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

   1 #include "secnet.h"
   2 #include <stdio.h>
   3 #include <assert.h>
   4 #include <limits.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 const char *configfile="/etc/secnet/secnet.conf";
  19 static const 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 cstring_t require_root_privileges_explanation=NULL;
  27
  28 static pid_t secnet_pid;
  29
  30 /* Structures dealing with poll() call */
  31 struct poll_interest {
  32     beforepoll_fn *before;
  33     afterpoll_fn *after;
  34     void *state;
  35     int32_t max_nfds;
  36     int32_t nfds;
  37     cstring_t desc;
  38     struct poll_interest *next;
  39 };
  40 static struct poll_interest *reg=NULL;
  41 static int32_t total_nfds=10;
  42
  43 static bool_t finished=False;
  44
  45 /* Parse the command line options */
  46 static void parse_options(int argc, char **argv)
  47 {
  48     int c;
  49
  50     while (True) {
  51         int option_index = 0;
  52         static struct option long_options[] = {
  53             {"verbose", 0, 0, 'v'},
  54             {"nowarnings", 0, 0, 'w'},
  55             {"help", 0, 0, 2},
  56             {"version", 0, 0, 1},
  57             {"nodetach", 0, 0, 'n'},
  58             {"silent", 0, 0, 'f'},
  59             {"quiet", 0, 0, 'f'},
  60             {"debug", 1, 0, 'd'},
  61             {"config", 1, 0, 'c'},
  62             {"just-check-config", 0, 0, 'j'},
  63             {"sites-key", 1, 0, 's'},
  64             {0,0,0,0}
  65         };
  66
  67         c=getopt_long(argc, argv, "vwdnjc:ft:s:",
  68                       long_options, &option_index);
  69         if (c==-1)
  70             break;
  71
  72         switch(c) {
  73         case 2:
  74             /* Help */
  75             printf("Usage: secnet [OPTION]...\n\n"
  76                    "  -f, --silent, --quiet   suppress error messages\n"
  77                    "  -w, --nowarnings        suppress warnings\n"
  78                    "  -v, --verbose           output extra diagnostics\n"
  79                    "  -c, --config=filename   specify a configuration file\n"
  80                    "  -j, --just-check-config stop after reading "
  81                    "configuration file\n"
  82                    "  -s, --sites-key=name    configuration key that "
  83                    "specifies active sites\n"
  84                    "  -n, --nodetach          do not run in background\n"
  85                    "  -d, --debug=item,...    set debug options\n"
  86                    "      --help              display this help and exit\n"
  87                    "      --version           output version information "
  88                    "and exit\n"
  89                 );
  90             exit(0);
  91             break;
  92
  93         case 1:
  94             /* Version */
  95             printf("%s\n",version);
  96             exit(0);
  97             break;
  98
  99         case 'v':
 100             message_level|=M_INFO|M_NOTICE|M_WARNING|M_ERR|M_SECURITY|
 101                 M_FATAL;
 102             break;
 103
 104         case 'w':
 105             message_level&=(~M_WARNING);
 106             break;
 107
 108         case 'd':
 109             message_level|=M_DEBUG_CONFIG|M_DEBUG_PHASE|M_DEBUG;
 110             break;
 111
 112         case 'f':
 113             message_level=M_FATAL;
 114             break;
 115
 116         case 'n':
 117             background=False;
 118             break;
 119
 120         case 'c':
 121             if (optarg)
 122                 configfile=safe_strdup(optarg,"config_filename");
 123             else
 124                 fatal("secnet: no config filename specified");
 125             break;
 126
 127         case 'j':
 128             just_check_config=True;
 129             break;
 130
 131         case 's':
 132             if (optarg)
 133                 sites_key=safe_strdup(optarg,"sites-key");
 134             else
 135                 fatal("secnet: no sites key specified");
 136             break;
 137
 138         case '?':
 139             break;
 140
 141         default:
 142             Message(M_ERR,"secnet: Unknown getopt code %c\n",c);
 143         }
 144     }
 145
 146     if (argc-optind != 0) {
