1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22#include "server_setup.h"
23#include <stdlib.h>
24#include <string.h>
25#include "util.h"
26
27/* Function
28 *
29 * Accepts a TCP connection on a custom port (IPv4 or IPv6). Speaks MQTT.
30 *
31 * Read commands from FILE (set with --config). The commands control how to
32 * act and is reset to defaults each client TCP connect.
33 *
34 * Config file keywords:
35 *
36 * TODO
37 */
38
39/* based on sockfilt.c */
40
41#ifdef HAVE_SIGNAL_H
42#include <signal.h>
43#endif
44#ifdef HAVE_NETINET_IN_H
45#include <netinet/in.h>
46#endif
47#ifdef HAVE_NETINET_IN6_H
48#include <netinet/in6.h>
49#endif
50#ifdef HAVE_ARPA_INET_H
51#include <arpa/inet.h>
52#endif
53#ifdef HAVE_NETDB_H
54#include <netdb.h>
55#endif
56
57#define ENABLE_CURLX_PRINTF
58/* make the curlx header define all printf() functions to use the curlx_*
59 versions instead */
60#include "curlx.h" /* from the private lib dir */
61#include "getpart.h"
62#include "inet_pton.h"
63#include "util.h"
64#include "server_sockaddr.h"
65#include "warnless.h"
66
67/* include memdebug.h last */
68#include "memdebug.h"
69
70#ifdef USE_WINSOCK
71#undef EINTR
72#define EINTR 4 /* errno.h value */
73#undef EAGAIN
74#define EAGAIN 11 /* errno.h value */
75#undef ENOMEM
76#define ENOMEM 12 /* errno.h value */
77#undef EINVAL
78#define EINVAL 22 /* errno.h value */
79#endif
80
81#define DEFAULT_PORT 1883 /* MQTT default port */
82
83#ifndef DEFAULT_LOGFILE
84#define DEFAULT_LOGFILE "log/mqttd.log"
85#endif
86
87#ifndef DEFAULT_CONFIG
88#define DEFAULT_CONFIG "mqttd.config"
89#endif
90
91#define MQTT_MSG_CONNECT 0x10
92#define MQTT_MSG_CONNACK 0x20
93#define MQTT_MSG_PUBLISH 0x30
94#define MQTT_MSG_PUBACK 0x40
95#define MQTT_MSG_SUBSCRIBE 0x82
96#define MQTT_MSG_SUBACK 0x90
97#define MQTT_MSG_DISCONNECT 0xe0
98
99#define MQTT_CONNACK_LEN 4
100#define MQTT_SUBACK_LEN 5
101#define MQTT_CLIENTID_LEN 12 /* "curl0123abcd" */
102#define MQTT_HEADER_LEN 5 /* max 5 bytes */
103
104struct configurable {
105 unsigned char version; /* initial version byte in the request must match
106 this */
107 bool publish_before_suback;
108 bool short_publish;
109 bool excessive_remaining;
110 unsigned char error_connack;
111 int testnum;
112};
113
114#define REQUEST_DUMP "log/server.input"
115#define CONFIG_VERSION 5
116
117static struct configurable config;
118
119const char *serverlogfile = DEFAULT_LOGFILE;
120static const char *configfile = DEFAULT_CONFIG;
121
122#ifdef ENABLE_IPV6
123static bool use_ipv6 = FALSE;
124#endif
125static const char *ipv_inuse = "IPv4";
126static unsigned short port = DEFAULT_PORT;
127
128static void resetdefaults(void)
129{
130 logmsg("Reset to defaults");
131 config.version = CONFIG_VERSION;
132 config.publish_before_suback = FALSE;
133 config.short_publish = FALSE;
134 config.excessive_remaining = FALSE;
135 config.error_connack = 0;
136 config.testnum = 0;
137}
138
139static unsigned char byteval(char *value)
140{
141 unsigned long num = strtoul(value, NULL, 10);
142 return num & 0xff;
143}
144
145static void getconfig(void)
146{
147 FILE *fp = fopen(configfile, FOPEN_READTEXT);
148 resetdefaults();
149 if(fp) {
150 char buffer[512];
151 logmsg("parse config file");
152 while(fgets(buffer, sizeof(buffer), fp)) {
153 char key[32];
154 char value[32];
155 if(2 == sscanf(buffer, "%31s %31s", key, value)) {
