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_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 2
  35
  36 #define ETH_P_NMRP 0x0912
  37 #define IP_LEN 4
  38 #define MAX_LOOP_RECV 1024
  39
  40 #ifndef PACKED
  41 #define PACKED __attribute__((__packed__))
  42 #endif
  43
  44 enum nmrp_code {
  45         NMRP_C_NONE = 0,
  46         NMRP_C_ADVERTISE = 1,
  47         NMRP_C_CONF_REQ = 2,
  48         NMRP_C_CONF_ACK = 3,
  49         NMRP_C_CLOSE_REQ = 4,
  50         NMRP_C_CLOSE_ACK = 5,
  51         NMRP_C_KEEP_ALIVE_REQ = 6,
  52         NMRP_C_KEEP_ALIVE_ACK = 7,
  53         NMRP_C_TFTP_UL_REQ = 16
  54 };
  55
  56 enum nmrp_opt_type {
  57         NMRP_O_MAGIC_NO = 0x0001,
  58         NMRP_O_DEV_IP = 0x0002,
  59         NMRP_O_DEV_REGION = 0x0004,
  60         NMRP_O_FW_UP = 0x0101,
  61         NMRP_O_ST_UP = 0x0102,
  62         NMRP_O_FILE_NAME = 0x0181
  63 };
  64
  65 struct nmrp_opt {
  66         uint16_t type;
  67         uint16_t len;
  68         union {
  69                 uint8_t magic[4];
  70                 uint16_t region;
  71                 struct {
  72                         uint8_t addr[4];
  73                         uint8_t mask[4];
  74                 } ip;
  75         } val;
  76 } PACKED;
  77
  78 struct nmrp_msg {
  79         uint16_t reserved;
  80         uint8_t code;
  81         uint8_t id;
  82         uint16_t len;
  83         struct nmrp_opt opts[2];
  84         uint32_t num_opts;
  85 } PACKED;
  86
  87 struct eth_hdr {
  88         uint8_t ether_dhost[6];
  89         uint8_t ether_shost[6];
  90         uint16_t ether_type;
  91 } PACKED;
  92
  93 struct nmrp_pkt {
  94         struct eth_hdr eh;
  95         struct nmrp_msg msg;
  96 } PACKED;
  97
  98 static const char *msg_code_str(uint16_t code)
  99 {
 100 #define CASE_CODE(x) case NMRP_C_ ## x: return #x
 101         static char buf[16];
 102
 103         switch (code) {
 104                 CASE_CODE(ADVERTISE);
 105                 CASE_CODE(CONF_REQ);
 106                 CASE_CODE(CONF_ACK);
 107                 CASE_CODE(CLOSE_REQ);
 108                 CASE_CODE(CLOSE_ACK);
 109                 CASE_CODE(KEEP_ALIVE_REQ);
 110                 CASE_CODE(KEEP_ALIVE_ACK);
 111                 CASE_CODE(TFTP_UL_REQ);
 112                 default:
 113                         snprintf(buf, sizeof(buf), "%04x", code);
 114                         return buf;
 115         }
 116 #undef CASE_CODE
 117 }
 118
 119 static void msg_update_len(struct nmrp_msg *msg)
 120 {
 121         uint32_t i = 0;
 122         msg->len = NMRP_HDR_LEN;
 123         for (; i != msg->num_opts; ++i) {
 124                 msg->len += msg->opts[i].len;
 125         }
 126 }
 127
 128 static void msg_dump(struct nmrp_msg *msg, int dump_opts)
 129 {
 130         struct nmrp_opt *opt;
 131         int remain_len, len, i;
 132
 133         fprintf(stderr, "res=0x%04x, code=0x%02x, id=0x%02x, len=%u",
 134                         msg->reserved, msg->code, msg->id, msg->len);
 135
 136         remain_len = msg->len - NMRP_HDR_LEN;
 137         fprintf(stderr, "%s\n", remain_len ? "" : " (no opts)");
 138
 139         if (dump_opts) {
 140                 opt = msg->opts;
 141
 142                 while (remain_len > 0) {
 143                         len = opt->len;
 144                         fprintf(stderr, "  opt type=%u, len=%u", opt->type, len);
 145                         for (i = 0; i != len - NMRP_OPT_LEN; ++i) {
 146                                 if (!(i % 16)) {
 147                                         fprintf(stderr, "\n  ");
 148                                 }
 149
 150                                 fprintf(stderr, "%02x ", ((char*)&opt->val)[i] & 0xff);
 151                         }
 152                         fprintf(stderr, "\n");
 153                         remain_len -= len;
 154                         opt = (struct nmrp_opt*)(((char*)opt) + len);
 155                 }
 156         }
 157 }
 158
 159 static void msg_hton(struct nmrp_msg *msg)
 160 {
 161         uint32_t i = 0;
 162
 163         msg->reserved = htons(msg->reserved);
 164         msg->len = htons(msg->len);
 165
 166         for (; i != msg->num_opts; ++i) {
 167                 msg->opts[i].len = htons(msg->opts[i].len);
 168                 msg->opts[i].type = htons(msg->opts[i].type);
 169         }
 170 }
 171
 172 static void msg_hdr_ntoh(struct nmrp_msg *msg)
 173 {
 174         msg->reserved = ntohs(msg->reserved);
 175         msg->len = ntohs(msg->len);
 176 }
 177
 178 static int msg_ntoh(struct nmrp_msg *msg)
 179 {
 180         struct nmrp_opt *opt = msg->opts;
