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l2tpns/l2tpns.c
bodea d2c470fb4e use LOG for logging macro 
clean up initlcp handling
2004-11-05 04:55:25 +00:00

4150 lines
104 KiB
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// L2TP Network Server
// Adrian Kennard 2002
// Copyright (c) 2003, 2004 Optus Internet Engineering
// 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 1.44 2004/11/05 04:55:27 bodea Exp $";
#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/if_tun.h>
#define SYSLOG_NAMES
#include <syslog.h>
#include <malloc.h>
#include <math.h>
#include <net/route.h>
#include <sys/mman.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/wait.h>
#include <linux/if.h>
#include <stddef.h>
#include <time.h>
#include <dlfcn.h>
#include <unistd.h>
#include <sched.h>
#include <sys/sysinfo.h>
#include <libcli.h>
#include "md5.h"
#include "l2tpns.h"
#include "cluster.h"
#include "plugin.h"
#include "ll.h"
#include "constants.h"
#include "control.h"
#include "util.h"
#include "tbf.h"
// Globals
struct configt *config = NULL; // all configuration
int tunfd = -1; // tun interface file handle. (network device)
int udpfd = -1; // UDP file handle
int controlfd = -1; // Control signal handle
int snoopfd = -1; // UDP file handle for sending out intercept data
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.
int tunidx; // ifr_ifindex of tun device
u32 sessionid = 0; // session id for radius accounting
int syslog_log = 0; // are we logging to syslog
FILE *log_stream = NULL; // file handle for direct logging (i.e. direct into file, not via syslog).
extern int cluster_sockfd; // Intra-cluster communications socket.
u32 last_id = 0; // Last used PPP SID. Can I kill this?? -- mo
int clifd = 0; // Socket listening for CLI connections.
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
static void *ip_hash[256]; // Mapping from IP address to session structures.
u32 udp_tx = 0, udp_rx = 0, udp_rx_pkt = 0; // Global traffic counters.
u32 eth_tx = 0, eth_rx = 0, eth_rx_pkt = 0;
u32 ip_pool_size = 1; // Size of the pool of addresses used for dynamic address allocation.
time_t time_now = 0; // Current time in seconds since epoch.
char time_now_string[64] = {0}; // Current time as a string.
char main_quit = 0; // True if we're in the process of exiting.
char *_program_name = NULL;
linked_list *loaded_plugins;
linked_list *plugins[MAX_PLUGIN_TYPES];
#ifdef BGP
#include "bgp.h"
struct bgp_peer *bgp_peers = 0;
struct bgp_route_list *bgp_routes = 0;
int bgp_configured = 0;
#endif /* BGP */
#define membersize(STRUCT, MEMBER) sizeof(((STRUCT *)0)->MEMBER)
#define CONFIG(NAME, MEMBER, TYPE) { NAME, offsetof(struct configt, MEMBER), membersize(struct configt, MEMBER), TYPE }
struct config_descriptt config_values[] = {
CONFIG("debug", debug, INT),
CONFIG("log_file", log_filename, STRING),
CONFIG("pid_file", pid_file, STRING),
CONFIG("l2tp_secret", l2tpsecret, STRING),
CONFIG("primary_dns", default_dns1, IP),
CONFIG("secondary_dns", default_dns2, IP),
CONFIG("save_state", save_state, BOOL),
CONFIG("primary_radius", radiusserver[0], IP),
CONFIG("secondary_radius", radiusserver[1], IP),
CONFIG("primary_radius_port", radiusport[0], SHORT),
CONFIG("secondary_radius_port", radiusport[1], SHORT),
CONFIG("radius_accounting", radius_accounting, BOOL),
CONFIG("radius_secret", radiussecret, STRING),
CONFIG("bind_address", bind_address, IP),
CONFIG("peer_address", peer_address, IP),
CONFIG("send_garp", send_garp, BOOL),
CONFIG("throttle_speed", rl_rate, UNSIGNED_LONG),
CONFIG("throttle_buckets", num_tbfs, INT),
CONFIG("accounting_dir", accounting_dir, STRING),
CONFIG("setuid", target_uid, INT),
CONFIG("dump_speed", dump_speed, BOOL),
CONFIG("cleanup_interval", cleanup_interval, INT),
CONFIG("multi_read_count", multi_read_count, INT),
CONFIG("scheduler_fifo", scheduler_fifo, BOOL),
CONFIG("lock_pages", lock_pages, BOOL),
CONFIG("icmp_rate", icmp_rate, INT),
CONFIG("cluster_address", cluster_address, IP),
CONFIG("cluster_interface", cluster_interface, STRING),
CONFIG("cluster_hb_interval", cluster_hb_interval, INT),
CONFIG("cluster_hb_timeout", cluster_hb_timeout, INT),
#ifdef BGP
CONFIG("as_number", as_number, SHORT),
CONFIG("bgp_peer1", bgp_peer[0], STRING),
CONFIG("bgp_peer1_as", bgp_peer_as[0], SHORT),
CONFIG("bgp_peer2", bgp_peer[1], STRING),
CONFIG("bgp_peer2_as", bgp_peer_as[1], SHORT),
#endif /* BGP */
{ NULL, 0, 0, 0 },
};
char *plugin_functions[] = {
NULL,
"plugin_pre_auth",
"plugin_post_auth",
"plugin_packet_rx",
"plugin_packet_tx",
"plugin_timer",
"plugin_new_session",
"plugin_kill_session",
"plugin_control",
"plugin_radius_response",
"plugin_become_master",
"plugin_new_session_master",
};
#define max_plugin_functions (sizeof(plugin_functions) / sizeof(char *))
tunnelt *tunnel = NULL; // Array of tunnel structures.
sessiont *session = NULL; // Array of session structures.
sessioncountt *sess_count = NULL; // Array of partial per-session traffic counters.
radiust *radius = NULL; // Array of radius structures.
ippoolt *ip_address_pool = NULL; // Array of dynamic IP addresses.
controlt *controlfree = 0;
struct Tstats *_statistics = NULL;
#ifdef RINGBUFFER
struct Tringbuffer *ringbuffer = NULL;
#endif
void sigalrm_handler(int);
void sighup_handler(int);
void sigterm_handler(int);
void sigquit_handler(int);
void sigchild_handler(int);
void read_config_file();
void read_state();
void dump_state();
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);
// return internal time (10ths since process startup)
clockt now(void)
{
struct timeval t;
gettimeofday(&t, 0);
return (t.tv_sec - basetime) * 10 + t.tv_usec / 100000 + 1;
}
// work out a retry time based on try number
// This is a straight bounded exponential backoff.
// Maximum re-try time is 32 seconds. (2^5).
clockt backoff(u8 try)
{
if (try > 5) try = 5; // max backoff
return now() + 10 * (1 << try);
}
//
// Log a debug message. Typically called vias LOG macro
//
void _log(int level, ipt address, sessionidt s, tunnelidt t, const char *format, ...)
{
static char message[65536] = {0};
static char message2[65536] = {0};
va_list ap;
#ifdef RINGBUFFER
if (ringbuffer)
{
if (++ringbuffer->tail >= RINGBUFFER_SIZE)
ringbuffer->tail = 0;
if (ringbuffer->tail == ringbuffer->head)
if (++ringbuffer->head >= RINGBUFFER_SIZE)
ringbuffer->head = 0;
ringbuffer->buffer[ringbuffer->tail].level = level;
ringbuffer->buffer[ringbuffer->tail].address = address;
ringbuffer->buffer[ringbuffer->tail].session = s;
ringbuffer->buffer[ringbuffer->tail].tunnel = t;
va_start(ap, format);
vsnprintf(ringbuffer->buffer[ringbuffer->tail].message, 4095, format, ap);
va_end(ap);
}
#endif
if (config->debug < level) return;
va_start(ap, format);
if (log_stream)
{
vsnprintf(message2, 65535, format, ap);
snprintf(message, 65535, "%s %02d/%02d %s", time_now_string, t, s, message2);
fprintf(log_stream, "%s", message);
}
else if (syslog_log)
{
vsnprintf(message2, 65535, format, ap);
snprintf(message, 65535, "%02d/%02d %s", t, s, message2);
syslog(level + 2, message); // We don't need LOG_EMERG or LOG_ALERT
}
va_end(ap);
}
void _log_hex(int level, const char *title, const char *data, int maxsize)
{
int i, j;
const u8 *d = (const u8 *)data;
if (config->debug < level) return;
// No support for _log_hex to syslog
if (log_stream)
{
_log(level, 0, 0, 0, "%s (%d bytes):\n", title, maxsize);
setvbuf(log_stream, NULL, _IOFBF, 16384);
for (i = 0; i < maxsize; )
{
fprintf(log_stream, "%4X: ", i);
for (j = i; j < maxsize && j < (i + 16); j++)
{
fprintf(log_stream, "%02X ", d[j]);
if (j == i + 7)
fputs(": ", log_stream);
}
for (; j < i + 16; j++)
{
fputs(" ", log_stream);
if (j == i + 7)
fputs(": ", log_stream);
}
fputs(" ", log_stream);
for (j = i; j < maxsize && j < (i + 16); j++)
{
if (d[j] >= 0x20 && d[j] < 0x7f && d[j] != 0x20)
fputc(d[j], log_stream);
else
fputc('.', log_stream);
if (j == i + 7)
fputs(" ", log_stream);
}
i = j;
fputs("\n", log_stream);
}
fflush(log_stream);
setbuf(log_stream, NULL);
}
}
// Add a route
//
// This adds it to the routing table, advertises it
// via iBGP if enabled, and stuffs it into the
// 'sessionbyip' cache.
//
// 'ip' and 'mask' must be in _host_ order.
//
void routeset(sessionidt s, ipt ip, ipt mask, ipt gw, u8 add)
{
struct rtentry r;
int i;
if (!mask) mask = 0xffffffff;
ip &= mask; // Force the ip to be the first one in the route.
memset(&r, 0, sizeof(r));
r.rt_dev = config->tundevice;
r.rt_dst.sa_family = AF_INET;
*(u32 *) & (((struct sockaddr_in *) &r.rt_dst)->sin_addr.s_addr) = htonl(ip);
r.rt_gateway.sa_family = AF_INET;
*(u32 *) & (((struct sockaddr_in *) &r.rt_gateway)->sin_addr.s_addr) = htonl(gw);
r.rt_genmask.sa_family = AF_INET;
*(u32 *) & (((struct sockaddr_in *) &r.rt_genmask)->sin_addr.s_addr) = htonl(mask);
r.rt_flags = (RTF_UP | RTF_STATIC);
if (gw)
r.rt_flags |= RTF_GATEWAY;
else if (mask == 0xffffffff)
r.rt_flags |= RTF_HOST;
LOG(1, ip, 0, 0, "Route %s %u.%u.%u.%u/%u.%u.%u.%u %u.%u.%u.%u\n",
add ? "add" : "del",
ip >> 24, ip >> 16 & 0xff, ip >> 8 & 0xff, ip & 0xff,
mask >> 24, mask >> 16 & 0xff, mask >> 8 & 0xff, mask & 0xff,
gw >> 24, gw >> 16 & 0xff, gw >> 8 & 0xff, gw & 0xff);
if (ioctl(ifrfd, add ? SIOCADDRT : SIOCDELRT, (void *) &r) < 0)
LOG(0, 0, 0, 0, "routeset() error in ioctl: %s\n", strerror(errno));
#ifdef BGP
if (add)
bgp_add_route(htonl(ip), htonl(mask));
else
bgp_del_route(htonl(ip), htonl(mask));
#endif /* BGP */
// Add/Remove the IPs to the 'sessionbyip' cache.
// Note that we add the zero address in the case of
// a network route. Roll on CIDR.
// Note that 's == 0' implies this is the address pool.
// We still cache it here, because it will pre-fill
// the malloc'ed tree.
if (s)
{
if (!add) // Are we deleting a route?
s = 0; // Caching the session as '0' is the same as uncaching.
for (i = ip; (i&mask) == (ip&mask) ; ++i)
cache_ipmap(i, s);
}
}
//
// Set up TUN interface
void inittun(void)
{
struct ifreq ifr;
struct sockaddr_in sin = {0};
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TUN;
tunfd = open(TUNDEVICE, O_RDWR);
if (tunfd < 0)
{ // fatal
LOG(0, 0, 0, 0, "Can't open %s: %s\n", TUNDEVICE, strerror(errno));
exit(1);
}
{
int flags = fcntl(tunfd, F_GETFL, 0);
fcntl(tunfd, F_SETFL, flags | O_NONBLOCK);
}
if (ioctl(tunfd, TUNSETIFF, (void *) &ifr) < 0)
{
LOG(0, 0, 0, 0, "Can't set tun interface: %s\n", strerror(errno));
exit(1);
}
assert(strlen(ifr.ifr_name) < sizeof(config->tundevice));
strncpy(config->tundevice, ifr.ifr_name, sizeof(config->tundevice) - 1);
ifrfd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = config->bind_address ? config->bind_address : 0x01010101; // 1.1.1.1
memcpy(&ifr.ifr_addr, &sin, sizeof(struct sockaddr));
if (ioctl(ifrfd, SIOCSIFADDR, (void *) &ifr) < 0)
{
LOG(0, 0, 0, 0, "Error setting tun address: %s\n", strerror(errno));
exit(1);
}
/* Bump up the qlen to deal with bursts from the network */
ifr.ifr_qlen = 1000;
if (ioctl(ifrfd, SIOCSIFTXQLEN, (void *) &ifr) < 0)
{
LOG(0, 0, 0, 0, "Error setting tun queue length: %s\n", strerror(errno));
exit(1);
}
ifr.ifr_flags = IFF_UP;
if (ioctl(ifrfd, SIOCSIFFLAGS, (void *) &ifr) < 0)
{
LOG(0, 0, 0, 0, "Error setting tun flags: %s\n", strerror(errno));
exit(1);
}
if (ioctl(ifrfd, SIOCGIFINDEX, (void *) &ifr) < 0)
{
LOG(0, 0, 0, 0, "Error setting tun ifindex: %s\n", strerror(errno));
exit(1);
}
tunidx = ifr.ifr_ifindex;
}
// set up UDP port
void initudp(void)
{
int on = 1;
struct sockaddr_in addr;
// Tunnel
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(L2TPPORT);
addr.sin_addr.s_addr = config->bind_address;
udpfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
setsockopt(udpfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
{
int flags = fcntl(udpfd, F_GETFL, 0);
fcntl(udpfd, F_SETFL, flags | O_NONBLOCK);
}
if (bind(udpfd, (void *) &addr, sizeof(addr)) < 0)
{
LOG(0, 0, 0, 0, "Error in UDP bind: %s\n", strerror(errno));
exit(1);
}
snoopfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
// Control
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(1702);
controlfd = socket(AF_INET, SOCK_DGRAM, 17);
setsockopt(controlfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
if (bind(controlfd, (void *) &addr, sizeof(addr)) < 0)
{
LOG(0, 0, 0, 0, "Error in control bind: %s\n", strerror(errno));
exit(1);
}
}
//
// Find session by IP, < 1 for not found
//
// Confusingly enough, this 'ip' must be
// in _network_ order. This being the common
// case when looking it up from IP packet headers.
