// 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 1.75 2005/01/07 07:18:33 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.89 2005/04/01 06:39:00 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("l2tp_secret", l2tpsecret, STRING),
CONFIG("primary_dns", default_dns1, IPv4),
CONFIG("secondary_dns", default_dns2, IPv4),
- CONFIG("save_state", save_state, BOOL),
CONFIG("primary_radius", radiusserver[0], IPv4),
CONFIG("secondary_radius", radiusserver[1], IPv4),
CONFIG("primary_radius_port", radiusport[0], SHORT),
CONFIG("scheduler_fifo", scheduler_fifo, BOOL),
CONFIG("lock_pages", lock_pages, BOOL),
CONFIG("icmp_rate", icmp_rate, INT),
+ CONFIG("packet_limit", max_packets, INT),
CONFIG("cluster_address", cluster_address, IPv4),
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 },
};
tunnelt *tunnel = NULL; // Array of tunnel structures.
sessiont *session = NULL; // Array of session structures.
-sessioncountt *sess_count = NULL; // Array of partial per-session traffic counters.
+sessionlocalt *sess_local = NULL; // Array of local per-session counters.
radiust *radius = NULL; // Array of radius structures.
ippoolt *ip_address_pool = NULL; // Array of dynamic IP addresses.
ip_filtert *ip_filters = NULL; // Array of named filters.
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);
static void sigterm_handler(int sig);
static void sigquit_handler(int sig);
static void sigchild_handler(int sig);
-static void read_state(void);
-static void dump_state(void);
static void build_chap_response(char *challenge, uint8_t id, uint16_t challenge_length, char **challenge_response);
static void update_config(void);
static void read_config_file(void);
static void plugins_done(void);
static void processcontrol(uint8_t *buf, int len, struct sockaddr_in *addr, int alen);
static tunnelidt new_tunnel(void);
-static int unhide_avp(uint8_t *avp, tunnelidt t, sessionidt s, uint16_t length);
+static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len);
// return internal time (10ths since process startup)
static clockt now(void)
}
}
+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];
}
+static 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);
CSTAT(sessionbyip);
- if (s > 0 && s < MAXSESSION && session[s].tunnel)
+ if (s > 0 && s < MAXSESSION && session[s].opened)
return (sessionidt) s;
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].opened)
+ 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.
//
int s;
CSTAT(sessionbyuser);
- for (s = 1; s < MAXSESSION ; ++s)
+ for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
{
+ if (!session[s].opened)
+ continue;
+
if (session[s].walled_garden)
continue; // Skip walled garden users.
sendarp(ifr.ifr_ifindex, mac, ip);
}
-// Find session by username, 0 for not found
static sessiont *sessiontbysessionidt(sessionidt s)
{
- if (!s || s > MAXSESSION) return NULL;
+ if (!s || s >= MAXSESSION) return NULL;
return &session[s];
}
static sessionidt sessionidtbysessiont(sessiont *s)
{
sessionidt val = s-session;
- if (s < session || val > MAXSESSION) return 0;
+ if (s < session || val >= MAXSESSION) return 0;
return val;
}
tunnelidt t;
in_addr_t ip;
- char * data = buf; // Keep a copy of the originals.
+ char *data = buf; // Keep a copy of the originals.
int size = len;
uint8_t b[MAXETHER + 20];
if (len < MIN_IP_SIZE)
{
LOG(1, 0, 0, "Short IP, %d bytes\n", len);
- STAT(tunnel_tx_errors);
+ STAT(tun_rx_errors);
return;
}
if (len >= MAXETHER)
{
LOG(1, 0, 0, "Oversize IP packet %d bytes\n", len);
- STAT(tunnel_tx_errors);
+ STAT(tun_rx_errors);
return;
}
t = session[s].tunnel;
sp = &session[s];
+ // DoS prevention: enforce a maximum number of packets per 0.1s for a session
+ if (config->max_packets > 0)
+ {
+ if (sess_local[s].last_packet_out == TIME)
+ {
+ int max = config->max_packets;
+
+ // All packets for throttled sessions are handled by the
+ // master, so further limit by using the throttle rate.