 181         int remaining;
 182
 183         remaining = msg->len - NMRP_HDR_LEN;
 184
 185         // FIXME maximum of two options supported, maximum option
 186         // size is 12
 187         if (remaining < NMRP_MAX_OPT_NUM * NMRP_MAX_OPT_SIZE) {
 188                 while (remaining > 0) {
 189                         if (remaining < NMRP_OPT_LEN) {
 190                                 break;
 191                         }
 192
 193                         opt->type = ntohs(opt->type);
 194                         opt->len = ntohs(opt->len);
 195
 196                         if (opt->len > NMRP_MAX_OPT_SIZE) {
 197                                 break;
 198                         }
 199
 200                         remaining -= opt->len;
 201                         ++opt;
 202                 }
 203
 204                 if (!remaining) {
 205                         return 0;
 206                 }
 207         }
 208
 209         fprintf(stderr, "Unexpected message format.\n");
 210         msg_dump(msg, 0);
 211         return 1;
 212 }
 213
 214 static void *msg_opt_data(struct nmrp_msg *msg, int type, uint16_t *len)
 215 {
 216         static char buf[128];
 217         struct nmrp_opt *opt = msg->opts;
 218         int remaining = msg->len - NMRP_HDR_LEN;
 219
 220         memset(buf, 0, sizeof(buf));
 221
 222         while (remaining > 0) {
 223                 if (opt->type == type) {
 224                         if (opt->len == NMRP_OPT_LEN) {
 225                                 return NULL;
 226                         }
 227                         *len = opt->len - NMRP_OPT_LEN;
 228                         memcpy(buf, &opt->val, MIN(*len, sizeof(buf)-1));
 229                         return buf;
 230                 }
 231
 232                 remaining -= opt->len;
 233                 opt = (struct nmrp_opt*)((char*)opt) + opt->len;
 234         }
 235
 236         return NULL;
 237 }
 238
 239 static int pkt_send(struct ethsock *sock, struct nmrp_pkt *pkt)
 240 {
 241         size_t len = ntohs(pkt->msg.len) + sizeof(pkt->eh);
 242         return ethsock_send(sock, pkt, len);
 243 }
 244
 245 static int pkt_recv(struct ethsock *sock, struct nmrp_pkt *pkt)
 246 {
 247         ssize_t bytes, len;
 248
 249         memset(pkt, 0, sizeof(*pkt));
 250         bytes = ethsock_recv(sock, pkt, sizeof(*pkt));
 251         if (bytes < 0) {
 252                 return 1;
 253         } else if (!bytes) {
 254                 return 2;
 255         } else if (bytes < NMRP_MIN_PKT_LEN) {
 256                 fprintf(stderr, "Short packet (%d bytes)\n", (int)bytes);
 257                 return 1;
 258         }
 259
 260         msg_hdr_ntoh(&pkt->msg);
 261         len = pkt->msg.len + sizeof(pkt->eh);
 262
 263         if (bytes < len) {
 264                 fprintf(stderr, "Short packet (expected %d, got %d).\n",
 265                                 (int)len, (int)bytes);
 266                 return 1;
 267         }
 268
 269         return msg_ntoh(&pkt->msg);
 270 }
 271
 272 static int mac_parse(const char *str, uint8_t *hwaddr)
 273 {
 274         int i;
 275         unsigned data[6];
 276
 277         sscanf(str, "%02x:%02x:%02x:%02x:%02x:%02x%n",
 278                         data, data + 1, data + 2, data + 3, data + 4, data + 5, &i);
 279
 280         if (i == strlen(str)) {
 281                 for (i = 0; i != 6; ++i) {
 282                         if (data[i] > 255) {
 283                                 break;
 284                         }
 285
 286                         hwaddr[i] = data[i] & 0xff;
 287                 }
 288
 289                 if (i == 6) {
 290                         return 1;
 291                 }
 292         }
 293         return 0;
 294 }
 295
 296 struct is_valid_ip_arg
 297 {
 298         struct in_addr *ipaddr;
 299         struct in_addr *ipmask;
 300         int result;
 301 };
 302
 303 static int is_valid_ip_cb(struct ethsock_ip_callback_args *args)
 304 {
 305 #define SUBNET(x) ((x)->ipaddr->s_addr & (x)->ipmask->s_addr)
 306         struct is_valid_ip_arg *arg = args->arg;
 307         if (SUBNET(args) == SUBNET(arg)) {
 308                 arg->result = args->ipaddr->s_addr != arg->ipaddr->s_addr;
 309                 return 0;
 310         }
 311
 312         return 1;
 313 #undef SUBNET
 314 }
 315
 316 static int is_valid_ip(struct ethsock *sock, struct in_addr *ipaddr,
 317                 struct in_addr *ipmask)
 318 {
 319         int status;
 320         struct is_valid_ip_arg arg = {
 321                 .ipaddr = ipaddr,
 322                 .ipmask = ipmask,
 323                 .result = 0
