process rbtree. add syscall for initrd_file access.

8 files changed, 280 insertions, 9 deletions

diff --git a/api/syscall.h b/api/syscall.h
index 1cdc941..9f8ec13 100644
--- a/api/syscall.h
+++ b/api/syscall.h
@@ -29,15 +29,15 @@ struct syscall_generic_write
     char data[];
 };
 
-/* If the message is too small for path, the kernel will return ETOOSMALL.
- * If the path does not point to an object, the kernel will return EBADPATH.
- * */
 struct syscall_generic_objpath
 {
     uint16_t pathlen;
     objpath_part_t path[];
 };
 
+/**JOVE_OBJ_UNTYPED syscalls.
+ * */
+
 enum
 {
     _SYSCALL_UNTYPED_BADCALL = 0,
@@ -60,6 +60,9 @@ struct syscall_untyped_split
     objpath_part_t dest_path[];
 };
 
+/**JOVE_OBJ_OBJDIR syscalls.
+ * */
+
 enum
 {
     _SYSCALL_OBJDIR_BADCALL = 0,
@@ -68,6 +71,9 @@ enum
 
 #define SYSCALL_PERM_OBJDIR_OBJTYPE JOVE_PERM_READ
 
+/* JOVE_OBJ_PAGEDIR syscalls
+ * */
+
 enum
 {
     _SYSCALL_PAGEDIR_NONE = 0,
@@ -117,6 +123,35 @@ struct syscall_pagedir_unmap
     objpath_part_t none_path[];
 };
 
+/**JOVE_OBJ_INITRD_FILE syscalls
+ * */
+
+enum
+{
+    _SYSCALL_INITRD_FILE_NONE = 0,
+    SYSCALL_INITRD_FILE_NAME,
+    SYSCALL_INITRD_FILE_SIZE,
+    SYSCALL_INITRD_FILE_READ
+};
+
+#define SYSCALL_PERM_INITRD_FILE_NAME (JOVE_PERM_READ)
+#define SYSCALL_PERM_INITRD_FILE_SIZE (JOVE_PERM_READ)
+#define SYSCALL_PERM_INITRD_FILE_READ (JOVE_PERM_READ)
+
+struct syscall_initrd_file_name_ret
+{
+    size_t len;
+    char c_str[];
+};
+
+struct syscall_initrd_file_read
+{
+    size_t start_index;
+    size_t read_size;
+};
+
+/**JOVE_OBJ_VIRTTERM syscalls.*/
+
 enum
 {
     _SYSCALL_VTT_NONE = 0,
diff --git a/arch/x86_64/proc/process.c b/arch/x86_64/proc/process.c
index 55af85a..0c5c282 100644
--- a/arch/x86_64/proc/process.c
+++ b/arch/x86_64/proc/process.c
@@ -32,6 +32,7 @@ processing_setup(void (*process_main))
     uintptr_t ksp = ((uintptr_t)&_init_pcb_bytes) + 0xFF8;
 
     _init_pcb->tree_node.get_key = (void*)pcb_pid;
+    _init_pcb->tree_node.color = 1;
 
     _init_pcb->pid = 1;
     _init_pcb->ksp = (void*)ksp;
diff --git a/doc/syscall.md b/doc/syscall.md
index 9304785..3bfa00b 100644
--- a/doc/syscall.md
+++ b/doc/syscall.md
@@ -8,9 +8,9 @@ To resolve the message object, the kernel requires an object path and a path len
 
 On x86_64, the encoding is as follows:
 
-|          | Message Path | Message Path Length |
-|----------|--------------|---------------------|
-| Register |      rdi     |         rsi         |
+| Message Path | Message Path Length |
+|--------------|---------------------|
+|      rdi     |         rsi         |
 
 If the message path exceeds the width of the message path register, the kernel will return `-EBADPATH`.
 
