diff options
Diffstat (limited to 'src/aclk/mqtt_websockets/mqtt_ng.c')
| -rw-r--r-- | src/aclk/mqtt_websockets/mqtt_ng.c | 2237 |
1 files changed, 2237 insertions, 0 deletions
diff --git a/src/aclk/mqtt_websockets/mqtt_ng.c b/src/aclk/mqtt_websockets/mqtt_ng.c new file mode 100644 index 000000000..f570fde71 --- /dev/null +++ b/src/aclk/mqtt_websockets/mqtt_ng.c @@ -0,0 +1,2237 @@ +// Copyright: SPDX-License-Identifier: GPL-3.0-only + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif + +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <pthread.h> +#include <inttypes.h> + +#include "c_rhash/c_rhash.h" + +#include "common_internal.h" +#include "mqtt_constants.h" +#include "mqtt_wss_log.h" +#include "mqtt_ng.h" + +#define UNIT_LOG_PREFIX "mqtt_client: " +#define FATAL(fmt, ...) mws_fatal(client->log, UNIT_LOG_PREFIX fmt, ##__VA_ARGS__) +#define ERROR(fmt, ...) mws_error(client->log, UNIT_LOG_PREFIX fmt, ##__VA_ARGS__) +#define WARN(fmt, ...) mws_warn (client->log, UNIT_LOG_PREFIX fmt, ##__VA_ARGS__) +#define INFO(fmt, ...) mws_info (client->log, UNIT_LOG_PREFIX fmt, ##__VA_ARGS__) +#define DEBUG(fmt, ...) mws_debug(client->log, UNIT_LOG_PREFIX fmt, ##__VA_ARGS__) + +#define SMALL_STRING_DONT_FRAGMENT_LIMIT 128 + +#define MIN(a,b) (((a)<(b))?(a):(b)) + +#define LOCK_HDR_BUFFER(buffer) pthread_mutex_lock(&((buffer)->mutex)) +#define UNLOCK_HDR_BUFFER(buffer) pthread_mutex_unlock(&((buffer)->mutex)) + +#define BUFFER_FRAG_GARBAGE_COLLECT 0x01 +// some packets can be marked for garbage collection +// immediately when they are sent (e.g. sent PUBACK on QoS1) +#define BUFFER_FRAG_GARBAGE_COLLECT_ON_SEND 0x02 +// as buffer fragment can point to both +// external data and data in the same buffer +// we mark the former case with BUFFER_FRAG_DATA_EXTERNAL +#define BUFFER_FRAG_DATA_EXTERNAL 0x04 +// as single MQTT Packet can be stored into multiple +// buffer fragments (depending on copy requirements) +// this marks this fragment to be the first/last +#define BUFFER_FRAG_MQTT_PACKET_HEAD 0x10 +#define BUFFER_FRAG_MQTT_PACKET_TAIL 0x20 + +typedef uint16_t buffer_frag_flag_t; +struct buffer_fragment { + size_t len; + size_t sent; + buffer_frag_flag_t flags; + void (*free_fnc)(void *ptr); + unsigned char *data; + + uint16_t packet_id; + + struct buffer_fragment *next; +}; + +typedef struct buffer_fragment *mqtt_msg_data; + +// buffer used for MQTT headers only +// not for actual data sent +struct header_buffer { + size_t size; + unsigned char *data; + unsigned char *tail; + struct buffer_fragment *tail_frag; +}; + +struct transaction_buffer { + struct header_buffer hdr_buffer; + // used while building new message + // to be able to revert state easily + // in case of error mid processing + struct header_buffer state_backup; + pthread_mutex_t mutex; + struct buffer_fragment *sending_frag; +}; + +enum mqtt_client_state { + RAW = 0, + CONNECT_PENDING, + CONNECTING, + CONNECTED, + ERROR, + DISCONNECTED +}; + +enum parser_state { + MQTT_PARSE_FIXED_HEADER_PACKET_TYPE = 0, + MQTT_PARSE_FIXED_HEADER_LEN, + MQTT_PARSE_VARIABLE_HEADER, + MQTT_PARSE_MQTT_PACKET_DONE +}; + +enum varhdr_parser_state { + MQTT_PARSE_VARHDR_INITIAL = 0, + MQTT_PARSE_VARHDR_OPTIONAL_REASON_CODE, + MQTT_PARSE_VARHDR_PROPS, + MQTT_PARSE_VARHDR_TOPICNAME, + MQTT_PARSE_VARHDR_POST_TOPICNAME, + MQTT_PARSE_VARHDR_PACKET_ID, + MQTT_PARSE_REASONCODES, + MQTT_PARSE_PAYLOAD +}; + +struct mqtt_vbi_parser_ctx { + char data[MQTT_VBI_MAXBYTES]; + uint8_t bytes; + uint32_t result; +}; + +enum mqtt_datatype { + MQTT_TYPE_UNKNOWN = 0, + MQTT_TYPE_UINT_8, + MQTT_TYPE_UINT_16, + MQTT_TYPE_UINT_32, + MQTT_TYPE_VBI, + MQTT_TYPE_STR, + MQTT_TYPE_STR_PAIR, + MQTT_TYPE_BIN +}; + +struct mqtt_property { + uint8_t id; + enum mqtt_datatype type; + union { + char *strings[2]; + void *bindata; + uint8_t uint8; + uint16_t uint16; + uint32_t uint32; + } data; + size_t bindata_len; + struct mqtt_property *next; +}; + +enum mqtt_properties_parser_state { + PROPERTIES_LENGTH = 0, + PROPERTY_CREATE, + PROPERTY_ID, + PROPERTY_TYPE_UINT8, + PROPERTY_TYPE_UINT16, + PROPERTY_TYPE_UINT32, + PROPERTY_TYPE_STR_BIN_LEN, + PROPERTY_TYPE_STR, + PROPERTY_TYPE_BIN, + PROPERTY_TYPE_VBI, + PROPERTY_NEXT +}; + +struct mqtt_properties_parser_ctx { + enum mqtt_properties_parser_state state; + struct mqtt_property *head; + struct mqtt_property *tail; + uint32_t properties_length; + uint32_t vbi_length; + struct mqtt_vbi_parser_ctx vbi_parser_ctx; + size_t bytes_consumed; + int str_idx; +}; + +struct mqtt_connack { + uint8_t flags; + uint8_t reason_code; +}; +struct mqtt_puback { + uint16_t packet_id; + uint8_t reason_code; +}; + +struct mqtt_suback { + uint16_t packet_id; + uint8_t *reason_codes; + uint8_t reason_code_count; + uint8_t reason_codes_pending; +}; + +struct mqtt_publish { + uint16_t topic_len; + char *topic; + uint16_t packet_id; + size_t data_len; + char *data; + uint8_t qos; +}; + +struct mqtt_disconnect { + uint8_t reason_code; +}; + +struct mqtt_ng_parser { + rbuf_t received_data; + + uint8_t mqtt_control_packet_type; + uint32_t mqtt_fixed_hdr_remaining_length; + size_t mqtt_parsed_len; + + struct mqtt_vbi_parser_ctx vbi_parser; + struct mqtt_properties_parser_ctx properties_parser; + + enum parser_state state; + enum varhdr_parser_state varhdr_state; + + struct mqtt_property *varhdr_properties; + + union { + struct mqtt_connack connack; + struct mqtt_puback puback; + struct mqtt_suback suback; + struct mqtt_publish publish; + struct mqtt_disconnect disconnect; + } mqtt_packet; +}; + +struct topic_alias_data { + uint16_t idx; + uint32_t usage_count; +}; + +struct topic_aliases_data { + c_rhash stoi_dict; + uint32_t idx_max; + uint32_t idx_assigned; + pthread_rwlock_t rwlock; +}; + +struct mqtt_ng_client { + struct transaction_buffer main_buffer; + + enum mqtt_client_state client_state; + + mqtt_msg_data connect_msg; + + mqtt_wss_log_ctx_t log; + + mqtt_ng_send_fnc_t send_fnc_ptr; + void *user_ctx; + + // time when last fragment of MQTT message was sent + time_t time_of_last_send; + + struct mqtt_ng_parser parser; + + size_t max_mem_bytes; + + void (*puback_callback)(uint16_t packet_id); + void (*connack_callback)(void* user_ctx, int connack_reply); + void (*msg_callback)(const char *topic, const void *msg, size_t msglen, int qos); + + unsigned int ping_pending:1; + + struct mqtt_ng_stats stats; + pthread_mutex_t stats_mutex; + + struct topic_aliases_data tx_topic_aliases; + c_rhash rx_aliases; + + size_t max_msg_size; +}; + +unsigned char pingreq[] = { MQTT_CPT_PINGREQ << 4, 0x00 }; + +struct buffer_fragment ping_frag = { + .data = pingreq, + .flags = BUFFER_FRAG_MQTT_PACKET_HEAD | BUFFER_FRAG_MQTT_PACKET_TAIL, + .free_fnc = NULL, + .len = sizeof(pingreq), + .next = NULL, + .sent = 0, + .packet_id = 0 +}; + +int uint32_to_mqtt_vbi(uint32_t input, unsigned char *output) { + int i = 1; + *output = 0; + + /* MQTT 5 specs allows max 4 bytes of output + making it 0xFF, 0xFF, 0xFF, 0x7F + representing number 268435455 decimal + see 1.5.5. Variable Byte Integer */ + if(input >= 256 * 1024 * 1024) + return 0; + + if(!input) { + *output = 0; + return 1; + } + + while(input) { + output[i-1] = input & MQTT_VBI_DATA_MASK; + input >>= 7; + if (input) + output[i-1] |= MQTT_VBI_CONTINUATION_FLAG; + i++; + } + return i - 1; +} + +int mqtt_vbi_to_uint32(char *input, uint32_t *output) { + // dont want to operate directly on output + // as I want it to be possible for input and output + // pointer to be the same + uint32_t result = 0; + uint32_t multiplier = 1; + + do { + result += (uint32_t)(*input & MQTT_VBI_DATA_MASK) * multiplier; + if (multiplier > 128*128*128) + return 1; + multiplier <<= 7; + } while (*input++ & MQTT_VBI_CONTINUATION_FLAG); + *output = result; + return 0; +} + +#ifdef TESTS +#include <stdio.h> +#define MQTT_VBI_MAXLEN 4 +// we add extra byte to check we dont write out of bounds +// in case where 4 bytes are supposed to be written +static const char _mqtt_vbi_0[MQTT_VBI_MAXLEN + 1] = { 0x00, 0x00, 0x00, 0x00, 0x00 }; +static const char _mqtt_vbi_127[MQTT_VBI_MAXLEN + 1] = { 0x7F, 0x00, 0x00, 0x00, 0x00 }; +static const char _mqtt_vbi_128[MQTT_VBI_MAXLEN + 1] = { 0x80, 0x01, 0x00, 0x00, 0x00 }; +static const char _mqtt_vbi_16383[MQTT_VBI_MAXLEN + 1] = { 0xFF, 0x7F, 0x00, 0x00, 0x00 }; +static const char _mqtt_vbi_16384[MQTT_VBI_MAXLEN + 1] = { 0x80, 0x80, 0x01, 0x00, 0x00 }; +static const char _mqtt_vbi_2097151[MQTT_VBI_MAXLEN + 1] = { 0xFF, 0xFF, 0x7F, 0x00, 0x00 }; +static const char _mqtt_vbi_2097152[MQTT_VBI_MAXLEN + 1] = { 0x80, 0x80, 0x80, 0x01, 0x00 }; +static const char _mqtt_vbi_268435455[MQTT_VBI_MAXLEN + 1] = { 0xFF, 0xFF, 0xFF, 0x7F, 0x00 }; +static const char _mqtt_vbi_999999999[MQTT_VBI_MAXLEN + 1] = { 0x80, 0x80, 0x80, 0x80, 0x01 }; + +#define MQTT_VBI_TESTCASE(case, expected_len) \ + { \ + memset(buf, 0, MQTT_VBI_MAXLEN + 1); \ + int len; \ + if ((len=uint32_to_mqtt_vbi(case, buf)) != expected_len) { \ + fprintf(stderr, "uint32_to_mqtt_vbi(case:%d, line:%d): Incorrect length returned. Expected %d, Got %d\n", case, __LINE__, expected_len, len); \ + return 1; \ + } \ + if (memcmp(buf, _mqtt_vbi_ ## case, MQTT_VBI_MAXLEN + 1 )) { \ + fprintf(stderr, "uint32_to_mqtt_vbi(case:%d, line:%d): Wrong output\n", case, __LINE__); \ + return 1; \ + } } + + +int test_uint32_mqtt_vbi() { + char buf[MQTT_VBI_MAXLEN + 1]; + + MQTT_VBI_TESTCASE(0, 1) + MQTT_VBI_TESTCASE(127, 1) + MQTT_VBI_TESTCASE(128, 2) + MQTT_VBI_TESTCASE(16383, 2) + MQTT_VBI_TESTCASE(16384, 3) + MQTT_VBI_TESTCASE(2097151, 3) + MQTT_VBI_TESTCASE(2097152, 4) + MQTT_VBI_TESTCASE(268435455, 4) + + memset(buf, 0, MQTT_VBI_MAXLEN + 1); + int len; + if ((len=uint32_to_mqtt_vbi(268435456, buf)) != 0) { + fprintf(stderr, "uint32_to_mqtt_vbi(case:268435456, line:%d): Incorrect length returned. Expected 0, Got %d\n", __LINE__, len); + return 1; + } + + return 0; +} + +#define MQTT_VBI2UINT_TESTCASE(case, expected_error) \ + { \ + uint32_t result; \ + int ret = mqtt_vbi_to_uint32(_mqtt_vbi_ ## case, &result); \ + if (ret && !