iface.c File Reference

interface handling for the Commotion daemon More...

#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <net/if.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <linux/sockios.h>
#include "extern/wpa_ctrl.h"
#include "obj.h"
#include "debug.h"
#include "iface.h"
#include "util.h"
#include "id.h"
#include "list.h"

Functions
int	co_ifaces_create (void)
	checks for available interfaces
void	co_ifaces_shutdown (void)
	removes all interfaces
int	co_iface_remove (char *iface_name)
	removes an interface from the list of available interfaces More...
co_obj_t *	co_iface_add (const char *iface_name, const int family)
	adds a new interface to the list of available interfaces, and checks whether it is IPv4 and IPv6 capable, and whether it is wireless More...
int	co_iface_get_mac (co_obj_t *iface, unsigned char *output, int output_size)
int	co_iface_set_ip (co_obj_t *iface_obj, const char *ip_addr, const char *netmask)
	sets ip address and netmask for commotion interface More...
int	co_iface_unset_ip (co_obj_t *iface_obj)
	Resets ip address of chosen interface. More...
int	co_iface_wpa_disconnect (co_obj_t *iface_obj)
	turns off wpa supplicant More...
int	co_iface_wpa_connect (co_obj_t *iface_obj)
	connects the commotion interface to wpa supplicant More...
int	co_iface_set_ssid (co_obj_t *iface, const char *ssid)
	sets SSID from profile or uses default More...
int	co_iface_set_bssid (co_obj_t *iface, const char *bssid)
	sets BSSID from profile or uses default More...
int	co_iface_set_frequency (co_obj_t *iface, const int frequency)
	sets wireless frequency (eg. channel) from profile or uses default More...
int	co_iface_set_encryption (co_obj_t *iface, const char *proto)
	specifies the wpa encryption protocol More...
int	co_iface_set_key (co_obj_t *iface, const char *key)
	specifies the wpa encryption key More...
int	co_iface_set_mode (co_obj_t *iface, const char *mode)
	specifies the Wi-Fi mode More...
int	co_iface_set_apscan (co_obj_t *iface, const int value)
	sets AP_SCAN value More...
int	co_iface_wireless_enable (co_obj_t *iface)
	enables specified wireless network More...
int	co_iface_wireless_disable (co_obj_t *iface)
	disables specified wireless network More...
int	co_set_dns (const char *dnsserver, const char *searchdomain, const char *resolvpath)
	sets DNS name server and sets search domain More...
int	co_generate_ip (const char *base, const char *genmask, const nodeid_t id, char *output, int type)
	generates an ip table for a commotion interface More...
char *	co_iface_profile (char *iface_name)
	sets node configuration profile More...
co_obj_t *	co_iface_get (char *iface_name)
	retrieves node configuration profile More...

Detailed Description

interface handling for the Commotion daemon

Author

Josh King (jheretic), jking.nosp@m.@cha.nosp@m.mbana.nosp@m..net

Function Documentation

int co_generate_ip	(	const char *	base,
		const char *	genmask,
		const nodeid_t	id,
		char *	output,
		int	type
	)

generates an ip table for a commotion interface

Parameters

base	base address
genmask	genmask
id	the node id
type	whether the device is a gateway (1) or not (0)

                                                                                                     {
  nodeid_t addr;
  addr.id = 0;
  struct in_addr baseaddr;
  struct in_addr generatedaddr;
  struct in_addr genmaskaddr;
  CHECK(inet_aton(base, &baseaddr) != 0, "Invalid base ip address %s", base); 
  CHECK(inet_aton(genmask, &genmaskaddr) != 0, "Invalid genmask address %s", genmask); 

  /*
   * Turn the IP address into a 
   * network address.
   */
  generatedaddr.s_addr = (baseaddr.s_addr & genmaskaddr.s_addr);

  /*
   * get the matching octet from 
   * the mac and and then move it
   * left to the proper spot.
   */
  for (int i = 0; i < 4; i++)
    addr.bytes[i] = (id.bytes[i]&0xff)%0xfe;

  /* 
   * if address is of a gateway
   * type, then set the last byte 
   * to '1'
   * */
  if(type) {
    /* 
     * shift us over by one 
     * to ensure that we are
     * getting maximum entropy 
     * from the mac address.
     */
    addr.bytes[1] = addr.bytes[2];
    addr.bytes[2] = addr.bytes[3];
    addr.bytes[3] = 1;
  }

  /*
   * mask out the parts of address
   * that overlap with the genmask 
   */
  addr.id &= ~(genmaskaddr.s_addr);
  /*
   * add back the user-supplied 
   * base ip address.
   */
  generatedaddr.s_addr = (generatedaddr.s_addr|addr.id);

  strcpy(output, inet_ntoa(generatedaddr));
  return 1;
error:
  return 0;
}

co_obj_t* co_iface_add	(	const char *	iface_name,
		const int	family
	)

adds a new interface to the list of available interfaces, and checks whether it is IPv4 and IPv6 capable, and whether it is wireless

Parameters

iface_name	name of the interface
family	address family of the interface. Must be AF_INET (IPv4) or AF_INET6 (IPv6), which uses host and port number for addressing

References co_list_append(), and strlcpy().

