nmrp.c

   1 /**
   2  * nmrpflash - Netgear Unbrick Utility
   3  * Copyright (C) 2016 Joseph Lehner <joseph.c.lehner@gmail.com>
   4  *
   5  * nmrpflash is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * nmrpflash is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with nmrpflash.  If not, see <http://www.gnu.org/licenses/>.
  17  *
  18  */
  19
  20 #include <signal.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <errno.h>
  25 #include <stdio.h>
  26 #include <time.h>
  27 #include "nmrpd.h"
  28
  29 #define NMRP_HDR_LEN 6
  30 #define NMRP_OPT_HDR_LEN 4
  31 #define NMRP_MIN_PKT_LEN (sizeof(struct eth_hdr) +  NMRP_HDR_LEN)
  32
  33 #define NMRP_MAX_OPT_SIZE 12
  34 #define NMRP_MAX_OPT_NUM 3
  35
  36 #define NMRP_OPT_NEXT(x) ((struct nmrp_opt*)(((char*)x) + x->len))
  37
  38 #define ETH_P_NMRP 0x0912
  39 #define IP_LEN 4
  40 #define MAX_LOOP_RECV 1024
  41
  42 #ifndef PACKED
  43 #define PACKED __attribute__((__packed__))
  44 #endif
  45
  46 enum nmrp_code {
  47         NMRP_C_NONE = 0,
  48         NMRP_C_ADVERTISE = 1,
  49         NMRP_C_CONF_REQ = 2,
  50         NMRP_C_CONF_ACK = 3,
  51         NMRP_C_CLOSE_REQ = 4,
  52         NMRP_C_CLOSE_ACK = 5,
  53         NMRP_C_KEEP_ALIVE_REQ = 6,
  54         NMRP_C_KEEP_ALIVE_ACK = 7,
  55         NMRP_C_TFTP_UL_REQ = 16
  56 };
  57
  58 enum nmrp_opt_type {
  59         NMRP_O_MAGIC_NO = 0x0001,
  60         NMRP_O_DEV_IP = 0x0002,
  61         NMRP_O_DEV_REGION = 0x0004,
  62         NMRP_O_FW_UP = 0x0101,
  63         NMRP_O_ST_UP = 0x0102,
  64         NMRP_O_FILE_NAME = 0x0181
  65 };
  66
  67 struct nmrp_opt {
  68         uint16_t type;
  69         uint16_t len;
  70         union {
  71                 uint8_t magic[4];
  72                 uint16_t region;
  73                 struct {
  74                         uint8_t addr[4];
  75                         uint8_t mask[4];
  76                 } ip;
  77         } val;
  78 } PACKED;
  79
  80 struct nmrp_msg {
  81         uint16_t reserved;
  82         uint8_t code;
  83         uint8_t id;
  84         uint16_t len;
  85         /* only opts[0] is valid! think of this as a char* */
  86         struct nmrp_opt opts[NMRP_MAX_OPT_NUM];
  87         /* this is NOT part of the transmitted packet */
  88         uint32_t num_opts;
  89 } PACKED;
  90
  91 struct nmrp_pkt {
  92         struct eth_hdr eh;
  93         struct nmrp_msg msg;
  94 } PACKED;
  95
  96 static const char *msg_code_str(uint16_t code)
  97 {
  98 #define CASE_CODE(x) case NMRP_C_ ## x: return #x
  99         static char buf[16];
 100
 101         switch (code) {
 102                 CASE_CODE(ADVERTISE);
 103                 CASE_CODE(CONF_REQ);
 104                 CASE_CODE(CONF_ACK);
 105                 CASE_CODE(CLOSE_REQ);
 106                 CASE_CODE(CLOSE_ACK);
 107                 CASE_CODE(KEEP_ALIVE_REQ);
 108                 CASE_CODE(KEEP_ALIVE_ACK);
 109                 CASE_CODE(TFTP_UL_REQ);
 110                 default:
 111                         snprintf(buf, sizeof(buf), "%04x", code);
 112                         return buf;
 113         }
 114 #undef CASE_CODE
 115 }
 116
 117 static uint16_t to_region_code(const char *region)
 118 {
 119 #define REGION_CODE(r, c) if (!strcasecmp(region, r)) return c
 120         REGION_CODE("NA", 0x0001);
 121         REGION_CODE("WW", 0x0002);
 122         REGION_CODE("GR", 0x0003);
 123         REGION_CODE("PR", 0x0004);
 124         REGION_CODE("RU", 0x0005);
 125         REGION_CODE("BZ", 0x0006);
 126         REGION_CODE("IN", 0x0007);
 127         REGION_CODE("KO", 0x0008);
 128         REGION_CODE("JP", 0x0009);
 129 #undef REGION_CODE
 130         return 0;
 131 }
 132
 133 static void msg_dump(struct nmrp_msg *msg, int dump_opts)
 134 {
 135         struct nmrp_opt *opt;
 136         int remain_len, len, i;
 137
 138         fprintf(stderr, "res=0x%04x, code=0x%02x, id=0x%02x, len=%u",
 139                         msg->reserved, msg->code, msg->id, msg->len);
