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[oweals/nmrpflash.git] / nmrp.c
1 /**
2  * nmrpflash - Netgear Unbrick Utility
3  * Copyright (C) 2016 Joseph Lehner <joseph.c.lehner@gmail.com>
4  *
5  * nmrpflash is free software: you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation, either version 3 of the License, or
8  * (at your option) any later version.
9  *
10  * nmrpflash is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with nmrpflash.  If not, see <http://www.gnu.org/licenses/>.
17  *
18  */
19
20 #include <signal.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <unistd.h>
24 #include <errno.h>
25 #include <stdio.h>
26 #include <time.h>
27 #include "nmrpd.h"
28
29 #define NMRP_HDR_LEN 6
30 #define NMRP_OPT_HDR_LEN 4
31 #define NMRP_MIN_PKT_LEN (sizeof(struct eth_hdr) +  NMRP_HDR_LEN)
32
33 #define NMRP_MAX_OPT_SIZE 12
34 #define NMRP_MAX_OPT_NUM 3
35
36 #define NMRP_OPT_NEXT(x) ((struct nmrp_opt*)(((char*)x) + x->len))
37
38 #define ETH_P_NMRP 0x0912
39 #define IP_LEN 4
40 #define MAX_LOOP_RECV 1024
41
42 #ifndef PACKED
43 #define PACKED __attribute__((__packed__))
44 #endif
45
46 enum nmrp_code {
47         NMRP_C_NONE = 0,
48         NMRP_C_ADVERTISE = 1,
49         NMRP_C_CONF_REQ = 2,
50         NMRP_C_CONF_ACK = 3,
51         NMRP_C_CLOSE_REQ = 4,
52         NMRP_C_CLOSE_ACK = 5,
53         NMRP_C_KEEP_ALIVE_REQ = 6,
54         NMRP_C_KEEP_ALIVE_ACK = 7,
55         NMRP_C_TFTP_UL_REQ = 16
56 };
57
58 enum nmrp_opt_type {
59         NMRP_O_MAGIC_NO = 0x0001,
60         NMRP_O_DEV_IP = 0x0002,
61         NMRP_O_DEV_REGION = 0x0004,
62         NMRP_O_FW_UP = 0x0101,
63         NMRP_O_ST_UP = 0x0102,
64         NMRP_O_FILE_NAME = 0x0181
65 };
66
67 struct nmrp_opt {
68         uint16_t type;
69         uint16_t len;
70         union {
71                 uint8_t magic[4];
72                 uint16_t region;
73                 struct {
74                         uint8_t addr[4];
75                         uint8_t mask[4];
76                 } ip;
77         } val;
78 } PACKED;
79
80 struct nmrp_msg {
81         uint16_t reserved;
82         uint8_t code;
83         uint8_t id;
84         uint16_t len;
85         /* only opts[0] is valid! think of this as a char* */
86         struct nmrp_opt opts[NMRP_MAX_OPT_NUM];
87         /* this is NOT part of the transmitted packet */
88         uint32_t num_opts;
89 } PACKED;
90
91 struct eth_hdr {
92         uint8_t ether_dhost[6];
93         uint8_t ether_shost[6];
94         uint16_t ether_type;
95 } PACKED;
96
97 struct nmrp_pkt {
98         struct eth_hdr eh;
99         struct nmrp_msg msg;
100 } PACKED;
101
102 static const char *msg_code_str(uint16_t code)
103 {
104 #define CASE_CODE(x) case NMRP_C_ ## x: return #x
105         static char buf[16];
106
107         switch (code) {
108                 CASE_CODE(ADVERTISE);
109                 CASE_CODE(CONF_REQ);
110                 CASE_CODE(CONF_ACK);
111                 CASE_CODE(CLOSE_REQ);
112                 CASE_CODE(CLOSE_ACK);
113                 CASE_CODE(KEEP_ALIVE_REQ);
114                 CASE_CODE(KEEP_ALIVE_ACK);
115                 CASE_CODE(TFTP_UL_REQ);
116                 default:
117                         snprintf(buf, sizeof(buf), "%04x", code);
118                         return buf;
119         }
120 #undef CASE_CODE
121 }
122
123 static uint16_t to_region_code(const char *region)
124 {
125 #define REGION_CODE(r, c) if (!strcasecmp(region, r)) return c
126         REGION_CODE("NA", 0x0001);
127         REGION_CODE("WW", 0x0002);
128         REGION_CODE("GR", 0x0003);
129         REGION_CODE("PR", 0x0004);
130         REGION_CODE("RU", 0x0005);
131         REGION_CODE("BZ", 0x0006);
132         REGION_CODE("IN", 0x0007);
133         REGION_CODE("KO", 0x0008);
134         REGION_CODE("JP", 0x0009);
135 #undef REGION_CODE
136         return 0;
137 }
138
139 static void msg_dump(struct nmrp_msg *msg, int dump_opts)
140 {
141         struct nmrp_opt *opt;
142         int remain_len, len, i;
143
144         fprintf(stderr, "res=0x%04x, code=0x%02x, id=0x%02x, len=%u",
145                         msg->reserved, msg->code, msg->id, msg->len);
146
147         remain_len = msg->len - NMRP_HDR_LEN;
148         fprintf(stderr, "%s\n", remain_len ? "" : " (no opts)");
149
150         if (dump_opts) {
151                 opt = msg->opts;
152