 147         Message(M_ERR,"secnet: You gave extra command line parameters, "
 148                 "which were ignored.\n");
 149     }
 150 }
 151
 152 static void setup(dict_t *config)
 153 {
 154     list_t *l;
 155     item_t *site;
 156     dict_t *system;
 157     struct passwd *pw;
 158     struct cloc loc;
 159     int i;
 160
 161     l=dict_lookup(config,"system");
 162
 163     if (!l || list_elem(l,0)->type!=t_dict) {
 164         fatal("configuration does not include a \"system\" dictionary");
 165     }
 166     system=list_elem(l,0)->data.dict;
 167     loc=list_elem(l,0)->loc;
 168
 169     /* Arrange systemwide log facility */
 170     l=dict_lookup(system,"log");
 171     if (!l) {
 172         fatal("configuration does not include a system/log facility");
 173     }
 174     system_log=init_log(l);
 175
 176     /* Who are we supposed to run as? */
 177     userid=dict_read_string(system,"userid",False,"system",loc);
 178     if (userid) {
 179         do {
 180             pw=getpwent();
 181             if (pw && strcmp(pw->pw_name,userid)==0) {
 182                 uid=pw->pw_uid;
 183                 break;
 184             }
 185         } while(pw);
 186         endpwent();
 187         if (uid==0) {
 188             fatal("userid \"%s\" not found",userid);
 189         }
 190     }
 191
 192     /* Pidfile name */
 193     pidfile=dict_read_string(system,"pidfile",False,"system",loc);
 194
 195     /* Check whether we need root privileges */
 196     if (require_root_privileges && uid!=0) {
 197         fatal("the configured feature \"%s\" requires "
 198               "that secnet retain root privileges while running.",
 199               require_root_privileges_explanation);
 200     }
 201
 202     /* Go along site list, starting sites */
 203     l=dict_lookup(config,sites_key);
 204     if (!l) {
 205         Message(M_WARNING,"secnet: configuration key \"%s\" is missing; no "
 206                 "remote sites are defined\n",sites_key);
 207     } else {
 208         i=0;
 209         while ((site=list_elem(l, i++))) {
 210             struct site_if *s;
 211             if (site->type!=t_closure) {
 212                 cfgfatal(site->loc,"system","non-closure in site list");
 213             }
 214             if (site->data.closure->type!=CL_SITE) {
 215                 cfgfatal(site->loc,"system","non-site closure in site list");
 216             }
 217             s=site->data.closure->interface;
 218             s->control(s->st,True);
 219         }
 220     }
 221 }
 222
 223 void register_for_poll(void *st, beforepoll_fn *before,
 224                        afterpoll_fn *after, int32_t max_nfds, cstring_t desc)
 225 {
 226     struct poll_interest *i;
 227
 228     i=safe_malloc(sizeof(*i),"register_for_poll");
 229     i->before=before;
 230     i->after=after;
 231     i->state=st;
 232     i->max_nfds=max_nfds;
 233     i->nfds=0;
 234     i->desc=desc;
 235     assert(total_nfds < INT_MAX - max_nfds);
 236     total_nfds+=max_nfds;
 237     i->next=reg;
 238     reg=i;
 239     return;
 240 }
 241
 242 static void system_phase_hook(void *sst, uint32_t newphase)
 243 {
 244     if (newphase==PHASE_SHUTDOWN && pidfile) {
 245         /* Try to unlink the pidfile; don't care if it fails */
 246         unlink(pidfile);
 247     }
 248 }
 249
 250 static void run(void)
 251 {
 252     struct timeval tv_now;
 253     uint64_t now;
 254     struct poll_interest *i;
 255     int rv, nfds, remain, idx;
 256     int timeout;
 257     struct pollfd *fds;
 258
 259     fds=safe_malloc(sizeof(*fds)*total_nfds, "run");
 260
 261     Message(M_NOTICE,"%s [%d]: starting\n",version,secnet_pid);
 262
 263     do {
 264         if (gettimeofday(&tv_now, NULL)!=0) {
 265             fatal_perror("main loop: gettimeofday");
 266         }
 267         now=((uint64_t)tv_now.tv_sec*(uint64_t)1000)+
 268             ((uint64_t)tv_now.tv_usec/(uint64_t)1000);
 269         idx=0;
 270         for (i=reg; i; i=i->next) {
 271             i->after(i->state, fds+idx, i->nfds, &tv_now, &now);
 272             idx+=i->nfds;
 273         }
 274         remain=total_nfds;
 275         idx=0;
 276         timeout=-1;
 277         for (i=reg; i; i=i->next) {
 278             nfds=remain;
 279             rv=i->before(i->state, fds+idx, &nfds, &timeout, &tv_now, &now);
