opnsense-src/tests/sys/kern/socket_msg_trunc.c
Alexander V. Chernikov be1f485d7d sockets: add MSG_TRUNC flag handling for recvfrom()/recvmsg().
Implement Linux-variant of MSG_TRUNC input flag used in recv(), recvfrom() and recvmsg().
Posix defines MSG_TRUNC as an output flag, indicating packet/datagram truncation.
Linux extended it a while (~15+ years) ago to act as input flag,
resulting in returning the full packet size regarless of the input
buffer size.
It's a (relatively) popular pattern to do recvmsg( MSG_PEEK | MSG_TRUNC) to get the
packet size, allocate the buffer and issue another call to fetch the packet.
In particular, it's popular in userland netlink code, which is the primary driving factor of this change.

This commit implements the MSG_TRUNC support for SOCK_DGRAM sockets (udp, unix and all soreceive_generic() users).

PR:		kern/176322
Reviewed by:	pauamma(doc)
Differential Revision: https://reviews.freebsd.org/D35909
MFC after:	1 month
2022-07-30 18:21:51 +00:00

169 lines
4.9 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2022 Alexander V. Chernikov
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <stdio.h>
#include <stdlib.h>
#include <sys/errno.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <poll.h>
#include <atf-c.h>
static void
check_recvmsg(const char *test_name)
{
int ss, cs, rc;
struct sockaddr *sa;
struct sockaddr_in sin;
struct sockaddr_in6 sin6;
struct sockaddr_un saun;
int *sizes, sizes_count;
int one = 1;
if (!strcmp(test_name, "udp")) {
ss = socket(PF_INET, SOCK_DGRAM, 0);
ATF_CHECK(ss >= 0);
rc = setsockopt(ss, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));
ATF_CHECK_EQ(0, rc);
bzero(&sin, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_len = sizeof(sin);
sin.sin_port = htons(6666);
sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
sa = (struct sockaddr *)&sin;
rc = bind(ss, sa, sa->sa_len);
ATF_CHECK_EQ(0, rc);
cs = socket(PF_INET, SOCK_DGRAM, 0);
ATF_CHECK(cs >= 0);
int inet_sizes[] = {80, 255, 256, 1024, 4096, 9000};
sizes_count = sizeof(inet_sizes) / sizeof(int);
sizes = malloc(sizeof(inet_sizes));
memcpy(sizes, inet_sizes, sizeof(inet_sizes));
} else if (!strcmp(test_name, "udp6")) {
ss = socket(PF_INET6, SOCK_DGRAM, 0);
ATF_CHECK(ss >= 0);
rc = setsockopt(ss, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));
ATF_CHECK_EQ(0, rc);
bzero(&sin6, sizeof(sin6));
sin6.sin6_family = AF_INET6;
sin6.sin6_len = sizeof(sin6);
sin6.sin6_port = htons(6666);
const struct in6_addr in6loopback = IN6ADDR_LOOPBACK_INIT;
sin6.sin6_addr = in6loopback;
sa = (struct sockaddr *)&sin6;
rc = bind(ss, sa, sa->sa_len);
ATF_CHECK_EQ(0, rc);
cs = socket(PF_INET6, SOCK_DGRAM, 0);
ATF_CHECK(cs >= 0);
int inet_sizes[] = {80, 255, 256, 1024, 4096, 9000};
sizes_count = sizeof(inet_sizes) / sizeof(int);
sizes = malloc(sizeof(inet_sizes));
memcpy(sizes, inet_sizes, sizeof(inet_sizes));
} else if (!strcmp(test_name, "unix")) {
const char *PATH = "/tmp/test_check_recvmsg_socket";
ss = socket(PF_UNIX, SOCK_DGRAM, 0);
ATF_CHECK(ss >= 0);
rc = setsockopt(ss, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));
ATF_CHECK_EQ(0, rc);
bzero(&saun, sizeof(saun));
saun.sun_family = AF_UNIX;
strcpy(saun.sun_path, PATH);
saun.sun_len = sizeof(saun);
sa = (struct sockaddr *)&saun;
unlink(PATH);
rc = bind(ss, sa, sa->sa_len);
ATF_CHECK_EQ(0, rc);
cs = socket(PF_UNIX, SOCK_DGRAM, 0);
ATF_CHECK(cs >= 0);
int unix_sizes[] = {80, 255, 256, 1024, 2000};
sizes_count = sizeof(unix_sizes) / sizeof(int);
sizes = malloc(sizeof(unix_sizes));
memcpy(sizes, unix_sizes, sizeof(unix_sizes));
} else
return;
char buf[4096];
memset(buf, 0xFF, sizeof(buf));
for (int i = 0; i < sizes_count; i++) {
int sz = sizes[i];
char tbuf[1];
rc = sendto(cs, buf, sz, 0, sa, sa->sa_len);
ATF_REQUIRE_EQ(rc, sz);
rc = recv(ss, NULL, 0, MSG_PEEK | MSG_TRUNC);
ATF_CHECK_EQ(rc, sz);
rc = recv(ss, tbuf, sizeof(tbuf), MSG_PEEK | MSG_TRUNC);
ATF_CHECK_EQ(rc, sz);
rc = recv(ss, tbuf, sizeof(tbuf), MSG_TRUNC);
ATF_CHECK_EQ(rc, sz);
}
close(ss);
close(cs);
}
ATF_TC_WITHOUT_HEAD(socket_afinet_udp_recv_trunc);
ATF_TC_BODY(socket_afinet_udp_recv_trunc, tc)
{
check_recvmsg("udp");
}
ATF_TC_WITHOUT_HEAD(socket_afinet6_udp_recv_trunc);
ATF_TC_BODY(socket_afinet6_udp_recv_trunc, tc)
{
check_recvmsg("udp6");
}
ATF_TC_WITHOUT_HEAD(socket_afunix_recv_trunc);
ATF_TC_BODY(socket_afunix_recv_trunc, tc)
{
check_recvmsg("unix");
}
ATF_TP_ADD_TCS(tp)
{
ATF_TP_ADD_TC(tp, socket_afinet_udp_recv_trunc);
ATF_TP_ADD_TC(tp, socket_afinet6_udp_recv_trunc);
ATF_TP_ADD_TC(tp, socket_afunix_recv_trunc);
return atf_no_error();
}