[3611] | 1 | /* Get permissions of a file. -*- coding: utf-8 -*-
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| 2 |
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| 3 | Copyright (C) 2002-2003, 2005-2022 Free Software Foundation, Inc.
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| 4 |
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| 5 | This program is free software: you can redistribute it and/or modify
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| 6 | it under the terms of the GNU General Public License as published by
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| 7 | the Free Software Foundation, either version 3 of the License, or
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| 8 | (at your option) any later version.
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| 9 |
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| 10 | This program is distributed in the hope that it will be useful,
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 13 | GNU General Public License for more details.
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| 14 |
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| 15 | You should have received a copy of the GNU General Public License
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| 16 | along with this program. If not, see <https://www.gnu.org/licenses/>.
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| 17 |
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| 18 | Written by Paul Eggert, Andreas GrÃŒnbacher, and Bruno Haible. */
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| 19 |
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| 20 | #include <config.h>
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| 21 |
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| 22 | #include <string.h>
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| 23 | #include "acl.h"
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| 24 |
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| 25 | #include "acl-internal.h"
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| 26 |
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| 27 | /* Read the permissions of a file into CTX. If DESC is a valid file descriptor,
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| 28 | use file descriptor operations, else use filename based operations on NAME.
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| 29 | MODE is the file mode obtained from a previous stat call.
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| 30 | Return 0 if successful. Return -1 and set errno upon failure. */
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| 31 |
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| 32 | int
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| 33 | get_permissions (const char *name, int desc, mode_t mode,
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| 34 | struct permission_context *ctx)
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| 35 | {
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| 36 | memset (ctx, 0, sizeof *ctx);
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| 37 | ctx->mode = mode;
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| 38 |
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| 39 | #if USE_ACL && HAVE_ACL_GET_FILE
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| 40 | /* POSIX 1003.1e (draft 17 -- abandoned) specific version. */
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| 41 | /* Linux, FreeBSD, Mac OS X, IRIX, Tru64, Cygwin >= 2.5 */
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| 42 | # if !HAVE_ACL_TYPE_EXTENDED
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| 43 | /* Linux, FreeBSD, IRIX, Tru64, Cygwin >= 2.5 */
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| 44 |
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| 45 | if (HAVE_ACL_GET_FD && desc != -1)
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| 46 | ctx->acl = acl_get_fd (desc);
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| 47 | else
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| 48 | ctx->acl = acl_get_file (name, ACL_TYPE_ACCESS);
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| 49 | if (ctx->acl == NULL)
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| 50 | return acl_errno_valid (errno) ? -1 : 0;
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| 51 |
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| 52 | /* With POSIX ACLs, a file cannot have "no" acl; a file without
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| 53 | extended permissions has a "minimal" acl which is equivalent to the
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| 54 | file mode. */
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| 55 |
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| 56 | if (S_ISDIR (mode))
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| 57 | {
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| 58 | ctx->default_acl = acl_get_file (name, ACL_TYPE_DEFAULT);
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| 59 | if (ctx->default_acl == NULL)
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| 60 | return -1;
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| 61 | }
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| 62 |
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| 63 | # if HAVE_ACL_TYPE_NFS4 /* FreeBSD */
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| 64 |
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| 65 | /* TODO (see set_permissions). */
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| 66 |
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| 67 | # endif
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| 68 |
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| 69 | # else /* HAVE_ACL_TYPE_EXTENDED */
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| 70 | /* Mac OS X */
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| 71 |
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| 72 | /* On Mac OS X, acl_get_file (name, ACL_TYPE_ACCESS)
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| 73 | and acl_get_file (name, ACL_TYPE_DEFAULT)
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| 74 | always return NULL / EINVAL. You have to use
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| 75 | acl_get_file (name, ACL_TYPE_EXTENDED)
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| 76 | or acl_get_fd (open (name, ...))
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| 77 | to retrieve an ACL.
