blob: b8265ee9923f2b11af7884d365b2e5af9323ff3a [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <stddef.h>
#include <arpa/inet.h>
#include <error.h>
#include <errno.h>
#include <net/if.h>
#include <linux/in.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <netinet/if_ether.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <netinet/udp.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#ifndef ETH_MAX_MTU
#define ETH_MAX_MTU 0xFFFFU
#endif
#ifndef UDP_SEGMENT
#define UDP_SEGMENT 103
#endif
#ifndef UDP_MAX_SEGMENTS
#define UDP_MAX_SEGMENTS (1 << 6UL)
#endif
#define CONST_MTU_TEST 1500
#define CONST_HDRLEN_V4 (sizeof(struct iphdr) + sizeof(struct udphdr))
#define CONST_HDRLEN_V6 (sizeof(struct ip6_hdr) + sizeof(struct udphdr))
#define CONST_MSS_V4 (CONST_MTU_TEST - CONST_HDRLEN_V4)
#define CONST_MSS_V6 (CONST_MTU_TEST - CONST_HDRLEN_V6)
#define CONST_MAX_SEGS_V4 (ETH_MAX_MTU / CONST_MSS_V4)
#define CONST_MAX_SEGS_V6 (ETH_MAX_MTU / CONST_MSS_V6)
static bool cfg_do_ipv4;
static bool cfg_do_ipv6;
static bool cfg_do_connected;
static bool cfg_do_connectionless;
static bool cfg_do_msgmore;
static bool cfg_do_setsockopt;
static int cfg_specific_test_id = -1;
static const char cfg_ifname[] = "lo";
static unsigned short cfg_port = 9000;
static char buf[ETH_MAX_MTU];
struct testcase {
int tlen; /* send() buffer size, may exceed mss */
bool tfail; /* send() call is expected to fail */
int gso_len; /* mss after applying gso */
int r_num_mss; /* recv(): number of calls of full mss */
int r_len_last; /* recv(): size of last non-mss dgram, if any */
};
const struct in6_addr addr6 = IN6ADDR_LOOPBACK_INIT;
const struct in_addr addr4 = { .s_addr = __constant_htonl(INADDR_LOOPBACK + 2) };
struct testcase testcases_v4[] = {
{
/* no GSO: send a single byte */
.tlen = 1,
.r_len_last = 1,
},
{
/* no GSO: send a single MSS */
.tlen = CONST_MSS_V4,
.r_num_mss = 1,
},
{
/* no GSO: send a single MSS + 1B: fail */
.tlen = CONST_MSS_V4 + 1,
.tfail = true,
},
{
/* send a single MSS: will fail with GSO, because the segment
* logic in udp4_ufo_fragment demands a gso skb to be > MTU
*/
.tlen = CONST_MSS_V4,
.gso_len = CONST_MSS_V4,
.tfail = true,
.r_num_mss = 1,
},
{
/* send a single MSS + 1B */
.tlen = CONST_MSS_V4 + 1,
.gso_len = CONST_MSS_V4,
.r_num_mss = 1,
.r_len_last = 1,
},
{
/* send exactly 2 MSS */
.tlen = CONST_MSS_V4 * 2,
.gso_len = CONST_MSS_V4,
.r_num_mss = 2,
},
{
/* send 2 MSS + 1B */
.tlen = (CONST_MSS_V4 * 2) + 1,
.gso_len = CONST_MSS_V4,
.r_num_mss = 2,
.r_len_last = 1,
},
{
/* send MAX segs */
.tlen = (ETH_MAX_MTU / CONST_MSS_V4) * CONST_MSS_V4,
.gso_len = CONST_MSS_V4,
.r_num_mss = (ETH_MAX_MTU / CONST_MSS_V4),
},
{
/* send MAX bytes */
.tlen = ETH_MAX_MTU - CONST_HDRLEN_V4,
.gso_len = CONST_MSS_V4,
.r_num_mss = CONST_MAX_SEGS_V4,
.r_len_last = ETH_MAX_MTU - CONST_HDRLEN_V4 -
(CONST_MAX_SEGS_V4 * CONST_MSS_V4),
},
{
/* send MAX + 1: fail */
