6to4: Add 6to4 tunnel support.
authorJukka Rissanen <jukka.rissanen@nokia.com>
Fri, 25 Mar 2011 13:03:15 +0000 (15:03 +0200)
committerSamuel Ortiz <sameo@linux.intel.com>
Fri, 25 Mar 2011 13:45:40 +0000 (14:45 +0100)
Netlink support routines taken from iproute2 package.
Iproute2 source code can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/shemminger/iproute2.git

Makefile.am
src/6to4.c [new file with mode: 0644]
src/connman.h

index 3ad1ee9..95aefc7 100644 (file)
@@ -77,7 +77,7 @@ src_connmand_SOURCES = $(gdbus_sources) $(gdhcp_sources) \
                        src/wifi.c src/storage.c src/dbus.c src/config.c \
                        src/technology.c src/counter.c src/location.c \
                        src/session.c src/tethering.c src/wpad.c src/wispr.c \
-                       src/stats.c src/iptables.c src/dnsproxy.c
+                       src/stats.c src/iptables.c src/dnsproxy.c src/6to4.c
 
 src_connmand_LDADD = $(builtin_libadd) @GLIB_LIBS@ @DBUS_LIBS@ \
                                @CAPNG_LIBS@ @XTABLES_LIBS@ -lresolv -ldl
diff --git a/src/6to4.c b/src/6to4.c
new file mode 100644 (file)
index 0000000..767c866
--- /dev/null
@@ -0,0 +1,497 @@
+/*
+ *
+ *  Connection Manager
+ *
+ *  Copyright (C) 2011  Nokia Corporation. All rights reserved.
+ *  Copyright (C) Alexey Kuznetsov et al. from iproute2 package.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <linux/ip.h>
+#include <linux/if_tunnel.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+#include "connman.h"
+#include <connman/log.h>
+#include <connman/ipconfig.h>
+
+static int tunnel_created;
+static int tunnel_pending;
+static char *tunnel_ip_address;
+
+#define NLMSG_TAIL(nmsg) \
+       ((struct rtattr *) (((void *)(nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
+
+#ifndef IP_DF
+#define IP_DF          0x4000          /* Flag: "Don't Fragment"       */
+#endif
+
+struct rtnl_handle {
+       int                     fd;
+       struct sockaddr_nl      local;
+       struct sockaddr_nl      peer;
+       __u32                   seq;
+       __u32                   dump;
+};
+
+static int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
+{
+       int len = RTA_LENGTH(4);
+       struct rtattr *rta;
+       if (NLMSG_ALIGN(n->nlmsg_len) + len > (unsigned int)maxlen) {
+               DBG("Error! max allowed bound %d exceeded", maxlen);
+               return -1;
+       }
+       rta = NLMSG_TAIL(n);
+       rta->rta_type = type;
+       rta->rta_len = len;
+       memcpy(RTA_DATA(rta), &data, 4);
+       n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
+
+       return 0;
+}
+
+static int addattr_l(struct nlmsghdr *n, int maxlen, int type,
+                       const void *data, int alen)
+{
+       int len = RTA_LENGTH(alen);
+       struct rtattr *rta;
+
+       if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) >
+                                       (unsigned int)maxlen) {
+               DBG("addattr_l message exceeded bound of %d", maxlen);
+               return -1;
+       }
+       rta = NLMSG_TAIL(n);
+       rta->rta_type = type;
+       rta->rta_len = len;
+       memcpy(RTA_DATA(rta), data, alen);
+       n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
+
+       return 0;
+}
+
+static void rtnl_close(struct rtnl_handle *rth)
+{
+       if (rth->fd >= 0) {
+               close(rth->fd);
+               rth->fd = -1;
+       }
+}
+
+static int rtnl_open(struct rtnl_handle *rth)
+{
+       socklen_t addr_len;
+       int sndbuf = 1024;
+
+       memset(rth, 0, sizeof(*rth));
+
+       rth->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+       if (rth->fd < 0) {
+               connman_error("Can not open netlink socket: %s",
+                                               strerror(errno));
+               return -1;
+       }
+
+       if (setsockopt(rth->fd, SOL_SOCKET, SO_SNDBUF, &sndbuf,
+                       sizeof(sndbuf)) < 0) {
+               connman_error("SO_SNDBUF: %s", strerror(errno));
