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9ba75048c

Denys Vlasenko

2011-11-07

FAILED Duration: 247s

Subject

udhcpc6: new applet. Not yet functional.

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

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Build Log

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Commit Diff GitHub →

networking/udhcp/d6_common.h +118 -0 networking/udhcp/d6_dhcpc.c +1404 -0 networking/udhcp/d6_packet.c +168 -0 networking/udhcp/d6_socket.c +34 -0

networking/udhcp/d6_common.h+118 -0

@@ -0,0 +1,118 @@
+	/* vi: set sw=4 ts=4: */
+	/*
+	* Copyright (C) 2011 Denys Vlasenko.
+	*
+	* Licensed under GPLv2, see file LICENSE in this source tree.
+	*/
+	#ifndef UDHCP_D6_COMMON_H
+	#define UDHCP_D6_COMMON_H 1
+
+	#include <netinet/ip6.h>
+
+	PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
+
+
+	/* DHCPv6 packet */
+
+	/* DHCPv6 protocol. See RFC 3315 */
+	#define D6_MSG_SOLICIT 1
+	#define D6_MSG_ADVERTISE 2
+	#define D6_MSG_REQUEST 3
+	#define D6_MSG_CONFIRM 4
+	#define D6_MSG_RENEW 5
+	#define D6_MSG_REBIND 6
+	#define D6_MSG_REPLY 7
+	#define D6_MSG_RELEASE 8
+	#define D6_MSG_DECLINE 9
+	#define D6_MSG_RECONFIGURE 10
+	#define D6_MSG_INFORMATION_REQUEST 11
+	#define D6_MSG_RELAY_FORW 12
+	#define D6_MSG_RELAY_REPL 13
+
+	struct d6_packet {
+	union {
+	uint8_t d6_msg_type;
+	uint32_t d6_xid32;
+	} d6_u;
+	uint8_t d6_options[576 - sizeof(struct iphdr) - sizeof(struct udphdr) - 4
+	+ CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS];
+	} PACKED;
+	#define d6_msg_type d6_u.d6_msg_type
+	#define d6_xid32 d6_u.d6_xid32
+
+	struct ip6_udp_d6_packet {
+	struct ip6_hdr ip6;
+	struct udphdr udp;
+	struct d6_packet data;
+	} PACKED;
+
+	struct udp_d6_packet {
+	struct udphdr udp;
+	struct d6_packet data;
+	} PACKED;
+
+	/* Options */
+
+	struct d6_option {
+	uint8_t code;
+	uint8_t code_hi;
+	uint8_t len;
+	uint8_t len_hi;
+	uint8_t data[1];
+	} PACKED;
+
+	#define D6_OPT_CLIENTID 1
+	#define D6_OPT_SERVERID 2
+	#define D6_OPT_IA_NA 3
+	#define D6_OPT_IA_TA 4
+	#define D6_OPT_IAADDR 5
+	#define D6_OPT_ORO 6
+	#define D6_OPT_PREFERENCE 7
+	#define D6_OPT_ELAPSED_TIME 8
+	#define D6_OPT_RELAY_MSG 9
+	#define D6_OPT_AUTH 11
+	#define D6_OPT_UNICAST 12
+	#define D6_OPT_STATUS_CODE 13
+	#define D6_OPT_RAPID_COMMIT 14
+	#define D6_OPT_USER_CLASS 15
+	#define D6_OPT_VENDOR_CLASS 16
+	#define D6_OPT_VENDOR_OPTS 17
+	#define D6_OPT_INTERFACE_ID 18
+	#define D6_OPT_RECONF_MSG 19
+	#define D6_OPT_RECONF_ACCEPT 20
+
+	/* Other shared functions */
+
+	struct client6_data_t {
+	struct d6_option *server_id;
+	struct d6_option *ia_na;
+	};
+
+	#define client6_data ((struct client6_data_t)(&bb_common_bufsiz1[COMMON_BUFSIZE - sizeof(struct client6_data_t)]))
+
+	int FAST_FUNC d6_listen_socket(int port, const char *inf);
+
+	int FAST_FUNC d6_recv_kernel_packet(
+	struct in6_addr *peer_ipv6,
+	struct d6_packet *packet, int fd
+	);
+
+	int FAST_FUNC d6_send_raw_packet(
+	struct d6_packet *d6_pkt, unsigned d6_pkt_size,
+	struct in6_addr *src_ipv6, int source_port,
+	struct in6_addr dst_ipv6, int dest_port, const uint8_t dest_arp,
+	int ifindex
+	);
+
+	int FAST_FUNC d6_send_kernel_packet(
+	struct d6_packet *d6_pkt, unsigned d6_pkt_size,
+	struct in6_addr *src_ipv6, int source_port,
+	struct in6_addr *dst_ipv6, int dest_port
+	);
+
+	void FAST_FUNC d6_dump_packet(struct d6_packet *packet);
+
+
+	POP_SAVED_FUNCTION_VISIBILITY
+
+	#endif

