@@ -45,14 +45,18 @@ routines := htonl htons \
in6_addr getnameinfo if_index ifaddrs inet6_option \
getipv4sourcefilter setipv4sourcefilter \
getsourcefilter setsourcefilter inet6_opt inet6_rth \
- inet6_scopeid_pton
+ inet6_scopeid_pton deadline
aux := check_pf check_native ifreq
tests := htontest test_ifindex tst-ntoa tst-ether_aton tst-network \
tst-gethnm test-ifaddrs bug-if1 test-inet6_opt tst-ether_line \
tst-getni1 tst-getni2 tst-inet6_rth tst-checks tst-checks-posix \
- tst-sockaddr tst-inet6_scopeid_pton test-hnto-types
+ tst-sockaddr tst-inet6_scopeid_pton test-hnto-types tst-deadline
+
+# tst-deadline must be linked statically so that we can access
+# internal functions.
+tests-static += tst-deadline
include ../Rules
new file mode 100644
@@ -0,0 +1,122 @@
+/* Computing deadlines for timeouts.
+ Copyright (C) 2017 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 <net-internal.h>
+
+#include <assert.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <time.h>
+
+struct deadline_current_time internal_function
+__deadline_current_time (void)
+{
+ struct deadline_current_time result;
+ if (__clock_gettime (CLOCK_MONOTONIC, &result.current) != 0)
+ {
+ struct timeval current_tv;
+ if (__gettimeofday (¤t_tv, NULL) == 0)
+ __libc_fatal ("Fatal error: gettimeofday system call failed\n");
+ result.current.tv_sec = current_tv.tv_sec;
+ result.current.tv_nsec = current_tv.tv_usec * 1000;
+ }
+ assert (result.current.tv_sec >= 0);
+ return result;
+}
+
+/* A special deadline value for which __deadline_is_infinite is
+ true. */
+static inline struct deadline
+infinite_deadline (void)
+{
+ return (struct deadline) { { -1, -1 } };
+}
+
+struct deadline internal_function
+__deadline_from_timeval (struct deadline_current_time current,
+ struct timeval tv)
+{
+ assert (__is_timeval_valid_timeout (tv));
+
+ /* Compute second-based deadline. Perform the addition in
+ uintmax_t, which is unsigned, to simply overflow detection. */
+ uintmax_t sec = current.current.tv_sec;
+ sec += tv.tv_sec;
+ if (sec < (uintmax_t) tv.tv_sec)
+ return infinite_deadline ();
+
+ /* Compute nanosecond deadline. */
+ int nsec = current.current.tv_nsec + tv.tv_usec * 1000;
+ if (nsec >= 1000 * 1000 * 1000)
+ {
+ /* Carry nanosecond overflow to seconds. */
+ nsec -= 1000 * 1000 * 1000;
+ if (sec + 1 < sec)
+ return infinite_deadline ();
+ ++sec;
+ }
+ /* This uses a GCC extension, otherwise these casts for detecting
+ overflow would not be defined. */
+ if ((time_t) sec < 0 || sec != (uintmax_t) (time_t) sec)
+ return infinite_deadline ();
+
+ return (struct deadline) { { sec, nsec } };
+}
+
+int internal_function
+__deadline_to_ms (struct deadline_current_time current,
+ struct deadline deadline)
+{
+ if (__deadline_is_infinite (deadline))
+ return INT_MAX;
+
+ if (current.current.tv_sec > deadline.absolute.tv_sec
+ || (current.current.tv_sec == deadline.absolute.tv_sec
+ && current.current.tv_nsec >= deadline.absolute.tv_nsec))
+ return 0;
+ time_t sec = deadline.absolute.tv_sec - current.current.tv_sec;
+ if (sec >= INT_MAX)
+ /* This value will overflow below. */
+ return INT_MAX;
+ int nsec = deadline.absolute.tv_nsec - current.current.tv_nsec;
+ if (nsec < 0)
+ {
+ /* Borrow from the seconds field. */
+ assert (sec > 0);
+ --sec;
+ nsec += 1000 * 1000 * 1000;
+ }
+
+ /* Prepare for rounding up to milliseconds. */
+ nsec += 999999;
+ if (nsec > 1000 * 1000 * 1000)
+ {
+ assert (sec < INT_MAX);
+ ++sec;
+ nsec -= 1000 * 1000 * 1000;
+ }
+
+ unsigned int msec = nsec / (1000 * 1000);
+ if (sec > INT_MAX / 1000)
+ return INT_MAX;
+ msec += sec * 1000;
+ if (msec > INT_MAX)
+ return INT_MAX;
+ return msec;
+}
@@ -20,11 +20,100 @@
#define _NET_INTERNAL_H 1
#include <arpa/inet.h>
+#include <stdbool.h>
#include <stdint.h>
+#include <sys/time.h>
int __inet6_scopeid_pton (const struct in6_addr *address,
const char *scope, uint32_t *result)
internal_function attribute_hidden;
libc_hidden_proto (__inet6_scopeid_pton)
+
+/* Deadline handling for enforcing timeouts.
