src/lxc/lxc.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_h
  24 #define __lxc_h
  25
  26 #ifdef __cplusplus
  27 extern "C" {
  28 #endif
  29
  30 #include <stddef.h>
  31 #include <sys/select.h>
  32 #include <sys/types.h>
  33 #include "state.h"
  34
  35 struct lxc_msg;
  36 struct lxc_conf;
  37 struct lxc_arguments;
  38
  39 /**
  40  Following code is for liblxc.
  41
  42  lxc/lxc.h will contain exports of liblxc
  43  **/
  44
  45 /*
  46  * Start the specified command inside a system container
  47  * @name     : the name of the container
  48  * @argv     : an array of char * corresponding to the commande line
  49  * @conf     : configuration
  50  * Returns 0 on sucess, < 0 otherwise
  51  */
  52 extern int lxc_start(const char *name, char *const argv[], struct lxc_conf *conf,
  53                      const char *lxcpath);
  54
  55 /*
  56  * Start the specified command inside an application container
  57  * @name     : the name of the container
  58  * @argv     : an array of char * corresponding to the commande line
  59  * @quiet    : if != 0 then lxc-init won't produce any output
  60  * @conf     : configuration
  61  * Returns 0 on sucess, < 0 otherwise
  62  */
  63 extern int lxc_execute(const char *name, char *const argv[], int quiet,
  64                        struct lxc_conf *conf, const char *lxcpath);
  65
  66 /*
  67  * Open the monitoring mechanism for a specific container
  68  * The function will return an fd corresponding to the events
  69  * Returns a file descriptor on success, < 0 otherwise
  70  */
  71 extern int lxc_monitor_open(const char *lxcpath);
  72
  73 /*
  74  * Blocking read for the next container state change
  75  * @fd  : the file descriptor provided by lxc_monitor_open
  76  * @msg : the variable which will be filled with the state
  77  * Returns 0 if the monitored container has exited, > 0 if
  78  * data was read, < 0 otherwise
  79  */
  80 extern int lxc_monitor_read(int fd, struct lxc_msg *msg);
  81
  82 /*
  83  * Blocking read for the next container state change with timeout
  84  * @fd      : the file descriptor provided by lxc_monitor_open
  85  * @msg     : the variable which will be filled with the state
  86  * @timeout : the timeout in seconds to wait for a state change
  87  * Returns 0 if the monitored container has exited, > 0 if
  88  * data was read, < 0 otherwise
  89  */
  90 extern int lxc_monitor_read_timeout(int fd, struct lxc_msg *msg, int timeout);
  91
  92 /*
  93  * Blocking read from multiple monitors for the next container state
  94  * change with timeout
  95  * @rfds    : an fd_set of file descriptors provided by lxc_monitor_open
  96  * @nfds    : the maximum fd number in rfds + 1
  97  * @msg     : the variable which will be filled with the state
  98  * @timeout : the timeout in seconds to wait for a state change
  99  * Returns 0 if the monitored container has exited, > 0 if
 100  * data was read, < 0 otherwise
 101  */
 102 extern int lxc_monitor_read_fdset(fd_set *rfds, int nfds, struct lxc_msg *msg, int timeout);
 103
 104 /*
 105  * Close the fd associated with the monitoring
 106  * @fd : the file descriptor provided by lxc_monitor_open
 107  * Returns 0 on success, < 0 otherwise
 108  */
 109 extern int lxc_monitor_close(int fd);
 110
 111 /*
 112  * Freeze all the tasks running inside the container <name>
 113  * @name : the container name
 114  * Returns 0 on success, < 0 otherwise
 115  */
 116 extern int lxc_freeze(const char *name, const char *lxcpath);
 117
 118 /*
 119  * Unfreeze all previously frozen tasks.
