ircd/uping.c

   1 /*
   2  * IRC - Internet Relay Chat, ircd/uping.c
   3  * Copyright (C) 1994 Carlo Wood ( Run @ undernet.org )
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2, or (at your option)
   8  * any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19 /** @file
  20  * @brief UDP ping implementation.
  21  * @version $Id: uping.c,v 1.23 2005/03/20 16:06:30 entrope Exp $
  22  */
  23 #include "config.h"
  24
  25 #include "uping.h"
  26 #include "client.h"
  27 #include "ircd.h"
  28 #include "ircd_alloc.h"
  29 #include "ircd_events.h"
  30 #include "ircd_log.h"
  31 #include "ircd_osdep.h"
  32 #include "ircd_string.h"
  33 #include "match.h"
  34 #include "msg.h"
  35 #include "numeric.h"
  36 #include "numnicks.h"
  37 #include "s_bsd.h"    /* VirtualHost */
  38 #include "s_conf.h"
  39 #include "s_debug.h"
  40 #include "s_misc.h"
  41 #include "s_user.h"
  42 #include "send.h"
  43 #include "sys.h"
  44
  45 /* #include <assert.h> -- Now using assert in ircd_log.h */
  46 #include <errno.h>
  47 #include <netdb.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <sys/socket.h>
  52 #include <sys/time.h>
  53 #include <unistd.h>
  54
  55 #define UPINGTIMEOUT 60   /**< Timeout waiting for ping responses */
  56
  57 static struct UPing* pingList = 0; /**< Linked list of UPing structs */
  58 static struct Socket upingSock_v4; /**< Socket struct for IPv4 upings */
  59 static struct Socket upingSock_v6; /**< Socket struct for IPv6 upings */
  60
  61 /** Start iteration of uping list.
  62  * @return Start of uping list.
  63  */
  64 struct UPing* uping_begin(void)
  65 {
  66   return pingList;
  67 }
  68
  69 /** Removes \a p from uping list.
  70  * @param[in,out] p UPing to remove from list.
  71  */
  72 static void uping_erase(struct UPing* p)
  73 {
  74   struct UPing* it;
  75   struct UPing* last = 0;
  76
  77   assert(0 != p);
  78
  79   for (it = pingList; it; last = it, it = it->next) {
  80     if (p == it) {
  81       if (last)
  82         last->next = p->next;
  83       else
  84         pingList = p->next;
  85       break;
  86     }
  87   }
  88 }
  89
  90 /** Callback for uping listener socket.
  91  * Reads a uping from the socket and respond, but not more than 10
  92  * times per second.
  93  * @param[in] ev I/O event for uping socket.
  94  */
  95 static void uping_echo_callback(struct Event* ev)
  96 {
  97   struct Socket      *sock;
  98   struct irc_sockaddr from;
  99   unsigned int       len = 0;
 100   static time_t      last = 0;
 101   static int         counter = 0;
 102   char               buf[BUFSIZE + 1];
 103
 104   assert(ev_type(ev) == ET_READ || ev_type(ev) == ET_ERROR);
 105   sock = ev_socket(ev);
 106   assert(sock == &upingSock_v4 || sock == &upingSock_v6);
 107
 108   Debug((DEBUG_DEBUG, "UPING: uping_echo"));
 109
 110   if (IO_SUCCESS != os_recvfrom_nonb(s_fd(sock), buf, BUFSIZE, &len, &from))
 111     return;
 112   /*
 113    * count em even if we're getting flooded so we can tell we're getting
 114    * flooded.
 115    */
 116   ++ServerStats->uping_recv;
 117   if (len < 19)
 118     return;
 119   else if (CurrentTime != last) {
 120     counter = 0;
 121     last = CurrentTime;
 122   } else if (++counter > 10)
 123     return;
 124   os_sendto_nonb(s_fd(sock), buf, len, NULL, 0, &from);
 125 }
 126
 127 /** Initialize a UDP socket for upings.
 128  * @returns 0 on success, -1 on error.
