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