Upgrade licence to GPLv3+.

[userv.git] / servexec.c

diff --git a/servexec.c b/servexec.c
index c1614f0d9952aeacf71f763b6094658cbfb5b579..5fa8e1f3787babb29de15abf783a495cfbb4f450 100644 (file)
--- a/servexec.c
+++ b/servexec.c
@@ -2,11 +2,14 @@
  * userv - execserv.c
  * daemon code which executes actual service (ie child process)
  *
- * Copyright (C)1996-1997,1999 Ian Jackson
+ * userv is
+ * Copyright 1996-2017 Ian Jackson <ian@davenant.greenend.org.uk>.
+ * Copyright 2000      Ben Harris <bjh21@cam.ac.uk>
+ * Copyright 2016-2017 Peter Benie <pjb1008@cam.ac.uk>
  *
  * This is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
+ * the Free Software Foundation; either version 3 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but
@@ -15,8 +18,7 @@
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with userv; if not, write to the Free Software
- * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with userv; if not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <stdio.h>
@@ -35,6 +37,7 @@
 #include "common.h"
 #include "daemon.h"
 #include "lib.h"
+#include "both.h"
 #include "version.h"
 
 static void NONRETURNING serv_syscallfail(const char *msg) {
@@ -58,11 +61,19 @@ void bisexec_parameter(const char *const *argv) {
   serv_checkstdoutexit();
 }
   
+void bisexec_help(const char *const *argv) {
+  const char *const *pp;
+  
+  fputs("recognised builtin services:\n",stdout);
+  for (pp= builtinservicehelpstrings; *pp; pp++) printf("  %s\n",*pp);
+  serv_checkstdoutexit();
+}
+  
 void bisexec_version(const char *const *argv) {
   const unsigned char *p;
   int i;
   
-  printf("uservd version " VERSION VEREXT "; copyright (C)1996-1997 Ian Jackson.\n"
+  printf("uservd version " VERSION VEREXT "\n"
 #ifdef DEBUG
         "DEBUGGING VERSION"
 #else
@@ -84,7 +95,8 @@ void bisexec_version(const char *const *argv) {
   printf("\n"
         "rendezvous socket: `" RENDEZVOUSPATH "'\n"
         "system config dir: `" SYSTEMCONFIGDIR "'\n"
-        "pipe filename format: `%s' (max length %d)\n",
+        "pipe filename format: `%s' (max length %d)\n"
+        COPYRIGHT("","\n"),
         PIPEFORMAT, PIPEMAXLEN);
   serv_checkstdoutexit();
 }
@@ -129,6 +141,15 @@ void bisexec_execute(const char *const *argv) {
   serv_checkstdoutexit();
 }
 
+void bisexec_shutdown(const char *const *argv) {
+  /* This is only reached if the serviceuser_uid test in
+   * process.c:servicerequest() fails (we have to handle the
+   * shutdown request there, unfortunately).
+   */
+  fputs("uservd: builtin service shutdown: permission denied\n",stderr);
+  _exit(-1);
+}
+
 static void serv_resetsignal(int signo) {
   struct sigaction sig;
   
@@ -173,7 +194,7 @@ static const char *see_c_group(void) {
 static const char *seei_gid(int i) {
   static char buf[CHAR_BIT*sizeof(gid_t)/3+4];
   
-  snyprintf(buf,sizeof(buf),"%d",calling_gids[i]);
+  snyprintf(buf,sizeof(buf),"%ld",(long)calling_gids[i]);
   return buf;
 }
 static const char *see_c_gid(void) {
@@ -206,7 +227,7 @@ void execservice(const int synchsocket[], int clientfd) {
     "-",
     0
   };
-  int fd, realfd, holdfd, newfd, r, envvarbufsize=0, targ, nargs, i, l;
+  int fd, realfd, holdfd, newfd, r, envvarbufsize=0, targ, nargs, i, l, fdflags;
   char *envvarbuf=0;
   const char **args, *const *cpp;
   char *const *pp;
@@ -232,7 +253,16 @@ void execservice(const int synchsocket[], int clientfd) {
 
   if (close(clientfd)) serv_syscallfail("close client socket fd");
 
-  /* Now we have to make all the fd's work.  It's rather a complicated
+  /* First we need to close the holding writing ends of the pipes
+   * inherited from our parent: */
+  for (fd=0; fd<fdarrayused; fd++) {
+    if (fdarray[fd].holdfd == -1) continue;
+    if (close(fdarray[fd].holdfd)) serv_syscallfail("close pipe hold fd");
+    fdarray[fd].holdfd= -1;
+  }
+  /* Now we can reuse the .holdfd member of the fdarray entries. */
+
+  /* We have to make all the fd's work.  It's rather a complicated
    * algorithm, unfortunately.  We remember in holdfd[fd] whether fd
    * is being used to hold a file descriptor we actually want for some
    * other real fd in the service program; holdfd[fd] contains the fd
@@ -243,12 +273,8 @@ void execservice(const int synchsocket[], int clientfd) {
    * move it out of the way with dup and record its new location.
    */
   for (fd=0; fd<fdarrayused; fd++) {
-    if (fdarray[fd].holdfd == -1) continue;
-    if (close(fdarray[fd].holdfd)) serv_syscallfail("close pipe hold fd");
-    fdarray[fd].holdfd= -1;
-  }
-  for (fd=0; fd<fdarrayused; fd++) {
-    if (fdarray[fd].realfd < fdarrayused) fdarray[fdarray[fd].realfd].holdfd= fd;
+    if (fdarray[fd].realfd < fdarrayused && fdarray[fd].realfd >= 0)
+      fdarray[fdarray[fd].realfd].holdfd= fd;
   }
   for (fd=0; fd<fdarrayused; fd++) {
     realfd= fdarray[fd].realfd;
@@ -267,7 +293,8 @@ void execservice(const int synchsocket[], int clientfd) {
     }
     if (dup2(fdarray[fd].realfd,fd)<0) serv_syscallfail("dup2 set up fd");
     if (close(fdarray[fd].realfd)) serv_syscallfail("close old fd");
-    if (fcntl(fd,F_SETFD,0)<0) serv_syscallfail("set no-close-on-exec on fd");
+    fdflags= fcntl(fd,F_GETFD); if (fdflags<0) serv_syscallfail("get fd flags");
+    if (fcntl(fd,F_SETFD,fdflags&~FD_CLOEXEC)==-1) serv_syscallfail("set no-close-on-exec on fd");
     fdarray[fd].realfd= fd;
   }