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l2tpns/radius.c
bodea def1dfd3cc - set hostname in CLI prompt 
- add assertions to help identify odd LASTSEEN breakage
- make cluster_hb_interval work; include interval/timeout in heartbeats
  so that a change on the master is propagated immediately to the slaves
- use fast heartbeats when there are slaves not up to date
- ensure basetime of shut down master is set to zero (prevent delayed election)
- fix radius session leak on IPCP timeout
- fix some off-by-one errors in tunnel/session loops
2004-07-07 09:09:53 +00:00

669 lines
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C
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// L2TPNS Radius Stuff
char const *cvs_id_radius = "$Id: radius.c,v 1.7 2004/07/07 09:09:53 bodea Exp $";
#include <time.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <malloc.h>
#include <string.h>
#include <fcntl.h>
#include <arpa/inet.h>
#include <ctype.h>
#include <netinet/in.h>
#include "md5.h"
#include "constants.h"
#include "l2tpns.h"
#include "plugin.h"
#include "util.h"
extern radiust *radius;
extern sessiont *session;
extern tunnelt *tunnel;
extern u32 sessionid;
extern struct configt *config;
extern int *radfds;
const char *radius_state(int state)
{
static char *tmp = NULL;
int i;
for (i = 0; radius_states[i]; i++)
if (i == state) return radius_states[i];
if (tmp == NULL) tmp = (char *)calloc(64, 1);
sprintf(tmp, "%d", state);
return tmp;
}
// Set up socket for radius requests
void initrad(void)
{
int i;
log(3, 0, 0, 0, "Creating %d sockets for RADIUS queries\n", config->num_radfds);
radfds = calloc(sizeof(int), config->num_radfds);
for (i = 0; i < config->num_radfds; i++)
{
int flags;
if (!radfds[i]) radfds[i] = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
flags = fcntl(radfds[i], F_GETFL, 0);
fcntl(radfds[i], F_SETFL, flags | O_NONBLOCK);
}
}
void radiusclear(u16 r, sessionidt s)
{
if (s) session[s].radius = 0;
memset(&radius[r], 0, sizeof(radius[r])); // radius[r].state = RADIUSNULL;
}
static u16 get_free_radius()
{
int count;
static u32 next_radius_id = 0;
for (count = MAXRADIUS; count > 0 ; --count)
{
++next_radius_id; // Find the next ID to check.
if (next_radius_id >= MAXRADIUS)
next_radius_id = 1;
if (radius[next_radius_id].state == RADIUSNULL)
{
return next_radius_id;
}
}
log(0, 0, 0, 0, "Can't find a free radius session! This is very bad!\n");
return 0;
}
u16 radiusnew(sessionidt s)
{
u16 r = session[s].radius;
/* re-use */
if (r)
{
log(3, 0, s, session[s].tunnel, "Re-used radius %d\n", r);
return r;
}
if (!(r = get_free_radius()))
{
log(1, 0, s, session[s].tunnel, "No free RADIUS sessions\n");
STAT(radius_overflow);
return 0;
};
memset(&radius[r], 0, sizeof(radius[r]));
session[s].radius = r;
radius[r].session = s;
radius[r].state = RADIUSWAIT;
radius[r].retry = TIME + 1200; // Wait at least 120 seconds to re-claim this.