//
// We actually use this cache for two things.
// #1. For used IP addresses, this maps to the
// session ID that it's used by.
// #2. For un-used IP addresses, this maps to the
// index into the pool table that contains that
// IP address.
//
int lookup_ipmap(ipt ip)
{
u8 *a = (u8 *)&ip;
char **d = (char **) ip_hash;
int s;
if (!(d = (char **) d[(size_t) *a++])) return 0;
if (!(d = (char **) d[(size_t) *a++])) return 0;
if (!(d = (char **) d[(size_t) *a++])) return 0;
s = (ipt) d[(size_t) *a];
return s;
}
sessionidt sessionbyip(ipt ip)
{
int s = lookup_ipmap(ip);
CSTAT(call_sessionbyip);
if (s > 0 && s < MAXSESSION && session[s].tunnel)
return s;
return 0;
}
//
// Take an IP address in HOST byte order and
// add it to the sessionid by IP cache.
//
// (It's actually cached in network order)
//
static void cache_ipmap(ipt ip, int s)
{
ipt nip = htonl(ip); // MUST be in network order. I.e. MSB must in be ((char*)(&ip))[0]
u8 *a = (u8 *) &nip;
char **d = (char **) ip_hash;
int i;
for (i = 0; i < 3; i++)
{
if (!d[(size_t) a[i]])
{
if (!(d[(size_t) a[i]] = calloc(256, sizeof (void *))))
return;
}
d = (char **) d[(size_t) a[i]];
}
d[(size_t) a[3]] = (char *)((int)s);
if (s > 0)
LOG(4, ip, s, session[s].tunnel, "Caching ip address %s\n", inet_toa(nip));
else if (s == 0)
LOG(4, ip, 0, 0, "Un-caching ip address %s\n", inet_toa(nip));
// else a map to an ip pool index.
}
static void uncache_ipmap(ipt ip)
{
cache_ipmap(ip, 0); // Assign it to the NULL session.
}
//
// CLI list to dump current ipcache.
//
int cmd_show_ipcache(struct cli_def *cli, char *command, char **argv, int argc)
{
char **d = (char **) ip_hash, **e, **f, **g;
int i, j, k, l;
int count = 0;
if (CLI_HELP_REQUESTED)
return CLI_HELP_NO_ARGS;
cli_print(cli, "%7s %s", "Sess#", "IP Address");
for (i = 0; i < 256; ++i)
{
if (!d[i])
continue;
e = (char**) d[i];
for (j = 0; j < 256; ++j)
{
if (!e[j])
continue;
f = (char**) e[j];
for (k = 0; k < 256; ++k)
{
if (!f[k])
continue;
g = (char**)f[k];
for (l = 0; l < 256; ++l)
{
if (!g[l])
continue;
cli_print(cli, "%7d %d.%d.%d.%d", (int) g[l], i, j, k, l);
++count;
}
}
}
}
cli_print(cli, "%d entries in cache", count);
return CLI_OK;
}
// Find session by username, 0 for not found
// walled garden users aren't authenticated, so the username is
// reasonably useless. Ignore them to avoid incorrect actions
//
// This is VERY inefficent. Don't call it often. :)
//
sessionidt sessionbyuser(char *username)
{
int s;
CSTAT(call_sessionbyuser);
for (s = 1; s < MAXSESSION ; ++s)
{
if (session[s].walled_garden)
continue; // Skip walled garden users.
if (!strncmp(session[s].user, username, 128))
return s;
}
return 0; // Not found.
}
void send_garp(ipt ip)
{
int s;
struct ifreq ifr;
u8 mac[6];
s = socket(PF_INET, SOCK_DGRAM, 0);
if (s < 0)
{
LOG(0, 0, 0, 0, "Error creating socket for GARP: %s\n", strerror(errno));
return;
}
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, "eth0", sizeof(ifr.ifr_name) - 1);
if (ioctl(s, SIOCGIFHWADDR, &ifr) < 0)
{
LOG(0, 0, 0, 0, "Error getting eth0 hardware address for GARP: %s\n", strerror(errno));
close(s);
return;
}
memcpy(mac, &ifr.ifr_hwaddr.sa_data, 6*sizeof(char));
if (ioctl(s, SIOCGIFINDEX, &ifr) < 0)
{
LOG(0, 0, 0, 0, "Error getting eth0 interface index for GARP: %s\n", strerror(errno));
close(s);
return;
}
close(s);
sendarp(ifr.ifr_ifindex, mac, ip);
}
// Find session by username, 0 for not found
sessiont *sessiontbysessionidt(sessionidt s)
{
if (!s || s > MAXSESSION) return NULL;
return &session[s];
}
sessionidt sessionidtbysessiont(sessiont *s)
{
sessionidt val = s-session;
if (s < session || val > MAXSESSION) return 0;
return val;
}
// actually send a control message for a specific tunnel
void tunnelsend(u8 * buf, u16 l, tunnelidt t)
{
struct sockaddr_in addr;
CSTAT(call_tunnelsend);
if (!t)
{
static int backtrace_count = 0;
LOG(0, 0, 0, t, "tunnelsend called with 0 as tunnel id\n");
STAT(tunnel_tx_errors);
log_backtrace(backtrace_count, 5)
return;
}
if (!tunnel[t].ip)
{
static int backtrace_count = 0;
LOG(1, 0, 0, t, "Error sending data out tunnel: no remote endpoint (tunnel not set up)\n");
log_backtrace(backtrace_count, 5)
STAT(tunnel_tx_errors);
return;
}
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
*(u32 *) & addr.sin_addr = htonl(tunnel[t].ip);
addr.sin_port = htons(tunnel[t].port);
// sequence expected, if sequence in message
if (*buf & 0x08) *(u16 *) (buf + ((*buf & 0x40) ? 10 : 8)) = htons(tunnel[t].nr);
// If this is a control message, deal with retries
if (*buf & 0x80)
{
tunnel[t].last = time_now; // control message sent
tunnel[t].retry = backoff(tunnel[t].try); // when to resend
if (tunnel[t].try > 1)
{
STAT(tunnel_retries);
LOG(3, tunnel[t].ip, 0, t, "Control message resend try %d\n", tunnel[t].try);
}
}
if (sendto(udpfd, buf, l, 0, (void *) &addr, sizeof(addr)) < 0)
{
LOG(0, tunnel[t].ip, ntohs((*(u16 *) (buf + 6))), t, "Error sending data out tunnel: %s (udpfd=%d, buf=%p, len=%d, dest=%s)\n",
strerror(errno), udpfd, buf, l, inet_ntoa(addr.sin_addr));
STAT(tunnel_tx_errors);
return;
}
LOG_HEX(5, "Send Tunnel Data", buf, l);
STAT(tunnel_tx_packets);
INC_STAT(tunnel_tx_bytes, l);
}
//
// Tiny helper function to write data to
// the 'tun' device.
//
int tun_write(u8 * data, int size)
{
return write(tunfd, data, size);
}
// process outgoing (to tunnel) IP
//
void processipout(u8 * buf, int len)
{
sessionidt s;
sessiont *sp;
tunnelidt t;
ipt ip;
char * data = buf; // Keep a copy of the originals.
int size = len;
u8 b[MAXETHER + 20];
CSTAT(call_processipout);
if (len < MIN_IP_SIZE)
{
LOG(1, 0, 0, 0, "Short IP, %d bytes\n", len);
STAT(tunnel_tx_errors);
return;
}
if (len >= MAXETHER)
{
LOG(1, 0, 0, 0, "Oversize IP packet %d bytes\n", len);
STAT(tunnel_tx_errors);
return;
}
// Skip the tun header
buf += 4;
len -= 4;
// Got an IP header now
if (*(u8 *)(buf) >> 4 != 4)
{
LOG(1, 0, 0, 0, "IP: Don't understand anything except IPv4\n");
return;
}
ip = *(u32 *)(buf + 16);
if (!(s = sessionbyip(ip)))
{
// Is this a packet for a session that doesn't exist?
static int rate = 0; // Number of ICMP packets we've sent this second.
static int last = 0; // Last time we reset the ICMP packet counter 'rate'.
if (last != time_now)
{
last = time_now;
rate = 0;
}
if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
{
LOG(4, 0, 0, 0, "IP: Sending ICMP host unreachable to %s\n", inet_toa(*(u32 *)(buf + 12)));
host_unreachable(*(u32 *)(buf + 12), *(u16 *)(buf + 4), ip, buf, (len < 64) ? 64 : len);
}
return;
}
t = session[s].tunnel;
sp = &session[s];
if (sp->tbf_out)
{
// Are we throttling this session?
if (config->cluster_iam_master)
tbf_queue_packet(sp->tbf_out, data, size);
else
master_throttle_packet(sp->tbf_out, data, size);
return;
}
else if (sp->walled_garden && !config->cluster_iam_master)
{
// We are walled-gardening this
master_garden_packet(s, data, size);
return;
}
// Snooping this session, send it to intercept box
if (sp->snoop_ip && sp->snoop_port)
snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
LOG(5, session[s].ip, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
// Add on L2TP header
{
u8 *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIP);
if (!p)
{
LOG(3, session[s].ip, s, t, "failed to send packet in processipout.\n");
return;
}
tunnelsend(b, len + (p-b), t); // send it...
}
sp->cout += len; // byte count
sp->total_cout += len; // byte count
sp->pout++;
udp_tx += len;
sess_count[s].cout += len; // To send to master..
}
//
// Helper routine for the TBF filters.
// Used to send queued data in to the user!
//
void send_ipout(sessionidt s, u8 *buf, int len)
{
sessiont *sp;
tunnelidt t;
ipt ip;
u8 b[MAXETHER + 20];
if (len < 0 || len > MAXETHER)
{
LOG(1,0,0,0, "Odd size IP packet: %d bytes\n", len);
return;
}
// Skip the tun header
buf += 4;
len -= 4;
ip = *(u32 *)(buf + 16);
if (!session[s].ip)
return;
t = session[s].tunnel;
sp = &session[s];
LOG(5, session[s].ip, s, t, "Ethernet -> Tunnel (%d bytes)\n", len);
// Snooping this session.
if (sp->snoop_ip && sp->snoop_port)
snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
// Add on L2TP header
{
u8 *p = makeppp(b, sizeof(b), buf, len, t, s, PPPIP);
if (!p)
{
LOG(3, session[s].ip, s, t, "failed to send packet in send_ipout.\n");
return;
}
tunnelsend(b, len + (p-b), t); // send it...
}
sp->cout += len; // byte count
sp->total_cout += len; // byte count
sp->pout++;
udp_tx += len;
sess_count[s].cout += len; // To send to master..
}
// add an AVP (16 bit)
void control16(controlt * c, u16 avp, u16 val, u8 m)
{
u16 l = (m ? 0x8008 : 0x0008);
*(u16 *) (c->buf + c->length + 0) = htons(l);
*(u16 *) (c->buf + c->length + 2) = htons(0);
*(u16 *) (c->buf + c->length + 4) = htons(avp);
*(u16 *) (c->buf + c->length + 6) = htons(val);
c->length += 8;
}
// add an AVP (32 bit)
void control32(controlt * c, u16 avp, u32 val, u8 m)
{
u16 l = (m ? 0x800A : 0x000A);
*(u16 *) (c->buf + c->length + 0) = htons(l);
*(u16 *) (c->buf + c->length + 2) = htons(0);
*(u16 *) (c->buf + c->length + 4) = htons(avp);
*(u32 *) (c->buf + c->length + 6) = htonl(val);
c->length += 10;
}
// add an AVP (32 bit)
void controls(controlt * c, u16 avp, char *val, u8 m)
{
u16 l = ((m ? 0x8000 : 0) + strlen(val) + 6);
*(u16 *) (c->buf + c->length + 0) = htons(l);
*(u16 *) (c->buf + c->length + 2) = htons(0);
*(u16 *) (c->buf + c->length + 4) = htons(avp);
memcpy(c->buf + c->length + 6, val, strlen(val));
c->length += 6 + strlen(val);
}
// add a binary AVP
void controlb(controlt * c, u16 avp, char *val, unsigned int len, u8 m)
{
u16 l = ((m ? 0x8000 : 0) + len + 6);
*(u16 *) (c->buf + c->length + 0) = htons(l);
*(u16 *) (c->buf + c->length + 2) = htons(0);
*(u16 *) (c->buf + c->length + 4) = htons(avp);
memcpy(c->buf + c->length + 6, val, len);
c->length += 6 + len;
}
// new control connection
controlt *controlnew(u16 mtype)
{
controlt *c;
if (!controlfree)
c = malloc(sizeof(controlt));
else
{
c = controlfree;
controlfree = c->next;
}
assert(c);
c->next = 0;
*(u16 *) (c->buf + 0) = htons(0xC802); // flags/ver
c->length = 12;
control16(c, 0, mtype, 1);
return c;
}
// send zero block if nothing is waiting
// (ZLB send).
void controlnull(tunnelidt t)
{
u8 buf[12];
if (tunnel[t].controlc) // Messages queued; They will carry the ack.
return;
*(u16 *) (buf + 0) = htons(0xC802); // flags/ver
*(u16 *) (buf + 2) = htons(12); // length
*(u16 *) (buf + 4) = htons(tunnel[t].far); // tunnel
*(u16 *) (buf + 6) = htons(0); // session
*(u16 *) (buf + 8) = htons(tunnel[t].ns); // sequence
*(u16 *) (buf + 10) = htons(tunnel[t].nr); // sequence
tunnelsend(buf, 12, t);
}
// add a control message to a tunnel, and send if within window
void controladd(controlt * c, tunnelidt t, sessionidt s)
{
*(u16 *) (c->buf + 2) = htons(c->length); // length
*(u16 *) (c->buf + 4) = htons(tunnel[t].far); // tunnel
*(u16 *) (c->buf + 6) = htons(s ? session[s].far : 0); // session
*(u16 *) (c->buf + 8) = htons(tunnel[t].ns); // sequence
tunnel[t].ns++; // advance sequence
// link in message in to queue
if (tunnel[t].controlc)
tunnel[t].controle->next = c;
else
tunnel[t].controls = c;
tunnel[t].controle = c;
tunnel[t].controlc++;
// send now if space in window
if (tunnel[t].controlc <= tunnel[t].window)
{
tunnel[t].try = 0; // first send
tunnelsend(c->buf, c->length, t);
}
}
//
// Throttle or Unthrottle a session
//
// Throttle the data from/to through a session to no more than
// 'rate_in' kbit/sec in (from user) or 'rate_out' kbit/sec out (to
// user).
