Remove network interface under Solaris

Under Solaris, it is very more easy to remove than to add. The network interface can be found thanks to the couple (name, inet address):
N.B.: All checks have been removed for better legibility, but it is very important to check returned code after each request.

// We consider the existence of the variables (unsigned char *) "networkInterfaceName", "inetAddress" which could be respectively "eth0" and "192.168.80.1" for instance.

int socketDescriptor;
struct sockaddr_in *addr;
struct lifreq lifr;

sd = socket(AF_INET, SOCK_DGRAM, 0);

memset(&lifr, 0, sizeof(lifr));
addr = (struct sockaddr_in *) &(lifr.lifr_addr);
strncpy(lifr.lifr_name, networkInterfaceName, sizeof(lifr.lifr_name));
addr->sin_family = AF_INET;
addr->sin_addr.s_addr = inet_addr(inetAddress);
ioctl(socketDescriptor, SIOCLIFREMOVEIF, (caddr_t) &lifr)
close(socketDescriptor);

Remove network interface under GNU/Linux

It is enough to switch down the corresponding alias network interface:
N.B.: All checks have been removed for better legibility, but it is very important to check returned code after each request.

// We consider the existence of the variable (unsigned char *) "aliasInterfaceName" ("eth0:myAlias" for instance).
int sd;
struct ifreq ifr;

sd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));

memset(&ifr, 0, sizeof(struct ifreq));
strncpy(ifr.lifr_name, aliasInterfaceName, sizeof(ifr.ifr_name));
ifr.ifr_flags = ~IFF_UP;
ioctl(sd, SIOCSIFFLAGS, &ifr);
close(sd);

Add network interface under Solaris

Under Solairs, it is not trivial to add a network interface, there is no alias, and it seems to not be possible to specify the additional network interface name (so it must be got and kept).
N.B.: All checks have been removed for better legibility, but it is very important to check returned code after each request.

// We consider the existence of the variables (unsigned char *) "networkInterfaceName", "inetAddress", "broadcastAddress" and "netmaskAddress" which could be respectively "eth0", "192.168.80.1", "192.168.80.255" and "255.255.255.0" for instance.

int sd;
struct sockaddr_in *addr;
struct lifreq lifr, lifrBroadcast, lifrNetmask, lifrFlags;
const char *aliasName;

// Resets structure.
memset(&lifr, 0, sizeof(lifr));
strncpy(lifr.lifr_name, networkInterfaceName, sizeof(lifr.lifr_name));

sd = socket(AF_INET, SOCK_DGRAM, 0);
ioctl(sd, SIOCLIFADDIF, (caddr_t) &lifr);

// Very important to get the alias name to update network interface parameters.
aliasName = lifr.lifr_name;

// Manages broadcast.
memset(&lifrBroadcast, 0, sizeof(lifrBroadcast));
addr = (struct sockaddr_in *) &(lifrBroadcast.lifr_broadaddr);
strncpy(lifrBroadcast.lifr_name, aliasName, sizeof(lifrBroadcast.lifr_name));
addr->sin_family = AF_INET;
addr->sin_addr.s_addr = inet_addr(broadcastAddress);
ioctl(sd, SIOCSLIFBRDADDR, (caddr_t) &lifrBroadcast);

// Manages netmask.
memset(&lifrNetmask, 0, sizeof(lifrNetmask));
addr = (struct sockaddr_in *) &(lifrNetmask.lifr_addr);
strncpy(lifrNetmask.lifr_name, aliasName, sizeof(lifrNetmask.lifr_name));
addr->sin_family = AF_INET;
addr->sin_addr.s_addr = inet_addr(netmaskAddress);
ioctl(sd, SIOCSLIFNETMASK, (caddr_t) &lifrNetmask);

// Defines the address of the new interface.
addr = (struct sockaddr_in *) &(lifr.lifr_addr);
addr->sin_family = AF_INET;
addr->sin_addr.s_addr = inet_addr(inetAddress);
ioctl(sd, SIOCSLIFADDR, (caddr_t) &lifr);

// Sets the new interface UP.
memset(&lifrFlags, 0, sizeof(lifrFlags));
strncpy(lifrFlags.lifr_name, aliasName, sizeof(lifrFlags.lifr_name));
ioctl(sd, SIOCGLIFFLAGS, (caddr_t) &lifrFlags)
lifrFlags.lifr_flags |= IFF_UP;
ioctl(sd, SIOCSLIFFLAGS, (caddr_t) &lifrFlags);
close(sd);

Add network interface under GNU/Linux

It is not so hard to perform it under GNU/Linux with alias.
The aim, is to add an alias to an existing network interface with the wished inet, broadcast and netmask addresses:
N.B.: All checks have been removed for better legibility, but it is very important to check returned code after each request.

