static rlm_rcode_t arp_process(REQUEST *request)
{
CONF_SECTION *unlang;
request->server_cs = request->listener->server_cs;
unlang = cf_section_find(request->server_cs, "arp", NULL);
request->component = "arp";
return unlang_interpret(request, unlang, RLM_MODULE_NOOP);
}
static rlm_rcode_t dhcp_process(REQUEST *request)
{
rlm_rcode_t rcode;
unsigned int i;
VALUE_PAIR *vp;
dhcp_socket_t *sock;
/*
* If there's a giaddr, save it as the Relay-IP-Address
* in the response. That way the later code knows where
* to send the reply.
*/
vp = fr_pair_find_by_num(request->packet->vps, DHCP_MAGIC_VENDOR, 266, TAG_ANY); /* DHCP-Gateway-IP-Address */
if (vp && (vp->vp_ipv4addr != htonl(INADDR_ANY))) {
VALUE_PAIR *relay;
/* DHCP-Relay-IP-Address */
MEM(relay = fr_pair_afrom_num(request->reply, DHCP_MAGIC_VENDOR, 222));
relay->vp_ipv4addr = vp->vp_ipv4addr;
fr_pair_add(&request->reply->vps, relay);
}
vp = fr_pair_find_by_num(request->packet->vps, DHCP_MAGIC_VENDOR, 53, TAG_ANY); /* DHCP-Message-Type */
if (vp) {
fr_dict_enum_t *dv = fr_dict_enum_by_value(vp->da, &vp->data);
if (dv) {
CONF_SECTION *server, *unlang;
RDEBUG("Trying sub-section dhcp %s {...}", dv->alias);
server = cf_item_to_section(cf_parent(request->listener->cs));
unlang = cf_section_find(server, "dhcp", dv->alias);
rcode = unlang_interpret(request, unlang, RLM_MODULE_NOOP);
} else {
REDEBUG("Unknown DHCP-Message-Type %d", vp->vp_uint8);
rcode = RLM_MODULE_FAIL;
}
} else {
REDEBUG("Failed to find DHCP-Message-Type in packet!");
rcode = RLM_MODULE_FAIL;
}
vp = fr_pair_find_by_num(request->reply->vps, DHCP_MAGIC_VENDOR, 53, TAG_ANY); /* DHCP-Message-Type */
if (vp) {
request->reply->code = vp->vp_uint8;
}
else switch (rcode) {
case RLM_MODULE_OK:
case RLM_MODULE_UPDATED:
if (request->packet->code == FR_DHCP_DISCOVER) {
request->reply->code = FR_DHCP_OFFER;
break;
} else if (request->packet->code == FR_DHCP_REQUEST) {
request->reply->code = FR_DHCP_ACK;
break;
}
request->reply->code = FR_DHCP_NAK;
break;
default:
case RLM_MODULE_REJECT:
case RLM_MODULE_FAIL:
case RLM_MODULE_INVALID:
case RLM_MODULE_NOOP:
case RLM_MODULE_NOTFOUND:
if (request->packet->code == FR_DHCP_DISCOVER) {
request->reply->code = 0; /* ignore the packet */
} else {
request->reply->code = FR_DHCP_NAK;
}
break;
case RLM_MODULE_HANDLED:
request->reply->code = 0; /* ignore the packet */
break;
}
/*
* TODO: Handle 'output' of RLM_MODULE when acting as a
* DHCP relay We may want to not forward packets in
* certain circumstances.
*/
/*
* Handle requests when acting as a DHCP relay
*/
vp = fr_pair_find_by_num(request->packet->vps, DHCP_MAGIC_VENDOR, 256, TAG_ANY); /* DHCP-Opcode */
if (!vp) {
RPEDEBUG("Someone deleted the DHCP-Opcode!");
return RLM_MODULE_FAIL;
}
/* BOOTREPLY received on port 67 (i.e. from a server) */
if (vp->vp_uint8 == 2) {
return dhcprelay_process_server_reply(request);
}
/* Packet from client, and we have DHCP-Relay-To-IP-Address */
if (fr_pair_find_by_num(request->control, DHCP_MAGIC_VENDOR, 270, TAG_ANY)) {
return dhcprelay_process_client_request(request);
}
/* else it's a packet from a client, without relaying */
rad_assert(vp->vp_uint8 == 1); /* BOOTREQUEST */
sock = request->listener->data;
/*
* Handle requests when acting as a DHCP server
*/
/*
* Releases don't get replies.
*/
if (request->packet->code == FR_DHCP_RELEASE) {
request->reply->code = 0;
}
if (request->reply->code == 0) {
return RLM_MODULE_OK;
}
request->reply->sockfd = request->packet->sockfd;
/*
* Copy specific fields from packet to reply, if they
* don't already exist
*/
for (i = 0; i < sizeof(attrnums) / sizeof(attrnums[0]); i++) {
uint32_t attr = attrnums[i];
if (fr_pair_find_by_num(request->reply->vps, DHCP_MAGIC_VENDOR, attr, TAG_ANY)) continue;
vp = fr_pair_find_by_num(request->packet->vps, DHCP_MAGIC_VENDOR, attr, TAG_ANY);
if (vp) {
fr_pair_add(&request->reply->vps, fr_pair_copy(request->reply, vp));
}
}
vp = fr_pair_find_by_num(request->reply->vps, DHCP_MAGIC_VENDOR, 256, TAG_ANY); /* DHCP-Opcode */
rad_assert(vp != NULL);
vp->vp_uint8 = 2; /* BOOTREPLY */
/*
* Allow NAKs to be delayed for a short period of time.
