268 lines
7.4 KiB
C
268 lines
7.4 KiB
C
/* mqtt_client.c - 精简版 MQTT 3.1.1 客户端（ESP-01S TCP 透传之上）
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*
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* 只做设备需要的最小集：CONNECT / SUBSCRIBE(QoS0) / PUBLISH(QoS0) / PINGREQ，
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* 以及 CONNACK / SUBACK / PINGRESP / PUBLISH 的解析。
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* 服务器下发的 PUBLISH payload(JSON) 直接交给 network.c 的 net_dispatch_message()。
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*/
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#include "mqtt_client.h"
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#include "esp8266.h"
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#include "air780e.h" /* U2_CopyBuff / bg_delay */
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#include "network.h"
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#include "log.h"
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#include "main.h"
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#include "string.h"
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#define MQTT_TX_BUF_SIZE 512 /* 单发送缓冲：CONNECT/SUB/PUBLISH 最大约 350B */
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#define MQTT_RX_JSON_SIZE 384 /* 下行 PUBLISH payload 暂存 */
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static uint8_t tx_buf[MQTT_TX_BUF_SIZE];
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static char s_cid[24];
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static char s_user[24];
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static char s_pass[24];
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static volatile uint8_t s_connack_ok = 0;
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static volatile uint8_t s_suback_ok = 0;
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volatile uint8_t g_mqttc_ping_outstanding = 0;
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void mqttc_init(const char *client_id, const char *user, const char *pass)
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{
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strncpy(s_cid, client_id, sizeof(s_cid) - 1); s_cid[sizeof(s_cid)-1] = 0;
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strncpy(s_user, user, sizeof(s_user) - 1); s_user[sizeof(s_user)-1] = 0;
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strncpy(s_pass, pass, sizeof(s_pass) - 1); s_pass[sizeof(s_pass)-1] = 0;
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s_connack_ok = 0;
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s_suback_ok = 0;
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g_mqttc_ping_outstanding = 0;
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}
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/*==== 剩余长度编码（MQTT 变长编码，我们的报文 < 16KB，最多 3 字节）====*/
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static uint8_t encode_rl(uint8_t *out, uint32_t len)
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{
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uint8_t n = 0;
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do {
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uint8_t b = len % 128;
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len /= 128;
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if (len > 0) b |= 0x80;
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out[n++] = b;
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} while (len > 0);
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return n;
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}
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/* 追加一个带 2 字节长度前缀的 UTF-8 字符串，返回新偏移 */
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static uint16_t put_str(uint8_t *buf, uint16_t pos, const char *s)
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{
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uint16_t l = strlen(s);
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buf[pos++] = (uint8_t)(l >> 8);
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buf[pos++] = (uint8_t)(l & 0xFF);
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memcpy(buf + pos, s, l);
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return pos + l;
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}
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/*==== CONNECT：clean session + username + password ====*/
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int mqttc_connect(void)
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{
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uint16_t pos, var_pos, rl_pos;
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uint8_t rl_len;
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tx_buf[0] = 0x10;
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var_pos = 1 + 3; /* 预留剩余长度(最多3字节)，最后回填 */
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/* 可变头: "MQTT" + 协议级别4 + 连接标志0xC2 + keepalive */
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var_pos = put_str(tx_buf, var_pos, "MQTT");
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tx_buf[var_pos++] = 0x04;
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tx_buf[var_pos++] = 0xC2;
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tx_buf[var_pos++] = (uint8_t)(MQTT_KEEPALIVE_S >> 8);
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tx_buf[var_pos++] = (uint8_t)(MQTT_KEEPALIVE_S & 0xFF);
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/* 载荷: ClientID / Username / Password */
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var_pos = put_str(tx_buf, var_pos, s_cid);
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var_pos = put_str(tx_buf, var_pos, s_user);
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var_pos = put_str(tx_buf, var_pos, s_pass);
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/* 回填剩余长度（把可变头整体后移对齐到编码长度） */
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pos = var_pos - (1 + 3);
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rl_len = encode_rl(tx_buf + 1, pos);
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if (rl_len < 3) {
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memmove(tx_buf + 1 + rl_len, tx_buf + 1 + 3, pos);
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var_pos -= (3 - rl_len);
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}
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rl_pos = var_pos;
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log_info("> WiFi MQTT: CONNECT cid=%s", s_cid);
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esp_send(tx_buf, rl_pos);
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/* 等 CONNACK，最多 5s，期间切片喂狗 */
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s_connack_ok = 0;
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for (int i = 0; i < 50; i++) {
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bg_delay(100);
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while (mqttc_process() == 1) { }
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if (s_connack_ok) {
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log_info("> WiFi MQTT: CONNACK 成功");
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return 0;
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}
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}
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log_warn("> WiFi MQTT: CONNACK 超时");
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return -1;
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}
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/*==== SUBSCRIBE QoS0，包标识固定 1 ====*/
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int mqttc_subscribe(const char *topic)
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{
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uint16_t pos = 0;
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tx_buf[pos++] = 0x82;
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/* 剩余长度 = 2(包标识) + 2 + topic + 1(QoS) */
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pos += encode_rl(tx_buf + pos, (uint32_t)(2 + 2 + strlen(topic) + 1));
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tx_buf[pos++] = 0x00;
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tx_buf[pos++] = 0x01;
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pos = put_str(tx_buf, pos, topic);
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tx_buf[pos++] = 0x00;
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log_info("> WiFi MQTT: SUB %s", topic);
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esp_send(tx_buf, pos);
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s_suback_ok = 0;
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for (int i = 0; i < 50; i++) {
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bg_delay(100);
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while (mqttc_process() == 1) { }
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if (s_suback_ok) {
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log_info("> WiFi MQTT: SUBACK 成功");
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return 0;
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}
