
to avoid segmentation faults, out of bounds access and integer overflow make parseable for splint suppress splint warnings about datatype cc_t fix type of return value for read() add checks before accessing tty
241 lines
6.1 KiB
C
Executable File
241 lines
6.1 KiB
C
Executable File
//------------------------------------------------------------------------------
|
|
// Copyright (C) 2011, Robert Johansson, Raditex AB
|
|
// All rights reserved.
|
|
//
|
|
// rSCADA
|
|
// http://www.rSCADA.se
|
|
// info@rscada.se
|
|
//
|
|
//------------------------------------------------------------------------------
|
|
|
|
#include <unistd.h>
|
|
#include <limits.h>
|
|
#include <fcntl.h>
|
|
|
|
#include <sys/socket.h>
|
|
#include <sys/types.h>
|
|
|
|
#include <arpa/inet.h>
|
|
#include <netinet/in.h>
|
|
#include <netdb.h>
|
|
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <strings.h>
|
|
#include <errno.h>
|
|
|
|
#include "mbus-tcp.h"
|
|
|
|
#define PACKET_BUFF_SIZE 2048
|
|
|
|
//------------------------------------------------------------------------------
|
|
/// Setup a TCP/IP handle.
|
|
//------------------------------------------------------------------------------
|
|
int
|
|
mbus_tcp_connect(mbus_handle *handle)
|
|
{
|
|
char error_str[128], *host;
|
|
struct hostent *host_addr;
|
|
struct sockaddr_in s;
|
|
struct timeval time_out;
|
|
mbus_tcp_data *tcp_data;
|
|
uint16_t port;
|
|
|
|
if (handle == NULL)
|
|
return -1;
|
|
|
|
tcp_data = (mbus_tcp_data *) handle->auxdata;
|
|
if (tcp_data == NULL || tcp_data->host == NULL)
|
|
return -1;
|
|
|
|
host = tcp_data->host;
|
|
port = tcp_data->port;
|
|
|
|
//
|
|
// create the TCP connection
|
|
//
|
|
if ((handle->fd = socket(AF_INET,SOCK_STREAM, 0)) < 0)
|
|
{
|
|
snprintf(error_str, sizeof(error_str), "%s: failed to setup a socket.", __PRETTY_FUNCTION__);
|
|
mbus_error_str_set(error_str);
|
|
return -1;
|
|
}
|
|
|
|
s.sin_family = AF_INET;
|
|
s.sin_port = htons(port);
|
|
|
|
/* resolve hostname */
|
|
if ((host_addr = gethostbyname(host)) == NULL)
|
|
{
|
|
snprintf(error_str, sizeof(error_str), "%s: unknown host: %s", __PRETTY_FUNCTION__, host);
|
|
mbus_error_str_set(error_str);
|
|
return -1;
|
|
}
|
|
|
|
memcpy((void *)(&s.sin_addr), (void *)(host_addr->h_addr), host_addr->h_length);
|
|
|
|
if (connect(handle->fd, (struct sockaddr *)&s, sizeof(s)) < 0)
|
|
{
|
|
snprintf(error_str, sizeof(error_str), "%s: Failed to establish connection to %s:%d", __PRETTY_FUNCTION__, host, port);
|
|
mbus_error_str_set(error_str);
|
|
return -1;
|
|
}
|
|
|
|
// Set a timeout
|
|
time_out.tv_sec = 4; //seconds
|
|
time_out.tv_usec = 0;
|
|
setsockopt(handle->fd, SOL_SOCKET, SO_SNDTIMEO, &time_out, sizeof(time_out));
|
|
setsockopt(handle->fd, SOL_SOCKET, SO_RCVTIMEO, &time_out, sizeof(time_out));
|
|
|
|
return 0;
|
|
}
|
|
|
|
void
|
|
mbus_tcp_data_free(mbus_handle *handle)
|
|
{
|
|
mbus_tcp_data *tcp_data;
|
|
|
|
if (handle)
|
|
{
|
|
tcp_data = (mbus_tcp_data *) handle->auxdata;
|
|
|
|
if (tcp_data == NULL)
|
|
{
|
|
return;
|
|
}
|
|
|
|
free(tcp_data->host);
|
|
free(tcp_data);
|
|
handle->auxdata = NULL;
|
|
}
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
