Crash_Override/MMDVMHost-Private
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added setuid and setgid code, tidied up logging

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This commit is contained in:
Simon 2016-05-04 20:06:15 +01:00
parent fbef96ca88
commit 25d993b8b3
1 changed files with 46 additions and 6 deletions
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52
MMDVMHost.cpp
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@ -39,6 +39,7 @@
#include <unistd.h>
#include <signal.h>
#include <fcntl.h>
#include <pwd.h>
#endif
#if defined(_WIN32) || defined(_WIN64)
@ -134,22 +135,61 @@ int CMMDVMHost::run()
if (m_daemon) {
// Create new process
pid_t pid = ::fork();
if (pid == -1)
return -1;
if (pid == -1) {
::LogMessage("Couldn't fork() , exiting");
return -1;
}
else if (pid != 0)
exit(EXIT_SUCCESS);
// Create new session and process group
if (::setsid() == -1)
return -1;
if (::setsid() == -1){
::LogMessage("Couldn't setsid(), exiting");
return -1;
}
// Set the working directory to the root directory
if (::chdir("/") == -1)
return -1;
if (::chdir("/") == -1){
::LogMessage("Couldn't cd /, exiting");
return -1;
}
::close(STDIN_FILENO);
::close(STDOUT_FILENO);
::close(STDERR_FILENO);
//If we are currently root...
if (getuid() == 0) {
//get UID for mmdvm user
uid_t mmdvm_uid = getpwnam("mmdvm")->pw_uid;
if (mmdvm_uid == NULL) {
::LogMessage("Could not get mmdvm UID, exiting");
return -1;
}
//get GID for mmdvm user
gid_t mmdvm_gid = getpwnam("mmdvm")->pw_gid;
if (mmdvm_gid == NULL) {
::LogMessage("Could not get mmdvm GID, exiting");
return -1;
}
//Set user and group ID's to mmdvm:mmdvm
if (setgid(mmdvm_gid) != 0) {
::LogMessage("Could not set mmdvm GID, exiting");
return -1;
}
if (setuid(mmdvm_uid) != 0) {
::LogMessage("Could not set mmdvm UID, exiting");
return -1;
}
//Double check it worked (AKA Paranoia)
if (setuid(0) != -1){
::LogMessage("It's possible to regain root - something is wrong!, exiting");
return -1;
}
}
}
#endif