+
+ Code should call __deadline_current_time to obtain the current time
+ and cache it locally. The cache needs to updated after every
+ long-running or potentially blocking operation. Deadlines relative
+ to the current time can be computed using __deadline_from_timeval.
+ The deadlines may have to be recomputed in response to certain
+ events (such as an incoming packet), but they are absolute (not
+ relative to the current time). A timeout suitable for use with the
+ poll function can be computed from such a deadline using
+ __deadline_to_ms.
+
+ The fields in the structs defined belowed should only be used
+ within the implementation. */
+
+/* Cache of the current time. Used to compute deadlines from relative
+ timeouts and vice versa. */
+struct deadline_current_time
+{
+ struct timespec current;
+};
+
+/* Return the current time. Terminates the process if the current
+ time is not available. */
+struct deadline_current_time __deadline_current_time (void)
+ internal_function attribute_hidden;
+
+/* Computed absolute deadline. */
+struct deadline
+{
+ struct timespec absolute;
+};
+
+
+/* For internal use only. */
+static inline bool
+__deadline_is_infinite (struct deadline deadline)
+{
+ return deadline.absolute.tv_nsec < 0;
+}
+
+/* Return true if the current time is at the deadline or past it. */
+static inline bool
+__deadline_elapsed (struct deadline_current_time current,
+ struct deadline deadline)
+{
+ return !__deadline_is_infinite (deadline)
+ && (current.current.tv_sec > deadline.absolute.tv_sec
+ || (current.current.tv_sec == deadline.absolute.tv_sec
+ && current.current.tv_nsec >= deadline.absolute.tv_nsec));
+}
+
+/* Return the deadline which occurs first. */
+static inline struct deadline
+__deadline_first (struct deadline left, struct deadline right)
+{
+ if (__deadline_is_infinite (right)
+ || left.absolute.tv_sec < right.absolute.tv_sec
+ || (left.absolute.tv_sec == right.absolute.tv_sec
+ && left.absolute.tv_nsec < right.absolute.tv_nsec))
+ return left;
+ else
+ return right;
+}
+
+/* Add TV to the current time and return it. Returns a special
+ infinite absolute deadline on overflow. */
+struct deadline __deadline_from_timeval (struct deadline_current_time,
+ struct timeval tv)
+ internal_function attribute_hidden;
+
+/* Compute the number of milliseconds until the specified deadline,
+ from the current time in the argument. The result is mainly for
+ use with poll. If the deadline has already passed, return 0. If
+ the result would overflow an int, return INT_MAX. */
+int __deadline_to_ms (struct deadline_current_time, struct deadline)
+ internal_function attribute_hidden;
+
+/* Return true if TV.tv_sec is non-negative and TV.tv_usec is in the
+ interval [0, 999999]. */
+static inline bool
+__is_timeval_valid_timeout (struct timeval tv)
+{
+ return tv.tv_sec >= 0 && tv.tv_usec >= 0 && tv.tv_usec < 1000 * 1000;
+}
+
#endif /* _NET_INTERNAL_H */
new file mode 100644
@@ -0,0 +1,188 @@
+/* Tests for computing deadlines for timeouts.
