| /* vi: set sw=4 ts=4: */ |
| /* |
| * DHCPv6 client. |
| * |
| * Copyright (C) 2011-2017 Denys Vlasenko. |
| * |
| * Licensed under GPLv2, see file LICENSE in this source tree. |
| */ |
| //config:config UDHCPC6 |
| //config: bool "udhcpc6 (21 kb)" |
| //config: default y |
| //config: depends on FEATURE_IPV6 |
| //config: help |
| //config: udhcpc6 is a DHCPv6 client |
| //config: |
| //config:config FEATURE_UDHCPC6_RFC3646 |
| //config: bool "Support RFC 3646 (DNS server and search list)" |
| //config: default y |
| //config: depends on UDHCPC6 |
| //config: help |
| //config: List of DNS servers and domain search list can be requested with |
| //config: "-O dns" and "-O search". If server gives these values, |
| //config: they will be set in environment variables "dns" and "search". |
| //config: |
| //config:config FEATURE_UDHCPC6_RFC4704 |
| //config: bool "Support RFC 4704 (Client FQDN)" |
| //config: default y |
| //config: depends on UDHCPC6 |
| //config: help |
| //config: You can request FQDN to be given by server using "-O fqdn". |
| //config: |
| //config:config FEATURE_UDHCPC6_RFC4833 |
| //config: bool "Support RFC 4833 (Timezones)" |
| //config: default y |
| //config: depends on UDHCPC6 |
| //config: help |
| //config: You can request POSIX timezone with "-O tz" and timezone name |
| //config: with "-O timezone". |
| //config: |
| //config:config FEATURE_UDHCPC6_RFC5970 |
| //config: bool "Support RFC 5970 (Network Boot)" |
| //config: default y |
| //config: depends on UDHCPC6 |
| //config: help |
| //config: You can request bootfile-url with "-O bootfile_url" and |
| //config: bootfile-params with "-O bootfile_params". |
| |
| //applet:IF_UDHCPC6(APPLET(udhcpc6, BB_DIR_USR_BIN, BB_SUID_DROP)) |
| |
| //kbuild:lib-$(CONFIG_UDHCPC6) += d6_dhcpc.o d6_packet.o d6_socket.o common.o socket.o signalpipe.o |
| //kbuild:lib-$(CONFIG_FEATURE_UDHCPC6_RFC3646) += domain_codec.o |
| //kbuild:lib-$(CONFIG_FEATURE_UDHCPC6_RFC4704) += domain_codec.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_data_t client_data" is in bb_common_bufsiz1 */ |
| |
| static const struct dhcp_optflag d6_optflags[] = { |
| #if ENABLE_FEATURE_UDHCPC6_RFC3646 |
| { OPTION_6RD | OPTION_LIST | OPTION_REQ, D6_OPT_DNS_SERVERS }, |
| { OPTION_DNS_STRING | OPTION_LIST | OPTION_REQ, D6_OPT_DOMAIN_LIST }, |
| #endif |
| #if ENABLE_FEATURE_UDHCPC6_RFC4704 |
| { OPTION_DNS_STRING, D6_OPT_CLIENT_FQDN }, |
| #endif |
| #if ENABLE_FEATURE_UDHCPC6_RFC4833 |
| { OPTION_STRING, D6_OPT_TZ_POSIX }, |
| { OPTION_STRING, D6_OPT_TZ_NAME }, |
| #endif |
| #if ENABLE_FEATURE_UDHCPC6_RFC5970 |
| { OPTION_STRING, D6_OPT_BOOT_URL }, |
| { OPTION_STRING, D6_OPT_BOOT_PARAM }, |
| #endif |
| { OPTION_STRING, 0xd1 }, /* DHCP_PXE_CONF_FILE */ |
| { OPTION_STRING, 0xd2 }, /* DHCP_PXE_PATH_PREFIX */ |
| { 0, 0 } |
| }; |
| /* Must match d6_optflags[] order */ |
| static const char d6_option_strings[] ALIGN1 = |
| #if ENABLE_FEATURE_UDHCPC6_RFC3646 |
| "dns" "\0" /* D6_OPT_DNS_SERVERS */ |
| "search" "\0" /* D6_OPT_DOMAIN_LIST */ |
| #endif |
| #if ENABLE_FEATURE_UDHCPC6_RFC4704 |
| "fqdn" "\0" /* D6_OPT_CLIENT_FQDN */ |
| #endif |
| #if ENABLE_FEATURE_UDHCPC6_RFC4833 |
| "tz" "\0" /* D6_OPT_TZ_POSIX */ |
| "timezone" "\0" /* D6_OPT_TZ_NAME */ |
| #endif |
| #if ENABLE_FEATURE_UDHCPC6_RFC5970 |
| "bootfile_url" "\0" /* D6_OPT_BOOT_URL */ |
| "bootfile_param" "\0" /* D6_OPT_BOOT_PARAM */ |
| #endif |
| "pxeconffile" "\0" /* DHCP_PXE_CONF_FILE */ |
| "pxepathprefix" "\0" /* DHCP_PXE_PATH_PREFIX */ |
| "\0"; |
| |
| #if ENABLE_LONG_OPTS |
| static const char udhcpc6_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" |
| "requestprefix\0" No_argument "d" |
| "script\0" Required_argument "s" |
| "timeout\0" Required_argument "T" |
| "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" |
| "stateless\0" No_argument "l" |
| USE_FOR_MMU( |
| "background\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_l = 1 << 15, |
| OPT_d = 1 << 16, |
| /* The rest has variable bit positions, need to be clever */ |
| OPTBIT_d = 16, |
| 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,) |
| }; |
| |
| #if ENABLE_FEATURE_UDHCPC6_RFC4704 |
| static const char opt_fqdn_req[] = { |
| (D6_OPT_CLIENT_FQDN >> 8), (D6_OPT_CLIENT_FQDN & 0xff), |
| 0, 2, /* optlen */ |
