1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 2020 - 2022, Daniel Stenberg, <[email protected]>, et al.
9 * Copyright (C) 2019, Björn Stenberg, <[email protected]>
10 *
11 * This software is licensed as described in the file COPYING, which
12 * you should have received as part of this distribution. The terms
13 * are also available at https://curl.se/docs/copyright.html.
14 *
15 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
16 * copies of the Software, and permit persons to whom the Software is
17 * furnished to do so, under the terms of the COPYING file.
18 *
19 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
20 * KIND, either express or implied.
21 *
22 * SPDX-License-Identifier: curl
23 *
24 ***************************************************************************/
25
26#include "curl_setup.h"
27
28#ifndef CURL_DISABLE_MQTT
29
30#include "urldata.h"
31#include <curl/curl.h>
32#include "transfer.h"
33#include "sendf.h"
34#include "progress.h"
35#include "mqtt.h"
36#include "select.h"
37#include "strdup.h"
38#include "url.h"
39#include "escape.h"
40#include "warnless.h"
41#include "curl_printf.h"
42#include "curl_memory.h"
43#include "multiif.h"
44#include "rand.h"
45
46/* The last #include file should be: */
47#include "memdebug.h"
48
49#define MQTT_MSG_CONNECT 0x10
50#define MQTT_MSG_CONNACK 0x20
51#define MQTT_MSG_PUBLISH 0x30
52#define MQTT_MSG_SUBSCRIBE 0x82
53#define MQTT_MSG_SUBACK 0x90
54#define MQTT_MSG_DISCONNECT 0xe0
55
56#define MQTT_CONNACK_LEN 2
57#define MQTT_SUBACK_LEN 3
58#define MQTT_CLIENTID_LEN 12 /* "curl0123abcd" */
59
60/*
61 * Forward declarations.
62 */
63
64static CURLcode mqtt_do(struct Curl_easy *data, bool *done);
65static CURLcode mqtt_done(struct Curl_easy *data,
66 CURLcode status, bool premature);
67static CURLcode mqtt_doing(struct Curl_easy *data, bool *done);
68static int mqtt_getsock(struct Curl_easy *data, struct connectdata *conn,
69 curl_socket_t *sock);
70static CURLcode mqtt_setup_conn(struct Curl_easy *data,
71 struct connectdata *conn);
72
73/*
74 * MQTT protocol handler.
75 */
76
77const struct Curl_handler Curl_handler_mqtt = {
78 "MQTT", /* scheme */
79 mqtt_setup_conn, /* setup_connection */
80 mqtt_do, /* do_it */
81 mqtt_done, /* done */
82 ZERO_NULL, /* do_more */
83 ZERO_NULL, /* connect_it */
84 ZERO_NULL, /* connecting */
85 mqtt_doing, /* doing */
86 ZERO_NULL, /* proto_getsock */
87 mqtt_getsock, /* doing_getsock */
88 ZERO_NULL, /* domore_getsock */
89 ZERO_NULL, /* perform_getsock */
90 ZERO_NULL, /* disconnect */
91 ZERO_NULL, /* readwrite */
92 ZERO_NULL, /* connection_check */
93 ZERO_NULL, /* attach connection */
94 PORT_MQTT, /* defport */
95 CURLPROTO_MQTT, /* protocol */
96 CURLPROTO_MQTT, /* family */
97 PROTOPT_NONE /* flags */
98};
99
100static CURLcode mqtt_setup_conn(struct Curl_easy *data,
101 struct connectdata *conn)
102{
103 /* allocate the HTTP-specific struct for the Curl_easy, only to survive
104 during this request */
105 struct MQTT *mq;
106 (void)conn;
107 DEBUGASSERT(data->req.p.mqtt == NULL);
108
109 mq = calloc(1, sizeof(struct MQTT));
110 if(!mq)
111 return CURLE_OUT_OF_MEMORY;
112 data->req.p.mqtt = mq;
113 return CURLE_OK;
114}
115
116static CURLcode mqtt_send(struct Curl_easy *data,
117 char *buf, size_t len)
118{
119 CURLcode result = CURLE_OK;
120 struct connectdata *conn = data->conn;
121 curl_socket_t sockfd = conn->sock[FIRSTSOCKET];
122 struct MQTT *mq = data->req.p.mqtt;
123 ssize_t n;
124 result = Curl_write(data, sockfd, buf, len, &n);
125 if(!result)
126 Curl_debug(data, CURLINFO_HEADER_OUT, buf, (size_t)n);
127 if(len != (size_t)n) {
128 size_t nsend = len - n;
129 char *sendleftovers = Curl_memdup(&buf[n], nsend);
130 if(!sendleftovers)
131 return CURLE_OUT_OF_MEMORY;
