[17c6ad6a] | 1 | /** |
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| 2 | * @file |
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| 3 | * |
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| 4 | * @brief RTEMS File Sysyem Path Eval Support |
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| 5 | * @ingroup LibIOInternal |
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| 6 | */ |
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| 7 | |
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[3b7c123] | 8 | /* |
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| 9 | * Copyright (c) 2012 embedded brains GmbH. All rights reserved. |
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| 10 | * |
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| 11 | * embedded brains GmbH |
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| 12 | * Obere Lagerstr. 30 |
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| 13 | * 82178 Puchheim |
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| 14 | * Germany |
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| 15 | * <rtems@embedded-brains.de> |
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| 16 | * |
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| 17 | * The license and distribution terms for this file may be |
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| 18 | * found in the file LICENSE in this distribution or at |
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[c499856] | 19 | * http://www.rtems.org/license/LICENSE. |
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[3b7c123] | 20 | */ |
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| 21 | |
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| 22 | #if HAVE_CONFIG_H |
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| 23 | #include "config.h" |
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| 24 | #endif |
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| 25 | |
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| 26 | #include <rtems/libio_.h> |
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| 27 | |
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[7660e8b3] | 28 | #include <string.h> |
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| 29 | |
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[3b7c123] | 30 | static size_t get_parentpathlen(const char *path, size_t pathlen) |
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| 31 | { |
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| 32 | while (pathlen > 0) { |
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| 33 | size_t i = pathlen - 1; |
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| 34 | |
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| 35 | if (rtems_filesystem_is_delimiter(path [i])) { |
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| 36 | return pathlen; |
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| 37 | } |
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| 38 | |
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| 39 | pathlen = i; |
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| 40 | } |
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| 41 | |
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| 42 | return 0; |
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| 43 | } |
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| 44 | |
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| 45 | static void set_startloc( |
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| 46 | rtems_filesystem_eval_path_context_t *ctx, |
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| 47 | rtems_filesystem_global_location_t *const *global_root_ptr, |
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| 48 | rtems_filesystem_global_location_t *const *global_current_ptr |
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| 49 | ) |
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| 50 | { |
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| 51 | if (ctx->pathlen > 0) { |
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| 52 | char c = ctx->path [0]; |
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| 53 | |
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| 54 | ctx->rootloc = rtems_filesystem_global_location_obtain(global_root_ptr); |
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| 55 | |
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| 56 | if (rtems_filesystem_is_delimiter(c)) { |
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| 57 | ++ctx->path; |
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| 58 | --ctx->pathlen; |
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| 59 | ctx->startloc = rtems_filesystem_global_location_obtain( |
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| 60 | &ctx->rootloc |
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| 61 | ); |
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| 62 | } else { |
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| 63 | ctx->startloc = rtems_filesystem_global_location_obtain( |
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| 64 | global_current_ptr |
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| 65 | ); |
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| 66 | } |
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| 67 | } else { |
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| 68 | ctx->rootloc = rtems_filesystem_global_location_obtain_null(); |
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| 69 | ctx->startloc = rtems_filesystem_global_location_obtain_null(); |
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| 70 | errno = ENOENT; |
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| 71 | } |
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| 72 | } |
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| 73 | |
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| 74 | static void check_access( |
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| 75 | rtems_filesystem_eval_path_context_t *ctx, |
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| 76 | int eval_flags |
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| 77 | ) |
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| 78 | { |
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| 79 | const rtems_filesystem_location_info_t *currentloc = &ctx->currentloc; |
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[3ba4f828] | 80 | const rtems_filesystem_mount_table_entry_t *mt_entry = currentloc->mt_entry; |
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| 81 | |
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[2563410] | 82 | if ((eval_flags & RTEMS_FS_PERMS_WRITE) == 0 || mt_entry->writeable) { |
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[3ba4f828] | 83 | struct stat st; |
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| 84 | int rv; |
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| 85 | |
