mirror of
https://passt.top/passt
synced 2024-11-10 06:30:13 +00:00
ba74b1fea1
This test program verifies that we can receive and discard datagrams by using recv() with a NULL buffer and zero-length. Extend it to verify it also works using recvmsg() and either an iov with a zero-length NULL buffer or an iov that itself is NULL and zero-length. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> [sbrivio: Fixed printf() message in main of recv-zero.c] Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
119 lines
2.6 KiB
C
119 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
|
|
/* recv-zero.c
|
|
*
|
|
* Verify that we're able to discard datagrams by recv()ing into a zero-length
|
|
* buffer.
|
|
*
|
|
* Copyright Red Hat
|
|
* Author: David Gibson <david@gibson.dropbear.id.au>
|
|
*/
|
|
|
|
#include <arpa/inet.h>
|
|
#include <errno.h>
|
|
#include <net/if.h>
|
|
#include <netinet/in.h>
|
|
#include <stdbool.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
#include "common.h"
|
|
|
|
#define DSTPORT 13257U
|
|
|
|
enum discard_method {
|
|
DISCARD_NULL_BUF,
|
|
DISCARD_ZERO_IOV,
|
|
DISCARD_NULL_IOV,
|
|
NUM_METHODS,
|
|
};
|
|
|
|
/* 127.0.0.1:DSTPORT */
|
|
static const struct sockaddr_in lo_dst = SOCKADDR_INIT(INADDR_LOOPBACK, DSTPORT);
|
|
|
|
static void test_discard(enum discard_method method)
|
|
{
|
|
struct iovec zero_iov = { .iov_base = NULL, .iov_len = 0, };
|
|
struct msghdr mh_zero = {
|
|
.msg_iov = &zero_iov,
|
|
.msg_iovlen = 1,
|
|
};
|
|
struct msghdr mh_null = {
|
|
.msg_iov = NULL,
|
|
.msg_iovlen = 0,
|
|
};
|
|
long token1, token2;
|
|
int recv_s, send_s;
|
|
ssize_t rc;
|
|
|
|
token1 = random();
|
|
token2 = random();
|
|
|
|
recv_s = sock_reuseaddr();
|
|
if (bind(recv_s, (struct sockaddr *)&lo_dst, sizeof(lo_dst)) < 0)
|
|
die("bind(): %s\n", strerror(errno));
|
|
|
|
send_s = sock_reuseaddr();
|
|
if (connect(send_s, (struct sockaddr *)&lo_dst, sizeof(lo_dst)) < 0)
|
|
die("connect(): %s\n", strerror(errno));
|
|
|
|
send_token(send_s, token1);
|
|
send_token(send_s, token2);
|
|
|
|
switch (method) {
|
|
case DISCARD_NULL_BUF:
|
|
/* cppcheck-suppress nullPointer */
|
|
rc = recv(recv_s, NULL, 0, MSG_DONTWAIT);
|
|
if (rc < 0)
|
|
die("discarding recv(): %s\n", strerror(errno));
|
|
break;
|
|
|
|
case DISCARD_ZERO_IOV:
|
|
rc = recvmsg(recv_s, &mh_zero, MSG_DONTWAIT);
|
|
if (rc < 0)
|
|
die("recvmsg() with zero-length buffer: %s\n",
|
|
strerror(errno));
|
|
if (!((unsigned)mh_zero.msg_flags & MSG_TRUNC))
|
|
die("Missing MSG_TRUNC flag\n");
|
|
break;
|
|
|
|
case DISCARD_NULL_IOV:
|
|
rc = recvmsg(recv_s, &mh_null, MSG_DONTWAIT);
|
|
if (rc < 0)
|
|
die("recvmsg() with zero-length iov: %s\n",
|
|
strerror(errno));
|
|
if (!((unsigned)mh_null.msg_flags & MSG_TRUNC))
|
|
die("Missing MSG_TRUNC flag\n");
|
|
break;
|
|
|
|
default:
|
|
die("Bad method\n");
|
|
}
|
|
|
|
recv_token(recv_s, token2);
|
|
|
|
/* cppcheck-suppress nullPointer */
|
|
rc = recv(recv_s, NULL, 0, MSG_DONTWAIT);
|
|
if (rc < 0 && errno != EAGAIN)
|
|
die("redundant discarding recv(): %s\n", strerror(errno));
|
|
if (rc >= 0)
|
|
die("Unexpected receive: rc=%zd\n", rc);
|
|
}
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
enum discard_method method;
|
|
|
|
(void)argc;
|
|
(void)argv;
|
|
|
|
for (method = 0; method < NUM_METHODS; method++)
|
|
test_discard(method);
|
|
|
|
printf("Discarding datagrams with 0-length receives seems to work\n");
|
|
|
|
exit(0);
|
|
}
|