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 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 /* 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     cstring_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, cstring_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=safe_malloc(sizeof(*fds)*total_nfds, "run");
 267
 268     Message(M_NOTICE,"%s [%d]: starting\n",version,secnet_pid);
 269
 270     do {
 271         if (gettimeofday(&tv_now, NULL)!=0) {
 272             fatal_perror("main loop: gettimeofday");
 273         }
 274         now=((uint64_t)tv_now.tv_sec*(uint64_t)1000)+
 275             ((uint64_t)tv_now.tv_usec/(uint64_t)1000);
 276         idx=0;
 277         for (i=reg; i; i=i->next) {
 278             i->after(i->state, fds+idx, i->nfds, &tv_now, &now);
 279             idx+=i->nfds;
 280         }
 281         remain=total_nfds;
 282         idx=0;
 283         timeout=-1;
 284         for (i=reg; i; i=i->next) {
 285             nfds=remain;
 286             rv=i->before(i->state, fds+idx, &nfds, &timeout, &tv_now, &now);
 287             if (rv!=0) {
 288                 /* XXX we need to handle this properly: increase the
 289                    nfds available */
 290                 fatal("run: beforepoll_fn (%s) returns %d",i->desc,rv);
 291             }
 292             if (timeout<-1) {
 293                 fatal("run: beforepoll_fn (%s) set timeout to %d",timeout);
 294             }
 295             idx+=nfds;
 296             remain-=nfds;
 297             i->nfds=nfds;
 298         }
 299         do {
 300             if (finished) break;
 301             rv=poll(fds, idx, timeout);
 302             if (rv<0) {
 303                 if (errno!=EINTR) {
 304                     fatal_perror("run: poll");
 305                 }
 306             }
 307         } while (rv<0);
 308     } while (!finished);
 309     free(fds);
 310 }
 311
 312 static void droppriv(void)
 313 {
 314     FILE *pf=NULL;
 315     pid_t p;
 316     int errfds[2];
 317
 318     add_hook(PHASE_SHUTDOWN,system_phase_hook,NULL);
 319
 320     /* Open the pidfile for writing now: we may be unable to do so
 321        once we drop privileges. */
 322     if (pidfile) {
 323         pf=fopen(pidfile,"w");
 324         if (!pf) {
 325             fatal_perror("cannot open pidfile \"%s\"",pidfile);
 326         }
 327     }
 328     if (!background && pf) {
 329         fprintf(pf,"%d\n",getpid());
 330         fclose(pf);
 331     }
 332
 333     /* Now drop privileges */
 334     if (uid!=0) {
 335         if (setuid(uid)!=0) {
 336             fatal_perror("can't set uid to \"%s\"",userid);
 337         }
 338     }
 339     if (background) {
 340         p=fork();
 341         if (p>0) {
 342             if (pf) {
 343                 /* Parent process - write pidfile, exit */
 344                 fprintf(pf,"%d\n",p);
 345                 fclose(pf);
 346             }
 347             exit(0);
 348         } else if (p==0) {
 349             /* Child process - all done, just carry on */
 350             if (pf) fclose(pf);
 351             /* Close stdin and stdout; we don't need them any more.
 352                stderr is redirected to the system/log facility */
 353             if (pipe(errfds)!=0) {
 354                 fatal_perror("can't create pipe for stderr");
 355             }
 356             close(0);
 357             close(1);
 358             close(2);
 359             dup2(errfds[1],0);
 360             dup2(errfds[1],1);
 361             dup2(errfds[1],2);
 362             secnet_is_daemon=True;
 363             setsid();
 364             log_from_fd(errfds[0],"stderr",system_log);
 365         } else {
 366             /* Error */
 367             fatal_perror("cannot fork");
 368             exit(1);
 369         }
 370     }
 371     secnet_pid=getpid();
 372 }
 373
 374 static signal_notify_fn finish,ignore_hup;
 375 static void finish(void *st, int signum)
 376 {
 377     finished=True;
 378     Message(M_NOTICE,"%s [%d]: received %s\n",version,secnet_pid,(string_t)st);
 379 }
 380 static void ignore_hup(void *st, int signum)
 381 {
 382     Message(M_INFO,"%s [%d]: received SIGHUP\n",version,secnet_pid);
 383     return;
 384 }
 385
 386 int main(int argc, char **argv)
 387 {
 388     dict_t *config;
 389
 390     enter_phase(PHASE_GETOPTS);
 391     parse_options(argc,argv);
 392
 393     enter_phase(PHASE_READCONFIG);
 394     config=read_conffile(configfile);
 395
 396     enter_phase(PHASE_SETUP);
 397     setup(config);
 398
 399     if (just_check_config) {
 400         Message(M_INFO,"configuration file check complete\n");
 401         exit(0);
 402     }
 403
 404     enter_phase(PHASE_GETRESOURCES);
 405     /* Appropriate phase hooks will have been run */
 406
 407     enter_phase(PHASE_DROPPRIV);
 408     droppriv();
 409
 410     start_signal_handling();
 411     request_signal_notification(SIGTERM,finish,safe_strdup("SIGTERM","run"));
 412     if (!background) request_signal_notification(SIGINT,finish,
 413                                                  safe_strdup("SIGINT","run"));
 414     request_signal_notification(SIGHUP,ignore_hup,NULL);
 415     enter_phase(PHASE_RUN);
 416     run();
 417
 418     enter_phase(PHASE_SHUTDOWN);
 419     Message(M_NOTICE,"%s [%d]: finished\n",version,secnet_pid);
 420
 421     return 0;
 422 }