// 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 1.117 2005/08/10 08:04:26 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.133 2005/09/16 05:04:29 bodea Exp $";
#include <arpa/inet.h>
#include <assert.h>
static FILE *log_stream = 0; // file handle for direct logging (i.e. direct into file, not via syslog).
uint32_t last_id = 0; // Unique ID for radius accounting
+// calculated from config->l2tp_mtu
+uint16_t MRU = 0; // PPP MRU
+uint16_t MSS = 0; // TCP MSS
+
struct cli_session_actions *cli_session_actions = NULL; // Pending session changes requested by CLI
struct cli_tunnel_actions *cli_tunnel_actions = NULL; // Pending tunnel changes required by CLI
CONFIG("log_file", log_filename, STRING),
CONFIG("pid_file", pid_file, STRING),
CONFIG("random_device", random_device, STRING),
- CONFIG("l2tp_secret", l2tpsecret, STRING),
+ CONFIG("l2tp_secret", l2tp_secret, STRING),
+ CONFIG("l2tp_mtu", l2tp_mtu, INT),
CONFIG("ppp_restart_time", ppp_restart_time, INT),
CONFIG("ppp_max_configure", ppp_max_configure, INT),
CONFIG("ppp_max_failure", ppp_max_failure, INT),
CONFIG("packet_limit", max_packets, INT),
CONFIG("cluster_address", cluster_address, IPv4),
CONFIG("cluster_interface", cluster_interface, STRING),
+ CONFIG("cluster_mcast_ttl", cluster_mcast_ttl, INT),
CONFIG("cluster_hb_interval", cluster_hb_interval, INT),
CONFIG("cluster_hb_timeout", cluster_hb_timeout, INT),
CONFIG("cluster_master_min_adv", cluster_master_min_adv, INT),
return write(tunfd, data, size);
}
+// adjust tcp mss to avoid fragmentation (called only for tcp packets with syn set)
+void adjust_tcp_mss(sessionidt s, tunnelidt t, uint8_t *buf, int len, uint8_t *tcp)
+{
+ int d = (tcp[12] >> 4) * 4;
+ uint8_t *mss = 0;
+ uint8_t *data;
+
+ if ((tcp[13] & 0x3f) & ~(TCP_FLAG_SYN|TCP_FLAG_ACK)) // only want SYN and SYN,ACK
+ return;
+
+ if (tcp + d > buf + len) // short?
+ return;
+
+ data = tcp + d;
+ tcp += 20;
+
+ while (tcp < data)
+ {
+ if (*tcp == 2 && tcp[1] == 4) // mss option (2), length 4
+ {
+ mss = tcp + 2;
+ if (mss + 2 > data) return; // short?
+ break;
+ }
+
+ if (*tcp == 0) return; // end of options
+ if (*tcp == 1 || !tcp[1]) // no op (one byte), or no length (prevent loop)
+ tcp++;
+ else
+ tcp += tcp[1]; // skip over option
+ }
+
+ if (!mss) return; // not found
+ if (ntohl(*(uint16_t *) mss) <= MSS) return; // mss OK
+
+ LOG(5, s, t, "TCP: %s:%u -> %s:%u SYN%s, adjusted mss from %u to %u\n",
+ fmtaddr(*(in_addr_t *)(buf + 12), 0), *(uint16_t *)tcp,
+ fmtaddr(*(in_addr_t *)(buf + 16), 1), *(uint16_t *)(tcp + 2),
+ (tcp[13] & TCP_FLAG_ACK) ? ",ACK" : "",
+ ntohl(*(uint16_t *) mss), MSS);
+
+ // FIXME
+}
+
// process outgoing (to tunnel) IP
//
static void processipout(uint8_t *buf, int len)
if (session[s].filter_out && !ip_filter(buf, len, session[s].filter_out - 1))
return;
+ // adjust MSS on SYN and SYN,ACK packets with options
+ if ((ntohs(*(uint16_t *) (buf + 6)) & 0x1fff) == 0 && buf[9] == IPPROTO_TCP) // first tcp fragment
+ {
+ int ihl = (buf[0] & 0xf) * 4; // length of IP header
+ if (len >= ihl + 20 && (buf[ihl + 13] & TCP_FLAG_SYN) && ((buf[ihl + 12] >> 4) > 5))
+ adjust_tcp_mss(s, t, buf, len, buf + ihl);
+ }
+
if (sp->tbf_out)
{
// Are we throttling this session?