.tlen = ETH_MAX_MTU - CONST_HDRLEN_V4 + 1,
.gso_len = CONST_MSS_V4,
.tfail = true,
},
{
/* send a single 1B MSS: will fail, see single MSS above */
.tlen = 1,
.gso_len = 1,
.tfail = true,
.r_num_mss = 1,
},
{
/* send 2 1B segments */
.tlen = 2,
.gso_len = 1,
.r_num_mss = 2,
},
{
/* send 2B + 2B + 1B segments */
.tlen = 5,
.gso_len = 2,
.r_num_mss = 2,
.r_len_last = 1,
},
{
/* send max number of min sized segments */
.tlen = UDP_MAX_SEGMENTS - CONST_HDRLEN_V4,
.gso_len = 1,
.r_num_mss = UDP_MAX_SEGMENTS - CONST_HDRLEN_V4,
},
{
/* send max number + 1 of min sized segments: fail */
.tlen = UDP_MAX_SEGMENTS - CONST_HDRLEN_V4 + 1,
.gso_len = 1,
.tfail = true,
},
{
/* EOL */
}
};
#ifndef IP6_MAX_MTU
#define IP6_MAX_MTU (ETH_MAX_MTU + sizeof(struct ip6_hdr))
#endif
struct testcase testcases_v6[] = {
{
/* no GSO: send a single byte */
.tlen = 1,
.r_len_last = 1,
},
{
/* no GSO: send a single MSS */
.tlen = CONST_MSS_V6,
.r_num_mss = 1,
},
{
/* no GSO: send a single MSS + 1B: fail */
.tlen = CONST_MSS_V6 + 1,
.tfail = true,
},
{
/* send a single MSS: will fail with GSO, because the segment
* logic in udp4_ufo_fragment demands a gso skb to be > MTU
*/
.tlen = CONST_MSS_V6,
.gso_len = CONST_MSS_V6,
.tfail = true,
.r_num_mss = 1,
},
{
/* send a single MSS + 1B */
.tlen = CONST_MSS_V6 + 1,
.gso_len = CONST_MSS_V6,
.r_num_mss = 1,
.r_len_last = 1,
},
{
/* send exactly 2 MSS */
.tlen = CONST_MSS_V6 * 2,
.gso_len = CONST_MSS_V6,
.r_num_mss = 2,
},
{
/* send 2 MSS + 1B */
.tlen = (CONST_MSS_V6 * 2) + 1,
.gso_len = CONST_MSS_V6,
.r_num_mss = 2,
.r_len_last = 1,
},
{
/* send MAX segs */
.tlen = (IP6_MAX_MTU / CONST_MSS_V6) * CONST_MSS_V6,
.gso_len = CONST_MSS_V6,
.r_num_mss = (IP6_MAX_MTU / CONST_MSS_V6),
},
{
/* send MAX bytes */
.tlen = IP6_MAX_MTU - CONST_HDRLEN_V6,
.gso_len = CONST_MSS_V6,
.r_num_mss = CONST_MAX_SEGS_V6,
.r_len_last = IP6_MAX_MTU - CONST_HDRLEN_V6 -
(CONST_MAX_SEGS_V6 * CONST_MSS_V6),
},
{
/* send MAX + 1: fail */
.tlen = IP6_MAX_MTU - CONST_HDRLEN_V6 + 1,
.gso_len = CONST_MSS_V6,
.tfail = true,
},
{
/* send a single 1B MSS: will fail, see single MSS above */
.tlen = 1,
.gso_len = 1,
.tfail = true,
.r_num_mss = 1,
},
{
/* send 2 1B segments */
.tlen = 2,
.gso_len = 1,
.r_num_mss = 2,
},
{
/* send 2B + 2B + 1B segments */
.tlen = 5,
.gso_len = 2,
.r_num_mss = 2,
.r_len_last = 1,
},
{
/* send max number of min sized segments */
.tlen = UDP_MAX_SEGMENTS - CONST_HDRLEN_V6,
.gso_len = 1,
.r_num_mss = UDP_MAX_SEGMENTS - CONST_HDRLEN_V6,
},
{
/* send max number + 1 of min sized segments: fail */
.tlen = UDP_MAX_SEGMENTS - CONST_HDRLEN_V6 + 1,
.gso_len = 1,
.tfail = true,
},
{
/* EOL */
}
};
static unsigned int get_device_mtu(int fd, const char *ifname)
{
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
strcpy(ifr.ifr_name, ifname);
if (ioctl(fd, SIOCGIFMTU, &ifr))
error(1, errno, "ioctl get mtu");
return ifr.ifr_mtu;
}
static void __set_device_mtu(int fd, const char *ifname, unsigned int mtu)