 280             if (rv!=0) {
 281                 /* XXX we need to handle this properly: increase the
 282                    nfds available */
 283                 fatal("run: beforepoll_fn (%s) returns %d",i->desc,rv);
 284             }
 285             if (timeout<-1) {
 286                 fatal("run: beforepoll_fn (%s) set timeout to %d",timeout);
 287             }
 288             idx+=nfds;
 289             remain-=nfds;
 290             i->nfds=nfds;
 291         }
 292         do {
 293             if (finished) break;
 294             rv=poll(fds, idx, timeout);
 295             if (rv<0) {
 296                 if (errno!=EINTR) {
 297                     fatal_perror("run: poll");
 298                 }
 299             }
 300         } while (rv<0);
 301     } while (!finished);
 302     free(fds);
 303 }
 304
 305 static void droppriv(void)
 306 {
 307     FILE *pf=NULL;
 308     pid_t p;
 309     int errfds[2];
 310
 311     add_hook(PHASE_SHUTDOWN,system_phase_hook,NULL);
 312
 313     /* Open the pidfile for writing now: we may be unable to do so
 314        once we drop privileges. */
 315     if (pidfile) {
 316         pf=fopen(pidfile,"w");
 317         if (!pf) {
 318             fatal_perror("cannot open pidfile \"%s\"",pidfile);
 319         }
 320     }
 321     if (!background && pf) {
 322         fprintf(pf,"%d\n",getpid());
 323         fclose(pf);
 324     }
 325
 326     /* Now drop privileges */
 327     if (uid!=0) {
 328         if (setuid(uid)!=0) {
 329             fatal_perror("can't set uid to \"%s\"",userid);
 330         }
 331     }
 332     if (background) {
 333         p=fork();
 334         if (p>0) {
 335             if (pf) {
 336                 /* Parent process - write pidfile, exit */
 337                 fprintf(pf,"%d\n",p);
 338                 fclose(pf);
 339             }
 340             exit(0);
 341         } else if (p==0) {
 342             /* Child process - all done, just carry on */
 343             if (pf) fclose(pf);
 344             /* Close stdin and stdout; we don't need them any more.
 345                stderr is redirected to the system/log facility */
 346             if (pipe(errfds)!=0) {
 347                 fatal_perror("can't create pipe for stderr");
 348             }
 349             close(0);
 350             close(1);
 351             close(2);
 352             dup2(errfds[1],0);
 353             dup2(errfds[1],1);
 354             dup2(errfds[1],2);
 355             secnet_is_daemon=True;
 356             setsid();
 357             log_from_fd(errfds[0],"stderr",system_log);
 358         } else {
 359             /* Error */
 360             fatal_perror("cannot fork");
 361             exit(1);
 362         }
 363     }
 364     secnet_pid=getpid();
 365 }
 366
 367 static signal_notify_fn finish,ignore_hup;
 368 static void finish(void *st, int signum)
 369 {
 370     finished=True;
 371     Message(M_NOTICE,"%s [%d]: received %s\n",version,secnet_pid,(string_t)st);
 372 }
 373 static void ignore_hup(void *st, int signum)
 374 {
 375     Message(M_INFO,"%s [%d]: received SIGHUP\n",version,secnet_pid);
 376     return;
 377 }
 378
 379 int main(int argc, char **argv)
 380 {
 381     dict_t *config;
 382
 383     enter_phase(PHASE_GETOPTS);
 384     parse_options(argc,argv);
 385
 386     enter_phase(PHASE_READCONFIG);
 387     config=read_conffile(configfile);
 388
 389     enter_phase(PHASE_SETUP);
 390     setup(config);
 391
 392     if (just_check_config) {
 393         Message(M_INFO,"configuration file check complete\n");
 394         exit(0);
 395     }
 396
 397     enter_phase(PHASE_GETRESOURCES);
 398     /* Appropriate phase hooks will have been run */
 399
 400     enter_phase(PHASE_DROPPRIV);
 401     droppriv();
 402
 403     start_signal_handling();
 404     request_signal_notification(SIGTERM,finish,safe_strdup("SIGTERM","run"));
 405     if (!background) request_signal_notification(SIGINT,finish,
 406                                                  safe_strdup("SIGINT","run"));
 407     request_signal_notification(SIGHUP,ignore_hup,NULL);
 408     enter_phase(PHASE_RUN);
 409     run();
 410
 411     enter_phase(PHASE_SHUTDOWN);
 412     Message(M_NOTICE,"%s [%d]: finished\n",version,secnet_pid);
 413
 414     return 0;
 415 }