strongswan/src/libcharon/plugins/socket_default/socket_default_socket.c

787 lines
18 KiB
C

/*
* Copyright (C) 2006-2013 Tobias Brunner
* Copyright (C) 2006 Daniel Roethlisberger
* Copyright (C) 2005-2010 Martin Willi
* Copyright (C) 2005 Jan Hutter
* Hochschule fuer Technik Rapperswil
*
* 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. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* 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.
*/
/* for struct in6_pktinfo */
#define _GNU_SOURCE
#ifdef __sun
#define _XPG4_2
#define __EXTENSIONS__
#endif
/* make sure to use the proper defs on Mac OS X */
#define __APPLE_USE_RFC_3542
#include "socket_default_socket.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <net/if.h>
#include <hydra.h>
#include <daemon.h>
#include <threading/thread.h>
/* Maximum size of a packet */
#define MAX_PACKET 10000
/* these are not defined on some platforms */
#ifndef SOL_IP
#define SOL_IP IPPROTO_IP
#endif
#ifndef SOL_IPV6
#define SOL_IPV6 IPPROTO_IPV6
#endif
#ifndef IPV6_TCLASS
#define IPV6_TCLASS 67
#endif
/* IPV6_RECVPKTINFO is defined in RFC 3542 which obsoletes RFC 2292 that
* previously defined IPV6_PKTINFO */
#ifndef IPV6_RECVPKTINFO
#define IPV6_RECVPKTINFO IPV6_PKTINFO
#endif
#ifndef IN6ADDR_ANY_INIT
#define IN6ADDR_ANY_INIT {{{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}}}
#endif
#ifndef HAVE_IN6ADDR_ANY
static const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
#endif
typedef struct private_socket_default_socket_t private_socket_default_socket_t;
/**
* Private data of an socket_t object
*/
struct private_socket_default_socket_t {
/**
* public functions
*/
socket_default_socket_t public;
/**
* Configured port (or random, if initially 0)
*/
u_int16_t port;
/**
* Configured port for NAT-T (or random, if initially 0)
*/
u_int16_t natt;
/**
* IPv4 socket (500 or port)
*/
int ipv4;
/**
* IPv4 socket for NAT-T (4500 or natt)
*/
int ipv4_natt;
/**
* IPv6 socket (500 or port)
*/
int ipv6;
/**
* IPv6 socket for NAT-T (4500 or natt)
*/
int ipv6_natt;
/**
* DSCP value set on IPv4 socket
*/
u_int8_t dscp4;
/**
* DSCP value set on IPv4 socket for NAT-T (4500 or natt)
*/
u_int8_t dscp4_natt;
/**
* DSCP value set on IPv6 socket (500 or port)
*/
u_int8_t dscp6;
/**
* DSCP value set on IPv6 socket for NAT-T (4500 or natt)
*/
u_int8_t dscp6_natt;
/**
* Maximum packet size to receive
*/
int max_packet;
/**
* TRUE if the source address should be set on outbound packets
*/
bool set_source;
};
METHOD(socket_t, receiver, status_t,
private_socket_default_socket_t *this, packet_t **packet)
{
char buffer[this->max_packet];
chunk_t data;
packet_t *pkt;
host_t *source = NULL, *dest = NULL;
int bytes_read = 0;
bool oldstate;
fd_set rfds;
int max_fd = 0, selected = 0;
u_int16_t port = 0;
FD_ZERO(&rfds);
if (this->ipv4 != -1)
{
FD_SET(this->ipv4, &rfds);
max_fd = max(max_fd, this->ipv4);
}
if (this->ipv4_natt != -1)
{
FD_SET(this->ipv4_natt, &rfds);
max_fd = max(max_fd, this->ipv4_natt);
}
if (this->ipv6 != -1)
{
FD_SET(this->ipv6, &rfds);
max_fd = max(max_fd, this->ipv6);
}
if (this->ipv6_natt != -1)
{
FD_SET(this->ipv6_natt, &rfds);
max_fd = max(max_fd, this->ipv6_natt);
}
DBG2(DBG_NET, "waiting for data on sockets");
oldstate = thread_cancelability(TRUE);
