1 files changed, 206 insertions, 0 deletions
diff --git a/sys/fs/procfs.c b/sys/fs/procfs.c
new file mode 100644
index 0000000..3a0e2d3
--- /dev/null
+++ b/sys/fs/procfs.c
@@ -0,0 +1,206 @@
+/*
+ * Copyright (c) 2023-2024 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.
+ */
+
+#include <sys/types.h>
+#include <sys/mount.h>
+#include <sys/queue.h>
+#include <sys/errno.h>
+#include <vm/dynalloc.h>
+#include <sys/vfs.h>
+#include <fs/procfs.h>
+#include <string.h>
+
+struct proc_node {
+    struct spinlock lock;
+    struct proc_entry *entry;
+    char *name;
+    TAILQ_ENTRY(proc_node) link;
+};
+
+static TAILQ_HEAD(, proc_node) proc_nodes;
+static bool nodelist_init = false;
+
+static struct proc_node *
+name_to_node(const char *name)
+{
+    struct proc_node *n;
+
+    TAILQ_FOREACH(n, &proc_nodes, link) {
+        if (strcmp(n->name, name) == 0) {
+            return n;
+        }
+    }
+
+    return NULL;
+}
+
+static int
+procfs_make_node(const char *name, struct proc_node **res)
+{
+    size_t name_len = 0;
+    const char *p = name;
+    struct proc_node *n;
+
+    /* Disallow paths */
+    for (; *p; ++p, ++name_len) {
+        if (*p == '/') {
+            return -EINVAL;
+        }
+    }
+
+    if (!vfs_is_valid_path(name))
+        return -EINVAL;
+
+    n = dynalloc(sizeof(struct proc_node));
+    if (n == NULL)
+        return -ENOMEM;
+
+    n->name = dynalloc(sizeof(char) * name_len);
+    if (n->name == NULL)
+        return -ENOMEM;
+
+    memcpy(n->name, name, name_len + 1);
+    *res = n;
+    return 0;
+}
+
+struct proc_entry *
+procfs_alloc_entry(void)
+{
+    struct proc_entry *entry;
+
+    entry = dynalloc(sizeof(*entry));
+    if (entry == NULL)
+        return NULL;
+
+    memset(entry, 0, sizeof(*entry));
+    return entry;
+}
+
+int
+procfs_add_entry(const char *name, struct proc_entry *entry)
+{
+    struct proc_node *proc;
+    int status;
+
+    if (name == NULL || entry == NULL)
+        return -EINVAL;
+    if ((status = procfs_make_node(name, &proc)) != 0)
+        return status;
+
+    proc->entry = entry;
+    TAILQ_INSERT_HEAD(&proc_nodes, proc, link);
+    return 0;
+}
+
+static int
+procfs_init(struct fs_info *info, struct vnode *source)
+{
+    if (source != NULL)
+        return -EINVAL;
+
+
+    TAILQ_INIT(&proc_nodes);
+    nodelist_init = true;
+    procfs_populate();
+    return 0;
+}
+
+static int
+procfs_rw_vnode(struct vnode *vp, struct sio_txn *sio, bool write)
+{
+    struct proc_node *proc;
+    struct proc_entry *entry;
+
+    if (vp == NULL)
+        return -EIO;
+
+    proc = vp->data;
+    entry = proc->entry;
+
+    return write ? entry->write(entry, sio)
+                 : entry->read(entry, sio);
+}
+
+static int
+vop_write(struct vnode *vp, struct sio_txn *sio)
+{
+    return procfs_rw_vnode(vp, sio, true);
+}
+
+static int
+vop_read(struct vnode *vp, struct sio_txn *sio)
+{
+    return procfs_rw_vnode(vp, sio, false);
+}
+
+static int
+vop_open(struct vnode *vp)
+{
+    return 0;
+}
+
+static int
+vop_close(struct vnode *vp)
+{
+    return 0;
+}
+
+static int
+vop_vget(struct vnode *parent, const char *name, struct vnode **vp)
+{
+    struct proc_node *proc;
+    struct vnode *vnode;
+    int status;
+
+    if (!nodelist_init)
+        return -EIO;
+    if ((proc = name_to_node(name)) == NULL)
+        return -ENOENT;
+    if ((status = vfs_alloc_vnode(&vnode, NULL, VREG)) != 0)
+        return status;
+
+    vnode->parent = parent;
+    vnode->data = proc;
+    vnode->vops = &g_procfs_vops;
+    *vp = vnode;
+    return 0;
+}
+
+struct vfsops g_procfs_ops = {
+    .init = procfs_init
+};
+
+struct vops g_procfs_vops = {
+    .vget = vop_vget,
+    .read = vop_read,
+    .write = vop_write,
+    .open = vop_open,
+    .close = vop_close
+};