| 0, /* flags: */ |
| /* S=0: server SHOULD NOT perform AAAA RR updates */ |
| /* O=0: client MUST set this bit to 0 */ |
| /* N=0: server SHOULD perform updates (PTR RR only in our case, since S=0) */ |
| 0 /* empty DNS-encoded name */ |
| }; |
| #endif |
| |
| /*** 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[3] > 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[0] != 0 || option[2] != 0) |
| return NULL; |
| /* Option seems to be valid */ |
| /* Does its code match? */ |
| if (option[1] == code) |
| return option; /* yes! */ |
| len_m4 -= option[3] + 4; |
| option += option[3] + 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 xmemdup(opt, opt[3] + 4); |
| } |
| |
| /*** Script execution code ***/ |
| |
| static char** new_env(void) |
| { |
| client6_data.env_ptr = xrealloc_vector(client6_data.env_ptr, 3, client6_data.env_idx); |
| return &client6_data.env_ptr[client6_data.env_idx++]; |
| } |
| |
| static char *string_option_to_env(const uint8_t *option, |
| const uint8_t *option_end) |
| { |
| const char *ptr, *name = NULL; |
| unsigned val_len; |
| int i; |
| |
| ptr = d6_option_strings; |
| i = 0; |
| while (*ptr) { |
| if (d6_optflags[i].code == option[1]) { |
| name = ptr; |
| goto found; |
| } |
| ptr += strlen(ptr) + 1; |
| i++; |
| } |
| bb_error_msg("can't find option name for 0x%x, skipping", option[1]); |
| return NULL; |
| |
| found: |
| val_len = (option[2] << 8) | option[3]; |
| if (val_len + &option[D6_OPT_DATA] > option_end) { |
| bb_simple_error_msg("option data exceeds option length"); |
| return NULL; |
| } |
| return xasprintf("%s=%.*s", name, val_len, (char*)option + 4); |
| } |
| |
| /* put all the parameters into the environment */ |
| static void option_to_env(const uint8_t *option, const uint8_t *option_end) |
| { |
| #if ENABLE_FEATURE_UDHCPC6_RFC3646 |
| int addrs, option_offset; |
| #endif |
| /* "length minus 4" */ |
| int len_m4 = option_end - option - 4; |
| |
| while (len_m4 >= 0) { |
| uint32_t v32; |
| char ipv6str[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff")]; |
| |
| if (option[0] != 0 || option[2] != 0) |
| break; |
| |
| /* Check if option-length exceeds size of option */ |
| if (option[3] > len_m4) |
| break; |
| |
| switch (option[1]) { |
| //case D6_OPT_CLIENTID: |
| //case D6_OPT_SERVERID: |
| case D6_OPT_IA_NA: |
| case D6_OPT_IA_PD: |
| option_to_env(option + 16, option + 4 + option[3]); |
| break; |
| //case D6_OPT_IA_TA: |
| case D6_OPT_IAADDR: |
| /* 0 1 2 3 |
| * 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 |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| * | OPTION_IAADDR | option-len | |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| * | | |
| * | IPv6 address | |
| * | | |
| * | | |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| * | preferred-lifetime | |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| * | valid-lifetime | |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| */ |
| /* Make sure payload contains an address */ |
| if (option[3] < 24) |
| break; |
| |
| sprint_nip6(ipv6str, option + 4); |
| *new_env() = xasprintf("ipv6=%s", ipv6str); |
| |
| move_from_unaligned32(v32, option + 4 + 16 + 4); |
| *new_env() = xasprintf("lease=%u", (unsigned)v32); |
| break; |
| |
| //case D6_OPT_ORO: |
| //case D6_OPT_PREFERENCE: |
| //case D6_OPT_ELAPSED_TIME: |
| //case D6_OPT_RELAY_MSG: |
| //case D6_OPT_AUTH: |
| //case D6_OPT_UNICAST: |
| //case D6_OPT_STATUS_CODE: |
| //case D6_OPT_RAPID_COMMIT: |
| //case D6_OPT_USER_CLASS: |
| //case D6_OPT_VENDOR_CLASS: |
| //case D6_OPT_VENDOR_OPTS: |
| //case D6_OPT_INTERFACE_ID: |
| //case D6_OPT_RECONF_MSG: |
| //case D6_OPT_RECONF_ACCEPT: |
| |
| case D6_OPT_IAPREFIX: |
| /* 0 1 2 3 |
| * 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 |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| * | OPTION_IAPREFIX | option-length | |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| * | preferred-lifetime | |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| * | valid-lifetime | |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| * | prefix-length | | |
| * +-+-+-+-+-+-+-+-+ IPv6 prefix | |
| * | (16 octets) | |
| * | | |
| * | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| * | | |
| * +-+-+-+-+-+-+-+-+ |
| */ |
