// 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 1.131 2005-09-13 14:27:14 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.142 2005-09-19 02:39:57 bodea Exp $";
#include <arpa/inet.h>
#include <assert.h>
static FILE *log_stream = 0; // file handle for direct logging (i.e. direct into file, not via syslog).
uint32_t last_id = 0; // Unique ID for radius accounting
+// calculated from config->l2tp_mtu
+uint16_t MRU = 0; // PPP MRU
+uint16_t MSS = 0; // TCP MSS
+
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 uint32_t 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.
static char time_now_string[64] = {0}; // Current time as a string.
+int time_changed = 0; // time_now changed
char main_quit = 0; // True if we're in the process of exiting.
+char main_reload = 0; // Re-load pending
linked_list *loaded_plugins;
linked_list *plugins[MAX_PLUGIN_TYPES];
CONFIG("log_file", log_filename, STRING),
CONFIG("pid_file", pid_file, STRING),
CONFIG("random_device", random_device, STRING),
- CONFIG("l2tp_secret", l2tpsecret, STRING),
+ CONFIG("l2tp_secret", l2tp_secret, STRING),
+ CONFIG("l2tp_mtu", l2tp_mtu, INT),
CONFIG("ppp_restart_time", ppp_restart_time, INT),
CONFIG("ppp_max_configure", ppp_max_configure, INT),
CONFIG("ppp_max_failure", ppp_max_failure, INT),
static void free_ip_address(sessionidt s);
static void dump_acct_info(int all);
static void sighup_handler(int sig);
-static void sigalrm_handler(int sig);
static void shutdown_handler(int sig);
static void sigchild_handler(int sig);
static void build_chap_response(uint8_t *challenge, uint8_t id, uint16_t challenge_length, uint8_t **challenge_response);
#define QUIT_SHUTDOWN 2 // SIGQUIT: shutdown sessions/tunnels, reject new connections
// return internal time (10ths since process startup), set f if given
+// as a side-effect sets time_now, and time_changed
static clockt now(double *f)
{
struct timeval t;
gettimeofday(&t, 0);
if (f) *f = t.tv_sec + t.tv_usec / 1000000.0;
+ if (t.tv_sec != time_now)
+ {
+ time_now = t.tv_sec;
+ time_changed++;
+ }
return (t.tv_sec - basetime) * 10 + t.tv_usec / 100000 + 1;
}
return write(tunfd, data, size);
}
+// adjust tcp mss to avoid fragmentation (called only for tcp packets with syn set)
+void adjust_tcp_mss(sessionidt s, tunnelidt t, uint8_t *buf, int len, uint8_t *tcp)
+{
+ int d = (tcp[12] >> 4) * 4;
+ uint8_t *mss = 0;
+ uint8_t *opts;
+ uint8_t *data;
+ uint16_t orig;
+ uint32_t sum;
+
+ if ((tcp[13] & 0x3f) & ~(TCP_FLAG_SYN|TCP_FLAG_ACK)) // only want SYN and SYN,ACK
+ return;
+
+ if (tcp + d > buf + len) // short?
+ return;
+
+ opts = tcp + 20;
+ data = tcp + d;
+
+ while (opts < data)
+ {
+ if (*opts == 2 && opts[1] == 4) // mss option (2), length 4
+ {
+ mss = opts + 2;
+ if (mss + 2 > data) return; // short?
+ break;
+ }
+
+ if (*opts == 0) return; // end of options
+ if (*opts == 1 || !opts[1]) // no op (one byte), or no length (prevent loop)
+ opts++;
+ else
+ opts += opts[1]; // skip over option
+ }
+
+ if (!mss) return; // not found
+ orig = ntohs(*(uint16_t *) mss);
+
+ if (orig <= MSS) return; // mss OK
+
+ LOG(5, s, t, "TCP: %s:%u -> %s:%u SYN%s: adjusted mss from %u to %u\n",
+ fmtaddr(*(in_addr_t *) (buf + 12), 0), ntohs(*(uint16_t *) tcp),
+ fmtaddr(*(in_addr_t *) (buf + 16), 1), ntohs(*(uint16_t *) (tcp + 2)),
+ (tcp[13] & TCP_FLAG_ACK) ? ",ACK" : "", orig, MSS);
+
+ // set mss
+ *(int16_t *) mss = htons(MSS);
+
+ // adjust checksum (see rfc1141)
+ sum = orig + (~MSS & 0xffff);
+ sum += ntohs(*(uint16_t *) (tcp + 16));
+ sum = (sum & 0xffff) + (sum >> 16);
+ *(uint16_t *) (tcp + 16) = htons(sum);
+}
+
// process outgoing (to tunnel) IP
//
static void processipout(uint8_t *buf, int len)
if (session[s].filter_out && !ip_filter(buf, len, session[s].filter_out - 1))
return;
+ // adjust MSS on SYN and SYN,ACK packets with options
+ if ((ntohs(*(uint16_t *) (buf + 6)) & 0x1fff) == 0 && buf[9] == IPPROTO_TCP) // first tcp fragment
+ {
+ int ihl = (buf[0] & 0xf) * 4; // length of IP header
+ if (len >= ihl + 20 && (buf[ihl + 13] & TCP_FLAG_SYN) && ((buf[ihl + 12] >> 4) > 5))
+ adjust_tcp_mss(s, t, buf, len, buf + ihl);
+ }
+
if (sp->tbf_out)
{
// Are we throttling this session?
