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28d45505ad4b3a8c98771fa28abd8354efc7bf1e
bacnet_stack/bacnet-stack/ports/linux/ethernet.c
T
skarg 28d45505ad refactored the handlers
2005-05-04 13:07:26 +00:00

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/*####COPYRIGHTBEGIN####
-------------------------------------------
Copyright (C) 2005 Steve Karg
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to:
The Free Software Foundation, Inc.
59 Temple Place - Suite 330
Boston, MA 02111-1307, USA.
As a special exception, if other files instantiate templates or
use macros or inline functions from this file, or you compile
this file and link it with other works to produce a work based
on this file, this file does not by itself cause the resulting
work to be covered by the GNU General Public License. However
the source code for this file must still be made available in
accordance with section (3) of the GNU General Public License.
This exception does not invalidate any other reasons why a work
based on this file might be covered by the GNU General Public
License.
-------------------------------------------
####COPYRIGHTEND####*/
#include <stdint.h> // for standard integer types uint8_t etc.
#include <stdbool.h> // for the standard bool type.
/* common unix sockets headers needed */
#include <sys/types.h> /* basic system data types */
#include <sys/time.h> /* timeval{} for select() */
#include <time.h> /* timespec{} for pselect() */
#include <netinet/in.h> /* sockaddr_in{} and other Internet defns */
#include <arpa/inet.h> /* inet(3) functions */
#include <errno.h>
#include <fcntl.h> /* for nonblocking */
#include <netdb.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h> /* for S_xxx file mode constants */
#include <sys/uio.h> /* for iovec{} and readv/writev */
#include <unistd.h>
#include <sys/wait.h>
#include <sys/un.h> /* for Unix domain sockets */
#ifdef HAVE_SYS_SELECT_H
# include <sys/select.h> /* for convenience */
#endif
#ifdef HAVE_POLL_H
# include <poll.h> /* for convenience */
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h> /* for convenience */
#endif
/* Three headers are normally needed for socket/file ioctl's:
* <sys/ioctl.h>, <sys/filio.h>, and <sys/sockio.h>.
*/
#ifdef HAVE_SYS_IOCTL_H
# include <sys/ioctl.h>
#endif
#ifdef HAVE_SYS_FILIO_H
# include <sys/filio.h>
#endif
#ifdef HAVE_SYS_SOCKIO_H
# include <sys/sockio.h>
#endif
#ifdef HAVE_PTHREAD_H
# include <pthread.h>
#endif
#define ENUMS
#include <sys/socket.h>
#include <net/route.h>
#include <net/if.h>
#include <features.h> /* for the glibc version number */
#if __GLIBC__ >= 2 && __GLIBC_MINOR >= 1
#include <netpacket/packet.h>
#include <net/ethernet.h> /* the L2 protocols */
#else
#include <asm/types.h>
#include <linux/if_packet.h>
#include <linux/if_ether.h> /* The L2 protocols */
#endif
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/un.h>
#include <sys/ioctl.h>
#include <netdb.h>
#include "bacdef.h"
#include "ethernet.h"
#include "bacdcode.h"
// commonly used comparison address for ethernet
uint8_t Ethernet_Broadcast[MAX_MAC_LEN] =
{ 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
// commonly used empty address for ethernet quick compare
uint8_t Ethernet_Empty_MAC[MAX_MAC_LEN] = { 0, 0, 0, 0, 0, 0 };
// my local device data - MAC address
uint8_t Ethernet_MAC_Address[MAX_MAC_LEN] = { 0 };
static int eth802_sockfd = -1; /* 802.2 file handle */
static struct sockaddr eth_addr = { 0 }; // used for binding 802.2
bool ethernet_valid(void)
{
return (eth802_sockfd >= 0);
}
void ethernet_cleanup(void)
{
if (ethernet_valid())
close(eth802_sockfd);
eth802_sockfd = -1;
return;
}
/*----------------------------------------------------------------------
Portable function to set a socket into nonblocking mode.
Calling this on a socket causes all future read() and write() calls on
that socket to do only as much as they can immediately, and return
without waiting.
If no data can be read or written, they return -1 and set errno
to EAGAIN (or EWOULDBLOCK).
Thanks to Bjorn Reese for this code.
