conf, confile: introduce basic structs for shared mount point

src/lxc/conf.c

@@ -2714,6 +2714,8 @@ struct lxc_conf *lxc_conf_init(void)
 	new->lsm_aa_profile = NULL;
 	new->lsm_se_context = NULL;
 	new->tmp_umount_proc = false;
+	new->lxc_shmount.path_host = NULL;
+	new->lxc_shmount.path_cont = NULL;
 
 	/* if running in a new user namespace, init and COMMAND
 	 * default to running as UID/GID 0 when using lxc-execute */
@@ -4041,6 +4043,8 @@ void lxc_conf_free(struct lxc_conf *conf)
 	lxc_clear_procs(conf, "lxc.proc");
 	free(conf->cgroup_meta.dir);
 	free(conf->cgroup_meta.controllers);
+	free(conf->lxc_shmount.path_host);
+	free(conf->lxc_shmount.path_cont);
 	free(conf);
 }
 

src/lxc/conf.h

@@ -189,6 +189,9 @@ enum {
 	LXC_AUTO_CGROUP_FULL_NOSPEC   = 0x0E0, /* /sys/fs/cgroup (full mount, r/w or mixed, depending on caps) */
 	LXC_AUTO_CGROUP_FORCE         = 0x100, /* mount cgroups even when cgroup namespaces are supported */
 	LXC_AUTO_CGROUP_MASK          = 0x1F0, /* all known cgroup options, doe not contain LXC_AUTO_CGROUP_FORCE */
+
+	LXC_AUTO_SHMOUNTS             = 0x200, /* shared mount point */
+	LXC_AUTO_SHMOUNTS_MASK        = 0x200, /* shared mount point mask */
 	LXC_AUTO_ALL_MASK             = 0x1FF, /* all known settings */
 };
 
@@ -367,6 +370,13 @@ struct lxc_conf {
 
 	/* procs */
 	struct lxc_list procs;
+
+	struct lxc_shmount {
+		/* Absolute path to the shared mount point on the host */
+		char *path_host;
+		/* Absolute path (in the container) to the shared mount point */
+		char *path_cont;
+	} lxc_shmount;
 };
 
 extern int write_id_mapping(enum idtype idtype, pid_t pid, const char *buf,

src/lxc/confile.c

@@ -1659,6 +1659,7 @@ static int set_config_mount_auto(const char *key, const char *value,
 	    { "cgroup-full:mixed:force", LXC_AUTO_CGROUP_MASK, LXC_AUTO_CGROUP_FULL_MIXED | LXC_AUTO_CGROUP_FORCE  },
 	    { "cgroup-full:ro:force",    LXC_AUTO_CGROUP_MASK, LXC_AUTO_CGROUP_FULL_RO | LXC_AUTO_CGROUP_FORCE     },
 	    { "cgroup-full:rw:force",    LXC_AUTO_CGROUP_MASK, LXC_AUTO_CGROUP_FULL_RW | LXC_AUTO_CGROUP_FORCE     },
+	    { "shmounts:",               LXC_AUTO_SHMOUNTS_MASK, LXC_AUTO_SHMOUNTS                                 },
 	    /* For adding anything that is just a single on/off, but has no
 	    *  options: keep mask and flag identical and just define the enum
 	    *  value as an unused bit so far