Date: Wed, 11 Feb 2009 20:24:59 +0000 (UTC) From: Ed Schouten <ed@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r188497 - in head: include lib/libc/gen lib/libc/stdlib Message-ID: <200902112024.n1BKOxcc035265@svn.freebsd.org>
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Author: ed Date: Wed Feb 11 20:24:59 2009 New Revision: 188497 URL: http://svn.freebsd.org/changeset/base/188497 Log: Add two new routines: fdevname() and fdevname_r(). A more elegant way of obtaining a name of a character device by its file descriptor on FreeBSD, is to use the FIODGNAME ioctl. Because a valid file descriptor implies a file descriptor is visible in /dev, it will always resolve a valid device name. I'm adding a more friendly wrapper for this ioctl, called fdevname(). It is a lot easier to use than devname() and also has better error handling. When a device name cannot be resolved, it will just return NULL instead of a generated device name that makes no sense. Discussed with: kib Added: head/lib/libc/gen/fdevname.c (contents, props changed) Modified: head/include/stdlib.h head/lib/libc/gen/Makefile.inc head/lib/libc/gen/Symbol.map head/lib/libc/gen/devname.3 head/lib/libc/gen/ttyname.c head/lib/libc/stdlib/ptsname.c Modified: head/include/stdlib.h ============================================================================== --- head/include/stdlib.h Wed Feb 11 18:42:56 2009 (r188496) +++ head/include/stdlib.h Wed Feb 11 20:24:59 2009 (r188497) @@ -256,6 +256,8 @@ int cgetustr(char *, const char *, char int daemon(int, int); char *devname(__dev_t, __mode_t); char *devname_r(__dev_t, __mode_t, char *, int); +char *fdevname(int); +char *fdevname_r(int, char *, int); int getloadavg(double [], int); __const char * getprogname(void); Modified: head/lib/libc/gen/Makefile.inc ============================================================================== --- head/lib/libc/gen/Makefile.inc Wed Feb 11 18:42:56 2009 (r188496) +++ head/lib/libc/gen/Makefile.inc Wed Feb 11 20:24:59 2009 (r188497) @@ -10,7 +10,7 @@ SRCS+= __getosreldate.c __xuname.c \ clock.c closedir.c confstr.c \ crypt.c ctermid.c daemon.c devname.c dirname.c disklabel.c \ dlfcn.c dlfunc.c drand48.c erand48.c err.c errlst.c errno.c \ - exec.c feature_present.c fmtcheck.c fmtmsg.c fnmatch.c \ + exec.c fdevname.c feature_present.c fmtcheck.c fmtmsg.c fnmatch.c \ fpclassify.c frexp.c fstab.c ftok.c fts.c fts-compat.c ftw.c \ getbootfile.c getbsize.c \ getcap.c getcwd.c getdomainname.c getgrent.c getgrouplist.c \ @@ -78,6 +78,8 @@ MLINKS+=arc4random.3 arc4random_addrando arc4random.3 arc4random_buf.3 arc4random.3 arc4random_uniform.3 MLINKS+=ctermid.3 ctermid_r.3 MLINKS+=devname.3 devname_r.3 +MLINKS+=devname.3 fdevname.3 +MLINKS+=devname.3 fdevname_r.3 MLINKS+=directory.3 closedir.3 directory.3 dirfd.3 directory.3 opendir.3 \ directory.3 fdopendir.3 \ directory.3 readdir.3 directory.3 readdir_r.3 directory.3 rewinddir.3 \ Modified: head/lib/libc/gen/Symbol.map ============================================================================== --- head/lib/libc/gen/Symbol.map Wed Feb 11 18:42:56 2009 (r188496) +++ head/lib/libc/gen/Symbol.map Wed Feb 11 20:24:59 2009 (r188497) @@ -331,6 +331,8 @@ FBSD_1.0 { FBSD_1.1 { arc4random_buf; arc4random_uniform; + fdevname; + fdevname_r; fdopendir; feature_present; fts_open; Modified: head/lib/libc/gen/devname.3 ============================================================================== --- head/lib/libc/gen/devname.3 Wed Feb 11 18:42:56 2009 (r188496) +++ head/lib/libc/gen/devname.3 Wed Feb 11 20:24:59 2009 (r188497) @@ -43,6 +43,10 @@ .Fn devname "dev_t dev" "mode_t type" .Ft char * .Fn devname_r "dev_t dev" "mode_t type" "char *buf" "int len" +.Ft char * +.Fn fdevname "int fd" +.Ft char * +.Fn fdevname_r "int fd" "char *buf" "int len" .Sh DESCRIPTION The .Fn devname @@ -69,11 +73,24 @@ and .Fa type in a human-readable format. .Pp +The +.Fn