don't break in the absence of sendmail

If for whatever reason notify child isn't properly spawned, don't die and still
try to launch process in question

Signed-off-by: Michael Krelin <hacker@klever.net>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/process.cc b/src/process.cc
index 6d3b2a2..4807b98 100644
--- a/src/process.cc
+++ b/src/process.cc
@@ -109,147 +109,152 @@ void process::launch(const string& id,configuration& config) {
                     throw runtime_error(string(__PRETTY_FUNCTION__)+": failed to chroot()");
             }
             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
+    int status;
+    if(waitpid(pid,&status,WNOHANG)) {
+        close(files[0]);
+        close(files[1]);
+        throw runtime_error("vfork()ed sendmail child exited unexpectedly");
+    }
     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
 }
 
 void process::signal(int signum) const {
     if(!pidfile.empty()) {
         ifstream pids(pidfile.c_str(),ios::in);
         if(!pids)
             throw runtime_error("no pidfile found");
         pid_t pid = 0;
         pids >> pid;
         pids.close();
         if(!pid)
             throw runtime_error("no pid in pidfile");
         if(kill(pid,signum))
             throw runtime_error("failed to signal process");
     }else if(!process_name.empty()) {
         if(procpids.empty())
             gather_proc_info();
         pair<multimap<string,pid_t>::const_iterator,multimap<string,pid_t>::const_iterator> range = procpids.equal_range(process_name);
         int count = 0;
         for(multimap<string,pid_t>::const_iterator i=range.first;i!=range.second;++i) {
             pid_t pid = i->second;
             if(kill(i->second,signum))
                 throw runtime_error("failed to signal process");
             count++;
         }
         if(!count)
             throw runtime_error("no running instance detected");
     }else
         throw runtime_error("nothing is known about the process");
 }
 
 void process::prepare_herd() {
     procpids.clear();
 }
 void process::unprepare_herd() {
     procpids.clear();
 }
 void process::gather_proc_info() {
     vector<pid_t> allpids;
     DIR *pd = opendir("/proc");
     if(!pd)
         throw runtime_error("failed to open /proc");
     struct dirent *pde;
     pid_t selfpid = getpid();
     while(pde=readdir(pd)) {
         errno=0;
         pid_t pid = atoi(pde->d_name);
         if((!pid) || pid==selfpid)
             continue;
         allpids.push_back(pid);
     }
     closedir(pd);
     char s[256];
     procpids.clear();
     for(vector<pid_t>::const_iterator i=allpids.begin();i!=allpids.end();++i) {
         int r = snprintf(s,sizeof(s),"/proc/%d/stat",*i);
         if(r>=sizeof(s) || r<1)
             continue;
         string cmd;
         ifstream ss(s,ios::in);
         if(ss) {
             getline(ss,cmd);