Add mtu6 option to override IPv6 MTU

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

diff --git a/system-linux.c b/system-linux.c
index 6dc9acd..b44eb76 100644 (file)
--- a/system-linux.c
+++ b/system-linux.c
@@ -1019,6 +1019,10 @@ system_if_get_settings(struct device *dev, struct device_settings *s)
                s->flags |= DEV_OPT_MTU;
        }
 
+       s->mtu6 = system_update_ipv6_mtu(dev, 0);
+       if (s->mtu6 > 0)
+               s->flags |= DEV_OPT_MTU6;
+
        if (ioctl(sock_ioctl, SIOCGIFTXQLEN, &ifr) == 0) {
                s->txqueuelen = ifr.ifr_qlen;
                s->flags |= DEV_OPT_TXQUEUELEN;
@@ -1114,6 +1118,9 @@ system_if_apply_settings(struct device *dev, struct device_settings *s, unsigned
                if (ioctl(sock_ioctl, SIOCSIFMTU, &ifr) < 0)
                        s->flags &= ~DEV_OPT_MTU;
        }
+       if (s->flags & DEV_OPT_MTU6 & apply_mask) {
+               system_update_ipv6_mtu(dev, s->mtu6);
+       }
        if (s->flags & DEV_OPT_TXQUEUELEN & apply_mask) {
                ifr.ifr_qlen = s->txqueuelen;
                if (ioctl(sock_ioctl, SIOCSIFTXQLEN, &ifr) < 0)
@@ -2163,19 +2170,18 @@ int system_update_ipv6_mtu(struct device *dev, int mtu)
                        dev->ifname);
 
        int fd = open(buf, O_RDWR);
-       ssize_t len = read(fd, buf, sizeof(buf) - 1);
-       if (len < 0)
-               goto out;
 
-       buf[len] = 0;
-       ret = atoi(buf);
+       if (!mtu) {
+               ssize_t len = read(fd, buf, sizeof(buf) - 1);
+               if (len < 0)
+                       goto out;
 
-       if (!mtu || ret <= mtu)
-               goto out;
-
-       lseek(fd, 0, SEEK_SET);
-       if (write(fd, buf, snprintf(buf, sizeof(buf), "%i", mtu)) <= 0)
-               ret = -1;
+               buf[len] = 0;
+               ret = atoi(buf);
+       } else {
+               if (write(fd, buf, snprintf(buf, sizeof(buf), "%i", mtu)) > 0)
+                       ret = mtu;
+       }
 
 out:
        close(fd);