log(3,0,s, session[s].tunnel, "Allocated radius %d\n", r);
return r;
}
// Send a RADIUS request
void radiussend(u16 r, u8 state)
{
struct sockaddr_in addr;
u8 b[4096]; // RADIUS packet
char pass[129];
int pl;
u8 *p;
sessionidt s;
CSTAT(call_radiussend);
s = radius[r].session;
if (!config->numradiusservers)
{
log(0, 0, s, session[s].tunnel, "No RADIUS servers\n");
return;
}
if (!*config->radiussecret)
{
log(0, 0, s, session[s].tunnel, "No RADIUS secret\n");
return;
}
if (state != RADIUSAUTH && !config->radius_accounting)
{
// Radius accounting is turned off
radiusclear(r, s);
return;
}
if (radius[r].state != state)
radius[r].try = 0;
radius[r].state = state;
radius[r].retry = backoff(radius[r].try++);
log(4, 0, s, session[s].tunnel, "Send RADIUS id %d sock %d state %s try %d\n",
r >> RADIUS_SHIFT, r & RADIUS_MASK,
radius_state(radius[r].state), radius[r].try);
if (radius[r].try > config->numradiusservers * 2)
{
if (s)
{
if (state == RADIUSAUTH)
sessionshutdown(s, "RADIUS timeout");
else
{
log(1, 0, s, session[s].tunnel, "RADIUS timeout, but in state %s so don't timeout session\n",
radius_states[state]);
radiusclear(r, s);
}
STAT(radius_timeout);
}
else
{
STAT(radius_retries);
radius[r].state = RADIUSWAIT;
radius[r].retry = 100;
}
return ;
}
// contruct RADIUS access request
switch (state)
{
case RADIUSAUTH:
b[0] = 1; // access request
break;
case RADIUSSTART:
case RADIUSSTOP:
b[0] = 4; // accounting request
break;
default:
log(0, 0, 0, 0, "Unknown radius state %d\n", state);
}
b[1] = r >> RADIUS_SHIFT; // identifier
memcpy(b + 4, radius[r].auth, 16);
p = b + 20;
if (s)
{
*p = 1; // user name
p[1] = strlen(session[s].user) + 2;
strcpy(p + 2, session[s].user);
p += p[1];
}
if (state == RADIUSAUTH)
{
if (radius[r].chap)
{
*p = 3; // CHAP password
p[1] = 19; // length
p[2] = radius[r].id; // ID
memcpy(p + 3, radius[r].pass, 16); // response from CHAP request
p += p[1];
*p = 60; // CHAP Challenge
p[1] = 18; // length
memcpy(p + 2, radius[r].auth, 16);
p += p[1];
}
else
{
strcpy(pass, radius[r].pass);
pl = strlen(pass);
while (pl & 15)
pass[pl++] = 0; // pad
if (pl)
{ // encrypt
hasht hash;
int p = 0;
while (p < pl)
{
MD5_CTX ctx;
MD5Init(&ctx);
MD5Update(&ctx, config->radiussecret, strlen(config->radiussecret));
if (p)
MD5Update(&ctx, pass + p - 16, 16);
else
MD5Update(&ctx, radius[r].auth, 16);
MD5Final(hash, &ctx);
do
{
pass[p] ^= hash[p & 15];
p++;
}
while (p & 15);
}
}
*p = 2; // password
p[1] = pl + 2;
if (pl)
memcpy(p + 2, pass, pl);
p += p[1];
}
}
else if (state == RADIUSSTART || state == RADIUSSTOP)
{ // accounting
*p = 40; // accounting type
p[1] = 6;
*(u32 *) (p + 2) = htonl((state == RADIUSSTART) ? 1 : 2);
p += p[1];
if (s)
{
*p = 44; // session ID
p[1] = 18;
sprintf(p + 2, "%08X%08X", session[s].id, session[s].opened);
p += p[1];
if (state == RADIUSSTOP)
{ // stop
*p = 42; // input octets
p[1] = 6;
*(u32 *) (p + 2) = htonl(session[s].cin);
p += p[1];
*p = 43; // output octets
p[1] = 6;
*(u32 *) (p + 2) = htonl(session[s].cout);
p += p[1];
*p = 46; // session time
p[1] = 6;
*(u32 *) (p + 2) = htonl(time(NULL) - session[s].opened);
p += p[1];
*p = 47; // input packets
p[1] = 6;
*(u32 *) (p + 2) = htonl(session[s].pin);
p += p[1];
*p = 48; // output spackets
p[1] = 6;
*(u32 *) (p + 2) = htonl(session[s].pout);
p += p[1];
}
else
{ // start
*p = 41; // delay
p[1] = 6;