//
// If either value is -1, the current value is retained for that
// direction.
//
void throttle_session(sessionidt s, int rate_in, int rate_out)
{
if (!session[s].tunnel)
return; // No-one home.
if (!*session[s].user)
return; // User not logged in
if (rate_in >= 0)
{
int bytes = rate_in * 1024 / 8; // kbits to bytes
if (session[s].tbf_in)
free_tbf(session[s].tbf_in);
if (rate_in > 0)
session[s].tbf_in = new_tbf(s, bytes * 2, bytes, send_ipin);
else
session[s].tbf_in = 0;
session[s].throttle_in = rate_in;
}
if (rate_out >= 0)
{
int bytes = rate_out * 1024 / 8;
if (session[s].tbf_out)
free_tbf(session[s].tbf_out);
if (rate_out > 0)
session[s].tbf_out = new_tbf(s, bytes * 2, bytes, send_ipout);
else
session[s].tbf_out = 0;
session[s].throttle_out = rate_out;
}
}
// start tidy shutdown of session
void sessionshutdown(sessionidt s, char *reason)
{
int dead = session[s].die;
int walled_garden = session[s].walled_garden;
CSTAT(call_sessionshutdown);
if (!session[s].tunnel)
{
LOG(3, session[s].ip, s, session[s].tunnel, "Called sessionshutdown on a session with no tunnel.\n");
return; // not a live session
}
if (!dead)
LOG(2, 0, s, session[s].tunnel, "Shutting down session %d: %s\n", s, reason);
session[s].die = now() + 150; // Clean up in 15 seconds
{
struct param_kill_session data = { &tunnel[session[s].tunnel], &session[s] };
run_plugins(PLUGIN_KILL_SESSION, &data);
}
// RADIUS Stop message
if (session[s].opened && !walled_garden && !dead)
{
u16 r = session[s].radius;
if (!r)
{
if (!(r = radiusnew(s)))
{
LOG(1, 0, s, session[s].tunnel, "No free RADIUS sessions for Stop message\n");
STAT(radius_overflow);
}
else
{
int n;
for (n = 0; n < 15; n++)
radius[r].auth[n] = rand();
}
}
if (r && radius[r].state != RADIUSSTOP)
radiussend(r, RADIUSSTOP); // stop, if not already trying
}
if (session[s].ip)
{ // IP allocated, clear and unroute
int r;
for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
{
routeset(s, session[s].route[r].ip, session[s].route[r].mask, session[s].ip, 0);
session[s].route[r].ip = 0;
}
if (session[s].ip_pool_index == -1) // static ip
{
routeset(s, session[s].ip, 0, 0, 0); // Delete route.
session[s].ip = 0;
}
else
free_ip_address(s);
}
if (session[s].throttle_in || session[s].throttle_out) // Unthrottle if throttled.
throttle_session(s, 0, 0);
{ // Send CDN
controlt *c = controlnew(14); // sending CDN
control16(c, 1, 3, 1); // result code (admin reasons - TBA make error, general error, add message
control16(c, 14, s, 1); // assigned session (our end)
controladd(c, session[s].tunnel, s); // send the message
}
cluster_send_session(s);
}
void sendipcp(tunnelidt t, sessionidt s)
{
u8 buf[MAXCONTROL];
u16 r = session[s].radius;
u8 *q;
CSTAT(call_sendipcp);
if (!r)
r = radiusnew(s);
if (radius[r].state != RADIUSIPCP)
{
radius[r].state = RADIUSIPCP;
radius[r].try = 0;
}
radius[r].retry = backoff(radius[r].try++);
if (radius[r].try > 10)
{
radiusclear(r, s); // Clear radius session.
sessionshutdown(s, "No reply on IPCP");
return;
}
q = makeppp(buf,sizeof(buf), 0, 0, t, s, PPPIPCP);
if (!q)
{
LOG(3, session[s].ip, s, t, "failed to send packet in sendipcp.\n");
return;
}
*q = ConfigReq;
q[1] = r << RADIUS_SHIFT; // ID, dont care, we only send one type of request
*(u16 *) (q + 2) = htons(10);
q[4] = 3;
q[5] = 6;
*(u32 *) (q + 6) = config->peer_address ? config->peer_address :
config->bind_address ? config->bind_address :
my_address; // send my IP
tunnelsend(buf, 10 + (q - buf), t); // send it
session[s].flags &= ~SF_IPCP_ACKED; // Clear flag.
}
// kill a session now
void sessionkill(sessionidt s, char *reason)
{
CSTAT(call_sessionkill);
session[s].die = now();
sessionshutdown(s, reason); // close radius/routes, etc.
if (session[s].radius)
radiusclear(session[s].radius, s); // cant send clean accounting data, session is killed
LOG(2, 0, s, session[s].tunnel, "Kill session %d (%s): %s\n", s, session[s].user, reason);
memset(&session[s], 0, sizeof(session[s]));
session[s].tunnel = T_FREE; // Mark it as free.
session[s].next = sessionfree;
sessionfree = s;
cli_session_actions[s].action = 0;
cluster_send_session(s);
}
// kill a tunnel now
void tunnelkill(tunnelidt t, char *reason)
{
sessionidt s;
controlt *c;
CSTAT(call_tunnelkill);
tunnel[t].state = TUNNELDIE;
// free control messages
while ((c = tunnel[t].controls))
{
controlt * n = c->next;
tunnel[t].controls = n;
tunnel[t].controlc--;
c->next = controlfree;
controlfree = c;
}
// kill sessions
for (s = 1; s < MAXSESSION; s++)
if (session[s].tunnel == t)
sessionkill(s, reason);
// free tunnel
tunnelclear(t);
LOG(1, 0, 0, t, "Kill tunnel %d: %s\n", t, reason);
cli_tunnel_actions[s].action = 0;
cluster_send_tunnel(t);
}
// shut down a tunnel cleanly
void tunnelshutdown(tunnelidt t, char *reason)
{
sessionidt s;
CSTAT(call_tunnelshutdown);
if (!tunnel[t].last || !tunnel[t].far || tunnel[t].state == TUNNELFREE)
{
// never set up, can immediately kill
tunnelkill(t, reason);
return;
}
LOG(1, 0, 0, t, "Shutting down tunnel %d (%s)\n", t, reason);
// close session
for (s = 1; s < MAXSESSION; s++)
if (session[s].tunnel == t)
sessionkill(s, reason);
tunnel[t].state = TUNNELDIE;
tunnel[t].die = now() + 700; // Clean up in 70 seconds
cluster_send_tunnel(t);
// TBA - should we wait for sessions to stop?
{ // Send StopCCN
controlt *c = controlnew(4); // sending StopCCN
control16(c, 1, 1, 1); // result code (admin reasons - TBA make error, general error, add message
control16(c, 9, t, 1); // assigned tunnel (our end)
controladd(c, t, 0); // send the message
}
}
// read and process packet on tunnel (UDP)
void processudp(u8 * buf, int len, struct sockaddr_in *addr)
{
char *chapresponse = NULL;
u16 l = len, t = 0, s = 0, ns = 0, nr = 0;
u8 *p = buf + 2;
CSTAT(call_processudp);
udp_rx += len;
udp_rx_pkt++;
LOG_HEX(5, "UDP Data", buf, len);
STAT(tunnel_rx_packets);
INC_STAT(tunnel_rx_bytes, len);
if (len < 6)
{
LOG(1, ntohl(addr->sin_addr.s_addr), 0, 0, "Short UDP, %d bytes\n", len);
STAT(tunnel_rx_errors);
return;
}
if ((buf[1] & 0x0F) != 2)
{
LOG(1, ntohl(addr->sin_addr.s_addr), 0, 0, "Bad L2TP ver %d\n", (buf[1] & 0x0F) != 2);
STAT(tunnel_rx_errors);
return;
}
if (*buf & 0x40)
{ // length
l = ntohs(*(u16 *) p);
p += 2;
}
t = ntohs(*(u16 *) p);
p += 2;
s = ntohs(*(u16 *) p);
p += 2;
if (s >= MAXSESSION)
{
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Received UDP packet with invalid session ID\n");
STAT(tunnel_rx_errors);
return;
}
if (t >= MAXTUNNEL)
{
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Received UDP packet with invalid tunnel ID\n");
STAT(tunnel_rx_errors);
return;
}
if (*buf & 0x08)
{ // ns/nr
ns = ntohs(*(u16 *) p);
p += 2;
nr = ntohs(*(u16 *) p);
p += 2;
}
if (*buf & 0x02)
{ // offset
u16 o = ntohs(*(u16 *) p);
p += o + 2;
}
if ((p - buf) > l)
{
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Bad length %d>%d\n", (p - buf), l);
STAT(tunnel_rx_errors);
return;
}
l -= (p - buf);
if (*buf & 0x80)
{ // control
u16 message = 0xFFFF; // message type
u8 fatal = 0;
u8 mandatorymessage = 0;
u8 chap = 0; // if CHAP being used
u16 asession = 0; // assigned session
u32 amagic = 0; // magic number
u8 aflags = 0; // flags from last LCF
u16 version = 0x0100; // protocol version (we handle 0.0 as well and send that back just in case)
int requestchap = 0; // do we request PAP instead of original CHAP request?
char called[MAXTEL] = ""; // called number
char calling[MAXTEL] = ""; // calling number
if (!config->cluster_iam_master)
{
master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
return;
}
if ((*buf & 0xCA) != 0xC8)
{
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Bad control header %02X\n", *buf);
STAT(tunnel_rx_errors);
return;
}
LOG(3, ntohl(addr->sin_addr.s_addr), s, t, "Control message (%d bytes): (unacked %d) l-ns %d l-nr %d r-ns %d r-nr %d\n",
l, tunnel[t].controlc, tunnel[t].ns, tunnel[t].nr, ns, nr);
// if no tunnel specified, assign one
if (!t)
{
int i;
//
// Is this a duplicate of the first packet? (SCCRQ)
//
for (i = 1; i <= config->cluster_highest_tunnelid ; ++i)
{
if (tunnel[i].state != TUNNELOPENING ||
tunnel[i].ip != ntohl(*(ipt *) & addr->sin_addr) ||
tunnel[i].port != ntohs(addr->sin_port) )
continue;
t = i;
break;
}
}
if (!t)
{
if (!(t = new_tunnel()))
{
LOG(1, ntohl(addr->sin_addr.s_addr), 0, 0, "No more tunnels\n");
STAT(tunnel_overflow);
return;
}
tunnelclear(t);
tunnel[t].ip = ntohl(*(ipt *) & addr->sin_addr);
tunnel[t].port = ntohs(addr->sin_port);
tunnel[t].window = 4; // default window
LOG(1, ntohl(addr->sin_addr.s_addr), 0, t, " New tunnel from %u.%u.%u.%u/%u ID %d\n", tunnel[t].ip >> 24, tunnel[t].ip >> 16 & 255, tunnel[t].ip >> 8 & 255, tunnel[t].ip & 255, tunnel[t].port, t);
STAT(tunnel_created);
}
// 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
// some to clear maybe?
while (tunnel[t].controlc && (((tunnel[t].ns - tunnel[t].controlc) - nr) & 0x8000))
{
controlt *c = tunnel[t].controls;
tunnel[t].controls = c->next;
tunnel[t].controlc--;
c->next = controlfree;
controlfree = c;
skip--;
tunnel[t].try = 0; // we have progress
}
// If the 'ns' just received is not the 'nr' we're
// expecting, just send an ack and drop it.
//
// if 'ns' is less, then we got a retransmitted packet.
// if 'ns' is greater than missed a packet. Either way
// we should ignore it.
if (ns != tunnel[t].nr)
{
// is this the sequence we were expecting?
