// L2TPNS PPP Stuff
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.21 2004-11-05 04:55:27 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.31 2004-11-27 05:19:53 bodea Exp $";
#include <stdio.h>
#include <string.h>
extern char hostname[];
extern u32 eth_tx;
extern time_t time_now;
-extern struct configt *config;
+extern configt *config;
-void sendccp(tunnelidt t, sessionidt s);
+static void initccp(tunnelidt t, sessionidt s);
// Process PAP messages
void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
u8 b[MAXCONTROL];
u8 id = p[1];
u8 *p = makeppp(b, sizeof(b), 0, 0, t, s, PPPPAP);
- if (!p) { // Failed to make ppp header!
- LOG(1,0,0,0, "Failed to make PPP header in process pap!\n");
- return;
- }
+ if (!p) return;
+
if (session[s].ip)
*p = 2; // ACK
else
radiussend(r, RADIUSAUTH);
}
-char *ppp_lcp_types[] = {
+static char *ppp_lcp_types[] = {
NULL,
"ConfigReq",
"ConfigAck",
"IdentRequest",
};
-void dumplcp(u8 *p, int l)
+static void dumplcp(u8 *p, int l)
{
int x = l - 4;
u8 *o = (p + 4);
else
LOG(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length);
break;
+ case 2: // Async-Control-Character-Map
+ if (length == 6)
+ {
+ u32 asyncmap = ntohl(*(u32 *)(o + 2));
+ LOG(4, 0, 0, 0, " %s %x\n", lcp_types[type], asyncmap);
+ }
+ else
+ LOG(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length);
+ break;
case 3: // Authentication-Protocol
+ if (length == 4)
{
- if (length == 4)
- {
- int proto = ntohs(*(u16 *)(o + 2));
- LOG(4, 0, 0, 0, " %s 0x%x (%s)\n", lcp_types[type], proto,
- proto == PPPCHAP ? "CHAP" :
- proto == PPPPAP ? "PAP" : "UNKNOWN");
- }
- else
- LOG(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length);
- break;
+ int proto = ntohs(*(u16 *)(o + 2));
+ LOG(4, 0, 0, 0, " %s 0x%x (%s)\n", lcp_types[type], proto,
+ proto == PPPCHAP ? "CHAP" :
+ proto == PPPPAP ? "PAP" : "UNKNOWN");
}
+ else
+ LOG(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length);
+ break;
case 4: // Quality-Protocol
{
u32 qp = ntohl(*(u32 *)(o + 2));
LOG(4, 0, 0, 0, " %s %x\n", lcp_types[type], qp);
- break;
}
+ break;
case 5: // Magic-Number
+ if (length == 6)
{
- if (length == 6)
- {
- u32 magicno = ntohl(*(u32 *)(o + 2));
- LOG(4, 0, 0, 0, " %s %x\n", lcp_types[type], magicno);
- }
- else
- LOG(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length);
- break;
+ u32 magicno = ntohl(*(u32 *)(o + 2));
+ LOG(4, 0, 0, 0, " %s %x\n", lcp_types[type], magicno);
}
+ else
+ LOG(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length);
+ break;
case 7: // Protocol-Field-Compression
- {
- LOG(4, 0, 0, 0, " %s\n", lcp_types[type]);
- break;
- }
case 8: // Address-And-Control-Field-Compression
- {
- LOG(4, 0, 0, 0, " %s\n", lcp_types[type]);
- break;
- }
+ LOG(4, 0, 0, 0, " %s\n", lcp_types[type]);
+ break;
default:
LOG(2, 0, 0, 0, " Unknown PPP LCP Option type %d\n", type);
break;
{
int x = l - 4;
u8 *o = (p + 4);
+ u8 response = 0;
LOG(3, session[s].ip, s, t, "LCP: ConfigReq (%d bytes)...\n", l);
if (config->debug > 3) dumplcp(p, l);
{
int type = o[0];
int length = o[1];
- if (length == 0 || type == 0) break;
+ if (length == 0 || type == 0 || x < length) break;
switch (type)
{
case 1: // Maximum-Receive-Unit
session[s].mru = ntohs(*(u16 *)(o + 2));
break;
- case 2: // asyncmap
- LOG_HEX(2, "PPP LCP Packet", p, l);
- LOG(2, 0, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_types[(int)*p], ntohs( ((u16 *) p)[1]) );
+
+ case 2: // Async-Control-Character-Map
+ if (!ntohl(*(u32 *)(o + 2))) // all bits zero is OK
+ break;
+
