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-rw-r--r--lib/mqtt.c561
1 files changed, 561 insertions, 0 deletions
diff --git a/lib/mqtt.c b/lib/mqtt.c
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index 000000000..3e244694d
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+++ b/lib/mqtt.c
@@ -0,0 +1,561 @@
+/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 2019, Björn Stenberg, <bjorn@haxx.se>
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#ifdef CURL_ENABLE_MQTT
+
+#include "urldata.h"
+#include <curl/curl.h>
+#include "transfer.h"
+#include "sendf.h"
+#include "progress.h"
+#include "mqtt.h"
+#include "select.h"
+#include "strdup.h"
+#include "url.h"
+#include "escape.h"
+#include "warnless.h"
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "multiif.h"
+#include "rand.h"
+
+/* The last #include file should be: */
+#include "memdebug.h"
+
+#define MQTT_MSG_CONNECT 0x10
+#define MQTT_MSG_CONNACK 0x20
+#define MQTT_MSG_PUBLISH 0x30
+#define MQTT_MSG_SUBSCRIBE 0x82
+#define MQTT_MSG_SUBACK 0x90
+#define MQTT_MSG_DISCONNECT 0xe0
+
+#define MQTT_CONNACK_LEN 4
+#define MQTT_SUBACK_LEN 5
+#define MQTT_CLIENTID_LEN 12 /* "curl0123abcd" */
+
+/*
+ * Forward declarations.
+ */
+
+static CURLcode mqtt_do(struct connectdata *conn, bool *done);
+static CURLcode mqtt_doing(struct connectdata *conn, bool *done);
+static int mqtt_getsock(struct connectdata *conn, curl_socket_t *sock);
+static CURLcode mqtt_setup_conn(struct connectdata *conn);
+
+/*
+ * MQTT protocol handler.
+ */
+
+const struct Curl_handler Curl_handler_mqtt = {
+ "MQTT", /* scheme */
+ mqtt_setup_conn, /* setup_connection */
+ mqtt_do, /* do_it */
+ ZERO_NULL, /* done */
+ ZERO_NULL, /* do_more */
+ ZERO_NULL, /* connect_it */
+ ZERO_NULL, /* connecting */
+ mqtt_doing, /* doing */
+ ZERO_NULL, /* proto_getsock */
+ mqtt_getsock, /* doing_getsock */
+ ZERO_NULL, /* domore_getsock */
+ ZERO_NULL, /* perform_getsock */
+ ZERO_NULL, /* disconnect */
+ ZERO_NULL, /* readwrite */
+ ZERO_NULL, /* connection_check */
+ PORT_MQTT, /* defport */
+ CURLPROTO_MQTT, /* protocol */
+ PROTOPT_NONE /* flags */
+};
+
+static CURLcode mqtt_setup_conn(struct connectdata *conn)
+{
+ /* allocate the HTTP-specific struct for the Curl_easy, only to survive
+ during this request */
+ struct MQTT *mq;
+ struct Curl_easy *data = conn->data;
+ DEBUGASSERT(data->req.protop == NULL);
+
+ mq = calloc(1, sizeof(struct MQTT));
+ if(!mq)
+ return CURLE_OUT_OF_MEMORY;
+ data->req.protop = mq;
+ return CURLE_OK;
+}
+
+static CURLcode mqtt_send(struct connectdata *conn,
+ char *buf, size_t len)
+{
+ CURLcode result = CURLE_OK;
+ curl_socket_t sockfd = conn->sock[FIRSTSOCKET];
+ struct Curl_easy *data = conn->data;
+ struct MQTT *mq = data->req.protop;
+ ssize_t n;
+ result = Curl_write(conn, sockfd, buf, len, &n);
