refactor: memory management and security changes

also add navigation code comments

1 files changed, 139 insertions, 16 deletions

diff --git a/src/dapp.c b/src/dapp.c
index 6d7d651..a277d1d 100644
--- a/src/dapp.c
+++ b/src/dapp.c
@@ -1,5 +1,6 @@
 #define _POSIX_C_SOURCE 200809L
 
+#include <errno.h>
 #include <gio/gdesktopappinfo.h>
 #include <gtk/gtk.h>
 #include <signal.h>
@@ -17,11 +18,36 @@ typedef struct {
 
 typedef struct {
     GPtrArray *entries;
+    GHashTable *seen_paths;
     GtkWidget *window;
     GtkWidget *list;
     GtkWidget *status_label;
 } LauncherState;
 
+// nav: limits
+enum {
+    MAX_INPUT_LINE_BYTES = 4096,
+    MAX_DESKTOP_ENTRIES = 4096,
+    MAX_APP_NAME_CHARS = 160
+};
+
+// nav: state cleanup
+static void launcher_state_cleanup(LauncherState *state) {
+    if (state == NULL) {
+        return;
+    }
+
+    if (state->entries != NULL) {
+        g_ptr_array_free(state->entries, TRUE);
+        state->entries = NULL;
+    }
+
+    if (state->seen_paths != NULL) {
+        g_hash_table_destroy(state->seen_paths);
+        state->seen_paths = NULL;
+    }
+}
+
 static void app_entry_free(gpointer data) {
     AppEntry *entry = (AppEntry *)data;
     if (entry == NULL) {
@@ -55,6 +81,7 @@ static char *trim_in_place(char *text) {
     return start;
 }
 
+// nav: path helpers
 static char *expand_path(const char *path) {
     if (path == NULL || *path == '\0') {
         return NULL;
@@ -74,18 +101,80 @@ static char *expand_path(const char *path) {
     return g_strdup(path);
 }
 
+static char *normalize_desktop_path(const char *raw_path) {
+    char *expanded = NULL;
+    char *canonical = NULL;
+
+    expanded = expand_path(raw_path);
+    if (expanded == NULL) {
+        return NULL;
+    }
+
+    canonical = g_canonicalize_filename(expanded, NULL);
+    g_free(expanded);
+
+    if (canonical == NULL || !g_path_is_absolute(canonical)) {
+        g_free(canonical);
+        return NULL;
+    }
+
+    return canonical;
+}
+
+static char *build_safe_display_name(GDesktopAppInfo *app, const char *fallback_path) {
+    const char *name = g_app_info_get_display_name(G_APP_INFO(app));
+    char *safe_name = NULL;
+
+    if (name == NULL || *name == '\0') {
+        name = g_app_info_get_name(G_APP_INFO(app));
+    }
+
+    if (name == NULL || *name == '\0') {
+        name = fallback_path;
+    }
+
+    safe_name = g_utf8_make_valid(name != NULL ? name : "app", -1);
+    if (safe_name == NULL || *safe_name == '\0') {
+        g_free(safe_name);
+        safe_name = g_strdup("app");
+    }
+
+    if (g_utf8_strlen(safe_name, -1) > MAX_APP_NAME_CHARS) {
+        char *truncated = g_utf8_substring(safe_name, 0, MAX_APP_NAME_CHARS);
+        g_free(safe_name);
+        safe_name = truncated;
+    }
+
+    return safe_name;
+}
+
+// nav: desktop entry loading
 static gboolean add_desktop_path(LauncherState *state, const char *raw_path) {
     char *path = NULL;
     GDesktopAppInfo *app = NULL;
-    const char *display_name = NULL;
+    char *safe_name = NULL;
     AppEntry *entry = NULL;
 
-    path = expand_path(raw_path);
+    if (state->entries->len >= MAX_DESKTOP_ENTRIES) {
+        return FALSE;
+    }
+
+    path = normalize_desktop_path(raw_path);
     if (path == NULL) {
         return FALSE;
     }
 
-    if (!g_file_test(path, G_FILE_TEST_IS_REGULAR)) {
+    if (!g_str_has_suffix(path, ".desktop")) {
+        g_free(path);
+        return FALSE;
+    }
+
+    if (g_hash_table_contains(state->seen_paths, path)) {
+        g_free(path);
+        return FALSE;
+    }
+
+    if (!g_file_test(path, G_FILE_TEST_IS_REGULAR) || access(path, R_OK) != 0) {
         g_free(path);
         return FALSE;
     }
@@ -96,32 +185,47 @@ static gboolean add_desktop_path(LauncherState *state, const char *raw_path) {
         return FALSE;
     }
 