132 mq->sendleftovers = sendleftovers;
133 mq->nsend = nsend;
134 }
135 else {
136 mq->sendleftovers = NULL;
137 mq->nsend = 0;
138 }
139 return result;
140}
141
142/* Generic function called by the multi interface to figure out what socket(s)
143 to wait for and for what actions during the DOING and PROTOCONNECT
144 states */
145static int mqtt_getsock(struct Curl_easy *data,
146 struct connectdata *conn,
147 curl_socket_t *sock)
148{
149 (void)data;
150 sock[0] = conn->sock[FIRSTSOCKET];
151 return GETSOCK_READSOCK(FIRSTSOCKET);
152}
153
154static int mqtt_encode_len(char *buf, size_t len)
155{
156 unsigned char encoded;
157 int i;
158
159 for(i = 0; (len > 0) && (i<4); i++) {
160 encoded = len % 0x80;
161 len /= 0x80;
162 if(len)
163 encoded |= 0x80;
164 buf[i] = encoded;
165 }
166
167 return i;
168}
169
170/* add the passwd to the CONNECT packet */
171static int add_passwd(const char *passwd, const size_t plen,
172 char *pkt, const size_t start, int remain_pos)
173{
174 /* magic number that need to be set properly */
175 const size_t conn_flags_pos = remain_pos + 8;
176 if(plen > 0xffff)
177 return 1;
178
179 /* set password flag */
180 pkt[conn_flags_pos] |= 0x40;
181
182 /* length of password provided */
183 pkt[start] = (char)((plen >> 8) & 0xFF);
184 pkt[start + 1] = (char)(plen & 0xFF);
185 memcpy(&pkt[start + 2], passwd, plen);
186 return 0;
187}
188
189/* add user to the CONN packet */
190static int add_user(const char *username, const size_t ulen,
191 unsigned char *pkt, const size_t start, int remain_pos)
192{
193 /* magic number that need to be set properly */
194 const size_t conn_flags_pos = remain_pos + 8;
195 if(ulen > 0xffff)
196 return 1;
197
198 /* set username flag */
199 pkt[conn_flags_pos] |= 0x80;
200 /* length of username provided */
201 pkt[start] = (unsigned char)((ulen >> 8) & 0xFF);
202 pkt[start + 1] = (unsigned char)(ulen & 0xFF);
203 memcpy(&pkt[start + 2], username, ulen);
204 return 0;
205}
206
207/* add client ID to the CONN packet */
208static int add_client_id(const char *client_id, const size_t client_id_len,
209 char *pkt, const size_t start)
210{
211 if(client_id_len != MQTT_CLIENTID_LEN)
212 return 1;
213 pkt[start] = 0x00;
214 pkt[start + 1] = MQTT_CLIENTID_LEN;
215 memcpy(&pkt[start + 2], client_id, MQTT_CLIENTID_LEN);
216 return 0;
217}
218
219/* Set initial values of CONN packet */
220static int init_connpack(char *packet, char *remain, int remain_pos)
221{
222 /* Fixed header starts */
223 /* packet type */
224 packet[0] = MQTT_MSG_CONNECT;
225 /* remaining length field */
226 memcpy(&packet[1], remain, remain_pos);
227 /* Fixed header ends */
228
229 /* Variable header starts */
230 /* protocol length */
231 packet[remain_pos + 1] = 0x00;
232 packet[remain_pos + 2] = 0x04;
233 /* protocol name */
234 packet[remain_pos + 3] = 'M';
235 packet[remain_pos + 4] = 'Q';
236 packet[remain_pos + 5] = 'T';
237 packet[remain_pos + 6] = 'T';
238 /* protocol level */
239 packet[remain_pos + 7] = 0x04;
240 /* CONNECT flag: CleanSession */
241 packet[remain_pos + 8] = 0x02;
242 /* keep-alive 0 = disabled */
243 packet[remain_pos + 9] = 0x00;
244 packet[remain_pos + 10] = 0x3c;
245 /*end of variable header*/
246 return remain_pos + 10;
247}
248
249static CURLcode mqtt_connect(struct Curl_easy *data)
250{
251 CURLcode result = CURLE_OK;
252 int pos = 0;
253 int rc = 0;
254 /*remain length*/
255 int remain_pos = 0;
256 char remain[4] = {0};
257 size_t packetlen = 0;
258 size_t payloadlen = 0;
259 size_t start_user = 0;
260 size_t start_pwd = 0;
261 char client_id[MQTT_CLIENTID_LEN + 1] = "curl";
262 const size_t clen = strlen("curl");
263 char *packet = NULL;
264
265 /* extracting username from request */
266 const char *username = data->state.aptr.user ?
