dhcp.diff

index d8515aa..60b5365 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -291,8 +291,8 @@ int dhcp(const struct ctx *c, const struct pool *p)
        const struct ethhdr *eh;
        const struct iphdr *iph;
        const struct udphdr *uh;
+       struct msg *m, resp;
        unsigned int i;
-       struct msg *m;
 
        eh  = packet_get(p, 0, offset, sizeof(*eh),  NULL);
        offset += sizeof(*eh);
@@ -321,6 +321,8 @@ int dhcp(const struct ctx *c, const struct pool *p)
            m->op != BOOTREQUEST)
                return -1;
 
+       memcpy(&resp, m, mlen);
+
        offset += offsetof(struct msg, o);
 
        for (i = 0; i < ARRAY_SIZE(opts); i++)
@@ -362,9 +364,9 @@ int dhcp(const struct ctx *c, const struct pool *p)
                return -1;
        }
 
-       info("    from %s", eth_ntop(m->chaddr, macstr, sizeof(macstr)));
+       info("    from %s", eth_ntop(resp.chaddr, macstr, sizeof(macstr)));
 
-       m->yiaddr = c->ip4.addr;
+       resp.yiaddr = c->ip4.addr;
        mask.s_addr = htonl(0xffffffff << (32 - c->ip4.prefix_len));
        memcpy(opts[1].s,  &mask,                sizeof(mask));
        memcpy(opts[3].s,  &c->ip4.guest_gw,     sizeof(c->ip4.guest_gw));
@@ -399,16 +401,16 @@ int dhcp(const struct ctx *c, const struct pool *p)
                opts[6].slen = -1;
 
        if (!c->no_dhcp_dns_search)
-               opt_set_dns_search(c, sizeof(m->o));
+               opt_set_dns_search(c, sizeof(resp.o));
 
-       dlen = offsetof(struct msg, o) + fill(m);
+       dlen = offsetof(struct msg, o) + fill(&resp);
 
        if (m->flags & FLAG_BROADCAST)
                dst = in4addr_broadcast;
        else
                dst = c->ip4.addr;
 
-       tap_udp4_send(c, c->ip4.our_tap_addr, 67, dst, 68, m, dlen);
+       tap_udp4_send(c, c->ip4.our_tap_addr, 67, dst, 68, &resp, dlen);
 
        return 1;