153                 while (remain_len > 0) {
154                         len = opt->len;
155                         fprintf(stderr, "  opt type=%u, len=%u", opt->type, len);
156                         if (len) {
157                                 for (i = 0; i != len - NMRP_OPT_HDR_LEN; ++i) {
158                                         if (!(i % 16)) {
159                                                 fprintf(stderr, "\n  ");
160                                         }
161
162                                         fprintf(stderr, "%02x ", ((char*)&opt->val)[i] & 0xff);
163                                 }
164                                 fprintf(stderr, "\n");
165                         }
166                         remain_len -= len;
167                         opt = NMRP_OPT_NEXT(opt);
168                 }
169         }
170 }
171
172 static void msg_hton(struct nmrp_msg *msg)
173 {
174         uint32_t i = 0;
175         struct nmrp_opt *opt = msg->opts, *next;
176
177         msg->reserved = htons(msg->reserved);
178         msg->len = htons(msg->len);
179
180         for (; i != msg->num_opts; ++i) {
181                 next = NMRP_OPT_NEXT(opt);
182                 opt->len = htons(opt->len);
183                 opt->type = htons(opt->type);
184                 opt = next;
185         }
186 }
187
188 static void msg_hdr_ntoh(struct nmrp_msg *msg)
189 {
190         msg->reserved = ntohs(msg->reserved);
191         msg->len = ntohs(msg->len);
192 }
193
194 static int msg_ntoh(struct nmrp_msg *msg)
195 {
196         struct nmrp_opt *opt = msg->opts;
197         int remaining;
198
199         remaining = msg->len - NMRP_HDR_LEN;
200
201         // FIXME maximum of two options supported, maximum option
202         // size is 12
203         if (remaining < NMRP_MAX_OPT_NUM * NMRP_MAX_OPT_SIZE) {
204                 while (remaining > 0) {
205                         if (remaining < NMRP_OPT_HDR_LEN) {
206                                 break;
207                         }
208
209                         opt->type = ntohs(opt->type);
210                         opt->len = ntohs(opt->len);
211
212                         if (opt->len > NMRP_MAX_OPT_SIZE) {
213                                 break;
214                         }
215
216                         remaining -= opt->len;
217                         opt = NMRP_OPT_NEXT(opt);
218                 }
219
220                 if (!remaining) {
221                         return 0;
222                 }
223         }
224
225         fprintf(stderr, "Unexpected message format.\n");
226         msg_dump(msg, 0);
227         return 1;
228 }
229
230 static void *msg_opt_data(struct nmrp_msg *msg, uint16_t type, uint16_t *len)
231 {
232         static char buf[128];
233         struct nmrp_opt *opt = msg->opts;
234         int remaining = msg->len - NMRP_HDR_LEN;
235
236         memset(buf, 0, sizeof(buf));
237
238         while (remaining > 0) {
239                 if (opt->type == type) {
240                         if (opt->len == NMRP_OPT_HDR_LEN) {
241                                 return NULL;
242                         }
243                         *len = opt->len - NMRP_OPT_HDR_LEN;
244                         memcpy(buf, &opt->val, MIN(*len, sizeof(buf)-1));
245                         return buf;
246                 }
247
248                 remaining -= opt->len;
249                 opt = NMRP_OPT_NEXT(opt);
250         }
251
252         return NULL;
253 }
254
255 static void msg_opt_add(struct nmrp_msg *msg, uint16_t type, void *data,
256                 uint16_t len)
257 {
258         uint32_t i = 0;
259         struct nmrp_opt *opt = msg->opts;
260
261         if (len + NMRP_OPT_HDR_LEN > NMRP_MAX_OPT_SIZE
262                         || msg->num_opts == NMRP_MAX_OPT_NUM) {
263                 fprintf(stderr, "Invalid option - this is a bug.\n");
264         }
265
266         for (; i <= msg->num_opts; ++i) {
267                 opt = NMRP_OPT_NEXT(opt);
268         }
269
270         opt->len = NMRP_OPT_HDR_LEN + len;
271         opt->type = type;
272
273         if (len) {
274                 memcpy(&opt->val, data, len);
275         }
276
277         msg->len += opt->len;
278         ++msg->num_opts;
279 }
280
281 static inline void msg_init(struct nmrp_msg *msg, uint16_t code)
282 {
283         memset(msg, 0, sizeof(*msg));