-    display_name = g_app_info_get_display_name(G_APP_INFO(app));
-    if (display_name == NULL || *display_name == '\0') {
-        display_name = g_app_info_get_name(G_APP_INFO(app));
+    safe_name = build_safe_display_name(app, path);
+    if (safe_name == NULL) {
+        g_clear_object(&app);
+        g_free(path);
+        return FALSE;
     }
 
     entry = g_new0(AppEntry, 1);
     entry->desktop_path = path;
-    entry->name = g_strdup(display_name != NULL ? display_name : raw_path);
+    entry->name = safe_name;
     entry->app = app;
 
     g_ptr_array_add(state->entries, entry);
+    g_hash_table_add(state->seen_paths, g_strdup(path));
     return TRUE;
 }
 
+// nav: input loading
 static void load_paths_from_stream(LauncherState *state, FILE *stream, const char *source_name) {
-    char *line = NULL;
-    size_t line_cap = 0;
-    ssize_t line_len = 0;
+    char line[MAX_INPUT_LINE_BYTES + 2];
     guint line_no = 0;
 
-    while ((line_len = getline(&line, &line_cap, stream)) != -1) {
+    while (fgets(line, sizeof(line), stream) != NULL) {
         char *trimmed = NULL;
+        size_t line_len = strlen(line);
+        gboolean long_line = FALSE;
+
         line_no++;
 
         if (line_len > 0 && line[line_len - 1] == '\n') {
             line[line_len - 1] = '\0';
+        } else if (!feof(stream)) {
+            int ch = 0;
+            long_line = TRUE;
+            while ((ch = fgetc(stream)) != '\n' && ch != EOF) {
+            }
+        }
+
+        if (long_line) {
+            g_printerr("skipping long line at %s:%u\n", source_name, line_no);
+            continue;
         }
 
         trimmed = trim_in_place(line);
@@ -132,9 +236,16 @@ static void load_paths_from_stream(LauncherState *state, FILE *stream, const cha
         if (!add_desktop_path(state, trimmed)) {
             g_printerr("skipping invalid desktop path at %s:%u -> %s\n", source_name, line_no, trimmed);
         }
+
+        if (state->entries->len >= MAX_DESKTOP_ENTRIES) {
+            g_printerr("entry limit reached (%u)\n", MAX_DESKTOP_ENTRIES);
+            break;
+        }
     }
 
-    free(line);
+    if (ferror(stream)) {
+        g_printerr("read error from %s: %s\n", source_name, g_strerror(errno));
+    }
 }
 
 static gboolean load_paths_from_stdin(LauncherState *state) {
@@ -193,11 +304,14 @@ static gboolean load_paths_from_config(LauncherState *state) {
 
     load_paths_from_stream(state, config, path);
 
-    fclose(config);
+    if (fclose(config) != 0) {
+        g_printerr("warning: failed to close config file: %s\n", path);
+    }
     g_free(path);
     return state->entries->len > old_len;
 }
 
+// nav: ui events
 static gboolean on_delete_event(GtkWidget *widget, GdkEvent *event, gpointer user_data) {
     (void)widget;
     (void)event;
@@ -345,6 +459,7 @@ static gboolean on_list_leave(GtkWidget *widget, GdkEventCrossing *event, gpoint
     return FALSE;
 }
 
+// nav: ui build
 static GtkWidget *create_entry_row(AppEntry *entry) {
     GtkWidget *row = gtk_list_box_row_new();
     GtkWidget *box = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 26);
@@ -428,6 +543,7 @@ static void apply_css(void) {
     g_object_unref(provider);
 }
 
+// nav: process setup
 static void ignore_nonfatal_signals(void) {
     struct sigaction sa;
 
@@ -452,6 +568,13 @@ int main(int argc, char **argv) {
 
     memset(&state, 0, sizeof(state));
     state.entries = g_ptr_array_new_with_free_func(app_entry_free);
+    state.seen_paths = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);
+
+    if (state.entries == NULL || state.seen_paths == NULL) {
+        g_printerr("failed to initialize launcher state\n");
+        launcher_state_cleanup(&state);
+        return EXIT_FAILURE;
+    }
 
     ignore_nonfatal_signals();
 
@@ -462,13 +585,13 @@ int main(int argc, char **argv) {
 
     if (!loaded_from_stdin && !loaded_from_config) {
         g_printerr("no desktop entries found from stdin or config\n");
-        g_ptr_array_free(state.entries, TRUE);
+        launcher_state_cleanup(&state);
         return EXIT_FAILURE;
     }
 
     if (state.entries->len == 0) {
         g_printerr("no valid desktop entries were loaded\n");
-        g_ptr_array_free(state.entries, TRUE);
+        launcher_state_cleanup(&state);
         return EXIT_FAILURE;
     }
 
@@ -526,6 +649,6 @@ int main(int argc, char **argv) {
 
     gtk_main();
 
-    g_ptr_array_free(state.entries, TRUE);
+    launcher_state_cleanup(&state);
     return EXIT_SUCCESS;
 }