 129  */
 130 int uping_init(void)
 131 {
 132   struct irc_sockaddr from;
 133   int fd;
 134
 135   memcpy(&from, &VirtualHost_v4, sizeof(from));
 136   from.port = atoi(UDP_PORT);
 137
 138   fd = os_socket(&from, SOCK_DGRAM, "IPv4 uping listener");
 139   if (fd < 0)
 140     return -1;
 141   if (!socket_add(&upingSock_v4, uping_echo_callback, 0, SS_DATAGRAM,
 142                   SOCK_EVENT_READABLE, fd)) {
 143     Debug((DEBUG_ERROR, "UPING: Unable to queue fd to event system"));
 144     close(fd);
 145     return -1;
 146   }
 147
 148   memcpy(&from, &VirtualHost_v6, sizeof(from));
 149   from.port = atoi(UDP_PORT);
 150
 151   fd = os_socket(&from, SOCK_DGRAM, "IPv6 uping listener");
 152   if (fd < 0)
 153     return -1;
 154   if (!socket_add(&upingSock_v6, uping_echo_callback, 0, SS_DATAGRAM,
 155                   SOCK_EVENT_READABLE, fd)) {
 156     Debug((DEBUG_ERROR, "UPING: Unable to queue fd to event system"));
 157     close(fd);
 158     return -1;
 159   }
 160
 161   return 0;
 162 }
 163
 164
 165 /** Callback for socket activity on an outbound uping socket.
 166  * @param[in] ev I/O event for socket.
 167  */
 168 static void uping_read_callback(struct Event* ev)
 169 {
 170   struct UPing *pptr;
 171
 172   assert(0 != ev_socket(ev));
 173   assert(0 != s_data(ev_socket(ev)));
 174
 175   pptr = (struct UPing*) s_data(ev_socket(ev));
 176
 177   Debug((DEBUG_SEND, "uping_read_callback called, %p (%d)", pptr,
 178          ev_type(ev)));
 179
 180   if (ev_type(ev) == ET_DESTROY) { /* being destroyed */
 181     pptr->freeable &= ~UPING_PENDING_SOCKET;
 182
 183     if (!pptr->freeable)
 184       MyFree(pptr); /* done with it, finally */
 185   } else {
 186     assert(ev_type(ev) == ET_READ || ev_type(ev) == ET_ERROR);
 187
 188     uping_read(pptr); /* read uping response */
 189   }
 190 }
 191
 192 /** Timer callback to send another outbound uping.
 193  * @param[in] ev Event for uping timer.
 194  */
 195 static void uping_sender_callback(struct Event* ev)
 196 {
 197   struct UPing *pptr;
 198
 199   assert(0 != ev_timer(ev));
 200   assert(0 != t_data(ev_timer(ev)));
 201
 202   pptr = (struct UPing*) t_data(ev_timer(ev));
 203
 204   Debug((DEBUG_SEND, "uping_sender_callback called, %p (%d)", pptr,
 205          ev_type(ev)));
 206
 207   if (ev_type(ev) == ET_DESTROY) { /* being destroyed */
 208     pptr->freeable &= ~UPING_PENDING_SENDER;
 209
 210     if (!pptr->freeable)
 211       MyFree(pptr); /* done with it, finally */
 212   } else {
 213     assert(ev_type(ev) == ET_EXPIRE);
 214
 215     pptr->lastsent = CurrentTime; /* store last ping time */
 216     uping_send(pptr); /* send a ping */
 217
 218     if (pptr->sent == pptr->count) /* done sending pings, don't send more */
 219       timer_del(ev_timer(ev));
 220   }
 221 }
 222
 223 /** Timer callback to stop upings.
 224  * @param[in] ev Event for uping expiration.
 225  */
 226 static void uping_killer_callback(struct Event* ev)
 227 {
 228   struct UPing *pptr;
 229
 230   assert(0 != ev_timer(ev));
 231   assert(0 != t_data(ev_timer(ev)));
 232
 233   pptr = (struct UPing*) t_data(ev_timer(ev));
 234
 235   Debug((DEBUG_SEND, "uping_killer_callback called, %p (%d)", pptr,
 236          ev_type(ev)));
 237
 238   if (ev_type(ev) == ET_DESTROY) { /* being destroyed */
 239     pptr->freeable &= ~UPING_PENDING_KILLER;
 240
 241     if (!pptr->freeable)
 242       MyFree(pptr); /* done with it, finally */
 243   } else {
 244     assert(ev_type(ev) == ET_EXPIRE);
 245
 246     uping_end(pptr); /* <FUDD>kill the uping, kill the uping!</FUDD> */
 247   }
 248 }
 249
 250 /** Start a uping.
 251  * This sets up the timers, UPing flags, and sends a notice to the
 252  * requesting client.
 253  */
 254 static void uping_start(struct UPing* pptr)
 255 {
 256   assert(0 != pptr);
 257
 258   timer_add(timer_init(&pptr->sender), uping_sender_callback, (void*) pptr,
 259             TT_PERIODIC, 1);
 260   timer_add(timer_init(&pptr->killer), uping_killer_callback, (void*) pptr,
 261             TT_RELATIVE, UPINGTIMEOUT);
 262   pptr->freeable |= UPING_PENDING_SENDER | UPING_PENDING_KILLER;
 263
 264   sendcmdto_one(&me, CMD_NOTICE, pptr->client, "%C :Sending %d ping%s to %s",
 265                 pptr->client, pptr->count, (pptr->count == 1) ? "" : "s",
 266                 pptr->name);
 267   pptr->active = 1;
 268 }
 269
 270 /** Send a uping to another server.