+ if(!result && data->set.verbose)
+ Curl_debug(data, CURLINFO_HEADER_OUT, buf, (size_t)n);
+ if(len != (size_t)n) {
+ size_t nsend = len - n;
+ char *sendleftovers = Curl_memdup(&buf[n], nsend);
+ if(!sendleftovers)
+ return CURLE_OUT_OF_MEMORY;
+ mq->sendleftovers = sendleftovers;
+ mq->nsend = nsend;
+ }
+ return result;
+}
+
+/* Generic function called by the multi interface to figure out what socket(s)
+ to wait for and for what actions during the DOING and PROTOCONNECT
+ states */
+static int mqtt_getsock(struct connectdata *conn,
+ curl_socket_t *sock)
+{
+ sock[0] = conn->sock[FIRSTSOCKET];
+ return GETSOCK_READSOCK(FIRSTSOCKET);
+}
+
+static CURLcode mqtt_connect(struct connectdata *conn)
+{
+ CURLcode result = CURLE_OK;
+ const size_t client_id_offset = 14;
+ const size_t packetlen = client_id_offset + MQTT_CLIENTID_LEN;
+ char client_id[MQTT_CLIENTID_LEN + 1] = "curl";
+ const size_t curl_len = strlen("curl");
+ char packet[32] = {
+ MQTT_MSG_CONNECT, /* packet type */
+ 0x00, /* remaining length */
+ 0x00, 0x04, /* protocol length */
+ 'M','Q','T','T', /* protocol name */
+ 0x04, /* protocol level */
+ 0x02, /* CONNECT flag: CleanSession */
+ 0x00, 0x3c, /* keep-alive 0 = disabled */
+ 0x00, 0x00 /* payload1 length */
+ };
+ packet[1] = (packetlen - 2) & 0x7f;
+ packet[client_id_offset - 1] = MQTT_CLIENTID_LEN;
+
+ result = Curl_rand_hex(conn->data, (unsigned char *)&client_id[curl_len],
+ MQTT_CLIENTID_LEN - curl_len + 1);
+ memcpy(&packet[client_id_offset], client_id, MQTT_CLIENTID_LEN);
+ infof(conn->data, "Using client id '%s'\n", client_id);
+ if(!result)
+ result = mqtt_send(conn, packet, packetlen);
+ return result;
+}
+
+static CURLcode mqtt_disconnect(struct connectdata *conn)
+{
+ CURLcode result = CURLE_OK;
+ result = mqtt_send(conn, (char *)"\xe0\x00", 2);
+ return result;
+}
+
+static CURLcode mqtt_verify_connack(struct connectdata *conn)
+{
+ CURLcode result;
+ curl_socket_t sockfd = conn->sock[FIRSTSOCKET];
+ unsigned char readbuf[MQTT_CONNACK_LEN];
+ ssize_t nread;
+ struct Curl_easy *data = conn->data;
+
+ result = Curl_read(conn, sockfd, (char *)readbuf, MQTT_CONNACK_LEN, &nread);
+ if(result)
+ goto fail;
+
+ if(data->set.verbose)
+ Curl_debug(data, CURLINFO_HEADER_IN, (char *)readbuf, (size_t)nread);
+
+ /* fixme */
+ if(nread < MQTT_CONNACK_LEN) {
+ result = CURLE_WEIRD_SERVER_REPLY;
+ goto fail;
+ }
+
+ /* verify CONNACK */
+ if(readbuf[0] != MQTT_MSG_CONNACK ||
+ readbuf[1] != 0x02 ||
+ readbuf[2] != 0x00 ||
+ readbuf[3] != 0x00) {
+ failf(data, "Expected %02x%02x%02x%02x but got %02x%02x%02x%02x",
+ MQTT_MSG_CONNACK, 0x02, 0x00, 0x00,
+ readbuf[0], readbuf[1], readbuf[2], readbuf[3]);
+ result = CURLE_WEIRD_SERVER_REPLY;
+ }
+
+fail:
+ return result;
+}
+
+static CURLcode mqtt_get_topic(struct connectdata *conn,
