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                 struct {
  71                         uint8_t addr[4];
  72                         uint8_t mask[4];
  73                 } ip;
  74         } val;
  75 } PACKED;
  76
  77 struct nmrp_msg {
  78         uint16_t reserved;
  79         uint8_t code;
  80         uint8_t id;
  81         uint16_t len;
  82         struct nmrp_opt opts[2];
  83         uint32_t num_opts;
  84 } PACKED;
  85
  86 struct eth_hdr {
  87         uint8_t ether_dhost[6];
  88         uint8_t ether_shost[6];
  89         uint16_t ether_type;
  90 } PACKED;
  91
  92 struct nmrp_pkt {
  93         struct eth_hdr eh;
  94         struct nmrp_msg msg;
  95 } PACKED;
  96
  97 static void msg_update_len(struct nmrp_msg *msg)
  98 {
  99         uint32_t i = 0;
 100         msg->len = NMRP_HDR_LEN;
 101         for (; i != msg->num_opts; ++i) {
 102                 msg->len += msg->opts[i].len;
 103         }
 104 }
 105
 106 static void msg_dump(struct nmrp_msg *msg, int dump_opts)
 107 {
 108         struct nmrp_opt *opt;
 109         int remain_len, len, i;
 110
 111         fprintf(stderr, "res=0x%04x, code=0x%02x, id=0x%02x, len=%u",
 112                         msg->reserved, msg->code, msg->id, msg->len);
 113
 114         remain_len = msg->len - NMRP_HDR_LEN;
 115         fprintf(stderr, "%s\n", remain_len ? "" : " (no opts)");
 116
 117         if (dump_opts) {
 118                 opt = msg->opts;
 119
 120                 while (remain_len > 0) {
 121                         len = opt->len;
 122                         fprintf(stderr, "  opt type=%u, len=%u", opt->type, len);
 123                         for (i = 0; i != len - NMRP_OPT_LEN; ++i) {
 124                                 if (!(i % 16)) {
 125                                         fprintf(stderr, "\n  ");
 126                                 }
 127
 128                                 fprintf(stderr, "%02x ", ((char*)&opt->val)[i] & 0xff);
 129                         }
 130                         fprintf(stderr, "\n");
 131                         remain_len -= len;
 132                         opt = (struct nmrp_opt*)(((char*)opt) + len);
 133                 }
 134         }
 135 }
 136
 137 static void msg_hton(struct nmrp_msg *msg)
 138 {
 139         uint32_t i = 0;
 140
 141         msg->reserved = htons(msg->reserved);
 142         msg->len = htons(msg->len);
 143
 144         for (; i != msg->num_opts; ++i) {
 145                 msg->opts[i].len = htons(msg->opts[i].len);
 146                 msg->opts[i].type = htons(msg->opts[i].type);
 147         }
 148 }
 149
 150 static void msg_hdr_ntoh(struct nmrp_msg *msg)
 151 {
 152         msg->reserved = ntohs(msg->reserved);
 153         msg->len = ntohs(msg->len);
 154 }
 155
 156 static int msg_ntoh(struct nmrp_msg *msg)
 157 {
 158         struct nmrp_opt *opt = msg->opts;
 159         int remaining;
 160
 161         remaining = msg->len - NMRP_HDR_LEN;
 162
 163         // FIXME maximum of two options supported, maximum option
 164         // size is 12
 165         if (remaining < NMRP_MAX_OPT_NUM * NMRP_MAX_OPT_SIZE) {
 166                 while (remaining > 0) {
 167                         if (remaining < NMRP_OPT_LEN) {
 168                                 break;
 169                         }
 170
 171                         opt->type = ntohs(opt->type);
 172                         opt->len = ntohs(opt->len);
 173
 174                         if (opt->len > NMRP_MAX_OPT_SIZE) {
 175                                 break;
 176                         }
 177
 178                         remaining -= opt->len;
 179                         ++opt;
 180                 }
 181
 182                 if (!remaining) {
 183                         return 0;
 184                 }
 185         }
 186
 187         fprintf(stderr, "Unexpected message format.\n");
 188         msg_dump(msg, 0);
 189         return 1;
 190 }
 191
 192 static void *msg_opt_data(struct nmrp_msg *msg, int type, uint16_t *len)
 193 {
 194         struct nmrp_opt *opt = msg->opts;
 195         int remaining = msg->len - NMRP_HDR_LEN;
 196
 197         while (remaining > 0) {
 198                 if (opt->type == type) {
 199                         *len = opt->len - NMRP_OPT_LEN;
 200                         return (char*)&opt->val;
 201                 }
 202
 203                 remaining -= opt->len;
 204                 opt = (struct nmrp_opt*)((char*)opt) + opt->len;
 205         }
 206
 207         return NULL;
 208 }
 209
 210 static int pkt_send(struct ethsock *sock, struct nmrp_pkt *pkt)
 211 {
