diff options
author | Lennart Poettering <lennart@poettering.net> | 2010-05-16 18:45:24 +0200 |
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committer | Lennart Poettering <lennart@poettering.net> | 2010-05-16 18:45:24 +0200 |
commit | e99e38bbdcca3fe5956823bdb3d38544ccf93221 (patch) | |
tree | 109871cf2bdcad19105d55f4eea62d5495a8f614 /namespace.c | |
parent | e9da3678fcfc774b325dc1eaa054d0e00028a1fc (diff) |
build-sys: move source files to subdirectory
Diffstat (limited to 'namespace.c')
-rw-r--r-- | namespace.c | 331 |
1 files changed, 0 insertions, 331 deletions
diff --git a/namespace.c b/namespace.c deleted file mode 100644 index 09bcaff968..0000000000 --- a/namespace.c +++ /dev/null @@ -1,331 +0,0 @@ -/*-*- Mode: C; c-basic-offset: 8 -*-*/ - -/*** - This file is part of systemd. - - Copyright 2010 Lennart Poettering - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - systemd is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - General Public License for more details. - - You should have received a copy of the GNU General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. -***/ - -#include <errno.h> -#include <sys/mount.h> -#include <string.h> -#include <stdio.h> -#include <unistd.h> -#include <sys/stat.h> -#include <sys/types.h> -#include <sched.h> -#include <sys/syscall.h> -#include <limits.h> -#include <linux/fs.h> - -#include "strv.h" -#include "util.h" -#include "namespace.h" -#include "missing.h" - -typedef enum PathMode { - /* This is ordered by priority! */ - INACCESSIBLE, - READONLY, - PRIVATE, - READWRITE -} PathMode; - -typedef struct Path { - const char *path; - PathMode mode; -} Path; - -static int append_paths(Path **p, char **strv, PathMode mode) { - char **i; - - STRV_FOREACH(i, strv) { - - if (!path_is_absolute(*i)) - return -EINVAL; - - (*p)->path = *i; - (*p)->mode = mode; - (*p)++; - } - - return 0; -} - -static int path_compare(const void *a, const void *b) { - const Path *p = a, *q = b; - - if (path_equal(p->path, q->path)) { - - /* If the paths are equal, check the mode */ - if (p->mode < q->mode) - return -1; - - if (p->mode > q->mode) - return 1; - - return 0; - } - - /* If the paths are not equal, then order prefixes first */ - if (path_startswith(p->path, q->path)) - return 1; - - if (path_startswith(q->path, p->path)) - return -1; - - return 0; -} - -static void drop_duplicates(Path *p, unsigned *n, bool *need_inaccessible, bool *need_private) { - Path *f, *t, *previous; - - assert(p); - assert(n); - assert(need_inaccessible); - assert(need_private); - - for (f = p, t = p, previous = NULL; f < p+*n; f++) { - - if (previous && path_equal(f->path, previous->path)) - continue; - - t->path = f->path; - t->mode = f->mode; - - if (t->mode == PRIVATE) - *need_private = true; - - if (t->mode == INACCESSIBLE) - *need_inaccessible = true; - - previous = t; - - t++; - } - - *n = t - p; -} - -static int apply_mount(Path *p, const char *root_dir, const char *inaccessible_dir, const char *private_dir, unsigned long flags) { - const char *what; - char *where; - int r; - - assert(p); - assert(root_dir); - assert(inaccessible_dir); - assert(private_dir); - - if (!