// Add on L2TP header
{
- uint8_t *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIP);
+ uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIP);
if (!p) return;
tunnelsend(b, len + (p-b), t); // send it...
}
// Add on L2TP header
{
- uint8_t *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIPV6);
+ uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIPV6);
if (!p) return;
tunnelsend(b, len + (p-b), t); // send it...
}
// Add on L2TP header
{
- uint8_t *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIP);
+ uint8_t *p = makeppp(b, sizeof(b), buf, len, s, t, PPPIP);
if (!p) return;
tunnelsend(b, len + (p-b), t); // send it...
}
}
// add a control message to a tunnel, and send if within window
-static void controladd(controlt * c, tunnelidt t, sessionidt far)
+static void controladd(controlt *c, sessionidt far, tunnelidt t)
{
*(uint16_t *) (c->buf + 2) = htons(c->length); // length
*(uint16_t *) (c->buf + 4) = htons(tunnel[t].far); // tunnel
control16(c, 1, result, 1);
control16(c, 14, s, 1); // assigned session (our end)
- controladd(c, session[s].tunnel, session[s].far); // send the message
+ controladd(c, session[s].far, session[s].tunnel); // send the message
}
if (!session[s].die)
cluster_send_session(s);
}
-void sendipcp(tunnelidt t, sessionidt s)
+void sendipcp(sessionidt s, tunnelidt t)
{
- uint8_t buf[MAXCONTROL];
+ uint8_t buf[MAXETHER];
uint8_t *q;
CSTAT(sendipcp);
+ LOG(3, s, t, "IPCP: send ConfigReq\n");
if (!session[s].unique_id)
{
session[s].unique_id = last_id;
}
- q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPCP);
+ q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPCP);
if (!q) return;
*q = ConfigReq;
tunnelsend(buf, 10 + (q - buf), t); // send it
}
-void sendipv6cp(tunnelidt t, sessionidt s)
+void sendipv6cp(sessionidt s, tunnelidt t)
{
- uint8_t buf[MAXCONTROL];
+ uint8_t buf[MAXETHER];
uint8_t *q;
CSTAT(sendipv6cp);
+ LOG(3, s, t, "IPV6CP: send ConfigReq\n");
- q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPV6CP);
+ q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPIPV6CP);
if (!q) return;
*q = ConfigReq;
control16(c, 1, result, 1);
control16(c, 9, t, 1); // assigned tunnel (our end)
- controladd(c, t, 0); // send the message
+ controladd(c, 0, t); // send the message
}
}
return;
}
l -= (p - buf);
+
+ // used to time out old tunnels
+ if (t && tunnel[t].state == TUNNELOPEN)
+ tunnel[t].lastrec = time_now;
+
if (*buf & 0x80)
{ // control
uint16_t message = 0xFFFF; // message type
uint8_t fatal = 0;
uint8_t mandatory = 0;
- uint8_t authtype = 0; // proxy auth type
uint16_t asession = 0; // assigned session
uint32_t amagic = 0; // magic number
uint8_t aflags = 0; // flags from last LCF
return;
}
- // This is used to time out old tunnels
- tunnel[t].lastrec = time_now;
-
// check sequence of this message
{
int skip = tunnel[t].window; // track how many in-window packets are still in queue
uint16_t orig_len;
// handle hidden AVPs
- if (!*config->l2tpsecret)
+ if (!*config->l2tp_secret)
{
LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n");
fatal = flags;
{
uint16_t atype = ntohs(*(uint16_t *)b);
LOG(4, s, t, " Proxy Auth Type %d (%s)\n", atype, ppp_auth_type(atype));