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| 86 | st.st_mode = 0; |
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| 87 | st.st_uid = 0; |
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| 88 | st.st_gid = 0; |
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| 89 | rv = (*currentloc->handlers->fstat_h)(currentloc, &st); |
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| 90 | if (rv == 0) { |
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| 91 | bool access_ok = rtems_filesystem_check_access( |
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| 92 | eval_flags, |
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| 93 | st.st_mode, |
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| 94 | st.st_uid, |
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| 95 | st.st_gid |
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| 96 | ); |
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| 97 | |
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| 98 | if (!access_ok) { |
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| 99 | rtems_filesystem_eval_path_error(ctx, EACCES); |
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| 100 | } |
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| 101 | } else { |
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| 102 | rtems_filesystem_eval_path_error(ctx, 0); |
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[3b7c123] | 103 | } |
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| 104 | } else { |
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[3ba4f828] | 105 | rtems_filesystem_eval_path_error(ctx, EROFS); |
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[3b7c123] | 106 | } |
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| 107 | } |
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| 108 | |
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| 109 | void rtems_filesystem_eval_path_continue( |
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| 110 | rtems_filesystem_eval_path_context_t *ctx |
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| 111 | ) |
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| 112 | { |
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| 113 | int eval_flags; |
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| 114 | |
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| 115 | while (ctx->pathlen > 0) { |
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[da154e14] | 116 | (*ctx->currentloc.mt_entry->ops->eval_path_h)(ctx); |
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[3b7c123] | 117 | } |
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| 118 | |
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| 119 | eval_flags = rtems_filesystem_eval_path_get_flags(ctx); |
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| 120 | if (rtems_filesystem_eval_path_has_token(ctx)) { |
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[2563410] | 121 | bool make = (eval_flags & RTEMS_FS_MAKE) != 0; |
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[3b7c123] | 122 | |
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| 123 | if (make) { |
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[2563410] | 124 | check_access(ctx, RTEMS_FS_PERMS_WRITE); |
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[3b7c123] | 125 | } else { |
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| 126 | rtems_filesystem_eval_path_error(ctx, ENOENT); |
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| 127 | } |
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| 128 | } else { |
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[2563410] | 129 | bool exclusive = (eval_flags & RTEMS_FS_EXCLUSIVE) != 0; |
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[3b7c123] | 130 | |
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| 131 | if (!exclusive) { |
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| 132 | check_access(ctx, ctx->flags); |
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| 133 | } else { |
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| 134 | rtems_filesystem_eval_path_error(ctx, EEXIST); |
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| 135 | } |
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| 136 | } |
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| 137 | } |
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| 138 | |
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[e079b33e] | 139 | rtems_filesystem_location_info_t * |
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| 140 | rtems_filesystem_eval_path_start_with_root_and_current( |
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[3b7c123] | 141 | rtems_filesystem_eval_path_context_t *ctx, |
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| 142 | const char *path, |
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| 143 | size_t pathlen, |
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| 144 | int eval_flags, |
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| 145 | rtems_filesystem_global_location_t *const *global_root_ptr, |
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| 146 | rtems_filesystem_global_location_t *const *global_current_ptr |
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| 147 | ) |
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| 148 | { |
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| 149 | memset(ctx, 0, sizeof(*ctx)); |
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| 150 | |
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| 151 | ctx->path = path; |
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| 152 | ctx->pathlen = pathlen; |
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| 153 | ctx->flags = eval_flags; |
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| 154 | |
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| 155 | set_startloc(ctx, global_root_ptr, global_current_ptr); |
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| 156 | |
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| 157 | rtems_filesystem_instance_lock(&ctx->startloc->location); |
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| 158 | |
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| 159 | rtems_filesystem_location_clone( |
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| 160 | &ctx->currentloc, |
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| 161 | &ctx->startloc->location |
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| 162 | ); |
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| 163 | |
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| 164 | rtems_filesystem_eval_path_continue(ctx); |
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| 165 | |
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| 166 | return &ctx->currentloc; |
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| 167 | } |
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| 168 | |
