rsync flags: -a, -n, -p, --exclude, --delete

Feature changes across 15 files:

- -a/--archive: enables -c -m -M (no -s, which slows transfers)
- -n/--dry-run: scan + print without connecting or transferring
- -p <port>: custom SSH port (passed as -p to ssh via execvp)
- --exclude <pattern>: glob-based filename filtering in scanner
- --delete: sender collects file manifest; receiver deletes unlisted files

Protocol: added STATUS_MANIFEST, use_delete field in Config wire format.
New utilities: glob_match(), delete_extras() with recursive directory walk.
Scanner: accepts exclude patterns; skips matching entries.
SSH transport: switched from execlp to execvp for dynamic port arg.
Server + multiprocessing: handle STATUS_MANIFEST in both single and
multithreaded receive paths.

Builds clean, all 7 tests pass.

src/shared/config.c

@@ -23,11 +23,16 @@ Config *config_create(char *version, char *send_directory,
   config->use_compression = use_compression;
   config->use_metadata = use_metadata;
   config->show_progress = false;
+  config->dry_run = false;
+  config->use_delete = false;
   config->compression_level = compression_level;
   config->use_sendfile = use_sendfile;
   config->chunk_size = chunk_size > 0 ? chunk_size : DEFAULT_CHUNK_SIZE;
+  config->ssh_port = 22;
   config->transport = TRANSPORT_TCP;
   config->ssh_destination = NULL;
+  config->exclude_patterns = NULL;
+  config->exclude_count = 0;
   return config;
 }
 
@@ -57,6 +62,9 @@ void config_delete(Config *config) {
   free(config->send_directory);
   free(config->receive_root_directory);
   free(config->ssh_destination);
+  for (int i = 0; i < config->exclude_count; i++)
+    free(config->exclude_patterns[i]);
+  free(config->exclude_patterns);
   free(config);
 }
 
@@ -72,6 +80,7 @@ void config_send(int file_descriptor, Config *config) {
   send_int(file_descriptor, config->compression_level);
   send_int(file_descriptor, (int)config->chunk_size);
   send_int(file_descriptor, config->use_sendfile);
+  send_int(file_descriptor, config->use_delete);
   if (receive_status(file_descriptor) != STATUS_OK) {
     perror("Error transmitting config!");
     exit(EXIT_FAILURE);
@@ -91,8 +100,14 @@ Config *config_receive(int file_descriptor) {
   config->compression_level = receive_int(file_descriptor);
   config->chunk_size = (unsigned long long)receive_int(file_descriptor);
   config->use_sendfile = receive_int(file_descriptor);
+  config->use_delete = receive_int(file_descriptor);
+  config->show_progress = false;
+  config->dry_run = false;
+  config->ssh_port = 22;
   config->transport = TRANSPORT_TCP;
   config->ssh_destination = NULL;
+  config->exclude_patterns = NULL;
+  config->exclude_count = 0;
   send_status(file_descriptor, STATUS_OK);
   return config;
 }

src/shared/config.h

@@ -19,10 +19,15 @@ typedef struct Config {
   bool use_sendfile;
   bool use_metadata;
   bool show_progress;
+  bool dry_run;
+  bool use_delete;
   int compression_level;
   unsigned long long chunk_size;
+  int ssh_port;
   TransportType transport;
   char *ssh_destination;
+  char **exclude_patterns;
+  int exclude_count;
 } Config;
 
 #define DEFAULT_CHUNK_SIZE (10 * 1024 * 1024)

src/shared/multiprocessing.c

@@ -1,4 +1,5 @@
 #include "multiprocessing.h"
+#include "array_list.h"
 #include "chunk.h"
 #include "compression.h"
 #include "config.h"
@@ -36,6 +37,11 @@ PipelineContextSender *pipeline_context_sender_create(Config *config,
 }
 
 void pipeline_context_sender_destroy(PipelineContextSender *context) {
+  if (context->manifest) {
+    for (int i = 0; i < context->manifest->size; i++)
+      free(context->manifest->items[i]);
+    array_list_delete(context->manifest);
+  }
   config_delete(context->config);
   queue_destroy(context->queue_scanner);
   queue_destroy(context->queue_loader);
@@ -119,6 +125,17 @@ int receive_thread(void *pipeline_context) {
     }
     status = receive_status(file_descriptor);
   }
+  if (status == STATUS_MANIFEST) {
+    int count = receive_int(file_descriptor);
+    ArrayList *manifest = array_list_create(free);
+    for (int i = 0; i < count; i++)
+      array_list_add(manifest, receive_str(file_descriptor));
+    delete_extras(context->config->receive_root_directory, manifest);
+    for (int i = 0; i < manifest->size; i++)
+      free(manifest->items[i]);
+    array_list_delete(manifest);
+    status = receive_status(file_descriptor);
+  }
   mtx_lock(&context->mutex);
   context->receiver_done = true;
   cnd_signal(&context->condition_not_empty);

src/shared/multiprocessing.h

@@ -3,6 +3,7 @@
 
 #include <threads.h>
 
+#include "array_list.h"
 #include "config.h"
 #include "file.h"
 #include "queue.h"
@@ -19,6 +20,7 @@ typedef struct {
   cnd_t condition_not_full_loader;
   cnd_t condition_not_empty_loader;
   bool loader_done;
+  ArrayList *manifest;
 } PipelineContextSender;
 
 typedef struct PipelineContextReceiver {

src/shared/protocol.h

@@ -5,7 +5,7 @@
 #include <stddef.h>
 
 typedef int Status;
-enum NET_STATUS { STATUS_OK, STATUS_ERROR, STATUS_FINISHED, STATUS_NEXT, STATUS_CHUNK };
+enum NET_STATUS { STATUS_OK, STATUS_ERROR, STATUS_FINISHED, STATUS_NEXT, STATUS_CHUNK, STATUS_MANIFEST };
 
 void io_set_fds(int read_fd, int write_fd);
 void send_n_data(int file_descriptor, void *data, size_t data_size);

src/shared/transport_ssh.c

@@ -42,7 +42,7 @@ static int parse_remote_dest(const char *dest, RemoteDest *r) {
   return 0;
 }
 