+ if (response && response != ConfigNak) // rej already queued
+ break;
+
+ LOG(2, session[s].ip, s, t, " Remote requesting asyncmap. Rejecting.\n");
+ if (!response)
+ {
+ q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
+ if (!q) break;
+ response = *q++ = ConfigNak;
+ }
+
+ if ((q - b + 11) > sizeof(b))
+ {
+ LOG(2, session[s].ip, s, t, "LCP overflow for asyncmap ConfigNak.\n");
+ break;
+ }
+
+ *q++ = type;
+ *q++ = 6;
+ memset(q, 0, 4); // asyncmap 0
+ q += 4;
break;
+
case 3: // Authentication-Protocol
{
int proto = ntohs(*(u16 *)(o + 2));
+ char proto_name[] = "0x0000";
+ if (proto == PPPPAP)
+ break;
+
+ if (response && response != ConfigNak) // rej already queued
+ break;
+
if (proto == PPPCHAP)
+ strcpy(proto_name, "CHAP");
+ else
+ sprintf(proto_name, "%#4.4x", proto);
+
+ LOG(2, session[s].ip, s, t, " Remote requesting %s authentication. Rejecting.\n", proto_name);
+
+ if (!response)
{
- LOG(2, session[s].ip, s, t, " Remote end is trying to do CHAP. Rejecting it.\n");
-
- if (!q)
- {
- q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
- if (!q) {
- LOG(2, session[s].ip, s, t, " Failed to send packet.\n");
- break;
- }
- *q++ = ConfigNak;
- }
- memcpy(q, o, length);
- *(u16 *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead
- q += length;
+ q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
+ if (!q) break;
+ response = *q++ = ConfigNak;
}
- break;
+
+ if ((q - b + length) > sizeof(b))
+ {
+ LOG(2, session[s].ip, s, t, "LCP overflow for %s ConfigNak.\n", proto_name);
+ break;
+ }
+
+ memcpy(q, o, length);
+ *(u16 *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead
+ q += length;
}
+ break;
+
case 5: // Magic-Number
- {
- magicno = ntohl(*(u32 *)(o + 2));
- break;
- }
+ magicno = ntohl(*(u32 *)(o + 2));
+ break;
+
case 4: // Quality-Protocol
case 7: // Protocol-Field-Compression
case 8: // Address-And-Control-Field-Compression
+ break;
+
+ default: // Reject any unknown options
+ LOG(2, session[s].ip, s, t, " Rejecting PPP LCP Option type %d\n", type);
+ if (!response || response != ConfigRej) // drop nak in favour of rej
+ {
+ q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
+ if (!q) return;
+ response = *q++ = ConfigRej;
+ }
+
+ if ((q - b + length) > sizeof(b))
+ {
+ LOG(2, session[s].ip, s, t, "LCP overflow for ConfigRej (type=%d).\n", type);
break;
- case 13: // CallBack option for LCP extention of win2000/routers L2TP client
- case 17:
- case 18:
- {
- // Reject LCP CallBack
- LOG(2, session[s].ip, s, t, " PPP LCP Option type %d, len=%d\n", type, length);
- memcpy(p + 4, o, length);
- *(u16 *)(p + 2) = htons(length + 4);
- *p = ConfigRej;
- q = makeppp(b,sizeof(b), p, length + 4, t, s, PPPLCP);
- tunnelsend(b, 12 + length + 4, t);
- return;
}
- default:
- // Reject Unknown LCP Option to stop to send it again
- LOG(2, session[s].ip, s, t, " Unknown PPP LCP Option type %d\n", type);
- memcpy(p + 4, o, length);
- *(u16 *)(p + 2) = htons(length + 4);
- *p = ConfigRej;
- q = makeppp(b,sizeof(b), p, length + 4, t, s, PPPLCP);
- tunnelsend(b, 12 + length + 4, t);
- return;
+ memcpy(q, o, length);
+ q += length;
}
x -= length;
o += length;
}
- if (!(session[s].flags & SF_LCP_ACKED))
- initlcp(t, s);
-
- if (!q)
+ if (!response)
{
// Send back a ConfigAck
- LOG(3, session[s].ip, s, t, "ConfigReq accepted, sending as Ack\n");
q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
- if (!q)
- {
- LOG(3, session[s].ip, s, t, " failed to create packet.\n");
- return;
- }
- *q = ConfigAck;
- tunnelsend(b, l + (q - b), t);
- }
- else
- {
- // Already built a ConfigNak... send it