267 data->state.aptr.user : "";
268 const size_t ulen = strlen(username);
269 /* extracting password from request */
270 const char *passwd = data->state.aptr.passwd ?
271 data->state.aptr.passwd : "";
272 const size_t plen = strlen(passwd);
273
274 payloadlen = ulen + plen + MQTT_CLIENTID_LEN + 2;
275 /* The plus 2 are for the MSB and LSB describing the length of the string to
276 * be added on the payload. Refer to spec 1.5.2 and 1.5.4 */
277 if(ulen)
278 payloadlen += 2;
279 if(plen)
280 payloadlen += 2;
281
282 /* getting how much occupy the remain length */
283 remain_pos = mqtt_encode_len(remain, payloadlen + 10);
284
285 /* 10 length of variable header and 1 the first byte of the fixed header */
286 packetlen = payloadlen + 10 + remain_pos + 1;
287
288 /* allocating packet */
289 if(packetlen > 268435455)
290 return CURLE_WEIRD_SERVER_REPLY;
291 packet = malloc(packetlen);
292 if(!packet)
293 return CURLE_OUT_OF_MEMORY;
294 memset(packet, 0, packetlen);
295
296 /* set initial values for CONN pack */
297 pos = init_connpack(packet, remain, remain_pos);
298
299 result = Curl_rand_hex(data, (unsigned char *)&client_id[clen],
300 MQTT_CLIENTID_LEN - clen + 1);
301 /* add client id */
302 rc = add_client_id(client_id, strlen(client_id), packet, pos + 1);
303 if(rc) {
304 failf(data, "Client ID length mismatched: [%lu]", strlen(client_id));
305 result = CURLE_WEIRD_SERVER_REPLY;
306 goto end;
307 }
308 infof(data, "Using client id '%s'", client_id);
309
310 /* position where starts the user payload */
311 start_user = pos + 3 + MQTT_CLIENTID_LEN;
312 /* position where starts the password payload */
313 start_pwd = start_user + ulen;
314 /* if user name was provided, add it to the packet */
315 if(ulen) {
316 start_pwd += 2;
317
318 rc = add_user(username, ulen,
319 (unsigned char *)packet, start_user, remain_pos);
320 if(rc) {
321 failf(data, "Username is too large: [%lu]", ulen);
322 result = CURLE_WEIRD_SERVER_REPLY;
323 goto end;
324 }
325 }
326
327 /* if passwd was provided, add it to the packet */
328 if(plen) {
329 rc = add_passwd(passwd, plen, packet, start_pwd, remain_pos);
330 if(rc) {
331 failf(data, "Password is too large: [%lu]", plen);
332 result = CURLE_WEIRD_SERVER_REPLY;
333 goto end;
334 }
335 }
336
337 if(!result)
338 result = mqtt_send(data, packet, packetlen);
339
340end:
341 if(packet)
342 free(packet);
343 Curl_safefree(data->state.aptr.user);
344 Curl_safefree(data->state.aptr.passwd);
345 return result;
346}
347
348static CURLcode mqtt_disconnect(struct Curl_easy *data)
349{
350 CURLcode result = CURLE_OK;
351 struct MQTT *mq = data->req.p.mqtt;
