mdw@git.distorted.org.uk Git - secnet/blob - secnet.c

   1 extern char version[];
   2
   3 #include "secnet.h"
   4 #include <stdio.h>
   5 #include <string.h>
   6 #include <getopt.h>
   7 #include <errno.h>
   8 #include <unistd.h>
   9 #include <sys/socket.h>
  10 #include <arpa/inet.h>
  11 #include <pwd.h>
  12
  13 #include "util.h"
  14 #include "conffile.h"
  15 #include "process.h"
  16
  17 /* XXX should be from autoconf */
  18 static char *configfile="/etc/secnet/secnet.conf";
  19 static char *sites_key="sites";
  20 bool_t just_check_config=False;
  21 static char *userid=NULL;
  22 static uid_t uid=0;
  23 bool_t background=True;
  24 static char *pidfile=NULL;
  25 bool_t require_root_privileges=False;
  26 string_t require_root_privileges_explanation=NULL;
  27
  28 static pid_t secnet_pid;
  29
  30 /* from log.c */
  31 extern uint32_t message_level;
  32 extern bool_t secnet_is_daemon;
  33 extern struct log_if *system_log;
  34
  35 /* from process.c */
  36 extern void start_signal_handling(void);
  37
  38 /* Structures dealing with poll() call */
  39 struct poll_interest {
  40     beforepoll_fn *before;
  41     afterpoll_fn *after;
  42     void *state;
  43     uint32_t max_nfds;
  44     uint32_t nfds;
  45     string_t desc;
  46     struct poll_interest *next;
  47 };
  48 static struct poll_interest *reg=NULL;
  49 static uint32_t total_nfds=10;
  50
  51 static bool_t finished=False;
  52
  53 /* Parse the command line options */
  54 static void parse_options(int argc, char **argv)
  55 {
  56     int c;
  57
  58     while (True) {
  59         int option_index = 0;
  60         static struct option long_options[] = {
  61             {"verbose", 0, 0, 'v'},
  62             {"nowarnings", 0, 0, 'w'},
  63             {"help", 0, 0, 2},
  64             {"version", 0, 0, 1},
  65             {"nodetach", 0, 0, 'n'},
  66             {"silent", 0, 0, 'f'},
  67             {"quiet", 0, 0, 'f'},
  68             {"debug", 1, 0, 'd'},
  69             {"config", 1, 0, 'c'},
  70             {"just-check-config", 0, 0, 'j'},
  71             {"sites-key", 1, 0, 's'},
  72             {0,0,0,0}
  73         };
  74
  75         c=getopt_long(argc, argv, "vwdnjc:ft:s:",
  76                       long_options, &option_index);
  77         if (c==-1)
  78             break;
  79
  80         switch(c) {
  81         case 2:
  82             /* Help */
  83             fprintf(stderr,
  84                     "Usage: secnet [OPTION]...\n\n"
  85                     "  -f, --silent, --quiet   suppress error messages\n"
  86                     "  -w, --nowarnings        suppress warnings\n"
  87                     "  -v, --verbose           output extra diagnostics\n"
  88                     "  -c, --config=filename   specify a configuration file\n"
  89                     "  -j, --just-check-config stop after reading "
  90                     "configuration file\n"
  91                     "  -s, --sites-key=name    configuration key that "
  92                     "specifies active sites\n"
  93                     "  -n, --nodetach          do not run in background\n"
  94                     "  -d, --debug=item,...    set debug options\n"
  95                     "      --help              display this help and exit\n"
  96                     "      --version           output version information "
  97                     "and exit\n"
  98                 );
  99             exit(0);
 100             break;
 101
 102         case 1:
 103             /* Version */
 104             fprintf(stderr,"%s\n",version);
 105             exit(0);
 106             break;
 107
 108         case 'v':
 109             message_level|=M_INFO|M_NOTICE|M_WARNING|M_ERR|M_SECURITY|
 110                 M_FATAL;
 111             break;
 112
 113         case 'w':
 114             message_level&=(~M_WARNING);
 115             break;
 116
 117         case 'd':
 118             message_level|=M_DEBUG_CONFIG|M_DEBUG_PHASE|M_DEBUG;
 119             break;
 120
 121         case 'f':
 122             message_level=M_FATAL;
 123             break;
 124
 125         case 'n':
 126             background=False;
 127             break;
 128
 129         case 'c':
 130             if (optarg)
 131                 configfile=safe_strdup(optarg,"config_filename");
 132             else
 133                 fatal("secnet: no config filename specified");
 134             break;
 135