@@ -118,7 +118,7 @@ If the entry index exceeds `JOVE_OBJDIR_ENTRIES`, the kernel returns `-EOOB`.
 |-----------------------------|:-------------------------------:|:-------------------------------------------------:|:-------------------------------:|
 | SYSCALL_PAGEDIR_MAP_FRAME   | JOVE_PERM_READ, JOVE_PERM_WRITE | JOVE_PERM_MUTATE                                  | JOVE_PERM_READ, JOVE_PERM_WRITE |
 | SYSCALL_PAGEDIR_MAP_TABLE   | JOVE_PERM_READ, JOVE_PERM_WRITE | JOVE_PERM_READ, JOVE_PERM_WRITE, JOVE_PERM_MUTATE |                                 |
-| SYSCALL_PAGEDIR_MAP_SHMEM   | JOVE_PERM_READ, JOVE_PERM_WRITE |                                                   | JOVE_PERM_READ, JOVE_PERM_WRITE |
+| SYSCALL_PAGEDIR_MAP_SHMEM   | JOVE_PERM_READ, JOVE_PERM_WRITE | JOVE_PERM_READ                                    | JOVE_PERM_WRITE                 |
 | SYSCALL_PAGEDIR_UNMAP_FRAME | JOVE_PERM_READ, JOVE_PERM_WRITE |                                                   |                                 |
 | SYSCALL_PAGEDIR_UNMAP_TABLE | JOVE_PERM_READ, JOVE_PERM_WRITE |                                                   |                                 |
 | SYSCALL_PAGEDIR_UNMAP_SHMEM | JOVE_PERM_READ, JOVE_PERM_WRITE |                                                   |                                 |
@@ -262,3 +262,55 @@ If the virtual address does not have a page frame associated with it, the kernel
 If the page frame pointed to by virtual address does not correspond to a shared memory frame, the kernel will return `-EBADOBJ`.
 
