3 files changed, 168 insertions, 0 deletions
diff --git a/sys/include/sys/limits.h b/sys/include/sys/limits.h
index f6aed9d..963d113 100644
--- a/sys/include/sys/limits.h
+++ b/sys/include/sys/limits.h
@@ -36,4 +36,6 @@
 #define ARG_MAX 4096
 #define CHAR_BIT 8
 #define CPU_MAX 256
+#define VSR_MAX_DOMAIN 16
+#define VSR_MAX_CAPSULE 16
 #endif  /* !_SYS_LIMITS_H_ */
diff --git a/sys/include/sys/proc.h b/sys/include/sys/proc.h
index 9cc9238..89fe638 100644
--- a/sys/include/sys/proc.h
+++ b/sys/include/sys/proc.h
@@ -39,6 +39,8 @@
 #include <sys/syscall.h>
 #include <sys/exec.h>
 #include <sys/ucred.h>
+#include <sys/limits.h>
+#include <sys/vsr.h>
 #include <sys/filedesc.h>
 #include <sys/signal.h>
 #include <sys/vnode.h>
@@ -88,6 +90,7 @@ struct proc {
     struct ucred cred;
     struct ksiginfo *ksig_list[PROC_SIGMAX];
     struct filedesc *fds[PROC_MAX_FILEDES];
+    struct vsr_domain *vsr_tab[VSR_MAX_DOMAIN];
     struct mmap_lgdr *mlgdr;
     struct vcache *vcache;
     struct spinlock vcache_lock;
diff --git a/sys/include/sys/vsr.h b/sys/include/sys/vsr.h
new file mode 100644
index 0000000..88cb659
--- /dev/null
+++ b/sys/include/sys/vsr.h
@@ -0,0 +1,163 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _SYS_VSR_H_
+#define _SYS_VSR_H_
+
+#include <sys/types.h>
+#include <sys/queue.h>
+#include <sys/param.h>
+#include <sys/ucred.h>
+#include <sys/limits.h>
+#if defined(_KERNEL)
+#include <sys/mutex.h>
+#endif  /* _KERNEL */
+
+#define VSR_FILE    0x00000000  /* Represented by file */
+
+/*
+ * Defines the access semantics of whether
+ * r/w operations should be passed down to the
+ * global state or soley affecting a per-process
+ * shallow copy.
+ */
+typedef uint32_t vsr_mode_t;
+
+/*
+ * The Virtual System Resource namespace consists of
+ * domains containing named "capsules". The domain is
+ * simply a table indexed by a type value e.g. VSR_FILE
+ * and a capsule is simply a structure containing global data
+ * as well as a shallow copy which is controlled locally by the
+ * process. The capsule also contains various access semantics
+ * that help the VSR subsystem determine whether the access should
+ * be passed down globally or virtualized locally within the process.
+ */
+typedef uint8_t vsr_domain_t;
+
+/*
+ * VSR mode bits
+ */
+#define VSR_GLOB_WRITE  BIT(0)   /* Writes are global */
+#define VSR_GLOB_READ   BIT(1)   /* Reads are global */
+#define VSR_GLOB_CRED   BIT(2)   /* Global for specific creds */
+
+#if defined(_KERNEL)
+
+struct vsr_capsule;
+
+/*
+ * VSR capsule operations
+ *
+ * @reclaim: Cleanup resources
+ */
+struct capsule_ops {
+    int(*reclaim)(struct vsr_capsule *cap, int flags);
+};
+
+/*
+ * Virtual system resource access
+ * semantics.
+ *
+ * @glob: Global data
+ * @shallow: Local per process copy
+ * @mode: VSR mode (see VSR_GLOB_*)
+ * @cred: Creds (used if VSR_GLOBAL_CRED set)
+ */
+struct vsr_access {
+    void *glob;
+    void *shallow;
+    vsr_mode_t mode;
+    struct ucred cred;
+};
+
+/*
+ * A virtual system resource capsule containing
+ * resource owner specific data and hashmap
+ * buckets.
+ *
+ * @name: Capsule name (e.g., "consfeat"), must be freed
+ * @data: Owner specific data
+ * @shadow: Local shadow copy (per-process)
+ * @buckets: Hashmap buckets
+ * @link: Bucket link
+ * @ops: Capsule operations
+ * @lock: Mutex lock protecting fields
+ */
+struct vsr_capsule {
+    char *name;
+    void *data;
+    void *shadow;
+    TAILQ_HEAD(, vsr_capsule) buckets;
+    TAILQ_ENTRY(vsr_capsule) link;
+    struct capsule_ops ops;
+    struct mutex lock;
+};
+
+/*
+ * Virtual system resource table containg
+ * VSRs for various types.
+ *
+ * Each VSR table belongs to a VSR domain
+ * (e.g., VSR_FILE).
+ *
+ * @ncaps: Number of capsules
+ * @is_init: Set if hashmap is set up
+ * @capsules: VSR capsule hashmap
+ */
+struct vsr_table {
+    struct vsr_capsule *capsules[VSR_MAX_CAPSULE];
+};
+
+/*
+ * Virtual system resource domain (VSR).
+ *
+ * A VSR is represented by a specific VSR type
+ * (see VSR_*). Each VSR has a table of VSR capsules
+ * looked up by a VSR capsule name.
+ *
+ * One per process.
+ *
+ * @type: VSR type
+ * @table: VSR table
+ */
+struct vsr_domain {
+    int type;
+    struct vsr_table table;
+};
+
+void vsr_init_domains(void);
+void vsr_destroy_domains(void);
+
+struct vsr_domain *vsr_new_domain(vsr_domain_t type);
+struct vsr_capsule *vsr_new_capsule(vsr_domain_t type, const char *name);
+struct vsr_capsule *vsr_lookup_capsule(vsr_domain_t type, const char *name);
+
+#endif  /* _KERNEL */
+#endif  /* !_SYS_VSR_H_ */