LOG(1, ntohl(addr->sin_addr.s_addr), 0, t, " Out of sequence tunnel %d, (%d is not the expected %d)\n", t, ns, tunnel[t].nr);
STAT(tunnel_rx_errors);
if (l) // Is this not a ZLB?
controlnull(t);
return;
}
// receiver advance (do here so quoted correctly in any sends below)
if (l) tunnel[t].nr = (ns + 1);
if (skip < 0) skip = 0;
if (skip < tunnel[t].controlc)
{
// some control packets can now be sent that were previous stuck out of window
int tosend = tunnel[t].window - skip;
controlt *c = tunnel[t].controls;
while (c && skip)
{
c = c->next;
skip--;
}
while (c && tosend)
{
tunnel[t].try = 0; // first send
tunnelsend(c->buf, c->length, t);
c = c->next;
tosend--;
}
}
if (!tunnel[t].controlc)
tunnel[t].retry = 0; // caught up
}
if (l)
{ // if not a null message
// process AVPs
while (l && !(fatal & 0x80))
{
u16 n = (ntohs(*(u16 *) p) & 0x3FF);
u8 *b = p;
u8 flags = *p;
u16 mtype;
p += n; // next
if (l < n)
{
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Invalid length in AVP\n");
STAT(tunnel_rx_errors);
fatal = flags;
return;
}
l -= n;
if (flags & 0x40)
{
// handle hidden AVPs
if (!*config->l2tpsecret)
{
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Hidden AVP requested, but no L2TP secret.\n");
fatal = flags;
continue;
}
if (!session[s].random_vector_length)
{
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Hidden AVP requested, but no random vector.\n");
fatal = flags;
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)
{
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Unrecognised AVP flags %02X\n", *b);
fatal = flags;
continue; // next
}
b += 2;
if (*(u16 *) (b))
{
LOG(2, ntohl(addr->sin_addr.s_addr), s, t, "Unknown AVP vendor %d\n", ntohs(*(u16 *) (b)));
fatal = flags;
continue; // next
}
b += 2;
mtype = ntohs(*(u16 *) (b));
b += 2;
n -= 6;
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " AVP %d (%s) len %d\n", mtype, avpnames[mtype], n);
switch (mtype)
{
case 0: // message type
message = ntohs(*(u16 *) b);
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Message type = %d (%s)\n", *b,
l2tp_message_types[message]);
mandatorymessage = flags;
break;
case 1: // result code
{
u16 rescode = ntohs(*(u16 *)(b));
const char* resdesc = "(unknown)";
if (message == 4)
{ /* StopCCN */
if (rescode <= MAX_STOPCCN_RESULT_CODE)
resdesc = stopccn_result_codes[rescode];
}
else if (message == 14)
{ /* CDN */
if (rescode <= MAX_CDN_RESULT_CODE)
resdesc = cdn_result_codes[rescode];
}
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Result Code %d: %s\n",
rescode, resdesc);
if (n >= 4)
{
u16 errcode = ntohs(*(u16 *)(b + 2));
const char* errdesc = "(unknown)";
if (errcode <= MAX_ERROR_CODE)
errdesc = error_codes[errcode];
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Error Code %d: %s\n",
errcode, errdesc);
}
if (n > 4)
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Error String: %.*s\n",
n-4, b+4);
break;
}
break;
case 2: // protocol version
{
version = ntohs(*(u16 *) (b));
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Protocol version = %d\n", version);
if (version && version != 0x0100)
{ // allow 0.0 and 1.0
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, " Bad protocol version %04X\n",
version);
fatal = flags;
continue; // next
}
}
break;
case 3: // framing capabilities
// LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "Framing capabilities\n");
break;
case 4: // bearer capabilities
// LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "Bearer capabilities\n");
break;
case 5: // tie breaker
// We never open tunnels, so we don't care about tie breakers
// LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "Tie breaker\n");
continue;
case 6: // firmware revision
// LOG(4, ntohl(addr->sin_addr.s_addr), s, t, "Firmware revision\n");
break;
case 7: // host name
memset(tunnel[t].hostname, 0, 128);
memcpy(tunnel[t].hostname, b, (n >= 127) ? 127 : n);
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Tunnel hostname = \"%s\"\n", tunnel[t].hostname);
// TBA - to send to RADIUS
break;
case 8: // vendor name
memset(tunnel[t].vendor, 0, sizeof(tunnel[t].vendor));
memcpy(tunnel[t].vendor, b, (n >= sizeof(tunnel[t].vendor) - 1) ? sizeof(tunnel[t].vendor) - 1 : n);
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Vendor name = \"%s\"\n", tunnel[t].vendor);
break;
case 9: // assigned tunnel
tunnel[t].far = ntohs(*(u16 *) (b));
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Remote tunnel id = %d\n", tunnel[t].far);
break;
case 10: // rx window
tunnel[t].window = ntohs(*(u16 *) (b));
if (!tunnel[t].window)
tunnel[t].window = 1; // window of 0 is silly
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " rx window = %d\n", tunnel[t].window);
break;
case 11: // Challenge
{
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " LAC requested CHAP authentication for tunnel\n");
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);
break;
case 15: // call serial number
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " call serial number = %d\n", ntohl(*(u32 *)b));
break;
case 18: // bearer type
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " bearer type = %d\n", ntohl(*(u32 *)b));
// TBA - for RADIUS
break;
case 19: // framing type
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " framing type = %d\n", ntohl(*(u32 *)b));
// TBA
break;
case 21: // called number
memset(called, 0, MAXTEL);
memcpy(called, b, (n >= MAXTEL) ? (MAXTEL-1) : n);
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Called <%s>\n", called);
break;
case 22: // calling number
memset(calling, 0, MAXTEL);
memcpy(calling, b, (n >= MAXTEL) ? (MAXTEL-1) : n);
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Calling <%s>\n", calling);
break;
case 23: // subtype
break;
case 24: // tx connect speed
if (n == 4)
{
session[s].tx_connect_speed = ntohl(*(u32 *)b);
}
else
{
// AS5300s send connect speed as a string
char tmp[30] = {0};
memcpy(tmp, b, (n >= 30) ? 30 : n);
session[s].tx_connect_speed = atol(tmp);
}
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " TX connect speed <%u>\n",
session[s].tx_connect_speed);
break;
case 38: // rx connect speed
if (n == 4)
{
session[s].rx_connect_speed = ntohl(*(u32 *)b);
}
else
{
// AS5300s send connect speed as a string
char tmp[30] = {0};
memcpy(tmp, b, (n >= 30) ? 30 : n);
session[s].rx_connect_speed = atol(tmp);
}
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " RX connect speed <%u>\n",
session[s].rx_connect_speed);
break;
case 25: // Physical Channel ID
{
u32 tmp = ntohl(*(u32 *)b);
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Physical Channel ID <%X>\n", tmp);
break;
}
case 29: // Proxy Authentication Type
{
u16 authtype = ntohs(*(u16 *)b);
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Proxy Auth Type %d (%s)\n",
authtype, authtypes[authtype]);
requestchap = (authtype == 2);
break;
}
case 30: // Proxy Authentication Name
{
char authname[64] = {0};
memcpy(authname, b, (n > 63) ? 63 : n);
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Proxy Auth Name (%s)\n",
authname);
break;
}
case 31: // Proxy Authentication Challenge
{
memcpy(radius[session[s].radius].auth, b, 16);
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Proxy Auth Challenge\n");
break;
}
case 32: // Proxy Authentication ID
{
u16 authid = ntohs(*(u16 *)(b));
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Proxy Auth ID (%d)\n",
authid);
if (session[s].radius)
radius[session[s].radius].id = authid;
break;
}
case 33: // Proxy Authentication Response
{
char authresp[64] = {0};
memcpy(authresp, b, (n > 63) ? 63 : n);
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Proxy Auth Response\n");
break;
}
case 27: // last send lcp
{ // find magic number
u8 *p = b, *e = p + n;
while (p + 1 < e && p[1] && p + p[1] <= e)
{
if (*p == 5 && p[1] == 6) // Magic-Number
amagic = ntohl(*(u32 *) (p + 2));
else if (*p == 3 && p[1] == 5 && *(u16 *) (p + 2) == htons(PPPCHAP) && p[4] == 5) // Authentication-Protocol
chap = 1;
else if (*p == 7) // Protocol-Field-Compression
aflags |= SESSIONPFC;
else if (*p == 8) // Address-and-Control-Field-Compression
aflags |= SESSIONACFC;
p += p[1];
}
}
break;
case 28: // last recv lcp confreq
break;
case 26: // Initial Received LCP CONFREQ
break;
case 39: // seq required - we control it as an LNS anyway...
break;
case 36: // Random Vector
LOG(4, ntohl(addr->sin_addr.s_addr), s, t, " Random Vector received. Enabled AVP Hiding.\n");
memset(session[s].random_vector, 0, sizeof(session[s].random_vector));
memcpy(session[s].random_vector, b, n);
session[s].random_vector_length = n;
break;
default:
LOG(2, ntohl(addr->sin_addr.s_addr), s, t, " Unknown AVP type %d\n", mtype);
fatal = flags;
continue; // next
}
}
// process message
if (fatal & 0x80)
tunnelshutdown(t, "Unknown Mandatory AVP");
else
switch (message)
{
case 1: // SCCRQ - Start Control Connection Request
{
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)
if (chapresponse) controlb(c, 13, chapresponse, 16, 1); // Challenge response
control16(c, 9, t, 1); // assigned tunnel
controladd(c, t, s); // send the resply
}
tunnel[t].state = TUNNELOPENING;
break;
case 2: // SCCRP
tunnel[t].state = TUNNELOPEN;
break;
case 3: // SCCN
tunnel[t].state = TUNNELOPEN;
controlnull(t); // ack
break;
case 4: // StopCCN
controlnull(t); // ack
tunnelshutdown(t, "Stopped"); // Shut down cleanly
tunnelkill(t, "Stopped"); // Immediately force everything dead
break;
case 6: // HELLO
controlnull(t); // simply ACK
break;
case 7: // OCRQ
// TBA
break;
case 8: // OCRO
// TBA
break;
case 9: // OCCN
// TBA
break;
case 10: // ICRQ
if (!sessionfree)
{
STAT(session_overflow);
tunnelshutdown(t, "No free sessions");
}
else
{
u16 r;
controlt *c;
s = sessionfree;
sessionfree = session[s].next;
memset(&session[s], 0, sizeof(session[s]));
if (s > config->cluster_highest_sessionid)
config->cluster_highest_sessionid = s;
// make a RADIUS session
if (!(r = radiusnew(s)))
{
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "No free RADIUS sessions for ICRQ\n");
sessionkill(s, "no free RADIUS sesions");
return;
}
c = controlnew(11); // sending ICRP
session[s].id = sessionid++;
session[s].opened = time(NULL);
session[s].tunnel = t;
session[s].far = asession;
session[s].last_packet = time_now;
LOG(3, ntohl(addr->sin_addr.s_addr), s, t, "New session (%d/%d)\n", tunnel[t].far, session[s].far);
control16(c, 14, s, 1); // assigned session
controladd(c, t, s); // send the reply
{
// Generate a random challenge
int n;
for (n = 0; n < 15; n++)
radius[r].auth[n] = rand();
}
strncpy(radius[r].calling, calling, sizeof(radius[r].calling) - 1);
strncpy(session[s].called, called, sizeof(session[s].called) - 1);
strncpy(session[s].calling, calling, sizeof(session[s].calling) - 1);
STAT(session_created);
}
break;
case 11: // ICRP
// TBA
break;
case 12: // ICCN
if (amagic == 0) amagic = time_now;
session[s].magic = amagic; // set magic number
session[s].l2tp_flags = aflags; // set flags received
LOG(3, ntohl(addr->sin_addr.s_addr), s, t, "Magic %X Flags %X\n", amagic, aflags);
controlnull(t); // ack
// In CHAP state, request PAP instead
if (requestchap)
initlcp(t, s);
break;
case 14: // CDN
controlnull(t); // ack
sessionshutdown(s, "Closed (Received CDN)");
break;
case 0xFFFF:
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Missing message type\n");
break;
default:
STAT(tunnel_rx_errors);
if (mandatorymessage & 0x80)
tunnelshutdown(t, "Unknown message");
else
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Unknown message type %d\n", message);
break;
}
if (chapresponse) free(chapresponse);
cluster_send_tunnel(t);
}
else
{
LOG(4, 0, s, t, " Got a ZLB ack\n");
}
}
else
{ // data
u16 prot;
LOG_HEX(5, "Receive Tunnel Data", p, l);
if (l > 2 && p[0] == 0xFF && p[1] == 0x03)
{ // HDLC address header, discard
p += 2;
l -= 2;
}
if (l < 2)
{
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Short ppp length %d\n", l);
STAT(tunnel_rx_errors);
return;
}
if (*p & 1)
{
prot = *p++;
l--;
}
else
{
prot = ntohs(*(u16 *) p);
p += 2;
l -= 2;
}
if (s && !session[s].tunnel) // Is something wrong??
{
if (!config->cluster_iam_master)
{
// Pass it off to the master to deal with..
master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
return;
}
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "UDP packet contains session %d "
"but no session[%d].tunnel exists (LAC said"
" tunnel = %d). Dropping packet.\n", s, s, t);
STAT(tunnel_rx_errors);
return;
}
if (session[s].die)
{
LOG(3, ntohl(addr->sin_addr.s_addr), s, t, "Session %d is closing. Don't process PPP packets\n", s);
// I'm pretty sure this isn't right -- mo.
// return; // closing session, PPP not processed
}
if (prot == 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);
}
else if (prot == 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);
}
else if (prot == 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);
}
else if (prot == 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);
}
else if (prot == 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);
}
else if (prot == PPPIP)
{
session[s].last_packet = time_now;
if (session[s].walled_garden && !config->cluster_iam_master)
{
master_forward_packet(buf, len, addr->sin_addr.s_addr, addr->sin_port);
return;
}
processipin(t, s, p, l);
}
else
{
STAT(tunnel_rx_errors);
LOG(1, ntohl(addr->sin_addr.s_addr), s, t, "Unknown PPP protocol %04X\n", prot);
}
}
}
// read and process packet on tun
void processtun(u8 * buf, int len)
{
LOG_HEX(5, "Receive TUN Data", buf, len);
STAT(tun_rx_packets);
INC_STAT(tun_rx_bytes, len);
CSTAT(call_processtun);
eth_rx_pkt++;
eth_rx += len;
if (len < 22)
{
LOG(1, 0, 0, 0, "Short tun packet %d bytes\n", len);
STAT(tun_rx_errors);
return;
}
if (*(u16 *) (buf + 2) == htons(PKTIP)) // IP
processipout(buf, len);
// Else discard.
}
//
// Maximum number of actions to complete.
// This is to avoid sending out too many packets
// at once.