+               return -1;
+       }
+
+       memset(&rth->local, 0, sizeof(rth->local));
+       rth->local.nl_family = AF_NETLINK;
+       rth->local.nl_groups = 0;
+
+       if (bind(rth->fd, (struct sockaddr *)&rth->local,
+                       sizeof(rth->local)) < 0) {
+               connman_error("Can not bind netlink socket: %s",
+                                                       strerror(errno));
+               return -1;
+       }
+       addr_len = sizeof(rth->local);
+       if (getsockname(rth->fd, (struct sockaddr *)&rth->local,
+                               &addr_len) < 0) {
+               connman_error("Can not getsockname: %s", strerror(errno));
+               return -1;
+       }
+       if (addr_len != sizeof(rth->local)) {
+               connman_error("Wrong address length %d", addr_len);
+               return -1;
+       }
+       if (rth->local.nl_family != AF_NETLINK) {
+               connman_error("Wrong address family %d", rth->local.nl_family);
+               return -1;
+       }
+       rth->seq = time(NULL);
+
+       return 0;
+}
+
+static int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n)
+{
+       struct sockaddr_nl nladdr;
+       struct iovec iov = {
+               .iov_base = (void *)n,
+               .iov_len = n->nlmsg_len
+       };
+       struct msghdr msg = {
+               .msg_name = &nladdr,
+               .msg_namelen = sizeof(nladdr),
+               .msg_iov = &iov,
+               .msg_iovlen = 1,
+       };
+       unsigned seq;
+       int err;
+
+       memset(&nladdr, 0, sizeof(nladdr));
+       nladdr.nl_family = AF_NETLINK;
+
+       n->nlmsg_seq = seq = ++rtnl->seq;
+       n->nlmsg_flags |= NLM_F_ACK;
+
+       err = sendmsg(rtnl->fd, &msg, 0);
+       if (err < 0) {
+               connman_error("Can not talk to rtnetlink");
+               return err;
+       }
+
+       return 0;
+}
+
+static int tunnel_create(struct in_addr *addr)
+{
+       struct ip_tunnel_parm p;
+       struct ifreq ifr;
+       int fd = -1;
+       int ret;
+
+       /* ip tunnel add tun6to4 mode sit remote any local 1.2.3.4 ttl 64 */
+
+       memset(&p, 0, sizeof(struct ip_tunnel_parm));
+       memset(&ifr, 0, sizeof(struct ifreq));
+
+       p.iph.version = 4;
+       p.iph.ihl = 5;
+       p.iph.frag_off = htons(IP_DF);
+       p.iph.protocol = IPPROTO_IPV6;
+       p.iph.saddr = addr->s_addr;
+       p.iph.ttl = 64;
+       strncpy(p.name, "tun6to4", IFNAMSIZ);
+
+       strncpy(ifr.ifr_name, "sit0", IFNAMSIZ);
+       ifr.ifr_ifru.ifru_data = (void *)&p;
+       fd = socket(AF_INET, SOCK_DGRAM, 0);
+       ret = ioctl(fd, SIOCADDTUNNEL, &ifr);
+       if (ret)
+               connman_error("add tunnel %s failed: %s", ifr.ifr_name,
+                                                       strerror(errno));
+       close(fd);
+
+       return ret;
+}
+
+static void tunnel_destroy()
+{
+       struct ip_tunnel_parm p;
+       struct ifreq ifr;
+       int fd = -1;
+       int ret;
+
+       if (tunnel_created == 0)
+               return;
+
+       /* ip tunnel del tun6to4 */
+
+       memset(&p, 0, sizeof(struct ip_tunnel_parm));
+       memset(&ifr, 0, sizeof(struct ifreq));
+
+       p.iph.version = 4;
+       p.iph.ihl = 5;
+       p.iph.protocol = IPPROTO_IPV6;
+       strncpy(p.name, "tun6to4", IFNAMSIZ);
+
+       strncpy(ifr.ifr_name, "tun6to4", IFNAMSIZ);
+       ifr.ifr_ifru.ifru_data = (void *)&p;
+       fd = socket(AF_INET, SOCK_DGRAM, 0);
+       if (fd < 0) {
+               connman_error("socket failed: %s", strerror(errno));
+               return;
+       }
+
+       ret = ioctl(fd, SIOCDELTUNNEL, &ifr);
+       if (ret)
+               connman_error("del tunnel %s failed: %s", ifr.ifr_name,
+                                                       strerror(errno));
+       else
+               tunnel_created = 0;
+
+       tunnel_pending = 0;
+       close(fd);
+
+       g_free(tunnel_ip_address);
+       tunnel_ip_address = NULL;
+}
+
+static int tunnel_add_route()