| move_from_unaligned32(v32, option + 4 + 4); |
| *new_env() = xasprintf("ipv6prefix_lease=%u", (unsigned)v32); |
| |
| sprint_nip6(ipv6str, option + 4 + 4 + 4 + 1); |
| *new_env() = xasprintf("ipv6prefix=%s/%u", ipv6str, (unsigned)(option[4 + 4 + 4])); |
| break; |
| #if ENABLE_FEATURE_UDHCPC6_RFC3646 |
| case D6_OPT_DNS_SERVERS: { |
| char *dlist; |
| |
| /* Make sure payload-size is a multiple of 16 */ |
| if ((option[3] & 0x0f) != 0) |
| break; |
| |
| /* Get the number of addresses on the option */ |
| addrs = option[3] >> 4; |
| |
| /* Setup environment variable */ |
| *new_env() = dlist = xmalloc(4 + addrs * 40 - 1); |
| dlist = stpcpy(dlist, "dns="); |
| option_offset = 0; |
| |
| while (addrs--) { |
| sprint_nip6(dlist, option + 4 + option_offset); |
| dlist += 39; |
| option_offset += 16; |
| if (addrs) |
| *dlist++ = ' '; |
| } |
| |
| break; |
| } |
| case D6_OPT_DOMAIN_LIST: { |
| char *dlist; |
| |
| dlist = dname_dec(option + 4, (option[2] << 8) | option[3], "search="); |
| if (!dlist) |
| break; |
| *new_env() = dlist; |
| break; |
| } |
| #endif |
| #if ENABLE_FEATURE_UDHCPC6_RFC4704 |
| case D6_OPT_CLIENT_FQDN: { |
| char *dlist; |
| |
| if (option[3] == 0) |
| break; |
| /* Work around broken ISC DHCPD6. |
| * ISC DHCPD6 does not implement RFC 4704 correctly: It says the first |
| * byte of option-payload should contain flags where the bits 7-3 are |
| * reserved for future use and MUST be zero. Instead ISC DHCPD6 just |
| * writes the entire FQDN as string to option-payload. We assume a |
| * broken server here if any of the reserved bits are set. |
| */ |
| if (option[4] & 0xf8) { |
| *new_env() = xasprintf("fqdn=%.*s", (int)option[3], (char*)option + 4); |
| break; |
| } |
| dlist = dname_dec(option + 5, (/*(option[2] << 8) |*/ option[3]) - 1, "fqdn="); |
| if (!dlist) |
| break; |
| *new_env() = dlist; |
| break; |
| } |
| #endif |
| #if ENABLE_FEATURE_UDHCPC6_RFC4833 |
| /* RFC 4833 Timezones */ |
| case D6_OPT_TZ_POSIX: |
| *new_env() = xasprintf("tz=%.*s", (int)option[3], (char*)option + 4); |
| break; |
| case D6_OPT_TZ_NAME: |
| *new_env() = xasprintf("tz_name=%.*s", (int)option[3], (char*)option + 4); |
| break; |
| #endif |
| case D6_OPT_BOOT_URL: |
| case D6_OPT_BOOT_PARAM: |
| case 0xd1: /* DHCP_PXE_CONF_FILE */ |
| case 0xd2: /* DHCP_PXE_PATH_PREFIX */ |
| { |
| char *tmp = string_option_to_env(option, option_end); |
| if (tmp) |
| *new_env() = tmp; |
| break; |
| } |
| } |
| len_m4 -= 4 + option[3]; |
| option += 4 + option[3]; |
| } |
| } |
| |
| static char **fill_envp(const uint8_t *option, const uint8_t *option_end) |
| { |
| char **envp, **curr; |
| |
| client6_data.env_ptr = NULL; |
| client6_data.env_idx = 0; |
| |
| *new_env() = xasprintf("interface=%s", client_data.interface); |
| |
| if (option) |
| option_to_env(option, option_end); |
| |
| envp = curr = client6_data.env_ptr; |
| while (*curr) |
| putenv(*curr++); |
| |
| return envp; |
| } |
| |
| /* Call a script with a par file and env vars */ |
| static void d6_run_script(const uint8_t *option, const uint8_t *option_end, |
| const char *name) |
| { |
| char **envp, **curr; |
| char *argv[3]; |
| |
| envp = fill_envp(option, option_end); |
| |
| /* call script */ |
| log1("executing %s %s", client_data.script, name); |
| argv[0] = (char*) client_data.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); |
| } |
| |
| /* Call a script with a par file and no env var */ |
| static void d6_run_script_no_option(const char *name) |
| { |
| d6_run_script(NULL, NULL, name); |
| } |
| |
| /*** 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) |
| { |
| uint8_t *ptr; |
| struct d6_option *clientid; |
| unsigned secs; |
| |
| memset(packet, 0, sizeof(*packet)); |
| |
| packet->d6_xid32 = xid; |
| packet->d6_msg_type = type; |
| |
| /* ELAPSED_TIME option is required to be present by the RFC, |
| * and some servers do check for its presense. [which?] |
| */ |
| ptr = packet->d6_options; /* NB: it is 32-bit aligned */ |
| *((uint32_t*)ptr) = htonl((D6_OPT_ELAPSED_TIME << 16) + 2); |
| ptr += 4; |
| client_data.last_secs = monotonic_sec(); |
| if (client_data.first_secs == 0) |
| client_data.first_secs = client_data.last_secs; |
| secs = client_data.last_secs - client_data.first_secs; |
| *((uint16_t*)ptr) = (secs < 0xffff) ? htons(secs) : 0xffff; |
