db_sync: verify sig before send + fix total_processed double-count

src/db_sync.c

@@ -772,6 +772,7 @@ static int si_send_data_batch(struct DB_SYNC_INSTANCE* si, uint64_t dst, uint32_
     }
     sqlite3_bind_int64(stmt, 1, (sqlite3_int64)count);
     sqlite3_bind_int64(stmt, 2, (sqlite3_int64)from);
+    int bad_del = 0;
     while (sqlite3_step(stmt) == SQLITE_ROW) {
         uint64_t rid   = (uint64_t)sqlite3_column_int64(stmt, 0);
         uint64_t rts   = (uint64_t)sqlite3_column_int64(stmt, 1);
@@ -780,6 +781,19 @@ static int si_send_data_batch(struct DB_SYNC_INSTANCE* si, uint64_t dst, uint32_
         uint32_t rdl = (uint32_t)sqlite3_column_bytes(stmt, 3); if (!rd) rdl = 0;
         const uint8_t* rsig = (const uint8_t*)sqlite3_column_blob(stmt, 4);
         int rsl = sqlite3_column_bytes(stmt, 4); if (!rsig) rsl = 0;
+        if (rsl == DB_SIG_SIZE && db_verify_author_sig(si, rts, rauth, (const char*)rd, rdl, rsig) != 0) {
+            uint32_t del_pos = si_find_pos(si, rts, rsig);
+            sqlite3_stmt* del;
+            if (si_prep(si, &del, "DELETE FROM \"%s\" WHERE timestamp=? AND author_signature=?") == SQLITE_OK) {
+                sqlite3_bind_int64(del, 1, (sqlite3_int64)rts);
+                sqlite3_bind_blob(del, 2, rsig, DB_SIG_SIZE, SQLITE_STATIC);
+                sqlite3_step(del);
+                sqlite3_finalize(del);
+                db_cascade_from(si, del_pos);
+                bad_del++;
+            }
+            continue;
+        }
         int rec_sz = 28 + rdl + 1 + rsl;
         if (off + rec_sz > 8000) break;
         memcpy(buf + off, &rid, 8);   off += 8;
@@ -795,9 +809,9 @@ static int si_send_data_batch(struct DB_SYNC_INSTANCE* si, uint64_t dst, uint32_
 
     *rcp = rc;
     db_sync_send(si, dst, buf, off);
-    DEBUG_INFO(DEBUG_CATEGORY_DB_SYNC, "sync [%s:%04llX] → SEND DATA: %u records from pos=%u",
+    DEBUG_INFO(DEBUG_CATEGORY_DB_SYNC, "sync [%s:%04llX] → SEND DATA: %u records from pos=%u%s",
-               SI_SHRT(si), (unsigned long long)(dst >> 16), rc, from);
+               SI_SHRT(si), (unsigned long long)(dst >> 16), rc, from, bad_del > 0 ? (rc > 0 ? " (bad_sig deleted)" : " (all bad_sig deleted)") : "");
-    if (rc == 0 && count > 0) {
+    if (rc == 0 && count > 0 && bad_del == 0) {
         DEBUG_ERROR(DEBUG_CATEGORY_DB_SYNC, "sync [%s:%04llX] SEND_DATA batch: loaded 0 records from pos=%u count=%u — SQL error or empty range",
                     SI_SHRT(si), (unsigned long long)(dst >> 16), from, count);
     }
@@ -916,11 +930,11 @@ static void db_handle_send_data(struct DB_SYNC_INSTANCE* si, uint64_t src, const
         if (ret == 0 && si->on_insert) si->on_insert(si, rts, (const char*)rdata, rdlen, src, si->on_insert_arg);
     }
 
-    uint16_t total_processed = received + duplicates + bad_sigs;
+    uint16_t total_processed = count - parse_fails;
 
     if (total_processed > 0) {
         uint32_t rst = (from < old_synced_pos) ? from : old_synced_pos;
-        db_cascade_range(si, rst, from + received);
+        db_cascade_range(si, rst, from + total_processed);
         if (sp) sp->synced_pos = from + total_processed - 1;
         for (int j = 0; j < si->peer_count; j++) {
             if (si->peers[j].synced_pos >= rst && &si->peers[j] != sp)
@@ -931,7 +945,7 @@ static void db_handle_send_data(struct DB_SYNC_INSTANCE* si, uint64_t src, const
         if (bad_sigs) { size_t el = strlen(extra_buf); snprintf(extra_buf+el, sizeof(extra_buf)-el, "%s%u bad_sig", extra_buf[0]?", ":" (", bad_sigs); if (!extra_buf[0]) extra_buf[0]=' '; }
         DEBUG_INFO(DEBUG_CATEGORY_DB_SYNC, "sync [%s:%04llX] ← DATA: from=%u count=%u vp=%u → inserted %u [id=%llu..%llu]%s cascade=[%u..%u] synced=%u→%u",
                    SI_SHRT(si), (unsigned long long)(src >> 16), from, count, vp, received, (unsigned long long)first_id, (unsigned long long)last_id,
-                   extra_buf, rst, from+received-1, old_synced_pos, sp?sp->synced_pos:0);
+                   extra_buf, rst, from+total_processed-1, old_synced_pos, sp?sp->synced_pos:0);
 
         int relay_count = 0;
         uint8_t push_buf[2560]; uint32_t push_off;