 136         case 'j':
 137             just_check_config=True;
 138             break;
 139
 140         case 's':
 141             if (optarg)
 142                 sites_key=safe_strdup(optarg,"sites-key");
 143             else
 144                 fatal("secnet: no sites key specified");
 145             break;
 146
 147         case '?':
 148             break;
 149
 150         default:
 151             Message(M_ERR,"secnet: Unknown getopt code %c\n",c);
 152         }
 153     }
 154
 155     if (argc-optind != 0) {
 156         Message(M_ERR,"secnet: You gave extra command line parameters, "
 157                 "which were ignored.\n");
 158     }
 159 }
 160
 161 static void setup(dict_t *config)
 162 {
 163     list_t *l;
 164     item_t *site;
 165     dict_t *system;
 166     struct passwd *pw;
 167     struct cloc loc;
 168     int i;
 169
 170     l=dict_lookup(config,"system");
 171
 172     if (!l || list_elem(l,0)->type!=t_dict) {
 173         fatal("configuration does not include a \"system\" dictionary\n");
 174     }
 175     system=list_elem(l,0)->data.dict;
 176     loc=list_elem(l,0)->loc;
 177
 178     /* Arrange systemwide log facility */
 179     l=dict_lookup(system,"log");
 180     if (!l) {
 181         fatal("configuration does not include a system/log facility\n");
 182     }
 183     system_log=init_log(l);
 184
 185     /* Who are we supposed to run as? */
 186     userid=dict_read_string(system,"userid",False,"system",loc);
 187     if (userid) {
 188         do {
 189             pw=getpwent();
 190             if (pw && strcmp(pw->pw_name,userid)==0) {
 191                 uid=pw->pw_uid;
 192                 break;
 193             }
 194         } while(pw);
 195         endpwent();
 196         if (uid==0) {
 197             fatal("userid \"%s\" not found\n",userid);
 198         }
 199     }
 200
 201     /* Pidfile name */
 202     pidfile=dict_read_string(system,"pidfile",False,"system",loc);
 203
 204     /* Check whether we need root privileges */
 205     if (require_root_privileges && uid!=0) {
 206         fatal("the following configured feature (\"%s\") requires "
 207               "that secnet retain root privileges while running.\n",
 208               require_root_privileges_explanation);
 209     }
 210
 211     /* Go along site list, starting sites */
 212     l=dict_lookup(config,sites_key);
 213     if (!l) {
 214         Message(M_WARNING,"secnet: configuration key \"%s\" is missing; no "
 215                 "remote sites are defined\n",sites_key);
 216     } else {
 217         i=0;
 218         while ((site=list_elem(l, i++))) {
 219             struct site_if *s;
 220             if (site->type!=t_closure) {
 221                 cfgfatal(site->loc,"system","non-closure in site list");
 222             }
 223             if (site->data.closure->type!=CL_SITE) {
 224                 cfgfatal(site->loc,"system","non-site closure in site list");
 225             }
 226             s=site->data.closure->interface;
 227             s->control(s->st,True);
 228         }
 229     }
 230 }
 231
 232 void register_for_poll(void *st, beforepoll_fn *before,
 233                        afterpoll_fn *after, uint32_t max_nfds, string_t desc)
 234 {
 235     struct poll_interest *i;
 236
 237     i=safe_malloc(sizeof(*i),"register_for_poll");
 238     i->before=before;
 239     i->after=after;
 240     i->state=st;
 241     i->max_nfds=max_nfds;
 242     i->nfds=0;
 243     i->desc=desc;
 244     total_nfds+=max_nfds;
 245     i->next=reg;
 246     reg=i;
 247     return;
 248 }
 249
 250 static void system_phase_hook(void *sst, uint32_t newphase)
 251 {
 252     if (newphase==PHASE_SHUTDOWN && pidfile) {
 253         /* Try to unlink the pidfile; don't care if it fails */
 254         unlink(pidfile);
 255     }
 256 }
 257
 258 static void run(void)
 259 {
 260     struct timeval tv_now;
 261     uint64_t now;
 262     struct poll_interest *i;
 263     int rv, nfds, remain, idx;
 264     int timeout;
 265     struct pollfd *fds;
 266
 267     fds=alloca(sizeof(*fds)*total_nfds);
 268     if (!fds) {
 269         fatal("run: couldn't alloca\n");
 270     }
 271
 272     Message(M_NOTICE,"%s [%d]: starting\n",version,secnet_pid);
 273
 274     do {
 275         if (gettimeofday(&tv_now, NULL)!=0) {
 276             fatal_perror("main loop: gettimeofday");
 277         }
 278         now=((uint64_t)tv_now.tv_sec*(uint64_t)1000)+
