source: trunk/third/moira/server/mr_main.c @ 24250

Revision 24250, 10.7 KB checked in by broder, 15 years ago (diff)
New Moira snapshot from subversion. Sorry for the large diff - looks like all of the keywords changed in the SVN import process.
Line 
1/* $Id: mr_main.c,v 1.56 2009-06-01 21:05:02 zacheiss Exp $
2 *
3 * Moira server process.
4 *
5 * Copyright (C) 1987-1998 by the Massachusetts Institute of Technology
6 * For copying and distribution information, please see the file
7 * <mit-copyright.h>.
8 *
9 */
10
11#include <mit-copyright.h>
12#include "mr_server.h"
13
14#include <sys/socket.h>
15#include <sys/stat.h>
16#include <sys/types.h>
17#include <sys/utsname.h>
18#include <sys/wait.h>
19
20#include <netinet/in.h>
21#include <arpa/inet.h>
22
23#include <ctype.h>
24#include <errno.h>
25#include <signal.h>
26#include <stdio.h>
27#include <stdlib.h>
28#include <string.h>
29#include <unistd.h>
30
31#ifdef HAVE_KRB4
32#include <krb.h>
33#endif
34#include <krb5.h>
35
36RCSID("$Header: /afs/.athena.mit.edu/astaff/project/moiradev/repository/moira/server/mr_main.c,v 1.56 2009-06-01 21:05:02 zacheiss Exp $");
37
38client *cur_client;
39
40char *whoami;
41char *takedown;
42FILE *journal;
43
44time_t now;
45
46char *host;
47krb5_context context = NULL;
48char *krb_realm = NULL;
49
50/* Client array and associated data. This needs to be global for _list_users */
51client **clients;
52int nclients, clientssize;
53
54int dormant;
55int child_exited_abnormally = 0;
56int child_pid, child_signal, child_status;
57
58void reapchild(int x);
59void godormant(int x);
60void gowakeup(int x);
61void clist_append(client *cp);
62void mr_setup_signals(void);
63
64/*
65 * Main Moira server loop.
66 *
67 * Initialize the world, then start accepting connections and
68 * making progress on current connections.
69 */
70
71int main(int argc, char **argv)
72{
73  int status, i, listener;
74  time_t tardy;
75  char *port, *p;
76  extern char *database;
77  struct stat stbuf;
78  struct utsname uts;
79  fd_set readfds, writefds, xreadfds, xwritefds;
80  int nfds, counter = 0;
81
82  whoami = argv[0];
83  /*
84   * Error handler init.
85   */
86  mr_init();
87  set_com_err_hook(mr_com_err);
88  setvbuf(stderr, NULL, _IOLBF, BUFSIZ);
89
90  port = strchr(MOIRA_SERVER, ':') + 1;
91
92  for (i = 1; i < argc; i++)
93    {
94      if (!strcmp(argv[i], "-db") && i + 1 < argc)
95        {
96          database = argv[i + 1];
97          i++;
98        }
99      else if (!strcmp(argv[i], "-p") && i + 1 < argc)
100        {
101          port = argv[i + 1];
102          i++;
103        }
104      else
105        {
106          com_err(whoami, 0, "Usage: moirad [-db database][-p port]");
107          exit(1);
108        }
109    }
110
111  status = krb5_init_context(&context);
112  if (status)
113    {
114      com_err(whoami, status, "Initializing krb5 context.");
115      exit(1);
116    }
117
118  status = krb5_get_default_realm(context, &krb_realm);
119  if (status)
120    {
121      com_err(whoami, status, "Getting default Kerberos realm.");
122      exit(1);
123    }
124
125  /*
126   * Database initialization.  Only init if database should be open.
127   */
128
129  if (stat(MOIRA_MOTD_FILE, &stbuf) != 0)
130    {
131      if ((status = mr_open_database()))
132        {
133          com_err(whoami, status, "trying to open database.");
134          exit(1);
135        }
136      sanity_check_database();
137    }
138  else
139    {
140      dormant = ASLEEP;
141      com_err(whoami, 0, "sleeping, not opening database");
142    }
143
144  sanity_check_queries();
145
146  /*
147   * Get moira server hostname for authentication
148   */
149  if (uname(&uts) < 0)
150    {
151      com_err(whoami, errno, "Unable to get local hostname");
152      exit(1);
153    }
154  host = canonicalize_hostname(xstrdup(uts.nodename));
155  for (p = host; *p && *p != '.'; p++)
156    {
157      if (isupper(*p))
158        *p = tolower(*p);
159    }
160  *p = '\0';
161
162  /*
163   * Set up client array handler.
164   */
165  nclients = 0;
166  clientssize = 10;
167  clients = xmalloc(clientssize * sizeof(client *));
168
169  mr_setup_signals();
170
171  journal = fopen(JOURNAL, "a");
172  if (!journal)
173    {
174      com_err(whoami, errno, "opening journal file");
175      exit(1);
176    }
177
178  /*
179   * Establish template connection.