 324         };
 325
 326         status = ethsock_for_each_ip(sock, is_valid_ip_cb, &arg);
 327         return status < 0 ? status : arg.result;
 328 }
 329
 330 static struct ethsock *gsock = NULL;
 331
 332 static void sigh(int sig)
 333 {
 334         printf("\n");
 335         if (gsock) {
 336                 ethsock_close(gsock);
 337         }
 338
 339         exit(1);
 340 }
 341
 342 static const char *spinner = "\\|/-";
 343
 344 int nmrp_do(struct nmrpd_args *args)
 345 {
 346         struct nmrp_pkt tx, rx;
 347         uint8_t *src, dest[6];
 348         uint16_t len;
 349         char *filename;
 350         struct in_addr ipaddr, ipmask;
 351         time_t beg;
 352         int i, status, ulreqs, expect;
 353         struct ethsock *sock;
 354         void (*sigh_orig)(int);
 355
 356         if (args->op != NMRP_UPLOAD_FW) {
 357                 fprintf(stderr, "Operation not implemented.\n");
 358                 return 1;
 359         }
 360
 361         if (!mac_parse(args->mac, dest)) {
 362                 fprintf(stderr, "Invalid MAC address '%s'.\n", args->mac);
 363                 return 1;
 364         }
 365
 366         if ((ipaddr.s_addr = inet_addr(args->ipaddr)) == INADDR_NONE) {
 367                 fprintf(stderr, "Invalid IP address '%s'.\n", args->ipaddr);
 368                 return 1;
 369         }
 370
 371         if ((ipmask.s_addr = inet_addr(args->ipmask)) == INADDR_NONE) {
 372                 fprintf(stderr, "Invalid subnet mask '%s'.\n", args->ipmask);
 373                 return 1;
 374         }
 375
 376         if (strcmp(args->file_local, "-") && access(args->file_local, R_OK) == -1) {
 377                 fprintf(stderr, "Error accessing file '%s'.\n", args->file_local);
 378                 return 1;
 379         }
 380
 381         if (args->file_remote) {
 382                 if (!tftp_is_valid_filename(args->file_remote)) {
 383                         fprintf(stderr, "Invalid remote filename '%s'.\n",
 384                                         args->file_remote);
 385                         return 1;
 386                 }
 387         }
 388
 389         status = 1;
 390
 391         sock = ethsock_create(args->intf, ETH_P_NMRP);
 392         if (!sock) {
 393                 return 1;
 394         }
 395
 396         status = is_valid_ip(sock, &ipaddr, &ipmask);
 397         if (status <= 0) {
 398                 if (!status) {
 399                         fprintf(stderr, "Address %s/%s cannot be used on interface %s.\n",
 400                                         args->ipaddr, args->ipmask, args->intf);
 401                 }
 402                 goto out;
 403         }
 404
 405         gsock = sock;
 406         sigh_orig = signal(SIGINT, sigh);
 407
 408         if (ethsock_set_timeout(sock, args->rx_timeout)) {
 409                 goto out;
 410         }
 411
 412         src = ethsock_get_hwaddr(sock);
 413         if (!src) {
 414                 goto out;
 415         }
 416
 417         memcpy(tx.eh.ether_shost, src, 6);
 418         memcpy(tx.eh.ether_dhost, dest, 6);
 419         tx.eh.ether_type = htons(ETH_P_NMRP);
 420
 421         tx.msg.reserved = 0;
 422         tx.msg.code = NMRP_C_ADVERTISE;
 423         tx.msg.id = 0;
 424         tx.msg.num_opts = 1;
 425         tx.msg.opts[0].type = NMRP_O_MAGIC_NO;
 426         tx.msg.opts[0].len = NMRP_OPT_LEN + 4;
 427         tx.msg.opts[0].val.magic[0] = 'N';
 428         tx.msg.opts[0].val.magic[1] = 'T';
 429         tx.msg.opts[0].val.magic[2] = 'G';
 430         tx.msg.opts[0].val.magic[3] = 'R';
 431
 432         msg_update_len(&tx.msg);
 433         msg_hton(&tx.msg);
 434
 435         i = 0;
 436         beg = time(NULL);
 437
 438         while (1) {
 439                 printf("\rAdvertising NMRP server on %s ... %c",
 440                                 args->intf, spinner[i]);
 441                 fflush(stdout);
 442                 i = (i + 1) & 3;
 443
 444                 if (pkt_send(sock, &tx) < 0) {
 445                         perror("sendto");
 446                         goto out;
 447                 }
 448
 449                 status = pkt_recv(sock, &rx);
 450                 if (status == 0 && memcmp(rx.eh.ether_dhost, src, 6) == 0) {
 451                         break;
 452                 } else if (status == 1) {
 453                         printf("ERR\n");
 454                         goto out;
 455                 } else {
 456                         if ((time(NULL) - beg) >= 60) {
 457                                 printf("\nNo response after 60 seconds. Bailing out.\n");
 458                                 goto out;