156 if(!strcmp(key, "version")) {
157 config.version = byteval(value);
158 logmsg("version [%d] set", config.version);
159 }
160 else if(!strcmp(key, "PUBLISH-before-SUBACK")) {
161 logmsg("PUBLISH-before-SUBACK set");
162 config.publish_before_suback = TRUE;
163 }
164 else if(!strcmp(key, "short-PUBLISH")) {
165 logmsg("short-PUBLISH set");
166 config.short_publish = TRUE;
167 }
168 else if(!strcmp(key, "error-CONNACK")) {
169 config.error_connack = byteval(value);
170 logmsg("error-CONNACK = %d", config.error_connack);
171 }
172 else if(!strcmp(key, "Testnum")) {
173 config.testnum = atoi(value);
174 logmsg("testnum = %d", config.testnum);
175 }
176 else if(!strcmp(key, "excessive-remaining")) {
177 logmsg("excessive-remaining set");
178 config.excessive_remaining = TRUE;
179 }
180 }
181 }
182 fclose(fp);
183 }
184 else {
185 logmsg("No config file '%s' to read", configfile);
186 }
187}
188
189static void loghex(unsigned char *buffer, ssize_t len)
190{
191 char data[12000];
192 ssize_t i;
193 unsigned char *ptr = buffer;
194 char *optr = data;
195 ssize_t width = 0;
196 int left = sizeof(data);
197
198 for(i = 0; i<len && (left >= 0); i++) {
199 msnprintf(optr, left, "%02x", ptr[i]);
200 width += 2;
201 optr += 2;
202 left -= 2;
203 }
204 if(width)
205 logmsg("'%s'", data);
206}
207
208typedef enum {
209 FROM_CLIENT,
210 FROM_SERVER
211} mqttdir;
212
213static void logprotocol(mqttdir dir,
214 const char *prefix, size_t remlen,
215 FILE *output,
216 unsigned char *buffer, ssize_t len)
217{
218 char data[12000] = "";
219 ssize_t i;
220 unsigned char *ptr = buffer;
221 char *optr = data;
222 int left = sizeof(data);
223
224 for(i = 0; i<len && (left >= 0); i++) {
225 msnprintf(optr, left, "%02x", ptr[i]);
226 optr += 2;
227 left -= 2;
228 }
229 fprintf(output, "%s %s %zx %s\n",
230 dir == FROM_CLIENT? "client": "server",
231 prefix, remlen,
232 data);
233}
234
235
236/* return 0 on success */
237static int connack(FILE *dump, curl_socket_t fd)
238{
239 unsigned char packet[]={
240 MQTT_MSG_CONNACK, 0x02,
241 0x00, 0x00
242 };
243 ssize_t rc;
244
245 packet[3] = config.error_connack;
246
247 rc = swrite(fd, (char *)packet, sizeof(packet));
248 if(rc > 0) {
249 logmsg("WROTE %d bytes [CONNACK]", rc);
250 loghex(packet, rc);
251 logprotocol(FROM_SERVER, "CONNACK", 2, dump, packet, sizeof(packet));
252 }
253 if(rc == sizeof(packet)) {
254 return 0;
255 }
256 return 1;
257}
258
259/* return 0 on success */
260static int suback(FILE *dump, curl_socket_t fd, unsigned short packetid)
261{
262 unsigned char packet[]={
263 MQTT_MSG_SUBACK, 0x03,
264 0, 0, /* filled in below */
265 0x00
266 };
267 ssize_t rc;
268 packet[2] = (unsigned char)(packetid >> 8);
269 packet[3] = (unsigned char)(packetid & 0xff);
270
271 rc = swrite(fd, (char *)packet, sizeof(packet));
272 if(rc == sizeof(packet)) {
273 logmsg("WROTE %d bytes [SUBACK]", rc);
274 loghex(packet, rc);
275 logprotocol(FROM_SERVER, "SUBACK", 3, dump, packet, rc);
276 return 0;
277 }
278 return 1;
279}
280
281#ifdef QOS
282/* return 0 on success */
283static int puback(FILE *dump, curl_socket_t fd, unsigned short packetid)
284{
285 unsigned char packet[]={
286 MQTT_MSG_PUBACK, 0x00,
287 0, 0 /* filled in below */
288 };
289 ssize_t rc;
290 packet[2] = (unsigned char)(packetid >> 8);
291 packet[3] = (unsigned char)(packetid & 0xff);
292
293 rc = swrite(fd, (char *)packet, sizeof(packet));
