[3621] | 1 | /* vi: set sw=4 ts=4: */
|
---|
| 2 | /*
|
---|
| 3 | * DHCPv6 client.
|
---|
| 4 | *
|
---|
| 5 | * 2011-11.
|
---|
| 6 | * WARNING: THIS CODE IS INCOMPLETE. IT IS NOWHERE NEAR
|
---|
| 7 | * TO BE READY FOR PRODUCTION USE.
|
---|
| 8 | *
|
---|
| 9 | * Copyright (C) 2011 Denys Vlasenko.
|
---|
| 10 | *
|
---|
| 11 | * Licensed under GPLv2, see file LICENSE in this source tree.
|
---|
| 12 | */
|
---|
| 13 |
|
---|
| 14 | //config:config UDHCPC6
|
---|
| 15 | //config: bool "udhcp client for DHCPv6 (udhcpc6)"
|
---|
| 16 | //config: default n # not yet ready
|
---|
| 17 | //config: depends on FEATURE_IPV6
|
---|
| 18 | //config: help
|
---|
| 19 | //config: udhcpc6 is a DHCPv6 client
|
---|
| 20 |
|
---|
| 21 | //applet:IF_UDHCPC6(APPLET(udhcpc6, BB_DIR_USR_BIN, BB_SUID_DROP))
|
---|
| 22 |
|
---|
| 23 | //kbuild:lib-$(CONFIG_UDHCPC6) += d6_dhcpc.o d6_packet.o d6_socket.o common.o socket.o signalpipe.o
|
---|
| 24 |
|
---|
| 25 |
|
---|
| 26 | #include <syslog.h>
|
---|
| 27 | /* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
|
---|
| 28 | #define WANT_PIDFILE 1
|
---|
| 29 | #include "common.h"
|
---|
| 30 | #include "dhcpd.h"
|
---|
| 31 | #include "dhcpc.h"
|
---|
| 32 | #include "d6_common.h"
|
---|
| 33 |
|
---|
| 34 | #include <netinet/if_ether.h>
|
---|
| 35 | #include <netpacket/packet.h>
|
---|
| 36 | #include <linux/filter.h>
|
---|
| 37 |
|
---|
| 38 | /* "struct client_config_t client_config" is in bb_common_bufsiz1 */
|
---|
| 39 |
|
---|
| 40 |
|
---|
| 41 | #if ENABLE_LONG_OPTS
|
---|
| 42 | static const char udhcpc6_longopts[] ALIGN1 =
|
---|
| 43 | "interface\0" Required_argument "i"
|
---|
| 44 | "now\0" No_argument "n"
|
---|
| 45 | "pidfile\0" Required_argument "p"
|
---|
| 46 | "quit\0" No_argument "q"
|
---|
| 47 | "release\0" No_argument "R"
|
---|
| 48 | "request\0" Required_argument "r"
|
---|
| 49 | "script\0" Required_argument "s"
|
---|
| 50 | "timeout\0" Required_argument "T"
|
---|
| 51 | "retries\0" Required_argument "t"
|
---|
| 52 | "tryagain\0" Required_argument "A"
|
---|
| 53 | "syslog\0" No_argument "S"
|
---|
| 54 | "request-option\0" Required_argument "O"
|
---|
| 55 | "no-default-options\0" No_argument "o"
|
---|
| 56 | "foreground\0" No_argument "f"
|
---|
| 57 | "background\0" No_argument "b"
|
---|
| 58 | /// IF_FEATURE_UDHCPC_ARPING("arping\0" No_argument "a")
|
---|
| 59 | IF_FEATURE_UDHCP_PORT("client-port\0" Required_argument "P")
|
---|
| 60 | ;
|
---|
| 61 | #endif
|
---|
| 62 | /* Must match getopt32 option string order */
|
---|
| 63 | enum {
|
---|
| 64 | OPT_i = 1 << 0,
|
---|
| 65 | OPT_n = 1 << 1,
|
---|
| 66 | OPT_p = 1 << 2,
|
---|
| 67 | OPT_q = 1 << 3,
|
---|
| 68 | OPT_R = 1 << 4,
|
---|
| 69 | OPT_r = 1 << 5,
|
---|
| 70 | OPT_s = 1 << 6,
|
---|
| 71 | OPT_T = 1 << 7,
|
---|
| 72 | OPT_t = 1 << 8,
|
---|
| 73 | OPT_S = 1 << 9,
|
---|
| 74 | OPT_A = 1 << 10,
|
---|
| 75 | OPT_O = 1 << 11,
|
---|
| 76 | OPT_o = 1 << 12,
|
---|
| 77 | OPT_x = 1 << 13,
|
---|
| 78 | OPT_f = 1 << 14,
|
---|
| 79 | /* The rest has variable bit positions, need to be clever */
|
---|
| 80 | OPTBIT_f = 14,
|
---|
| 81 | USE_FOR_MMU( OPTBIT_b,)
|
---|
| 82 | ///IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,)
|
---|
| 83 | IF_FEATURE_UDHCP_PORT( OPTBIT_P,)
|
---|
| 84 | USE_FOR_MMU( OPT_b = 1 << OPTBIT_b,)
|
---|
| 85 | ///IF_FEATURE_UDHCPC_ARPING(OPT_a = 1 << OPTBIT_a,)
|
---|
| 86 | IF_FEATURE_UDHCP_PORT( OPT_P = 1 << OPTBIT_P,)
|
---|
| 87 | };
|
---|
| 88 |
|
---|
| 89 |
|
---|
| 90 | /*** Utility functions ***/
|
---|
| 91 |
|
---|
| 92 | static void *d6_find_option(uint8_t *option, uint8_t *option_end, unsigned code)
|
---|
| 93 | {
|
---|
| 94 | /* "length minus 4" */
|
---|
| 95 | int len_m4 = option_end - option - 4;
|
---|
| 96 | while (len_m4 >= 0) {
|
---|
| 97 | /* Next option's len is too big? */
|
---|
| 98 | if (option[3] > len_m4)
|
---|
| 99 | return NULL; /* yes. bogus packet! */
|
---|
| 100 | /* So far we treat any opts with code >255
|
---|
| 101 | * or len >255 as bogus, and stop at once.
|
---|
| 102 | * This simplifies big-endian handling.
|
---|
| 103 | */
|
---|
| 104 | if (option[0] != 0 || option[2] != 0)
|
---|
| 105 | return NULL;
|
---|
| 106 | /* Option seems to be valid */
|
---|
| 107 | /* Does its code match? */
|
---|
| 108 | if (option[1] == code)
|
---|
| 109 | return option; /* yes! */
|
---|
| 110 | option += option[3] + 4;
|
---|
| 111 | len_m4 -= option[3] + 4;
|
---|
| 112 | }
|
---|
| 113 | return NULL;
|
---|
| 114 | }
|
---|
| 115 |
|
---|
| 116 | static void *d6_copy_option(uint8_t *option, uint8_t *option_end, unsigned code)
|
---|
| 117 | {
|
---|
| 118 | uint8_t *opt = d6_find_option(option, option_end, code);
|
---|
| 119 | if (!opt)
|
---|
| 120 | return opt;
|
---|
| 121 | return xmemdup(opt, opt[3] + 4);
|
---|
| 122 | }
|
---|
| 123 |
|
---|
| 124 | static void *d6_store_blob(void *dst, const void *src, unsigned len)
|
---|
| 125 | {
|
---|
| 126 | memcpy(dst, src, len);
|
---|
| 127 | return dst + len;
|
---|
| 128 | }
|
---|
| 129 |
|
---|
| 130 |
|
---|
| 131 | /*** Script execution code ***/
|
---|
| 132 |
|
---|
| 133 | static char** new_env(void)
|
---|
| 134 | {
|
---|
| 135 | client6_data.env_ptr = xrealloc_vector(client6_data.env_ptr, 3, client6_data.env_idx);
|
---|
| 136 | return &client6_data.env_ptr[client6_data.env_idx++];
|
---|
| 137 | }
|
---|
| 138 |
|
---|
| 139 | /* put all the parameters into the environment */
|
---|
| 140 | static void option_to_env(uint8_t *option, uint8_t *option_end)
|
---|
| 141 | {
|
---|
| 142 | /* "length minus 4" */
|
---|
| 143 | int len_m4 = option_end - option - 4;
|
---|
| 144 | while (len_m4 >= 0) {
|
---|
| 145 | uint32_t v32;
|
---|
| 146 | char ipv6str[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff")];
|
---|
| 147 |
|
---|
| 148 | if (option[0] != 0 || option[2] != 0)
|
---|
| 149 | break;
|
---|
| 150 |
|
---|
| 151 | switch (option[1]) {
|
---|
| 152 | //case D6_OPT_CLIENTID:
|
---|
| 153 | //case D6_OPT_SERVERID:
|
---|
| 154 | case D6_OPT_IA_NA:
|
---|
| 155 | case D6_OPT_IA_PD:
|
---|
| 156 | option_to_env(option + 16, option + 4 + option[3]);
|
---|
| 157 | break;
|
---|
| 158 | //case D6_OPT_IA_TA:
|
---|
| 159 | case D6_OPT_IAADDR:
|
---|
| 160 | /* 0 1 2 3
|
---|
| 161 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
|
---|
| 162 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 163 | * | OPTION_IAADDR | option-len |
|
---|
| 164 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 165 | * | |
|
---|
| 166 | * | IPv6 address |
|
---|
| 167 | * | |
|
---|
| 168 | * | |
|
---|
| 169 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 170 | * | preferred-lifetime |
|
---|
| 171 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 172 | * | valid-lifetime |
|
---|
| 173 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 174 | */
|
---|
| 175 | sprint_nip6(ipv6str, option + 4);
|
---|
| 176 | *new_env() = xasprintf("ipv6=%s", ipv6str);
|
---|
| 177 |
|
---|
| 178 | move_from_unaligned32(v32, option + 4 + 16 + 4);
|
---|
| 179 | *new_env() = xasprintf("lease=%u", (unsigned)v32);
|
---|
| 180 | break;
|
---|
| 181 |
|
---|
| 182 | //case D6_OPT_ORO:
|
---|
| 183 | //case D6_OPT_PREFERENCE:
|
---|
| 184 | //case D6_OPT_ELAPSED_TIME:
|
---|
| 185 | //case D6_OPT_RELAY_MSG:
|
---|
| 186 | //case D6_OPT_AUTH:
|
---|
| 187 | //case D6_OPT_UNICAST:
|
---|
| 188 | //case D6_OPT_STATUS_CODE:
|
---|
| 189 | //case D6_OPT_RAPID_COMMIT:
|
---|
| 190 | //case D6_OPT_USER_CLASS:
|
---|
| 191 | //case D6_OPT_VENDOR_CLASS:
|
---|
| 192 | //case D6_OPT_VENDOR_OPTS:
|
---|
| 193 | //case D6_OPT_INTERFACE_ID:
|
---|
| 194 | //case D6_OPT_RECONF_MSG:
|
---|
| 195 | //case D6_OPT_RECONF_ACCEPT:
|
---|
| 196 |
|
---|
| 197 | case D6_OPT_IAPREFIX:
|
---|
