[#17478] free blocks in more places

Bug 17478 was caused by `wtap_rec.block` being allocated for each
packet, but not freed when it was done being used -- typically at the
end of a loop.

Rather than requiring each caller of `wtap_read()` to know to free a
member of `rec`, I added a new function `wtap_rec_reset()` for a
slightly cleaner API. Added calls to it everywhere that seemed to make
sense.

Fixes #17478

capinfos.c

@@ -1324,6 +1324,7 @@ process_cap_file(const char *filename, gboolean need_separator)
       }
     }
 
+    wtap_rec_reset(&rec);
   } /* while */
   wtap_rec_cleanup(&rec);
   ws_buffer_free(&buf);

debian/libwiretap0.symbols

@@ -154,6 +154,7 @@ libwiretap.so.0 libwiretap0 #MINVER#
  wtap_read_so_far@Base 1.9.1
  wtap_rec_cleanup@Base 2.5.1
  wtap_rec_init@Base 2.5.1
+ wtap_rec_reset@Base 3.5.0
  wtap_register_encap_type@Base 1.9.1
  wtap_register_file_type_extension@Base 1.12.0~rc1
  wtap_register_file_type_subtype@Base 3.5.0

editcap.c

@@ -1155,6 +1155,7 @@ main(int argc, char *argv[])
     unsigned int                 seed = 0;
 
     cmdarg_err_init(editcap_cmdarg_err, editcap_cmdarg_err_cont);
+    memset(&read_rec, 0, sizeof *rec);
 
     /* Initialize log handler early so we can have proper logging during startup. */
     ws_log_init("editcap", vcmdarg_err);
@@ -2216,6 +2217,7 @@ main(int argc, char *argv[])
             written_count++;
         }
         count++;
+        wtap_rec_reset(&read_rec);
     }
     wtap_rec_cleanup(&read_rec);
     ws_buffer_free(&read_buf);
@@ -2285,6 +2287,7 @@ main(int argc, char *argv[])
     wtap_dump_params_cleanup(&params);
     if (wth != NULL)
         wtap_close(wth);
+    wtap_rec_reset(&read_rec);
     wtap_cleanup();
     free_progdirs();
     if (capture_comments != NULL) {

file.c

@@ -653,6 +653,7 @@ cf_read(capture_file *cf, gboolean reloading)
         break;
       }
       read_record(cf, &rec, &buf, dfcode, &edt, cinfo, data_offset);
+      wtap_rec_reset(&rec);
     }
   }
   CATCH(OutOfMemoryError) {
@@ -842,6 +843,7 @@ cf_continue_tail(capture_file *cf, volatile int to_read, wtap_rec *rec,
       }
       to_read--;
     }
+    wtap_rec_reset(rec);
   }
   CATCH(OutOfMemoryError) {
     simple_message_box(ESD_TYPE_ERROR, NULL,
@@ -968,6 +970,7 @@ cf_finish_tail(capture_file *cf, wtap_rec *rec, Buffer *buf, int *err)
       break;
     }
     read_record(cf, rec, buf, dfcode, &edt, cinfo, data_offset);
+    wtap_rec_reset(rec);
   }
 
   /* Cleanup and release all dfilter resources */
@@ -1895,6 +1898,7 @@ rescan_packets(capture_file *cf, const char *action, const char *action_item, gb
        on the next pass through the loop. */
     prev_frame_num = fdata->num;
     prev_frame = fdata;
+    wtap_rec_reset(&rec);
   }
 
   epan_dissect_cleanup(&edt);
@@ -2212,6 +2216,7 @@ process_specified_records(capture_file *cf, packet_range_t *range,
       ret = PSP_FAILED;
       break;
     }
+    wtap_rec_reset(&rec);
   }
 
   /* We're done printing the packets; destroy the progress bar if

reordercap.c

@@ -122,6 +122,7 @@ frame_write(FrameRecord_t *frame, wtap *wth, wtap_dumper *pdh,
                                     wtap_file_type_subtype(wth));
         exit(1);
     }
+    wtap_rec_reset(rec);
 }
 
 /* Comparing timestamps between 2 frames.
@@ -328,6 +329,7 @@ main(int argc, char *argv[])
 
         g_ptr_array_add(frames, newFrameRecord);
         prevFrame = newFrameRecord;
+        wtap_rec_reset(&rec);
     }
     wtap_rec_cleanup(&rec);
     ws_buffer_free(&buf);

sharkd.c

@@ -371,6 +371,7 @@ load_cap_file(capture_file *cf, int max_packet_count, gint64 max_byte_count)
 
     while (wtap_read(cf->provider.wth, &rec, &buf, &err, &err_info, &data_offset)) {
       if (process_packet(cf, edt, data_offset, &rec, &buf)) {
+        wtap_rec_reset(&rec);
         /* Stop reading if we have the maximum number of packets;
          * When the -c option has not been used, max_packet_count
          * starts at 0, which practically means, never stop reading.
@@ -556,6 +557,7 @@ sharkd_dissect_request(guint32 framenum, guint32 frame_ref_num,
      cinfo, (dissect_flags & SHARKD_DISSECT_FLAG_BYTES) ? edt.pi.data_src : NULL,
      data);
 