*(u32 *) (p + 2) = htonl(time(NULL) - session[s].opened);
p += p[1];
}
}
}
if (s)
{
*p = 5; // NAS-Port
p[1] = 6;
*(u32 *) (p + 2) = htonl(s);
p += p[1];
}
if (s && session[s].ip)
{
*p = 8; // Framed-IP-Address
p[1] = 6;
*(u32 *) (p + 2) = htonl(session[s].ip);
p += p[1];
}
if (*session[s].called)
{
*p = 30; // called
p[1] = strlen(session[s].called) + 2;
strcpy(p + 2, session[s].called);
p += p[1];
}
if (*radius[r].calling)
{
*p = 31; // calling
p[1] = strlen(radius[r].calling) + 2;
strcpy(p + 2, radius[r].calling);
p += p[1];
}
else if (*session[s].calling)
{
*p = 31; // calling
p[1] = strlen(session[s].calling) + 2;
strcpy(p + 2, session[s].calling);
p += p[1];
}
// NAS-IP-Address
*p = 4;
p[1] = 6;
*(u32 *)(p + 2) = config->bind_address;
p += p[1];
// All AVpairs added
*(u16 *) (b + 2) = htons(p - b);
if (state != RADIUSAUTH)
{
// Build auth for accounting packet
char z[16] = {0};
char hash[16] = {0};
MD5_CTX ctx;
MD5Init(&ctx);
MD5Update(&ctx, b, 4);
MD5Update(&ctx, z, 16);
MD5Update(&ctx, b + 20, (p - b) - 20);
MD5Update(&ctx, config->radiussecret, strlen(config->radiussecret));
MD5Final(hash, &ctx);
memcpy(b + 4, hash, 16);
memcpy(radius[r].auth, hash, 16);
}
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
*(u32 *) & addr.sin_addr = config->radiusserver[(radius[r].try - 1) % config->numradiusservers];
addr.sin_port = htons((state == RADIUSAUTH) ? RADPORT : RADAPORT);
log_hex(5, "RADIUS Send", b, (p - b));
sendto(radfds[r & RADIUS_MASK], b, p - b, 0, (void *) &addr, sizeof(addr));
}
// process RADIUS response
void processrad(u8 *buf, int len, char socket_index)
{
u8 b[MAXCONTROL];
MD5_CTX ctx;
u16 r;
sessionidt s;
tunnelidt t = 0;
hasht hash;
u8 routes = 0;
int r_code, r_id ; // Radius code.
r_code = buf[0]; // First byte in radius packet.
r_id = buf[1]; // radius reply indentifier.
CSTAT(call_processrad);
log_hex(5, "RADIUS Response", buf, len);
if (len < 20 || len < ntohs(*(u16 *) (buf + 2)))
{
log(1, 0, 0, 0, "Duff RADIUS response length %d\n", len);
return ;
}
len = ntohs(*(u16 *) (buf + 2));
r = socket_index | (r_id << RADIUS_SHIFT);
s = radius[r].session;
log(3, 0, s, session[s].tunnel, "Received %s, radius %d response for session %u (code %d, id %d)\n",
radius_states[radius[r].state], r, s, r_code, r_id);
if (!s && radius[r].state != RADIUSSTOP)
{
log(1, 0, s, session[s].tunnel, " Unexpected RADIUS response\n");
return;
}
if (radius[r].state != RADIUSAUTH && radius[r].state != RADIUSSTART && radius[r].state != RADIUSSTOP)
{
log(1, 0, s, session[s].tunnel, " Unexpected RADIUS response\n");
return;
}
t = session[s].tunnel;
MD5Init(&ctx);
MD5Update(&ctx, buf, 4);
MD5Update(&ctx, radius[r].auth, 16);
MD5Update(&ctx, buf + 20, len - 20);
MD5Update(&ctx, config->radiussecret, strlen(config->radiussecret));
MD5Final(hash, &ctx);
do {
if (memcmp(hash, buf + 4, 16))
{
log(0, 0, s, session[s].tunnel, " Incorrect auth on RADIUS response!! (wrong secret in radius config?)\n");
return; // Do nothing. On timeout, it will try the next radius server.
}
if ((radius[r].state == RADIUSAUTH && *buf != 2 && *buf != 3) ||
((radius[r].state == RADIUSSTART || radius[r].state == RADIUSSTOP) && *buf != 5))
{
log(1, 0, s, session[s].tunnel, " Unexpected RADIUS response %d\n", *buf);
return; // We got something we didn't expect. Let the timeouts take
// care off finishing the radius session if that's really correct.
