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| | // SPDX-License-Identifier: GPL-2.0-or-later
/* tcp-close-rst.c
*
* Check what operations on a TCP socket will trigger an RST.
*
* Copyright Red Hat
* Author: David Gibson <david@gibson.dropbear.id.au>
*/
#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
#include "common.h"
#define DSTPORT 13258U
#define SRCADDR(n) \
(0x7f000000U | (n) << 16U | (n) << 8U | 0x1U)
#define BASENUM 100
/* 127.0.0.1:DSTPORT */
static const struct sockaddr_in lo_dst = SOCKADDR_INIT(INADDR_LOOPBACK, DSTPORT);
#define LINGER 0x01U
#define SHUT_CLIENT 0x02U
#define SHUT_SERVER 0x04U
#define NUM_OPTIONS (SHUT_SERVER << 1U)
static void client_close(int sl, unsigned flags)
{
struct sockaddr_in src = SOCKADDR_INIT(SRCADDR(flags), 0);
struct linger linger0 = {
.l_onoff = 1,
.l_linger = 0,
};
int sockerr, sc, sa;
socklen_t errlen = sizeof(sockerr);
printf("Client close %u:%s%s%s\n", flags,
flags & LINGER ? " LINGER" : "",
flags & SHUT_CLIENT ? " SHUT_CLIENT" : "",
flags & SHUT_SERVER ? " SHUT_SERVER" : "");
sc = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (sc < 0)
die("socket() for connect(): %s\n", strerror(errno));
if (bind(sc, (struct sockaddr *)&src, sizeof(src)) < 0)
die("bind() for connect: %s\n", strerror(errno));
if (connect(sc, (struct sockaddr *)&lo_dst, sizeof(lo_dst)) < 0)
die("connect(): %s\n", strerror(errno));
/* cppcheck-suppress [android-cloexec-accept,unmatchedSuppression] */
sa = accept(sl, NULL, NULL);
if (sa < 0)
die("accept(): %s\n", strerror(errno));
if (flags & SHUT_SERVER)
if (shutdown(sa, SHUT_WR) < 0)
die("shutdown() server: %s\n", strerror(errno));
if (flags & SHUT_CLIENT)
if (shutdown(sc, SHUT_WR) < 0)
die("shutdown() client: %s\n", strerror(errno));
if (flags & LINGER)
if (setsockopt(sc, SOL_SOCKET, SO_LINGER,
&linger0, sizeof(linger0)) < 0)
die("SO_LINGER: %s\n", strerror(errno));
close(sc);
if (getsockopt(sa, SOL_SOCKET, SO_ERROR, &sockerr, &errlen) < 0)
die("SO_ERROR: %s\n", strerror(errno));
if (errlen != sizeof(sockerr))
die("SO_ERROR: bad option length\n");
printf("Server error: %s\n", strerror(sockerr));
if (flags & LINGER) {
if (!(flags & SHUT_SERVER) || !(flags & SHUT_CLIENT)) {
if (sockerr == 0)
die("No error after abrupt close(), no RST?\n");
} else {
if (sockerr != 0)
die("Error after full shutdown, bogus RST?\n");
}
}
close(sa);
}
static void server_close(int sl, unsigned flags)
{
struct sockaddr_in src = SOCKADDR_INIT(SRCADDR(flags), 0);
struct linger linger0 = {
.l_onoff = 1,
.l_linger = 0,
};
int sockerr, sc, sa;
socklen_t errlen = sizeof(sockerr);
printf("Server close %u:%s%s%s\n", flags,
flags & LINGER ? " LINGER" : "",
flags & SHUT_CLIENT ? " SHUT_CLIENT" : "",
flags & SHUT_SERVER ? " SHUT_SERVER" : "");
sc = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (sc < 0)
die("socket() for connect(): %s\n", strerror(errno));
if (bind(sc, (struct sockaddr *)&src, sizeof(src)) < 0)
die("bind() for connect: %s\n", strerror(errno));
if (connect(sc, (struct sockaddr *)&lo_dst, sizeof(lo_dst)) < 0)
die("connect(): %s\n", strerror(errno));
/* cppcheck-suppress [android-cloexec-accept,unmatchedSuppression] */
sa = accept(sl, NULL, NULL);
if (sa < 0)
die("accept(): %s\n", strerror(errno));
if (flags & SHUT_SERVER)
if (shutdown(sa, SHUT_WR) < 0)
die("shutdown() server: %s\n", strerror(errno));
if (flags & SHUT_CLIENT)
if (shutdown(sc, SHUT_WR) < 0)
die("shutdown() client: %s\n", strerror(errno));
if (flags & LINGER)
if (setsockopt(sa, SOL_SOCKET, SO_LINGER,
&linger0, sizeof(linger0)) < 0)
die("SO_LINGER: %s\n", strerror(errno));
close(sa);
if (getsockopt(sc, SOL_SOCKET, SO_ERROR, &sockerr, &errlen) < 0)
die("SO_ERROR: %s\n", strerror(errno));
if (errlen != sizeof(sockerr))
die("SO_ERROR: bad option length\n");
printf("Client error: %s\n", strerror(sockerr));
if (flags & LINGER) {
if (!(flags & SHUT_SERVER) || !(flags & SHUT_CLIENT)) {
if (sockerr == 0)
die("No error after abrupt close(), no RST?\n");
} else {
if (sockerr != 0)
die("Error after full shutdown, bogus RST?\n");
}
}
close(sc);
}
int main(int argc, char *argv[])
{
unsigned flags;
int y = 1;
int sl;
(void)argc;
(void)argv;
sl = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (sl < 0)
die("socket() for listen: %s\n", strerror(errno));
if (setsockopt(sl, SOL_SOCKET, SO_REUSEADDR, &y, sizeof(y)) < 0)
die("SO_REUSEADDR for listen: %s\n", strerror(errno));
if (bind(sl, (struct sockaddr *)&lo_dst, sizeof(lo_dst)) < 0)
die("bind() for listen: %s\n", strerror(errno));
if (listen(sl, 1) < 0)
die("listen(): %s\n", strerror(errno));
printf("Listening on port %u\n", DSTPORT);
for (flags = 0; flags < NUM_OPTIONS; flags++) {
client_close(sl, flags);
server_close(sl, flags);
}
close(sl);
exit(0);
}
|