352 result = mqtt_send(data, (char *)"\xe0\x00", 2);
353 Curl_safefree(mq->sendleftovers);
354 return result;
355}
356
357static CURLcode mqtt_verify_connack(struct Curl_easy *data)
358{
359 CURLcode result;
360 struct connectdata *conn = data->conn;
361 curl_socket_t sockfd = conn->sock[FIRSTSOCKET];
362 unsigned char readbuf[MQTT_CONNACK_LEN];
363 ssize_t nread;
364
365 result = Curl_read(data, sockfd, (char *)readbuf, MQTT_CONNACK_LEN, &nread);
366 if(result)
367 goto fail;
368
369 Curl_debug(data, CURLINFO_HEADER_IN, (char *)readbuf, (size_t)nread);
370
371 /* fixme */
372 if(nread < MQTT_CONNACK_LEN) {
373 result = CURLE_WEIRD_SERVER_REPLY;
374 goto fail;
375 }
376
377 /* verify CONNACK */
378 if(readbuf[0] != 0x00 || readbuf[1] != 0x00) {
379 failf(data, "Expected %02x%02x but got %02x%02x",
380 0x00, 0x00, readbuf[0], readbuf[1]);
381 result = CURLE_WEIRD_SERVER_REPLY;
382 }
383
384fail:
385 return result;
386}
387
388static CURLcode mqtt_get_topic(struct Curl_easy *data,
389 char **topic, size_t *topiclen)
390{
391 char *path = data->state.up.path;
392 if(strlen(path) > 1)
393 return Curl_urldecode(path + 1, 0, topic, topiclen, REJECT_NADA);
394 failf(data, "No MQTT topic found. Forgot to URL encode it?");
395 return CURLE_URL_MALFORMAT;
396}
397
398static CURLcode mqtt_subscribe(struct Curl_easy *data)
399{
400 CURLcode result = CURLE_OK;
401 char *topic = NULL;
402 size_t topiclen;
403 unsigned char *packet = NULL;
404 size_t packetlen;
405 char encodedsize[4];
406 size_t n;
407 struct connectdata *conn = data->conn;
408
409 result = mqtt_get_topic(data, &topic, &topiclen);
410 if(result)
411 goto fail;
412
413 conn->proto.mqtt.packetid++;
414
415 packetlen = topiclen + 5; /* packetid + topic (has a two byte length field)
416 + 2 bytes topic length + QoS byte */
417 n = mqtt_encode_len((char *)encodedsize, packetlen);
418 packetlen += n + 1; /* add one for the control packet type byte */
419
420 packet = malloc(packetlen);
421 if(!packet) {
422 result = CURLE_OUT_OF_MEMORY;
423 goto fail;
424 }
425
426 packet[0] = MQTT_MSG_SUBSCRIBE;
427 memcpy(&packet[1], encodedsize, n);
428 packet[1 + n] = (conn->proto.mqtt.packetid >> 8) & 0xff;
429 packet[2 + n] = conn->proto.mqtt.packetid & 0xff;
430 packet[3 + n] = (topiclen >> 8) & 0xff;
431 packet[4 + n ] = topiclen & 0xff;
432 memcpy(&packet[5 + n], topic, topiclen);
433 packet[5 + n + topiclen] = 0; /* QoS zero */
434
435 result = mqtt_send(data, (char *)packet, packetlen);
436
437fail:
438 free(topic);
439 free(packet);
440 return result;
441}
442
443/*
444 * Called when the first byte was already read.
