| 1 | /* |
| 2 | * 9p user. xattr callback |
| 3 | * |
| 4 | * Copyright IBM, Corp. 2010 |
| 5 | * |
| 6 | * Authors: |
| 7 | * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> |
| 8 | * |
| 9 | * This work is licensed under the terms of the GNU GPL, version 2. See |
| 10 | * the COPYING file in the top-level directory. |
| 11 | * |
| 12 | */ |
| 13 | |
| 14 | /* |
| 15 | * Not so fast! You might want to read the 9p developer docs first: |
| 16 | * https://wiki.qemu.org/Documentation/9p |
| 17 | */ |
| 18 | |
| 19 | #include "qemu/osdep.h" |
| 20 | #include "9p.h" |
| 21 | #include "fsdev/file-op-9p.h" |
| 22 | #include "9p-xattr.h" |
| 23 | |
| 24 | |
| 25 | static ssize_t mp_user_getxattr(FsContext *ctx, const char *path, |
| 26 | const char *name, void *value, size_t size) |
| 27 | { |
| 28 | if (strncmp(name, "user.virtfs.", 12) == 0) { |
| 29 | /* |
| 30 | * Don't allow fetch of user.virtfs namespace |
| 31 | * in case of mapped security |
| 32 | */ |
| 33 | errno = ENOATTR; |
| 34 | return -1; |
| 35 | } |
| 36 | return local_getxattr_nofollow(ctx, path, name, value, size); |
| 37 | } |
| 38 | |
| 39 | static ssize_t mp_user_listxattr(FsContext *ctx, const char *path, |
| 40 | char *name, void *value, size_t size) |
| 41 | { |
| 42 | int name_size = strlen(name) + 1; |
| 43 | if (strncmp(name, "user.virtfs.", 12) == 0) { |
| 44 | |
| 45 | /* check if it is a mapped posix acl */ |
| 46 | if (strncmp(name, "user.virtfs.system.posix_acl_", 29) == 0) { |
| 47 | /* adjust the name and size */ |
| 48 | name += 12; |
| 49 | name_size -= 12; |
| 50 | } else { |
| 51 | /* |
| 52 | * Don't allow fetch of user.virtfs namespace |
| 53 | * in case of mapped security |
| 54 | */ |
| 55 | return 0; |
| 56 | } |
| 57 | } |
| 58 | if (!value) { |
| 59 | return name_size; |
| 60 | } |
| 61 | |
| 62 | if (size < name_size) { |
| 63 | errno = ERANGE; |
| 64 | return -1; |
| 65 | } |
| 66 | |
| 67 | /* name_size includes the trailing NUL. */ |
| 68 | memcpy(value, name, name_size); |
| 69 | return name_size; |
| 70 | } |
| 71 | |
| 72 | static int mp_user_setxattr(FsContext *ctx, const char *path, const char *name, |
| 73 | void *value, size_t size, int flags) |
| 74 | { |
| 75 | if (strncmp(name, "user.virtfs.", 12) == 0) { |
| 76 | /* |
| 77 | * Don't allow fetch of user.virtfs namespace |
| 78 | * in case of mapped security |
| 79 | */ |
| 80 | errno = EACCES; |
| 81 | return -1; |
| 82 | } |
| 83 | return local_setxattr_nofollow(ctx, path, name, value, size, flags); |
| 84 | } |
| 85 | |
| 86 | static int mp_user_removexattr(FsContext *ctx, |
| 87 | const char *path, const char *name) |
| 88 | { |
| 89 | if (strncmp(name, "user.virtfs.", 12) == 0) { |
| 90 | /* |
| 91 | * Don't allow fetch of user.virtfs namespace |
| 92 | * in case of mapped security |
| 93 | */ |
| 94 | errno = EACCES; |
| 95 | return -1; |
| 96 | } |
| 97 | return local_removexattr_nofollow(ctx, path, name); |
| 98 | } |
| 99 | |
| 100 | XattrOperations mapped_user_xattr = { |
| 101 | .name = "user.", |
| 102 | .getxattr = mp_user_getxattr, |
| 103 | .setxattr = mp_user_setxattr, |
| 104 | .listxattr = mp_user_listxattr, |
| 105 | .removexattr = mp_user_removexattr, |
| 106 | }; |
| 107 | |
| 108 | XattrOperations passthrough_user_xattr = { |
| 109 | .name = "user.", |
| 110 | .getxattr = pt_getxattr, |
| 111 | .setxattr = pt_setxattr, |
| 112 | .listxattr = pt_listxattr, |
| 113 | .removexattr = pt_removexattr, |
| 114 | }; |