Re: [libvirt] [PATCH] systemd: directly notify systemd instead of using sd_notify

On Mon, Jun 06, 2016 at 15:16:50 +0100, Daniel Berrange wrote: > The sd_notify method is used to tell systemd when libvirtd > has finished starting up. All it does is send a datagram > containing the string parameter to systemd on a UNIX socket > named in the NOTIFY_SOCKET environment variable. Rather than > pulling in the systemd libraries for this, just code the > notification directly in libvirt as this is a stable ABI > from systemd's POV which explicitly allows independant > implementations: > > See "Reimplementable Independently" column in the > "$NOTIFY_SOCKET Daemon Notifications" row: > > https://www.freedesktop.org/wiki/Software/systemd/InterfacePortabilityAnd... > > Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; > --- > configure.ac | 2 -- > libvirt.spec.in | 12 ----------- > m4/virt-systemd-daemon.m4 | 34 ------------------------------- > src/Makefile.am | 4 ++-- > src/util/virsystemd.c | 52 ++++++++++++++++++++++++++++++++++++++++++----- > 5 files changed, 49 insertions(+), 55 deletions(-) > delete mode 100644 m4/virt-systemd-daemon.m4 [...] > diff --git a/src/util/virsystemd.c b/src/util/virsystemd.c > index 4883f94..71b8f33 100644 > --- a/src/util/virsystemd.c > +++ b/src/util/virsystemd.c [...] > @@ -480,9 +482,49 @@ int virSystemdTerminateMachine(const char *name) > void > virSystemdNotifyStartup(void) > { > -#ifdef WITH_SYSTEMD_DAEMON > - sd_notify(0, "READY=1"); > -#endif > +#ifdef HAVE_SYS_UN_H > + const char *path; > + const char *msg = "READY=1"; > + int fd; > + struct sockaddr_un un = { > + .sun_family = AF_UNIX, > + }; > + struct iovec iov = { > + .iov_base = (char *)msg, > + .iov_len = strlen(msg), > + }; > + struct msghdr mh = { > + .msg_name = &un, > + .msg_namelen = sizeof(un), > + .msg_iov = &iov, > + .msg_iovlen = 1, > + }; > + > + if (!(path = virGetEnvBlockSUID("NOTIFY_SOCKET"))) { > + VIR_DEBUG("Skipping systemd notify, not requested"); > + return; > + } > + > + if (strlen(path) > sizeof(un.sun_path)) { Off-by-one by not considering the trailing \0

> + VIR_WARN("Systemd notify socket path '%s' too long", path); > + return; > + } ACK