+ Copyright (C) 2017 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 <inet/net-internal.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <support/check.h>
+
+/* Find the maximum value which can be represented in a time_t. */
+static time_t
+time_t_max (void)
+{
+ _Static_assert (0 > (time_t) -1, "time_t is signed");
+ uintmax_t current = 1;
+ while (true)
+ {
+ uintmax_t next = current * 2;
+ /* This cannot happen because time_t is signed. */
+ TEST_VERIFY_EXIT (next > current);
+ ++next;
+ if ((time_t) next < 0 || next != (uintmax_t) (time_t) next)
+ /* Value cannot be represented in time_t. Return the previous
+ value. */
+ return current;
+ current = next;
+ }
+}
+
+static int
+do_test (void)
+{
+ {
+ struct deadline_current_time current_time = __deadline_current_time ();
+ TEST_VERIFY (current_time.current.tv_sec >= 0);
+ current_time = __deadline_current_time ();
+ /* Due to CLOCK_MONOTONIC, either seconds or nanoseconds are
+ greater than zero. This is also true for the gettimeofday
+ fallback. */
+ TEST_VERIFY (current_time.current.tv_sec >= 0);
+ TEST_VERIFY (current_time.current.tv_sec > 0
+ || current_time.current.tv_nsec > 0);
+ }
+
+ /* Check basic computations of deadlines. */
+ struct deadline_current_time current_time = { { 1, 123456789 } };
+ struct deadline deadline = __deadline_from_timeval
+ (current_time, (struct timeval) { 0, 1 });
+ TEST_VERIFY (deadline.absolute.tv_sec == 1);
+ TEST_VERIFY (deadline.absolute.tv_nsec == 123457789);
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1);
+
+ deadline = __deadline_from_timeval
+ (current_time, ((struct timeval) { 0, 2 }));
+ TEST_VERIFY (deadline.absolute.tv_sec == 1);
+ TEST_VERIFY (deadline.absolute.tv_nsec == 123458789);
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1);
+
+ deadline = __deadline_from_timeval
+ (current_time, ((struct timeval) { 1, 0 }));
+ TEST_VERIFY (deadline.absolute.tv_sec == 2);
+ TEST_VERIFY (deadline.absolute.tv_nsec == 123456789);
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1000);
+
+ /* Check if timeouts are correctly rounded up to the next
+ millisecond. */
+ for (int i = 0; i < 999999; ++i)
+ {
+ ++current_time.current.tv_nsec;
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1000);
+ }
+
+ /* A full millisecond has elapsed, so the time to the deadline is
+ now less than 1000. */
+ ++current_time.current.tv_nsec;
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 999);
+
+ /* Check __deadline_to_ms carry-over. */
+ current_time = (struct deadline_current_time) { { 9, 123456789 } };
+ deadline = (struct deadline) { { 10, 122456789 } };
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 999);
+ deadline = (struct deadline) { { 10, 122456790 } };
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1000);
+ deadline = (struct deadline) { { 10, 123456788 } };
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1000);
+ deadline = (struct deadline) { { 10, 123456789 } };
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1000);
+
+ /* Check __deadline_to_ms overflow. */
+ deadline = (struct deadline) { { INT_MAX - 1, 1 } };
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == INT_MAX);
+
+ /* Check __deadline_to_ms for elapsed deadlines. */
+ current_time = (struct deadline_current_time) { { 9, 123456789 } };
+ deadline.absolute = current_time.current;
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 0);
+ current_time = (struct deadline_current_time) { { 9, 123456790 } };