 140
 141         remain_len = msg->len - NMRP_HDR_LEN;
 142         fprintf(stderr, "%s\n", remain_len ? "" : " (no opts)");
 143
 144         if (dump_opts) {
 145                 opt = msg->opts;
 146
 147                 while (remain_len > 0) {
 148                         len = opt->len;
 149                         fprintf(stderr, "  opt type=%u, len=%u", opt->type, len);
 150                         if (len) {
 151                                 for (i = 0; i != len - NMRP_OPT_HDR_LEN; ++i) {
 152                                         if (!(i % 16)) {
 153                                                 fprintf(stderr, "\n  ");
 154                                         }
 155
 156                                         fprintf(stderr, "%02x ", ((char*)&opt->val)[i] & 0xff);
 157                                 }
 158                                 fprintf(stderr, "\n");
 159                         }
 160                         remain_len -= len;
 161                         opt = NMRP_OPT_NEXT(opt);
 162                 }
 163         }
 164 }
 165
 166 static void msg_hton(struct nmrp_msg *msg)
 167 {
 168         uint32_t i = 0;
 169         struct nmrp_opt *opt = msg->opts, *next;
 170
 171         msg->reserved = htons(msg->reserved);
 172         msg->len = htons(msg->len);
 173
 174         for (; i != msg->num_opts; ++i) {
 175                 next = NMRP_OPT_NEXT(opt);
 176                 opt->len = htons(opt->len);
 177                 opt->type = htons(opt->type);
 178                 opt = next;
 179         }
 180 }
 181
 182 static void msg_hdr_ntoh(struct nmrp_msg *msg)
 183 {
 184         msg->reserved = ntohs(msg->reserved);
 185         msg->len = ntohs(msg->len);
 186 }
 187
 188 static int msg_ntoh(struct nmrp_msg *msg)
 189 {
 190         struct nmrp_opt *opt = msg->opts;
 191         int remaining;
 192
 193         remaining = msg->len - NMRP_HDR_LEN;
 194
 195         // FIXME maximum of two options supported, maximum option
 196         // size is 12
 197         if (remaining < NMRP_MAX_OPT_NUM * NMRP_MAX_OPT_SIZE) {
 198                 while (remaining > 0) {
 199                         if (remaining < NMRP_OPT_HDR_LEN) {
 200                                 break;
 201                         }
 202
 203                         opt->type = ntohs(opt->type);
 204                         opt->len = ntohs(opt->len);
 205
 206                         if (opt->len > NMRP_MAX_OPT_SIZE) {
 207                                 break;
 208                         }
 209
 210                         remaining -= opt->len;
 211                         opt = NMRP_OPT_NEXT(opt);
 212                 }
 213
 214                 if (!remaining) {
 215                         return 0;
 216                 }
 217         }
 218
 219         fprintf(stderr, "Unexpected message format.\n");
 220         msg_dump(msg, 0);
 221         return 1;
 222 }
 223
 224 static void *msg_opt_data(struct nmrp_msg *msg, uint16_t type, uint16_t *len)
 225 {
 226         static char buf[128];
 227         struct nmrp_opt *opt = msg->opts;
 228         int remaining = msg->len - NMRP_HDR_LEN;
 229
 230         memset(buf, 0, sizeof(buf));
 231
 232         while (remaining > 0) {
 233                 if (opt->type == type) {
 234                         if (opt->len == NMRP_OPT_HDR_LEN) {
 235                                 return NULL;
 236                         }
 237                         *len = opt->len - NMRP_OPT_HDR_LEN;
 238                         memcpy(buf, &opt->val, MIN(*len, sizeof(buf)-1));
 239                         return buf;
 240                 }
 241
 242                 remaining -= opt->len;
 243                 opt = NMRP_OPT_NEXT(opt);
 244         }
 245
 246         return NULL;
 247 }
 248
 249 static void msg_opt_add(struct nmrp_msg *msg, uint16_t type, void *data,
 250                 uint16_t len)
 251 {
 252         uint32_t i = 0;