if (select(max_fd + 1, &rfds, NULL, NULL, NULL) <= 0)
{
thread_cancelability(oldstate);
return FAILED;
}
thread_cancelability(oldstate);
if (this->ipv4 != -1 && FD_ISSET(this->ipv4, &rfds))
{
port = this->port;
selected = this->ipv4;
}
if (this->ipv4_natt != -1 && FD_ISSET(this->ipv4_natt, &rfds))
{
port = this->natt;
selected = this->ipv4_natt;
}
if (this->ipv6 != -1 && FD_ISSET(this->ipv6, &rfds))
{
port = this->port;
selected = this->ipv6;
}
if (this->ipv6_natt != -1 && FD_ISSET(this->ipv6_natt, &rfds))
{
port = this->natt;
selected = this->ipv6_natt;
}
if (selected)
{
struct msghdr msg;
struct cmsghdr *cmsgptr;
struct iovec iov;
char ancillary[64];
union {
struct sockaddr_in in4;
struct sockaddr_in6 in6;
} src;
msg.msg_name = &src;
msg.msg_namelen = sizeof(src);
iov.iov_base = buffer;
iov.iov_len = this->max_packet;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = ancillary;
msg.msg_controllen = sizeof(ancillary);
msg.msg_flags = 0;
bytes_read = recvmsg(selected, &msg, 0);
if (bytes_read < 0)
{
DBG1(DBG_NET, "error reading socket: %s", strerror(errno));
return FAILED;
}
if (msg.msg_flags & MSG_TRUNC)
{
DBG1(DBG_NET, "receive buffer too small, packet discarded");
return FAILED;
}
DBG3(DBG_NET, "received packet %b", buffer, bytes_read);
/* read ancillary data to get destination address */
for (cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != NULL;
cmsgptr = CMSG_NXTHDR(&msg, cmsgptr))
{
if (cmsgptr->cmsg_len == 0)
{
DBG1(DBG_NET, "error reading ancillary data");
return FAILED;
}
#ifdef HAVE_IN6_PKTINFO
if (cmsgptr->cmsg_level == SOL_IPV6 &&
cmsgptr->cmsg_type == IPV6_PKTINFO)
{
struct in6_pktinfo *pktinfo;
pktinfo = (struct in6_pktinfo*)CMSG_DATA(cmsgptr);
struct sockaddr_in6 dst;
memset(&dst, 0, sizeof(dst));
memcpy(&dst.sin6_addr, &pktinfo->ipi6_addr, sizeof(dst.sin6_addr));
dst.sin6_family = AF_INET6;
dst.sin6_port = htons(port);
dest = host_create_from_sockaddr((sockaddr_t*)&dst);
}
#endif /* HAVE_IN6_PKTINFO */
if (cmsgptr->cmsg_level == SOL_IP &&
#ifdef IP_PKTINFO
cmsgptr->cmsg_type == IP_PKTINFO
#elif defined(IP_RECVDSTADDR)
cmsgptr->cmsg_type == IP_RECVDSTADDR
#else
FALSE
#endif
)
{
struct in_addr *addr;
struct sockaddr_in dst;
#ifdef IP_PKTINFO
struct in_pktinfo *pktinfo;
pktinfo = (struct in_pktinfo*)CMSG_DATA(cmsgptr);
addr = &pktinfo->ipi_addr;
#elif defined(IP_RECVDSTADDR)
addr = (struct in_addr*)CMSG_DATA(cmsgptr);
#endif
memset(&dst, 0, sizeof(dst));
memcpy(&dst.sin_addr, addr, sizeof(dst.sin_addr));
dst.sin_family = AF_INET;
dst.sin_port = htons(port);
dest = host_create_from_sockaddr((sockaddr_t*)&dst);
}
if (dest)
{
break;
}
}
if (dest == NULL)
{
DBG1(DBG_NET, "error reading IP header");
return FAILED;
}
source = host_create_from_sockaddr((sockaddr_t*)&src);
pkt = packet_create();
pkt->set_source(pkt, source);
pkt->set_destination(pkt, dest);
DBG2(DBG_NET, "received packet: from %#H to %#H", source, dest);
data = chunk_create(buffer, bytes_read);
pkt->set_data(pkt, chunk_clone(data));
}
else
{
/* oops, shouldn't happen */
return FAILED;
}
/* return packet */
*packet = pkt;
return SUCCESS;
}
METHOD(socket_t, sender, status_t,
private_socket_default_socket_t *this, packet_t *packet)
{
int sport, skt = -1, family;
ssize_t bytes_sent;
chunk_t data;
host_t *src, *dst;
struct msghdr msg;
struct cmsghdr *cmsg;
