wiretap: refactor common parameters for pcapng dump routines

Four variants of wtap_dump_open_ng exists, each of them take the same
three parameters for the SHB, IDB and NRB blocks that has to be written
before packets are even written. Similarly, a lot of tools always create
these arguments based on an existing capture file session (wth).

Address the former duplication by creating a new data structure to hold
the arguments. Address the second issue by creating new helper functions
to initialize the parameters based on a wth. This refactoring should
make it easier to add the new Decryption Secrets Block (DSB).

No functional change intended.

Change-Id: I42c019dc1d48a476773459212ca213de91a55684
Reviewed-on: https://code.wireshark.org/review/30578
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Petri-Dish: Guy Harris <guy@alum.mit.edu>
Tested-by: Petri Dish Buildbot
Reviewed-by: Guy Harris <guy@alum.mit.edu>
Reviewed-by: Peter Wu <peter@lekensteyn.nl>

1 files changed, 16 insertions, 22 deletions

diff --git a/file.c b/file.c
index 299c0e3ae8..731934c973 100644
--- a/file.c
+++ b/file.c
@@ -4448,15 +4448,11 @@ cf_save_records(capture_file *cf, const char *fname, guint save_format,
        or moving the capture file, we have to do it by writing the packets
        out in Wiretap. */
 
-    GArray                      *shb_hdrs = NULL;
-    wtapng_iface_descriptions_t *idb_inf = NULL;
-    GArray                      *nrb_hdrs = NULL;
+    wtapng_dump_params ng_params;
     int encap;
 
-    /* XXX: what free's this shb_hdr? */
-    shb_hdrs = wtap_file_get_shb_for_new_file(cf->provider.wth);
-    idb_inf = wtap_file_get_idb_info(cf->provider.wth);
-    nrb_hdrs = wtap_file_get_nrb_for_new_file(cf->provider.wth);
+    /* XXX: what free's ng_params.shb_hdr? */
+    wtap_dump_params_init(&ng_params, cf->provider.wth);
 
     /* Determine what file encapsulation type we should use. */
     encap = wtap_dump_file_encap_type(cf->linktypes);
@@ -4471,13 +4467,14 @@ cf_save_records(capture_file *cf, const char *fname, guint save_format,
          from which we're reading the packets that we're writing!) */
       fname_new = g_strdup_printf("%s~", fname);
       pdh = wtap_dump_open_ng(fname_new, save_format, encap, cf->snap,
-                              compressed, shb_hdrs, idb_inf, nrb_hdrs, &err);
+                              compressed, &ng_params, &err);
     } else {
       pdh = wtap_dump_open_ng(fname, save_format, encap, cf->snap,
-                              compressed, shb_hdrs, idb_inf, nrb_hdrs, &err);
+                              compressed, &ng_params, &err);
     }
-    g_free(idb_inf);
-    idb_inf = NULL;
+    /* XXX idb_inf is documented to be used until wtap_dump_close. */
+    g_free(ng_params.idb_inf);
+    ng_params.idb_inf = NULL;
 
     if (pdh == NULL) {
       cfile_dump_open_failure_alert_box(fname, err, save_format);
@@ -4698,9 +4695,7 @@ cf_export_specified_packets(capture_file *cf, const char *fname,
   int                          err;
   wtap_dumper                 *pdh;
   save_callback_args_t         callback_args;
-  GArray                      *shb_hdrs = NULL;
-  wtapng_iface_descriptions_t *idb_inf = NULL;
-  GArray                      *nrb_hdrs = NULL;
+  wtapng_dump_params           ng_params;
   int                          encap;
 
   packet_range_process_init(range);
@@ -4710,10 +4705,8 @@ cf_export_specified_packets(capture_file *cf, const char *fname,
      written, don't special-case the operation - read each packet
      and then write it out if it's one of the specified ones. */
 
-  /* XXX: what free's this shb_hdr? */
-  shb_hdrs = wtap_file_get_shb_for_new_file(cf->provider.wth);
-  idb_inf = wtap_file_get_idb_info(cf->provider.wth);
-  nrb_hdrs = wtap_file_get_nrb_for_new_file(cf->provider.wth);
+  /* XXX: what free's ng_params.shb_hdr? */
+  wtap_dump_params_init(&ng_params, cf->provider.wth);
 
   /* Determine what file encapsulation type we should use. */
   encap = wtap_dump_file_encap_type(cf->linktypes);
@@ -4728,13 +4721,14 @@ cf_export_specified_packets(capture_file *cf, const char *fname,
        from which we're reading the packets that we're writing!) */
     fname_new = g_strdup_printf("%s~", fname);
     pdh = wtap_dump_open_ng(fname_new, save_format, encap, cf->snap,
-                            compressed, shb_hdrs, idb_inf, nrb_hdrs, &err);
+                            compressed, &ng_params, &err);
   } else {
     pdh = wtap_dump_open_ng(fname, save_format, encap, cf->snap,
-                            compressed, shb_hdrs, idb_inf, nrb_hdrs, &err);
+                            compressed, &ng_params, &err);
   }
-  g_free(idb_inf);
-  idb_inf = NULL;
+    /* XXX idb_inf is documented to be used until wtap_dump_close. */
+  g_free(ng_params.idb_inf);
+  ng_params.idb_inf = NULL;
 
   if (pdh == NULL) {
     cfile_dump_open_failure_alert_box(fname, err, save_format);