----------------------------------------------------------------------*/
int setNonblocking(int fd)
{
int flags;
if (-1 == (flags = fcntl(fd, F_GETFL, 0)))
flags = 0;
return fcntl(fd, F_SETFL, flags | O_NONBLOCK);
}
/* opens an 802.2 socket to receive and send packets */
static int ethernet_bind(struct sockaddr *eth_addr, char *interface_name)
{
int sock_fd = -1; // return value
int uid = 0;
fprintf(stderr,"ethernet: opening \"%s\"\n",interface_name);
/* check to see if we are being run as root */
uid = getuid();
if (uid != 0) {
fprintf(stderr,
"ethernet: Unable to open an 802.2 socket. "
"Try running with root priveleges.\n");
return sock_fd;
}
// note: on some systems you may have to add or enable in
// modules.conf (or in modutils/alias on Debian with update-modules)
// alias net-pf-17 af_packet
// Then follow it by: # modprobe af_packet
/* Attempt to open the socket for 802.2 ethernet frames */
if ((sock_fd = socket(PF_INET, SOCK_PACKET, htons(ETH_P_802_2))) < 0)
{
/* Error occured */
fprintf(stderr,
"ethernet: Error opening socket: %s\n",
strerror(errno));
fprintf(stderr,
"You might need to add the following to modules.conf\n"
"(or in /etc/modutils/alias on Debian with update-modules):\n"
"alias net-pf-17 af_packet\n"
"Also, add af_packet to /etc/modules.\n"
"Then follow it by:\n"
"# modprobe af_packet\n");
exit(-1);
}
/* Bind the socket to an address */
eth_addr->sa_family = PF_INET;
/* Clear the memory before copying */
memset(eth_addr->sa_data, '\0', sizeof(eth_addr->sa_data));
/* Strcpy the interface name into the address */
strncpy(eth_addr->sa_data, interface_name, sizeof(eth_addr->sa_data)-1);
fprintf(stderr,"ethernet: binding \"%s\"\n",eth_addr->sa_data);
/* Attempt to bind the socket to the interface */
if (bind(sock_fd, eth_addr, sizeof(struct sockaddr)) != 0)
{
/* Bind problem, close socket and return */
fprintf(stderr,
"ethernet: Unable to bind 802.2 socket : %s\n",
strerror(errno));
fprintf(stderr,
"You might need to add the following to modules.conf\n"
"(or in /etc/modutils/alias on Debian with update-modules):\n"
"alias net-pf-17 af_packet\n"
"Also, add af_packet to /etc/modules.\n"
"Then follow it by:\n"
"# modprobe af_packet\n");
/* Close the socket */
close(sock_fd);
exit(-1);
}
atexit(ethernet_cleanup);
return sock_fd;
}
/* function to find the local ethernet MAC address */
static int get_local_hwaddr(const char *ifname, unsigned char *mac)
{
struct ifreq ifr;
int fd;
int rv; // return value - error value from df or ioctl call
/* determine the local MAC address */
strcpy(ifr.ifr_name, ifname);
fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
if (fd < 0)
rv = fd;
else {
rv = ioctl(fd, SIOCGIFHWADDR, &ifr);
if (rv >= 0) /* worked okay */
memcpy(mac, ifr.ifr_hwaddr.sa_data, IFHWADDRLEN);
}
return rv;
}
bool ethernet_init(char *interface_name)
{
get_local_hwaddr(interface_name, Ethernet_MAC_Address);
eth802_sockfd =
ethernet_bind(&eth_addr, interface_name);
return ethernet_valid();
}
/* function to send a packet out the 802.2 socket */
/* returns 0 on success, non-zero on failure */
int ethernet_send(
BACNET_ADDRESS *dest, // destination address
BACNET_ADDRESS *src, // source address
uint8_t *pdu, // any data to be sent - may be null
unsigned pdu_len) // number of bytes of data
{
int status = -1;
int bytes = 0;
uint8_t mtu[MAX_MPDU] = { 0 };
int mtu_len = 0;
int i = 0;
// don't waste time if the socket is not valid
if (eth802_sockfd < 0)
{
fprintf(stderr, "ethernet: 802.2 socket is invalid!\n");
return status;
}
/* load destination ethernet MAC address */
if (dest->mac_len == 6)
{
for (i = 0; i < 6; i++)
{
mtu[mtu_len] = dest->mac[i];
mtu_len++;
}
}
else
{
fprintf(stderr, "ethernet: invalid destination MAC address!\n");
return status;
}
/* load source ethernet MAC address */
if (src->mac_len == 6)
{
for (i = 0; i < 6; i++)
{
mtu[mtu_len] = src->mac[i];
mtu_len++;
}
}
else
{
fprintf(stderr, "ethernet: invalid source MAC address!\n");
return status;
}
if ((14 + 3 + pdu_len) > MAX_MPDU)
{
fprintf(stderr, "ethernet: PDU is too big to send!\n");
return status;
}
/* packet length */
mtu_len += encode_unsigned16(&mtu[12],
3 /*DSAP,SSAP,LLC*/ + pdu_len);
// Logical PDU portion
mtu[mtu_len++] = 0x82; /* DSAP for BACnet */
mtu[mtu_len++] = 0x82; /* SSAP for BACnet */
mtu[mtu_len++] = 0x03; /* Control byte in header */
memcpy(&mtu[mtu_len], pdu, pdu_len);
mtu_len += pdu_len;
/* Send the packet */
bytes =
sendto(eth802_sockfd, &mtu, mtu_len, 0,
(struct sockaddr *) &eth_addr, sizeof(struct sockaddr));
/* did it get sent? */
if (bytes < 0) {
fprintf(stderr,"ethernet: Error sending packet: %s\n",
strerror(errno));
return status;
}
// got this far - must be good!
