refactor: split transfer and protocol responsibilities

src/shared/multiprocessing.c

@@ -1,4 +1,5 @@
 #include "multiprocessing.h"
+#include "receiver.h"
 
 #include "array_list.h"
 #include "chunk.h"
@@ -14,10 +15,6 @@
 #include <string.h>
 #include <threads.h>
 
-static bool valid_batch_path(const char* path) {
-  return path && path[0] != '\0' && path[0] != '/' && !has_path_traversal(path);
-}
-
 PipelineContextSender* pipeline_context_sender_create(Config* config, Queue* queue_scanner,
                                                       Queue* queue_loader) {
   PipelineContextSender* context = malloc(sizeof(PipelineContextSender));
@@ -101,6 +98,8 @@ PipelineContextReceiver* pipeline_context_receiver_create(Config* config, Queue*
   context->queue = queue;
   context->file_descriptor = file_descriptor;
   context->ssl = ssl;
+  protocol_session_init(&context->session, file_descriptor, file_descriptor);
+  protocol_session_set_ssl(&context->session, ssl);
   context->receiver_done = false;
   atomic_init(&context->cancelled, false);
   int init = 0;
@@ -137,24 +136,14 @@ void pipeline_context_receiver_destroy(PipelineContextReceiver* context) {
   free(context);
 }
 
-static bool receive_chunk_enqueue(int file_descriptor, PipelineContextReceiver* context) {
-  Chunk* chunk = receive_chunk_data(file_descriptor, context->config);
-  if (chunk == NULL)
-    return false;
-
-  for (int i = 0; i < chunk->element_count; i++) {
-    File* file = chunk->items[i];
-    chunk->items[i] = NULL;
-    if (!queue_enqueue_multithreaded_cancel(context->queue, file, &context->mutex,
-                                            &context->condition_not_empty,
-                                            &context->condition_not_full, &context->cancelled)) {
-      file_destroy(file);
-      chunk_destroy(chunk);
-      return false;
-    }
-  }
-  chunk_destroy(chunk);
-  return true;
+static bool receiver_enqueue_file(File* file, void* context_pointer) {
+  PipelineContextReceiver* context = context_pointer;
+  if (queue_enqueue_multithreaded_cancel(context->queue, file, &context->mutex,
+                                         &context->condition_not_empty,
+                                         &context->condition_not_full, &context->cancelled))
+    return true;
+  file_destroy(file);
+  return false;
 }
 
 static void receiver_thread_fail(PipelineContextReceiver* context) {
@@ -167,119 +156,29 @@ static void receiver_thread_fail(PipelineContextReceiver* context) {
 }
 
 int receive_thread(void* pipeline_context) {
-#define RECEIVE_THREAD_FAIL()                                                                      \
-  do {                                                                                             \
-    receiver_thread_fail(context);                                                                 \
-    return thrd_error;                                                                             \
-  } while (0)
   PipelineContextReceiver* context = (PipelineContextReceiver*)pipeline_context;
-  if (context->ssl)
-    io_set_ssl(context->ssl);
+  protocol_session_bind(&context->session);
   mtx_lock(&context->mutex);
   int file_descriptor = context->file_descriptor;
   const Config* config = context->config;
   mtx_unlock(&context->mutex);
 