180   */
181  listener = mr_listen(port);
182  if (listener == -1)
183    {
184      com_err(whoami, MR_ABORTED, "trying to create listening connection");
185      exit(1);
186    }
187  FD_ZERO(&xreadfds);
188  FD_ZERO(&xwritefds);
189  FD_SET(listener, &xreadfds);
190  nfds = listener + 1;
191
192  com_err(whoami, 0, "started (pid %d)", getpid());
193  com_err(whoami, 0, rcsid);
194  if (dormant != ASLEEP)
195    send_zgram("MOIRA", "server started");
196  else
197    send_zgram("MOIRA", "server started, but database closed");
198
199  /*
200   * Run until shut down.
201   */
202  while (!takedown)
203    {
204      int i;
205      struct timeval timeout = {60, 0}; /* 1 minute */
206
207      /* If we're supposed to go down and we can, do it */
208      if (((dormant == AWAKE) && (nclients == 0) &&
209           (stat(MOIRA_MOTD_FILE, &stbuf) == 0)) ||
210          (dormant == SLEEPY))
211        {
212          mr_close_database();
213          com_err(whoami, 0, "database closed");
214          mr_setup_signals();
215          send_zgram("MOIRA", "database closed");
216          dormant = ASLEEP;
217        }
218
219      /* Block until something happens. */
220      memcpy(&readfds, &xreadfds, sizeof(readfds));
221      memcpy(&writefds, &xwritefds, sizeof(writefds));
222      if (select(nfds, &readfds, &writefds, NULL, &timeout) == -1)
223        {
224          if (errno != EINTR)
225            com_err(whoami, errno, "in select");
226          if (!inc_running || now - inc_started > INC_TIMEOUT)
227            next_incremental();
228          continue;
229        }
230
231      if (takedown)
232        break;
233
234      if (child_exited_abnormally)
235        {
236          critical_alert(whoami, "moirad", "%d: child exits with signal %d status %d",
237                         child_pid, child_signal, child_status);
238          child_exited_abnormally = 0;
239        }
240
241      time(&now);
242      if (!inc_running || now - inc_started > INC_TIMEOUT)
243        next_incremental();
244      tardy = now - 30 * 60;
245
246      /* If we're asleep and we should wake up, do it */
247      if ((dormant == ASLEEP) && (stat(MOIRA_MOTD_FILE, &stbuf) == -1) &&
248          (errno == ENOENT))
249        {
250          mr_open_database();
251          com_err(whoami, 0, "database open");
252          mr_setup_signals();
253          send_zgram("MOIRA", "database open again");
254          dormant = AWAKE;
255        }
256
257      /* Handle any new connections */
258      if (FD_ISSET(listener, &readfds))
259        {
260          int newconn, addrlen = sizeof(struct sockaddr_in);
261          struct sockaddr_in addr;
262          client *cp;
263
264          newconn = accept(listener, (struct sockaddr *)&addr, &addrlen);
265          if (newconn == -1)
266            com_err(whoami, errno, "accepting new connection");
267          else if (newconn > 0)
268            {
269              if (newconn + 1 > nfds)
270                nfds = newconn + 1;
271              FD_SET(newconn, &xreadfds);
272
273              /* Add a new client to the array */
274              nclients++;
275              if (nclients > clientssize)
276                {
277                  clientssize = 2 * clientssize;
278                  clients = xrealloc(clients, clientssize * sizeof(client *));
279                }
280
281              clients[nclients - 1] = cp = xmalloc(sizeof(client));
282              memset(cp, 0, sizeof(client));
283              cp->con = newconn;
284              cp->id = counter++;
285              cp->last_time_used = now;
286              cp->haddr = addr;
287              cp->tuplessize = 1;
288              cp->tuples = xmalloc(sizeof(mr_params));
289              memset(cp->tuples, 0, sizeof(mr_params));
290              cp->state = CL_ACCEPTING;
291              cp->version = 2;
292
293              cur_client = cp;
294              com_err(whoami, 0,
295                      "New connection from %s port %d (now %d client%s)",
296                      inet_ntoa(cp->haddr.sin_addr),
297                      (int)ntohs(cp->haddr.sin_port),
298                      nclients, nclients != 1 ? "s" : "");
299            }
300        }
301
302      /* Handle any existing connections. */
303      for (i = 0; i < nclients; i++)
304        {
305          cur_client = clients[i];
306
307          if (FD_ISSET(clients[i]->con, &writefds))
308            {
309              client_write(clients[i]);
310              if (!clients[i]->ntuples)
311                {
312                  FD_CLR(clients[i]->con, &xwritefds);
313                  FD_SET(clients[i]->con, &xreadfds);
314                }
315              clients[i]->last_time_used = now;
316            }
317
318          if (FD_ISSET(clients[i]->con, &readfds))
319            {
