From ee7334652f4bcf14a9c61d0dd1c6e456ce459c51 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Tue, 27 Dec 2005 07:56:33 +0000 Subject: (rpl_chown) [CHOWN_MODIFIES_SYMLINK]: Don't try O_WRONLY unless O_RDONLY failed wth EACCES. Fall back on chown if open failed with EACCES. --- lib/chown.c | 37 +++++++++++++++++++++++++++---------- 1 file changed, 27 insertions(+), 10 deletions(-) (limited to 'lib/chown.c') diff --git a/lib/chown.c b/lib/chown.c index 729dd3b0b..2a7bba1a6 100644 --- a/lib/chown.c +++ b/lib/chown.c @@ -27,12 +27,15 @@ most systems. */ #undef chown +#include #include #include #include #include #include +#include "stat-macros.h" + /* Provide a more-closely POSIX-conforming version of chown on systems with one or both of the following problems: - chown doesn't treat an ID of -1 as meaning @@ -66,20 +69,34 @@ rpl_chown (const char *file, uid_t uid, gid_t gid) on the symlink itself. To work around that, we open the file (but this can fail due to lack of read or write permission) and use fchown on the resulting descriptor. */ - int fd = open (file, O_RDONLY | O_NONBLOCK | O_NOCTTY); - if (fd < 0 - && (fd = open (file, O_WRONLY | O_NONBLOCK | O_NOCTTY)) < 0) - return -1; - if (fchown (fd, uid, gid)) + int open_flags = O_NONBLOCK | O_NOCTTY; + int fd = open (file, O_RDONLY | open_flags); + if (0 <= fd + || (errno == EACCES + && 0 <= (fd = open (file, O_WRONLY | open_flags)))) { + int result = fchown (fd, uid, gid); int saved_errno = errno; + + /* POSIX says fchown can fail with errno == EINVAL on sockets, + so fall back on chown in that case. */ + struct stat sb; + bool fchown_socket_failure = + (result != 0 && saved_errno == EINVAL + && fstat (fd, &sb) == 0 && S_ISFIFO (sb.st_mode)); + close (fd); - errno = saved_errno; - return -1; + + if (! fchown_socket_failure) + { + errno = saved_errno; + return result; + } } - return close (fd); + else if (errno != EACCES) + return -1; } -#else - return chown (file, uid, gid); #endif + + return chown (file, uid, gid); } -- cgit v1.2.3-70-g09d2