{
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_mtu = mtu;
strcpy(ifr.ifr_name, ifname);
if (ioctl(fd, SIOCSIFMTU, &ifr))
error(1, errno, "ioctl set mtu");
}
static void set_device_mtu(int fd, int mtu)
{
int val;
val = get_device_mtu(fd, cfg_ifname);
fprintf(stderr, "device mtu (orig): %u\n", val);
__set_device_mtu(fd, cfg_ifname, mtu);
val = get_device_mtu(fd, cfg_ifname);
if (val != mtu)
error(1, 0, "unable to set device mtu to %u\n", val);
fprintf(stderr, "device mtu (test): %u\n", val);
}
static void set_pmtu_discover(int fd, bool is_ipv4)
{
int level, name, val;
if (is_ipv4) {
level = SOL_IP;
name = IP_MTU_DISCOVER;
val = IP_PMTUDISC_DO;
} else {
level = SOL_IPV6;
name = IPV6_MTU_DISCOVER;
val = IPV6_PMTUDISC_DO;
}
if (setsockopt(fd, level, name, &val, sizeof(val)))
error(1, errno, "setsockopt path mtu");
}
static unsigned int get_path_mtu(int fd, bool is_ipv4)
{
socklen_t vallen;
unsigned int mtu;
int ret;
vallen = sizeof(mtu);
if (is_ipv4)
ret = getsockopt(fd, SOL_IP, IP_MTU, &mtu, &vallen);
else
ret = getsockopt(fd, SOL_IPV6, IPV6_MTU, &mtu, &vallen);
if (ret)
error(1, errno, "getsockopt mtu");
fprintf(stderr, "path mtu (read): %u\n", mtu);
return mtu;
}
/* very wordy version of system("ip route add dev lo mtu 1500 127.0.0.3/32") */
static void set_route_mtu(int mtu, bool is_ipv4)
{
struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
struct nlmsghdr *nh;
struct rtattr *rta;
struct rtmsg *rt;
char data[NLMSG_ALIGN(sizeof(*nh)) +
NLMSG_ALIGN(sizeof(*rt)) +
NLMSG_ALIGN(RTA_LENGTH(sizeof(addr6))) +
NLMSG_ALIGN(RTA_LENGTH(sizeof(int))) +
NLMSG_ALIGN(RTA_LENGTH(0) + RTA_LENGTH(sizeof(int)))];
int fd, ret, alen, off = 0;
alen = is_ipv4 ? sizeof(addr4) : sizeof(addr6);
fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
if (fd == -1)
error(1, errno, "socket netlink");
memset(data, 0, sizeof(data));
nh = (void *)data;
nh->nlmsg_type = RTM_NEWROUTE;
nh->nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE;
off += NLMSG_ALIGN(sizeof(*nh));
rt = (void *)(data + off);
rt->rtm_family = is_ipv4 ? AF_INET : AF_INET6;
rt->rtm_table = RT_TABLE_MAIN;
rt->rtm_dst_len = alen << 3;
rt->rtm_protocol = RTPROT_BOOT;
rt->rtm_scope = RT_SCOPE_UNIVERSE;
rt->rtm_type = RTN_UNICAST;
off += NLMSG_ALIGN(sizeof(*rt));
rta = (void *)(data + off);
rta->rta_type = RTA_DST;
rta->rta_len = RTA_LENGTH(alen);
if (is_ipv4)
memcpy(RTA_DATA(rta), &addr4, alen);
else
memcpy(RTA_DATA(rta), &addr6, alen);
off += NLMSG_ALIGN(rta->rta_len);
rta = (void *)(data + off);
rta->rta_type = RTA_OIF;
rta->rta_len = RTA_LENGTH(sizeof(int));
*((int *)(RTA_DATA(rta))) = 1; //if_nametoindex("lo");
off += NLMSG_ALIGN(rta->rta_len);
/* MTU is a subtype in a metrics type */
rta = (void *)(data + off);
rta->rta_type = RTA_METRICS;
rta->rta_len = RTA_LENGTH(0) + RTA_LENGTH(sizeof(int));
off += NLMSG_ALIGN(rta->rta_len);
/* now fill MTU subtype. Note that it fits within above rta_len */
