X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=userv.git;a=blobdiff_plain;f=process.c;h=fa8302f93c4e8b41b3a979686c8a4c7b40e96dcd;hp=b091f4e5b8876b490f6159eb0a0f071eac07a51d;hb=HEAD;hpb=4544c87c6355037a095e296b5280ccb3ff25ac4b

diff --git a/process.c b/process.c
index b091f4e..2a2955e 100644
--- a/process.c
+++ b/process.c
@@ -2,11 +2,12 @@
  * userv - process.c
  * daemon code to process one request (is parent of service process)
  *
- * Copyright (C)1996-1997 Ian Jackson
+ * userv is copyright Ian Jackson and other contributors.
+ * See README for full authorship information.
  *
  * 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 +16,7 @@
  * 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/>.
  */
 
 /*
@@ -49,17 +49,19 @@
 #include <syslog.h>
 #include <pwd.h>
 #include <grp.h>
-#include <ctype.h>
 #include <limits.h>
+#include <fcntl.h>
 #include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/resource.h>
 #include <sys/types.h>
-#include <sys/fcntl.h>
 #include <sys/stat.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 
 #include "config.h"
 #include "common.h"
+#include "both.h"
 #include "daemon.h"
 #include "lib.h"
 #include "tokens.h"
@@ -73,7 +75,7 @@ int fdarraysize, fdarrayused;
 int restfdwantstate= tokv_word_rejectfd, restfdwantrw;
 int service_ngids;
 char **argarray;
-char *serviceuser, *service, *logname, *cwd;
+char *serviceuser, *service, *loginname, *cwd;
 char *overridedata, *userrcfile;
 char *serviceuser_dir, *serviceuser_shell, *callinguser_shell;
 gid_t *calling_gids, *service_gids;
@@ -147,7 +149,7 @@ static void xfflush(FILE *file) {
 
 static void xfread(void *p, size_t sz) {
   size_t nr;
-  nr= fread(p,1,sz,srfile); if (nr == sz) return;
+  nr= working_fread(p,sz,srfile); if (nr == sz) return;
   if (ferror(srfile)) syscallerror("reading from client");
   blocksignals();
   assert(feof(srfile));
@@ -269,8 +271,18 @@ void NONRETURNING disconnect(int exitstatus) {
   _exit(exitstatus);
 }
 
-static void NONRETURNING sighandler_chld(int ignored) {
+static void reporttermination(int status) {
   struct progress_msg progress_mbuf;
+  
+  memset(&progress_mbuf,0,sizeof(progress_mbuf));
+  progress_mbuf.magic= PROGRESS_MAGIC;
+  progress_mbuf.type= pt_terminated;
+  progress_mbuf.data.terminated.status= status;
+  xfwrite(&progress_mbuf,sizeof(progress_mbuf),swfile);
+  xfflush(swfile);
+}
+
+static void NONRETURNING sighandler_chld(int ignored) {
   int status;
   pid_t returned;
 
@@ -280,13 +292,7 @@ static void NONRETURNING sighandler_chld(int ignored) {
   if (returned!=child) syscallerror("spurious child process");
   child= childtokill= -1;
 
-  memset(&progress_mbuf,0,sizeof(progress_mbuf));
-  progress_mbuf.magic= PROGRESS_MAGIC;
-  progress_mbuf.type= pt_terminated;
-  progress_mbuf.data.terminated.status= status;
-  xfwrite(&progress_mbuf,sizeof(progress_mbuf),swfile);
-  xfflush(swfile);
-
+  reporttermination(status);
   syslog(LOG_INFO,"service completed (status %d %d)",(status>>8)&0x0ff,status&0x0ff);
   _exit(0);
 }
@@ -413,7 +419,7 @@ static void receive_request(void) {
   serviceuser= xfreadsetstring(request_mbuf.serviceuserlen);
   service= xfreadsetstring(request_mbuf.servicelen);
   assert(request_mbuf.spoofed==0 || request_mbuf.spoofed==1);
-  logname= xfreadsetstring(request_mbuf.lognamelen);
+  loginname= xfreadsetstring(request_mbuf.loginnamelen);
   cwd= xfreadsetstring(request_mbuf.cwdlen);
   if (request_mbuf.overridelen >= 0) {
     assert(request_mbuf.overridelen <= MAX_OVERRIDE_LEN);
@@ -437,6 +443,8 @@ static void receive_request(void) {
     assert(fdarray[fd].iswrite == -1);
     fdarray[fd].iswrite= (i>=request_mbuf.nreadfds);
   }
+  /* fdarray[].iswrite now set; rest is still blank
+   * (ie want reject read, no realfd holdfd). */
 
