/* * Based on LiMon - BOOTP. * * Copyright 1994, 1995, 2000 Neil Russell. * (See License) * Copyright 2000 Roland Borde * Copyright 2000 Paolo Scaffardi * Copyright 2000-2004 Wolfgang Denk, wd@denx.de */ #include #include #include #include #include #include #include #include #include #include #include #include #include #define DHCP_DEFAULT_RETRY 20 #define OPT_SIZE 312 /* Minimum DHCP Options size per RFC2131 - results in 576 byte pkt */ struct bootp { uint8_t bp_op; /* Operation */ #define OP_BOOTREQUEST 1 #define OP_BOOTREPLY 2 uint8_t bp_htype; /* Hardware type */ #define HWT_ETHER 1 uint8_t bp_hlen; /* Hardware address length */ #define HWL_ETHER 6 uint8_t bp_hops; /* Hop count (gateway thing) */ uint32_t bp_id; /* Transaction ID */ uint16_t bp_secs; /* Seconds since boot */ uint16_t bp_spare1; /* Alignment */ IPaddr_t bp_ciaddr; /* Client IP address */ IPaddr_t bp_yiaddr; /* Your (client) IP address */ IPaddr_t bp_siaddr; /* Server IP address */ IPaddr_t bp_giaddr; /* Gateway IP address */ uint8_t bp_chaddr[16]; /* Client hardware address */ char bp_sname[64]; /* Server host name */ char bp_file[128]; /* Boot file name */ char bp_vend[0]; /* Vendor information */ }; /* DHCP States */ typedef enum { INIT, INIT_REBOOT, REBOOTING, SELECTING, REQUESTING, REBINDING, BOUND, RENEWING, } dhcp_state_t; #define DHCP_DISCOVER 1 #define DHCP_OFFER 2 #define DHCP_REQUEST 3 #define DHCP_DECLINE 4 #define DHCP_ACK 5 #define DHCP_NAK 6 #define DHCP_RELEASE 7 #define BOOTP_VENDOR_MAGIC 0x63825363 /* RFC1048 Magic Cookie */ #define PORT_BOOTPS 67 /* BOOTP server UDP port */ #define PORT_BOOTPC 68 /* BOOTP client UDP port */ #define DHCP_MIN_EXT_LEN 64 /* minimal length of extension list */ static uint32_t Bootp_id; static dhcp_state_t dhcp_state; static uint32_t dhcp_leasetime; static IPaddr_t net_dhcp_server_ip; static uint64_t dhcp_start; static char dhcp_tftpname[256]; static const char* dhcp_get_barebox_global(const char * var) { char * var_global = asprintf("global.dhcp.%s", var); const char *val; if (!var_global) return NULL; val = getenv(var_global); free(var_global); return val; } static int dhcp_set_barebox_global(const char * var, char *val) { char * var_global = asprintf("global.dhcp.%s", var); int ret; if (!var_global) return -ENOMEM; ret = setenv(var_global, val); free(var_global); return ret; } struct dhcp_opt { unsigned char option; /* request automatically the option when creating the DHCP request */ bool optional; bool copy_only_if_valid; const char *barebox_var_name; const char *barebox_dhcp_global; void (*handle)(struct dhcp_opt *opt, unsigned char *data, int tlen); void *data; struct bootp *bp; }; static void netmask_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen) { IPaddr_t ip; ip = net_read_ip(popt); net_set_netmask(ip); } static void gateway_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen) { IPaddr_t ip; ip = net_read_ip(popt); net_set_gateway(ip); } static void env_ip_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen) { IPaddr_t ip; ip = net_read_ip(popt); setenv_ip(opt->barebox_var_name, ip); } static void env_str_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen) { char str[256]; char *tmp = str; if (opt->data) tmp = opt->data; memcpy(tmp, popt, optlen); tmp[optlen] = 0; if (opt->copy_only_if_valid && !strlen(tmp)) return; if (opt->barebox_var_name) setenv(opt->barebox_var_name, tmp); if (opt->barebox_dhcp_global) dhcp_set_barebox_global(opt->barebox_dhcp_global, tmp); } static void copy_uint32_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen) { net_copy_uint32(opt->data, (uint32_t *)popt); }; static void copy_ip_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen) { net_copy_ip(opt->data, popt); }; static void bootfile_vendorex_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen) { if (opt->bp->bp_file[0] != '\0') return; /* * only use vendor boot file if we didn't * receive a boot file in the main non-vendor * part of the packet - god only knows why * some vendors chose not to use this perfectly * good spot to store the boot file (join on * Tru64 Unix) it seems mind bogglingly crazy * to me */ pr_warn("*** WARNING: using vendor optional boot file\n"); /* * I can't use dhcp_vendorex_proc here because I need * to write into the bootp packet - even then I had to * pass the bootp packet pointer into here as the * second arg */ env_str_handle(opt, popt, optlen); } struct dhcp_opt dhcp_options[] = { { .option = 1, .handle = netmask_handle, }, { .option = 3, .handle = gateway_handle, }, { .option = 6, .handle = env_ip_handle, .barebox_var_name = "net.nameserver", }, { .option = 12, .copy_only_if_valid = 1, .handle = env_str_handle, .barebox_var_name = "global.hostname", }, { .option = 15, .handle = env_str_handle, .barebox_var_name = "net.domainname", }, { .option = 17, .handle = env_str_handle, .barebox_dhcp_global = "rootpath", }, { .option = 51, .handle = copy_uint32_handle, .data = &dhcp_leasetime, }, { .option = 54, .handle = copy_ip_handle, .data = &net_dhcp_server_ip, .optional = true, }, { .option = 66, .handle = env_str_handle, .barebox_dhcp_global = "tftp_server_name", .data = dhcp_tftpname, }, { .option = 67, .handle = bootfile_vendorex_handle, .barebox_dhcp_global = "bootfile", }, { .option = 224, .handle = env_str_handle, .barebox_dhcp_global = "oftree_file", }, }; struct dhcp_param { unsigned char option; const char *barebox_var_name; const char *barebox_dhcp_global; int (*handle)(struct dhcp_param *param, u8 *e); void *data; }; static int dhcp_set_string_options(struct dhcp_param *param, u8 *e) { int str_len; char* str = param->data; if (!str && param->barebox_var_name) str = (char*)getenv(param->barebox_var_name); if (!str && param->barebox_dhcp_global) str = (char*)dhcp_get_barebox_global(param->barebox_dhcp_global); if (!str) return 0; str_len = strlen(str); if (!str_len) return 0; *e++ = param->option; *e++ = str_len; memcpy(e, str, str_len); return str_len + 2; } #define DHCP_HOSTNAME 12 #define DHCP_VENDOR_ID 60 #define DHCP_CLIENT_ID 61 #define DHCP_USER_CLASS 77 #define DHCP_CLIENT_UUID 97 struct dhcp_param dhcp_params[] = { { .option = DHCP_HOSTNAME, .handle = dhcp_set_string_options, .barebox_var_name = "global.hostname", }, { .option = DHCP_VENDOR_ID, .handle = dhcp_set_string_options, .barebox_dhcp_global = "vendor_id", }, { .option = DHCP_CLIENT_ID, .handle = dhcp_set_string_options, .barebox_dhcp_global = "client_id", }, { .option = DHCP_USER_CLASS, .handle = dhcp_set_string_options, .barebox_dhcp_global = "user_class", }, { .option = DHCP_CLIENT_UUID, .handle = dhcp_set_string_options, .barebox_dhcp_global = "client_uuid", } }; static void dhcp_set_param_data(int option, void* data) { struct dhcp_param *param; int i; for (i = 0; i < ARRAY_SIZE(dhcp_params); i++) { param = &dhcp_params[i]; if (param->option == option) { param->data = data; return; } } } static int dhcp_set_ip_options(int option, u8 *e, IPaddr_t ip) { int tmp; if (!ip) return 0; tmp = ntohl(ip); *e++ = option; *e++ = 4; *e++ = tmp >> 24; *e++ = tmp >> 16; *e++ = tmp >> 8; *e++ = tmp & 0xff; return 6; } static int bootp_check_packet(unsigned char *pkt, unsigned src, unsigned len) { struct bootp *bp = (struct bootp *) pkt; int retval = 0; if (src != PORT_BOOTPS) retval = -1; else if (len < sizeof(struct bootp)) retval = -2; else if (bp->bp_op != OP_BOOTREQUEST && bp->bp_op != OP_BOOTREPLY && bp->bp_op != DHCP_OFFER && bp->bp_op != DHCP_ACK && bp->bp_op != DHCP_NAK ) { retval = -3; } else if (bp->bp_htype != HWT_ETHER) retval = -4; else if (bp->bp_hlen != HWL_ETHER) retval = -5; else if (net_read_uint32(&bp->bp_id) != Bootp_id) { retval = -6; } debug("Filtering pkt = %d\n", retval); return retval; } /* * Copy parameters of interest from BOOTP_REPLY/DHCP_OFFER packet */ static void bootp_copy_net_params(struct bootp *bp) { IPaddr_t tmp_ip; tmp_ip = net_read_ip(&bp->bp_yiaddr); net_set_ip(tmp_ip); tmp_ip = net_read_ip(&bp->bp_siaddr); if (tmp_ip != 0) net_set_serverip(tmp_ip); if (strlen(bp->bp_file) > 0) { setenv("bootfile", bp->bp_file); dhcp_set_barebox_global("bootfile", bp->bp_file); } debug("bootfile: %s\n", bp->bp_file); } /* * Initialize BOOTP extension fields in the request. */ static int dhcp_extended (u8 *e, int message_type, IPaddr_t ServerID, IPaddr_t RequestedIP) { int i; u8 *start = e; u8 *cnt; *e++ = 99; /* RFC1048 Magic Cookie */ *e++ = 130; *e++ = 83; *e++ = 99; *e++ = 53; /* DHCP Message Type */ *e++ = 1; *e++ = message_type; *e++ = 57; /* Maximum DHCP Message Size */ *e++ = 2; *e++ = (576 - 312 + OPT_SIZE) >> 8; *e++ = (576 - 312 + OPT_SIZE) & 0xff; e += dhcp_set_ip_options(50, e, RequestedIP); e += dhcp_set_ip_options(54, e, ServerID); for (i = 0; i < ARRAY_SIZE(dhcp_params); i++) e += dhcp_params[i].handle(&dhcp_params[i], e); *e++ = 55; /* Parameter Request List */ cnt = e++; /* Pointer to count of requested items */ *cnt = 0; for (i = 0; i < ARRAY_SIZE(dhcp_options); i++) { if (dhcp_options[i].optional) continue; *e++ = dhcp_options[i].option; *cnt += 1; } *e++ = 255; /* End of the list */ /* Pad to minimal length */ while ((e - start) <= DHCP_MIN_EXT_LEN) *e++ = 0; return e - start; } static struct net_connection *dhcp_con; static int bootp_request(void) { struct bootp *bp; int ext_len; int ret; unsigned char *payload = net_udp_get_payload(dhcp_con); const char *bfile; dhcp_state = INIT; debug("BOOTP broadcast\n"); bp = (struct bootp *)payload; bp->bp_op = OP_BOOTREQUEST; bp->bp_htype = HWT_ETHER; bp->bp_hlen = HWL_ETHER; bp->bp_hops = 0; bp->bp_secs = htons(get_time_ns() >> 30); net_write_ip(&bp->bp_ciaddr, 0); net_write_ip(&bp->bp_yiaddr, 0); net_write_ip(&bp->bp_siaddr, 0); net_write_ip(&bp->bp_giaddr, 0); memcpy(bp->bp_chaddr, dhcp_con->et->et_src, 6); bfile = getenv("bootfile"); if (bfile) safe_strncpy (bp->bp_file, bfile, sizeof(bp->bp_file)); /* Request additional information from the BOOTP/DHCP server */ ext_len = dhcp_extended((u8 *)bp->bp_vend, DHCP_DISCOVER, 0, 0); Bootp_id = (uint32_t)get_time_ns(); net_copy_uint32(&bp->bp_id, &Bootp_id); dhcp_state = SELECTING; ret = net_udp_send(dhcp_con, sizeof(*bp) + ext_len); return ret; } static int dhcp_options_handle(unsigned char option, unsigned char *popt, int optlen, struct bootp *bp) { int i; struct dhcp_opt *opt; for (i = 0; i < ARRAY_SIZE(dhcp_options); i++) { opt = &dhcp_options[i]; if (opt->option == option) { opt->bp = bp; opt->handle(opt, popt, optlen); goto end; } } end: return i; } static void dhcp_options_process(unsigned char *popt, struct bootp *bp) { unsigned char *end = popt + sizeof(*bp) + OPT_SIZE; int oplen; unsigned char option; int i; while (popt < end && *popt != 0xff) { oplen = *(popt + 1); option = *popt; i = dhcp_options_handle(option, popt + 2, oplen, bp); if (i == ARRAY_SIZE(dhcp_options)) debug("*** Unhandled DHCP Option in OFFER/ACK: %d\n", option); popt += oplen + 2; /* Process next option */ } } static int dhcp_message_type(unsigned char *popt) { if (net_read_uint32((uint32_t *)popt) != htonl(BOOTP_VENDOR_MAGIC)) return -1; popt += 4; while ( *popt != 0xff ) { if ( *popt == 53 ) /* DHCP Message Type */ return *(popt + 2); popt += *(popt + 1) + 2; /* Scan through all options */ } return -1; } static void dhcp_send_request_packet(struct bootp *bp_offer) { struct bootp *bp; int extlen; IPaddr_t OfferedIP; unsigned char *payload = net_udp_get_payload(dhcp_con); debug("%s: Sending DHCPREQUEST\n", __func__); bp = (struct bootp *)payload; bp->bp_op = OP_BOOTREQUEST; bp->bp_htype = HWT_ETHER; bp->bp_hlen = HWL_ETHER; bp->bp_hops = 0; bp->bp_secs = htons(get_time_ns() >> 30); /* * RFC3046 requires Relay Agents to discard packets with * nonzero and offered giaddr */ net_write_ip(&bp->bp_giaddr, 0); memcpy(bp->bp_chaddr, dhcp_con->et->et_src, 6); /* * ID is the id of the OFFER packet */ net_copy_uint32(&bp->bp_id, &bp_offer->bp_id); /* * Copy options from OFFER packet if present */ net_copy_ip(&OfferedIP, &bp_offer->bp_yiaddr); extlen = dhcp_extended((u8 *)bp->bp_vend, DHCP_REQUEST, net_dhcp_server_ip, OfferedIP); debug("Transmitting DHCPREQUEST packet\n"); net_udp_send(dhcp_con, sizeof(*bp) + extlen); } /* * Handle DHCP received packets. */ static void dhcp_handler(void *ctx, char *packet, unsigned int len) { char *pkt = net_eth_to_udp_payload(packet); struct udphdr *udp = net_eth_to_udphdr(packet); struct bootp *bp = (struct bootp *)pkt; len = net_eth_to_udplen(packet); debug("DHCPHandler: got packet: (len=%d) state: %d\n", len, dhcp_state); if (bootp_check_packet(pkt, ntohs(udp->uh_sport), len)) /* Filter out pkts we don't want */ return; switch (dhcp_state) { case SELECTING: /* * Wait an appropriate time for any potential DHCPOFFER packets * to arrive. Then select one, and generate DHCPREQUEST response. * If filename is in format we recognize, assume it is a valid * OFFER from a server we want. */ debug ("%s: state SELECTING, bp_file: \"%s\"\n", __func__, bp->bp_file); dhcp_state = REQUESTING; if (net_read_uint32((uint32_t *)&bp->bp_vend[0]) == htonl(BOOTP_VENDOR_MAGIC)) dhcp_options_process((u8 *)&bp->bp_vend[4], bp); bootp_copy_net_params(bp); /* Store net params from reply */ dhcp_start = get_time_ns(); dhcp_send_request_packet(bp); break; case REQUESTING: debug ("%s: State REQUESTING\n", __func__); if (dhcp_message_type((u8 *)bp->bp_vend) == DHCP_ACK ) { if (net_read_uint32((uint32_t *)&bp->bp_vend[0]) == htonl(BOOTP_VENDOR_MAGIC)) dhcp_options_process((u8 *)&bp->bp_vend[4], bp); bootp_copy_net_params(bp); /* Store net params from reply */ dhcp_state = BOUND; puts ("DHCP client bound to address "); print_IPaddr(net_get_ip()); putchar('\n'); return; } break; default: debug("%s: INVALID STATE\n", __func__); break; } } static void dhcp_reset_env(void) { struct dhcp_opt *opt; int i; for (i = 0; i < ARRAY_SIZE(dhcp_options); i++) { opt = &dhcp_options[i]; if (!opt->barebox_var_name || opt->copy_only_if_valid) continue; setenv(opt->barebox_var_name,""); if (opt->barebox_dhcp_global) dhcp_set_barebox_global(opt->barebox_dhcp_global,""); } } static void dhcp_global_add(const char *var) { char * var_global = asprintf("dhcp.