- LOG(3, session[s].ip, s, t, "Sending ConfigNak\n");
- tunnelsend(b, l + (q - b), t);
+ if (!q) return;
+ response = *q = ConfigAck;
}
+
+ LOG(3, session[s].ip, s, t, "Sending %s\n", ppp_lcp_types[response]);
+ tunnelsend(b, l + (q - b), t);
+
+ if (!(session[s].flags & SF_LCP_ACKED))
+ initlcp(t, s);
}
else if (*p == ConfigNak)
{
- LOG(1, session[s].ip, s, t, "Remote end sent a ConfigNak. Ignoring\n");
+ LOG(1, session[s].ip, s, t, "Remote end sent a ConfigNak. Ignoring\n");
if (config->debug > 3) dumplcp(p, l);
return ;
}
else if (*p == TerminateReq)
{
+ LOG(3, session[s].ip, s, t, "LCP: Received TerminateReq. Sending TerminateAck\n");
*p = TerminateAck; // close
q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
- if (!q) {
- LOG(3, session[s].ip, s, t, "Failed to create PPP packet in processlcp.\n");
- return;
- }
- LOG(3, session[s].ip, s, t, "LCP: Received TerminateReq. Sending TerminateAck\n");
- sessionshutdown(s, "Remote end closed connection.");
+ if (!q) return;
tunnelsend(b, l + (q - b), t); // send it
+ sessionshutdown(s, "Remote end closed connection.");
}
else if (*p == TerminateAck)
{
}
else if (*p == EchoReq)
{
+ LOG(5, session[s].ip, s, t, "LCP: Received EchoReq. Sending EchoReply\n");
*p = EchoReply; // reply
*(u32 *) (p + 4) = htonl(session[s].magic); // our magic number
q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
- if (!q) {
- LOG(3, session[s].ip, s, t, " failed to send EchoReply.\n");
- return;
- }
- LOG(5, session[s].ip, s, t, "LCP: Received EchoReq. Sending EchoReply\n");
+ if (!q) return;
tunnelsend(b, l + (q - b), t); // send it
}
else if (*p == EchoReply)
l = 1400;
}
q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
- if (!q)
- {
- LOG(3, session[s].ip, s, t, "Failed to create IdentRej.\n");
- return;
- }
+ if (!q) return;
LOG_HEX(5, "LCPIdentRej", q, l + 4);
tunnelsend(b, 12 + 4 + l, t);
}
}
}
+// find a PPP option, returns point to option, or 0 if not found
+static u8 *findppp(u8 *b, u8 mtype)
+{
+ u16 l = ntohs(*(u16 *) (b + 2));
+ if (l < 4)
+ return 0;
+ b += 4;
+ l -= 4;
+ while (l)
+ {
+ if (l < b[1] || !b[1])
+ return 0; // faulty
+ if (*b == mtype)
+ return b;
+ l -= b[1];
+ b += b[1];
+ }
+ return 0;
+}
+
// Process IPCP messages
void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
{
session[s].flags |= SF_IPCP_ACKED;
LOG(3, session[s].ip, s, t, "IPCP Acked, session is now active\n");
+
+ // clear LCP_ACKED/CCP_ACKED flag for possible fast renegotiaion for routers
+ session[s].flags &= ~(SF_LCP_ACKED|SF_CCP_ACKED);
+
return;
}
if (*p != ConfigReq)
u16 n = 4;
i = p + l;
if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP)))
- {
- LOG(2, 0, s, t, "Failed to send IPCP ConfigRej\n");
return;
- }
+
*q = ConfigRej;
p += 4;
while (p < i && p[1])
inet_toa(htonl(session[s].ip)));
}
if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP)))
- {
- LOG(2, 0, s, t, " Failed to send IPCP packet.\n");
return;
- }
+
tunnelsend(b, l + (q - b), t); // send it
}
}
return;
}
- if (session[s].snoop_ip && session[s].snoop_port)
- {
- // Snooping this session
- snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
- }
-
// Add on the tun header
p -= 4;
*(u32 *)p = htonl(0x00000800);
return;
}
- session[s].cin += l - 4;
- session[s].total_cin += l - 4;
- sess_count[s].cin += l - 4;
-
- session[s].pin++;
- eth_tx += l - 4;
-
- STAT(tun_tx_packets);
- INC_STAT(tun_tx_bytes, l);
-
if (session[s].tbf_in && config->cluster_iam_master) { // Are we throttled and a master?? actually handle the throttled packets.
