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

   1 /* $Log: secnet.c,v $
   2  * Revision 1.1  1996/03/13 22:27:41  sde1000
   3  * Initial revision
   4  *
   5  */
   6
   7 extern char version[];
   8
   9 #include "secnet.h"
  10 #include <stdio.h>
  11 #include <string.h>
  12 #include <getopt.h>
  13 #include <errno.h>
  14 #include <unistd.h>
  15 #include <sys/socket.h>
  16 #include <arpa/inet.h>
  17 #include <pwd.h>
  18
  19 #include "util.h"
  20 #include "conffile.h"
  21
  22 /* Command-line options (possibly config-file options too) */
  23 static char *configfile="/etc/secnet/secnet.conf";
  24 bool_t just_check_config=False;
  25 static char *userid=NULL;
  26 static uid_t uid=0;
  27 static bool_t background=True;
  28 static char *pidfile=NULL;
  29 bool_t require_root_privileges=False;
  30 string_t require_root_privileges_explanation=NULL;
  31
  32 /* Structures dealing with poll() call */
  33 struct poll_interest {
  34     beforepoll_fn *before;
  35     afterpoll_fn *after;
  36     void *state;
  37     uint32_t max_nfds;
  38     uint32_t nfds;
  39     string_t desc;
  40     struct poll_interest *next;
  41 };
  42 static struct poll_interest *reg=NULL;
  43 static uint32_t total_nfds=10;
  44
  45 static bool_t finished=False;
  46
  47 /* Parse the command line options */
  48 static void parse_options(int argc, char **argv)
  49 {
  50     int c;
  51
  52     while (True) {
  53         int option_index = 0;
  54         static struct option long_options[] = {
  55             {"verbose", 0, 0, 'v'},
  56             {"nowarnings", 0, 0, 'w'},
  57             {"help", 0, 0, 2},
  58             {"version", 0, 0, 1},
  59             {"nodetach", 0, 0, 'n'},
  60             {"silent", 0, 0, 'f'},
  61             {"quiet", 0, 0, 'f'},
  62             {"debug", 1, 0, 'd'},
  63             {"config", 1, 0, 'c'},
  64             {"just-check-config", 0, 0, 'j'},
  65             {0,0,0,0}
  66         };
  67
  68         c=getopt_long(argc, argv, "vwdnjc:ft:",
  69                       long_options, &option_index);
  70         if (c==-1)
  71             break;
  72
  73         switch(c) {
  74         case 2:
  75             /* Help */
  76             fprintf(stderr,
  77                     "Usage: secnet [OPTION]...\n\n"
  78                     "  -f, --silent, --quiet   suppress error messages\n"
  79                     "  -w, --nowarnings        suppress warnings\n"
  80                     "  -v, --verbose           output extra diagnostics\n"
  81                     "  -c, --config=filename   specify a configuration file\n"
  82                     "  -j, --just-check-config stop after reading configfile\n"
  83                     "  -n, --nodetach          do not run in background\n"
  84                     "  -d, --debug=item,...    set debug options\n"
  85                     "      --help              display this help and exit\n"
  86                     "      --version           output version information and exit\n"
  87                 );
  88             exit(0);
  89             break;
  90
  91         case 1:
  92             /* Version */
  93             fprintf(stderr,"%s\n",version);
  94             exit(0);
  95             break;
  96
  97         case 'v':
  98             message_level|=M_INFO|M_WARNING|M_ERROR|M_FATAL;
  99             break;
 100
 101         case 'n':
 102             background=False;
 103             break;
 104
 105         case 'd':
 106             message_level|=M_DEBUG_CONFIG|M_DEBUG_PHASE;
 107             break;
 108
 109         case 'f':
 110             message_level=M_FATAL;
 111             break;
 112
 113         case 'c':
 114             if (optarg)
 115                 configfile=safe_strdup(optarg,"config_filename");
 116             else
 117                 fatal("secnet: no config filename specified");
 118             break;
 119
 120         case 'j':
