1 files changed, 107 insertions, 11 deletions

diff --git a/src/process.cc b/src/process.cc
index 1ffac9f..8a5b5d2 100644
--- a/src/process.cc
+++ b/src/process.cc
@@ -1,189 +1,285 @@
 #include <stdio.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <signal.h>
 #include <pwd.h>
 #include <grp.h>
+#include <dirent.h>
 #include <sys/wait.h>
 #include <syslog.h>
 #include <errno.h>
 #include <iostream>
 #include <fstream>
+#include <sstream>
 #include <stdexcept>
+#include <string>
+#include <vector>
 using namespace std;
 #include "process.h"
 #include "configuration.h"
 
+static multimap<string,pid_t> procpids;
+
+void process::check() const {
+    if(!pidfile.empty()) {
+	signal(0);
+    }else if(!process_name.empty()) {
+	if(procpids.empty())
+	    gather_proc_info();
+	if(procpids.find(process_name)==procpids.end())
+	    throw runtime_error("no such process");
+    } // XXX: or else?
+}
 void process::check(const string& id,configuration& config) {
     try {
-	signal(0);
+	check();
 	patience = 0;
     }catch(exception& e) {
 	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 = (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");
 	}
     }
     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(!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
 }
 
 void process::signal(int signum) const {
-    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");
+    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)
+	    continue;
+	getline(ss,cmd);
+	string::size_type op = cmd.find('(');
+	if(op==string::npos)
+	    continue;
+	cmd.erase(0,op+1);
+	string::size_type cp = cmd.find(')');
+	if(cp==string::npos)
+	    continue;
+	cmd.erase(cp);
+	r = snprintf(s,sizeof(s),"/proc/%d/cmdline",*i);
+	if(r>=sizeof(s) || r<1)
+	    continue;
+	ifstream cs(s,ios::binary);
+	if(!cs)
+	    continue;
+	string command;
+	while(cs) {
+	    string cl;
+	    getline(cs,cl,(char)0);
+	    string::size_type lsl = cl.rfind('/');
+	    if(lsl!=string::npos)
+		cl.erase(0,lsl+1);
+	    if(cl.substr(0,cmd.length())==cmd) {
+		command = cl;
+		break;
+	    }
+	}
+	procpids.insert(pair<string,pid_t>(cmd,*i));
+	if((!command.empty()) && cmd!=command)
+	    procpids.insert(pair<string,pid_t>(command,*i));
+    }
 }