+ // A bit of a kludge, since throttle rate is in kbps,
+ // but should still be generous given our average DSL
+ // packet size is 200 bytes: a limit of 28kbps equates
+ // to around 180 packets per second.
+ if (!config->cluster_iam_master && sp->throttle_out && sp->throttle_out < max)
+ max = sp->throttle_out;
+
+ if (++sess_local[s].packets_out > max)
+ {
+ sess_local[s].packets_dropped++;
+ return;
+ }
+ }
+ else
+ {
+ if (sess_local[s].packets_dropped)
+ {
+ 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_dropped, sess_local[s].packets_out,
+ fmtaddr(ip, 0), sp->throttle_out ? "throttled " : "",
+ sp->user);
+ }
+
+ sess_local[s].last_packet_out = TIME;
+ sess_local[s].packets_out = 1;
+ sess_local[s].packets_dropped = 0;
+ }
+ }
+
// run access-list if any
if (session[s].filter_out && !ip_filter(buf, len, session[s].filter_out - 1))
return;
sp->total_cout += len; // byte count
sp->pout++;
udp_tx += len;
- sess_count[s].cout += len; // To send to master..
+ sess_local[s].cout += len; // To send to master..
+}
+
+// process outgoing (to tunnel) IPv6
+//
+static 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..
}
//
sp->total_cout += len; // byte count
sp->pout++;
udp_tx += len;
- sess_count[s].cout += len; // To send to master..
+ sess_local[s].cout += len; // To send to master..
}
// add an AVP (16 bit)
c->length += 10;
}
-// add an AVP (32 bit)
+// add an AVP (string)
static void controls(controlt * c, uint16_t avp, char *val, uint8_t m)
{
uint16_t l = ((m ? 0x8000 : 0) + strlen(val) + 6);
//
void throttle_session(sessionidt s, int rate_in, int rate_out)
{
- if (!session[s].tunnel)
+ if (!session[s].opened)
return; // No-one home.
if (!*session[s].user)
}
// add/remove filters from session (-1 = no change)
-void filter_session(sessionidt s, int filter_in, int filter_out)
+static void filter_session(sessionidt s, int filter_in, int filter_out)
{
- if (!session[s].tunnel)
+ if (!session[s].opened)
return; // No-one home.
if (!*session[s].user)
}
// start tidy shutdown of session
-void sessionshutdown(sessionidt s, char *reason)
+void sessionshutdown(sessionidt s, char *reason, int result, int error)
{
int walled_garden = session[s].walled_garden;
CSTAT(sessionshutdown);
- if (!session[s].tunnel)
+ if (!session[s].opened)
{
- LOG(3, s, session[s].tunnel, "Called sessionshutdown on a session with no tunnel.\n");
+ LOG(3, s, session[s].tunnel, "Called sessionshutdown on an unopened session.\n");
return; // not a live session
}
run_plugins(PLUGIN_KILL_SESSION, &data);
}
- if (session[s].opened && !walled_garden && !session[s].die)
+ if (session[s].ip && !walled_garden && !session[s].die)
{
// RADIUS Stop message
uint16_t r = session[s].radius;
}
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.
throttle_session(s, 0, 0);
+ if (result)
{ // Send CDN
controlt *c = controlnew(14); // sending CDN
- control16(c, 1, 3, 1); // result code (admin reasons - TBA make error, general error, add message
+ if (error)
+ {
+ char buf[4];
+ *(uint16_t *) buf = htons(result);
+ *(uint16_t *) (buf+2) = htons(error);
+ controlb(c, 1, buf, 4, 1);
+ }
+ else
+ control16(c, 1, result, 1);
+
control16(c, 14, s, 1); // assigned session (our end)
controladd(c, session[s].tunnel, s); // send the message
}
if (!session[s].die)
- session[s].die = now() + 150; // Clean up in 15 seconds
+ session[s].die = TIME + 150; // Clean up in 15 seconds
// update filter refcounts
if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
if (radius[r].try > 10)
{
radiusclear(r, s); // Clear radius session.
