/* fcntl module */ #define PY_SSIZE_T_CLEAN #include "Python.h" #ifdef HAVE_SYS_FILE_H #include #endif #include #include #ifdef HAVE_STROPTS_H #include #endif /*[clinic input] module fcntl [clinic start generated code]*/ /*[clinic end generated code: output=da39a3ee5e6b4b0d input=124b58387c158179]*/ #include "clinic/fcntlmodule.c.h" /*[clinic input] fcntl.fcntl fd: fildes cmd as code: int arg: object(c_default='NULL') = 0 / Perform the operation `cmd` on file descriptor fd. The values used for `cmd` are operating system dependent, and are available as constants in the fcntl module, using the same names as used in the relevant C header files. The argument arg is optional, and defaults to 0; it may be an int or a string. If arg is given as a string, the return value of fcntl is a string of that length, containing the resulting value put in the arg buffer by the operating system. The length of the arg string is not allowed to exceed 1024 bytes. If the arg given is an integer or if none is specified, the result value is an integer corresponding to the return value of the fcntl call in the C code. [clinic start generated code]*/ static PyObject * fcntl_fcntl_impl(PyObject *module, int fd, int code, PyObject *arg) /*[clinic end generated code: output=888fc93b51c295bd input=7955340198e5f334]*/ { unsigned int int_arg = 0; int ret; char *str; Py_ssize_t len; char buf[1024]; int async_err = 0; if (PySys_Audit("fcntl.fcntl", "iiO", fd, code, arg ? arg : Py_None) < 0) { return NULL; } if (arg != NULL) { int parse_result; if (PyArg_Parse(arg, "s#", &str, &len)) { if ((size_t)len > sizeof buf) { PyErr_SetString(PyExc_ValueError, "fcntl string arg too long"); return NULL; } memcpy(buf, str, len); do { Py_BEGIN_ALLOW_THREADS ret = fcntl(fd, code, buf); Py_END_ALLOW_THREADS } while (ret == -1 && errno == EINTR && !(async_err = PyErr_CheckSignals())); if (ret < 0) { return !async_err ? PyErr_SetFromErrno(PyExc_OSError) : NULL; } return PyBytes_FromStringAndSize(buf, len); } PyErr_Clear(); parse_result = PyArg_Parse(arg, "I;fcntl requires a file or file descriptor," " an integer and optionally a third integer or a string", &int_arg); if (!parse_result) { return NULL; } } do { Py_BEGIN_ALLOW_THREADS ret = fcntl(fd, code, (int)int_arg); Py_END_ALLOW_THREADS } while (ret == -1 && errno == EINTR && !(async_err = PyErr_CheckSignals())); if (ret < 0) { return !async_err ? PyErr_SetFromErrno(PyExc_OSError) : NULL; } return PyLong_FromLong((long)ret); } /*[clinic input] fcntl.ioctl fd: fildes request as code: unsigned_int(bitwise=True) arg as ob_arg: object(c_default='NULL') = 0 mutate_flag as mutate_arg: bool = True / Perform the operation `request` on file descriptor `fd`. The values used for `request` are operating system dependent, and are available as constants in the fcntl or termios library modules, using the same names as used in the relevant C header files. The argument `arg` is optional, and defaults to 0; it may be an int or a buffer containing character data (most likely a string or an array). If the argument is a mutable buffer (such as an array) and if the mutate_flag argument (which is only allowed in this case) is true then the buffer is (in effect) passed to the operating system and changes made by the OS will be reflected in the contents of the buffer after the call has returned. The return value is the integer returned by the ioctl system call. If the argument is a mutable buffer and the mutable_flag argument is false, the behavior is as