//
|
|
//------------------------------------------------------------------------------
|
|
int
|
|
mbus_tcp_disconnect(mbus_handle *handle)
|
|
{
|
|
if (handle == NULL)
|
|
{
|
|
return -1;
|
|
}
|
|
|
|
close(handle->fd);
|
|
|
|
return 0;
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
//
|
|
//------------------------------------------------------------------------------
|
|
int
|
|
mbus_tcp_send_frame(mbus_handle *handle, mbus_frame *frame)
|
|
{
|
|
unsigned char buff[PACKET_BUFF_SIZE];
|
|
int len, ret;
|
|
char error_str[128];
|
|
|
|
if (handle == NULL || frame == NULL)
|
|
{
|
|
return -1;
|
|
}
|
|
|
|
if ((len = mbus_frame_pack(frame, buff, sizeof(buff))) == -1)
|
|
{
|
|
snprintf(error_str, sizeof(error_str), "%s: mbus_frame_pack failed\n", __PRETTY_FUNCTION__);
|
|
mbus_error_str_set(error_str);
|
|
return -1;
|
|
}
|
|
|
|
if ((ret = write(handle->fd, buff, len)) == len)
|
|
{
|
|
//
|
|
// call the send event function, if the callback function is registered
|
|
//
|
|
if (_mbus_send_event)
|
|
_mbus_send_event(MBUS_HANDLE_TYPE_TCP, buff, len);
|
|
}
|
|
else
|
|
{
|
|
snprintf(error_str, sizeof(error_str), "%s: Failed to write frame to socket (ret = %d)\n", __PRETTY_FUNCTION__, ret);
|
|
mbus_error_str_set(error_str);
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
//
|
|
//------------------------------------------------------------------------------
|
|
int mbus_tcp_recv_frame(mbus_handle *handle, mbus_frame *frame)
|
|
{
|
|
char buff[PACKET_BUFF_SIZE];
|
|
int remaining;
|
|
ssize_t len, nread;
|
|
|
|
if (handle == NULL || frame == NULL) {
|
|
fprintf(stderr, "%s: Invalid parameter.\n", __PRETTY_FUNCTION__);
|
|
return MBUS_RECV_RESULT_ERROR;
|
|
}
|
|
|
|
memset((void *) buff, 0, sizeof(buff));
|
|
|
|
//
|
|
// read data until a packet is received
|
|
//
|
|
remaining = 1; // start by reading 1 byte
|
|
len = 0;
|
|
|
|
do {
|
|
retry:
|
|
if (len + remaining > PACKET_BUFF_SIZE)
|
|
{
|
|
// avoid out of bounds access
|
|
return MBUS_RECV_RESULT_ERROR;
|
|
}
|
|
|
|
nread = read(handle->fd, &buff[len], remaining);
|
|
switch (nread) {
|
|
case -1:
|
|
if (errno == EINTR)
|
|
goto retry;
|
|
|
|
if (errno == EAGAIN || errno == EWOULDBLOCK) {
|
|
mbus_error_str_set("M-Bus tcp transport layer response timeout has been reached.");
|
|
return MBUS_RECV_RESULT_TIMEOUT;
|
|
}
|
|
|
|
mbus_error_str_set("M-Bus tcp transport layer failed to read data.");
|
|
return MBUS_RECV_RESULT_ERROR;
|
|
case 0:
|
|
mbus_error_str_set("M-Bus tcp transport layer connection closed by remote host.");
|
|
return MBUS_RECV_RESULT_RESET;
|
|
default:
|
|
if (len > (SSIZE_MAX-nread))
|
|
{
|
|
// avoid overflow
|
|
return MBUS_RECV_RESULT_ERROR;
|
|
}
|
|
|
|
len += nread;
|
|
}
|
|
} while ((remaining = mbus_parse(frame, buff, len)) > 0);
|
|
|
|
//
|
|
// call the receive event function, if the callback function is registered
|
|
//
|
|
if (_mbus_recv_event)
|
|
_mbus_recv_event(MBUS_HANDLE_TYPE_TCP, buff, len);
|
|
|
|
if (remaining < 0) {
|
|
mbus_error_str_set("M-Bus layer failed to parse data.");
|
|
return MBUS_RECV_RESULT_INVALID;
|
|
}
|
|
|
|
return MBUS_RECV_RESULT_OK;
|
|
}
|
|
|
|
|