+ char **topic, size_t *topiclen)
+{
+ CURLcode result = CURLE_OK;
+ char *path = conn->data->state.up.path;
+
+ if(strlen(path) > 1) {
+ result = Curl_urldecode(conn->data, path + 1, 0, topic, topiclen, FALSE);
+ }
+ else {
+ failf(conn->data, "Error: No topic specified.");
+ result = CURLE_URL_MALFORMAT;
+ }
+ return result;
+}
+
+
+static int mqtt_encode_len(char *buf, size_t len)
+{
+ unsigned char encoded;
+ int i;
+
+ for(i = 0; (len > 0) && (i<4); i++) {
+ encoded = len % 0x80;
+ len /= 0x80;
+ if(len)
+ encoded |= 0x80;
+ buf[i] = encoded;
+ }
+
+ return i;
+}
+
+static CURLcode mqtt_subscribe(struct connectdata *conn)
+{
+ CURLcode result = CURLE_OK;
+ char *topic = NULL;
+ size_t topiclen;
+ unsigned char *packet = NULL;
+ size_t packetlen;
+ char encodedsize[4];
+ size_t n;
+
+ result = mqtt_get_topic(conn, &topic, &topiclen);
+ if(result)
+ goto fail;
+
+ conn->proto.mqtt.packetid++;
+
+ packetlen = topiclen + 5; /* packetid + topic (has a two byte length field)
+ + 2 bytes topic length + QoS byte */
+ n = mqtt_encode_len((char *)encodedsize, packetlen);
+ packetlen += n + 1; /* add one for the control packet type byte */
+
+ packet = malloc(packetlen);
+ if(!packet) {
+ result = CURLE_OUT_OF_MEMORY;
+ goto fail;
+ }
+
+ packet[0] = MQTT_MSG_SUBSCRIBE;
+ memcpy(&packet[1], encodedsize, n);
+ packet[1 + n] = (conn->proto.mqtt.packetid >> 8) & 0xff;
+ packet[2 + n] = conn->proto.mqtt.packetid & 0xff;
+ packet[3 + n] = (topiclen >> 8) & 0xff;
+ packet[4 + n ] = topiclen & 0xff;
+ memcpy(&packet[5 + n], topic, topiclen);
+ packet[5 + n + topiclen] = 0; /* QoS zero */
+
+ result = mqtt_send(conn, (char *)packet, packetlen);
+
+fail:
+ free(topic);
+ free(packet);
+ return result;
+}
+
+static CURLcode mqtt_verify_suback(struct connectdata *conn)
+{
+ CURLcode result;
+ curl_socket_t sockfd = conn->sock[FIRSTSOCKET];
+ unsigned char readbuf[MQTT_SUBACK_LEN];
+ ssize_t nread;
+ struct mqtt_conn *mqtt = &conn->proto.mqtt;
+
+ result = Curl_read(conn, sockfd, (char *)readbuf, MQTT_SUBACK_LEN, &nread);
+ if(result)
+ goto fail;
+
+ if(conn->data->set.verbose)
+ Curl_debug(conn->data, CURLINFO_HEADER_IN, (char *)readbuf, (size_t)nread);
+
+ /* fixme */
+ if(nread < MQTT_SUBACK_LEN) {
+ result = CURLE_WEIRD_SERVER_REPLY;
+ goto fail;
+ }
+
+ /* verify SUBACK */
+ if(readbuf[0] != MQTT_MSG_SUBACK ||
+ readbuf[1] != 0x03 ||
+ readbuf[2] != ((mqtt->packetid >> 8) & 0xff) ||
+ readbuf[3] != (mqtt->packetid & 0xff) ||
+ readbuf[4] != 0x00)
+ result = CURLE_WEIRD_SERVER_REPLY;
+
+fail:
+ return result;
+}
+
+static CURLcode mqtt_publish(struct connectdata *conn)
+{
+ CURLcode result;
+ char *payload = conn->data->set.postfields;
+ size_t payloadlen = (size_t)conn->data->set.postfieldsize;
+ char *topic = NULL;
+ size_t topiclen;
+ unsigned char *pkt = NULL;