struct iovec iov;
u_int8_t *dscp;
src = packet->get_source(packet);
dst = packet->get_destination(packet);
data = packet->get_data(packet);
DBG2(DBG_NET, "sending packet: from %#H to %#H", src, dst);
/* send data */
sport = src->get_port(src);
family = dst->get_family(dst);
if (sport == 0 || sport == this->port)
{
switch (family)
{
case AF_INET:
skt = this->ipv4;
dscp = &this->dscp4;
break;
case AF_INET6:
skt = this->ipv6;
dscp = &this->dscp6;
break;
default:
return FAILED;
}
}
else if (sport == this->natt)
{
switch (family)
{
case AF_INET:
skt = this->ipv4_natt;
dscp = &this->dscp4_natt;
break;
case AF_INET6:
skt = this->ipv6_natt;
dscp = &this->dscp6_natt;
break;
default:
return FAILED;
}
}
if (skt == -1)
{
DBG1(DBG_NET, "no socket found to send IPv%d packet from port %d",
family == AF_INET ? 4 : 6, sport);
return FAILED;
}
/* setting DSCP values per-packet in a cmsg seems not to be supported
* on Linux. We instead setsockopt() before sending it, this should be
* safe as only a single thread calls send(). */
if (*dscp != packet->get_dscp(packet))
{
if (family == AF_INET)
{
u_int8_t ds4;
ds4 = packet->get_dscp(packet) << 2;
if (setsockopt(skt, SOL_IP, IP_TOS, &ds4, sizeof(ds4)) == 0)
{
*dscp = packet->get_dscp(packet);
}
else
{
DBG1(DBG_NET, "unable to set IP_TOS on socket: %s",
strerror(errno));
}
}
else
{
u_int ds6;
ds6 = packet->get_dscp(packet) << 2;
if (setsockopt(skt, SOL_IPV6, IPV6_TCLASS, &ds6, sizeof(ds6)) == 0)
{
*dscp = packet->get_dscp(packet);
}
else
{
DBG1(DBG_NET, "unable to set IPV6_TCLASS on socket: %s",
strerror(errno));
}
}
}
memset(&msg, 0, sizeof(struct msghdr));
msg.msg_name = dst->get_sockaddr(dst);;
msg.msg_namelen = *dst->get_sockaddr_len(dst);
iov.iov_base = data.ptr;
iov.iov_len = data.len;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_flags = 0;
if (this->set_source && !src->is_anyaddr(src))
{
if (family == AF_INET)
{
#if defined(IP_PKTINFO) || defined(IP_SENDSRCADDR)
struct in_addr *addr;
struct sockaddr_in *sin;
#ifdef IP_PKTINFO
char buf[CMSG_SPACE(sizeof(struct in_pktinfo))];
struct in_pktinfo *pktinfo;
#elif defined(IP_SENDSRCADDR)
char buf[CMSG_SPACE(sizeof(struct in_addr))];
#endif
memset(buf, 0, sizeof(buf));
msg.msg_control = buf;
msg.msg_controllen = sizeof(buf);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_IP;
#ifdef IP_PKTINFO
cmsg->cmsg_type = IP_PKTINFO;
cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
pktinfo = (struct in_pktinfo*)CMSG_DATA(cmsg);
addr = &pktinfo->ipi_spec_dst;
#elif defined(IP_SENDSRCADDR)
cmsg->cmsg_type = IP_SENDSRCADDR;
cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_addr));
addr = (struct in_addr*)CMSG_DATA(cmsg);
#endif
sin = (struct sockaddr_in*)src->get_sockaddr(src);
memcpy(addr, &sin->sin_addr, sizeof(struct in_addr));
#endif /* IP_PKTINFO || IP_SENDSRCADDR */
}
#ifdef HAVE_IN6_PKTINFO
else
{
char buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
struct in6_pktinfo *pktinfo;
struct sockaddr_in6 *sin;
memset(buf, 0, sizeof(buf));
msg.msg_control = buf;
msg.msg_controllen = sizeof(buf);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_IPV6;
cmsg->cmsg_type = IPV6_PKTINFO;
cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
pktinfo = (struct in6_pktinfo*)CMSG_DATA(cmsg);
sin = (struct sockaddr_in6*)src->get_sockaddr(src);