284         msg->len = NMRP_HDR_LEN;
285         msg->code = code;
286 }
287
288 static int pkt_send(struct ethsock *sock, struct nmrp_pkt *pkt)
289 {
290         size_t len = ntohs(pkt->msg.len) + sizeof(pkt->eh);
291         return ethsock_send(sock, pkt, len);
292 }
293
294 static int pkt_recv(struct ethsock *sock, struct nmrp_pkt *pkt)
295 {
296         ssize_t bytes, len;
297
298         memset(pkt, 0, sizeof(*pkt));
299         bytes = ethsock_recv(sock, pkt, sizeof(*pkt));
300         if (bytes < 0) {
301                 return 1;
302         } else if (!bytes) {
303                 return 2;
304         } else if (bytes < NMRP_MIN_PKT_LEN) {
305                 fprintf(stderr, "Short packet (%d bytes)\n", (int)bytes);
306                 return 1;
307         }
308
309         msg_hdr_ntoh(&pkt->msg);
310         len = pkt->msg.len + sizeof(pkt->eh);
311
312         if (bytes < len) {
313                 fprintf(stderr, "Short packet (expected %d, got %d).\n",
314                                 (int)len, (int)bytes);
315                 return 1;
316         }
317
318         return msg_ntoh(&pkt->msg);
319 }
320
321 static int mac_parse(const char *str, uint8_t *hwaddr)
322 {
323         int i;
324         unsigned data[6];
325
326         sscanf(str, "%02x:%02x:%02x:%02x:%02x:%02x%n",
327                         data, data + 1, data + 2, data + 3, data + 4, data + 5, &i);
328
329         if (i == strlen(str)) {
330                 for (i = 0; i != 6; ++i) {
331                         if (data[i] > 255) {
332                                 break;
333                         }
334
335                         hwaddr[i] = data[i] & 0xff;
336                 }
337
338                 if (i == 6) {
339                         return 1;
340                 }
341         }
342         return 0;
343 }
344
345 struct is_valid_ip_arg
346 {
347         struct in_addr *ipaddr;
348         struct in_addr *ipmask;
349         int result;
350 };
351
352 static int is_valid_ip_cb(struct ethsock_ip_callback_args *args)
353 {
354 #define SUBNET(x) ((x)->ipaddr->s_addr & (x)->ipmask->s_addr)
355         struct is_valid_ip_arg *arg = args->arg;
356         if (SUBNET(args) == SUBNET(arg)) {
357                 arg->result = args->ipaddr->s_addr != arg->ipaddr->s_addr;
358                 return 0;
359         }
360
361         return 1;
362 #undef SUBNET
363 }
364
365 static int is_valid_ip(struct ethsock *sock, struct in_addr *ipaddr,
366                 struct in_addr *ipmask)
367 {
368         int status;
369         struct is_valid_ip_arg arg = {
370                 .ipaddr = ipaddr,
371                 .ipmask = ipmask,
372                 .result = 0
373         };
374
375         status = ethsock_for_each_ip(sock, is_valid_ip_cb, &arg);
376         return status < 0 ? status : arg.result;
377 }
378
379 static struct ethsock *gsock = NULL;
380 static int garp = 0;
381 static struct in_addr arpip = { 0 };
382 static uint8_t arpmac[6] = { 0 };
383
384 static void sigh(int sig)
385 {
386         printf("\n");
387         if (gsock) {
388                 if (garp) {
389                         ethsock_arp_del(gsock, arpmac, &arpip);
390                 }
391                 ethsock_close(gsock);
392                 gsock = NULL;
393         }
394
395         exit(1);
396 }
397
398 static const char *spinner = "\\|/-";
399
400 int nmrp_do(struct nmrpd_args *args)
401 {
402         struct nmrp_pkt tx, rx;
403         uint8_t *src, dest[6];
404         uint16_t len, region;
405         char *filename;
406         time_t beg;
407         int i, status, ulreqs, expect, upload_ok;
408         struct ethsock *sock;
409         void (*sigh_orig)(int);
410         struct {
411                 struct in_addr addr;
412                 struct in_addr mask;
413         } PACKED ipconf;
414
415         if (args->op != NMRP_UPLOAD_FW) {
416                 fprintf(stderr, "Operation not implemented.\n");
417                 return 1;
418         }
419
420         if (!mac_parse(args->mac, dest)) {
421                 fprintf(stderr, "Invalid MAC address '%s'.\n", args->mac);
422                 return 1;
423         }
424
425         if ((ipconf.addr.s_addr = inet_addr(args->ipaddr)) == INADDR_NONE) {
426                 fprintf(stderr, "Invalid IP address '%s'.\n", args->ipaddr);
427                 return 1;