 279             ((uint64_t)tv_now.tv_usec/(uint64_t)1000);
 280         idx=0;
 281         for (i=reg; i; i=i->next) {
 282             i->after(i->state, fds+idx, i->nfds, &tv_now, &now);
 283             idx+=i->nfds;
 284         }
 285         remain=total_nfds;
 286         idx=0;
 287         timeout=-1;
 288         for (i=reg; i; i=i->next) {
 289             nfds=remain;
 290             rv=i->before(i->state, fds+idx, &nfds, &timeout, &tv_now, &now);
 291             if (rv!=0) {
 292                 /* XXX we need to handle this properly: increase the
 293                    nfds available */
 294                 fatal("run: beforepoll_fn (%s) returns %d\n",i->desc,rv);
 295             }
 296             if (timeout<-1) {
 297                 fatal("run: beforepoll_fn (%s) set timeout to %d\n",timeout);
 298             }
 299             idx+=nfds;
 300             remain-=nfds;
 301             i->nfds=nfds;
 302         }
 303         do {
 304             if (finished) break;
 305             rv=poll(fds, idx, timeout);
 306             if (rv<0) {
 307                 if (errno!=EINTR) {
 308                     fatal_perror("run: poll");
 309                 }
 310             }
 311         } while (rv<0);
 312     } while (!finished);
 313 }
 314
 315 static void droppriv(void)
 316 {
 317     FILE *pf=NULL;
 318     pid_t p;
 319
 320     add_hook(PHASE_SHUTDOWN,system_phase_hook,NULL);
 321
 322     /* Open the pidfile for writing now: we may be unable to do so
 323        once we drop privileges. */
 324     if (pidfile) {
 325         pf=fopen(pidfile,"w");
 326         if (!pf) {
 327             fatal_perror("cannot open pidfile \"%s\"",pidfile);
 328         }
 329     }
 330     if (!background && pf) {
 331         fprintf(pf,"%d\n",getpid());
 332         fclose(pf);
 333     }
 334
 335     /* Now drop privileges */
 336     if (uid!=0) {
 337         if (setuid(uid)!=0) {
 338             fatal_perror("can't set uid to \"%s\"",userid);
 339         }
 340     }
 341     if (background) {
 342         p=fork();
 343         if (p>0) {
 344             if (pf) {
 345                 /* Parent process - write pidfile, exit */
 346                 fprintf(pf,"%d\n",p);
 347                 fclose(pf);
 348             }
 349             exit(0);
 350         } else if (p==0) {
 351             /* Child process - all done, just carry on */
 352             if (pf) fclose(pf);
 353             /* Close stdin, stdout and stderr; we don't need them any more */
 354             /* XXX we must leave stderr pointing to something useful -
 355                a pipe to a log destination, for example, or just leave
 356                it alone. */
 357             close(0);
 358             close(1);
 359             /* XXX close(2); */
 360             secnet_is_daemon=True;
 361             setsid();
 362         } else {
 363             /* Error */
 364             fatal_perror("cannot fork");
 365             exit(1);
 366         }
 367     }
 368     secnet_pid=getpid();
 369 }
 370
 371 static signal_notify_fn finish,ignore_hup;
 372 static void finish(void *st, int signum)
 373 {
 374     finished=True;
 375     Message(M_NOTICE,"%s [%d]: received %s\n",version,secnet_pid,(string_t)st);
 376 }
 377 static void ignore_hup(void *st, int signum)
 378 {
 379     Message(M_INFO,"%s [%d]: received SIGHUP\n",version,secnet_pid);
 380     return;
 381 }
 382
 383 int main(int argc, char **argv)
 384 {
 385     dict_t *config;
 386
 387     enter_phase(PHASE_GETOPTS);
 388     parse_options(argc,argv);
 389
 390     enter_phase(PHASE_READCONFIG);
 391     config=read_conffile(configfile);
 392
 393     enter_phase(PHASE_SETUP);
 394     setup(config);
 395
 396     if (just_check_config) {
 397         Message(M_INFO,"configuration file check complete\n");
 398         exit(0);
 399     }
 400
 401     enter_phase(PHASE_GETRESOURCES);
 402     /* Appropriate phase hooks will have been run */
 403
 404     enter_phase(PHASE_DROPPRIV);
 405     droppriv();
 406
 407     start_signal_handling();
 408     request_signal_notification(SIGTERM,finish,"SIGTERM");
 409     if (!background) request_signal_notification(SIGINT,finish,"SIGINT");
 410     request_signal_notification(SIGHUP,ignore_hup,NULL);
 411     enter_phase(PHASE_RUN);
 412     run();
 413
 414     enter_phase(PHASE_SHUTDOWN);
 415     Message(M_NOTICE,"%s [%d]: finished\n",version,secnet_pid);
 416
 417     return 0;
 418 }