rta = (void *)(((char *) rta) + RTA_LENGTH(0));
rta->rta_type = RTAX_MTU;
rta->rta_len = RTA_LENGTH(sizeof(int));
*((int *)(RTA_DATA(rta))) = mtu;
nh->nlmsg_len = off;
ret = sendto(fd, data, off, 0, (void *)&nladdr, sizeof(nladdr));
if (ret != off)
error(1, errno, "send netlink: %uB != %uB\n", ret, off);
if (close(fd))
error(1, errno, "close netlink");
fprintf(stderr, "route mtu (test): %u\n", mtu);
}
static bool __send_one(int fd, struct msghdr *msg, int flags)
{
int ret;
ret = sendmsg(fd, msg, flags);
if (ret == -1 &&
(errno == EMSGSIZE || errno == ENOMEM || errno == EINVAL))
return false;
if (ret == -1)
error(1, errno, "sendmsg");
if (ret != msg->msg_iov->iov_len)
error(1, 0, "sendto: %d != %lu", ret, msg->msg_iov->iov_len);
if (msg->msg_flags)
error(1, 0, "sendmsg: return flags 0x%x\n", msg->msg_flags);
return true;
}
static bool send_one(int fd, int len, int gso_len,
struct sockaddr *addr, socklen_t alen)
{
char control[CMSG_SPACE(sizeof(uint16_t))] = {0};
struct msghdr msg = {0};
struct iovec iov = {0};
struct cmsghdr *cm;
iov.iov_base = buf;
iov.iov_len = len;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_name = addr;
msg.msg_namelen = alen;
if (gso_len && !cfg_do_setsockopt) {
msg.msg_control = control;
msg.msg_controllen = sizeof(control);
cm = CMSG_FIRSTHDR(&msg);
cm->cmsg_level = SOL_UDP;
cm->cmsg_type = UDP_SEGMENT;
cm->cmsg_len = CMSG_LEN(sizeof(uint16_t));
*((uint16_t *) CMSG_DATA(cm)) = gso_len;
}
/* If MSG_MORE, send 1 byte followed by remainder */
if (cfg_do_msgmore && len > 1) {
iov.iov_len = 1;
if (!__send_one(fd, &msg, MSG_MORE))
error(1, 0, "send 1B failed");
iov.iov_base++;
iov.iov_len = len - 1;
}
return __send_one(fd, &msg, 0);
}
static int recv_one(int fd, int flags)
{
int ret;
ret = recv(fd, buf, sizeof(buf), flags);
if (ret == -1 && errno == EAGAIN && (flags & MSG_DONTWAIT))
return 0;
if (ret == -1)
error(1, errno, "recv");
return ret;
}
static void run_one(struct testcase *test, int fdt, int fdr,
struct sockaddr *addr, socklen_t alen)
{
int i, ret, val, mss;
bool sent;
fprintf(stderr, "ipv%d tx:%d gso:%d %s\n",
addr->sa_family == AF_INET ? 4 : 6,
test->tlen, test->gso_len,
test->tfail ? "(fail)" : "");
val = test->gso_len;
if (cfg_do_setsockopt) {
if (setsockopt(fdt, SOL_UDP, UDP_SEGMENT, &val, sizeof(val)))
error(1, errno, "setsockopt udp segment");
}
sent = send_one(fdt, test->tlen, test->gso_len, addr, alen);
if (sent && test->tfail)
error(1, 0, "send succeeded while expecting failure");
if (!sent && !test->tfail)
error(1, 0, "send failed while expecting success");
if (!sent)
return;
if (test->gso_len)
mss = test->gso_len;
else
mss = addr->sa_family == AF_INET ? CONST_MSS_V4 : CONST_MSS_V6;
/* Recv all full MSS datagrams */
for (i = 0; i < test->r_num_mss; i++) {
ret = recv_one(fdr, 0);
if (ret != mss)
error(1, 0, "recv.%d: %d != %d", i, ret, mss);
}