428         }
429
430         if ((ipconf.mask.s_addr = inet_addr(args->ipmask)) == INADDR_NONE) {
431                 fprintf(stderr, "Invalid subnet mask '%s'.\n", args->ipmask);
432                 return 1;
433         }
434
435         if (args->file_local && strcmp(args->file_local, "-") && access(args->file_local, R_OK) == -1) {
436                 fprintf(stderr, "Error accessing file '%s'.\n", args->file_local);
437                 return 1;
438         }
439
440         if (args->file_remote) {
441                 if (!tftp_is_valid_filename(args->file_remote)) {
442                         fprintf(stderr, "Invalid remote filename '%s'.\n",
443                                         args->file_remote);
444                         return 1;
445                 }
446         }
447
448         if (args->region) {
449                 region = htons(to_region_code(args->region));
450                 if (!region) {
451                         fprintf(stderr, "Invalid region code '%s'.\n", args->region);
452                         return 1;
453                 }
454         } else {
455                 region = 0;
456         }
457
458         status = 1;
459
460         sock = ethsock_create(args->intf, ETH_P_NMRP);
461         if (!sock) {
462                 return 1;
463         }
464
465         status = is_valid_ip(sock, &ipaddr, &ipmask);
466         if (status <= 0) {
467                 if (!status) {
468                         fprintf(stderr, "Address %s/%s cannot be used on interface %s.\n",
469                                         args->ipaddr, args->ipmask, args->intf);
470                 }
471                 goto out;
472         }
473
474         gsock = sock;
475         garp = 0;
476         sigh_orig = signal(SIGINT, sigh);
477
478         if (ethsock_set_timeout(sock, args->rx_timeout)) {
479                 goto out;
480         }
481
482         src = ethsock_get_hwaddr(sock);
483         if (!src) {
484                 goto out;
485         }
486
487         memcpy(tx.eh.ether_shost, src, 6);
488         memcpy(tx.eh.ether_dhost, dest, 6);
489         tx.eh.ether_type = htons(ETH_P_NMRP);
490
491         msg_init(&tx.msg, NMRP_C_ADVERTISE);
492         msg_opt_add(&tx.msg, NMRP_O_MAGIC_NO, "NTGR", 4);
493         msg_hton(&tx.msg);
494
495         i = 0;
496         upload_ok = 0;
497         beg = time(NULL);
498
499         while (1) {
500                 printf("\rAdvertising NMRP server on %s ... %c",
501                                 args->intf, spinner[i]);
502                 fflush(stdout);
503                 i = (i + 1) & 3;
504
505                 if (pkt_send(sock, &tx) < 0) {
506                         perror("sendto");
507                         goto out;
508                 }
509
510                 status = pkt_recv(sock, &rx);
511                 if (status == 0 && memcmp(rx.eh.ether_dhost, src, 6) == 0) {
512                         break;
513                 } else if (status == 1) {
514                         printf("ERR\n");
515                         goto out;
516                 } else {
517                         if ((time(NULL) - beg) >= 60) {
518                                 printf("\nNo response after 60 seconds. Bailing out.\n");
519                                 goto out;
520                         }
521                 }
522         }
523
524         printf("\n");
525
526         expect = NMRP_C_CONF_REQ;
527         ulreqs = 0;
528
529         do {
530                 if (expect != NMRP_C_NONE && rx.msg.code != expect) {
531                         fprintf(stderr, "Received %s while waiting for %s!\n",
532                                         msg_code_str(rx.msg.code), msg_code_str(expect));
533                 }
534
535                 msg_init(&tx.msg, NMRP_C_NONE);
536
537                 status = 1;
538
539                 switch (rx.msg.code) {
540                         case NMRP_C_ADVERTISE:
541                                 printf("Received NMRP advertisement from %s.\n",
542                                                 mac_to_str(rx.eh.ether_shost));
543                                 status = 1;
544                                 goto out;
545                         case NMRP_C_CONF_REQ:
546                                 tx.msg.code = NMRP_C_CONF_ACK;
547
