mongoose/src/mqtt.c

280 lines
8.9 KiB
C

#include "mqtt.h"
#include "arch.h"
#include "base64.h"
#include "event.h"
#include "log.h"
#include "url.h"
#include "util.h"
#define MQTT_CLEAN_SESSION 0x02
#define MQTT_HAS_WILL 0x04
#define MQTT_WILL_RETAIN 0x20
#define MQTT_HAS_PASSWORD 0x40
#define MQTT_HAS_USER_NAME 0x80
enum { MQTT_OK, MQTT_INCOMPLETE, MQTT_MALFORMED };
void mg_mqtt_send_header(struct mg_connection *c, uint8_t cmd, uint8_t flags,
uint32_t len) {
uint8_t buf[1 + sizeof(len)], *vlen = &buf[1];
buf[0] = (uint8_t) ((cmd << 4) | flags);
do {
*vlen = len % 0x80;
len /= 0x80;
if (len > 0) *vlen |= 0x80;
vlen++;
} while (len > 0 && vlen < &buf[sizeof(buf)]);
mg_send(c, buf, (size_t) (vlen - buf));
}
static void mg_send_u16(struct mg_connection *c, uint16_t value) {
mg_send(c, &value, sizeof(value));
}
void mg_mqtt_login(struct mg_connection *c, struct mg_mqtt_opts *opts) {
char rnd[9], client_id[16];
struct mg_str cid = opts->client_id;
uint32_t total_len = 7 + 1 + 2 + 2;
uint8_t connflag = (uint8_t) ((opts->will_qos & 3) << 3);
if (cid.len == 0) {
mg_random(rnd, sizeof(rnd));
mg_base64_encode((unsigned char *) rnd, sizeof(rnd), client_id);
client_id[sizeof(client_id) - 1] = '\0';
cid = mg_str(client_id);
}
if (opts->user.len > 0) {
total_len += 2 + (uint32_t) opts->user.len;
connflag |= MQTT_HAS_USER_NAME;
}
if (opts->pass.len > 0) {
total_len += 2 + (uint32_t) opts->pass.len;
connflag |= MQTT_HAS_PASSWORD;
}
if (opts->will_topic.len > 0 && opts->will_message.len > 0) {
total_len +=
4 + (uint32_t) opts->will_topic.len + (uint32_t) opts->will_message.len;
connflag |= MQTT_HAS_WILL;
}
if (opts->clean || cid.len == 0) connflag |= MQTT_CLEAN_SESSION;
if (opts->will_retain) connflag |= MQTT_WILL_RETAIN;
total_len += (uint32_t) cid.len;
mg_mqtt_send_header(c, MQTT_CMD_CONNECT, 0, total_len);
mg_send(c, "\00\04MQTT\04", 7);
mg_send(c, &connflag, sizeof(connflag));
// keepalive == 0 means "do not disconnect us!"
