src/lxc/conf.h

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2008
   5  *
   6  * Authors:
   7  * Daniel Lezcano <daniel.lezcano at free.fr>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23 #ifndef __LXC_CONF_H
  24 #define __LXC_CONF_H
  25
  26 #ifndef _GNU_SOURCE
  27 #define _GNU_SOURCE 1
  28 #endif
  29 #include <linux/magic.h>
  30 #include <net/if.h>
  31 #include <netinet/in.h>
  32 #include <stdbool.h>
  33 #include <stdio.h>
  34 #include <sys/param.h>
  35 #include <sys/types.h>
  36 #include <sys/vfs.h>
  37
  38 #include "compiler.h"
  39 #include "config.h"
  40 #include "list.h"
  41 #include "ringbuf.h"
  42 #include "start.h"
  43 #include "terminal.h"
  44
  45 #if HAVE_SYS_RESOURCE_H
  46 #include <sys/resource.h>
  47 #endif
  48
  49 #if HAVE_SCMP_FILTER_CTX
  50 typedef void * scmp_filter_ctx;
  51 #endif
  52
  53 /* worth moving to configure.ac? */
  54 #define subuidfile "/etc/subuid"
  55 #define subgidfile "/etc/subgid"
  56
  57 /*
  58  * Defines a generic struct to configure the control group. It is up to the
  59  * programmer to specify the right subsystem.
  60  * @subsystem : the targeted subsystem
  61  * @value     : the value to set
  62  * @version   : The version of the cgroup filesystem on which the controller
  63  *              resides.
  64  *
  65  * @controllers : The controllers to use for this container.
  66  * @dir         : The name of the directory containing the container's cgroup.
  67  *                Not that this is a per-container setting.
  68  */
  69 struct lxc_cgroup {
  70         union {
  71                 /* information about a specific controller */
  72                 struct /* controller */ {
  73                         int version;
  74                         char *subsystem;
  75                         char *value;
  76                 };
  77
  78                 /* meta information about cgroup configuration */
  79                 struct /* meta */ {
  80                         char *controllers;
  81                         char *dir;
  82                         bool relative;
  83                 };
  84         };
  85 };
  86
  87 #if !HAVE_SYS_RESOURCE_H
  88 #define RLIM_INFINITY ((unsigned long)-1)
  89 struct rlimit {
  90         unsigned long rlim_cur;
  91         unsigned long rlim_max;
  92 };
  93 #endif
  94
  95 /*
  96  * Defines a structure to configure resource limits to set via setrlimit().
  97  * @resource : the resource name in lowercase without the RLIMIT_ prefix
  98  * @limit    : the limit to set
  99  */
 100 struct lxc_limit {
 101         char *resource;
 102         struct rlimit limit;
 103 };
 104
 105 enum idtype {
 106         ID_TYPE_UID,
 107         ID_TYPE_GID
 108 };
 109
 110 /*
 111  * Defines a structure to configure kernel parameters at runtime.
 112  * @key      : the kernel parameters will be configured without the "lxc.sysctl" prefix
 113  * @value    : the value to set
 114  */
 115 struct lxc_sysctl {
 116         char *key;
 117         char *value;
 118 };
 119
 120 /*
 121  * Defines a structure to configure proc filesystem at runtime.
 122  * @filename : the proc filesystem will be configured without the "lxc.proc" prefix
 123  * @value    : the value to set
 124  */
 125 struct lxc_proc {
 126         char *filename;
 127         char *value;
 128 };
 129
 130 /*
 131  * id_map is an id map entry.  Form in confile is:
 132  * lxc.idmap = u 0    9800 100
 133  * lxc.idmap = u 1000 9900 100
 134  * lxc.idmap = g 0    9800 100
 135  * lxc.idmap = g 1000 9900 100
 136  * meaning the container can use uids and gids 0-99 and 1000-1099,
 137  * with [ug]id 0 mapping to [ug]id 9800 on the host, and [ug]id 1000 to
 138  * [ug]id 9900 on the host.
