// Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced
// vim: sw=8 ts=8
-char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.78 2005-01-13 07:57:36 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.80 2005-01-25 04:19:05 bodea Exp $";
#include <arpa/inet.h>
#include <assert.h>
#include <sys/mman.h>
#include <netdb.h>
#include <netinet/in.h>
+#include <netinet/ip6.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
int snoopfd = -1; // UDP file handle for sending out intercept data
int *radfds = NULL; // RADIUS requests file handles
int ifrfd = -1; // File descriptor for routing, etc
+int ifr6fd = -1; // File descriptor for IPv6 routing, etc
static int rand_fd = -1; // Random data source
time_t basetime = 0; // base clock
char hostname[1000] = ""; // us.
+static int tunidx; // ifr_ifindex of tun device
static uint32_t sessionid = 0; // session id for radius accounting
static int syslog_log = 0; // are we logging to syslog
static FILE *log_stream = NULL; // file handle for direct logging (i.e. direct into file, not via syslog).
struct cli_tunnel_actions *cli_tunnel_actions = NULL; // Pending tunnel changes required by CLI
static void *ip_hash[256]; // Mapping from IP address to session structures.
+struct ipv6radix {
+ int sess;
+ struct ipv6radix *branch;
+} ipv6_hash[256]; // Mapping from IPv6 address to session structures.
// Traffic counters.
static uint32_t udp_rx = 0, udp_rx_pkt = 0, udp_tx = 0;
CONFIG("cluster_interface", cluster_interface, STRING),
CONFIG("cluster_hb_interval", cluster_hb_interval, INT),
CONFIG("cluster_hb_timeout", cluster_hb_timeout, INT),
+ CONFIG("ipv6_prefix", ipv6_prefix, IPv6),
{ NULL, 0, 0, 0 },
};
static void cache_ipmap(in_addr_t ip, int s);
static void uncache_ipmap(in_addr_t ip);
+static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s);
static void free_ip_address(sessionidt s);
static void dump_acct_info(int all);
static void sighup_handler(int sig);
}
}
+void route6set(sessionidt s, struct in6_addr ip, int prefixlen, int add)
+{
+ struct in6_rtmsg rt;
+ char ipv6addr[INET6_ADDRSTRLEN];
+
+ if (ifr6fd < 0)
+ {
+ LOG(0, 0, 0, "Asked to set IPv6 route, but IPv6 not setup.\n");
+ return;
+ }
+
+ memset(&rt, 0, sizeof(rt));
+
+ memcpy(&rt.rtmsg_dst, &ip, sizeof(struct in6_addr));
+ rt.rtmsg_dst_len = prefixlen;
+ rt.rtmsg_metric = 1;
+ rt.rtmsg_flags = RTF_UP;
+ rt.rtmsg_ifindex = tunidx;
+
+ LOG(1, 0, 0, "Route %s %s/%d\n",
+ add ? "add" : "del",
+ inet_ntop(AF_INET6, &ip, ipv6addr, INET6_ADDRSTRLEN),
+ prefixlen);
+
+ if (ioctl(ifr6fd, add ? SIOCADDRT : SIOCDELRT, (void *) &rt) < 0)
+ LOG(0, 0, 0, "route6set() error in ioctl: %s\n",
+ strerror(errno));
+
+ // FIXME: need to add BGP routing (RFC2858)
+
+ if (s)
+ {
+ if (!add) // Are we deleting a route?
+ s = 0; // Caching the session as '0' is the same as uncaching.
