From cea9be24359eda18e04e8b95f9674a376a016675 Mon Sep 17 00:00:00 2001 From: dkf Date: Mon, 16 Jul 2012 22:40:10 +0000 Subject: [Bug 3544683]: Backport of reentrancy fix for super-POSIX correctness of the passwd/group access functions. --- ChangeLog | 9 ++ unix/tclUnixCompat.c | 270 ++++++++++++++++++++++++++++++++++++++++----------- 2 files changed, 225 insertions(+), 54 deletions(-) diff --git a/ChangeLog b/ChangeLog index aecbf9c..ae28d4f 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2012-07-16 Donal K. Fellows + + * unix/tclUnixCompat.c (TclpGetPwNam, TclpGetPwUid, TclpGetGrNam) + (TclpGetGrGid): [Bug 3544683]: Use the elaborate memory management + scheme outlined on http://www.opengroup.org/austin/docs/austin_328.txt + to handle Tcl's use of standard reentrant versions of the passwd/group + access functions so that everything can work on all BSDs. Problem + identified by Stuart Cassoff. + 2012-07-11 Jan Nijtmans * win/tclWinReg.c: [Bug #3362446]: registry keys command fails diff --git a/unix/tclUnixCompat.c b/unix/tclUnixCompat.c index f582c0c..8b067af 100644 --- a/unix/tclUnixCompat.c +++ b/unix/tclUnixCompat.c @@ -13,8 +13,10 @@ #include #include -/* See also: SC_BLOCKING_STYLE in unix/tcl.m4 +/* + * See also: SC_BLOCKING_STYLE in unix/tcl.m4 */ + #ifdef USE_FIONBIO # ifdef HAVE_SYS_FILIO_H # include /* For FIONBIO. */ @@ -23,39 +25,6 @@ # include # endif #endif /* USE_FIONBIO */ - -/* - *--------------------------------------------------------------------------- - * - * TclUnixSetBlockingMode -- - * - * Set the blocking mode of a file descriptor. - * - * Results: - * - * 0 on success, -1 (with errno set) on error. - * - *--------------------------------------------------------------------------- - */ -int -TclUnixSetBlockingMode( - int fd, /* File descriptor */ - int mode) /* TCL_MODE_BLOCKING or TCL_MODE_NONBLOCKING */ -{ -#ifndef USE_FIONBIO - int flags = fcntl(fd, F_GETFL); - - if (mode == TCL_MODE_BLOCKING) { - flags &= ~O_NONBLOCK; - } else { - flags |= O_NONBLOCK; - } - return fcntl(fd, F_SETFL, flags); -#else /* USE_FIONBIO */ - int state = (mode == TCL_MODE_NONBLOCKING); - return ioctl(fd, FIONBIO, &state); -#endif /* !USE_FIONBIO */ -} /* * Used to pad structures at size'd boundaries @@ -82,10 +51,22 @@ TclUnixSetBlockingMode( typedef struct ThreadSpecificData { struct passwd pwd; +#if defined(HAVE_GETPWNAM_R_5) || defined(HAVE_GETPWUID_R_5) +#define NEED_PW_CLEANER 1 + char *pbuf; + int pbuflen; +#else char pbuf[2048]; +#endif struct group grp; +#if defined(HAVE_GETGRNAM_R_5) || defined(HAVE_GETGRGID_R_5) +#define NEED_GR_CLEANER 1 + char *gbuf; + int gbuflen; +#else char gbuf[2048]; +#endif #if !defined(HAVE_MTSAFE_GETHOSTBYNAME) || !defined(HAVE_MTSAFE_GETHOSTBYADDR) struct hostent hent; @@ -124,14 +105,57 @@ static int CopyGrp(struct group *tgtPtr, char *buf, int buflen); static int CopyHostent(struct hostent *tgtPtr, char *buf, int buflen); static int CopyPwd(struct passwd *tgtPtr, char *buf, int buflen); -static int CopyString(CONST char *src, char *buf, int buflen); +static int CopyString(const char *src, char *buf, int buflen); #endif + +#ifdef NEED_PW_CLEANER +static void FreePwBuf(ClientData ignored); +#endif +#ifdef NEED_GR_CLEANER +static void FreeGrBuf(ClientData ignored); +#endif #endif /* TCL_THREADS */ /* *--------------------------------------------------------------------------- * + * TclUnixSetBlockingMode -- + * + * Set the blocking mode of a file descriptor. + * + * Results: + * + * 0 on success, -1 (with errno set) on