[newlib-cygwin] Cygwin: getaddrinfo: return valid ai_socktype and ai_protocol values
Corinna Vinschen
corinna@sourceware.org
Fri Jul 30 10:40:51 GMT 2021
https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=582c7f9664c54266deae94771f84cc3b405fbae1
commit 582c7f9664c54266deae94771f84cc3b405fbae1
Author: Corinna Vinschen <corinna@vinschen.de>
Date: Fri Jul 30 12:40:35 2021 +0200
Cygwin: getaddrinfo: return valid ai_socktype and ai_protocol values
If a service is supported as TCP and UDP service, GetAddrInfo does not
return two entries, one for TCP, one for UDP, as on Linux. Rather, it
just returns a single entry with ai_socktype and ai_protocol set to 0.
If the service only exists as TCP or UDP service, then ai->ai_socktype
is set, but ai_protocol isn't.
Fortunately we copy over the result from Windows into local storage
anyway, so this patch adds code to fix up the fields neglected by
Windows. In case ai_socktype as well as ai_protocol are 0, duplicate
the entry with valid values for ai_socktype and ai_protocol.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
Diff:
---
winsup/cygwin/net.cc | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 50 insertions(+), 2 deletions(-)
diff --git a/winsup/cygwin/net.cc b/winsup/cygwin/net.cc
index 5bdc8709f..9ff155c22 100644
--- a/winsup/cygwin/net.cc
+++ b/winsup/cygwin/net.cc
@@ -2910,14 +2910,62 @@ ga_duplist (struct addrinfoW *ai, bool v4mapped, int idn_flags, int &err)
{
struct addrinfo *tmp, *nai = NULL, *nai0 = NULL;
- for (; ai; ai = ai->ai_next, nai = tmp)
- {
+ for (; ai; ai = ai->ai_next)
+ {
+ /* Workaround for a Windows weirdness. If a service is supported as
+ TCP and UDP service, GetAddrInfo does not return two entries, one
+ for TCP, one for UDP, as on Linux. Rather, it just returns a single
+ entry with ai_socktype and ai_protocol set to 0, kind of like a
+ placeholder. If the service only exists as TCP or UDP service, then
+ ai->ai_socktype is set, but ai_protocol isn't. Fix up the fields,
+ and in case ai_socktype and ai_protocol are 0 duplicate the entry
+ with valid values for ai_socktype and ai_protocol. */
+ switch (ai->ai_socktype)
+ {
+ case SOCK_STREAM:
+ if (ai->ai_protocol == 0)
+ ai->ai_protocol = IPPROTO_TCP;
+ break;
+ case SOCK_DGRAM:
+ if (ai->ai_protocol == 0)
+ ai->ai_protocol = IPPROTO_UDP;
+ break;
+ case 0:
+ switch (ai->ai_protocol)
+ {
+ case IPPROTO_TCP:
+ ai->ai_socktype = SOCK_STREAM;
+ break;
+ case IPPROTO_UDP:
+ ai->ai_socktype = SOCK_DGRAM;
+ break;
+ case 0:
+ ai->ai_socktype = SOCK_STREAM;
+ ai->ai_protocol = IPPROTO_TCP;
+ if (!(tmp = ga_dup (ai, v4mapped, idn_flags, err)))
+ goto bad;
+ if (!nai0)
+ nai0 = tmp;
+ if (nai)
+ nai->ai_next = tmp;
+ nai = tmp;
+ ai->ai_socktype = SOCK_DGRAM;
+ ai->ai_protocol = IPPROTO_UDP;
+ break;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
if (!(tmp = ga_dup (ai, v4mapped, idn_flags, err)))
goto bad;
if (!nai0)
nai0 = tmp;
if (nai)
nai->ai_next = tmp;
+ nai = tmp;
}
return nai0;
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