 459                         }
 460                 }
 461         }
 462
 463         printf("\n");
 464
 465         expect = NMRP_C_CONF_REQ;
 466         ulreqs = 0;
 467
 468         do {
 469                 if (expect != NMRP_C_NONE && rx.msg.code != expect) {
 470                         fprintf(stderr, "Received %s while waiting for %s!\n",
 471                                         msg_code_str(rx.msg.code), msg_code_str(expect));
 472                 }
 473
 474                 tx.msg.code = NMRP_C_NONE;
 475                 tx.msg.reserved = 0;
 476                 tx.msg.id = 0;
 477                 tx.msg.num_opts = 0;
 478                 tx.msg.len = 0;
 479
 480                 status = 1;
 481
 482                 switch (rx.msg.code) {
 483                         case NMRP_C_ADVERTISE:
 484                                 printf("Received NMRP advertisement from %s.\n",
 485                                                 mac_to_str(rx.eh.ether_shost));
 486                                 status = 1;
 487                                 goto out;
 488                         case NMRP_C_CONF_REQ:
 489                                 tx.msg.code = NMRP_C_CONF_ACK;
 490                                 tx.msg.num_opts = 2;
 491
 492                                 tx.msg.opts[0].type = NMRP_O_DEV_IP;
 493                                 tx.msg.opts[0].len = NMRP_OPT_LEN + 2 * 4;
 494
 495                                 memcpy(tx.msg.opts[0].val.ip.addr, &ipaddr, 4);
 496                                 memcpy(tx.msg.opts[0].val.ip.mask, &ipmask, 4);
 497
 498                                 tx.msg.opts[1].type = NMRP_O_FW_UP;
 499                                 tx.msg.opts[1].len = NMRP_OPT_LEN;
 500
 501 #ifdef NMRPFLASH_SET_REGION
 502                                 tx.msg.num_opts = 3;
 503
 504                                 tx.msg.opts[2].type = NMRP_O_DEV_REGION;
 505                                 tx.msg.opts[2].len = NMRP_OPT_LEN + 2;
 506                                 tx.msg.opts[2].val.region = args->region;
 507 #endif
 508
 509                                 expect = NMRP_C_TFTP_UL_REQ;
 510
 511                                 printf("Received configuration request from %s.\n",
 512                                                 mac_to_str(rx.eh.ether_shost));
 513
 514                                 memcpy(tx.eh.ether_dhost, rx.eh.ether_shost, 6);
 515
 516                                 printf("Sending configuration: ip %s, mask %s.\n",
 517                                                 args->ipaddr, args->ipmask);
 518
 519                                 break;
 520                         case NMRP_C_TFTP_UL_REQ:
 521                                 if (++ulreqs > 5) {
 522                                         fprintf(stderr, "Device re-requested file upload %d "
 523                                                         "times; aborting.\n", ulreqs);
 524                                         tx.msg.code = NMRP_C_CLOSE_REQ;
 525                                         break;
 526                                 }
 527
 528                                 len = 0;
 529                                 filename = msg_opt_data(&rx.msg, NMRP_O_FILE_NAME, &len);
 530                                 if (filename) {
 531                                         if (!args->file_remote) {
 532                                                 args->file_remote = filename;
 533                                         }
 534                                         printf("Received upload request: filename '%.*s'.\n",
 535                                                         len, filename);
 536                                 } else if (!args->file_remote) {
 537                                         args->file_remote = args->file_local;
 538                                         printf("Received upload request with empty filename.");
 539                                 }
 540
 541                                 status = 0;
 542
 543                                 if (args->tftpcmd) {
 544                                         printf("Executing '%s' ... ", args->tftpcmd);
 545                                         fflush(stdout);
 546                                         status = system(args->tftpcmd);
 547                                         if (!status) {
 548                                                 printf("OK\n");
 549                                         } else {
 550                                                 printf("ERR\n");
 551                                         }
