litex/vpi/ipc.c

158 lines
2.8 KiB
C

/*
* Copyright (C) 2012 Vermeer Manufacturing Co.
* License: GPLv3 with additional permissions (see README).
*/
#include <assert.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "ipc.h"
struct ipc_softc {
int socket;
go_handler h_go;
write_handler h_write;
read_handler h_read;
void *user;
};
struct ipc_softc *ipc_connect(const char *sockaddr,
go_handler h_go, write_handler h_write, read_handler h_read, void *user)
{
struct ipc_softc *sc;
struct sockaddr_un addr;
sc = malloc(sizeof(struct ipc_softc));
if(!sc) return NULL;
sc->h_go = h_go;
sc->h_write = h_write;
sc->h_read = h_read;
sc->user = user;
sc->socket = socket(AF_UNIX, SOCK_SEQPACKET, 0);
if(sc->socket < 0) {
free(sc);
return NULL;
}
addr.sun_family = AF_UNIX;
strcpy(addr.sun_path, sockaddr);
if(connect(sc->socket, (struct sockaddr *)&addr, sizeof(addr)) != 0) {
close(sc->socket);
free(sc);
return NULL;
}
return sc;
}
void ipc_destroy(struct ipc_softc *sc)
{
close(sc->socket);
free(sc);
}
enum {
MESSAGE_TICK = 0,
MESSAGE_GO,
MESSAGE_WRITE,
MESSAGE_READ,
MESSAGE_READ_REPLY
};
#define MAX_LEN 2048
/*
* 0 -> error
* 1 -> success
* 2 -> graceful shutdown
*/
int ipc_receive(struct ipc_softc *sc)
{
unsigned char buffer[MAX_LEN];
ssize_t l;
int i;
l = recv(sc->socket, buffer, MAX_LEN, 0);
if(l == 0)
return 2;
if((l < 0) || (l >= MAX_LEN))
return 0;
i = 0;
switch(buffer[i++]) {
case MESSAGE_GO:
assert(l == 1);
return sc->h_go(sc->user);
case MESSAGE_WRITE: {
char *name;
int nchunks;
unsigned char *chunks;
unsigned int index;
name = (char *)&buffer[i];
i += strlen(name) + 1;
assert((i+4) < l);
index = buffer[i] | buffer[i+1] << 8 | buffer[i+2] << 16 | buffer[i+3] << 24;
i += 4;
nchunks = buffer[i++];
assert(i + nchunks == l);
chunks = (unsigned char *)&buffer[i];
return sc->h_write(name, index, nchunks, chunks, sc->user);
}
case MESSAGE_READ: {
char *name;
unsigned int index;
name = (char *)&buffer[i];
i += strlen(name) + 1;
assert((i+4) == l);
index = buffer[i] | buffer[i+1] << 8 | buffer[i+2] << 16 | buffer[i+3] << 24;
return sc->h_read(name, index, sc->user);
}
default:
return 0;
}
}
int ipc_tick(struct ipc_softc *sc)
{
char c;
ssize_t l;
c = MESSAGE_TICK;
l = send(sc->socket, &c, 1, 0);
if(l != 1)
return 0;
return 1;
}
int ipc_read_reply(struct ipc_softc *sc, int nchunks, const unsigned char *chunks)
{
int len;
char buffer[MAX_LEN];
ssize_t l;
len = nchunks + 2;
assert(len < MAX_LEN);
assert(nchunks < 256);
buffer[0] = MESSAGE_READ_REPLY;
buffer[1] = nchunks;
memcpy(&buffer[2], chunks, nchunks);
l = send(sc->socket, buffer, len, 0);
if(l != len)
return 0;
return 1;
}