Fix ipc to support null pointer.

Ubiquitous/XiZi_AIoT/services/app/Makefile

@@ -27,7 +27,7 @@ INC_DIR = 	-I$(KERNEL_ROOT)/services/shell/letter-shell \
 			-I$(KERNEL_ROOT)/services/app 
 
 ifeq ($(BOARD), imx6q-sabrelite)
-all: init test_fault simple_client simple_server shell fs_server semaphore_server test_thread test_irq_hdlr test_irq_block test_irq_send eth_driver epit_server readme.txt | bin
+all: init test_fault simple_client simple_server shell fs_server semaphore_server test_ipc_null test_thread test_irq_hdlr test_irq_block test_irq_send eth_driver epit_server readme.txt | bin
 else 
 all: init test_fault simple_client simple_server shell fs_server test_irq_hdlr readme.txt | bin
 endif
@@ -53,6 +53,10 @@ epit_server: timer.o epit.o ccm_pll.o usyscall.o arch_usyscall.o libserial.o pri
 	@${objdump} -S $@ > $@.asm
 endif
 
+test_ipc_null: test_ipc_null.o libserial.o printf.o usyscall.o arch_usyscall.o libipc.o session.o
+	@${ld} ${user_ldflags} -e main -o $@ $^ ${board_specs}
+	@${objdump} -S $@ > $@.asm
+
 semaphore_server: semaphore_server.o libserial.o printf.o usyscall.o arch_usyscall.o libipc.o session.o
 	@${ld} ${user_ldflags} -e main -o $@ $^ ${board_specs}
 	@${objdump} -S $@ > $@.asm

Ubiquitous/XiZi_AIoT/services/app/test_ipc_null.c

@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2020 AIIT XUOS Lab
+ * XiUOS is licensed under Mulan PSL v2.
+ * You can use this software according to the terms and conditions of the Mulan PSL v2.
+ * You may obtain a copy of Mulan PSL v2 at:
+ *        http://license.coscl.org.cn/MulanPSL2
+ * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+ * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+ * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+ * See the Mulan PSL v2 for more details.
+ */
+#include <stdbool.h>
+#include <string.h>
+
+#include "libipc.h"
+#include "libserial.h"
+#include "usyscall.h"
+
+IPC_SERVICES(IpcTestNull, Ipc_test_null);
+#define TEST_BUF_SIZE 32
+
+static char test_null_server_name[] = "TestNullServer";
+static char test_null_client_name[] = "TestNullClient";
+
+// client side
+static char buf[TEST_BUF_SIZE];
+
+IPC_INTERFACE(Ipc_test_null, 1, ptr, sizeof(buf));
+int test_null(struct Session* session, char* ptr)
+{
+    return IPC_CALL(Ipc_test_null)(session, ptr);
+}
+
+// client thread
+int server_thread(int argc, char** argv);
+int main(int argc, char** argv)
+{
+    struct Session session;
+    bool server_enabled = false;
+    while (connect_session(&session, test_null_server_name, 4096) < 0) {
+        if (!server_enabled) {
+            char* server_param[] = { test_null_server_name, NULL };
+            if (thread(server_thread, test_null_server_name, server_param) >= 0) {
+                server_enabled = true;
+            }
+        }
+    }
+
+    printf("[%s] Call using NULL ptr.\n", test_null_client_name);
+    test_null(&session, NULL);
+    printf("[%s] Call using non-NULL ptr.\n", test_null_client_name);
+    test_null(&session, buf);
+
+    exit(0);
+    return 0;
+}
+
+// server side
+int IPC_DO_SERVE_FUNC(Ipc_test_null)(void* ptr)
+{
+    if (ptr == NULL) {
+        printf("[%s]: A NULL ptr ipc call.\n", test_null_server_name);
+    } else {
+        printf("[%s]: A non-NULL ptr ipc call.\n", test_null_server_name);
+    }
+
+    return 0;
+}
+
+IPC_SERVER_INTERFACE(Ipc_test_null, 1);
+IPC_SERVER_REGISTER_INTERFACES(IpcTestNull, 1, Ipc_test_null);
+
+// server threads
+int server_thread(int argc, char** argv)
+{
+    if (register_server(test_null_server_name) < 0) {
+        printf("[%s] Register %s server failed.\n", test_null_server_name, test_null_server_name);
+        exit(1);
+        return 1;
+    }
+    ipc_server_loop(&IpcTestNull);
+
+    exit(0);
+    return 0;
+}

Ubiquitous/XiZi_AIoT/services/lib/ipc/libipc.c

@@ -83,11 +83,22 @@ bool ipc_msg_set_nth_arg(struct IpcMsg* msg, const int arg_num, const void* cons
         return false;
     }
     struct IpcArgInfo* nth_arg_info = IPCMSG_ARG_INFO(msg, arg_num);
-    if (len > nth_arg_info->len) {
+    if (len < 0 || (uint32_t)len > (uint32_t)nth_arg_info->len) {
         printf("[%s] IPC: size of arg out of buffer range, given len: %d, len %u\n", __func__, len, nth_arg_info->len);
         return false;
     }
+
     void* buf = ipc_msg_get_nth_arg_buf(msg, arg_num);
+
+    // handle attributes of different params
+    if (data == NULL) {
+        nth_arg_info->null_ptr = 1;
+        memset(buf, 0x0, len);
+        return true;
+    } else {
+        nth_arg_info->null_ptr = 0;
+    }
+
     memmove(buf, data, len);
     return true;
 }
@@ -109,6 +120,12 @@ bool ipc_msg_get_nth_arg(struct IpcMsg* msg, const int arg_num, void* data, cons
         printf("[%s] IPC: size of arg out of buffer range", __func__);
         return false;
     }
+
+    // handle null ptr: do nothing
+    if (nth_arg_info->null_ptr == 1) {
+        return true;
+    }
+
     void* buf = ipc_msg_get_nth_arg_buf(msg, arg_num);
     memmove(data, buf, len);
     return true;

Ubiquitous/XiZi_AIoT/services/lib/ipc/libipc.h

@@ -60,6 +60,13 @@ typedef struct {
 struct IpcArgInfo {
     uint16_t offset;
     uint16_t len;
+    union {
+        uint16_t attr;
+        struct {
+            uint16_t null_ptr : 1;
+            uint16_t reserved : 15;
+        };
+    };
 } __attribute__((packed));
 
 /* [header, ipc_arg_buffer_len[], ipc_arg_buffer[]] */
@@ -104,6 +111,10 @@ struct IpcNode {
 /// @return
 __attribute__((__always_inline__)) static inline void* ipc_msg_get_nth_arg_buf(struct IpcMsg* msg, int arg_num)
 {
+    if (IPCMSG_ARG_INFO(msg, arg_num)->null_ptr == 1) {
+        return NULL;
+    }
+
     return (void*)((char*)msg + IPCMSG_ARG_INFO(msg, arg_num)->offset);
 }