#include "config.h" // IWYU pragma: keep #include "redirection.h" #include "wutil.h" #include /// File descriptor redirection error message. #define FD_ERROR "An error occurred while redirecting file descriptor %s" #define NOCLOB_ERROR _(L"The file '%s' already exists") #define FILE_ERROR _(L"An error occurred while redirecting file '%s'") /// Base open mode to pass to calls to open. #define OPEN_MASK 0666 dup2_list_t::~dup2_list_t() = default; maybe_t dup2_list_t::resolve_chain(const io_chain_t &io_chain) { ASSERT_IS_NOT_FORKED_CHILD(); dup2_list_t result; for (const auto &io_ref : io_chain) { switch (io_ref->io_mode) { case io_mode_t::file: { // Here we definitely do not want to set CLO_EXEC because our child needs access. // Open the file. const io_file_t *io_file = static_cast(io_ref.get()); int file_fd = open(io_file->filename_cstr, io_file->flags, OPEN_MASK); if (file_fd < 0) { if ((io_file->flags & O_EXCL) && (errno == EEXIST)) { debug(1, NOCLOB_ERROR, io_file->filename_cstr); } else { debug(1, FILE_ERROR, io_file->filename_cstr); if (should_debug(1)) wperror(L"open"); } return none(); } // If by chance we got the file we want, we're done. Otherwise move the fd to an // unused place and dup2 it. // Note move_fd_to_unused() will close the incoming file_fd. if (file_fd != io_file->fd) { file_fd = move_fd_to_unused(file_fd, io_chain, false /* cloexec */); if (file_fd < 0) { debug(1, FILE_ERROR, io_file->filename_cstr); if (should_debug(1)) wperror(L"dup"); return none(); } } // Record that we opened this file, so we will auto-close it. assert(file_fd >= 0 && "Should have a valid file_fd"); result.opened_fds_.emplace_back(file_fd); // Mark our dup2 and our close actions. result.add_dup2(file_fd, io_file->fd); result.add_close(file_fd); break; } case io_mode_t::close: { const io_close_t *io = static_cast(io_ref.get()); result.add_close(io->fd); break; } case io_mode_t::fd: { const io_fd_t *io = static_cast(io_ref.get()); result.add_dup2(io->old_fd, io->fd); break; } case io_mode_t::pipe: { const io_pipe_t *io = static_cast(io_ref.get()); result.add_dup2(io->pipe_fd(), io->fd); result.add_close(io->pipe_fd()); break; } case io_mode_t::bufferfill: { const io_bufferfill_t *io = static_cast(io_ref.get()); result.add_dup2(io->write_fd(), io->fd); result.add_close(io->write_fd()); break; } } } return {std::move(result)}; }