chiark / gitweb /
integer arithmetic types: correct perhaps-possible negative timeout situation
[secnet.git] / secnet.c
index be94f95e6398c84c8a288bbe9315037abcaaeefe..f6931b5e36fa0fcf291710842664b71165597890 100644 (file)
--- a/secnet.c
+++ b/secnet.c
@@ -1,13 +1,7 @@
-/* $Log: secnet.c,v $
- * Revision 1.1  1996/03/13 22:27:41  sde1000
- * Initial revision
- *
- */
-
-extern char version[];
-
 #include "secnet.h"
 #include <stdio.h>
+#include <assert.h>
+#include <limits.h>
 #include <string.h>
 #include <getopt.h>
 #include <errno.h>
@@ -18,14 +12,20 @@ extern char version[];
 
 #include "util.h"
 #include "conffile.h"
+#include "process.h"
 
-/* Command-line options (possibly config-file options too) */
-static char *configfile="/etc/secnet/secnet.conf";
+/* XXX should be from autoconf */
+static const char *configfile="/etc/secnet/secnet.conf";
+static const char *sites_key="sites";
 bool_t just_check_config=False;
 static char *userid=NULL;
 static uid_t uid=0;
-static bool_t background=True;
+bool_t background=True;
 static char *pidfile=NULL;
+bool_t require_root_privileges=False;
+cstring_t require_root_privileges_explanation=NULL;
+
+static pid_t secnet_pid;
 
 /* Structures dealing with poll() call */
 struct poll_interest {
@@ -34,7 +34,7 @@ struct poll_interest {
     void *state;
     uint32_t max_nfds;
     uint32_t nfds;
-    string_t desc;
+    cstring_t desc;
     struct poll_interest *next;
 };
 static struct poll_interest *reg=NULL;
@@ -60,10 +60,11 @@ static void parse_options(int argc, char **argv)
            {"debug", 1, 0, 'd'},
            {"config", 1, 0, 'c'},
            {"just-check-config", 0, 0, 'j'},
+           {"sites-key", 1, 0, 's'},
            {0,0,0,0}
        };
 
-       c=getopt_long(argc, argv, "vwdnjc:ft:",
+       c=getopt_long(argc, argv, "vwdnjc:ft:s:",
                      long_options, &option_index);
        if (c==-1)
            break;
@@ -71,43 +72,51 @@ static void parse_options(int argc, char **argv)
        switch(c) {
        case 2:
            /* Help */
-           fprintf(stderr,
-                   "Usage: secnet [OPTION]...\n\n"
-                   "  -f, --silent, --quiet   suppress error messages\n"
-                   "  -w, --nowarnings        suppress warnings\n"
-                   "  -v, --verbose           output extra diagnostics\n"
-                   "  -c, --config=filename   specify a configuration file\n"
-                   "  -j, --just-check-config stop after reading configfile\n"
-                   "  -n, --nodetach          do not run in background\n"
-                   "  -d, --debug=item,...    set debug options\n"
-                   "      --help              display this help and exit\n"
-                   "      --version           output version information and exit\n"
+           printf("Usage: secnet [OPTION]...\n\n"
+                  "  -f, --silent, --quiet   suppress error messages\n"
+                  "  -w, --nowarnings        suppress warnings\n"
+                  "  -v, --verbose           output extra diagnostics\n"
+                  "  -c, --config=filename   specify a configuration file\n"
+                  "  -j, --just-check-config stop after reading "
+                  "configuration file\n"
+                  "  -s, --sites-key=name    configuration key that "
+                  "specifies active sites\n"
+                  "  -n, --nodetach          do not run in background\n"
+                  "  -d, --debug=item,...    set debug options\n"
+                  "      --help              display this help and exit\n"
+                  "      --version           output version information "
+                  "and exit\n"
                );
            exit(0);
            break;
       
        case 1:
            /* Version */
-           fprintf(stderr,"%s\n",version);
+           printf("%s\n",version);
            exit(0);
            break;
 
        case 'v':
-           message_level|=M_INFO|M_WARNING|M_ERROR|M_FATAL;
+           message_level|=M_INFO|M_NOTICE|M_WARNING|M_ERR|M_SECURITY|
+               M_FATAL;
            break;
 
-       case 'n':
-           background=False;
+       case 'w':
+           message_level&=(~M_WARNING);
            break;
 
        case 'd':
-           message_level|=M_DEBUG_CONFIG|M_DEBUG_PHASE;
+           message_level|=M_DEBUG_CONFIG|M_DEBUG_PHASE|M_DEBUG;
            break;
 
        case 'f':
            message_level=M_FATAL;
            break;
 
+       case 'n':
+           background=False;
+           break;
+
        case 'c':
            if (optarg)
                configfile=safe_strdup(optarg,"config_filename");
@@ -119,16 +128,23 @@ static void parse_options(int argc, char **argv)
            just_check_config=True;
            break;
 