445 */
446static CURLcode mqtt_verify_suback(struct Curl_easy *data)
447{
448 CURLcode result;
449 struct connectdata *conn = data->conn;
450 curl_socket_t sockfd = conn->sock[FIRSTSOCKET];
451 unsigned char readbuf[MQTT_SUBACK_LEN];
452 ssize_t nread;
453 struct mqtt_conn *mqtt = &conn->proto.mqtt;
454
455 result = Curl_read(data, sockfd, (char *)readbuf, MQTT_SUBACK_LEN, &nread);
456 if(result)
457 goto fail;
458
459 Curl_debug(data, CURLINFO_HEADER_IN, (char *)readbuf, (size_t)nread);
460
461 /* fixme */
462 if(nread < MQTT_SUBACK_LEN) {
463 result = CURLE_WEIRD_SERVER_REPLY;
464 goto fail;
465 }
466
467 /* verify SUBACK */
468 if(readbuf[0] != ((mqtt->packetid >> 8) & 0xff) ||
469 readbuf[1] != (mqtt->packetid & 0xff) ||
470 readbuf[2] != 0x00)
471 result = CURLE_WEIRD_SERVER_REPLY;
472
473fail:
474 return result;
475}
476
477static CURLcode mqtt_publish(struct Curl_easy *data)
478{
479 CURLcode result;
480 char *payload = data->set.postfields;
481 size_t payloadlen;
482 char *topic = NULL;
483 size_t topiclen;
484 unsigned char *pkt = NULL;
485 size_t i = 0;
486 size_t remaininglength;
487 size_t encodelen;
488 char encodedbytes[4];
489 curl_off_t postfieldsize = data->set.postfieldsize;
490
491 if(!payload)
492 return CURLE_BAD_FUNCTION_ARGUMENT;
493 if(postfieldsize < 0)
494 payloadlen = strlen(payload);
495 else
496 payloadlen = (size_t)postfieldsize;
497
498 result = mqtt_get_topic(data, &topic, &topiclen);
499 if(result)
500 goto fail;
501
502 remaininglength = payloadlen + 2 + topiclen;
503 encodelen = mqtt_encode_len(encodedbytes, remaininglength);
504
505 /* add the control byte and the encoded remaining length */
506 pkt = malloc(remaininglength + 1 + encodelen);
507 if(!pkt) {
508 result = CURLE_OUT_OF_MEMORY;
509 goto fail;
510 }
511
512 /* assemble packet */
513 pkt[i++] = MQTT_MSG_PUBLISH;
514 memcpy(&pkt[i], encodedbytes, encodelen);
515 i += encodelen;
516 pkt[i++] = (topiclen >> 8) & 0xff;
517 pkt[i++] = (topiclen & 0xff);
518 memcpy(&pkt[i], topic, topiclen);
519 i += topiclen;
520 memcpy(&pkt[i], payload, payloadlen);
521 i += payloadlen;
522 result = mqtt_send(data, (char *)pkt, i);
523
524fail:
525 free(pkt);
526 free(topic);
527 return result;
528}
529
530static size_t mqtt_decode_len(unsigned char *buf,
531 size_t buflen, size_t *lenbytes)
532{
533 size_t len = 0;
534 size_t mult = 1;
535 size_t i;
536 unsigned char encoded = 128;
537
538 for(i = 0; (i < buflen) && (encoded & 128); i++) {
539 encoded = buf[i];
540 len += (encoded & 127) * mult;
541 mult *= 128;
542 }
543
544 if(lenbytes)
545 *lenbytes = i;
546
547 return len;
548}
549
550#ifdef CURLDEBUG
551static const char *statenames[]={
552 "MQTT_FIRST",
553 "MQTT_REMAINING_LENGTH",
554 "MQTT_CONNACK",
555 "MQTT_SUBACK",
556 "MQTT_SUBACK_COMING",
557 "MQTT_PUBWAIT",
558 "MQTT_PUB_REMAIN",
559
560 "NOT A STATE"
561};
562#endif
563
564/* The only way to change state */
565static void mqstate(struct Curl_easy *data,
566 enum mqttstate state,
567 enum mqttstate nextstate) /* used if state == FIRST */
568{
569 struct connectdata *conn = data->conn;
570 struct mqtt_conn *mqtt = &conn->proto.mqtt;
571#ifdef CURLDEBUG
572 infof(data, "%s (from %s) (next is %s)",
573 statenames[state],
574 statenames[mqtt->state],