if a string had been passed. If the argument is an immutable buffer (most likely a string) then a copy of the buffer is passed to the operating system and the return value is a string of the same length containing whatever the operating system put in the buffer. The length of the arg buffer in this case is not allowed to exceed 1024 bytes. If the arg given is an integer or if none is specified, the result value is an integer corresponding to the return value of the ioctl call in the C code. [clinic start generated code]*/ static PyObject * fcntl_ioctl_impl(PyObject *module, int fd, unsigned int code, PyObject *ob_arg, int mutate_arg) /*[clinic end generated code: output=7f7f5840c65991be input=967b4a4cbeceb0a8]*/ { #define IOCTL_BUFSZ 1024 /* We use the unsigned non-checked 'I' format for the 'code' parameter because the system expects it to be a 32bit bit field value regardless of it being passed as an int or unsigned long on various platforms. See the termios.TIOCSWINSZ constant across platforms for an example of this. If any of the 64bit platforms ever decide to use more than 32bits in their unsigned long ioctl codes this will break and need special casing based on the platform being built on. */ int arg = 0; int ret; Py_buffer pstr; char *str; Py_ssize_t len; char buf[IOCTL_BUFSZ+1]; /* argument plus NUL byte */ if (PySys_Audit("fcntl.ioctl", "iIO", fd, code, ob_arg ? ob_arg : Py_None) < 0) { return NULL; } if (ob_arg != NULL) { if (PyArg_Parse(ob_arg, "w*:ioctl", &pstr)) { char *arg; str = pstr.buf; len = pstr.len; if (mutate_arg) { if (len <= IOCTL_BUFSZ) { memcpy(buf, str, len); buf[len] = '\0'; arg = buf; } else { arg = str; } } else { if (len > IOCTL_BUFSZ) { PyBuffer_Release(&pstr); PyErr_SetString(PyExc_ValueError, "ioctl string arg too long"); return NULL; } else { memcpy(buf, str, len); buf[len] = '\0'; arg = buf; } } if (buf == arg) { Py_BEGIN_ALLOW_THREADS /* think array.resize() */ ret = ioctl(fd, code, arg); Py_END_ALLOW_THREADS } else { ret = ioctl(fd, code, arg); } if (mutate_arg && (len <= IOCTL_BUFSZ)) { memcpy(str, buf, len); } PyBuffer_Release(&pstr); /* No further access to str below this point */ if (ret < 0) { PyErr_SetFromErrno(PyExc_OSError); return NULL; } if (mutate_arg) { return PyLong_FromLong(ret); } else { return PyBytes_FromStringAndSize(buf, len); } } PyErr_Clear(); if (PyArg_Parse(ob_arg, "s*:ioctl", &pstr)) { str = pstr.buf; len = pstr.len; if (len > IOCTL_BUFSZ) { PyBuffer_Release(&pstr); PyErr_SetString(PyExc_ValueError, "ioctl string arg too long"); return NULL; } memcpy(buf, str, len); buf[len] = '\0'; Py_BEGIN_ALLOW_THREADS ret = ioctl(fd, code, buf); Py_END_ALLOW_THREADS if (ret < 0) { PyBuffer_Release(&pstr); PyErr_SetFromErrno(PyExc_OSError); return NULL; } PyBuffer_Release(&pstr); return PyBytes_FromStringAndSize(buf, len); } PyErr_Clear(); if (!PyArg_Parse(ob_arg, "i;ioctl requires a file or file descriptor," " an integer and optionally an integer or buffer argument", &arg)) { return NULL; } // Fall-through to outside the 'if' statement. } Py_BEGIN_ALLOW_THREADS ret = ioctl(fd, code, arg); Py_END_ALLOW_THREADS if (ret < 0) { PyErr_SetFromErrno(PyExc_OSError); return NULL; } return PyLong_FromLong((long)ret); #undef IOCTL_BUFSZ } /*[clinic input] fcntl.flock fd: fildes operation as code: int / Perform the lock operation `operation` on file descriptor `fd`. See the Unix manual page for flock(2) for details (On some systems, this function is emulated using fcntl()). [clinic start generated code]*/ static PyObject * fcntl_flock_impl(PyObject *module, int fd, int code) /*[clinic end generated code: output=84059e2b37d2fc64 input=0bfc00f795953452]*/ { int ret; int async_err = 0; if (PySys_Audit("fcntl.flock", "ii", fd, code) < 0) { return NULL; } #ifdef HAVE_FLOCK do { Py_BEGIN_ALLOW_THREADS ret = flock(fd, code); Py_END_ALLOW_THREADS } while (ret == -1 && errno == EINTR && !