}
if (radius[r].state == RADIUSAUTH)
{
log(4, 0, s, session[s].tunnel, " Original response is \"%s\"\n", (*buf == 2) ? "accept" : "reject");
// process auth response
if (radius[r].chap)
{
// CHAP
u8 *p = makeppp(b, sizeof(b), 0, 0, t, s, PPPCHAP);
if (!p) {
return; // Abort!
}
{
struct param_post_auth packet = { &tunnel[t], &session[s], session[s].user, (*buf == 2), PPPCHAP };
run_plugins(PLUGIN_POST_AUTH, &packet);
*buf = packet.auth_allowed ? 2 : 3;
}
log(3, 0, s, session[s].tunnel, " CHAP User %s authentication %s.\n", session[s].user,
(*buf == 2) ? "allowed" : "denied");
*p = (*buf == 2) ? 3 : 4; // ack/nak
p[1] = radius[r].id;
*(u16 *) (p + 2) = ntohs(4); // no message
tunnelsend(b, (p - b) + 4, t); // send it
}
else
{
// PAP
u8 *p = makeppp(b, sizeof(b), 0, 0, t, s, PPPPAP);
if (!p)
return; // Abort!
{
struct param_post_auth packet = { &tunnel[t], &session[s], session[s].user, (*buf == 2), PPPPAP };
run_plugins(PLUGIN_POST_AUTH, &packet);
*buf = packet.auth_allowed ? 2 : 3;
}
log(3, 0, s, session[s].tunnel, " PAP User %s authentication %s.\n", session[s].user,
(*buf == 2) ? "allowed" : "denied");
// ack/nak
*p = *buf;
p[1] = radius[r].id;
*(u16 *) (p + 2) = ntohs(5);
p[4] = 0; // no message
tunnelsend(b, (p - b) + 5, t); // send it
}
if (*buf == 2)
{
// Login successful
// Extract IP, routes, etc
u8 *p = buf + 20;
u8 *e = buf + len;
for (p = buf + 20; p < e && p[1]; p += p[1])
{
if (*p == 8)
{
// Statically assigned address
log(3, 0, s, session[s].tunnel, " Radius reply contains IP address %s\n", inet_toa(*(u32 *) (p + 2)));
session[s].ip = ntohl(*(u32 *) (p + 2));
session[s].ip_pool_index = -1;
}
else if (*p == 135)
{
// DNS address
log(3, 0, s, session[s].tunnel, " Radius reply contains primary DNS address %s\n", inet_toa(*(u32 *) (p + 2)));
session[s].dns1 = ntohl(*(u32 *) (p + 2));
}
else if (*p == 136)
{
// DNS address
log(3, 0, s, session[s].tunnel, " Radius reply contains secondary DNS address %s\n", inet_toa(*(u32 *) (p + 2)));
session[s].dns2 = ntohl(*(u32 *) (p + 2));
}
else if (*p == 22)
{
// framed-route
ipt ip = 0, mask = 0;
u8 u = 0;
u8 bits = 0;
u8 *n = p + 2;
u8 *e = p + p[1];
while (n < e && (isdigit(*n) || *n == '.'))
{
if (*n == '.')