status = 0;
return status;
}
/* function to send a packet out the 802.2 socket */
/* returns zero on success, non-zero on failure */
int ethernet_send_pdu(
BACNET_ADDRESS *dest, // destination address
uint8_t *pdu, // any data to be sent - may be null
unsigned pdu_len) // number of bytes of data
{
int i = 0; // counter
BACNET_ADDRESS src = {0}; // source address
for (i = 0; i < 6; i++)
{
src.mac[i] = Ethernet_MAC_Address[i];
src.mac_len++;
}
/* function to send a packet out the 802.2 socket */
/* returns 1 on success, 0 on failure */
return ethernet_send(dest, // destination address
&src, // source address
pdu, // any data to be sent - may be null
pdu_len); // number of bytes of data
}
// receives an 802.2 framed packet
// returns the number of octets in the PDU, or zero on failure
uint16_t ethernet_receive(
BACNET_ADDRESS *src, // source address
uint8_t *pdu, // PDU data
uint16_t max_pdu, // amount of space available in the PDU
unsigned timeout) // number of milliseconds to wait for a packet
{
int received_bytes;
uint8_t buf[MAX_MPDU] = {0}; // data
uint16_t pdu_len = 0; // return value
fd_set read_fds;
int max;
struct timeval select_timeout;
/* Make sure the socket is open */
if (eth802_sockfd <= 0)
return 0;
/* we could just use a non-blocking socket, but that consumes all
the CPU time. We can use a timeout; it is only supported as
a select. */
if (timeout >= 1000)
{
select_timeout.tv_sec = timeout / 1000;
select_timeout.tv_usec =
1000 * (timeout - select_timeout.tv_sec * 1000);
}
else
{
select_timeout.tv_sec = 0;
select_timeout.tv_usec = 1000 * timeout;
}
FD_ZERO(&read_fds);
FD_SET(eth802_sockfd, &read_fds);
max = eth802_sockfd;
if (select(max + 1, &read_fds, NULL, NULL, &select_timeout) > 0)
received_bytes = read(eth802_sockfd, &buf[0], MAX_MPDU);
else
return 0;
/* See if there is a problem */
if (received_bytes < 0) {
// EAGAIN Non-blocking I/O has been selected
// using O_NONBLOCK and no data
// was immediately available for reading.
if (errno != EAGAIN)
fprintf(stderr,"ethernet: Read error in receiving packet: %s\n",
strerror(errno));
return 0;
}
if (received_bytes == 0)
return 0;
/* the signature of an 802.2 BACnet packet */
if ((buf[14] != 0x82) && (buf[15] != 0x82)) {
//fprintf(stderr,"ethernet: Non-BACnet packet\n");
return 0;
}
// copy the source address
src->mac_len = 6;
memmove(src->mac, &buf[6], 6);
// check destination address for when
// the Ethernet card is in promiscious mode
if ((memcmp(&buf[0], Ethernet_MAC_Address,6) != 0)
&& (memcmp(&buf[0], Ethernet_Broadcast, 6) != 0))
{
//fprintf(stderr, "ethernet: This packet isn't for us\n");
return 0;
}
(void)decode_unsigned16(&buf[12],&pdu_len);
pdu_len -= 3 /* DSAP, SSAP, LLC Control */ ;
// copy the buffer into the PDU
if (pdu_len < max_pdu)
memmove(&pdu[0],&buf[17],pdu_len);
return pdu_len;
}
void ethernet_get_my_address(BACNET_ADDRESS *my_address)
{
int i = 0;
my_address->mac_len = 0;
for (i = 0; i < 6; i++)
{
my_address->mac[i] = Ethernet_MAC_Address[i];
my_address->mac_len++;
}
my_address->net = 0; // local only, no routing
my_address->len = 0;
for (i = 0; i < MAX_MAC_LEN; i++)
{
my_address->adr[i] = 0;
}
return;
}
void ethernet_get_broadcast_address(
BACNET_ADDRESS *dest) // destination address
{
int i = 0; // counter
if (dest)
{
for (i = 0; i < 6; i++)
{
dest->mac[i] = Ethernet_Broadcast[i];
}
dest->mac_len = 6;
dest->net = BACNET_BROADCAST_NETWORK;
dest->len = 0; // denotes broadcast address
for (i = 0; i < MAX_MAC_LEN; i++)
{
dest->adr[i] = 0;
}
}
return;
}
void ethernet_debug_address(
const char *info,
BACNET_ADDRESS *dest)
{
int i = 0; // counter
if (info)
fprintf(stderr,"%s",info);
if (dest)
{
fprintf(stderr,"Address:\n");
fprintf(stderr," MAC Length=%d\n",dest->mac_len);
fprintf(stderr," MAC Address=");
for (i = 0; i < MAX_MAC_LEN; i++)
{
fprintf(stderr,"%02X ",(unsigned)dest->mac[i]);
}
fprintf(stderr,"\n");
fprintf(stderr," Net=%hu\n",dest->net);
fprintf(stderr," Len=%d\n",dest->len);
fprintf(stderr," Adr=");
for (i = 0; i < MAX_MAC_LEN; i++)
{
fprintf(stderr,"%02X ",(unsigned)dest->adr[i]);
}
fprintf(stderr,"\n");
}
return;
}
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