294 if(rc == sizeof(packet)) {
295 logmsg("WROTE %d bytes [PUBACK]", rc);
296 loghex(packet, rc);
297 logprotocol(FROM_SERVER, dump, packet, rc);
298 return 0;
299 }
300 logmsg("Failed sending [PUBACK]");
301 return 1;
302}
303#endif
304
305/* return 0 on success */
306static int disconnect(FILE *dump, curl_socket_t fd)
307{
308 unsigned char packet[]={
309 MQTT_MSG_DISCONNECT, 0x00,
310 };
311 ssize_t rc = swrite(fd, (char *)packet, sizeof(packet));
312 if(rc == sizeof(packet)) {
313 logmsg("WROTE %d bytes [DISCONNECT]", rc);
314 loghex(packet, rc);
315 logprotocol(FROM_SERVER, "DISCONNECT", 0, dump, packet, rc);
316 return 0;
317 }
318 logmsg("Failed sending [DISCONNECT]");
319 return 1;
320}
321
322
323
324/*
325 do
326
327 encodedByte = X MOD 128
328
329 X = X DIV 128
330
331 // if there are more data to encode, set the top bit of this byte
332
333 if ( X > 0 )
334
335 encodedByte = encodedByte OR 128
336
337 endif
338
339 'output' encodedByte
340
341 while ( X > 0 )
342
343*/
344
345/* return number of bytes used */
346static int encode_length(size_t packetlen,
347 unsigned char *remlength) /* 4 bytes */
348{
349 int bytes = 0;
350 unsigned char encode;
351
352 do {
353 encode = packetlen % 0x80;
354 packetlen /= 0x80;
355 if(packetlen)
356 encode |= 0x80;
357
358 remlength[bytes++] = encode;
359
360 if(bytes > 3) {
361 logmsg("too large packet!");
362 return 0;
363 }
364 } while(packetlen);
365
366 return bytes;
367}
368
369
370static size_t decode_length(unsigned char *buf,
371 size_t buflen, size_t *lenbytes)
372{
373 size_t len = 0;
374 size_t mult = 1;
375 size_t i;
376 unsigned char encoded = 0x80;
377
378 for(i = 0; (i < buflen) && (encoded & 0x80); i++) {
379 encoded = buf[i];
380 len += (encoded & 0x7f) * mult;
381 mult *= 0x80;
382 }
383
384 if(lenbytes)
385 *lenbytes = i;
386
387 return len;
388}
389
390
391/* return 0 on success */
392static int publish(FILE *dump,
393 curl_socket_t fd, unsigned short packetid,
394 char *topic, char *payload, size_t payloadlen)
395{
396 size_t topiclen = strlen(topic);
397 unsigned char *packet;
398 size_t payloadindex;
399 ssize_t remaininglength = topiclen + 2 + payloadlen;
400 ssize_t packetlen;
401 ssize_t sendamount;
402 ssize_t rc;
403 unsigned char rembuffer[4];
404 int encodedlen;
405
406 if(config.excessive_remaining) {
407 /* manually set illegal remaining length */
408 rembuffer[0] = 0xff;
409 rembuffer[1] = 0xff;
410 rembuffer[2] = 0xff;
411 rembuffer[3] = 0x80; /* maximum allowed here by spec is 0x7f */
412 encodedlen = 4;
413 }
414 else
415 encodedlen = encode_length(remaininglength, rembuffer);
416
417 /* one packet type byte (possibly two more for packetid) */
418 packetlen = remaininglength + encodedlen + 1;
419 packet = malloc(packetlen);
420 if(!packet)
421 return 1;
422
423 packet[0] = MQTT_MSG_PUBLISH; /* TODO: set QoS? */
424 memcpy(&packet[1], rembuffer, encodedlen);
425
426 (void)packetid;
427 /* packet_id if QoS is set */
428
429 packet[1 + encodedlen] = (unsigned char)(topiclen >> 8);
430 packet[2 + encodedlen] = (unsigned char)(topiclen & 0xff);
431 memcpy(&packet[3 + encodedlen], topic, topiclen);
432
433 payloadindex = 3 + topiclen + encodedlen;
434 memcpy(&packet[payloadindex], payload, payloadlen);
435
436 sendamount = packetlen;
437 if(config.short_publish)
438 sendamount -= 2;
439
440 rc = swrite(fd, (char *)packet, sendamount);
