// 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 1.25 2004/09/02 04:18:07 fred_nerk Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.31 2004/10/25 15:07:51 bodea Exp $";
#include <arpa/inet.h>
#include <assert.h>
int *radfds = NULL; // RADIUS requests file handles
int ifrfd = -1; // File descriptor for routing, etc
time_t basetime = 0; // base clock
-char hostname[1000] = ""; // us.
+char *hostname = NULL; // us.
int tunidx; // ifr_ifindex of tun device
u32 sessionid = 0; // session id for radius accounting
int syslog_log = 0; // are we logging to syslog
CONFIG("debug", debug, INT),
CONFIG("log_file", log_filename, STRING),
CONFIG("pid_file", pid_file, STRING),
+ CONFIG("hostname", hostname, STRING),
CONFIG("l2tp_secret", l2tpsecret, STRING),
CONFIG("primary_dns", default_dns1, IP),
CONFIG("secondary_dns", default_dns2, IP),
void tunnel_clean();
tunnelidt new_tunnel();
void update_config();
+int unhide_avp(u8 *avp, tunnelidt t, sessionidt s, u16 length);
static void cache_ipmap(ipt ip, int s);
static void uncache_ipmap(ipt ip);
continue;
}
log(4, ntohl(addr->sin_addr.s_addr), s, t, "Hidden AVP\n");
+ // Unhide the AVP
+ n = unhide_avp(b, t, s, n);
+ if (n == 0)
+ {
+ fatal = flags;
+ continue;
+ }
}
if (*b & 0x3C)
{
build_chap_response(b, 2, n, &chapresponse);
}
break;
+ case 13: // Response
+ // Why did they send a response? We never challenge.
+ log(2, ntohl(addr->sin_addr.s_addr), s, t, " received unexpected challenge response\n");
+ break;
+
case 14: // assigned session
asession = session[s].far = ntohs(*(u16 *) (b));
log(4, ntohl(addr->sin_addr.s_addr), s, t, " assigned session = %d\n", asession);
if (++count >= MAX_ACTIONS) break;
}
}
-
- if (config->accounting_dir && next_acct <= TIME)
+ if (*config->accounting_dir && next_acct <= TIME)
{
// Dump accounting data
next_acct = TIME + ACCT_TIME;
}
// Init data structures
-void initdata(void)
+void initdata(int optdebug, char *optconfig)
{
int i;
+ char *p;
- if ((_statistics = shared_malloc(sizeof(struct Tstats))) == MAP_FAILED)
+ if (!(_statistics = shared_malloc(sizeof(struct Tstats))))
{
log(0, 0, 0, 0, "Error doing malloc for _statistics: %s\n", strerror(errno));
exit(1);
}
- if ((config = shared_malloc(sizeof(struct configt))) == MAP_FAILED)
+ if (!(config = shared_malloc(sizeof(struct configt))))
{
log(0, 0, 0, 0, "Error doing malloc for configuration: %s\n", strerror(errno));
exit(1);
}
memset(config, 0, sizeof(struct configt));
time(&config->start_time);
- strncpy(config->config_file, CONFIGFILE, sizeof(config->config_file) - 1);
- if ((tunnel = shared_malloc(sizeof(tunnelt) * MAXTUNNEL)) == MAP_FAILED);
+ config->debug = optdebug;
+ strncpy(config->config_file, optconfig, strlen(optconfig));
+ if (!(tunnel = shared_malloc(sizeof(tunnelt) * MAXTUNNEL)))
{
log(0, 0, 0, 0, "Error doing malloc for tunnels: %s\n", strerror(errno));
exit(1);
}
- if ((session = shared_malloc(sizeof(sessiont) * MAXSESSION)) == MAP_FAILED)
+ if (!(session = shared_malloc(sizeof(sessiont) * MAXSESSION)))
{
log(0, 0, 0, 0, "Error doing malloc for sessions: %s\n", strerror(errno));
exit(1);
}
- if ((sess_count = shared_malloc(sizeof(sessioncountt) * MAXSESSION)) == MAP_FAILED)
+ if (!(sess_count = shared_malloc(sizeof(sessioncountt) * MAXSESSION)))
{
log(0, 0, 0, 0, "Error doing malloc for sessions_count: %s\n", strerror(errno));
exit(1);
}
- if ((radius = shared_malloc(sizeof(radiust) * MAXRADIUS)) == MAP_FAILED)
+ if (!(radius = shared_malloc(sizeof(radiust) * MAXRADIUS)))
{
log(0, 0, 0, 0, "Error doing malloc for radius: %s\n", strerror(errno));
exit(1);
}
- if ((ip_address_pool = shared_malloc(sizeof(ippoolt) * MAXIPPOOL)) == MAP_FAILED)
+ if (!(ip_address_pool = shared_malloc(sizeof(ippoolt) * MAXIPPOOL)))
{
log(0, 0, 0, 0, "Error doing malloc for ip_address_pool: %s\n", strerror(errno));
exit(1);
}
#ifdef RINGBUFFER
- if ((ringbuffer = shared_malloc(sizeof(struct Tringbuffer))) == MAP_FAILED)
+ if (!(ringbuffer = shared_malloc(sizeof(struct Tringbuffer))))
{
log(0, 0, 0, 0, "Error doing malloc for ringbuffer: %s\n", strerror(errno));
exit(1);
memset(ringbuffer, 0, sizeof(struct Tringbuffer));
#endif
- if ((cli_session_actions = shared_malloc(sizeof(struct cli_session_actions) * MAXSESSION))
- == MAP_FAILED)
+ if (!(cli_session_actions = shared_malloc(sizeof(struct cli_session_actions) * MAXSESSION)))
{
log(0, 0, 0, 0, "Error doing malloc for cli session actions: %s\n", strerror(errno));
exit(1);
}
memset(cli_session_actions, 0, sizeof(struct cli_session_actions) * MAXSESSION);
- if ((cli_tunnel_actions = shared_malloc(sizeof(struct cli_tunnel_actions) * MAXSESSION))
- == MAP_FAILED)
+ if (!(cli_tunnel_actions = shared_malloc(sizeof(struct cli_tunnel_actions) * MAXSESSION)))
{
log(0, 0, 0, 0, "Error doing malloc for cli tunnel actions: %s\n", strerror(errno));
exit(1);
for (i = 1; i < MAXTUNNEL- 1; i++)
tunnel[i].state = TUNNELUNDEF; // mark it as not filled in.