+{
+       struct rtnl_handle rth;
+       struct in6_addr addr6;
+       int index;
+       int ret = 0;
+
+       struct {
+               struct nlmsghdr n;
+               struct rtmsg    r;
+               char            buf[1024];
+       } req;
+
+       /* ip -6 route add ::/0 via ::192.88.99.1 dev tun6to4 metric 1 */
+
+       index = if_nametoindex("tun6to4");
+       if (index == 0) {
+               DBG("Can not find device tun6to4");
+               return -1;
+       }
+
+       memset(&req, 0, sizeof(req));
+
+       req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
+       req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL;
+       req.n.nlmsg_type = RTM_NEWROUTE;
+       req.r.rtm_family = AF_INET6;
+       req.r.rtm_table = RT_TABLE_MAIN;
+       req.r.rtm_protocol = RTPROT_BOOT;
+       req.r.rtm_scope = RT_SCOPE_UNIVERSE;
+       req.r.rtm_type = RTN_UNICAST;
+       req.r.rtm_dst_len = 0;
+
+       inet_pton(AF_INET6, "::192.88.99.1", &addr6);
+
+       addattr_l(&req.n, sizeof(req), RTA_GATEWAY, &addr6.s6_addr, 16);
+       addattr32(&req.n, sizeof(req), RTA_OIF, index);
+       addattr32(&req.n, sizeof(req), RTA_PRIORITY, 1);
+
+       ret = rtnl_open(&rth);
+       if (ret < 0)
+               goto done;
+
+       ret = rtnl_talk(&rth, &req.n);
+
+done:
+       rtnl_close(&rth);
+       return ret;
+}
+
+static int tunnel_set_addr(unsigned int a, unsigned int b,
+                       unsigned int c, unsigned int d)
+{
+       struct rtnl_handle rth;
+       struct in6_addr addr6;
+       char *ip6addr;
+       int ret;
+
+       struct {
+               struct nlmsghdr n;
+               struct ifaddrmsg ifa;
+               char buf[256];
+       } req;
+
+       /* ip -6 addr add dev tun6to4 2002:0102:0304::1/64 */
+
+       memset(&req, 0, sizeof(req));
+
+       req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg));
+       req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL;
+       req.n.nlmsg_type = RTM_NEWADDR;
+       req.ifa.ifa_family = AF_INET6;
+       req.ifa.ifa_prefixlen = 64;
+       req.ifa.ifa_index = if_nametoindex("tun6to4");
+       if (req.ifa.ifa_index == 0) {
+               connman_error("Can not find device tun6to4");
+               ret = -1;
+               goto done;
+       }
+
+       ip6addr = g_strdup_printf("2002:%02x%02x:%02x%02x::1", a, b, c, d);
+       inet_pton(AF_INET6, ip6addr, &addr6);
+       DBG("ipv6 address %s", ip6addr);
+       g_free(ip6addr);
+
+       addattr_l(&req.n, sizeof(req), IFA_LOCAL, &addr6.s6_addr, 16);
+       addattr_l(&req.n, sizeof(req), IFA_ADDRESS, &addr6.s6_addr, 16);
+
+       ret = rtnl_open(&rth);
+       if (ret < 0)
+               goto done;
+
+       ret = rtnl_talk(&rth, &req.n);
+
+done:
+       rtnl_close(&rth);
+       return ret;
+}
+
+static int init_6to4(struct in_addr *ip4addr)
+{
+       unsigned int a, b, c, d;
+       in_addr_t addr;
+       int ret;
+
+       DBG("");
+
+       addr = ntohl(ip4addr->s_addr);
+
+       a = (addr & 0xff000000) >> 24;
+       b = (addr & 0x00ff0000) >> 16;
+       c = (addr & 0x0000ff00) >> 8;
+       d = addr & 0x000000ff;
+
+       ret = tunnel_create(ip4addr);
+       if (ret)
+               return -1;
+
+       tunnel_created = 1;
+
+       ret = connman_inet_setup_tunnel("tun6to4", 1472);
+       if (ret)
+               goto error;
+
+       ret = tunnel_set_addr(a, b, c, d);
+       if (ret)
+               goto error;
+
+       ret = tunnel_add_route();
+       if (ret)
+               goto error;
+
+       tunnel_pending = 0;
+       return 0;
+
+error:
+       tunnel_destroy();
+       return -1;
+}
+
+static void receive_rs_reply(struct nd_router_advert *reply, void *user_data)
+{
+       char *address = user_data;
+       struct in_addr ip4addr;
+
+       DBG("reply %p address %s", reply, address);
+
+       /* We try to create tunnel if autoconfiguration did not work i.e.,
+        * we did not receive any reply to router solicitation message.