| 198 | /* 0 1 2 3
|
---|
| 199 | * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
|
---|
| 200 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 201 | * | OPTION_IAPREFIX | option-length |
|
---|
| 202 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 203 | * | preferred-lifetime |
|
---|
| 204 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 205 | * | valid-lifetime |
|
---|
| 206 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 207 | * | prefix-length | |
|
---|
| 208 | * +-+-+-+-+-+-+-+-+ IPv6 prefix |
|
---|
| 209 | * | (16 octets) |
|
---|
| 210 | * | |
|
---|
| 211 | * | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 212 | * | |
|
---|
| 213 | * +-+-+-+-+-+-+-+-+
|
---|
| 214 | */
|
---|
| 215 | //move_from_unaligned32(v32, option + 4 + 4);
|
---|
| 216 | //*new_env() = xasprintf("lease=%u", (unsigned)v32);
|
---|
| 217 |
|
---|
| 218 | sprint_nip6(ipv6str, option + 4 + 4 + 1);
|
---|
| 219 | *new_env() = xasprintf("ipv6prefix=%s/%u", ipv6str, (unsigned)(option[4 + 4]));
|
---|
| 220 | }
|
---|
| 221 | option += 4 + option[3];
|
---|
| 222 | len_m4 -= 4 + option[3];
|
---|
| 223 | }
|
---|
| 224 | }
|
---|
| 225 |
|
---|
| 226 | static char **fill_envp(struct d6_packet *packet)
|
---|
| 227 | {
|
---|
| 228 | char **envp, **curr;
|
---|
| 229 |
|
---|
| 230 | client6_data.env_ptr = NULL;
|
---|
| 231 | client6_data.env_idx = 0;
|
---|
| 232 |
|
---|
| 233 | *new_env() = xasprintf("interface=%s", client_config.interface);
|
---|
| 234 |
|
---|
| 235 | if (packet)
|
---|
| 236 | option_to_env(packet->d6_options, packet->d6_options + sizeof(packet->d6_options));
|
---|
| 237 |
|
---|
| 238 | envp = curr = client6_data.env_ptr;
|
---|
| 239 | while (*curr)
|
---|
| 240 | putenv(*curr++);
|
---|
| 241 |
|
---|
| 242 | return envp;
|
---|
| 243 | }
|
---|
| 244 |
|
---|
| 245 | /* Call a script with a par file and env vars */
|
---|
| 246 | static void d6_run_script(struct d6_packet *packet, const char *name)
|
---|
| 247 | {
|
---|
| 248 | char **envp, **curr;
|
---|
| 249 | char *argv[3];
|
---|
| 250 |
|
---|
| 251 | envp = fill_envp(packet);
|
---|
| 252 |
|
---|
| 253 | /* call script */
|
---|
| 254 | log1("executing %s %s", client_config.script, name);
|
---|
| 255 | argv[0] = (char*) client_config.script;
|
---|
| 256 | argv[1] = (char*) name;
|
---|
| 257 | argv[2] = NULL;
|
---|
| 258 | spawn_and_wait(argv);
|
---|
| 259 |
|
---|
| 260 | for (curr = envp; *curr; curr++) {
|
---|
| 261 | log2(" %s", *curr);
|
---|
| 262 | bb_unsetenv_and_free(*curr);
|
---|
| 263 | }
|
---|
| 264 | free(envp);
|
---|
| 265 | }
|
---|
| 266 |
|
---|
| 267 |
|
---|
| 268 | /*** Sending/receiving packets ***/
|
---|
| 269 |
|
---|
| 270 | static ALWAYS_INLINE uint32_t random_xid(void)
|
---|
| 271 | {
|
---|
| 272 | uint32_t t = rand() & htonl(0x00ffffff);
|
---|
| 273 | return t;
|
---|
| 274 | }
|
---|
| 275 |
|
---|
| 276 | /* Initialize the packet with the proper defaults */
|
---|
| 277 | static uint8_t *init_d6_packet(struct d6_packet *packet, char type, uint32_t xid)
|
---|
| 278 | {
|
---|
| 279 | struct d6_option *clientid;
|
---|
| 280 |
|
---|
| 281 | memset(packet, 0, sizeof(*packet));
|
---|
| 282 |
|
---|
| 283 | packet->d6_xid32 = xid;
|
---|
| 284 | packet->d6_msg_type = type;
|
---|
| 285 |
|
---|
| 286 | clientid = (void*)client_config.clientid;
|
---|
| 287 | return d6_store_blob(packet->d6_options, clientid, clientid->len + 2+2);
|
---|
| 288 | }
|
---|
| 289 |
|
---|
| 290 | static uint8_t *add_d6_client_options(uint8_t *ptr)
|
---|
| 291 | {
|
---|
| 292 | return ptr;
|
---|
| 293 | //uint8_t c;
|
---|
| 294 | //int i, end, len;
|
---|
| 295 |
|
---|
| 296 | /* Add a "param req" option with the list of options we'd like to have
|
---|
| 297 | * from stubborn DHCP servers. Pull the data from the struct in common.c.
|
---|
| 298 | * No bounds checking because it goes towards the head of the packet. */
|
---|
| 299 | //...
|
---|
| 300 |
|
---|
| 301 | /* Add -x options if any */
|
---|
| 302 | //...
|
---|
| 303 | }
|
---|
| 304 |
|
---|
| 305 | static int d6_mcast_from_client_config_ifindex(struct d6_packet *packet, uint8_t *end)
|
---|
| 306 | {
|
---|
| 307 | static const uint8_t FF02__1_2[16] = {
|
---|
| 308 | 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
|
---|
| 309 | 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02,
|
---|
| 310 | };
|
---|
| 311 |
|
---|
| 312 | return d6_send_raw_packet(
|
---|
| 313 | packet, (end - (uint8_t*) packet),
|
---|
| 314 | /*src*/ NULL, CLIENT_PORT6,
|
---|
| 315 | /*dst*/ (struct in6_addr*)FF02__1_2, SERVER_PORT6, MAC_BCAST_ADDR,
|
---|
| 316 | client_config.ifindex
|
---|
| 317 | );
|
---|
| 318 | }
|
---|
| 319 |
|
---|
| 320 | /* Milticast a DHCPv6 Solicit packet to the network, with an optionally requested IP.
|
---|
| 321 | *
|
---|
| 322 | * RFC 3315 17.1.1. Creation of Solicit Messages
|
---|
| 323 | *
|
---|
| 324 | * The client MUST include a Client Identifier option to identify itself
|
---|
| 325 | * to the server. The client includes IA options for any IAs to which
|
---|
| 326 | * it wants the server to assign addresses. The client MAY include
|
---|
| 327 | * addresses in the IAs as a hint to the server about addresses for
|
---|
| 328 | * which the client has a preference. ...
|
---|
| 329 | *
|
---|
| 330 | * The client uses IA_NA options to request the assignment of non-
|
---|
| 331 | * temporary addresses and uses IA_TA options to request the assignment
|
---|
| 332 | * of temporary addresses. Either IA_NA or IA_TA options, or a
|
---|
| 333 | * combination of both, can be included in DHCP messages.
|
---|
| 334 | *
|
---|
| 335 | * The client SHOULD include an Option Request option (see section 22.7)
|
---|
| 336 | * to indicate the options the client is interested in receiving. The
|
---|
| 337 | * client MAY additionally include instances of those options that are
|
---|
| 338 | * identified in the Option Request option, with data values as hints to
|
---|
| 339 | * the server about parameter values the client would like to have
|
---|
| 340 | * returned.
|
---|
| 341 | *
|
---|
| 342 | * The client includes a Reconfigure Accept option (see section 22.20)
|
---|
| 343 | * if the client is willing to accept Reconfigure messages from the
|
---|
| 344 | * server.
|
---|
| 345 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 346 | | OPTION_CLIENTID | option-len |
|
---|
| 347 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 348 | . .
|
---|
| 349 | . DUID .
|
---|
| 350 | . (variable length) .
|
---|
| 351 | . .
|
---|
| 352 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 353 |
|
---|
| 354 |
|
---|
| 355 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 356 | | OPTION_IA_NA | option-len |
|
---|
| 357 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 358 | | IAID (4 octets) |
|
---|
| 359 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 360 | | T1 |
|
---|
| 361 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 362 | | T2 |
|
---|
| 363 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 364 | | |
|
---|
| 365 | . IA_NA-options .
|
---|
| 366 | . .
|
---|
| 367 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 368 |
|
---|
| 369 |
|
---|
| 370 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 371 | | OPTION_IAADDR | option-len |
|
---|
| 372 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 373 | | |
|
---|
| 374 | | IPv6 address |
|
---|
| 375 | | |
|
---|
| 376 | | |
|
---|
| 377 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 378 | | preferred-lifetime |
|
---|
| 379 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 380 | | valid-lifetime |
|
---|
| 381 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 382 | . .
|
---|
| 383 | . IAaddr-options .
|
---|
| 384 | . .