- sessionshutdown(s, "No reply on IPCP");
+ sessionshutdown(s, "No reply on IPCP", 3, 0);
return;
}
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
-static void sessionkill(sessionidt s, char *reason)
+void sessionkill(sessionidt s, char *reason)
{
CSTAT(sessionkill);
- session[s].die = now();
- sessionshutdown(s, reason); // close radius/routes, etc.
+ if (!session[s].opened) // not alive
+ return;
+
+ if (session[s].next)
+ {
+ LOG(0, s, session[s].tunnel, "Tried to kill a session with next pointer set (%d)\n", session[s].next);
+ return;
+ }
+
+ session[s].die = TIME;
+ sessionshutdown(s, reason, 3, 0); // close radius/routes, etc.
if (session[s].radius)
radiusclear(session[s].radius, s); // cant send clean accounting data, session is killed
controlfree = c;
}
// kill sessions
- for (s = 1; s < MAXSESSION; s++)
+ for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
if (session[s].tunnel == t)
sessionkill(s, reason);
// free tunnel
tunnelclear(t);
LOG(1, 0, t, "Kill tunnel %d: %s\n", t, reason);
- cli_tunnel_actions[s].action = 0;
+ cli_tunnel_actions[t].action = 0;
cluster_send_tunnel(t);
}
// shut down a tunnel cleanly
-static void tunnelshutdown(tunnelidt t, char *reason)
+static void tunnelshutdown(tunnelidt t, char *reason, int result, int error, char *msg)
{
sessionidt s;
LOG(1, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
// close session
- for (s = 1; s < MAXSESSION; s++)
+ for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
if (session[s].tunnel == t)
- sessionshutdown(s, reason);
+ sessionshutdown(s, reason, 3, 0);
tunnel[t].state = TUNNELDIE;
- tunnel[t].die = now() + 700; // Clean up in 70 seconds
+ tunnel[t].die = TIME + 700; // Clean up in 70 seconds
cluster_send_tunnel(t);
// TBA - should we wait for sessions to stop?
- { // Send StopCCN
- controlt *c = controlnew(4); // sending StopCCN
- control16(c, 1, 1, 1); // result code (admin reasons - TBA make error, general error, add message)
- control16(c, 9, t, 1); // assigned tunnel (our end)
- controladd(c, t, 0); // send the message
+ if (result)
+ {
+ controlt *c = controlnew(4); // sending StopCCN
+ if (error)
+ {
+ char buf[64];
+ int l = 4;
+ *(uint16_t *) buf = htons(result);
+ *(uint16_t *) (buf+2) = htons(error);
+ if (msg)
+ {
+ int m = strlen(msg);
+ if (m + 4 > sizeof(buf))
+ m = sizeof(buf) - 4;
+
+ memcpy(buf+4, msg, m);
+ l += m;
+ }
+
+ controlb(c, 1, buf, l, 1);
+ }
+ else
+ control16(c, 1, result, 1);
+
+ control16(c, 9, t, 1); // assigned tunnel (our end)
+ controladd(c, t, 0); // send the message
}
}
{ // control
uint16_t message = 0xFFFF; // message type
uint8_t fatal = 0;
- uint8_t mandatorymessage = 0;
+ uint8_t mandatory = 0;
uint8_t chap = 0; // if CHAP being used
uint16_t asession = 0; // assigned session
uint32_t amagic = 0; // magic number
return;
}
- if ((*buf & 0xCA) != 0xC8)
+ // control messages must have bits 0x80|0x40|0x08
+ // (type, length and sequence) set, and bits 0x02|0x01
+ // (offset and priority) clear
+ if ((*buf & 0xCB) != 0xC8)
{
LOG(1, s, t, "Bad control header %02X\n", *buf);
STAT(tunnel_rx_errors);
}
if (l)
{ // if not a null message
+ int result = 0;
+ int error = 0;
+ char *msg = 0;
+
// process AVPs
- while (l && !(fatal & 0x80))
+ while (l && !(fatal & 0x80)) // 0x80 = mandatory AVP
{