#define MAX_ACTIONS 500
int regular_cleanups(void)
{
static sessionidt s = 0; // Next session to check for actions on.
tunnelidt t;
int count=0,i;
u16 r;
static clockt next_acct = 0;
int a;
LOG(3, 0, 0, 0, "Begin regular cleanup\n");
for (r = 1; r < MAXRADIUS; r++)
{
if (!radius[r].state)
continue;
if (radius[r].retry)
{
if (radius[r].retry <= TIME)
radiusretry(r);
} else
radius[r].retry = backoff(radius[r].try+1); // Is this really needed? --mo
}
for (t = 1; t <= config->cluster_highest_tunnelid; t++)
{
// check for expired tunnels
if (tunnel[t].die && tunnel[t].die <= TIME)
{
STAT(tunnel_timeout);
tunnelkill(t, "Expired");
continue;
}
// check for message resend
if (tunnel[t].retry && tunnel[t].controlc)
{
// resend pending messages as timeout on reply
if (tunnel[t].retry <= TIME)
{
controlt *c = tunnel[t].controls;
u8 w = tunnel[t].window;
tunnel[t].try++; // another try
if (tunnel[t].try > 5)
tunnelkill(t, "Timeout on control message"); // game over
else
while (c && w--)
{
tunnelsend(c->buf, c->length, t);
c = c->next;
}
}
}
// Send hello
if (tunnel[t].state == TUNNELOPEN && tunnel[t].lastrec < TIME + 600)
{
controlt *c = controlnew(6); // sending HELLO
controladd(c, t, 0); // send the message
LOG(3, tunnel[t].ip, 0, t, "Sending HELLO message\n");
}
// Check for tunnel changes requested from the CLI
if ((a = cli_tunnel_actions[t].action))
{
cli_tunnel_actions[t].action = 0;
if (a & CLI_TUN_KILL)
{
LOG(2, tunnel[t].ip, 0, t, "Dropping tunnel by CLI\n");
tunnelshutdown(t, "Requested by administrator");
}
}
}
count = 0;
for (i = 1; i <= config->cluster_highest_sessionid; i++)
{
s++;
if (s > config->cluster_highest_sessionid)
s = 1;
if (!session[s].tunnel) // Session isn't in use
continue;
if (!session[s].die && session[s].ip && !(session[s].flags & SF_IPCP_ACKED))
{
// IPCP has not completed yet. Resend
LOG(3, session[s].ip, s, session[s].tunnel, "No ACK for initial IPCP ConfigReq... resending\n");
sendipcp(session[s].tunnel, s);
}
// check for expired sessions
if (session[s].die && session[s].die <= TIME)
{
sessionkill(s, "Expired");
if (++count >= MAX_ACTIONS) break;
continue;
}
// Drop sessions who have not responded within IDLE_TIMEOUT seconds
if (session[s].last_packet && (time_now - session[s].last_packet >= IDLE_TIMEOUT))
{
sessionkill(s, "No response to LCP ECHO requests");
STAT(session_timeout);
if (++count >= MAX_ACTIONS) break;
continue;
}
// No data in IDLE_TIMEOUT seconds, send LCP ECHO
if (session[s].user[0] && (time_now - session[s].last_packet >= ECHO_TIMEOUT))
{
u8 b[MAXCONTROL] = {0};
u8 *q = makeppp(b, sizeof(b), 0, 0, session[s].tunnel, s, PPPLCP);
if (!q)
{
LOG(3, session[s].ip, s, t, "failed to send ECHO packet.\n");
continue;
}
*q = EchoReq;
*(u8 *)(q + 1) = (time_now % 255); // ID
*(u16 *)(q + 2) = htons(8); // Length
*(u32 *)(q + 4) = 0; // Magic Number (not supported)
LOG(4, session[s].ip, s, session[s].tunnel, "No data in %d seconds, sending LCP ECHO\n",
(int)(time_now - session[s].last_packet));
tunnelsend(b, 24, session[s].tunnel); // send it
if (++count >= MAX_ACTIONS) break;
}
// Check for actions requested from the CLI
if ((a = cli_session_actions[s].action))
{
int send = 0;
cli_session_actions[s].action = 0;
if (a & CLI_SESS_KILL)
{
LOG(2, 0, s, session[s].tunnel, "Dropping session by CLI\n");
sessionshutdown(s, "Requested by administrator");
a = 0; // dead, no need to check for other actions
}
if (a & CLI_SESS_NOSNOOP)
{
LOG(2, 0, s, session[s].tunnel, "Unsnooping session by CLI\n");
session[s].snoop_ip = 0;
session[s].snoop_port = 0;
send++;
}
else if (a & CLI_SESS_SNOOP)
{
LOG(2, 0, s, session[s].tunnel, "Snooping session by CLI (to %s:%d)\n",
inet_toa(cli_session_actions[s].snoop_ip), cli_session_actions[s].snoop_port);
session[s].snoop_ip = cli_session_actions[s].snoop_ip;
session[s].snoop_port = cli_session_actions[s].snoop_port;
send++;
}
if (a & CLI_SESS_NOTHROTTLE)
{
LOG(2, 0, s, session[s].tunnel, "Un-throttling session by CLI\n");
throttle_session(s, 0, 0);
send++;
}
else if (a & CLI_SESS_THROTTLE)
{
LOG(2, 0, s, session[s].tunnel, "Throttling session by CLI (to %dkb/s up and %dkb/s down)\n",
cli_session_actions[s].throttle_in,
cli_session_actions[s].throttle_out);
throttle_session(s, cli_session_actions[s].throttle_in, cli_session_actions[s].throttle_out);
send++;
}
if (send)
cluster_send_session(s);
if (++count >= MAX_ACTIONS) break;
}
}
if (*config->accounting_dir && next_acct <= TIME)
{
// Dump accounting data
next_acct = TIME + ACCT_TIME;
dump_acct_info();
}
if (count >= MAX_ACTIONS)
return 1; // Didn't finish!
LOG(3, 0, 0, 0, "End regular cleanup (%d actions), next in %d seconds\n", count, config->cleanup_interval);
return 0;
}
//
// Are we in the middle of a tunnel update, or radius
// requests??
//
int still_busy(void)
{
int i;
static clockt last_talked = 0;
static clockt start_busy_wait = 0;
if (start_busy_wait == 0)
start_busy_wait = TIME;
for (i = config->cluster_highest_tunnelid ; i > 0 ; --i)
{
if (!tunnel[i].controlc)
continue;
if (last_talked != TIME)
{
LOG(2,0,0,0, "Tunnel %d still has un-acked control messages.\n", i);
last_talked = TIME;
}
return 1;
}
// We stop waiting for radius after BUSY_WAIT_TIME 1/10th seconds
if (abs(TIME - start_busy_wait) > BUSY_WAIT_TIME)
{
LOG(1, 0, 0, 0, "Giving up waiting for RADIUS to be empty. Shutting down anyway.\n");
return 0;
}
for (i = 1; i < MAXRADIUS; i++)
{
if (radius[i].state == RADIUSNULL)
continue;
if (radius[i].state == RADIUSWAIT)
continue;
if (last_talked != TIME)
{
LOG(2,0,0,0, "Radius session %d is still busy (sid %d)\n", i, radius[i].session);
last_talked = TIME;
}
return 1;
}
return 0;
}
static fd_set readset;
static int readset_n = 0;
// main loop - gets packets on tun or udp and processes them
void mainloop(void)
{
int i;
u8 buf[65536];
struct timeval to;
clockt next_cluster_ping = 0; // send initial ping immediately
time_t next_clean = time_now + config->cleanup_interval;
LOG(4, 0, 0, 0, "Beginning of main loop. udpfd=%d, tunfd=%d, cluster_sockfd=%d, controlfd=%d\n",
udpfd, tunfd, cluster_sockfd, controlfd);
FD_ZERO(&readset);
FD_SET(udpfd, &readset);
FD_SET(tunfd, &readset);
FD_SET(controlfd, &readset);
FD_SET(clifd, &readset);
if (cluster_sockfd) FD_SET(cluster_sockfd, &readset);
readset_n = udpfd;
if (tunfd > readset_n) readset_n = tunfd;
if (controlfd > readset_n) readset_n = controlfd;
if (clifd > readset_n) readset_n = clifd;
if (cluster_sockfd > readset_n) readset_n = cluster_sockfd;
while (!main_quit || still_busy())
{
fd_set r;
int n = readset_n;
#ifdef BGP
fd_set w;
int bgp_set[BGP_NUM_PEERS];
#endif /* BGP */
if (config->reload_config)
{
// Update the config state based on config settings
update_config();
}
memcpy(&r, &readset, sizeof(fd_set));
to.tv_sec = 0;
to.tv_usec = 100000; // 1/10th of a second.
#ifdef BGP
FD_ZERO(&w);
for (i = 0; i < BGP_NUM_PEERS; i++)
{
bgp_set[i] = bgp_select_state(&bgp_peers[i]);
if (bgp_set[i] & 1)
{
FD_SET(bgp_peers[i].sock, &r);
if (bgp_peers[i].sock > n)
n = bgp_peers[i].sock;
}
if (bgp_set[i] & 2)
{
FD_SET(bgp_peers[i].sock, &w);
if (bgp_peers[i].sock > n)
n = bgp_peers[i].sock;
}
}
n = select(n + 1, &r, &w, 0, &to);
#else /* BGP */
n = select(n + 1, &r, 0, 0, &to);
#endif /* BGP */
TIME = now();
if (n < 0)
{
if (errno == EINTR ||
errno == ECHILD) // EINTR was clobbered by sigchild_handler()
continue;
LOG(0, 0, 0, 0, "Error returned from select(): %s\n", strerror(errno));
main_quit++;
break;
}
else if (n)
{
struct sockaddr_in addr;
int alen = sizeof(addr);
if (FD_ISSET(udpfd, &r))
{
int c, n;
for (c = 0; c < config->multi_read_count; c++)
{
if ((n = recvfrom(udpfd, buf, sizeof(buf), 0, (void *) &addr, &alen)) > 0)
processudp(buf, n, &addr);
else
break;
}
}
if (FD_ISSET(tunfd, &r))
{
int c, n;
for (c = 0; c < config->multi_read_count; c++)
{
if ((n = read(tunfd, buf, sizeof(buf))) > 0)
processtun(buf, n);
else
break;
}
}
if (config->cluster_iam_master)
for (i = 0; i < config->num_radfds; i++)
if (FD_ISSET(radfds[i], &r))
processrad(buf, recv(radfds[i], buf, sizeof(buf), 0), i);
if (FD_ISSET(cluster_sockfd, &r))
{
int size;
size = recvfrom(cluster_sockfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen);
processcluster(buf, size, addr.sin_addr.s_addr);
}
if (FD_ISSET(controlfd, &r))
processcontrol(buf, recvfrom(controlfd, buf, sizeof(buf), MSG_WAITALL, (void *) &addr, &alen), &addr);
if (FD_ISSET(clifd, &r))
{
struct sockaddr_in addr;
int sockfd;
int len = sizeof(addr);
if ((sockfd = accept(clifd, (struct sockaddr *)&addr, &len)) <= 0)
{
LOG(0, 0, 0, 0, "accept error: %s\n", strerror(errno));
continue;
}
else
{
cli_do(sockfd);
close(sockfd);
}
}
}
// Runs on every machine (master and slaves).
if (cluster_sockfd && next_cluster_ping <= TIME)
{
// Check to see which of the cluster is still alive..
cluster_send_ping(basetime); // Only does anything if we're a slave
cluster_check_master(); // ditto.
cluster_heartbeat(); // Only does anything if we're a master.
cluster_check_slaves(); // ditto.
master_update_counts(); // If we're a slave, send our byte counters to our master.
if (config->cluster_iam_master && !config->cluster_iam_uptodate)
next_cluster_ping = TIME + 1; // out-of-date slaves, do fast updates
else
next_cluster_ping = TIME + config->cluster_hb_interval;
}
// Run token bucket filtering queue..
// Only run it every 1/10th of a second.
// Runs on all machines both master and slave.
{
static clockt last_run = 0;
if (last_run != TIME)
{
last_run = TIME;
tbf_run_timer();
}
}
/* Handle timeouts. Make sure that this gets run anyway, even if there was
* something to read, else under load this will never actually run....
*
*/
if (config->cluster_iam_master && next_clean <= time_now)
{
if (regular_cleanups())
{
// Did it finish?
next_clean = time_now + 1 ; // Didn't finish. Check quickly.
}
else
{
next_clean = time_now + config->cleanup_interval; // Did. Move to next interval.
}
}
#ifdef BGP
for (i = 0; i < BGP_NUM_PEERS; i++)
{
bgp_process(&bgp_peers[i],
bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &r) : 0,
bgp_set[i] ? FD_ISSET(bgp_peers[i].sock, &w) : 0);
}
#endif /* BGP */
}
// Are we the master and shutting down??
if (config->cluster_iam_master)
cluster_heartbeat(); // Flush any queued changes..
// Ok. Notify everyone we're shutting down. If we're
// the master, this will force an election.
cluster_send_ping(0);
//
// Important!!! We MUST not process any packets past this point!
}
static void stripdomain(char *host)
{
char *p;
if ((p = strchr(host, '.')))
{
char *domain = 0;
char _domain[1024];
// strip off domain
FILE *resolv = fopen("/etc/resolv.conf", "r");
if (resolv)
{
char buf[1024];
char *b;
while (fgets(buf, sizeof(buf), resolv))
{
if (strncmp(buf, "domain", 6) && strncmp(buf, "search", 6))
continue;
if (!isspace(buf[6]))
continue;
b = buf + 7;
while (isspace(*b)) b++;
if (*b)
{
char *d = b;
while (*b && !isspace(*b)) b++;
*b = 0;
if (buf[0] == 'd') // domain is canonical
{
domain = d;
break;
}
// first search line
if (!domain)
{
// hold, may be subsequent domain line
strncpy(_domain, d, sizeof(_domain))[sizeof(_domain)-1] = 0;
domain = _domain;
}
}
}
fclose(resolv);
}
if (domain)
{
int hl = strlen(host);
int dl = strlen(domain);
if (dl < hl && host[hl - dl - 1] == '.' && !strcmp(host + hl - dl, domain))
host[hl -dl - 1] = 0;
}
else
{
*p = 0; // everything after first dot
}
}
}
// Init data structures
void initdata(int optdebug, char *optconfig)
{
int i;
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))))
{
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, optconfig, strlen(optconfig));
config->debug = optdebug;
config->num_tbfs = MAXTBFS;
config->rl_rate = 28; // 28kbps
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)))
{
LOG(0, 0, 0, 0, "Error doing malloc for sessions: %s\n", strerror(errno));
exit(1);
}
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)))
{
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)))
{
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))))
{
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)))
{
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)))
{
LOG(0, 0, 0, 0, "Error doing malloc for cli tunnel actions: %s\n", strerror(errno));
exit(1);
}
memset(cli_tunnel_actions, 0, sizeof(struct cli_tunnel_actions) * MAXSESSION);
memset(tunnel, 0, sizeof(tunnelt) * MAXTUNNEL);
memset(session, 0, sizeof(sessiont) * MAXSESSION);
memset(radius, 0, sizeof(radiust) * MAXRADIUS);
memset(ip_address_pool, 0, sizeof(ippoolt) * MAXIPPOOL);
// Put all the sessions on the free list marked as undefined.
for (i = 1; i < MAXSESSION - 1; i++)
{
session[i].next = i + 1;
session[i].tunnel = T_UNDEF; // mark it as not filled in.