| ptr += 2; |
| |
| /* add CLIENTID option */ |
| clientid = (void*)client_data.clientid; |
| return mempcpy(ptr, clientid, clientid->len + 2+2); |
| } |
| |
| static uint8_t *add_d6_client_options(uint8_t *ptr) |
| { |
| struct option_set *curr; |
| uint8_t *start = ptr; |
| unsigned option; |
| uint16_t len; |
| |
| ptr += 4; |
| for (option = 1; option < 256; option++) { |
| if (client_data.opt_mask[option >> 3] & (1 << (option & 7))) { |
| ptr[0] = (option >> 8); |
| ptr[1] = option; |
| ptr += 2; |
| } |
| } |
| |
| if ((ptr - start - 4) != 0) { |
| start[0] = (D6_OPT_ORO >> 8); |
| start[1] = D6_OPT_ORO; |
| start[2] = ((ptr - start - 4) >> 8); |
| start[3] = (ptr - start - 4); |
| } else |
| ptr = start; |
| |
| #if ENABLE_FEATURE_UDHCPC6_RFC4704 |
| ptr = mempcpy(ptr, &opt_fqdn_req, sizeof(opt_fqdn_req)); |
| #endif |
| /* Add -x options if any */ |
| curr = client_data.options; |
| while (curr) { |
| len = (curr->data[D6_OPT_LEN] << 8) | curr->data[D6_OPT_LEN + 1]; |
| ptr = mempcpy(ptr, curr->data, D6_OPT_DATA + len); |
| curr = curr->next; |
| } |
| |
| return ptr; |
| } |
| |
| static int d6_mcast_from_client_data_ifindex(struct d6_packet *packet, uint8_t *end) |
| { |
| /* FF02::1:2 is "All_DHCP_Relay_Agents_and_Servers" address */ |
| 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*/ &client6_data.ll_ip6, CLIENT_PORT6, |
| /*dst*/ (struct in6_addr*)FF02__1_2, SERVER_PORT6, MAC_BCAST_ADDR, |
| client_data.ifindex |
| ); |
| } |
| |
| /* RFC 3315 18.1.5. Creation and Transmission of Information-request Messages |
| * |
| * The client uses an Information-request message to obtain |
| * configuration information without having addresses assigned to it. |
| * |
| * The client sets the "msg-type" field to INFORMATION-REQUEST. The |
| * client generates a transaction ID and inserts this value in the |
| * "transaction-id" field. |
| * |
| * The client SHOULD include a Client Identifier option to identify |
| * itself to the server. If the client does not include a Client |
| * Identifier option, the server will not be able to return any client- |
| * specific options to the client, or the server may choose not to |
| * respond to the message at all. The client MUST include a Client |
| * Identifier option if the Information-Request message will be |
| * authenticated. |
| * |
| * 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_info_request(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_INFORMATION_REQUEST, xid); |
| |
| /* Add options: |
| * "param req" option according to -O, options specified with -x |
| */ |
| opt_ptr = add_d6_client_options(opt_ptr); |
| |
| bb_error_msg("sending %s", "info request"); |
| return d6_mcast_from_client_data_ifindex(&packet, opt_ptr); |
| } |
| |
| /* 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); |
| client6_data.ia_na = NULL; |
| if (option_mask32 & OPT_r) { |
| 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; |
| *(bb__aliased_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 = mempcpy(opt_ptr, client6_data.ia_na, len); |
| } |
| |
| /* IA_PD */ |
| free(client6_data.ia_pd); |
| client6_data.ia_pd = NULL; |
| if (option_mask32 & OPT_d) { |
| len = 2+2+4+4+4; |
| client6_data.ia_pd = xzalloc(len); |
| client6_data.ia_pd->code = D6_OPT_IA_PD; |
| client6_data.ia_pd->len = len - 4; |
| *(bb__aliased_uint32_t*)client6_data.ia_pd->data = rand(); /* IAID */ |
| opt_ptr = mempcpy(opt_ptr, client6_data.ia_pd, 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 %s", "discover"); |
| return d6_mcast_from_client_data_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 = mempcpy(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2); |
| /* IA NA (contains requested IP) */ |
| if (client6_data.ia_na) |
| opt_ptr = mempcpy(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2); |
| /* IA PD */ |
| if (client6_data.ia_pd) |
| opt_ptr = mempcpy(opt_ptr, client6_data.ia_pd, client6_data.ia_pd->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 %s", "select"); |
| return d6_mcast_from_client_data_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 = mempcpy(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2); |
| /* IA NA (contains requested IP) */ |
| if (client6_data.ia_na) |
| opt_ptr = mempcpy(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2); |