|
---|
| 385 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 386 |
|
---|
| 387 |
|
---|
| 388 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 389 | | OPTION_ORO | option-len |
|
---|
| 390 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 391 | | requested-option-code-1 | requested-option-code-2 |
|
---|
| 392 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 393 | | ... |
|
---|
| 394 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 395 |
|
---|
| 396 |
|
---|
| 397 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 398 | | OPTION_RECONF_ACCEPT | 0 |
|
---|
| 399 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 400 | */
|
---|
| 401 | /* NOINLINE: limit stack usage in caller */
|
---|
| 402 | static NOINLINE int send_d6_discover(uint32_t xid, struct in6_addr *requested_ipv6)
|
---|
| 403 | {
|
---|
| 404 | struct d6_packet packet;
|
---|
| 405 | uint8_t *opt_ptr;
|
---|
| 406 | unsigned len;
|
---|
| 407 |
|
---|
| 408 | /* Fill in: msg type, client id */
|
---|
| 409 | opt_ptr = init_d6_packet(&packet, D6_MSG_SOLICIT, xid);
|
---|
| 410 |
|
---|
| 411 | /* Create new IA_NA, optionally with included IAADDR with requested IP */
|
---|
| 412 | free(client6_data.ia_na);
|
---|
| 413 | len = requested_ipv6 ? 2+2+4+4+4 + 2+2+16+4+4 : 2+2+4+4+4;
|
---|
| 414 | client6_data.ia_na = xzalloc(len);
|
---|
| 415 | client6_data.ia_na->code = D6_OPT_IA_NA;
|
---|
| 416 | client6_data.ia_na->len = len - 4;
|
---|
| 417 | *(uint32_t*)client6_data.ia_na->data = rand(); /* IAID */
|
---|
| 418 | if (requested_ipv6) {
|
---|
| 419 | struct d6_option *iaaddr = (void*)(client6_data.ia_na->data + 4+4+4);
|
---|
| 420 | iaaddr->code = D6_OPT_IAADDR;
|
---|
| 421 | iaaddr->len = 16+4+4;
|
---|
| 422 | memcpy(iaaddr->data, requested_ipv6, 16);
|
---|
| 423 | }
|
---|
| 424 | opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, len);
|
---|
| 425 |
|
---|
| 426 | /* Add options:
|
---|
| 427 | * "param req" option according to -O, options specified with -x
|
---|
| 428 | */
|
---|
| 429 | opt_ptr = add_d6_client_options(opt_ptr);
|
---|
| 430 |
|
---|
| 431 | bb_error_msg("sending %s", "discover");
|
---|
| 432 | return d6_mcast_from_client_config_ifindex(&packet, opt_ptr);
|
---|
| 433 | }
|
---|
| 434 |
|
---|
| 435 | /* Multicast a DHCPv6 request message
|
---|
| 436 | *
|
---|
| 437 | * RFC 3315 18.1.1. Creation and Transmission of Request Messages
|
---|
| 438 | *
|
---|
| 439 | * The client uses a Request message to populate IAs with addresses and
|
---|
| 440 | * obtain other configuration information. The client includes one or
|
---|
| 441 | * more IA options in the Request message. The server then returns
|
---|
| 442 | * addresses and other information about the IAs to the client in IA
|
---|
| 443 | * options in a Reply message.
|
---|
| 444 | *
|
---|
| 445 | * The client generates a transaction ID and inserts this value in the
|
---|
| 446 | * "transaction-id" field.
|
---|
| 447 | *
|
---|
| 448 | * The client places the identifier of the destination server in a
|
---|
| 449 | * Server Identifier option.
|
---|
| 450 | *
|
---|
| 451 | * The client MUST include a Client Identifier option to identify itself
|
---|
| 452 | * to the server. The client adds any other appropriate options,
|
---|
| 453 | * including one or more IA options (if the client is requesting that
|
---|
| 454 | * the server assign it some network addresses).
|
---|
| 455 | *
|
---|
| 456 | * The client MUST include an Option Request option (see section 22.7)
|
---|
| 457 | * to indicate the options the client is interested in receiving. The
|
---|
| 458 | * client MAY include options with data values as hints to the server
|
---|
| 459 | * about parameter values the client would like to have returned.
|
---|
| 460 | *
|
---|
| 461 | * The client includes a Reconfigure Accept option (see section 22.20)
|
---|
| 462 | * indicating whether or not the client is willing to accept Reconfigure
|
---|
| 463 | * messages from the server.
|
---|
| 464 | */
|
---|
| 465 | /* NOINLINE: limit stack usage in caller */
|
---|
| 466 | static NOINLINE int send_d6_select(uint32_t xid)
|
---|
| 467 | {
|
---|
| 468 | struct d6_packet packet;
|
---|
| 469 | uint8_t *opt_ptr;
|
---|
| 470 |
|
---|
| 471 | /* Fill in: msg type, client id */
|
---|
| 472 | opt_ptr = init_d6_packet(&packet, D6_MSG_REQUEST, xid);
|
---|
| 473 |
|
---|
| 474 | /* server id */
|
---|
| 475 | opt_ptr = d6_store_blob(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
|
---|
| 476 | /* IA NA (contains requested IP) */
|
---|
| 477 | opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2);
|
---|
| 478 |
|
---|
| 479 | /* Add options:
|
---|
| 480 | * "param req" option according to -O, options specified with -x
|
---|
| 481 | */
|
---|
| 482 | opt_ptr = add_d6_client_options(opt_ptr);
|
---|
| 483 |
|
---|
| 484 | bb_error_msg("sending %s", "select");
|
---|
| 485 | return d6_mcast_from_client_config_ifindex(&packet, opt_ptr);
|
---|
| 486 | }
|
---|
| 487 |
|
---|
| 488 | /* Unicast or broadcast a DHCP renew message
|
---|
| 489 | *
|
---|
| 490 | * RFC 3315 18.1.3. Creation and Transmission of Renew Messages
|
---|
| 491 | *
|
---|
| 492 | * To extend the valid and preferred lifetimes for the addresses
|
---|
| 493 | * associated with an IA, the client sends a Renew message to the server
|
---|
| 494 | * from which the client obtained the addresses in the IA containing an
|
---|
| 495 | * IA option for the IA. The client includes IA Address options in the
|
---|
| 496 | * IA option for the addresses associated with the IA. The server
|
---|
| 497 | * determines new lifetimes for the addresses in the IA according to the
|
---|
| 498 | * administrative configuration of the server. The server may also add
|
---|
| 499 | * new addresses to the IA. The server may remove addresses from the IA
|
---|
| 500 | * by setting the preferred and valid lifetimes of those addresses to
|
---|
| 501 | * zero.
|
---|
| 502 | *
|
---|
| 503 | * The server controls the time at which the client contacts the server
|
---|
| 504 | * to extend the lifetimes on assigned addresses through the T1 and T2
|
---|
| 505 | * parameters assigned to an IA.
|
---|
| 506 | *
|
---|
| 507 | * At time T1 for an IA, the client initiates a Renew/Reply message
|
---|
| 508 | * exchange to extend the lifetimes on any addresses in the IA. The
|
---|
| 509 | * client includes an IA option with all addresses currently assigned to
|
---|
| 510 | * the IA in its Renew message.
|
---|
| 511 | *
|
---|
| 512 | * If T1 or T2 is set to 0 by the server (for an IA_NA) or there are no
|
---|
| 513 | * T1 or T2 times (for an IA_TA), the client may send a Renew or Rebind
|
---|
| 514 | * message, respectively, at the client's discretion.
|
---|
| 515 | *
|
---|
| 516 | * The client sets the "msg-type" field to RENEW. The client generates
|
---|
| 517 | * a transaction ID and inserts this value in the "transaction-id"
|
---|
| 518 | * field.
|
---|
| 519 | *
|
---|
| 520 | * The client places the identifier of the destination server in a
|
---|
| 521 | * Server Identifier option.
|
---|
| 522 | *
|
---|
| 523 | * The client MUST include a Client Identifier option to identify itself
|
---|
| 524 | * to the server. The client adds any appropriate options, including
|
---|
| 525 | * one or more IA options. The client MUST include the list of
|
---|
| 526 | * addresses the client currently has associated with the IAs in the
|
---|
| 527 | * Renew message.
|
---|
| 528 | *
|
---|
| 529 | * The client MUST include an Option Request option (see section 22.7)
|
---|
| 530 | * to indicate the options the client is interested in receiving. The
|
---|
| 531 | * client MAY include options with data values as hints to the server
|
---|
| 532 | * about parameter values the client would like to have returned.
|
---|
| 533 | */
|
---|
| 534 | /* NOINLINE: limit stack usage in caller */
|
---|
| 535 | static NOINLINE int send_d6_renew(uint32_t xid, struct in6_addr *server_ipv6, struct in6_addr *our_cur_ipv6)
|
---|
| 536 | {
|
---|
| 537 | struct d6_packet packet;
|
---|
| 538 | uint8_t *opt_ptr;
|
---|
| 539 |
|
---|
| 540 | /* Fill in: msg type, client id */
|
---|
| 541 | opt_ptr = init_d6_packet(&packet, DHCPREQUEST, xid);
|
---|
| 542 |
|
---|
| 543 | /* server id */
|
---|
| 544 | opt_ptr = d6_store_blob(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
|
---|
| 545 | /* IA NA (contains requested IP) */
|
---|
| 546 | opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2);
|
---|
| 547 |
|
---|
| 548 | /* Add options:
|
---|
| 549 | * "param req" option according to -O, options specified with -x
|
---|
| 550 | */
|
---|
| 551 | opt_ptr = add_d6_client_options(opt_ptr);
|
---|
| 552 |
|
---|
| 553 | bb_error_msg("sending %s", "renew");
|
---|
| 554 | if (server_ipv6)
|
---|
| 555 | return d6_send_kernel_packet(
|
---|
| 556 | &packet, (opt_ptr - (uint8_t*) &packet),
|
---|
| 557 | our_cur_ipv6, CLIENT_PORT6,
|
---|
| 558 | server_ipv6, SERVER_PORT6
|
---|
| 559 | );
|
---|
| 560 | return d6_mcast_from_client_config_ifindex(&packet, opt_ptr);
|
---|
| 561 | }
|
---|
| 562 |
|
---|
| 563 | /* Unicast a DHCP release message */
|
---|
| 564 | static int send_d6_release(struct in6_addr *server_ipv6, struct in6_addr *our_cur_ipv6)
|
---|
| 565 | {
|
---|
| 566 | struct d6_packet packet;
|
---|
| 567 | uint8_t *opt_ptr;
|
---|
| 568 |
|
---|
| 569 | /* Fill in: msg type, client id */
|
---|
| 570 | opt_ptr = init_d6_packet(&packet, D6_MSG_RELEASE, random_xid());
|
---|
| 571 | /* server id */
|
---|
| 572 | opt_ptr = d6_store_blob(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2);
|
---|
| 573 | /* IA NA (contains our current IP) */
|
---|
| 574 | opt_ptr = d6_store_blob(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2);
|
---|
| 575 |
|
---|
| 576 | bb_error_msg("sending %s", "release");
|
---|
| 577 | return d6_send_kernel_packet(
|
---|
| 578 | &packet, (opt_ptr - (uint8_t*) &packet),
|
---|
| 579 | our_cur_ipv6, CLIENT_PORT6,
|
---|
| 580 | server_ipv6, SERVER_PORT6
|
---|
| 581 | );
|
---|
| 582 | }
|
---|
| 583 |
|
---|
| 584 | /* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
|
---|
| 585 | /* NOINLINE: limit stack usage in caller */
|
---|
| 586 | static NOINLINE int d6_recv_raw_packet(struct in6_addr *peer_ipv6
|
---|
| 587 | UNUSED_PARAM
|
---|
| 588 | , struct d6_packet *d6_pkt, int fd)
|
---|
| 589 | {
|
---|
| 590 | int bytes;
|
---|
| 591 | struct ip6_udp_d6_packet packet;
|
---|
| 592 |
|
---|
| 593 | bytes = safe_read(fd, &packet, sizeof(packet));
|
---|
| 594 | if (bytes < 0) {
|
---|
| 595 | log1("packet read error, ignoring");
|
---|
| 596 | /* NB: possible down interface, etc. Caller should pause. */
|
---|
| 597 | return bytes; /* returns -1 */
|
---|
| 598 | }
|
---|
| 599 |
|
---|
| 600 | if (bytes < (int) (sizeof(packet.ip6) + sizeof(packet.udp))) {
|
---|
| 601 | log1("packet is too short, ignoring");
|
---|
| 602 | return -2;
|
---|
| 603 | }
|
---|
| 604 |
|
---|
| 605 | if (bytes < sizeof(packet.ip6) + ntohs(packet.ip6.ip6_plen)) {
|
---|
| 606 | /* packet is bigger than sizeof(packet), we did partial read */
|
---|
| 607 | log1("oversized packet, ignoring");
|
---|
| 608 | return -2;
|
---|
| 609 | }
|
---|
| 610 |
|
---|
| 611 | /* ignore any extra garbage bytes */
|
---|
| 612 | bytes = sizeof(packet.ip6) + ntohs(packet.ip6.ip6_plen);
|
---|
| 613 |
|
---|
| 614 | /* make sure its the right packet for us, and that it passes sanity checks */
|
---|
| 615 | if (packet.ip6.ip6_nxt != IPPROTO_UDP
|
---|
| 616 | || (packet.ip6.ip6_vfc >> 4) != 6
|
---|
| 617 | || packet.udp.dest != htons(CLIENT_PORT6)
|
---|
| 618 | /* || bytes > (int) sizeof(packet) - can't happen */
|
---|
| 619 | || packet.udp.len != packet.ip6.ip6_plen
|
---|
| 620 | ) {
|
---|
| 621 | log1("unrelated/bogus packet, ignoring");
|
---|
| 622 | return -2;
|
---|
| 623 | }
|
---|
| 624 |
|
---|
| 625 | //How to do this for ipv6?