+
+ cache_ipv6map(ip, prefixlen, s);
+ }
+
+ return;
+}
+
+// defined in linux/ipv6.h, but tricky to include from user-space
+// TODO: move routing to use netlink rather than ioctl
+struct in6_ifreq {
+ struct in6_addr ifr6_addr;
+ __u32 ifr6_prefixlen;
+ unsigned int ifr6_ifindex;
+};
+
//
// Set up TUN interface
static void inittun(void)
{
struct ifreq ifr;
+ struct in6_ifreq ifr6;
struct sockaddr_in sin = {0};
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TUN;
LOG(0, 0, 0, "Error setting tun flags: %s\n", strerror(errno));
exit(1);
}
+ if (ioctl(ifrfd, SIOCGIFINDEX, (void *) &ifr) < 0)
+ {
+ LOG(0, 0, 0, "Error getting tun ifindex: %s\n", strerror(errno));
+ exit(1);
+ }
+ tunidx = ifr.ifr_ifindex;
+
+ // Only setup IPv6 on the tun device if we have a configured prefix
+ if (config->ipv6_prefix.s6_addr[0] > 0) {
+ ifr6fd = socket(PF_INET6, SOCK_DGRAM, 0);
+
+ // Link local address is FE80::1
+ memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr));
+ ifr6.ifr6_addr.s6_addr[0] = 0xFE;
+ ifr6.ifr6_addr.s6_addr[1] = 0x80;
+ ifr6.ifr6_addr.s6_addr[15] = 1;
+ ifr6.ifr6_prefixlen = 64;
+ ifr6.ifr6_ifindex = ifr.ifr_ifindex;
+ if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0)
+ {
+ LOG(0, 0, 0, "Error setting tun IPv6 link local address:"
+ " %s\n", strerror(errno));
+ }
+
+ // Global address is prefix::1
+ memset(&ifr6.ifr6_addr, 0, sizeof(ifr6.ifr6_addr));
+ ifr6.ifr6_addr = config->ipv6_prefix;
+ ifr6.ifr6_addr.s6_addr[15] = 1;
+ ifr6.ifr6_prefixlen = 64;
+ ifr6.ifr6_ifindex = ifr.ifr_ifindex;
+ if (ioctl(ifr6fd, SIOCSIFADDR, (void *) &ifr6) < 0)
+ {
+ LOG(0, 0, 0, "Error setting tun IPv6 global address: %s\n",
+ strerror(errno));
+ }
+ }
}
// set up UDP port
return (int) (intptr_t) d[(size_t) *a];
}
+int lookup_ipv6map(struct in6_addr ip)
+{
+ struct ipv6radix *curnode;
+ int i;
+ int s;
+ char ipv6addr[INET6_ADDRSTRLEN];
+
+ curnode = &ipv6_hash[ip.s6_addr[0]];
+ i = 1;
+ s = curnode->sess;
+
+ while (s == 0 && i < 15 && curnode->branch != NULL)
+ {
+ curnode = &curnode->branch[ip.s6_addr[i]];
+ s = curnode->sess;
+ i++;
+ }
+
+ LOG(4, s, session[s].tunnel, "Looking up address %s and got %d\n",
+ inet_ntop(AF_INET6, &ip, ipv6addr,
+ INET6_ADDRSTRLEN),
+ s);
+
+ return s;
+}
+
sessionidt sessionbyip(in_addr_t ip)
{
int s = lookup_ipmap(ip);
return 0;
}
+sessionidt sessionbyipv6(struct in6_addr ip)
+{
+ int s;
+ CSTAT(sessionbyipv6);
+
+ if (!memcmp(&config->ipv6_prefix, &ip, 8) ||
+ (ip.s6_addr[0] == 0xFE && ip.s6_addr[1] == 0x80 &&
+ (ip.s6_addr16[1] == ip.s6_addr16[2] == ip.s6_addr16[3] == 0))) {
+ s = lookup_ipmap(*(in_addr_t *) &ip.s6_addr[8]);
+ } else {
+ s = lookup_ipv6map(ip);
+ }
+
+ if (s > 0 && s < MAXSESSION && session[s].tunnel)
+ return s;
+
+ return 0;
+}
+
//
// Take an IP address in HOST byte order and
// add it to the sessionid by IP cache.
cache_ipmap(ip, 0); // Assign it to the NULL session.
