Allow wtap_read() and wtap_seek_read() to return non-packet records.

This is the first step towards implementing the mechanisms requestd in
bug 8590; currently, we don't return any records other than packet
records from libwiretap, and just ignore non-packet records in the rest
of Wireshark, but this at least gets the ball rolling.

Change-Id: I34a45b54dd361f69fdad1a758d8ca4f42d67d574
Reviewed-on: https://code.wireshark.org/review/1736
Reviewed-by: Guy Harris <guy@alum.mit.edu>

1 files changed, 131 insertions, 112 deletions

diff --git a/tshark.c b/tshark.c
index f52b00502f..afbf6310ac 100644
--- a/tshark.c
+++ b/tshark.c
@@ -2651,11 +2651,11 @@ capture_input_new_file(capture_session *cap_session, gchar *new_file)
 }
 
 
-/* capture child tells us we have new packets to read */
+/* capture child tells us we have new records to read */
 void
-capture_input_new_packets(capture_session *cap_session, int to_read)
+capture_input_new_records(capture_session *cap_session, int to_read)
 {
-  gboolean      ret;
+  int           rec_type;
   int           err;
   gchar        *err_info;
   gint64        data_offset;
@@ -2696,20 +2696,21 @@ capture_input_new_packets(capture_session *cap_session, int to_read)
 
     while (to_read-- && cf->wth) {
       wtap_cleareof(cf->wth);
-      ret = wtap_read(cf->wth, &err, &err_info, &data_offset);
-      if (ret == FALSE) {
+      rec_type = wtap_read(cf->wth, &err, &err_info, &data_offset);
+      if (rec_type == -1) {
         /* read from file failed, tell the capture child to stop */
         sync_pipe_stop(cap_session);
         wtap_close(cf->wth);
         cf->wth = NULL;
       } else {
-        ret = process_packet(cf, edt, data_offset, wtap_phdr(cf->wth),
+      	if (rec_type == REC_TYPE_PACKET) {
+          if (process_packet(cf, edt, data_offset, wtap_phdr(cf->wth),
                              wtap_buf_ptr(cf->wth),
-                             tap_flags);
-      }
-      if (ret != FALSE) {
-        /* packet successfully read and gone through the "Read Filter" */
-        packet_count++;
+                             tap_flags)) {
+            /* packet successfully read and gone through the "Read Filter" */
+            packet_count++;
+          }
+        }
       }
     }
 
@@ -3062,9 +3063,11 @@ load_cap_file(capture_file *cf, char *save_file, int out_file_type,
   int          snapshot_length;
   wtap_dumper *pdh;
   guint32      framenum;
+  int          rec_type;
   int          err;
   gchar       *err_info = NULL;
   gint64       data_offset;
+  gboolean     packet_count_reached = FALSE;
   char        *save_file_string = NULL;
   gboolean     filtering_tap_listeners;
   guint        tap_flags;
@@ -3191,17 +3194,19 @@ load_cap_file(capture_file *cf, char *save_file, int out_file_type,
       edt = epan_dissect_new(cf->epan, create_proto_tree, FALSE);
     }
 
-    while (wtap_read(cf->wth, &err, &err_info, &data_offset)) {
-      if (process_packet_first_pass(cf, edt, data_offset, wtap_phdr(cf->wth),
-                         wtap_buf_ptr(cf->wth))) {
-        /* 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.
-         * (unless we roll over max_packet_count ?)
-         */
-        if ( (--max_packet_count == 0) || (max_byte_count != 0 && data_offset >= max_byte_count)) {
-          err = 0; /* This is not an error */
-          break;
+    while ((rec_type = wtap_read(cf->wth, &err, &err_info, &data_offset)) != -1) {
+      if (rec_type == REC_TYPE_PACKET) {
+        if (process_packet_first_pass(cf, edt, data_offset, wtap_phdr(cf->wth),
+                                      wtap_buf_ptr(cf->wth))) {
+          /* 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.
+           * (unless we roll over max_packet_count ?)
+           */
+          if ( (--max_packet_count == 0) || (max_byte_count != 0 && data_offset >= max_byte_count)) {
+            err = 0; /* This is not an error */
+            break;
+          }
         }
       }
     }
@@ -3240,15 +3245,101 @@ load_cap_file(capture_file *cf, char *save_file, int out_file_type,
 
