kvm/internal/audio/c/ipc_protocol.c

310 lines
8.3 KiB
C

/*
* JetKVM Audio IPC Protocol Implementation
*
* Implements Unix domain socket communication with exact byte-level
* compatibility with Go implementation in internal/audio/ipc_*.go
*/
#include "ipc_protocol.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/uio.h>
#include <endian.h>
// ============================================================================
// HELPER FUNCTIONS
// ============================================================================
/**
* Read exactly N bytes from socket (loops until complete or error).
* This is critical because read() may return partial data.
*/
int ipc_read_full(int sock, void *buf, size_t len) {
uint8_t *ptr = (uint8_t *)buf;
size_t remaining = len;
while (remaining > 0) {
ssize_t n = read(sock, ptr, remaining);
if (n < 0) {
if (errno == EINTR) {
continue; // Interrupted by signal, retry
}
return -1; // Read error
}
if (n == 0) {
return -1; // EOF (connection closed)
}
ptr += n;
remaining -= n;
}
return 0; // Success
}
/**
* Get current time in nanoseconds (Unix epoch).
* Compatible with Go time.Now().UnixNano().
*/
int64_t ipc_get_time_ns(void) {
struct timespec ts;
if (clock_gettime(CLOCK_REALTIME, &ts) != 0) {
return 0; // Fallback on error
}
return (int64_t)ts.tv_sec * 1000000000LL + (int64_t)ts.tv_nsec;
}
// ============================================================================
// MESSAGE READ/WRITE
// ============================================================================
/**
* Read a complete IPC message from socket.
* Returns 0 on success, -1 on error.
* Caller MUST free msg->data if non-NULL!
*/
int ipc_read_message(int sock, ipc_message_t *msg, uint32_t expected_magic) {
if (msg == NULL) {
return -1;
}
// Initialize message
memset(msg, 0, sizeof(ipc_message_t));
// 1. Read header (17 bytes)
if (ipc_read_full(sock, &msg->header, IPC_HEADER_SIZE) != 0) {
return -1;
}
// 2. Convert from little-endian (required on big-endian systems)
msg->header.magic = le32toh(msg->header.magic);
msg->header.length = le32toh(msg->header.length);
msg->header.timestamp = le64toh(msg->header.timestamp);
// Note: type is uint8_t, no conversion needed
// 3. Validate magic number
if (msg->header.magic != expected_magic) {
fprintf(stderr, "IPC: Invalid magic number: got 0x%08X, expected 0x%08X\n",
msg->header.magic, expected_magic);
return -1;
}
// 4. Validate length
if (msg->header.length > IPC_MAX_FRAME_SIZE) {
fprintf(stderr, "IPC: Message too large: %u bytes (max %d)\n",
msg->header.length, IPC_MAX_FRAME_SIZE);
return -1;
}
// 5. Read payload if present
if (msg->header.length > 0) {
msg->data = malloc(msg->header.length);
if (msg->data == NULL) {
fprintf(stderr, "IPC: Failed to allocate %u bytes for payload\n",
msg->header.length);
return -1;
}
if (ipc_read_full(sock, msg->data, msg->header.length) != 0) {
free(msg->data);
msg->data = NULL;
return -1;
}
}
return 0; // Success
}
/**
* Write a complete IPC message to socket.
* Uses writev() for atomic header+payload write.
* Returns 0 on success, -1 on error.