 552                                 }
 553
 554                                 if (!status && args->file_local) {
 555                                         status = is_valid_ip(sock, &ipaddr, &ipmask);
 556                                         if (status < 0) {
 557                                                 goto out;
 558                                         } else if (!status) {
 559                                                 printf("IP address of %s has changed. Please assign a "
 560                                                                 "static ip to the interface.\n", args->intf);
 561                                                 tx.msg.code = NMRP_C_CLOSE_REQ;
 562                                                 break;
 563                                         }
 564
 565                                         if (verbosity) {
 566                                                 printf("Using remote filename '%s'.\n",
 567                                                                 args->file_remote);
 568                                         }
 569
 570                                         if (!strcmp(args->file_local, "-")) {
 571                                                 printf("Uploading from stdin ... ");
 572                                         } else {
 573                                                 printf("Uploading %s ... ", args->file_local);
 574                                         }
 575                                         fflush(stdout);
 576                                         status = tftp_put(args);
 577                                 }
 578
 579                                 if (!status) {
 580                                         printf("OK\nWaiting for remote to respond.\n");
 581                                         ethsock_set_timeout(sock, args->ul_timeout);
 582                                         expect = NMRP_C_NONE;
 583                                 } else if (status == -2) {
 584                                         expect = NMRP_C_TFTP_UL_REQ;
 585                                 } else {
 586                                         goto out;
 587                                 }
 588
 589                                 break;
 590                         case NMRP_C_KEEP_ALIVE_REQ:
 591                                 tx.msg.code = NMRP_C_KEEP_ALIVE_ACK;
 592                                 ethsock_set_timeout(sock, 15000);
 593                                 printf("Received keep-alive request.\n");
 594                                 break;
 595                         case NMRP_C_CLOSE_REQ:
 596                                 tx.msg.code = NMRP_C_CLOSE_ACK;
 597                                 break;
 598                         case NMRP_C_CLOSE_ACK:
 599                                 status = 0;
 600                                 goto out;
 601                         default:
 602                                 fprintf(stderr, "Unknown message code 0x%02x!\n",
 603                                                 rx.msg.code);
 604                                 msg_dump(&rx.msg, 0);
 605                 }
 606
 607                 if (tx.msg.code != NMRP_C_NONE) {
 608                         msg_update_len(&tx.msg);
 609                         msg_hton(&tx.msg);
 610
 611                         if (pkt_send(sock, &tx) < 0) {
 612                                 perror("sendto");
 613                                 goto out;
 614                         }
 615                 }
 616
 617                 if (rx.msg.code == NMRP_C_CLOSE_REQ) {
 618                         printf("Remote finished. Closing connection.\n");
 619                         break;
 620                 }
 621
 622                 status = pkt_recv(sock, &rx);
 623                 if (status) {
 624                         if (status == 2) {
 625                                 fprintf(stderr, "Timeout while waiting for %s.\n",
 626                                                 msg_code_str(expect));
 627                         }
 628                         goto out;
 629                 }
 630
 631                 ethsock_set_timeout(sock, args->rx_timeout);
 632
 633         } while (1);
 634
 635         status = 0;
 636
 637         if (ulreqs) {
 638                 printf("Reboot your device now.\n");
 639         } else {
 640                 printf("No upload request received.\n");
 641         }
 642
 643 out:
 644         signal(SIGINT, sigh_orig);
 645         gsock = NULL;
 646         ethsock_close(sock);
 647         return status;
 648 }