| -rw-r--r-- | src/process.cc | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/src/process.cc b/src/process.cc new file mode 100644 index 0000000..fda35e8 --- a/dev/null +++ b/src/process.cc @@ -0,0 +1,184 @@ +#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; + if(!user.empty()) { + struct passwd *ptmp = getpwnam(user.c_str()); + if(ptmp) { + uid = ptmp->pw_uid; + }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(!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 +} |