uint16_t n = (ntohs(*(uint16_t *) p) & 0x3FF);
uint8_t *b = p;
uint8_t flags = *p;
uint16_t mtype;
- p += n; // next
- if (l < n)
+ if (n > l)
{
LOG(1, s, t, "Invalid length in AVP\n");
STAT(tunnel_rx_errors);
- fatal = flags;
return;
}
+ p += n; // next
l -= n;
+ if (flags & 0x3C) // reserved bits, should be clear
+ {
+ LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b);
+ fatal = flags;
+ result = 2; // general error
+ error = 3; // reserved field non-zero
+ msg = 0;
+ continue; // next
+ }
+ b += 2;
+ if (*(uint16_t *) (b))
+ {
+ LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b)));
+ fatal = flags;
+ result = 2; // general error
+ error = 6; // generic vendor-specific error
+ msg = "unsupported vendor-specific";
+ continue; // next
+ }
+ b += 2;
+ mtype = ntohs(*(uint16_t *) (b));
+ b += 2;
+ n -= 6;
+
if (flags & 0x40)
{
+ uint16_t orig_len;
+
// handle hidden AVPs
if (!*config->l2tpsecret)
{
LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n");
fatal = flags;
+ result = 2; // general error
+ error = 6; // generic vendor-specific error
+ msg = "secret not specified";
continue;
}
if (!session[s].random_vector_length)
{
LOG(1, s, t, "Hidden AVP requested, but no random vector.\n");
fatal = flags;
+ result = 2; // general error
+ error = 6; // generic
+ msg = "no random vector";
+ continue;
+ }
+ if (n < 8)
+ {
+ LOG(2, s, t, "Short hidden AVP.\n");
+ fatal = flags;
+ result = 2; // general error
+ error = 2; // length is wrong
+ msg = 0;
continue;
}
+
LOG(4, s, t, "Hidden AVP\n");
+
// Unhide the AVP
- n = unhide_avp(b, t, s, n);
- if (n == 0)
+ unhide_value(b, n, mtype, session[s].random_vector, session[s].random_vector_length);
+
+ orig_len = ntohs(*(uint16_t *) b);
+ if (orig_len > n + 2)
{
+ LOG(1, s, t, "Original length %d too long in hidden AVP of length %d; wrong secret?\n",
+ orig_len, n);
+
fatal = flags;
+ result = 2; // general error
+ error = 2; // length is wrong
+ msg = 0;
continue;
}
+
+ b += 2;
+ n = orig_len;
}
- if (*b & 0x3C)
- {
- LOG(1, s, t, "Unrecognised AVP flags %02X\n", *b);
- fatal = flags;
- continue; // next
- }
- b += 2;
- if (*(uint16_t *) (b))
- {
- LOG(2, s, t, "Unknown AVP vendor %d\n", ntohs(*(uint16_t *) (b)));
- fatal = flags;
- continue; // next
- }
- b += 2;
- mtype = ntohs(*(uint16_t *) (b));
- b += 2;
- n -= 6;
LOG(4, s, t, " AVP %d (%s) len %d\n", mtype, avp_name(mtype), n);
switch (mtype)
{
case 0: // message type
message = ntohs(*(uint16_t *) b);
+ mandatory = flags & 0x80;
LOG(4, s, t, " Message type = %d (%s)\n", *b, l2tp_message_type(message));
- mandatorymessage = flags;
break;
case 1: // result code
{
{ // allow 0.0 and 1.0
LOG(1, s, t, " Bad protocol version %04X\n", version);
fatal = flags;
+ result = 5; // unspported protocol version
+ error = 0x0100; // supported version
+ msg = 0;
continue; // next
}
}
session[s].random_vector_length = n;
break;
default:
- LOG(2, s, t, " Unknown AVP type %d\n", mtype);
- fatal = flags;
- continue; // next
+ {
+ static char e[] = "unknown AVP 0xXXXX";
+ LOG(2, s, t, " Unknown AVP type %d\n", mtype);
+ fatal = flags;
+ result = 2; // general error
+ error = 8; // unknown mandatory AVP
+ sprintf((msg = e) + 14, "%04x", mtype);
+ continue; // next
+ }
}
}
// process message
if (fatal & 0x80)
- tunnelshutdown(t, "Unknown Mandatory AVP");