|
---|
| 626 | // /* verify UDP checksum. IP header has to be modified for this */
|
---|
| 627 | // memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
|
---|
| 628 | // /* ip.xx fields which are not memset: protocol, check, saddr, daddr */
|
---|
| 629 | // packet.ip.tot_len = packet.udp.len; /* yes, this is needed */
|
---|
| 630 | // check = packet.udp.check;
|
---|
| 631 | // packet.udp.check = 0;
|
---|
| 632 | // if (check && check != inet_cksum((uint16_t *)&packet, bytes)) {
|
---|
| 633 | // log1("packet with bad UDP checksum received, ignoring");
|
---|
| 634 | // return -2;
|
---|
| 635 | // }
|
---|
| 636 |
|
---|
| 637 | log1("received %s", "a packet");
|
---|
| 638 | d6_dump_packet(&packet.data);
|
---|
| 639 |
|
---|
| 640 | bytes -= sizeof(packet.ip6) + sizeof(packet.udp);
|
---|
| 641 | memcpy(d6_pkt, &packet.data, bytes);
|
---|
| 642 | return bytes;
|
---|
| 643 | }
|
---|
| 644 |
|
---|
| 645 |
|
---|
| 646 | /*** Main ***/
|
---|
| 647 |
|
---|
| 648 | static int sockfd = -1;
|
---|
| 649 |
|
---|
| 650 | #define LISTEN_NONE 0
|
---|
| 651 | #define LISTEN_KERNEL 1
|
---|
| 652 | #define LISTEN_RAW 2
|
---|
| 653 | static smallint listen_mode;
|
---|
| 654 |
|
---|
| 655 | /* initial state: (re)start DHCP negotiation */
|
---|
| 656 | #define INIT_SELECTING 0
|
---|
| 657 | /* discover was sent, DHCPOFFER reply received */
|
---|
| 658 | #define REQUESTING 1
|
---|
| 659 | /* select/renew was sent, DHCPACK reply received */
|
---|
| 660 | #define BOUND 2
|
---|
| 661 | /* half of lease passed, want to renew it by sending unicast renew requests */
|
---|
| 662 | #define RENEWING 3
|
---|
| 663 | /* renew requests were not answered, lease is almost over, send broadcast renew */
|
---|
| 664 | #define REBINDING 4
|
---|
| 665 | /* manually requested renew (SIGUSR1) */
|
---|
| 666 | #define RENEW_REQUESTED 5
|
---|
| 667 | /* release, possibly manually requested (SIGUSR2) */
|
---|
| 668 | #define RELEASED 6
|
---|
| 669 | static smallint state;
|
---|
| 670 |
|
---|
| 671 | static int d6_raw_socket(int ifindex)
|
---|
| 672 | {
|
---|
| 673 | int fd;
|
---|
| 674 | struct sockaddr_ll sock;
|
---|
| 675 |
|
---|
| 676 | /*
|
---|
| 677 | * Comment:
|
---|
| 678 | *
|
---|
| 679 | * I've selected not to see LL header, so BPF doesn't see it, too.
|
---|
| 680 | * The filter may also pass non-IP and non-ARP packets, but we do
|
---|
| 681 | * a more complete check when receiving the message in userspace.
|
---|
| 682 | *
|
---|
| 683 | * and filter shamelessly stolen from:
|
---|
| 684 | *
|
---|
| 685 | * http://www.flamewarmaster.de/software/dhcpclient/
|
---|
| 686 | *
|
---|
| 687 | * There are a few other interesting ideas on that page (look under
|
---|
| 688 | * "Motivation"). Use of netlink events is most interesting. Think
|
---|
| 689 | * of various network servers listening for events and reconfiguring.
|
---|
| 690 | * That would obsolete sending HUP signals and/or make use of restarts.
|
---|
| 691 | *
|
---|
| 692 | * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
|
---|
| 693 | * License: GPL v2.
|
---|
| 694 | *
|
---|
| 695 | * TODO: make conditional?
|
---|
| 696 | */
|
---|
| 697 | #if 0
|
---|
| 698 | static const struct sock_filter filter_instr[] = {
|
---|
| 699 | /* load 9th byte (protocol) */
|
---|
| 700 | BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
|
---|
| 701 | /* jump to L1 if it is IPPROTO_UDP, else to L4 */
|
---|
| 702 | BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6),
|
---|
| 703 | /* L1: load halfword from offset 6 (flags and frag offset) */
|
---|
| 704 | BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6),
|
---|
| 705 | /* jump to L4 if any bits in frag offset field are set, else to L2 */
|
---|
| 706 | BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0),
|
---|
| 707 | /* L2: skip IP header (load index reg with header len) */
|
---|
| 708 | BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0),
|
---|
| 709 | /* load udp destination port from halfword[header_len + 2] */
|
---|
| 710 | BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2),
|
---|
| 711 | /* jump to L3 if udp dport is CLIENT_PORT6, else to L4 */
|
---|
| 712 | BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1),
|
---|
| 713 | /* L3: accept packet */
|
---|
| 714 | BPF_STMT(BPF_RET|BPF_K, 0x7fffffff),
|
---|
| 715 | /* L4: discard packet */
|
---|
| 716 | BPF_STMT(BPF_RET|BPF_K, 0),
|
---|
| 717 | };
|
---|
| 718 | static const struct sock_fprog filter_prog = {
|
---|
| 719 | .len = sizeof(filter_instr) / sizeof(filter_instr[0]),
|
---|
| 720 | /* casting const away: */
|
---|
| 721 | .filter = (struct sock_filter *) filter_instr,
|
---|
| 722 | };
|
---|
| 723 | #endif
|
---|
| 724 |
|
---|
| 725 | log1("opening raw socket on ifindex %d", ifindex); //log2?
|
---|
| 726 |
|
---|
| 727 | fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IPV6));
|
---|
| 728 | log1("got raw socket fd %d", fd); //log2?
|
---|
| 729 |
|
---|
| 730 | sock.sll_family = AF_PACKET;
|
---|
| 731 | sock.sll_protocol = htons(ETH_P_IPV6);
|
---|
| 732 | sock.sll_ifindex = ifindex;
|
---|
| 733 | xbind(fd, (struct sockaddr *) &sock, sizeof(sock));
|
---|
| 734 |
|
---|
| 735 | #if 0
|
---|
| 736 | if (CLIENT_PORT6 == 546) {
|
---|
| 737 | /* Use only if standard port is in use */
|
---|
| 738 | /* Ignoring error (kernel may lack support for this) */
|
---|
| 739 | if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
|
---|
| 740 | sizeof(filter_prog)) >= 0)
|
---|
| 741 | log1("attached filter to raw socket fd %d", fd); // log?