                                                                 {
  co_iface_t *iface = h_calloc(1,sizeof(co_iface_t));
  iface->_len = (sizeof(co_iface_t));
  iface->_exttype = _iface;
  iface->_header._type = _ext8;
  iface->_header._flags = 0;
  iface->_header._ref = 0;
  
  iface->fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
  strlcpy(iface->ifr.ifr_name, iface_name, IFNAMSIZ);
  
 /* Check whether interface is IPv4 or IPv6 */
  if((family & AF_INET) == AF_INET) {
    iface->ifr.ifr_addr.sa_family = AF_INET; 
  } else if((family & AF_INET6) == AF_INET6) {
    iface->ifr.ifr_addr.sa_family = AF_INET6; 
  } else {
    ERROR("Invalid address family!");
    co_obj_free((co_obj_t*)iface);
    return NULL;
  }

  /* Check whether interface is wireless or not */
  if(_co_iface_is_wireless((co_obj_t*)iface)) iface->wireless = true;
  iface->wpa_id = -1;
    
  co_list_append(ifaces, (co_obj_t*)iface);
  return (co_obj_t*)iface; 
}

co_obj_t* co_iface_get

(

char *

iface_name

)

retrieves node configuration profile

Parameters

iface_name

name of interface

References co_list_parse().

                                         {
  co_obj_t *iface = NULL;
  CHECK((iface = co_list_parse(ifaces, _co_iface_match_i, iface_name)) != NULL, "Failed to get interface %s!", iface_name);
  return iface;
error:
  return NULL;
}

int co_iface_get_mac	(	co_obj_t *	iface,
		unsigned char *	output,
		int	output_size
	)

Parameters

iface	interface object
output	output of hardware MAC address lookup
output_size	size of MAC address. Must be six bytes

                                                                              {
  CHECK(IS_IFACE(iface),"Not an iface.");
  co_iface_t *maciface = NULL;
  CHECK(output_size == 6, "output_size does not equal six");

  maciface = malloc(sizeof(co_iface_t));
  memset(maciface, '\0', sizeof(co_iface_t));
  memmove(maciface, iface, sizeof(co_iface_t));
  if (0 == ioctl(((co_iface_t*)iface)->fd, SIOCGIFHWADDR, &maciface->ifr)) {
    DEBUG("Received MAC Address : %02x:%02x:%02x:%02x:%02x:%02x\n",
                maciface->ifr.ifr_hwaddr.sa_data[0],maciface->ifr.ifr_hwaddr.sa_data[1],maciface->ifr.ifr_hwaddr.sa_data[2]
                ,maciface->ifr.ifr_hwaddr.sa_data[3],maciface->ifr.ifr_hwaddr.sa_data[4],maciface->ifr.ifr_hwaddr.sa_data[5]);
    memmove(output, maciface->ifr.ifr_addr.sa_data, output_size);
    free(maciface);
    return 1;
  }
  free(maciface);
error:
  return 0;
}

char* co_iface_profile

(

char *

iface_name

)

sets node configuration profile

Parameters

iface_name

name of interface

References co_list_parse().

                                         {
  co_obj_t *iface = NULL;
  CHECK((iface = co_list_parse(ifaces, _co_iface_match_i, iface_name)) != NULL, "Failed to get interface %s profile!", iface_name);
  return ((co_iface_t*)iface)->profile;
error:
  return NULL;
}

int co_iface_remove

(

char *

iface_name

)

removes an interface from the list of available interfaces

Parameters

iface_name

name of interface to be removed

References co_iface_unset_ip(), co_iface_wireless_disable(), co_iface_wpa_disconnect(), co_list_delete(), and co_list_parse().