+ tunnelshutdown(t, "Invalid mandatory AVP", result, error, msg);
else
switch (message)
{
break;
case 4: // StopCCN
controlnull(t); // ack
- tunnelshutdown(t, "Stopped"); // Shut down cleanly
- tunnelkill(t, "Stopped"); // Immediately force everything dead
+ tunnelshutdown(t, "Stopped", 0, 0, 0); // Shut down cleanly
break;
case 6: // HELLO
controlnull(t); // simply ACK
if (!sessionfree)
{
STAT(session_overflow);
- tunnelshutdown(t, "No free sessions");
+ LOG(1, 0, t, "No free sessions");
+ return;
}
else
{
c = controlnew(11); // sending ICRP
session[s].id = sessionid++;
- session[s].opened = time(NULL);
+ session[s].opened = time_now;
session[s].tunnel = t;
session[s].far = asession;
session[s].last_packet = time_now;
break;
case 14: // CDN
controlnull(t); // ack
- sessionshutdown(s, "Closed (Received CDN)");
+ sessionshutdown(s, "Closed (Received CDN)", 0, 0);
break;
case 0xFFFF:
LOG(1, s, t, "Missing message type\n");
break;
default:
STAT(tunnel_rx_errors);
- if (mandatorymessage & 0x80)
- tunnelshutdown(t, "Unknown message");
+ if (mandatory)
+ tunnelshutdown(t, "Unknown message type", 2, 6, "unknown message type");
else
LOG(1, s, t, "Unknown message type %d\n", message);
break;
l -= 2;
}
- if (s && !session[s].tunnel) // Is something wrong??
+ if (s && !session[s].opened) // Is something wrong??
{
if (!config->cluster_iam_master)
{
}
- LOG(1, s, t, "UDP packet contains session %d but no session[%d].tunnel "
- "exists (LAC said tunnel = %d). Dropping packet.\n", s, s, t);
-
+ LOG(1, s, t, "UDP packet contains session which is not opened. Dropping packet.\n");
STAT(tunnel_rx_errors);
return;
}
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.
}
if (a & CLI_TUN_KILL)
{
LOG(2, 0, t, "Dropping tunnel by CLI\n");
- tunnelshutdown(t, "Requested by administrator");
+ tunnelshutdown(t, "Requested by administrator", 1, 0, 0);
}
}
if (s > config->cluster_highest_sessionid)
s = 1;
- if (!session[s].tunnel) // Session isn't in use
+ if (!session[s].opened) // Session isn't in use
continue;
if (!session[s].die && session[s].ip && !(session[s].flags & SF_IPCP_ACKED))
// Drop sessions who have not responded within IDLE_TIMEOUT seconds
if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
{
- sessionshutdown(s, "No response to LCP ECHO requests");
+ sessionshutdown(s, "No response to LCP ECHO requests", 3, 0);
STAT(session_timeout);
if (++count >= MAX_ACTIONS) break;
continue;
}
- // No data in IDLE_TIMEOUT seconds, send LCP ECHO
+ // No data in ECHO_TIMEOUT seconds, send LCP ECHO
if (session[s].user[0] && (time_now - session[s].last_packet >= ECHO_TIMEOUT))
{
uint8_t b[MAXCONTROL] = {0};
if (a & CLI_SESS_KILL)
{
LOG(2, s, session[s].tunnel, "Dropping session by CLI\n");
- sessionshutdown(s, "Requested by administrator");
+ sessionshutdown(s, "Requested by administrator", 3, 0);
a = 0; // dead, no need to check for other actions
}
exit(1);
}
- if (!(sess_count = shared_malloc(sizeof(sessioncountt) * MAXSESSION)))
+ if (!(sess_local = shared_malloc(sizeof(sessionlocalt) * MAXSESSION)))
{
- LOG(0, 0, 0, "Error doing malloc for sessions_count: %s\n", strerror(errno));
+ LOG(0, 0, 0, "Error doing malloc for sess_local: %s\n", strerror(errno));
exit(1);
}
memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
// Put all the sessions on the free list marked as undefined.