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| 78 | On the other hand,
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| 79 | acl_set_file (name, ACL_TYPE_ACCESS, acl)
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| 80 | and acl_set_file (name, ACL_TYPE_DEFAULT, acl)
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| 81 | have the same effect as
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| 82 | acl_set_file (name, ACL_TYPE_EXTENDED, acl):
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| 83 | Each of these calls sets the file's ACL. */
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| 84 |
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| 85 | if (HAVE_ACL_GET_FD && desc != -1)
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| 86 | ctx->acl = acl_get_fd (desc);
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| 87 | else
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| 88 | ctx->acl = acl_get_file (name, ACL_TYPE_EXTENDED);
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| 89 | if (ctx->acl == NULL)
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| 90 | return acl_errno_valid (errno) ? -1 : 0;
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| 91 |
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| 92 | # endif
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| 93 |
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| 94 | #elif USE_ACL && defined GETACL /* Solaris, Cygwin, not HP-UX */
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| 95 |
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| 96 | /* Solaris 2.5 through Solaris 10, Cygwin, and contemporaneous versions
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| 97 | of Unixware. The acl() call returns the access and default ACL both
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| 98 | at once. */
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| 99 | # ifdef ACE_GETACL
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| 100 | /* Solaris also has a different variant of ACLs, used in ZFS and NFSv4
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| 101 | file systems (whereas the other ones are used in UFS file systems).
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| 102 | There is an API
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| 103 | pathconf (name, _PC_ACL_ENABLED)
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| 104 | fpathconf (desc, _PC_ACL_ENABLED)
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| 105 | that allows us to determine which of the two kinds of ACLs is supported
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| 106 | for the given file. But some file systems may implement this call
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| 107 | incorrectly, so better not use it.
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| 108 | When fetching the source ACL, we simply fetch both ACL types.
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| 109 | When setting the destination ACL, we try either ACL types, assuming
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| 110 | that the kernel will translate the ACL from one form to the other.
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| 111 | (See in <https://docs.oracle.com/cd/E86824_01/html/E54765/acl-2.html>
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| 112 | the description of ENOTSUP.) */
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| 113 | for (;;)
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| 114 | {
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| 115 | int ret;
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| 116 |
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| 117 | if (desc != -1)
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| 118 | ret = facl (desc, ACE_GETACLCNT, 0, NULL);
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| 119 | else
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| 120 | ret = acl (name, ACE_GETACLCNT, 0, NULL);
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| 121 | if (ret < 0)
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| 122 | {
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| 123 | if (errno == ENOSYS || errno == EINVAL)
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| 124 | ret = 0;
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| 125 | else
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| 126 | return -1;
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| 127 | }
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| 128 | ctx->ace_count = ret;
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| 129 |
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| 130 | if (ctx->ace_count == 0)
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| 131 | break;
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| 132 |
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| 133 | ctx->ace_entries = (ace_t *) malloc (ctx->ace_count * sizeof (ace_t));
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| 134 | if (ctx->ace_entries == NULL)
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| 135 | {
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| 136 | errno = ENOMEM;
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| 137 | return -1;
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| 138 | }
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| 139 |
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| 140 | if (desc != -1)
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| 141 | ret = facl (desc, ACE_GETACL, ctx->ace_count, ctx->ace_entries);
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| 142 | else
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| 143 | ret = acl (name, ACE_GETACL, ctx->ace_count, ctx->ace_entries);
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| 144 | if (ret < 0)
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| 145 | {
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| 146 | if (errno == ENOSYS || errno == EINVAL)
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| 147 | {
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| 148 | free (ctx->ace_entries);
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| 149 | ctx->ace_entries = NULL;
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| 150 | ctx->ace_count = 0;
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| 151 | break;
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| 152 | }
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| 153 | else
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| 154 | return -1;
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| 155 | }
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| 156 | if (ret <= ctx->ace_count)
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| 157 | {
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| 158 | ctx->ace_count = ret;
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| 159 | break;
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| 160 | }
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| 161 | /* Huh? The number of ACL entries has increased since the last call.