 121             just_check_config=True;
 122             break;
 123
 124         case '?':
 125             break;
 126
 127         default:
 128             Message(M_WARNING,"secnet: Unknown getopt code %c\n",c);
 129         }
 130     }
 131
 132     if (argc-optind != 0) {
 133         Message(M_WARNING,"secnet: You gave extra command line parameters, "
 134                 "which were ignored.\n");
 135     }
 136 }
 137
 138 static void setup(dict_t *config)
 139 {
 140     list_t *l;
 141     item_t *site;
 142     dict_t *system;
 143     struct log_if *log;
 144     struct passwd *pw;
 145     struct cloc loc;
 146     int i;
 147
 148     l=dict_lookup(config,"system");
 149
 150     if (!l || list_elem(l,0)->type!=t_dict) {
 151         fatal("configuration does not include a \"system\" dictionary\n");
 152     }
 153     system=list_elem(l,0)->data.dict;
 154     loc=list_elem(l,0)->loc;
 155
 156     /* Arrange systemwide log facility */
 157     l=dict_lookup(system,"log");
 158     if (!l) {
 159         fatal("configuration does not include a system/log facility\n");
 160     }
 161     log=init_log(l);
 162     log->log(log->st,LOG_DEBUG,"%s: logging started",version);
 163
 164     /* Who are we supposed to run as? */
 165     userid=dict_read_string(system,"userid",False,"system",loc);
 166     if (userid) {
 167         do {
 168             pw=getpwent();
 169             if (pw && strcmp(pw->pw_name,userid)==0) {
 170                 uid=pw->pw_uid;
 171                 break;
 172             }
 173         } while(pw);
 174         endpwent();
 175         if (uid==0) {
 176             fatal("userid \"%s\" not found\n",userid);
 177         }
 178     }
 179
 180     /* Pidfile name */
 181     pidfile=dict_read_string(system,"pidfile",False,"system",loc);
 182
 183     /* Check whether we need root privileges */
 184     if (require_root_privileges && uid!=0) {
 185         fatal("the following configured feature (\"%s\") requires "
 186               "that secnet retain root privileges while running.\n",
 187               require_root_privileges_explanation);
 188     }
 189
 190     /* Go along site list, starting sites */
 191     l=dict_lookup(config,"sites");
 192     if (!l) {
 193         Message(M_WARNING,"secnet: configuration did not define any "
 194                 "remote sites\n");
 195     } else {
 196         i=0;
 197         while ((site=list_elem(l, i++))) {
 198             struct site_if *s;
 199             if (site->type!=t_closure) {
 200                 cfgfatal(site->loc,"system","non-closure in site list");
 201             }
 202             if (site->data.closure->type!=CL_SITE) {
 203                 cfgfatal(site->loc,"system","non-site closure in site list");
 204             }
 205             s=site->data.closure->interface;
 206             s->control(s->st,True);
 207         }
 208     }
 209 }
 210
 211 void register_for_poll(void *st, beforepoll_fn *before,
 212                        afterpoll_fn *after, uint32_t max_nfds, string_t desc)
 213 {
 214     struct poll_interest *i;
 215
 216     i=safe_malloc(sizeof(*i),"register_for_poll");
 217     i->before=before;
 218     i->after=after;
 219     i->state=st;
 220     i->max_nfds=max_nfds;
 221     i->nfds=0;
 222     i->desc=desc;
 223     total_nfds+=max_nfds;
 224     i->next=reg;
 225     reg=i;
 226     return;
 227 }
 228
 229 static void system_phase_hook(void *sst, uint32_t newphase)
 230 {
 231     if (newphase==PHASE_SHUTDOWN && pidfile) {
 232         /* Try to unlink the pidfile; don't care if it fails */
 233         unlink(pidfile);
 234     }
 235 }
 236
 237 static void run(void)
 238 {
 239     struct timeval tv_now;
 240     uint64_t now;
 241     struct poll_interest *i;
 242     int rv, nfds, remain, idx;
 243     int timeout;
 244     struct pollfd *fds;
 245
 246     fds=alloca(sizeof(*fds)*total_nfds);
 247     if (!fds) {
 248         fatal("run: couldn't alloca\n");
