Re: [libvirt] [PATCH] use -w flag if supported by iptables

This will properly lock libvirt's usage of iptables with others (like ufw). (See https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1245322) Signed-off-by: Serge Hallyn <serge.hallyn(a)ubuntu.com&gt; --- src/util/viriptables.c | 30 ++++++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-) diff --git a/src/util/viriptables.c b/src/util/viriptables.c index 16f571e..30d59b6 100644 --- a/src/util/viriptables.c +++ b/src/util/viriptables.c @@ -50,19 +50,25 @@ #include "virstring.h" #include "virutil.h" +bool iptables_supports_xlock = false; + #if HAVE_FIREWALLD static char *firewall_cmd_path = NULL; +#endif static int virIpTablesOnceInit(void) { + virCommandPtr cmd; + int status; + +#if HAVE_FIREWALLD firewall_cmd_path = virFindFileInPath("firewall-cmd"); if (!firewall_cmd_path) { VIR_INFO("firewall-cmd not found on system. " "firewalld support disabled for iptables."); } else { - virCommandPtr cmd = virCommandNew(firewall_cmd_path); - int status; + virCommandNew(firewall_cmd_path);

virCommandAddArgList(cmd, "--state", NULL); if (virCommandRun(cmd, &status) < 0 || status != 0) { @@ -74,13 +80,26 @@ virIpTablesOnceInit(void) } virCommandFree(cmd); } + + if (firewall_cmd_path) + return 0; + +#endif + + cmd = virCommandNew(IPTABLES_PATH); + virCommandAddArgList(cmd, "-w", "-L", "-n", NULL); + if (virCommandRun(cmd, &status) < 0 || status != 0) { + VIR_INFO("xtables locking not supported by your iptables"); + } else { + VIR_INFO("using xtables locking for iptables"); + iptables_supports_xlock = true; + } + virCommandFree(cmd); return 0; } VIR_ONCE_GLOBAL_INIT(virIpTables) -#endif - #define VIR_FROM_THIS VIR_FROM_NONE enum { @@ -104,6 +123,9 @@ iptablesCommandNew(const char *table, const char *chain, int family, int action) if (cmd == NULL) { cmd = virCommandNew((family == AF_INET6) ? IP6TABLES_PATH : IPTABLES_PATH); + + if (iptables_supports_xlock) + virCommandAddArgList(cmd, "-w", NULL); } virCommandAddArgList(cmd, "--table", table,