                                      {
  co_obj_t *iface = NULL;
  CHECK((iface = co_list_parse(ifaces, _co_iface_match_i, iface_name)) != NULL, "Failed to delete interface %s!", iface_name);
  iface = co_list_delete(ifaces, iface);
  co_iface_unset_ip(iface);
  co_iface_wireless_disable(iface);
  co_iface_wpa_disconnect(iface);
  co_obj_free(iface);
  return 1;

error:
  return 0;
}

int co_iface_set_apscan	(	co_obj_t *	iface,
		const int	value
	)

sets AP_SCAN value

Parameters

iface	interface object
value	desired value for AP_SCAN

                                                          {
  CHECK(IS_IFACE(iface),"Not an iface.");
  char cmd[256];
  char buf[WPA_REPLY_SIZE];
  size_t len;

  snprintf(cmd, sizeof(cmd), "AP_SCAN %d", value);
  cmd[sizeof(cmd) - 1] = '\0';

  return _co_iface_wpa_command(iface, cmd, buf, &len);
error:
  return 0;
}

int co_iface_set_bssid	(	co_obj_t *	iface,
		const char *	bssid
	)

sets BSSID from profile or uses default

Parameters

iface	interface object
bssid	desired BSSID

                                                           {
  CHECK(IS_IFACE(iface),"Not an iface.");
  char cmd[256], *pos, *end;
  int ret;
  char buf[WPA_REPLY_SIZE];
  size_t len;

  end = cmd + sizeof(cmd);
  pos = cmd;
  ret = snprintf(pos, end - pos, "BSSID");
  if (ret < 0 || ret >= end - pos) {
    ERROR("Too long BSSID command.");
    return 0;
  }
  pos += ret;
  ret = snprintf(pos, end - pos, " %d %s", ((co_iface_t*)iface)->wpa_id, bssid);
  if (ret < 0 || ret >= end - pos) {
    ERROR("Too long BSSID command.");
    return 0;
  }
  pos += ret;

  return _co_iface_wpa_command(iface, cmd, buf, &len);
error:
  return 0;
}

int co_iface_set_encryption	(	co_obj_t *	iface,
		const char *	proto
	)

specifies the wpa encryption protocol

Parameters

iface	interface object
proto	desired protocol

                                                                {
  CHECK(IS_IFACE(iface),"Not an iface.");
  return _co_iface_wpa_set(iface, "proto", proto); 
error:
  return 0;
}

int co_iface_set_frequency	(	co_obj_t *	iface,
		const int	frequency
	)

sets wireless frequency (eg. channel) from profile or uses default

Parameters

iface	interface object
frequency	desired frequency

                                                                 {
  CHECK(IS_IFACE(iface),"Not an iface.");
  char freq[FREQ_LEN]; 
  snprintf(freq, FREQ_LEN, "%d", frequency);
  return _co_iface_wpa_set(iface, "frequency", freq); 
error:
  return 0;
}

int co_iface_set_ip	(	co_obj_t *	iface,
		const char *	ip_addr,
		const char *	netmask
	)

sets ip address and netmask for commotion interface

Parameters

iface	interface object
ip_addr	ip address for the socket
netmask	netmask for the socket

                                                                                   {
  CHECK_MEM(iface_obj); 
  co_iface_t *iface = (co_iface_t*)iface_obj;
  struct sockaddr_in *addr = (struct sockaddr_in *)&iface->ifr.ifr_addr;

  DEBUG("Setting address %s and netmask %s.", ip_addr, netmask);
 
  // Convert IP from numbers and dots to binary notation
  inet_pton(AF_INET, ip_addr, &addr->sin_addr);
  CHECK((ioctl(iface->fd, SIOCSIFADDR, &iface->ifr) == 0), "Failed to set IP address for interface: %s", iface->ifr.ifr_name);

  inet_pton(AF_INET, netmask, &addr->sin_addr);
  CHECK((ioctl(iface->fd, SIOCSIFNETMASK, &iface->ifr) == 0), "Failed to set IP address for interface: %s", iface->ifr.ifr_name);

  //Get and set interface flags.
  CHECK((ioctl(iface->fd, SIOCGIFFLAGS, &iface->ifr) == 0), "Interface shutdown: %s", iface->ifr.ifr_name);
  iface->ifr.ifr_flags |= IFF_UP;
  iface->ifr.ifr_flags |= IFF_RUNNING;
  CHECK((ioctl(iface->fd, SIOCSIFFLAGS, &iface->ifr) == 0), "Interface up failed: %s", iface->ifr.ifr_name);
 
  DEBUG("Addressing for interface %s is done!", iface->ifr.ifr_name);
  return 1;

error:
  return 0;
}

int co_iface_set_key	(	co_obj_t *	iface,
		const char *	key
	)

specifies the wpa encryption key

Parameters

iface	interface object
key	desired key

                                                       {
  CHECK(IS_IFACE(iface),"Not an iface.");
  return _co_iface_wpa_set(iface, "psk", key); 
error:
  return 0;
}

int co_iface_set_mode	(	co_obj_t *	iface,
		const char *	mode
	)

specifies the Wi-Fi mode

Parameters

iface	interface object
mode	desired mode

                                                         {
  CHECK(IS_IFACE(iface),"Not an iface.");
  return _co_iface_wpa_set(iface, "mode", mode); 
error:
  return 0;
}

int co_iface_set_ssid	(	co_obj_t *	iface,
		const char *	ssid
	)

sets SSID from profile or uses default

Parameters

iface	interface object
ssid	desired SSID

                                                         {
  CHECK(IS_IFACE(iface),"Not an iface.");
  return _co_iface_wpa_set(iface, "ssid", ssid); 
error:
  return 0;
}

int co_iface_unset_ip

(

co_obj_t *

iface

)

Resets ip address of chosen interface.

