nsresult nsProfileLock::LockWithSymlink(nsIFile *aLockFile, bool aHaveFcntlLock)
{
nsresult rv;
nsAutoCString lockFilePath;
rv = aLockFile->GetNativePath(lockFilePath);
if (NS_FAILED(rv)) {
NS_ERROR("Could not get native path");
return rv;
}
// don't replace an existing lock time if fcntl already got one
if (!mReplacedLockTime)
aLockFile->GetLastModifiedTimeOfLink(&mReplacedLockTime);
struct in_addr inaddr;
inaddr.s_addr = htonl(INADDR_LOOPBACK);
char hostname[256];
PRStatus status = PR_GetSystemInfo(PR_SI_HOSTNAME, hostname, sizeof hostname);
if (status == PR_SUCCESS)
{
char netdbbuf[PR_NETDB_BUF_SIZE];
PRHostEnt hostent;
status = PR_GetHostByName(hostname, netdbbuf, sizeof netdbbuf, &hostent);
if (status == PR_SUCCESS)
memcpy(&inaddr, hostent.h_addr, sizeof inaddr);
}
char *signature =
PR_smprintf("%s:%s%lu", inet_ntoa(inaddr), aHaveFcntlLock ? "+" : "",
(unsigned long)getpid());
const char *fileName = lockFilePath.get();
int symlink_rv, symlink_errno = 0, tries = 0;
// use ns4.x-compatible symlinks if the FS supports them
while ((symlink_rv = symlink(signature, fileName)) < 0)
{
symlink_errno = errno;
if (symlink_errno != EEXIST)
break;
if (!IsSymlinkStaleLock(&inaddr, fileName, aHaveFcntlLock))
break;
// Lock seems to be bogus: try to claim it. Give up after a large
// number of attempts (100 comes from the 4.x codebase).
(void) unlink(fileName);
if (++tries > 100)
break;
}
PR_smprintf_free(signature);
signature = nullptr;
if (symlink_rv == 0)
{
// We exclusively created the symlink: record its name for eventual
// unlock-via-unlink.
rv = NS_OK;
mHaveLock = true;
mPidLockFileName = strdup(fileName);
if (mPidLockFileName)
{
PR_APPEND_LINK(this, &mPidLockList);
if (!setupPidLockCleanup++)
{
// Clean up on normal termination.
// This instanciates a dummy class, and will trigger the class
// destructor when libxul is unloaded. This is equivalent to atexit(),
// but gracefully handles dlclose().
static RemovePidLockFilesExiting r;
// Clean up on abnormal termination, using POSIX sigaction.
// Don't arm a handler if the signal is being ignored, e.g.,
// because mozilla is run via nohup.
if (!sDisableSignalHandling) {
struct sigaction act, oldact;
#ifdef SA_SIGINFO
act.sa_sigaction = FatalSignalHandler;
act.sa_flags = SA_SIGINFO;
#else
act.sa_handler = FatalSignalHandler;
#endif
sigfillset(&act.sa_mask);
#define CATCH_SIGNAL(signame) \
PR_BEGIN_MACRO \
if (sigaction(signame, nullptr, &oldact) == 0 && \
oldact.sa_handler != SIG_IGN) \
{ \
sigaction(signame, &act, &signame##_oldact); \
} \
PR_END_MACRO
CATCH_SIGNAL(SIGHUP);
CATCH_SIGNAL(SIGINT);
CATCH_SIGNAL(SIGQUIT);
CATCH_SIGNAL(SIGILL);
CATCH_SIGNAL(SIGABRT);
CATCH_SIGNAL(SIGSEGV);
CATCH_SIGNAL(SIGTERM);
#undef CATCH_SIGNAL
}
}
}
}
else if (symlink_errno == EEXIST)
rv = NS_ERROR_FILE_ACCESS_DENIED;
else
{
#ifdef DEBUG
printf("symlink() failed. errno = %d\n", errno);
#endif
rv = NS_ERROR_FAILURE;
}
return rv;
}
nsresult nsProfileLock::LockWithSymlink(const nsACString& lockFilePath, PRBool aHaveFcntlLock)
{
nsresult rv;
struct in_addr inaddr;
inaddr.s_addr = htonl(INADDR_LOOPBACK);
char hostname[256];
PRStatus status = PR_GetSystemInfo(PR_SI_HOSTNAME, hostname, sizeof hostname);
if (status == PR_SUCCESS)
{
char netdbbuf[PR_NETDB_BUF_SIZE];
PRHostEnt hostent;
status = PR_GetHostByName(hostname, netdbbuf, sizeof netdbbuf, &hostent);
if (status == PR_SUCCESS)
memcpy(&inaddr, hostent.h_addr, sizeof inaddr);
}
char *signature =
PR_smprintf("%s:%s%lu", inet_ntoa(inaddr), aHaveFcntlLock ? "+" : "",
(unsigned long)getpid());
const nsPromiseFlatCString& flat = PromiseFlatCString(lockFilePath);
const char *fileName = flat.get();
int symlink_rv, symlink_errno = 0, tries = 0;
// use ns4.x-compatible symlinks if the FS supports them
while ((symlink_rv = symlink(signature, fileName)) < 0)
{
symlink_errno = errno;
if (symlink_errno != EEXIST)
break;
if (!IsSymlinkStaleLock(&inaddr, fileName, aHaveFcntlLock))
break;
// Lock seems to be bogus: try to claim it. Give up after a large
// number of attempts (100 comes from the 4.x codebase).
(void) unlink(fileName);
if (++tries > 100)
break;
}
PR_smprintf_free(signature);
signature = nsnull;
if (symlink_rv == 0)
{
// We exclusively created the symlink: record its name for eventual
// unlock-via-unlink.
rv = NS_OK;
mHaveLock = PR_TRUE;
mPidLockFileName = strdup(fileName);
if (mPidLockFileName)
{
PR_APPEND_LINK(this, &mPidLockList);
if (!setupPidLockCleanup++)
{
// Clean up on normal termination.
atexit(RemovePidLockFilesExiting);
// Clean up on abnormal termination, using POSIX sigaction.
// Don't arm a handler if the signal is being ignored, e.g.,
// because mozilla is run via nohup.
if (!sDisableSignalHandling) {
struct sigaction act, oldact;
#ifdef SA_SIGINFO
act.sa_sigaction = FatalSignalHandler;
act.sa_flags = SA_SIGINFO;
#else
act.sa_handler = FatalSignalHandler;
#endif
sigfillset(&act.sa_mask);
#define CATCH_SIGNAL(signame) \
PR_BEGIN_MACRO \
if (sigaction(signame, NULL, &oldact) == 0 && \
oldact.sa_handler != SIG_IGN) \
{ \
sigaction(signame, &act, &signame##_oldact); \
} \
PR_END_MACRO
CATCH_SIGNAL(SIGHUP);
CATCH_SIGNAL(SIGINT);
CATCH_SIGNAL(SIGQUIT);
CATCH_SIGNAL(SIGILL);
CATCH_SIGNAL(SIGABRT);
CATCH_SIGNAL(SIGSEGV);
CATCH_SIGNAL(SIGTERM);
#undef CATCH_SIGNAL
}
}
}
}
else if (symlink_errno == EEXIST)
rv = NS_ERROR_FILE_ACCESS_DENIED;
else
{
#ifdef DEBUG
printf("symlink() failed. errno = %d\n", errno);
#endif
rv = NS_ERROR_FAILURE;
}
return rv;
}
