working syscalls.

1 files changed, 111 insertions, 0 deletions

diff --git a/sys/syscall.c b/sys/syscall.c
new file mode 100644
index 0000000..1eadf50
--- /dev/null
+++ b/sys/syscall.c
@@ -0,0 +1,111 @@
+#include "sys/syscall.h"
+#include "arch/x86_64/hal/obj.h"
+#include "hal/smp.h"
+#include "hal/process.h"
+#include "jove.h"
+#include "lib/printf.h"
+#include "sys/message.h"
+
+int
+_syscall_handle_generic(
+        jove_owned_obj_t *pcb_obj,
+        jove_owned_obj_t *objdir,
+        jove_owned_obj_t *message_obj,
+        jove_owned_obj_t *target_obj,
+        struct syscall_header *header,
+        size_t bytes_left,
+        void *payload)
+{
+    pcb_t *pcb = obj_deref(pcb_obj);
+    kprintf("syscall: Process %i encountered stub syscall on object %P\n", pcb_pid(pcb), header->path, header->pathlen);
+    return EBADOBJ;
+}
+
+static const syscall_handle_t s_syscall_handles[128] = {
+    [JOVE_OBJ_NONE] = NULL,
+    [JOVE_OBJ_UNTYPED] = _syscall_handle_generic,
+    [JOVE_OBJ_OBJDIR] = _syscall_handle_generic,
+    [JOVE_OBJ_PAGEDIR] = _syscall_handle_generic,
+    [JOVE_OBJ_PROCESSOR] = _syscall_handle_generic,
+    [JOVE_OBJ_PROCESS] = _syscall_handle_generic,
+    [JOVE_OBJ_PAGEFRAME] = _syscall_handle_generic,
+    [JOVE_OBJ_INITRD_FILE] = _syscall_handle_generic,
+    [JOVE_OBJ_FRAMEBUFFER] = _syscall_handle_generic,
+    [JOVE_OBJ_VIRTTERM] = _syscall_handle_generic,
+    [JOVE_OBJ_MESSAGE] = _syscall_handle_generic,
+};
+
+int
+syscall_handler(uintmax_t message_path_raw, uint16_t message_pathlen)
+{
+    uint16_t *message_path = (uint16_t*)&message_path_raw;
+    if(message_pathlen > sizeof(uintmax_t) >> 1) {
+        return EBADPATH;
+    }
+
+    jove_owned_obj_t *pcb_obj = process_current();
+    pcb_t *pcb = obj_deref(pcb_obj);
+
+    jove_owned_obj_t *objdir = pcb_rootdir(pcb);
+    kprintf("Syscall: %p : %P \n", objdir, message_path, message_pathlen);
+
+    jove_owned_obj_t *message_obj = objdir_getobj(objdir, message_path, message_pathlen);
+    if(message_obj == 0) {
+        obj_release(objdir);
+        obj_release(pcb_obj);
+        return errno;
+    }
+
+#define SYSCALL_MIDWAY_CLEANUP \
+    obj_release(message_obj); \
+    obj_release(objdir); \
+    obj_release(pcb_obj)
+
+    if(obj_gettype(message_obj) != JOVE_OBJ_MESSAGE) {
+        kprintf("syscall: Process %i tried to call syscall with invalid object: %P\n", pcb_pid(pcb), message_path, message_pathlen);
+        SYSCALL_MIDWAY_CLEANUP;
+        return EBADOBJ;
+    }
+
+    size_t messagelen = message_len(message_obj);
+    void *messagedata = message_data(message_obj);
+    struct syscall_header *header = messagedata;
+
+    size_t header_bytes = sizeof(struct syscall_header) + header->pathlen * 2;
+    int bytes_left = messagelen - header_bytes;
+    kprintf("syscall: Payload %p len %i\n", messagedata, header->pathlen);
+    if(bytes_left < 0) {
+        //Target path exceeds message length.
+        kprintf("syscall: Process %i tried to call syscall with OOB target path.\n", pcb_pid(pcb));
+        SYSCALL_MIDWAY_CLEANUP;
+        return EBADPATH;
+    }
+    jove_owned_obj_t *target = objdir_getobj(objdir, header->path, header->pathlen);
+    if(target == 0) {
+        //Could not find payload target in pcb rootdir.
+        kprintf("syscall: Process %i tried to call syscall with bad target path %P\n", 
+                pcb_pid(pcb), header->path, header->pathlen);
+        SYSCALL_MIDWAY_CLEANUP;
+        return errno;
+    }
+    int sysret = 0;
+
+    uint8_t target_type = obj_gettype(target);
+    if(target_type > 0x7F) {
+        sysret = syscall_handle_arch(pcb_obj, objdir, message_obj, target,
+                header, bytes_left, messagedata + header_bytes);
+    }else{
+        syscall_handle_t call_handle = s_syscall_handles[obj_gettype(target)];
+        if(call_handle == NULL) {
+            kprintf("syscall: Process %i tried to call syscall on object %P which doesn't support syscalls!\n",
+                    pcb_pid(pcb), header->path, header->pathlen);
+            sysret = EBADOBJ;
+        }else 
+            sysret = call_handle(pcb_obj, objdir, message_obj, target, 
+                header, bytes_left, message_data + header_bytes);
+    }
+
+    obj_release(target);
+    SYSCALL_MIDWAY_CLEANUP;
+    return sysret;
+}