441 if(rc > 0) {
442 logmsg("WROTE %d bytes [PUBLISH]", rc);
443 loghex(packet, rc);
444 logprotocol(FROM_SERVER, "PUBLISH", remaininglength, dump, packet, rc);
445 }
446 if(rc == packetlen)
447 return 0;
448 return 1;
449}
450
451#define MAX_TOPIC_LENGTH 65535
452#define MAX_CLIENT_ID_LENGTH 32
453
454static char topic[MAX_TOPIC_LENGTH + 1];
455
456static int fixedheader(curl_socket_t fd,
457 unsigned char *bytep,
458 size_t *remaining_lengthp,
459 size_t *remaining_length_bytesp)
460{
461 /* get the fixed header */
462 unsigned char buffer[10];
463
464 /* get the first two bytes */
465 ssize_t rc = sread(fd, (char *)buffer, 2);
466 int i;
467 if(rc < 2) {
468 logmsg("READ %d bytes [SHORT!]", rc);
469 return 1; /* fail */
470 }
471 logmsg("READ %d bytes", rc);
472 loghex(buffer, rc);
473 *bytep = buffer[0];
474
475 /* if the length byte has the top bit set, get the next one too */
476 i = 1;
477 while(buffer[i] & 0x80) {
478 i++;
479 rc = sread(fd, (char *)&buffer[i], 1);
480 if(rc != 1) {
481 logmsg("Remaining Length broken");
482 return 1;
483 }
484 }
485 *remaining_lengthp = decode_length(&buffer[1], i, remaining_length_bytesp);
486 logmsg("Remaining Length: %ld [%d bytes]", (long) *remaining_lengthp,
487 *remaining_length_bytesp);
488 return 0;
489}
490
491static curl_socket_t mqttit(curl_socket_t fd)
492{
493 size_t buff_size = 10*1024;
494 unsigned char *buffer = NULL;
495 ssize_t rc;
496 unsigned char byte;
497 unsigned short packet_id;
498 size_t payload_len;
499 size_t client_id_length;
500 unsigned int topic_len;
501 size_t remaining_length = 0;
502 size_t bytes = 0; /* remaining length field size in bytes */
503 char client_id[MAX_CLIENT_ID_LENGTH];
504 long testno;
505 FILE *stream = NULL;
506
507
508 static const char protocol[7] = {
509 0x00, 0x04, /* protocol length */
510 'M','Q','T','T', /* protocol name */
511 0x04 /* protocol level */
512 };
513 FILE *dump = fopen(REQUEST_DUMP, "ab");
514 if(!dump)
515 goto end;
516
517 getconfig();
518
519 testno = config.testnum;
520
521 if(testno)
522 logmsg("Found test number %ld", testno);
523
524 buffer = malloc(buff_size);
525 if(!buffer) {
526 logmsg("Out of memory, unable to allocate buffer");
527 goto end;
528 }
529
530 do {
531 unsigned char usr_flag = 0x80;
532 unsigned char passwd_flag = 0x40;
533 unsigned char conn_flags;
534 const size_t client_id_offset = 12;
535 size_t start_usr;
536 size_t start_passwd;
537
538 /* get the fixed header */
539 rc = fixedheader(fd, &byte, &remaining_length, &bytes);
540 if(rc)
541 break;
542
543 if(remaining_length >= buff_size) {
544 buff_size = remaining_length;
545 buffer = realloc(buffer, buff_size);
546 if(!buffer) {
547 logmsg("Failed realloc of size %lu", buff_size);
548 goto end;
549 }
550 }
551
552 if(remaining_length) {
553 /* reading variable header and payload into buffer */
554 rc = sread(fd, (char *)buffer, remaining_length);
555 if(rc > 0) {
556 logmsg("READ %d bytes", rc);
557 loghex(buffer, rc);
558 }
559 }
560
561 if(byte == MQTT_MSG_CONNECT) {
562 logprotocol(FROM_CLIENT, "CONNECT", remaining_length,
563 dump, buffer, rc);
564
565 if(memcmp(protocol, buffer, sizeof(protocol))) {
566 logmsg("Protocol preamble mismatch");
567 goto end;
568 }
569 /* ignore the connect flag byte and two keepalive bytes */
570 payload_len = (buffer[10] << 8) | buffer[11];
571 /* first part of the payload is the client ID */