networking/udhcp/d6_dhcpc.c+1404 -0

@@ -0,0 +1,1404 @@
+	/* vi: set sw=4 ts=4: */
+	/*
+	* DHCPv6 client.
+	*
+	* 2011-11.
+	* WARNING: THIS CODE IS INCOMPLETE. IT IS NOWHERE NEAR
+	* TO BE READY FOR PRODUCTION USE.
+	*
+	* Copyright (C) 2011 Denys Vlasenko.
+	*
+	* Licensed under GPLv2, see file LICENSE in this source tree.
+	*/
+
+	//config:config UDHCPC6
+	//config: bool "udhcp client for DHCPv6 (udhcpc6)"
+	//config: default n # not yet ready
+	//config: help
+	//config: udhcpc6 is a DHCPv6 client
+
+	//applet:IF_UDHCPC6(APPLET(udhcpc6, BB_DIR_USR_BIN, BB_SUID_DROP))
+
+	//kbuild:lib-$(CONFIG_UDHCPC6) += d6_dhcpc.o d6_packet.o d6_socket.o common.o
+
+
+	#include <syslog.h>
+	/* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
+	#define WANT_PIDFILE 1
+	#include "common.h"
+	#include "dhcpd.h"
+	#include "dhcpc.h"
+	#include "d6_common.h"
+
+	#include <netinet/if_ether.h>
+	#include <netpacket/packet.h>
+	#include <linux/filter.h>
+
+	/* "struct client_config_t client_config" is in bb_common_bufsiz1 */
+
+
+	#if ENABLE_LONG_OPTS
+	static const char udhcpc_longopts[] ALIGN1 =
+	"interface\0" Required_argument "i"
+	"now\0" No_argument "n"
+	"pidfile\0" Required_argument "p"
+	"quit\0" No_argument "q"
+	"release\0" No_argument "R"
+	"request\0" Required_argument "r"
+	"script\0" Required_argument "s"
+	"timeout\0" Required_argument "T"
+	"version\0" No_argument "v"
+	"retries\0" Required_argument "t"
+	"tryagain\0" Required_argument "A"
+	"syslog\0" No_argument "S"
+	"request-option\0" Required_argument "O"
+	"no-default-options\0" No_argument "o"
+	"foreground\0" No_argument "f"
+	"background\0" No_argument "b"
+	"broadcast\0" No_argument "B"
+	/// IF_FEATURE_UDHCPC_ARPING("arping\0" No_argument "a")
+	IF_FEATURE_UDHCP_PORT("client-port\0" Required_argument "P")
+	;
+	#endif
+	/* Must match getopt32 option string order */
+	enum {
+	OPT_i = 1 << 0,
+	OPT_n = 1 << 1,
+	OPT_p = 1 << 2,
+	OPT_q = 1 << 3,
+	OPT_R = 1 << 4,
+	OPT_r = 1 << 5,
+	OPT_s = 1 << 6,
+	OPT_T = 1 << 7,
+	OPT_t = 1 << 8,
+	OPT_S = 1 << 9,
+	OPT_A = 1 << 10,
+	OPT_O = 1 << 11,
+	OPT_o = 1 << 12,
+	OPT_x = 1 << 13,
+	OPT_f = 1 << 14,
+	OPT_B = 1 << 15,
+	/* The rest has variable bit positions, need to be clever */
+	OPTBIT_B = 15,
+	USE_FOR_MMU( OPTBIT_b,)
+	///IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,)
+	IF_FEATURE_UDHCP_PORT( OPTBIT_P,)
+	USE_FOR_MMU( OPT_b = 1 << OPTBIT_b,)
+	///IF_FEATURE_UDHCPC_ARPING(OPT_a = 1 << OPTBIT_a,)
+	IF_FEATURE_UDHCP_PORT( OPT_P = 1 << OPTBIT_P,)
+	};
+
+
+	/* Utility functions */
+
+	static void d6_find_option(uint8_t option, uint8_t *option_end, unsigned code)
+	{
+	/* "length minus 4" */
+	int len_m4 = option_end - option - 4;
+	while (len_m4 >= 0) {
+	/* Next option's len is too big? */
+	if (option[2] > len_m4)
+	return NULL; /* yes. bogus packet! */
+	/* So far we treat any opts with code >255
+	* or len >255 as bogus, and stop at once.
+	* This simplifies big-endian handling.
+	*/
+	if (option[1] != 0 \|\| option[3] != 0)
+	return NULL;
+	/* Option seems to be valid */
+	/* Does its code match? */
+	if (option[0] == code)
+	return option; /* yes! */
+	option += option[2] + 4;
+	len_m4 -= option[2] + 4;
+	}
+	return NULL;
+	}
+
+	static void d6_copy_option(uint8_t option, uint8_t *option_end, unsigned code)
+	{
+	uint8_t *opt = d6_find_option(option, option_end, code);
+	if (!opt)
+	return opt;
+	return memcpy(xmalloc(opt[2] + 4), opt, opt[2] + 4);
+	}
+
+	static void d6_store_blob(void dst, const void *src, unsigned len)
+	{
+	memcpy(dst, src, len);
+	return dst + len;
+	}
+
+
+	/* Script execution code */
+
+	/* put all the parameters into the environment */
+	static char *fill_envp(struct d6_packet packet
+	UNUSED_PARAM
+	)
+	{
+	int envc;
+	char envp, curr;
+
+	#define BITMAP unsigned
+	#define BBITS (sizeof(BITMAP) * 8)
+	#define BMASK(i) (1 << (i & (sizeof(BITMAP) * 8 - 1)))
+	#define FOUND_OPTS(i) (found_opts[(unsigned)i / BBITS])
+	///BITMAP found_opts[256 / BBITS];
+
+	///memset(found_opts, 0, sizeof(found_opts));
+
+	/* We need 2 elements for:
+	* "interface=IFACE"
+	* terminating NULL
+	*/
+	envc = 2;
+
+	curr = envp = xzalloc(sizeof(envp[0]) * envc);
+
+	*curr = xasprintf("interface=%s", client_config.interface);
+	putenv(*curr++);
+
+	return envp;
+	}
+
+	/* Call a script with a par file and env vars */
+	static void d6_run_script(struct d6_packet packet, const char name)
+	{
+	char envp, curr;
+	char *argv[3];
+
+	envp = fill_envp(packet);
+
+	/* call script */
+	log1("Executing %s %s", client_config.script, name);
+	argv[0] = (char*) client_config.script;
+	argv[1] = (char*) name;
+	argv[2] = NULL;
+	spawn_and_wait(argv);
+
+	for (curr = envp; *curr; curr++) {
+	log2(" %s", *curr);
+	bb_unsetenv_and_free(*curr);
+	}
+	free(envp);
+	}
+
+
+	/* Sending/receiving packets */
+
+	static ALWAYS_INLINE uint32_t random_xid(void)
+	{
+	uint32_t t = rand() & htonl(0x00ffffff);
+	return t;
+	}
+
+	/* Initialize the packet with the proper defaults */
+	static uint8_t init_d6_packet(struct d6_packet packet, char type, uint32_t xid)
+	{
+	struct d6_option *clientid;
+
+	memset(packet, 0, sizeof(*packet));
+
+	packet->d6_xid32 = xid;
+	packet->d6_msg_type = type;
+
+	clientid = (void*)client_config.clientid;
+	return d6_store_blob(packet->d6_options, clientid, clientid->len + 2+2);
+	}
+
+	static uint8_t add_d6_client_options(uint8_t ptr)
+	{
+	return ptr;
+	//uint8_t c;
+	//int i, end, len;
+
+	/* Add a "param req" option with the list of options we'd like to have
+	* from stubborn DHCP servers. Pull the data from the struct in common.c.
+	* No bounds checking because it goes towards the head of the packet. */
+	//...
+
+	/* Add -x options if any */
+	//...
+	}
+
+	static int d6_mcast_from_client_config_ifindex(struct d6_packet packet, uint8_t end)
+	{
+	static const uint8_t FF02__1_2[16] = {
+	0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02,
+	};
+
+	return d6_send_raw_packet(
+	packet, (end - (uint8_t*) packet),
+	/src/ NULL, CLIENT_PORT,
+	/dst/ (struct in6_addr*)FF02__1_2, SERVER_PORT, MAC_BCAST_ADDR,
+	client_config.ifindex
+	);
+	}
+
+	/* Milticast a DHCPv6 Solicit packet to the network, with an optionally requested IP.
+	*
+	* RFC 3315 17.1.1. Creation of Solicit Messages
+	*
+	* The client MUST include a Client Identifier option to identify itself
+	* to the server. The client includes IA options for any IAs to which
+	* it wants the server to assign addresses. The client MAY include
+	* addresses in the IAs as a hint to the server about addresses for
+	* which the client has a preference. ...
+	*
+	* The client uses IA_NA options to request the assignment of non-
+	* temporary addresses and uses IA_TA options to request the assignment
+	* of temporary addresses. Either IA_NA or IA_TA options, or a
+	* combination of both, can be included in DHCP messages.
+	*
+	* The client SHOULD include an Option Request option (see section 22.7)
+	* to indicate the options the client is interested in receiving. The
+	* client MAY additionally include instances of those options that are
+	* identified in the Option Request option, with data values as hints to
+	* the server about parameter values the client would like to have
+	* returned.
+	*
+	* The client includes a Reconfigure Accept option (see section 22.20)
+	* if the client is willing to accept Reconfigure messages from the
+	* server.
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| OPTION_CLIENTID \| option-len \|
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	. .