 271  * @param[in] pptr Descriptor for uping.
 272  */
 273 void uping_send(struct UPing* pptr)
 274 {
 275   struct timeval tv;
 276   char buf[BUFSIZE + 1];
 277
 278   assert(0 != pptr);
 279   if (pptr->sent == pptr->count)
 280     return;
 281   memset(buf, 0, sizeof(buf));
 282
 283   gettimeofday(&tv, NULL);
 284   sprintf(buf, " %10lu%c%6lu", (unsigned long)tv.tv_sec, '\0', (unsigned long)tv.tv_usec);
 285
 286   Debug((DEBUG_SEND, "send_ping: sending [%s %s] to %s.%d on %d",
 287           buf, &buf[12],
 288           ircd_ntoa(&pptr->addr.addr), pptr->addr.port,
 289           pptr->fd));
 290
 291   if (os_sendto_nonb(pptr->fd, buf, BUFSIZE, NULL, 0, &pptr->addr) != IO_SUCCESS)
 292   {
 293     const char* msg = strerror(errno);
 294     if (!msg)
 295       msg = "Unknown error";
 296     if (pptr->client)
 297       sendcmdto_one(&me, CMD_NOTICE, pptr->client, "%C :UPING: send failed: "
 298                     "%s", pptr->client, msg);
 299     Debug((DEBUG_DEBUG, "UPING: send_ping: sendto failed on %d: %s", pptr->fd, msg));
 300     uping_end(pptr);
 301     return;
 302   }
 303   ++pptr->sent;
 304 }
 305
 306 /** Read the response from an outbound uping.
 307  * @param[in] pptr UPing to check.
 308  */
 309 void uping_read(struct UPing* pptr)
 310 {
 311   struct irc_sockaddr sin;
 312   struct timeval     tv;
 313   unsigned int       len;
 314   unsigned int       pingtime;
 315   char*              s;
 316   char               buf[BUFSIZE + 1];
 317   IOResult           ior;
 318
 319   assert(0 != pptr);
 320
 321   gettimeofday(&tv, NULL);
 322
 323   ior = os_recvfrom_nonb(pptr->fd, buf, BUFSIZE, &len, &sin);
 324   if (IO_BLOCKED == ior)
 325     return;
 326   else if (IO_FAILURE == ior) {
 327     const char* msg = strerror(errno);
 328     if (!msg)
 329       msg = "Unknown error";
 330     sendcmdto_one(&me, CMD_NOTICE, pptr->client, "%C :UPING: receive error: "
 331                   "%s", pptr->client, msg);
 332     uping_end(pptr);
 333     return;
 334   }
 335
 336   if (len < 19)
 337     return;                     /* Broken packet */
 338
 339   ++pptr->received;
 340
 341   buf[len] = 0;
 342   pingtime = (tv.tv_sec - atol(&buf[1])) * 1000
 343              + (tv.tv_usec - atol(buf + strlen(buf) + 1)) / 1000;
 344
 345   pptr->ms_ave += pingtime;
 346   if (!pptr->ms_min || pptr->ms_min > pingtime)
 347     pptr->ms_min = pingtime;
 348   if (pingtime > pptr->ms_max)
 349     pptr->ms_max = pingtime;
 350
 351   timer_chg(&pptr->killer, TT_RELATIVE, UPINGTIMEOUT);
 352
 353   s = pptr->buf + strlen(pptr->buf);
 354   sprintf(s, " %u", pingtime);
 355
 356   if (pptr->received == pptr->count)
 357     uping_end(pptr);
 358   return;
 359 }
 360
 361 /** Start sending upings to a server.
 362  * @param[in] sptr Client requesting the upings.
 363  * @param[in] aconf ConfItem containing the address to ping.
 364  * @param[in] port Port number to ping.
 365  * @param[in] count Number of times to ping (should be at least 20).
 366  * @return Zero.