- for (i = 1; i < MAXSESSION - 1; i++)
+ for (i = 1; i < MAXSESSION; i++)
{
session[i].next = i + 1;
session[i].tunnel = T_UNDEF; // mark it as not filled in.
sessionfree = 1;
// Mark all the tunnels as undefined (waiting to be filled in by a download).
- for (i = 1; i < MAXTUNNEL- 1; i++)
+ for (i = 1; i < MAXTUNNEL; i++)
tunnel[i].state = TUNNELUNDEF; // mark it as not filled in.
if (!*hostname)
for (i = 0; i < MAXSESSION; ++i)
{
int ipid;
- if (!session[i].ip || !session[i].tunnel)
+ if (!(session[i].opened && session[i].ip))
continue;
+
ipid = - lookup_ipmap(htonl(session[i].ip));
if (session[i].ip_pool_index < 0)
initrad();
initippool();
- read_state();
-
signal(SIGHUP, sighup_handler);
signal(SIGTERM, sigterm_handler);
signal(SIGINT, sigterm_handler);
static void sigterm_handler(int sig)
{
LOG(1, 0, 0, "Shutting down cleanly\n");
- if (config->save_state)
- dump_state();
-
main_quit++;
}
for (i = 1; i < MAXTUNNEL; i++)
{
if (tunnel[i].ip || tunnel[i].state)
- tunnelshutdown(i, "L2TPNS Closing");
+ tunnelshutdown(i, "L2TPNS Closing", 6, 0, 0);
}
}
;
}
-static void read_state()
-{
- struct stat sb;
- int i;
- ippoolt itmp;
- FILE *f;
- char magic[sizeof(DUMP_MAGIC) - 1];
- uint32_t buf[2];
-
- if (!config->save_state)
- {
- unlink(STATEFILE);
- return ;
- }
-
- if (stat(STATEFILE, &sb) < 0)
- {
- unlink(STATEFILE);
- return ;
- }
-
- if (sb.st_mtime < (time(NULL) - 60))
- {
- LOG(0, 0, 0, "State file is too old to read, ignoring\n");
- unlink(STATEFILE);
- return ;
- }
-
- f = fopen(STATEFILE, "r");
- unlink(STATEFILE);
-
- if (!f)
- {
- LOG(0, 0, 0, "Can't read state file: %s\n", strerror(errno));
- exit(1);
- }
-
- if (fread(magic, sizeof(magic), 1, f) != 1 || strncmp(magic, DUMP_MAGIC, sizeof(magic)))
- {
- LOG(0, 0, 0, "Bad state file magic\n");
- exit(1);
- }
-
- LOG(1, 0, 0, "Reading state information\n");
- if (fread(buf, sizeof(buf), 1, f) != 1 || buf[0] > MAXIPPOOL || buf[1] != sizeof(ippoolt))
- {
- LOG(0, 0, 0, "Error/mismatch reading ip pool header from state file\n");
- exit(1);
- }
-
- if (buf[0] > ip_pool_size)
- {
- LOG(0, 0, 0, "ip pool has shrunk! state = %d, current = %d\n", buf[0], ip_pool_size);
- exit(1);
- }
-
- LOG(2, 0, 0, "Loading %u ip addresses\n", buf[0]);
- for (i = 0; i < buf[0]; i++)
- {
- if (fread(&itmp, sizeof(itmp), 1, f) != 1)
- {
- LOG(0, 0, 0, "Error reading ip %d from state file: %s\n", i, strerror(errno));
- exit(1);
- }
-
- if (itmp.address != ip_address_pool[i].address)
- {
- LOG(0, 0, 0, "Mismatched ip %d from state file: pool may only be extended\n", i);
- exit(1);
- }
-
- memcpy(&ip_address_pool[i], &itmp, sizeof(itmp));
- }
-
- if (fread(buf, sizeof(buf), 1, f) != 1 || buf[0] != MAXTUNNEL || buf[1] != sizeof(tunnelt))
- {
- LOG(0, 0, 0, "Error/mismatch reading tunnel header from state file\n");
- exit(1);
- }
-
- LOG(2, 0, 0, "Loading %u tunnels\n", MAXTUNNEL);
- if (fread(tunnel, sizeof(tunnelt), MAXTUNNEL, f) != MAXTUNNEL)
