Split out commonChildInit

This commit is contained in:
John Ericson 2020-10-11 16:38:46 +00:00
parent 725488b892
commit aef44cbaa9
3 changed files with 31 additions and 29 deletions

View file

@ -456,35 +456,6 @@ void Goal::trace(const FormatOrString & fs)
////////////////////////////////////////////////////////////////////// //////////////////////////////////////////////////////////////////////
/* Common initialisation performed in child processes. */
static void commonChildInit(Pipe & logPipe)
{
restoreSignals();
/* Put the child in a separate session (and thus a separate
process group) so that it has no controlling terminal (meaning
that e.g. ssh cannot open /dev/tty) and it doesn't receive
terminal signals. */
if (setsid() == -1)
throw SysError("creating a new session");
/* Dup the write side of the logger pipe into stderr. */
if (dup2(logPipe.writeSide.get(), STDERR_FILENO) == -1)
throw SysError("cannot pipe standard error into log file");
/* Dup stderr to stdout. */
if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1)
throw SysError("cannot dup stderr into stdout");
/* Reroute stdin to /dev/null. */
int fdDevNull = open(pathNullDevice.c_str(), O_RDWR);
if (fdDevNull == -1)
throw SysError("cannot open '%1%'", pathNullDevice);
if (dup2(fdDevNull, STDIN_FILENO) == -1)
throw SysError("cannot dup null device into stdin");
close(fdDevNull);
}
void handleDiffHook( void handleDiffHook(
uid_t uid, uid_t gid, uid_t uid, uid_t gid,
const Path & tryA, const Path & tryB, const Path & tryA, const Path & tryB,

View file

@ -1660,4 +1660,33 @@ string showBytes(uint64_t bytes)
} }
void commonChildInit(Pipe & logPipe)
{
const static string pathNullDevice = "/dev/null";
restoreSignals();
/* Put the child in a separate session (and thus a separate
process group) so that it has no controlling terminal (meaning
that e.g. ssh cannot open /dev/tty) and it doesn't receive
terminal signals. */
if (setsid() == -1)
throw SysError("creating a new session");
/* Dup the write side of the logger pipe into stderr. */
if (dup2(logPipe.writeSide.get(), STDERR_FILENO) == -1)
throw SysError("cannot pipe standard error into log file");
/* Dup stderr to stdout. */
if (dup2(STDERR_FILENO, STDOUT_FILENO) == -1)
throw SysError("cannot dup stderr into stdout");
/* Reroute stdin to /dev/null. */
int fdDevNull = open(pathNullDevice.c_str(), O_RDWR);
if (fdDevNull == -1)
throw SysError("cannot open '%1%'", pathNullDevice);
if (dup2(fdDevNull, STDIN_FILENO) == -1)
throw SysError("cannot dup null device into stdin");
close(fdDevNull);
}
} }

View file

@ -536,6 +536,8 @@ typedef std::function<bool(const Path & path)> PathFilter;
extern PathFilter defaultPathFilter; extern PathFilter defaultPathFilter;
/* Common initialisation performed in child processes. */
void commonChildInit(Pipe & logPipe);
/* Create a Unix domain socket in listen mode. */ /* Create a Unix domain socket in listen mode. */
AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode); AutoCloseFD createUnixDomainSocket(const Path & path, mode_t mode);