system-linux: do not pull ifindex/flags from netlink messages on rtnl events

rtnl event processing might be delayed due to other calls / state changes.
That can lead to devices toggled up/down unnecessarily.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/system-linux.c b/system-linux.c
index 4463a2a8282a1151cb99734d65dd57689a7fad52..5c175633272d76627d5b9fb5952a61ab03d97203 100644 (file)
--- a/system-linux.c
+++ b/system-linux.c
@@ -697,13 +697,34 @@ static int system_get_arp_accept(struct device *dev, char *buf, const size_t buf
                        dev->ifname, buf, buf_sz);
 }
 
+static int
+system_device_ifreq(struct ifreq *ifr, const char *ifname, int cmd)
+{
+       memset(ifr, 0, sizeof(*ifr));
+       strncpy(ifr->ifr_name, ifname, sizeof(ifr->ifr_name) - 1);
+       return ioctl(sock_ioctl, cmd, ifr);
+}
+
+static int system_if_get_flags(const char *ifname)
+{
+       struct ifreq ifr;
+
+       if (system_device_ifreq(&ifr, ifname, SIOCGIFFLAGS))
+               return 0;
+
+       return ifr.ifr_flags;
+}
+
 #ifndef IFF_LOWER_UP
 #define IFF_LOWER_UP   0x10000
 #endif
 
 static void
-system_device_update_state(struct device *dev, unsigned int flags, unsigned int ifindex)
+system_device_update_state(struct device *dev)
 {
+       unsigned int ifindex = system_if_resolve(dev);
+       int flags = system_if_get_flags(dev->ifname);
+
        if (dev->type == &simple_device_type) {
                if (dev->external)
                        device_set_disabled(dev, !(flags & IFF_UP));
@@ -717,7 +738,6 @@ system_device_update_state(struct device *dev, unsigned int flags, unsigned int
 static int cb_rtnl_event(struct nl_msg *msg, void *arg)
 {
        struct nlmsghdr *nh = nlmsg_hdr(msg);
-       struct ifinfomsg *ifi = NLMSG_DATA(nh);
        struct nlattr *nla[__IFLA_MAX];
        struct device *dev;
 
@@ -732,7 +752,7 @@ static int cb_rtnl_event(struct nl_msg *msg, void *arg)
        if (!dev)
                return 0;
 
-       system_device_update_state(dev, ifi->ifi_flags, ifi->ifi_index);
+       system_device_update_state(dev);
        return 0;
 }
 
@@ -1142,21 +1162,17 @@ int system_if_resolve(struct device *dev)
 {
        struct ifreq ifr;
 
-       memset(&ifr, 0, sizeof(ifr));
-       strncpy(ifr.ifr_name, dev->ifname, sizeof(ifr.ifr_name) - 1);
-       if (!ioctl(sock_ioctl, SIOCGIFINDEX, &ifr))
-               return ifr.ifr_ifindex;
-       else
+       if (system_device_ifreq(&ifr, dev->ifname, SIOCGIFINDEX))
                return 0;
+
+       return ifr.ifr_ifindex;
 }
 
 static int system_if_flags(const char *ifname, unsigned add, unsigned rem)
 {
        struct ifreq ifr;
 
-       memset(&ifr, 0, sizeof(ifr));
-       strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name) - 1);
-       if (ioctl(sock_ioctl, SIOCGIFFLAGS, &ifr) < 0)
+       if (system_device_ifreq(&ifr, ifname, SIOCGIFFLAGS))
                return -1;
 
        ifr.ifr_flags |= add;
@@ -2372,13 +2388,12 @@ struct if_check_data {
 static int cb_if_check_valid(struct nl_msg *msg, void *arg)
 {
        struct nlmsghdr *nh = nlmsg_hdr(msg);
-       struct ifinfomsg *ifi = NLMSG_DATA(nh);
        struct if_check_data *chk = (struct if_check_data *)arg;
 
        if (nh->nlmsg_type != RTM_NEWLINK)
                return NL_SKIP;
 
-       system_device_update_state(chk->dev, ifi->ifi_flags, ifi->ifi_index);
+       system_device_update_state(chk->dev);
        return NL_OK;
 }