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