 212         size_t len = ntohs(pkt->msg.len) + sizeof(pkt->eh);
 213         return ethsock_send(sock, pkt, len);
 214 }
 215
 216 static int pkt_recv(struct ethsock *sock, struct nmrp_pkt *pkt)
 217 {
 218         ssize_t bytes, len;
 219
 220         memset(pkt, 0, sizeof(*pkt));
 221         bytes = ethsock_recv(sock, pkt, sizeof(*pkt));
 222         if (bytes < 0) {
 223                 return 1;
 224         } else if (!bytes) {
 225                 return 2;
 226         } else if (bytes < NMRP_MIN_PKT_LEN) {
 227                 fprintf(stderr, "Short packet (%d bytes)\n", (int)bytes);
 228                 return 1;
 229         }
 230
 231         msg_hdr_ntoh(&pkt->msg);
 232         len = pkt->msg.len + sizeof(pkt->eh);
 233
 234         if (bytes < len) {
 235                 fprintf(stderr, "Short packet (expected %d, got %d).\n",
 236                                 (int)len, (int)bytes);
 237                 return 1;
 238         }
 239
 240         return msg_ntoh(&pkt->msg);
 241 }
 242
 243 static int mac_parse(const char *str, uint8_t *hwaddr)
 244 {
 245         int i;
 246         unsigned data[6];
 247
 248         sscanf(str, "%02x:%02x:%02x:%02x:%02x:%02x%n",
 249                         data, data + 1, data + 2, data + 3, data + 4, data + 5, &i);
 250
 251         if (i == strlen(str)) {
 252                 for (i = 0; i != 6; ++i) {
 253                         if (data[i] > 255) {
 254                                 break;
 255                         }
 256
 257                         hwaddr[i] = data[i] & 0xff;
 258                 }
 259
 260                 if (i == 6) {
 261                         return 1;
 262                 }
 263         }
 264         return 0;
 265 }
 266
 267 static struct ethsock *gsock = NULL;
 268
 269 static void sigh(int sig)
 270 {
 271         printf("\n");
 272         if (gsock) {
 273                 ethsock_close(gsock);
 274         }
 275
 276         exit(1);
 277 }
 278
 279 static const char *spinner = "\\|/-";
 280
 281 int nmrp_do(struct nmrpd_args *args)
 282 {
 283         struct nmrp_pkt tx, rx;
 284         uint8_t *src, dest[6];
 285         uint16_t len;
 286         char *filename;
 287         struct in_addr ipaddr, ipmask;
 288         time_t beg;
 289         int i, err, ulreqs, expect;
 290         struct ethsock *sock;
 291         void (*sigh_orig)(int);
 292
 293         if (args->op != NMRP_UPLOAD_FW) {
 294                 fprintf(stderr, "Operation not implemented.\n");
 295                 return 1;
 296         }
 297
 298         if (!mac_parse(args->mac, dest)) {
 299                 fprintf(stderr, "Invalid MAC address '%s'.\n", args->mac);
 300                 return 1;
 301         }
 302
 303         if ((ipaddr.s_addr = inet_addr(args->ipaddr)) == INADDR_NONE) {
 304                 fprintf(stderr, "Invalid IP address '%s'.\n", args->ipaddr);
 305                 return 1;
 306         }
 307
 308         if ((ipmask.s_addr = inet_addr(args->ipmask)) == INADDR_NONE) {
 309                 fprintf(stderr, "Invalid subnet mask '%s'.\n", args->ipmask);
 310                 return 1;
 311         }
 312
 313         if (strcmp(args->file_local, "-") && access(args->file_local, R_OK) == -1) {
 314                 fprintf(stderr, "Error accessing file '%s'.\n", args->file_local);
 315                 return 1;
 316         }
 317
 318         if (args->file_remote) {
 319                 if (!tftp_is_valid_filename(args->file_remote)) {
 320                         fprintf(stderr, "Invalid remote filename '%s'.\n",
 321                                         args->file_remote);
 322                         return 1;
 323                 }
 324         }
 325
 326         err = 1;
 327
 328         sock = ethsock_create(args->intf, ETH_P_NMRP);
 329         if (!sock) {
 330                 return 1;
 331         }
 332
 333         gsock = sock;
 334         sigh_orig = signal(SIGINT, sigh);
 335
 336         if (ethsock_set_timeout(sock, args->rx_timeout)) {
 337                 goto out;
 338         }
 339
 340         src = ethsock_get_hwaddr(sock);
 341         if (!src) {
 342                 goto out;
 343         }
 344
 345         memcpy(tx.eh.ether_shost, src, 6);
 346         memcpy(tx.eh.ether_dhost, dest, 6);
 347         tx.eh.ether_type = htons(ETH_P_NMRP);
 348
 349         tx.msg.reserved = 0;
 350         tx.msg.code = NMRP_C_ADVERTISE;
 351         tx.msg.id = 0;
 352         tx.msg.num_opts = 1;
 353         tx.msg.opts[0].type = NMRP_O_MAGIC_NO;
 354         tx.msg.opts[0].len = NMRP_OPT_LEN + 4;
 355         tx.msg.opts[0].val.magic[0] = 'N';
 356         tx.msg.opts[0].val.magic[1] = 'T';