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| 169 | rtems_filesystem_location_info_t * |
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| 170 | rtems_filesystem_eval_path_start( |
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| 171 | rtems_filesystem_eval_path_context_t *ctx, |
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| 172 | const char *path, |
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| 173 | int eval_flags |
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| 174 | ) |
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| 175 | { |
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| 176 | return rtems_filesystem_eval_path_start_with_root_and_current( |
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| 177 | ctx, |
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| 178 | path, |
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[e079b33e] | 179 | strlen(path), |
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[3b7c123] | 180 | eval_flags, |
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| 181 | &rtems_filesystem_root, |
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| 182 | &rtems_filesystem_current |
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| 183 | ); |
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| 184 | } |
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| 185 | |
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| 186 | rtems_filesystem_location_info_t * |
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| 187 | rtems_filesystem_eval_path_start_with_parent( |
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| 188 | rtems_filesystem_eval_path_context_t *ctx, |
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| 189 | const char *path, |
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| 190 | int eval_flags, |
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| 191 | rtems_filesystem_location_info_t *parentloc, |
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| 192 | int parent_eval_flags |
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| 193 | ) |
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| 194 | { |
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| 195 | size_t pathlen = strlen(path); |
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| 196 | const char *parentpath = path; |
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| 197 | size_t parentpathlen = get_parentpathlen(path, pathlen); |
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| 198 | const char *name = NULL; |
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| 199 | size_t namelen = 0; |
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| 200 | const rtems_filesystem_location_info_t *currentloc = NULL; |
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| 201 | |
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| 202 | if (pathlen > 0) { |
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| 203 | if (parentpathlen == 0) { |
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| 204 | parentpath = "."; |
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| 205 | parentpathlen = 1; |
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| 206 | name = path; |
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| 207 | namelen = pathlen; |
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| 208 | } else { |
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| 209 | name = path + parentpathlen; |
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| 210 | namelen = pathlen - parentpathlen; |
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| 211 | } |
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| 212 | } |
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| 213 | |
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[e079b33e] | 214 | currentloc = rtems_filesystem_eval_path_start_with_root_and_current( |
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[3b7c123] | 215 | ctx, |
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| 216 | parentpath, |
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| 217 | parentpathlen, |
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| 218 | parent_eval_flags, |
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| 219 | &rtems_filesystem_root, |
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| 220 | &rtems_filesystem_current |
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| 221 | ); |
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| 222 | |
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| 223 | rtems_filesystem_location_clone(parentloc, currentloc); |
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| 224 | |
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| 225 | ctx->path = name; |
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| 226 | ctx->pathlen = namelen; |
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| 227 | ctx->flags = eval_flags; |
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| 228 | |
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| 229 | rtems_filesystem_eval_path_continue(ctx); |
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| 230 | |
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| 231 | return &ctx->currentloc; |
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| 232 | } |
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| 233 | |
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| 234 | void rtems_filesystem_eval_path_recursive( |
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| 235 | rtems_filesystem_eval_path_context_t *ctx, |
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| 236 | const char *path, |
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| 237 | size_t pathlen |
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| 238 | ) |
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| 239 | { |
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| 240 | if (pathlen > 0) { |
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| 241 | if (ctx->recursionlevel < RTEMS_FILESYSTEM_SYMLOOP_MAX) { |
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| 242 | const char *saved_path = ctx->path; |
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| 243 | size_t saved_pathlen = ctx->pathlen; |
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| 244 | |
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| 245 | if (rtems_filesystem_is_delimiter(path [0])) { |
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| 246 | rtems_filesystem_eval_path_restart(ctx, &ctx->rootloc); |
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| 247 | } |
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| 248 | |
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| 249 | ctx->path = path; |
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| 250 | ctx->pathlen = pathlen; |
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| 251 | |
