lib: add orch_ipc_msg_payload() to peel off the payload

This is a little bit cleaner, requires less knowledge about message structure. Fixes #10 Signed-off-by: Kyle Evans <[email protected]>
kevans91 · Jan 28, 2024 · e56af70 · e56af70
1 parent 4c757e4
commit e56af70
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Showing 4 changed files with 29 additions and 9 deletions.
diff --git a/lib/core/orch_ipc.c b/lib/core/orch_ipc.c
@@ -127,6 +127,22 @@ orch_ipc_msg_alloc(enum orch_ipc_tag tag, size_t payloadsz, void **payload)
 	return (msg);
 }
 
+void *
+orch_ipc_msg_payload(struct orch_ipc_msg *msg, size_t *odatasz)
+{
+	size_t datasz = msg->hdr.size - sizeof(msg->hdr);
+
+	/*
+	 * orch_ipc_drain() should have rejected negative payload indications.
+	 */
+	assert(datasz >= 0);
+	if (odatasz != NULL)
+		*odatasz = datasz;
+	if (datasz == 0)
+		return (NULL);
+	return (msg + 1);
+}
+
 void
 orch_ipc_msg_free(struct orch_ipc_msg *msg)
 {

diff --git a/lib/core/orch_lua.c b/lib/core/orch_lua.c
@@ -267,9 +267,12 @@ orchlua_child_error(orch_ipc_t ipc __unused, struct orch_ipc_msg *msg,
     void *cookie)
 {
 	struct orch_process *proc = cookie;
+	const char *childstr;
+	size_t datasz;
 
-	fprintf(stderr, "CHILD ERROR: %.*s\n",
-	    (int)(msg->hdr.size - sizeof(msg->hdr)), msg->data);
+	childstr = orch_ipc_msg_payload(msg, &datasz);
+	if (datasz != 0)
+		fprintf(stderr, "CHILD ERROR: %.*s\n", (int)datasz, childstr);
 	proc->error = true;
 	return (0);
 }
@@ -751,11 +754,12 @@ orchlua_process_term_set(orch_ipc_t ipc __unused, struct orch_ipc_msg *msg,
     void *cookie)
 {
 	struct orch_term *term = cookie;
+	struct termios *child_termios;
 	struct termios *parent_termios = &term->term;
-	struct termios *child_termios = (void *)(msg + 1);
-	size_t datasz = msg->hdr.size - sizeof(msg->hdr);
+	size_t datasz;
 
-	if (datasz != sizeof(*child_termios)) {
+	child_termios = orch_ipc_msg_payload(msg, &datasz);
+	if (child_termios == NULL || datasz != sizeof(*child_termios)) {
 		errno = EINVAL;
 		return (-1);
 	}

diff --git a/lib/core/orch_spawn.c b/lib/core/orch_spawn.c
@@ -244,15 +244,14 @@ orch_child_termios_set(orch_ipc_t ipc, struct orch_ipc_msg *msg, void *cookie)
 	struct orch_ipc_msg ack = {
 		.hdr = { .size = sizeof(ack), .tag = IPC_TERMIOS_ACK }
 	};
-	size_t datasz = msg->hdr.size - sizeof(msg->hdr);
+	size_t datasz;
 
-	if (datasz != sizeof(*updated_termios)) {
+	updated_termios = orch_ipc_msg_payload(msg, &datasz);
+	if (updated_termios == NULL || datasz != sizeof(*updated_termios)) {
 		errno = EINVAL;
 		return (-1);
 	}
 
-	updated_termios = (void *)(msg + 1);
-
 	/*
 	 * We don't need to keep track of the updated state, but we do so
 	 * anyways.

diff --git a/lib/orch_lib.h b/lib/orch_lib.h
@@ -88,6 +88,7 @@ orch_ipc_t orch_ipc_open(int);
 bool orch_ipc_okay(orch_ipc_t);
 int orch_ipc_recv(orch_ipc_t, struct orch_ipc_msg **);
 struct orch_ipc_msg *orch_ipc_msg_alloc(enum orch_ipc_tag, size_t, void **);
+void *orch_ipc_msg_payload(struct orch_ipc_msg *, size_t *);
 void orch_ipc_msg_free(struct orch_ipc_msg *);
 int orch_ipc_register(orch_ipc_t, enum orch_ipc_tag, orch_ipc_handler *, void *);
 int orch_ipc_send(orch_ipc_t, struct orch_ipc_msg *);