From: Corey Minyard <minyard@acm.org>
To: Vlad Yasevich <vyasevich@gmail.com>,
Neil Horman <nhorman@tuxdriver.com>,
Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>,
linux-sctp@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Subject: Strange problem with SCTP+IPv6
Date: Sun, 21 Jun 2020 15:56:04 +0000 [thread overview]
Message-ID: <20200621155604.GA23135@minyard.net> (raw)
I've stumbled upon a strange problem with SCTP and IPv6. If I create an
sctp listening socket on :: and set the IPV6_V6ONLY socket option on it,
then I make a connection to it using ::1, the connection will drop after
2.5 seconds with an ECONNRESET error.
It only happens on SCTP, it doesn't have the issue if you connect to a
full IPv6 address instead of ::1, and it doesn't happen if you don't
set IPV6_V6ONLY. I have verified current end of tree kernel.org.
I tried on an ARM system and x86_64.
I haven't dug into the kernel to see if I could find anything yet, but I
thought I would go ahead and report it. I am attaching a reproducer.
Basically, compile the following code:
gcc -g -o sctptest -Wall sctptest.c
and run it in one window as a server:
./sctptest a
(Pass in any option to be the server) and run the following in another
window as the client:
./sctptest
It disconnects after about 2.5 seconds. If it works, it should just sit
there forever.
-corey
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/select.h>
#include <arpa/inet.h>
#include <netinet/sctp.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
static int
getaddr(const char *addr, const char *port, bool listen,
struct addrinfo **rai)
{
struct addrinfo *ai, hints;
memset(&hints, 0, sizeof(hints));
hints.ai_flags = AI_ADDRCONFIG;
if (listen)
hints.ai_flags |= AI_PASSIVE;
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_SCTP;
if (getaddrinfo(addr, port, &hints, &ai)) {
perror("getaddrinfo");
return -1;
}
*rai = ai;
return 0;
}
static int
waitread(int s)
{
char data[1];
ssize_t rv;
rv = read(s, data, sizeof(data));
if (rv = -1) {
perror("read");
return -1;
}
printf("Read %d bytes\n", (int) rv);
return 0;
}
static int
do_server(void)
{
int err, ls, s, optval;
struct addrinfo *ai;
printf("Server\n");
err = getaddr("::", "3023", true, &ai);
if (err)
return err;
ls = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
if (ls = -1) {
perror("socket");
return -1;
}
optval = 1;
if (setsockopt(ls, SOL_SOCKET, SO_REUSEADDR,
(void *)&optval, sizeof(optval)) = -1) {
perror("setsockopt reuseaddr");
return -1;
}
/* Comment this out and it will work. */
if (setsockopt(ls, IPPROTO_IPV6, IPV6_V6ONLY, &optval,
sizeof(optval)) = -1) {
perror("setsockopt ipv6 only");
return -1;
}
err = bind(ls, ai->ai_addr, ai->ai_addrlen);
if (err = -1) {
perror("bind");
return -1;
}
err = listen(ls, 5);
if (err = -1) {
perror("listen");
return -1;
}
s = accept(ls, NULL, NULL);
if (s = -1) {
perror("accept");
return -1;
}
close(ls);
err = waitread(s);
close(s);
return err;
}
static int
do_client(void)
{
int err, s;
struct addrinfo *ai;
printf("Client\n");
err = getaddr("::1", "3023", false, &ai);
if (err)
return err;
s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
if (s = -1) {
perror("socket");
return -1;
}
err = connect(s, ai->ai_addr, ai->ai_addrlen);
if (err = -1) {
perror("connect");
return -1;
}
err = waitread(s);
close(s);
return err;
}
int
main(int argc, char *argv[])
{
int err;
if (argc > 1)
err = do_server();
else
err = do_client();
return !!err;
}
next reply other threads:[~2020-06-21 15:56 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-21 15:56 Corey Minyard [this message]
2020-06-22 11:52 ` Strange problem with SCTP+IPv6 Xin Long
2020-06-22 12:32 ` Michael Tuexen
2020-06-22 16:57 ` Corey Minyard
2020-06-22 18:01 ` Michael Tuexen
2020-06-22 18:32 ` Marcelo Ricardo Leitner
2020-06-22 18:34 ` Michael Tuexen
2020-06-23 10:13 ` Xin Long
2020-06-23 13:29 ` Corey Minyard
2020-06-23 15:40 ` Xin Long
2020-06-23 16:00 ` Corey Minyard
2020-06-24 6:58 ` Xin Long
2020-06-26 16:13 ` David Laight
2020-06-26 16:27 ` Michael Tuexen
2020-06-23 13:17 ` David Laight
2020-06-23 16:04 ` [PATCH] sctp: Don't advertise IPv4 addresses if ipv6only is set on the socket minyard
2020-06-24 20:31 ` Marcelo Ricardo Leitner
2020-06-24 20:34 ` [PATCH net] " Marcelo Ricardo Leitner
2020-06-24 20:53 ` Corey Minyard
2020-06-25 23:12 ` David Miller
2020-06-23 16:17 ` Strange problem with SCTP+IPv6 Corey Minyard
2020-06-23 21:21 ` 'Marcelo Ricardo Leitner'
2020-06-23 21:24 ` Michael Tuexen
2020-06-23 21:31 ` Marcelo Ricardo Leitner
2020-06-23 21:48 ` Michael Tuexen
2020-06-24 7:25 ` Xin Long
2020-06-24 9:18 ` Michael Tuexen
2020-06-23 17:09 ` Michael Tuexen
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