*/
if (request->reply->code == FR_DHCP_NAK) {
vp = fr_pair_find_by_num(request->reply->vps, 0, FR_FREERADIUS_RESPONSE_DELAY, TAG_ANY);
if (vp) {
if (vp->vp_uint32 <= 10) {
request->response_delay.tv_sec = vp->vp_uint32;
request->response_delay.tv_usec = 0;
} else {
request->response_delay.tv_sec = 10;
request->response_delay.tv_usec = 0;
}
} else {
#ifndef USEC
#define USEC 1000000
#endif
vp = fr_pair_find_by_num(request->reply->vps, 0, FR_FREERADIUS_RESPONSE_DELAY_USEC, TAG_ANY);
if (vp) {
if (vp->vp_uint32 <= 10 * USEC) {
request->response_delay.tv_sec = vp->vp_uint32 / USEC;
request->response_delay.tv_usec = vp->vp_uint32 % USEC;
} else {
request->response_delay.tv_sec = 10;
request->response_delay.tv_usec = 0;
}
}
}
}
/*
* Prepare the reply packet for sending through dhcp_socket_send()
*/
request->reply->dst_ipaddr.af = AF_INET;
request->reply->src_ipaddr.af = AF_INET;
request->reply->src_ipaddr.prefix = 32;
/*
* Packet-Src-IP-Address has highest precedence
*/
vp = fr_pair_find_by_num(request->reply->vps, 0, FR_PACKET_SRC_IP_ADDRESS, TAG_ANY);
if (vp) {
request->reply->if_index = 0; /* Must be 0, we don't know the outbound if_index */
request->reply->src_ipaddr.addr.v4.s_addr = vp->vp_ipv4addr;
/*
* The request was unicast (via a relay)
*/
} else if (request->packet->dst_ipaddr.addr.v4.s_addr != htonl(INADDR_BROADCAST) &&
request->packet->dst_ipaddr.addr.v4.s_addr != htonl(INADDR_ANY)) {
request->reply->src_ipaddr.addr.v4.s_addr = request->packet->dst_ipaddr.addr.v4.s_addr;
request->reply->if_index = request->packet->if_index;
/*
* The listener was bound to an IP address, or we determined
* the address automatically, as it was the only address bound
* to the interface, and we bound to the interface.
*/
} else if (sock->src_ipaddr.addr.v4.s_addr != htonl(INADDR_ANY)) {
request->reply->src_ipaddr.addr.v4.s_addr = sock->src_ipaddr.addr.v4.s_addr;
#ifdef WITH_IFINDEX_IPADDR_RESOLUTION
/*
* We built with udpfromto and have the if_index of the receiving
* interface, which we can now resolve to an IP address.
*/
} else if (request->packet->if_index > 0) {
fr_ipaddr_t primary;
if (fr_ipaddr_from_ifindex(&primary, request->packet->sockfd, request->packet->dst_ipaddr.af,
request->packet->if_index) < 0) {
RPEDEBUG("Failed determining src_ipaddr from if_index");
return RLM_MODULE_FAIL;
}
request->reply->src_ipaddr.addr.v4.s_addr = primary.addr.v4.s_addr;
#endif
/*
* There's a Server-Identification attribute
*/
} else if ((vp = fr_pair_find_by_num(request->reply->vps, DHCP_MAGIC_VENDOR, 54, TAG_ANY))) {
request->reply->src_ipaddr.addr.v4.s_addr = vp->vp_ipv4addr;
} else {
REDEBUG("Unable to determine correct src_ipaddr for response");
return RLM_MODULE_FAIL;
}
request->reply->dst_port = request->packet->src_port;
request->reply->src_port = request->packet->dst_port;
/*
* Answer to client's nearest DHCP relay.
*
* Which may be different than the giaddr given in the
* packet to the client. i.e. the relay may have a
* public IP, but the gateway a private one.
*/
vp = fr_pair_find_by_num(request->reply->vps, DHCP_MAGIC_VENDOR, 272, TAG_ANY); /* DHCP-Relay-IP-Address */
if (vp && (vp->vp_ipv4addr != ntohl(INADDR_ANY))) {
RDEBUG2("Reply will be unicast to giaddr from original packet");
request->reply->dst_ipaddr.addr.v4.s_addr = vp->vp_ipv4addr;
request->reply->dst_port = request->packet->dst_port;
vp = fr_pair_find_by_num(request->reply->vps, 0, FR_PACKET_DST_PORT, TAG_ANY);
if (vp) request->reply->dst_port = vp->vp_uint16;
return RLM_MODULE_OK;
}
/*
* Answer to client's nearest DHCP gateway. In this
* case, the client can reach the gateway, as can the
* server.
