proxy.c File Reference

Main event loop, related operations. More...

#include <signal.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/epoll.h>
#include "args.h"
#include "log.h"
#include "packet.h"
#include "process.h"

Include dependency graph for proxy.c:

Functions
static void	check_signals (void)
	Check and set signal counters. More...
static int	create_epoll (void)
	Create an epoll instance. More...
static void	spurious_event (char *name, uint32_t events)
	Log an error on receiving a spurious epoll event. More...
void	proxy (struct iface_t *ifaces)
	Main event loop. More...

Variables
volatile sig_atomic_t	sig_hup
volatile sig_atomic_t	sig_int
volatile sig_atomic_t	sig_usr1
volatile sig_atomic_t	sig_term
struct args_t	args
	Program arguments data structure. More...

Detailed Description

Main event loop, related operations.

Function Documentation

static void check_signals ( void  )

static

Check and set signal counters.

static int create_epoll ( void  )

static

Create an epoll instance.

Returns

0 if successful, -1 if unsuccessful

static void spurious_event ( char *  name, uint32_t  events  )

static

Log an error on receiving a spurious epoll event.

Parameters

name	The name of a network interface
events	The events field of a struct epoll_event

See also

epoll(4)

void proxy

(

struct iface_t *

ifaces

)

Main event loop.

The loop flow approximates the following:

1. Ingress phase: Receive an EAPOL packet (packet) on a configured interface (iface).
   packet is an Ethernet frame containing an EAPOL MPDU and iface is a network interface configured in the config file.
   • If packet is the first EAPOL packet to be received on iface, and any other interfaces are configured to have their MAC address set from the source MAC address of such a packet:
     • Set each such interface's MAC address.
     • Drop packet entirely and restart the loop.
   • If iface has an ingress script defined matching the EAPOL Packet Type or EAP Code of packet, execute the ingress script.
   • If iface has an ingress filter defined matching packet, apply the ingress filter (i.e. drop packet entirely and restart the loop).
2. Egress phase: Proxy to other configured interfaces ("egress interfaces").
   For each egress interface (eiface):
   • Make a local copy of packet (epacket).
   • If eiface has a dot1q option defined, add/change/remove the 802.1Q VLAN tag in epacket.
   • If eiface has an egress filter defined matching epacket, apply the egress filter.
     This means dropping epacket entirely on eiface and moving on to proxying packet on the next egress interface.
   • If eiface has an egress script defined matching epacket, execute the egress script.
   • Send epacket on eiface.
3. Restart the loop.

Parameters

ifaces

Pointer to a list of struct iface_t structures representing network interfaces

Variable Documentation

volatile sig_atomic_t sig_hup

volatile sig_atomic_t sig_int

volatile sig_atomic_t sig_usr1

volatile sig_atomic_t sig_term

struct args_t args

Program arguments data structure.

Note

Global