error. + * + *--------------------------------------------------------------------------- + */ + +int +TclUnixSetBlockingMode( + int fd, /* File descriptor */ + int mode) /* Either TCL_MODE_BLOCKING or + * TCL_MODE_NONBLOCKING. */ +{ +#ifndef USE_FIONBIO + int flags = fcntl(fd, F_GETFL); + + if (mode == TCL_MODE_BLOCKING) { + flags &= ~O_NONBLOCK; + } else { + flags |= O_NONBLOCK; + } + return fcntl(fd, F_SETFL, flags); +#else /* USE_FIONBIO */ + int state = (mode == TCL_MODE_NONBLOCKING); + + return ioctl(fd, FIONBIO, &state); +#endif /* !USE_FIONBIO */ +} + +/* + *--------------------------------------------------------------------------- + * * TclpGetPwNam -- * * Thread-safe wrappers for getpwnam(). See "man getpwnam" for more @@ -158,8 +182,33 @@ TclpGetPwNam( #if defined(HAVE_GETPWNAM_R_5) struct passwd *pwPtr = NULL; - return (getpwnam_r(name, &tsdPtr->pwd, tsdPtr->pbuf, sizeof(tsdPtr->pbuf), - &pwPtr) == 0 && pwPtr != NULL) ? &tsdPtr->pwd : NULL; + /* + * How to allocate a buffer of the right initial size. If you want the + * gory detail, see http://www.opengroup.org/austin/docs/austin_328.txt + * and weep. + */ + + if (tsdPtr->pbuf == NULL) { + tsdPtr->pbuflen = (int) sysconf(_SC_GETPW_R_SIZE_MAX); + if (tsdPtr->pbuflen < 1) { + tsdPtr->pbuflen = 1024; + } + tsdPtr->pbuf = ckalloc(tsdPtr->pbuflen); + Tcl_CreateThreadExitHandler(FreePwBuf, NULL); + } + while (1) { + int e = getpwnam_r(name, &tsdPtr->pwd, tsdPtr->pbuf, tsdPtr->pbuflen, + &pwPtr); + + if (e == 0) { + break; + } else if (e != ERANGE) { + return NULL; + } + tsdPtr->pbuflen *= 2; + tsdPtr->pbuf = ckrealloc(tsdPtr->pbuf, tsdPtr->pbuflen); + } + return (pwPtr != NULL ? &tsdPtr->pwd : NULL); #elif defined(HAVE_GETPWNAM_R_4) return getpwnam_r(name, &tsdPtr->pwd, tsdPtr->pbuf, sizeof(tsdPtr->pbuf)); @@ -214,8 +263,33 @@ TclpGetPwUid( #if defined(HAVE_GETPWUID_R_5) struct passwd *pwPtr = NULL; - return (getpwuid_r(uid, &tsdPtr->pwd, tsdPtr->pbuf, sizeof(tsdPtr->pbuf), - &pwPtr) == 0 && pwPtr != NULL) ? &tsdPtr->pwd : NULL; + /* + * How to allocate a buffer of the right initial size. If you want the + * gory detail, see http://www.opengroup.org/austin/docs/austin_328.txt + * and weep. + */ + + if (tsdPtr->pbuf == NULL) { + tsdPtr->pbuflen = (int) sysconf(_SC_GETPW_R_SIZE_MAX); + if (tsdPtr->pbuflen < 1) { + tsdPtr->pbuflen = 1024; + } + tsdPtr->pbuf = ckalloc(tsdPtr->pbuflen); + Tcl_CreateThreadExitHandler(FreePwBuf, NULL); + } + while (1) { + int e = getpwuid_r(uid, &tsdPtr->pwd, tsdPtr->pbuf, tsdPtr->pbuflen, + &pwPtr); + + if (e == 0) { + break; + } else if (e != ERANGE) { + return NULL; + } + tsdPtr->pbuflen *= 2; + tsdPtr->pbuf = ckrealloc(tsdPtr->pbuf, tsdPtr->pbuflen); + } + return (pwPtr != NULL ? &tsdPtr->pwd : NULL); #elif defined(HAVE_GETPWUID_R_4) return getpwuid_r(uid, &tsdPtr->pwd, tsdPtr->pbuf, sizeof(tsdPtr->pbuf)); @@ -244,6 +318,29 @@ TclpGetPwUid( /* *--------------------------------------------------------------------------- * + * FreePwBuf -- + * + * Helper that is used to dispose of space allocated and referenced from + * the ThreadSpecificData for user entries. (Darn that baroque POSIX + * reentrant interface.) + * + *--------------------------------------------------------------------------- + */ + +#ifdef NEED_PW_CLEANER +static void +FreePwBuf( + ClientData ignored) +{ + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); + + ckfree(tsdPtr->pbuf); +} +#endif /* NEED_PW_CLEANER */ + +/* + *--------------------------------------------------------------------------- + * * TclpGetGrNam -- * * Thread-safe wrappers for getgrnam(). See "man getgrnam" for more @@ -267,11 +364,36 @@ TclpGetGrNam( #else ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); -#if defined(HAVE_GETGRNAM_R_5) +#ifdef HAVE_GETGRNAM_R_5 struct group *grPtr = NULL; - return (getgrnam_r(name, &tsdPtr->grp, tsdPtr->gbuf, sizeof(tsdPtr->gbuf), - &grPtr) == 0 && grPtr != NULL) ? &tsdPtr->grp : NULL; + /* + * How to allocate a buffer of the right initial size. If you want the + * gory detail, see http://www.opengroup.org/austin/docs/austin_328.txt + * and weep. + */ + + if (tsdPtr->gbuf == NULL) { + tsdPtr->gbuflen = (int) sysconf(_SC_GETGR_R_SIZE_MAX); + if (tsdPtr->gbuflen < 1) { + tsdPtr->gbuflen = 1024; + } + tsdPtr->gbuf = ckalloc(tsdPtr->gbuflen); + Tcl_CreateThreadExitHandler(FreeGrBuf, NULL); + } + while (1) { + int e = getgrnam_r(name, &tsdPtr->grp, tsdPtr->gbuf, tsdPtr->gbuflen, + &grPtr); + + if (e == 0) { + break; + } else if (e != ERANGE) { + return NULL; + } + tsdPtr->gbuflen *= 2; + tsdPtr->gbuf = ckrealloc(tsdPtr->gbuf, tsdPtr->gbuflen); + } + return (grPtr != NULL ? &tsdPtr->grp : NULL); #elif defined(HAVE_GETGRNAM_R_4) return getgrnam_r(name, &tsdPtr->grp, tsdPtr->gbuf, sizeof(tsdPtr->gbuf)); @@ -326,8 +448,33 @@ TclpGetGrGid( #if defined(HAVE_GETGRGID_R_5) struct group *grPtr = NULL; - return (getgrgid_r(gid, &tsdPtr->grp, tsdPtr->gbuf, sizeof(tsdPtr->gbuf), - &grPtr) == 0 && grPtr != NULL) ? &tsdPtr->grp : NULL; + /* + * How to allocate a buffer of the right initial size. If you want the + * gory detail, see http://www.opengroup.org/austin/docs/austin_328.txt + * and weep. + */ + + if (tsdPtr->gbuf == NULL) { + tsdPtr->gbuflen = (int) sysconf(_SC_GETGR_R_SIZE_MAX); + if (tsdPtr->gbuflen < 1) { + tsdPtr->gbuflen = 1024; + } + tsdPtr->gbuf = ckalloc(tsdPtr->gbuflen); + Tcl_CreateThreadExitHandler(FreeGrBuf, NULL); + } + while (1) { + int e = getgrgid_r(gid, &tsdPtr->grp, tsdPtr->gbuf, tsdPtr->gbuflen, + &grPtr); + + if (e == 0) { + break; + } else if (e != ERANGE) { + return NULL; + } + tsdPtr->gbuflen *= 2; + tsdPtr->gbuf = ckrealloc(tsdPtr->gbuf, tsdPtr->gbuflen); + } + return (grPtr != NULL ? &tsdPtr->grp : NULL); #elif defined(HAVE_GETGRGID_R_4) return getgrgid_r(gid, &tsdPtr->grp, tsdPtr->gbuf, sizeof(tsdPtr->gbuf)); @@ -356,6 +503,29 @@ TclpGetGrGid( /* *--------------------------------------------------------------------------- * + * FreeGrBuf -- + * + * Helper that is used to dispose of space allocated and referenced from + * the ThreadSpecificData for group entries. (Darn that baroque POSIX + * reentrant interface.) + * + *--------------------------------------------------------------------------- + */ + +#ifdef NEED_GR_CLEANER +static void +FreeGrBuf( + ClientData ignored) +{ + ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&dataKey); + + ckfree(tsdPtr->gbuf); +} +#endif /* NEED_GR_CLEANER */ + +/* + *--------------------------------------------------------------------------- + * * TclpGetHostByName -- * * Thread-safe wrappers for gethostbyname(). See "man gethostbyname" for @@ -769,7 +939,7 @@ CopyArray( #ifdef NEED_COPYSTRING static int CopyString( - CONST char *src, /* String to copy. */ + const char *src, /* String to copy. */ char *buf, /* Buffer to copy into. */ int buflen) /* Size of buffer. */ { @@ -788,14 +958,6 @@ CopyString( #endif /* NEED_COPYSTRING */ /* - * Local Variables: - * mode: c - * c-basic-offset: 4 - * fill-column: 78 - * End: - */ - -/* *------------------------------------------------------------------------ * * TclWinCPUID -- @@ -831,7 +993,7 @@ TclWinCPUID( #endif return status; } - + /* * Local Variables: * mode: c -- cgit v0.12