+       case 's':
+           if (optarg)
+               sites_key=safe_strdup(optarg,"sites-key");
+           else
+               fatal("secnet: no sites key specified");
+           break;
+
        case '?':
            break;
 
        default:
-           Message(M_WARNING,"secnet: Unknown getopt code %c\n",c);
+           Message(M_ERR,"secnet: Unknown getopt code %c\n",c);
        }
     }
 
     if (argc-optind != 0) {
-       Message(M_WARNING,"secnet: You gave extra command line parameters, "
+       Message(M_ERR,"secnet: You gave extra command line parameters, "
                "which were ignored.\n");
     }
 }
@@ -138,7 +154,6 @@ static void setup(dict_t *config)
     list_t *l;
     item_t *site;
     dict_t *system;
-    struct log_if *log;
     struct passwd *pw;
     struct cloc loc;
     int i;
@@ -146,7 +161,7 @@ static void setup(dict_t *config)
     l=dict_lookup(config,"system");
 
     if (!l || list_elem(l,0)->type!=t_dict) {
-       fatal("configuration does not include a \"system\" dictionary\n");
+       fatal("configuration does not include a \"system\" dictionary");
     }
     system=list_elem(l,0)->data.dict;
     loc=list_elem(l,0)->loc;
@@ -154,10 +169,9 @@ static void setup(dict_t *config)
     /* Arrange systemwide log facility */
     l=dict_lookup(system,"log");
     if (!l) {
-       fatal("configuration does not include a system/log facility\n");
+       fatal("configuration does not include a system/log facility");
     }
-    log=init_log(l);
-    log->log(log->st,LOG_DEBUG,"%s: logging started",version);
+    system_log=init_log(l);
 
     /* Who are we supposed to run as? */
     userid=dict_read_string(system,"userid",False,"system",loc);
@@ -171,34 +185,43 @@ static void setup(dict_t *config)
        } while(pw);
        endpwent();
        if (uid==0) {
-           fatal("userid \"%s\" not found\n",userid);
+           fatal("userid \"%s\" not found",userid);
        }
     }
 
     /* Pidfile name */
     pidfile=dict_read_string(system,"pidfile",False,"system",loc);
 
+    /* Check whether we need root privileges */
+    if (require_root_privileges && uid!=0) {
+       fatal("the configured feature \"%s\" requires "
+             "that secnet retain root privileges while running.",
+             require_root_privileges_explanation);
+    }
+
     /* Go along site list, starting sites */
-    l=dict_lookup(config,"sites");
+    l=dict_lookup(config,sites_key);
     if (!l) {
-       fatal("configuration did not define any remote sites\n");
-    }
-    i=0;
-    while ((site=list_elem(l, i++))) {
-       struct site_if *s;
-       if (site->type!=t_closure) {
-           cfgfatal(site->loc,"system","non-closure in site list");
-       }
-       if (site->data.closure->type!=CL_SITE) {
-           cfgfatal(site->loc,"system","non-site closure in site list");
+       Message(M_WARNING,"secnet: configuration key \"%s\" is missing; no "
+               "remote sites are defined\n",sites_key);
+    } else {
+       i=0;
+       while ((site=list_elem(l, i++))) {
+           struct site_if *s;
+           if (site->type!=t_closure) {
+               cfgfatal(site->loc,"system","non-closure in site list");
+           }
+           if (site->data.closure->type!=CL_SITE) {
+               cfgfatal(site->loc,"system","non-site closure in site list");
+           }
+           s=site->data.closure->interface;
+           s->control(s->st,True);
        }
-       s=site->data.closure->interface;
-       s->control(s->st,True);
     }
 }
 
 void register_for_poll(void *st, beforepoll_fn *before,
-                      afterpoll_fn *after, uint32_t max_nfds, string_t desc)
+                      afterpoll_fn *after, uint32_t max_nfds, cstring_t desc)
 {
     struct poll_interest *i;
 
@@ -209,6 +232,7 @@ void register_for_poll(void *st, beforepoll_fn *before,
     i->max_nfds=max_nfds;
     i->nfds=0;
     i->desc=desc;
+    assert(total_nfds < INT_MAX - max_nfds);
     total_nfds+=max_nfds;
     i->next=reg;
     reg=i;
@@ -232,16 +256,16 @@ static void run(void)
     int timeout;
     struct pollfd *fds;
 
-    fds=alloca(sizeof(*fds)*total_nfds);
-    if (!fds) {
-       fatal("run: couldn't alloca\n");
-    }
+    fds=safe_malloc(sizeof(*fds)*total_nfds, "run");
+
+    Message(M_NOTICE,"%s [%d]: starting\n",version,secnet_pid);
 