-Client *client_connect_ssh(char *destination) {
+Client *client_connect_ssh(char *destination, int port) {
   RemoteDest r;
   if (parse_remote_dest(destination, &r) != 0) {
     fprintf(stderr, "Invalid remote destination: %s\n", destination);
@@ -90,10 +90,26 @@ Client *client_connect_ssh(char *destination) {
     else
       snprintf(ssh_user, sizeof(ssh_user), "%s", r.host);
 
-    execlp("ssh", "ssh", "-o", "Compression=no", "-o",
-           "ControlMaster=auto", "-o",
-           "ControlPath=~/.cache/fastsync-%r@%h:%p", ssh_user,
-           "fastsync-server", "--stdio", (char *)NULL);
+    char *ssh_argv[16];
+    int ac = 0;
+    char port_str[16];
+    ssh_argv[ac++] = "ssh";
+    ssh_argv[ac++] = "-o";
+    ssh_argv[ac++] = "Compression=no";
+    ssh_argv[ac++] = "-o";
+    ssh_argv[ac++] = "ControlMaster=auto";
+    ssh_argv[ac++] = "-o";
+    ssh_argv[ac++] = "ControlPath=~/.cache/fastsync-%r@%h:%p";
+    if (port > 0 && port != 22) {
+      ssh_argv[ac++] = "-p";
+      snprintf(port_str, sizeof(port_str), "%d", port);
+      ssh_argv[ac++] = port_str;
+    }
+    ssh_argv[ac++] = ssh_user;
+    ssh_argv[ac++] = "fastsync-server";
+    ssh_argv[ac++] = "--stdio";
+    ssh_argv[ac] = NULL;
+    execvp("ssh", ssh_argv);
     perror("exec of ssh failed");
     ssize_t wret = write(exec_pipe[1], "x", 1);
     (void)wret;

src/shared/transport_ssh.h

@@ -3,6 +3,6 @@
 
 #include "transport_tcp.h"
 
-Client *client_connect_ssh(char *destination);
+Client *client_connect_ssh(char *destination, int port);
 
 #endif

src/shared/utils.c

@@ -1,9 +1,12 @@
 #include "utils.h"
+#include "array_list.h"
 #include "libgen.h"
+#include <dirent.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <unistd.h>
 
 void mkdir_r(char *path) {
   char *path_duplicate = malloc(strlen(path) + 1);
@@ -44,6 +47,75 @@ char *str_dup(const char *string) {
   return new_string;
 }
 
+bool glob_match(const char *pattern, const char *str) {
+  while (*pattern) {
+    if (*pattern == '*') {
+      pattern++;
+      while (*str && *str != '/') {
+        if (glob_match(pattern, str))
+          return true;
+        str++;
+      }
+      return glob_match(pattern, str);
+    } else if (*pattern == '?') {
+      if (!*str || *str == '/')
+        return false;
+      pattern++;
+      str++;
+    } else {
+      if (*pattern != *str)
+        return false;
+      pattern++;
+      str++;
+    }
+  }
+  return *str == '\0';
+}
+
+static void delete_extras_walk(const char *abs_path, const char *rel_path,
+                               ArrayList *manifest) {
+  DIR *dir = opendir(abs_path);
+  if (!dir)
+    return;
+  struct dirent *entry;
+  while ((entry = readdir(dir)) != NULL) {
+    if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
+      continue;
+    char *child_abs = path_cat((char *)abs_path, entry->d_name);
+    char *child_rel = path_cat((char *)rel_path, entry->d_name);
+    struct stat st;
+    if (stat(child_abs, &st) != 0) {
+      free(child_abs);
+      free(child_rel);
+      continue;
+    }
+    if (S_ISDIR(st.st_mode)) {
+      delete_extras_walk(child_abs, child_rel, manifest);
+    } else {
+      // Check if relative path is in manifest
+      bool found = false;
+      for (int i = 0; i < manifest->size; i++) {
+        if (strcmp((char *)manifest->items[i], child_rel) == 0) {
+          found = true;
+          break;
+        }
+      }
+      if (!found) {
+        unlink(child_abs);
+        fprintf(stderr, "  Deleted: %s\n", child_rel);
+      }
+    }
+    free(child_abs);
+    free(child_rel);
+  }
+  closedir(dir);
+  rmdir(abs_path);
+}
+
+void delete_extras(const char *dest_root, ArrayList *manifest) {
+  delete_extras_walk(dest_root, "", manifest);
+}
+
 char *path_cat(char *path1, char *path2) {
   if (path1 == NULL || *path1 == '\0')
     return str_dup(path2);

src/shared/utils.h

@@ -1,8 +1,13 @@
 #ifndef UTILS_H
 #define UTILS_H
 
+#include "array_list.h"
+#include <stdbool.h>
+
 void mkdir_r(char *path);
 char *str_dup(const char *string);
 char *path_cat(char *path1, char *path2);
+bool glob_match(const char *pattern, const char *str);
+void delete_extras(const char *dest_root, ArrayList *manifest);
 
 #endif