+	. DUID .
+	. (variable length) .
+	. .
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| OPTION_IA_NA \| option-len \|
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| IAID (4 octets) \|
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| T1 \|
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| T2 \|
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| \|
+	. IA_NA-options .
+	. .
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| OPTION_IAADDR \| option-len \|
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| \|
+	\| IPv6 address \|
+	\| \|
+	\| \|
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| preferred-lifetime \|
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| valid-lifetime \|
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	. .
+	. IAaddr-options .
+	. .
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| OPTION_ORO \| option-len \|
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| requested-option-code-1 \| requested-option-code-2 \|
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| ... \|
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	\| OPTION_RECONF_ACCEPT \| 0 \|
+	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	*/
+	/* NOINLINE: limit stack usage in caller */
+	static NOINLINE int send_d6_discover(uint32_t xid, struct in6_addr *requested_ipv6)
+	{
+	struct d6_packet packet;
+	uint8_t *opt_ptr;
+	unsigned len;
+
+	/* Fill in: msg type, client id */
+	opt_ptr = init_d6_packet(&packet, D6_MSG_SOLICIT, xid);
+
+	/* Create new IA_NA, optionally with included IAADDR with requested IP */
+	free(client6_data.ia_na);
+	len = requested_ipv6 ? 2+2+4+4+4 + 2+2+16+4+4 : 2+2+4+4+4;
+	client6_data.ia_na = xzalloc(len);
+	client6_data.ia_na->code = D6_OPT_IA_NA;
+	client6_data.ia_na->len = len - 4;
+	(uint32_t)client6_data.ia_na->data = rand(); /* IAID */
+	if (requested_ipv6) {
+	struct d6_option iaaddr = (void)(client6_data.ia_na->data + 4+4+4);
+	iaaddr->code = D6_OPT_IAADDR;
+	iaaddr->len = 16+4+4;
+	memcpy(iaaddr->data, requested_ipv6, 16);
+	}
+	opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, len);
+
+	/* Add options:
+	* "param req" option according to -O, options specified with -x
+	*/
+	opt_ptr = add_d6_client_options(opt_ptr);
+
+	bb_info_msg("Sending discover...");
+	return d6_mcast_from_client_config_ifindex(&packet, opt_ptr);
+	}
+
+	/* Multicast a DHCPv6 request message
+	*
+	* RFC 3315 18.1.1. Creation and Transmission of Request Messages
+	*
+	* The client uses a Request message to populate IAs with addresses and
+	* obtain other configuration information. The client includes one or
+	* more IA options in the Request message. The server then returns
+	* addresses and other information about the IAs to the client in IA
+	* options in a Reply message.
+	*
+	* The client generates a transaction ID and inserts this value in the
+	* "transaction-id" field.
+	*
+	* The client places the identifier of the destination server in a
+	* Server Identifier option.
+	*
+	* The client MUST include a Client Identifier option to identify itself
+	* to the server. The client adds any other appropriate options,
+	* including one or more IA options (if the client is requesting that
+	* the server assign it some network addresses).
+	*
+	* The client MUST include an Option Request option (see section 22.7)
+	* to indicate the options the client is interested in receiving. The
+	* client MAY include options with data values as hints to the server
+	* about parameter values the client would like to have returned.
+	*
+	* The client includes a Reconfigure Accept option (see section 22.20)
+	* indicating whether or not the client is willing to accept Reconfigure
+	* messages from the server.
+	*/
+	/* NOINLINE: limit stack usage in caller */
+	static NOINLINE int send_d6_select(uint32_t xid)
+	{
+	struct d6_packet packet;
+	uint8_t *opt_ptr;
+
+	/* Fill in: msg type, client id */
+	opt_ptr = init_d6_packet(&packet, D6_MSG_REQUEST, xid);
+
+	/* server id */
+	opt_ptr = d6_store_blob(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
+	/* IA NA (contains requested IP) */
+	opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2);
+
+	/* Add options:
+	* "param req" option according to -O, options specified with -x
+	*/
+	opt_ptr = add_d6_client_options(opt_ptr);
+
+	bb_info_msg("Sending select...");
+	return d6_mcast_from_client_config_ifindex(&packet, opt_ptr);
+	}
+
+	/* Unicast or broadcast a DHCP renew message
+	*
+	* RFC 3315 18.1.3. Creation and Transmission of Renew Messages
+	*
+	* To extend the valid and preferred lifetimes for the addresses
+	* associated with an IA, the client sends a Renew message to the server
+	* from which the client obtained the addresses in the IA containing an
+	* IA option for the IA. The client includes IA Address options in the
+	* IA option for the addresses associated with the IA. The server
+	* determines new lifetimes for the addresses in the IA according to the
+	* administrative configuration of the server. The server may also add
+	* new addresses to the IA. The server may remove addresses from the IA
+	* by setting the preferred and valid lifetimes of those addresses to
+	* zero.
+	*
+	* The server controls the time at which the client contacts the server
+	* to extend the lifetimes on assigned addresses through the T1 and T2
+	* parameters assigned to an IA.
+	*
+	* At time T1 for an IA, the client initiates a Renew/Reply message
+	* exchange to extend the lifetimes on any addresses in the IA. The
+	* client includes an IA option with all addresses currently assigned to
+	* the IA in its Renew message.
+	*
+	* If T1 or T2 is set to 0 by the server (for an IA_NA) or there are no
+	* T1 or T2 times (for an IA_TA), the client may send a Renew or Rebind
+	* message, respectively, at the client's discretion.
+	*
+	* The client sets the "msg-type" field to RENEW. The client generates
+	* a transaction ID and inserts this value in the "transaction-id"
+	* field.
+	*
+	* The client places the identifier of the destination server in a
+	* Server Identifier option.
+	*
+	* The client MUST include a Client Identifier option to identify itself
+	* to the server. The client adds any appropriate options, including
+	* one or more IA options. The client MUST include the list of
+	* addresses the client currently has associated with the IAs in the
+	* Renew message.
+	*
+	* The client MUST include an Option Request option (see section 22.7)
+	* to indicate the options the client is interested in receiving. The
+	* client MAY include options with data values as hints to the server
+	* about parameter values the client would like to have returned.
+	*/
+	/* NOINLINE: limit stack usage in caller */
+	static NOINLINE int send_d6_renew(uint32_t xid, struct in6_addr server_ipv6, struct in6_addr our_cur_ipv6)
+	{
+	struct d6_packet packet;
+	uint8_t *opt_ptr;
+
+	/* Fill in: msg type, client id */
+	opt_ptr = init_d6_packet(&packet, DHCPREQUEST, xid);
+
+	/* server id */
+	opt_ptr = d6_store_blob(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
+	/* IA NA (contains requested IP) */
+	opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2);
+
+	/* Add options:
+	* "param req" option according to -O, options specified with -x
+	*/
+	opt_ptr = add_d6_client_options(opt_ptr);
+
+	bb_info_msg("Sending renew...");
+	if (server_ipv6)
+	return d6_send_kernel_packet(
+	&packet, (opt_ptr - (uint8_t*) &packet),