(expected_error)) { \ + fprintf(stderr, "mqtt_vbi_to_uint(case:%d, line:%d): Unexpectedly Errored\n", (case), __LINE__); \ + return 1; \ + } \ + if (!ret && (expected_error)) { \ + fprintf(stderr, "mqtt_vbi_to_uint(case:%d, line:%d): Should return error but didnt\n", (case), __LINE__); \ + return 1; \ + } \ + if (!ret && result != (case)) { \ + fprintf(stderr, "mqtt_vbi_to_uint(case:%d, line:%d): Returned wrong result %d\n", (case), __LINE__, result); \ + return 1; \ + }} + + +int test_mqtt_vbi_to_uint32() { + MQTT_VBI2UINT_TESTCASE(0, 0) + MQTT_VBI2UINT_TESTCASE(127, 0) + MQTT_VBI2UINT_TESTCASE(128, 0) + MQTT_VBI2UINT_TESTCASE(16383, 0) + MQTT_VBI2UINT_TESTCASE(16384, 0) + MQTT_VBI2UINT_TESTCASE(2097151, 0) + MQTT_VBI2UINT_TESTCASE(2097152, 0) + MQTT_VBI2UINT_TESTCASE(268435455, 0) + MQTT_VBI2UINT_TESTCASE(999999999, 1) + return 0; +} +#endif /* TESTS */ + +// this helps with switch statements +// as they have to use integer type (not pointer) +enum memory_mode { + MEMCPY, + EXTERNAL_FREE_AFTER_USE, + CALLER_RESPONSIBLE +}; + +static inline enum memory_mode ptr2memory_mode(void * ptr) { + if (ptr == NULL) + return MEMCPY; + if (ptr == CALLER_RESPONSIBILITY) + return CALLER_RESPONSIBLE; + return EXTERNAL_FREE_AFTER_USE; +} + +#define frag_is_marked_for_gc(frag) ((frag->flags & BUFFER_FRAG_GARBAGE_COLLECT) || ((frag->flags & BUFFER_FRAG_GARBAGE_COLLECT_ON_SEND) && frag->sent == frag->len)) +#define FRAG_SIZE_IN_BUFFER(frag) (sizeof(struct buffer_fragment) + ((frag->flags & BUFFER_FRAG_DATA_EXTERNAL) ? 0 : frag->len)) + +static void buffer_frag_free_data(struct buffer_fragment *frag) +{ + if ( frag->flags & BUFFER_FRAG_DATA_EXTERNAL && frag->data != NULL) { + switch (ptr2memory_mode(frag->free_fnc)) { + case MEMCPY: + mw_free(frag->data); + break; + case EXTERNAL_FREE_AFTER_USE: + frag->free_fnc(frag->data); + break; + case CALLER_RESPONSIBLE: + break; + } + frag->data = NULL; + } +} + +#define HEADER_BUFFER_SIZE 1024*1024 +#define GROWTH_FACTOR 1.25 + +#define BUFFER_BYTES_USED(buf) ((size_t)((buf)->tail - (buf)->data)) +#define BUFFER_BYTES_AVAILABLE(buf) ((buf)->size - BUFFER_BYTES_USED(buf)) +#define BUFFER_FIRST_FRAG(buf) ((struct buffer_fragment *)((buf)->tail_frag ? (buf)->data : NULL)) +static void buffer_purge(struct header_buffer *buf) { + struct buffer_fragment *frag = BUFFER_FIRST_FRAG(buf); + while (frag) { + buffer_frag_free_data(frag); + frag = frag->next; + } + buf->tail = buf->data; + buf->tail_frag = NULL; +} + +#define FRAG_PADDING(addr) ((MQTT_WSS_FRAG_MEMALIGN - ((uintptr_t)addr % MQTT_WSS_FRAG_MEMALIGN)) % MQTT_WSS_FRAG_MEMALIGN) +static struct buffer_fragment *buffer_new_frag(struct header_buffer *buf, buffer_frag_flag_t flags) +{ + uint8_t padding = FRAG_PADDING(buf->tail); + + if (BUFFER_BYTES_AVAILABLE(buf) < sizeof(struct buffer_fragment) + padding) + return NULL; + + struct buffer_fragment *frag = (struct buffer_fragment *)(buf->tail + padding); + + memset(frag, 0, sizeof(*frag)); + buf->tail += sizeof(*frag) + padding; + + if (/*!((frag)->flags & BUFFER_FRAG_MQTT_PACKET_HEAD) &&*/ buf->tail_frag) + buf->tail_frag->next = frag; + + buf->tail_frag = frag; + + frag->data = buf->tail; + + frag->flags = flags; + + return frag; +} + +static void buffer_rebuild(struct header_buffer *buf) +{ + struct buffer_fragment *frag = (struct buffer_fragment*)buf->data; + do { + buf->tail = (unsigned char *) frag + sizeof(struct buffer_fragment); + buf->tail_frag = frag; + if (!(frag->flags & BUFFER_FRAG_DATA_EXTERNAL)) { + buf->tail_frag->data = buf->tail; + buf->tail += frag->len; + } + if (frag->next != NULL) + frag->next = (struct buffer_fragment*)(buf->tail + FRAG_PADDING(buf->tail)); + frag = frag->next; + } while(frag); +} + +static void buffer_garbage_collect(struct header_buffer *buf, mqtt_wss_log_ctx_t log_ctx) +{ +#if !defined(MQTT_DEBUG_VERBOSE) && !defined(ADDITIONAL_CHECKS) + (void) log_ctx; +#endif +#ifdef MQTT_DEBUG_VERBOSE + mws_debug(log_ctx, "Buffer Garbage Collection!"); +#endif + + struct buffer_fragment *frag = BUFFER_FIRST_FRAG(buf); + while (frag) { + if (!frag_is_marked_for_gc(frag)) + break; + + buffer_frag_free_data(frag); + + frag = frag->next; + } + + if (frag == BUFFER_FIRST_FRAG(buf)) { +#ifdef MQTT_DEBUG_VERBOSE + mws_debug(log_ctx, "Buffer Garbage Collection! No Space Reclaimed!"); +#endif + return; + } + + if (!frag) { + buf->tail_frag = NULL; + buf->tail = buf->data; + return; + } + +#ifdef ADDITIONAL_CHECKS + if (!(frag->flags & BUFFER_FRAG_MQTT_PACKET_HEAD)) { + mws_error(log_ctx, "Expected to find end of buffer (NULL) or next packet head!"); + return; + } +#endif + + memmove(buf->data, frag, buf->tail - (unsigned char *) frag); + buffer_rebuild(buf); +} + +static void transaction_buffer_garbage_collect(struct transaction_buffer *buf, mqtt_wss_log_ctx_t log_ctx) +{ +#ifdef MQTT_DEBUG_VERBOSE + mws_debug(log_ctx, "Transaction Buffer Garbage Collection! %s", buf->sending_frag == NULL ? "NULL" : "in flight message"); +#endif + + // Invalidate the cached sending fragment + // as we will move data around + if (buf->sending_frag != &ping_frag) + buf->sending_frag = NULL; + + buffer_garbage_collect(&buf->hdr_buffer, log_ctx); +} + +static int transaction_buffer_grow(struct transaction_buffer *buf, mqtt_wss_log_ctx_t log_ctx, float rate, size_t max) +{ + if (buf->hdr_buffer.size >= max) + return 0; + + // Invalidate the cached sending fragment + // as we will move data around + if (buf->sending_frag != &ping_frag) + buf->sending_frag = NULL; + + buf->hdr_buffer.size *= rate; + if (buf->hdr_buffer.size > max) + buf->hdr_buffer.size = max; + + void *ret = mw_realloc(buf->hdr_buffer.data, buf->hdr_buffer.size); + if (ret == NULL) { + mws_warn(log_ctx, "Buffer growth failed (realloc)"); + return 1; + } + + mws_debug(log_ctx, "Message metadata buffer was grown"); + + buf->hdr_buffer.data = ret; + buffer_rebuild(&buf->hdr_buffer); + return 0; +} + +inline static int transaction_buffer_init(struct transaction_buffer *to_init, size_t size) +{ + pthread_mutex_init(&to_init->mutex, NULL); + + to_init->hdr_buffer.size = size; + to_init->hdr_buffer.data = mw_malloc(size); + if (to_init->hdr_buffer.data == NULL) + return 1; + + to_init->hdr_buffer.tail = to_init->hdr_buffer.data; + to_init->hdr_buffer.tail_frag = NULL; + return 0; +} + +static void transaction_buffer_destroy(struct transaction_buffer *to_init) +{ + buffer_purge(&to_init->hdr_buffer); + pthread_mutex_destroy(&to_init->mutex); + mw_free(to_init->hdr_buffer.data); +} + +// Creates transaction +// saves state of buffer before any operation was done +// allowing for rollback if things go wrong +#define transaction_buffer_transaction_start(buf) \ + { LOCK_HDR_BUFFER(buf); \ + memcpy(&(buf)->state_backup, &(buf)->hdr_buffer, sizeof((buf)->hdr_buffer)); } + +#define transaction_buffer_transaction_commit(buf) UNLOCK_HDR_BUFFER(buf); + +void transaction_buffer_transaction_rollback(struct transaction_buffer *buf, struct buffer_fragment *frag) +{ + memcpy(&buf->hdr_buffer, &buf->state_backup, sizeof(buf->hdr_buffer)); + if (buf->hdr_buffer.tail_frag != NULL) + buf->hdr_buffer.tail_frag->next = NULL; + + while(frag) { + buffer_frag_free_data(frag); + // we are not actually freeing the structure itself + // just the data it manages + // structure itself is in permanent buffer + // which is locked by HDR_BUFFER lock + frag = frag->next; + } + + UNLOCK_HDR_BUFFER(buf); +} + +#define TX_ALIASES_INITIALIZE() c_rhash_new(0) +#define RX_ALIASES_INITIALIZE() c_rhash_new(UINT16_MAX >> 8) +struct mqtt_ng_client *mqtt_ng_init(struct mqtt_ng_init *settings) +{ + struct mqtt_ng_client *client = mw_calloc(1, sizeof(struct mqtt_ng_client)); + if (client == NULL) + return NULL; + + if (transaction_buffer_init(&client->main_buffer, HEADER_BUFFER_SIZE)) + goto err_free_client; + + client->rx_aliases = RX_ALIASES_INITIALIZE(); + if (client->rx_aliases == NULL) + goto err_free_trx_buf; + + if (pthread_mutex_init(&client->stats_mutex, NULL)) + goto err_free_rx_alias; + + client->tx_topic_aliases.stoi_dict = TX_ALIASES_INITIALIZE(); + if (client->tx_topic_aliases.stoi_dict == NULL) + goto err_free_stats_mutex; + client->tx_topic_aliases.idx_max = UINT16_MAX; + + if (pthread_rwlock_init(&client->tx_topic_aliases.rwlock, NULL)) + goto err_free_tx_alias; + + // TODO just embed the struct into mqtt_ng_client + client->parser.received_data = settings->data_in; + client->send_fnc_ptr = settings->data_out_fnc; + client->user_ctx = settings->user_ctx; + + client->log = settings->log; + + client->puback_callback = settings->puback_callback; + client->connack_callback = settings->connack_callback; + client->msg_callback = settings->msg_callback; + + return client; + +err_free_tx_alias: + c_rhash_destroy(client->tx_topic_aliases.stoi_dict); +err_free_stats_mutex: + pthread_mutex_destroy(&client->stats_mutex); +err_free_rx_alias: + c_rhash_destroy(client->rx_aliases); +err_free_trx_buf: + transaction_buffer_destroy(&client->main_buffer); +err_free_client: + mw_free(client); + return NULL; +} + +static inline uint8_t get_control_packet_type(uint8_t first_hdr_byte) +{ + return first_hdr_byte >> 4; +} + +static void mqtt_ng_destroy_rx_alias_hash(c_rhash hash) +{ + c_rhash_iter_t i = C_RHASH_ITER_T_INITIALIZER; + uint64_t stored_key; + void *to_free; + while(!c_rhash_iter_uint64_keys(hash, &i, &stored_key)) { + c_rhash_get_ptr_by_uint64(hash, stored_key, &to_free); + mw_free(to_free); + } + c_rhash_destroy(hash); +} + +static void mqtt_ng_destroy_tx_alias_hash(c_rhash hash) +{ + c_rhash_iter_t i = C_RHASH_ITER_T_INITIALIZER; + const char *stored_key; + void *to_free; + while(!c_rhash_iter_str_keys(hash, &i, &stored_key)) { + c_rhash_get_ptr_by_str(hash, stored_key, &to_free); + mw_free(to_free); + } + c_rhash_destroy(hash); +} + +void mqtt_ng_destroy(struct mqtt_ng_client *client) +{ + transaction_buffer_destroy(&client->main_buffer); + pthread_mutex_destroy(&client->stats_mutex); + + mqtt_ng_destroy_tx_alias_hash(client->tx_topic_aliases.stoi_dict); + pthread_rwlock_destroy(&client->tx_topic_aliases.rwlock); + mqtt_ng_destroy_rx_alias_hash(client->rx_aliases); + + mw_free(client); +} + +int frag_set_external_data(mqtt_wss_log_ctx_t log, struct buffer_fragment *frag, void *data, size_t data_len, free_fnc_t data_free_fnc) +{ + if (frag->len) { + // TODO?: This could potentially be done in future if we set rule + // external data always follows in buffer data + // could help reduce fragmentation in some messages but + // currently not worth it considering time is tight + mws_fatal(log, UNIT_LOG_PREFIX "INTERNAL ERROR: Cannot set external data to fragment already containing in buffer data!"); + return 1; + } + + switch (ptr2memory_mode(data_free_fnc)) { + case MEMCPY: + frag->data = mw_malloc(data_len); + if (frag->data == NULL) { + mws_error(log, UNIT_LOG_PREFIX "OOM while malloc @_optimized_add"); + return 1; + } + memcpy(frag->data, data, data_len); + break; + case EXTERNAL_FREE_AFTER_USE: + case CALLER_RESPONSIBLE: + frag->data = data; + break; + } + frag->free_fnc = data_free_fnc; + frag->len = data_len; + + frag->flags |= BUFFER_FRAG_DATA_EXTERNAL; + return 0; + } + +// this is fixed part of variable header for connect packet +// mqtt-v5.0-cs1, 3.1.2.1, 2.1.2.2 +static const char mqtt_protocol_name_frag[] = + { 0x00, 0x04, 'M', 'Q', 'T', 'T', MQTT_VERSION_5_0 }; + +#define MQTT_UTF8_STRING_SIZE(string) (2 + strlen(string)) + +// see 1.5.5 +#define MQTT_VARSIZE_INT_BYTES(value) ( value > 2097152 ? 4 : ( value > 16384 ? 3 : ( value > 128 ? 2 : 1 ) ) ) + +static size_t mqtt_ng_connect_size(struct mqtt_auth_properties *auth, + struct mqtt_lwt_properties *lwt) +{ + // First get the size of payload + variable header + size_t size = + + sizeof(mqtt_protocol_name_frag) /* Proto Name and Version */ + + 1 /* Connect Flags */ + + 2 /* Keep Alive */ + + 4 /* 3.1.2.11.1 Property Length - for now fixed to only Topic Alias Maximum, TODO TODO*/; + + // CONNECT payload. 3.1.3 + if (auth->client_id) + size += MQTT_UTF8_STRING_SIZE(auth->client_id); + + if (lwt) { + // 3.1.3.2 will properties TODO TODO + size += 1; + + // 3.1.3.3 + if (lwt->will_topic) + size += MQTT_UTF8_STRING_SIZE(lwt->will_topic); + + // 3.1.3.4 will payload + if (lwt->will_message) { + size += 2 + lwt->will_message_size; + } + } + + // 3.1.3.5 + if (auth->username) + size += MQTT_UTF8_STRING_SIZE(auth->username); + + // 3.1.3.6 + if (auth->password) + size += MQTT_UTF8_STRING_SIZE(auth->password); + + return size; +} + +#define BUFFER_TRANSACTION_NEW_FRAG(buf, flags, frag, on_fail) \ + { if(frag==NULL) { \ + frag = buffer_new_frag(buf, (flags)); } \ + if(frag==NULL) { on_fail; }} + +#define CHECK_BYTES_AVAILABLE(buf, needed, fail) \ + { if (BUFFER_BYTES_AVAILABLE(buf) < (size_t)needed) { \ + fail; } } + +#define DATA_ADVANCE(buf, bytes, frag) { size_t b = (bytes); (buf)->tail += b; (frag)->len += b; } + +// TODO maybe just user client->buf.tail? +#define WRITE_POS(frag) (&(frag->data[frag->len])) + +// [MQTT-1.5.2] Two Byte Integer +#define PACK_2B_INT(buffer, integer, frag) { *(uint16_t *)WRITE_POS(frag) = htobe16((integer)); \ + DATA_ADVANCE(buffer, sizeof(uint16_t), frag); } + +static int _optimized_add(struct header_buffer *buf, mqtt_wss_log_ctx_t log_ctx, void *data, size_t data_len, free_fnc_t data_free_fnc, struct buffer_fragment **frag) +{ + if (data_len > SMALL_STRING_DONT_FRAGMENT_LIMIT) { + buffer_frag_flag_t flags = BUFFER_FRAG_DATA_EXTERNAL; + if ((*frag)->flags & BUFFER_FRAG_GARBAGE_COLLECT_ON_SEND) + flags |= BUFFER_FRAG_GARBAGE_COLLECT_ON_SEND; + if( (*frag = buffer_new_frag(buf, flags)) == NULL ) { + mws_error(log_ctx, "Out of buffer space while generating the message"); + return 1; + } + if (frag_set_external_data(log_ctx, *frag, data, data_len, data_free_fnc)) { + mws_error(log_ctx, "Error adding external data to newly created fragment"); + return 1; + } + // we dont want to write to this fragment anymore + *frag = NULL; + } else if (data_len) { + // if the data are small dont bother creating new fragments + // store in buffer directly + CHECK_BYTES_AVAILABLE(buf, data_len, return 1); + memcpy(buf->tail, data, data_len); + DATA_ADVANCE(buf, data_len, *frag); + } + return 0; +} + +#define TRY_GENERATE_MESSAGE(generator_function, client, ...) \ + int rc = generator_function(&client->main_buffer, client->log, ##__VA_ARGS__); \ + if (rc == MQTT_NG_MSGGEN_BUFFER_OOM) { \ + LOCK_HDR_BUFFER(&client->main_buffer); \ + transaction_buffer_garbage_collect((&client->main_buffer), client->log); \ + UNLOCK_HDR_BUFFER(&client->main_buffer); \ + rc = generator_function(&client->main_buffer, client->log, ##__VA_ARGS__); \ + if (rc == MQTT_NG_MSGGEN_BUFFER_OOM && client->max_mem_bytes) { \ + LOCK_HDR_BUFFER(&client->main_buffer); \ + transaction_buffer_grow((&client->main_buffer), client->log, GROWTH_FACTOR, client->max_mem_bytes); \ + UNLOCK_HDR_BUFFER(&client->main_buffer); \ + rc = generator_function(&client->main_buffer, client->log, ##__VA_ARGS__); \ + } \ + if (rc == MQTT_NG_MSGGEN_BUFFER_OOM) \ + mws_error(client->log, "%s failed to generate message due to insufficient buffer space (line %d)", __FUNCTION__, __LINE__); \ + } \ + if (rc == MQTT_NG_MSGGEN_OK) { \ + pthread_mutex_lock(&client->stats_mutex); \ + client->stats.tx_messages_queued++; \ + pthread_mutex_unlock(&client->stats_mutex); \ + } \ + return rc; + +mqtt_msg_data mqtt_ng_generate_connect(struct transaction_buffer *trx_buf, + mqtt_wss_log_ctx_t log_ctx, + struct mqtt_auth_properties *auth, + struct mqtt_lwt_properties *lwt, + uint8_t clean_start, + uint16_t keep_alive) +{ + // Sanity Checks First (are given parameters correct and up to MQTT spec) + if (!auth->client_id) { + mws_error(log_ctx, "ClientID must be set. [MQTT-3.1.3-3]"); + return NULL; + } + + size_t len = strlen(auth->client_id); + if (!len) { + // [MQTT-3.1.3-6] server MAY allow empty client_id and treat it + // as specific client_id (not same as client_id not given) + // however server MUST allow ClientIDs between 1-23 bytes [MQTT-3.1.3-5] + // so we will warn client server might not like this and he is using it + // at his own risk! + mws_warn(log_ctx, "client_id provided is empty string. This might not be allowed by server [MQTT-3.1.3-6]"); + } + if(len > MQTT_MAX_CLIENT_ID) { + // [MQTT-3.1.3-5] server MUST allow client_id length 1-32 + // server MAY allow longer client_id, if user provides longer client_id + // warn them he is doing so at his own risk! + mws_warn(log_ctx, "client_id provided is longer than 23 bytes, server might not allow that [MQTT-3.1.3-5]"); + } + + if (lwt) { + if (lwt->will_message && lwt->will_message_size > 65535) { + mws_error(log_ctx, "Will message cannot be longer than 65535 bytes due to MQTT protocol limitations [MQTT-3.1.3-4] and [MQTT-1.5.6]"); + return NULL; + } + + if (!lwt->will_topic) { //TODO topic given with strlen==0 ? check specs + mws_error(log_ctx, "If will message is given will topic must also be given [MQTT-3.1.3.3]"); + return NULL; + } + + if (lwt->will_qos > MQTT_MAX_QOS) { + // refer to [MQTT-3-1.2-12] + mws_error(log_ctx, "QOS for LWT message is bigger than max"); + return NULL; + } + } + + // >> START THE RODEO << + transaction_buffer_transaction_start(trx_buf); + + // Calculate the resulting message size sans fixed MQTT header + size_t size = mqtt_ng_connect_size(auth, lwt); + + // Start generating the message + struct buffer_fragment *frag = NULL; + mqtt_msg_data ret = NULL; + + BUFFER_TRANSACTION_NEW_FRAG(&trx_buf->hdr_buffer, BUFFER_FRAG_MQTT_PACKET_HEAD, frag, goto fail_rollback ); + ret = frag; + + // MQTT Fixed Header + size_t needed_bytes = 1 /* Packet type */ + MQTT_VARSIZE_INT_BYTES(size) + sizeof(mqtt_protocol_name_frag) + 1 /* CONNECT FLAGS */ + 2 /* keepalive */ + 1 /* Properties TODO now fixed 0*/; + CHECK_BYTES_AVAILABLE(&trx_buf->hdr_buffer, needed_bytes, goto fail_rollback); + + *WRITE_POS(frag) = MQTT_CPT_CONNECT << 4; + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + DATA_ADVANCE(&trx_buf->hdr_buffer, uint32_to_mqtt_vbi(size, WRITE_POS(frag)), frag); + + memcpy(WRITE_POS(frag), mqtt_protocol_name_frag, sizeof(mqtt_protocol_name_frag)); + DATA_ADVANCE(&trx_buf->hdr_buffer, sizeof(mqtt_protocol_name_frag), frag); + + // [MQTT-3.1.2.3] Connect flags + unsigned char *connect_flags = WRITE_POS(frag); + *connect_flags = 0; + if (auth->username) + *connect_flags |= MQTT_CONNECT_FLAG_USERNAME; + if (auth->password) + *connect_flags |= MQTT_CONNECT_FLAG_PASSWORD; + if (lwt) { + *connect_flags |= MQTT_CONNECT_FLAG_LWT; + *connect_flags |= lwt->will_qos << MQTT_CONNECT_FLAG_QOS_BITSHIFT; + if (lwt->will_retain) + *connect_flags |= MQTT_CONNECT_FLAG_LWT_RETAIN; + } + if (clean_start) + *connect_flags |= MQTT_CONNECT_FLAG_CLEAN_START; + + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + + PACK_2B_INT(&trx_buf->hdr_buffer, keep_alive, frag); + + // TODO Property Length [MQTT-3.1.3.2.1] temporary fixed to 3 (one property topic alias max) + DATA_ADVANCE(&trx_buf->hdr_buffer, uint32_to_mqtt_vbi(3, WRITE_POS(frag)), frag); + *WRITE_POS(frag) = MQTT_PROP_TOPIC_ALIAS_MAX; + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + + PACK_2B_INT(&trx_buf->hdr_buffer, 65535, frag); + + // [MQTT-3.1.3.1] Client identifier + CHECK_BYTES_AVAILABLE(&trx_buf->hdr_buffer, 2, goto fail_rollback); + PACK_2B_INT(&trx_buf->hdr_buffer, strlen(auth->client_id), frag); + if (_optimized_add(&trx_buf->hdr_buffer, log_ctx, auth->client_id, strlen(auth->client_id), auth->client_id_free, &frag)) + goto fail_rollback; + + if (lwt != NULL) { + // Will Properties [MQTT-3.1.3.2] + // TODO for now fixed 0 + BUFFER_TRANSACTION_NEW_FRAG(&trx_buf->hdr_buffer, 0, frag, goto fail_rollback); + CHECK_BYTES_AVAILABLE(&trx_buf->hdr_buffer, 1, goto fail_rollback); + *WRITE_POS(frag) = 0; + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + + // Will Topic [MQTT-3.1.3.3] + CHECK_BYTES_AVAILABLE(&trx_buf->hdr_buffer, 2, goto fail_rollback); + PACK_2B_INT(&trx_buf->hdr_buffer, strlen(lwt->will_topic), frag); + if (_optimized_add(&trx_buf->hdr_buffer, log_ctx, lwt->will_topic, strlen(lwt->will_topic), lwt->will_topic_free, &frag)) + goto fail_rollback; + + // Will Payload [MQTT-3.1.3.4] + if (lwt->will_message_size) { + BUFFER_TRANSACTION_NEW_FRAG(&trx_buf->hdr_buffer, 0, frag, goto fail_rollback); + CHECK_BYTES_AVAILABLE(&trx_buf->hdr_buffer, 2, goto fail_rollback); + PACK_2B_INT(&trx_buf->hdr_buffer, lwt->will_message_size, frag); + if (_optimized_add(&trx_buf->hdr_buffer, log_ctx, lwt->will_message, lwt->will_message_size, lwt->will_topic_free, &frag)) + goto fail_rollback; + } + } + + // [MQTT-3.1.3.5] + if (auth->username) { + BUFFER_TRANSACTION_NEW_FRAG(&trx_buf->hdr_buffer, 0, frag, goto fail_rollback); + CHECK_BYTES_AVAILABLE(&trx_buf->hdr_buffer, 2, goto fail_rollback); + PACK_2B_INT(&trx_buf->hdr_buffer, strlen(auth->username), frag); + if (_optimized_add(&trx_buf->hdr_buffer, log_ctx, auth->username, strlen(auth->username), auth->username_free, &frag)) + goto fail_rollback; + } + + // [MQTT-3.1.3.6] + if (auth->password) { + BUFFER_TRANSACTION_NEW_FRAG(&trx_buf->hdr_buffer, 0, frag, goto fail_rollback); + CHECK_BYTES_AVAILABLE(&trx_buf->hdr_buffer, 2, goto fail_rollback); + PACK_2B_INT(&trx_buf->hdr_buffer, strlen(auth->password), frag); + if (_optimized_add(&trx_buf->hdr_buffer, log_ctx, auth->password, strlen(auth->password), auth->password_free, &frag)) + goto fail_rollback; + } + trx_buf->hdr_buffer.tail_frag->flags |= BUFFER_FRAG_MQTT_PACKET_TAIL; + transaction_buffer_transaction_commit(trx_buf); + return ret; +fail_rollback: + transaction_buffer_transaction_rollback(trx_buf, ret); + return NULL; +} + +int mqtt_ng_connect(struct mqtt_ng_client *client, + struct mqtt_auth_properties *auth, + struct mqtt_lwt_properties *lwt, + uint8_t clean_start, + uint16_t keep_alive) +{ + client->client_state = RAW; + client->parser.state = MQTT_PARSE_FIXED_HEADER_PACKET_TYPE; + + LOCK_HDR_BUFFER(&client->main_buffer); + client->main_buffer.sending_frag = NULL; + if (clean_start) + buffer_purge(&client->main_buffer.hdr_buffer); + UNLOCK_HDR_BUFFER(&client->main_buffer); + + pthread_rwlock_wrlock(&client->tx_topic_aliases.rwlock); + // according to MQTT spec topic aliases should not be persisted + // even if clean session is true + mqtt_ng_destroy_tx_alias_hash(client->tx_topic_aliases.stoi_dict); + client->tx_topic_aliases.stoi_dict = TX_ALIASES_INITIALIZE(); + if (client->tx_topic_aliases.stoi_dict == NULL) { + pthread_rwlock_unlock(&client->tx_topic_aliases.rwlock); + return 1; + } + client->tx_topic_aliases.idx_assigned = 0; + pthread_rwlock_unlock(&client->tx_topic_aliases.rwlock); + + mqtt_ng_destroy_rx_alias_hash(client->rx_aliases); + client->rx_aliases = RX_ALIASES_INITIALIZE(); + if (client->rx_aliases == NULL) + return 1; + + client->connect_msg = mqtt_ng_generate_connect(&client->main_buffer, client->log, auth, lwt, clean_start, keep_alive); + if (client->connect_msg == NULL) + return 1; + + pthread_mutex_lock(&client->stats_mutex); + if (clean_start) + client->stats.tx_messages_queued = 1; + else + client->stats.tx_messages_queued++; + + client->stats.tx_messages_sent = 0; + client->stats.rx_messages_rcvd = 0; + pthread_mutex_unlock(&client->stats_mutex); + + client->client_state = CONNECT_PENDING; + return 0; +} + +uint16_t get_unused_packet_id() { + static uint16_t packet_id = 0; + packet_id++; + return packet_id ? packet_id : ++packet_id; +} + +static inline size_t mqtt_ng_publish_size(const char *topic, + size_t msg_len, + uint16_t topic_id) +{ + size_t retval = 2 /* Topic Name Length */ + + (topic == NULL ? 0 : strlen(topic)) + + 2 /* Packet identifier */ + + 1 /* Properties Length TODO for now fixed to 1 property */ + + msg_len; + + if (topic_id) + retval += 3; + + return retval; +} + +int mqtt_ng_generate_publish(struct transaction_buffer *trx_buf, + mqtt_wss_log_ctx_t log_ctx, + char *topic, + free_fnc_t topic_free, + void *msg, + free_fnc_t msg_free, + size_t msg_len, + uint8_t publish_flags, + uint16_t *packet_id, + uint16_t topic_alias) +{ + // >> START THE RODEO << + transaction_buffer_transaction_start(trx_buf); + + // Calculate the resulting message size sans fixed MQTT header + size_t size = mqtt_ng_publish_size(topic, msg_len, topic_alias); + + // Start generating the message + struct buffer_fragment *frag = NULL; + mqtt_msg_data mqtt_msg = NULL; + + BUFFER_TRANSACTION_NEW_FRAG(&trx_buf->hdr_buffer, BUFFER_FRAG_MQTT_PACKET_HEAD, frag, goto fail_rollback ); + // in case of QOS 0 we can garbage collect immediatelly after sending + uint8_t qos = (publish_flags >> 1) & 0x03; + if (!qos) + frag->flags |= BUFFER_FRAG_GARBAGE_COLLECT_ON_SEND; + mqtt_msg = frag; + + // MQTT Fixed Header + size_t needed_bytes = 1 /* Packet type */ + MQTT_VARSIZE_INT_BYTES(size) + size - msg_len; + CHECK_BYTES_AVAILABLE(&trx_buf->hdr_buffer, needed_bytes, goto fail_rollback); + + *WRITE_POS(frag) = (MQTT_CPT_PUBLISH << 4) | (publish_flags & 0xF); + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + DATA_ADVANCE(&trx_buf->hdr_buffer, uint32_to_mqtt_vbi(size, WRITE_POS(frag)), frag); + + // MQTT Variable Header + // [MQTT-3.3.2.1] + PACK_2B_INT(&trx_buf->hdr_buffer, topic == NULL ? 0 : strlen(topic), frag); + if (topic != NULL) { + if (_optimized_add(&trx_buf->hdr_buffer, log_ctx, topic, strlen(topic), topic_free, &frag)) + goto fail_rollback; + BUFFER_TRANSACTION_NEW_FRAG(&trx_buf->hdr_buffer, 0, frag, goto fail_rollback); + } + + // [MQTT-3.3.2.2] + mqtt_msg->packet_id = get_unused_packet_id(); + *packet_id = mqtt_msg->packet_id; + PACK_2B_INT(&trx_buf->hdr_buffer, mqtt_msg->packet_id, frag); + + // [MQTT-3.3.2.3.1] TODO Property Length for now fixed 0 + *WRITE_POS(frag) = topic_alias ? 3 : 0; + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + + if(topic_alias) { + *WRITE_POS(frag) = MQTT_PROP_TOPIC_ALIAS; + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + + PACK_2B_INT(&trx_buf->hdr_buffer, topic_alias, frag); + } + + if( (frag = buffer_new_frag(&trx_buf->hdr_buffer, BUFFER_FRAG_DATA_EXTERNAL)) == NULL ) + goto fail_rollback; + + if (frag_set_external_data(log_ctx, frag, msg, msg_len, msg_free)) + goto fail_rollback; + + trx_buf->hdr_buffer.tail_frag->flags |= BUFFER_FRAG_MQTT_PACKET_TAIL; + if (!qos) + trx_buf->hdr_buffer.tail_frag->flags |= BUFFER_FRAG_GARBAGE_COLLECT_ON_SEND; + transaction_buffer_transaction_commit(trx_buf); + return MQTT_NG_MSGGEN_OK; +fail_rollback: + transaction_buffer_transaction_rollback(trx_buf, mqtt_msg); + return MQTT_NG_MSGGEN_BUFFER_OOM; +} + +#define PUBLISH_SP_SIZE 64 +int mqtt_ng_publish(struct mqtt_ng_client *client, + char *topic, + free_fnc_t topic_free, + void *msg, + free_fnc_t msg_free, + size_t msg_len, + uint8_t publish_flags, + uint16_t *packet_id) +{ + struct topic_alias_data *alias = NULL; + pthread_rwlock_rdlock(&client->tx_topic_aliases.rwlock); + c_rhash_get_ptr_by_str(client->tx_topic_aliases.stoi_dict, topic, (void**)&alias); + pthread_rwlock_unlock(&client->tx_topic_aliases.rwlock); + + uint16_t topic_id = 0; + + if (alias != NULL) { + topic_id = alias->idx; + uint32_t cnt = __atomic_fetch_add(&alias->usage_count, 1, __ATOMIC_SEQ_CST); + if (cnt) { + topic = NULL; + topic_free = NULL; + } + } + + if (client->max_msg_size && PUBLISH_SP_SIZE + mqtt_ng_publish_size(topic, msg_len, topic_id) > client->max_msg_size) { + mws_error(client->log, "Message too big for server: %zu", msg_len); + return MQTT_NG_MSGGEN_MSG_TOO_BIG; + } + + TRY_GENERATE_MESSAGE(mqtt_ng_generate_publish, client, topic, topic_free, msg, msg_free, msg_len, publish_flags, packet_id, topic_id); +} + +static inline size_t mqtt_ng_subscribe_size(struct mqtt_sub *subs, size_t sub_count) +{ + size_t len = 2 /* Packet Identifier */ + 1 /* Properties Length TODO for now fixed 0 */; + len += sub_count * (2 /* topic filter string length */ + 1 /* [MQTT-3.8.3.1] Subscription Options Byte */); + + for (size_t i = 0; i < sub_count; i++) { + len += strlen(subs[i].topic); + } + return len; +} + +int mqtt_ng_generate_subscribe(struct transaction_buffer *trx_buf, mqtt_wss_log_ctx_t log_ctx, struct mqtt_sub *subs, size_t sub_count) +{ + // >> START THE RODEO << + transaction_buffer_transaction_start(trx_buf); + + // Calculate the resulting message size sans fixed MQTT header + size_t size = mqtt_ng_subscribe_size(subs, sub_count); + + // Start generating the message + struct buffer_fragment *frag = NULL; + mqtt_msg_data ret = NULL; + + BUFFER_TRANSACTION_NEW_FRAG(&trx_buf->hdr_buffer, BUFFER_FRAG_MQTT_PACKET_HEAD, frag, goto fail_rollback); + ret = frag; + + // MQTT Fixed Header + size_t needed_bytes = 1 /* Packet type */ + MQTT_VARSIZE_INT_BYTES(size) + 3 /*Packet ID + Property Length*/; + CHECK_BYTES_AVAILABLE(&trx_buf->hdr_buffer, needed_bytes, goto fail_rollback); + + *WRITE_POS(frag) = (MQTT_CPT_SUBSCRIBE << 4) | 0x2 /* [MQTT-3.8.1-1] */; + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + DATA_ADVANCE(&trx_buf->hdr_buffer, uint32_to_mqtt_vbi(size, WRITE_POS(frag)), frag); + + // MQTT Variable Header + // [MQTT-3.8.2] PacketID + ret->packet_id = get_unused_packet_id(); + PACK_2B_INT(&trx_buf->hdr_buffer, ret->packet_id, frag); + + // [MQTT-3.8.2.1.1] Property Length // TODO for now fixed 0 + *WRITE_POS(frag) = 0; + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + + for (size_t i = 0; i < sub_count; i++) { + BUFFER_TRANSACTION_NEW_FRAG(&trx_buf->hdr_buffer, 0, frag, goto fail_rollback); + PACK_2B_INT(&trx_buf->hdr_buffer, strlen(subs[i].topic), frag); + if (_optimized_add(&trx_buf->hdr_buffer, log_ctx, subs[i].topic, strlen(subs[i].topic), subs[i].topic_free, &frag)) + goto fail_rollback; + BUFFER_TRANSACTION_NEW_FRAG(&trx_buf->hdr_buffer, 0, frag, goto fail_rollback); + *WRITE_POS(frag) = subs[i].options; + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + } + + trx_buf->hdr_buffer.tail_frag->flags |= BUFFER_FRAG_MQTT_PACKET_TAIL; + transaction_buffer_transaction_commit(trx_buf); + return MQTT_NG_MSGGEN_OK; +fail_rollback: + transaction_buffer_transaction_rollback(trx_buf, ret); + return MQTT_NG_MSGGEN_BUFFER_OOM; +} + +int mqtt_ng_subscribe(struct mqtt_ng_client *client, struct mqtt_sub *subs, size_t sub_count) +{ + TRY_GENERATE_MESSAGE(mqtt_ng_generate_subscribe, client, subs, sub_count); +} + +int mqtt_ng_generate_disconnect(struct transaction_buffer *trx_buf, mqtt_wss_log_ctx_t log_ctx, uint8_t reason_code) +{ + (void) log_ctx; + // >> START THE RODEO << + transaction_buffer_transaction_start(trx_buf); + + // Calculate the resulting message size sans fixed MQTT header + size_t size = reason_code ? 1 : 0; + + // Start generating the message + struct buffer_fragment *frag = NULL; + mqtt_msg_data ret = NULL; + + BUFFER_TRANSACTION_NEW_FRAG(&trx_buf->hdr_buffer, BUFFER_FRAG_MQTT_PACKET_HEAD, frag, goto fail_rollback); + ret = frag; + + // MQTT Fixed Header + size_t needed_bytes = 1 /* Packet type */ + MQTT_VARSIZE_INT_BYTES(size) + (reason_code ? 1 : 0); + CHECK_BYTES_AVAILABLE(&trx_buf->hdr_buffer, needed_bytes, goto fail_rollback); + + *WRITE_POS(frag) = MQTT_CPT_DISCONNECT << 4; + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + DATA_ADVANCE(&trx_buf->hdr_buffer, uint32_to_mqtt_vbi(size, WRITE_POS(frag)), frag); + + if (reason_code) { + // MQTT Variable Header + // [MQTT-3.14.2.1] PacketID + *WRITE_POS(frag) = reason_code; + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + } + + trx_buf->hdr_buffer.tail_frag->flags |= BUFFER_FRAG_MQTT_PACKET_TAIL; + transaction_buffer_transaction_commit(trx_buf); + return MQTT_NG_MSGGEN_OK; +fail_rollback: + transaction_buffer_transaction_rollback(trx_buf, ret); + return MQTT_NG_MSGGEN_BUFFER_OOM; +} + +int mqtt_ng_disconnect(struct mqtt_ng_client *client, uint8_t reason_code) +{ + TRY_GENERATE_MESSAGE(mqtt_ng_generate_disconnect, client, reason_code); +} + +static int mqtt_generate_puback(struct transaction_buffer *trx_buf, mqtt_wss_log_ctx_t log_ctx, uint16_t packet_id, uint8_t reason_code) +{ + (void) log_ctx; + // >> START THE RODEO << + transaction_buffer_transaction_start(trx_buf); + + // Calculate the resulting message size sans fixed MQTT header + size_t size = 2 /* Packet ID */ + (reason_code ? 1 : 0) /* reason code */; + + // Start generating the message + struct buffer_fragment *frag = NULL; + + BUFFER_TRANSACTION_NEW_FRAG(&trx_buf->hdr_buffer, BUFFER_FRAG_MQTT_PACKET_HEAD | BUFFER_FRAG_GARBAGE_COLLECT_ON_SEND, frag, goto fail_rollback); + + // MQTT Fixed Header + size_t needed_bytes = 1 /* Packet type */ + MQTT_VARSIZE_INT_BYTES(size) + size; + CHECK_BYTES_AVAILABLE(&trx_buf->hdr_buffer, needed_bytes, goto fail_rollback); + + *WRITE_POS(frag) = MQTT_CPT_PUBACK << 4; + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + DATA_ADVANCE(&trx_buf->hdr_buffer, uint32_to_mqtt_vbi(size, WRITE_POS(frag)), frag); + + // MQTT Variable Header + PACK_2B_INT(&trx_buf->hdr_buffer, packet_id, frag); + + if (reason_code) { + // MQTT Variable Header + // [MQTT-3.14.2.1] PacketID + *WRITE_POS(frag) = reason_code; + DATA_ADVANCE(&trx_buf->hdr_buffer, 1, frag); + } + + trx_buf->hdr_buffer.tail_frag->flags |= BUFFER_FRAG_MQTT_PACKET_TAIL; + transaction_buffer_transaction_commit(trx_buf); + return MQTT_NG_MSGGEN_OK; +fail_rollback: + transaction_buffer_transaction_rollback(trx_buf, frag); + return MQTT_NG_MSGGEN_BUFFER_OOM; +} + +static int mqtt_ng_puback(struct mqtt_ng_client *client, uint16_t packet_id, uint8_t reason_code) +{ + TRY_GENERATE_MESSAGE(mqtt_generate_puback, client, packet_id, reason_code); +} + +int mqtt_ng_ping(struct mqtt_ng_client *client) +{ + client->ping_pending = 1; + return MQTT_NG_MSGGEN_OK; +} + +#define MQTT_NG_CLIENT_NEED_MORE_BYTES 0x10 +#define MQTT_NG_CLIENT_MQTT_PACKET_DONE 0x11 +#define MQTT_NG_CLIENT_PARSE_DONE 0x12 +#define MQTT_NG_CLIENT_WANT_WRITE 0x13 +#define MQTT_NG_CLIENT_OK_CALL_AGAIN 0 +#define MQTT_NG_CLIENT_PROTOCOL_ERROR -1 +#define MQTT_NG_CLIENT_SERVER_RETURNED_ERROR -2 +#define MQTT_NG_CLIENT_NOT_IMPL_YET -3 +#define MQTT_NG_CLIENT_OOM -4 +#define MQTT_NG_CLIENT_INTERNAL_ERROR -5 + +#define BUF_READ_CHECK_AT_LEAST(buf, x) \ + if (rbuf_bytes_available(buf) < (x)) \ + return MQTT_NG_CLIENT_NEED_MORE_BYTES; + +#define vbi_parser_reset_ctx(ctx) memset(ctx, 0, sizeof(struct mqtt_vbi_parser_ctx)) + +static int vbi_parser_parse(struct mqtt_vbi_parser_ctx *ctx, rbuf_t data, mqtt_wss_log_ctx_t log) +{ + if (ctx->bytes > MQTT_VBI_MAXBYTES - 1) { + mws_error(log, "MQTT Variable Byte Integer can't be longer than %d bytes", MQTT_VBI_MAXBYTES); + return MQTT_NG_CLIENT_PROTOCOL_ERROR; + } + if (!ctx->bytes || ctx->data[ctx->bytes-1] & MQTT_VBI_CONTINUATION_FLAG) { + BUF_READ_CHECK_AT_LEAST(data, 1); + ctx->bytes++; + rbuf_pop(data, &ctx->data[ctx->bytes-1], 1); + if ( ctx->data[ctx->bytes-1] & MQTT_VBI_CONTINUATION_FLAG ) + return MQTT_NG_CLIENT_OK_CALL_AGAIN; + } + + if (mqtt_vbi_to_uint32(ctx->data, &ctx->result)) { + mws_error(log, "MQTT Variable Byte Integer failed to be parsed."); + return MQTT_NG_CLIENT_PROTOCOL_ERROR; + } + + return MQTT_NG_CLIENT_PARSE_DONE; +} + +static void mqtt_properties_parser_ctx_reset(struct mqtt_properties_parser_ctx *ctx) +{ + ctx->state = PROPERTIES_LENGTH; + while (ctx->head) { + struct mqtt_property *f = ctx->head; + ctx->head = ctx->head->next; + if (f->type == MQTT_TYPE_STR || f->type == MQTT_TYPE_STR_PAIR) + mw_free(f->data.strings[0]); + if (f->type == MQTT_TYPE_STR_PAIR) + mw_free(f->data.strings[1]); + if (f->type == MQTT_TYPE_BIN) + mw_free(f->data.bindata); + mw_free(f); + } + ctx->tail = NULL; + ctx->properties_length = 0; + ctx->bytes_consumed = 0; + vbi_parser_reset_ctx(&ctx->vbi_parser_ctx); +} + +struct mqtt_property_type { + uint8_t id; + enum mqtt_datatype datatype; + const char* name; +}; + +const struct mqtt_property_type mqtt_property_types[] = { + { .id = MQTT_PROP_TOPIC_ALIAS, .name = MQTT_PROP_TOPIC_ALIAS_NAME, .datatype = MQTT_TYPE_UINT_16 }, + + { .id = MQTT_PROP_PAYLOAD_FMT_INDICATOR, .name = MQTT_PROP_PAYLOAD_FMT_INDICATOR_NAME, .datatype = MQTT_TYPE_UINT_8 }, + { .id = MQTT_PROP_MSG_EXPIRY_INTERVAL, .name = MQTT_PROP_MSG_EXPIRY_INTERVAL_NAME, .datatype = MQTT_TYPE_UINT_32 }, + { .id = MQTT_PROP_CONTENT_TYPE, .name = MQTT_PROP_CONTENT_TYPE_NAME, .datatype = MQTT_TYPE_STR }, + { .id = MQTT_PROP_RESPONSE_TOPIC, .name = MQTT_PROP_RESPONSE_TOPIC_NAME, .datatype = MQTT_TYPE_STR }, + { .id = MQTT_PROP_CORRELATION_DATA, .name = MQTT_PROP_CORRELATION_DATA_NAME, .datatype = MQTT_TYPE_BIN }, + { .id = MQTT_PROP_SUB_IDENTIFIER, .name = MQTT_PROP_SUB_IDENTIFIER_NAME, .datatype = MQTT_TYPE_VBI }, + { .id = MQTT_PROP_SESSION_EXPIRY_INTERVAL, .name = MQTT_PROP_SESSION_EXPIRY_INTERVAL_NAME, .datatype = MQTT_TYPE_UINT_32 }, + { .id = MQTT_PROP_ASSIGNED_CLIENT_ID, .name = MQTT_PROP_ASSIGNED_CLIENT_ID_NAME, .datatype = MQTT_TYPE_STR }, + { .id = MQTT_PROP_SERVER_KEEP_ALIVE, .name = MQTT_PROP_SERVER_KEEP_ALIVE_NAME, .datatype = MQTT_TYPE_UINT_16 }, + { .id = MQTT_PROP_AUTH_METHOD, .name = MQTT_PROP_AUTH_METHOD_NAME, .datatype = MQTT_TYPE_STR }, + { .id = MQTT_PROP_AUTH_DATA, .name = MQTT_PROP_AUTH_DATA_NAME, .datatype = MQTT_TYPE_BIN }, + { .id = MQTT_PROP_REQ_PROBLEM_INFO, .name = MQTT_PROP_REQ_PROBLEM_INFO_NAME, .datatype = MQTT_TYPE_UINT_8 }, + { .id = MQTT_PROP_WILL_DELAY_INTERVAL, .name = MQTT_PROP_WIIL_DELAY_INTERVAL_NAME, .datatype = MQTT_TYPE_UINT_32 }, + { .id = MQTT_PROP_REQ_RESP_INFORMATION, .name = MQTT_PROP_REQ_RESP_INFORMATION_NAME, .datatype = MQTT_TYPE_UINT_8 }, + { .id = MQTT_PROP_RESP_INFORMATION, .name = MQTT_PROP_RESP_INFORMATION_NAME, .datatype = MQTT_TYPE_STR }, + { .id = MQTT_PROP_SERVER_REF, .name = MQTT_PROP_SERVER_REF_NAME, .datatype = MQTT_TYPE_STR }, + { .id = MQTT_PROP_REASON_STR, .name = MQTT_PROP_REASON_STR_NAME, .datatype = MQTT_TYPE_STR }, + { .id = MQTT_PROP_RECEIVE_MAX, .name = MQTT_PROP_RECEIVE_MAX_NAME, .datatype = MQTT_TYPE_UINT_16 }, + { .id = MQTT_PROP_TOPIC_ALIAS_MAX, .name = MQTT_PROP_TOPIC_ALIAS_MAX_NAME, .datatype = MQTT_TYPE_UINT_16 }, + // MQTT_PROP_TOPIC_ALIAS is first as it is most often used + { .id = MQTT_PROP_MAX_QOS, .name = MQTT_PROP_MAX_QOS_NAME, .datatype = MQTT_TYPE_UINT_8 }, + { .id = MQTT_PROP_RETAIN_AVAIL, .name = MQTT_PROP_RETAIN_AVAIL_NAME, .datatype = MQTT_TYPE_UINT_8 }, + { .id = MQTT_PROP_USR, .name = MQTT_PROP_USR_NAME, .datatype = MQTT_TYPE_STR_PAIR }, + { .id = MQTT_PROP_MAX_PKT_SIZE, .name = MQTT_PROP_MAX_PKT_SIZE_NAME, .datatype = MQTT_TYPE_UINT_32 }, + { .id = MQTT_PROP_WILDCARD_SUB_AVAIL, .name = MQTT_PROP_WILDCARD_SUB_AVAIL_NAME, .datatype = MQTT_TYPE_UINT_8 }, + { .id = MQTT_PROP_SUB_ID_AVAIL, .name = MQTT_PROP_SUB_ID_AVAIL_NAME, .datatype = MQTT_TYPE_UINT_8 }, + { .id = MQTT_PROP_SHARED_SUB_AVAIL, .name = MQTT_PROP_SHARED_SUB_AVAIL_NAME, .datatype = MQTT_TYPE_UINT_8 }, + { .id = 0, .name = NULL, .datatype = MQTT_TYPE_UNKNOWN } +}; + +static int get_property_type_by_id(uint8_t property_id) { + for (int i = 0; mqtt_property_types[i].datatype != MQTT_TYPE_UNKNOWN; i++) { + if (mqtt_property_types[i].id == property_id) + return mqtt_property_types[i].datatype; + } + return MQTT_TYPE_UNKNOWN; +} + +struct mqtt_property *get_property_by_id(struct mqtt_property *props, uint8_t property_id) +{ + while (props) { + if (props->id == property_id) { + return props; + } + props = props->next; + } + return NULL; +} + +// Parses [MQTT-2.2.2] +static int parse_properties_array(struct mqtt_properties_parser_ctx *ctx, rbuf_t data, mqtt_wss_log_ctx_t log) +{ + int rc; + switch (ctx->state) { + case PROPERTIES_LENGTH: + rc = vbi_parser_parse(&ctx->vbi_parser_ctx, data, log); + if (rc == MQTT_NG_CLIENT_PARSE_DONE) { + ctx->properties_length = ctx->vbi_parser_ctx.result; + ctx->bytes_consumed += ctx->vbi_parser_ctx.bytes; + ctx->vbi_length = ctx->vbi_parser_ctx.bytes; + if (!ctx->properties_length) + return MQTT_NG_CLIENT_PARSE_DONE; + ctx->state = PROPERTY_CREATE; + break; + } + return rc; + case PROPERTY_CREATE: + BUF_READ_CHECK_AT_LEAST(data, 1); + struct mqtt_property *prop = mw_calloc(1, sizeof(struct mqtt_property)); + if (ctx->head == NULL) { + ctx->head = prop; + ctx->tail = prop; + } else { + ctx->tail->next = prop; + ctx->tail = ctx->tail->next; + } + ctx->state = PROPERTY_ID; + /* FALLTHROUGH */ + case PROPERTY_ID: + rbuf_pop(data, (char*)&ctx->tail->id, 1); + ctx->bytes_consumed += 1; + ctx->tail->type = get_property_type_by_id(ctx->tail->id); + switch (ctx->tail->type) { + case MQTT_TYPE_UINT_16: + ctx->state = PROPERTY_TYPE_UINT16; + break; + case MQTT_TYPE_UINT_32: + ctx->state = PROPERTY_TYPE_UINT32; + break; + case MQTT_TYPE_UINT_8: + ctx->state = PROPERTY_TYPE_UINT8; + break; + case MQTT_TYPE_VBI: + ctx->state = PROPERTY_TYPE_VBI; + vbi_parser_reset_ctx(&ctx->vbi_parser_ctx); + break; + case MQTT_TYPE_STR: + case MQTT_TYPE_STR_PAIR: + ctx->str_idx = 0; + /* FALLTHROUGH */ + case MQTT_TYPE_BIN: + ctx->state = PROPERTY_TYPE_STR_BIN_LEN; + break; + default: + mws_error(log, "Unsupported property type %d for property id %d.", (int)ctx->tail->type, (int)ctx->tail->id); + return MQTT_NG_CLIENT_PROTOCOL_ERROR; + } + break; + case PROPERTY_TYPE_STR_BIN_LEN: + BUF_READ_CHECK_AT_LEAST(data, sizeof(uint16_t)); + rbuf_pop(data, (char*)&ctx->tail->bindata_len, sizeof(uint16_t)); + ctx->tail->bindata_len = be16toh(ctx->tail->bindata_len); + ctx->bytes_consumed += 2; + switch (ctx->tail->type) { + case MQTT_TYPE_BIN: + ctx->state = PROPERTY_TYPE_BIN; + break; + case MQTT_TYPE_STR: + case MQTT_TYPE_STR_PAIR: + ctx->state = PROPERTY_TYPE_STR; + break; + default: + mws_error(log, "Unexpected datatype in PROPERTY_TYPE_STR_BIN_LEN %d", (int)ctx->tail->type); + return MQTT_NG_CLIENT_INTERNAL_ERROR; + } + break; + case PROPERTY_TYPE_STR: + BUF_READ_CHECK_AT_LEAST(data, ctx->tail->bindata_len); + ctx->tail->data.strings[ctx->str_idx] = mw_malloc(ctx->tail->bindata_len + 1); + rbuf_pop(data, ctx->tail->data.strings[ctx->str_idx], ctx->tail->bindata_len); + ctx->tail->data.strings[ctx->str_idx][ctx->tail->bindata_len] = 0; + ctx->str_idx++; + ctx->bytes_consumed += ctx->tail->bindata_len; + if (ctx->tail->type == MQTT_TYPE_STR_PAIR && ctx->str_idx < 2) { + ctx->state = PROPERTY_TYPE_STR_BIN_LEN; + break; + } + ctx->state = PROPERTY_NEXT; + break; + case PROPERTY_TYPE_BIN: + BUF_READ_CHECK_AT_LEAST(data, ctx->tail->bindata_len); + ctx->tail->data.bindata = mw_malloc(ctx->tail->bindata_len); + rbuf_pop(data, ctx->tail->data.bindata, ctx->tail->bindata_len); + ctx->bytes_consumed += ctx->tail->bindata_len; + ctx->state = PROPERTY_NEXT; + break; + case PROPERTY_TYPE_VBI: + rc = vbi_parser_parse(&ctx->vbi_parser_ctx, data, log); + if (rc == MQTT_NG_CLIENT_PARSE_DONE) { + ctx->tail->data.uint32 = ctx->vbi_parser_ctx.result; + ctx->bytes_consumed += ctx->vbi_parser_ctx.bytes; + ctx->state = PROPERTY_NEXT; + break; + } + return rc; + case PROPERTY_TYPE_UINT8: + BUF_READ_CHECK_AT_LEAST(data, sizeof(uint8_t)); + rbuf_pop(data, (char*)&ctx->tail->data.uint8, sizeof(uint8_t)); + ctx->bytes_consumed += sizeof(uint8_t); + ctx->state = PROPERTY_NEXT; + break; + case PROPERTY_TYPE_UINT32: + BUF_READ_CHECK_AT_LEAST(data, sizeof(uint32_t)); + rbuf_pop(data, (char*)&ctx->tail->data.uint32, sizeof(uint32_t)); + ctx->tail->data.uint32 = be32toh(ctx->tail->data.uint32); + ctx->bytes_consumed += sizeof(uint32_t); + ctx->state = PROPERTY_NEXT; + break; + case PROPERTY_TYPE_UINT16: + BUF_READ_CHECK_AT_LEAST(data, sizeof(uint16_t)); + rbuf_pop(data, (char*)&ctx->tail->data.uint16, sizeof(uint16_t)); + ctx->tail->data.uint16 = be16toh(ctx->tail->data.uint16); + ctx->bytes_consumed += sizeof(uint16_t); + ctx->state = PROPERTY_NEXT; + /* FALLTHROUGH */ + case PROPERTY_NEXT: + if (ctx->properties_length > ctx->bytes_consumed - ctx->vbi_length) { + ctx->state = PROPERTY_CREATE; + break; + } else + return MQTT_NG_CLIENT_PARSE_DONE; + } + return MQTT_NG_CLIENT_OK_CALL_AGAIN; +} + +static int parse_connack_varhdr(struct mqtt_ng_client *client) +{ + struct mqtt_ng_parser *parser = &client->parser; + switch (parser->varhdr_state) { + case MQTT_PARSE_VARHDR_INITIAL: + BUF_READ_CHECK_AT_LEAST(parser->received_data, 2); + rbuf_pop(parser->received_data, (char*)&parser->mqtt_packet.connack.flags, 1); + rbuf_pop(parser->received_data, (char*)&parser->mqtt_packet.connack.reason_code, 1); + parser->varhdr_state = MQTT_PARSE_VARHDR_PROPS; + mqtt_properties_parser_ctx_reset(&parser->properties_parser); + break; + case MQTT_PARSE_VARHDR_PROPS: + return parse_properties_array(&parser->properties_parser, parser->received_data, client->log); + default: + ERROR("invalid state for connack varhdr parser"); + return MQTT_NG_CLIENT_INTERNAL_ERROR; + } + return MQTT_NG_CLIENT_OK_CALL_AGAIN; +} + +static int parse_disconnect_varhdr(struct mqtt_ng_client *client) +{ + struct mqtt_ng_parser *parser = &client->parser; + switch (parser->varhdr_state) { + case MQTT_PARSE_VARHDR_INITIAL: + if (!parser->mqtt_fixed_hdr_remaining_length) { + // [MQTT-3.14.2.1] if reason code omitted act same as == 0 + parser->mqtt_packet.disconnect.reason_code = 0; + return MQTT_NG_CLIENT_PARSE_DONE; + } + BUF_READ_CHECK_AT_LEAST(parser->received_data, 1); + rbuf_pop(parser->received_data, (char*)&parser->mqtt_packet.connack.reason_code, 1); + if (parser->mqtt_fixed_hdr_remaining_length == 1) + return MQTT_NG_CLIENT_PARSE_DONE; + parser->varhdr_state = MQTT_PARSE_VARHDR_PROPS; + mqtt_properties_parser_ctx_reset(&parser->properties_parser); + break; + case MQTT_PARSE_VARHDR_PROPS: + return parse_properties_array(&parser->properties_parser, parser->received_data, client->log); + default: + ERROR("invalid state for connack varhdr parser"); + return MQTT_NG_CLIENT_INTERNAL_ERROR; + } + return MQTT_NG_CLIENT_OK_CALL_AGAIN; +} + +static int parse_puback_varhdr(struct mqtt_ng_client *client) +{ + struct mqtt_ng_parser *parser = &client->parser; + switch (parser->varhdr_state) { + case MQTT_PARSE_VARHDR_INITIAL: + BUF_READ_CHECK_AT_LEAST(parser->received_data, 2); + rbuf_pop(parser->received_data, (char*)&parser->mqtt_packet.puback.packet_id, 2); + parser->mqtt_packet.puback.packet_id = be16toh(parser->mqtt_packet.puback.packet_id); + if (parser->mqtt_fixed_hdr_remaining_length < 3) { + // [MQTT-3.4.2.1] if length is not big enough for reason code + // it is omitted and handled same as if it was present and == 0 + // initially missed this detail and was wondering WTF is going on (sigh) + parser->mqtt_packet.puback.reason_code = 0; + return MQTT_NG_CLIENT_PARSE_DONE; + } + parser->varhdr_state = MQTT_PARSE_VARHDR_OPTIONAL_REASON_CODE; + /* FALLTHROUGH */ + case MQTT_PARSE_VARHDR_OPTIONAL_REASON_CODE: + BUF_READ_CHECK_AT_LEAST(parser->received_data, 1); + rbuf_pop(parser->received_data, (char*)&parser->mqtt_packet.puback.reason_code, 1); + // LOL so in CONNACK you have to have 0 byte to + // signify empty properties list + // but in PUBACK it can be omitted if remaining