 139  */
 140 struct id_map {
 141         enum idtype idtype;
 142         unsigned long hostid, nsid, range;
 143 };
 144
 145 /* Defines the number of tty configured and contains the
 146  * instantiated ptys
 147  * @max = number of configured ttys
 148  */
 149 struct lxc_tty_info {
 150         size_t max;
 151         char *dir;
 152         char *tty_names;
 153         struct lxc_terminal_info *tty;
 154 };
 155
 156 /* Defines a structure to store the rootfs location, the
 157  * optionals pivot_root, rootfs mount paths
 158  * @path       : the rootfs source (directory or device)
 159  * @mount      : where it is mounted
 160  * @bev_type   : optional backing store type
 161  * @options    : mount options
 162  * @mountflags : the portion of @options that are flags
 163  * @data       : the portion of @options that are not flags
 164  * @managed    : whether it is managed by LXC
 165  */
 166 struct lxc_rootfs {
 167         char *path;
 168         char *mount;
 169         char *bdev_type;
 170         char *options;
 171         unsigned long mountflags;
 172         char *data;
 173         bool managed;
 174 };
 175
 176 /*
 177  * Automatic mounts for LXC to perform inside the container
 178  */
 179 enum {
 180         LXC_AUTO_PROC_RW              = 0x001, /* /proc read-write */
 181         LXC_AUTO_PROC_MIXED           = 0x002, /* /proc/sys and /proc/sysrq-trigger read-only */
 182         LXC_AUTO_PROC_MASK            = 0x003,
 183
 184         LXC_AUTO_SYS_RW               = 0x004, /* /sys */
 185         LXC_AUTO_SYS_RO               = 0x008, /* /sys read-only */
 186         LXC_AUTO_SYS_MIXED            = 0x00C, /* /sys read-only and /sys/class/net read-write */
 187         LXC_AUTO_SYS_MASK             = 0x00C,
 188
 189         LXC_AUTO_CGROUP_RO            = 0x010, /* /sys/fs/cgroup (partial mount, read-only) */
 190         LXC_AUTO_CGROUP_RW            = 0x020, /* /sys/fs/cgroup (partial mount, read-write) */
 191         LXC_AUTO_CGROUP_MIXED         = 0x030, /* /sys/fs/cgroup (partial mount, paths r/o, cgroup r/w) */
 192         LXC_AUTO_CGROUP_FULL_RO       = 0x040, /* /sys/fs/cgroup (full mount, read-only) */
 193         LXC_AUTO_CGROUP_FULL_RW       = 0x050, /* /sys/fs/cgroup (full mount, read-write) */
 194         LXC_AUTO_CGROUP_FULL_MIXED    = 0x060, /* /sys/fs/cgroup (full mount, parent r/o, own r/w) */
 195         /*
 196          * These are defined in such a way as to retain binary compatibility
 197          * with earlier versions of this code. If the previous mask is applied,
 198          * both of these will default back to the _MIXED variants, which is
 199          * safe.
 200          */
 201         LXC_AUTO_CGROUP_NOSPEC        = 0x0B0, /* /sys/fs/cgroup (partial mount, r/w or mixed, depending on caps) */
 202         LXC_AUTO_CGROUP_FULL_NOSPEC   = 0x0E0, /* /sys/fs/cgroup (full mount, r/w or mixed, depending on caps) */
 203         LXC_AUTO_CGROUP_FORCE         = 0x100, /* mount cgroups even when cgroup namespaces are supported */
 204         LXC_AUTO_CGROUP_MASK          = 0x1F0, /* all known cgroup options, doe not contain LXC_AUTO_CGROUP_FORCE */
 205
 206         LXC_AUTO_SHMOUNTS             = 0x200, /* shared mount point */
 207         LXC_AUTO_SHMOUNTS_MASK        = 0x200, /* shared mount point mask */
 208         LXC_AUTO_ALL_MASK             = 0x1FF, /* all known settings */
 209 };
 210
 211 enum lxchooks {
 212         LXCHOOK_PRESTART,
 213         LXCHOOK_PREMOUNT,
 214         LXCHOOK_MOUNT,
 215         LXCHOOK_AUTODEV,
 216         LXCHOOK_START,
 217         LXCHOOK_STOP,
 218         LXCHOOK_POSTSTOP,
 219         LXCHOOK_CLONE,
 220         LXCHOOK_DESTROY,
 221         LXCHOOK_START_HOST,
 222         NUM_LXC_HOOKS
 223 };
 224
 225 extern char *lxchook_names[NUM_LXC_HOOKS];
 226
 227 struct lxc_state_client {
 228         int clientfd;
 229         lxc_state_t states[MAX_STATE];
 230 };
 231
 232 struct lxc_conf {
 233         /* Pointer to the name of the container. Do not free! */
 234         const char *name;
 235         bool is_execute;
 236         int reboot;
 237         signed long personality;
 238         struct utsname *utsname;
 239
 240         struct {
 241                 struct lxc_list cgroup;
 242                 struct lxc_list cgroup2;
 243         };
 244
 245         struct {
 246                 struct lxc_list id_map;
 247
 248                 /*
 249                  * Pointer to the idmap entry for the container's root uid in
 250                  * the id_map list. Do not free!
 251                  */
 252                 const struct id_map *root_nsuid_map;
 253
 254                 /*
 255                  * Pointer to the idmap entry for the container's root gid in
 256                  * the id_map list. Do not free!
