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 ETH_P_NMRP 0x0912
  34
  35 #ifndef PACKED
  36 #define PACKED __attribute__((__packed__))
  37 #endif
  38
  39 #ifdef NMRPFLASH_WINDOWS
  40 #define setenv(name, value, overwrite) SetEnvironmentVariable(name, value)
  41 #endif
  42
  43 enum nmrp_code {
  44         NMRP_C_NONE = 0,
  45         NMRP_C_ADVERTISE = 1,
  46         NMRP_C_CONF_REQ = 2,
  47         NMRP_C_CONF_ACK = 3,
  48         NMRP_C_CLOSE_REQ = 4,
  49         NMRP_C_CLOSE_ACK = 5,
  50         NMRP_C_KEEP_ALIVE_REQ = 6,
  51         NMRP_C_KEEP_ALIVE_ACK = 7,
  52         NMRP_C_TFTP_UL_REQ = 16
  53 };
  54
  55 enum nmrp_opt_type {
  56         NMRP_O_MAGIC_NO = 0x0001,
  57         NMRP_O_DEV_IP = 0x0002,
  58         NMRP_O_DEV_REGION = 0x0004,
  59         NMRP_O_FW_UP = 0x0101,
  60         NMRP_O_ST_UP = 0x0102,
  61         NMRP_O_FILE_NAME = 0x0181
  62 };
  63
  64 struct nmrp_opt {
  65         uint16_t type;
  66         uint16_t len;
  67         char val[1];
  68 } PACKED;
  69
  70 struct nmrp_msg {
  71         uint16_t reserved;
  72         uint8_t code;
  73         uint8_t id;
  74         uint16_t len;
  75         char opts[44];
  76 } PACKED;
  77
  78 struct nmrp_pkt {
  79         struct eth_hdr eh;
  80         struct nmrp_msg msg;
  81 } PACKED;
  82
  83 static const char *msg_code_str(uint16_t code)
  84 {
  85 #define MSG_CODE(x) case NMRP_C_ ## x: return #x
  86         static char buf[16];
  87
  88         switch (code) {
  89                 MSG_CODE(ADVERTISE);
  90                 MSG_CODE(CONF_REQ);
  91                 MSG_CODE(CONF_ACK);
  92                 MSG_CODE(CLOSE_REQ);
  93                 MSG_CODE(CLOSE_ACK);
  94                 MSG_CODE(KEEP_ALIVE_REQ);
  95                 MSG_CODE(KEEP_ALIVE_ACK);
  96                 MSG_CODE(TFTP_UL_REQ);
  97                 default:
  98                         snprintf(buf, sizeof(buf), "%04x", ntohs(code));
  99                         return buf;
 100         }
 101 #undef MSG_CODE
 102 }
 103
 104 static uint16_t to_region_code(const char *region)
 105 {
 106 #define REGION_CODE(r, c) if (!strcasecmp(region, r)) return htons(c)
 107         REGION_CODE("NA", 0x0001);
 108         REGION_CODE("WW", 0x0002);
 109         REGION_CODE("GR", 0x0003);
 110         REGION_CODE("PR", 0x0004);
 111         REGION_CODE("RU", 0x0005);
 112         REGION_CODE("BZ", 0x0006);
 113         REGION_CODE("IN", 0x0007);
 114         REGION_CODE("KO", 0x0008);
 115         REGION_CODE("JP", 0x0009);
 116 #undef REGION_CODE
 117         return 0;
 118 }
 119
 120 static void msg_dump(struct nmrp_msg *msg)
 121 {
 122         int rem;
 123
 124         fprintf(stderr, "res=0x%04x, code=0x%02x, id=0x%02x, len=%u",
 125                         ntohs(msg->reserved), msg->code, msg->id, ntohs(msg->len));
 126
 127         rem = ntohs(msg->len) - NMRP_HDR_LEN;
 128         fprintf(stderr, "%s\n", rem ? "" : " (no opts)");
 129 }
 130
 131 static void *msg_opt(struct nmrp_msg *msg, uint16_t type, uint16_t* len)
 132 {
 133         struct nmrp_opt* opt = (struct nmrp_opt*)msg->opts;
 134         size_t rem = ntohs(msg->len) - NMRP_HDR_LEN;
 135         uint16_t olen;
 136
 137         do {
 138                 olen = ntohs(opt->len);
 139                 if (olen < NMRP_OPT_HDR_LEN || olen > rem) {
 140                         break;
 141                 }
 142
 143                 if (ntohs(opt->type) == type) {
 144                         if (len) {
 145                                 *len = olen;
 146                         }
 147
 148                         return opt->val;
 149                 }
 150
 151                 opt = (struct nmrp_opt*)(((char *)opt) + olen);
 152                 rem -= olen;
 153         } while (rem);
 154