(async_err = PyErr_CheckSignals())); #else #ifndef LOCK_SH #define LOCK_SH 1 /* shared lock */ #define LOCK_EX 2 /* exclusive lock */ #define LOCK_NB 4 /* don't block when locking */ #define LOCK_UN 8 /* unlock */ #endif { struct flock l; if (code == LOCK_UN) l.l_type = F_UNLCK; else if (code & LOCK_SH) l.l_type = F_RDLCK; else if (code & LOCK_EX) l.l_type = F_WRLCK; else { PyErr_SetString(PyExc_ValueError, "unrecognized flock argument"); return NULL; } l.l_whence = l.l_start = l.l_len = 0; do { Py_BEGIN_ALLOW_THREADS ret = fcntl(fd, (code & LOCK_NB) ? F_SETLK : F_SETLKW, &l); Py_END_ALLOW_THREADS } while (ret == -1 && errno == EINTR && !(async_err = PyErr_CheckSignals())); } #endif /* HAVE_FLOCK */ if (ret < 0) { return !async_err ? PyErr_SetFromErrno(PyExc_OSError) : NULL; } Py_RETURN_NONE; } /*[clinic input] fcntl.lockf fd: fildes cmd as code: int len as lenobj: object(c_default='NULL') = 0 start as startobj: object(c_default='NULL') = 0 whence: int = 0 / A wrapper around the fcntl() locking calls. `fd` is the file descriptor of the file to lock or unlock, and operation is one of the following values: LOCK_UN - unlock LOCK_SH - acquire a shared lock LOCK_EX - acquire an exclusive lock When operation is LOCK_SH or LOCK_EX, it can also be bitwise ORed with LOCK_NB to avoid blocking on lock acquisition. If LOCK_NB is used and the lock cannot be acquired, an OSError will be raised and the exception will have an errno attribute set to EACCES or EAGAIN (depending on the operating system -- for portability, check for either value). `len` is the number of bytes to lock, with the default meaning to lock to EOF. `start` is the byte offset, relative to `whence`, to that the lock starts. `whence` is as with fileobj.seek(), specifically: 0 - relative to the start of the file (SEEK_SET) 1 - relative to the current buffer position (SEEK_CUR) 2 - relative to the end of the file (SEEK_END) [clinic start generated code]*/ static PyObject * fcntl_lockf_impl(PyObject *module, int fd, int code, PyObject *lenobj, PyObject *startobj, int whence) /*[clinic end generated code: output=4985e7a172e7461a input=5480479fc63a04b8]*/ { int ret; int async_err = 0; if (PySys_Audit("fcntl.lockf", "iiOOi", fd, code, lenobj ? lenobj : Py_None, startobj ? startobj : Py_None, whence) < 0) { return NULL; } #ifndef LOCK_SH #define LOCK_SH 1 /* shared lock */ #define LOCK_EX 2 /* exclusive lock */ #define LOCK_NB 4 /* don't block when locking */ #define LOCK_UN 8 /* unlock */ #endif /* LOCK_SH */ { struct flock l; if (code == LOCK_UN) l.l_type = F_UNLCK; else if (code & LOCK_SH) l.l_type = F_RDLCK; else if (code & LOCK_EX) l.l_type = F_WRLCK; else { PyErr_SetString(PyExc_ValueError, "unrecognized lockf argument"); return NULL; } l.l_start = l.l_len = 0; if (startobj != NULL) { #if !defined(HAVE_LARGEFILE_SUPPORT) l.l_start = PyLong_AsLong(startobj); #else l.l_start = PyLong_Check(startobj) ? PyLong_AsLongLong(startobj) : PyLong_AsLong(startobj); #endif if (PyErr_Occurred()) return NULL; } if (lenobj != NULL) { #if !defined(HAVE_LARGEFILE_SUPPORT) l.l_len = PyLong_AsLong(lenobj); #else l.l_len = PyLong_Check(lenobj) ? PyLong_AsLongLong(lenobj) : PyLong_AsLong(lenobj); #endif if (PyErr_Occurred()) return NULL; } l.l_whence = whence; do { Py_BEGIN_ALLOW_THREADS ret = fcntl(fd, (code & LOCK_NB) ? F_SETLK : F_SETLKW, &l); Py_END_ALLOW_THREADS } while (ret == -1 && errno == EINTR && !