4 files changed, 124 insertions, 12 deletions

diff --git a/src/configuration.cc b/src/configuration.cc
index eb010c1..edc8c04 100644
--- a/src/configuration.cc
+++ b/src/configuration.cc
@@ -71,72 +71,77 @@ static DOTCONF_CB(dco_notify) { dc_context *dcc = (dc_context*)ctx;
             break;
         case DCC_PROCESS:
             dcc->ps->notify = cmd->data.str;
             break;
         default:
             return "Unexpected Notify";
     }
     return NULL;
 }
 
 static DOTCONF_CB(dco_process) { dc_context *dcc = (dc_context*)ctx;
     string id = cmd->data.str;
     if(id[id.length()-1]=='>')
         id.erase(id.length()-1);
     dcc->ps = &(dcc->cf->processes[id]);
     dcc->ctx = DCC_PROCESS;
     return NULL;
 }
 static DOTCONF_CB(dco__process) { dc_context *dcc = (dc_context*)ctx;
     dcc->ps = NULL;
     dcc->ctx = DCC_ROOT;
     return NULL;
 }
 
+static DOTCONF_CB(dco_process_name) { dc_context *dcc = (dc_context*)ctx;
+    dcc->ps->process_name = cmd->data.str;
+    return NULL;
+}
 static DOTCONF_CB(dco_restart_command) { dc_context *dcc = (dc_context*)ctx;
     dcc->ps->restart_cmd = cmd->data.str;
     return NULL;
 }
 static DOTCONF_CB(dco_user) { dc_context *dcc = (dc_context*)ctx;
     dcc->ps->user = cmd->data.str;
     return NULL;
 }
 static DOTCONF_CB(dco_group) { dc_context *dcc = (dc_context*)ctx;
     dcc->ps->group = cmd->data.str;
     return NULL;
 }
 static DOTCONF_CB(dco_chroot) { dc_context *dcc = (dc_context*)ctx;
     dcc->ps->chroot = cmd->data.str;
     return NULL;
 }
 
 static const configoption_t dc_options[] = {
     { "CheckInterval", ARG_INT, dco_check_interval, NULL, DCC_ROOT },
     { "Daemonize", ARG_TOGGLE, dco_daemonize, NULL, DCC_ROOT },
     { "PidFile", ARG_STR, dco_pid_file, NULL, DCC_ROOT|DCC_PROCESS },
     { "MailtoHeader", ARG_STR, dco_mailto_header, NULL, DCC_ROOT|DCC_PROCESS },
     { "Notify", ARG_STR, dco_notify, NULL, DCC_ROOT|DCC_PROCESS },
     { "<Process", ARG_STR, dco_process, NULL, DCC_ROOT },
+    {  "ProcessName", ARG_STR, dco_process_name, NULL, DCC_PROCESS },
     {  "RestartCommand", ARG_STR, dco_restart_command, NULL, DCC_PROCESS },
     {  "User", ARG_STR, dco_user, NULL, DCC_PROCESS },
     {  "Group", ARG_STR, dco_group, NULL, DCC_PROCESS },
     {  "Chroot", ARG_STR, dco_chroot, NULL, DCC_PROCESS },
     { "</Process>", ARG_NONE, dco__process, NULL, DCC_PROCESS },
     LAST_OPTION
 };
 
 static const char *dc_context_checker(command_t *cmd,unsigned long mask) {
     dc_context *dcc = (dc_context*)cmd->context;
     if( (mask==CTX_ALL) || ((mask&dcc->ctx)==dcc->ctx) )
         return NULL;
     return "misplaced option";
 }
 static FUNC_ERRORHANDLER(dc_error_handler) {
     throw runtime_error(string("error parsing config file: ")+msg);
 }
     
 void configuration::parse(const string& cfile) {
     struct dc_context dcc;
     dcc.cf = this;
     dcc.ctx = DCC_ROOT;
     configfile_t *cf = dotconf_create((char*)cfile.c_str(),dc_options,(context_t*)&dcc,CASE_INSENSITIVE);
     if(!cf)
diff --git a/src/dudki.cc b/src/dudki.cc
index 9562079..c966695 100644
--- a/src/dudki.cc
+++ b/src/dudki.cc
@@ -14,50 +14,52 @@ using namespace std;
 # include <getopt.h>
 #endif
 
