| 1 | /* Entering namespaces for test case isolation. |
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| 2 | Copyright (C) 2016-2024 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library 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 GNU |
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| 13 | Lesser 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 Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #ifndef SUPPORT_NAMESPACE_H |
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| 20 | #define SUPPORT_NAMESPACE_H |
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| 21 | |
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| 22 | #include <stdbool.h> |
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| 23 | #include <sys/cdefs.h> |
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| 24 | |
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| 25 | __BEGIN_DECLS |
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| 26 | |
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| 27 | /* Attempts to become root (or acquire root-like privileges), possibly |
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| 28 | with the help of user namespaces. Return true if (restricted) root |
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| 29 | privileges could be attained in some way. Print diagnostics to |
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| 30 | standard output. |
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| 31 | |
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| 32 | Note that this function generally has to be called before a process |
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| 33 | becomes multi-threaded, otherwise it may fail with insufficient |
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| 34 | privileges on systems which would support this operation for |
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| 35 | single-threaded processes. */ |
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| 36 | bool support_become_root (void); |
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| 37 | |
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| 38 | /* Return true if this process can perform a chroot operation. In |
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| 39 | general, this is only possible if support_become_root has been |
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| 40 | called. Note that the actual test is performed in a subprocess, |
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| 41 | after fork, so that the file system root of the original process is |
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| 42 | not changed. */ |
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| 43 | bool support_can_chroot (void); |
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| 44 | |
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| 45 | /* Enter a network namespace (and a UTS namespace if possible) and |
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| 46 | configure the loopback interface. Return true if a network |
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| 47 | namespace could be created. Print diagnostics to standard output. |
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| 48 | If a network namespace could be created, but networking in it could |
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| 49 | not be configured, terminate the process. It is recommended to |
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| 50 | call support_become_root before this function so that the process |
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| 51 | has sufficient privileges. */ |
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| 52 | bool support_enter_network_namespace (void); |
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| 53 | |
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| 54 | /* Enter a mount namespace and mark / as private (not shared). If |
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| 55 | this function returns true, mount operations in this process will |
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| 56 | not affect the host system afterwards. */ |
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| 57 | bool support_enter_mount_namespace (void); |
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| 58 | |
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| 59 | /* Return true if support_enter_network_namespace managed to enter a |
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| 60 | UTS namespace. */ |
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| 61 | bool support_in_uts_namespace (void); |
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| 62 | |
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| 63 | /* Invoke CALLBACK (CLOSURE) in a subprocess created using fork. |
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| 64 | Terminate the calling process if the subprocess exits with a |
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| 65 | non-zero exit status. */ |
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| 66 | void support_isolate_in_subprocess (void (*callback) (void *), void *closure); |
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| 67 | |
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| 68 | /* Describe the setup of a chroot environment, for |
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| 69 | support_chroot_create below. */ |
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| 70 | struct support_chroot_configuration |
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| 71 | { |
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| 72 | /* File contents. The files are not created if the field is |
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| 73 | NULL. */ |
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| 74 | const char *resolv_conf; /* /etc/resolv.conf. */ |
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| 75 | const char *hosts; /* /etc/hosts. */ |
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| 76 | const char *host_conf; /* /etc/host.conf. */ |
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| 77 | const char *aliases; /* /etc/aliases. */ |
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| 78 | }; |
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| 79 | |
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| 80 | /* The result of the creation of a chroot. */ |
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| 81 | struct support_chroot |
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| 82 | { |
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| 83 | /* Path information. All these paths are relative to the parent |
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| 84 | chroot. */ |
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| 85 | |
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| 86 | /* Path to the chroot directory. */ |
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| 87 | char *path_chroot; |
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| 88 | |
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| 89 | /* Paths to files in the chroot. These are absolute and outside of |
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| 90 | the chroot. */ |
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| 91 | char *path_resolv_conf; /* /etc/resolv.conf. */ |
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| 92 | char *path_hosts; /* /etc/hosts. */ |
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| 93 | char *path_host_conf; /* /etc/host.conf. */ |
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| 94 | char *path_aliases; /* /etc/aliases. */ |
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| 95 | }; |
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| 96 | |
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| 97 | /* Create a chroot environment. The returned data should be freed |
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| 98 | using support_chroot_free below. The files will be deleted when |
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| 99 | the process exits. This function does not enter the chroot. */ |
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| 100 | struct support_chroot *support_chroot_create |
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| 101 | (struct support_chroot_configuration); |
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| 102 | |
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| 103 | /* Deallocate the chroot information created by |
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| 104 | support_chroot_create. */ |
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| 105 | void support_chroot_free (struct support_chroot *); |
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| 106 | |
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| 107 | __END_DECLS |
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| 108 | |
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| 109 | #endif |
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| 110 | |
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