572 client_id_length = payload_len;
573
574 /* checking if user and password flags were set */
575 conn_flags = buffer[7];
576
577 start_usr = client_id_offset + payload_len;
578 if(usr_flag == (unsigned char)(conn_flags & usr_flag)) {
579 logmsg("User flag is present in CONN flag");
580 payload_len += (buffer[start_usr] << 8) | buffer[start_usr + 1];
581 payload_len += 2; /* MSB and LSB for user length */
582 }
583
584 start_passwd = client_id_offset + payload_len;
585 if(passwd_flag == (char)(conn_flags & passwd_flag)) {
586 logmsg("Password flag is present in CONN flags");
587 payload_len += (buffer[start_passwd] << 8) | buffer[start_passwd + 1];
588 payload_len += 2; /* MSB and LSB for password length */
589 }
590
591 /* check the length of the payload */
592 if((ssize_t)payload_len != (rc - 12)) {
593 logmsg("Payload length mismatch, expected %x got %x",
594 rc - 12, payload_len);
595 goto end;
596 }
597 /* check the length of the client ID */
598 else if((client_id_length + 1) > MAX_CLIENT_ID_LENGTH) {
599 logmsg("Too large client id");
600 goto end;
601 }
602 memcpy(client_id, &buffer[12], client_id_length);
603 client_id[client_id_length] = 0;
604
605 logmsg("MQTT client connect accepted: %s", client_id);
606
607 /* The first packet sent from the Server to the Client MUST be a
608 CONNACK Packet */
609
610 if(connack(dump, fd)) {
611 logmsg("failed sending CONNACK");
612 goto end;
613 }
614 }
615 else if(byte == MQTT_MSG_SUBSCRIBE) {
616 int error;
617 char *data;
618 size_t datalen;
619 logprotocol(FROM_CLIENT, "SUBSCRIBE", remaining_length,
620 dump, buffer, rc);
621 logmsg("Incoming SUBSCRIBE");
622
623 if(rc < 6) {
624 logmsg("Too small SUBSCRIBE");
625 goto end;
626 }
627
628 /* two bytes packet id */
629 packet_id = (unsigned short)((buffer[0] << 8) | buffer[1]);
630
631 /* two bytes topic length */
632 topic_len = (buffer[2] << 8) | buffer[3];
633 if(topic_len != (remaining_length - 5)) {
634 logmsg("Wrong topic length, got %d expected %d",
635 topic_len, remaining_length - 5);
636 goto end;
637 }
638 memcpy(topic, &buffer[4], topic_len);
639 topic[topic_len] = 0;
640
641 /* there's a QoS byte (two bits) after the topic */
642
643 logmsg("SUBSCRIBE to '%s' [%d]", topic, packet_id);
644 stream = test2fopen(testno);
645 error = getpart(&data, &datalen, "reply", "data", stream);
646 if(!error) {
647 if(!config.publish_before_suback) {
648 if(suback(dump, fd, packet_id)) {
649 logmsg("failed sending SUBACK");
650 goto end;
651 }
652 }
653 if(publish(dump, fd, packet_id, topic, data, datalen)) {
654 logmsg("PUBLISH failed");
655 goto end;
656 }
657 if(config.publish_before_suback) {
658 if(suback(dump, fd, packet_id)) {
659 logmsg("failed sending SUBACK");
660 goto end;
661 }
662 }
663 }
664 else {
665 char *def = (char *)"this is random payload yes yes it is";
666 publish(dump, fd, packet_id, topic, def, strlen(def));
667 }
668 disconnect(dump, fd);
669 }
670 else if((byte & 0xf0) == (MQTT_MSG_PUBLISH & 0xf0)) {
671 size_t topiclen;
672
673 logmsg("Incoming PUBLISH");
674 logprotocol(FROM_CLIENT, "PUBLISH", remaining_length,
675 dump, buffer, rc);
676
677 topiclen = (buffer[1 + bytes] << 8) | buffer[2 + bytes];
678 logmsg("Got %d bytes topic", topiclen);
679 /* TODO: verify topiclen */
680
681#ifdef QOS
682 /* TODO: handle packetid if there is one. Send puback if QoS > 0 */