320              if (clients[i]->state == CL_ACCEPTING)
321                {
322                  switch(mr_cont_accept(clients[i]->con,
323                                        &clients[i]->hsbuf,
324                                        &clients[i]->hslen))
325                    {
326                    case -1:
327                      break;
328
329                    case 0:
330                      clients[i]->state = CL_CLOSING;
331                      break;
332
333                    default:
334                      clients[i]->state = CL_ACTIVE;
335                      clients[i]->hsbuf = NULL;
336                      break;
337                    }
338                }
339              else
340                {
341                  client_read(clients[i]);
342                  if (clients[i]->ntuples)
343                    {
344                      FD_CLR(clients[i]->con, &xreadfds);
345                      FD_SET(clients[i]->con, &xwritefds);
346                    }
347                  clients[i]->last_time_used = now;
348                }
349            }
350
351          if (clients[i]->last_time_used < tardy)
352            {
353              com_err(whoami, 0, "Shutting down connection due to inactivity");
354              clients[i]->state = CL_CLOSING;
355            }
356
357          if (clients[i]->state == CL_CLOSING)
358            {
359              client *old;
360
361              com_err(whoami, 0, "Closed connection (now %d client%s, "
362                      "%d queries)", nclients - 1, nclients != 2 ? "s" : "",
363                      newqueries);
364
365              shutdown(clients[i]->con, 2);
366              close(clients[i]->con);
367              FD_CLR(clients[i]->con, &xreadfds);
368              FD_CLR(clients[i]->con, &xwritefds);
369              free_rtn_tuples(clients[i]);
370              free(clients[i]->tuples);
371              free(clients[i]->hsbuf);
372              old = clients[i];
373              clients[i] = clients[--nclients];
374              free(old);
375            }
376
377          cur_client = NULL;
378          if (takedown)
379            break;
380        }
381    }
382
383  com_err(whoami, 0, "%s", takedown);
384  if (dormant != ASLEEP)
385    mr_close_database();
386  send_zgram("MOIRA", takedown);
387  return 0;
388}
389
390void reapchild(int x)
391{
392  int status, pid;
393
394  while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
395    {
396      if (pid == inc_pid)
397        inc_running = 0;
398      if (!takedown && (WTERMSIG(status) != 0 || WEXITSTATUS(status) != 0))
399        {
400          child_exited_abnormally = 1;
401          child_pid = pid;
402          child_signal = WTERMSIG(status);
403          child_status = WEXITSTATUS(status);
404        }
405    }
406}
407
408
409void godormant(int x)
410{
411  switch (dormant)
412    {
413    case AWAKE:
414    case GROGGY:
415      com_err(whoami, 0, "requested to go dormant");
416      break;
417    case ASLEEP:
418      com_err(whoami, 0, "already asleep");
419      break;
420    case SLEEPY:
421      break;
422    }
423  dormant = SLEEPY;
424}
425
426
427void gowakeup(int x)
428{
429  switch (dormant)
430    {
431    case ASLEEP:
432    case SLEEPY:
433      com_err(whoami, 0, "Good morning");
434      break;
435    case AWAKE:
436      com_err(whoami, 0, "already awake");
437      break;
438    case GROGGY:
439      break;
440    }
441  dormant = GROGGY;
442}
443
444
445void mr_setup_signals(void)
446{
447  struct sigaction action;
448
449  action.sa_flags = 0;
450  sigemptyset(&action.sa_mask);
451
452  /* There should probably be a few more of these. */
453
454  action.sa_handler = sigshut;
455  if ((sigaction(SIGTERM, &action, NULL) < 0) ||
456      (sigaction(SIGINT, &action, NULL) < 0) ||
457      (sigaction(SIGHUP, &action, NULL) < 0))
458    {
459      com_err(whoami, errno, "Unable to establish signal handlers.");
460      exit(1);
461    }
462
463  action.sa_handler = godormant;
464  if (sigaction(SIGUSR1, &action, NULL) < 0)
465    {
466      com_err(whoami, errno, "Unable to establish signal handlers.");
467      exit(1);
468    }
469
470  action.sa_handler = gowakeup;
471  if (sigaction(SIGUSR2, &action, NULL) < 0)
472    {
473      com_err(whoami, errno, "Unable to establish signal handlers.");
474      exit(1);
475    }
476
477  action.sa_handler = SIG_IGN;
478  if (sigaction(SIGPIPE, &action, NULL) < 0)
479    {
480      com_err(whoami, errno, "Unable to establish signal handlers.");
481      exit(1);
482    }
483
484  action.sa_handler = reapchild;
485  sigaddset(&action.sa_mask, SIGCHLD);
486  if (sigaction(SIGCHLD, &action, NULL) < 0)
487    {
488      com_err(whoami, errno, "Unable to establish signal handlers.");
489      exit(1);
490    }
491}
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