- {
- LOG(0, 0, 0, "Error reading tunnel data from state file\n");
- exit(1);
- }
-
- for (i = 0; i < MAXTUNNEL; i++)
- {
- tunnel[i].controlc = 0;
- tunnel[i].controls = NULL;
- tunnel[i].controle = NULL;
- if (*tunnel[i].hostname)
- LOG(3, 0, 0, "Created tunnel for %s\n", tunnel[i].hostname);
- }
-
- if (fread(buf, sizeof(buf), 1, f) != 1 || buf[0] != MAXSESSION || buf[1] != sizeof(sessiont))
- {
- LOG(0, 0, 0, "Error/mismatch reading session header from state file\n");
- exit(1);
- }
-
- LOG(2, 0, 0, "Loading %u sessions\n", MAXSESSION);
- if (fread(session, sizeof(sessiont), MAXSESSION, f) != MAXSESSION)
- {
- LOG(0, 0, 0, "Error reading session data from state file\n");
- exit(1);
- }
-
- for (i = 0; i < MAXSESSION; i++)
- {
- session[i].tbf_in = 0;
- session[i].tbf_out = 0;
- if (session[i].opened)
- {
- LOG(2, i, 0, "Loaded active session for user %s\n", session[i].user);
- if (session[i].ip)
- sessionsetup(session[i].tunnel, i);
- }
- }
-
- fclose(f);
- LOG(0, 0, 0, "Loaded saved state information\n");
-}
-
-static void dump_state()
-{
- FILE *f;
- uint32_t buf[2];
-
- if (!config->save_state)
- return;
-
- do
- {
- if (!(f = fopen(STATEFILE, "w")))
- break;
-
- LOG(1, 0, 0, "Dumping state information\n");
-
- if (fwrite(DUMP_MAGIC, sizeof(DUMP_MAGIC) - 1, 1, f) != 1)
- break;
-
- LOG(2, 0, 0, "Dumping %u ip addresses\n", ip_pool_size);
- buf[0] = ip_pool_size;
- buf[1] = sizeof(ippoolt);
- if (fwrite(buf, sizeof(buf), 1, f) != 1)
- break;
- if (fwrite(ip_address_pool, sizeof(ippoolt), ip_pool_size, f) != ip_pool_size)
- break;
-
- LOG(2, 0, 0, "Dumping %u tunnels\n", MAXTUNNEL);
- buf[0] = MAXTUNNEL;
- buf[1] = sizeof(tunnelt);
- if (fwrite(buf, sizeof(buf), 1, f) != 1)
- break;
- if (fwrite(tunnel, sizeof(tunnelt), MAXTUNNEL, f) != MAXTUNNEL)
- break;
-
- LOG(2, 0, 0, "Dumping %u sessions\n", MAXSESSION);
- buf[0] = MAXSESSION;
- buf[1] = sizeof(sessiont);
- if (fwrite(buf, sizeof(buf), 1, f) != 1)
- break;
- if (fwrite(session, sizeof(sessiont), MAXSESSION, f) != MAXSESSION)
- break;
-
- if (fclose(f) == 0)
- return ; // OK
- }
- while (0);
-
- LOG(0, 0, 0, "Can't write state information: %s\n", strerror(errno));
- unlink(STATEFILE);
-}
-
static void build_chap_response(char *challenge, uint8_t id, uint16_t challenge_length, char **challenge_response)
{
MD5_CTX ctx;
LOG(3, s, t, "Doing session setup for session\n");
- if (!session[s].ip || session[s].ip == 0xFFFFFFFE)
+ if (!session[s].ip)
{
assign_ip_address(s);
if (!session[s].ip)
{
LOG(0, s, t, " No IP allocated. The IP address pool is FULL!\n");
- sessionshutdown(s, "No IP addresses available");
+ sessionshutdown(s, "No IP addresses available", 2, 7);
return 0;
}
LOG(3, s, t, " No IP allocated. Assigned %s from pool\n",
// 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]))
{
{
for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
{
- if (!session[s].tunnel) // Not an in-use session.
