// L2TPNS PPP Stuff
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.23 2004-11-09 05:42:53 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.28 2004-11-25 02:45:27 bodea Exp $";
#include <stdio.h>
#include <string.h>
extern time_t time_now;
extern struct configt *config;
-void sendccp(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);
LOG(2, session[s].ip, s, t, " Remote requesting asyncmap. Rejecting.\n");
if (!response)
{
- 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 = 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
if (!response)
{
- 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 = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
+ if (!q) break;
response = *q++ = ConfigNak;
}
+
+ 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;
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), p, l, t, s, PPPLCP);
- if (!q)
- {
- LOG(2, session[s].ip, s, t, " Failed to send packet.\n");
- break;
- }
+ 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;
+ }
+
memcpy(q, o, length);
q += length;
}
{
// Send back a ConfigAck
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;
- }
+ if (!q) return;
response = *q = ConfigAck;
}
}
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 flag for possible fast renegotiaion for routers
+ session[s].flags &= ~SF_LCP_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
}
}
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);
+ snoop_send_packet(buf + 4, len - 4, session[s].snoop_ip, session[s].snoop_port);
}
// Increment packet counters
eth_tx += len - 4;
STAT(tun_tx_packets);
- INC_STAT(tun_tx_bytes, l - 4);
+ 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)
- {
- if (l < 6)
- {
- *p = ConfigAck; // accept no compression
- }
- else
- {
- *p = ConfigRej; // reject
- sendccp(t, s);
- }
- }
+ case ConfigReq:
+ if (l < 6)
+ *p = ConfigAck; // accept no compression
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
+ *p = ConfigRej; // reject
+
+ break;
+
+ case TerminateReq:
+ *p = TerminateAck;
+ break;
+
+ default:
+ if (l > 1)
+ LOG(1, 0, s, t, "Unexpected CCP request code %d\n", *p);
+ else
+ 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
{
char b[500] = {0}, *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
*(u16 *)(q + 12) = htons(PPPPAP); // PAP
tunnelsend(b, 12 + 14, t);
}
-
-// Send CCP reply
-void sendccp(tunnelidt t, sessionidt s)
-{
- char *q, b[500] = {0};
-
- q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP);
- *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