+ size_t i = 0;
+ size_t remaininglength;
+ size_t encodelen;
+ char encodedbytes[4];
+
+ result = mqtt_get_topic(conn, &topic, &topiclen);
+ if(result)
+ goto fail;
+
+ remaininglength = payloadlen + 2 + topiclen;
+ encodelen = mqtt_encode_len(encodedbytes, remaininglength);
+
+ /* add the control byte and the encoded remaining length */
+ pkt = malloc(remaininglength + 1 + encodelen);
+ if(!pkt) {
+ result = CURLE_OUT_OF_MEMORY;
+ goto fail;
+ }
+
+ /* assemble packet */
+ pkt[i++] = MQTT_MSG_PUBLISH;
+ memcpy(&pkt[i], encodedbytes, encodelen);
+ i += encodelen;
+ pkt[i++] = (topiclen >> 8) & 0xff;
+ pkt[i++] = (topiclen & 0xff);
+ memcpy(&pkt[i], topic, topiclen);
+ i += topiclen;
+ memcpy(&pkt[i], payload, payloadlen);
+ i += payloadlen;
+ result = mqtt_send(conn, (char *)pkt, i);
+
+fail:
+ free(pkt);
+ free(topic);
+ return result;
+}
+
+static size_t mqtt_decode_len(unsigned char *buf,
+ size_t buflen, size_t *lenbytes)
+{
+ size_t len = 0;
+ size_t mult = 1;
+ size_t i;
+ unsigned char encoded = 128;
+
+ for(i = 0; (i < buflen) && (encoded & 128); i++) {
+ encoded = buf[i];
+ len += (encoded & 127) * mult;
+ mult *= 128;
+ }
+
+ *lenbytes = i;
+
+ return len;
+}
+
+/* for the publish packet */
+#define MQTT_HEADER_LEN 5 /* max 5 bytes */
+
+static CURLcode mqtt_read_publish(struct connectdata *conn,
+ bool *done)
+{
+ CURLcode result;
+ curl_socket_t sockfd = conn->sock[FIRSTSOCKET];
+ ssize_t nread;
+ struct Curl_easy *data = conn->data;
+ unsigned char *pkt = (unsigned char *)data->state.buffer;
+ size_t remlen, lenbytes;
+ struct mqtt_conn *mqtt = &conn->proto.mqtt;
+ struct MQTT *mq = data->req.protop;
+
+ switch(mqtt->state) {
+ case MQTT_SUBWAIT:
+ /* Read the initial byte and the entire Remaining Length field
+ in this state */
+ result = Curl_read(conn, sockfd, (char *)&pkt[mq->npacket], 1, &nread);
+ if(result)
+ goto end;
+ if(data->set.verbose)
+ Curl_debug(data, CURLINFO_HEADER_IN, (char *)&pkt[mq->npacket], 1);
+ /* we are expecting a PUBLISH message */
+ if(!mq->npacket && ((pkt[0] & 0xf0) != MQTT_MSG_PUBLISH)) {
+ if(pkt[0] == MQTT_MSG_DISCONNECT) {
+ infof(data, "Got DISCONNECT\n");
+ *done = TRUE;
+ goto end;
+ }
+ result = CURLE_WEIRD_SERVER_REPLY;
+ goto end;
+ }
+ else if((mq->npacket >= 1) && !(pkt[mq->npacket] & 0x80))
+ /* as long as the high bit is set in the length byte, we read one more
+ byte, then get the remainder of the PUBLISH */
+ mqtt->state = MQTT_SUB_REMAIN;
+ mq->npacket++;
+ if(mqtt->state == MQTT_SUBWAIT)
+ return result;
+
+ /* -- switched state -- */
+
+ /* remember the first byte */
+ mq->firstbyte = pkt[0];
+
+ remlen = mqtt_decode_len(&pkt[1], 4, &lenbytes);
+
+ infof(data, "Remaining length: %zd bytes\n", remlen);
+ Curl_pgrsSetDownloadSize(data, remlen);
+ data->req.bytecount = 0;
+ data->req.size = remlen;