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| 252 | ++ctx->recursionlevel; |
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| 253 | while (ctx->pathlen > 0) { |
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[da154e14] | 254 | (*ctx->currentloc.mt_entry->ops->eval_path_h)(ctx); |
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[3b7c123] | 255 | } |
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| 256 | --ctx->recursionlevel; |
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| 257 | |
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| 258 | ctx->path = saved_path; |
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| 259 | ctx->pathlen = saved_pathlen; |
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| 260 | } else { |
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| 261 | rtems_filesystem_eval_path_error(ctx, ELOOP); |
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| 262 | } |
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| 263 | } else { |
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| 264 | rtems_filesystem_eval_path_error(ctx, ENOENT); |
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| 265 | } |
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| 266 | } |
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| 267 | |
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| 268 | void rtems_filesystem_eval_path_error( |
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| 269 | rtems_filesystem_eval_path_context_t *ctx, |
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| 270 | int eno |
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| 271 | ) |
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| 272 | { |
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| 273 | ctx->path = NULL; |
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| 274 | ctx->pathlen = 0; |
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| 275 | ctx->token = NULL; |
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| 276 | ctx->tokenlen = 0; |
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| 277 | |
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| 278 | if (!rtems_filesystem_location_is_null(&ctx->currentloc)) { |
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| 279 | if (eno != 0) { |
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| 280 | errno = eno; |
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| 281 | } |
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| 282 | |
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| 283 | rtems_filesystem_location_detach(&ctx->currentloc); |
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| 284 | } |
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| 285 | } |
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| 286 | |
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| 287 | static void free_location(rtems_filesystem_location_info_t *loc) |
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| 288 | { |
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| 289 | rtems_filesystem_mt_entry_declare_lock_context(lock_context); |
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| 290 | |
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[da154e14] | 291 | (*loc->mt_entry->ops->freenod_h)(loc); |
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[3b7c123] | 292 | |
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| 293 | rtems_filesystem_mt_entry_lock(lock_context); |
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| 294 | rtems_chain_extract_unprotected(&loc->mt_entry_node); |
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| 295 | rtems_filesystem_mt_entry_unlock(lock_context); |
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| 296 | } |
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| 297 | |
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| 298 | void rtems_filesystem_eval_path_cleanup( |
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| 299 | rtems_filesystem_eval_path_context_t *ctx |
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| 300 | ) |
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| 301 | { |
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| 302 | free_location(&ctx->currentloc); |
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| 303 | rtems_filesystem_instance_unlock(&ctx->startloc->location); |
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[66fac03] | 304 | rtems_filesystem_global_location_release(ctx->startloc, false); |
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| 305 | rtems_filesystem_global_location_release(ctx->rootloc, false); |
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[3b7c123] | 306 | } |
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| 307 | |
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| 308 | void rtems_filesystem_eval_path_cleanup_with_parent( |
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| 309 | rtems_filesystem_eval_path_context_t *ctx, |
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| 310 | rtems_filesystem_location_info_t *parentloc |
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| 311 | ) |
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| 312 | { |
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| 313 | free_location(parentloc); |
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| 314 | rtems_filesystem_eval_path_cleanup(ctx); |
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| 315 | } |
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| 316 | |
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| 317 | void rtems_filesystem_eval_path_restart( |
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| 318 | rtems_filesystem_eval_path_context_t *ctx, |
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| 319 | rtems_filesystem_global_location_t **newstartloc_ptr |
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| 320 | ) |
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| 321 | { |
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| 322 | free_location(&ctx->currentloc); |
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| 323 | rtems_filesystem_instance_unlock(&ctx->startloc->location); |
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| 324 | rtems_filesystem_global_location_assign( |
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| 325 | &ctx->startloc, |
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| 326 | rtems_filesystem_global_location_obtain(newstartloc_ptr) |
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| 327 | ); |
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| 328 | rtems_filesystem_instance_lock(&ctx->startloc->location); |
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| 329 | rtems_filesystem_location_clone(&ctx->currentloc, &ctx->startloc->location); |
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| 330 | } |
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