 155         return NULL;
 156 }
 157
 158 static char *msg_filename(struct nmrp_msg *msg)
 159 {
 160         static char buf[256];
 161         uint16_t len;
 162         char *p = msg_opt(msg, NMRP_O_FILE_NAME, &len);
 163         if (p) {
 164                 len = MIN(sizeof(buf) - 1, len);
 165                 memcpy(buf, p, len);
 166                 buf[len] = '\0';
 167                 return buf;
 168         }
 169
 170         return NULL;
 171 }
 172
 173 static inline void msg_init(struct nmrp_msg *msg, uint16_t code)
 174 {
 175         memset(msg, 0, sizeof(*msg));
 176         msg->len = htons(NMRP_HDR_LEN);
 177         msg->code = code;
 178 }
 179
 180 static char *msg_mkopt(struct nmrp_msg *msg, char *p, uint16_t type, const void *val, size_t len)
 181 {
 182         struct nmrp_opt* opt = (struct nmrp_opt*)p;
 183
 184         len &= 0xffff;
 185
 186         msg->len = ntohs(msg->len);
 187
 188         if ((msg->len + len > sizeof(*msg))) {
 189                 fprintf(stderr, "Error: invalid option - this is a bug\n");
 190                 exit(1);
 191         }
 192
 193         opt->type = htons(type);
 194         opt->len = NMRP_OPT_HDR_LEN + len;
 195
 196         if (val) {
 197                 memcpy(opt->val, val, len);
 198         }
 199
 200         msg->len += opt->len;
 201         p += opt->len;
 202
 203         msg->len = htons(msg->len);
 204         opt->len = htons(opt->len);
 205
 206         return p;
 207 }
 208
 209 static void msg_mkadvertise(struct nmrp_msg *msg, const char *magic)
 210 {
 211         msg_init(msg, NMRP_C_ADVERTISE);
 212         msg_mkopt(msg, msg->opts, NMRP_O_MAGIC_NO, magic, strlen(magic));
 213 }
 214
 215 static void msg_mkconfack(struct nmrp_msg *msg, uint32_t ipaddr, uint32_t ipmask, uint16_t region)
 216 {
 217         char *p;
 218         uint32_t ip[2] = { ipaddr, ipmask };
 219
 220         msg_init(msg, NMRP_C_CONF_ACK);
 221         p = msg_mkopt(msg, msg->opts, NMRP_O_DEV_IP, &ip, 8);
 222         p = msg_mkopt(msg, p, NMRP_O_FW_UP, NULL, 0);
 223
 224 #ifdef NMRPFLASH_SET_REGION
 225         if (region) {
 226                 p = msg_mkopt(msg, p, NMRP_O_DEV_REGION, &region, 2);
 227         }
 228 #endif
 229 }
 230
 231 #ifdef NMRPFLASH_FUZZ
 232 #define NMRP_INITIAL_TIMEOUT 0
 233 #define ethsock_create(a, b) ((struct ethsock*)1)
 234 #define ethsock_get_hwaddr(a) ethsock_get_hwaddr_fake(a)
 235 #define ethsock_recv(sock, buf, len) read(STDIN_FILENO, buf, len)
 236 #define ethsock_send(a, b, c) (0)
 237 #define ethsock_set_timeout(a, b) (0)
 238 #define ethsock_arp_add(a, b, c, d) (0)
 239 #define ethsock_arp_del(a, b) (0)
 240 #define ethsock_ip_add(a, b, c, d) (0)
 241 #define ethsock_ip_del(a, b) (0)
 242 #define ethsock_close(a) (0)
 243 #define tftp_put(a) (0)
 244
 245 static uint8_t *ethsock_get_hwaddr_fake(struct ethsock* sock)
 246 {
 247         static uint8_t hwaddr[6] = { 0xfa, 0xfa, 0xfa, 0xfa, 0xfa, 0xfa };
 248         return hwaddr;
 249 }
 250 #else
 251 #define NMRP_INITIAL_TIMEOUT 60
 252 #endif
 253
 254 static int pkt_send(struct ethsock *sock, struct nmrp_pkt *pkt)
 255 {
 256         return ethsock_send(sock, pkt, sizeof(*pkt));
 257 }
 258
 259 static int pkt_recv(struct ethsock *sock, struct nmrp_pkt *pkt)
 260 {
 261         ssize_t bytes, mlen;
 262
 263         memset(pkt, 0, sizeof(*pkt));
 264         bytes = ethsock_recv(sock, pkt, sizeof(*pkt));
 265         if (bytes < 0) {
 266                 return 1;
 267         } else if (!bytes) {
 268                 return 2;
 269         }
 270
 271         mlen = ntohs(pkt->msg.len);
 272
 273         if (bytes < (mlen + sizeof(pkt->eh))
 274                         || bytes < NMRP_MIN_PKT_LEN
 275                         || mlen < NMRP_HDR_LEN) {
