ipc: fix aligment issue of data buffer

The pointer `data` is cast to a more strictly aligned pointer type. To
prevent issues, the `data32` buffer is removed and its occurrences are
replaced with an offset from the `data` buffer.

1 files changed, 4 insertions, 6 deletions

diff --git a/sway/ipc-server.c b/sway/ipc-server.c
index 62bdccb8..8ba8b9ba 100644
--- a/sway/ipc-server.c
+++ b/sway/ipc-server.c
@@ -242,7 +242,6 @@ int ipc_client_handle_readable(int client_fd, uint32_t mask, void *data) {
         }
 
         uint8_t buf[IPC_HEADER_SIZE];
-        uint32_t *buf32 = (uint32_t*)(buf + sizeof(ipc_magic));
         // Should be fully available, because read_available >= IPC_HEADER_SIZE
         ssize_t received = recv(client_fd, buf, IPC_HEADER_SIZE, 0);
         if (received == -1) {
@@ -257,8 +256,8 @@ int ipc_client_handle_readable(int client_fd, uint32_t mask, void *data) {
                 return 0;
         }
 
-        memcpy(&client->pending_length, &buf32[0], sizeof(buf32[0]));
-        memcpy(&client->pending_type, &buf32[1], sizeof(buf32[1]));
+        memcpy(&client->pending_length, buf + sizeof(ipc_magic), sizeof(uint32_t));
+        memcpy(&client->pending_type, buf + sizeof(ipc_magic) + sizeof(uint32_t), sizeof(uint32_t));
 
         if (read_available - received >= (long)client->pending_length) {
                 // Reset pending values.
@@ -920,11 +919,10 @@ bool ipc_send_reply(struct ipc_client *client, enum ipc_command_type payload_typ
         assert(payload);
 
         char data[IPC_HEADER_SIZE];
-        uint32_t *data32 = (uint32_t*)(data + sizeof(ipc_magic));
 
         memcpy(data, ipc_magic, sizeof(ipc_magic));
-        memcpy(&data32[0], &payload_length, sizeof(payload_length));
-        memcpy(&data32[1], &payload_type, sizeof(payload_type));
+        memcpy(data + sizeof(ipc_magic), &payload_length, sizeof(payload_length));
+        memcpy(data + sizeof(ipc_magic) + sizeof(payload_length), &payload_type, sizeof(payload_type));
 
         while (client->write_buffer_len + IPC_HEADER_SIZE + payload_length >=
                                  client->write_buffer_size) {