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| 162 | Repeat. */
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| 163 | free (ctx->ace_entries);
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| 164 | ctx->ace_entries = NULL;
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| 165 | }
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| 166 | # endif
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| 167 |
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| 168 | for (;;)
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| 169 | {
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| 170 | int ret;
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| 171 |
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| 172 | if (desc != -1)
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| 173 | ret = facl (desc, GETACLCNT, 0, NULL);
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| 174 | else
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| 175 | ret = acl (name, GETACLCNT, 0, NULL);
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| 176 | if (ret < 0)
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| 177 | {
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| 178 | if (errno == ENOSYS || errno == ENOTSUP || errno == EOPNOTSUPP)
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| 179 | ret = 0;
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| 180 | else
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| 181 | return -1;
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| 182 | }
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| 183 | ctx->count = ret;
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| 184 |
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| 185 | if (ctx->count == 0)
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| 186 | break;
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| 187 |
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| 188 | ctx->entries = (aclent_t *) malloc (ctx->count * sizeof (aclent_t));
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| 189 | if (ctx->entries == NULL)
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| 190 | {
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| 191 | errno = ENOMEM;
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| 192 | return -1;
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| 193 | }
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| 194 |
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| 195 | if (desc != -1)
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| 196 | ret = facl (desc, GETACL, ctx->count, ctx->entries);
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| 197 | else
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| 198 | ret = acl (name, GETACL, ctx->count, ctx->entries);
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| 199 | if (ret < 0)
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| 200 | {
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| 201 | if (errno == ENOSYS || errno == ENOTSUP || errno == EOPNOTSUPP)
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| 202 | {
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| 203 | free (ctx->entries);
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| 204 | ctx->entries = NULL;
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| 205 | ctx->count = 0;
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| 206 | break;
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| 207 | }
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| 208 | else
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| 209 | return -1;
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| 210 | }
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| 211 | if (ret <= ctx->count)
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| 212 | {
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| 213 | ctx->count = ret;
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| 214 | break;
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| 215 | }
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| 216 | /* Huh? The number of ACL entries has increased since the last call.
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| 217 | Repeat. */
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| 218 | free (ctx->entries);
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| 219 | ctx->entries = NULL;
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| 220 | }
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| 221 |
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| 222 | #elif USE_ACL && HAVE_GETACL /* HP-UX */
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| 223 |
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| 224 | {
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| 225 | int ret;
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| 226 |
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| 227 | if (desc != -1)
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| 228 | ret = fgetacl (desc, NACLENTRIES, ctx->entries);
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| 229 | else
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| 230 | ret = getacl (name, NACLENTRIES, ctx->entries);
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| 231 | if (ret < 0)
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| 232 | {
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| 233 | if (errno == ENOSYS || errno == EOPNOTSUPP || errno == ENOTSUP)
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| 234 | ret = 0;
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| 235 | else
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| 236 | return -1;
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| 237 | }
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| 238 | else if (ret > NACLENTRIES)
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| 239 | /* If NACLENTRIES cannot be trusted, use dynamic memory allocation. */
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| 240 | abort ();
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| 241 | ctx->count = ret;
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| 242 |
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| 243 | # if HAVE_ACLV_H
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| 244 | ret = acl ((char *) name, ACL_GET, NACLVENTRIES, ctx->aclv_entries);
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| 245 | if (ret < 0)
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| 246 | {
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| 247 | if (errno == ENOSYS || errno == EOPNOTSUPP || errno == EINVAL)
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| 248 | ret = 0;
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| 249 | else
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| 250 | return -2;
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| 251 | }
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| 252 | else if (ret > NACLVENTRIES)
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| 253 | /* If NACLVENTRIES cannot be trusted, use dynamic memory allocation. */
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| 254 | abort ();
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| 255 | ctx->aclv_count = ret;
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| 256 | # endif
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| 257 | }
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| 258 |
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| 259 | #elif USE_ACL && HAVE_ACLX_GET && ACL_AIX_WIP /* AIX */
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| 260 |
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| 261 | /* TODO (see set_permissions). */
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| 262 |
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| 263 | #elif USE_ACL && HAVE_STATACL /* older AIX */
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| 264 |
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| 265 | {
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| 266 | int ret;
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| 267 | if (desc != -1)
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| 268 | ret = fstatacl (desc, STX_NORMAL, &ctx->u.a, sizeof ctx->u);
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| 269 | else
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| 270 | ret = statacl ((char *) name, STX_NORMAL, &ctx->u.a, sizeof ctx->u);
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| 271 | if (ret == 0)
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| 272 | ctx->have_u = true;
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| 273 | }
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| 274 |
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| 275 | #elif USE_ACL && HAVE_ACLSORT /* NonStop Kernel */
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| 276 |
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| 277 | {
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| 278 | int ret = acl ((char *) name, ACL_GET, NACLENTRIES, ctx->entries);
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| 279 | if (ret < 0)
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| 280 | return -1;
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| 281 | else if (ret > NACLENTRIES)
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| 282 | /* If NACLENTRIES cannot be trusted, use dynamic memory allocation. */
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| 283 | abort ();
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| 284 | ctx->count = ret;
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| 285 | }
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| 286 |
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| 287 | #endif
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| 288 |
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| 289 | return 0;
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| 290 |
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| 291 | }
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