- if (atype == 2)
- authtype = AUTHCHAP;
- else if (atype == 3)
- authtype = AUTHPAP;
-
break;
}
case 30: // Proxy Authentication Name
{
if (*p == 5 && p[1] == 6) // Magic-Number
amagic = ntohl(*(uint32_t *) (p + 2));
- else if (*p == 3 && p[1] == 4 && *(uint16_t *) (p + 2) == htons(PPPPAP)) // Authentication-Protocol (PAP)
- authtype = AUTHPAP;
- else if (*p == 3 && p[1] == 5 && *(uint16_t *) (p + 2) == htons(PPPCHAP) && p[4] == 5) // Authentication-Protocol (CHAP)
- authtype = AUTHCHAP;
else if (*p == 7) // Protocol-Field-Compression
aflags |= SESSIONPFC;
else if (*p == 8) // Address-and-Control-Field-Compression
controlt *c = controlnew(2); // sending SCCRP
control16(c, 2, version, 1); // protocol version
control32(c, 3, 3, 1); // framing
- controls(c, 7, tunnel[t].hostname, 1); // host name (TBA)
+ controls(c, 7, hostname, 1); // host name
if (chapresponse) controlb(c, 13, chapresponse, 16, 1); // Challenge response
control16(c, 9, t, 1); // assigned tunnel
- controladd(c, t, 0); // send the resply
+ controladd(c, 0, t); // send the resply
}
else
{
session[s].last_packet = time_now;
LOG(3, s, t, "New session (%d/%d)\n", tunnel[t].far, session[s].far);
control16(c, 14, s, 1); // assigned session
- controladd(c, t, asession); // send the reply
+ controladd(c, asession, t); // send the reply
strncpy(session[s].called, called, sizeof(session[s].called) - 1);
strncpy(session[s].calling, calling, sizeof(session[s].calling) - 1);
else
control16(c, 1, 2, 7); // shutting down, try another
- controladd(c, t, asession); // send the message
+ controladd(c, asession, t); // send the message
}
return;
case 11: // ICRP
if (amagic == 0) amagic = time_now;
session[s].magic = amagic; // set magic number
session[s].l2tp_flags = aflags; // set flags received
- LOG(3, s, t, "Magic %X Flags %X\n", amagic, aflags);
+ session[s].mru = PPPMTU; // default
controlnull(t); // ack
- // proxy authentication type is not supported
- if (!(config->radius_authtypes & authtype))
- authtype = config->radius_authprefer;
-
// start LCP
- sendlcp(t, s, authtype);
sess_local[s].lcp.restart = time_now + config->ppp_restart_time;
sess_local[s].lcp.conf_sent = 1;
sess_local[s].lcp.nak_sent = 0;
- sess_local[s].lcp_authtype = authtype;
+ sess_local[s].lcp_authtype = config->radius_authprefer;
+ sess_local[s].ppp_mru = MRU;
session[s].ppp.lcp = RequestSent;
+ sendlcp(s, t);
break;
case 14: // CDN
}
else
{ // data
- uint16_t prot;
+ uint16_t proto;
LOG_HEX(5, "Receive Tunnel Data", p, l);
if (l > 2 && p[0] == 0xFF && p[1] == 0x03)
}
if (*p & 1)
{
- prot = *p++;
+ proto = *p++;
l--;
}
else
{
- prot = ntohs(*(uint16_t *) p);
+ proto = ntohs(*(uint16_t *) p);
p += 2;
l -= 2;
}
return;
}
- if (prot == PPPPAP)
+ if (proto == PPPPAP)
{
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; }
- processpap(t, s, p, l);
+ processpap(s, t, p, l);
}
- else if (prot == PPPCHAP)
+ else if (proto == PPPCHAP)
{
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; }
- processchap(t, s, p, l);
+ processchap(s, t, p, l);
}
- else if (prot == PPPLCP)
+ else if (proto == PPPLCP)
{
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; }
- processlcp(t, s, p, l);
+ processlcp(s, t, p, l);
