Changeset e8039a86 in mainline for kernel/generic/src/ipc/ops/dataread.c

Timestamp:

2012-08-20T23:21:41Z (12 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

0343a1b

Parents:

642dc72

Message:

Separate system IPC logic into dedicated ops structure hooks.

File:

• kernel/generic/src/ipc/ops/dataread.c (modified) (1 diff)

kernel/generic/src/ipc/ops/dataread.c

@@ -34 +34 @@
 
 #include <ipc/sysipc_ops.h>
+#include <ipc/ipc.h>
+#include <mm/slab.h>
+#include <abi/errno.h>
+#include <syscall/copy.h>
+#include <config.h>
+
+static int request_preprocess(call_t *call, phone_t *phone)
+{
+        size_t size = IPC_GET_ARG2(call->data);
+
+        if (size > DATA_XFER_LIMIT) {
+                int flags = IPC_GET_ARG3(call->data);
+
+                if (flags & IPC_XF_RESTRICT)
+                        IPC_SET_ARG2(call->data, DATA_XFER_LIMIT);
+                else
+                        return ELIMIT;
+        }
+
+        return EOK;
+}
+
+static int answer_preprocess(call_t *answer, ipc_data_t *olddata)
+{
+        ASSERT(!answer->buffer);
+
+        if (!IPC_GET_RETVAL(answer->data)) {
+                /* The recipient agreed to send data. */
+                uintptr_t src = IPC_GET_ARG1(answer->data);
+                uintptr_t dst = IPC_GET_ARG1(*olddata);
+                size_t max_size = IPC_GET_ARG2(*olddata);
+                size_t size = IPC_GET_ARG2(answer->data);
+                if (size && size <= max_size) {
+                        /*
+                         * Copy the destination VA so that this piece of
+                         * information is not lost.
+                         */
+                        IPC_SET_ARG1(answer->data, dst);
+                                
+                        answer->buffer = malloc(size, 0);
+                        int rc = copy_from_uspace(answer->buffer,
+                            (void *) src, size);
+                        if (rc) {
+                                IPC_SET_RETVAL(answer->data, rc);
+                                free(answer->buffer);
+                                answer->buffer = NULL;
+                        }
+                } else if (!size) {
+                        IPC_SET_RETVAL(answer->data, EOK);
+                } else {
+                        IPC_SET_RETVAL(answer->data, ELIMIT);
+                }
+        }
+
+        return EOK;
+}
 
 sysipc_ops_t ipc_m_data_read_ops = {
-        .request_preprocess = null_request_preprocess,
+        .request_preprocess = request_preprocess,
         .request_process = null_request_process,
-        .answer_preprocess = null_answer_preprocess,
+        .answer_preprocess = answer_preprocess,
         .answer_process = null_answer_process,
 };