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