--- /dev/null
+/* 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 <sux@loplof.de>.
+ * 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;
+}
projects / oweals / busybox.git / commitdiff