 253         struct nmrp_opt *opt = msg->opts;
 254
 255         if (len + NMRP_OPT_HDR_LEN > NMRP_MAX_OPT_SIZE
 256                         || msg->num_opts == NMRP_MAX_OPT_NUM) {
 257                 fprintf(stderr, "Invalid option - this is a bug.\n");
 258         }
 259
 260         for (; i <= msg->num_opts; ++i) {
 261                 opt = NMRP_OPT_NEXT(opt);
 262         }
 263
 264         opt->len = NMRP_OPT_HDR_LEN + len;
 265         opt->type = type;
 266
 267         if (len) {
 268                 memcpy(&opt->val, data, len);
 269         }
 270
 271         msg->len += opt->len;
 272         ++msg->num_opts;
 273 }
 274
 275 static inline void msg_init(struct nmrp_msg *msg, uint16_t code)
 276 {
 277         memset(msg, 0, sizeof(*msg));
 278         msg->len = NMRP_HDR_LEN;
 279         msg->code = code;
 280 }
 281
 282 static int pkt_send(struct ethsock *sock, struct nmrp_pkt *pkt)
 283 {
 284         size_t len = ntohs(pkt->msg.len) + sizeof(pkt->eh);
 285         return ethsock_send(sock, pkt, len);
 286 }
 287
 288 static int pkt_recv(struct ethsock *sock, struct nmrp_pkt *pkt)
 289 {
 290         ssize_t bytes, len;
 291
 292         memset(pkt, 0, sizeof(*pkt));
 293         bytes = ethsock_recv(sock, pkt, sizeof(*pkt));
 294         if (bytes < 0) {
 295                 return 1;
 296         } else if (!bytes) {
 297                 return 2;
 298         } else if (bytes < NMRP_MIN_PKT_LEN) {
 299                 fprintf(stderr, "Short packet (%d bytes)\n", (int)bytes);
 300                 return 1;
 301         }
 302
 303         msg_hdr_ntoh(&pkt->msg);
 304         len = pkt->msg.len + sizeof(pkt->eh);
 305
 306         if (bytes < len) {
 307                 fprintf(stderr, "Short packet (expected %d, got %d).\n",
 308                                 (int)len, (int)bytes);
 309                 return 1;
 310         }
 311
 312         return msg_ntoh(&pkt->msg);
 313 }
 314
 315 static int mac_parse(const char *str, uint8_t *hwaddr)
 316 {
 317         int i;
 318         unsigned data[6];
 319
 320         sscanf(str, "%02x:%02x:%02x:%02x:%02x:%02x%n",
 321                         data, data + 1, data + 2, data + 3, data + 4, data + 5, &i);
 322
 323         if (i == strlen(str)) {
 324                 for (i = 0; i != 6; ++i) {
 325                         if (data[i] > 255) {
 326                                 break;
 327                         }
 328
 329                         hwaddr[i] = data[i] & 0xff;
 330                 }
 331
 332                 if (i == 6) {
 333                         return 1;
 334                 }
 335         }
 336         return 0;
 337 }
 338
 339 struct is_valid_ip_arg
 340 {
 341         struct in_addr *ipaddr;
 342         struct in_addr *ipmask;
 343         int result;
 344 };
 345
 346 static int is_valid_ip_cb(struct ethsock_ip_callback_args *args)
 347 {
 348 #define SUBNET(x) ((x)->ipaddr->s_addr & (x)->ipmask->s_addr)
 349         struct is_valid_ip_arg *arg = args->arg;
 350         if (SUBNET(args) == SUBNET(arg)) {
 351                 arg->result = args->ipaddr->s_addr != arg->ipaddr->s_addr;
 352                 return 0;
 353         }
 354
 355         return 1;
 356 #undef SUBNET
 357 }
 358
 359 static int is_valid_ip(struct ethsock *sock, struct in_addr *ipaddr,
 360                 struct in_addr *ipmask)
 361 {
 362         int status;
 363         struct is_valid_ip_arg arg = {
 364                 .ipaddr = ipaddr,
 365                 .ipmask = ipmask,
 366                 .result = 0
 367         };
 368
 369         status = ethsock_for_each_ip(sock, is_valid_ip_cb, &arg);
 370         return status < 0 ? status : arg.result;
 371 }
 372
 373 static struct ethsock *gsock = NULL;
 374 static struct ethsock_ip_undo *gundo = NULL;
 375 static int garp = 0;
 376 static struct in_addr arpip = { 0 };
 377 static uint8_t arpmac[6] = { 0 };
 378
 379 static void sigh(int sig)
 380 {
 381         printf("\n");
 382         if (gsock) {