mg_send_u16(c, mg_htons((uint16_t) opts->keepalive));
mg_send_u16(c, mg_htons((uint16_t) cid.len));
mg_send(c, cid.ptr, cid.len);
if (connflag & MQTT_HAS_WILL) {
mg_send_u16(c, mg_htons((uint16_t) opts->will_topic.len));
mg_send(c, opts->will_topic.ptr, opts->will_topic.len);
mg_send_u16(c, mg_htons((uint16_t) opts->will_message.len));
mg_send(c, opts->will_message.ptr, opts->will_message.len);
}
if (opts->user.len > 0) {
mg_send_u16(c, mg_htons((uint16_t) opts->user.len));
mg_send(c, opts->user.ptr, opts->user.len);
}
if (opts->pass.len > 0) {
mg_send_u16(c, mg_htons((uint16_t) opts->pass.len));
mg_send(c, opts->pass.ptr, opts->pass.len);
}
}
void mg_mqtt_pub(struct mg_connection *c, struct mg_str *topic,
struct mg_str *data, int qos, bool retain) {
uint8_t flags = (uint8_t) (((qos & 3) << 1) | (retain ? 1 : 0));
uint32_t total_len = 2 + (uint32_t) topic->len + (uint32_t) data->len;
LOG(LL_DEBUG, ("%lu [%.*s] -> [%.*s]", c->id, (int) topic->len,
(char *) topic->ptr, (int) data->len, (char *) data->ptr));
if (qos > 0) total_len += 2;
mg_mqtt_send_header(c, MQTT_CMD_PUBLISH, flags, total_len);
mg_send_u16(c, mg_htons((uint16_t) topic->len));
mg_send(c, topic->ptr, topic->len);
if (qos > 0) {
static uint16_t s_id;
if (++s_id == 0) s_id++;
mg_send_u16(c, mg_htons(s_id));
}
mg_send(c, data->ptr, data->len);
}
void mg_mqtt_sub(struct mg_connection *c, struct mg_str *topic, int qos) {
static uint16_t s_id;
uint8_t qos_ = qos & 3;
uint32_t total_len = 2 + (uint32_t) topic->len + 2 + 1;
mg_mqtt_send_header(c, MQTT_CMD_SUBSCRIBE, 2, total_len);
if (++s_id == 0) ++s_id;
mg_send_u16(c, mg_htons(s_id));
mg_send_u16(c, mg_htons((uint16_t) topic->len));
mg_send(c, topic->ptr, topic->len);
mg_send(c, &qos_, sizeof(qos_));
}
int mg_mqtt_parse(const uint8_t *buf, size_t len, struct mg_mqtt_message *m) {
uint8_t lc = 0, *p, *end;
uint32_t n = 0, len_len = 0;
memset(m, 0, sizeof(*m));
m->dgram.ptr = (char *) buf;
if (len < 2) return MQTT_INCOMPLETE;
m->cmd = (uint8_t) (buf[0] >> 4);
m->qos = (buf[0] >> 1) & 3;
n = len_len = 0;
p = (uint8_t *) buf + 1;
while ((size_t) (p - buf) < len) {
lc = *((uint8_t *) p++);
n += (uint32_t) ((lc & 0x7f) << 7 * len_len);
len_len++;
if (!(lc & 0x80)) break;
if (len_len >= 4) return MQTT_MALFORMED;
}
end = p + n;
if (lc & 0x80 || end > buf + len) return MQTT_INCOMPLETE;
m->dgram.len = (size_t) (end - buf);
switch (m->cmd) {
case MQTT_CMD_CONNACK:
if (end - p < 2) return MQTT_MALFORMED;
m->ack = p[1];
break;
case MQTT_CMD_PUBACK:
case MQTT_CMD_PUBREC:
case MQTT_CMD_PUBREL:
case MQTT_CMD_PUBCOMP:
case MQTT_CMD_SUBACK:
if (p + 2 > end) return MQTT_MALFORMED;
m->id = (uint16_t) ((((uint16_t) p[0]) << 8) | p[1]);
break;
case MQTT_CMD_SUBSCRIBE: {
if (p + 2 > end) return MQTT_MALFORMED;
m->id = (uint16_t) ((((uint16_t) p[0]) << 8) | p[1]);
p += 2;
break;
}
case MQTT_CMD_PUBLISH: {
if (p + 2 > end) return MQTT_MALFORMED;
m->topic.len = (uint16_t) ((((uint16_t) p[0]) << 8) | p[1]);
m->topic.ptr = (char *) p + 2;
p += 2 + m->topic.len;
