diff options
Diffstat (limited to 'Utilities/cmcurl/lib/mqtt.c')
| -rw-r--r-- | Utilities/cmcurl/lib/mqtt.c | 823 |
1 files changed, 823 insertions, 0 deletions
diff --git a/Utilities/cmcurl/lib/mqtt.c b/Utilities/cmcurl/lib/mqtt.c new file mode 100644 index 0000000000..8ba826f4fb --- /dev/null +++ b/Utilities/cmcurl/lib/mqtt.c @@ -0,0 +1,823 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 2020 - 2022, 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.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. + * + * SPDX-License-Identifier: curl + * + ***************************************************************************/ + +#include "curl_setup.h" + +#ifndef CURL_DISABLE_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 2 +#define MQTT_SUBACK_LEN 3 +#define MQTT_CLIENTID_LEN 12 /* "curl0123abcd" */ + +/* + * Forward declarations. + */ + +static CURLcode mqtt_do(struct Curl_easy *data, bool *done); +static CURLcode mqtt_done(struct Curl_easy *data, + CURLcode status, bool premature); +static CURLcode mqtt_doing(struct Curl_easy *data, bool *done); +static int mqtt_getsock(struct Curl_easy *data, struct connectdata *conn, + curl_socket_t *sock); +static CURLcode mqtt_setup_conn(struct Curl_easy *data, + struct connectdata *conn); + +/* + * MQTT protocol handler. + */ + +const struct Curl_handler Curl_handler_mqtt = { + "MQTT", /* scheme */ + mqtt_setup_conn, /* setup_connection */ + mqtt_do, /* do_it */ + mqtt_done, /* 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 */ + ZERO_NULL, /* attach connection */ + PORT_MQTT, /* defport */ + CURLPROTO_MQTT, /* protocol */ + CURLPROTO_MQTT, /* family */ + PROTOPT_NONE /* flags */ +}; + +static CURLcode mqtt_setup_conn(struct Curl_easy *data, + struct connectdata *conn) +{ + /* allocate the HTTP-specific struct for the Curl_easy, only to survive + during this request */ + struct MQTT *mq; + (void)conn; + DEBUGASSERT(data->req.p.mqtt == NULL); + + mq = calloc(1, sizeof(struct MQTT)); + if(!mq) + return CURLE_OUT_OF_MEMORY; + data->req.p.mqtt = mq; + return CURLE_OK; +} + +static CURLcode mqtt_send(struct Curl_easy *data, + char *buf, size_t len) +{ + CURLcode result = CURLE_OK; + struct connectdata *conn = data->conn; + curl_socket_t sockfd = conn->sock[FIRSTSOCKET]; + struct MQTT *mq = data->req.p.mqtt; + ssize_t n; + result = Curl_write(data, sockfd, buf, len, &n); + if(!result) + 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; + } + else { + mq->sendleftovers = NULL; + mq->nsend = 0; + } + 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 Curl_easy *data, + struct connectdata *conn, + curl_socket_t *sock) +{ + (void)data; + sock[0] = conn->sock[FIRSTSOCKET]; + return GETSOCK_READSOCK(FIRSTSOCKET); +} + +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; +} + +/* add the passwd to the CONNECT packet */ +static int add_passwd(const char *passwd, const size_t plen, + char *pkt, const size_t start, int remain_pos) +{ + /* magic number that need to be set properly */ + const size_t conn_flags_pos = remain_pos + 8; + if(plen > 0xffff) + return 1; + + /* set password flag */ + pkt[conn_flags_pos] |= 0x40; + + /* length of password provided */ + pkt[start] = (char)((plen >> 8) & 0xFF); + pkt[start + 1] = (char)(plen & 0xFF); + memcpy(&pkt[start + 2], passwd, plen); + return 0; +} + +/* add user to the CONNECT packet */ +static int add_user(const char *username, const size_t ulen, + unsigned