| 1 | /* rename.c -- rename a file, preserving symlinks. |
| 2 | Copyright (C) 1999-2020 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GNU Binutils. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 3 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA |
| 19 | 02110-1301, USA. */ |
| 20 | |
| 21 | #include "sysdep.h" |
| 22 | #include "bfd.h" |
| 23 | #include "bucomm.h" |
| 24 | |
| 25 | #ifdef HAVE_GOOD_UTIME_H |
| 26 | #include <utime.h> |
| 27 | #else /* ! HAVE_GOOD_UTIME_H */ |
| 28 | #ifdef HAVE_UTIMES |
| 29 | #include <sys/time.h> |
| 30 | #endif /* HAVE_UTIMES */ |
| 31 | #endif /* ! HAVE_GOOD_UTIME_H */ |
| 32 | |
| 33 | #if ! defined (_WIN32) || defined (__CYGWIN32__) |
| 34 | static int simple_copy (const char *, const char *); |
| 35 | |
| 36 | /* The number of bytes to copy at once. */ |
| 37 | #define COPY_BUF 8192 |
| 38 | |
| 39 | /* Copy file FROM to file TO, performing no translations. |
| 40 | Return 0 if ok, -1 if error. */ |
| 41 | |
| 42 | static int |
| 43 | simple_copy (const char *from, const char *to) |
| 44 | { |
| 45 | int fromfd, tofd, nread; |
| 46 | int saved; |
| 47 | char buf[COPY_BUF]; |
| 48 | |
| 49 | fromfd = open (from, O_RDONLY | O_BINARY); |
| 50 | if (fromfd < 0) |
| 51 | return -1; |
| 52 | #ifdef O_CREAT |
| 53 | tofd = open (to, O_CREAT | O_WRONLY | O_TRUNC | O_BINARY, 0777); |
| 54 | #else |
| 55 | tofd = creat (to, 0777); |
| 56 | #endif |
| 57 | if (tofd < 0) |
| 58 | { |
| 59 | saved = errno; |
| 60 | close (fromfd); |
| 61 | errno = saved; |
| 62 | return -1; |
| 63 | } |
| 64 | while ((nread = read (fromfd, buf, sizeof buf)) > 0) |
| 65 | { |
| 66 | if (write (tofd, buf, nread) != nread) |
| 67 | { |
| 68 | saved = errno; |
| 69 | close (fromfd); |
| 70 | close (tofd); |
| 71 | errno = saved; |
| 72 | return -1; |
| 73 | } |
| 74 | } |
| 75 | saved = errno; |
| 76 | close (fromfd); |
| 77 | close (tofd); |
| 78 | if (nread < 0) |
| 79 | { |
| 80 | errno = saved; |
| 81 | return -1; |
| 82 | } |
| 83 | return 0; |
| 84 | } |
| 85 | #endif /* __CYGWIN32__ or not _WIN32 */ |
| 86 | |
| 87 | /* Set the times of the file DESTINATION to be the same as those in |
| 88 | STATBUF. */ |
| 89 | |
| 90 | void |
| 91 | set_times (const char *destination, const struct stat *statbuf) |
| 92 | { |
| 93 | int result; |
| 94 | |
| 95 | { |
| 96 | #ifdef HAVE_GOOD_UTIME_H |
| 97 | struct utimbuf tb; |
| 98 | |
| 99 | tb.actime = statbuf->st_atime; |
| 100 | tb.modtime = statbuf->st_mtime; |
| 101 | result = utime (destination, &tb); |
| 102 | #else /* ! HAVE_GOOD_UTIME_H */ |
| 103 | #ifndef HAVE_UTIMES |
| 104 | long tb[2]; |
| 105 | |
| 106 | tb[0] = statbuf->st_atime; |
| 107 | tb[1] = statbuf->st_mtime; |
| 108 | result = utime (destination, tb); |
| 109 | #else /* HAVE_UTIMES */ |
| 110 | struct timeval tv[2]; |
| 111 | |
| 112 | tv[0].tv_sec = statbuf->st_atime; |
| 113 | tv[0].tv_usec = 0; |
| 114 | tv[1].tv_sec = statbuf->st_mtime; |
| 115 | tv[1].tv_usec = 0; |
| 116 | result = utimes (destination, tv); |
| 117 | #endif /* HAVE_UTIMES */ |
| 118 | #endif /* ! HAVE_GOOD_UTIME_H */ |
| 119 | } |
| 120 | |
