// 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 <net/if.h>
#include <linux/if_tun.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <linux/virtio_net.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#include "../kselftest_harness.h"
static const char param_dev_tap_name[] = "xmacvtap0";
static const char param_dev_dummy_name[] = "xdummy0";
static unsigned char param_hwaddr_src[] = { 0x00, 0xfe, 0x98, 0x14, 0x22, 0x42 };
static unsigned char param_hwaddr_dest[] = {
0x00, 0xfe, 0x98, 0x94, 0xd2, 0x43
};
#define MAX_RTNL_PAYLOAD (2048)
#define PKT_DATA 0xCB
#define TEST_PACKET_SZ (sizeof(struct virtio_net_hdr) + ETH_HLEN + ETH_MAX_MTU)
static struct rtattr *rtattr_add(struct nlmsghdr *nh, unsigned short type,
unsigned short len)
{
struct rtattr *rta =
(struct rtattr *)((uint8_t *)nh + RTA_ALIGN(nh->nlmsg_len));
rta->rta_type = type;
rta->rta_len = RTA_LENGTH(len);
nh->nlmsg_len = RTA_ALIGN(nh->nlmsg_len) + RTA_ALIGN(rta->rta_len);
return rta;
}
static struct rtattr *rtattr_begin(struct nlmsghdr *nh, unsigned short type)
{
return rtattr_add(nh, type, 0);
}
static void rtattr_end(struct nlmsghdr *nh, struct rtattr *attr)
{
uint8_t *end = (uint8_t *)nh + nh->nlmsg_len;
attr->rta_len = end - (uint8_t *)attr;
}
static struct rtattr *rtattr_add_str(struct nlmsghdr *nh, unsigned short type,
const char *s)
{
struct rtattr *rta = rtattr_add(nh, type, strlen(s));
memcpy(RTA_DATA(rta), s, strlen(s));
return rta;
}
static struct rtattr *rtattr_add_strsz(struct nlmsghdr *nh, unsigned short type,
const char *s)
{
struct rtattr *rta = rtattr_add(nh, type, strlen(s) + 1);
strcpy(RTA_DATA(rta), s);
return rta;
}
static struct rtattr *rtattr_add_any(struct nlmsghdr *nh, unsigned short type,
const void *arr, size_t len)
{
struct rtattr *rta = rtattr_add(nh, type, len);
memcpy(RTA_DATA(rta), arr, len);
return rta;
}
static int dev_create(const char *dev, const char *link_type,
int (*fill_rtattr)(struct nlmsghdr *nh),
int (*fill_info_data)(struct nlmsghdr *nh))
{
struct {
struct nlmsghdr nh;
struct ifinfomsg info;
unsigned char data[MAX_RTNL_PAYLOAD];
} req;
struct rtattr *link_info, *info_data;
int ret, rtnl;
rtnl = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
if (rtnl < 0) {
fprintf(stderr, "%s: socket %s\n", __func__, strerror(errno));
return 1;
}
memset(&req, 0, sizeof(req));
req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.info));
req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE;
req.nh.nlmsg_type = RTM_NEWLINK;
req.info.ifi_family = AF_UNSPEC;
req.info.ifi_type = 1;
req.info.ifi_index = 0;
req.info.ifi_flags = IFF_BROADCAST | IFF_UP;
req.info.ifi_change = 0xffffffff;
rtattr_add_str(&req.nh, IFLA_IFNAME, dev);
if (fill_rtattr) {
ret = fill_rtattr(&req.nh);
if (ret)
return ret;
}
link_info = rtattr_begin(&req.nh, IFLA_LINKINFO);
rtattr_add_strsz(&req.nh, IFLA_INFO_KIND, link_type);
if (fill_info_data) {
info_data = rtattr_begin(&req.nh, IFLA_INFO_DATA);
ret = fill_info_data(&req.nh);
if (ret)
return ret;
rtattr_end(&req.nh, info_data);
}
rtattr_end(&req.nh, link_info);
ret = send(rtnl, &req, req.nh.nlmsg_len, 0);
if (ret < 0)
fprintf(stderr, "%s: send %s\n", __func__, strerror(errno));