548                                 msg_opt_add(&tx.msg, NMRP_O_DEV_IP, &ipconf, 8);
549                                 msg_opt_add(&tx.msg, NMRP_O_FW_UP, NULL, 0);
550
551 #ifdef NMRPFLASH_SET_REGION
552                                 if (region) {
553                                         msg_opt_add(&tx.msg, NMRP_O_DEV_REGION, &region, 2);
554                                 }
555 #endif
556
557                                 expect = NMRP_C_TFTP_UL_REQ;
558
559                                 printf("Received configuration request from %s.\n",
560                                                 mac_to_str(rx.eh.ether_shost));
561
562                                 memcpy(tx.eh.ether_dhost, rx.eh.ether_shost, 6);
563
564                                 printf("Sending configuration: ip %s, mask %s.\n",
565                                                 args->ipaddr, args->ipmask);
566
567                                 memcpy(arpmac, rx.eh.ether_shost, 6);
568                                 memcpy(&arpip, &ipconf.addr, sizeof(ipconf.addr));
569
570                                 if (ethsock_arp_add(sock, arpmac, &arpip) != 0) {
571                                         goto out;
572                                 }
573
574                                 garp = 1;
575
576                                 break;
577                         case NMRP_C_TFTP_UL_REQ:
578                                 if (!upload_ok) {
579                                         if (++ulreqs > 5) {
580                                                 printf("Bailing out after %d upload requests.\n",
581                                                                 ulreqs);
582                                                 tx.msg.code = NMRP_C_CLOSE_REQ;
583                                                 break;
584                                         }
585                                 } else {
586                                         if (verbosity) {
587                                                 printf("Ignoring extra upload request.\n");
588                                         }
589                                         ethsock_set_timeout(sock, args->ul_timeout);
590                                         tx.msg.code = NMRP_C_KEEP_ALIVE_REQ;
591                                         break;
592                                 }
593
594                                 len = 0;
595                                 filename = msg_opt_data(&rx.msg, NMRP_O_FILE_NAME, &len);
596                                 if (filename) {
597                                         if (!args->file_remote) {
598                                                 args->file_remote = filename;
599                                         }
600                                         printf("Received upload request: filename '%.*s'.\n",
601                                                         len, filename);
602                                 } else if (!args->file_remote) {
603                                         args->file_remote = args->file_local;
604                                         printf("Received upload request with empty filename.\n");
605                                 }
606
607                                 status = 0;
608
609                                 if (args->tftpcmd) {
610                                         printf("Executing '%s' ... ", args->tftpcmd);
611                                         fflush(stdout);
612                                         status = system(args->tftpcmd);
613                                         if (!status) {
614                                                 printf("OK\n");
615                                         } else {
616                                                 printf("ERR\n");
617                                         }
618                                 }
619
620                                 if (!status && args->file_local) {
621                                         status = is_valid_ip(sock, &ipconf.addr, &ipconf.mask);
622                                         if (status < 0) {
623                                                 goto out;
624                                         } else if (!status) {
625                                                 printf("IP address of %s has changed. Please assign a "