| /* IA PD */ |
| if (client6_data.ia_pd) |
| opt_ptr = mempcpy(opt_ptr, client6_data.ia_pd, client6_data.ia_pd->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 %s", "renew"); |
| if (server_ipv6) |
| return d6_send_kernel_packet( |
| &packet, (opt_ptr - (uint8_t*) &packet), |
| our_cur_ipv6, CLIENT_PORT6, |
| server_ipv6, SERVER_PORT6, |
| client_data.ifindex |
| ); |
| return d6_mcast_from_client_data_ifindex(&packet, opt_ptr); |
| } |
| |
| /* Unicast a DHCP release message */ |
| static |
| ALWAYS_INLINE /* one caller, help compiler to use this fact */ |
| 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 = mempcpy(opt_ptr, client6_data.server_id, client6_data.server_id->len + 2+2); |
| /* IA NA (contains our current IP) */ |
| if (client6_data.ia_na) |
| opt_ptr = mempcpy(opt_ptr, client6_data.ia_na, client6_data.ia_na->len + 2+2); |
| /* IA PD */ |
| if (client6_data.ia_pd) |
| opt_ptr = mempcpy(opt_ptr, client6_data.ia_pd, client6_data.ia_pd->len + 2+2); |
| |
| bb_info_msg("sending %s", "release"); |
| return d6_send_kernel_packet( |
| &packet, (opt_ptr - (uint8_t*) &packet), |
| our_cur_ipv6, CLIENT_PORT6, |
| server_ipv6, SERVER_PORT6, |
| client_data.ifindex |
| ); |
| } |
| |
| /* 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, 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) { |
| log1s("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))) { |
| log1s("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 */ |
| log1s("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_PORT6) |
| /* || bytes > (int) sizeof(packet) - can't happen */ |
| || packet.udp.len != packet.ip6.ip6_plen |
| ) { |
| log1s("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; |
| // } |
| |
| if (peer_ipv6) |
| *peer_ipv6 = packet.ip6.ip6_src; /* struct copy */ |
| |
| log1("received %s", "a packet"); |
| d6_dump_packet(&packet.data); |
| |
| bytes -= sizeof(packet.ip6) + sizeof(packet.udp); |
| memcpy(d6_pkt, &packet.data, bytes); |
| return bytes; |
| } |
| |
| /*** Main ***/ |
| |
| /* Values for client_data.listen_mode */ |
| #define LISTEN_NONE 0 |
| #define LISTEN_KERNEL 1 |
| #define LISTEN_RAW 2 |
| |
| /* Values for client_data.state */ |
| /* 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 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_PORT6, else to L4 */ |
| BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1), |
| /* L3: accept packet */ |
| BPF_STMT(BPF_RET|BPF_K, 0x7fffffff), |
| /* 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 |
| |
| log2("opening raw socket on ifindex %d", ifindex); |
| |
| fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IPV6)); |
| log3("got raw socket fd %d", fd); |
| |
| memset(&sock, 0, sizeof(sock)); /* let's be deterministic */ |
| sock.sll_family = AF_PACKET; |
| sock.sll_protocol = htons(ETH_P_IPV6); |
| sock.sll_ifindex = ifindex; |
| /*sock.sll_hatype = ARPHRD_???;*/ |
| /*sock.sll_pkttype = PACKET_???;*/ |
| /*sock.sll_halen = ???;*/ |
| /*sock.sll_addr[8] = ???;*/ |
| xbind(fd, (struct sockaddr *) &sock, sizeof(sock)); |
| |
| #if 0 |
| if (CLIENT_PORT6 == 546) { |
| /* 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 |
| |
| log1s("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" |
| ); |
| |
| client_data.listen_mode = new_mode; |
| if (client_data.sockfd >= 0) { |
| close(client_data.sockfd); |
| client_data.sockfd = -1; |
| } |
| if (new_mode == LISTEN_KERNEL) |
| client_data.sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT6, client_data.interface); |
| else if (new_mode != LISTEN_NONE) |
| client_data.sockfd = d6_raw_socket(client_data.ifindex); |
| /* else LISTEN_NONE: client_data.sockfd stays closed */ |
| } |
| |
| /* Called only on SIGUSR1 */ |
| static void perform_renew(void) |
| { |
| bb_simple_info_msg("performing DHCP renew"); |
| switch (client_data.state) { |
| case BOUND: |
| change_listen_mode(LISTEN_KERNEL); |
| case RENEWING: |
| case REBINDING: |
| client_data.state = RENEW_REQUESTED; |
| break; |
| case RENEW_REQUESTED: /* impatient are we? fine, square 1 */ |
| d6_run_script_no_option("deconfig"); |
| case REQUESTING: |
| case RELEASED: |
| change_listen_mode(LISTEN_RAW); |
| client_data.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 (client_data.state == BOUND |