575 (state == MQTT_FIRST)? statenames[nextstate] : "");
576#endif
577 mqtt->state = state;
578 if(state == MQTT_FIRST)
579 mqtt->nextstate = nextstate;
580}
581
582
583/* for the publish packet */
584#define MQTT_HEADER_LEN 5 /* max 5 bytes */
585
586static CURLcode mqtt_read_publish(struct Curl_easy *data, bool *done)
587{
588 CURLcode result = CURLE_OK;
589 struct connectdata *conn = data->conn;
590 curl_socket_t sockfd = conn->sock[FIRSTSOCKET];
591 ssize_t nread;
592 unsigned char *pkt = (unsigned char *)data->state.buffer;
593 size_t remlen;
594 struct mqtt_conn *mqtt = &conn->proto.mqtt;
595 struct MQTT *mq = data->req.p.mqtt;
596 unsigned char packet;
597
598 switch(mqtt->state) {
599 MQTT_SUBACK_COMING:
600 case MQTT_SUBACK_COMING:
601 result = mqtt_verify_suback(data);
602 if(result)
603 break;
604
605 mqstate(data, MQTT_FIRST, MQTT_PUBWAIT);
606 break;
607
608 case MQTT_SUBACK:
609 case MQTT_PUBWAIT:
610 /* we are expecting PUBLISH or SUBACK */
611 packet = mq->firstbyte & 0xf0;
612 if(packet == MQTT_MSG_PUBLISH)
613 mqstate(data, MQTT_PUB_REMAIN, MQTT_NOSTATE);
614 else if(packet == MQTT_MSG_SUBACK) {
615 mqstate(data, MQTT_SUBACK_COMING, MQTT_NOSTATE);
616 goto MQTT_SUBACK_COMING;
617 }
618 else if(packet == MQTT_MSG_DISCONNECT) {
619 infof(data, "Got DISCONNECT");
620 *done = TRUE;
621 goto end;
622 }
623 else {
624 result = CURLE_WEIRD_SERVER_REPLY;
625 goto end;
626 }
627
628 /* -- switched state -- */
629 remlen = mq->remaining_length;
630 infof(data, "Remaining length: %zd bytes", remlen);
631 if(data->set.max_filesize &&
632 (curl_off_t)remlen > data->set.max_filesize) {
633 failf(data, "Maximum file size exceeded");
634 result = CURLE_FILESIZE_EXCEEDED;
635 goto end;
636 }
637 Curl_pgrsSetDownloadSize(data, remlen);
638 data->req.bytecount = 0;
639 data->req.size = remlen;
640 mq->npacket = remlen; /* get this many bytes */
641 /* FALLTHROUGH */
642 case MQTT_PUB_REMAIN: {
643 /* read rest of packet, but no more. Cap to buffer size */
644 struct SingleRequest *k = &data->req;
645 size_t rest = mq->npacket;
646 if(rest > (size_t)data->set.buffer_size)
647 rest = (size_t)data->set.buffer_size;
648 result = Curl_read(data, sockfd, (char *)pkt, rest, &nread);
649 if(result) {
650 if(CURLE_AGAIN == result) {
651 infof(data, "EEEE AAAAGAIN");
652 }
653 goto end;
654 }
655 if(!nread) {
656 infof(data, "server disconnected");
657 result = CURLE_PARTIAL_FILE;
658 goto end;
659 }
660 Curl_debug(data, CURLINFO_DATA_IN, (char *)pkt, (size_t)nread);
661
662 mq->npacket -= nread;
663 k->bytecount += nread;
664 Curl_pgrsSetDownloadCounter(data, k->bytecount);
665
666 /* if QoS is set, message contains packet id */
667
668 result = Curl_client_write(data, CLIENTWRITE_BODY, (char *)pkt, nread);
669 if(result)
670 goto end;
671
672 if(!mq->npacket)
673 /* no more PUBLISH payload, back to subscribe wait state */
674 mqstate(data, MQTT_FIRST, MQTT_PUBWAIT);
675 break;
676 }
677 default:
678 DEBUGASSERT(NULL); /* illegal state */
679 result = CURLE_WEIRD_SERVER_REPLY;
680 goto end;
681 }
682 end:
683 return result;
684}
685
686static CURLcode mqtt_do(struct Curl_easy *data, bool *done)
687{
688 CURLcode result = CURLE_OK;
689 *done = FALSE; /* unconditionally */
690
691 result = mqtt_connect(data);