}
session[MAXSESSION - 1].next = 0;
sessionfree = 1;
// Mark all the tunnels as undefined (waiting to be filled in by a download).
for (i = 1; i < MAXTUNNEL- 1; i++)
tunnel[i].state = TUNNELUNDEF; // mark it as not filled in.
if (!*hostname)
{
// Grab my hostname unless it's been specified
gethostname(hostname, sizeof(hostname));
stripdomain(hostname);
}
_statistics->start_time = _statistics->last_reset = time(NULL);
#ifdef BGP
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);
}
#endif /* BGP */
}
void initiptables(void)
{
/* Flush the tables here so that we have a clean slate */
// Not needed. 'nat' is setup by garden.c
// mangle isn't used (as throttling is done by tbf inhouse).
}
int assign_ip_address(sessionidt s)
{
u32 i;
int best = -1;
time_t best_time = time_now;
char *u = session[s].user;
char reuse = 0;
CSTAT(call_assign_ip_address);
for (i = 1; i < ip_pool_size; i++)
{
if (!ip_address_pool[i].address || ip_address_pool[i].assigned)
continue;
if (!session[s].walled_garden && ip_address_pool[i].user[0] && !strcmp(u, ip_address_pool[i].user))
{
best = i;
reuse = 1;
break;
}
if (ip_address_pool[i].last < best_time)
{
best = i;
if (!(best_time = ip_address_pool[i].last))
break; // never used, grab this one
}
}
if (best < 0)
{
LOG(0, 0, s, session[s].tunnel, "assign_ip_address(): out of addresses\n");
return 0;
}
session[s].ip = ip_address_pool[best].address;
session[s].ip_pool_index = best;
ip_address_pool[best].assigned = 1;
ip_address_pool[best].last = time_now;
ip_address_pool[best].session = s;
if (session[s].walled_garden)
/* Don't track addresses of users in walled garden (note: this
means that their address isn't "sticky" even if they get
un-gardened). */
ip_address_pool[best].user[0] = 0;
else
strncpy(ip_address_pool[best].user, u, sizeof(ip_address_pool[best].user) - 1);
STAT(ip_allocated);
LOG(4, ip_address_pool[best].address, s, session[s].tunnel,
"assign_ip_address(): %s ip address %d from pool\n", reuse ? "Reusing" : "Allocating", best);
return 1;
}
void free_ip_address(sessionidt s)
{
int i = session[s].ip_pool_index;
if (!session[s].ip)
return; // what the?
if (i < 0) // Is this actually part of the ip pool?
i = 0;
STAT(ip_freed);
cache_ipmap(session[s].ip, -i); // Change the mapping to point back to the ip pool index.
session[s].ip = 0;
ip_address_pool[i].assigned = 0;
ip_address_pool[i].session = 0;
ip_address_pool[i].last = time_now;
CSTAT(call_free_ip_address);
}
//
// Fsck the address pool against the session table.
// Normally only called when we become a master.
//
// This isn't perfect: We aren't keep tracking of which
// users used to have an IP address.
//
void rebuild_address_pool(void)
{
int i;
//
// Zero the IP pool allocation, and build
// a map from IP address to pool index.
for (i = 1; i < MAXIPPOOL; ++i)
{
ip_address_pool[i].assigned = 0;
ip_address_pool[i].session = 0;
if (!ip_address_pool[i].address)
continue;
cache_ipmap(ip_address_pool[i].address, -i); // Map pool IP to pool index.
}
for (i = 0; i < MAXSESSION; ++i)
{
int ipid;
if (!session[i].ip || !session[i].tunnel)
continue;
ipid = - lookup_ipmap(htonl(session[i].ip));
if (session[i].ip_pool_index < 0)
{
// Not allocated out of the pool.
if (ipid < 1) // Not found in the pool either? good.
continue;
LOG(0, 0, i, 0, "Session %d has an IP address (%s) that was marked static, but is in the pool (%d)!\n",
i, inet_toa(session[i].ip), ipid);
// Fall through and process it as part of the pool.
}
if (ipid > MAXIPPOOL || ipid < 0)
{
LOG(0, 0, i, 0, "Session %d has a pool IP that's not found in the pool! (%d)\n", i, ipid);
ipid = -1;
session[i].ip_pool_index = ipid;
continue;
}
ip_address_pool[ipid].assigned = 1;
ip_address_pool[ipid].session = i;
ip_address_pool[ipid].last = time_now;
strncpy(ip_address_pool[ipid].user, session[i].user, sizeof(ip_address_pool[ipid].user) - 1);
session[i].ip_pool_index = ipid;
cache_ipmap(session[i].ip, i); // Fix the ip map.
}
}
//
// Fix the address pool to match a changed session.
// (usually when the master sends us an update).
void fix_address_pool(int sid)
{
int ipid;
ipid = session[sid].ip_pool_index;
if (ipid > ip_pool_size)
return; // Ignore it. rebuild_address_pool will fix it up.
if (ip_address_pool[ipid].address != session[sid].ip)
return; // Just ignore it. rebuild_address_pool will take care of it.
ip_address_pool[ipid].assigned = 1;
ip_address_pool[ipid].session = sid;
ip_address_pool[ipid].last = time_now;
strncpy(ip_address_pool[ipid].user, session[sid].user, sizeof(ip_address_pool[ipid].user) - 1);
}
//
// Add a block of addresses to the IP pool to hand out.
//
void add_to_ip_pool(u32 addr, u32 mask)
{
int i;
if (mask == 0)
mask = 0xffffffff; // Host route only.
addr &= mask;
if (ip_pool_size >= MAXIPPOOL) // Pool is full!
return ;
for (i = addr ;(i & mask) == addr; ++i)
{
if ((i & 0xff) == 0 || (i&0xff) == 255)
continue; // Skip 0 and broadcast addresses.
ip_address_pool[ip_pool_size].address = i;
ip_address_pool[ip_pool_size].assigned = 0;
++ip_pool_size;
if (ip_pool_size >= MAXIPPOOL)
{
LOG(0,0,0,0, "Overflowed IP pool adding %s\n", inet_toa(htonl(addr)) );
return;
}
}
}
// Initialize the IP address pool
void initippool()
{
FILE *f;
char *p;
char buf[4096];
memset(ip_address_pool, 0, sizeof(ip_address_pool));
if (!(f = fopen(IPPOOLFILE, "r")))
{
LOG(0, 0, 0, 0, "Can't load pool file " IPPOOLFILE ": %s\n", strerror(errno));
exit(1);
}
while (ip_pool_size < MAXIPPOOL && fgets(buf, 4096, f))
{
char *pool = buf;
buf[4095] = 0; // Force it to be zero terminated/
if (*buf == '#' || *buf == '\n')
continue; // Skip comments / blank lines
if ((p = (char *)strrchr(buf, '\n'))) *p = 0;
if ((p = (char *)strchr(buf, ':')))
{
ipt src;
*p = '\0';
src = inet_addr(buf);
if (src == INADDR_NONE)
{
LOG(0, 0, 0, 0, "Invalid address pool IP %s\n", buf);
exit(1);
}
// This entry is for a specific IP only
if (src != config->bind_address)
continue;
*p = ':';
pool = p+1;
}
if ((p = (char *)strchr(pool, '/')))
{
// It's a range
int numbits = 0;
u32 start = 0, mask = 0;
LOG(2, 0, 0, 0, "Adding IP address range %s\n", buf);
*p++ = 0;
if (!*p || !(numbits = atoi(p)))
{
LOG(0, 0, 0, 0, "Invalid pool range %s\n", buf);
continue;
}
start = ntohl(inet_addr(pool));
mask = (u32)(pow(2, numbits) - 1) << (32 - numbits);
// Add a static route for this pool
LOG(5, 0, 0, 0, "Adding route for address pool %s/%u\n", inet_toa(htonl(start)), 32 + mask);
routeset(0, start, mask, 0, 1);
add_to_ip_pool(start, mask);
}
else
{
// It's a single ip address
add_to_ip_pool(inet_addr(pool), 0);
}
}
fclose(f);
LOG(1, 0, 0, 0, "IP address pool is %d addresses\n", ip_pool_size - 1);
}
void snoop_send_packet(char *packet, u16 size, ipt destination, u16 port)
{
struct sockaddr_in snoop_addr = {0};
if (!destination || !port || snoopfd <= 0 || size <= 0 || !packet)
return;
snoop_addr.sin_family = AF_INET;
snoop_addr.sin_addr.s_addr = destination;
snoop_addr.sin_port = ntohs(port);
LOG(5, 0, 0, 0, "Snooping packet at %p (%d bytes) to %s:%d\n",
packet, size, inet_toa(snoop_addr.sin_addr.s_addr), htons(snoop_addr.sin_port));
if (sendto(snoopfd, packet, size, MSG_DONTWAIT | MSG_NOSIGNAL, (void *) &snoop_addr, sizeof(snoop_addr)) < 0)
LOG(0, 0, 0, 0, "Error sending intercept packet: %s\n", strerror(errno));
STAT(packets_snooped);
}
void dump_acct_info()
{
char filename[1024];
char timestr[64];
time_t t = time(NULL);
int i;
FILE *f = NULL;
CSTAT(call_dump_acct_info);
strftime(timestr, 64, "%Y%m%d%H%M%S", localtime(&t));
snprintf(filename, 1024, "%s/%s", config->accounting_dir, timestr);
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)
continue;
if (!f)
{
time_t now = time(NULL);
if (!(f = fopen(filename, "w")))
{
LOG(0, 0, 0, 0, "Can't write accounting info to %s: %s\n", filename, strerror(errno));
return ;
}
LOG(3, 0, 0, 0, "Dumping accounting information to %s\n", filename);
fprintf(f, "# dslwatch.pl dump file V1.01\n"
"# host: %s\n"
"# time: %ld\n"
"# uptime: %ld\n"
"# format: username ip qos uptxoctets downrxoctets\n",
hostname,
now,
now - basetime);
}
LOG(4, 0, 0, 0, "Dumping accounting information for %s\n", session[i].user);
fprintf(f, "%s %s %d %u %u\n",
session[i].user, // username
inet_toa(htonl(session[i].ip)), // ip
(session[i].throttle_in || session[i].throttle_out) ? 2 : 1, // qos
(u32)session[i].cin, // uptxoctets
(u32)session[i].cout); // downrxoctets
session[i].pin = session[i].cin = 0;
session[i].pout = session[i].cout = 0;
}
if (f)
fclose(f);
}
// Main program
int main(int argc, char *argv[])
{
int o;
int optdebug = 0;
char *optconfig = CONFIGFILE;
_program_name = strdup(argv[0]);
time(&basetime); // start clock
// scan args
while ((o = getopt(argc, argv, "dvc:h:")) >= 0)
{
switch (o)
{
case 'd':
// Double fork to detach from terminal
if (fork()) exit(0);
if (fork()) exit(0);
break;
case 'v':
optdebug++;
break;
case 'c':
optconfig = optarg;
break;
case 'h':
snprintf(hostname, sizeof(hostname), "%s", optarg);
break;
default:
printf("Args are:\n"
"\t-d\tDetach from terminal\n"
"\t-c <file>\tConfig file\n"
"\t-h <hostname>\tForce hostname\n"
"\t-a <address>\tUse specific address\n"
"\t-v\t\tDebug\n");
return (0);
break;
}
}
// Start the timer routine off
time(&time_now);
strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
signal(SIGALRM, sigalrm_handler);
siginterrupt(SIGALRM, 0);
initiptables();
initplugins();
initdata(optdebug, optconfig);
init_cli(hostname);
read_config_file();
init_tbf(config->num_tbfs);
LOG(0, 0, 0, 0, "L2TPNS version " VERSION "\n");
LOG(0, 0, 0, 0, "Copyright (c) 2003, 2004 Optus Internet Engineering\n");
LOG(0, 0, 0, 0, "Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced\n");
{
struct rlimit rlim;
rlim.rlim_cur = RLIM_INFINITY;
rlim.rlim_max = RLIM_INFINITY;
// Remove the maximum core size
if (setrlimit(RLIMIT_CORE, &rlim) < 0)
LOG(0, 0, 0, 0, "Can't set ulimit: %s\n", strerror(errno));
// Make core dumps go to /tmp
chdir("/tmp");
}
if (config->scheduler_fifo)
{
int ret;
struct sched_param params = {0};
params.sched_priority = 1;
if (get_nprocs() < 2)
{
LOG(0, 0, 0, 0, "Not using FIFO scheduler, there is only 1 processor in the system.\n");
config->scheduler_fifo = 0;
}
else
{
if ((ret = sched_setscheduler(0, SCHED_FIFO, &params)) == 0)
{
LOG(1, 0, 0, 0, "Using FIFO scheduler. Say goodbye to any other processes running\n");
}
else
{
LOG(0, 0, 0, 0, "Error setting scheduler to FIFO: %s\n", strerror(errno));
config->scheduler_fifo = 0;
}
}
}
/* Set up the cluster communications port. */
if (cluster_init(config->bind_address) < 0)
exit(1);
#ifdef BGP
signal(SIGPIPE, SIG_IGN);
bgp_setup(config->as_number);
bgp_add_route(config->bind_address, 0xffffffff);
if (*config->bgp_peer[0])
bgp_start(&bgp_peers[0], config->bgp_peer[0],
config->bgp_peer_as[0], 0); /* 0 = routing disabled */
if (*config->bgp_peer[1])
bgp_start(&bgp_peers[1], config->bgp_peer[1],
config->bgp_peer_as[1], 0);
#endif /* BGP */
inittun();
LOG(1, 0, 0, 0, "Set up on interface %s\n", config->tundevice);
initudp();
initrad();
initippool();
read_state();
signal(SIGHUP, sighup_handler);
signal(SIGTERM, sigterm_handler);
signal(SIGINT, sigterm_handler);
signal(SIGQUIT, sigquit_handler);
signal(SIGCHLD, sigchild_handler);
// Prevent us from getting paged out
if (config->lock_pages)
{
if (!mlockall(MCL_CURRENT))
LOG(1, 0, 0, 0, "Locking pages into memory\n");
else
LOG(0, 0, 0, 0, "Can't lock pages: %s\n", strerror(errno));
