diff options
| -rw-r--r-- | dhcp.c | 11 |
1 files changed, 11 insertions, 0 deletions
@@ -308,6 +308,17 @@ int dhcp(struct ctx *c, struct ethhdr *eh, size_t len) *(unsigned long *)opts[3].s = c->gw4; *(unsigned long *)opts[54].s = c->gw4; + /* If the gateway is not on the assigned subnet, send an option 121 + * (Classless Static Routing) adding a dummy route to it. + */ + if ((c->addr4 & c->mask4) != (c->gw4 & c->mask4)) { + /* a.b.c.d/32:0.0.0.0, 0:a.b.c.d */ + opts[121].slen = 14; + opts[121].s[0] = 32; + *(unsigned long *)&opts[121].s[1] = c->gw4; + *(unsigned long *)&opts[121].s[10] = c->gw4; + } + if (c->mtu) { opts[26].slen = 2; opts[26].s[0] = c->mtu / 256; |