 357         tx.msg.opts[0].val.magic[2] = 'G';
 358         tx.msg.opts[0].val.magic[3] = 'R';
 359
 360         msg_update_len(&tx.msg);
 361         msg_hton(&tx.msg);
 362
 363         i = 0;
 364         beg = time(NULL);
 365
 366         while (1) {
 367                 printf("\rAdvertising NMRP server on interface ... %c",
 368                                 spinner[i]);
 369                 fflush(stdout);
 370                 i = (i + 1) & 3;
 371
 372                 if (pkt_send(sock, &tx) < 0) {
 373                         perror("sendto");
 374                         goto out;
 375                 }
 376
 377                 err = pkt_recv(sock, &rx);
 378                 if (err == 0 && memcmp(rx.eh.ether_dhost, src, 6) == 0) {
 379                         break;
 380                 } else if (err == 1) {
 381                         printf("ERR\n");
 382                         goto out;
 383                 } else {
 384                         if ((time(NULL) - beg) >= 60) {
 385                                 printf("\nNo response after 60 seconds. Bailing out.\n");
 386                                 goto out;
 387                         }
 388                 }
 389         }
 390
 391         printf("\n");
 392
 393         expect = NMRP_C_CONF_REQ;
 394         ulreqs = 0;
 395
 396         do {
 397                 if (expect != NMRP_C_NONE && rx.msg.code != expect) {
 398                         fprintf(stderr, "Received code 0x%02x while waiting for 0x%02x!\n",
 399                                         rx.msg.code, expect);
 400                 }
 401
 402                 tx.msg.code = NMRP_C_NONE;
 403                 tx.msg.reserved = 0;
 404                 tx.msg.id = 0;
 405                 tx.msg.num_opts = 0;
 406                 tx.msg.len = 0;
 407
 408                 err = 1;
 409
 410                 switch (rx.msg.code) {
 411                         case NMRP_C_ADVERTISE:
 412                                 printf("Received NMRP advertisement from %s.\n",
 413                                                 mac_to_str(rx.eh.ether_shost));
 414                                 err = 1;
 415                                 goto out;
 416                         case NMRP_C_CONF_REQ:
 417                                 tx.msg.code = NMRP_C_CONF_ACK;
 418                                 tx.msg.num_opts = 2;
 419
 420                                 tx.msg.opts[0].type = NMRP_O_DEV_IP;
 421                                 tx.msg.opts[0].len = NMRP_OPT_LEN + 2 * 4;
 422
 423                                 memcpy(tx.msg.opts[0].val.ip.addr, &ipaddr, 4);
 424                                 memcpy(tx.msg.opts[0].val.ip.mask, &ipmask, 4);
 425
 426                                 tx.msg.opts[1].type = NMRP_O_FW_UP;
 427                                 tx.msg.opts[1].len = NMRP_OPT_LEN;
 428
 429                                 expect = NMRP_C_TFTP_UL_REQ;
 430
 431                                 printf("Received configuration request from %s.\n",
 432                                                 mac_to_str(rx.eh.ether_shost));
 433
 434                                 memcpy(tx.eh.ether_dhost, rx.eh.ether_shost, 6);
 435
 436                                 printf("Sending configuration: ip %s, mask %s.\n",
 437                                                 args->ipaddr, args->ipmask);
 438
 439                                 break;
 440                         case NMRP_C_TFTP_UL_REQ:
 441                                 if (++ulreqs > 5) {
 442                                         fprintf(stderr, "Device re-requested file upload %d "
 443                                                         "times; aborting.\n", ulreqs);
 444                                         tx.msg.code = NMRP_C_CLOSE_REQ;
 445                                         break;
 446                                 }
 447
 448                                 len = 0;
 449                                 filename = msg_opt_data(&rx.msg, NMRP_O_FILE_NAME, &len);
 450                                 if (filename) {
 451                                         if (!args->file_remote) {
 452                                                 args->file_remote = filename;
 453                                         }
 454                                         printf("Received upload request: filename '%.*s'.\n",
 455                                                         len, filename);
 456                                 } else if (!args->file_remote) {
 457                                         if (tftp_is_valid_filename(args->file_local)) {
