dhclient.c

DHCP服务器源码

	/* Allocate space for options. */
	option_state_allocate (op, MDL);

	/* Send the server identifier if provided. */
	if (sid)
		save_option (&dhcp_universe, *op, sid);

	oc = (struct option_cache *)0;

	/* Send the requested address if provided. */
	if (rip) {
		client -> requested_address = *rip;
		if (!(make_const_option_cache
		      (&oc, (struct buffer **)0, rip -> iabuf, rip -> len,
		       &dhcp_options [DHO_DHCP_REQUESTED_ADDRESS], MDL)))
			log_error ("can't make requested address cache.");
		else {
			save_option (&dhcp_universe, *op, oc);
			option_cache_dereference (&oc, MDL);
		}
	} else {
		client -> requested_address.len = 0;
	}

	if (!(make_const_option_cache
	      (&oc, (struct buffer **)0,
	       type, 1, &dhcp_options [DHO_DHCP_MESSAGE_TYPE], MDL)))
		log_error ("can't make message type.");
	else {
		save_option (&dhcp_universe, *op, oc);
		option_cache_dereference (&oc, MDL);
	}

	if (prl) {
		/* Figure out how many parameters were requested. */
		for (i = 0; prl [i]; i++)
			;
		if (!buffer_allocate (&bp, i, MDL))
			log_error ("can't make parameter list buffer.");
		else {
			for (i = 0; prl [i]; i++)
				bp -> data [i] = prl [i];
			if (!(make_const_option_cache
			      (&oc, &bp, (u_int8_t *)0, i,
			       &dhcp_options [DHO_DHCP_PARAMETER_REQUEST_LIST],
			       MDL)))
				log_error ("can't make option cache");
			else {
				save_option (&dhcp_universe, *op, oc);
				option_cache_dereference (&oc, MDL);
			}
		}
	}

	/* Run statements that need to be run on transmission. */
	if (client -> config -> on_transmission)
		execute_statements_in_scope
			((struct binding_value **)0,
			 (struct packet *)0, (struct lease *)0, client,
			 (lease ? lease -> options : (struct option_state *)0),
			 *op, &global_scope,
			 client -> config -> on_transmission,
			 (struct group *)0);
}

void make_discover (client, lease)
	struct client_state *client;
	struct client_lease *lease;
{
	unsigned char discover = DHCPDISCOVER;
	int i;
	struct option_state *options = (struct option_state *)0;

	memset (&client -> packet, 0, sizeof (client -> packet));

	make_client_options (client,
			     lease, &discover, (struct option_cache *)0,
			     lease ? &lease -> address : (struct iaddr *)0,
			     client -> config -> requested_options,
			     &options);

	/* Set up the option buffer... */
	client -> packet_length =
		cons_options ((struct packet *)0, &client -> packet,
			      (struct lease *)0, client,
			      /* maximum packet size */1500,
			      (struct option_state *)0,
			      options,
			      /* scope */ &global_scope,
			      /* overload */ 0,
			      /* terminate */0,
			      /* bootpp    */0,
			      (struct data_string *)0,
			      client -> config -> vendor_space_name);

	option_state_dereference (&options, MDL);
	if (client -> packet_length < BOOTP_MIN_LEN)
		client -> packet_length = BOOTP_MIN_LEN;

	client -> packet.op = BOOTREQUEST;
	client -> packet.htype = client -> interface -> hw_address.hbuf [0];
	client -> packet.hlen = client -> interface -> hw_address.hlen - 1;
	client -> packet.hops = 0;
	client -> packet.xid = random ();
	client -> packet.secs = 0; /* filled in by send_discover. */

	if (can_receive_unicast_unconfigured (client -> interface))
		client -> packet.flags = 0;
	else
		client -> packet.flags = htons (BOOTP_BROADCAST);

	memset (&(client -> packet.ciaddr),
		0, sizeof client -> packet.ciaddr);
	memset (&(client -> packet.yiaddr),
		0, sizeof client -> packet.yiaddr);
	memset (&(client -> packet.siaddr),
		0, sizeof client -> packet.siaddr);
	client -> packet.giaddr = giaddr;
	if (client -> interface -> hw_address.hlen > 0)
	    memcpy (client -> packet.chaddr,
		    &client -> interface -> hw_address.hbuf [1],
		    (unsigned)(client -> interface -> hw_address.hlen - 1));

#ifdef DEBUG_PACKET
	dump_raw ((unsigned char *)&client -> packet, client -> packet_length);
#endif
}


void make_request (client, lease)
	struct client_state *client;
	struct client_lease *lease;
{
	unsigned char request = DHCPREQUEST;
	int i, j;
	unsigned char *tmp, *digest;
	unsigned char *old_digest_loc;
	struct option_cache *oc;

	memset (&client -> packet, 0, sizeof (client -> packet));

	if (client -> state == S_REQUESTING)
		oc = lookup_option (&dhcp_universe, lease -> options,
				    DHO_DHCP_SERVER_IDENTIFIER);
	else
		oc = (struct option_cache *)0;

	make_client_options (client, lease, &request, oc,
			     ((client -> state == S_REQUESTING ||
			       client -> state == S_REBOOTING)
			      ? &lease -> address
			      : (struct iaddr *)0),
			     client -> config -> requested_options,
			     &client -> sent_options);