|
---|
| 742 | }
|
---|
| 743 | #endif
|
---|
| 744 |
|
---|
| 745 | log1("created raw socket");
|
---|
| 746 |
|
---|
| 747 | return fd;
|
---|
| 748 | }
|
---|
| 749 |
|
---|
| 750 | static void change_listen_mode(int new_mode)
|
---|
| 751 | {
|
---|
| 752 | log1("entering listen mode: %s",
|
---|
| 753 | new_mode != LISTEN_NONE
|
---|
| 754 | ? (new_mode == LISTEN_KERNEL ? "kernel" : "raw")
|
---|
| 755 | : "none"
|
---|
| 756 | );
|
---|
| 757 |
|
---|
| 758 | listen_mode = new_mode;
|
---|
| 759 | if (sockfd >= 0) {
|
---|
| 760 | close(sockfd);
|
---|
| 761 | sockfd = -1;
|
---|
| 762 | }
|
---|
| 763 | if (new_mode == LISTEN_KERNEL)
|
---|
| 764 | sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT6, client_config.interface);
|
---|
| 765 | else if (new_mode != LISTEN_NONE)
|
---|
| 766 | sockfd = d6_raw_socket(client_config.ifindex);
|
---|
| 767 | /* else LISTEN_NONE: sockfd stays closed */
|
---|
| 768 | }
|
---|
| 769 |
|
---|
| 770 | /* Called only on SIGUSR1 */
|
---|
| 771 | static void perform_renew(void)
|
---|
| 772 | {
|
---|
| 773 | bb_error_msg("performing DHCP renew");
|
---|
| 774 | switch (state) {
|
---|
| 775 | case BOUND:
|
---|
| 776 | change_listen_mode(LISTEN_KERNEL);
|
---|
| 777 | case RENEWING:
|
---|
| 778 | case REBINDING:
|
---|
| 779 | state = RENEW_REQUESTED;
|
---|
| 780 | break;
|
---|
| 781 | case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
|
---|
| 782 | d6_run_script(NULL, "deconfig");
|
---|
| 783 | case REQUESTING:
|
---|
| 784 | case RELEASED:
|
---|
| 785 | change_listen_mode(LISTEN_RAW);
|
---|
| 786 | state = INIT_SELECTING;
|
---|
| 787 | break;
|
---|
| 788 | case INIT_SELECTING:
|
---|
| 789 | break;
|
---|
| 790 | }
|
---|
| 791 | }
|
---|
| 792 |
|
---|
| 793 | static void perform_d6_release(struct in6_addr *server_ipv6, struct in6_addr *our_cur_ipv6)
|
---|
| 794 | {
|
---|
| 795 | /* send release packet */
|
---|
| 796 | if (state == BOUND || state == RENEWING || state == REBINDING) {
|
---|
| 797 | bb_error_msg("unicasting a release");
|
---|
| 798 | send_d6_release(server_ipv6, our_cur_ipv6); /* unicast */
|
---|
| 799 | d6_run_script(NULL, "deconfig");
|
---|
| 800 | }
|
---|
| 801 | bb_error_msg("entering released state");
|
---|
| 802 |
|
---|
| 803 | change_listen_mode(LISTEN_NONE);
|
---|
| 804 | state = RELEASED;
|
---|
| 805 | }
|
---|
| 806 |
|
---|
| 807 | ///static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
|
---|
| 808 | ///{
|
---|
| 809 | /// uint8_t *storage;
|
---|
| 810 | /// int len = strnlen(str, 255);
|
---|
| 811 | /// storage = xzalloc(len + extra + OPT_DATA);
|
---|
| 812 | /// storage[OPT_CODE] = code;
|
---|
| 813 | /// storage[OPT_LEN] = len + extra;
|
---|
| 814 | /// memcpy(storage + extra + OPT_DATA, str, len);
|
---|
| 815 | /// return storage;
|
---|
| 816 | ///}
|
---|
| 817 |
|
---|
| 818 | #if BB_MMU
|
---|
| 819 | static void client_background(void)
|
---|
| 820 | {
|
---|
| 821 | bb_daemonize(0);
|
---|
| 822 | logmode &= ~LOGMODE_STDIO;
|
---|
| 823 | /* rewrite pidfile, as our pid is different now */
|
---|
| 824 | write_pidfile(client_config.pidfile);
|
---|
| 825 | }
|
---|
| 826 | #endif
|
---|
| 827 |
|
---|
| 828 | //usage:#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
|
---|
| 829 | //usage:# define IF_UDHCP_VERBOSE(...) __VA_ARGS__
|
---|
| 830 | //usage:#else
|
---|
| 831 | //usage:# define IF_UDHCP_VERBOSE(...)
|
---|
| 832 | //usage:#endif
|
---|
| 833 | //usage:#define udhcpc6_trivial_usage
|
---|
| 834 | //usage: "[-fbnq"IF_UDHCP_VERBOSE("v")"oR] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE]\n"
|
---|
| 835 | //usage: " [-x OPT:VAL]... [-O OPT]..." IF_FEATURE_UDHCP_PORT(" [-P N]")
|
---|
| 836 | //usage:#define udhcpc6_full_usage "\n"
|
---|
| 837 | //usage: IF_LONG_OPTS(
|
---|
| 838 | //usage: "\n -i,--interface IFACE Interface to use (default eth0)"
|
---|
| 839 | //usage: "\n -p,--pidfile FILE Create pidfile"
|
---|
| 840 | //usage: "\n -s,--script PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
|
---|
| 841 | //usage: "\n -B,--broadcast Request broadcast replies"
|
---|
| 842 | //usage: "\n -t,--retries N Send up to N discover packets"
|
---|
| 843 | //usage: "\n -T,--timeout N Pause between packets (default 3 seconds)"
|
---|
| 844 | //usage: "\n -A,--tryagain N Wait N seconds after failure (default 20)"
|
---|
| 845 | //usage: "\n -f,--foreground Run in foreground"
|
---|
| 846 | //usage: USE_FOR_MMU(
|
---|
| 847 | //usage: "\n -b,--background Background if lease is not obtained"
|
---|
| 848 | //usage: )
|
---|
| 849 | //usage: "\n -n,--now Exit if lease is not obtained"
|
---|
| 850 | //usage: "\n -q,--quit Exit after obtaining lease"
|
---|
| 851 | //usage: "\n -R,--release Release IP on exit"
|
---|
| 852 | //usage: "\n -S,--syslog Log to syslog too"
|
---|
| 853 | //usage: IF_FEATURE_UDHCP_PORT(
|
---|
| 854 | //usage: "\n -P,--client-port N Use port N (default 546)"
|
---|
| 855 | //usage: )
|
---|
| 856 | ////usage: IF_FEATURE_UDHCPC_ARPING(
|
---|
| 857 | ////usage: "\n -a,--arping Use arping to validate offered address"
|
---|
| 858 | ////usage: )
|
---|
| 859 | //usage: "\n -O,--request-option OPT Request option OPT from server (cumulative)"
|
---|
| 860 | //usage: "\n -o,--no-default-options Don't request any options (unless -O is given)"
|
---|
| 861 | //usage: "\n -r,--request IP Request this IP address"
|
---|
| 862 | //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
|
---|
| 863 | //usage: "\n Examples of string, numeric, and hex byte opts:"
|
---|
| 864 | //usage: "\n -x hostname:bbox - option 12"
|
---|
| 865 | //usage: "\n -x lease:3600 - option 51 (lease time)"
|
---|
| 866 | //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
|
---|
| 867 | //usage: IF_UDHCP_VERBOSE(
|
---|
| 868 | //usage: "\n -v Verbose"
|
---|
| 869 | //usage: )
|
---|
| 870 | //usage: )
|
---|
| 871 | //usage: IF_NOT_LONG_OPTS(
|
---|
| 872 | //usage: "\n -i IFACE Interface to use (default eth0)"
|
---|
| 873 | //usage: "\n -p FILE Create pidfile"
|
---|
| 874 | //usage: "\n -s PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
|
---|
| 875 | //usage: "\n -B Request broadcast replies"
|
---|
| 876 | //usage: "\n -t N Send up to N discover packets"
|
---|
| 877 | //usage: "\n -T N Pause between packets (default 3 seconds)"
|
---|
| 878 | //usage: "\n -A N Wait N seconds (default 20) after failure"
|
---|
| 879 | //usage: "\n -f Run in foreground"
|
---|
| 880 | //usage: USE_FOR_MMU(
|
---|
| 881 | //usage: "\n -b Background if lease is not obtained"
|
---|
| 882 | //usage: )
|
---|
| 883 | //usage: "\n -n Exit if lease is not obtained"
|
---|
| 884 | //usage: "\n -q Exit after obtaining lease"
|
---|
| 885 | //usage: "\n -R Release IP on exit"
|
---|
| 886 | //usage: "\n -S Log to syslog too"
|
---|
| 887 | //usage: IF_FEATURE_UDHCP_PORT(
|
---|
| 888 | //usage: "\n -P N Use port N (default 546)"
|
---|
| 889 | //usage: )
|
---|
| 890 | ////usage: IF_FEATURE_UDHCPC_ARPING(
|
---|
| 891 | ////usage: "\n -a Use arping to validate offered address"
|
---|
| 892 | ////usage: )
|
---|
| 893 | //usage: "\n -O OPT Request option OPT from server (cumulative)"
|
---|
| 894 | //usage: "\n -o Don't request any options (unless -O is given)"
|
---|
| 895 | //usage: "\n -r IP Request this IP address"
|
---|
| 896 | //usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
|
---|
| 897 | //usage: "\n Examples of string, numeric, and hex byte opts:"
|
---|
| 898 | //usage: "\n -x hostname:bbox - option 12"
|
---|
| 899 | //usage: "\n -x lease:3600 - option 51 (lease time)"
|
---|
| 900 | //usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
|
---|
| 901 | //usage: IF_UDHCP_VERBOSE(
|
---|
| 902 | //usage: "\n -v Verbose"
|
---|
| 903 | //usage: )
|
---|
| 904 | //usage: )
|
---|
| 905 | //usage: "\nSignals:"
|
---|
| 906 | //usage: "\n USR1 Renew lease"
|
---|
| 907 | //usage: "\n USR2 Release lease"
|
---|
| 908 |
|
---|
| 909 |
|
---|
| 910 | int udhcpc6_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
---|
| 911 | int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
|
---|
| 912 | {
|
---|
| 913 | const char *str_r;
|
---|
| 914 | IF_FEATURE_UDHCP_PORT(char *str_P;)
|
---|
| 915 | void *clientid_mac_ptr;
|
---|
| 916 | llist_t *list_O = NULL;
|
---|
| 917 | llist_t *list_x = NULL;
|
---|
| 918 | int tryagain_timeout = 20;
|
---|
| 919 | int discover_timeout = 3;
|
---|
| 920 | int discover_retries = 3;
|
---|
| 921 | struct in6_addr srv6_buf;
|
---|
| 922 | struct in6_addr ipv6_buf;
|
---|
| 923 | struct in6_addr *requested_ipv6;
|
---|
| 924 | uint32_t xid = 0;
|
---|
| 925 | int packet_num;
|
---|
| 926 | int timeout; /* must be signed */
|
---|
| 927 | unsigned already_waited_sec;
|
---|
| 928 | unsigned opt;
|
---|
| 929 | int max_fd;
|
---|
| 930 | int retval;
|
---|
| 931 | fd_set rfds;
|
---|
| 932 |
|
---|
| 933 | setup_common_bufsiz();
|
---|
| 934 |
|
---|
| 935 | /* Default options */
|
---|
| 936 | IF_FEATURE_UDHCP_PORT(SERVER_PORT6 = 547;)
|
---|
| 937 | IF_FEATURE_UDHCP_PORT(CLIENT_PORT6 = 546;)
|
---|