683 puback(dump, fd, 0);
684#endif
685 /* expect a disconnect here */
686 /* get the request */
687 rc = sread(fd, (char *)&buffer[0], 2);
688
689 logmsg("READ %d bytes [DISCONNECT]", rc);
690 loghex(buffer, rc);
691 logprotocol(FROM_CLIENT, "DISCONNECT", 0, dump, buffer, rc);
692 goto end;
693 }
694 else {
695 /* not supported (yet) */
696 goto end;
697 }
698 } while(1);
699
700 end:
701 if(buffer)
702 free(buffer);
703 if(dump)
704 fclose(dump);
705 if(stream)
706 fclose(stream);
707 return CURL_SOCKET_BAD;
708}
709
710/*
711 sockfdp is a pointer to an established stream or CURL_SOCKET_BAD
712
713 if sockfd is CURL_SOCKET_BAD, listendfd is a listening socket we must
714 accept()
715*/
716static bool incoming(curl_socket_t listenfd)
717{
718 fd_set fds_read;
719 fd_set fds_write;
720 fd_set fds_err;
721 int clients = 0; /* connected clients */
722
723 if(got_exit_signal) {
724 logmsg("signalled to die, exiting...");
725 return FALSE;
726 }
727
728#ifdef HAVE_GETPPID
729 /* As a last resort, quit if socks5 process becomes orphan. */
730 if(getppid() <= 1) {
731 logmsg("process becomes orphan, exiting");
732 return FALSE;
733 }
734#endif
735
736 do {
737 ssize_t rc;
738 int error = 0;
739 curl_socket_t sockfd = listenfd;
740 int maxfd = (int)sockfd;
741
742 FD_ZERO(&fds_read);
743 FD_ZERO(&fds_write);
744 FD_ZERO(&fds_err);
745
746 /* there's always a socket to wait for */
747 FD_SET(sockfd, &fds_read);
748
749 do {
750 /* select() blocking behavior call on blocking descriptors please */
751 rc = select(maxfd + 1, &fds_read, &fds_write, &fds_err, NULL);
752 if(got_exit_signal) {
753 logmsg("signalled to die, exiting...");
754 return FALSE;
755 }
756 } while((rc == -1) && ((error = SOCKERRNO) == EINTR));
757
758 if(rc < 0) {
759 logmsg("select() failed with error: (%d) %s",
760 error, strerror(error));
761 return FALSE;
762 }
763
764 if(FD_ISSET(sockfd, &fds_read)) {
765 curl_socket_t newfd = accept(sockfd, NULL, NULL);
766 if(CURL_SOCKET_BAD == newfd) {
767 error = SOCKERRNO;
768 logmsg("accept(%d, NULL, NULL) failed with error: (%d) %s",
769 sockfd, error, strerror(error));
770 }
771 else {
772 logmsg("====> Client connect, fd %d. Read config from %s",
773 newfd, configfile);
774 set_advisor_read_lock(SERVERLOGS_LOCK);
775 (void)mqttit(newfd); /* until done */
776 clear_advisor_read_lock(SERVERLOGS_LOCK);
777
778 logmsg("====> Client disconnect");
779 sclose(newfd);
780 }
781 }
782 } while(clients);
783
784 return TRUE;
785}
786
787static curl_socket_t sockdaemon(curl_socket_t sock,
788 unsigned short *listenport)
789{
790 /* passive daemon style */
791 srvr_sockaddr_union_t listener;
792 int flag;
793 int rc;
794 int totdelay = 0;
795 int maxretr = 10;
796 int delay = 20;
797 int attempt = 0;
798 int error = 0;
799
800 do {
801 attempt++;
802 flag = 1;
803 rc = setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
804 (void *)&flag, sizeof(flag));
805 if(rc) {
806 error = SOCKERRNO;
807 logmsg("setsockopt(SO_REUSEADDR) failed with error: (%d) %s",
808 error, strerror(error));
809 if(maxretr) {
810 rc = wait_ms(delay);
811 if(rc) {
812 /* should not happen */
813 logmsg("wait_ms() failed with error: %d", rc);
814 sclose(sock);
815 return CURL_SOCKET_BAD;
816 }
817 if(got_exit_signal) {
818 logmsg("signalled to die, exiting...");
819 sclose(sock);
820 return CURL_SOCKET_BAD;
821 }
822 totdelay += delay;