+  wtap_rec_reset(rec);
   epan_dissect_cleanup(&edt);
   return DISSECT_REQUEST_SUCCESS;
 }
@@ -610,6 +612,7 @@ sharkd_retap(void)
     epan_dissect_run_with_taps(&edt, cfile.cd_t, &rec,
                                frame_tvbuff_new_buffer(&cfile.provider, fdata, &buf),
                                fdata, cinfo);
+    wtap_rec_reset(&rec);
     epan_dissect_reset(&edt);
   }
 
@@ -687,6 +690,7 @@ sharkd_filter(const char *dftext, guint8 **result)
 
     /* if passed or ref -> frame_data_set_after_dissect */
 
+    wtap_rec_reset(&rec);
     epan_dissect_reset(&edt);
   }
 

tshark.c

@@ -2831,6 +2831,7 @@ capture_input_new_packets(capture_session *cap_session, int to_read)
         /* packet successfully read and gone through the "Read Filter" */
         packet_count++;
       }
+      wtap_rec_reset(&rec);
     }
 
     epan_dissect_free(edt);
@@ -3184,6 +3185,7 @@ process_cap_file_first_pass(capture_file *cf, int max_packet_count,
         break;
       }
     }
+    wtap_rec_reset(&rec);
   }
   if (*err != 0)
     status = PASS_READ_ERROR;
@@ -3413,6 +3415,7 @@ process_cap_file_second_pass(capture_file *cf, wtap_dumper *pdh,
         }
       }
     }
+    wtap_rec_reset(&rec);
   }
 
   if (edt)
@@ -3540,6 +3543,7 @@ process_cap_file_single_pass(capture_file *cf, wtap_dumper *pdh,
       *err = 0; /* This is not an error */
       break;
     }
+    wtap_rec_reset(&rec);
   }
   if (*err != 0 && status == PASS_SUCCEEDED) {
     /* Error reading from the input file. */

ui/capture.c

@@ -504,6 +504,7 @@ capture_info_new_packets(int to_read, wtap *wth, info_data_t* cap_info)
                 /*ws_warning("new packet");*/
                 to_read--;
             }
+            wtap_rec_reset(&rec);
         }
     }
     wtap_rec_cleanup(&rec);

ui/file_dialog.c

@@ -83,6 +83,7 @@ get_stats_for_preview(wtap *wth, ws_file_preview_stats *stats,
                 break;
             }
         }
+        wtap_rec_reset(&rec);
     }
 
     stats->have_times = have_times;

wiretap/merge.c

@@ -945,6 +945,7 @@ merge_process_packets(wtap_dumper *pdh, const int file_type,
             status = MERGE_ERR_CANT_WRITE_OUTFILE;
             break;
         }
+        wtap_rec_reset(rec);
     }
 
     if (cb)

wiretap/wtap.c

@@ -1669,13 +1669,20 @@ wtap_rec_init(wtap_rec *rec)
 	 */
 }
 
-/* clean up record metadata */
+/* re-initialize record */
 void
-wtap_rec_cleanup(wtap_rec *rec)
+wtap_rec_reset(wtap_rec *rec)
 {
 	wtap_block_unref(rec->block);
 	rec->block = NULL;
 	rec->block_was_modified = FALSE;
+}
+
+/* clean up record metadata */
+void
+wtap_rec_cleanup(wtap_rec *rec)
+{
+	wtap_rec_reset(rec);
 	ws_buffer_free(&rec->options_buf);
 }
 

wiretap/wtap.h

@@ -1752,6 +1752,10 @@ gboolean wtap_seek_read(wtap *wth, gint64 seek_off, wtap_rec *rec,
 WS_DLL_PUBLIC
 void wtap_rec_init(wtap_rec *rec);
 
+/*** Re-initialize a wtap_rec structure ***/
+WS_DLL_PUBLIC
+void wtap_rec_reset(wtap_rec *rec);
+
 /*** clean up a wtap_rec structure, freeing what wtap_rec_init() allocated */
 WS_DLL_PUBLIC
 void wtap_rec_cleanup(wtap_rec *rec);