*/
int ipc_write_message(int sock, uint32_t magic, uint8_t type,
const uint8_t *data, uint32_t length) {
// Validate length
if (length > IPC_MAX_FRAME_SIZE) {
fprintf(stderr, "IPC: Message too large: %u bytes (max %d)\n",
length, IPC_MAX_FRAME_SIZE);
return -1;
}
// Prepare header
ipc_header_t header;
header.magic = htole32(magic);
header.type = type;
header.length = htole32(length);
header.timestamp = htole64(ipc_get_time_ns());
// Use writev for atomic write (if possible)
struct iovec iov[2];
iov[0].iov_base = &header;
iov[0].iov_len = IPC_HEADER_SIZE;
iov[1].iov_base = (void *)data;
iov[1].iov_len = length;
int iovcnt = (length > 0) ? 2 : 1;
size_t total_len = IPC_HEADER_SIZE + length;
ssize_t written = writev(sock, iov, iovcnt);
if (written < 0) {
if (errno == EINTR) {
// Retry once on interrupt
written = writev(sock, iov, iovcnt);
}
if (written < 0) {
perror("IPC: writev failed");
return -1;
}
}
if ((size_t)written != total_len) {
fprintf(stderr, "IPC: Partial write: %zd/%zu bytes\n", written, total_len);
return -1;
}
return 0; // Success
}
// ============================================================================
// CONFIGURATION PARSING
// ============================================================================
/**
* Parse Opus configuration from message data (36 bytes, little-endian).
*/
int ipc_parse_opus_config(const uint8_t *data, uint32_t length, ipc_opus_config_t *config) {
if (data == NULL || config == NULL) {
return -1;
}
if (length != 36) {
fprintf(stderr, "IPC: Invalid Opus config size: %u bytes (expected 36)\n", length);
return -1;
}
// Parse little-endian uint32 fields
const uint32_t *u32_data = (const uint32_t *)data;
config->sample_rate = le32toh(u32_data[0]);
config->channels = le32toh(u32_data[1]);
config->frame_size = le32toh(u32_data[2]);
config->bitrate = le32toh(u32_data[3]);
config->complexity = le32toh(u32_data[4]);
config->vbr = le32toh(u32_data[5]);
config->signal_type = le32toh(u32_data[6]);
config->bandwidth = le32toh(u32_data[7]);
config->dtx = le32toh(u32_data[8]);
return 0; // Success
}
/**
* Parse basic audio configuration from message data (12 bytes, little-endian).
*/
int ipc_parse_config(const uint8_t *data, uint32_t length, ipc_config_t *config) {
if (data == NULL || config == NULL) {
return -1;
}
if (length != 12) {
fprintf(stderr, "IPC: Invalid config size: %u bytes (expected 12)\n", length);
return -1;
}
// Parse little-endian uint32 fields
const uint32_t *u32_data = (const uint32_t *)data;
config->sample_rate = le32toh(u32_data[0]);
config->channels = le32toh(u32_data[1]);
config->frame_size = le32toh(u32_data[2]);
return 0; // Success
}
/**
* Free message resources.
*/
void ipc_free_message(ipc_message_t *msg) {
if (msg != NULL && msg->data != NULL) {
free(msg->data);
msg->data = NULL;
}
}
// ============================================================================
// SOCKET MANAGEMENT
// ============================================================================
/**
* Create Unix domain socket server.
*/
int ipc_create_server(const char *socket_path) {
if (socket_path == NULL) {
return -1;
}
// 1. Create socket
int sock = socket(AF_UNIX, SOCK_STREAM, 0);
if (sock < 0) {
perror("IPC: socket() failed");
return -1;
}
// 2. Remove existing socket file (ignore errors)
unlink(socket_path);
// 3. Bind to path
struct sockaddr_un addr;
memset(&addr, 0, sizeof(addr));
addr.sun_family = AF_UNIX;
if (strlen(socket_path) >= sizeof(addr.sun_path)) {
fprintf(stderr, "IPC: Socket path too long: %s\n", socket_path);
close(sock);
return -1;
}
strncpy(addr.sun_path, socket_path, sizeof(addr.sun_path) - 1);
if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
perror("IPC: bind() failed");
close(sock);
return -1;
}
// 4. Listen with backlog=1 (single client)
if (listen(sock, 1) < 0) {
perror("IPC: listen() failed");
close(sock);
return -1;
}
printf("IPC: Server listening on %s\n", socket_path);
return sock;
}
/**
* Accept client connection.
*/
int ipc_accept_client(int server_sock) {
int client_sock = accept(server_sock, NULL, NULL);
if (client_sock < 0) {
perror("IPC: accept() failed");
return -1;
}
printf("IPC: Client connected (fd=%d)\n", client_sock);
return client_sock;
}