(async_err = PyErr_CheckSignals())); } if (ret < 0) { return !async_err ? PyErr_SetFromErrno(PyExc_OSError) : NULL; } Py_RETURN_NONE; } /* List of functions */ static PyMethodDef fcntl_methods[] = { FCNTL_FCNTL_METHODDEF FCNTL_IOCTL_METHODDEF FCNTL_FLOCK_METHODDEF FCNTL_LOCKF_METHODDEF {NULL, NULL} /* sentinel */ }; PyDoc_STRVAR(module_doc, "This module performs file control and I/O control on file\n\ descriptors. It is an interface to the fcntl() and ioctl() Unix\n\ routines. File descriptors can be obtained with the fileno() method of\n\ a file or socket object."); /* Module initialisation */ static int all_ins(PyObject* m) { if (PyModule_AddIntMacro(m, LOCK_SH)) return -1; if (PyModule_AddIntMacro(m, LOCK_EX)) return -1; if (PyModule_AddIntMacro(m, LOCK_NB)) return -1; if (PyModule_AddIntMacro(m, LOCK_UN)) return -1; /* GNU extensions, as of glibc 2.2.4 */ #ifdef LOCK_MAND if (PyModule_AddIntMacro(m, LOCK_MAND)) return -1; #endif #ifdef LOCK_READ if (PyModule_AddIntMacro(m, LOCK_READ)) return -1; #endif #ifdef LOCK_WRITE if (PyModule_AddIntMacro(m, LOCK_WRITE)) return -1; #endif #ifdef LOCK_RW if (PyModule_AddIntMacro(m, LOCK_RW)) return -1; #endif #ifdef F_DUPFD if (PyModule_AddIntMacro(m, F_DUPFD)) return -1; #endif #ifdef F_DUPFD_CLOEXEC if (PyModule_AddIntMacro(m, F_DUPFD_CLOEXEC)) return -1; #endif #ifdef F_GETFD if (PyModule_AddIntMacro(m, F_GETFD)) return -1; #endif #ifdef F_SETFD if (PyModule_AddIntMacro(m, F_SETFD)) return -1; #endif #ifdef F_GETFL if (PyModule_AddIntMacro(m, F_GETFL)) return -1; #endif #ifdef F_SETFL if (PyModule_AddIntMacro(m, F_SETFL)) return -1; #endif #ifdef F_GETLK if (PyModule_AddIntMacro(m, F_GETLK)) return -1; #endif #ifdef F_SETLK if (PyModule_AddIntMacro(m, F_SETLK)) return -1; #endif #ifdef F_SETLKW if (PyModule_AddIntMacro(m, F_SETLKW)) return -1; #endif #ifdef F_OFD_GETLK if (PyModule_AddIntMacro(m, F_OFD_GETLK)) return -1; #endif #ifdef F_OFD_SETLK if (PyModule_AddIntMacro(m, F_OFD_SETLK)) return -1; #endif #ifdef F_OFD_SETLKW if (PyModule_AddIntMacro(m, F_OFD_SETLKW)) return -1; #endif #ifdef F_GETOWN if (PyModule_AddIntMacro(m, F_GETOWN)) return -1; #endif #ifdef F_SETOWN if (PyModule_AddIntMacro(m, F_SETOWN)) return -1; #endif #ifdef F_GETPATH if (PyModule_AddIntMacro(m, F_GETPATH)) return -1; #endif #ifdef F_GETSIG if (PyModule_AddIntMacro(m, F_GETSIG)) return -1; #endif #ifdef F_SETSIG if (PyModule_AddIntMacro(m, F_SETSIG)) return -1; #endif #ifdef F_RDLCK if (PyModule_AddIntMacro(m, F_RDLCK)) return -1; #endif #ifdef F_WRLCK if (PyModule_AddIntMacro(m, F_WRLCK)) return -1; #endif #ifdef F_UNLCK if (PyModule_AddIntMacro(m, F_UNLCK)) return -1; #endif /* LFS constants */ #ifdef F_GETLK64 if (PyModule_AddIntMacro(m, F_GETLK64)) return -1; #endif #ifdef F_SETLK64 if (PyModule_AddIntMacro(m, F_SETLK64)) return -1; #endif #ifdef F_SETLKW64 if (PyModule_AddIntMacro(m, F_SETLKW64)) return -1; #endif /* GNU extensions, as of glibc 2.2.4. */ #ifdef FASYNC if (PyModule_AddIntMacro(m, FASYNC)) return -1; #endif #ifdef F_SETLEASE if (PyModule_AddIntMacro(m, F_SETLEASE)) return -1; #endif #ifdef F_GETLEASE if (PyModule_AddIntMacro(m, F_GETLEASE)) return -1; #endif #ifdef F_NOTIFY if (PyModule_AddIntMacro(m, F_NOTIFY)) return -1; #endif /* Old BSD flock(). */ #ifdef F_EXLCK if (PyModule_AddIntMacro(m, F_EXLCK)) return -1; #endif #ifdef F_SHLCK if (PyModule_AddIntMacro(m, F_SHLCK)) return -1; #endif /* OS X specifics */ #ifdef F_FULLFSYNC if (PyModule_AddIntMacro(m, F_FULLFSYNC)) return -1; #endif #ifdef F_NOCACHE if (PyModule_AddIntMacro(m, F_NOCACHE)) return -1; #endif /* For F_{GET|SET}FL */ #ifdef FD_CLOEXEC if (PyModule_AddIntMacro(m, FD_CLOEXEC)) return -1; #endif /* For F_NOTIFY */ #ifdef DN_ACCESS if (PyModule_AddIntMacro(m, DN_ACCESS)) return -1; #endif #ifdef DN_MODIFY if (PyModule_AddIntMacro(m, DN_MODIFY)) return -1; #endif #ifdef DN_CREATE if (PyModule_AddIntMacro(m, DN_CREATE)) return -1; #endif #ifdef DN_DELETE if (PyModule_AddIntMacro(m, DN_DELETE)) return -1; #endif #ifdef DN_RENAME if (PyModule_AddIntMacro(m, DN_RENAME)) return -1; #endif #ifdef DN_ATTRIB if (PyModule_AddIntMacro(m, DN_ATTRIB)) return -1; #endif #ifdef DN_MULTISHOT if (PyModule_AddIntMacro(m, DN_MULTISHOT)) return -1; #endif #ifdef HAVE_STROPTS_H /* Unix 98 guarantees that these are in stropts.h. */ if (PyModule_AddIntMacro(m, I_PUSH)) return -1; if (PyModule_AddIntMacro(m, I_POP)) return -1; if (PyModule_AddIntMacro(m, I_LOOK)) return -1; if (PyModule_AddIntMacro(m, I_FLUSH)) return -1; if (PyModule_AddIntMacro(m, I_FLUSHBAND)) return -1; if (PyModule_AddIntMacro(m, I_SETSIG)) return -1; if (PyModule_AddIntMacro(m, I_GETSIG)) return -1; if (PyModule_AddIntMacro(m, I_FIND)) return -1; if (PyModule_AddIntMacro(m, I_PEEK)) return -1; if (PyModule_AddIntMacro(m, I_SRDOPT)) return -1; if (PyModule_AddIntMacro(m, I_GRDOPT)) return -1; if (PyModule_AddIntMacro(m, I_NREAD)) return -1; if (PyModule_AddIntMacro(m, I_FDINSERT)) return -1; if (PyModule_AddIntMacro(m, I_STR)) return -1; if (PyModule_AddIntMacro(m, I_SWROPT)) return -1; #ifdef I_GWROPT /* despite the comment above, old-ish glibcs miss a couple... */ if (PyModule_AddIntMacro(m, I_GWROPT)) return -1; #endif if (PyModule_AddIntMacro(m, I_SENDFD)) return -1; if (PyModule_AddIntMacro(m, I_RECVFD)) return -1; if (PyModule_AddIntMacro(m, I_LIST)) return -1; if (PyModule_AddIntMacro(m, I_ATMARK)) return -1; if (PyModule_AddIntMacro(m, I_CKBAND)) return -1; if (PyModule_AddIntMacro(m, I_GETBAND)) return -1; if (PyModule_AddIntMacro(m, I_CANPUT)) return -1; if (PyModule_AddIntMacro(m, I_SETCLTIME)) return -1; #ifdef I_GETCLTIME if (PyModule_AddIntMacro(m, I_GETCLTIME)) return -1; #endif if (PyModule_AddIntMacro(m, I_LINK)) return -1; if (PyModule_AddIntMacro(m, I_UNLINK)) return -1; if (PyModule_AddIntMacro(m, I_PLINK)) return -1; if (PyModule_AddIntMacro(m, I_PUNLINK)) return -1; #endif #ifdef F_ADD_SEALS /* Linux: file sealing for memfd_create() */ if (PyModule_AddIntMacro(m, F_ADD_SEALS)) return -1; if (PyModule_AddIntMacro(m, F_GET_SEALS)) return -1; if (PyModule_AddIntMacro(m, F_SEAL_SEAL)) return -1; if (PyModule_AddIntMacro(m, F_SEAL_SHRINK)) return -1; if (PyModule_AddIntMacro(m, F_SEAL_GROW)) return -1; if (PyModule_AddIntMacro(m, F_SEAL_WRITE)) return -1; #endif return 0; } static int fcntl_exec(PyObject *module) { if (all_ins(module) < 0) { return -1; } return 0; } static PyModuleDef_Slot fcntl_slots[] = { {Py_mod_exec, fcntl_exec}, {0, NULL} }; static struct PyModuleDef fcntlmodule = { PyModuleDef_HEAD_INIT, .m_name = "fcntl", .m_doc = module_doc, .m_size = 0, .m_methods = fcntl_methods, .m_slots = fcntl_slots, }; PyMODINIT_FUNC PyInit_fcntl(void) { return PyModuleDef_Init(&fcntlmodule); }