ret = (unsigned int)ret != req.nh.nlmsg_len;
close(rtnl);
return ret;
}
static int dev_delete(const char *dev)
{
struct {
struct nlmsghdr nh;
struct ifinfomsg info;
unsigned char data[MAX_RTNL_PAYLOAD];
} req;
int ret, rtnl;
rtnl = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
if (rtnl < 0) {
fprintf(stderr, "%s: socket %s\n", __func__, strerror(errno));
return 1;
}
memset(&req, 0, sizeof(req));
req.nh.nlmsg_len = NLMSG_LENGTH(sizeof(req.info));
req.nh.nlmsg_flags = NLM_F_REQUEST;
req.nh.nlmsg_type = RTM_DELLINK;
req.info.ifi_family = AF_UNSPEC;
rtattr_add_str(&req.nh, IFLA_IFNAME, dev);
ret = send(rtnl, &req, req.nh.nlmsg_len, 0);
if (ret < 0)
fprintf(stderr, "%s: send %s\n", __func__, strerror(errno));
ret = (unsigned int)ret != req.nh.nlmsg_len;
close(rtnl);
return ret;
}
static int macvtap_fill_rtattr(struct nlmsghdr *nh)
{
int ifindex;
ifindex = if_nametoindex(param_dev_dummy_name);
if (ifindex == 0) {
fprintf(stderr, "%s: ifindex %s\n", __func__, strerror(errno));
return -errno;
}
rtattr_add_any(nh, IFLA_LINK, &ifindex, sizeof(ifindex));
rtattr_add_any(nh, IFLA_ADDRESS, param_hwaddr_src, ETH_ALEN);
return 0;
}
static int opentap(const char *devname)
{
int ifindex;
char buf[256];
int fd;
struct ifreq ifr;
ifindex = if_nametoindex(devname);
if (ifindex == 0) {
fprintf(stderr, "%s: ifindex %s\n", __func__, strerror(errno));
return -errno;
}
sprintf(buf, "/dev/tap%d", ifindex);
fd = open(buf, O_RDWR | O_NONBLOCK);
if (fd < 0) {
fprintf(stderr, "%s: open %s\n", __func__, strerror(errno));
return -errno;
}
memset(&ifr, 0, sizeof(ifr));
strcpy(ifr.ifr_name, devname);
ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR | IFF_MULTI_QUEUE;
if (ioctl(fd, TUNSETIFF, &ifr, sizeof(ifr)) < 0)
return -errno;
return fd;
}
size_t build_eth(uint8_t *buf, uint16_t proto)
{
struct ethhdr *eth = (struct ethhdr *)buf;
eth->h_proto = htons(proto);
memcpy(eth->h_source, param_hwaddr_src, ETH_ALEN);
memcpy(eth->h_dest, param_hwaddr_dest, ETH_ALEN);
return ETH_HLEN;
}
static uint32_t add_csum(const uint8_t *buf, int len)
{
uint32_t sum = 0;
uint16_t *sbuf = (uint16_t *)buf;
while (len > 1) {
sum += *sbuf++;
len -= 2;
}
if (len)
sum += *(uint8_t *)sbuf;
return sum;
}
static uint16_t finish_ip_csum(uint32_t sum)
{
uint16_t lo = sum & 0xffff;
uint16_t hi = sum >> 16;
return ~(lo + hi);
}
static uint16_t build_ip_csum(const uint8_t *buf, int len,
uint32_t sum)
{
sum += add_csum(buf, len);
return finish_ip_csum(sum);
}
static int build_ipv4_header(uint8_t *buf, int payload_len)
{
struct iphdr *iph = (struct iphdr *)buf;
iph->ihl = 5;
iph->version = 4;
iph->ttl = 8;
iph->tot_len =
htons(sizeof(*iph) + sizeof(struct udphdr) + payload_len);
iph->id = htons(1337);
iph->protocol = IPPROTO_UDP;
iph->saddr = htonl((172 << 24) | (17 << 16) | 2);
iph->daddr = htonl((172 << 24) | (17 << 16) | 1);
iph->check = build_ip_csum(buf, iph->ihl << 2, 0);
return iph->ihl << 2;
}
static int build_udp_packet(uint8_t *buf, int payload_len, bool csum_off)
{
const int ip4alen = sizeof(uint32_t);
struct udphdr *udph = (struct udphdr *)buf;
int len = sizeof(*udph) + payload_len;
uint32_t sum = 0;
udph->source = htons(22);
udph->dest = htons(58822);
udph->len = htons(len);