| || client_data.state == RENEWING |
| || client_data.state == REBINDING |
| || client_data.state == RENEW_REQUESTED |
| ) { |
| bb_simple_info_msg("unicasting a release"); |
| send_d6_release(server_ipv6, our_cur_ipv6); /* unicast */ |
| } |
| bb_simple_info_msg("entering released state"); |
| /* |
| * We can be here on: SIGUSR2, |
| * or on exit (SIGTERM) and -R "release on quit" is specified. |
| * Users requested to be notified in all cases, even if not in one |
| * of the states above. |
| */ |
| d6_run_script_no_option("deconfig"); |
| change_listen_mode(LISTEN_NONE); |
| client_data.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_data.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")"odR] [-i IFACE] [-r IPv6] [-s PROG] [-p PIDFILE]\n" |
| //usage: " [-x OPT:VAL]... [-O OPT]..." IF_FEATURE_UDHCP_PORT(" [-P N]") |
| //usage:#define udhcpc6_full_usage "\n" |
| //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 546)" |
| //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 IPv6 Request this address ('no' to not request any IP)" |
| //usage: "\n -d Request prefix" |
| //usage: "\n -l Send 'information request' instead of 'solicit'" |
| //usage: "\n (used for servers which do not assign IPv6 addresses)" |
| //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: "\n -x 14:'\"dumpfile\"' - option 14 (shell-quoted)" |
| //usage: IF_UDHCP_VERBOSE( |
| //usage: "\n -v Verbose" |
| //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 retval; |
| |
| setup_common_bufsiz(); |
| /* We want random_xid to be random */ |
| srand(monotonic_us()); |
| |
| /* Default options */ |
| IF_FEATURE_UDHCP_PORT(SERVER_PORT6 = 547;) |
| IF_FEATURE_UDHCP_PORT(CLIENT_PORT6 = 546;) |
| client_data.interface = "eth0"; |
| client_data.script = CONFIG_UDHCPC_DEFAULT_SCRIPT; |
| client_data.sockfd = -1; |
| |
| /* Make sure fd 0,1,2 are open */ |
| /* Set up the signal pipe on fds 3,4 - must be before openlog() */ |
| udhcp_sp_setup(); |
| |
| /* Parse command line */ |
| opt = getopt32long(argv, "^" |
| /* O,x: list; -T,-t,-A take numeric param */ |
| "i:np:qRr:s:T:+t:+SA:+O:*ox:*fld" |
| USE_FOR_MMU("b") |
| ///IF_FEATURE_UDHCPC_ARPING("a") |
| IF_FEATURE_UDHCP_PORT("P:") |
| "v" |
| "\0" IF_UDHCP_VERBOSE("vv") /* -v is a counter */ |
| , udhcpc6_longopts |
| , &client_data.interface, &client_data.pidfile, &str_r /* i,p */ |
| , &client_data.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; |
| option_mask32 |= OPT_r; |
| if (opt & OPT_l) { |
| /* for -l, do not require IPv6 assignment from server */ |
| option_mask32 &= ~OPT_r; |
| } else if (opt & OPT_r) { |
| /* explicit "-r ARG" given */ |
| if (strcmp(str_r, "no") == 0) { |
| option_mask32 &= ~OPT_r; |
| } else { |
| 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_PORT6 = xatou16(str_P); |
| SERVER_PORT6 = CLIENT_PORT6 + 1; |
| } |
| #endif |
| 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, d6_option_strings); |
| n = d6_optflags[n].code; |
| } |
| client_data.opt_mask[n >> 3] |= 1 << (n & 7); |
| } |
| if (!(opt & OPT_o)) { |
| unsigned i, n; |
| for (i = 0; (n = d6_optflags[i].code) != 0; i++) { |
| if (d6_optflags[i].flags & OPTION_REQ) { |
| client_data.opt_mask[n >> 3] |= 1 << (n & 7); |
| } |
| } |
| } |
| while (list_x) { |
| char *optstr = xstrdup(llist_pop(&list_x)); |
| udhcp_str2optset(optstr, &client_data.options, |
| d6_optflags, d6_option_strings, |
| /*dhcpv6:*/ 1 |
| ); |
| free(optstr); |
| } |
| |
| if (d6_read_interface(client_data.interface, |
| &client_data.ifindex, |
| &client6_data.ll_ip6, |
| client_data.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[1] = 3; /* DUID-LL */ |
| clientid->data[3] = 1; /* ethernet */ |
| clientid_mac_ptr = clientid->data + 2+2; |
| memcpy(clientid_mac_ptr, client_data.client_mac, 6); |
| client_data.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; |
| } |
| |
| /* Create pidfile */ |
| write_pidfile(client_data.pidfile); |
| /* Goes to stdout (unless NOMMU) and possibly syslog */ |
| bb_simple_info_msg("started, v"BB_VER); |
| |
| client_data.state = INIT_SELECTING; |
| d6_run_script_no_option("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 (;;) { |
| int tv; |
| struct pollfd pfds[2]; |
| 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", client_data.sockfd, client_data.listen_mode); |
