initgroups() call added when changing uid

1 files changed, 10 insertions, 7 deletions

diff --git a/src/process.cc b/src/process.cc
index fda35e8..bfab311 100644
--- a/src/process.cc
+++ b/src/process.cc
@@ -1,184 +1,187 @@
 #include <stdio.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <signal.h>
 #include <pwd.h>
 #include <grp.h>
 #include <sys/wait.h>
 #include <syslog.h>
 #include <errno.h>
 #include <iostream>
 #include <fstream>
 #include <stdexcept>
 using namespace std;
 #include "process.h"
 #include "configuration.h"
 
 void process::check(const string& id,configuration& config) {
     bool running = false;
     ifstream pids(pidfile.c_str(),ios::in);
     if(pids) {
         pid_t pid = 0;
         pids >> pid;
         pids.close();
         if(pid) {
             if(!kill(pid,0)) {
                 running = true;
             }
         }
     }
     if(running){
         patience = 0;
     }else{
         if(patience>60) { // TODO: configurable
             patience = 0;
         }else{
             if(patience<10) { // TODO: configurable
                 syslog(LOG_NOTICE,"The process '%s' is down, trying to launch.",id.c_str());
                 do_notify(id,"Starting up",
                         "The named process seems to be down. Dudki will try\n"
                         "to revive it by running the specified command.\n",
                         config);
                 try {
                     launch(id,config);
                 }catch(exception& e) {
                     syslog(LOG_ERR,"Error trying to launch process '%s': %s",id.c_str(),e.what());
                 }
             }else if(patience==10){ // TODO: configurable like the above
                 syslog(LOG_NOTICE,"Giving up on process '%s' for a while",id.c_str());
                 do_notify(id,"Giving up",
                         "After a number of attempts to relaunch the named process\n"
                         "It still seems to be down. Dudki is giving up attempts\n"
                         "to revive the process for a while.\n",
                         config);
             }
             patience++;
         }
     }
 }
 
 void process::launch(const string& id,configuration& config) {
-    uid_t uid = 0;
+    uid_t uid = (uid_t)-1;
+    gid_t gid = (gid_t)-1;
     if(!user.empty()) {
         struct passwd *ptmp = getpwnam(user.c_str());
         if(ptmp) {
             uid = ptmp->pw_uid;
+            gid = ptmp->pw_gid;
         }else{
             errno=0;
             uid = strtol(user.c_str(),NULL,0);
             if(errno)
                 throw runtime_error("Failed to resolve User value to uid");
         }
     }
-    gid_t gid = 0;
     if(!group.empty()) {
         struct group *gtmp = getgrnam(group.c_str());
         if(gtmp) {
             gid = gtmp->gr_gid;
         }else{
             errno = 0;
             gid = strtol(group.c_str(),NULL,0);
             if(errno)
                 throw runtime_error("Failed to reslove Group value to gid");
         }
     }
     pid_t p = fork();
     if(p<0)
         throw runtime_error(string(__PRETTY_FUNCTION__)+": failed to fork()");
     if(!p) {
         // child
         try {
             setsid();
+            if(user.empty()) {
+                if((getgid()!=gid) && setgid(gid))
+                    throw runtime_error(string(__PRETTY_FUNCTION__)+": failed to setgid()");
+            }else{
+                if(initgroups(user.c_str(),gid))
+                    throw runtime_error(string(__PRETTY_FUNCTION__)+": failed to initgroups()");
+            }
             if(!chroot.empty()) {
                 if(::chroot(chroot.c_str()))
                     throw runtime_error(string(__PRETTY_FUNCTION__)+": failed to chroot()");
             }
-            if(!group.empty()) {
-                // TODO: initgroups()?
-                if((getgid()!=gid) && setgid(gid))
-                    throw runtime_error(string(__PRETTY_FUNCTION__)+": failed to setgid()");
-            }
             if(!user.empty()) {
                 if((getuid()!=uid) && setuid(uid))
                     throw runtime_error(string(__PRETTY_FUNCTION__)+": failed to setuid()");
             }
             char *argv[] = { "/bin/sh", "-c", (char*)restart_cmd.c_str(), NULL };
             close(0); close(1); close(2);
             execv("/bin/sh",argv);
         }catch(exception& e) {
             syslog(LOG_ERR,"Error trying to launch process '%s': %s",id.c_str(),e.what());
         }
         _exit(-1);
     }
     // parent
     int rv;
     if(waitpid(p,&rv,0)<0)
         throw runtime_error(string(__PRETTY_FUNCTION__)+": failed to waitpid()");
 }
 
 void process::do_notify(const string& id,const string& event,const string& description,configuration& config) {
     string the_notify;
     if(!notify.empty())
         the_notify=notify;
     else if(!config.notify.empty())
         the_notify=config.notify;
     else
         return;
     try {
         string::size_type colon = the_notify.find(':');
         if(colon==string::npos)
             throw runtime_error("invalid notify action specification");
         string nschema = the_notify.substr(0,colon);
         string ntarget = the_notify.substr(colon+1);
         if(nschema=="mailto") {
             notify_mailto(ntarget,id,event,description,config);
         }else
             throw runtime_error("unrecognized notification schema");
     }catch(exception& e) {
         syslog(LOG_ERR,"Notification error: %s",e.what());
     }
 }
 
 void process::notify_mailto(const string& email,const string& id,const string& event,const string& description,configuration& config) {
     int files[2];
     if(pipe(files))
         throw runtime_error("Failed to pipe()");
     pid_t pid = vfork();
     if(pid==-1) {
         close(files[0]);
         close(files[1]);
         throw runtime_error("Failed to vfork()");
     }
     if(!pid) {
         // child
         if(dup2(files[0],0)!=0)
             _exit(-1);
         close(1);
         close(files[0]);
         close(files[1]);
         execl("/usr/sbin/sendmail","usr/sbin/sendmail","-i",email.c_str(),NULL);
         _exit(-1);
     }
     // parent
     close(files[0]);
     FILE *mta = fdopen(files[1],"w");
     for(headers_t::const_iterator i=mailto_headers.begin();i!=mailto_headers.end();++i) {
         fprintf(mta,"%s: %s\n",i->first.c_str(),i->second.c_str());
     }
     for(headers_t::const_iterator i=config.mailto_headers.begin();i!=config.mailto_headers.end();++i) {
         if(mailto_headers.find(i->first)!=mailto_headers.end())
             continue;
         fprintf(mta,"%s: %s\n",i->first.c_str(),i->second.c_str());
     }
     fprintf(mta,
             "Subject: [%s] %s\n\n"
             "%s\n"
             "---\n"
             "This message was sent automatically by the 'dudki' daemon\n",
             id.c_str(), event.c_str(),
             description.c_str() );
     fclose(mta);
     int status;
     waitpid(pid,&status,0);
     // TODO: check the return code
 }