From 41510fba34cda98cb85a8d04e46dcfdd9a91aa61 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Thu, 24 Dec 2020 12:53:03 -0500 Subject: [PATCH 3/5] util: Introduce qemu_get_host_name() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Marc-André Lureau Message-id: <20201224125304.62697-3-marcandre.lureau@redhat.com> Patchwork-id: 100499 O-Subject: [RHEL-8.4.0 qemu-kvm PATCH 2/3] util: Introduce qemu_get_host_name() Bugzilla: 1910326 RH-Acked-by: Daniel P. Berrange RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Philippe Mathieu-Daudé From: Michal Privoznik This function offers operating system agnostic way to fetch host name. It is implemented for both POSIX-like and Windows systems. Signed-off-by: Michal Privoznik Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Daniel P. Berrangé Cc: qemu-stable@nongnu.org Signed-off-by: Michael Roth (cherry picked from commit e47f4765afcab2b78dfa5b0115abf64d1d49a5d3) Signed-off-by: Marc-André Lureau Signed-off-by: Danilo C. L. de Paula --- include/qemu/osdep.h | 10 ++++++++++ util/oslib-posix.c | 35 +++++++++++++++++++++++++++++++++++ util/oslib-win32.c | 13 +++++++++++++ 3 files changed, 58 insertions(+) diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h index 0f97d68586a..d427e81a427 100644 --- a/include/qemu/osdep.h +++ b/include/qemu/osdep.h @@ -620,4 +620,14 @@ static inline void qemu_reset_optind(void) #endif } +/** + * qemu_get_host_name: + * @errp: Error object + * + * Operating system agnostic way of querying host name. + * + * Returns allocated hostname (caller should free), NULL on failure. + */ +char *qemu_get_host_name(Error **errp); + #endif diff --git a/util/oslib-posix.c b/util/oslib-posix.c index 5a291cc9820..8f88e4dbe10 100644 --- a/util/oslib-posix.c +++ b/util/oslib-posix.c @@ -726,3 +726,38 @@ void sigaction_invoke(struct sigaction *action, } action->sa_sigaction(info->ssi_signo, &si, NULL); } + +#ifndef HOST_NAME_MAX +# ifdef _POSIX_HOST_NAME_MAX +# define HOST_NAME_MAX _POSIX_HOST_NAME_MAX +# else +# define HOST_NAME_MAX 255 +# endif +#endif + +char *qemu_get_host_name(Error **errp) +{ + long len = -1; + g_autofree char *hostname = NULL; + +#ifdef _SC_HOST_NAME_MAX + len = sysconf(_SC_HOST_NAME_MAX); +#endif /* _SC_HOST_NAME_MAX */ + + if (len < 0) { + len = HOST_NAME_MAX; + } + + /* Unfortunately, gethostname() below does not guarantee a + * NULL terminated string. Therefore, allocate one byte more + * to be sure. */ + hostname = g_new0(char, len + 1); + + if (gethostname(hostname, len) < 0) { + error_setg_errno(errp, errno, + "cannot get hostname"); + return NULL; + } + + return g_steal_pointer(&hostname); +} diff --git a/util/oslib-win32.c b/util/oslib-win32.c index e9b14ab1784..3b49d272972 100644 --- a/util/oslib-win32.c +++ b/util/oslib-win32.c @@ -808,3 +808,16 @@ bool qemu_write_pidfile(const char *filename, Error **errp) } return true; } + +char *qemu_get_host_name(Error **errp) +{ + wchar_t tmp[MAX_COMPUTERNAME_LENGTH + 1]; + DWORD size = G_N_ELEMENTS(tmp); + + if (GetComputerNameW(tmp, &size) == 0) { + error_setg_win32(errp, GetLastError(), "failed close handle"); + return NULL; + } + + return g_utf16_to_utf8(tmp, size, NULL, NULL, NULL); +} -- 2.27.0