| 938 | client_config.interface = "eth0";
|
---|
| 939 | client_config.script = CONFIG_UDHCPC_DEFAULT_SCRIPT;
|
---|
| 940 |
|
---|
| 941 | /* Parse command line */
|
---|
| 942 | /* O,x: list; -T,-t,-A take numeric param */
|
---|
| 943 | opt_complementary = "O::x::T+:t+:A+" IF_UDHCP_VERBOSE(":vv") ;
|
---|
| 944 | IF_LONG_OPTS(applet_long_options = udhcpc6_longopts;)
|
---|
| 945 | opt = getopt32(argv, "i:np:qRr:s:T:t:SA:O:ox:f"
|
---|
| 946 | USE_FOR_MMU("b")
|
---|
| 947 | ///IF_FEATURE_UDHCPC_ARPING("a")
|
---|
| 948 | IF_FEATURE_UDHCP_PORT("P:")
|
---|
| 949 | "v"
|
---|
| 950 | , &client_config.interface, &client_config.pidfile, &str_r /* i,p */
|
---|
| 951 | , &client_config.script /* s */
|
---|
| 952 | , &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
|
---|
| 953 | , &list_O
|
---|
| 954 | , &list_x
|
---|
| 955 | IF_FEATURE_UDHCP_PORT(, &str_P)
|
---|
| 956 | IF_UDHCP_VERBOSE(, &dhcp_verbose)
|
---|
| 957 | );
|
---|
| 958 | requested_ipv6 = NULL;
|
---|
| 959 | if (opt & OPT_r) {
|
---|
| 960 | if (inet_pton(AF_INET6, str_r, &ipv6_buf) <= 0)
|
---|
| 961 | bb_error_msg_and_die("bad IPv6 address '%s'", str_r);
|
---|
| 962 | requested_ipv6 = &ipv6_buf;
|
---|
| 963 | }
|
---|
| 964 | #if ENABLE_FEATURE_UDHCP_PORT
|
---|
| 965 | if (opt & OPT_P) {
|
---|
| 966 | CLIENT_PORT6 = xatou16(str_P);
|
---|
| 967 | SERVER_PORT6 = CLIENT_PORT6 + 1;
|
---|
| 968 | }
|
---|
| 969 | #endif
|
---|
| 970 | while (list_O) {
|
---|
| 971 | char *optstr = llist_pop(&list_O);
|
---|
| 972 | unsigned n = bb_strtou(optstr, NULL, 0);
|
---|
| 973 | if (errno || n > 254) {
|
---|
| 974 | n = udhcp_option_idx(optstr);
|
---|
| 975 | n = dhcp_optflags[n].code;
|
---|
| 976 | }
|
---|
| 977 | client_config.opt_mask[n >> 3] |= 1 << (n & 7);
|
---|
| 978 | }
|
---|
| 979 | if (!(opt & OPT_o)) {
|
---|
| 980 | /*
|
---|
| 981 | unsigned i, n;
|
---|
| 982 | for (i = 0; (n = dhcp_optflags[i].code) != 0; i++) {
|
---|
| 983 | if (dhcp_optflags[i].flags & OPTION_REQ) {
|
---|
| 984 | client_config.opt_mask[n >> 3] |= 1 << (n & 7);
|
---|
| 985 | }
|
---|
| 986 | }
|
---|
| 987 | */
|
---|
| 988 | }
|
---|
| 989 | while (list_x) {
|
---|
| 990 | char *optstr = llist_pop(&list_x);
|
---|
| 991 | char *colon = strchr(optstr, ':');
|
---|
| 992 | if (colon)
|
---|
| 993 | *colon = ' ';
|
---|
| 994 | /* now it looks similar to udhcpd's config file line:
|
---|
| 995 | * "optname optval", using the common routine: */
|
---|
| 996 | udhcp_str2optset(optstr, &client_config.options);
|
---|
| 997 | }
|
---|
| 998 |
|
---|
| 999 | if (udhcp_read_interface(client_config.interface,
|
---|
| 1000 | &client_config.ifindex,
|
---|
| 1001 | NULL,
|
---|
| 1002 | client_config.client_mac)
|
---|
| 1003 | ) {
|
---|
| 1004 | return 1;
|
---|
| 1005 | }
|
---|
| 1006 |
|
---|
| 1007 | /* Create client ID based on mac, set clientid_mac_ptr */
|
---|
| 1008 | {
|
---|
| 1009 | struct d6_option *clientid;
|
---|
| 1010 | clientid = xzalloc(2+2+2+2+6);
|
---|
| 1011 | clientid->code = D6_OPT_CLIENTID;
|
---|
| 1012 | clientid->len = 2+2+6;
|
---|
| 1013 | clientid->data[1] = 3; /* DUID-LL */
|
---|
| 1014 | clientid->data[3] = 1; /* ethernet */
|
---|
| 1015 | clientid_mac_ptr = clientid->data + 2+2;
|
---|
| 1016 | memcpy(clientid_mac_ptr, client_config.client_mac, 6);
|
---|
| 1017 | client_config.clientid = (void*)clientid;
|
---|
| 1018 | }
|
---|
| 1019 |
|
---|
| 1020 | #if !BB_MMU
|
---|
| 1021 | /* on NOMMU reexec (i.e., background) early */
|
---|
| 1022 | if (!(opt & OPT_f)) {
|
---|
| 1023 | bb_daemonize_or_rexec(0 /* flags */, argv);
|
---|
| 1024 | logmode = LOGMODE_NONE;
|
---|
| 1025 | }
|
---|
| 1026 | #endif
|
---|
| 1027 | if (opt & OPT_S) {
|
---|
| 1028 | openlog(applet_name, LOG_PID, LOG_DAEMON);
|
---|
| 1029 | logmode |= LOGMODE_SYSLOG;
|
---|
| 1030 | }
|
---|
| 1031 |
|
---|
| 1032 | /* Make sure fd 0,1,2 are open */
|
---|
| 1033 | bb_sanitize_stdio();
|
---|
| 1034 | /* Equivalent of doing a fflush after every \n */
|
---|
| 1035 | setlinebuf(stdout);
|
---|
| 1036 | /* Create pidfile */
|
---|
| 1037 | write_pidfile(client_config.pidfile);
|
---|
| 1038 | /* Goes to stdout (unless NOMMU) and possibly syslog */
|
---|
| 1039 | bb_error_msg("started, v"BB_VER);
|
---|
| 1040 | /* Set up the signal pipe */
|
---|
| 1041 | udhcp_sp_setup();
|
---|
| 1042 | /* We want random_xid to be random... */
|
---|
| 1043 | srand(monotonic_us());
|
---|
| 1044 |
|
---|
| 1045 | state = INIT_SELECTING;
|
---|
| 1046 | d6_run_script(NULL, "deconfig");
|
---|
| 1047 | change_listen_mode(LISTEN_RAW);
|
---|
| 1048 | packet_num = 0;
|
---|
| 1049 | timeout = 0;
|
---|
| 1050 | already_waited_sec = 0;
|
---|
| 1051 |
|
---|
| 1052 | /* Main event loop. select() waits on signal pipe and possibly
|
---|
| 1053 | * on sockfd.
|
---|
| 1054 | * "continue" statements in code below jump to the top of the loop.
|
---|
| 1055 | */
|
---|
| 1056 | for (;;) {
|
---|
| 1057 | struct timeval tv;
|
---|
| 1058 | struct d6_packet packet;
|
---|
| 1059 | uint8_t *packet_end;
|
---|
| 1060 | /* silence "uninitialized!" warning */
|
---|
| 1061 | unsigned timestamp_before_wait = timestamp_before_wait;
|
---|
| 1062 |
|
---|
| 1063 | //bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode);
|
---|
| 1064 |
|
---|
| 1065 | /* Was opening raw or udp socket here
|
---|
| 1066 | * if (listen_mode != LISTEN_NONE && sockfd < 0),
|
---|
| 1067 | * but on fast network renew responses return faster
|
---|
| 1068 | * than we open sockets. Thus this code is moved
|
---|
| 1069 | * to change_listen_mode(). Thus we open listen socket
|
---|
| 1070 | * BEFORE we send renew request (see "case BOUND:"). */
|
---|
| 1071 |
|
---|
| 1072 | max_fd = udhcp_sp_fd_set(&rfds, sockfd);
|
---|
| 1073 |
|
---|
| 1074 | tv.tv_sec = timeout - already_waited_sec;
|
---|
| 1075 | tv.tv_usec = 0;
|
---|
| 1076 | retval = 0;
|
---|
| 1077 | /* If we already timed out, fall through with retval = 0, else... */
|
---|
| 1078 | if ((int)tv.tv_sec > 0) {
|
---|
| 1079 | log1("waiting on select %u seconds", (int)tv.tv_sec);
|
---|
| 1080 | timestamp_before_wait = (unsigned)monotonic_sec();
|
---|
| 1081 | retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
|
---|
| 1082 | if (retval < 0) {
|
---|
| 1083 | /* EINTR? A signal was caught, don't panic */
|
---|
| 1084 | if (errno == EINTR) {
|
---|
| 1085 | already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
|
---|
| 1086 | continue;
|
---|
| 1087 | }
|
---|
| 1088 | /* Else: an error occured, panic! */
|
---|
| 1089 | bb_perror_msg_and_die("select");
|
---|
| 1090 | }
|
---|
| 1091 | }
|
---|
| 1092 |
|
---|
| 1093 | /* If timeout dropped to zero, time to become active:
|
---|
| 1094 | * resend discover/renew/whatever
|
---|
| 1095 | */
|
---|
| 1096 | if (retval == 0) {
|
---|
| 1097 | /* When running on a bridge, the ifindex may have changed
|
---|
| 1098 | * (e.g. if member interfaces were added/removed
|
---|
| 1099 | * or if the status of the bridge changed).
|
---|
| 1100 | * Refresh ifindex and client_mac:
|
---|
| 1101 | */
|
---|
| 1102 | if (udhcp_read_interface(client_config.interface,
|
---|
| 1103 | &client_config.ifindex,
|
---|
| 1104 | NULL,
|
---|
| 1105 | client_config.client_mac)
|
---|
| 1106 | ) {
|
---|
| 1107 | goto ret0; /* iface is gone? */
|
---|
| 1108 | }
|
---|
| 1109 | memcpy(clientid_mac_ptr, client_config.client_mac, 6);
|
---|
| 1110 |
|
---|
| 1111 | /* We will restart the wait in any case */
|
---|
| 1112 | already_waited_sec = 0;
|
---|
| 1113 |
|
---|
| 1114 | switch (state) {
|
---|
| 1115 | case INIT_SELECTING:
|
---|
| 1116 | if (!discover_retries || packet_num < discover_retries) {
|
---|
| 1117 | if (packet_num == 0)
|
---|
| 1118 | xid = random_xid();
|
---|
| 1119 | /* multicast */
|
---|
| 1120 | send_d6_discover(xid, requested_ipv6);
|
---|
| 1121 | timeout = discover_timeout;
|
---|
| 1122 | packet_num++;
|
---|
| 1123 | continue;
|
---|
| 1124 | }
|
---|
| 1125 | leasefail:
|
---|
| 1126 | d6_run_script(NULL, "leasefail");
|
---|
| 1127 | #if BB_MMU /* -b is not supported on NOMMU */
|
---|
| 1128 | if (opt & OPT_b) { /* background if no lease */
|
---|
| 1129 | bb_error_msg("no lease, forking to background");
|
---|
| 1130 | client_background();
|
---|
| 1131 | /* do not background again! */
|
---|
| 1132 | opt = ((opt & ~OPT_b) | OPT_f);
|
---|
| 1133 | } else
|
---|
| 1134 | #endif
|
---|
| 1135 | if (opt & OPT_n) { /* abort if no lease */
|
---|
| 1136 | bb_error_msg("no lease, failing");
|
---|
| 1137 | retval = 1;
|
---|
| 1138 | goto ret;
|
---|
| 1139 | }
|
---|
| 1140 | /* wait before trying again */
|
---|
| 1141 | timeout = tryagain_timeout;
|
---|
| 1142 | packet_num = 0;
|
---|
| 1143 | continue;
|
---|
| 1144 | case REQUESTING:
|
---|
| 1145 | if (!discover_retries || packet_num < discover_retries) {
|
---|
| 1146 | /* send multicast select packet */
|
---|
| 1147 | send_d6_select(xid);
|
---|
| 1148 | timeout = discover_timeout;
|
---|
| 1149 | packet_num++;
|
---|
| 1150 | continue;
|
---|
| 1151 | }
|
---|
| 1152 | /* Timed out, go back to init state.
