diff options
Diffstat (limited to 'arp.c')
| -rw-r--r-- | arp.c | 34 |
1 files changed, 34 insertions, 0 deletions
@@ -112,3 +112,37 @@ int arp(const struct ctx *c, struct iov_tail *data) return 1; } + +/** + * arp_send_init_req() - Send initial ARP request to retrieve guest MAC address + * @c: Execution context + */ +void arp_send_init_req(const struct ctx *c) +{ + struct { + struct ethhdr eh; + struct arphdr ah; + struct arpmsg am; + } __attribute__((__packed__)) req; + + /* Ethernet header */ + req.eh.h_proto = htons(ETH_P_ARP); + memcpy(req.eh.h_dest, MAC_BROADCAST, sizeof(req.eh.h_dest)); + memcpy(req.eh.h_source, c->our_tap_mac, sizeof(req.eh.h_source)); + + /* ARP header */ + req.ah.ar_op = htons(ARPOP_REQUEST); + req.ah.ar_hrd = htons(ARPHRD_ETHER); + req.ah.ar_pro = htons(ETH_P_IP); + req.ah.ar_hln = ETH_ALEN; + req.ah.ar_pln = 4; + + /* ARP message */ + memcpy(req.am.sha, c->our_tap_mac, sizeof(req.am.sha)); + memcpy(req.am.sip, &c->ip4.our_tap_addr, sizeof(req.am.sip)); + memcpy(req.am.tha, MAC_BROADCAST, sizeof(req.am.tha)); + memcpy(req.am.tip, &c->ip4.addr, sizeof(req.am.tip)); + + debug("Sending initial ARP request for guest MAC address"); + tap_send_single(c, &req, sizeof(req)); +} |