/* Test timeout handling in the UDP client.
Copyright (C) 2017-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <netinet/in.h>
#include <rpc/clnt.h>
#include <rpc/svc.h>
#include <stdbool.h>
#include <string.h>
#include <support/check.h>
#include <support/namespace.h>
#include <support/test-driver.h>
#include <support/xsocket.h>
#include <support/xunistd.h>
#include <sys/socket.h>
#include <time.h>
#include <unistd.h>
/* Test data serialization and deserialization. */
struct test_query
{
uint32_t a;
uint32_t b;
uint32_t timeout_ms;
uint32_t wait_for_seq;
uint32_t garbage_packets;
};
static bool_t
xdr_test_query (XDR *xdrs, void *data, ...)
{
struct test_query *p = data;
return xdr_uint32_t (xdrs, &p->a)
&& xdr_uint32_t (xdrs, &p->b)
&& xdr_uint32_t (xdrs, &p->timeout_ms)
&& xdr_uint32_t (xdrs, &p->wait_for_seq)
&& xdr_uint32_t (xdrs, &p->garbage_packets);
}
struct test_response
{
uint32_t seq;
uint32_t sum;
};
static bool_t
xdr_test_response (XDR *xdrs, void *data, ...)
{
struct test_response *p = data;
return xdr_uint32_t (xdrs, &p->seq)
&& xdr_uint32_t (xdrs, &p->sum);
}
/* Implementation of the test server. */
enum
{
/* RPC parameters, chosen at random. */
PROGNUM = 15717,
VERSNUM = 13689,
/* Main RPC operation. */
PROC_ADD = 1,
/* Reset the sequence number. */
PROC_RESET_SEQ,
/* Request process termination. */
PROC_EXIT,
/* Special exit status to mark successful processing. */
EXIT_MARKER = 55,
};
static void
server_dispatch (struct svc_req *request, SVCXPRT *transport)
{
/* Query sequence number. */
static uint32_t seq = 0;
++seq;
if (test_verbose)
printf ("info: server_dispatch seq=%u rq_proc=%lu\n",
seq, request->rq_proc);
switch (request->rq_proc)
{
case PROC_ADD:
{
struct test_query query;
memset (&query, 0xc0, sizeof (query));
TEST_VERIFY_EXIT
(svc_getargs (transport, xdr_test_query,
(void *) &query));
if (test_verbose)
printf (" a=%u b=%u timeout_ms=%u wait_for_seq=%u"
" garbage_packets=%u\n",
query.a, query.b, query.timeout_ms, query.wait_for_seq,
query.garbage_packets);
if (seq < query.wait_for_seq)
{
/* No response at this point. */
if (test_verbose)
printf (" skipped response\n");
break;
}
if (query.garbage_packets > 0)
{
int per_packet_timeout;
if (query.timeout_ms > 0)
per_packet_timeout
= query.timeout_ms * 1000 / query.garbage_packets;
else
per_packet_timeout = 0;
char buf[20];
memset (&buf, 0xc0, sizeof (buf));
for (int i = 0; i < query.garbage_packets; ++i)
{
/* 13 is relatively prime to 20 = sizeof (buf) + 1, so
the len variable will cover the entire interval
[0, 20] if query.garbage_packets is sufficiently
large. */
size_t len = (i * 13 + 1) % (sizeof (buf) + 1);
TEST_VERIFY (sendto (transport->xp_sock,
buf, len, MSG_NOSIGNAL,
(struct sockaddr *) &transport->xp_raddr,
transport->xp_addrlen) == len);
if (per_packet_timeout > 0)
usleep (per_packet_timeout);
}
}
else if (query.timeout_ms > 0)
usleep (query.timeout_ms * 1000);
struct test_response response =
{
.seq = seq,
.sum = query.a + query.b,
};
TEST_VERIFY (svc_sendreply (transport, xdr_test_response,
(void *) &response));
}
break;
case PROC_RESET_SEQ:
seq = 0;
TEST_VERIFY (svc_sendreply (transport, (xdrproc_t) xdr_void, NULL));