 383                 if (garp) {
 384                         ethsock_arp_del(gsock, arpmac, &arpip);
 385                 }
 386                 ethsock_del_ip(gsock, &gundo);
 387                 ethsock_close(gsock);
 388                 gsock = NULL;
 389         }
 390
 391         exit(1);
 392 }
 393
 394 static const char *spinner = "\\|/-";
 395
 396 int nmrp_do(struct nmrpd_args *args)
 397 {
 398         struct nmrp_pkt tx, rx;
 399         uint8_t *src, dest[6];
 400         uint16_t len, region;
 401         char *filename;
 402         time_t beg;
 403         int i, status, ulreqs, expect, upload_ok, autoip;
 404         struct ethsock *sock;
 405         uint32_t intf_addr;
 406         void (*sigh_orig)(int);
 407         struct {
 408                 struct in_addr addr;
 409                 struct in_addr mask;
 410         } PACKED ipconf;
 411
 412         if (args->op != NMRP_UPLOAD_FW) {
 413                 fprintf(stderr, "Operation not implemented.\n");
 414                 return 1;
 415         }
 416
 417         if (!mac_parse(args->mac, dest)) {
 418                 fprintf(stderr, "Invalid MAC address '%s'.\n", args->mac);
 419                 return 1;
 420         }
 421
 422         if ((ipconf.mask.s_addr = inet_addr(args->ipmask)) == INADDR_NONE) {
 423                 fprintf(stderr, "Invalid subnet mask '%s'.\n", args->ipmask);
 424                 return 1;
 425         }
 426
 427         if (!args->ipaddr) {
 428                 autoip = true;
 429                 args->ipaddr = "10.11.12.254";
 430
 431                 if (!args->ipaddr_intf) {
 432                         args->ipaddr_intf = "10.11.12.253";
 433                 }
 434         } else if (args->ipaddr_intf) {
 435                 autoip = true;
 436         } else {
 437                 autoip = false;
 438         }
 439
 440         if ((ipconf.addr.s_addr = inet_addr(args->ipaddr)) == INADDR_NONE) {
 441                 fprintf(stderr, "Invalid IP address '%s'.\n", args->ipaddr);
 442                 return 1;
 443         }
 444
 445         if (args->ipaddr_intf && (intf_addr = inet_addr(args->ipaddr_intf)) == INADDR_NONE) {
 446                 fprintf(stderr, "Invalid IP address '%s'.\n", args->ipaddr_intf);
 447                 return 1;
 448         }
 449
 450         if (args->file_local && strcmp(args->file_local, "-") && access(args->file_local, R_OK) == -1) {
 451                 fprintf(stderr, "Error accessing file '%s'.\n", args->file_local);
 452                 return 1;
 453         }
 454
 455         if (args->file_remote) {
 456                 if (!tftp_is_valid_filename(args->file_remote)) {
 457                         fprintf(stderr, "Invalid remote filename '%s'.\n",
 458                                         args->file_remote);
 459                         return 1;
 460                 }
 461         }
 462
 463         if (args->region) {
 464                 region = htons(to_region_code(args->region));
 465                 if (!region) {
 466                         fprintf(stderr, "Invalid region code '%s'.\n", args->region);
 467                         return 1;
 468                 }
 469         } else {
 470                 region = 0;
 471         }
 472
 473         status = 1;
 474
 475         sock = ethsock_create(args->intf, ETH_P_NMRP);
 476         if (!sock) {
 477                 return 1;
 478         }
 479
 480         gsock = sock;
 481         garp = 0;
 482         sigh_orig = signal(SIGINT, sigh);
 483
 484         if (!autoip) {
 485                 status = is_valid_ip(sock, &ipconf.addr, &ipconf.mask);
 486                 if (status <= 0) {
 487                         if (!status) {
 488                                 fprintf(stderr, "Address %s/%s cannot be used on interface %s.\n",
 489                                                 args->ipaddr, args->ipmask, args->intf);
 490                         }
 491                         goto out;
