lkml.org 
[lkml]   [2017]   [Sep]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject319554f284dd ("inet: don't use sk_v6_rcv_saddr directly") causes bind port regression
Date
Hi,

Fedora got a bug report
https://bugzilla.redhat.com/show_bug.cgi?id=1432684 of a regression with
automatic spice port
assignment. The libvirt team reduced this to the attached test
case run as follows:

In a separate terminal, qemu-kvm -vnc 127.0.0.1:0 to grab port 5900.
Then do this:

$ gcc bind-collision.c && ./a.out
bind: Address already in use
AF_INET check failed.
$ gcc -D CHECK_IPV6 bind-collision.c && ./a.out
AF_INET6 success
AF_INET success
$ gcc bind-collision.c && ./a.out
AF_INET success

Bisection showed this behavior to be caused by

commit 319554f284dda9f2737d09df82ba3610bd8ddea3
Author: Josef Bacik <jbacik@fb.com>
Date: Thu Jan 19 17:47:46 2017 -0500

inet: don't use sk_v6_rcv_saddr directly

When comparing two sockets we need to use inet6_rcv_saddr so we get
a NULL
sk_v6_rcv_saddr if the socket isn't AF_INET6, otherwise our
comparison function
can be wrong.

Fixes: 637bc8b ("inet: reset tb->fastreuseport when adding a
reuseport sk")
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>


And reverting fixed both the standalone test case and the spice issue.

Any ideas?

Thanks,
Laura
#include <arpa/inet.h>
#include <netinet/in.h>
#include <stdbool.h>
#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

/* Reproducer for https://bugzilla.redhat.com/show_bug.cgi?id=1432684
Simply do something like: qemu-kvm -vnc 127.0.0.1:0
*/

#define PORT 5900

int check_port(int family) {
int fd = -1;
int reuseaddr = 1;
int v6only = 1;
int addrlen;
int ret = -1;
bool ipv6 = false;
struct sockaddr *addr;

struct sockaddr_in6 addr6 = {
.sin6_family = AF_INET6,
.sin6_port = htons(PORT),
.sin6_addr = in6addr_any
};
struct sockaddr_in addr4 = {
.sin_family = AF_INET,
.sin_port = htons(PORT),
.sin_addr.s_addr = htonl(INADDR_ANY)
};


if (family == AF_INET6) {
addr = (struct sockaddr*)&addr6;
addrlen = sizeof(addr6);
ipv6 = true;
} else if (family == AF_INET) {
addr = (struct sockaddr*)&addr4;
addrlen = sizeof(addr4);
} else {
printf("Unknown family\n");
goto out;
}

if ((fd = socket(family, SOCK_STREAM, 0)) < 0) {
perror("socket");
goto out;
}

if (ipv6 && setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, (void*)&v6only,
sizeof(v6only)) < 0) {
perror("setsockopt IPV6_V6ONLY");
goto out;
}

if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
&reuseaddr, sizeof(reuseaddr)) < 0) {
perror("setsockopt SO_REUSEADDR");
goto out;
}

if (bind(fd, addr, addrlen) < 0) {
perror("bind");
goto out;
}

ret = 0;
out:
close(fd);
return ret;
}

int main(void) {
#ifdef CHECK_IPV6
if (check_port(AF_INET6) < 0) {
printf("AF_INET6 check failed.\n");
return -1;
}
printf("AF_INET6 success\n");
#endif

if (check_port(AF_INET) < 0) {
printf("AF_INET check failed.\n");
return -1;
}
printf("AF_INET success\n");

return 0;
}
\
 
 \ /
  Last update: 2017-09-13 00:36    [W:0.105 / U:2.676 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site