tbf_queue_packet(session[s].tbf_in, p, l);
return;
STAT(tun_tx_errors);
LOG(0, 0, s, t, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
l, strerror(errno), tunfd, p);
+
+ return;
}
+ if (session[s].snoop_ip && session[s].snoop_port)
+ {
+ // Snooping this session
+ snoop_send_packet(p + 4, l - 4, session[s].snoop_ip, session[s].snoop_port);
+ }
+
+ session[s].cin += l - 4;
+ session[s].total_cin += l - 4;
+ sess_count[s].cin += l - 4;
+
+ session[s].pin++;
+ eth_tx += l - 4;
+
+ STAT(tun_tx_packets);
+ INC_STAT(tun_tx_bytes, l - 4);
}
//
void send_ipin(sessionidt s, u8 *buf, int len)
{
LOG_HEX(5, "IP in throttled", buf, len);
+
if (write(tunfd, buf, len) < 0)
{
STAT(tun_tx_errors);
LOG(0, 0, 0, 0, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
len, strerror(errno), tunfd, buf);
+
+ return;
+ }
+
+ if (session[s].snoop_ip && session[s].snoop_port)
+ {
+ // Snooping this session
+ snoop_send_packet(buf + 4, len - 4, session[s].snoop_ip, session[s].snoop_port);
}
// Increment packet counters
session[s].pin++;
eth_tx += len - 4;
+
+ STAT(tun_tx_packets);
+ INC_STAT(tun_tx_bytes, len - 4);
}
// Process CCP messages
void processccp(tunnelidt t, sessionidt s, u8 *p, u16 l)
{
+ u8 b[MAXCONTROL];
+ u8 *q;
CSTAT(call_processccp);
LOG_HEX(5, "CCP", p, l);
- if (l < 2 || (*p != ConfigReq && *p != TerminateReq))
+ switch (l > 1 ? *p : 0)
{
- LOG(1, 0, s, t, "Unexpected CCP request code %d\n", *p);
- STAT(tunnel_rx_errors);
- return ;
- }
- // reject
- {
- u8 b[MAXCONTROL];
- u8 *q;
- if (*p == ConfigReq)
+ case ConfigAck:
+ session[s].flags |= SF_CCP_ACKED;
+ return;
+
+ case ConfigReq:
+ if (l < 6) // accept no compression
{
- if (l < 6)
- {
- *p = ConfigAck; // accept no compression
- }
- else
- {
- *p = ConfigRej; // reject
- sendccp(t, s);
- }
+ *p = ConfigAck;
+ break;
}
+
+ // compression requested--reject
+ *p = ConfigRej;
+
+ // send CCP request for no compression for our end if not negotiated
+ if (!(session[s].flags & SF_CCP_ACKED))
+ initccp(t, s);
+
+ break;
+
+ case TerminateReq:
+ *p = TerminateAck;
+ break;
+
+ default:
+ if (l > 1)
+ LOG(1, 0, s, t, "Unexpected CCP request code %d\n", *p);
else
- *p = TerminateAck; // close
- if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP)))
- {
- LOG(1,0,0,0, "Failed to send CCP packet.\n");
- return;
- }
- tunnelsend(b, l + (q - b), t); // send it
+ LOG(1, 0, s, t, "Short CCP packet\n");
+
+ STAT(tunnel_rx_errors);
+ return;
}
+
+ if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP)))
+ return;
+
+ tunnelsend(b, l + (q - b), t); // send it
}
// send a CHAP PP packet
return ;
}
q = makeppp(b, sizeof(b), 0, 0, t, s, PPPCHAP);
- if (!q) {
- LOG(1, 0, s, t, "failed to send CHAP challenge.\n");
- return;
- }
+ if (!q) return;
+
*q = 1; // challenge
q[1] = radius[r].id; // ID
q[4] = 16; // length
// returns start of PPP frame
u8 *makeppp(u8 *b, int size, u8 *p, int l, tunnelidt t, sessionidt s, u16 mtype)
{
- if (size < 12)
- return NULL; // Need more space than this!!