| |
| /* Was opening raw or udp socket here |
| * if (client_data.listen_mode != LISTEN_NONE && client_data.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:"). */ |
| |
| udhcp_sp_fd_set(pfds, client_data.sockfd); |
| |
| tv = timeout - already_waited_sec; |
| retval = 0; |
| /* If we already timed out, fall through with retval = 0, else... */ |
| if (tv > 0) { |
| log1("waiting %u seconds", tv); |
| timestamp_before_wait = (unsigned)monotonic_sec(); |
| retval = poll(pfds, 2, tv < INT_MAX/1000 ? tv * 1000 : INT_MAX); |
| 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_simple_perror_msg_and_die("poll"); |
| } |
| } |
| |
| /* 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 (d6_read_interface(client_data.interface, |
| &client_data.ifindex, |
| &client6_data.ll_ip6, |
| client_data.client_mac) |
| ) { |
| goto ret0; /* iface is gone? */ |
| } |
| |
| memcpy(clientid_mac_ptr, client_data.client_mac, 6); |
| |
| /* We will restart the wait in any case */ |
| already_waited_sec = 0; |
| |
| switch (client_data.state) { |
| case INIT_SELECTING: |
| if (!discover_retries || packet_num < discover_retries) { |
| if (packet_num == 0) |
| xid = random_xid(); |
| /* multicast */ |
| if (opt & OPT_l) |
| send_d6_info_request(xid); |
| else |
| send_d6_discover(xid, requested_ipv6); |
| timeout = discover_timeout; |
| packet_num++; |
| continue; |
| } |
| leasefail: |
| d6_run_script_no_option("leasefail"); |
| #if BB_MMU /* -b is not supported on NOMMU */ |
| if (opt & OPT_b) { /* background if no lease */ |
| bb_simple_info_msg("no lease, forking to background"); |
| client_background(); |
| /* do not background again! */ |
| opt = ((opt & ~(OPT_b|OPT_n)) | OPT_f); |
| /* ^^^ also disables -n (-b takes priority over -n): |
| * ifup's default udhcpc options are -R -n, |
| * and users want to be able to add -b |
| * (in a config file) to make it background |
| * _and not exit_. |
| */ |
| } else |
| #endif |
| if (opt & OPT_n) { /* abort if no lease */ |
| bb_simple_info_msg("no lease, failing"); |
| retval = 1; |
| goto ret; |
| } |
| /* wait before trying again */ |
| timeout = tryagain_timeout; |
| packet_num = 0; |
| continue; |
| case REQUESTING: |
| if (!discover_retries || 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); |
| client_data.state = INIT_SELECTING; |
| goto leasefail; |
| case BOUND: |
| /* 1/2 lease passed, enter renewing state */ |
| client_data.state = RENEWING; |
| client_data.first_secs = 0; /* make secs field count from 0 */ |
| change_listen_mode(LISTEN_KERNEL); |
| log1s("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. |
| */ |
| if (opt & OPT_l) |
| send_d6_info_request(xid); |
| else |
| send_d6_renew(xid, &srv6_buf, requested_ipv6); |
| timeout >>= 1; |
| continue; |
| } |
| /* Timed out, enter rebinding state */ |
| log1s("entering rebinding state"); |
| client_data.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) { |
| if (opt & OPT_l) |
| send_d6_info_request(xid); |
| else /* send a broadcast renew request */ |
| send_d6_renew(xid, /*server_ipv6:*/ NULL, requested_ipv6); |
| timeout >>= 1; |
| continue; |
| } |
| /* Timed out, enter init state */ |
| bb_simple_info_msg("lease lost, entering init state"); |
| d6_run_script_no_option("deconfig"); |
| client_data.state = INIT_SELECTING; |
| client_data.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 poll timed out */ |
| |
| /* poll() didn't timeout, something happened */ |
| |
| /* Is it a signal? */ |
| switch (udhcp_sp_read()) { |
| case SIGUSR1: |
| client_data.first_secs = 0; /* make secs field count from 0 */ |
| already_waited_sec = 0; |
| perform_renew(); |
| if (client_data.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. |
| */ |
| if (timeout > 60) |
| timeout = 60; |
| 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 %s", "SIGTERM"); |
| goto ret0; |
| } |
| |
| /* Is it a packet? */ |
| if (!pfds[1].revents) |
| continue; /* no */ |
| |
| { |
| int len; |
| |
| /* A packet is ready, read it */ |
| if (client_data.listen_mode == LISTEN_KERNEL) |
| len = d6_recv_kernel_packet(&srv6_buf, &packet, client_data.sockfd); |
| else |
| len = d6_recv_raw_packet(&srv6_buf, &packet, client_data.sockfd); |
| if (len == -1) { |
| /* Error is severe, reopen socket */ |