+	our_cur_ipv6, CLIENT_PORT,
+	server_ipv6, SERVER_PORT
+	);
+	return d6_mcast_from_client_config_ifindex(&packet, opt_ptr);
+	}
+
+	/* Unicast a DHCP release message */
+	static int send_d6_release(struct in6_addr server_ipv6, struct in6_addr our_cur_ipv6)
+	{
+	struct d6_packet packet;
+	uint8_t *opt_ptr;
+
+	/* Fill in: msg type, client id */
+	opt_ptr = init_d6_packet(&packet, D6_MSG_RELEASE, random_xid());
+	/* server id */
+	opt_ptr = d6_store_blob(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
+	/* IA NA (contains our current IP) */
+	opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2);
+
+	bb_info_msg("Sending release...");
+	return d6_send_kernel_packet(
+	&packet, (opt_ptr - (uint8_t*) &packet),
+	our_cur_ipv6, CLIENT_PORT,
+	server_ipv6, SERVER_PORT
+	);
+	}
+
+	/* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
+	/* NOINLINE: limit stack usage in caller */
+	static NOINLINE int d6_recv_raw_packet(struct in6_addr *peer_ipv6
+	UNUSED_PARAM
+	, struct d6_packet *d6_pkt, int fd)
+	{
+	int bytes;
+	struct ip6_udp_d6_packet packet;
+
+	bytes = safe_read(fd, &packet, sizeof(packet));
+	if (bytes < 0) {
+	log1("Packet read error, ignoring");
+	/* NB: possible down interface, etc. Caller should pause. */
+	return bytes; /* returns -1 */
+	}
+
+	if (bytes < (int) (sizeof(packet.ip6) + sizeof(packet.udp))) {
+	log1("Packet is too short, ignoring");
+	return -2;
+	}
+
+	if (bytes < sizeof(packet.ip6) + ntohs(packet.ip6.ip6_plen)) {
+	/* packet is bigger than sizeof(packet), we did partial read */
+	log1("Oversized packet, ignoring");
+	return -2;
+	}
+
+	/* ignore any extra garbage bytes */
+	bytes = sizeof(packet.ip6) + ntohs(packet.ip6.ip6_plen);
+
+	/* make sure its the right packet for us, and that it passes sanity checks */
+	if (packet.ip6.ip6_nxt != IPPROTO_UDP
+	\|\| (packet.ip6.ip6_vfc >> 4) != 6
+	\|\| packet.udp.dest != htons(CLIENT_PORT)
+	/* \|\| bytes > (int) sizeof(packet) - can't happen */
+	\|\| packet.udp.len != packet.ip6.ip6_plen
+	) {
+	log1("Unrelated/bogus packet, ignoring");
+	return -2;
+	}
+
+	//How to do this for ipv6?
+	// /* verify UDP checksum. IP header has to be modified for this */
+	// memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
+	// /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
+	// packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
+	// check = packet.udp.check;
+	// packet.udp.check = 0;
+	// if (check && check != inet_cksum((uint16_t *)&packet, bytes)) {
+	// log1("Packet with bad UDP checksum received, ignoring");
+	// return -2;
+	// }
+
+	log1("Received a packet");
+	d6_dump_packet(&packet.data);
+
+	bytes -= sizeof(packet.ip6) + sizeof(packet.udp);
+	memcpy(d6_pkt, &packet.data, bytes);
+	return bytes;
+	}
+
+
+	/* Main */
+
+	static int sockfd = -1;
+
+	#define LISTEN_NONE 0
+	#define LISTEN_KERNEL 1
+	#define LISTEN_RAW 2
+	static smallint listen_mode;
+
+	/* initial state: (re)start DHCP negotiation */
+	#define INIT_SELECTING 0
+	/* discover was sent, DHCPOFFER reply received */
+	#define REQUESTING 1
+	/* select/renew was sent, DHCPACK reply received */
+	#define BOUND 2
+	/* half of lease passed, want to renew it by sending unicast renew requests */
+	#define RENEWING 3
+	/* renew requests were not answered, lease is almost over, send broadcast renew */
+	#define REBINDING 4
+	/* manually requested renew (SIGUSR1) */
+	#define RENEW_REQUESTED 5
+	/* release, possibly manually requested (SIGUSR2) */
+	#define RELEASED 6
+	static smallint state;
+
+	static int d6_raw_socket(int ifindex)
+	{
+	int fd;
+	struct sockaddr_ll sock;
+
+	/*
+	* Comment:
+	*
+	* I've selected not to see LL header, so BPF doesn't see it, too.
+	* The filter may also pass non-IP and non-ARP packets, but we do
+	* a more complete check when receiving the message in userspace.
+	*
+	* and filter shamelessly stolen from:
+	*
+	* http://www.flamewarmaster.de/software/dhcpclient/
+	*
+	* There are a few other interesting ideas on that page (look under
+	* "Motivation"). Use of netlink events is most interesting. Think
+	* of various network servers listening for events and reconfiguring.
+	* That would obsolete sending HUP signals and/or make use of restarts.
+	*
+	* Copyright: 2006, 2007 Stefan Rompf <[email protected]>.
+	* License: GPL v2.
+	*
+	* TODO: make conditional?
+	*/
+	#if 0
+	static const struct sock_filter filter_instr[] = {
+	/* load 9th byte (protocol) */
+	BPF_STMT(BPF_LD\|BPF_B\|BPF_ABS, 9),
+	/* jump to L1 if it is IPPROTO_UDP, else to L4 */
+	BPF_JUMP(BPF_JMP\|BPF_JEQ\|BPF_K, IPPROTO_UDP, 0, 6),
+	/* L1: load halfword from offset 6 (flags and frag offset) */
+	BPF_STMT(BPF_LD\|BPF_H\|BPF_ABS, 6),
+	/* jump to L4 if any bits in frag offset field are set, else to L2 */
+	BPF_JUMP(BPF_JMP\|BPF_JSET\|BPF_K, 0x1fff, 4, 0),
+	/* L2: skip IP header (load index reg with header len) */
+	BPF_STMT(BPF_LDX\|BPF_B\|BPF_MSH, 0),
+	/* load udp destination port from halfword[header_len + 2] */
+	BPF_STMT(BPF_LD\|BPF_H\|BPF_IND, 2),
+	/* jump to L3 if udp dport is CLIENT_PORT, else to L4 */
+	BPF_JUMP(BPF_JMP\|BPF_JEQ\|BPF_K, 68, 0, 1),
+	/* L3: accept packet */
+	BPF_STMT(BPF_RET\|BPF_K, 0xffffffff),
+	/* L4: discard packet */
+	BPF_STMT(BPF_RET\|BPF_K, 0),
+	};
+	static const struct sock_fprog filter_prog = {
+	.len = sizeof(filter_instr) / sizeof(filter_instr[0]),
+	/* casting const away: */
+	.filter = (struct sock_filter *) filter_instr,
+	};
+	#endif
+
+	log1("Opening raw socket on ifindex %d", ifindex); //log2?
+
+	fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IPV6));
+	log1("Got raw socket fd %d", fd); //log2?
+
+	sock.sll_family = AF_PACKET;
+	sock.sll_protocol = htons(ETH_P_IPV6);
+	sock.sll_ifindex = ifindex;
+	xbind(fd, (struct sockaddr *) &sock, sizeof(sock));
+
+	#if 0
+	if (CLIENT_PORT == 68) {
+	/* Use only if standard port is in use */
+	/* Ignoring error (kernel may lack support for this) */
+	if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
+	sizeof(filter_prog)) >= 0)
+	log1("Attached filter to raw socket fd %d", fd); // log?
+	}
+	#endif
+
+	log1("Created raw socket");
+
+	return fd;
+	}
+
+	static void change_listen_mode(int new_mode)
+	{
+	log1("Entering listen mode: %s",
+	new_mode != LISTEN_NONE
+	? (new_mode == LISTEN_KERNEL ? "kernel" : "raw")
+	: "none"
+	);
+
+	listen_mode = new_mode;
+	if (sockfd >= 0) {
+	close(sockfd);
+	sockfd = -1;
+	}
+	if (new_mode == LISTEN_KERNEL)
+	sockfd = udhcp_listen_socket(/INADDR_ANY,/ CLIENT_PORT, client_config.interface);
+	else if (new_mode != LISTEN_NONE)
+	sockfd = d6_raw_socket(client_config.ifindex);
+	/* else LISTEN_NONE: sockfd stays closed */
+	}
+
+	/* Called only on SIGUSR1 */
+	static void perform_renew(void)
+	{
+	bb_info_msg("Performing a DHCP renew");
+	switch (state) {
+	case BOUND:
+	change_listen_mode(LISTEN_KERNEL);
+	case RENEWING:
+	case REBINDING:
+	state = RENEW_REQUESTED;
+	break;
+	case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
+	d6_run_script(NULL, "deconfig");
+	case REQUESTING:
+	case RELEASED:
+	change_listen_mode(LISTEN_RAW);
+	state = INIT_SELECTING;
+	break;
+	case INIT_SELECTING:
+	break;
+	}
+	}
+
+	static void perform_d6_release(struct in6_addr server_ipv6, struct in6_addr our_cur_ipv6)
+	{
+	/* send release packet */
+	if (state == BOUND \|\| state == RENEWING \|\| state == REBINDING) {
+	bb_info_msg("Unicasting a release");
+	send_d6_release(server_ipv6, our_cur_ipv6); /* unicast */
+	d6_run_script(NULL, "deconfig");
+	}
+	bb_info_msg("Entering released state");
+