if (p > end) return MQTT_MALFORMED;
if (m->qos > 0) {
if (p + 2 > end) return MQTT_MALFORMED;
m->id = (uint16_t) ((((uint16_t) p[0]) << 8) | p[1]);
p += 2;
}
if (p > end) return MQTT_MALFORMED;
m->data.ptr = (char *) p;
m->data.len = (size_t) (end - p);
break;
}
default:
break;
}
return MQTT_OK;
}
static size_t mg_mqtt_next_topic(struct mg_mqtt_message *msg,
struct mg_str *topic, uint8_t *qos,
size_t pos) {
unsigned char *buf = (unsigned char *) msg->dgram.ptr + pos;
size_t new_pos;
if (pos >= msg->dgram.len) return 0;
topic->len = (size_t) (((unsigned) buf[0]) << 8 | buf[1]);
topic->ptr = (char *) buf + 2;
new_pos = pos + 2 + topic->len + (qos == NULL ? 0 : 1);
if ((size_t) new_pos > msg->dgram.len) return 0;
if (qos != NULL) *qos = buf[2 + topic->len];
return new_pos;
}
size_t mg_mqtt_next_sub(struct mg_mqtt_message *msg, struct mg_str *topic,
uint8_t *qos, size_t pos) {
uint8_t tmp;
return mg_mqtt_next_topic(msg, topic, qos == NULL ? &tmp : qos, pos);
}
size_t mg_mqtt_next_unsub(struct mg_mqtt_message *msg, struct mg_str *topic,
size_t pos) {
return mg_mqtt_next_topic(msg, topic, NULL, pos);
}
static void mqtt_cb(struct mg_connection *c, int ev, void *ev_data,
void *fn_data) {
if (ev == MG_EV_READ) {
for (;;) {
struct mg_mqtt_message mm;
int rc = mg_mqtt_parse(c->recv.buf, c->recv.len, &mm);
if (rc == MQTT_MALFORMED) {
LOG(LL_ERROR, ("%lu MQTT malformed message", c->id));
c->is_closing = 1;
break;
} else if (rc == MQTT_OK) {
LOG(LL_VERBOSE_DEBUG,
("%p MQTT CMD %d len %d [%.*s]", c->fd, mm.cmd, (int) mm.dgram.len,
(int) mm.data.len, mm.data.ptr));
switch (mm.cmd) {
case MQTT_CMD_CONNACK:
mg_call(c, MG_EV_MQTT_OPEN, &mm.ack);
if (mm.ack == 0) {
LOG(LL_INFO, ("%lu Connected", c->id));
} else {
LOG(LL_ERROR, ("%lu MQTT auth failed, code %d", c->id, mm.ack));
c->is_closing = 1;
}
break;
case MQTT_CMD_PUBLISH: {
LOG(LL_DEBUG, ("%lu [%.*s] -> [%.*s]", c->id, (int) mm.topic.len,
mm.topic.ptr, (int) mm.data.len, mm.data.ptr));
mg_call(c, MG_EV_MQTT_MSG, &mm);
break;
}
}
mg_call(c, MG_EV_MQTT_CMD, &mm);
mg_iobuf_del(&c->recv, 0, mm.dgram.len);
} else {
break;
}
}
}
(void) ev_data;
(void) fn_data;
}
void mg_mqtt_ping(struct mg_connection *nc) {
mg_mqtt_send_header(nc, MQTT_CMD_PINGREQ, 0, 0);
}
void mg_mqtt_pong(struct mg_connection *nc) {
mg_mqtt_send_header(nc, MQTT_CMD_PINGRESP, 0, 0);
}
void mg_mqtt_disconnect(struct mg_connection *nc) {
mg_mqtt_send_header(nc, MQTT_CMD_DISCONNECT, 0, 0);
}
struct mg_connection *mg_mqtt_connect(struct mg_mgr *mgr, const char *url,
struct mg_mqtt_opts *opts,
mg_event_handler_t fn, void *fn_data) {
struct mg_connection *c = mg_connect(mgr, url, fn, fn_data);
if (c != NULL) {
struct mg_mqtt_opts empty;
memset(&empty, 0, sizeof(empty));
mg_mqtt_login(c, opts == NULL ? &empty : opts);
c->pfn = mqtt_cb;
}
return c;
}
struct mg_connection *mg_mqtt_listen(struct mg_mgr *mgr, const char *url,
mg_event_handler_t fn, void *fn_data) {
struct mg_connection *c = mg_listen(mgr, url, fn, fn_data);
if (c != NULL) c->pfn = mqtt_cb, c->pfn_data = mgr;
return c;
}