|
---|
| 1153 | * "discover...select...discover..." loops
|
---|
| 1154 | * were seen in the wild. Treat them similarly
|
---|
| 1155 | * to "no response to discover" case */
|
---|
| 1156 | change_listen_mode(LISTEN_RAW);
|
---|
| 1157 | state = INIT_SELECTING;
|
---|
| 1158 | goto leasefail;
|
---|
| 1159 | case BOUND:
|
---|
| 1160 | /* 1/2 lease passed, enter renewing state */
|
---|
| 1161 | state = RENEWING;
|
---|
| 1162 | client_config.first_secs = 0; /* make secs field count from 0 */
|
---|
| 1163 | change_listen_mode(LISTEN_KERNEL);
|
---|
| 1164 | log1("entering renew state");
|
---|
| 1165 | /* fall right through */
|
---|
| 1166 | case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
|
---|
| 1167 | case_RENEW_REQUESTED:
|
---|
| 1168 | case RENEWING:
|
---|
| 1169 | if (timeout > 60) {
|
---|
| 1170 | /* send an unicast renew request */
|
---|
| 1171 | /* Sometimes observed to fail (EADDRNOTAVAIL) to bind
|
---|
| 1172 | * a new UDP socket for sending inside send_renew.
|
---|
| 1173 | * I hazard to guess existing listening socket
|
---|
| 1174 | * is somehow conflicting with it, but why is it
|
---|
| 1175 | * not deterministic then?! Strange.
|
---|
| 1176 | * Anyway, it does recover by eventually failing through
|
---|
| 1177 | * into INIT_SELECTING state.
|
---|
| 1178 | */
|
---|
| 1179 | send_d6_renew(xid, &srv6_buf, requested_ipv6);
|
---|
| 1180 | timeout >>= 1;
|
---|
| 1181 | continue;
|
---|
| 1182 | }
|
---|
| 1183 | /* Timed out, enter rebinding state */
|
---|
| 1184 | log1("entering rebinding state");
|
---|
| 1185 | state = REBINDING;
|
---|
| 1186 | /* fall right through */
|
---|
| 1187 | case REBINDING:
|
---|
| 1188 | /* Switch to bcast receive */
|
---|
| 1189 | change_listen_mode(LISTEN_RAW);
|
---|
| 1190 | /* Lease is *really* about to run out,
|
---|
| 1191 | * try to find DHCP server using broadcast */
|
---|
| 1192 | if (timeout > 0) {
|
---|
| 1193 | /* send a broadcast renew request */
|
---|
| 1194 | send_d6_renew(xid, /*server_ipv6:*/ NULL, requested_ipv6);
|
---|
| 1195 | timeout >>= 1;
|
---|
| 1196 | continue;
|
---|
| 1197 | }
|
---|
| 1198 | /* Timed out, enter init state */
|
---|
| 1199 | bb_error_msg("lease lost, entering init state");
|
---|
| 1200 | d6_run_script(NULL, "deconfig");
|
---|
| 1201 | state = INIT_SELECTING;
|
---|
| 1202 | client_config.first_secs = 0; /* make secs field count from 0 */
|
---|
| 1203 | /*timeout = 0; - already is */
|
---|
| 1204 | packet_num = 0;
|
---|
| 1205 | continue;
|
---|
| 1206 | /* case RELEASED: */
|
---|
| 1207 | }
|
---|
| 1208 | /* yah, I know, *you* say it would never happen */
|
---|
| 1209 | timeout = INT_MAX;
|
---|
| 1210 | continue; /* back to main loop */
|
---|
| 1211 | } /* if select timed out */
|
---|
| 1212 |
|
---|
| 1213 | /* select() didn't timeout, something happened */
|
---|
| 1214 |
|
---|
| 1215 | /* Is it a signal? */
|
---|
| 1216 | /* note: udhcp_sp_read checks FD_ISSET before reading */
|
---|
| 1217 | switch (udhcp_sp_read(&rfds)) {
|
---|
| 1218 | case SIGUSR1:
|
---|
| 1219 | client_config.first_secs = 0; /* make secs field count from 0 */
|
---|
| 1220 | already_waited_sec = 0;
|
---|
| 1221 | perform_renew();
|
---|
| 1222 | if (state == RENEW_REQUESTED) {
|
---|
| 1223 | /* We might be either on the same network
|
---|
| 1224 | * (in which case renew might work),
|
---|
| 1225 | * or we might be on a completely different one
|
---|
| 1226 | * (in which case renew won't ever succeed).
|
---|
| 1227 | * For the second case, must make sure timeout
|
---|
| 1228 | * is not too big, or else we can send
|
---|
| 1229 | * futile renew requests for hours.
|
---|
| 1230 | * (Ab)use -A TIMEOUT value (usually 20 sec)
|
---|
| 1231 | * as a cap on the timeout.
|
---|
| 1232 | */
|
---|
| 1233 | if (timeout > tryagain_timeout)
|
---|
| 1234 | timeout = tryagain_timeout;
|
---|
| 1235 | goto case_RENEW_REQUESTED;
|
---|
| 1236 | }
|
---|
| 1237 | /* Start things over */
|
---|
| 1238 | packet_num = 0;
|
---|
| 1239 | /* Kill any timeouts, user wants this to hurry along */
|
---|
| 1240 | timeout = 0;
|
---|
| 1241 | continue;
|
---|
| 1242 | case SIGUSR2:
|
---|
| 1243 | perform_d6_release(&srv6_buf, requested_ipv6);
|
---|
| 1244 | timeout = INT_MAX;
|
---|
| 1245 | continue;
|
---|
| 1246 | case SIGTERM:
|
---|
| 1247 | bb_error_msg("received %s", "SIGTERM");
|
---|
| 1248 | goto ret0;
|
---|
| 1249 | }
|
---|
| 1250 |
|
---|
| 1251 | /* Is it a packet? */
|
---|
| 1252 | if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds))
|
---|
| 1253 | continue; /* no */
|
---|
| 1254 |
|
---|
| 1255 | {
|
---|
| 1256 | int len;
|
---|
| 1257 |
|
---|
| 1258 | /* A packet is ready, read it */
|
---|
| 1259 | if (listen_mode == LISTEN_KERNEL)
|
---|
| 1260 | len = d6_recv_kernel_packet(&srv6_buf, &packet, sockfd);
|
---|
| 1261 | else
|
---|
| 1262 | len = d6_recv_raw_packet(&srv6_buf, &packet, sockfd);
|
---|
| 1263 | if (len == -1) {
|
---|
| 1264 | /* Error is severe, reopen socket */
|
---|
| 1265 | bb_error_msg("read error: %s, reopening socket", strerror(errno));
|
---|
| 1266 | sleep(discover_timeout); /* 3 seconds by default */
|
---|
| 1267 | change_listen_mode(listen_mode); /* just close and reopen */
|
---|
| 1268 | }
|
---|
| 1269 | /* If this packet will turn out to be unrelated/bogus,
|
---|
| 1270 | * we will go back and wait for next one.
|
---|
| 1271 | * Be sure timeout is properly decreased. */
|
---|
| 1272 | already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
|
---|
| 1273 | if (len < 0)
|
---|
| 1274 | continue;
|
---|
| 1275 | packet_end = (uint8_t*)&packet + len;
|
---|
| 1276 | }
|
---|
| 1277 |
|
---|
| 1278 | if ((packet.d6_xid32 & htonl(0x00ffffff)) != xid) {
|
---|
| 1279 | log1("xid %x (our is %x), ignoring packet",
|
---|
| 1280 | (unsigned)(packet.d6_xid32 & htonl(0x00ffffff)), (unsigned)xid);
|
---|
| 1281 | continue;
|
---|
| 1282 | }
|
---|
| 1283 |
|
---|
| 1284 | switch (state) {
|
---|
| 1285 | case INIT_SELECTING:
|
---|
| 1286 | if (packet.d6_msg_type == D6_MSG_ADVERTISE)
|
---|
| 1287 | goto type_is_ok;
|
---|
| 1288 | /* DHCPv6 has "Rapid Commit", when instead of Advertise,
|
---|
| 1289 | * server sends Reply right away.
|
---|
| 1290 | * Fall through to check for this case.
|
---|
| 1291 | */
|
---|
| 1292 | case REQUESTING:
|
---|
| 1293 | case RENEWING:
|
---|
| 1294 | case RENEW_REQUESTED:
|
---|
| 1295 | case REBINDING:
|
---|
| 1296 | if (packet.d6_msg_type == D6_MSG_REPLY) {
|
---|
| 1297 | uint32_t lease_seconds;
|
---|
| 1298 | struct d6_option *option, *iaaddr;
|
---|
| 1299 | type_is_ok:
|
---|
| 1300 | option = d6_find_option(packet.d6_options, packet_end, D6_OPT_STATUS_CODE);
|
---|
| 1301 | if (option && option->data[4] != 0) {
|
---|
| 1302 | /* return to init state */
|
---|
| 1303 | bb_error_msg("received DHCP NAK (%u)", option->data[4]);
|
---|
| 1304 | d6_run_script(&packet, "nak");
|
---|
| 1305 | if (state != REQUESTING)
|
---|
| 1306 | d6_run_script(NULL, "deconfig");
|
---|
| 1307 | change_listen_mode(LISTEN_RAW);
|
---|
| 1308 | sleep(3); /* avoid excessive network traffic */
|
---|
| 1309 | state = INIT_SELECTING;
|
---|
| 1310 | client_config.first_secs = 0; /* make secs field count from 0 */
|
---|
| 1311 | requested_ipv6 = NULL;
|
---|
| 1312 | timeout = 0;
|
---|
| 1313 | packet_num = 0;
|
---|
| 1314 | already_waited_sec = 0;
|
---|
| 1315 | continue;
|
---|
| 1316 | }
|
---|
| 1317 | option = d6_copy_option(packet.d6_options, packet_end, D6_OPT_SERVERID);
|
---|
| 1318 | if (!option) {
|
---|
| 1319 | bb_error_msg("no server ID, ignoring packet");
|
---|
| 1320 | continue;
|
---|
| 1321 | /* still selecting - this server looks bad */
|
---|
| 1322 | }
|
---|
| 1323 | //Note: we do not bother comparing server IDs in Advertise and Reply msgs.