/* Recv the non-full last datagram, if tlen was not a multiple of mss */
if (test->r_len_last) {
ret = recv_one(fdr, 0);
if (ret != test->r_len_last)
error(1, 0, "recv.%d: %d != %d (last)",
i, ret, test->r_len_last);
}
/* Verify received all data */
ret = recv_one(fdr, MSG_DONTWAIT);
if (ret)
error(1, 0, "recv: unexpected datagram");
}
static void run_all(int fdt, int fdr, struct sockaddr *addr, socklen_t alen)
{
struct testcase *tests, *test;
tests = addr->sa_family == AF_INET ? testcases_v4 : testcases_v6;
for (test = tests; test->tlen; test++) {
/* if a specific test is given, then skip all others */
if (cfg_specific_test_id == -1 ||
cfg_specific_test_id == test - tests)
run_one(test, fdt, fdr, addr, alen);
}
}
static void run_test(struct sockaddr *addr, socklen_t alen)
{
struct timeval tv = { .tv_usec = 100 * 1000 };
int fdr, fdt, val;
fdr = socket(addr->sa_family, SOCK_DGRAM, 0);
if (fdr == -1)
error(1, errno, "socket r");
if (bind(fdr, addr, alen))
error(1, errno, "bind");
/* Have tests fail quickly instead of hang */
if (setsockopt(fdr, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)))
error(1, errno, "setsockopt rcv timeout");
fdt = socket(addr->sa_family, SOCK_DGRAM, 0);
if (fdt == -1)
error(1, errno, "socket t");
/* Do not fragment these datagrams: only succeed if GSO works */
set_pmtu_discover(fdt, addr->sa_family == AF_INET);
if (cfg_do_connectionless) {
set_device_mtu(fdt, CONST_MTU_TEST);
run_all(fdt, fdr, addr, alen);
}
if (cfg_do_connected) {
set_device_mtu(fdt, CONST_MTU_TEST + 100);
set_route_mtu(CONST_MTU_TEST, addr->sa_family == AF_INET);
if (connect(fdt, addr, alen))
error(1, errno, "connect");
val = get_path_mtu(fdt, addr->sa_family == AF_INET);
if (val != CONST_MTU_TEST)
error(1, 0, "bad path mtu %u\n", val);
run_all(fdt, fdr, addr, 0 /* use connected addr */);
}
if (close(fdt))
error(1, errno, "close t");
if (close(fdr))
error(1, errno, "close r");
}
static void run_test_v4(void)
{
struct sockaddr_in addr = {0};
addr.sin_family = AF_INET;
addr.sin_port = htons(cfg_port);
addr.sin_addr = addr4;
run_test((void *)&addr, sizeof(addr));
}
static void run_test_v6(void)
{
struct sockaddr_in6 addr = {0};
addr.sin6_family = AF_INET6;
addr.sin6_port = htons(cfg_port);
addr.sin6_addr = addr6;
run_test((void *)&addr, sizeof(addr));
}
static void parse_opts(int argc, char **argv)
{
int c;
while ((c = getopt(argc, argv, "46cCmst:")) != -1) {
switch (c) {
case '4':
cfg_do_ipv4 = true;
break;
case '6':
cfg_do_ipv6 = true;
break;
case 'c':
cfg_do_connected = true;
break;
case 'C':
cfg_do_connectionless = true;
break;
case 'm':
cfg_do_msgmore = true;
break;
case 's':
cfg_do_setsockopt = true;
break;
case 't':
cfg_specific_test_id = strtoul(optarg, NULL, 0);
break;
default:
error(1, 0, "%s: parse error", argv[0]);
}
}
}
int main(int argc, char **argv)
{
parse_opts(argc, argv);
if (cfg_do_ipv4)
run_test_v4();
if (cfg_do_ipv6)
run_test_v6();
fprintf(stderr, "OK\n");
return 0;
}