- if (!*hostname)
- {
- char *p;
- // Grab my hostname unless it's been specified
- gethostname(hostname, sizeof(hostname));
- if ((p = strchr(hostname, '.'))) *p = 0;
- }
+ // Grab my hostname unless it's been specified
+ gethostname(config->hostname, sizeof(config->hostname));
+ if ((p = strchr(config->hostname, '.'))) *p = 0;
+ hostname = config->hostname;
+
_statistics->start_time = _statistics->last_reset = time(NULL);
#ifdef BGP
- if ((bgp_peers = shared_malloc(sizeof(struct bgp_peer) * BGP_NUM_PEERS)) == MAP_FAILED)
+ if (!(bgp_peers = shared_malloc(sizeof(struct bgp_peer) * BGP_NUM_PEERS)))
{
log(0, 0, 0, 0, "Error doing malloc for bgp: %s\n", strerror(errno));
exit(1);
for (i = 0; i < MAXSESSION; i++)
{
- if (!session[i].opened || !session[i].ip || !session[i].cin || !session[i].cout || !*session[i].user || session[i].walled_garden)
+ if (!session[i].opened || !session[i].ip || (!session[i].cin && !session[i].cout) || !*session[i].user || session[i].walled_garden)
continue;
if (!f)
{
{
int o;
int optdebug = 0;
+ char *optconfig = CONFIGFILE;
_program_name = strdup(argv[0]);
time(&basetime); // start clock
// scan args
- while ((o = getopt(argc, argv, "vc:h:a:")) >= 0)
+ while ((o = getopt(argc, argv, "dvc:h:")) >= 0)
{
switch (o)
{
case 'v':
optdebug++;
break;
+ case 'c':
+ optconfig = optarg;
+ break;
case 'h':
snprintf(hostname, sizeof(hostname), "%s", optarg);
break;
- case '?':
default:
printf("Args are:\n"
"\t-d\tDetach from terminal\n"
initiptables();
initplugins();
- initdata();
-
- config->debug = optdebug;
+ initdata(optdebug, optconfig);
init_tbf();
- init_cli(hostname);
+ init_cli();
read_config_file();
log(0, 0, 0, 0, "L2TPNS version " VERSION "\n");
CSTAT(call_sessionsetup);
-
log(3, session[s].ip, s, t, "Doing session setup for session\n");
if (!session[s].ip || session[s].ip == 0xFFFFFFFE)
log(3, 0, s, t, " No IP allocated. Assigned %s from pool\n",
inet_toa(htonl(session[s].ip)));
else
+ {
log(0, 0, s, t, " No IP allocated. The IP address pool is FULL!\n");
+ sessionshutdown(s, "No IP addresses available");
+ return 0;
+ }
}
cli_print(cli, "%d total sessions open.", count);
return CLI_OK;
}
+
+/* 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.
+ */
+int unhide_avp(u8 *avp, tunnelidt t, sessionidt s, u16 length)
+{
+ MD5_CTX ctx;
+ u8 *cursor;
+ u8 digest[16];
+ u8 working_vector[16];
+ uint16_t hidden_length;
+ u8 type[2];
+ size_t done, todo;
+ u8 *output;
+
+ // Find the AVP type.
+ type[0] = *(avp + 4);
+ type[1] = *(avp + 5);
+
+ // Line up with the hidden data
+ cursor = output = avp + 6;
+
+ // Compute initial pad
+ MD5Init(&ctx);
+ MD5Update(&ctx, type, 2);
+ MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
+ MD5Update(&ctx, session[s].random_vector, session[s].random_vector_length);
+ 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, 0, s, t, "Hidden length %d too long in AVP of length %d\n", (int) hidden_length, (int) length);
+ return 0;
+ }
+
+ /* Decrypt remainder */
+ done = 2;
+ todo = hidden_length;
+ while (todo)
+ {
+ working_vector[done] = *cursor;
+ *output = digest[done] ^ *cursor;
+ ++output;
+ ++cursor;
+ --todo;
+ ++done;
+ if (done == 16 && todo)
+ {
+ // Compute new digest
+ done = 0;
+ MD5Init(&ctx);
+ MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
+ MD5Update(&ctx, &working_vector, 16);
+ MD5Final(digest, &ctx);
+ }
+ }
+
+ return hidden_length + 6;
+}
+
projects / l2tpns.git / blobdiff