 492                 }
 493         }
 494
 495         if (ethsock_set_timeout(sock, args->rx_timeout)) {
 496                 goto out;
 497         }
 498
 499         src = ethsock_get_hwaddr(sock);
 500         if (!src) {
 501                 goto out;
 502         }
 503
 504         memcpy(tx.eh.ether_shost, src, 6);
 505         memcpy(tx.eh.ether_dhost, dest, 6);
 506         tx.eh.ether_type = htons(ETH_P_NMRP);
 507
 508         msg_init(&tx.msg, NMRP_C_ADVERTISE);
 509         msg_opt_add(&tx.msg, NMRP_O_MAGIC_NO, "NTGR", 4);
 510         msg_hton(&tx.msg);
 511
 512         i = 0;
 513         upload_ok = 0;
 514         beg = time(NULL);
 515
 516         while (1) {
 517                 printf("\rAdvertising NMRP server on %s ... %c",
 518                                 args->intf, spinner[i]);
 519                 fflush(stdout);
 520                 i = (i + 1) & 3;
 521
 522                 if (pkt_send(sock, &tx) < 0) {
 523                         perror("sendto");
 524                         goto out;
 525                 }
 526
 527                 status = pkt_recv(sock, &rx);
 528                 if (status == 0 && memcmp(rx.eh.ether_dhost, src, 6) == 0) {
 529                         break;
 530                 } else if (status == 1) {
 531                         goto out;
 532                 } else {
 533                         if ((time(NULL) - beg) >= 60) {
 534                                 printf("\nNo response after 60 seconds. Bailing out.\n");
 535                                 goto out;
 536                         }
 537                 }
 538         }
 539
 540         printf("\n");
 541
 542         expect = NMRP_C_CONF_REQ;
 543         ulreqs = 0;
 544
 545         do {
 546                 if (expect != NMRP_C_NONE && rx.msg.code != expect) {
 547                         fprintf(stderr, "Received %s while waiting for %s!\n",
 548                                         msg_code_str(rx.msg.code), msg_code_str(expect));
 549                 }
 550
 551                 msg_init(&tx.msg, NMRP_C_NONE);
 552
 553                 status = 1;
 554
 555                 switch (rx.msg.code) {
 556                         case NMRP_C_ADVERTISE:
 557                                 printf("Received NMRP advertisement from %s.\n",
 558                                                 mac_to_str(rx.eh.ether_shost));
 559                                 status = 1;
 560                                 goto out;
 561                         case NMRP_C_CONF_REQ:
 562                                 tx.msg.code = NMRP_C_CONF_ACK;
 563
 564                                 msg_opt_add(&tx.msg, NMRP_O_DEV_IP, &ipconf, 8);
 565                                 msg_opt_add(&tx.msg, NMRP_O_FW_UP, NULL, 0);
 566
 567 #ifdef NMRPFLASH_SET_REGION
 568                                 if (region) {
 569                                         msg_opt_add(&tx.msg, NMRP_O_DEV_REGION, &region, 2);
 570                                 }
 571 #endif
 572
 573                                 expect = NMRP_C_TFTP_UL_REQ;
 574
 575                                 printf("Received configuration request from %s.\n",
 576                                                 mac_to_str(rx.eh.ether_shost));
 577
 578                                 memcpy(tx.eh.ether_dhost, rx.eh.ether_shost, 6);
 579
 580                                 printf("Sending configuration: ip %s, mask %s.\n",
 581                                                 args->ipaddr, args->ipmask);
 582
 583                                 memcpy(arpmac, rx.eh.ether_shost, 6);
 584                                 memcpy(&arpip, &ipconf.addr, sizeof(ipconf.addr));
 585
 586                                 if (ethsock_arp_add(sock, arpmac, &arpip) != 0) {
 587                                         goto out;
 588                                 }
 589
 590                                 garp = 1;
 591
 592                                 break;