+	change_listen_mode(LISTEN_NONE);
+	state = RELEASED;
+	}
+
+	///static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
+	///{
+	/// uint8_t *storage;
+	/// int len = strnlen(str, 255);
+	/// storage = xzalloc(len + extra + OPT_DATA);
+	/// storage[OPT_CODE] = code;
+	/// storage[OPT_LEN] = len + extra;
+	/// memcpy(storage + extra + OPT_DATA, str, len);
+	/// return storage;
+	///}
+
+	#if BB_MMU
+	static void client_background(void)
+	{
+	bb_daemonize(0);
+	logmode &= ~LOGMODE_STDIO;
+	/* rewrite pidfile, as our pid is different now */
+	write_pidfile(client_config.pidfile);
+	}
+	#endif
+
+	//usage:#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
+	//usage:# define IF_UDHCP_VERBOSE(...) __VA_ARGS__
+	//usage:#else
+	//usage:# define IF_UDHCP_VERBOSE(...)
+	//usage:#endif
+	//usage:#define udhcpc6_trivial_usage
+	//usage: "[-fbnq"IF_UDHCP_VERBOSE("v")"oRB] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE]\n"
+	//usage: " [-x OPT:VAL]... [-O OPT]..." IF_FEATURE_UDHCP_PORT(" [-P N]")
+	//usage:#define udhcpc6_full_usage "\n"
+	//usage: IF_LONG_OPTS(
+	//usage: "\n -i,--interface IFACE Interface to use (default eth0)"
+	//usage: "\n -p,--pidfile FILE Create pidfile"
+	//usage: "\n -s,--script PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
+	//usage: "\n -B,--broadcast Request broadcast replies"
+	//usage: "\n -t,--retries N Send up to N discover packets"
+	//usage: "\n -T,--timeout N Pause between packets (default 3 seconds)"
+	//usage: "\n -A,--tryagain N Wait N seconds after failure (default 20)"
+	//usage: "\n -f,--foreground Run in foreground"
+	//usage: USE_FOR_MMU(
+	//usage: "\n -b,--background Background if lease is not obtained"
+	//usage: )
+	//usage: "\n -n,--now Exit if lease is not obtained"
+	//usage: "\n -q,--quit Exit after obtaining lease"
+	//usage: "\n -R,--release Release IP on exit"
+	//usage: "\n -S,--syslog Log to syslog too"
+	//usage: IF_FEATURE_UDHCP_PORT(
+	//usage: "\n -P,--client-port N Use port N (default 68)"
+	//usage: )
+	////usage: IF_FEATURE_UDHCPC_ARPING(
+	////usage: "\n -a,--arping Use arping to validate offered address"
+	////usage: )
+	//usage: "\n -O,--request-option OPT Request option OPT from server (cumulative)"
+	//usage: "\n -o,--no-default-options Don't request any options (unless -O is given)"
+	//usage: "\n -r,--request IP Request this IP address"
+	//usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
+	//usage: "\n Examples of string, numeric, and hex byte opts:"
+	//usage: "\n -x hostname:bbox - option 12"
+	//usage: "\n -x lease:3600 - option 51 (lease time)"
+	//usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
+	//usage: IF_UDHCP_VERBOSE(
+	//usage: "\n -v Verbose"
+	//usage: )
+	//usage: )
+	//usage: IF_NOT_LONG_OPTS(
+	//usage: "\n -i IFACE Interface to use (default eth0)"
+	//usage: "\n -p FILE Create pidfile"
+	//usage: "\n -s PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
+	//usage: "\n -B Request broadcast replies"
+	//usage: "\n -t N Send up to N discover packets"
+	//usage: "\n -T N Pause between packets (default 3 seconds)"
+	//usage: "\n -A N Wait N seconds (default 20) after failure"
+	//usage: "\n -f Run in foreground"
+	//usage: USE_FOR_MMU(
+	//usage: "\n -b Background if lease is not obtained"
+	//usage: )
+	//usage: "\n -n Exit if lease is not obtained"
+	//usage: "\n -q Exit after obtaining lease"
+	//usage: "\n -R Release IP on exit"
+	//usage: "\n -S Log to syslog too"
+	//usage: IF_FEATURE_UDHCP_PORT(
+	//usage: "\n -P N Use port N (default 68)"
+	//usage: )
+	////usage: IF_FEATURE_UDHCPC_ARPING(
+	////usage: "\n -a Use arping to validate offered address"
+	////usage: )
+	//usage: "\n -O OPT Request option OPT from server (cumulative)"
+	//usage: "\n -o Don't request any options (unless -O is given)"
+	//usage: "\n -r IP Request this IP address"
+	//usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
+	//usage: "\n Examples of string, numeric, and hex byte opts:"
+	//usage: "\n -x hostname:bbox - option 12"
+	//usage: "\n -x lease:3600 - option 51 (lease time)"
+	//usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
+	//usage: IF_UDHCP_VERBOSE(
+	//usage: "\n -v Verbose"
+	//usage: )
+	//usage: )
+	//usage: "\nSignals:"
+	//usage: "\n USR1 Renew lease"
+	//usage: "\n USR2 Release lease"
+
+
+	int udhcpc6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+	int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
+	{
+	const char *str_r;
+	IF_FEATURE_UDHCP_PORT(char *str_P;)
+	void *clientid_mac_ptr;
+	llist_t *list_O = NULL;
+	llist_t *list_x = NULL;
+	int tryagain_timeout = 20;
+	int discover_timeout = 3;
+	int discover_retries = 3;
+	struct in6_addr srv6_buf;
+	struct in6_addr ipv6_buf;
+	struct in6_addr *requested_ipv6;
+	uint32_t xid = 0;
+	int packet_num;
+	int timeout; /* must be signed */
+	unsigned already_waited_sec;
+	unsigned opt;
+	int max_fd;
+	int retval;
+	fd_set rfds;
+
+	/* Default options */
+	IF_FEATURE_UDHCP_PORT(SERVER_PORT = 547;)
+	IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 546;)
+	client_config.interface = "eth0";
+	client_config.script = CONFIG_UDHCPC_DEFAULT_SCRIPT;
+
+	/* Parse command line */
+	/* O,x: list; -T,-t,-A take numeric param */
+	opt_complementary = "O::x::T+:t+:A+" IF_UDHCP_VERBOSE(":vv") ;
+	IF_LONG_OPTS(applet_long_options = udhcpc_longopts;)
+	opt = getopt32(argv, "i:np:qRr:s:T:t:SA:O:ox:fB"
+	USE_FOR_MMU("b")
+	///IF_FEATURE_UDHCPC_ARPING("a")
+	IF_FEATURE_UDHCP_PORT("P:")
+	"v"
+	, &client_config.interface, &client_config.pidfile, &str_r /* i,p */
+	, &client_config.script /* s */
+	, &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
+	, &list_O
+	, &list_x
+	IF_FEATURE_UDHCP_PORT(, &str_P)
+	IF_UDHCP_VERBOSE(, &dhcp_verbose)
+	);
+	requested_ipv6 = NULL;
+	if (opt & OPT_r) {
+	if (inet_pton(AF_INET6, str_r, &ipv6_buf) <= 0)
+	bb_error_msg_and_die("bad IPv6 address '%s'", str_r);
+	requested_ipv6 = &ipv6_buf;
+	}
+	#if ENABLE_FEATURE_UDHCP_PORT
+	if (opt & OPT_P) {
+	CLIENT_PORT = xatou16(str_P);
+	SERVER_PORT = CLIENT_PORT - 1;
+	}
+	#endif
+	if (opt & OPT_o)
+	client_config.no_default_options = 1;
+	while (list_O) {
+	char *optstr = llist_pop(&list_O);
+	unsigned n = bb_strtou(optstr, NULL, 0);
+	if (errno \|\| n > 254) {
+	n = udhcp_option_idx(optstr);
+	n = dhcp_optflags[n].code;
+	}
+	client_config.opt_mask[n >> 3] \|= 1 << (n & 7);
+	}
+	while (list_x) {
+	char *optstr = llist_pop(&list_x);
+	char *colon = strchr(optstr, ':');
+	if (colon)
+	*colon = ' ';
+	/* now it looks similar to udhcpd's config file line:
+	* "optname optval", using the common routine: */
+	udhcp_str2optset(optstr, &client_config.options);
+	}
+
+	if (udhcp_read_interface(client_config.interface,
+	&client_config.ifindex,
+	NULL,
+	client_config.client_mac)
+	) {
+	return 1;
+	}
+
+	/* Create client ID based on mac, set clientid_mac_ptr */
+	{
+	struct d6_option *clientid;
+	clientid = xzalloc(2+2+2+2+6);
+	clientid->code = D6_OPT_CLIENTID;
+	clientid->len = 2+2+6;
+	clientid->data[0] = 3; /* DUID-LL */
+	clientid->data[2] = 1; /* ethernet */
+	clientid_mac_ptr = clientid->data + 2+2;
+	memcpy(clientid_mac_ptr, client_config.client_mac, 6);
+	client_config.clientid = (void*)clientid;
+	}
+
+	#if !BB_MMU
+	/* on NOMMU reexec (i.e., background) early */
+	if (!(opt & OPT_f)) {
+	bb_daemonize_or_rexec(0 /* flags */, argv);
+	logmode = LOGMODE_NONE;
+	}
+	#endif
+	if (opt & OPT_S) {
+	openlog(applet_name, LOG_PID, LOG_DAEMON);
+	logmode \|= LOGMODE_SYSLOG;
+	}
+
+	/* Make sure fd 0,1,2 are open */