-  Status status;
-  if (!receive_status(file_descriptor, &status))
-    RECEIVE_THREAD_FAIL();
-  while (status == STATUS_NEXT || status == STATUS_CHUNK || status == STATUS_CHECK ||
-         status == STATUS_KEEPALIVE || status == STATUS_ABORT || status == STATUS_CHECK_BATCH) {
-    if (status == STATUS_KEEPALIVE) {
-      if (!send_status(file_descriptor, STATUS_KEEPALIVE))
-        RECEIVE_THREAD_FAIL();
-      goto next;
-    }
-    if (status == STATUS_ABORT) {
-      log_message(LOG_LEVEL_INFO, "Received abort from client, cleaning up");
-      RECEIVE_THREAD_FAIL();
-    }
-    if (status == STATUS_CHECK) {
-      bool skipped;
-      File* file = receive_incremental_check(file_descriptor, config, &skipped);
-      if (!skipped) {
-        if (file == NULL)
-          RECEIVE_THREAD_FAIL();
-        if (!queue_enqueue_multithreaded_cancel(
-                context->queue, file, &context->mutex, &context->condition_not_empty,
-                &context->condition_not_full, &context->cancelled)) {
-          file_destroy(file);
-          RECEIVE_THREAD_FAIL();
-        }
-      }
-    } else if (status == STATUS_CHUNK) {
-      if (!receive_chunk_enqueue(file_descriptor, context))
-        RECEIVE_THREAD_FAIL();
-    } else if (status == STATUS_CHECK_BATCH) {
-      int count;
-      if (config->checksum || !receive_int(file_descriptor, &count) || count < 0 ||
-          count > MAX_MANIFEST_ENTRIES)
-        RECEIVE_THREAD_FAIL();
-      for (int i = 0; i < count; i++) {
-        char* check_path = receive_str(file_descriptor);
-        if (!check_path)
-          RECEIVE_THREAD_FAIL();
-        unsigned long long check_size;
-        long long check_mtime;
-        if (!receive_n_data(file_descriptor, &check_size, sizeof(check_size)) ||
-            !receive_n_data(file_descriptor, &check_mtime, sizeof(check_mtime))) {
-          free(check_path);
-          RECEIVE_THREAD_FAIL();
-        }
-        if (!valid_batch_path(check_path)) {
-          free(check_path);
-          if (!send_status(file_descriptor, STATUS_ERROR))
-            RECEIVE_THREAD_FAIL();
-          RECEIVE_THREAD_FAIL();
-        }
-        char* full_path = path_cat(config->receive_root_directory, check_path);
-        struct stat st;
-        bool has_old = full_path && lstat(full_path, &st) == 0;
-        bool match = has_old && (unsigned long long)st.st_size == check_size &&
-                     (long long)st.st_mtime == check_mtime;
-        if (!send_status(file_descriptor, match ? STATUS_OK : STATUS_NEXT))
-          RECEIVE_THREAD_FAIL();
-        free(full_path);
-        free(check_path);
-      }
-      goto next;
-    } else {
-      File* file = file_receive(config, file_descriptor);
-      if (file) {
-        if (!queue_enqueue_multithreaded_cancel(
-                context->queue, file, &context->mutex, &context->condition_not_empty,
-                &context->condition_not_full, &context->cancelled)) {
-          file_destroy(file);
-          receiver_thread_fail(context);
-          return thrd_error;
-        }
-      } else {
-        log_message(LOG_LEVEL_ERROR, "Failed to receive file");
-        RECEIVE_THREAD_FAIL();
-      }
-    }
-  next:
-    if (!receive_status(file_descriptor, &status))
-      RECEIVE_THREAD_FAIL();
+  ReceiverSink sink = {receiver_enqueue_file, context, false, false};
+  if (receiver_process((Config*)config, file_descriptor, &sink) != 0) {
+    receiver_thread_fail(context);
+    protocol_session_unbind();
+    return thrd_error;
   }
-  if (status == STATUS_MANIFEST) {
-    if (receive_manifest(file_descriptor, config, &status) != 0)
-      RECEIVE_THREAD_FAIL();
-  }
-  if (status != STATUS_FINISHED)
-    RECEIVE_THREAD_FAIL();
   mtx_lock(&context->mutex);
   context->receiver_done = true;
   cnd_signal(&context->condition_not_empty);
   mtx_unlock(&context->mutex);
-#undef RECEIVE_THREAD_FAIL
+  protocol_session_unbind();
   return thrd_success;
 }
 
 int write_thread(void* pipeline_context) {
   PipelineContextReceiver* context = (PipelineContextReceiver*)pipeline_context;
-  if (context->ssl)
-    io_set_ssl(context->ssl);
   mtx_lock(&context->mutex);
   bool save_to_disk = context->config->save_to_disk;
   char* root_directory = str_dup(context->config->receive_root_directory);