{
ip = (ip << 8) + u;
u = 0;
}
else
u = u * 10 + *n - '0';
n++;
}
ip = (ip << 8) + u;
if (*n == '/')
{
n++;
while (n < e && isdigit(*n))
bits = bits * 10 + *n++ - '0';
mask = (( -1) << (32 - bits));
}
else if ((ip >> 24) < 128)
mask = 0xFF0000;
else if ((ip >> 24) < 192)
mask = 0xFFFF0000;
else
mask = 0xFFFFFF00;
if (routes == MAXROUTE)
{
log(1, 0, s, session[s].tunnel, " Too many routes\n");
}
else if (ip)
{
char *ips, *masks;
ips = strdup(inet_toa(htonl(ip)));
masks = strdup(inet_toa(htonl(mask)));
log(3, 0, s, session[s].tunnel, " Radius reply contains route for %s/%s\n", ips, masks);
free(ips);
free(masks);
session[s].route[routes].ip = ip;
session[s].route[routes].mask = mask;
routes++;
}
}
else if (*p == 26)
{
// Vendor-Specific Attribute
int vendor = ntohl(*(int *)(p + 2));
char attrib = *(p + 6);
char attrib_length = *(p + 7) - 2;
log(3, 0, s, session[s].tunnel, " Radius reply contains Vendor-Specific. Vendor=%d Attrib=%d Length=%d\n", vendor, attrib, attrib_length);
if (attrib_length == 0) continue;
if (attrib != 1)
log(3, 0, s, session[s].tunnel, " Unknown vendor-specific\n");
else
{
char *avpair, *value, *key, *newp;
avpair = key = calloc(attrib_length + 1, 1);
memcpy(avpair, p + 8, attrib_length);
log(3, 0, s, session[s].tunnel, " Cisco-Avpair value: %s\n", avpair);
do {
value = strchr(key, '=');
if (!value) break;
*value++ = 0;
// Trim quotes off reply string
if (*value == '\'' || *value == '\"')
{
char *x;
value++;
x = value + strlen(value) - 1;
if (*x == '\'' || *x == '\"')
*x = 0;
}
// Run hooks
newp = strchr(value, ',');
if (newp) *newp++ = 0;
{
struct param_radius_response p = { &tunnel[session[s].tunnel], &session[s], key, value };
run_plugins(PLUGIN_RADIUS_RESPONSE, &p);
}
key = newp;
} while (newp);
free(avpair);
}
}
}
}
else if (*buf == 3)
{
log(2, 0, s, session[s].tunnel, " Authentication denied for %s\n", session[s].user);
//FIXME: We should tear down the session here!
break;
}
if (!session[s].dns1 && config->default_dns1)
{
session[s].dns1 = htonl(config->default_dns1);
log(3, 0, s, t, " Sending dns1 = %s\n", inet_toa(config->default_dns1));
}
if (!session[s].dns2 && config->default_dns2)
{
session[s].dns2 = htonl(config->default_dns2);
log(3, 0, s, t, " Sending dns2 = %s\n", inet_toa(config->default_dns2));
}
// Valid Session, set it up
session[s].sid = 0;
sessionsetup(t, s);
}
else
{
// An ack for a stop or start record.
log(3, 0, s, t, " RADIUS accounting ack recv in state %s\n", radius_states[radius[r].state]);
break;
}
} while (0);
// finished with RADIUS
radiusclear(r, s);
}
// Send a retry for RADIUS/CHAP message
void radiusretry(u16 r)
{
sessionidt s = radius[r].session;
tunnelidt t = 0;
CSTAT(call_radiusretry);
if (s)
t = session[s].tunnel;
radius[r].retry = backoff(radius[r].try + 1);
switch (radius[r].state)
{
case RADIUSCHAP: // sending CHAP down PPP
sendchap(t, s);
break;
case RADIUSIPCP:
sendipcp(t, s); // send IPCP
break;
case RADIUSAUTH: // sending auth to RADIUS server
radiussend(r, RADIUSAUTH);
break;
case RADIUSSTART: // sending start accounting to RADIUS server
radiussend(r, RADIUSSTART);
break;
case RADIUSSTOP: // sending stop accounting to RADIUS server
radiussend(r, RADIUSSTOP);
break;
default:
case RADIUSNULL: // Not in use
case RADIUSWAIT: // waiting timeout before available, in case delayed reply from RADIUS server
// free up RADIUS task
radiusclear(r, s);
log(3, 0, s, session[s].tunnel, "Freeing up radius session %d\n", r);
break;
}
}
void radius_clean()
{
int i;
log(1, 0, 0, 0, "Cleaning radius session array\n");
for (i = 1; i < MAXRADIUS; i++)
{
if (radius[i].retry == 0
|| !session[radius[i].session].opened
|| session[radius[i].session].die
|| session[radius[i].session].tunnel == 0)
radiusclear(i, 0);
}
}
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