket listen() failed\n");
+ goto out;
+ }
+ if (connect(s[1], &a.sa, sizeof(a)) >= 0 || errno != EINPROGRESS) {
+ ksft_perror("Temporary socket connect() failed\n");
+ goto out;
+ }
+ recv_sock = accept(s[0], NULL, NULL);
+ if (recv_sock <= 0) {
+ ksft_perror("Temporary 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:
+ if (recv_sock >= 0)
+ close(recv_sock);
+ if (s[1] >= 0)
+ close(s[1]);
+ if (s[0] >= 0)
+ 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;
+}
+