 Successful unmapping returns `0`.
+
+### JOVE_OBJ_INITRD_FILE
+
+| Syscall                  | Target Permissions |
+|--------------------------|--------------------|
+| SYSCALL_INITRD_FILE_NAME | JOVE_PERM_READ     |
+| SYSCALL_INITRD_FILE_SIZE | JOVE_PERM_READ     |
+| SYSCALL_INITRD_FILE_READ | JOVE_PERM_READ     |
+
+#### SYSCALL_INITRD_FILE_NAME
+
+Populates the message with the name of the target file.
+
+Names start with a size_t length specifier, which is followed by a NULL-terminated c-string.
+
+| Data         | Name Length    | Name        | Null Terminator |
+|--------------|----------------|-------------|-----------------|
+| Size (bytes) | sizeof(size_t) | Name Length |        1        |
+
+
+If the message is too small for the file name, the kernel will return `-ETOOSMALL`.
+
+#### SYSCALL_INITRD_FILE_SIZE
+
+Returns the size of the target file in bytes.
+
+#### SYSCALL_INITRD_FILE_READ
+
+Populates the message with the bytes read from the target file.
+
+##### Payload
+
+| Data         | Starting index | Read size      |
+|--------------|----------------|----------------|
+| Size (bytes) | sizeof(size_t) | sizeof(size_t) |
+
+##### Return
+
+| Data         | Data      |
+|--------------|-----------|
+| Size (bytes) | Read size |
+
+
+If the message is too small for the syscall payload, the kernel will return `-ETOOSMALL`.
+
+If the starting index exceeds the file length, the kernel will return `-EOOB`.
+
+If the read size + starting index > file size, the kernel will return `-EOOB`.
+
+If the message is too small for the read bytes, the kernel will return `-ETOOBIG`.
+
+Successful reading returns `0`.
diff --git a/lib/rbtree.c b/lib/rbtree.c
new file mode 100644
index 0000000..dc9caf1
--- /dev/null
+++ b/lib/rbtree.c
@@ -0,0 +1,84 @@
+#include "rbtree.h"
+
+static inline int
+s_direction(const struct rbtree_node *node)
+{
+    return node == node->parent->children[0] ? 0 : 1;
+}
+
+static struct rbtree_node*
+s_rotate(struct rbtree_node *sub, int dir)
+{
+    int opp = 1 - dir;
+    struct rbtree_node *sub_parent = sub->parent;
+    struct rbtree_node *new_root = sub_parent->children[opp];
+    struct rbtree_node *new_child = new_root->children[dir];
+
+    sub_parent->children[opp] = new_child;
+    if(new_child) new_child->parent = sub;
+
+    new_root->children[dir] = sub;
+    new_root->parent = sub_parent;
+    sub->parent = new_root;
+
+    if(sub_parent)
+        sub_parent->children[s_direction(sub)] = new_root;
+    return new_root;
+}
+
+void
+rbtree_insert(struct rbtree_node *root, struct rbtree_node *node)
+{
+    struct rbtree_node *parent = root;
+    int direction;
+    while(1) {
+        direction = parent->get_key(parent) < node->get_key(node);
+        if(parent->children[direction] == 0) break;
+        parent = parent->children[direction];
+    }
+
+    node->color = 1;
+    parent->children[direction] = node;
+    node->parent = parent;
+
+    //Rebalance the tree
+    do {
+        //Tree is already balanced, return
+        if(parent->color == 0) return;
+        struct rbtree_node *gparent = parent->parent;
+
+        //Parent is the root node, set parent to black.
+        if(!gparent) {
+            parent->color = 0;
+            return;
+        }
+
+        direction = s_direction(parent);
+        struct rbtree_node *uncle = gparent->children[1-direction];
+        if(!uncle || uncle->color == 0) {
+            //If the uncle node DNE or is black, the tree has to be rotated.
+            if(node == parent->children[1-direction]) {
+                //Rotate parent node so that node is the new parent.
+                s_rotate(parent, direction);
+                node = parent;
+                parent = gparent->children[direction];
+            }
+
+            //Rotate the parent node so that the gparent is the new parent.
+            s_rotate(gparent, 1-direction);
+            parent->color = 0;
+            gparent->color = 1;
+            return;
+        }
+
+        //Both the parent and uncle are red. Push up the red and iterate up.
+        parent->color = 0;
+        uncle->color = 0;
+        gparent->color = 1;
+        node = gparent;
+    } while((parent = node->parent));
+
+    //Tree is balanced now.
+}
+
+
diff --git a/lib/rbtree.h b/lib/rbtree.h
index 1dbd5b2..22c44f8 100644
--- a/lib/rbtree.h
+++ b/lib/rbtree.h
@@ -12,6 +12,6 @@ struct rbtree_node
     intmax_t (*get_key)(struct rbtree_node*);
 };
 
-
+void rbtree_insert(struct rbtree_node *parent, struct rbtree_node *node);
 
 #endif
diff --git a/sys/syscall.c b/sys/syscall.c
index 5cef3d6..1c9af45 100644
--- a/sys/syscall.c
+++ b/sys/syscall.c
@@ -39,7 +39,7 @@ static const syscall_handle_t s_syscall_handles[128] = {
     [JOVE_OBJ_SHMEMORY] = _syscall_handle_generic,
     [JOVE_OBJ_PCB] = _syscall_handle_generic,
     [JOVE_OBJ_INT_HANDLE] = _syscall_handle_generic,
-    [JOVE_OBJ_INITRD_FILE] = _syscall_handle_generic,
+    [JOVE_OBJ_INITRD_FILE] = _syscall_handle_initrd_file,
     [JOVE_OBJ_FRAMEBUFFER] = _syscall_handle_generic,
     [JOVE_OBJ_VIRTTERM] = _syscall_handle_vtt,
     [JOVE_OBJ_MESSAGE] = _syscall_handle_generic,
diff --git a/sys/syscall.h b/sys/syscall.h
index e6358cb..ab13118 100644
--- a/sys/syscall.h
+++ b/sys/syscall.h
@@ -57,5 +57,6 @@ int _syscall_handle_vtt(syscall_context_t *ctx);
 int _syscall_handle_objdir(syscall_context_t *ctx);
 int _syscall_handle_untyped(syscall_context_t *ctx);
 int _syscall_handle_pagedir(syscall_context_t *ctx);
+int _syscall_handle_initrd_file(syscall_context_t *ctx);
 
