On Tue, Dec 19, 2017 at 12:21:05AM +0000, Antonio Huete Jiménez wrote:
> From f57cdc7ec2d5a5e906fa8b795eeede2d7b66aa56 Mon Sep 17 00:00:00 2001
> From: Antonio Huete Jimenez <tuxi...@quantumachine.net>
> Date: Fri, 15 Dec 2017 01:08:10 +0100
> Subject: [PATCH] sockets: Fix test for DragonFly BSD
>
> DragonFly BSD does not implement AI_V4MAPPED for its getaddrinfo() so
> probe and discard that flag instead of aborting the test.
>
> Test that fails:
> ERROR:tests/test-char.c:448:char_udp_test_internal: 'chr' should not be
> NULL
>
> Signed-off-by: Antonio Huete Jimenez <tuxi...@quantumachine.net>
> ---
> util/qemu-sockets.c | 25 ++++++++++++++++++++++---
> 1 file changed, 22 insertions(+), 3 deletions(-)
>
> diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
> index af4f01211a..5a9c55c303 100644
> --- a/util/qemu-sockets.c
> +++ b/util/qemu-sockets.c
> @@ -43,6 +43,8 @@
> # define AI_NUMERICSERV 0
> #endif
>
> +int useV4Mapped = 1;
> +
>
> static int inet_getport(struct addrinfo *e)
> {
> @@ -383,7 +385,6 @@ static struct addrinfo
> *inet_parse_connect_saddr(InetSocketAddress *saddr,
> struct addrinfo ai, *res;
> int rc;
> Error *err = NULL;
> - static int useV4Mapped = 1;
>
> memset(&ai, 0, sizeof(ai));
>
> @@ -474,7 +475,11 @@ static int inet_dgram_saddr(InetSocketAddress *sraddr,
>
> /* lookup peer addr */
> memset(&ai,0, sizeof(ai));
> - ai.ai_flags = AI_CANONNAME | AI_V4MAPPED | AI_ADDRCONFIG;
> + ai.ai_flags = AI_CANONNAME | AI_ADDRCONFIG;
> + if (atomic_read(&useV4Mapped)) {
> + ai.ai_flags |= AI_V4MAPPED;
> + }
> +
> ai.ai_family = inet_ai_family_from_address(sraddr, &err);
> ai.ai_socktype = SOCK_DGRAM;
>
> @@ -493,7 +498,21 @@ static int inet_dgram_saddr(InetSocketAddress *sraddr,
> goto err;
> }
>
> - if ((rc = getaddrinfo(addr, port, &ai, &peer)) != 0) {
> + /* lookup */
> + rc = getaddrinfo(addr, port, &ai, &peer);
> +
> + /* At least FreeBSD and OS-X 10.6 declare AI_V4MAPPED but
> + * then don't implement it in their getaddrinfo(). Detect
> + * this and retry without the flag since that's preferrable
> + * to a fatal error
> + */
> + if (rc == EAI_BADFLAGS &&
> + (ai.ai_flags & AI_V4MAPPED)) {
> + atomic_set(&useV4Mapped, 0);
> + ai.ai_flags &= ~AI_V4MAPPED;
> + rc = getaddrinfo(addr, port, &ai, &peer);
> + }
Rather than duplicating this repeated calls to getaddrinfo in multiple
methods, I think it would be better to define a wrapper method. ie
create a 'qemu_getaddrinfo()' method in this file that does the magic
re-try without AI_V4MAPPED. Export it in include/qemu/sockets.h too.
Then call that from all places in QEMU that currently use getaddrinfo()
directly - there are 5 in this file, another in io/dns-resolver.c,
and some more in net/ & test/. That way we are't going to mistakely
reintroduce the bug in other places later.
We should probably also move the #ifdef AI_* code into qemu/sockets.h
too, so we can remove the duplication in test suites.
Regards,
Daniel
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