| 121 | if (result != 0) |
| 122 | non_fatal (_("%s: cannot set time: %s"), destination, strerror (errno)); |
| 123 | } |
| 124 | |
| 125 | #ifndef S_ISLNK |
| 126 | #ifdef S_IFLNK |
| 127 | #define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK) |
| 128 | #else |
| 129 | #define S_ISLNK(m) 0 |
| 130 | #define lstat stat |
| 131 | #endif |
| 132 | #endif |
| 133 | |
| 134 | /* Rename FROM to TO, copying if TO is a link. |
| 135 | Return 0 if ok, -1 if error. */ |
| 136 | |
| 137 | int |
| 138 | smart_rename (const char *from, const char *to, int preserve_dates ATTRIBUTE_UNUSED) |
| 139 | { |
| 140 | bfd_boolean exists; |
| 141 | struct stat s; |
| 142 | int ret = 0; |
| 143 | |
| 144 | exists = lstat (to, &s) == 0; |
| 145 | |
| 146 | #if defined (_WIN32) && !defined (__CYGWIN32__) |
| 147 | /* Win32, unlike unix, will not erase `to' in `rename(from, to)' but |
| 148 | fail instead. Also, chown is not present. */ |
| 149 | |
| 150 | if (exists) |
| 151 | remove (to); |
| 152 | |
| 153 | ret = rename (from, to); |
| 154 | if (ret != 0) |
| 155 | { |
| 156 | /* We have to clean up here. */ |
| 157 | non_fatal (_("unable to rename '%s'; reason: %s"), to, strerror (errno)); |
| 158 | unlink (from); |
| 159 | } |
| 160 | #else |
| 161 | /* Use rename only if TO is not a symbolic link and has |
| 162 | only one hard link, and we have permission to write to it. */ |
| 163 | if (! exists |
| 164 | || (!S_ISLNK (s.st_mode) |
| 165 | && S_ISREG (s.st_mode) |
| 166 | && (s.st_mode & S_IWUSR) |
| 167 | && s.st_nlink == 1) |
| 168 | ) |
| 169 | { |
| 170 | ret = rename (from, to); |
| 171 | if (ret == 0) |
| 172 | { |
| 173 | if (exists) |
| 174 | { |
| 175 | /* Try to preserve the permission bits and ownership of |
| 176 | TO. First get the mode right except for the setuid |
| 177 | bit. Then change the ownership. Then fix the setuid |
| 178 | bit. We do the chmod before the chown because if the |
| 179 | chown succeeds, and we are a normal user, we won't be |
| 180 | able to do the chmod afterward. We don't bother to |
| 181 | fix the setuid bit first because that might introduce |
| 182 | a fleeting security problem, and because the chown |
| 183 | will clear the setuid bit anyhow. We only fix the |
| 184 | setuid bit if the chown succeeds, because we don't |
| 185 | want to introduce an unexpected setuid file owned by |
| 186 | the user running objcopy. */ |
| 187 | chmod (to, s.st_mode & 0777); |
| 188 | if (chown (to, s.st_uid, s.st_gid) >= 0) |
| 189 | chmod (to, s.st_mode & 07777); |
| 190 | } |
| 191 | } |
| 192 | else |
| 193 | { |
| 194 | /* We have to clean up here. */ |
| 195 | non_fatal (_("unable to rename '%s'; reason: %s"), to, strerror (errno)); |
| 196 | unlink (from); |
| 197 | } |
| 198 | } |
| 199 | else |
| 200 | { |
| 201 | ret = simple_copy (from, to); |
| 202 | if (ret != 0) |
| 203 | non_fatal (_("unable to copy file '%s'; reason: %s"), to, strerror (errno)); |
| 204 | |
| 205 | if (preserve_dates) |
| 206 | set_times (to, &s); |
| 207 | unlink (from); |
| 208 | } |
| 209 | #endif /* _WIN32 && !__CYGWIN32__ */ |
| 210 | |
| 211 | return ret; |
| 212 | } |