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 0);
+ current_time = (struct deadline_current_time) { { 10, 0 } };
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 0);
+ current_time = (struct deadline_current_time) { { 10, 123456788 } };
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 0);
+ current_time = (struct deadline_current_time) { { 10, 123456789 } };
+ TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 0);
+
+ /* Check carry-over in __deadline_from_timeval. */
+ current_time = (struct deadline_current_time) { { 9, 998000001 } };
+ for (int i = 0; i < 2000; ++i)
+ {
+ deadline = __deadline_from_timeval
+ (current_time, (struct timeval) { 1, i });
+ TEST_VERIFY (deadline.absolute.tv_sec == 10);
+ TEST_VERIFY (deadline.absolute.tv_nsec == 998000001 + i * 1000);
+ }
+ for (int i = 2000; i < 3000; ++i)
+ {
+ deadline = __deadline_from_timeval
+ (current_time, (struct timeval) { 2, i });
+ TEST_VERIFY (deadline.absolute.tv_sec == 12);
+ TEST_VERIFY (deadline.absolute.tv_nsec == 1 + (i - 2000) * 1000);
+ }
+
+ /* Check infinite deadlines. */
+ deadline = __deadline_from_timeval
+ ((struct deadline_current_time) { { 0, 1000 * 1000 * 1000 - 1000 } },
+ (struct timeval) { time_t_max (), 1 });
+ TEST_VERIFY (__deadline_is_infinite (deadline));
+ deadline = __deadline_from_timeval
+ ((struct deadline_current_time) { { 0, 1000 * 1000 * 1000 - 1001 } },
+ (struct timeval) { time_t_max (), 1 });
+ TEST_VERIFY (!__deadline_is_infinite (deadline));
+ deadline = __deadline_from_timeval
+ ((struct deadline_current_time)
+ { { time_t_max (), 1000 * 1000 * 1000 - 1000 } },
+ (struct timeval) { 0, 1 });
+ TEST_VERIFY (__deadline_is_infinite (deadline));
+ deadline = __deadline_from_timeval
+ ((struct deadline_current_time)
+ { { time_t_max () / 2 + 1, 0 } },
+ (struct timeval) { time_t_max () / 2 + 1, 0 });
+ TEST_VERIFY (__deadline_is_infinite (deadline));
+
+ /* Check __deadline_first behavior. */
+ deadline = __deadline_first
+ ((struct deadline) { { 1, 2 } },
+ (struct deadline) { { 1, 3 } });
+ TEST_VERIFY (deadline.absolute.tv_sec == 1);
+ TEST_VERIFY (deadline.absolute.tv_nsec == 2);
+ deadline = __deadline_first
+ ((struct deadline) { { 1, 3 } },
+ (struct deadline) { { 1, 2 } });
+ TEST_VERIFY (deadline.absolute.tv_sec == 1);
+ TEST_VERIFY (deadline.absolute.tv_nsec == 2);
+ deadline = __deadline_first
+ ((struct deadline) { { 1, 2 } },
+ (struct deadline) { { 2, 1 } });
+ TEST_VERIFY (deadline.absolute.tv_sec == 1);
+ TEST_VERIFY (deadline.absolute.tv_nsec == 2);
+ deadline = __deadline_first
+ ((struct deadline) { { 1, 2 } },
+ (struct deadline) { { 2, 4 } });
+ TEST_VERIFY (deadline.absolute.tv_sec == 1);
+ TEST_VERIFY (deadline.absolute.tv_nsec == 2);
+ deadline = __deadline_first
+ ((struct deadline) { { 2, 4 } },
+ (struct deadline) { { 1, 2 } });
+ TEST_VERIFY (deadline.absolute.tv_sec == 1);
+ TEST_VERIFY (deadline.absolute.tv_nsec == 2);
+
+ return 0;
+}
+
+#include <support/test-driver.c>
@@ -98,7 +98,7 @@ xtests := tst-getmyaddr
ifeq ($(have-thread-library),yes)
xtests += thrsvc
-tests += tst-svc_register
+tests += tst-svc_register tst-udp-timeout tst-udp-garbage
endif
ifeq ($(run-built-tests),yes)
@@ -238,3 +238,7 @@ $(rpcgen-tests): $(objpfx)%.out: %.x $(objpfx)rpcgen
$(built-program-cmd) -c $< -o $@; \
$(evaluate-test)
endif
+
+$(objpfx)tst-udp-timeout: $(common-objpfx)linkobj/libc.so
+$(objpfx)tst-udp-garbage: \
