esphome/esphome/components/e131/e131_packet.cpp
2022-01-23 20:29:58 +13:00

144 lines
3.7 KiB
C++

#ifdef USE_ARDUINO
#include "e131.h"
#include "esphome/core/log.h"
#include "esphome/core/util.h"
#include "esphome/components/network/ip_address.h"
#include <cstring>
#include <lwip/init.h>
#include <lwip/ip_addr.h>
#include <lwip/ip4_addr.h>
#include <lwip/igmp.h>
namespace esphome {
namespace e131 {
static const char *const TAG = "e131";
static const uint8_t ACN_ID[12] = {0x41, 0x53, 0x43, 0x2d, 0x45, 0x31, 0x2e, 0x31, 0x37, 0x00, 0x00, 0x00};
static const uint32_t VECTOR_ROOT = 4;
static const uint32_t VECTOR_FRAME = 2;
static const uint8_t VECTOR_DMP = 2;
// E1.31 Packet Structure
union E131RawPacket {
struct {
// Root Layer
uint16_t preamble_size;
uint16_t postamble_size;
uint8_t acn_id[12];
uint16_t root_flength;
uint32_t root_vector;
uint8_t cid[16];
// Frame Layer
uint16_t frame_flength;
uint32_t frame_vector;
uint8_t source_name[64];
uint8_t priority;
uint16_t reserved;
uint8_t sequence_number;
uint8_t options;
uint16_t universe;
// DMP Layer
uint16_t dmp_flength;
uint8_t dmp_vector;
uint8_t type;
uint16_t first_address;
uint16_t address_increment;
uint16_t property_value_count;
uint8_t property_values[E131_MAX_PROPERTY_VALUES_COUNT];
} __attribute__((packed));
uint8_t raw[638];
};
// We need to have at least one `1` value
// Get the offset of `property_values[1]`
const size_t E131_MIN_PACKET_SIZE = reinterpret_cast<size_t>(&((E131RawPacket *) nullptr)->property_values[1]);
bool E131Component::join_igmp_groups_() {
if (listen_method_ != E131_MULTICAST)
return false;
if (!udp_)
return false;
for (auto universe : universe_consumers_) {
if (!universe.second)
continue;
ip4_addr_t multicast_addr = {static_cast<uint32_t>(
network::IPAddress(239, 255, ((universe.first >> 8) & 0xff), ((universe.first >> 0) & 0xff)))};
auto err = igmp_joingroup(IP4_ADDR_ANY4, &multicast_addr);
if (err) {
ESP_LOGW(TAG, "IGMP join for %d universe of E1.31 failed. Multicast might not work.", universe.first);
}
}
return true;
}
void E131Component::join_(int universe) {
// store only latest received packet for the given universe
auto consumers = ++universe_consumers_[universe];
if (consumers > 1) {
return; // we already joined before
}
if (join_igmp_groups_()) {
ESP_LOGD(TAG, "Joined %d universe for E1.31.", universe);
}
}
void E131Component::leave_(int universe) {
auto consumers = --universe_consumers_[universe];
if (consumers > 0) {
return; // we have other consumers of the given universe
}
if (listen_method_ == E131_MULTICAST) {
ip4_addr_t multicast_addr = {
static_cast<uint32_t>(network::IPAddress(239, 255, ((universe >> 8) & 0xff), ((universe >> 0) & 0xff)))};
igmp_leavegroup(IP4_ADDR_ANY4, &multicast_addr);
}
ESP_LOGD(TAG, "Left %d universe for E1.31.", universe);
}
bool E131Component::packet_(const std::vector<uint8_t> &data, int &universe, E131Packet &packet) {
if (data.size() < E131_MIN_PACKET_SIZE)
return false;
auto *sbuff = reinterpret_cast<const E131RawPacket *>(&data[0]);
if (memcmp(sbuff->acn_id, ACN_ID, sizeof(sbuff->acn_id)) != 0)
return false;
if (htonl(sbuff->root_vector) != VECTOR_ROOT)
return false;
if (htonl(sbuff->frame_vector) != VECTOR_FRAME)
return false;
if (sbuff->dmp_vector != VECTOR_DMP)
return false;
if (sbuff->property_values[0] != 0)
return false;
universe = htons(sbuff->universe);
packet.count = htons(sbuff->property_value_count);
if (packet.count > E131_MAX_PROPERTY_VALUES_COUNT)
return false;
memcpy(packet.values, sbuff->property_values, packet.count);
return true;
}
} // namespace e131
} // namespace esphome
#endif // USE_ARDUINO