length doesn't allow it (sigh) + if (parser->mqtt_fixed_hdr_remaining_length < 4) + return MQTT_NG_CLIENT_PARSE_DONE; + + parser->varhdr_state = MQTT_PARSE_VARHDR_PROPS; + mqtt_properties_parser_ctx_reset(&parser->properties_parser); + /* FALLTHROUGH */ + case MQTT_PARSE_VARHDR_PROPS: + return parse_properties_array(&parser->properties_parser, parser->received_data, client->log); + default: + ERROR("invalid state for puback varhdr parser"); + return MQTT_NG_CLIENT_INTERNAL_ERROR; + } + return MQTT_NG_CLIENT_OK_CALL_AGAIN; +} + +static int parse_suback_varhdr(struct mqtt_ng_client *client) +{ + int rc; + size_t avail; + struct mqtt_ng_parser *parser = &client->parser; + struct mqtt_suback *suback = &client->parser.mqtt_packet.suback; + switch (parser->varhdr_state) { + case MQTT_PARSE_VARHDR_INITIAL: + suback->reason_codes = NULL; + BUF_READ_CHECK_AT_LEAST(parser->received_data, 2); + rbuf_pop(parser->received_data, (char*)&suback->packet_id, 2); + suback->packet_id = be16toh(suback->packet_id); + parser->varhdr_state = MQTT_PARSE_VARHDR_PROPS; + parser->mqtt_parsed_len = 2; + mqtt_properties_parser_ctx_reset(&parser->properties_parser); + /* FALLTHROUGH */ + case MQTT_PARSE_VARHDR_PROPS: + rc = parse_properties_array(&parser->properties_parser, parser->received_data, client->log); + if (rc != MQTT_NG_CLIENT_PARSE_DONE) + return rc; + parser->mqtt_parsed_len += parser->properties_parser.bytes_consumed; + suback->reason_code_count = parser->mqtt_fixed_hdr_remaining_length - parser->mqtt_parsed_len; + suback->reason_codes = mw_calloc(suback->reason_code_count, sizeof(*suback->reason_codes)); + suback->reason_codes_pending = suback->reason_code_count; + parser->varhdr_state = MQTT_PARSE_REASONCODES; + /* FALLTHROUGH */ + case MQTT_PARSE_REASONCODES: + avail = rbuf_bytes_available(parser->received_data); + if (avail < 1) + return MQTT_NG_CLIENT_NEED_MORE_BYTES; + + suback->reason_codes_pending -= rbuf_pop(parser->received_data, (char*)suback->reason_codes, MIN(suback->reason_codes_pending, avail)); + + if (!suback->reason_codes_pending) + return MQTT_NG_CLIENT_PARSE_DONE; + + return MQTT_NG_CLIENT_NEED_MORE_BYTES; + default: + ERROR("invalid state for suback varhdr parser"); + return MQTT_NG_CLIENT_INTERNAL_ERROR; + } + return MQTT_NG_CLIENT_OK_CALL_AGAIN; +} + +static int parse_publish_varhdr(struct mqtt_ng_client *client) +{ + int rc; + struct mqtt_ng_parser *parser = &client->parser; + struct mqtt_publish *publish = &client->parser.mqtt_packet.publish; + switch (parser->varhdr_state) { + case MQTT_PARSE_VARHDR_INITIAL: + BUF_READ_CHECK_AT_LEAST(parser->received_data, 2); + publish->topic = NULL; + publish->qos = ((parser->mqtt_control_packet_type >> 1) & 0x03); + rbuf_pop(parser->received_data, (char*)&publish->topic_len, 2); + publish->topic_len = be16toh(publish->topic_len); + parser->mqtt_parsed_len = 2; + if (!publish->topic_len) { + parser->varhdr_state = MQTT_PARSE_VARHDR_POST_TOPICNAME; + break; + } + publish->topic = mw_calloc(1, publish->topic_len + 1 /* add 0x00 */); + if (publish->topic == NULL) + return MQTT_NG_CLIENT_OOM; + parser->varhdr_state = MQTT_PARSE_VARHDR_TOPICNAME; + /* FALLTHROUGH */ + case MQTT_PARSE_VARHDR_TOPICNAME: + // TODO check empty topic can be valid? In which case we have to skip this step + BUF_READ_CHECK_AT_LEAST(parser->received_data, publish->topic_len); + rbuf_pop(parser->received_data, publish->topic, publish->topic_len); + parser->mqtt_parsed_len += publish->topic_len; + parser->varhdr_state = MQTT_PARSE_VARHDR_POST_TOPICNAME; + /* FALLTHROUGH */ + case MQTT_PARSE_VARHDR_POST_TOPICNAME: + mqtt_properties_parser_ctx_reset(&parser->properties_parser); + if (!publish->qos) { // PacketID present only for QOS > 0 [MQTT-3.3.2.2] + parser->varhdr_state = MQTT_PARSE_VARHDR_PROPS; + break; + } + parser->varhdr_state = MQTT_PARSE_VARHDR_PACKET_ID; + /* FALLTHROUGH */ + case MQTT_PARSE_VARHDR_PACKET_ID: + BUF_READ_CHECK_AT_LEAST(parser->received_data, 2); + rbuf_pop(parser->received_data, (char*)&publish->packet_id, 2); + publish->packet_id = be16toh(publish->packet_id); + parser->varhdr_state = MQTT_PARSE_VARHDR_PROPS; + parser->mqtt_parsed_len += 2; + /* FALLTHROUGH */ + case MQTT_PARSE_VARHDR_PROPS: + rc = parse_properties_array(&parser->properties_parser, parser->received_data, client->log); + if (rc != MQTT_NG_CLIENT_PARSE_DONE) + return rc; + parser->mqtt_parsed_len += parser->properties_parser.bytes_consumed; + parser->varhdr_state = MQTT_PARSE_PAYLOAD; + /* FALLTHROUGH */ + case MQTT_PARSE_PAYLOAD: + if (parser->mqtt_fixed_hdr_remaining_length < parser->mqtt_parsed_len) { + mw_free(publish->topic); + publish->topic = NULL; + ERROR("Error parsing PUBLISH message"); + return MQTT_NG_CLIENT_PROTOCOL_ERROR; + } + publish->data_len = parser->mqtt_fixed_hdr_remaining_length - parser->mqtt_parsed_len; + if (!publish->data_len) { + publish->data = NULL; + return MQTT_NG_CLIENT_PARSE_DONE; // 0 length payload is OK [MQTT-3.3.3] + } + BUF_READ_CHECK_AT_LEAST(parser->received_data, publish->data_len); + + publish->data = mw_malloc(publish->data_len); + if (publish->data == NULL) { + mw_free(publish->topic); + publish->topic = NULL; + return MQTT_NG_CLIENT_OOM; + } + + rbuf_pop(parser->received_data, publish->data, publish->data_len); + parser->mqtt_parsed_len += publish->data_len; + + return MQTT_NG_CLIENT_PARSE_DONE; + default: + ERROR("invalid state for publish varhdr parser"); + return MQTT_NG_CLIENT_INTERNAL_ERROR; + } + return MQTT_NG_CLIENT_OK_CALL_AGAIN; +} + +// TODO move to separate file, dont send whole client pointer just to be able +// to access LOG context send parser only which should include log +static int parse_data(struct mqtt_ng_client *client) +{ + int rc; + struct mqtt_ng_parser *parser = &client->parser; + switch(parser->state) { + case MQTT_PARSE_FIXED_HEADER_PACKET_TYPE: + BUF_READ_CHECK_AT_LEAST(parser->received_data, 1); + rbuf_pop(parser->received_data, (char*)&parser->mqtt_control_packet_type, 1); + vbi_parser_reset_ctx(&parser->vbi_parser); + parser->state = MQTT_PARSE_FIXED_HEADER_LEN; + break; + case MQTT_PARSE_FIXED_HEADER_LEN: + rc = vbi_parser_parse(&parser->vbi_parser, parser->received_data, client->log); + if (rc == MQTT_NG_CLIENT_PARSE_DONE) { + parser->mqtt_fixed_hdr_remaining_length = parser->vbi_parser.result; + parser->state = MQTT_PARSE_VARIABLE_HEADER; + parser->varhdr_state = MQTT_PARSE_VARHDR_INITIAL; + break; + } + return rc; + case MQTT_PARSE_VARIABLE_HEADER: + switch (get_control_packet_type(parser->mqtt_control_packet_type)) { + case MQTT_CPT_CONNACK: + rc = parse_connack_varhdr(client); + if (rc == MQTT_NG_CLIENT_PARSE_DONE) { + parser->state = MQTT_PARSE_MQTT_PACKET_DONE; + break; + } + return rc; + case MQTT_CPT_PUBACK: + rc = parse_puback_varhdr(client); + if (rc == MQTT_NG_CLIENT_PARSE_DONE) { + parser->state = MQTT_PARSE_MQTT_PACKET_DONE; + break; + } + return rc; + case MQTT_CPT_SUBACK: + rc = parse_suback_varhdr(client); + if (rc != MQTT_NG_CLIENT_NEED_MORE_BYTES && rc != MQTT_NG_CLIENT_OK_CALL_AGAIN) { + mw_free(parser->mqtt_packet.suback.reason_codes); + } + if (rc == MQTT_NG_CLIENT_PARSE_DONE) { + parser->state = MQTT_PARSE_MQTT_PACKET_DONE; + break; + } + return rc; + case MQTT_CPT_PUBLISH: + rc = parse_publish_varhdr(client); + if (rc == MQTT_NG_CLIENT_PARSE_DONE) { + parser->state = MQTT_PARSE_MQTT_PACKET_DONE; + break; + } + return rc; + case MQTT_CPT_PINGRESP: + if (parser->mqtt_fixed_hdr_remaining_length) { + ERROR ("PINGRESP has to be 0 Remaining Length."); // [MQTT-3.13.1] + return MQTT_NG_CLIENT_PROTOCOL_ERROR; + } + parser->state = MQTT_PARSE_MQTT_PACKET_DONE; + break; + case MQTT_CPT_DISCONNECT: + rc = parse_disconnect_varhdr(client); + if (rc == MQTT_NG_CLIENT_PARSE_DONE) { + parser->state = MQTT_PARSE_MQTT_PACKET_DONE; + break; + } + return rc; + default: + ERROR("Parsing Control Packet Type %" PRIu8 " not implemented yet.", get_control_packet_type(parser->mqtt_control_packet_type)); + rbuf_bump_tail(parser->received_data, parser->mqtt_fixed_hdr_remaining_length); + parser->state = MQTT_PARSE_MQTT_PACKET_DONE; + return MQTT_NG_CLIENT_NOT_IMPL_YET; + } + // we could also return MQTT_NG_CLIENT_OK_CALL_AGAIN + // and be called again later + /* FALLTHROUGH */ + case MQTT_PARSE_MQTT_PACKET_DONE: + parser->state = MQTT_PARSE_FIXED_HEADER_PACKET_TYPE; + return MQTT_NG_CLIENT_MQTT_PACKET_DONE; + } + return MQTT_NG_CLIENT_OK_CALL_AGAIN; +} + +// set next MQTT fragment to send +// return 1 if nothing to send +// return -1 on error +// return 0 if there is fragment set +static int mqtt_ng_next_to_send(struct mqtt_ng_client *client) { + if (client->client_state == CONNECT_PENDING) { + client->main_buffer.sending_frag = client->connect_msg; + client->client_state = CONNECTING; + return 0; + } + if (client->client_state != CONNECTED) + return -1; + + struct buffer_fragment *frag = BUFFER_FIRST_FRAG(&client->main_buffer.hdr_buffer); + while (frag) { + if ( frag->sent != frag->len ) + break; + frag = frag->next; + } + + if ( client->ping_pending && (!frag || (frag->flags & BUFFER_FRAG_MQTT_PACKET_HEAD && frag->sent == 0)) ) { + client->ping_pending = 0; + ping_frag.sent = 0; + client->main_buffer.sending_frag = &ping_frag; + return 0; + } + + client->main_buffer.sending_frag = frag; + return frag == NULL ? 