-    while (!finished) {
+    do {
        if (gettimeofday(&tv_now, NULL)!=0) {
            fatal_perror("main loop: gettimeofday");
        }
-       now=(tv_now.tv_sec*1000)+(tv_now.tv_usec/1000);
+       now=((uint64_t)tv_now.tv_sec*(uint64_t)1000)+
+           ((uint64_t)tv_now.tv_usec/(uint64_t)1000);
        idx=0;
        for (i=reg; i; i=i->next) {
            i->after(i->state, fds+idx, i->nfds, &tv_now, &now);
@@ -256,16 +280,17 @@ static void run(void)
            if (rv!=0) {
                /* XXX we need to handle this properly: increase the
                   nfds available */
-               fatal("run: beforepoll_fn (%s) returns %d\n",i->desc,rv);
+               fatal("run: beforepoll_fn (%s) returns %d",i->desc,rv);
            }
            if (timeout<-1) {
-               fatal("run: beforepoll_fn (%s) set timeout to %d\n",timeout);
+               fatal("run: beforepoll_fn (%s) set timeout to %d",timeout);
            }
            idx+=nfds;
            remain-=nfds;
            i->nfds=nfds;
        }
        do {
+           if (finished) break;
            rv=poll(fds, idx, timeout);
            if (rv<0) {
                if (errno!=EINTR) {
@@ -273,31 +298,38 @@ static void run(void)
                }
            }
        } while (rv<0);
-    }
+    } while (!finished);
+    free(fds);
 }
 
 static void droppriv(void)
 {
     FILE *pf=NULL;
     pid_t p;
+    int errfds[2];
 
     add_hook(PHASE_SHUTDOWN,system_phase_hook,NULL);
 
-    /* Background now, if we're supposed to: we may be unable to write the
-       pidfile if we don't. */
-    if (background) {
-       printf("goto background\n");
-       /* Open the pidfile before forking - that way the parent can tell
-          whether it succeeds */
-       if (pidfile) {
-           pf=fopen(pidfile,"w");
-           if (!pf) {
-               fatal_perror("cannot open pidfile \"%s\"",pidfile);
-           }
-       } else {
-           Message(M_WARNING,"secnet: no pidfile configured, but "
-                   "backgrounding anyway\n");
+    /* Open the pidfile for writing now: we may be unable to do so
+       once we drop privileges. */
+    if (pidfile) {
+       pf=fopen(pidfile,"w");
+       if (!pf) {
+           fatal_perror("cannot open pidfile \"%s\"",pidfile);
        }
+    }
+    if (!background && pf) {
+       fprintf(pf,"%d\n",getpid());
+       fclose(pf);
+    }
+
+    /* Now drop privileges */
+    if (uid!=0) {
+       if (setuid(uid)!=0) {
+           fatal_perror("can't set uid to \"%s\"",userid);
+       }
+    }
+    if (background) {
        p=fork();
        if (p>0) {
            if (pf) {
@@ -309,29 +341,39 @@ static void droppriv(void)
        } else if (p==0) {
            /* Child process - all done, just carry on */
            if (pf) fclose(pf);
-           printf("child\n");
+           /* Close stdin and stdout; we don't need them any more.
+               stderr is redirected to the system/log facility */
+           if (pipe(errfds)!=0) {
+               fatal_perror("can't create pipe for stderr");
+           }
+           close(0);
+           close(1);
+           close(2);
+           dup2(errfds[1],0);
+           dup2(errfds[1],1);
+           dup2(errfds[1],2);
+           secnet_is_daemon=True;
+           setsid();
+           log_from_fd(errfds[0],"stderr",system_log);
        } else {
            /* Error */
            fatal_perror("cannot fork");
            exit(1);
        }
-    } else {
-       if (pidfile) {
-           pf=fopen(pidfile,"w");
-           if (!pf) {
-               fatal_perror("cannot open pidfile \"%s\"",pidfile);
-           }
-           fprintf(pf,"%d\n",getpid());
-           fclose(pf);
-       }
     }
+    secnet_pid=getpid();
+}
 
-    /* Drop privilege now, if configured to do so */
-    if (uid!=0) {
-       if (setuid(uid)!=0) {
-           fatal_perror("can't set uid to \"%s\"",userid);
-       }
-    }
+static signal_notify_fn finish,ignore_hup;
+static void finish(void *st, int signum)
+{
+    finished=True;
+    Message(M_NOTICE,"%s [%d]: received %s\n",version,secnet_pid,(string_t)st);
+}
+static void ignore_hup(void *st, int signum)
+{
+    Message(M_INFO,"%s [%d]: received SIGHUP\n",version,secnet_pid);
+    return;
 }
 
 int main(int argc, char **argv)
@@ -358,11 +400,16 @@ int main(int argc, char **argv)
     enter_phase(PHASE_DROPPRIV);
     droppriv();
 
+    start_signal_handling();
+    request_signal_notification(SIGTERM,finish,safe_strdup("SIGTERM","run"));
+    if (!background) request_signal_notification(SIGINT,finish,
+                                                safe_strdup("SIGINT","run"));
+    request_signal_notification(SIGHUP,ignore_hup,NULL);
     enter_phase(PHASE_RUN);
     run();
 
     enter_phase(PHASE_SHUTDOWN);
+    Message(M_NOTICE,"%s [%d]: finished\n",version,secnet_pid);
 
     return 0;
 }
-