1 files changed, 93 insertions, 2 deletions

diff --git a/sys/syscall_pagedir.c b/sys/syscall_pagedir.c
index 6e773bf..2b81dfa 100644
--- a/sys/syscall_pagedir.c
+++ b/sys/syscall_pagedir.c
@@ -1,3 +1,4 @@
+#include "api/memory.h"
 #include "api/syscall.h"
 #include "hal/memory.h"
 #include "jove.h"
@@ -58,6 +59,86 @@ s_syscall_pagedir_get_untyped(
 }
 
 static int
+s_syscall_pagedir_get_mapping(
+        jove_owned_obj_t *pagedir,
+        size_t bytes_left,
+        void *payload_data)
+{
+    size_t bytes_needed = sizeof(struct pagedir_mapping);
+    CHECK_TOOSMALL(bytes_needed, bytes_left, "Message too small for payload");
+
+    virtaddr_t vptr = *((virtaddr_t*)payload_data);
+    if(vptr > JOVE_USERMEMORY_LIMIT) {
+        klogf("Virtual address %p is out of bounds!\n", vptr);
+        return -EOOB;
+    }
+
+    virtaddr_t *mapping = pagedir_get_mapping(pagedir, vptr);
+    if(mapping == NULL) return -errno;
+
+    struct pagedir_mapping *payload = payload_data;
+
+    payload->pfn = pagedir_mapping_get_pfn(mapping);
+    payload->flags.present = pagedir_mapping_is_present(mapping);
+    payload->flags.writeable = pagedir_mapping_is_writeable(mapping);
+    payload->flags.executable = pagedir_mapping_is_executable(mapping);
+    return 0;
+}
+
+static int
+s_syscall_pagedir_transfer(
+        lockstack_t *lockstack,
+        jove_obj_t *rootdir,
+        jove_owned_obj_t *pagedir,
+        size_t bytes_left,
+        void *payload_data)
+{
+    //Verify the message is big enough for the payload.
+    size_t bytes_needed = sizeof(struct syscall_pagedir_transfer);
+    CHECK_TOOSMALL(bytes_needed, bytes_left, "Message too small for payload");
+
+    //Verify the payload is big enough for the target path.
+    struct syscall_pagedir_transfer *payload = payload_data;
+    bytes_needed += sizeof(objpath_part_t) * payload->target_path_length;
+    CHECK_TOOSMALL(bytes_needed, bytes_left, "Message too small for target path");
+
+    //Verify the target object is a pagedir with the correct permissions.
+    jove_perm_obj_t target = link_traverse_objdir(rootdir, payload->target_path_length, payload->target_path);
+    CHECK_OBJEXISTS(target.obj, "Target path does not point to a valid object");
+    lockstack_push(lockstack, target.obj);
+
+    CHECK_OBJTYPE(target.obj, JOVE_OBJ_PAGEDIR, "Target object is not a JOVE_OBJ_PAGEDIR");
+    CHECK_OBJPERM(target, SYSCALL_PERM_PAGEDIR_TRANSFER_TGT, "Not allowed to transfer to target");
+
+    //Verify subject has a mapping at the given address.
+    virtaddr_t *subject_mapping = pagedir_get_mapping(pagedir, payload->subject_address);
+    if(subject_mapping == NULL) {
+        klogf("Subject page directory does not have tables for %p\n", payload->subject_address);
+        return -errno;
+    }
+
+    //Verify target has a mapping at the given address.
+    virtaddr_t *target_mapping = pagedir_get_mapping(target.obj, payload->target_address);
+    if(target_mapping == NULL) {
+        klogf("Target page directory does not have tables for %p\n", payload->target_address);
+        return -errno;
+    }
+
+    //Verify target mapping is not marked present.
+    if(pagedir_mapping_is_present(target_mapping)) {
+        klogf("Target page at %p is marked as present\n", payload->target_address);
+        return -EBUSY;
+    }
+
+    //Move the mapping over and return.
+    *target_mapping = *subject_mapping;
+    *subject_mapping = 0;
+
+    pagedir_invlpg(payload->subject_address);
+    return 0;
+}
+
+static int
 s_syscall_pagedir_unmap(
         lockstack_t *lockstack,
         jove_obj_t *objdir,
@@ -111,7 +192,7 @@ s_syscall_pagedir_map_frame(
     }
 
     struct syscall_pagedir_map *payload = payload_data;
-    sysret = pagedir_map_untyped_frame(pagedir, &untyped, payload->virtual_address, payload->page_flags);
+    sysret = pagedir_map_untyped_frame(pagedir, &untyped, payload->virtual_address, payload->flags);
 
     if(sysret == 0)
         obj_settype(untyped.obj, JOVE_OBJ_NONE);
@@ -186,7 +267,7 @@ s_syscall_pagedir_map_shmem(
     }
 
     return pagedir_map_shmem_frame(pagedir, &shmem, payload->page_offset, 
-            payload->virtual_address, payload->page_flags);
+            payload->virtual_address, payload->flags);
 }
 
 static int
@@ -234,6 +315,16 @@ _syscall_handle_pagedir(syscall_context_t *ctx)
     void *payload = ctx->payload;
 
     switch(header->callid) {
+        case SYSCALL_PAGEDIR_GET_MAPPING:
+            if(target->permissions & SYSCALL_PERM_PAGEDIR_GET_MAPPING)
+                return s_syscall_pagedir_get_mapping(target->obj, bytes_left, payload);
+            return -EPERM;
+
+        case SYSCALL_PAGEDIR_TRANSFER:
+            if(target->permissions & SYSCALL_PERM_PAGEDIR_TRANSFER)
+                return s_syscall_pagedir_transfer(
+                        lockstack, objdir, target->obj, bytes_left, payload);
+
         case SYSCALL_PAGEDIR_MAP_FRAME:
             if(target->permissions & SYSCALL_PERM_PAGEDIR_MAP_FRAME)
                 return s_syscall_pagedir_map_frame(lockstack, objdir, target->obj, bytes_left, payload);