+        */
+       if (reply == NULL && inet_aton(address, &ip4addr) != 0)
+               init_6to4(&ip4addr);
+
+       g_free(address);
+}
+
+int __connman_6to4_probe(struct connman_service *service)
+{
+       struct connman_ipconfig *ip4config, *ip6config;
+       enum connman_ipconfig_method method;
+       unsigned int a, b, c, d;
+       struct in_addr ip4addr;
+       in_addr_t addr;
+       const char *address;
+       char *ip_address;
+       int index;
+
+       DBG("service %p", service);
+
+       if (tunnel_created || tunnel_pending)
+               return 0;
+
+       if (service == NULL)
+               return -1;
+
+       ip4config = __connman_service_get_ip4config(service);
+       if (ip4config == NULL)
+               return -1;
+
+       ip6config = __connman_service_get_ip6config(service);
+       if (ip6config == NULL)
+               return -1;
+
+       method = __connman_ipconfig_get_method(ip6config);
+       if (method != CONNMAN_IPCONFIG_METHOD_AUTO)
+               return -1;
+
+       address = __connman_ipconfig_get_local(ip4config);
+       if (address == NULL)
+               return -1;
+
+       if (inet_aton(address, &ip4addr) == 0)
+               return -1;
+
+       addr = ntohl(ip4addr.s_addr);
+
+       a = (addr & 0xff000000) >> 24;
+       b = (addr & 0x00ff0000) >> 16;
+       c = (addr & 0x0000ff00) >> 8;
+       d = addr & 0x000000ff;
+
+       /* 6to4 tunnel is only usable if we have a public IPv4 address */
+       if (a == 10 || (a == 192 && b == 168) ||
+                                       (a == 172 && (b >= 16 && b <= 31)))
+               return -1;
+
+       index = connman_ipconfig_get_index(ip4config);
+       ip_address = g_strdup(address);
+       tunnel_pending = 1;
+
+       g_free(tunnel_ip_address);
+       tunnel_ip_address = g_strdup(address);
+
+       return __connman_inet_ipv6_send_rs(index, 2, receive_rs_reply,
+                                                       ip_address);
+}
+
+void __connman_6to4_remove(struct connman_ipconfig *ip4config)
+{
+       const char *address;
+
+       DBG("tunnel ip address %s", tunnel_ip_address);
+
+       if (ip4config == NULL)
+               return;
+
+       address = __connman_ipconfig_get_local(ip4config);
+       if (address == NULL)
+               return;
+
+       if (g_strcmp0(address, tunnel_ip_address) != 0)
+               return;
+
+       if (tunnel_created)
+               tunnel_destroy();
+}
index 6150064..1ca73ed 100644 (file)
@@ -645,3 +645,6 @@ void __connman_dnsproxy_cleanup(void);
 int __connman_dnsproxy_append(const char *interface, const char *domain, const char *server);
 int __connman_dnsproxy_remove(const char *interface, const char *domain, const char *server);
 void __connman_dnsproxy_flush(void);
+
+int __connman_6to4_probe(struct connman_service *service);
+void __connman_6to4_remove(struct connman_ipconfig *ipconfig);