// We consider the existence of the variables (unsigned char *) "aliasInterfaceName", "inetAddress", "broadcastAddress" and "netmaskAddress" which could be respectively "eth0:myAlias"; "192.168.80.1", "192.168.80.255" and "255.255.255.0" for instance.

int sd;
struct sockaddr_in *addr;
struct ifreq ifr, ifrBroadcast, ifrNetmask;

sd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));

// Add alias.
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.lifr_name, aliasInterfaceName, sizeof(ifr.ifr_name));
addr = (struct sockaddr_in *) &(ifr.ifr_addr);
addr->sin_family=AF_INET;
addr->sin_addr.s_addr=inet_addr(inetAddress);
ioctl(sd, SIOCSIFADDR, &ifr);

// Manages broadcast.
memset(&ifrBroadcast, 0, sizeof(ifrBroadcast));
strncpy(ifrBroadcast.lifr_name, aliasInterfaceName, sizeof(ifrBroadcast.ifr_name));
addr = (struct sockaddr_in *) &(ifrBroadcast.ifr_addr);
addr->sin_family=AF_INET;
addr->sin_addr.s_addr=inet_addr(broadcastAddress);
ioctl(sd, SIOCSIFBRDADDR, &ifrBroadcast)

// Manages netmask.
memset(&ifrNetmask, 0, sizeof(ifrNetmask));
strncpy(ifrNetmask.lifr_name, aliasInterfaceName, sizeof(ifrNetmask.ifr_name));
addr = (struct sockaddr_in *) &(ifrNetmask.ifr_addr);
addr->sin_family=AF_INET;
addr->sin_addr.s_addr=inet_addr(netmaskAddress);
ioctl(sd, SIOCSIFNETMASK, &ifrNetmask);

close(sd);

Get MAC address under GNU/Linux or Solaris

This is a way to get MAC address of a network interface in C language.
Under GNU/Linux it can be done thanks to a RAW socket:
N.B.: All checks have been removed for better legibility, but it is very important to check returned code after each request.

// Consider a variable "networkInterfaceName" of type char * is defined ("eth0" for instance).
int sd;
struct ifreq ifr;
const unsigned char *hardwareAddress;

sd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
memset(&ifr, 0, sizeof(ifr));
setNameInIfreq(&ifr, networkInterfaceName);
hardwareAddress = (unsigned char *) &ifr.ifr_hwaddr.sa_data;
close(sd);

Under Solaris, it begins to be less easy, we need to use DLPI code:
// Consider a variable "devicePath" of type char * is defined ("/dev/eth0" for instance).
int sd;
dl_phys_addr_req_t dlpareq;
dl_phys_addr_ack_t *dlpaack;
struct strbuf msg;
char buf[128];
int flags = 0;
const unsigned char *hardwareAddress;

sd = open(devicePath, O_RDWR));
dlpareq.dl_primitive = DL_PHYS_ADDR_REQ;
dlpareq.dl_addr_type = DL_CURR_PHYS_ADDR;
msg.buf = (char *)&dlpareq;
msg.len = DL_PHYS_ADDR_REQ_SIZE;
putmsg(sd, &msg, NULL, 0);
dlpaack = (dl_phys_addr_ack_t *)buf;
msg.buf = (char *)buf;
msg.len = 0;
msg.maxlen = sizeof (buf);
getmsg(sd, &msg, NULL, &flags);
memcpy(hardwareAddress, &buf[dlpaack->dl_addr_offset], dlpaack->dl_addr_length);
close(sd);

Compile OpenVPN and TUN under Solaris

I've recently worked on Solaris and need to compile the source code of openVPN and TUN.
At first, it seemed easy but because of some compatibility issues, it was not.
You can follow those steps to get openvpn executable under Solaris:
- download the openVPN source code and uncompress it under [OPENVPN_DIRECTORY],
- download the TUN source code and uncompress it under [TUNE_DIRECTORY],
- copy the [TUNE_DIRECTORY]/solaris/if_tun.h file to [OPENVPN_DIRECTORY],
- edit the [OPENVPN_DIRECTORY]/tun.c file and add the #include "if_tun.h" line after the #include "tun.h" one,
- under [OPENVPN_DIRECTORY], execute ./configure --disable-lzo,
- ensure there is a make executable into your path, for instance create a symbolic link executing ln -s /usr/sfw/bin/gmake /usr/bin/make,
- then execute make under [OPENVPN_DIRECTORY],
- finally the openvpn executable is ready for Solaris.

Then, you can follow those steps to get the tun functionality under Solaris:
- create the subdirectory [TUNE_DIRECTORY] /solaris/sys,
- download the dditypes.h file and put it under [TUNE_DIRECTORY] /solaris/sys (it fixes an incompatibility issue),
- ensure there is a ld executable into your path, for instance create a symbolic link executing ln -s /usr/sfw/bin/gld /usr/bin/ld,
- execute make install under [TUNE_DIRECTORY],
- finally the tun functionality is ready for Solaris.

It is now possible to use openVPN and TUN under Solaris.