 276                 fprintf(stderr, "Short packet (%d raw, %d message)\n",
 277                                 (int)bytes, (int)mlen);
 278                 return 1;
 279         } else if (mlen > sizeof(pkt->msg)) {
 280                 printf("Truncating %d byte message.\n", (int)mlen);
 281                 pkt->msg.len = htons(sizeof(pkt->msg));
 282         }
 283
 284         return 0;
 285 }
 286
 287 static int mac_parse(const char *str, uint8_t *hwaddr)
 288 {
 289         int i;
 290         unsigned data[6];
 291
 292         sscanf(str, "%02x:%02x:%02x:%02x:%02x:%02x%n",
 293                         data, data + 1, data + 2, data + 3, data + 4, data + 5, &i);
 294
 295         if (i == strlen(str)) {
 296                 for (i = 0; i != 6; ++i) {
 297                         if (data[i] > 255) {
 298                                 break;
 299                         }
 300
 301                         hwaddr[i] = data[i] & 0xff;
 302                 }
 303
 304                 if (i == 6) {
 305                         return 1;
 306                 }
 307         }
 308         return 0;
 309 }
 310
 311 struct is_valid_ip_arg
 312 {
 313         struct in_addr *ipaddr;
 314         struct in_addr *ipmask;
 315         int result;
 316 };
 317
 318 static int is_valid_ip_cb(struct ethsock_ip_callback_args *args)
 319 {
 320 #define SUBNET(x) ((x)->ipaddr->s_addr & (x)->ipmask->s_addr)
 321         struct is_valid_ip_arg *arg = args->arg;
 322         if (SUBNET(args) == SUBNET(arg)) {
 323                 arg->result = args->ipaddr->s_addr != arg->ipaddr->s_addr;
 324                 return 0;
 325         }
 326
 327         return 1;
 328 #undef SUBNET
 329 }
 330
 331 static int is_valid_ip(struct ethsock *sock, struct in_addr *ipaddr,
 332                 struct in_addr *ipmask)
 333 {
 334         int status;
 335         struct is_valid_ip_arg arg = {
 336                 .ipaddr = ipaddr,
 337                 .ipmask = ipmask,
 338                 .result = 0
 339         };
 340
 341         status = ethsock_for_each_ip(sock, is_valid_ip_cb, &arg);
 342         return status < 0 ? status : arg.result;
 343 }
 344
 345 static void sigh(int sig)
 346 {
 347         g_interrupted = 1;
 348 }
 349
 350 static const char *spinner = "\\|/-";
 351
 352 int nmrp_do(struct nmrpd_args *args)
 353 {
 354         struct nmrp_pkt tx, rx;
 355         uint8_t *src, dest[6];
 356         uint16_t region;
 357         char *filename;
 358         time_t beg;
 359         int i, timeout, status, ulreqs, expect, upload_ok, autoip, ka_reqs, fake;
 360         struct ethsock *sock;
 361         struct ethsock_ip_undo *ip_undo = NULL;
 362         struct ethsock_arp_undo *arp_undo = NULL;
 363         uint32_t intf_addr = 0;
 364         void (*sigh_orig)(int);
 365         struct in_addr ipaddr;
 366         struct in_addr ipmask;
 367
 368         if (args->op != NMRP_UPLOAD_FW) {
 369                 fprintf(stderr, "Operation not implemented.\n");
 370                 return 1;
 371         }
 372
 373         if (!mac_parse(args->mac, dest)) {
 374                 fprintf(stderr, "Invalid MAC address '%s'.\n", args->mac);
 375                 return 1;
 376         }
 377
 378         ipmask.s_addr = inet_addr(args->ipmask);
 379         if (ipmask.s_addr == INADDR_NONE
 380                         || netmask(bitcount(ipmask.s_addr)) != ipmask.s_addr) {
 381                 fprintf(stderr, "Invalid subnet mask '%s'.\n", args->ipmask);
 382                 return 1;
 383         }
 384
 385         if (!args->ipaddr) {
 386                 autoip = true;
 387                 /* A random IP address. The MAC of the first device that was
 388                  * used to test this utility starts with a4:2b:8c, so we use
 389                  * 164 (0xa4) and 183 (0x2b + 0x8c).