 257                  */
 258                 const struct id_map *root_nsgid_map;
 259         };
 260
 261         struct lxc_list network;
 262
 263         struct {
 264                 char *fstab;
 265                 int auto_mounts;
 266                 struct lxc_list mount_list;
 267         };
 268
 269         struct lxc_list caps;
 270         struct lxc_list keepcaps;
 271
 272         /* /dev/tty<idx> devices */
 273         struct lxc_tty_info ttys;
 274         /* /dev/console device */
 275         struct lxc_terminal console;
 276         /* maximum pty devices allowed by devpts mount */
 277         size_t pty_max;
 278
 279         /* set to true when rootfs has been setup */
 280         bool rootfs_setup;
 281         struct lxc_rootfs rootfs;
 282
 283         bool close_all_fds;
 284
 285         struct {
 286                 unsigned int hooks_version;
 287                 struct lxc_list hooks[NUM_LXC_HOOKS];
 288         };
 289
 290         char *lsm_aa_profile;
 291         char *lsm_aa_profile_computed;
 292         bool lsm_aa_profile_created;
 293         unsigned int lsm_aa_allow_nesting;
 294         unsigned int lsm_aa_allow_incomplete;
 295         struct lxc_list lsm_aa_raw;
 296         char *lsm_se_context;
 297         bool tmp_umount_proc;
 298         char *seccomp;  /* filename with the seccomp rules */
 299         unsigned int seccomp_allow_nesting;
 300 #if HAVE_SCMP_FILTER_CTX
 301         scmp_filter_ctx seccomp_ctx;
 302 #endif
 303         int maincmd_fd;
 304         unsigned int autodev;  /* if 1, mount and fill a /dev at start */
 305         int haltsignal; /* signal used to halt container */
 306         int rebootsignal; /* signal used to reboot container */
 307         int stopsignal; /* signal used to hard stop container */
 308         char *rcfile;   /* Copy of the top level rcfile we read */
 309
 310         /* Logfile and loglevel can be set in a container config file. Those
 311          * function as defaults. The defaults can be overridden by command line.
 312          * However we don't want the command line specified values to be saved
 313          * on c->save_config(). So we store the config file specified values
 314          * here. */
 315         char *logfile; /* the logfile as specified in config */
 316         int loglevel; /* loglevel as specified in config (if any) */
 317         int logfd;
 318
 319         unsigned int start_auto;
 320         unsigned int start_delay;
 321         int start_order;
 322         struct lxc_list groups;
 323         int nbd_idx;
 324
 325         /* unshare the mount namespace in the monitor */
 326         unsigned int monitor_unshare;
 327         unsigned int monitor_signal_pdeath;
 328
 329         /* list of included files */
 330         struct lxc_list includes;
 331         /* config entries which are not "lxc.*" are aliens */
 332         struct lxc_list aliens;
 333
 334         /* list of environment variables we'll add to the container when
 335          * started */
 336         struct lxc_list environment;
 337
 338         /* text representation of the config file */
 339         char *unexpanded_config;
 340         size_t unexpanded_len;
 341         size_t unexpanded_alloced;
 342
 343         /* default command for lxc-execute */
 344         char *execute_cmd;
 345
 346         /* init command */
 347         char *init_cmd;
 348
 349         /* if running in a new user namespace, the UID/GID that init and COMMAND
 350          * should run under when using lxc-execute */
 351         uid_t init_uid;
 352         gid_t init_gid;
 353
 354         /* indicator if the container will be destroyed on shutdown */
 355         unsigned int ephemeral;
 356
 357         /* The facility to pass to syslog. Let's users establish as what type of
 358          * program liblxc is supposed to write to the syslog. */
 359         char *syslog;
 360
 361         /* Whether PR_SET_NO_NEW_PRIVS will be set for the container. */
 362         bool no_new_privs;
 363
 364         /* RLIMIT_* limits */
 365         struct lxc_list limits;
 366
 367         /* Contains generic info about the cgroup configuration for this
 368          * container. Note that struct lxc_cgroup contains a union. It is only
 369          * valid to access the members of the anonymous "meta" struct within
 370          * that union.