char *pkt, const size_t start, int remain_pos) +{ + /* magic number that need to be set properly */ + const size_t conn_flags_pos = remain_pos + 8; + if(ulen > 0xffff) + return 1; + + /* set username flag */ + pkt[conn_flags_pos] |= 0x80; + /* length of username provided */ + pkt[start] = (unsigned char)((ulen >> 8) & 0xFF); + pkt[start + 1] = (unsigned char)(ulen & 0xFF); + memcpy(&pkt[start + 2], username, ulen); + return 0; +} + +/* add client ID to the CONNECT packet */ +static int add_client_id(const char *client_id, const size_t client_id_len, + char *pkt, const size_t start) +{ + if(client_id_len != MQTT_CLIENTID_LEN) + return 1; + pkt[start] = 0x00; + pkt[start + 1] = MQTT_CLIENTID_LEN; + memcpy(&pkt[start + 2], client_id, MQTT_CLIENTID_LEN); + return 0; +} + +/* Set initial values of CONNECT packet */ +static int init_connpack(char *packet, char *remain, int remain_pos) +{ + /* Fixed header starts */ + /* packet type */ + packet[0] = MQTT_MSG_CONNECT; + /* remaining length field */ + memcpy(&packet[1], remain, remain_pos); + /* Fixed header ends */ + + /* Variable header starts */ + /* protocol length */ + packet[remain_pos + 1] = 0x00; + packet[remain_pos + 2] = 0x04; + /* protocol name */ + packet[remain_pos + 3] = 'M'; + packet[remain_pos + 4] = 'Q'; + packet[remain_pos + 5] = 'T'; + packet[remain_pos + 6] = 'T'; + /* protocol level */ + packet[remain_pos + 7] = 0x04; + /* CONNECT flag: CleanSession */ + packet[remain_pos + 8] = 0x02; + /* keep-alive 0 = disabled */ + packet[remain_pos + 9] = 0x00; + packet[remain_pos + 10] = 0x3c; + /* end of variable header */ + return remain_pos + 10; +} + +static CURLcode mqtt_connect(struct Curl_easy *data) +{ + CURLcode result = CURLE_OK; + int pos = 0; + int rc = 0; + /* remain length */ + int remain_pos = 0; + char remain[4] = {0}; + size_t packetlen = 0; + size_t payloadlen = 0; + size_t start_user = 0; + size_t start_pwd = 0; + char client_id[MQTT_CLIENTID_LEN + 1] = "curl"; + const size_t clen = strlen("curl"); + char *packet = NULL; + + /* extracting username from request */ + const char *username = data->state.aptr.user ? + data->state.aptr.user : ""; + const size_t ulen = strlen(username); + /* extracting password from request */ + const char *passwd = data->state.aptr.passwd ? + data->state.aptr.passwd : ""; + const size_t plen = strlen(passwd); + + payloadlen = ulen + plen + MQTT_CLIENTID_LEN + 2; + /* The plus 2 are for the MSB and LSB describing the length of the string to + * be added on the payload. Refer to spec 1.5.2 and 1.5.4 */ + if(ulen) + payloadlen += 2; + if(plen) + payloadlen += 2; + + /* getting how much occupy the remain length */ + remain_pos = mqtt_encode_len(remain, payloadlen + 10); + + /* 10 length of variable header and 1 the first byte of the fixed header */ + packetlen = payloadlen + 10 + remain_pos + 1; + + /* allocating packet */ + if(packetlen > 268435455) + return CURLE_WEIRD_SERVER_REPLY; + packet = malloc(packetlen); + if(!packet) + return CURLE_OUT_OF_MEMORY; + memset(packet, 0, packetlen); + + /* set initial values for the CONNECT packet */ + pos = init_connpack(packet, remain, remain_pos); + + result = Curl_rand_hex(data, (unsigned char *)&client_id[clen], + MQTT_CLIENTID_LEN - clen + 1); + /* add client id */ + rc = add_client_id(client_id, strlen(client_id), packet, pos + 1); + if(rc) { + failf(data, "Client ID length mismatched: [%lu]", strlen(client_id)); + result = CURLE_WEIRD_SERVER_REPLY; + goto end; + } + infof(data, "Using client id '%s'", client_id); + + /* position where starts the user payload */ + start_user = pos + 3 + MQTT_CLIENTID_LEN; + /* position where starts the password payload */ + start_pwd = start_user + ulen; + /* if user name was provided, add it to the packet */ + if(ulen) { + start_pwd += 2; + + rc = add_user(username, ulen, + (unsigned char *)packet, start_user, remain_pos); + if(rc) { + failf(data, "Username is too large: [%lu]", ulen); + result = CURLE_WEIRD_SERVER_REPLY; + goto end; + } + } + + /* if passwd was provided, add it to the packet */ + if(plen) { + rc = add_passwd(passwd, plen, packet, start_pwd, remain_pos); + if(rc) { + failf(data, "Password is too large: [%lu]", plen); + result = CURLE_WEIRD_SERVER_REPLY; + goto end; + } + } + + if(!result) + result = mqtt_send(data, packet, packetlen); + +end: + if(packet) + free(packet); + Curl_safefree(data->state.aptr.user); + Curl_safefree(data->state.aptr.passwd); + return result; +} + +static CURLcode mqtt_disconnect(struct Curl_easy *data) +{ + CURLcode result = CURLE_OK; + struct MQTT *mq = data->req.p.mqtt; + result = mqtt_send(data, (char *)"\xe0\x00", 2); + Curl_safefree(mq->sendleftovers); + return result; +} + +static CURLcode mqtt_verify_connack(struct Curl_easy *data) +{ + CURLcode result; + struct connectdata *conn = data->conn; + curl_socket_t sockfd = conn->sock[FIRSTSOCKET]; + unsigned char readbuf[MQTT_CONNACK_LEN]; + ssize_t nread; + + result = Curl_read(data, sockfd, (char *)readbuf, MQTT_CONNACK_LEN, &nread); + if(result) + goto fail; + + 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] != 0x00 || readbuf[1] != 0x00) { + failf(data, "Expected %02x%02x but got %02x%02x", + 0x00, 0x00, readbuf[0], readbuf[1]); + result = CURLE_WEIRD_SERVER_REPLY; + } + +fail: + return result; +} + +static CURLcode mqtt_get_topic(struct Curl_easy *data, + char **topic, size_t *topiclen) +{ + char *path = data->state.up.path; + CURLcode result = CURLE_URL_MALFORMAT; + if(strlen(path) > 1) { + result = Curl_urldecode(path + 1, 0, topic, topiclen, REJECT_NADA); + if(!result && (*topiclen > 0xffff)) { + failf(data, "Too long MQTT topic"); + result = CURLE_URL_MALFORMAT; + } + } + else + failf(data, "No MQTT topic found. Forgot to URL encode it?"); + + return result; +} + +static CURLcode mqtt_subscribe(struct Curl_easy *data) +{ + CURLcode result = CURLE_OK; + char *topic = NULL; + size_t topiclen; + unsigned char *packet = NULL; + size_t packetlen; + char encodedsize[4]; + size_t n; + struct connectdata *conn = data->conn; + + result = mqtt_get_topic(data, &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(data, (char *)packet, packetlen); + +fail: + free(topic); + free(packet); + return result; +} + +/* + * Called when the first byte was already read. + */ +static CURLcode mqtt_verify_suback(struct Curl_easy *data) +{ + CURLcode result; + struct connectdata *conn = data->conn; + 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(data, sockfd, (char *)readbuf, MQTT_SUBACK_LEN, &nread); + if(result) + goto fail; + + Curl_debug(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->packetid >> 8) & 0xff) || + readbuf[1] != (mqtt->packetid & 0xff) || + readbuf[2] != 0x00) + result = CURLE_WEIRD_SERVER_REPLY; + +fail: + return result; +} + +static CURLcode mqtt_publish(struct Curl_easy *data) +{ + CURLcode result; + char *payload = data->set.postfields; + size_t payloadlen; + char *topic = NULL; + size_t topiclen; + unsigned char *pkt = NULL; + size_t i = 0; + size_t remaininglength; + size_t encodelen; + char encodedbytes[4]; + curl_off_t postfieldsize = data->set.postfieldsize; + + if(!payload) + return CURLE_BAD_FUNCTION_ARGUMENT; + if(postfieldsize < 0) + payloadlen = strlen(payload); + else + payloadlen = (size_t)postfieldsize; + + result = mqtt_get_topic(data, &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(data, (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; + } + + if(lenbytes) + *lenbytes = i; + + return len; +} + +#ifdef CURLDEBUG +static const char *statenames[]={ + "MQTT_FIRST", + "MQTT_REMAINING_LENGTH", + "MQTT_CONNACK", + "MQTT_SUBACK", + "MQTT_SUBACK_COMING", + "MQTT_PUBWAIT", + "MQTT_PUB_REMAIN", + + "NOT A STATE" +}; +#endif + +/* The only way to change state */ +static void mqstate(struct Curl_easy *data, + enum mqttstate state, + enum mqttstate nextstate) /* used if state == FIRST */ +{ + struct connectdata *conn = data->conn; + struct mqtt_conn *mqtt = &conn->proto.mqtt; +#ifdef CURLDEBUG + infof(data, "%s (from %s) (next is %s)", + statenames[state], + statenames[mqtt->state], + (state == MQTT_FIRST)? statenames[nextstate] : ""); +#endif + mqtt->state = state; + if(state == MQTT_FIRST) + mqtt->nextstate = nextstate; +} + + +/* for the publish packet */ +#define MQTT_HEADER_LEN 5 /* max 5 bytes */ + +static CURLcode mqtt_read_publish(struct Curl_easy *data, bool *done) +{ + CURLcode result = CURLE_OK; + struct connectdata *conn = data->conn; + curl_socket_t sockfd = conn->sock[FIRSTSOCKET]; + ssize_t nread; + unsigned char *pkt = (unsigned char *)data->state.buffer; + size_t remlen; + struct mqtt_conn *mqtt = &conn->proto.mqtt; + struct MQTT *mq = data->req.p.mqtt; + unsigned char packet; + + switch(mqtt->state) { + MQTT_SUBACK_COMING: + case MQTT_SUBACK_COMING: + result = mqtt_verify_suback(data); + if(result) + break; + + mqstate(data, MQTT_FIRST, MQTT_PUBWAIT); + break; + + case MQTT_SUBACK: + case MQTT_PUBWAIT: + /* we are expecting PUBLISH or SUBACK */ + packet = mq->firstbyte & 0xf0; + if(packet == MQTT_MSG_PUBLISH) + mqstate(data, MQTT_PUB_REMAIN, MQTT_NOSTATE); + else if(packet == MQTT_MSG_SUBACK) { + mqstate(data, MQTT_SUBACK_COMING, MQTT_NOSTATE); + goto MQTT_SUBACK_COMING; + } + else if(packet == MQTT_MSG_DISCONNECT) { + infof(data, "Got DISCONNECT"); + *done = TRUE; + goto end; + } + else { + result = CURLE_WEIRD_SERVER_REPLY; + goto end; + } + + /* -- switched state -- */ + remlen = mq->remaining_length; + infof(data, "Remaining length: %zd bytes", remlen); + if(data->set.max_filesize && + (curl_off_t)remlen > data->set.max_filesize) { + failf(data, "Maximum file size exceeded"); + result = CURLE_FILESIZE_EXCEEDED; + goto end; + } + Curl_pgrsSetDownloadSize(data, remlen); + data->req.bytecount = 0; + data->req.size = remlen; + mq->npacket = remlen; /* get this many bytes */ + /* FALLTHROUGH */ + case MQTT_PUB_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(data, sockfd, (char *)pkt, rest, &nread); + if(result) { + if(CURLE_AGAIN == result) { + infof(data, "EEEE AAAAGAIN"); + } + goto end; + } + if(!nread) { + infof(data, "server disconnected"); + result = CURLE_PARTIAL_FILE; + goto end; + } + 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(data, CLIENTWRITE_BODY, (char *)pkt, nread); + if(result) + goto end; + + if(!mq->npacket) + /* no