692 if(result) {
693 failf(data, "Error %d sending MQTT CONN request", result);
694 return result;
695 }
696 mqstate(data, MQTT_FIRST, MQTT_CONNACK);
697 return CURLE_OK;
698}
699
700static CURLcode mqtt_done(struct Curl_easy *data,
701 CURLcode status, bool premature)
702{
703 struct MQTT *mq = data->req.p.mqtt;
704 (void)status;
705 (void)premature;
706 Curl_safefree(mq->sendleftovers);
707 return CURLE_OK;
708}
709
710static CURLcode mqtt_doing(struct Curl_easy *data, bool *done)
711{
712 CURLcode result = CURLE_OK;
713 struct connectdata *conn = data->conn;
714 struct mqtt_conn *mqtt = &conn->proto.mqtt;
715 struct MQTT *mq = data->req.p.mqtt;
716 ssize_t nread;
717 curl_socket_t sockfd = conn->sock[FIRSTSOCKET];
718 unsigned char *pkt = (unsigned char *)data->state.buffer;
719 unsigned char byte;
720
721 *done = FALSE;
722
723 if(mq->nsend) {
724 /* send the remainder of an outgoing packet */
725 char *ptr = mq->sendleftovers;
726 result = mqtt_send(data, mq->sendleftovers, mq->nsend);
727 free(ptr);
728 if(result)
729 return result;
730 }
731
732 infof(data, "mqtt_doing: state [%d]", (int) mqtt->state);
733 switch(mqtt->state) {
734 case MQTT_FIRST:
735 /* Read the initial byte only */
736 result = Curl_read(data, sockfd, (char *)&mq->firstbyte, 1, &nread);
737 if(result)
738 break;
739 else if(!nread) {
740 failf(data, "Connection disconnected");
741 *done = TRUE;
742 result = CURLE_RECV_ERROR;
743 break;
744 }
745 Curl_debug(data, CURLINFO_HEADER_IN, (char *)&mq->firstbyte, 1);
746 /* remember the first byte */
747 mq->npacket = 0;
748 mqstate(data, MQTT_REMAINING_LENGTH, MQTT_NOSTATE);
749 /* FALLTHROUGH */
750 case MQTT_REMAINING_LENGTH:
751 do {
752 result = Curl_read(data, sockfd, (char *)&byte, 1, &nread);
753 if(!nread)
754 break;
755 Curl_debug(data, CURLINFO_HEADER_IN, (char *)&byte, 1);
756 pkt[mq->npacket++] = byte;
757 } while((byte & 0x80) && (mq->npacket < 4));
758 if(nread && (byte & 0x80))
759 /* MQTT supports up to 127 * 128^0 + 127 * 128^1 + 127 * 128^2 +
760 127 * 128^3 bytes. server tried to send more */
761 result = CURLE_WEIRD_SERVER_REPLY;
762 if(result)
763 break;
764 mq->remaining_length = mqtt_decode_len(&pkt[0], mq->npacket, NULL);
765 mq->npacket = 0;
766 if(mq->remaining_length) {
767 mqstate(data, mqtt->nextstate, MQTT_NOSTATE);
768 break;
769 }
770 mqstate(data, MQTT_FIRST, MQTT_FIRST);
771
772 if(mq->firstbyte == MQTT_MSG_DISCONNECT) {
773 infof(data, "Got DISCONNECT");
774 *done = TRUE;
775 }
776 break;
777 case MQTT_CONNACK:
778 result = mqtt_verify_connack(data);
779 if(result)
780 break;
781
782 if(data->state.httpreq == HTTPREQ_POST) {
783 result = mqtt_publish(data);
784 if(!result) {
785 result = mqtt_disconnect(data);
786 *done = TRUE;
787 }
788 mqtt->nextstate = MQTT_FIRST;
789 }
790 else {
791 result = mqtt_subscribe(data);
792 if(!result) {
793 mqstate(data, MQTT_FIRST, MQTT_SUBACK);
794 }
795 }
796 break;
797
798 case MQTT_SUBACK:
799 case MQTT_PUBWAIT:
800 case MQTT_PUB_REMAIN:
801 result = mqtt_read_publish(data, done);
802 break;
803
804 default:
805 failf(data, "State not handled yet");
806 *done = TRUE;
807 break;
808 }
809
810 if(result == CURLE_AGAIN)
811 result = CURLE_OK;
812 return result;
813}
814
815#endif /* CURL_DISABLE_MQTT */
816