netifd: Add interface config support to enable/disable IPv6 in the kernel per device

[project/netifd.git] / system-linux.c

diff --git a/system-linux.c b/system-linux.c
index 12682dc..8f46705 100644 (file)
--- a/system-linux.c
+++ b/system-linux.c
@@ -211,6 +211,40 @@ static void system_set_disable_ipv6(struct device *dev, const char *val)
        system_set_dev_sysctl("/proc/sys/net/ipv6/conf/%s/disable_ipv6", dev->ifname, val);
 }
 
+static int system_get_sysctl(const char *path, char *buf, const size_t buf_sz)
+{
+       int fd = -1, ret = -1;
+
+       fd = open(path, O_RDONLY);
+       if (fd < 0)
+               goto out;
+
+       ssize_t len = read(fd, buf, buf_sz - 1);
+       if (len < 0)
+               goto out;
+
+       ret = buf[len] = 0;
+
+out:
+       if (fd >= 0)
+               close(fd);
+
+       return ret;
+}
+
+static int
+system_get_dev_sysctl(const char *path, const char *device, char *buf, const size_t buf_sz)
+{
+       snprintf(dev_buf, sizeof(dev_buf), path, device);
+       return system_get_sysctl(dev_buf, buf, buf_sz);
+}
+
+static int system_get_disable_ipv6(struct device *dev, char *buf, const size_t buf_sz)
+{
+       return system_get_dev_sysctl("/proc/sys/net/ipv6/conf/%s/disable_ipv6",
+                       dev->ifname, buf, buf_sz);
+}
+
 #ifndef IFF_LOWER_UP
 #define IFF_LOWER_UP   0x10000
 #endif
@@ -380,7 +414,6 @@ int system_bridge_addif(struct device *bridge, struct device *dev)
 {
        char *oldbr;
 
-       system_set_disable_ipv6(dev, "1");
        oldbr = system_get_bridge(dev->ifname, dev_buf, sizeof(dev_buf));
        if (oldbr && !strcmp(oldbr, bridge->ifname))
                return 0;
@@ -390,7 +423,6 @@ int system_bridge_addif(struct device *bridge, struct device *dev)
 
 int system_bridge_delif(struct device *bridge, struct device *dev)
 {
-       system_set_disable_ipv6(dev, "0");
        return system_bridge_if(bridge->ifname, dev, SIOCBRDELIF, NULL);
 }
 
@@ -777,6 +809,7 @@ static void
 system_if_get_settings(struct device *dev, struct device_settings *s)
 {
        struct ifreq ifr;
+       char buf[10];
 
        memset(&ifr, 0, sizeof(ifr));
        strncpy(ifr.ifr_name, dev->ifname, sizeof(ifr.ifr_name));
@@ -795,37 +828,47 @@ system_if_get_settings(struct device *dev, struct device_settings *s)
                memcpy(s->macaddr, &ifr.ifr_hwaddr.sa_data, sizeof(s->macaddr));
                s->flags |= DEV_OPT_MACADDR;
        }
+
+       if (!system_get_disable_ipv6(dev, buf, sizeof(buf))) {
+               s->ipv6 = !strtoul(buf, NULL, 0);
+               s->flags |= DEV_OPT_IPV6;
+       }
 }
 
 void
-system_if_apply_settings(struct device *dev, struct device_settings *s)
+system_if_apply_settings(struct device *dev, struct device_settings *s, unsigned int apply_mask)
 {
        struct ifreq ifr;
 
+       if (!apply_mask)
+               return;
+
        memset(&ifr, 0, sizeof(ifr));
        strncpy(ifr.ifr_name, dev->ifname, sizeof(ifr.ifr_name));
-       if (s->flags & DEV_OPT_MTU) {
+       if (s->flags & DEV_OPT_MTU & apply_mask) {
                ifr.ifr_mtu = s->mtu;
                if (ioctl(sock_ioctl, SIOCSIFMTU, &ifr) < 0)
                        s->flags &= ~DEV_OPT_MTU;
        }
-       if (s->flags & DEV_OPT_TXQUEUELEN) {
+       if (s->flags & DEV_OPT_TXQUEUELEN & apply_mask) {
                ifr.ifr_qlen = s->txqueuelen;
                if (ioctl(sock_ioctl, SIOCSIFTXQLEN, &ifr) < 0)
                        s->flags &= ~DEV_OPT_TXQUEUELEN;
        }
-       if ((s->flags & DEV_OPT_MACADDR) && !dev->external) {
+       if ((s->flags & DEV_OPT_MACADDR & apply_mask) && !dev->external) {
                ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER;
                memcpy(&ifr.ifr_hwaddr.sa_data, s->macaddr, sizeof(s->macaddr));
                if (ioctl(sock_ioctl, SIOCSIFHWADDR, &ifr) < 0)
                        s->flags &= ~DEV_OPT_MACADDR;
        }
+       if (s->flags & DEV_OPT_IPV6 & apply_mask)
+               system_set_disable_ipv6(dev, s->ipv6 ? "0" : "1");
 }
 
 int system_if_up(struct device *dev)
 {
        system_if_get_settings(dev, &dev->orig_settings);
-       system_if_apply_settings(dev, &dev->settings);
+       system_if_apply_settings(dev, &dev->settings, dev->settings.flags);
        device_set_ifindex(dev, system_if_resolve(dev));
        return system_if_flags(dev->ifname, IFF_UP, 0);
 }
@@ -834,7 +877,7 @@ int system_if_down(struct device *dev)
 {
        int ret = system_if_flags(dev->ifname, 0, IFF_UP);
        dev->orig_settings.flags &= dev->settings.flags;
-       system_if_apply_settings(dev, &dev->orig_settings);
+       system_if_apply_settings(dev, &dev->orig_settings, dev->orig_settings.flags);
        return ret;
 }