more PUBLISH payload, back to subscribe wait state */ + mqstate(data, MQTT_FIRST, MQTT_PUBWAIT); + break; + } + default: + DEBUGASSERT(NULL); /* illegal state */ + result = CURLE_WEIRD_SERVER_REPLY; + goto end; + } + end: + return result; +} + +static CURLcode mqtt_do(struct Curl_easy *data, bool *done) +{ + CURLcode result = CURLE_OK; + *done = FALSE; /* unconditionally */ + + result = mqtt_connect(data); + if(result) { + failf(data, "Error %d sending MQTT CONNECT request", result); + return result; + } + mqstate(data, MQTT_FIRST, MQTT_CONNACK); + return CURLE_OK; +} + +static CURLcode mqtt_done(struct Curl_easy *data, + CURLcode status, bool premature) +{ + struct MQTT *mq = data->req.p.mqtt; + (void)status; + (void)premature; + Curl_safefree(mq->sendleftovers); + return CURLE_OK; +} + +static CURLcode mqtt_doing(struct Curl_easy *data, bool *done) +{ + CURLcode result = CURLE_OK; + struct connectdata *conn = data->conn; + struct mqtt_conn *mqtt = &conn->proto.mqtt; + struct MQTT *mq = data->req.p.mqtt; + ssize_t nread; + curl_socket_t sockfd = conn->sock[FIRSTSOCKET]; + unsigned char *pkt = (unsigned char *)data->state.buffer; + unsigned char byte; + + *done = FALSE; + + if(mq->nsend) { + /* send the remainder of an outgoing packet */ + char *ptr = mq->sendleftovers; + result = mqtt_send(data, mq->sendleftovers, mq->nsend); + free(ptr); + if(result) + return result; + } + + infof(data, "mqtt_doing: state [%d]", (int) mqtt->state); + switch(mqtt->state) { + case MQTT_FIRST: + /* Read the initial byte only */ + result = Curl_read(data, sockfd, (char *)&mq->firstbyte, 1, &nread); + if(result) + break; + else if(!nread) { + failf(data, "Connection disconnected"); + *done = TRUE; + result = CURLE_RECV_ERROR; + break; + } + Curl_debug(data, CURLINFO_HEADER_IN, (char *)&mq->firstbyte, 1); + /* remember the first byte */ + mq->npacket = 0; + mqstate(data, MQTT_REMAINING_LENGTH, MQTT_NOSTATE); + /* FALLTHROUGH */ + case MQTT_REMAINING_LENGTH: + do { + result = Curl_read(data, sockfd, (char *)&byte, 1, &nread); + if(!nread) + break; + Curl_debug(data, CURLINFO_HEADER_IN, (char *)&byte, 1); + pkt[mq->npacket++] = byte; + } while((byte & 0x80) && (mq->npacket < 4)); + if(nread && (byte & 0x80)) + /* MQTT supports up to 127 * 128^0 + 127 * 128^1 + 127 * 128^2 + + 127 * 128^3 bytes. server tried to send more */ + result = CURLE_WEIRD_SERVER_REPLY; + if(result) + break; + mq->remaining_length = mqtt_decode_len(&pkt[0], mq->npacket, NULL); + mq->npacket = 0; + if(mq->remaining_length) { + mqstate(data, mqtt->nextstate, MQTT_NOSTATE); + break; + } + mqstate(data, MQTT_FIRST, MQTT_FIRST); + + if(mq->firstbyte == MQTT_MSG_DISCONNECT) { + infof(data, "Got DISCONNECT"); + *done = TRUE; + } + break; + case MQTT_CONNACK: + result = mqtt_verify_connack(data); + if(result) + break; + + if(data->state.httpreq == HTTPREQ_POST) { + result = mqtt_publish(data); + if(!result) { + result = mqtt_disconnect(data); + *done = TRUE; + } + mqtt->nextstate = MQTT_FIRST; + } + else { + result = mqtt_subscribe(data); + if(!result) { + mqstate(data, MQTT_FIRST, MQTT_SUBACK); + } + } + break; + + case MQTT_SUBACK: + case MQTT_PUBWAIT: + case MQTT_PUB_REMAIN: + result = mqtt_read_publish(data, done); + break; + + default: + failf(data, "State not handled yet"); + *done = TRUE; + break; + } + + if(result == CURLE_AGAIN) + result = CURLE_OK; + return result; +} + +#endif /* CURL_DISABLE_MQTT */ |