823 delay *= 2; /* double the sleep for next attempt */
824 }
825 }
826 } while(rc && maxretr--);
827
828 if(rc) {
829 logmsg("setsockopt(SO_REUSEADDR) failed %d times in %d ms. Error: (%d) %s",
830 attempt, totdelay, error, strerror(error));
831 logmsg("Continuing anyway...");
832 }
833
834 /* When the specified listener port is zero, it is actually a
835 request to let the system choose a non-zero available port. */
836
837#ifdef ENABLE_IPV6
838 if(!use_ipv6) {
839#endif
840 memset(&listener.sa4, 0, sizeof(listener.sa4));
841 listener.sa4.sin_family = AF_INET;
842 listener.sa4.sin_addr.s_addr = INADDR_ANY;
843 listener.sa4.sin_port = htons(*listenport);
844 rc = bind(sock, &listener.sa, sizeof(listener.sa4));
845#ifdef ENABLE_IPV6
846 }
847 else {
848 memset(&listener.sa6, 0, sizeof(listener.sa6));
849 listener.sa6.sin6_family = AF_INET6;
850 listener.sa6.sin6_addr = in6addr_any;
851 listener.sa6.sin6_port = htons(*listenport);
852 rc = bind(sock, &listener.sa, sizeof(listener.sa6));
853 }
854#endif /* ENABLE_IPV6 */
855 if(rc) {
856 error = SOCKERRNO;
857 logmsg("Error binding socket on port %hu: (%d) %s",
858 *listenport, error, strerror(error));
859 sclose(sock);
860 return CURL_SOCKET_BAD;
861 }
862
863 if(!*listenport) {
864 /* The system was supposed to choose a port number, figure out which
865 port we actually got and update the listener port value with it. */
866 curl_socklen_t la_size;
867 srvr_sockaddr_union_t localaddr;
868#ifdef ENABLE_IPV6
869 if(!use_ipv6)
870#endif
871 la_size = sizeof(localaddr.sa4);
872#ifdef ENABLE_IPV6
873 else
874 la_size = sizeof(localaddr.sa6);
875#endif
876 memset(&localaddr.sa, 0, (size_t)la_size);
877 if(getsockname(sock, &localaddr.sa, &la_size) < 0) {
878 error = SOCKERRNO;
879 logmsg("getsockname() failed with error: (%d) %s",
880 error, strerror(error));
881 sclose(sock);
882 return CURL_SOCKET_BAD;
883 }
884 switch(localaddr.sa.sa_family) {
885 case AF_INET:
886 *listenport = ntohs(localaddr.sa4.sin_port);
887 break;
888#ifdef ENABLE_IPV6
889 case AF_INET6:
890 *listenport = ntohs(localaddr.sa6.sin6_port);
891 break;
892#endif
893 default:
894 break;
895 }
896 if(!*listenport) {
897 /* Real failure, listener port shall not be zero beyond this point. */
898 logmsg("Apparently getsockname() succeeded, with listener port zero.");
899 logmsg("A valid reason for this failure is a binary built without");
900 logmsg("proper network library linkage. This might not be the only");
901 logmsg("reason, but double check it before anything else.");
902 sclose(sock);
903 return CURL_SOCKET_BAD;
904 }
905 }
906
907 /* start accepting connections */
908 rc = listen(sock, 5);
909 if(0 != rc) {
910 error = SOCKERRNO;
911 logmsg("listen(%d, 5) failed with error: (%d) %s",
912 sock, error, strerror(error));
913 sclose(sock);
914 return CURL_SOCKET_BAD;
915 }
916
917 return sock;
918}
919
920
921int main(int argc, char *argv[])
922{
923 curl_socket_t sock = CURL_SOCKET_BAD;
924 curl_socket_t msgsock = CURL_SOCKET_BAD;
925 int wrotepidfile = 0;
926 int wroteportfile = 0;
927 const char *pidname = ".mqttd.pid";
928 const char *portname = ".mqttd.port";
929 bool juggle_again;
930 int error;
931 int arg = 1;
932
933 while(argc>arg) {
934 if(!strcmp("--version", argv[arg])) {
935 printf("mqttd IPv4%s\n",
936#ifdef ENABLE_IPV6
937 "/IPv6"
938#else
939 ""
940#endif
941 );
942 return 0;
943 }