 390                  *
 391                  * These addresses should not cause collisions on most networks,
 392                  * and if they do, the user is probably "poweruser" enough to
 393                  * be able to use the -a and -A options.
 394                  */
 395                 args->ipaddr = "10.164.183.252";
 396
 397                 if (!args->ipaddr_intf) {
 398                         args->ipaddr_intf = "10.164.183.253";
 399                 }
 400         } else if (args->ipaddr_intf) {
 401                 autoip = true;
 402         } else {
 403                 autoip = false;
 404         }
 405
 406         if ((ipaddr.s_addr = inet_addr(args->ipaddr)) == INADDR_NONE) {
 407                 fprintf(stderr, "Invalid IP address '%s'.\n", args->ipaddr);
 408                 return 1;
 409         }
 410
 411         if (args->ipaddr_intf && (intf_addr = inet_addr(args->ipaddr_intf)) == INADDR_NONE) {
 412                 fprintf(stderr, "Invalid IP address '%s'.\n", args->ipaddr_intf);
 413                 return 1;
 414         }
 415
 416         if (args->file_local && strcmp(args->file_local, "-") && access(args->file_local, R_OK) == -1) {
 417                 fprintf(stderr, "Error accessing file '%s'.\n", args->file_local);
 418                 return 1;
 419         }
 420
 421         if (args->file_remote) {
 422                 if (!tftp_is_valid_filename(args->file_remote)) {
 423                         fprintf(stderr, "Invalid remote filename '%s'.\n",
 424                                         args->file_remote);
 425                         return 1;
 426                 }
 427         }
 428
 429         if (args->region) {
 430                 region = to_region_code(args->region);
 431                 if (!region) {
 432                         fprintf(stderr, "Invalid region code '%s'.\n", args->region);
 433                         return 1;
 434                 }
 435         } else {
 436                 region = 0;
 437         }
 438
 439         status = 1;
 440
 441         sock = ethsock_create(args->intf, ETH_P_NMRP);
 442         if (!sock) {
 443                 return 1;
 444         }
 445
 446         sigh_orig = signal(SIGINT, sigh);
 447
 448         if (!autoip) {
 449                 status = is_valid_ip(sock, &ipaddr, &ipmask);
 450                 if (status <= 0) {
 451                         if (!status) {
 452                                 fprintf(stderr, "Address %s/%s cannot be used on interface %s.\n",
 453                                                 args->ipaddr, args->ipmask, args->intf);
 454                         }
 455                         goto out;
 456                 }
 457         } else {
 458                 if (verbosity) {
 459                         printf("Adding %s to interface %s.\n", args->ipaddr_intf, args->intf);
 460                 }
 461
 462                 if (ethsock_ip_add(sock, intf_addr, ipmask.s_addr, &ip_undo) != 0) {
 463                         goto out;
 464                 }
 465         }
 466
 467         if (ethsock_set_timeout(sock, args->rx_timeout)) {
 468                 goto out;
 469         }
 470
 471         src = ethsock_get_hwaddr(sock);
 472         if (!src) {
 473                 goto out;
 474         }
 475
 476         memcpy(tx.eh.ether_shost, src, 6);
 477         memcpy(tx.eh.ether_dhost, dest, 6);
 478         tx.eh.ether_type = htons(ETH_P_NMRP);
 479
 480         msg_mkadvertise(&tx.msg, "NTGR");
 481
 482         i = 0;
 483         upload_ok = 0;
 484         fake = 0;
 485         timeout = args->blind ? 10 : NMRP_INITIAL_TIMEOUT;
 486         beg = time_monotonic();
 487
 488         while (!g_interrupted) {
 489                 printf("\rAdvertising NMRP server on %s ... %c",
 490                                 args->intf, spinner[i]);
 491                 fflush(stdout);
 492                 i = (i + 1) & 3;
 493
 494                 if (pkt_send(sock, &tx) < 0) {
 495                         goto out;
 496                 }
 497
 498                 status = pkt_recv(sock, &rx);
 499                 if (status == 0) {
 500                         if (memcmp(rx.eh.ether_dhost, src, 6) == 0) {
 501                                 break;
 502                         } else if (verbosity) {
 503                                 printf("\nIgnoring bogus response: %s -> %s.\n",
 504                                                 mac_to_str(rx.eh.ether_shost),
 505                                                 mac_to_str(rx.eh.ether_dhost));
 506                         }
 507                 } else if (status == 1) {
 508                         goto out;
 509                 } else {
 510                         /* because we don't want nmrpflash's exit status to be zero */
 511                         status = 1;
 512                         if ((time_monotonic() - beg) >= timeout) {
 513                                 printf("\nNo response after %d seconds. ", timeout);
 514                                 if (!args->blind) {
 515                                         printf("Bailing out.\n");
 516                                         goto out;
 517                                 } else {
 518                                         // we're blind, so fake a response from the MAC specified by -m
 519                                         memcpy(rx.eh.ether_shost, dest, 6);
