// 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 << 7UL)
#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_recv = true;
static bool cfg_do_setsockopt;
static int cfg_specific_test_id = -1;
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 */
bool v6_ext_hdr; /* send() dgrams with IPv6 extension headers */
};
const struct in6_addr addr6 = {
{ { 0xfd, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 } }, /* fd00::1 */
};
const struct in_addr addr4 = {
__constant_htonl(0x0a000001), /* 10.0.0.1 */
};
static const char ipv6_hopopts_pad1[8] = { 0 };
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 fall back to no GSO */
.tlen = CONST_MSS_V4,
.gso_len = CONST_MSS_V4,
.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 fall back to no GSO */
.tlen = 1,
.gso_len = 1,
.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,
.gso_len = 1,
.r_num_mss = UDP_MAX_SEGMENTS,
},
{
/* send max number + 1 of min sized segments: fail */
.tlen = UDP_MAX_SEGMENTS + 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 fall back to no GSO */
.tlen = CONST_MSS_V6,
.gso_len = CONST_MSS_V6,
.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 fall back to no GSO */
.tlen = 1,
.gso_len = 1,
.r_num_mss = 1,
},
{
/* send 2 1B segments */
.tlen = 2,
.gso_len = 1,
.r_num_mss = 2,
},
{
/* send 2 1B segments with extension headers */
.tlen = 2,
.gso_len = 1,
.r_num_mss = 2,
.v6_ext_hdr = true,
},
{
/* 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,
.gso_len = 1,
.r_num_mss = UDP_MAX_SEGMENTS,
},
{
/* send max number + 1 of min sized segments: fail */
.tlen = UDP_MAX_SEGMENTS + 1,
.gso_len = 1,
.tfail = true,
},
{
/* EOL */
}
};
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;
}
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 != %llu", ret,
(unsigned long long)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%s\n",
addr->sa_family == AF_INET ? 4 : 6,
test->tlen, test->gso_len,
test->v6_ext_hdr ? "ext-hdr " : "",
test->tfail ? "(fail)" : "");
if (test->v6_ext_hdr) {
if (setsockopt(fdt, IPPROTO_IPV6, IPV6_HOPOPTS,
ipv6_hopopts_pad1, sizeof(ipv6_hopopts_pad1)))
error(1, errno, "setsockopt ipv6 hopopts");
}
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 (test->v6_ext_hdr) {
if (setsockopt(fdt, IPPROTO_IPV6, IPV6_HOPOPTS, NULL, 0))
error(1, errno, "setsockopt ipv6 hopopts clear");
}
if (!sent)
return;
if (!cfg_do_recv)
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 (cfg_do_recv) {
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)
run_all(fdt, fdr, addr, alen);
if (cfg_do_connected) {
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, "46cCmRst:")) != -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 'R':
cfg_do_recv = false;
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;
}
Codebase Browser
linux