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}
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log_warn("> WiFi MQTT: SUBACK 超时");
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return -1;
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}
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/*==== PUBLISH QoS0 ====*/
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int mqttc_publish(const char *topic, const char *payload)
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{
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uint16_t pos = 0;
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uint32_t rl = 2 + strlen(topic) + strlen(payload);
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if (rl + 5 > MQTT_TX_BUF_SIZE) {
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log_warn("> WiFi MQTT: publish 报文过长 (%u)", (unsigned)rl);
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return -1;
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}
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tx_buf[pos++] = 0x30;
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pos += encode_rl(tx_buf + pos, rl);
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pos = put_str(tx_buf, pos, topic);
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memcpy(tx_buf + pos, payload, strlen(payload));
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pos += strlen(payload);
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esp_send(tx_buf, pos);
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return 0;
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}
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void mqttc_ping(void)
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{
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tx_buf[0] = 0xC0;
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tx_buf[1] = 0x00;
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esp_send(tx_buf, 2);
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g_mqttc_ping_outstanding = 1;
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}
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/*==== 接收解析 ====*/
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/* 二进制安全的子串查找（透传数据里可能含 0x00，如 PINGRESP 0xD0 0x00） */
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static uint8_t *memfind(uint8_t *hay, uint16_t hay_len, const char *needle)
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{
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uint16_t nlen = strlen(needle);
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if (hay_len < nlen) return NULL;
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for (uint16_t i = 0; i <= hay_len - nlen; i++) {
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if (memcmp(hay + i, needle, nlen) == 0) return hay + i;
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}
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return NULL;
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}
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/* 消费缓冲前 n 字节 */
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static void consume(uint16_t n)
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{
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if (n >= U2_CopyIndex) {
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U2_CopyIndex = 0;
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} else {
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memmove(U2_CopyBuff, U2_CopyBuff + n, U2_CopyIndex - n);
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U2_CopyIndex -= n;
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}
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U2_CopyBuff[U2_CopyIndex] = '\0';
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}
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int mqttc_process(void)
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{
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uint8_t *buf = U2_CopyBuff;
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uint16_t len = U2_CopyIndex;
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if (len == 0) {
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U2_CopyFlag = 0;
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return 0;
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}
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/* 断链检测：透传模式下 TCP 断开 ESP 会输出 "CLOSED" */
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if (memfind(buf, len, "CLOSED")) {
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consume(U2_CopyIndex);
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U2_CopyFlag = 0;
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return -1;
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}
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/* 帧同步：首字节高 4 位必须是合法报文类型(1~14)，否则逐字节丢弃 */
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uint8_t type = buf[0] >> 4;
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if (type < 1 || type > 14) {
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consume(1);
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return 1;
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}
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/* 解码剩余长度（最多 4 字节） */
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uint32_t rl = 0, mult = 1;
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uint8_t rl_bytes = 0;
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for (uint8_t i = 1; i <= 4; i++) {
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if (i >= len) return 0; /* 头还没收全，等数据 */
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rl += (uint32_t)(buf[i] & 0x7F) * mult;
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rl_bytes = i;
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if (!(buf[i] & 0x80)) break;
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mult *= 128;
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}
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if (rl_bytes == 0) return 0;
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uint32_t total = 1 + rl_bytes + rl;
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if (total > U2_COPY_SIZE - 1) {
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/* 异常巨型报文，丢弃首字节重新同步 */
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consume(1);
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return 1;
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}
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if (len < total) return 0; /* 报文没收全，等数据 */
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uint8_t *pkt = buf + 1 + rl_bytes;
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switch (type) {
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case 2: /* CONNACK: 0x20 0x02 0x00 rc */
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if (rl >= 2 && pkt[1] == 0) s_connack_ok = 1;
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else log_warn("> WiFi MQTT: CONNACK 被拒绝 rc=%u", rl >= 2 ? pkt[1] : 0xFF);
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break;
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case 9: /* SUBACK: 0x90 0x03 pktIdHi pktIdLo rc，rc=0x80 表示订阅被拒绝 */
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if (rl >= 3 && pkt[2] != 0x80) s_suback_ok = 1;
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else log_warn("> WiFi MQTT: SUBACK 被拒绝");
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break;
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case 13: /* PINGRESP */
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g_mqttc_ping_outstanding = 0;
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break;
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case 3: { /* PUBLISH QoS0：取 payload(JSON) 交网络层分发 */
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static char json[MQTT_RX_JSON_SIZE];
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uint16_t tlen = ((uint16_t)pkt[0] << 8) | pkt[1];
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if (2 + tlen <= rl) {
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uint32_t plen = rl - 2 - tlen;
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if (plen >= sizeof(json)) plen = sizeof(json) - 1;
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memcpy(json, pkt + 2 + tlen, plen);
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json[plen] = '\0';
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log_info("> WiFi MQTT 接收: %.200s", json);
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net_dispatch_message(json);
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}
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break;
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}
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default: /* PUBACK 等其他报文，忽略 */
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break;
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}
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consume((uint16_t)total);
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return 1;
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}
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