+	bb_sanitize_stdio();
+	/* Equivalent of doing a fflush after every \n */
+	setlinebuf(stdout);
+	/* Create pidfile */
+	write_pidfile(client_config.pidfile);
+	/* Goes to stdout (unless NOMMU) and possibly syslog */
+	bb_info_msg("%s (v"BB_VER") started", applet_name);
+	/* Set up the signal pipe */
+	udhcp_sp_setup();
+	/* We want random_xid to be random... */
+	srand(monotonic_us());
+
+	state = INIT_SELECTING;
+	d6_run_script(NULL, "deconfig");
+	change_listen_mode(LISTEN_RAW);
+	packet_num = 0;
+	timeout = 0;
+	already_waited_sec = 0;
+
+	/* Main event loop. select() waits on signal pipe and possibly
+	* on sockfd.
+	* "continue" statements in code below jump to the top of the loop.
+	*/
+	for (;;) {
+	struct timeval tv;
+	struct d6_packet packet;
+	uint8_t *packet_end;
+	/* silence "uninitialized!" warning */
+	unsigned timestamp_before_wait = timestamp_before_wait;
+
+	//bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode);
+
+	/* Was opening raw or udp socket here
+	* if (listen_mode != LISTEN_NONE && sockfd < 0),
+	* but on fast network renew responses return faster
+	* than we open sockets. Thus this code is moved
+	* to change_listen_mode(). Thus we open listen socket
+	* BEFORE we send renew request (see "case BOUND:"). */
+
+	max_fd = udhcp_sp_fd_set(&rfds, sockfd);
+
+	tv.tv_sec = timeout - already_waited_sec;
+	tv.tv_usec = 0;
+	retval = 0;
+	/* If we already timed out, fall through with retval = 0, else... */
+	if ((int)tv.tv_sec > 0) {
+	timestamp_before_wait = (unsigned)monotonic_sec();
+	log1("Waiting on select...");
+	retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
+	if (retval < 0) {
+	/* EINTR? A signal was caught, don't panic */
+	if (errno == EINTR) {
+	already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
+	continue;
+	}
+	/* Else: an error occured, panic! */
+	bb_perror_msg_and_die("select");
+	}
+	}
+
+	/* If timeout dropped to zero, time to become active:
+	* resend discover/renew/whatever
+	*/
+	if (retval == 0) {
+	/* When running on a bridge, the ifindex may have changed
+	* (e.g. if member interfaces were added/removed
+	* or if the status of the bridge changed).
+	* Refresh ifindex and client_mac:
+	*/
+	if (udhcp_read_interface(client_config.interface,
+	&client_config.ifindex,
+	NULL,
+	client_config.client_mac)
+	) {
+	goto ret0; /* iface is gone? */
+	}
+	memcpy(clientid_mac_ptr, client_config.client_mac, 6);
+
+	/* We will restart the wait in any case */
+	already_waited_sec = 0;
+
+	switch (state) {
+	case INIT_SELECTING:
+	if (packet_num < discover_retries) {
+	if (packet_num == 0)
+	xid = random_xid();
+	/* multicast */
+	send_d6_discover(xid, requested_ipv6);
+	timeout = discover_timeout;
+	packet_num++;
+	continue;
+	}
+	leasefail:
+	d6_run_script(NULL, "leasefail");
+	#if BB_MMU /* -b is not supported on NOMMU */
+	if (opt & OPT_b) { /* background if no lease */
+	bb_info_msg("No lease, forking to background");
+	client_background();
+	/* do not background again! */
+	opt = ((opt & ~OPT_b) \| OPT_f);
+	} else
+	#endif
+	if (opt & OPT_n) { /* abort if no lease */
+	bb_info_msg("No lease, failing");
+	retval = 1;
+	goto ret;
+	}
+	/* wait before trying again */
+	timeout = tryagain_timeout;
+	packet_num = 0;
+	continue;
+	case REQUESTING:
+	if (packet_num < discover_retries) {
+	/* send multicast select packet */
+	send_d6_select(xid);
+	timeout = discover_timeout;
+	packet_num++;
+	continue;
+	}
+	/* Timed out, go back to init state.
+	* "discover...select...discover..." loops
+	* were seen in the wild. Treat them similarly
+	* to "no response to discover" case */
+	change_listen_mode(LISTEN_RAW);
+	state = INIT_SELECTING;
+	goto leasefail;
+	case BOUND:
+	/* 1/2 lease passed, enter renewing state */
+	state = RENEWING;
+	client_config.first_secs = 0; /* make secs field count from 0 */
+	change_listen_mode(LISTEN_KERNEL);
+	log1("Entering renew state");
+	/* fall right through */
+	case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
+	case_RENEW_REQUESTED:
+	case RENEWING:
+	if (timeout > 60) {
+	/* send an unicast renew request */
+	/* Sometimes observed to fail (EADDRNOTAVAIL) to bind
+	* a new UDP socket for sending inside send_renew.
+	* I hazard to guess existing listening socket
+	* is somehow conflicting with it, but why is it
+	* not deterministic then?! Strange.
+	* Anyway, it does recover by eventually failing through
+	* into INIT_SELECTING state.
+	*/
+	send_d6_renew(xid, &srv6_buf, requested_ipv6);
+	timeout >>= 1;
+	continue;
+	}
+	/* Timed out, enter rebinding state */
+	log1("Entering rebinding state");
+	state = REBINDING;
+	/* fall right through */
+	case REBINDING:
+	/* Switch to bcast receive */
+	change_listen_mode(LISTEN_RAW);
+	/* Lease is really about to run out,
+	* try to find DHCP server using broadcast */
+	if (timeout > 0) {
+	/* send a broadcast renew request */
+	send_d6_renew(xid, /server_ipv6:/ NULL, requested_ipv6);
+	timeout >>= 1;
+	continue;
+	}
+	/* Timed out, enter init state */
+	bb_info_msg("Lease lost, entering init state");
+	d6_run_script(NULL, "deconfig");
+	state = INIT_SELECTING;
+	client_config.first_secs = 0; /* make secs field count from 0 */
+	/timeout = 0; - already is /
+	packet_num = 0;
+	continue;
+	/* case RELEASED: */
+	}
+	/* yah, I know, you say it would never happen */
+	timeout = INT_MAX;
+	continue; /* back to main loop */
+	} /* if select timed out */
+
+	/* select() didn't timeout, something happened */
+
+	/* Is it a signal? */
+	/* note: udhcp_sp_read checks FD_ISSET before reading */
+	switch (udhcp_sp_read(&rfds)) {
+	case SIGUSR1:
+	client_config.first_secs = 0; /* make secs field count from 0 */
+	already_waited_sec = 0;
+	perform_renew();
+	if (state == RENEW_REQUESTED) {
+	/* We might be either on the same network
+	* (in which case renew might work),
+	* or we might be on a completely different one
+	* (in which case renew won't ever succeed).
+	* For the second case, must make sure timeout
+	* is not too big, or else we can send
+	* futile renew requests for hours.
+	* (Ab)use -A TIMEOUT value (usually 20 sec)
+	* as a cap on the timeout.
+	*/
+	if (timeout > tryagain_timeout)
+	timeout = tryagain_timeout;
+	goto case_RENEW_REQUESTED;
+	}
+	/* Start things over */
+	packet_num = 0;
+	/* Kill any timeouts, user wants this to hurry along */
+	timeout = 0;
+	continue;
+	case SIGUSR2:
+	perform_d6_release(&srv6_buf, requested_ipv6);
+	timeout = INT_MAX;
+	continue;
+	case SIGTERM:
+	bb_info_msg("Received SIGTERM");
+	goto ret0;
+	}
+
+	/* Is it a packet? */
+	if (listen_mode == LISTEN_NONE \|\| !FD_ISSET(sockfd, &rfds))
+	continue; /* no */
+
+	{
+	int len;
+
+	/* A packet is ready, read it */
+	if (listen_mode == LISTEN_KERNEL)
+	len = d6_recv_kernel_packet(&srv6_buf, &packet, sockfd);
+	else
+	len = d6_recv_raw_packet(&srv6_buf, &packet, sockfd);
+	if (len == -1) {
+	/* Error is severe, reopen socket */
+	bb_info_msg("Read error: %s, reopening socket", strerror(errno));
+	sleep(discover_timeout); /* 3 seconds by default */
+	change_listen_mode(listen_mode); /* just close and reopen */
+	}
+	/* If this packet will turn out to be unrelated/bogus,
+	* we will go back and wait for next one.
+	* Be sure timeout is properly decreased. */
+	already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
+	if (len < 0)
+	continue;
+	packet_end = (uint8_t*)&packet + len;
+	}
+
+	if ((packet.d6_xid32 & htonl(0x00ffffff)) != xid) {
+	log1("xid %x (our is %x), ignoring packet",