 #endif
diff --git a/sys/syscall_initrd_file.c b/sys/syscall_initrd_file.c
new file mode 100644
index 0000000..8e34488
--- /dev/null
+++ b/sys/syscall_initrd_file.c
@@ -0,0 +1,98 @@
+#include "api/error.h"
+#include "boot/initrd.h"
+#include "lib/printf.h"
+#include "sys/message.h"
+#include "sys/syscall.h"
+#include "lib/string.h"
+
+int
+s_syscall_initrd_file_name(
+        jove_owned_obj_t *initrd_file,
+        jove_owned_obj_t *message)
+{
+    const char *filename = initrd_file_name(initrd_file);
+    size_t filename_len = strlen(filename);
+
+    size_t bytes_left = message_len(message);
+    size_t bytes_needed = filename_len + sizeof(struct syscall_initrd_file_name_ret);
+
+    CHECK_TOOSMALL(bytes_needed, bytes_left, "Message is too small for file name.");
+    struct syscall_initrd_file_name_ret *payload = message_data(message);
+
+    payload->len = filename_len;
+    memcpy(payload->c_str, filename, filename_len);
+    return 0;
+}
+
+int
+s_syscall_initrd_file_size(jove_owned_obj_t *initrd_file)
+{
+    return initrd_file_size(initrd_file);
+}
+
+int
+s_syscall_initrd_file_read(
+        jove_owned_obj_t *initrd_file,
+        jove_owned_obj_t *message,
+        size_t bytes_left,
+        void *payload_data)
+{
+    //Ensure that the message payload could hold the required read payload.
+    size_t bytes_needed = sizeof(struct syscall_initrd_file_read);
+    CHECK_TOOSMALL(bytes_needed, bytes_left, 
+            "Message is too small to hold read payload.");
+
+    struct syscall_initrd_file_read *payload = payload_data;
+    bytes_needed = payload->read_size;
+    bytes_left = message_len(message);
+
+    //Ensure that the message is big enough to hold the read file data.
+    CHECK_TOOSMALL(bytes_needed, bytes_left,
+            "Message is too small to hold read bytes.");
+
+    size_t file_size = initrd_file_size(initrd_file);
+    char *file_data = initrd_file_data(initrd_file);
+
+    //Ensure that the start index is within the file.
+    if(payload->start_index >= file_size) {
+        klogf("Start index exceeds file length! (%i > %i)\n",
+                payload->start_index, file_size);
+        return -EOOB;
+    }
+
+    //Ensure that the read bounds is within the file.
+    if(payload->start_index + payload->read_size > file_size) {
+        klogf("Read bounds exceed file length! (%i+%i > %i)\n",
+                payload->start_index, payload->read_size, file_size);
+        return -ETOOBIG;
+    }
+    
+    void *read_data = message_data(message);
+    memcpy(read_data, file_data + payload->start_index, payload->read_size);
+    return 0;
+}
+
+int
+_syscall_handle_initrd_file(syscall_context_t *ctx)
+{
+    switch(ctx->header->callid) {
+        case SYSCALL_INITRD_FILE_NAME:
+            if(ctx->target.permissions & SYSCALL_PERM_INITRD_FILE_NAME)
+                return s_syscall_initrd_file_name(
+                        ctx->target.obj, ctx->message.obj);
+            return -EPERM;
+        
+        case SYSCALL_INITRD_FILE_SIZE:
+            if(ctx->target.permissions & SYSCALL_PERM_INITRD_FILE_SIZE)
+                return s_syscall_initrd_file_size(ctx->target.obj);
+            return -EPERM;
+
+        case SYSCALL_INITRD_FILE_READ:
+            if(ctx->target.permissions & SYSCALL_PERM_INITRD_FILE_READ)
+                return s_syscall_initrd_file_read(
+                        ctx->target.obj, ctx->message.obj, ctx->bytes_left, ctx->payload);
+            return -EPERM;
+        default:
+            return -EBADCALL;
+    }
+}