 520                                         msg_init(&rx.msg, NMRP_C_CONF_REQ);
 521                                         printf("Continuing blindly.");
 522                                         fake = 1;
 523                                         break;
 524                                 }
 525                         }
 526                 }
 527         }
 528
 529         printf("\n");
 530
 531         memcpy(tx.eh.ether_dhost, rx.eh.ether_shost, 6);
 532
 533         if (ethsock_arp_add(sock, rx.eh.ether_shost, ipaddr.s_addr, &arp_undo) != 0) {
 534                 goto out;
 535         }
 536
 537         expect = NMRP_C_CONF_REQ;
 538         ulreqs = 0;
 539         ka_reqs = 0;
 540
 541         while (!g_interrupted) {
 542                 if (expect != NMRP_C_NONE && rx.msg.code != expect) {
 543                         fprintf(stderr, "Received %s while waiting for %s!\n",
 544                                         msg_code_str(rx.msg.code), msg_code_str(expect));
 545                 }
 546
 547                 msg_init(&tx.msg, NMRP_C_NONE);
 548
 549                 status = 1;
 550
 551                 switch (rx.msg.code) {
 552                         case NMRP_C_ADVERTISE:
 553                                 printf("Received NMRP advertisement from %s.\n",
 554                                                 mac_to_str(rx.eh.ether_shost));
 555                                 status = 1;
 556                                 goto out;
 557                         case NMRP_C_CONF_REQ:
 558                                 msg_mkconfack(&tx.msg, ipaddr.s_addr, ipmask.s_addr, region);
 559                                 expect = NMRP_C_TFTP_UL_REQ;
 560
 561                                 if (!fake) {
 562                                         printf("Received configuration request from %s.\n",
 563                                                         mac_to_str(rx.eh.ether_shost));
 564                                 }
 565
 566                                 printf("Sending configuration: %s/%d.\n",
 567                                                 args->ipaddr, bitcount(ipmask.s_addr));
 568
 569                                 break;
 570                         case NMRP_C_TFTP_UL_REQ:
 571                                 if (!upload_ok) {
 572                                         if (++ulreqs > 5) {
 573                                                 printf("Bailing out after %d upload requests.\n",
 574                                                                 ulreqs);
 575                                                 tx.msg.code = NMRP_C_CLOSE_REQ;
 576                                                 break;
 577                                         }
 578                                 } else {
 579                                         if (verbosity) {
 580                                                 printf("Ignoring extra upload request.\n");
 581                                         }
 582                                         ethsock_set_timeout(sock, args->ul_timeout);
 583                                         tx.msg.code = NMRP_C_KEEP_ALIVE_REQ;
 584                                         break;
 585                                 }
 586
 587                                 filename = msg_filename(&rx.msg);
 588                                 if (filename) {
 589                                         if (!args->file_remote) {
 590                                                 args->file_remote = filename;
 591                                         }
 592                                         printf("Received upload request: filename '%s'.\n", filename);
 593                                 } else if (!args->file_remote) {
 594                                         args->file_remote = leafname(args->file_local);
 595                                         if (!fake) {
 596                                                 printf("Received upload request without filename.\n");
 597                                         }
 598                                 }
 599
 600                                 status = 0;
 601
 602                                 if (args->tftpcmd) {
 603                                         printf("Executing '%s' ... \n", args->tftpcmd);
 604                                         setenv("IP", inet_ntoa(ipaddr), 1);
 605                                         setenv("PORT", lltostr(args->port, 10), 1);
 606                                         setenv("MAC", mac_to_str(rx.eh.ether_shost), 1);
 607                                         setenv("NETMASK", inet_ntoa(ipmask), 1);
 608                                         //setenv("FILENAME", args->file_remote ? args->file_remote : "", 1);
 609                                         status = system(args->tftpcmd);
 610                                 }
 611
 612                                 if (!status && args->file_local) {
 613                                         if (!autoip) {
 614                                                 status = is_valid_ip(sock, &ipaddr, &ipmask);
 615                                                 if (status < 0) {
 616                                                         goto out;
 617                                                 } else if (!status) {
 618                                                         printf("IP address of %s has changed. Please assign a "