1 : 0; +} + +// send current fragment +// return 0 if whole remaining length could be sent as a whole +// return -1 if send buffer was filled and +// nothing could be written anymore +// return 1 if last fragment of a message was fully sent +static int send_fragment(struct mqtt_ng_client *client) { + struct buffer_fragment *frag = client->main_buffer.sending_frag; + + // for readability + unsigned char *ptr = frag->data + frag->sent; + size_t bytes = frag->len - frag->sent; + + size_t processed = 0; + + if (bytes) + processed = client->send_fnc_ptr(client->user_ctx, ptr, bytes); + else + WARN("This fragment was fully sent already. This should not happen!"); + + frag->sent += processed; + if (frag->sent != frag->len) + return -1; + + if (frag->flags & BUFFER_FRAG_MQTT_PACKET_TAIL) { + client->time_of_last_send = time(NULL); + pthread_mutex_lock(&client->stats_mutex); + if (client->main_buffer.sending_frag != &ping_frag) + client->stats.tx_messages_queued--; + client->stats.tx_messages_sent++; + pthread_mutex_unlock(&client->stats_mutex); + client->main_buffer.sending_frag = NULL; + return 1; + } + + client->main_buffer.sending_frag = frag->next; + + return 0; +} + +// attempt sending all fragments of current single MQTT packet +static int send_all_message_fragments(struct mqtt_ng_client *client) { + int rc; + while ( !(rc = send_fragment(client)) ); + return rc; +} + +static void try_send_all(struct mqtt_ng_client *client) { + do { + if (client->main_buffer.sending_frag == NULL && mqtt_ng_next_to_send(client)) + return; + } while(send_all_message_fragments(client) >= 0); +} + +static inline void mark_message_for_gc(struct buffer_fragment *frag) +{ + while (frag) { + frag->flags |= BUFFER_FRAG_GARBAGE_COLLECT; + buffer_frag_free_data(frag); + if (frag->flags & BUFFER_FRAG_MQTT_PACKET_TAIL) + return; + frag = frag->next; + } +} + +static int mark_packet_acked(struct mqtt_ng_client *client, uint16_t packet_id) +{ + LOCK_HDR_BUFFER(&client->main_buffer); + struct buffer_fragment *frag = BUFFER_FIRST_FRAG(&client->main_buffer.hdr_buffer); + while (frag) { + if ( (frag->flags & BUFFER_FRAG_MQTT_PACKET_HEAD) && frag->packet_id == packet_id) { + if (!frag->sent) { + ERROR("Received packet_id (%" PRIu16 ") belongs to MQTT packet which was not yet sent!", packet_id); + UNLOCK_HDR_BUFFER(&client->main_buffer); + return 1; + } + mark_message_for_gc(frag); + UNLOCK_HDR_BUFFER(&client->main_buffer); + return 0; + } + frag = frag->next; + } + ERROR("Received packet_id (%" PRIu16 ") is unknown!", packet_id); + UNLOCK_HDR_BUFFER(&client->main_buffer); + return 1; +} + +int handle_incoming_traffic(struct mqtt_ng_client *client) +{ + int rc; + struct mqtt_publish *pub; + while( (rc = parse_data(client)) == MQTT_NG_CLIENT_OK_CALL_AGAIN ); + if ( rc == MQTT_NG_CLIENT_MQTT_PACKET_DONE ) { + struct mqtt_property *prop; +#ifdef MQTT_DEBUG_VERBOSE + DEBUG("MQTT Packet Parsed Successfully!"); +#endif + pthread_mutex_lock(&client->stats_mutex); + client->stats.rx_messages_rcvd++; + pthread_mutex_unlock(&client->stats_mutex); + + switch (get_control_packet_type(client->parser.mqtt_control_packet_type)) { + case MQTT_CPT_CONNACK: +#ifdef MQTT_DEBUG_VERBOSE + DEBUG("Received CONNACK"); +#endif + LOCK_HDR_BUFFER(&client->main_buffer); + mark_message_for_gc(client->connect_msg); + UNLOCK_HDR_BUFFER(&client->main_buffer); + client->connect_msg = NULL; + if (client->client_state != CONNECTING) { + ERROR("Received unexpected CONNACK"); + client->client_state = ERROR; + return MQTT_NG_CLIENT_PROTOCOL_ERROR; + } + if ((prop = get_property_by_id(client->parser.properties_parser.head, MQTT_PROP_MAX_PKT_SIZE)) != NULL) { + INFO("MQTT server limits message size to %" PRIu32, prop->data.uint32); + client->max_msg_size = prop->data.uint32; + } + if (client->connack_callback) + client->connack_callback(client->user_ctx, client->parser.mqtt_packet.connack.reason_code); + if (!client->parser.mqtt_packet.connack.reason_code) { + INFO("MQTT Connection Accepted By Server"); + client->client_state = CONNECTED; + break; + } + client->client_state = ERROR; + return MQTT_NG_CLIENT_SERVER_RETURNED_ERROR; + case MQTT_CPT_PUBACK: +#ifdef MQTT_DEBUG_VERBOSE + DEBUG("Received PUBACK %" PRIu16, client->parser.mqtt_packet.puback.packet_id); +#endif + if (mark_packet_acked(client, client->parser.mqtt_packet.puback.packet_id)) + return MQTT_NG_CLIENT_PROTOCOL_ERROR; + if (client->puback_callback) + client->puback_callback(client->parser.mqtt_packet.puback.packet_id); + break; + case MQTT_CPT_PINGRESP: +#ifdef MQTT_DEBUG_VERBOSE + DEBUG("Received PINGRESP"); +#endif + break; + case MQTT_CPT_SUBACK: +#ifdef MQTT_DEBUG_VERBOSE + DEBUG("Received SUBACK %" PRIu16, client->parser.mqtt_packet.suback.packet_id); +#endif + if (mark_packet_acked(client, client->parser.mqtt_packet.suback.packet_id)) + return MQTT_NG_CLIENT_PROTOCOL_ERROR; + break; + case MQTT_CPT_PUBLISH: +#ifdef MQTT_DEBUG_VERBOSE + DEBUG("Recevied PUBLISH"); +#endif + pub = &client->parser.mqtt_packet.publish; + if (pub->qos > 1) { + mw_free(pub->topic); + mw_free(pub->data); + return MQTT_NG_CLIENT_NOT_IMPL_YET; + } + if ( pub->qos == 1 && (rc = mqtt_ng_puback(client, pub->packet_id, 0)) ) { + client->client_state = ERROR; + ERROR("Error generating PUBACK reply for PUBLISH"); + return rc; + } + if ( (prop = get_property_by_id(client->parser.properties_parser.head, MQTT_PROP_TOPIC_ALIAS)) != NULL ) { + // Topic Alias property was sent from server + void *topic_ptr; + if (!c_rhash_get_ptr_by_uint64(client->rx_aliases, prop->data.uint8, &topic_ptr)) { + if (pub->topic != NULL) { + ERROR("We do not yet support topic alias reassignment"); + return MQTT_NG_CLIENT_NOT_IMPL_YET; + } + pub->topic = topic_ptr; + } else { + if (pub->topic == NULL) { + ERROR("Topic alias with id %d unknown and topic not set by server!", prop->data.uint8); + return MQTT_NG_CLIENT_PROTOCOL_ERROR; + } + c_rhash_insert_uint64_ptr(client->rx_aliases, prop->data.uint8, pub->topic); + } + } + if (client->msg_callback) + client->msg_callback(pub->topic, pub->data, pub->data_len, pub->qos); + // in case we have property topic alias and we have topic we take over the string + // and add pointer to it into topic alias list + if (prop == NULL) + mw_free(pub->topic); + mw_free(pub->data); + return MQTT_NG_CLIENT_WANT_WRITE; + case MQTT_CPT_DISCONNECT: + INFO ("Got MQTT DISCONNECT control packet from server. Reason code: %d", (int)client->parser.mqtt_packet.disconnect.reason_code); + client->client_state = DISCONNECTED; + break; + } + } + + return rc; +} + +int mqtt_ng_sync(struct mqtt_ng_client *client) +{ + if (client->client_state == RAW || client->client_state == DISCONNECTED) + return 0; + + if (client->client_state == ERROR) + return 1; + + LOCK_HDR_BUFFER(&client->main_buffer); + try_send_all(client); + UNLOCK_HDR_BUFFER(&client->main_buffer); + + int rc; + + while ((rc = handle_incoming_traffic(client)) != MQTT_NG_CLIENT_NEED_MORE_BYTES) { + if (rc < 0) + break; + if (rc == MQTT_NG_CLIENT_WANT_WRITE) { + LOCK_HDR_BUFFER(&client->main_buffer); + try_send_all(client); + UNLOCK_HDR_BUFFER(&client->main_buffer); + } + } + + if (rc < 0) + return rc; + + return 0; +} + +time_t mqtt_ng_last_send_time(struct mqtt_ng_client *client) +{ + return client->time_of_last_send; +} + +void mqtt_ng_set_max_mem(struct mqtt_ng_client *client, size_t bytes) +{ + client->max_mem_bytes = bytes; +} + +void mqtt_ng_get_stats(struct mqtt_ng_client *client, struct mqtt_ng_stats *stats) +{ + pthread_mutex_lock(&client->stats_mutex); + memcpy(stats, &client->stats, sizeof(struct mqtt_ng_stats)); + pthread_mutex_unlock(&client->stats_mutex); + + stats->tx_bytes_queued = 0; + stats->tx_buffer_reclaimable = 0; + + LOCK_HDR_BUFFER(&client->main_buffer); + stats->tx_buffer_used = BUFFER_BYTES_USED(&client->main_buffer.hdr_buffer); + stats->tx_buffer_free = BUFFER_BYTES_AVAILABLE(&client->main_buffer.hdr_buffer); + stats->tx_buffer_size = client->main_buffer.hdr_buffer.size; + struct buffer_fragment *frag = BUFFER_FIRST_FRAG(&client->main_buffer.hdr_buffer); + while (frag) { + stats->tx_bytes_queued += frag->len - frag->sent; + if (frag_is_marked_for_gc(frag)) + stats->tx_buffer_reclaimable += FRAG_SIZE_IN_BUFFER(frag); + + frag = frag->next; + } + UNLOCK_HDR_BUFFER(&client->main_buffer); +} + +int mqtt_ng_set_topic_alias(struct mqtt_ng_client *client, const char *topic) +{ + uint16_t idx; + pthread_rwlock_wrlock(&client->tx_topic_aliases.rwlock); + + if (client->tx_topic_aliases.idx_assigned >= client->tx_topic_aliases.idx_max) { + pthread_rwlock_unlock(&client->tx_topic_aliases.rwlock); + mws_error(client->log, "Tx topic alias indexes were exhausted (current version of the library doesn't support reassigning yet. Feel free to contribute."); + return 0; //0 is not a valid topic alias + } + + struct topic_alias_data *alias; + if (!c_rhash_get_ptr_by_str(client->tx_topic_aliases.stoi_dict, topic, (void**)&alias)) { + // this is not a problem for library but might be helpful to warn user + // as it might indicate bug in their program (but also might be expected) + idx = alias->idx; + pthread_rwlock_unlock(&client->tx_topic_aliases.rwlock); + mws_debug(client->log, "%s topic \"%s\" already has alias set. Ignoring.", __FUNCTION__, topic); + return idx; + } + + alias = mw_malloc(sizeof(struct topic_alias_data)); + idx = ++client->tx_topic_aliases.idx_assigned; + alias->idx = idx; + __atomic_store_n(&alias->usage_count, 0, __ATOMIC_SEQ_CST); + + c_rhash_insert_str_ptr(client->tx_topic_aliases.stoi_dict, topic, (void*)alias); + + pthread_rwlock_unlock(&client->tx_topic_aliases.rwlock); + return idx; +} |