 458                                                 args->file_remote = args->file_local;
 459                                         } else {
 460                                                 args->file_remote = "firmware";
 461                                         }
 462                                         printf("Received upload request with empty filename.");
 463                                 }
 464
 465                                 err = 0;
 466
 467                                 if (args->tftpcmd) {
 468                                         printf("Executing '%s' ... ", args->tftpcmd);
 469                                         fflush(stdout);
 470                                         err = system(args->tftpcmd);
 471                                         if (!err) {
 472                                                 printf("OK\n");
 473                                         } else {
 474                                                 printf("ERR\n");
 475                                         }
 476                                 }
 477
 478                                 if (!err && args->file_local) {
 479                                         if (verbosity) {
 480                                                 printf("Using remote filename '%s'.\n",
 481                                                                 args->file_remote);
 482                                         }
 483
 484                                         if (!strcmp(args->file_local, "-")) {
 485                                                 printf("Uploading from stdin ... ");
 486                                         } else {
 487                                                 printf("Uploading %s ... ", args->file_local);
 488                                         }
 489                                         fflush(stdout);
 490                                         err = tftp_put(args);
 491                                 }
 492
 493                                 if (!err) {
 494                                         printf("OK\nWaiting for remote to respond.\n");
 495                                         ethsock_set_timeout(sock, args->ul_timeout);
 496                                         expect = NMRP_C_CLOSE_REQ;
 497                                 } else if (err == -2) {
 498                                         expect = NMRP_C_TFTP_UL_REQ;
 499                                 } else {
 500                                         goto out;
 501                                 }
 502
 503                                 break;
 504                         case NMRP_C_KEEP_ALIVE_REQ:
 505                                 tx.msg.code = NMRP_C_KEEP_ALIVE_ACK;
 506                                 break;
 507                         case NMRP_C_CLOSE_REQ:
 508                                 tx.msg.code = NMRP_C_CLOSE_ACK;
 509                                 break;
 510                         case NMRP_C_CLOSE_ACK:
 511                                 err = 0;
 512                                 goto out;
 513                         default:
 514                                 fprintf(stderr, "Unknown message code 0x%02x!\n",
 515                                                 rx.msg.code);
 516                                 msg_dump(&rx.msg, 0);
 517                 }
 518
 519                 if (tx.msg.code != NMRP_C_NONE) {
 520                         msg_update_len(&tx.msg);
 521                         msg_hton(&tx.msg);
 522
 523                         if (pkt_send(sock, &tx) < 0) {
 524                                 perror("sendto");
 525                                 goto out;
 526                         }
 527                 }
 528
 529                 if (rx.msg.code == NMRP_C_CLOSE_REQ) {
 530                         printf("Remote finished. Closing connection.\n");
 531                         break;
 532                 }
 533
 534                 err = pkt_recv(sock, &rx);
 535                 if (err) {
 536                         if (err == 2) {
 537                                 fprintf(stderr, "Timeout while waiting for 0x%02x.\n", expect);
 538                         }
 539                         goto out;
 540                 }
 541
 542                 ethsock_set_timeout(sock, args->rx_timeout);
 543
 544         } while (1);
 545
 546         err = 0;
 547
 548         printf("Reboot your device now.\n");
 549
 550 out:
 551         signal(SIGINT, sigh_orig);
 552         gsock = NULL;
 553         ethsock_close(sock);
 554         return err;
 555 }