+ if (!session[s].opened) // Not an in-use session.
continue;
run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);
for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
{
int idle;
- if (!session[s].tunnel)
+ if (!session[s].opened)
continue;
idle = time_now - session[s].last_packet;
for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
{
int open = 0, d;
- if (!session[s].tunnel)
+ if (!session[s].opened)
continue;
d = time_now - session[s].opened;
/* Unhide an avp.
*
- * This unencodes the AVP using the L2TP CHAP secret and the
- * previously stored random vector. It replaces the hidden data with
- * the cleartext data and returns the length of the cleartext data
- * (including the AVP "header" of 6 bytes).
- *
- * Based on code from rp-l2tpd by Roaring Penguin Software Inc.
+ * This unencodes the AVP using the L2TP secret and the previously
+ * stored random vector. It overwrites the hidden data with the
+ * unhidden AVP subformat.
*/
-static int unhide_avp(uint8_t *avp, tunnelidt t, sessionidt s, uint16_t length)
+static void unhide_value(uint8_t *value, size_t len, uint16_t type, uint8_t *vector, size_t vec_len)
{
MD5_CTX ctx;
- uint8_t *cursor;
uint8_t digest[16];
- uint8_t working_vector[16];
- uint16_t hidden_length;
- uint8_t type[2];
- size_t done, todo;
- uint8_t *output;
-
- // Find the AVP type.
- type[0] = *(avp + 4);
- type[1] = *(avp + 5);
-
- // Line up with the hidden data
- cursor = output = avp + 6;
+ uint8_t *last;
+ size_t d = 0;
// Compute initial pad
MD5Init(&ctx);
- MD5Update(&ctx, type, 2);
+ MD5Update(&ctx, (uint8_t) (type >> 8) & 0xff, 1);
+ MD5Update(&ctx, (uint8_t) type & 0xff, 1);
MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
- MD5Update(&ctx, session[s].random_vector, session[s].random_vector_length);
+ MD5Update(&ctx, vector, vec_len);
MD5Final(digest, &ctx);
- // Get hidden length
- hidden_length = ((uint16_t) (digest[0] ^ cursor[0])) * 256 + (uint16_t) (digest[1] ^ cursor[1]);
-
- // Keep these for later use
- working_vector[0] = *cursor;
- working_vector[1] = *(cursor + 1);
- cursor += 2;
-
- if (hidden_length > length - 8)
- {
- LOG(1, s, t, "Hidden length %d too long in AVP of length %d\n", (int) hidden_length, (int) length);
- return 0;
- }
+ // pointer to last decoded 16 octets
+ last = value;
- /* Decrypt remainder */
- done = 2;
- todo = hidden_length;
- while (todo)
+ while (len > 0)
{
- working_vector[done] = *cursor;
- *output = digest[done] ^ *cursor;
- ++output;
- ++cursor;
- --todo;
- ++done;
- if (done == 16 && todo)
+ // calculate a new pad based on the last decoded block
+ if (d >= sizeof(digest))
{
- // Compute new digest
- done = 0;
MD5Init(&ctx);
MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
- MD5Update(&ctx, &working_vector, 16);
+ MD5Update(&ctx, last, sizeof(digest));
MD5Final(digest, &ctx);
+
+ d = 0;
+ last = value;
}
- }
- return hidden_length + 6;
+ *value++ ^= digest[d++];
+ len--;
+ }
}
static int ip_filter_port(ip_filter_portt *p, uint16_t port)
projects / l2tpns.git / blobdiff