	/* Set up the option buffer... */
	client -> packet_length =
		cons_options ((struct packet *)0, &client -> packet,
			      (struct lease *)0, client,
			      /* maximum packet size */1500,
			      (struct option_state *)0,
			      client -> sent_options, 
			      /* scope */ &global_scope,
			      /* overload */ 0,
			      /* terminate */0,
			      /* bootpp    */0,
			      (struct data_string *)0,
			      client -> config -> vendor_space_name);

	option_state_dereference (&client -> sent_options, MDL);
	if (client -> packet_length < BOOTP_MIN_LEN)
		client -> packet_length = BOOTP_MIN_LEN;

	client -> packet.op = BOOTREQUEST;
	client -> packet.htype = client -> interface -> hw_address.hbuf [0];
	client -> packet.hlen = client -> interface -> hw_address.hlen - 1;
	client -> packet.hops = 0;
	client -> packet.xid = client -> xid;
	client -> packet.secs = 0; /* Filled in by send_request. */

	/* If we own the address we're requesting, put it in ciaddr;
	   otherwise set ciaddr to zero. */
	if (client -> state == S_BOUND ||
	    client -> state == S_RENEWING ||
	    client -> state == S_REBINDING) {
		memcpy (&client -> packet.ciaddr,
			lease -> address.iabuf, lease -> address.len);
		client -> packet.flags = 0;
	} else {
		memset (&client -> packet.ciaddr, 0,
			sizeof client -> packet.ciaddr);
		if (can_receive_unicast_unconfigured (client -> interface))
			client -> packet.flags = 0;
		else
			client -> packet.flags = htons (BOOTP_BROADCAST);
	}

	memset (&client -> packet.yiaddr, 0,
		sizeof client -> packet.yiaddr);
	memset (&client -> packet.siaddr, 0,
		sizeof client -> packet.siaddr);
	if (client -> state != S_BOUND &&
	    client -> state != S_RENEWING)
		client -> packet.giaddr = giaddr;
	else
		memset (&client -> packet.giaddr, 0,
			sizeof client -> packet.giaddr);
	if (client -> interface -> hw_address.hlen > 0)
	    memcpy (client -> packet.chaddr,
		    &client -> interface -> hw_address.hbuf [1],
		    (unsigned)(client -> interface -> hw_address.hlen - 1));

#ifdef DEBUG_PACKET
	dump_raw ((unsigned char *)&client -> packet, client -> packet_length);
#endif
}

void make_decline (client, lease)
	struct client_state *client;
	struct client_lease *lease;
{
	unsigned char decline = DHCPDECLINE;
	int i;
	struct option_cache *oc;

	struct option_state *options = (struct option_state *)0;

	oc = lookup_option (&dhcp_universe, lease -> options,
			    DHO_DHCP_SERVER_IDENTIFIER);
	make_client_options (client, lease, &decline, oc,
			     &lease -> address, (u_int32_t *)0, &options);

	/* Set up the option buffer... */
	memset (&client -> packet, 0, sizeof (client -> packet));
	client -> packet_length =
		cons_options ((struct packet *)0, &client -> packet,
			      (struct lease *)0, client, 0,
			      (struct option_state *)0, options,
			      &global_scope, 0, 0, 0, (struct data_string *)0,
			      client -> config -> vendor_space_name);
	option_state_dereference (&options, MDL);
	if (client -> packet_length < BOOTP_MIN_LEN)
		client -> packet_length = BOOTP_MIN_LEN;
	option_state_dereference (&options, MDL);

	client -> packet.op = BOOTREQUEST;
	client -> packet.htype = client -> interface -> hw_address.hbuf [0];
	client -> packet.hlen = client -> interface -> hw_address.hlen - 1;
	client -> packet.hops = 0;
	client -> packet.xid = client -> xid;
	client -> packet.secs = 0; /* Filled in by send_request. */
	if (can_receive_unicast_unconfigured (client -> interface))
		client -> packet.flags = 0;
	else
		client -> packet.flags = htons (BOOTP_BROADCAST);

	/* ciaddr must always be zero. */
	memset (&client -> packet.ciaddr, 0,
		sizeof client -> packet.ciaddr);
	memset (&client -> packet.yiaddr, 0,
		sizeof client -> packet.yiaddr);
	memset (&client -> packet.siaddr, 0,
		sizeof client -> packet.siaddr);
	client -> packet.giaddr = giaddr;
	memcpy (client -> packet.chaddr,
		&client -> interface -> hw_address.hbuf [1],
		client -> interface -> hw_address.hlen);