break;
case PROC_EXIT:
TEST_VERIFY (svc_sendreply (transport, (xdrproc_t) xdr_void, NULL));
_exit (EXIT_MARKER);
break;
default:
FAIL_EXIT1 ("invalid rq_proc value: %lu", request->rq_proc);
break;
}
}
/* Implementation of the test client. */
static struct test_response
test_call (CLIENT *clnt, int proc, struct test_query query,
struct timeval timeout)
{
if (test_verbose)
printf ("info: test_call proc=%d timeout=%lu.%06lu\n",
proc, (unsigned long) timeout.tv_sec,
(unsigned long) timeout.tv_usec);
struct test_response response;
TEST_VERIFY_EXIT (clnt_call (clnt, proc,
xdr_test_query, (void *) &query,
xdr_test_response, (void *) &response,
timeout)
== RPC_SUCCESS);
return response;
}
static void
test_call_timeout (CLIENT *clnt, int proc, struct test_query query,
struct timeval timeout)
{
struct test_response response;
TEST_VERIFY (clnt_call (clnt, proc,
xdr_test_query, (void *) &query,
xdr_test_response, (void *) &response,
timeout)
== RPC_TIMEDOUT);
}
/* Complete one regular RPC call to drain the server socket
buffer. Resets the sequence number. */
static void
test_call_flush (CLIENT *clnt)
{
/* This needs a longer timeout to flush out all pending requests.
The choice of 5 seconds is larger than the per-response timeouts
requested via the timeout_ms field. */
if (test_verbose)
printf ("info: flushing pending queries\n");
TEST_VERIFY_EXIT (clnt_call (clnt, PROC_RESET_SEQ,
(xdrproc_t) xdr_void, NULL,
(xdrproc_t) xdr_void, NULL,
((struct timeval) { 5, 0 }))
== RPC_SUCCESS);
}
/* Return the number seconds since an arbitrary point in time. */
static double
get_ticks (void)
{
{
struct timespec ts;
if (clock_gettime (CLOCK_MONOTONIC, &ts) == 0)
return ts.tv_sec + ts.tv_nsec * 1e-9;
}
{
struct timeval tv;
TEST_VERIFY_EXIT (gettimeofday (&tv, NULL) == 0);
return tv.tv_sec + tv.tv_usec * 1e-6;
}
}
static void
test_udp_server (int port)
{
struct sockaddr_in sin =
{
.sin_family = AF_INET,
.sin_addr.s_addr = htonl (INADDR_LOOPBACK),
.sin_port = htons (port)
};
int sock = RPC_ANYSOCK;
/* The client uses a 1.5 second timeout for retries. The timeouts
are arbitrary, but chosen so that there is a substantial gap
between them, but the total time spent waiting is not too
large. */
CLIENT *clnt = clntudp_create (&sin, PROGNUM, VERSNUM,
(struct timeval) { 1, 500 * 1000 },
&sock);
TEST_VERIFY_EXIT (clnt != NULL);
/* Basic call/response test. */
struct test_response response = test_call
(clnt, PROC_ADD,
(struct test_query) { .a = 17, .b = 4 },
(struct timeval) { 3, 0 });
TEST_VERIFY (response.sum == 21);
TEST_VERIFY (response.seq == 1);
/* Check that garbage packets do not interfere with timeout
processing. */
double before = get_ticks ();
response = test_call
(clnt, PROC_ADD,
(struct test_query) {
.a = 19, .b = 4, .timeout_ms = 500, .garbage_packets = 21,
},
(struct timeval) { 3, 0 });
TEST_VERIFY (response.sum == 23);
TEST_VERIFY (response.seq == 2);
double after = get_ticks ();
if (test_verbose)
printf ("info: 21 garbage packets took %f seconds\n", after - before);
/* Expected timeout is 0.5 seconds. Add some slack in case process
scheduling delays processing the query or response, but do not