}
- else if (prot == PPPIPCP)
+ else if (proto == PPPIPCP)
{
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; }
- processipcp(t, s, p, l);
+ processipcp(s, t, p, l);
}
- else if (prot == PPPIPV6CP)
+ else if (proto == PPPIPV6CP && config->ipv6_prefix.s6_addr[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);
+ processipv6cp(s, t, p, l);
}
- else if (prot == PPPCCP)
+ else if (proto == PPPCCP)
{
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; }
- processccp(t, s, p, l);
+ processccp(s, t, p, l);
}
- else if (prot == PPPIP)
+ else if (proto == PPPIP)
{
if (session[s].die)
{
return;
}
- processipin(t, s, p, l);
+ processipin(s, t, p, l);
}
- else if (prot == PPPIPV6)
+ else if (proto == PPPIPV6 && config->ipv6_prefix.s6_addr[0])
{
- if (!config->ipv6_prefix.s6_addr[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;
}
- processipv6in(t, s, p, l);
+ processipv6in(s, t, p, l);
+ }
+ else if (session[s].ppp.lcp == Opened)
+ {
+ uint8_t buf[MAXETHER];
+ uint8_t *q;
+ int mru = session[s].mru;
+ if (mru > sizeof(buf)) mru = sizeof(buf);
+
+ l += 6;
+ if (l > mru) l = mru;
+
+ q = makeppp(buf, sizeof(buf), 0, 0, s, t, proto);
+ if (!q) return;
+
+ *q = CodeRej;
+ *(q + 1) = ++sess_local[s].lcp_ident;
+ *(uint16_t *)(q + 2) = l;
+ *(uint16_t *)(q + 4) = htons(proto);
+ memcpy(q + 6, p, l - 6);
+
+ if (proto == PPPIPV6CP)
+ LOG(3, s, t, "LCP: send ProtocolRej (IPV6CP: not configured)\n");
+ else
+ LOG(2, s, t, "LCP: sent ProtocolRej (0x%04X: unsupported)\n", proto);
+
+ tunnelsend(buf, l + (q - buf), t);
}
else
{
- STAT(tunnel_rx_errors);
- LOG(1, s, t, "Unknown PPP protocol %04X\n", prot);
+ LOG(2, s, t, "Unknown PPP protocol 0x%04X received in LCP %s state\n",
+ proto, ppp_state(session[s].ppp.lcp));
}
}
}
}
}
// Send hello
- if (tunnel[t].state == TUNNELOPEN && tunnel[t].lastrec < TIME + 600)
+ if (tunnel[t].state == TUNNELOPEN && (time_now - tunnel[t].lastrec) > 60)
{
controlt *c = controlnew(6); // sending HELLO
- controladd(c, t, 0); // send the message
+ controladd(c, 0, t); // send the message
LOG(3, 0, t, "Sending HELLO message\n");
t_actions++;
}
}
// PPP timeouts
- if (sess_local[s].lcp.restart >= time_now)
+ if (sess_local[s].lcp.restart <= time_now)
{
int next_state = session[s].ppp.lcp;
switch (session[s].ppp.lcp)
LOG(3, s, session[s].tunnel, "No ACK for LCP ConfigReq... resending\n");
sess_local[s].lcp.restart = time_now + config->ppp_restart_time;
sess_local[s].lcp.conf_sent++;
- sendlcp(t, s, sess_local[s].lcp_authtype);
+ sendlcp(s, session[s].tunnel);
change_state(s, lcp, next_state);
}
else
continue;
}
- if (sess_local[s].ipcp.restart >= time_now)
+ if (sess_local[s].ipcp.restart <= time_now)
{
int next_state = session[s].ppp.ipcp;
switch (session[s].ppp.ipcp)
LOG(3, s, session[s].tunnel, "No ACK for IPCP ConfigReq... resending\n");
sess_local[s].ipcp.restart = time_now + config->ppp_restart_time;
sess_local[s].ipcp.conf_sent++;
- sendipcp(t, s);
+ sendipcp(s, session[s].tunnel);
change_state(s, ipcp, next_state);
}
else
continue;
}
- if (sess_local[s].ipv6cp.restart >= time_now)
+ if (sess_local[s].ipv6cp.restart <= time_now)
{
int next_state = session[s].ppp.ipv6cp;
switch (session[s].ppp.ipv6cp)