 371          */
 372         struct lxc_cgroup cgroup_meta;
 373
 374         struct {
 375                 int ns_clone;
 376                 int ns_keep;
 377                 char *ns_share[LXC_NS_MAX];
 378         };
 379
 380         /* init working directory */
 381         char *init_cwd;
 382
 383         /* A list of clients registered to be informed about a container state. */
 384         struct lxc_list state_clients;
 385
 386         /* sysctls */
 387         struct lxc_list sysctls;
 388
 389         /* procs */
 390         struct lxc_list procs;
 391
 392         struct shmount {
 393                 /* Absolute path to the shared mount point on the host */
 394                 char *path_host;
 395                 /* Absolute path (in the container) to the shared mount point */
 396                 char *path_cont;
 397         } shmount;
 398 };
 399
 400 extern int write_id_mapping(enum idtype idtype, pid_t pid, const char *buf,
 401                             size_t buf_size);
 402
 403 #ifdef HAVE_TLS
 404 extern thread_local struct lxc_conf *current_config;
 405 #else
 406 extern struct lxc_conf *current_config;
 407 #endif
 408
 409 extern int run_lxc_hooks(const char *name, char *hook, struct lxc_conf *conf,
 410                          char *argv[]);
 411 extern int detect_shared_rootfs(void);
 412 extern struct lxc_conf *lxc_conf_init(void);
 413 extern void lxc_conf_free(struct lxc_conf *conf);
 414 extern int pin_rootfs(const char *rootfs);
 415 extern int lxc_map_ids(struct lxc_list *idmap, pid_t pid);
 416 extern int lxc_create_tty(const char *name, struct lxc_conf *conf);
 417 extern void lxc_delete_tty(struct lxc_tty_info *ttys);
 418 extern int lxc_clear_config_caps(struct lxc_conf *c);
 419 extern int lxc_clear_config_keepcaps(struct lxc_conf *c);
 420 extern int lxc_clear_cgroups(struct lxc_conf *c, const char *key, int version);
 421 extern int lxc_clear_mount_entries(struct lxc_conf *c);
 422 extern int lxc_clear_automounts(struct lxc_conf *c);
 423 extern int lxc_clear_hooks(struct lxc_conf *c, const char *key);
 424 extern int lxc_clear_idmaps(struct lxc_conf *c);
 425 extern int lxc_clear_groups(struct lxc_conf *c);
 426 extern int lxc_clear_environment(struct lxc_conf *c);
 427 extern int lxc_clear_limits(struct lxc_conf *c, const char *key);
 428 extern int lxc_delete_autodev(struct lxc_handler *handler);
 429 extern void lxc_clear_includes(struct lxc_conf *conf);
 430 extern int lxc_setup_rootfs_prepare_root(struct lxc_conf *conf,
 431                                          const char *name, const char *lxcpath);
 432 extern int lxc_setup(struct lxc_handler *handler);
 433 extern int lxc_setup_parent(struct lxc_handler *handler);
 434 extern int setup_resource_limits(struct lxc_list *limits, pid_t pid);
 435 extern int find_unmapped_nsid(struct lxc_conf *conf, enum idtype idtype);
 436 extern int mapped_hostid(unsigned id, struct lxc_conf *conf,
 437                          enum idtype idtype);
 438 extern int chown_mapped_root(const char *path, struct lxc_conf *conf);
 439 extern int userns_exec_1(struct lxc_conf *conf, int (*fn)(void *), void *data,
 440                          const char *fn_name);
 441 extern int userns_exec_full(struct lxc_conf *conf, int (*fn)(void *),
 442                             void *data, const char *fn_name);
 443 extern int parse_mntopts(const char *mntopts, unsigned long *mntflags,
 444                          char **mntdata);
 445 extern int parse_propagationopts(const char *mntopts, unsigned long *pflags);
 446 extern void tmp_proc_unmount(struct lxc_conf *lxc_conf);
 447 extern void remount_all_slave(void);
 448 extern void suggest_default_idmap(void);
 449 extern FILE *make_anonymous_mount_file(struct lxc_list *mount,
 450                                        bool include_nesting_helpers);
 451 extern struct lxc_list *sort_cgroup_settings(struct lxc_list *cgroup_settings);
 452 extern unsigned long add_required_remount_flags(const char *s, const char *d,
 453                                                 unsigned long flags);
 454 extern int run_script(const char *name, const char *section, const char *script,
 455                       ...);
 456 extern int run_script_argv(const char *name, unsigned int hook_version,
 457                            const char *section, const char *script,
 458                            const char *hookname, char **argsin);
 459 extern int in_caplist(int cap, struct lxc_list *caps);
 460 extern int setup_sysctl_parameters(struct lxc_list *sysctls);
 461 extern int lxc_clear_sysctls(struct lxc_conf *c, const char *key);
 462 extern int setup_proc_filesystem(struct lxc_list *procs, pid_t pid);
 463 extern int lxc_clear_procs(struct lxc_conf *c, const char *key);
 464 extern int lxc_clear_apparmor_raw(struct lxc_conf *c);
 465
 466 #endif /* __LXC_CONF_H */