944 else if(!strcmp("--pidfile", argv[arg])) {
945 arg++;
946 if(argc>arg)
947 pidname = argv[arg++];
948 }
949 else if(!strcmp("--portfile", argv[arg])) {
950 arg++;
951 if(argc>arg)
952 portname = argv[arg++];
953 }
954 else if(!strcmp("--config", argv[arg])) {
955 arg++;
956 if(argc>arg)
957 configfile = argv[arg++];
958 }
959 else if(!strcmp("--logfile", argv[arg])) {
960 arg++;
961 if(argc>arg)
962 serverlogfile = argv[arg++];
963 }
964 else if(!strcmp("--ipv6", argv[arg])) {
965#ifdef ENABLE_IPV6
966 ipv_inuse = "IPv6";
967 use_ipv6 = TRUE;
968#endif
969 arg++;
970 }
971 else if(!strcmp("--ipv4", argv[arg])) {
972 /* for completeness, we support this option as well */
973#ifdef ENABLE_IPV6
974 ipv_inuse = "IPv4";
975 use_ipv6 = FALSE;
976#endif
977 arg++;
978 }
979 else if(!strcmp("--port", argv[arg])) {
980 arg++;
981 if(argc>arg) {
982 char *endptr;
983 unsigned long ulnum = strtoul(argv[arg], &endptr, 10);
984 if((endptr != argv[arg] + strlen(argv[arg])) ||
985 ((ulnum != 0UL) && ((ulnum < 1025UL) || (ulnum > 65535UL)))) {
986 fprintf(stderr, "mqttd: invalid --port argument (%s)\n",
987 argv[arg]);
988 return 0;
989 }
990 port = curlx_ultous(ulnum);
991 arg++;
992 }
993 }
994 else {
995 puts("Usage: mqttd [option]\n"
996 " --config [file]\n"
997 " --version\n"
998 " --logfile [file]\n"
999 " --pidfile [file]\n"
1000 " --portfile [file]\n"
1001 " --ipv4\n"
1002 " --ipv6\n"
1003 " --port [port]\n");
1004 return 0;
1005 }
1006 }
1007
1008#ifdef WIN32
1009 win32_init();
1010 atexit(win32_cleanup);
1011
1012 setmode(fileno(stdin), O_BINARY);
1013 setmode(fileno(stdout), O_BINARY);
1014 setmode(fileno(stderr), O_BINARY);
1015#endif
1016
1017 install_signal_handlers(FALSE);
1018
1019#ifdef ENABLE_IPV6
1020 if(!use_ipv6)
1021#endif
1022 sock = socket(AF_INET, SOCK_STREAM, 0);
1023#ifdef ENABLE_IPV6
1024 else
1025 sock = socket(AF_INET6, SOCK_STREAM, 0);
1026#endif
1027
1028 if(CURL_SOCKET_BAD == sock) {
1029 error = SOCKERRNO;
1030 logmsg("Error creating socket: (%d) %s",
1031 error, strerror(error));
1032 goto mqttd_cleanup;
1033 }
1034
1035 {
1036 /* passive daemon style */
1037 sock = sockdaemon(sock, &port);
1038 if(CURL_SOCKET_BAD == sock) {
1039 goto mqttd_cleanup;
1040 }
1041 msgsock = CURL_SOCKET_BAD; /* no stream socket yet */
1042 }
1043
1044 logmsg("Running %s version", ipv_inuse);
1045 logmsg("Listening on port %hu", port);
1046
1047 wrotepidfile = write_pidfile(pidname);
1048 if(!wrotepidfile) {
1049 goto mqttd_cleanup;
1050 }
1051
1052 wroteportfile = write_portfile(portname, port);
1053 if(!wroteportfile) {
1054 goto mqttd_cleanup;
1055 }
1056
1057 do {
1058 juggle_again = incoming(sock);
1059 } while(juggle_again);
1060
1061mqttd_cleanup:
1062
1063 if((msgsock != sock) && (msgsock != CURL_SOCKET_BAD))
1064 sclose(msgsock);
1065
1066 if(sock != CURL_SOCKET_BAD)
1067 sclose(sock);
1068
1069 if(wrotepidfile)
1070 unlink(pidname);
1071 if(wroteportfile)
1072 unlink(portname);
1073
1074 restore_signal_handlers(FALSE);
1075
1076 if(got_exit_signal) {
1077 logmsg("============> mqttd exits with signal (%d)", exit_signal);
1078 /*
1079 * To properly set the return status of the process we
1080 * must raise the same signal SIGINT or SIGTERM that we
1081 * caught and let the old handler take care of it.
1082 */
1083 raise(exit_signal);
1084 }
1085
1086 logmsg("============> mqttd quits");
1087 return 0;
1088}
1089