}
+static void cache_ipv6map(struct in6_addr ip, int prefixlen, int s)
+{
+ int i;
+ int bytes;
+ struct ipv6radix *curnode;
+ char ipv6addr[INET6_ADDRSTRLEN];
+
+ curnode = &ipv6_hash[ip.s6_addr[0]];
+
+ bytes = prefixlen >> 3;
+ i = 1;
+ while (i < bytes) {
+ if (curnode->branch == NULL)
+ {
+ if (!(curnode->branch = calloc(256,
+ sizeof (struct ipv6radix))))
+ return;
+ }
+ curnode = &curnode->branch[ip.s6_addr[i]];
+ i++;
+ }
+
+ curnode->sess = s;
+
+ if (s > 0)
+ LOG(4, s, session[s].tunnel, "Caching ip address %s/%d\n",
+ inet_ntop(AF_INET6, &ip, ipv6addr,
+ INET6_ADDRSTRLEN),
+ prefixlen);
+ else if (s == 0)
+ LOG(4, 0, 0, "Un-caching ip address %s/%d\n",
+ inet_ntop(AF_INET6, &ip, ipv6addr,
+ INET6_ADDRSTRLEN),
+ prefixlen);
+}
+
//
// CLI list to dump current ipcache.
//
{
INC_STAT(tun_rx_dropped, sess_local[s].packets_dropped);
LOG(3, s, t, "Dropped %u/%u packets to %s for %suser %s\n",
- sess_local[s].packets_out, sess_local[s].packets_dropped,
+ sess_local[s].packets_dropped, sess_local[s].packets_out,
fmtaddr(ip, 0), sp->throttle_out ? "throttled " : "",
sp->user);
}
sess_local[s].cout += len; // To send to master..
}
+// process outgoing (to tunnel) IPv6
+//
+void processipv6out(uint8_t * buf, int len)
+{
+ sessionidt s;
+ sessiont *sp;
+ tunnelidt t;
+ in_addr_t ip;
+ struct in6_addr ip6;
+
+ char *data = buf; // Keep a copy of the originals.
+ int size = len;
+
+ uint8_t b[MAXETHER + 20];
+
+ CSTAT(processipv6out);
+
+ if (len < MIN_IP_SIZE)
+ {
+ LOG(1, 0, 0, "Short IPv6, %d bytes\n", len);
+ STAT(tunnel_tx_errors);
+ return;
+ }
+ if (len >= MAXETHER)
+ {
+ LOG(1, 0, 0, "Oversize IPv6 packet %d bytes\n", len);
+ STAT(tunnel_tx_errors);
+ return;
+ }
+
+ // Skip the tun header
+ buf += 4;
+ len -= 4;
+
+ // Got an IP header now
+ if (*(uint8_t *)(buf) >> 4 != 6)
+ {
+ LOG(1, 0, 0, "IP: Don't understand anything except IPv6\n");
+ return;
+ }
+
+ ip6 = *(struct in6_addr *)(buf+24);
+ s = sessionbyipv6(ip6);
+
+ if (s == 0)
+ {
+ ip = *(uint32_t *)(buf + 32);
+ s = sessionbyip(ip);
+ }
+
+ if (s == 0)
+ {
+ // Is this a packet for a session that doesn't exist?
+ static int rate = 0; // Number of ICMP packets we've sent this second.
+ static int last = 0; // Last time we reset the ICMP packet counter 'rate'.
+
+ if (last != time_now)
+ {
+ last = time_now;
+ rate = 0;
+ }
+
+ if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
+ {
+ // FIXME: Should send icmp6 host unreachable
+ }
+ return;
+ }
+ t = session[s].tunnel;
+ sp = &session[s];
+
+ // FIXME: add DoS prevention/filters?
+
+ if (sp->tbf_out)
+ {
+ // Are we throttling this session?
+ if (config->cluster_iam_master)
+ tbf_queue_packet(sp->tbf_out, data, size);
+ else
+ master_throttle_packet(sp->tbf_out, data, size);
+ return;
+ }
+ else if (sp->walled_garden && !config->cluster_iam_master)
+ {
+ // We are walled-gardening this
+ master_garden_packet(s, data, size);
+ return;
+ }
+
+ LOG(5, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
+
+ // Add on L2TP header
+ {
+ uint8_t *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIPV6);
+ if (!p) return;
+ tunnelsend(b, len + (p-b), t); // send it...