(where = strappend(root_dir, p->path))) - return -ENOMEM; - - switch (p->mode) { - - case INACCESSIBLE: - what = inaccessible_dir; - flags |= MS_RDONLY; - break; - - case READONLY: - flags |= MS_RDONLY; - /* Fall through */ - - case READWRITE: - what = p->path; - break; - - case PRIVATE: - what = private_dir; - break; - } - - if ((r = mount(what, where, NULL, MS_BIND|MS_REC, NULL)) >= 0) { - log_debug("Successfully mounted %s to %s", what, where); - - /* The bind mount will always inherit the original - * flags. If we want to set any flag we need - * to do so in a second indepdant step. */ - if (flags) - r = mount(NULL, where, NULL, MS_REMOUNT|MS_BIND|MS_REC|flags, NULL); - - /* Avoid expontial growth of trees */ - if (r >= 0 && path_equal(p->path, "/")) - r = mount(NULL, where, NULL, MS_REMOUNT|MS_BIND|MS_UNBINDABLE|flags, NULL); - - if (r < 0) { - r = -errno; - umount2(where, MNT_DETACH); - } - } - - free(where); - return r; -} - -int setup_namespace( - char **writable, - char **readable, - char **inaccessible, - bool private_tmp, - unsigned long flags) { - - char - tmp_dir[] = "/tmp/systemd-namespace-XXXXXX", - root_dir[] = "/tmp/systemd-namespace-XXXXXX/root", - old_root_dir[] = "/tmp/systemd-namespace-XXXXXX/root/tmp/old-root-XXXXXX", - inaccessible_dir[] = "/tmp/systemd-namespace-XXXXXX/inaccessible", - private_dir[] = "/tmp/systemd-namespace-XXXXXX/private"; - - Path *paths, *p; - unsigned n; - bool need_private = false, need_inaccessible = false; - bool remove_tmp = false, remove_root = false, remove_old_root = false, remove_inaccessible = false, remove_private = false; - int r; - const char *t; - - n = - strv_length(writable) + - strv_length(readable) + - strv_length(inaccessible) + - (private_tmp ? 2 : 1); - - if (!(paths = new(Path, n))) - return -ENOMEM; - - p = paths; - if ((r = append_paths(&p, writable, READWRITE)) < 0 || - (r = append_paths(&p, readable, READONLY)) < 0 || - (r = append_paths(&p, inaccessible, INACCESSIBLE)) < 0) - goto fail; - - if (private_tmp) { - p->path = "/tmp"; - p->mode = PRIVATE; - p++; - } - - p->path = "/"; - p->mode = READWRITE; - p++; - - assert(paths + n == p); - - qsort(paths, n, sizeof(Path), path_compare); - drop_duplicates(paths, &n, &need_inaccessible, &need_private); - - if (!mkdtemp(tmp_dir)) { - r = -errno; - goto fail; - } - remove_tmp = true; - - memcpy(root_dir, tmp_dir, sizeof(tmp_dir)-1); - if (mkdir(root_dir, 0777) < 0) { - r = -errno; - goto fail; - } - remove_root = true; - - if (need_inaccessible) { - memcpy(inaccessible_dir, tmp_dir, sizeof(tmp_dir)-1); - if (mkdir(inaccessible_dir, 0) < 0) { - r = -errno; - goto fail; - } - remove_inaccessible = true; - } - - if (need_private) { - memcpy(private_dir, tmp_dir, sizeof(tmp_dir)-1); - if (mkdir(private_dir, 0777 + S_ISVTX) < 0) { - r = -errno; - goto fail; - } - remove_private = true; - } - - if (unshare(CLONE_NEWNS) < 0) { - r = -errno; - goto fail; - } - - /* We assume that by default mount events from us won't be - * propagated to the root namespace. */ - - for (p = paths; p < paths + n; p++) - if ((r = apply_mount(p, root_dir, inaccessible_dir, private_dir, flags)) < 0) - goto undo_mounts; - - memcpy(old_root_dir, tmp_dir, sizeof(tmp_dir)-1); - if (!mkdtemp(old_root_dir)) { - r = -errno; - goto undo_mounts; - } - remove_old_root = true; - - if (chdir(root_dir) < 0) { - r = -errno; - goto undo_mounts; - } - - if (pivot_root(root_dir, old_root_dir) < 0) { - r = -errno; - goto undo_mounts; - } - - t = old_root_dir + sizeof(root_dir) - 1; - if (umount2(t, MNT_DETACH) < 0) - /* At this point it's too late to turn anything back, - * since we are already in the new root. */ - return -errno; - - if (rmdir(t) < 0) - return -errno; - - return 0; - -undo_mounts: - - for (p--; p >= paths; p--) { - char full_path[PATH_MAX]; - - snprintf(full_path, sizeof(full_path), "%s%s", root_dir, p->path); - char_array_0(full_path); - - umount2(full_path, MNT_DETACH); - } - -fail: - if (remove_old_root) - rmdir(old_root_dir); - - if (remove_inaccessible) - rmdir(inaccessible_dir); - - if (remove_private) - rmdir(private_dir); - - if (remove_root) - rmdir(root_dir); - - if (remove_tmp) - rmdir(tmp_dir); - - free(paths); - - return r; -} |