memcpy(&pktinfo->ipi6_addr, &sin->sin6_addr, sizeof(struct in6_addr));
}
#endif /* HAVE_IN6_PKTINFO */
}
bytes_sent = sendmsg(skt, &msg, 0);
if (bytes_sent != data.len)
{
DBG1(DBG_NET, "error writing to socket: %s", strerror(errno));
return FAILED;
}
return SUCCESS;
}
METHOD(socket_t, get_port, u_int16_t,
private_socket_default_socket_t *this, bool nat_t)
{
return nat_t ? this->natt : this->port;
}
METHOD(socket_t, supported_families, socket_family_t,
private_socket_default_socket_t *this)
{
socket_family_t families = SOCKET_FAMILY_NONE;
if (this->ipv4 != -1 || this->ipv4_natt != -1)
{
families |= SOCKET_FAMILY_IPV4;
}
if (this->ipv6 != -1 || this->ipv6_natt != -1)
{
families |= SOCKET_FAMILY_IPV6;
}
return families;
}
/**
* open a socket to send and receive packets
*/
static int open_socket(private_socket_default_socket_t *this,
int family, u_int16_t *port)
{
int on = TRUE;
union {
struct sockaddr sockaddr;
struct sockaddr_in sin;
struct sockaddr_in6 sin6;
} addr;
socklen_t addrlen;
u_int sol, pktinfo = 0;
int skt;
memset(&addr, 0, sizeof(addr));
addr.sockaddr.sa_family = family;
/* precalculate constants depending on address family */
switch (family)
{
case AF_INET:
addr.sin.sin_addr.s_addr = htonl(INADDR_ANY);
addr.sin.sin_port = htons(*port);
addrlen = sizeof(addr.sin);
sol = SOL_IP;
#ifdef IP_PKTINFO
pktinfo = IP_PKTINFO;
#elif defined(IP_RECVDSTADDR)
pktinfo = IP_RECVDSTADDR;
#endif
break;
case AF_INET6:
memcpy(&addr.sin6.sin6_addr, &in6addr_any, sizeof(in6addr_any));
addr.sin6.sin6_port = htons(*port);
addrlen = sizeof(addr.sin6);
sol = SOL_IPV6;
pktinfo = IPV6_RECVPKTINFO;
break;
default:
return -1;
}
skt = socket(family, SOCK_DGRAM, IPPROTO_UDP);
if (skt < 0)
{
DBG1(DBG_NET, "could not open socket: %s", strerror(errno));
return -1;
}
if (setsockopt(skt, SOL_SOCKET, SO_REUSEADDR, (void*)&on, sizeof(on)) < 0)
{
DBG1(DBG_NET, "unable to set SO_REUSEADDR on socket: %s", strerror(errno));
close(skt);
return -1;
}
/* bind the socket */
if (bind(skt, &addr.sockaddr, addrlen) < 0)
{
DBG1(DBG_NET, "unable to bind socket: %s", strerror(errno));
close(skt);
return -1;
}
/* retrieve randomly allocated port if needed */
if (*port == 0)
{
if (getsockname(skt, &addr.sockaddr, &addrlen) < 0)
{
DBG1(DBG_NET, "unable to determine port: %s", strerror(errno));
close(skt);
return -1;
}
switch (family)
{
case AF_INET:
*port = ntohs(addr.sin.sin_port);
break;
case AF_INET6:
*port = ntohs(addr.sin6.sin6_port);
break;
}
}
/* get additional packet info on receive */
if (pktinfo > 0)
{
if (setsockopt(skt, sol, pktinfo, &on, sizeof(on)) < 0)
{
DBG1(DBG_NET, "unable to set IP_PKTINFO on socket: %s", strerror(errno));
close(skt);
return -1;
}
}
#ifdef SO_MARK
{ /* set optional MARK on socket (requires CAP_NET_ADMIN) */
char *fwmark;
mark_t mark;
fwmark = lib->settings->get_str(lib->settings,
"%s.plugins.socket-default.fwmark", NULL, lib->ns);
if (fwmark && mark_from_string(fwmark, &mark))
{
if (setsockopt(skt, SOL_SOCKET, SO_MARK, &mark.value,
sizeof(mark.value)) < 0)
{
DBG1(DBG_NET, "unable to set SO_MARK on socket: %s",
strerror(errno));
}
}
}
#endif
if (!hydra->kernel_interface->bypass_socket(hydra->kernel_interface,
skt, family))
{
DBG1(DBG_NET, "installing IKE bypass policy failed");
}