+	(unsigned)(packet.d6_xid32 & htonl(0x00ffffff)), (unsigned)xid);
+	continue;
+	}
+
+	switch (state) {
+	case INIT_SELECTING:
+	if (packet.d6_msg_type == D6_MSG_ADVERTISE)
+	goto type_is_ok;
+	/* DHCPv6 has "Rapid Commit", when instead of Advertise,
+	* server sends Reply right away.
+	* Fall through to check for this case.
+	*/
+	case REQUESTING:
+	case RENEWING:
+	case RENEW_REQUESTED:
+	case REBINDING:
+	if (packet.d6_msg_type == D6_MSG_REPLY) {
+	uint32_t lease_seconds;
+	struct d6_option option, iaaddr;
+	type_is_ok:
+	option = d6_find_option(packet.d6_options, packet_end, D6_OPT_STATUS_CODE);
+	if (option && option->data[4] != 0) {
+	/* return to init state */
+	bb_info_msg("Received DHCP NAK (%u)", option->data[4]);
+	d6_run_script(&packet, "nak");
+	if (state != REQUESTING)
+	d6_run_script(NULL, "deconfig");
+	change_listen_mode(LISTEN_RAW);
+	sleep(3); /* avoid excessive network traffic */
+	state = INIT_SELECTING;
+	client_config.first_secs = 0; /* make secs field count from 0 */
+	requested_ipv6 = NULL;
+	timeout = 0;
+	packet_num = 0;
+	already_waited_sec = 0;
+	continue;
+	}
+	option = d6_copy_option(packet.d6_options, packet_end, D6_OPT_SERVERID);
+	if (!option) {
+	bb_error_msg("no server ID, ignoring packet");
+	continue;
+	/* still selecting - this server looks bad */
+	}
+	//Note: we do not bother comparing server IDs in Advertise and Reply msgs.
+	//server_id variable is used solely for creation of proper server_id option
+	//in outgoing packets. (why DHCPv6 even introduced it is a mystery).
+	free(client6_data.server_id);
+	client6_data.server_id = option;
+	if (packet.d6_msg_type == D6_MSG_ADVERTISE) {
+	/* enter requesting state */
+	state = REQUESTING;
+	timeout = 0;
+	packet_num = 0;
+	already_waited_sec = 0;
+	continue;
+	}
+	/* It's a D6_MSG_REPLY */
+	/*
+	* RFC 3315 18.1.8. Receipt of Reply Messages
+	*
+	* Upon the receipt of a valid Reply message in response to a Solicit
+	* (with a Rapid Commit option), Request, Confirm, Renew, Rebind or
+	* Information-request message, the client extracts the configuration
+	* information contained in the Reply. The client MAY choose to report
+	* any status code or message from the status code option in the Reply
+	* message.
+	*
+	* The client SHOULD perform duplicate address detection [17] on each of
+	* the addresses in any IAs it receives in the Reply message before
+	* using that address for traffic. If any of the addresses are found to
+	* be in use on the link, the client sends a Decline message to the
+	* server as described in section 18.1.7.
+	*
+	* If the Reply was received in response to a Solicit (with a Rapid
+	* Commit option), Request, Renew or Rebind message, the client updates
+	* the information it has recorded about IAs from the IA options
+	* contained in the Reply message:
+	*
+	* - Record T1 and T2 times.
+	*
+	* - Add any new addresses in the IA option to the IA as recorded by
+	* the client.
+	*
+	* - Update lifetimes for any addresses in the IA option that the
+	* client already has recorded in the IA.
+	*
+	* - Discard any addresses from the IA, as recorded by the client, that
+	* have a valid lifetime of 0 in the IA Address option.
+	*
+	* - Leave unchanged any information about addresses the client has
+	* recorded in the IA but that were not included in the IA from the
+	* server.
+	*
+	* Management of the specific configuration information is detailed in
+	* the definition of each option in section 22.
+	*
+	* If the client receives a Reply message with a Status Code containing
+	* UnspecFail, the server is indicating that it was unable to process
+	* the message due to an unspecified failure condition. If the client
+	* retransmits the original message to the same server to retry the
+	* desired operation, the client MUST limit the rate at which it
+	* retransmits the message and limit the duration of the time during
+	* which it retransmits the message.
+	*
+	* When the client receives a Reply message with a Status Code option
+	* with the value UseMulticast, the client records the receipt of the
+	* message and sends subsequent messages to the server through the
+	* interface on which the message was received using multicast. The
+	* client resends the original message using multicast.
+	*
+	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	* \| OPTION_IA_NA \| option-len \|
+	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	* \| IAID (4 octets) \|
+	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	* \| T1 \|
+	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	* \| T2 \|
+	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	* \| \|
+	* . IA_NA-options .
+	* . .
+	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	*
+	*
+	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	* \| OPTION_IAADDR \| option-len \|
+	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	* \| \|
+	* \| IPv6 address \|
+	* \| \|
+	* \| \|
+	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	* \| preferred-lifetime \|
+	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	* \| valid-lifetime \|
+	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	* . .
+	* . IAaddr-options .
+	* . .
+	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	*/
+	free(client6_data.ia_na);
+	client6_data.ia_na = d6_copy_option(packet.d6_options, packet_end, D6_OPT_IA_NA);
+	if (!client6_data.ia_na) {
+	bb_error_msg("no lease time, ignoring packet");
+	continue;
+	}
+	if (client6_data.ia_na->len < (4 + 4 + 4) + (2 + 2 + 16 + 4 + 4)) {
+	bb_error_msg("IA_NA option is too short:%d bytes", client6_data.ia_na->len);
+	continue;
+	}
+	iaaddr = d6_find_option(client6_data.ia_na->data,
+	client6_data.ia_na->data + client6_data.ia_na->len,
+	D6_OPT_IAADDR
+	);
+	if (!iaaddr) {
+	bb_error_msg("no lease time, ignoring packet");
+	continue;
+	}
+	if (iaaddr->len < (16 + 4 + 4)) {
+	bb_error_msg("IAADDR option is too short:%d bytes", iaaddr->len);
+	continue;
+	}
+	/* Note: the address is sufficiently aligned for cast:
+	* we _copied_ IA-NA, and copy is always well-aligned.
+	*/
+	requested_ipv6 = (struct in6_addr*) iaaddr->data;
+	move_from_unaligned32(lease_seconds, iaaddr->data + 16 + 4);
+	lease_seconds = ntohl(lease_seconds);
+	/* paranoia: must not be too small and not prone to overflows */
+	if (lease_seconds < 0x10)
+	lease_seconds = 0x10;
+	/// TODO: check for 0 lease time?
+	if (lease_seconds >= 0x10000000)
+	lease_seconds = 0x0fffffff;
+	/* enter bound state */
+	timeout = lease_seconds / 2;
+	bb_info_msg("Lease obtained, lease time %u",
+	/inet_ntoa(temp_addr),/ (unsigned)lease_seconds);
+	d6_run_script(&packet, state == REQUESTING ? "bound" : "renew");
+
+	state = BOUND;
+	change_listen_mode(LISTEN_NONE);
+	if (opt & OPT_q) { /* quit after lease */
+	goto ret0;
+	}
+	/* future renew failures should not exit (JM) */
+	opt &= ~OPT_n;
+	#if BB_MMU /* NOMMU case backgrounded earlier */
+	if (!(opt & OPT_f)) {
+	client_background();
+	/* do not background again! */
+	opt = ((opt & ~OPT_b) \| OPT_f);
+	}
+	#endif
+	already_waited_sec = 0;
+	continue; /* back to main loop */
+	}
+	continue;
+	/* case BOUND: - ignore all packets */
+	/* case RELEASED: - ignore all packets */
+	}
+	/* back to main loop */
+	} /* for (;;) - main loop ends */
+
+	ret0:
+	if (opt & OPT_R) /* release on quit */
+	perform_d6_release(&srv6_buf, requested_ipv6);
+	retval = 0;
+	ret:
+	/if (client_config.pidfile) - remove_pidfile has its own check /
+	remove_pidfile(client_config.pidfile);
+	return retval;
+	}

