hydrar/mistserver
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Fix for file descriptors getting hammered by StartPiped if 100, 101 or 102 were open.

Browse source
This commit is contained in:
Thulinma 2020-05-25 01:32:49 +02:00
parent d45e78387d
commit 67c0d6666f
1 changed files with 19 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

34
lib/procs.cpp
View file

@ -325,34 +325,38 @@ pid_t Util::Procs::StartPiped(const char *const *argv, int *fdin, int *fdout, in
}
pid = fork();
if (pid == 0){// child
int ch_stdin = 0, ch_stdout = 0, ch_stderr = 0;
handler_set = false;
if (!fdin){
dup2(devnull, 100);
ch_stdin = dup(devnull);
}else if (*fdin == -1){
close(pipein[1]); // close unused write end
dup2(pipein[0], 100);
ch_stdin = dup(pipein[0]);
close(pipein[0]);
}else{
dup2(*fdin, 100);
ch_stdin = dup(*fdin);
}
while (ch_stdin < 3){ch_stdin = dup(ch_stdin);}
if (!fdout){
dup2(devnull, 101);
ch_stdout = dup(devnull);
}else if (*fdout == -1){
close(pipeout[0]); // close unused read end
dup2(pipeout[1], 101);
ch_stdout = dup(pipeout[1]);
close(pipeout[1]);
}else{
dup2(*fdout, 101);
ch_stdout = dup(*fdout);
}
while (ch_stdout < 3){ch_stdout = dup(ch_stdout);}
if (!fderr){
dup2(devnull, 102);
ch_stderr = dup(devnull);
}else if (*fderr == -1){
close(pipeerr[0]); // close unused read end
dup2(pipeerr[1], 102);
ch_stderr = dup(pipeerr[1]);
close(pipeerr[1]);
}else{
dup2(*fderr, 102);
ch_stderr = dup(*fderr);
}
while (ch_stderr < 3){ch_stderr = dup(ch_stderr);}
if (fdin && *fdin != -1){close(*fdin);}
if (fdout && *fdout != -1){close(*fdout);}
if (fderr && *fderr != -1){close(*fderr);}
@ -363,12 +367,12 @@ pid_t Util::Procs::StartPiped(const char *const *argv, int *fdin, int *fdout, in
close(*it);
}
//Black magic to make sure if 0/1/2 are not what we think they are, we end up with them not mixed up and weird.
dup2(100, 0);
dup2(101, 1);
dup2(102, 2);
close(100);
close(101);
close(102);
dup2(ch_stdin, 0);
dup2(ch_stdout, 1);
dup2(ch_stderr, 2);
close(ch_stdout);
close(ch_stdin);
close(ch_stderr);
//There! Now we normalized our stdio
// Because execvp requires a char* const* and we have a const char* const*
execvp(argv[0], (char *const *)argv);