626                                                                 "static ip to the interface.\n", args->intf);
627                                                 tx.msg.code = NMRP_C_CLOSE_REQ;
628                                                 break;
629                                         }
630
631                                         if (verbosity) {
632                                                 printf("Using remote filename '%s'.\n",
633                                                                 args->file_remote);
634                                         }
635
636                                         if (!strcmp(args->file_local, "-")) {
637                                                 printf("Uploading from stdin ... ");
638                                         } else {
639                                                 printf("Uploading %s ... ", leafname(args->file_local));
640                                         }
641                                         fflush(stdout);
642                                         status = tftp_put(args);
643                                 }
644
645                                 if (!status) {
646                                         printf("OK\nWaiting for remote to respond.\n");
647                                         upload_ok = 1;
648                                         ethsock_set_timeout(sock, args->ul_timeout);
649                                         tx.msg.code = NMRP_C_KEEP_ALIVE_REQ;
650                                         expect = NMRP_C_NONE;
651                                 } else if (status == -2) {
652                                         expect = NMRP_C_TFTP_UL_REQ;
653                                 } else {
654                                         goto out;
655                                 }
656
657                                 break;
658                         case NMRP_C_KEEP_ALIVE_REQ:
659                                 tx.msg.code = NMRP_C_KEEP_ALIVE_ACK;
660                                 ethsock_set_timeout(sock, 15000);
661                                 printf("Received keep-alive request.\n");
662                                 break;
663                         case NMRP_C_CLOSE_REQ:
664                                 tx.msg.code = NMRP_C_CLOSE_ACK;
665                                 break;
666                         case NMRP_C_CLOSE_ACK:
667                                 status = 0;
668                                 goto out;
669                         default:
670                                 fprintf(stderr, "Unknown message code 0x%02x!\n",
671                                                 rx.msg.code);
672                                 msg_dump(&rx.msg, 0);
673                 }
674
675                 if (tx.msg.code != NMRP_C_NONE) {
676                         msg_hton(&tx.msg);
677
678                         if (pkt_send(sock, &tx) < 0) {
679                                 perror("sendto");
680                                 goto out;
681                         }
682
683                         if (tx.msg.code == NMRP_C_CLOSE_REQ) {
684                                 goto out;
685                         }
686                 }
687
688                 if (rx.msg.code == NMRP_C_CLOSE_REQ) {
689                         printf("Remote finished. Closing connection.\n");
690                         break;
691                 }
692
693                 status = pkt_recv(sock, &rx);
694                 if (status) {
695                         if (status == 2) {
696                                 fprintf(stderr, "Timeout while waiting for %s.\n",
697                                                 msg_code_str(expect));
698                         }
699                         goto out;
700                 }
701
702                 ethsock_set_timeout(sock, args->rx_timeout);
703
704         } while (1);
705
706         status = 0;
707
708         if (ulreqs) {
709                 printf("Reboot your device now.\n");
710         } else {
711                 printf("No upload request received.\n");
712         }
713
714 out:
715         signal(SIGINT, sigh_orig);
716         gsock = NULL;
717         ethsock_arp_del(sock, arpmac, &arpip);
718         ethsock_close(sock);
719         return status;
720 }