| bb_error_msg("read error: "STRERROR_FMT", reopening socket" STRERROR_ERRNO); |
| sleep(discover_timeout); /* 3 seconds by default */ |
| change_listen_mode(client_data.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 (client_data.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; |
| unsigned address_timeout; |
| unsigned prefix_timeout; |
| type_is_ok: |
| address_timeout = 0; |
| prefix_timeout = 0; |
| option = d6_find_option(packet.d6_options, packet_end, D6_OPT_STATUS_CODE); |
| if (option && (option->data[0] | option->data[1]) != 0) { |
| /* return to init state */ |
| bb_info_msg("received DHCP NAK (%u)", option->data[4]); |
| d6_run_script(packet.d6_options, |
| packet_end, "nak"); |
| if (client_data.state != REQUESTING) |
| d6_run_script_no_option("deconfig"); |
| change_listen_mode(LISTEN_RAW); |
| sleep(3); /* avoid excessive network traffic */ |
| client_data.state = INIT_SELECTING; |
| client_data.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_simple_info_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 */ |
| client_data.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 . |
| * . . |
| * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| */ |
| if (option_mask32 & OPT_r) { |
| struct d6_option *iaaddr; |
| |
| 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_info_msg("no %s option, ignoring packet", "IA_NA"); |
| continue; |
| } |
| if (client6_data.ia_na->len < (4 + 4 + 4) + (2 + 2 + 16 + 4 + 4)) { |
| bb_info_msg("%s option is too short:%d bytes", |
| "IA_NA", client6_data.ia_na->len); |
| continue; |
| } |
| iaaddr = d6_find_option(client6_data.ia_na->data + 4 + 4 + 4, |
| client6_data.ia_na->data + client6_data.ia_na->len, |
| D6_OPT_IAADDR |
| ); |
| if (!iaaddr) { |
| bb_info_msg("no %s option, ignoring packet", "IAADDR"); |
| continue; |
| } |
| if (iaaddr->len < (16 + 4 + 4)) { |
| bb_info_msg("%s option is too short:%d bytes", |
| "IAADDR", 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); |
| /// TODO: check for 0 lease time? |
| bb_info_msg("%s obtained, lease time %u", |
| "IPv6", /*inet_ntoa(temp_addr),*/ (unsigned)lease_seconds); |
| address_timeout = lease_seconds; |
| } |
| if (option_mask32 & OPT_d) { |
| struct d6_option *iaprefix; |
| |
| free(client6_data.ia_pd); |
| client6_data.ia_pd = d6_copy_option(packet.d6_options, packet_end, D6_OPT_IA_PD); |
| if (!client6_data.ia_pd) { |
| bb_info_msg("no %s option, ignoring packet", "IA_PD"); |
| continue; |
| } |
| if (client6_data.ia_pd->len < (4 + 4 + 4) + (2 + 2 + 4 + 4 + 1 + 16)) { |
| bb_info_msg("%s option is too short:%d bytes", |
| "IA_PD", client6_data.ia_pd->len); |
| continue; |
| } |
| iaprefix = d6_find_option(client6_data.ia_pd->data + 4 + 4 + 4, |
| client6_data.ia_pd->data + client6_data.ia_pd->len, |
| D6_OPT_IAPREFIX |
| ); |
| if (!iaprefix) { |
| bb_info_msg("no %s option, ignoring packet", "IAPREFIX"); |
| continue; |
| } |
| if (iaprefix->len < (4 + 4 + 1 + 16)) { |
| bb_info_msg("%s option is too short:%d bytes", |
| "IAPREFIX", iaprefix->len); |
| continue; |
| } |
| move_from_unaligned32(lease_seconds, iaprefix->data + 4); |
| lease_seconds = ntohl(lease_seconds); |
| bb_info_msg("%s obtained, lease time %u", |
| "prefix", /*inet_ntoa(temp_addr),*/ (unsigned)lease_seconds); |
| prefix_timeout = lease_seconds; |
| } |
| if (!address_timeout) |
| address_timeout = prefix_timeout; |
| if (!prefix_timeout) |
| prefix_timeout = address_timeout; |
| /* note: "int timeout" will not overflow even with 0xffffffff inputs here: */ |
| timeout = (prefix_timeout < address_timeout ? prefix_timeout : address_timeout) / 2; |
| if (opt & OPT_l) { |
| /* TODO: request OPTION_INFORMATION_REFRESH_TIME (32) |
| * and use its value instead of the default 1 day. |
| */ |
| timeout = 24 * 60 * 60; |
| } |
| /* paranoia: must not be too small */ |
| /* timeout > 60 - ensures at least one unicast renew attempt */ |
| if (timeout < 61) |
| timeout = 61; |
| /* enter bound state */ |
| d6_run_script(packet.d6_options, packet_end, |
| (client_data.state == REQUESTING ? "bound" : "renew")); |
| |
| client_data.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_data.pidfile) - remove_pidfile has its own check */ |
| remove_pidfile(client_data.pidfile); |
| return retval; |
| } |