+ mq->npacket = remlen; /* get this many bytes */
+ /* FALLTHROUGH */
+ case MQTT_SUB_REMAIN: {
+ /* read rest of packet, but no more. Cap to buffer size */
+ struct SingleRequest *k = &data->req;
+ size_t rest = mq->npacket;
+ if(rest > (size_t)data->set.buffer_size)
+ rest = (size_t)data->set.buffer_size;
+ result = Curl_read(conn, sockfd, (char *)pkt, rest, &nread);
+ if(result) {
+ if(CURLE_AGAIN == result) {
+ infof(data, "EEEE AAAAGAIN\n");
+ }
+ goto end;
+ }
+ if(data->set.verbose)
+ Curl_debug(data, CURLINFO_DATA_IN, (char *)pkt, (size_t)nread);
+
+ mq->npacket -= nread;
+ k->bytecount += nread;
+ Curl_pgrsSetDownloadCounter(data, k->bytecount);
+
+ /* if QoS is set, message contains packet id */
+
+ result = Curl_client_write(conn, CLIENTWRITE_BODY, (char *)pkt, nread);
+ if(result)
+ goto end;
+
+ if(!mq->npacket)
+ /* no more PUBLISH payload, back to subscribe wait state */
+ mqtt->state = MQTT_SUBWAIT;
+ break;
+ }
+ default:
+ DEBUGASSERT(NULL); /* illegal state */
+ result = CURLE_WEIRD_SERVER_REPLY;
+ goto end;
+ }
+ end:
+ return result;
+}
+
+static CURLcode mqtt_do(struct connectdata *conn, bool *done)
+{
+ CURLcode result = CURLE_OK;
+ struct Curl_easy *data = conn->data;
+ struct mqtt_conn *mqtt = &conn->proto.mqtt;
+
+ *done = FALSE; /* unconditionally */
+
+ result = mqtt_connect(conn);
+ if(result) {
+ failf(data, "Error %d sending MQTT CONN request", result);
+ return result;
+ }
+ mqtt->state = MQTT_CONNACK;
+ return CURLE_OK;
+}
+
+static CURLcode mqtt_doing(struct connectdata *conn, bool *done)
+{
+ CURLcode result = CURLE_OK;
+ struct mqtt_conn *mqtt = &conn->proto.mqtt;
+ struct Curl_easy *data = conn->data;
+ struct MQTT *mq = data->req.protop;
+
+ *done = FALSE;
+
+ if(mq->nsend) {
+ /* send the remainder of an outgoing packet */
+ char *ptr = mq->sendleftovers;
+ result = mqtt_send(conn, mq->sendleftovers, mq->nsend);
+ free(ptr);
+ if(result)
+ return result;
+ }
+
+ switch(mqtt->state) {
+ case MQTT_CONNACK:
+ result = mqtt_verify_connack(conn);
+ if(result)
+ break;
+
+ if(conn->data->set.httpreq == HTTPREQ_POST) {
+ result = mqtt_publish(conn);
+ if(!result) {
+ result = mqtt_disconnect(conn);
+ *done = TRUE;
+ }
+ }
+ else {
+ result = mqtt_subscribe(conn);
+ if(!result)
+ mqtt->state = MQTT_SUBACK;
+ }
+ break;
+
+ case MQTT_SUBACK:
+ result = mqtt_verify_suback(conn);
+ if(result)
+ break;
+
+ mqtt->state = MQTT_SUBWAIT;
+ break;
+
+ case MQTT_SUBWAIT:
+ case MQTT_SUB_REMAIN:
+ result = mqtt_read_publish(conn, done);
+ if(result)
+ break;
+ break;
+
+ default:
+ failf(conn->data, "State not handled yet");
+ *done = TRUE;
+ break;
+ }
+
+ if(result == CURLE_AGAIN)
+ result = CURLE_OK;
+ return result;
+}
+
+#endif /* CURL_ENABLE_MQTT */
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-04 21:52:24 +0000