+ $(common-objpfx)linkobj/libc.so $(shared-thread-library)
@@ -55,6 +55,7 @@
#endif
#include <kernel-features.h>
+#include <inet/net-internal.h>
extern u_long _create_xid (void);
@@ -278,28 +279,35 @@ clntudp_call (/* client handle */
int inlen;
socklen_t fromlen;
struct pollfd fd;
- int milliseconds = (cu->cu_wait.tv_sec * 1000) +
- (cu->cu_wait.tv_usec / 1000);
struct sockaddr_in from;
struct rpc_msg reply_msg;
XDR reply_xdrs;
- struct timeval time_waited;
bool_t ok;
int nrefreshes = 2; /* number of times to refresh cred */
- struct timeval timeout;
int anyup; /* any network interface up */
- if (cu->cu_total.tv_usec == -1)
- {
- timeout = utimeout; /* use supplied timeout */
- }
- else
- {
- timeout = cu->cu_total; /* use default timeout */
- }
+ struct deadline_current_time current_time = __deadline_current_time ();
+ struct deadline total_deadline; /* Determined once by overall timeout. */
+ struct deadline response_deadline; /* Determined anew for each query. */
+
+ /* Choose the timeout value. */
+ {
+ struct timeval tv;
+ if (cu->cu_total.tv_usec == -1)
+ /* Use supplied timeout. */
+ tv = utimeout;
+ else
+ /* Use default timeout. */
+ tv = cu->cu_total;
+ if (!__is_timeval_valid_timeout (tv))
+ return (cu->cu_error.re_status = RPC_TIMEDOUT);
+ total_deadline = __deadline_from_timeval (current_time, tv);
+ }
+
+ /* Guard against bad timeout specification. */
+ if (!__is_timeval_valid_timeout (cu->cu_wait))
+ return (cu->cu_error.re_status = RPC_TIMEDOUT);
- time_waited.tv_sec = 0;
- time_waited.tv_usec = 0;
call_again:
xdrs = &(cu->cu_outxdrs);
if (xargs == NULL)
@@ -325,27 +333,31 @@ send_again:
return (cu->cu_error.re_status = RPC_CANTSEND);
}
- /*
- * Hack to provide rpc-based message passing
- */
- if (timeout.tv_sec == 0 && timeout.tv_usec == 0)
- {
- return (cu->cu_error.re_status = RPC_TIMEDOUT);
- }
+ /* sendto may have blocked, so recompute the current time. */
+ current_time = __deadline_current_time ();
get_reply:
- /*
- * sub-optimal code appears here because we have
- * some clock time to spare while the packets are in flight.
- * (We assume that this is actually only executed once.)
- */
+ response_deadline = __deadline_from_timeval (current_time, cu->cu_wait);
+
reply_msg.acpted_rply.ar_verf = _null_auth;
reply_msg.acpted_rply.ar_results.where = resultsp;
reply_msg.acpted_rply.ar_results.proc = xresults;
fd.fd = cu->cu_sock;
fd.events = POLLIN;
anyup = 0;
+
+ /* Per-response retry loop. current_time must be up-to-date at the
+ top of the loop. */
for (;;)
{
+ if (__deadline_elapsed (current_time, total_deadline))
+ /* Overall timeout expired. */
+ return (cu->cu_error.re_status = RPC_TIMEDOUT);
+ int milliseconds = __deadline_to_ms
+ (current_time, __deadline_first (total_deadline, response_deadline));
+ if (milliseconds == 0)
+ /* Per-query timeout expired. */
+ goto send_again;
+
switch (__poll (&fd, 1, milliseconds))
{
@@ -356,27 +368,10 @@ send_again:
if (!anyup)
return (cu->cu_error.re_status = RPC_CANTRECV);
}
-
- time_waited.tv_sec += cu->cu_wait.tv_sec;
- time_waited.tv_usec += cu->cu_wait.tv_usec;
- while (time_waited.tv_usec >= 1000000)
- {
- time_waited.tv_sec++;
- time_waited.tv_usec -= 1000000;
- }
- if ((time_waited.tv_sec < timeout.tv_sec) ||
- ((time_waited.tv_sec == timeout.tv_sec) &&
- (time_waited.tv_usec < timeout.tv_usec)))
- goto send_again;
- return (cu->cu_error.re_status = RPC_TIMEDOUT);
-
- /*
- * buggy in other cases because time_waited is not being
- * updated.