   assert(request_mbuf.nargs <= MAX_ARGSDEFVAR);
   argarray= xmalloc(sizeof(char*)*(request_mbuf.nargs));
@@ -476,6 +484,14 @@ static void establish_pipes(void) {
     if (unlink(pipepathbuf)) syscallerror("unlink pipe");
     if (close(tempfd)) syscallerror("close prelim fd onto pipe");
   }
+  /* Now fdarray[].realfd is pipe end for service in case service
+   * wants it.  If it's an input pipe, then .holdfd is the other
+   * (writing) end of the pipe - we keep it around so that the service
+   * doesn't get an apparently clean EOF if the caller disappears (eg
+   * due to a file read error) or the like (ie so that on disconnect
+   * we can guarantee to send the service SIGHUP before it gets EOF on
+   * the input fd).  Otherwise, .holdfd=-1.
+   */
 }
 
 static void groupnames(int ngids, gid_t *gids, const char ***names_r) {
@@ -495,9 +511,9 @@ static void groupnames(int ngids, gid_t *gids, const char ***names_r) {
 static void lookup_uidsgids(void) {
   struct passwd *pw;
 
-  pw= getpwnam(logname);
+  pw= getpwnam(loginname);
   if (!pw) miscerror("look up calling user");
-  assert(!strcmp(pw->pw_name,logname));
+  assert(!strcmp(pw->pw_name,loginname));
   callinguser_shell= xstrsave(pw->pw_shell);
 
   pw= getpwnam(serviceuser);
@@ -639,7 +655,6 @@ static void check_fds(void) {
     case tokv_word_requirefd:
       if (fdarray[fd].realfd == -1)
 	failure("file descriptor %d required but not provided",fd);
-      assert(fdarray[fd].holdfd == -1);
       /* fall through */
     case tokv_word_allowfd:
       if (fdarray[fd].realfd == -1) {
@@ -656,6 +671,10 @@ static void check_fds(void) {
       }
     }
   }
+  /* Now fdarray[].realfd is exactly what service wants: pipe end or
+   * /dev/null or -1.  If .realfd is not -1 then .holdfd may be the fd
+   * for the writing end of the corresponding pipe.
+   */
 }
 
 static void send_progress_ok(void) {
@@ -722,7 +741,7 @@ void servicerequest(int sfd) {
   debug_dumprequest(mypid);
   syslog(LOG_INFO,"%s %s -> %s %c %s",
 	 request_mbuf.spoofed ? "spoof" : "user",
-	 logname, serviceuser, overridedata?'!':':', service);
+	 loginname, serviceuser, overridedata?'!':':', service);
 
   if (overridedata)
     r= parse_string(TOPLEVEL_OVERRIDDEN_CONFIGURATION,
@@ -744,6 +763,18 @@ void servicerequest(int sfd) {
   getevent(&event_mbuf);
   assert(event_mbuf.type == et_confirm);
 
+  if (execbuiltin == bisexec_shutdown && !serviceuser_uid) {
+    /* The check for the uid is just so we can give a nice
+     * error message (in the actual code for bisexec_shutdown).
+     * If this is spoofed somehow then the unlink() will simply fail.
+     */
+    r= unlink(RENDEZVOUSPATH);
+    if (r) syscallfailure("remove rendezvous socket %s",RENDEZVOUSPATH);
+    syslog(LOG_NOTICE,"arranging for termination, due to client request");
+    reporttermination(0);
+    _exit(10);
+  }
+
   fork_service_synch();
   
   getevent(&event_mbuf);