%s", var); if (!var_global) return; globalvar_add_simple(var_global, NULL); free(var_global); } static int dhcp_global_init(void) { struct dhcp_opt *opt; struct dhcp_param *param; int i; for (i = 0; i < ARRAY_SIZE(dhcp_options); i++) { opt = &dhcp_options[i]; if (!opt->barebox_dhcp_global) continue; dhcp_global_add(opt->barebox_dhcp_global); } for (i = 0; i < ARRAY_SIZE(dhcp_params); i++) { param = &dhcp_params[i]; if (!param->barebox_dhcp_global) continue; dhcp_global_add(param->barebox_dhcp_global); } return 0; } late_initcall(dhcp_global_init); static int do_dhcp(int argc, char *argv[]) { int ret, opt; int retries = DHCP_DEFAULT_RETRY; dhcp_reset_env(); getenv_uint("global.dhcp.retries", &retries); while((opt = getopt(argc, argv, "H:v:c:u:U:r:")) > 0) { switch(opt) { case 'H': dhcp_set_param_data(DHCP_HOSTNAME, optarg); break; case 'v': dhcp_set_param_data(DHCP_VENDOR_ID, optarg); break; case 'c': dhcp_set_param_data(DHCP_CLIENT_ID, optarg); break; case 'u': dhcp_set_param_data(DHCP_CLIENT_UUID, optarg); break; case 'U': dhcp_set_param_data(DHCP_USER_CLASS, optarg); break; case 'r': retries = simple_strtoul(optarg, NULL, 10); break; } } if (!retries) { printf("retries is set to zero, set it to %d\n", DHCP_DEFAULT_RETRY); retries = DHCP_DEFAULT_RETRY; } dhcp_con = net_udp_new(0xffffffff, PORT_BOOTPS, dhcp_handler, NULL); if (IS_ERR(dhcp_con)) { ret = PTR_ERR(dhcp_con); goto out; } ret = net_udp_bind(dhcp_con, PORT_BOOTPC); if (ret) goto out1; net_set_ip(0); dhcp_start = get_time_ns(); ret = bootp_request(); /* Basically same as BOOTP */ if (ret) goto out1; while (dhcp_state != BOUND) { if (ctrlc()) { ret = -EINTR; goto out1; } if (!retries) { ret = -ETIMEDOUT; goto out1; } net_poll(); if (is_timeout(dhcp_start, 3 * SECOND)) { dhcp_start = get_time_ns(); printf("T "); ret = bootp_request(); /* no need to check if retries > 0 as we check if != 0 */ retries--; if (ret) goto out1; } } if (dhcp_tftpname[0] != 0) { IPaddr_t tftpserver = resolv(dhcp_tftpname); if (tftpserver) net_set_serverip(tftpserver); } out1: net_unregister(dhcp_con); out: if (ret) printf("dhcp failed: %s\n", strerror(-ret)); return ret; } BAREBOX_CMD_HELP_START(dhcp) BAREBOX_CMD_HELP_TEXT("Options:") BAREBOX_CMD_HELP_OPT ("-H HOSTNAME", "hostname to send to the DHCP server") BAREBOX_CMD_HELP_OPT ("-v ID\t", "DHCP Vendor ID (code 60) submitted in DHCP requests") BAREBOX_CMD_HELP_OPT ("-c ID\t", "DHCP Client ID (code 61) submitted in DHCP requests") BAREBOX_CMD_HELP_OPT ("-u UUID\t", "DHCP Client UUID (code 97) submitted in DHCP requests") BAREBOX_CMD_HELP_OPT ("-U CLASS", "DHCP User class (code 77) submitted in DHCP requests") BAREBOX_CMD_HELP_OPT ("-r RETRY", "retry limit (default 20)"); BAREBOX_CMD_HELP_END BAREBOX_CMD_START(dhcp) .cmd = do_dhcp, BAREBOX_CMD_DESC("DHCP client to obtain IP or boot params") BAREBOX_CMD_OPTS("[-HvcuUr]") BAREBOX_CMD_GROUP(CMD_GRP_NET) BAREBOX_CMD_HELP(cmd_dhcp_help) BAREBOX_CMD_COMPLETE(empty_complete) BAREBOX_CMD_END BAREBOX_MAGICVAR_NAMED(global_dhcp_bootfile, global.dhcp.bootfile, "bootfile returned from DHCP request"); BAREBOX_MAGICVAR_NAMED(global_dhcp_rootpath, global.dhcp.rootpath, "rootpath returned from DHCP request"); BAREBOX_MAGICVAR_NAMED(global_dhcp_vendor_id, global.dhcp.vendor_id, "vendor id to send to the DHCP server"); BAREBOX_MAGICVAR_NAMED(global_dhcp_client_uuid, global.dhcp.client_uuid, "client uuid to send to the DHCP server"); BAREBOX_MAGICVAR_NAMED(global_dhcp_client_id, global.dhcp.client_id, "client id to send to the DHCP server"); BAREBOX_MAGICVAR_NAMED(global_dhcp_user_class, global.dhcp.user_class, "user class to send to the DHCP server"); BAREBOX_MAGICVAR_NAMED(global_dhcp_tftp_server_name, global.dhcp.tftp_server_name, "TFTP server Name returned from DHCP request"); BAREBOX_MAGICVAR_NAMED(global_dhcp_oftree_file, global.dhcp.oftree_file, "OF tree returned from DHCP request (option 224)"); BAREBOX_MAGICVAR_NAMED(global_dhcp_retries, global.dhcp.retries, "retry limit");