port: add function for checking and reading port messages

Remove duplicate code and add checks. Signed-off-by: Davide Bettio <davide@uninstall.it>
atomvm · Dec 25, 2023 · 76d4f8c · 76d4f8c
1 parent 273513f
commit 76d4f8c
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Showing 12 changed files with 221 additions and 143 deletions.
diff --git a/doc/src/apidocs/libatomvm/functions.rst b/doc/src/apidocs/libatomvm/functions.rst
@@ -140,7 +140,6 @@ Functions
 .. doxygenfunction:: port_heap_create_tuple2
 .. doxygenfunction:: port_heap_create_tuple3
 .. doxygenfunction:: port_heap_create_tuple_n
-.. doxygenfunction:: port_is_standard_port_command
 .. doxygenfunction:: port_send_message
 .. doxygenfunction:: port_send_message_nolock
 .. doxygenfunction:: posix_errno_to_term

diff --git a/src/libAtomVM/nifs.c b/src/libAtomVM/nifs.c
@@ -1000,6 +1000,8 @@ static NativeHandlerResult process_console_message(Context *ctx, term msg)
         AVM_ABORT();
     }
 
+    GenMessage gen_message;
+
     if (term_is_tuple(msg) && term_get_tuple_arity(msg) == 2 && term_get_tuple_element(msg, 1) == CLOSE_ATOM) {
         result = NativeTerminate;
         term pid = term_get_tuple_element(msg, 0);
@@ -1032,11 +1034,10 @@ static NativeHandlerResult process_console_message(Context *ctx, term msg)
             }
         }
 
-    } else if (port_is_standard_port_command(msg)) {
-
-        term pid = term_get_tuple_element(msg, 0);
-        term ref = term_get_tuple_element(msg, 1);
-        term cmd = term_get_tuple_element(msg, 2);
+    } else if (port_parse_gen_message(msg, &gen_message) == GenMessageParseOk) {
+        term pid = gen_message.pid;
+        term ref = gen_message.ref;
+        term cmd = gen_message.req;
 
         if (term_is_atom(cmd) && cmd == FLUSH_ATOM) {
             fflush(stdout);

diff --git a/src/libAtomVM/port.c b/src/libAtomVM/port.c
@@ -54,25 +54,6 @@ void port_ensure_available(Context *ctx, size_t size)
     }
 }
 
-int port_is_standard_port_command(term t)
-{
-    if (!term_is_tuple(t)) {
-        return 0;
-    } else if (term_get_tuple_arity(t) != 3) {
-        return 0;
-    } else {
-        term pid = term_get_tuple_element(t, 0);
-        term ref = term_get_tuple_element(t, 1);
-        if (!term_is_pid(pid)) {
-            return 0;
-        } else if (!term_is_reference(ref)) {
-            return 0;
-        } else {
-            return 1;
-        }
-    }
-}
-
 term port_heap_create_tuple2(Heap *heap, term a, term b)
 {
     term terms[2];
@@ -123,3 +104,24 @@ term port_heap_create_reply(Heap *heap, term ref, term payload)
 {
     return port_heap_create_tuple2(heap, ref, payload);
 }
+
+enum GenMessageParseResult port_parse_gen_message(term msg, GenMessage *gen_message)
+{
+    if (UNLIKELY(!term_is_tuple(msg) || term_get_tuple_arity(msg) != 3)) {
+        return GenMessageParseError;
+    }
+
+    gen_message->pid = term_get_tuple_element(msg, 0);
+    if (UNLIKELY(!term_is_pid(gen_message->pid))) {
+        return GenMessageParseError;
+    }
+
+    gen_message->ref = term_get_tuple_element(msg, 1);
+    if (UNLIKELY(!term_is_reference(gen_message->ref))) {
+        return GenMessageParseError;
+    }
+
+    gen_message->req = term_get_tuple_element(msg, 2);
+
+    return GenMessageParseOk;
+}
diff --git a/src/libAtomVM/port.h b/src/libAtomVM/port.h
@@ -74,7 +74,6 @@ static inline term port_create_reply(Context *ctx, term ref, term payload)
 void port_send_message(GlobalContext *glb, term pid, term msg);
 void port_send_message_nolock(GlobalContext *glb, term pid, term msg);
 void port_ensure_available(Context *ctx, size_t size);
-int port_is_standard_port_command(term msg);
 