 619                                                                         "static ip to the interface.\n", args->intf);
 620                                                         tx.msg.code = NMRP_C_CLOSE_REQ;
 621                                                         break;
 622                                                 }
 623                                         }
 624
 625                                         if (verbosity) {
 626                                                 printf("Using remote filename '%s'.\n",
 627                                                                 args->file_remote);
 628                                         }
 629
 630                                         if (!strcmp(args->file_local, "-")) {
 631                                                 printf("Uploading from stdin ... ");
 632                                         } else {
 633                                                 printf("Uploading %s ... ", leafname(args->file_local));
 634                                         }
 635                                         fflush(stdout);
 636                                         if (!(status = tftp_put(args))) {
 637                                                 printf("OK\n");
 638                                         }
 639
 640                                 }
 641
 642                                 if (!status) {
 643                                         if (args->blind) {
 644                                                 goto out;
 645                                         }
 646
 647                                         printf("Waiting for remote to respond.\n");
 648                                         upload_ok = 1;
 649                                         ethsock_set_timeout(sock, args->ul_timeout);
 650                                         tx.msg.code = NMRP_C_KEEP_ALIVE_REQ;
 651                                         expect = NMRP_C_NONE;
 652                                 } else if (status == -2) {
 653                                         expect = NMRP_C_TFTP_UL_REQ;
 654                                 } else {
 655                                         goto out;
 656                                 }
 657
 658                                 break;
 659                         case NMRP_C_KEEP_ALIVE_REQ:
 660                                 tx.msg.code = NMRP_C_KEEP_ALIVE_ACK;
 661                                 ethsock_set_timeout(sock, args->ul_timeout);
 662                                 printf("\rReceived keep-alive request (%d).  ", ++ka_reqs);
 663                                 break;
 664                         case NMRP_C_CLOSE_REQ:
 665                                 tx.msg.code = NMRP_C_CLOSE_ACK;
 666                                 break;
 667                         case NMRP_C_CLOSE_ACK:
 668                                 status = 0;
 669                                 goto out;
 670                         default:
 671                                 fprintf(stderr, "Unknown message code 0x%02x!\n",
 672                                                 rx.msg.code);
 673                                 msg_dump(&rx.msg);
 674                 }
 675
 676                 if (tx.msg.code != NMRP_C_NONE) {
 677                         if (pkt_send(sock, &tx) != 0 || tx.msg.code == NMRP_C_CLOSE_REQ) {
 678                                 goto out;
 679                         }
 680                 }
 681
 682                 if (rx.msg.code == NMRP_C_CLOSE_REQ) {
 683                         if (ka_reqs) {
 684                                 printf("\n");
 685                         }
 686
 687                         printf("Remote finished. Closing connection.\n");
 688                         break;
 689                 }
 690
 691                 status = pkt_recv(sock, &rx);
 692                 if (status) {
 693                         if (status == 2) {
 694                                 if (!args->blind) {
 695                                         fprintf(stderr, "Timeout while waiting for %s.\n",
 696                                                         msg_code_str(expect));
 697                                         goto out;
 698                                 }
 699
 700                                 // fake response
 701                                 msg_init(&rx.msg, expect);
 702                                 memcpy(rx.eh.ether_shost, tx.eh.ether_dhost, 6);
 703                                 fake = 1;
 704                         } else {
 705                                 goto out;
 706                         }
 707                 } else {
 708                         fake = 0;
 709                 }
 710
 711                 ethsock_set_timeout(sock, args->rx_timeout);
 712
 713         }
 714
 715         if (!g_interrupted) {
 716                 status = 0;
 717                 if (ulreqs) {
 718                         printf("Reboot your device now.\n");
 719                 } else {
 720                         printf("No upload request received.\n");
 721                 }
 722         }
 723
 724 out:
 725         signal(SIGINT, sigh_orig);
 726         ethsock_arp_del(sock, &arp_undo);
 727         ethsock_ip_del(sock, &ip_undo);
 728         ethsock_close(sock);
 729         return status;
 730 }