#ifdef DEBUG_PACKET
	dump_raw ((unsigned char *)&client -> packet, client -> packet_length);
#endif
}

void make_release (client, lease)
	struct client_state *client;
	struct client_lease *lease;
{
	unsigned char request = DHCPRELEASE;
	int i;
	struct option_cache *oc;

	struct option_state *options = (struct option_state *)0;

	memset (&client -> packet, 0, sizeof (client -> packet));

	oc = lookup_option (&dhcp_universe, lease -> options,
			    DHO_DHCP_SERVER_IDENTIFIER);
	make_client_options (client, lease, &request, oc,
			     (struct iaddr *)0, (u_int32_t *)0,
			     &options);

	/* Set up the option buffer... */
	client -> packet_length =
		cons_options ((struct packet *)0, &client -> packet,
			      (struct lease *)0, client,
			      /* maximum packet size */1500,
			      (struct option_state *)0,
			      options,
			      /* scope */ &global_scope,
			      /* overload */ 0,
			      /* terminate */0,
			      /* bootpp    */0,
			      (struct data_string *)0,
			      client -> config -> vendor_space_name);

	if (client -> packet_length < BOOTP_MIN_LEN)
		client -> packet_length = BOOTP_MIN_LEN;
	option_state_dereference (&options, MDL);

	client -> packet.op = BOOTREQUEST;
	client -> packet.htype = client -> interface -> hw_address.hbuf [0];
	client -> packet.hlen = client -> interface -> hw_address.hlen - 1;
	client -> packet.hops = 0;
	client -> packet.xid = random ();
	client -> packet.secs = 0;
	client -> packet.flags = 0;
	memcpy (&client -> packet.ciaddr,
		lease -> address.iabuf, lease -> address.len);
	memset (&client -> packet.yiaddr, 0,
		sizeof client -> packet.yiaddr);
	memset (&client -> packet.siaddr, 0,
		sizeof client -> packet.siaddr);
	client -> packet.giaddr = giaddr;
	memcpy (client -> packet.chaddr,
		&client -> interface -> hw_address.hbuf [1],
		client -> interface -> hw_address.hlen);

#ifdef DEBUG_PACKET
	dump_raw ((unsigned char *)&client -> packet, client -> packet_length);
#endif
}

void destroy_client_lease (lease)
	struct client_lease *lease;
{
	int i;

	if (lease -> server_name)
		dfree (lease -> server_name, MDL);
	if (lease -> filename)
		dfree (lease -> filename, MDL);
	option_state_dereference (&lease -> options, MDL);
	free_client_lease (lease, MDL);
}

FILE *leaseFile;

void rewrite_client_leases ()
{
	struct interface_info *ip;
	struct client_state *client;
	struct client_lease *lp;

	if (leaseFile)
		fclose (leaseFile);
	leaseFile = fopen (path_dhclient_db, "w");
	if (!leaseFile) {
		log_error ("can't create %s: %m", path_dhclient_db);
		return;
	}

	/* Write out all the leases attached to configured interfaces that
	   we know about. */
	for (ip = interfaces; ip; ip = ip -> next) {
		for (client = ip -> client; client; client = client -> next) {
			for (lp = client -> leases; lp; lp = lp -> next) {
				write_client_lease (client, lp, 1, 0);
			}
			if (client -> active)
				write_client_lease (client,
						    client -> active, 1, 0);
		}
	}

	/* Write out any leases that are attached to interfaces that aren't
	   currently configured. */
	for (ip = dummy_interfaces; ip; ip = ip -> next) {
		for (client = ip -> client; client; client = client -> next) {
			for (lp = client -> leases; lp; lp = lp -> next) {
				write_client_lease (client, lp, 1, 0);
			}
			if (client -> active)
				write_client_lease (client,
						    client -> active, 1, 0);
		}
	}
	fflush (leaseFile);
}

void write_lease_option (struct option_cache *oc,
			 struct packet *packet, struct lease *lease,
			 struct client_state *client_state,
			 struct option_state *in_options,
			 struct option_state *cfg_options,
			 struct binding_scope **scope,
			 struct universe *u, void *stuff)
{
	const char *name, *dot;
	struct data_string ds;
	int status;
	struct client_state *client;

	memset (&ds, 0, sizeof ds);

	if (u != &dhcp_universe) {
		name = u -> name;
		dot = ".";
	} else {
		name = "";
		dot = "";
	}
	if (evaluate_option_cache (&ds, packet, lease, client_state,
				   in_options, cfg_options, scope, oc, MDL)) {
		fprintf (leaseFile,
			 "  option %s%s%s %s;\n",
			 name, dot, oc -> option -> name,
			 pretty_print_option (oc -> option,
					      ds.data, ds.len, 1, 1));
		data_string_forget (&ds, MDL);
	}
}

int write_client_lease (client, lease, rewrite, makesure)
	struct client_state *client;
	struct client_lease *lease;
	int rewrite;
	int makesure;
{
	int i;
	struct tm *t;
	static int leases_written;
	struct option_cache *oc;
	struct data_string ds;
	pair *hash;
	int errors = 0;
	char *s;

	if (!rewrite) {
		if (leases_written++ > 20) {
			rewrite_client_leases ();
			leases_written = 0;
		}
	}

	/* If the lease came from the config file, we don't need to stash
	   a copy in the lease