 593                         case NMRP_C_TFTP_UL_REQ:
 594                                 if (!upload_ok) {
 595                                         if (++ulreqs > 5) {
 596                                                 printf("Bailing out after %d upload requests.\n",
 597                                                                 ulreqs);
 598                                                 tx.msg.code = NMRP_C_CLOSE_REQ;
 599                                                 break;
 600                                         }
 601                                 } else {
 602                                         if (verbosity) {
 603                                                 printf("Ignoring extra upload request.\n");
 604                                         }
 605                                         ethsock_set_timeout(sock, args->ul_timeout);
 606                                         tx.msg.code = NMRP_C_KEEP_ALIVE_REQ;
 607                                         break;
 608                                 }
 609
 610                                 len = 0;
 611                                 filename = msg_opt_data(&rx.msg, NMRP_O_FILE_NAME, &len);
 612                                 if (filename) {
 613                                         if (!args->file_remote) {
 614                                                 args->file_remote = filename;
 615                                         }
 616                                         printf("Received upload request: filename '%.*s'.\n",
 617                                                         len, filename);
 618                                 } else if (!args->file_remote) {
 619                                         args->file_remote = args->file_local;
 620                                         printf("Received upload request with empty filename.\n");
 621                                 }
 622
 623                                 status = 0;
 624
 625                                 if (autoip) {
 626                                         if (ethsock_set_ip(sock, intf_addr, ipconf.mask.s_addr, &gundo) != 0) {
 627                                                 goto out;
 628                                         }
 629                                 }
 630
 631                                 if (args->tftpcmd) {
 632                                         printf("Executing '%s' ... ", args->tftpcmd);
 633                                         fflush(stdout);
 634                                         status = system(args->tftpcmd);
 635                                         printf("\n");
 636                                 }
 637
 638                                 if (!status && args->file_local) {
 639                                         if (!autoip) {
 640                                                 status = is_valid_ip(sock, &ipconf.addr, &ipconf.mask);
 641                                                 if (status < 0) {
 642                                                         goto out;
 643                                                 } else if (!status) {
 644                                                         printf("IP address of %s has changed. Please assign a "
 645                                                                         "static ip to the interface.\n", args->intf);
 646                                                         tx.msg.code = NMRP_C_CLOSE_REQ;
 647                                                         break;
 648                                                 }
 649                                         }
 650
 651                                         if (verbosity) {
 652                                                 printf("Using remote filename '%s'.\n",
 653                                                                 args->file_remote);
 654                                         }
 655