 367  */
 368 int uping_server(struct Client* sptr, struct ConfItem* aconf, int port, int count)
 369 {
 370   int fd;
 371   struct UPing* pptr;
 372   struct irc_sockaddr *local;
 373
 374   assert(0 != sptr);
 375   assert(0 != aconf);
 376
 377   if (!irc_in_addr_valid(&aconf->address.addr)) {
 378     sendcmdto_one(&me, CMD_NOTICE, sptr, "%C :UPING: Host lookup failed for "
 379                   "%s", sptr, aconf->name);
 380     return 0;
 381   }
 382
 383   if (IsUPing(sptr))
 384     uping_cancel(sptr, sptr);  /* Cancel previous ping request */
 385
 386   local = irc_in_addr_is_ipv4(&aconf->address.addr) ? &VirtualHost_v4 : &VirtualHost_v6;
 387   fd = os_socket(local, SOCK_DGRAM, "Outbound uping socket");
 388   if (fd < 0)
 389     return 0;
 390
 391   pptr = (struct UPing*) MyMalloc(sizeof(struct UPing));
 392   assert(0 != pptr);
 393   memset(pptr, 0, sizeof(struct UPing));
 394
 395   if (!socket_add(&pptr->socket, uping_read_callback, (void*) pptr,
 396                   SS_DATAGRAM, SOCK_EVENT_READABLE, fd)) {
 397     sendcmdto_one(&me, CMD_NOTICE, sptr, "%C :UPING: Can't queue fd for "
 398                   "reading", sptr);
 399     close(fd);
 400     MyFree(pptr);
 401     return 0;
 402   }
 403
 404   pptr->fd                  = fd;
 405   memcpy(&pptr->addr.addr, &aconf->address.addr, sizeof(pptr->addr.addr));
 406   pptr->addr.port           = port;
 407   pptr->count               = IRCD_MIN(20, count);
 408   pptr->client              = sptr;
 409   pptr->freeable            = UPING_PENDING_SOCKET;
 410   strcpy(pptr->name, aconf->name);
 411
 412   pptr->next = pingList;
 413   pingList   = pptr;
 414
 415   SetUPing(sptr);
 416   uping_start(pptr);
 417   return 0;
 418 }
 419
 420 /** Clean up a UPing structure, reporting results to the requester.
 421  * @param[in,out] pptr UPing results.
 422  */
 423 void uping_end(struct UPing* pptr)
 424 {
 425   Debug((DEBUG_DEBUG, "uping_end: %p", pptr));
 426
 427   if (pptr->client) {
 428     if (pptr->lastsent) {
 429       if (0 < pptr->received) {
 430         sendcmdto_one(&me, CMD_NOTICE, pptr->client, "%C :UPING %s%s",
 431                       pptr->client, pptr->name, pptr->buf);
 432         sendcmdto_one(&me, CMD_NOTICE, pptr->client, "%C :UPING Stats: "
 433                       "sent %d recvd %d ; min/avg/max = %1lu/%1lu/%1lu ms",
 434                       pptr->client, pptr->sent, pptr->received, pptr->ms_min,
 435                       (2 * pptr->ms_ave) / (2 * pptr->received), pptr->ms_max);
 436       } else
 437         sendcmdto_one(&me, CMD_NOTICE, pptr->client, "%C :UPING: no response "
 438                       "from %s within %d seconds", pptr->client, pptr->name,
 439                       UPINGTIMEOUT);
 440     } else
 441       sendcmdto_one(&me, CMD_NOTICE, pptr->client, "%C :UPING: Could not "
 442                     "start ping to %s", pptr->client, pptr->name);
 443   }
 444
 445   close(pptr->fd);
 446   pptr->fd = -1;
 447   uping_erase(pptr);
 448   if (pptr->client)
 449     ClearUPing(pptr->client);
 450   if (pptr->freeable & UPING_PENDING_SOCKET)
 451     socket_del(&pptr->socket);
 452   if (pptr->freeable & UPING_PENDING_SENDER)
 453     timer_del(&pptr->sender);
 454   if (pptr->freeable & UPING_PENDING_KILLER)
 455     timer_del(&pptr->killer);
 456 }
 457
 458 /** Change notifications for any upings by \a sptr.
 459  * @param[in] sptr Client to stop notifying.
 460  * @param[in] acptr New client to notify (or NULL).
 461  */
 462 void uping_cancel(struct Client *sptr, struct Client* acptr)
 463 {
 464   struct UPing* ping;
 465   struct UPing* ping_next;
 466
 467   Debug((DEBUG_DEBUG, "UPING: canceling uping for %s", cli_name(sptr)));
 468   for (ping = pingList; ping; ping = ping_next) {
 469     ping_next = ping->next;
 470     if (sptr == ping->client) {
 471       ping->client = acptr;
 472       uping_end(ping);
 473     }
 474   }
 475   ClearUPing(sptr);
 476 }
 477
 478