Re: [libvirt] [PATCH] conf: Check migration_host is valid or not during libvirt restarts
On Fri, 2014-08-29 at 14:52 +0200, Jiri Denemark wrote:
On Fri, Aug 29, 2014 at 19:20:58 +0800, Chen Fan wrote:
> if user specified an invalid strings as migration hostname,
> like setting: migration_host = "XXXXXXX", libvirt should check
> it and return error during lbivirt restart.
>
> Signed-off-by: Chen Fan <chen.fan.fnst(a)cn.fujitsu.com>
> ---
> src/qemu/qemu_conf.c | 40 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 40 insertions(+)
>
> diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
> index e2ec54f..450ac5b 100644
> --- a/src/qemu/qemu_conf.c
> +++ b/src/qemu/qemu_conf.c
> @@ -33,6 +33,7 @@
> #include <fcntl.h>
> #include <sys/wait.h>
> #include <arpa/inet.h>
> +#include <netdb.h>
>
> #include "virerror.h"
> #include "qemu_conf.h"
> @@ -650,6 +651,45 @@ int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg,
> GET_VALUE_LONG("seccomp_sandbox", cfg->seccompSandbox);
>
> GET_VALUE_STR("migration_host", cfg->migrateHost);
> + if (cfg->migrateHost) {
> + struct addrinfo hints;
> + struct addrinfo *res;
> +
> + memset(&hints, 0, sizeof(hints));
> + hints.ai_flags = AI_ADDRCONFIG;
> + hints.ai_family = AF_UNSPEC;
> +
> + if (getaddrinfo(cfg->migrateHost, NULL, &hints, &res) != 0) {
> + virReportError(VIR_ERR_CONF_SYNTAX,
> + _("migration_host: '%s' is not a valid
hostname"),
> + cfg->migrateHost);
> + goto cleanup;
> + }
> +
> + if (res == NULL) {
> + virReportError(VIR_ERR_CONF_SYNTAX,
> + _("No IP address for host '%s'
found"),
> + cfg->migrateHost);
> + goto cleanup;
> + }
> +
> + freeaddrinfo(res);
I don't think this is a good idea. What if it's in fact valid and just
can't be resolved due to a temporary issue? It should only fail at the
time someone actually tries to migrate a domain.
What are these issues? usually, I think migration hosts always at the
same network, a valid hostname should be resolved by DNS. if can't be
resolved, libvirt should tell user the error at the time of libvirt
restart, Maybe we can output a warning or info to let user know that but
restart failure. what do you think?
Thanks,
Chen
> +
> + if (STRPREFIX(cfg->migrateHost, "localhost")) {
> + virReportError(VIR_ERR_CONF_SYNTAX, "%s",
> + _("setting migration_host to 'localhost' is
not allowed"));
> + goto cleanup;
> + }
> +
> + if (STREQ(cfg->migrateHost, "127.0.0.1") ||
> + STREQ(cfg->migrateHost, "::1")) {
> + virReportError(VIR_ERR_CONF_SYNTAX, "%s",
> + _("setting migration_host to '127.0.0.1' or
'::1' "
> + "is not allowed"));
> + goto cleanup;
> + }
> + }
> +
Checking for localhost could make sense.
> GET_VALUE_STR("migration_address", cfg->migrationAddress);
>
> GET_VALUE_BOOL("log_timestamp", cfg->logTimestamp);
Jirka