 120  * @name : the name of the container
 121  * Return 0 on sucess, < 0 otherwise
 122  */
 123 extern int lxc_unfreeze(const char *name, const char *lxcpath);
 124
 125 /*
 126  * Retrieve the container state
 127  * @name : the name of the container
 128  * Returns the state of the container on success, < 0 otherwise
 129  */
 130 extern lxc_state_t lxc_state(const char *name, const char *lxcpath);
 131
 132 struct lxc_handler;
 133 /*
 134  * Set a specified value for a specified subsystem. The specified
 135  * subsystem must be fully specified, eg. "cpu.shares"
 136  * @filename  : the cgroup attribute filename
 137  * @value     : the value to be set
 138  * @handler   : the lxc_handler structure of the container
 139  * Returns 0 on success, < 0 otherwise
 140  */
 141 extern int lxc_cgroup_set_handler(const char *filename, const char *value, struct lxc_handler *handler);
 142
 143 /*
 144  * Set a specified value for a specified subsystem. The specified
 145  * subsystem must be fully specified, eg. "cpu.shares"
 146  * @filename  : the cgroup attribute filename
 147  * @value     : the value to be set
 148  * @name      : the name of the container
 149  * @lxcpath   : lxc config path for container
 150  * Returns 0 on success, < 0 otherwise
 151  */
 152 extern int lxc_cgroup_set(const char *filename, const char *value, const char *name, const char *lxcpath);
 153
 154 /*
 155  * Get a specified value for a specified subsystem. The specified
 156  * subsystem must be fully specified, eg. "cpu.shares"
 157  * @filename  : the cgroup attribute filename
 158  * @value     : the value to be set
 159  * @len       : the len of the value variable
 160  * @name      : the name of the container
 161  * @lxcpath   : lxc config path for container
 162  * Returns the number of bytes read, < 0 on error
 163  */
 164 extern int lxc_cgroup_get(const char *filename, char *value, size_t len, const char *name, const char *lxcpath);
 165
 166 /*
 167  * Retrieve the error string associated with the error returned by
 168  * the function.
 169  * @error : the value of the error
 170  * Returns a string on success or NULL otherwise.
 171  */
 172 extern const char *lxc_strerror(int error);
 173
 174 /*
 175  * Checkpoint a container
 176  * @name : the name of the container being checkpointed
 177  * @sfd: fd on which the container is checkpointed
 178  * @flags : checkpoint flags (an ORed value)
 179  * Returns 0 on success, < 0 otherwise
 180  */
 181 extern int lxc_checkpoint(const char *name, int sfd, int flags);
 182 #define LXC_FLAG_PAUSE 1
 183 #define LXC_FLAG_HALT  2
 184
 185 /*
 186  * Restart a container
 187  * @name : the name of the container being restarted
 188  * @sfd: fd from which the container is restarted
 189  * @conf: lxc_conf structure.
 190  * @flags : restart flags (an ORed value)
 191  * @lxcpath: container path
 192  * Returns 0 on success, < 0 otherwise
 193  */
 194 extern int lxc_restart(const char *, int, struct lxc_conf *, int, const char *);
 195
 196 /*
 197  * Create and return a new lxccontainer struct.
 198  */
 199 extern struct lxc_container *lxc_container_new(const char *name, const char *configpath);
 200
 201 /*
 202  * Returns 1 on success, 0 on failure.
 203  */
 204 extern int lxc_container_get(struct lxc_container *c);
 205
 206 /*
 207  * Put a lxccontainer struct reference.
 208  * Return -1 on error.
 209  * Return 0 if this was not the last reference.
 210  * If it is the last reference, free the lxccontainer and return 1.
 211  */
 212 extern int lxc_container_put(struct lxc_container *c);
 213
 214 /*
 215  * Get a list of valid wait states.
 216  * If states is NULL, simply return the number of states
 217  */
 218 extern int lxc_get_wait_states(const char **states);
 219
 220 /*
 221  * Add a dependency to a container
 222  */
 223 extern int add_rdepend(struct lxc_conf *lxc_conf, char *rdepend);
 224
 225 #ifdef __cplusplus
 226 }
 227 #endif
 228
 229 #endif