+ if (size < 12) // Need more space than this!!
+ {
+ static int backtrace_count = 0;
+ LOG(0, session[s].ip, s, t, "makeppp buffer too small for L2TP header (size=%d)\n", size);
+ log_backtrace(backtrace_count, 5)
+ return NULL;
+ }
*(u16 *) (b + 0) = htons(0x0002); // L2TP with no options
*(u16 *) (b + 2) = htons(tunnel[t].far); // tunnel
b += 2;
}
- if (l + 12 > size) {
- LOG(3,0,0,0, "Would have overflowed the buffer in makeppp: size %d, len %d.\n", size, l);
- return NULL; // Run out of room to hold the packet!
+ if (l + 12 > size)
+ {
+ static int backtrace_count = 0;
+ LOG(2, session[s].ip, s, t, "makeppp would overflow buffer (size=%d, header+payload=%d)\n", size, l + 12);
+ log_backtrace(backtrace_count, 5)
+ return NULL;
}
+
if (p && l)
memcpy(b, p, l);
- return b;
-}
-// find a PPP option, returns point to option, or 0 if not found
-u8 *findppp(u8 *b, u8 mtype)
-{
- u16 l = ntohs(*(u16 *) (b + 2));
- if (l < 4)
- return 0;
- b += 4;
- l -= 4;
- while (l)
- {
- if (l < b[1] || !b[1])
- return 0; // faulty
- if (*b == mtype)
- return b;
- l -= b[1];
- b += b[1];
- }
- return 0;
+ return b;
}
-// Send initial LCP ConfigReq
+// Send initial LCP ConfigReq for PAP, set magic no.
void initlcp(tunnelidt t, sessionidt s)
{
- char b[500] = {0}, *q;
+ char b[500], *q;
- q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
- if (!q) {
- LOG(1, 0, s, t, "Failed to send LCP ConfigReq.\n");
+ if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP)))
return;
- }
+
LOG(4, 0, s, t, "Sending LCP ConfigReq for PAP\n");
*q = ConfigReq;
*(u8 *)(q + 1) = (time_now % 255) + 1; // ID
*(u8 *)(q + 10) = 3;
*(u8 *)(q + 11) = 4;
*(u16 *)(q + 12) = htons(PPPPAP); // PAP
- tunnelsend(b, 12 + 14, t);
+
+ LOG_HEX(5, "PPPLCP", q, 14);
+ tunnelsend(b, (q - b) + 14, t);
}
-// Send CCP reply
-void sendccp(tunnelidt t, sessionidt s)
+// Send CCP request for no compression
+static void initccp(tunnelidt t, sessionidt s)
{
- char *q, b[500] = {0};
+ char b[500], *q;
+
+ if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP)))
+ return;
- q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP);
+ LOG(4, 0, s, t, "Sending CCP ConfigReq for no compression\n");
*q = ConfigReq;
*(u8 *)(q + 1) = (time_now % 255) + 1; // ID
*(u16 *)(q + 2) = htons(4); // Length
+
LOG_HEX(5, "PPPCCP", q, 4);
tunnelsend(b, (q - b) + 4 , t);
}
-
projects / l2tpns.git / blobdiff