uint16_t orig_len;
// handle hidden AVPs
- if (!*config->l2tpsecret)
+ if (!*config->l2tp_secret)
{
LOG(1, s, t, "Hidden AVP requested, but no L2TP secret.\n");
fatal = flags;
if (amagic == 0) amagic = time_now;
session[s].magic = amagic; // set magic number
session[s].l2tp_flags = aflags; // set flags received
- session[s].mru = DEFAULT_MRU;
+ session[s].mru = PPPMTU; // default
controlnull(t); // ack
// start LCP
sess_local[s].lcp.conf_sent = 1;
sess_local[s].lcp.nak_sent = 0;
sess_local[s].lcp_authtype = config->radius_authprefer;
+ sess_local[s].ppp_mru = MRU;
session[s].ppp.lcp = RequestSent;
sendlcp(s, t);
uint8_t buf[MAXETHER];
uint8_t *q;
int mru = session[s].mru;
-
- if (!mru) mru = MAXMRU;
if (mru > sizeof(buf)) mru = sizeof(buf);
l += 6;
if (l > mru) l = mru;
- q = makeppp(buf, sizeof(buf), 0, 0, s, t, proto);
+ q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPLCP);
if (!q) return;
- *q = CodeRej;
+ *q = ProtocolRej;
*(q + 1) = ++sess_local[s].lcp_ident;
- *(uint16_t *)(q + 2) = l;
+ *(uint16_t *)(q + 2) = htons(l);
*(uint16_t *)(q + 4) = htons(proto);
memcpy(q + 6, p, l - 6);
int more = 0;
int n;
+
+ if (main_reload)
+ {
+ main_reload = 0;
+ read_config_file();
+ config->reload_config++;
+ }
+
if (config->reload_config)
{
- // Update the config state based on config settings
+ config->reload_config = 0;
update_config();
}
}
}
+ if (time_changed)
+ {
+ double Mbps = 1024.0 * 1024.0 / 8 * time_changed;
+
+ // 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 / Mbps), (eth_tx / Mbps), (eth_rx / Mbps), (udp_tx / Mbps),
+ ((udp_tx + udp_rx + eth_tx + eth_rx) / Mbps),
+ udp_rx_pkt / time_changed, eth_rx_pkt / time_changed);
+
+ udp_tx = udp_rx = 0;
+ udp_rx_pkt = eth_rx_pkt = 0;
+ eth_tx = eth_rx = 0;
+ time_changed = 0;
+
+ if (config->dump_speed)
+ printf("%s\n", config->bandwidth);
+
+ // Update the internal time counter
+ strftime(time_now_string, sizeof(time_now_string), "%Y-%m-%d %H:%M:%S", localtime(&time_now));
+
+ {
+ // Run timer hooks
+ struct param_timer p = { time_now };
+ run_plugins(PLUGIN_TIMER, &p);
+ }
+ }
+
// Runs on every machine (master and slaves).
if (next_cluster_ping <= TIME)
{
// 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);
initplugins();
initdata(optdebug, optconfig);
init_cli(hostname);
read_config_file();
+ update_config();
init_tbf(config->num_tbfs);
LOG(0, 0, 0, "L2TPNS version " VERSION "\n");
LOG(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);
static void sighup_handler(int sig)
{
- if (log_stream)
- {
- if (log_stream != stderr)
- fclose(log_stream);
-
- log_stream = NULL;
- }
-
- read_config_file();
-}
-
-static void sigalrm_handler(int sig)
-{
- // 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);
- }
-
+ main_reload++;
}
static void shutdown_handler(int sig)
{
- LOG(1, 0, 0, "Shutting down\n");
main_quit = (sig == SIGQUIT) ? QUIT_SHUTDOWN : QUIT_FAILOVER;
}
MD5_CTX ctx;
*challenge_response = NULL;
- if (!*config->l2tpsecret)
+ if (!*config->l2tp_secret)
{
LOG(0, 0, 0, "LNS requested CHAP authentication, but no l2tp secret is defined\n");
return;
MD5_Init(&ctx);
MD5_Update(&ctx, &id, 1);
- MD5_Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
+ MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
MD5_Update(&ctx, challenge, challenge_length);
MD5_Final(*challenge_response, &ctx);
setbuf(log_stream, NULL);
}
+#define L2TP_HDRS (20+8+6+4) // L2TP data encaptulation: ip + udp + l2tp (data) + ppp (inc hdlc)
+#define TCP_HDRS (20+20) // TCP encapsulation: ip + tcp
+
+ if (config->l2tp_mtu <= 0) config->l2tp_mtu = PPPMTU;
+ else if (config->l2tp_mtu < MINMTU) config->l2tp_mtu = MINMTU;
+ else if (config->l2tp_mtu > MAXMTU) config->l2tp_mtu = MAXMTU;
+
+ // reset MRU/MSS globals
+ MRU = config->l2tp_mtu - L2TP_HDRS;
+ MSS = MRU - TCP_HDRS;
+
// Update radius
config->numradiusservers = 0;
for (i = 0; i < MAXRADSERVER; i++)
LOG(0, 0, 0, "Can't write to PID file %s: %s\n", config->pid_file, strerror(errno));
}
}
-
- config->reload_config = 0;
}
static void read_config_file()
cli_do_file(f);
LOG(3, 0, 0, "Done reading config file\n");
fclose(f);
- update_config();
}
int sessionsetup(sessionidt s, tunnelidt t)
// Compute initial pad
MD5_Init(&ctx);
MD5_Update(&ctx, (unsigned char *) &m, 2);
- MD5_Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
+ MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
MD5_Update(&ctx, vector, vec_len);
MD5_Final(digest, &ctx);
if (d >= sizeof(digest))
{
MD5_Init(&ctx);
- MD5_Update(&ctx, config->l2tpsecret, strlen(config->l2tpsecret));
+ MD5_Update(&ctx, config->l2tp_secret, strlen(config->l2tp_secret));
MD5_Update(&ctx, last, sizeof(digest));
MD5_Final(digest, &ctx);
projects / l2tpns.git / blobdiff