Parameters

iface

interface object

Referenced by co_iface_remove().

                                           {
  CHECK_MEM(iface_obj); 
  CHECK(IS_IFACE(iface_obj),"Not an iface.");
  co_iface_t *iface = (co_iface_t*)iface_obj;
  //Get and set interface flags.
  CHECK((ioctl(iface->fd, SIOCGIFFLAGS, &iface->ifr) == 0), "Interface shutdown: %s", iface->ifr.ifr_name);
  iface->ifr.ifr_flags &= ~IFF_UP;
  iface->ifr.ifr_flags &= ~IFF_RUNNING;
  CHECK((ioctl(iface->fd, SIOCSIFFLAGS, &iface->ifr) == 0), "Interface up failed: %s", iface->ifr.ifr_name);
  return 1;
error:
  return 0;
}

int co_iface_wireless_disable

(

co_obj_t *

iface

)

disables specified wireless network

Parameters

iface

interface object

Referenced by co_iface_remove().

                                               {
  CHECK(IS_IFACE(iface),"Not an iface.");
  CHECK(_co_iface_wpa_disable_network(iface), "Failed to disable network %s", ((co_iface_t*)iface)->ifr.ifr_name);
  CHECK(_co_iface_wpa_remove_network(iface), "Failed to remove network %s", ((co_iface_t*)iface)->ifr.ifr_name);
  return 1;
error:
  return 0;
}

int co_iface_wireless_enable

(

co_obj_t *

iface

)

enables specified wireless network

Parameters

iface

interface object

                                              {
  CHECK(IS_IFACE(iface),"Not an iface.");
  char cmd[256];
  char buf[WPA_REPLY_SIZE];
  size_t len;

  snprintf(cmd, sizeof(cmd), "ENABLE_NETWORK %d", ((co_iface_t*)iface)->wpa_id);
  cmd[sizeof(cmd) - 1] = '\0';

  return _co_iface_wpa_command(iface, cmd, buf, &len);
error:
  return 0;
}

int co_iface_wpa_connect

(

co_obj_t *

iface

)

connects the commotion interface to wpa supplicant

Parameters

iface

interface object

                                              {
  CHECK(IS_IFACE(iface_obj),"Not an iface.");
  co_iface_t *iface = (co_iface_t*)iface_obj;
  char *filename = NULL;
  size_t length;

  CHECK(iface->wireless, "Not a wireless interface: %s", iface->ifr.ifr_name);

  length = strlen(wpa_control_dir) + strlen(iface->ifr.ifr_name) + 2;
  filename = calloc(1, length);
  CHECK_MEM(filename);
  snprintf(filename, length, "%s/%s", wpa_control_dir, iface->ifr.ifr_name);
  DEBUG("WPA control file: %s", filename);

  CHECK((iface->ctrl = wpa_ctrl_open(filename)), "Failed to connect to wpa_supplicant.");
  free(filename);
  return 1;

error:
  free(filename);
  return 0;
}

int co_iface_wpa_disconnect

(

co_obj_t *

iface

)

turns off wpa supplicant

Parameters

iface

interface object

Referenced by co_iface_remove().

                                                 {
  CHECK(IS_IFACE(iface_obj),"Not an iface.");
  co_iface_t *iface = (co_iface_t*)iface_obj;
  if(iface->ctrl) {
    wpa_ctrl_detach(iface->ctrl);
    wpa_ctrl_close(iface->ctrl);
    return 1;
  }
error:
  return 0;
}

int co_set_dns	(	const char *	dnsserver,
		const char *	searchdomain,
		const char *	resolvpath
	)

sets DNS name server and sets search domain

Parameters

dnsserver	IP addresss of DNS server
searchdomain	desired search domain
resolvpath	filepath to resolv.conf

                                                                                        {
  FILE *fp = fopen(resolvpath, "w+");
  if(fp != NULL) {
    if(searchdomain != NULL) fprintf(fp, "search %s\n", searchdomain); 
    fprintf(fp, "nameserver %s\n", dnsserver);
    fclose(fp);
    return 1;
  } else ERROR("Could not open file: %s", resolvpath);
  return 0;
}