memset(buf + sizeof(struct udphdr), PKT_DATA, payload_len);
sum = add_csum(buf - 2 * ip4alen, 2 * ip4alen);
sum += htons(IPPROTO_UDP) + udph->len;
if (!csum_off)
sum += add_csum(buf, len);
udph->check = finish_ip_csum(sum);
return sizeof(*udph) + payload_len;
}
size_t build_test_packet_valid_udp_gso(uint8_t *buf, size_t payload_len)
{
uint8_t *cur = buf;
struct virtio_net_hdr *vh = (struct virtio_net_hdr *)buf;
vh->hdr_len = ETH_HLEN + sizeof(struct iphdr) + sizeof(struct udphdr);
vh->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
vh->csum_start = ETH_HLEN + sizeof(struct iphdr);
vh->csum_offset = __builtin_offsetof(struct udphdr, check);
vh->gso_type = VIRTIO_NET_HDR_GSO_UDP;
vh->gso_size = ETH_DATA_LEN - sizeof(struct iphdr);
cur += sizeof(*vh);
cur += build_eth(cur, ETH_P_IP);
cur += build_ipv4_header(cur, payload_len);
cur += build_udp_packet(cur, payload_len, true);
return cur - buf;
}
size_t build_test_packet_valid_udp_csum(uint8_t *buf, size_t payload_len)
{
uint8_t *cur = buf;
struct virtio_net_hdr *vh = (struct virtio_net_hdr *)buf;
vh->flags = VIRTIO_NET_HDR_F_DATA_VALID;
vh->gso_type = VIRTIO_NET_HDR_GSO_NONE;
cur += sizeof(*vh);
cur += build_eth(cur, ETH_P_IP);
cur += build_ipv4_header(cur, payload_len);
cur += build_udp_packet(cur, payload_len, false);
return cur - buf;
}
size_t build_test_packet_crash_tap_invalid_eth_proto(uint8_t *buf,
size_t payload_len)
{
uint8_t *cur = buf;
struct virtio_net_hdr *vh = (struct virtio_net_hdr *)buf;
vh->hdr_len = ETH_HLEN + sizeof(struct iphdr) + sizeof(struct udphdr);
vh->flags = 0;
vh->gso_type = VIRTIO_NET_HDR_GSO_UDP;
vh->gso_size = ETH_DATA_LEN - sizeof(struct iphdr);
cur += sizeof(*vh);
cur += build_eth(cur, 0);
cur += sizeof(struct iphdr) + sizeof(struct udphdr);
cur += build_ipv4_header(cur, payload_len);
cur += build_udp_packet(cur, payload_len, true);
cur += payload_len;
return cur - buf;
}
FIXTURE(tap)
{
int fd;
};
FIXTURE_SETUP(tap)
{
int ret;
ret = dev_create(param_dev_dummy_name, "dummy", NULL, NULL);
EXPECT_EQ(ret, 0);
ret = dev_create(param_dev_tap_name, "macvtap", macvtap_fill_rtattr,
NULL);
EXPECT_EQ(ret, 0);
self->fd = opentap(param_dev_tap_name);
ASSERT_GE(self->fd, 0);
}
FIXTURE_TEARDOWN(tap)
{
int ret;
if (self->fd != -1)
close(self->fd);
ret = dev_delete(param_dev_tap_name);
EXPECT_EQ(ret, 0);
ret = dev_delete(param_dev_dummy_name);
EXPECT_EQ(ret, 0);
}
TEST_F(tap, test_packet_valid_udp_gso)
{
uint8_t pkt[TEST_PACKET_SZ];
size_t off;
int ret;
memset(pkt, 0, sizeof(pkt));
off = build_test_packet_valid_udp_gso(pkt, 1021);
ret = write(self->fd, pkt, off);
ASSERT_EQ(ret, off);
}
TEST_F(tap, test_packet_valid_udp_csum)
{
uint8_t pkt[TEST_PACKET_SZ];
size_t off;
int ret;
memset(pkt, 0, sizeof(pkt));
off = build_test_packet_valid_udp_csum(pkt, 1024);
ret = write(self->fd, pkt, off);
ASSERT_EQ(ret, off);
}
TEST_F(tap, test_packet_crash_tap_invalid_eth_proto)
{
uint8_t pkt[TEST_PACKET_SZ];
size_t off;
int ret;
memset(pkt, 0, sizeof(pkt));
off = build_test_packet_crash_tap_invalid_eth_proto(pkt, 1024);
ret = write(self->fd, pkt, off);
ASSERT_EQ(ret, -1);
ASSERT_EQ(errno, EINVAL);
}
TEST_HARNESS_MAIN
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