networking/udhcp/d6_packet.c+168 -0

@@ -0,0 +1,168 @@
+	/* vi: set sw=4 ts=4: */
+	/*
+	* Copyright (C) 2011 Denys Vlasenko.
+	*
+	* Licensed under GPLv2, see file LICENSE in this source tree.
+	*/
+	#include "common.h"
+	#include "d6_common.h"
+	#include "dhcpd.h"
+	#include <netinet/in.h>
+	#include <netinet/if_ether.h>
+	#include <netpacket/packet.h>
+
+	#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
+	void FAST_FUNC d6_dump_packet(struct d6_packet *packet)
+	{
+	if (dhcp_verbose < 2)
+	return;
+
+	bb_info_msg(
+	" xid %x"
+	, packet->d6_xid32
+	);
+	//bin2hex(buf, (void ) packet->chaddr, sizeof(packet->chaddr)) = '\0';
+	//bb_info_msg(" chaddr %s", buf);
+	}
+	#endif
+
+	int FAST_FUNC d6_recv_kernel_packet(struct in6_addr *peer_ipv6
+	UNUSED_PARAM
+	, struct d6_packet *packet, int fd)
+	{
+	int bytes;
+
+	memset(packet, 0, sizeof(*packet));
+	bytes = safe_read(fd, packet, sizeof(*packet));
+	if (bytes < 0) {
+	log1("Packet read error, ignoring");
+	return bytes; /* returns -1 */
+	}
+
+	if (bytes < offsetof(struct d6_packet, d6_options)) {
+	bb_info_msg("Packet with bad magic, ignoring");
+	return -2;
+	}
+	log1("Received a packet");
+	d6_dump_packet(packet);
+
+	return bytes;
+	}
+
+	/* Construct a ipv6+udp header for a packet, send packet */
+	int FAST_FUNC d6_send_raw_packet(
+	struct d6_packet *d6_pkt, unsigned d6_pkt_size,
+	struct in6_addr *src_ipv6, int source_port,
+	struct in6_addr dst_ipv6, int dest_port, const uint8_t dest_arp,
+	int ifindex)
+	{
+	struct sockaddr_ll dest_sll;
+	struct ip6_udp_d6_packet packet;
+	int fd;
+	int result = -1;
+	const char *msg;
+
+	fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IPV6));
+	if (fd < 0) {
+	msg = "socket(%s)";
+	goto ret_msg;
+	}
+
+	memset(&dest_sll, 0, sizeof(dest_sll));
+	memset(&packet, 0, offsetof(struct ip6_udp_d6_packet, data));
+	packet.data = d6_pkt; / struct copy */
+
+	dest_sll.sll_family = AF_PACKET;
+	dest_sll.sll_protocol = htons(ETH_P_IPV6);
+	dest_sll.sll_ifindex = ifindex;
+	dest_sll.sll_halen = 6;
+	memcpy(dest_sll.sll_addr, dest_arp, 6);
+
+	if (bind(fd, (struct sockaddr *)&dest_sll, sizeof(dest_sll)) < 0) {
+	msg = "bind(%s)";
+	goto ret_close;
+	}
+
+	packet.ip6.ip6_vfc = (6 << 4); /* 4 bits version, top 4 bits of tclass */
+	if (src_ipv6)
+	packet.ip6.ip6_src = src_ipv6; / struct copy */
+	packet.ip6.ip6_dst = dst_ipv6; / struct copy */
+	packet.udp.source = htons(source_port);
+	packet.udp.dest = htons(dest_port);
+	/* size, excluding IP header: */
+	packet.udp.len = htons(sizeof(struct udphdr) + d6_pkt_size);
+	packet.ip6.ip6_plen = packet.udp.len;
+	/* UDP checksum skips first four bytes of IP header.
+	* IPv6 'hop limit' field should be 0.
+	* 'next header' field should be summed as if it is in a different
+	* position, therefore we write its value into ip6_hlim:
+	*/
+	packet.ip6.ip6_hlim = IPPROTO_UDP;
+	packet.udp.check = inet_cksum((uint16_t *)&packet + 2,
+	offsetof(struct ip6_udp_d6_packet, data) - 4 + d6_pkt_size);
+	/* fix 'hop limit' and 'next header' after UDP checksumming */
+	packet.ip6.ip6_hlim = 8;
+	packet.ip6.ip6_nxt = IPPROTO_UDP;
+
+	d6_dump_packet(d6_pkt);
+	result = sendto(fd, &packet, offsetof(struct ip6_udp_d6_packet, data) + d6_pkt_size,
+	/flags:/ 0,
+	(struct sockaddr *) &dest_sll, sizeof(dest_sll)
+	);
+	msg = "sendto";
+	ret_close:
+	close(fd);
+	if (result < 0) {
+	ret_msg:
+	bb_perror_msg(msg, "PACKET");
+	}
+	return result;
+	}
+
+	/* Let the kernel do all the work for packet generation */
+	int FAST_FUNC d6_send_kernel_packet(
+	struct d6_packet *d6_pkt, unsigned d6_pkt_size,
+	struct in6_addr *src_ipv6, int source_port,
+	struct in6_addr *dst_ipv6, int dest_port)
+	{
+	struct sockaddr_in6 sa;
+	int fd;
+	int result = -1;
+	const char *msg;
+
+	fd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
+	if (fd < 0) {
+	msg = "socket(%s)";
+	goto ret_msg;
+	}
+	setsockopt_reuseaddr(fd);
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sin6_family = AF_INET6;
+	sa.sin6_port = htons(source_port);
+	sa.sin6_addr = src_ipv6; / struct copy */
+	if (bind(fd, (struct sockaddr *)&sa, sizeof(sa)) == -1) {
+	msg = "bind(%s)";
+	goto ret_close;
+	}
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sin6_family = AF_INET6;
+	sa.sin6_port = htons(dest_port);
+	sa.sin6_addr = dst_ipv6; / struct copy */
+	if (connect(fd, (struct sockaddr *)&sa, sizeof(sa)) == -1) {
+	msg = "connect";
+	goto ret_close;
+	}
+
+	d6_dump_packet(d6_pkt);
+	result = safe_write(fd, d6_pkt, d6_pkt_size);
+	msg = "write";
+	ret_close:
+	close(fd);
+	if (result < 0) {
+	ret_msg:
+	bb_perror_msg(msg, "UDP");
+	}
+	return result;
+	}

networking/udhcp/d6_socket.c+34 -0

@@ -0,0 +1,34 @@
+	/* vi: set sw=4 ts=4: */
+	/*
+	* Copyright (C) 2011 Denys Vlasenko.
+	*
+	* Licensed under GPLv2, see file LICENSE in this source tree.
+	*/
+	#include "common.h"
+	#include "d6_common.h"
+	#include <net/if.h>
+
+	int FAST_FUNC d6_listen_socket(int port, const char *inf)
+	{
+	int fd;
+	struct sockaddr_in6 addr;
+
+	log1("Opening listen socket on *:%d %s", port, inf);
+	fd = xsocket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
+
+	setsockopt_reuseaddr(fd);
+	if (setsockopt_broadcast(fd) == -1)
+	bb_perror_msg_and_die("SO_BROADCAST");
+
+	/* NB: bug 1032 says this doesn't work on ethernet aliases (ethN:M) */
+	if (setsockopt_bindtodevice(fd, inf))
+	xfunc_die(); /* warning is already printed */
+
+	memset(&addr, 0, sizeof(addr));
+	addr.sin6_family = AF_INET6;
+	addr.sin6_port = htons(port);
+	/* addr.sin6_addr is all-zeros */
+	xbind(fd, (struct sockaddr *)&addr, sizeof(addr));
+
+	return fd;
+	}