 // Helper to send a message from NIFs or from the native handler.
 static inline void port_send_reply(Context *ctx, term pid, term ref, term payload)
@@ -83,6 +82,23 @@ static inline void port_send_reply(Context *ctx, term pid, term ref, term payloa
     port_send_message(ctx->global, pid, reply);
 }
 
+typedef struct
+{
+    term from;
+    term req;
+
+    term pid;
+    term ref;
+} GenMessage;
+
+enum GenMessageParseResult
+{
+    GenMessageParseOk,
+    GenMessageParseError
+};
+
+enum GenMessageParseResult port_parse_gen_message(term msg, GenMessage *gen_message);
+
 #ifdef __cplusplus
 }
 #endif

diff --git a/src/platforms/esp32/components/avm_builtins/gpio_driver.c b/src/platforms/esp32/components/avm_builtins/gpio_driver.c
@@ -40,6 +40,7 @@
 #include "module.h"
 #include "nifs.h"
 #include "platform_defaultatoms.h"
+#include "port.h"
 #include "scheduler.h"
 #include "term.h"
 #include "utils.h"
@@ -477,35 +478,39 @@ static term create_pair(Context *ctx, term term1, term term2)
 static NativeHandlerResult consume_gpio_mailbox(Context *ctx)
 {
     Message *message = mailbox_first(&ctx->mailbox);
-    term msg = message->message;
-    term pid = term_get_tuple_element(msg, 0);
-    term req = term_get_tuple_element(msg, 2);
-    term cmd_term = term_get_tuple_element(req, 0);
+    GenMessage gen_message;
+    if (UNLIKELY(port_parse_gen_message(message->message, &gen_message) != GenMessageParseOk)) {
+        ESP_LOGW(TAG, "Received invalid message.");
+        mailbox_remove_message(&ctx->mailbox, &ctx->heap);
+        return NativeContinue;
+    }
+
+    term cmd_term = term_get_tuple_element(gen_message.req, 0);
 
-    int local_process_id = term_to_local_process_id(pid);
+    int local_process_id = term_to_local_process_id(gen_message.pid);
 
     term ret;
 
     enum gpio_cmd cmd = interop_atom_term_select_int(gpio_cmd_table, cmd_term, ctx->global);
     switch (cmd) {
         case GPIOSetLevelCmd:
-            ret = gpiodriver_set_level(ctx, req);
+            ret = gpiodriver_set_level(ctx, gen_message.req);
             break;
 
         case GPIOSetDirectionCmd:
-            ret = gpiodriver_set_direction(ctx, req);
+            ret = gpiodriver_set_direction(ctx, gen_message.req);
             break;
 
         case GPIOReadCmd:
-            ret = gpiodriver_read(req);
+            ret = gpiodriver_read(gen_message.req);
             break;
 
         case GPIOSetIntCmd:
-            ret = gpiodriver_set_int(ctx, local_process_id, req);
+            ret = gpiodriver_set_int(ctx, local_process_id, gen_message.req);
             break;
 
         case GPIORemoveIntCmd:
-            ret = gpiodriver_remove_int(ctx, req);
+            ret = gpiodriver_remove_int(ctx, gen_message.req);
             break;
 
         case GPIOCloseCmd:
@@ -521,8 +526,7 @@ static NativeHandlerResult consume_gpio_mailbox(Context *ctx)
     if (UNLIKELY(memory_ensure_free_with_roots(ctx, 3, 1, &ret, MEMORY_CAN_SHRINK) != MEMORY_GC_OK)) {
         ret_msg = OUT_OF_MEMORY_ATOM;
     } else {
-        term ref = term_get_tuple_element(msg, 1);
-        ret_msg = create_pair(ctx, ref, ret);
+        ret_msg = create_pair(ctx, gen_message.ref, ret);
     }
 
     globalcontext_send_message(ctx->global, local_process_id, ret_msg);