 #ifndef DEFAULT_CONF_FILE
 # define DEFAULT_CONF_FILE "/etc/dudki.conf"
 #endif
 
 #define PHEADER PACKAGE " Version " VERSION
 #define PCOPY   "Copyright (c) 2004 Klever Group"
 
 bool finishing = false;
 bool restarting = false;
 static char **_argv = NULL;
 
 static void lethal_signal_handler(int signum) {
     syslog(LOG_NOTICE,"Lethal signal received. Terminating.");
     finishing = true;
 }
 static void sighup_handler(int signum) {
     syslog(LOG_NOTICE,"SUGHUP received, reloading.");
     restarting = finishing = true;
 }
 
 void check_herd(configuration& config) {
+    process::prepare_herd();
     for(processes_t::iterator i=config.processes.begin();i!=config.processes.end();++i)
         i->second.check(i->first,config);
+    process::unprepare_herd();
 }
 
 void signal_self(const configuration& config,int signum) {
     ifstream pids(config.pidfile.c_str(),ios::in);
     if(!pids)
         throw runtime_error("Can't detect running instance");
     pid_t pid = 0;
     pids >> pid;
     if(!pid)
         throw runtime_error("Can't detect running instance");
     if(pid==getpid())
         throw 0;
     if(kill(pid,signum))
         throw runtime_error("Failed to signal running instance");
 }
 
 int main(int argc,char **argv) {
     try {
         _argv = new char*[argc+1];
         if(!_argv)
             throw runtime_error("memory allocation problem at the very start");
         memmove(_argv,argv,sizeof(*_argv)*(argc+1));
         string config_file = DEFAULT_CONF_FILE;
         enum {
@@ -199,49 +201,52 @@ int main(int argc,char **argv) {
         }
         const char *sid = *argv;
         const char *t;
         while(t = index(sid,'/')) {
             sid = t; sid++;
         }
         openlog(sid,LOG_CONS|LOG_PERROR|LOG_PID,LOG_DAEMON);
         configuration config;
         config.parse(config_file);
         switch(op) {
             case op_test:
                 cerr << "Configuration OK" << endl;
                 break;
             case op_signal:
                 try {
                     if(optind>=argc) {
                         signal_self(config,op_signum);
                     }else{
                         int failures = 0;
                         for(int narg=optind;narg<argc;narg++) {
                             try {
                                 processes_t::const_iterator i = config.processes.find(argv[narg]);
                                 if(i==config.processes.end())
                                     throw runtime_error("no such process configured");
-                                i->second.signal(op_signum);
+                                if(op_signum)
+                                    i->second.signal(op_signum);
+                                else
+                                    i->second.check();
                             }catch(exception& e) {
                                 cerr << "dudki(" << argv[narg] << "): " << e.what() << endl;
                                 failures++;
                             }
                         }
                         if(failures)
                             throw runtime_error("not all processes have been successfully signaled");
                     }
                     if(!op_signum)
                         exit(0);
                 }catch(exception& e) {
                     if(!op_signum)
                         exit(1);
                 }
             case op_ensure:
                 try {
                     signal_self(config,0);
                     break;
                 }catch(exception& e) {
                     syslog(LOG_NOTICE,"The dudki process is down, taking its place");
                     config.daemonize = true;
                 }catch(int zero) {
                     // we throw zero in case we're ensuring that this very process is running.
                     // we don't have to daemonize if we're daemonic.
diff --git a/src/process.cc b/src/process.cc
index 1ffac9f..8a5b5d2 100644
--- a/src/process.cc
+++ b/src/process.cc
@@ -1,43 +1,59 @@
 #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);
             }
@@ -155,35 +171,115 @@ void process::notify_mailto(const string& email,const string& id,const string& e
     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));
+    }
 }
diff --git a/src/process.h b/src/process.h
index 27ee049..90b12d9 100644
--- a/src/process.h
+++ b/src/process.h
@@ -1,38 +1,44 @@
 #ifndef __PROCESS_H
 #define __PROCESS_H
 
 #include <string>
 #include <map>
 using namespace std;
 
 class configuration;
 
 typedef map<string,string> headers_t;
 
 class process {
     public:
         string pidfile;
+        string process_name;
         string restart_cmd;
         string notify;
         string user;
         string group;
         string chroot;
         headers_t mailto_headers;
 
         int patience;
 
         process()
             : patience(0) { }
 
         void check(const string& id,configuration& config);
         void launch(const string& id,configuration& config);
         void do_notify(const string& id,const string& event,const string& description,configuration& config);
         void notify_mailto(const string& email,const string& id,const string& event,
                 const string& description,configuration& config);
 
         void signal(int signum) const;
+        void check() const;
+
+        static void prepare_herd();
+        static void gather_proc_info();
+        static void unprepare_herd();
 };
 
 typedef map<string,process> processes_t;
 
 #endif /* __PROCESS_H */