- */
+ goto next_response;
case -1:
if (errno == EINTR)
- continue;
+ goto next_response;
cu->cu_error.re_errno = errno;
return (cu->cu_error.re_status = RPC_CANTRECV);
}
@@ -440,20 +435,22 @@ send_again:
if (inlen < 0)
{
if (errno == EWOULDBLOCK)
- continue;
+ goto next_response;
cu->cu_error.re_errno = errno;
return (cu->cu_error.re_status = RPC_CANTRECV);
}
- if (inlen < 4)
- continue;
+ /* Accept the response if the packet is sufficiently long and
+ the transaction ID matches the query (if available). */
+ if (inlen >= 4
+ && (xargs == NULL
+ || memcmp (cu->cu_inbuf, cu->cu_outbuf,
+ sizeof (u_int32_t)) == 0))
+ break;
- /* see if reply transaction id matches sent id.
- Don't do this if we only wait for a replay */
- if (xargs != NULL
- && memcmp (cu->cu_inbuf, cu->cu_outbuf, sizeof (u_int32_t)) != 0)
- continue;
- /* we now assume we have the proper reply */
- break;
+ next_response:
+ /* Update the current time because poll and recvmsg waited for
+ an unknown time. */
+ current_time = __deadline_current_time ();
}
/*
new file mode 100644
@@ -0,0 +1,93 @@
+/* Test that garbage packets do not affect timeout handling.
+ Copyright (C) 2017 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 <support/check.h>
+#include <support/namespace.h>
+#include <support/xsocket.h>
+#include <support/xthread.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+/* Descriptor for the server UDP socket. */
+static int server_fd;
+
+static void *
+garbage_sender_thread (void *unused)
+{
+ while (true)
+ {
+ struct sockaddr_storage sa;
+ socklen_t salen = sizeof (sa);
+ char buf[1];
+ if (recvfrom (server_fd, buf, sizeof (buf), 0,
+ (struct sockaddr *) &sa, &salen) < 0)
+ FAIL_EXIT1 ("recvfrom: %m");
+
+ /* Send garbage packets indefinitely. */
+ buf[0] = 0;
+ while (true)
+ {
+ /* sendto can fail if the client closed the socket. */
+ if (sendto (server_fd, buf, sizeof (buf), 0,
+ (struct sockaddr *) &sa, salen) < 0)
+ break;
+ usleep (50 * 1000);
+ }
+ }
+}
+
+static int
+do_test (void)
+{
+ support_become_root ();
+ support_enter_network_namespace ();
+
+ server_fd = xsocket (AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
+ struct sockaddr_in server_address =
+ {
+ .sin_family = AF_INET,
+ .sin_addr.s_addr = htonl (INADDR_LOOPBACK),
+ };
+ xbind (server_fd,
+ (struct sockaddr *) &server_address, sizeof (server_address));
+ {
+ socklen_t sinlen = sizeof (server_address);
+ xgetsockname (server_fd, (struct sockaddr *) &server_address, &sinlen);
+ TEST_VERIFY (sizeof (server_address) == sinlen);
+ }
+
+ xpthread_detach (xpthread_create (NULL, garbage_sender_thread, NULL));
+
+ int client_fd = RPC_ANYSOCK;
+ CLIENT *clnt = clntudp_create (&server_address, 1, 2,
+ (struct timeval) { .tv_sec = 1, },
+ &client_fd);
+ if (clnt == NULL)
+ FAIL_EXIT1 ("clntudp_create: %m");
+
+ clnt_call (clnt, 3, (xdrproc_t) xdr_void, NULL, (xdrproc_t) xdr_void, NULL,
+ ((struct timeval) { .tv_sec = 1, }));
+
+ return 0;
+}
+
+#include <support/test-driver.c>
new file mode 100644
@@ -0,0 +1,384 @@
+/* Test timeout handling in the UDP client.
+ Copyright (C) 2017 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. */
+ 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)
+ {
+ 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));
+
+ if (request->rq_proc == PROC_EXIT)
+ _exit (EXIT_MARKER);
+ }
+ 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 long timeout to flush out all pending requests. */
+ 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);
+}
+
+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. */
+ 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 ();
+ printf ("info: 21 garbage packets took %f seconds\n", after - before);
+ 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);
+ 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, 300 * 1000 });
+ after = get_ticks ();
+ if (test_verbose)
+ printf ("info: test_udp_server: 2.3 second timeout took %f seconds"
+ " (garbage %d)\n",
+ after - before, with_garbage);
+ TEST_VERIFY (2.3 <= 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);
+ 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;
+}
+
+#include <support/test-driver.c>