}
alarm(1);
// Drop privileges here
if (config->target_uid > 0 && geteuid() == 0)
setuid(config->target_uid);
mainloop();
#ifdef BGP
/* try to shut BGP down cleanly; with luck the sockets will be
writable since we're out of the select */
{
int i;
for (i = 0; i < BGP_NUM_PEERS; i++)
if (bgp_peers[i].state == Established)
bgp_stop(&bgp_peers[i]);
}
#endif /* BGP */
/* remove plugins (so cleanup code gets run) */
plugins_done();
// Remove the PID file if we wrote it
if (config->wrote_pid && *config->pid_file == '/')
unlink(config->pid_file);
/* kill CLI children */
signal(SIGTERM, SIG_IGN);
kill(0, SIGTERM);
return 0;
}
void sighup_handler(int junk)
{
if (log_stream && log_stream != stderr)
{
fclose(log_stream);
log_stream = NULL;
}
read_config_file();
}
void sigalrm_handler(int junk)
{
// Log current traffic stats
snprintf(config->bandwidth, sizeof(config->bandwidth),
"UDP-ETH:%1.0f/%1.0f ETH-UDP:%1.0f/%1.0f TOTAL:%0.1f IN:%u OUT:%u",
(udp_rx / 1024.0 / 1024.0 * 8),
(eth_tx / 1024.0 / 1024.0 * 8),
(eth_rx / 1024.0 / 1024.0 * 8),
(udp_tx / 1024.0 / 1024.0 * 8),
((udp_tx + udp_rx + eth_tx + eth_rx) / 1024.0 / 1024.0 * 8),
udp_rx_pkt, eth_rx_pkt);
udp_tx = udp_rx = 0;
udp_rx_pkt = eth_rx_pkt = 0;
eth_tx = eth_rx = 0;
if (config->dump_speed)
printf("%s\n", config->bandwidth);
// Update the internal time counter
time(&time_now);
strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
alarm(1);
{
// Run timer hooks
struct param_timer p = { time_now };
run_plugins(PLUGIN_TIMER, &p);
}
}
void sigterm_handler(int junk)
{
LOG(1, 0, 0, 0, "Shutting down cleanly\n");
if (config->save_state)
dump_state();
main_quit++;
}
void sigquit_handler(int junk)
{
int i;
LOG(1, 0, 0, 0, "Shutting down without saving sessions\n");
for (i = 1; i < MAXSESSION; i++)
{
if (session[i].opened)
sessionkill(i, "L2TPNS Closing");
}
for (i = 1; i < MAXTUNNEL; i++)
{
if (tunnel[i].ip || tunnel[i].state)
tunnelshutdown(i, "L2TPNS Closing");
}
main_quit++;
}
void sigchild_handler(int signal)
{
while (waitpid(-1, NULL, WNOHANG) > 0)
;
}
void read_state()
{
struct stat sb;
int i;
ippoolt itmp;
FILE *f;
char magic[sizeof(DUMP_MAGIC) - 1];
u32 buf[2];
if (!config->save_state)
{
unlink(STATEFILE);
return ;
}
if (stat(STATEFILE, &sb) < 0)
{
unlink(STATEFILE);
return ;
}
if (sb.st_mtime < (time(NULL) - 60))
{
LOG(0, 0, 0, 0, "State file is too old to read, ignoring\n");
unlink(STATEFILE);
return ;
}
f = fopen(STATEFILE, "r");
unlink(STATEFILE);
if (!f)
{
LOG(0, 0, 0, 0, "Can't read state file: %s\n", strerror(errno));
exit(1);
}
if (fread(magic, sizeof(magic), 1, f) != 1 || strncmp(magic, DUMP_MAGIC, sizeof(magic)))
{
LOG(0, 0, 0, 0, "Bad state file magic\n");
exit(1);
}
LOG(1, 0, 0, 0, "Reading state information\n");
if (fread(buf, sizeof(buf), 1, f) != 1 || buf[0] > MAXIPPOOL || buf[1] != sizeof(ippoolt))
{
LOG(0, 0, 0, 0, "Error/mismatch reading ip pool header from state file\n");
exit(1);
}
if (buf[0] > ip_pool_size)
{
LOG(0, 0, 0, 0, "ip pool has shrunk! state = %d, current = %d\n", buf[0], ip_pool_size);
exit(1);
}
LOG(2, 0, 0, 0, "Loading %u ip addresses\n", buf[0]);
for (i = 0; i < buf[0]; i++)
{
if (fread(&itmp, sizeof(itmp), 1, f) != 1)
{
LOG(0, 0, 0, 0, "Error reading ip %d from state file: %s\n", i, strerror(errno));
exit(1);
}
if (itmp.address != ip_address_pool[i].address)
{
LOG(0, 0, 0, 0, "Mismatched ip %d from state file: pool may only be extended\n", i);
exit(1);
}
memcpy(&ip_address_pool[i], &itmp, sizeof(itmp));
}
if (fread(buf, sizeof(buf), 1, f) != 1 || buf[0] != MAXTUNNEL || buf[1] != sizeof(tunnelt))
{
LOG(0, 0, 0, 0, "Error/mismatch reading tunnel header from state file\n");
exit(1);
}
LOG(2, 0, 0, 0, "Loading %u tunnels\n", MAXTUNNEL);
if (fread(tunnel, sizeof(tunnelt), MAXTUNNEL, f) != MAXTUNNEL)
{
LOG(0, 0, 0, 0, "Error reading tunnel data from state file\n");
exit(1);
}
for (i = 0; i < MAXTUNNEL; i++)
{
tunnel[i].controlc = 0;
tunnel[i].controls = NULL;
tunnel[i].controle = NULL;
if (*tunnel[i].hostname)
LOG(3, 0, 0, 0, "Created tunnel for %s\n", tunnel[i].hostname);
}
if (fread(buf, sizeof(buf), 1, f) != 1 || buf[0] != MAXSESSION || buf[1] != sizeof(sessiont))
{
LOG(0, 0, 0, 0, "Error/mismatch reading session header from state file\n");
exit(1);
}
LOG(2, 0, 0, 0, "Loading %u sessions\n", MAXSESSION);
if (fread(session, sizeof(sessiont), MAXSESSION, f) != MAXSESSION)
{
LOG(0, 0, 0, 0, "Error reading session data from state file\n");
exit(1);
}
for (i = 0; i < MAXSESSION; i++)
{
session[i].tbf_in = 0;
session[i].tbf_out = 0;
if (session[i].opened)
{
LOG(2, 0, i, 0, "Loaded active session for user %s\n", session[i].user);
if (session[i].ip)
sessionsetup(session[i].tunnel, i);
}
}
fclose(f);
LOG(0, 0, 0, 0, "Loaded saved state information\n");
}
void dump_state()
{
FILE *f;
u32 buf[2];
if (!config->save_state)
return;
do
{
if (!(f = fopen(STATEFILE, "w")))
break;
LOG(1, 0, 0, 0, "Dumping state information\n");
if (fwrite(DUMP_MAGIC, sizeof(DUMP_MAGIC) - 1, 1, f) != 1)
break;
LOG(2, 0, 0, 0, "Dumping %u ip addresses\n", ip_pool_size);
buf[0] = ip_pool_size;
buf[1] = sizeof(ippoolt);
if (fwrite(buf, sizeof(buf), 1, f) != 1)
break;
if (fwrite(ip_address_pool, sizeof(ippoolt), ip_pool_size, f) != ip_pool_size)
break;
LOG(2, 0, 0, 0, "Dumping %u tunnels\n", MAXTUNNEL);
buf[0] = MAXTUNNEL;
buf[1] = sizeof(tunnelt);
if (fwrite(buf, sizeof(buf), 1, f) != 1)
break;
if (fwrite(tunnel, sizeof(tunnelt), MAXTUNNEL, f) != MAXTUNNEL)
break;
LOG(2, 0, 0, 0, "Dumping %u sessions\n", MAXSESSION);
buf[0] = MAXSESSION;
buf[1] = sizeof(sessiont);
if (fwrite(buf, sizeof(buf), 1, f) != 1)
break;
if (fwrite(session, sizeof(sessiont), MAXSESSION, f) != MAXSESSION)
break;
if (fclose(f) == 0)
return ; // OK
}
while (0);
LOG(0, 0, 0, 0, "Can't write state information: %s\n", strerror(errno));
unlink(STATEFILE);
}
void build_chap_response(char *challenge, u8 id, u16 challenge_length, char **challenge_response)
{
MD5_CTX ctx;
*challenge_response = NULL;
if (!*config->l2tpsecret)
{
LOG(0, 0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
return;
}
LOG(4, 0, 0, 0, " Building challenge response for CHAP request\n");
*challenge_response = (char *)calloc(17, 1);
MD5Init(&ctx);
MD5Update(&ctx, &id, 1);
MD5Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
MD5Update(&ctx, challenge, challenge_length);
MD5Final(*challenge_response, &ctx);
return;
}
static int facility_value(char *name)
{
int i;
for (i = 0; facilitynames[i].c_name; i++)
{
if (strcmp(facilitynames[i].c_name, name) == 0)
return facilitynames[i].c_val;
}
return 0;
}
void update_config()
{
int i;
static int timeout = 0;
static int interval = 0;
// Update logging
closelog();
syslog_log = 0;
if (log_stream)
{
fclose(log_stream);
log_stream = NULL;
}
if (*config->log_filename)
{
if (strstr(config->log_filename, "syslog:") == config->log_filename)
{
char *p = config->log_filename + 7;
if (*p)
{
openlog("l2tpns", LOG_PID, facility_value(p));
syslog_log = 1;
}
}
else if (strchr(config->log_filename, '/') == config->log_filename)
{
if ((log_stream = fopen((char *)(config->log_filename), "a")))
{
fseek(log_stream, 0, SEEK_END);
setbuf(log_stream, NULL);
}
else
{
log_stream = stderr;
setbuf(log_stream, NULL);
}
}
}
else
{
log_stream = stderr;
setbuf(log_stream, NULL);
}
// Update radius
config->numradiusservers = 0;
for (i = 0; i < MAXRADSERVER; i++)
if (config->radiusserver[i])
{
config->numradiusservers++;
// Set radius port: if not set, take the port from the
// first radius server. For the first radius server,
// take the #defined default value from l2tpns.h
// test twice, In case someone works with
// a secondary radius server without defining
// a primary one, this will work even then.
if (i>0 && !config->radiusport[i])
config->radiusport[i] = config->radiusport[i-1];
if (!config->radiusport[i])
config->radiusport[i] = RADPORT;
}
if (!config->numradiusservers)
{
LOG(0, 0, 0, 0, "No RADIUS servers defined!\n");
}
config->num_radfds = 2 << RADIUS_SHIFT;
// Update plugins
for (i = 0; i < MAXPLUGINS; i++)
{
if (strcmp(config->plugins[i], config->old_plugins[i]) == 0)
continue;
if (*config->plugins[i])
{
// Plugin added
add_plugin(config->plugins[i]);
}
else if (*config->old_plugins[i])
{
// Plugin removed
remove_plugin(config->old_plugins[i]);
}
}
memcpy(config->old_plugins, config->plugins, sizeof(config->plugins));
if (!config->cleanup_interval) config->cleanup_interval = 10;
if (!config->multi_read_count) config->multi_read_count = 10;
if (!config->cluster_address) config->cluster_address = inet_addr(DEFAULT_MCAST_ADDR);
if (!*config->cluster_interface)
strncpy(config->cluster_interface, DEFAULT_MCAST_INTERFACE, sizeof(config->cluster_interface) - 1);
if (!config->cluster_hb_interval)
config->cluster_hb_interval = PING_INTERVAL; // Heartbeat every 0.5 seconds.
if (!config->cluster_hb_timeout)
config->cluster_hb_timeout = HB_TIMEOUT; // 10 missed heartbeat triggers an election.
if (interval != config->cluster_hb_interval || timeout != config->cluster_hb_timeout)
{
// Paranoia: cluster_check_master() treats 2 x interval + 1 sec as
// late, ensure we're sufficiently larger than that
int t = 4 * config->cluster_hb_interval + 11;
if (config->cluster_hb_timeout < t)
{
LOG(0,0,0,0, "Heartbeat timeout %d too low, adjusting to %d\n", config->cluster_hb_timeout, t);
config->cluster_hb_timeout = t;
}
// Push timing changes to the slaves immediately if we're the master
if (config->cluster_iam_master)
cluster_heartbeat();
interval = config->cluster_hb_interval;
timeout = config->cluster_hb_timeout;
}
// Write PID file
if (*config->pid_file == '/' && !config->wrote_pid)
{
FILE *f;
if ((f = fopen(config->pid_file, "w")))
{
fprintf(f, "%d\n", getpid());
fclose(f);
config->wrote_pid = 1;
}
else
{
LOG(0, 0, 0, 0, "Can't write to PID file %s: %s\n", config->pid_file, strerror(errno));
}
}
config->reload_config = 0;
}
void read_config_file()
{
FILE *f;
if (!config->config_file) return;
if (!(f = fopen(config->config_file, "r")))
{
fprintf(stderr, "Can't open config file %s: %s\n", config->config_file, strerror(errno));
return;
}
LOG(3, 0, 0, 0, "Reading config file %s\n", config->config_file);
cli_do_file(f);
LOG(3, 0, 0, 0, "Done reading config file\n");
fclose(f);
update_config();
}
int sessionsetup(tunnelidt t, sessionidt s)
{
// A session now exists, set it up
ipt ip;
char *user;
sessionidt i;
int r;
CSTAT(call_sessionsetup);
LOG(3, session[s].ip, s, t, "Doing session setup for session\n");
if (!session[s].ip || session[s].ip == 0xFFFFFFFE)
{
assign_ip_address(s);
if (!session[s].ip)
{
LOG(0, 0, s, t, " No IP allocated. The IP address pool is FULL!\n");
sessionshutdown(s, "No IP addresses available");
return 0;
}
LOG(3, 0, s, t, " No IP allocated. Assigned %s from pool\n",
inet_toa(htonl(session[s].ip)));
}
// Make sure this is right
session[s].tunnel = t;
// zap old sessions with same IP and/or username
// Don't kill gardened sessions - doing so leads to a DoS
// from someone who doesn't need to know the password
{
ip = session[s].ip;
user = session[s].user;
for (i = 1; i <= config->cluster_highest_sessionid; i++)
{
if (i == s) continue;
if (ip == session[i].ip) sessionkill(i, "Duplicate IP address");
if (!session[s].walled_garden && !session[i].walled_garden && strcasecmp(user, session[i].user) == 0)
sessionkill(i, "Duplicate session for users");
}
}
// Add the route for this session.