/* enable UDP decapsulation for NAT-T sockets */
if (port == &this->natt &&
!hydra->kernel_interface->enable_udp_decap(hydra->kernel_interface,
skt, family, this->natt))
{
DBG1(DBG_NET, "enabling UDP decapsulation for %s on port %d failed",
family == AF_INET ? "IPv4" : "IPv6", this->natt);
}
return skt;
}
/**
* Check if we should use the given family
*/
static bool use_family(int family)
{
switch (family)
{
case AF_INET:
return lib->settings->get_bool(lib->settings,
"%s.plugins.socket-default.use_ipv4", TRUE, lib->ns);
case AF_INET6:
return lib->settings->get_bool(lib->settings,
"%s.plugins.socket-default.use_ipv6", TRUE, lib->ns);
default:
return FALSE;
}
}
/**
* Open a socket pair (normal and NAT traversal) for a given address family
*/
static void open_socketpair(private_socket_default_socket_t *this, int family,
int *skt, int *skt_natt, char *label)
{
if (!use_family(family))
{
*skt = -1;
*skt_natt = -1;
return;
}
*skt = open_socket(this, family, &this->port);
if (*skt == -1)
{
*skt_natt = -1;
DBG1(DBG_NET, "could not open %s socket, %s disabled", label, label);
}
else
{
*skt_natt = open_socket(this, family, &this->natt);
if (*skt_natt == -1)
{
DBG1(DBG_NET, "could not open %s NAT-T socket", label);
}
}
}
METHOD(socket_t, destroy, void,
private_socket_default_socket_t *this)
{
if (this->ipv4 != -1)
{
close(this->ipv4);
}
if (this->ipv4_natt != -1)
{
close(this->ipv4_natt);
}
if (this->ipv6 != -1)
{
close(this->ipv6);
}
if (this->ipv6_natt != -1)
{
close(this->ipv6_natt);
}
free(this);
}
/*
* See header for description
*/
socket_default_socket_t *socket_default_socket_create()
{
private_socket_default_socket_t *this;
INIT(this,
.public = {
.socket = {
.send = _sender,
.receive = _receiver,
.get_port = _get_port,
.supported_families = _supported_families,
.destroy = _destroy,
},
},
.port = lib->settings->get_int(lib->settings,
"%s.port", CHARON_UDP_PORT, lib->ns),
.natt = lib->settings->get_int(lib->settings,
"%s.port_nat_t", CHARON_NATT_PORT, lib->ns),
.max_packet = lib->settings->get_int(lib->settings,
"%s.max_packet", MAX_PACKET, lib->ns),
.set_source = lib->settings->get_bool(lib->settings,
"%s.plugins.socket-default.set_source", TRUE,
lib->ns),
);
if (this->port && this->port == this->natt)
{
DBG1(DBG_NET, "IKE ports can't be equal, will allocate NAT-T "
"port randomly");
this->natt = 0;
}
if ((this->port && this->port < 1024) || (this->natt && this->natt < 1024))
{
if (!lib->caps->check(lib->caps, CAP_NET_BIND_SERVICE))
{
/* required to bind ports < 1024 */
DBG1(DBG_NET, "socket-default plugin requires CAP_NET_BIND_SERVICE "
"capability");
destroy(this);
return NULL;
}
}
/* we allocate IPv6 sockets first as that will reserve randomly allocated
* ports also for IPv4. On OS X, we have to do it the other way round
* for the same effect. */
#ifdef __APPLE__
open_socketpair(this, AF_INET, &this->ipv4, &this->ipv4_natt, "IPv4");
open_socketpair(this, AF_INET6, &this->ipv6, &this->ipv6_natt, "IPv6");
#else /* !__APPLE__ */
open_socketpair(this, AF_INET6, &this->ipv6, &this->ipv6_natt, "IPv6");
open_socketpair(this, AF_INET, &this->ipv4, &this->ipv4_natt, "IPv4");
#endif /* __APPLE__ */
if (this->ipv4 == -1 && this->ipv6 == -1)
{
DBG1(DBG_NET, "could not create any sockets");
destroy(this);
return NULL;
}
return &this->public;
}