summaryrefslogtreecommitdiffabout
path: root/src/process.cc
Side-by-side diff
Diffstat (limited to 'src/process.cc') (more/less context) (show whitespace changes)
-rw-r--r--src/process.cc7
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
@@ -1,297 +1,302 @@
#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 {
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(!group.empty()) {
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
+ 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);
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);
}else{
r = snprintf(s,sizeof(s),"/proc/%d/status",*i);
if(r>=sizeof(s) || r<1)
continue;
ifstream ss(s,ios::in);
if(!ss)
continue;
ss >> cmd;
if(cmd.empty())
continue;
}
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));
}
}