//
// Static IPs need to be routed. Anything else
// is part of the IP address pool and is already routed,
// it just needs to be added to the IP cache.
if (session[s].ip_pool_index == -1) // static ip
routeset(s, session[s].ip, 0, 0, 1);
else
cache_ipmap(session[s].ip, s);
for (r = 0; r < MAXROUTE && session[s].route[r].ip; r++)
routeset(s, session[s].route[r].ip, session[s].route[r].mask, session[s].ip, 1);
if (!session[s].unique_id)
{
// did this session just finish radius?
LOG(3, session[s].ip, s, t, "Sending initial IPCP to client\n");
sendipcp(t, s);
session[s].unique_id = ++last_id;
}
// Run the plugin's against this new session.
{
struct param_new_session data = { &tunnel[t], &session[s] };
run_plugins(PLUGIN_NEW_SESSION, &data);
}
// Allocate TBFs if throttled
if (session[s].throttle_in || session[s].throttle_out)
throttle_session(s, session[s].throttle_in, session[s].throttle_out);
session[s].last_packet = time_now;
{
char *sessionip, *tunnelip;
sessionip = strdup(inet_toa(htonl(session[s].ip)));
tunnelip = strdup(inet_toa(htonl(tunnel[t].ip)));
LOG(2, session[s].ip, s, t, "Login by %s at %s from %s (%s)\n",
session[s].user, sessionip, tunnelip, tunnel[t].hostname);
if (sessionip) free(sessionip);
if (tunnelip) free(tunnelip);
}
cluster_send_session(s); // Mark it as dirty, and needing to the flooded to the cluster.
return 1; // RADIUS OK and IP allocated, done...
}
//
// This session just got dropped on us by the master or something.
// Make sure our tables up up to date...
//
int load_session(sessionidt s, sessiont *new)
{
int i;
// Sanity checks.
if (new->ip_pool_index >= MAXIPPOOL ||
new->tunnel >= MAXTUNNEL)
{
LOG(0,0,s,0, "Strange session update received!\n");
// FIXME! What to do here?
return 0;
}
//
// Ok. All sanity checks passed. Now we're committed to
// loading the new session.
//
session[s].tunnel = new->tunnel; // For logging in cache_ipmap
if (new->ip != session[s].ip) // Changed ip. fix up hash tables.
{
if (session[s].ip) // If there's an old one, remove it.
{
// Remove any routes if the IP has changed
for (i = 0; i < MAXROUTE && session[s].route[i].ip; i++)
{
routeset(s, session[s].route[i].ip, session[s].route[i].mask, session[s].ip, 0);
session[s].route[i].ip = 0;
}
if (session[s].ip_pool_index == -1) // static IP
routeset(s, session[s].ip, 0, 0, 0);
else // It's part of the IP pool, remove it manually.
uncache_ipmap(session[s].ip);
}
if (new->ip)
{
// If there's a new one, add it.
if (new->ip_pool_index == -1)
routeset(s, new->ip, 0, 0, 1);
else
cache_ipmap(new->ip, s);
}
}
// Update routed networks
for (i = 0; i < MAXROUTE && (session[s].route[i].ip || new->route[i].ip); i++)
{
if (new->route[i].ip == session[s].route[i].ip &&
new->route[i].mask == session[s].route[i].mask)
continue;
if (session[s].route[i].ip) // Remove the old one if it exists.
routeset(s, session[s].route[i].ip, session[s].route[i].mask, session[s].ip, 0);
if (new->route[i].ip) // Add the new one if it exists.
routeset(s, new->route[i].ip, new->route[i].mask, new->ip, 1);
}
if (new->tunnel && s > config->cluster_highest_sessionid) // Maintain this in the slave. It's used
// for walking the sessions to forward byte counts to the master.
config->cluster_highest_sessionid = s;
// TEMP: old session struct used a u32 to define the throttle
// speed for both up/down, new uses a u16 for each. Deal with
// sessions from an old master for migration.
if (new->throttle_out == 0 && new->tbf_out)
new->throttle_out = new->throttle_in;
memcpy(&session[s], new, sizeof(session[s])); // Copy over..
// Do fixups into address pool.
if (new->ip_pool_index != -1)
fix_address_pool(s);
return 1;
}
#ifdef RINGBUFFER
void ringbuffer_dump(FILE *stream)
{
int i = ringbuffer->head;
while (i != ringbuffer->tail)
{
if (*ringbuffer->buffer[i].message)
fprintf(stream, "%d-%s", ringbuffer->buffer[i].level, ringbuffer->buffer[i].message);
if (++i == ringbuffer->tail) break;
if (i == RINGBUFFER_SIZE) i = 0;
}
}
#endif
void initplugins()
{
int i;
loaded_plugins = ll_init();
// Initialize the plugins to nothing
for (i = 0; i < MAX_PLUGIN_TYPES; i++)
plugins[i] = ll_init();
}
static void *open_plugin(char *plugin_name, int load)
{
char path[256] = "";
snprintf(path, 256, PLUGINDIR "/%s.so", plugin_name);
LOG(2, 0, 0, 0, "%soading plugin from %s\n", load ? "L" : "Un-l", path);
return dlopen(path, RTLD_NOW);
}
void add_plugin(char *plugin_name)
{
static struct pluginfuncs funcs = {
_log,
_log_hex,
inet_toa,
sessionbyuser,
sessiontbysessionidt,
sessionidtbysessiont,
sessionkill,
radiusnew,
radiussend,
};
void *p = open_plugin(plugin_name, 1);
int (*initfunc)(struct pluginfuncs *);
int i;
if (!p)
{
LOG(1, 0, 0, 0, " Plugin load failed: %s\n", dlerror());
return;
}
if (ll_contains(loaded_plugins, p))
{
dlclose(p);
return;
}
{
int *v = dlsym(p, "__plugin_api_version");
if (!v || *v != PLUGIN_API_VERSION)
{
LOG(1, 0, 0, 0, " Plugin load failed: API version mismatch: %s\n", dlerror());
dlclose(p);
return;
}
}
if ((initfunc = dlsym(p, "plugin_init")))
{
if (!initfunc(&funcs))
{
LOG(1, 0, 0, 0, " Plugin load failed: plugin_init() returned FALSE: %s\n", dlerror());
dlclose(p);
return;
}
}
ll_push(loaded_plugins, p);
for (i = 0; i < max_plugin_functions; i++)
{
void *x;
if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
{
LOG(3, 0, 0, 0, " Supports function \"%s\"\n", plugin_functions[i]);
ll_push(plugins[i], x);
}
}
LOG(2, 0, 0, 0, " Loaded plugin %s\n", plugin_name);
}
static void run_plugin_done(void *plugin)
{
int (*donefunc)(void) = dlsym(plugin, "plugin_done");
if (donefunc)
donefunc();
}
void remove_plugin(char *plugin_name)
{
void *p = open_plugin(plugin_name, 0);
int i;
if (!p)
return;
for (i = 0; i < max_plugin_functions; i++)
{
void *x;
if (plugin_functions[i] && (x = dlsym(p, plugin_functions[i])))
ll_delete(plugins[i], x);
}
if (ll_contains(loaded_plugins, p))
{
ll_delete(loaded_plugins, p);
run_plugin_done(p);
}
dlclose(p);
LOG(2, 0, 0, 0, "Removed plugin %s\n", plugin_name);
}
int run_plugins(int plugin_type, void *data)
{
int (*func)(void *data);
if (!plugins[plugin_type] || plugin_type > max_plugin_functions) return 1;
ll_reset(plugins[plugin_type]);
while ((func = ll_next(plugins[plugin_type])))
{
int rc;
rc = func(data);
if (rc == PLUGIN_RET_STOP) return 1;
if (rc == PLUGIN_RET_ERROR) return 0;
}
return 1;
}
void plugins_done()
{
void *p;
ll_reset(loaded_plugins);
while ((p = ll_next(loaded_plugins)))
run_plugin_done(p);
}
void processcontrol(u8 * buf, int len, struct sockaddr_in *addr)
{
char *resp;
int l;
struct param_control param = { buf, len, ntohl(addr->sin_addr.s_addr), ntohs(addr->sin_port), NULL, 0, 0 };
if (log_stream && config->debug >= 4)
{
LOG(4, ntohl(addr->sin_addr.s_addr), 0, 0, "Received ");
dump_packet(buf, log_stream);
}
resp = calloc(1400, 1);
l = new_packet(PKT_RESP_ERROR, resp);
*(int *)(resp + 6) = *(int *)(buf + 6);
param.type = ntohs(*(short *)(buf + 2));
param.id = ntohl(*(int *)(buf + 6));
param.data_length = ntohs(*(short *)(buf + 4)) - 10;
param.data = (param.data_length > 0) ? (char *)(buf + 10) : NULL;
param.response = resp;
param.response_length = l;
run_plugins(PLUGIN_CONTROL, &param);
if (param.send_response)
{
send_packet(controlfd, ntohl(addr->sin_addr.s_addr), ntohs(addr->sin_port), param.response, param.response_length);
LOG(4, ntohl(addr->sin_addr.s_addr), 0, 0, "Sent Control packet response\n");
}
free(resp);
}
/*
* HACK
* Go through all of the tunnels and do some cleanups
*/
void tunnel_clean()
{
int i;
LOG(1, 0, 0, 0, "Cleaning tunnels array\n");
for (i = 1; i < MAXTUNNEL; i++)
{
if (!tunnel[i].ip
|| !*tunnel[i].hostname
|| (tunnel[i].state == TUNNELDIE && tunnel[i].die >= time_now))
{
tunnelclear(i);
}
}
}
void tunnelclear(tunnelidt t)
{
if (!t) return;
memset(&tunnel[t], 0, sizeof(tunnel[t]));
tunnel[t].state = TUNNELFREE;
}
tunnelidt new_tunnel()
{
tunnelidt i;
for (i = 1; i < MAXTUNNEL; i++)
{
if (tunnel[i].state == TUNNELFREE)
{
LOG(4, 0, 0, i, "Assigning tunnel ID %d\n", i);
if (i > config->cluster_highest_tunnelid)
config->cluster_highest_tunnelid = i;
return i;
}
}
LOG(0, 0, 0, 0, "Can't find a free tunnel! There shouldn't be this many in use!\n");
return 0;
}
//
// We're becoming the master. Do any required setup..
//
// This is principally telling all the plugins that we're
// now a master, and telling them about all the sessions
// that are active too..
//
void become_master(void)
{
int s, i;
run_plugins(PLUGIN_BECOME_MASTER, NULL);
// running a bunch of iptables commands is slow and can cause
// the master to drop tunnels on takeover--kludge around the
// problem by forking for the moment (note: race)
if (!fork_and_close())
{
for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
{
if (!session[s].tunnel) // Not an in-use session.
continue;
run_plugins(PLUGIN_NEW_SESSION_MASTER, &session[s]);
}
exit(0);
}
// add radius fds
for (i = 0; i < config->num_radfds; i++)
{
if (!radfds[i]) continue;
FD_SET(radfds[i], &readset);
if (radfds[i] > readset_n)
readset_n = radfds[i];
}
}
int cmd_show_hist_idle(struct cli_def *cli, char *command, char **argv, int argc)
{
int s, i;
int count = 0;
int buckets[64];
if (CLI_HELP_REQUESTED)
return CLI_HELP_NO_ARGS;
time(&time_now);
for (i = 0; i < 64;++i) buckets[i] = 0;
for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
{
int idle;
if (!session[s].tunnel)
continue;
idle = time_now - session[s].last_packet;
idle /= 5 ; // In multiples of 5 seconds.
if (idle < 0)
idle = 0;
if (idle > 63)
idle = 63;
++count;
++buckets[idle];
}
for (i = 0; i < 63; ++i)
{
cli_print(cli, "%3d seconds : %7.2f%% (%6d)", i * 5, (double) buckets[i] * 100.0 / count , buckets[i]);
}
cli_print(cli, "lots of secs : %7.2f%% (%6d)", (double) buckets[63] * 100.0 / count , buckets[i]);
cli_print(cli, "%d total sessions open.", count);
return CLI_OK;
}
int cmd_show_hist_open(struct cli_def *cli, char *command, char **argv, int argc)
{
int s, i;
int count = 0;
int buckets[64];
if (CLI_HELP_REQUESTED)
return CLI_HELP_NO_ARGS;
time(&time_now);
for (i = 0; i < 64;++i) buckets[i] = 0;
for (s = 1; s <= config->cluster_highest_sessionid ; ++s)
{
int open = 0, d;
if (!session[s].tunnel)
continue;
d = time_now - session[s].opened;
if (d < 0)
d = 0;
while (d > 1 && open < 32)
{
++open;
d >>= 1; // half.
}
++count;
++buckets[open];
}
s = 1;
for (i = 0; i < 30; ++i)
{
cli_print(cli, " < %8d seconds : %7.2f%% (%6d)", s, (double) buckets[i] * 100.0 / count , buckets[i]);
s <<= 1;
}
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;
}
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