 656                                         if (!strcmp(args->file_local, "-")) {
 657                                                 printf("Uploading from stdin ... ");
 658                                         } else {
 659                                                 printf("Uploading %s ... ", leafname(args->file_local));
 660                                         }
 661                                         fflush(stdout);
 662                                         status = tftp_put(args);
 663                                 }
 664
 665                                 if (ethsock_del_ip(sock, &gundo) != 0) {
 666                                         goto out;
 667                                 }
 668
 669                                 if (!status) {
 670                                         printf("OK\nWaiting for remote to respond.\n");
 671                                         upload_ok = 1;
 672                                         ethsock_set_timeout(sock, args->ul_timeout);
 673                                         tx.msg.code = NMRP_C_KEEP_ALIVE_REQ;
 674                                         expect = NMRP_C_NONE;
 675                                 } else if (status == -2) {
 676                                         expect = NMRP_C_TFTP_UL_REQ;
 677                                 } else {
 678                                         goto out;
 679                                 }
 680
 681                                 break;
 682                         case NMRP_C_KEEP_ALIVE_REQ:
 683                                 tx.msg.code = NMRP_C_KEEP_ALIVE_ACK;
 684                                 ethsock_set_timeout(sock, args->ul_timeout);
 685                                 printf("Received keep-alive request.\n");
 686                                 break;
 687                         case NMRP_C_CLOSE_REQ:
 688                                 tx.msg.code = NMRP_C_CLOSE_ACK;
 689                                 break;
 690                         case NMRP_C_CLOSE_ACK:
 691                                 status = 0;
 692                                 goto out;
 693                         default:
 694                                 fprintf(stderr, "Unknown message code 0x%02x!\n",
 695                                                 rx.msg.code);
 696                                 msg_dump(&rx.msg, 0);
 697                 }
 698
 699                 if (tx.msg.code != NMRP_C_NONE) {
 700                         msg_hton(&tx.msg);
 701
 702                         if (pkt_send(sock, &tx) < 0) {
 703                                 perror("sendto");
 704                                 goto out;
 705                         }
 706
 707                         if (tx.msg.code == NMRP_C_CLOSE_REQ) {
 708                                 goto out;
 709                         }
 710                 }
 711
 712                 if (rx.msg.code == NMRP_C_CLOSE_REQ) {
 713                         printf("Remote finished. Closing connection.\n");
 714                         break;
 715                 }
 716
 717                 status = pkt_recv(sock, &rx);
 718                 if (status) {
 719                         if (status == 2) {
 720                                 fprintf(stderr, "Timeout while waiting for %s.\n",
 721                                                 msg_code_str(expect));
 722                         }
 723                         goto out;
 724                 }
 725
 726                 ethsock_set_timeout(sock, args->rx_timeout);
 727
 728         } while (1);
 729
 730         status = 0;
 731
 732         if (ulreqs) {
 733                 printf("Reboot your device now.\n");
 734         } else {
 735                 printf("No upload request received.\n");
 736         }
 737
 738 out:
 739         signal(SIGINT, sigh_orig);
 740         gsock = NULL;
 741         ethsock_arp_del(sock, arpmac, &arpip);
 742         ethsock_close(sock);
 743         return status;
 744 }