diff --git a/src/platforms/esp32/components/avm_builtins/i2c_driver.c b/src/platforms/esp32/components/avm_builtins/i2c_driver.c
@@ -546,45 +546,48 @@ static term create_pair(Context *ctx, term term1, term term2)
 static NativeHandlerResult i2cdriver_consume_mailbox(Context *ctx)
 {
     Message *message = mailbox_first(&ctx->mailbox);
-    term msg = message->message;
-    term pid = term_get_tuple_element(msg, 0);
-    term req = term_get_tuple_element(msg, 2);
+    GenMessage gen_message;
+    if (UNLIKELY(port_parse_gen_message(message->message, &gen_message) != GenMessageParseOk)) {
+        ESP_LOGW(TAG, "Received invalid message.");
+        mailbox_remove_message(&ctx->mailbox, &ctx->heap);
+        return NativeContinue;
+    }
 
 #ifdef ENABLE_TRACE
     TRACE("message: ");
     term_display(stdout, msg, ctx);
     TRACE("\n");
 #endif
 
-    term cmd_term = term_get_tuple_element(req, 0);
+    term cmd_term = term_get_tuple_element(gen_message.req, 0);
 
-    int local_process_id = term_to_local_process_id(pid);
+    int local_process_id = term_to_local_process_id(gen_message.pid);
 
     term ret;
 
     enum i2c_cmd cmd = interop_atom_term_select_int(cmd_table, cmd_term, ctx->global);
     switch (cmd) {
         case I2CBeginTransmissionCmd:
-            ret = i2cdriver_begin_transmission(ctx, pid, req);
+            ret = i2cdriver_begin_transmission(ctx, gen_message.pid, gen_message.req);
             break;
 
         case I2CEndTransmissionCmd:
-            ret = i2cdriver_end_transmission(ctx, pid);
+            ret = i2cdriver_end_transmission(ctx, gen_message.pid);
             break;
 
         case I2CWriteByteCmd:
-            ret = i2cdriver_write_byte(ctx, pid, req);
+            ret = i2cdriver_write_byte(ctx, gen_message.pid, gen_message.req);
             break;
 
         case I2CReadBytesCmd:
-            ret = i2cdriver_read_bytes(ctx, pid, req);
+            ret = i2cdriver_read_bytes(ctx, gen_message.pid, gen_message.req);
             break;
 
         case I2CWriteBytesCmd:
-            if (term_get_tuple_arity(req) == 2) {
-                ret = i2cdriver_qwrite_bytes(ctx, pid, req);
+            if (term_get_tuple_arity(gen_message.req) == 2) {
+                ret = i2cdriver_qwrite_bytes(ctx, gen_message.pid, gen_message.req);
             } else {
-                ret = i2cdriver_write_bytes(ctx, pid, req);
+                ret = i2cdriver_write_bytes(ctx, gen_message.pid, gen_message.req);
             }
             break;
         case I2CCloseCmd:
@@ -601,8 +604,7 @@ static NativeHandlerResult i2cdriver_consume_mailbox(Context *ctx)
     if (UNLIKELY(memory_ensure_free_with_roots(ctx, 3, 1, &ret, MEMORY_CAN_SHRINK) != MEMORY_GC_OK)) {
         ret_msg = OUT_OF_MEMORY_ATOM;
     } else {
-        term ref = term_get_tuple_element(msg, 1);
-        ret_msg = create_pair(ctx, ref, ret);
+        ret_msg = create_pair(ctx, gen_message.ref, ret);
     }
 
     globalcontext_send_message(ctx->global, local_process_id, ret_msg);

diff --git a/src/platforms/esp32/components/avm_builtins/network_driver.c b/src/platforms/esp32/components/avm_builtins/network_driver.c
@@ -761,6 +761,7 @@ static NativeHandlerResult consume_mailbox(Context *ctx)
         return NativeContinue;
     }
 
+    //TODO: port this code to standard port (and gen_message)
     term pid = term_get_tuple_element(msg, 0);
     term ref = term_get_tuple_element(msg, 1);
     term cmd = term_get_tuple_element(msg, 2);