LOG(3, s, session[s].tunnel, "No ACK for IPV6CP ConfigReq... resending\n");
sess_local[s].ipv6cp.restart = time_now + config->ppp_restart_time;
sess_local[s].ipv6cp.conf_sent++;
- sendipv6cp(t, s);
+ sendipv6cp(s, session[s].tunnel);
change_state(s, ipv6cp, next_state);
}
else
}
}
- if (sess_local[s].ccp.restart >= time_now)
+ if (sess_local[s].ccp.restart <= time_now)
{
int next_state = session[s].ppp.ccp;
switch (session[s].ppp.ccp)
LOG(3, s, session[s].tunnel, "No ACK for CCP ConfigReq... resending\n");
sess_local[s].ccp.restart = time_now + config->ppp_restart_time;
sess_local[s].ccp.conf_sent++;
- sendccp(t, s);
+ sendccp(s, session[s].tunnel);
change_state(s, ccp, next_state);
}
else
// No data in ECHO_TIMEOUT seconds, send LCP ECHO
if (session[s].ppp.phase >= Establish && (time_now - session[s].last_packet >= ECHO_TIMEOUT))
{
- uint8_t b[MAXCONTROL] = {0};
+ uint8_t b[MAXETHER];
- uint8_t *q = makeppp(b, sizeof(b), 0, 0, session[s].tunnel, s, PPPLCP);
+ uint8_t *q = makeppp(b, sizeof(b), 0, 0, s, session[s].tunnel, PPPLCP);
if (!q) continue;
*q = EchoReq;
config->debug = optdebug;
config->num_tbfs = MAXTBFS;
config->rl_rate = 28; // 28kbps
+ config->cluster_mcast_ttl = 1;
config->cluster_master_min_adv = 1;
config->ppp_restart_time = 3;
config->ppp_max_configure = 10;
MD5_CTX ctx;
*challenge_response = NULL;
- if (!*config->l2tpsecret)
+ if (!*config->l2tp_secret)
{
LOG(0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
return;
MD5_Init(&ctx);
MD5_Update(&ctx, &id, 1);
- MD5_Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
+ MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
MD5_Update(&ctx, challenge, challenge_length);
MD5_Final(*challenge_response, &ctx);
setbuf(log_stream, NULL);
}
+#define L2TP_HDRS (20+8+6+4) // L2TP data encaptulation: ip + udp + l2tp (data) + ppp (inc hdlc)
+#define TCP_HDRS (20+20) // TCP encapsulation: ip + tcp
+
+ if (config->l2tp_mtu <= 0) config->l2tp_mtu = PPPMTU;
+ else if (config->l2tp_mtu < MINMTU) config->l2tp_mtu = MINMTU;
+ else if (config->l2tp_mtu > MAXMTU) config->l2tp_mtu = MAXMTU;
+
+ // reset MRU/MSS globals
+ MRU = config->l2tp_mtu - L2TP_HDRS;
+ MSS = MRU - TCP_HDRS;
+
// Update radius
config->numradiusservers = 0;
for (i = 0; i < MAXRADSERVER; i++)
update_config();
}
-int sessionsetup(tunnelidt t, sessionidt s)
+int sessionsetup(sessionidt s, tunnelidt t)
{
// A session now exists, set it up
in_addr_t ip;
}
sess_local[s].lcp_authtype = 0; // RADIUS authentication complete
- lcp_open(t, s); // transition to Network phase and send initial IPCP
+ lcp_open(s, t); // transition to Network phase and send initial IPCP
// Run the plugin's against this new session.
{
// Compute initial pad
MD5_Init(&ctx);
MD5_Update(&ctx, (unsigned char *) &m, 2);
- MD5_Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
+ MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
MD5_Update(&ctx, vector, vec_len);
MD5_Final(digest, &ctx);
if (d >= sizeof(digest))
{
MD5_Init(&ctx);
- MD5_Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
+ MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
MD5_Update(&ctx, last, sizeof(digest));
MD5_Final(digest, &ctx);
projects / l2tpns.git / blobdiff