selftest: tun: add test for NAPI dismantle

Being lazy does not pay, add the test for various
ordering of tun queue close / detach / destroy.

Link: https://lore.kernel.org/r/20220629181911.372047-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index 7ea54af55490956895f8583b4afb9576ad0f1048..ddad703ace348f624f7cce131c85a3e193115300 100644 (file)
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -54,7 +54,7 @@ TEST_GEN_FILES += ipsec
 TEST_GEN_FILES += ioam6_parser
 TEST_GEN_FILES += gro
 TEST_GEN_PROGS = reuseport_bpf reuseport_bpf_cpu reuseport_bpf_numa
-TEST_GEN_PROGS += reuseport_dualstack reuseaddr_conflict tls
+TEST_GEN_PROGS += reuseport_dualstack reuseaddr_conflict tls tun
 TEST_GEN_FILES += toeplitz
 TEST_GEN_FILES += cmsg_sender
 TEST_GEN_FILES += stress_reuseport_listen

diff --git a/tools/testing/selftests/net/tun.c b/tools/testing/selftests/net/tun.c
new file mode 100644 (file)
index 0000000..fa83918
--- /dev/null
+++ b/tools/testing/selftests/net/tun.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <linux/if.h>
+#include <linux/if_tun.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+
+#include "../kselftest_harness.h"
+
+static int tun_attach(int fd, char *dev)
+{
+       struct ifreq ifr;
+
+       memset(&ifr, 0, sizeof(ifr));
+       strcpy(ifr.ifr_name, dev);
+       ifr.ifr_flags = IFF_ATTACH_QUEUE;
+
+       return ioctl(fd, TUNSETQUEUE, (void *) &ifr);
+}
+
+static int tun_detach(int fd, char *dev)
+{
+       struct ifreq ifr;
+
+       memset(&ifr, 0, sizeof(ifr));
+       strcpy(ifr.ifr_name, dev);
+       ifr.ifr_flags = IFF_DETACH_QUEUE;
+
+       return ioctl(fd, TUNSETQUEUE, (void *) &ifr);
+}
+
+static int tun_alloc(char *dev)
+{
+       struct ifreq ifr;
+       int fd, err;
+
+       fd = open("/dev/net/tun", O_RDWR);
+       if (fd < 0) {
+               fprintf(stderr, "can't open tun: %s\n", strerror(errno));
+               return fd;
+       }
+
+       memset(&ifr, 0, sizeof(ifr));
+       strcpy(ifr.ifr_name, dev);
+       ifr.ifr_flags = IFF_TAP | IFF_NAPI | IFF_MULTI_QUEUE;
+
+       err = ioctl(fd, TUNSETIFF, (void *) &ifr);
+       if (err < 0) {
+               fprintf(stderr, "can't TUNSETIFF: %s\n", strerror(errno));
+               close(fd);
+               return err;
+       }
+       strcpy(dev, ifr.ifr_name);
+       return fd;
+}
+
+static int tun_delete(char *dev)
+{
+       struct {
+               struct nlmsghdr  nh;
+               struct ifinfomsg ifm;
+               unsigned char    data[64];
+       } req;
+       struct rtattr *rta;
+       int ret, rtnl;
+
+       rtnl = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
+       if (rtnl < 0) {
+               fprintf(stderr, "can't open rtnl: %s\n", strerror(errno));
+               return 1;
+       }
+
+       memset(&req, 0, sizeof(req));
+       req.nh.nlmsg_len = NLMSG_ALIGN(NLMSG_LENGTH(sizeof(req.ifm)));
+       req.nh.nlmsg_flags = NLM_F_REQUEST;
+       req.nh.nlmsg_type = RTM_DELLINK;
+
+       req.ifm.ifi_family = AF_UNSPEC;
+
+       rta = (struct rtattr *)(((char *)&req) + NLMSG_ALIGN(req.nh.nlmsg_len));
+       rta->rta_type = IFLA_IFNAME;
+       rta->rta_len = RTA_LENGTH(IFNAMSIZ);
+       req.nh.nlmsg_len += rta->rta_len;
+       memcpy(RTA_DATA(rta), dev, IFNAMSIZ);
+
+       ret = send(rtnl, &req, req.nh.nlmsg_len, 0);
+       if (ret < 0)
+               fprintf(stderr, "can't send: %s\n", strerror(errno));
+       ret = (unsigned int)ret != req.nh.nlmsg_len;
+
+       close(rtnl);
+       return ret;
+}
+
+FIXTURE(tun)
+{
+       char ifname[IFNAMSIZ];
+       int fd, fd2;
+};
+
+FIXTURE_SETUP(tun)
+{
+       memset(self->ifname, 0, sizeof(self->ifname));
+
+       self->fd = tun_alloc(self->ifname);
+       ASSERT_GE(self->fd, 0);
+
+       self->fd2 = tun_alloc(self->ifname);
+       ASSERT_GE(self->fd2, 0);
+}
+
+FIXTURE_TEARDOWN(tun)
+{
+       if (self->fd >= 0)
+               close(self->fd);
+       if (self->fd2 >= 0)
+               close(self->fd2);
+}
+
+TEST_F(tun, delete_detach_close) {
+       EXPECT_EQ(tun_delete(self->ifname), 0);
+       EXPECT_EQ(tun_detach(self->fd, self->ifname), -1);
+       EXPECT_EQ(errno, 22);
+}
+
+TEST_F(tun, detach_delete_close) {
+       EXPECT_EQ(tun_detach(self->fd, self->ifname), 0);
+       EXPECT_EQ(tun_delete(self->ifname), 0);
+}
+
+TEST_F(tun, detach_close_delete) {
+       EXPECT_EQ(tun_detach(self->fd, self->ifname), 0);
+       close(self->fd);
+       self->fd = -1;
+       EXPECT_EQ(tun_delete(self->ifname), 0);
+}
+
+TEST_F(tun, reattach_delete_close) {
+       EXPECT_EQ(tun_detach(self->fd, self->ifname), 0);
+       EXPECT_EQ(tun_attach(self->fd, self->ifname), 0);
+       EXPECT_EQ(tun_delete(self->ifname), 0);
+}
+
+TEST_F(tun, reattach_close_delete) {
+       EXPECT_EQ(tun_detach(self->fd, self->ifname), 0);
+       EXPECT_EQ(tun_attach(self->fd, self->ifname), 0);
+       close(self->fd);
+       self->fd = -1;
+       EXPECT_EQ(tun_delete(self->ifname), 0);
+}
+
+TEST_HARNESS_MAIN