 249     }
 250
 251     while (!finished) {
 252         if (gettimeofday(&tv_now, NULL)!=0) {
 253             fatal_perror("main loop: gettimeofday");
 254         }
 255         now=(tv_now.tv_sec*1000)+(tv_now.tv_usec/1000);
 256         idx=0;
 257         for (i=reg; i; i=i->next) {
 258             i->after(i->state, fds+idx, i->nfds, &tv_now, &now);
 259             idx+=i->nfds;
 260         }
 261         remain=total_nfds;
 262         idx=0;
 263         timeout=-1;
 264         for (i=reg; i; i=i->next) {
 265             nfds=remain;
 266             rv=i->before(i->state, fds+idx, &nfds, &timeout, &tv_now, &now);
 267             if (rv!=0) {
 268                 /* XXX we need to handle this properly: increase the
 269                    nfds available */
 270                 fatal("run: beforepoll_fn (%s) returns %d\n",i->desc,rv);
 271             }
 272             if (timeout<-1) {
 273                 fatal("run: beforepoll_fn (%s) set timeout to %d\n",timeout);
 274             }
 275             idx+=nfds;
 276             remain-=nfds;
 277             i->nfds=nfds;
 278         }
 279         do {
 280             rv=poll(fds, idx, timeout);
 281             if (rv<0) {
 282                 if (errno!=EINTR) {
 283                     fatal_perror("run: poll");
 284                 }
 285             }
 286         } while (rv<0);
 287     }
 288 }
 289
 290 static void droppriv(void)
 291 {
 292     FILE *pf=NULL;
 293     pid_t p;
 294
 295     add_hook(PHASE_SHUTDOWN,system_phase_hook,NULL);
 296
 297     /* Background now, if we're supposed to: we may be unable to write the
 298        pidfile if we don't. */
 299     if (background) {
 300         /* Open the pidfile before forking - that way the parent can tell
 301            whether it succeeds */
 302         if (pidfile) {
 303             pf=fopen(pidfile,"w");
 304             if (!pf) {
 305                 fatal_perror("cannot open pidfile \"%s\"",pidfile);
 306             }
 307         } else {
 308             Message(M_WARNING,"secnet: no pidfile configured, but "
 309                     "backgrounding anyway\n");
 310         }
 311         p=fork();
 312         if (p>0) {
 313             if (pf) {
 314                 /* Parent process - write pidfile, exit */
 315                 fprintf(pf,"%d\n",p);
 316                 fclose(pf);
 317             }
 318             exit(0);
 319         } else if (p==0) {
 320             /* Child process - all done, just carry on */
 321             if (pf) fclose(pf);
 322         } else {
 323             /* Error */
 324             fatal_perror("cannot fork");
 325             exit(1);
 326         }
 327     } else {
 328         if (pidfile) {
 329             pf=fopen(pidfile,"w");
 330             if (!pf) {
 331                 fatal_perror("cannot open pidfile \"%s\"",pidfile);
 332             }
 333             fprintf(pf,"%d\n",getpid());
 334             fclose(pf);
 335         }
 336     }
 337
 338     /* Drop privilege now, if configured to do so */
 339     if (uid!=0) {
 340         if (setuid(uid)!=0) {
 341             fatal_perror("can't set uid to \"%s\"",userid);
 342         }
 343     }
 344 }
 345
 346 int main(int argc, char **argv)
 347 {
 348     dict_t *config;
 349
 350     enter_phase(PHASE_GETOPTS);
 351     parse_options(argc,argv);
 352
 353     enter_phase(PHASE_READCONFIG);
 354     config=read_conffile(configfile);
 355
 356     enter_phase(PHASE_SETUP);
 357     setup(config);
 358
 359     if (just_check_config) {
 360         Message(M_INFO,"configuration file check complete\n");
 361         exit(0);
 362     }
 363
 364     enter_phase(PHASE_GETRESOURCES);
 365     /* Appropriate phase hooks will have been run */
 366
 367     enter_phase(PHASE_DROPPRIV);
 368     droppriv();
 369
 370     enter_phase(PHASE_RUN);
 371     run();
 372
 373     enter_phase(PHASE_SHUTDOWN);
 374
 375     return 0;
 376 }
 377