|
---|
| 1324 | //server_id variable is used solely for creation of proper server_id option
|
---|
| 1325 | //in outgoing packets. (why DHCPv6 even introduced it is a mystery).
|
---|
| 1326 | free(client6_data.server_id);
|
---|
| 1327 | client6_data.server_id = option;
|
---|
| 1328 | if (packet.d6_msg_type == D6_MSG_ADVERTISE) {
|
---|
| 1329 | /* enter requesting state */
|
---|
| 1330 | state = REQUESTING;
|
---|
| 1331 | timeout = 0;
|
---|
| 1332 | packet_num = 0;
|
---|
| 1333 | already_waited_sec = 0;
|
---|
| 1334 | continue;
|
---|
| 1335 | }
|
---|
| 1336 | /* It's a D6_MSG_REPLY */
|
---|
| 1337 | /*
|
---|
| 1338 | * RFC 3315 18.1.8. Receipt of Reply Messages
|
---|
| 1339 | *
|
---|
| 1340 | * Upon the receipt of a valid Reply message in response to a Solicit
|
---|
| 1341 | * (with a Rapid Commit option), Request, Confirm, Renew, Rebind or
|
---|
| 1342 | * Information-request message, the client extracts the configuration
|
---|
| 1343 | * information contained in the Reply. The client MAY choose to report
|
---|
| 1344 | * any status code or message from the status code option in the Reply
|
---|
| 1345 | * message.
|
---|
| 1346 | *
|
---|
| 1347 | * The client SHOULD perform duplicate address detection [17] on each of
|
---|
| 1348 | * the addresses in any IAs it receives in the Reply message before
|
---|
| 1349 | * using that address for traffic. If any of the addresses are found to
|
---|
| 1350 | * be in use on the link, the client sends a Decline message to the
|
---|
| 1351 | * server as described in section 18.1.7.
|
---|
| 1352 | *
|
---|
| 1353 | * If the Reply was received in response to a Solicit (with a Rapid
|
---|
| 1354 | * Commit option), Request, Renew or Rebind message, the client updates
|
---|
| 1355 | * the information it has recorded about IAs from the IA options
|
---|
| 1356 | * contained in the Reply message:
|
---|
| 1357 | *
|
---|
| 1358 | * - Record T1 and T2 times.
|
---|
| 1359 | *
|
---|
| 1360 | * - Add any new addresses in the IA option to the IA as recorded by
|
---|
| 1361 | * the client.
|
---|
| 1362 | *
|
---|
| 1363 | * - Update lifetimes for any addresses in the IA option that the
|
---|
| 1364 | * client already has recorded in the IA.
|
---|
| 1365 | *
|
---|
| 1366 | * - Discard any addresses from the IA, as recorded by the client, that
|
---|
| 1367 | * have a valid lifetime of 0 in the IA Address option.
|
---|
| 1368 | *
|
---|
| 1369 | * - Leave unchanged any information about addresses the client has
|
---|
| 1370 | * recorded in the IA but that were not included in the IA from the
|
---|
| 1371 | * server.
|
---|
| 1372 | *
|
---|
| 1373 | * Management of the specific configuration information is detailed in
|
---|
| 1374 | * the definition of each option in section 22.
|
---|
| 1375 | *
|
---|
| 1376 | * If the client receives a Reply message with a Status Code containing
|
---|
| 1377 | * UnspecFail, the server is indicating that it was unable to process
|
---|
| 1378 | * the message due to an unspecified failure condition. If the client
|
---|
| 1379 | * retransmits the original message to the same server to retry the
|
---|
| 1380 | * desired operation, the client MUST limit the rate at which it
|
---|
| 1381 | * retransmits the message and limit the duration of the time during
|
---|
| 1382 | * which it retransmits the message.
|
---|
| 1383 | *
|
---|
| 1384 | * When the client receives a Reply message with a Status Code option
|
---|
| 1385 | * with the value UseMulticast, the client records the receipt of the
|
---|
| 1386 | * message and sends subsequent messages to the server through the
|
---|
| 1387 | * interface on which the message was received using multicast. The
|
---|
| 1388 | * client resends the original message using multicast.
|
---|
| 1389 | *
|
---|
| 1390 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 1391 | * | OPTION_IA_NA | option-len |
|
---|
| 1392 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 1393 | * | IAID (4 octets) |
|
---|
| 1394 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 1395 | * | T1 |
|
---|
| 1396 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 1397 | * | T2 |
|
---|
| 1398 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 1399 | * | |
|
---|
| 1400 | * . IA_NA-options .
|
---|
| 1401 | * . .
|
---|
| 1402 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 1403 | *
|
---|
| 1404 | *
|
---|
| 1405 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 1406 | * | OPTION_IAADDR | option-len |
|
---|
| 1407 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 1408 | * | |
|
---|
| 1409 | * | IPv6 address |
|
---|
| 1410 | * | |
|
---|
| 1411 | * | |
|
---|
| 1412 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 1413 | * | preferred-lifetime |
|
---|
| 1414 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 1415 | * | valid-lifetime |
|
---|
| 1416 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 1417 | * . .
|
---|
| 1418 | * . IAaddr-options .
|
---|
| 1419 | * . .
|
---|
| 1420 | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
---|
| 1421 | */
|
---|
| 1422 | free(client6_data.ia_na);
|
---|
| 1423 | client6_data.ia_na = d6_copy_option(packet.d6_options, packet_end, D6_OPT_IA_NA);
|
---|
| 1424 | if (!client6_data.ia_na) {
|
---|
| 1425 | bb_error_msg("no %s option, ignoring packet", "IA_NA");
|
---|
| 1426 | continue;
|
---|
| 1427 | }
|
---|
| 1428 | if (client6_data.ia_na->len < (4 + 4 + 4) + (2 + 2 + 16 + 4 + 4)) {
|
---|
| 1429 | bb_error_msg("IA_NA option is too short:%d bytes", client6_data.ia_na->len);
|
---|
| 1430 | continue;
|
---|
| 1431 | }
|
---|
| 1432 | iaaddr = d6_find_option(client6_data.ia_na->data + 4 + 4 + 4,
|
---|
| 1433 | client6_data.ia_na->data + client6_data.ia_na->len,
|
---|
| 1434 | D6_OPT_IAADDR
|
---|
| 1435 | );
|
---|
| 1436 | if (!iaaddr) {
|
---|
| 1437 | bb_error_msg("no %s option, ignoring packet", "IAADDR");
|
---|
| 1438 | continue;
|
---|
| 1439 | }
|
---|
| 1440 | if (iaaddr->len < (16 + 4 + 4)) {
|
---|
| 1441 | bb_error_msg("IAADDR option is too short:%d bytes", iaaddr->len);
|
---|
| 1442 | continue;
|
---|
| 1443 | }
|
---|
| 1444 | /* Note: the address is sufficiently aligned for cast:
|
---|
| 1445 | * we _copied_ IA-NA, and copy is always well-aligned.
|
---|
| 1446 | */
|
---|
| 1447 | requested_ipv6 = (struct in6_addr*) iaaddr->data;
|
---|
| 1448 | move_from_unaligned32(lease_seconds, iaaddr->data + 16 + 4);
|
---|
| 1449 | lease_seconds = ntohl(lease_seconds);
|
---|
| 1450 | /* paranoia: must not be too small and not prone to overflows */
|
---|
| 1451 | if (lease_seconds < 0x10)
|
---|
| 1452 | lease_seconds = 0x10;
|
---|
| 1453 | /// TODO: check for 0 lease time?
|
---|
| 1454 | if (lease_seconds >= 0x10000000)
|
---|
| 1455 | lease_seconds = 0x0fffffff;
|
---|
| 1456 | /* enter bound state */
|
---|
| 1457 | timeout = lease_seconds / 2;
|
---|
| 1458 | bb_error_msg("lease obtained, lease time %u",
|
---|
| 1459 | /*inet_ntoa(temp_addr),*/ (unsigned)lease_seconds);
|
---|
| 1460 | d6_run_script(&packet, state == REQUESTING ? "bound" : "renew");
|
---|
| 1461 |
|
---|
| 1462 | state = BOUND;
|
---|
| 1463 | change_listen_mode(LISTEN_NONE);
|
---|
| 1464 | if (opt & OPT_q) { /* quit after lease */
|
---|
| 1465 | goto ret0;
|
---|
| 1466 | }
|
---|
| 1467 | /* future renew failures should not exit (JM) */
|
---|
| 1468 | opt &= ~OPT_n;
|
---|
| 1469 | #if BB_MMU /* NOMMU case backgrounded earlier */
|
---|
| 1470 | if (!(opt & OPT_f)) {
|
---|
| 1471 | client_background();
|
---|
| 1472 | /* do not background again! */
|
---|
| 1473 | opt = ((opt & ~OPT_b) | OPT_f);
|
---|
| 1474 | }
|
---|
| 1475 | #endif
|
---|
| 1476 | already_waited_sec = 0;
|
---|
| 1477 | continue; /* back to main loop */
|
---|
| 1478 | }
|
---|
| 1479 | continue;
|
---|
| 1480 | /* case BOUND: - ignore all packets */
|
---|
| 1481 | /* case RELEASED: - ignore all packets */
|
---|
| 1482 | }
|
---|
| 1483 | /* back to main loop */
|
---|
| 1484 | } /* for (;;) - main loop ends */
|
---|
| 1485 |
|
---|
| 1486 | ret0:
|
---|
| 1487 | if (opt & OPT_R) /* release on quit */
|
---|
| 1488 | perform_d6_release(&srv6_buf, requested_ipv6);
|
---|
| 1489 | retval = 0;
|
---|
| 1490 | ret:
|
---|
| 1491 | /*if (client_config.pidfile) - remove_pidfile has its own check */
|
---|
| 1492 | remove_pidfile(client_config.pidfile);
|
---|
| 1493 | return retval;
|
---|
| 1494 | }
|
---|