accept a retry (which would happen at 1.5 seconds). */
TEST_VERIFY (0.5 <= after - before);
TEST_VERIFY (after - before < 1.2);
test_call_flush (clnt);
/* Check that missing a response introduces a 1.5 second timeout, as
requested when calling clntudp_create. */
before = get_ticks ();
response = test_call
(clnt, PROC_ADD,
(struct test_query) { .a = 170, .b = 40, .wait_for_seq = 2 },
(struct timeval) { 3, 0 });
TEST_VERIFY (response.sum == 210);
TEST_VERIFY (response.seq == 2);
after = get_ticks ();
if (test_verbose)
printf ("info: skipping one response took %f seconds\n",
after - before);
/* Expected timeout is 1.5 seconds. Do not accept a second retry
(which would happen at 3 seconds). */
TEST_VERIFY (1.5 <= after - before);
TEST_VERIFY (after - before < 2.9);
test_call_flush (clnt);
/* Check that the overall timeout wins against the per-query
timeout. */
before = get_ticks ();
test_call_timeout
(clnt, PROC_ADD,
(struct test_query) { .a = 170, .b = 41, .wait_for_seq = 2 },
(struct timeval) { 0, 750 * 1000 });
after = get_ticks ();
if (test_verbose)
printf ("info: 0.75 second timeout took %f seconds\n",
after - before);
TEST_VERIFY (0.75 <= after - before);
TEST_VERIFY (after - before < 1.4);
test_call_flush (clnt);
for (int with_garbage = 0; with_garbage < 2; ++with_garbage)
{
/* Check that no response at all causes the client to bail out. */
before = get_ticks ();
test_call_timeout
(clnt, PROC_ADD,
(struct test_query) {
.a = 170, .b = 40, .timeout_ms = 1200,
.garbage_packets = with_garbage * 21
},
(struct timeval) { 0, 750 * 1000 });
after = get_ticks ();
if (test_verbose)
printf ("info: test_udp_server: 0.75 second timeout took %f seconds"
" (garbage %d)\n",
after - before, with_garbage);
TEST_VERIFY (0.75 <= after - before);
TEST_VERIFY (after - before < 1.4);
test_call_flush (clnt);
/* As above, but check the total timeout. */
before = get_ticks ();
test_call_timeout
(clnt, PROC_ADD,
(struct test_query) {
.a = 170, .b = 40, .timeout_ms = 3000,
.garbage_packets = with_garbage * 30
},
(struct timeval) { 2, 500 * 1000 });
after = get_ticks ();
if (test_verbose)
printf ("info: test_udp_server: 2.5 second timeout took %f seconds"
" (garbage %d)\n",
after - before, with_garbage);
TEST_VERIFY (2.5 <= after - before);
TEST_VERIFY (after - before < 3.0);
test_call_flush (clnt);
}
TEST_VERIFY_EXIT (clnt_call (clnt, PROC_EXIT,
(xdrproc_t) xdr_void, NULL,
(xdrproc_t) xdr_void, NULL,
((struct timeval) { 5, 0 }))
== RPC_SUCCESS);
clnt_destroy (clnt);
}
static int
do_test (void)
{
support_become_root ();
support_enter_network_namespace ();
SVCXPRT *transport = svcudp_create (RPC_ANYSOCK);
TEST_VERIFY_EXIT (transport != NULL);
TEST_VERIFY (svc_register (transport, PROGNUM, VERSNUM, server_dispatch, 0));
pid_t pid = xfork ();
if (pid == 0)
{
svc_run ();
FAIL_EXIT1 ("supposed to be unreachable");
}
test_udp_server (transport->xp_port);
int status;
xwaitpid (pid, &status, 0);
TEST_VERIFY (WIFEXITED (status) && WEXITSTATUS (status) == EXIT_MARKER);
SVC_DESTROY (transport);
return 0;
}
/* The minimum run time is around 17 seconds. */
#define TIMEOUT 25
#include <support/test-driver.c>