*
* We also use *our* source port as the destination port.
* Gateways are servers, and listen on the server port,
* not the client port.
*/
vp = fr_pair_find_by_num(request->reply->vps, DHCP_MAGIC_VENDOR, 266, TAG_ANY); /* DHCP-Gateway-IP-Address */
if (vp && (vp->vp_ipv4addr != htonl(INADDR_ANY))) {
RDEBUG2("Reply will be unicast to giaddr");
request->reply->dst_ipaddr.addr.v4.s_addr = vp->vp_ipv4addr;
request->reply->dst_port = request->packet->dst_port;
return RLM_MODULE_OK;
}
/*
* If it's a NAK, or the broadcast flag was set, ond
* there's no client-ip-address, send a broadcast.
*/
if ((request->reply->code == FR_DHCP_NAK) ||
((vp = fr_pair_find_by_num(request->reply->vps, DHCP_MAGIC_VENDOR, 262, TAG_ANY)) && /* DHCP-Flags */
(vp->vp_uint32 & 0x8000) &&
((vp = fr_pair_find_by_num(request->reply->vps, DHCP_MAGIC_VENDOR, 263, TAG_ANY)) && /* DHCP-Client-IP-Address */
(vp->vp_ipv4addr == htonl(INADDR_ANY))))) {
/*
* RFC 2131, page 23
*
* Broadcast on
* - DHCPNAK
* or
* - Broadcast flag is set up and ciaddr == NULL
*/
RDEBUG2("Reply will be broadcast");
request->reply->dst_ipaddr.addr.v4.s_addr = htonl(INADDR_BROADCAST);
return RLM_MODULE_OK;
}
/*
* RFC 2131, page 23
*
* Unicast to ciaddr if present, otherwise to yiaddr.
*/
if ((vp = fr_pair_find_by_num(request->reply->vps, DHCP_MAGIC_VENDOR, 263, TAG_ANY)) && /* DHCP-Client-IP-Address */
(vp->vp_ipv4addr != htonl(INADDR_ANY))) {
RDEBUG2("Reply will be sent unicast to &DHCP-Client-IP-Address");
request->reply->dst_ipaddr.addr.v4.s_addr = vp->vp_ipv4addr;
return RLM_MODULE_OK;
}
vp = fr_pair_find_by_num(request->reply->vps, DHCP_MAGIC_VENDOR, 264, TAG_ANY); /* DHCP-Your-IP-Address */
if (!vp) {
REDEBUG("Can't assign address to client: Neither &reply:DHCP-Client-IP-Address nor "
"&reply:DHCP-Your-IP-Address set");
/*
* There is nowhere to send the response to, so don't bother.
*/
request->reply->code = 0;
return RLM_MODULE_FAIL;
}
#ifdef SIOCSARP
/*
* The system is configured to listen for broadcast
* packets, which means we'll need to send unicast
* replies, to IPs which haven't yet been assigned.
* Therefore, we need to update the ARP table.
*
* However, they haven't specified a interface. So we
* can't update the ARP table. And we must send a
* broadcast response.
*/
if (sock->lsock.broadcast && !sock->src_interface) {
WARN("You MUST set \"interface\" if you have \"broadcast = yes\"");
RDEBUG2("Reply will be broadcast as no interface was defined");
request->reply->dst_ipaddr.addr.v4.s_addr = htonl(INADDR_BROADCAST);
return RLM_MODULE_OK;
}
RDEBUG2("Reply will be unicast to &DHCP-Your-IP-Address");
request->reply->dst_ipaddr.addr.v4.s_addr = vp->vp_ipv4addr;
/*
* When sending a DHCP_OFFER, make sure our ARP table
* contains an entry for the client IP address.
* Otherwise the packet may not be sent to the client, as
* the OS has no ARP entry for it.
*
* This is a cute hack to avoid us having to create a raw
* socket to send DHCP packets.
*/
if (request->reply->code == FR_DHCP_OFFER) {
VALUE_PAIR *hwvp = fr_pair_find_by_num(request->reply->vps, DHCP_MAGIC_VENDOR, 267, TAG_ANY); /* DHCP-Client-Hardware-Address */
if (!hwvp) return RLM_MODULE_FAIL;
if (fr_dhcpv4_udp_add_arp_entry(request->reply->sockfd, sock->src_interface,
&vp->vp_ip, hwvp->vp_ether) < 0) {
RPEDEBUG("Failed adding arp entry");
return RLM_MODULE_FAIL;
}
}
#else
if (request->packet->src_ipaddr.addr.v4.s_addr != ntohl(INADDR_NONE)) {
RDEBUG2("Reply will be unicast to the unicast source IP address");
request->reply->dst_ipaddr.addr.v4.s_addr = request->packet->src_ipaddr.addr.v4.s_addr;
} else {
RDEBUG2("Reply will be broadcast as this system does not support ARP updates");
request->reply->dst_ipaddr.addr.v4.s_addr = htonl(INADDR_BROADCAST);
}
#endif
return RLM_MODULE_OK;
}