fdevname +and +.Fn fdevname_r +function obtains the device name directly from a file descriptor +pointing to a character device. +If it is unable to come up with a suitable name, these functions will +return a NULL pointer. +.Pp .Fn devname -returns the name stored in a static buffer which will be overwritten +and +.Fn fdevname +return the name stored in a static buffer which will be overwritten on subsequent calls. .Fn devname_r -takes a buffer and length as argument to avoid this problem. +and +.Fn fdevname_r +take a buffer and length as argument to avoid this problem. .Sh EXAMPLES .Bd -literal -compact int fd; @@ -83,6 +100,7 @@ char *name; fd = open("/dev/tun"); fstat(fd, &buf); printf("devname is /dev/%s\en", devname(buf.st_rdev, S_IFCHR)); + printf("fdevname is /dev/%s\en", fdevname(fd)); .Ed .Sh SEE ALSO .Xr stat 2 @@ -91,3 +109,7 @@ The .Fn devname function appeared in .Bx 4.4 . +The +.Fn fdevname +function appeared in +.Fx 8.0 . Added: head/lib/libc/gen/fdevname.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/lib/libc/gen/fdevname.c Wed Feb 11 20:24:59 2009 (r188497) @@ -0,0 +1,54 @@ +/*- + * Copyright (c) 2009 Ed Schouten <ed@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "namespace.h" +#include <sys/param.h> +#include <sys/ioctl.h> +#include "un-namespace.h" + +char * +fdevname_r(int fd, char *buf, int len) +{ + struct fiodgname_arg fgn; + + fgn.buf = buf; + fgn.len = len; + + if (_ioctl(fd, FIODGNAME, &fgn) == -1) + return (NULL); + return (buf); +} + +char * +fdevname(int fd) +{ + static char buf[SPECNAMELEN + 1]; + + return (fdevname_r(fd, buf, sizeof(buf))); +} Modified: head/lib/libc/gen/ttyname.c ============================================================================== --- head/lib/libc/gen/ttyname.c Wed Feb 11 18:42:56 2009 (r188496) +++ head/lib/libc/gen/ttyname.c Wed Feb 11 20:24:59 2009 (r188497) @@ -35,7 +35,6 @@ __FBSDID("$FreeBSD$"); #include "namespace.h" #include <sys/types.h> -#include <sys/stat.h> #include <sys/ioctl.h> #include <sys/filio.h> #include <fcntl.h> @@ -60,8 +59,6 @@ static int ttyname_keycreated = 0; int ttyname_r(int fd, char *buf, size_t len) { - struct stat sb; - struct fiodgname_arg fgn; size_t used; *buf = '\0'; @@ -69,21 +66,14 @@ ttyname_r(int fd, char *buf, size_t len) /* Must be a terminal. */ if (!isatty(fd)) return (ENOTTY); - /* Must be a character device. */ - if (_fstat(fd, &sb) || !S_ISCHR(sb.st_mode)) - return (ENOTTY); /* Must have enough room */ if (len <= sizeof(_PATH_DEV)) return (ERANGE); strcpy(buf, _PATH_DEV); used = strlen(buf); - fgn.len = len - used; - fgn.buf = buf + used; - if (!_ioctl(fd, FIODGNAME, &fgn)) - return (0); - used = strlen(buf); - devname_r(sb.st_rdev, S_IFCHR, buf + used, len - used); + if (fdevname_r(fd, buf + used, len - used) == NULL) + return (ENOTTY); return (0); } Modified: head/lib/libc/stdlib/ptsname.c ============================================================================== --- head/lib/libc/stdlib/ptsname.c Wed Feb 11 18:42:56 2009 (r188496) +++ head/lib/libc/stdlib/ptsname.c Wed Feb 11 20:24:59 2009 (r188497) @@ -38,6 +38,7 @@ __FBSDID("$FreeBSD$"); #include <errno.h> #include <paths.h> +#include <stdlib.h> #include "un-namespace.h" /* @@ -75,7 +76,6 @@ char * ptsname(int fildes) { static char pt_slave[sizeof _PATH_DEV + SPECNAMELEN] = _PATH_DEV; - struct fiodgname_arg fgn; char *ret = NULL; int sverrno = errno; @@ -83,10 +83,8 @@ ptsname(int fildes) if (__isptmaster(fildes) != 0) goto done; - /* Obtain the device name through FIODGNAME. */ - fgn.len = sizeof pt_slave - (sizeof _PATH_DEV - 1); - fgn.buf = pt_slave + (sizeof _PATH_DEV - 1); - if (_ioctl(fildes, FIODGNAME, &fgn) == 0) + if (fdevname_r(fildes, pt_slave + (sizeof _PATH_DEV - 1), + sizeof pt_slave - (sizeof _PATH_DEV - 1)) != NULL) ret = pt_slave; done: /* Make sure ptsname() does not overwrite errno. */
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