+ }
+
+ // Snooping this session, send it to intercept box
+ if (sp->snoop_ip && sp->snoop_port)
+ snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
+
+ sp->cout += len; // byte count
+ sp->total_cout += len; // byte count
+ sp->pout++;
+ udp_tx += len;
+ sess_local[s].cout += len; // To send to master..
+}
+
//
// Helper routine for the TBF filters.
// Used to send queued data in to the user!
}
else
free_ip_address(s);
+
+ // unroute IPv6, if setup
+ if (session[s].flags & SF_IPV6_ROUTED)
+ route6set(s, session[s].ipv6route, session[s].ipv6prefixlen, 0);
}
if (session[s].throttle_in || session[s].throttle_out) // Unthrottle if throttled.
tunnelsend(buf, 10 + (q - buf), t); // send it
session[s].flags &= ~SF_IPCP_ACKED; // Clear flag.
+
+ // If we have an IPv6 prefix length configured, assume we should
+ // try to negotiate an IPv6 session as well. Unless we've had a
+ // (N)ACK for IPV6CP.
+ if (config->ipv6_prefix.s6_addr[0] > 0 &&
+ !(session[s].flags & SF_IPV6CP_ACKED) &&
+ !(session[s].flags & SF_IPV6_NACKED))
+ {
+ q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPV6CP);
+ if (!q) return;
+
+ *q = ConfigReq;
+ q[1] = r << RADIUS_SHIFT; // ID, don't care, we
+ // only send one type
+ // of request
+ *(uint16_t *) (q + 2) = htons(14);
+ q[4] = 1;
+ q[5] = 10;
+ *(uint32_t *) (q + 6) = 0; // We'll be prefix::1
+ *(uint32_t *) (q + 10) = 0;
+ q[13] = 1;
+
+ tunnelsend(buf, 14 + (q - buf), t); // send it
+ }
}
// kill a session now
if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
processipcp(t, s, p, l);
}
+ else if (prot == PPPIPV6CP)
+ {
+ if (config->ipv6_prefix.s6_addr[0] > 0)
+ {
+ session[s].last_packet = time_now;
+ if (!config->cluster_iam_master) { master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port); return; }
+ processipv6cp(t, s, p, l);
+ }
+ else
+ {
+ LOG(1, s, t, "IPv6 not configured; ignoring IPv6CP\n");
+ }
+ }
else if (prot == PPPCCP)
{
session[s].last_packet = time_now;
processipin(t, s, p, l);
}
+ else if (prot == PPPIPV6)
+ {
+ if (!config->ipv6_prefix.s6_addr[0] > 0)
+ {
+ LOG(1, s, t, "IPv6 not configured; yet received IPv6 packet. Ignoring.\n");
+ return;
+ }
+ if (session[s].die)
+ {
+ LOG(4, s, t, "Session %d is closing. Don't process PPP packets\n", s);
+ return; // closing session, PPP not processed
+ }
+
+ session[s].last_packet = time_now;
+ if (session[s].walled_garden && !config->cluster_iam_master)
+ {
+ master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
+ return;
+ }
+
+ processipv6in(t, s, p, l);
+ }
else
{
STAT(tunnel_rx_errors);
if (*(uint16_t *) (buf + 2) == htons(PKTIP)) // IPv4
processipout(buf, len);
+ else if (*(uint16_t *) (buf + 2) == htons(PKTIPV6) // IPV6
+ && config->ipv6_prefix.s6_addr[0] > 0)
+ processipv6out(buf, len);
+
// Else discard.
}
// convered by a Framed-Route. Anything else is part
// of the IP address pool and is already routed, it
// just needs to be added to the IP cache.
+ // IPv6 route setup is done in ppp.c, when IPV6CP is acked.
if (session[s].ip_pool_index == -1) // static ip
{
if (!routed) routeset(s, session[s].ip, 0, 0, 1);
}
}
+ // check v6 routing
+ if (new->flags & SF_IPV6_ROUTED && !(session[s].flags & SF_IPV6_ROUTED))
+ route6set(s, new->ipv6route, new->ipv6prefixlen, 1);
+
// check filters
if (new->filter_in && (new->filter_in > MAXFILTER || !ip_filters[new->filter_in - 1].name[0]))
{
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