     for (framenum = 1; err == 0 && framenum <= cf->count; framenum++) {
       fdata = frame_data_sequence_find(cf->frames, framenum);
-      if (wtap_seek_read(cf->wth, fdata->file_off, &phdr, &buf, &err,
-                         &err_info)) {
-        if (process_packet_second_pass(cf, edt, fdata, &phdr, &buf,
-                                       tap_flags)) {
+      if ((rec_type = wtap_seek_read(cf->wth, fdata->file_off, &phdr, &buf, &err,
+                                     &err_info)) == -1) {
+        if (rec_type == REC_TYPE_PACKET) {
+          if (process_packet_second_pass(cf, edt, fdata, &phdr, &buf,
+                                         tap_flags)) {
+            /* Either there's no read filtering or this packet passed the
+               filter, so, if we're writing to a capture file, write
+               this packet out. */
+            if (pdh != NULL) {
+              if (!wtap_dump(pdh, &phdr, buffer_start_ptr(&buf), &err)) {
+                /* Error writing to a capture file */
+                switch (err) {
+
+                case WTAP_ERR_UNSUPPORTED_ENCAP:
+                  /*
+                   * This is a problem with the particular frame we're writing
+                   * and the file type and subtype we're writing; note that,
+                   * and report the frame number and file type/subtype.
+                   *
+                   * XXX - framenum is not necessarily the frame number in
+                   * the input file if there was a read filter.
+                   */
+                  fprintf(stderr,
+                          "Frame %u of \"%s\" has a network type that can't be saved in a \"%s\" file.\n",
+                          framenum, cf->filename,
+                          wtap_file_type_subtype_short_string(out_file_type));
+                  break;
+
+                case WTAP_ERR_PACKET_TOO_LARGE:
+                  /*
+                   * This is a problem with the particular frame we're writing
+                   * and the file type and subtype we're writing; note that,
+                   * and report the frame number and file type/subtype.
+                   *
+                   * XXX - framenum is not necessarily the frame number in
+                   * the input file if there was a read filter.
+                   */
+                  fprintf(stderr,
+                          "Frame %u of \"%s\" is too large for a \"%s\" file.\n",
+                          framenum, cf->filename,
+                          wtap_file_type_subtype_short_string(out_file_type));
+                  break;
+
+                default:
+                  show_capture_file_io_error(save_file, err, FALSE);
+                  break;
+                }
+                wtap_dump_close(pdh, &err);
+                g_free(shb_hdr);
+                exit(2);
+              }
+            }
+          }
+        }
+      }
+    }
+
+    if (edt) {
+      epan_dissect_free(edt);
+      edt = NULL;
+    }
+
+    buffer_free(&buf);
+  }
+  else {
+    framenum = 0;
+
+    if (do_dissection) {
+      gboolean create_proto_tree;
+
+      if (cf->rfcode || cf->dfcode || print_details || filtering_tap_listeners ||
+          (tap_flags & TL_REQUIRES_PROTO_TREE) || have_custom_cols(&cf->cinfo))
+        create_proto_tree = TRUE;
+      else
+        create_proto_tree = FALSE;
+
+      /* The protocol tree will be "visible", i.e., printed, only if we're
+         printing packet details, which is true if we're printing stuff
+         ("print_packet_info" is true) and we're in verbose mode
+         ("packet_details" is true). */
+      edt = epan_dissect_new(cf->epan, create_proto_tree, print_packet_info && print_details);
+    }
+
+    while ((rec_type = wtap_read(cf->wth, &err, &err_info, &data_offset)) != -1) {
+      if (rec_type == REC_TYPE_PACKET) {
+        framenum++;
+
+        if (process_packet(cf, edt, data_offset, wtap_phdr(cf->wth),
+                           wtap_buf_ptr(cf->wth),
+                           tap_flags)) {
           /* Either there's no read filtering or this packet passed the
              filter, so, if we're writing to a capture file, write
              this packet out. */
           if (pdh != NULL) {
-            if (!wtap_dump(pdh, &phdr, buffer_start_ptr(&buf), &err)) {
+            if (!wtap_dump(pdh, wtap_phdr(cf->wth), wtap_buf_ptr(cf->wth), &err)) {
               /* Error writing to a capture file */
               switch (err) {
 
@@ -3257,9 +3348,6 @@ load_cap_file(capture_file *cf, char *save_file, int out_file_type,
                  * This is a problem with the particular frame we're writing
                  * and the file type and subtype we're writing; note that,
                  * and report the frame number and file type/subtype.
-                 *
-                 * XXX - framenum is not necessarily the frame number in
-                 * the input file if there was a read filter.
                  */
                 fprintf(stderr,
                         "Frame %u of \"%s\" has a network type that can't be saved in a \"%s\" file.\n",
@@ -3272,9 +3360,6 @@ load_cap_file(capture_file *cf, char *save_file, int out_file_type,
                  * This is a problem with the particular frame we're writing
                  * and the file type and subtype we're writing; note that,
                  * and report the frame number and file type/subtype.
-                 *
-                 * XXX - framenum is not necessarily the frame number in
-                 * the input file if there was a read filter.
                  */
                 fprintf(stderr,
                         "Frame %u of \"%s\" is too large for a \"%s\" file.\n",
@@ -3292,89 +3377,23 @@ load_cap_file(capture_file *cf, char *save_file, int out_file_type,
             }
           }
         }
-      }
-    }
-
-    if (edt) {
-      epan_dissect_free(edt);
-      edt = NULL;
-    }
-
-    buffer_free(&buf);
-  }
-  else {
-    framenum = 0;
-
-    if (do_dissection) {
-      gboolean create_proto_tree;
 
-      if (cf->rfcode || cf->dfcode || print_details || filtering_tap_listeners ||
-          (tap_flags & TL_REQUIRES_PROTO_TREE) || have_custom_cols(&cf->cinfo))
-        create_proto_tree = TRUE;
-      else
-        create_proto_tree = FALSE;
-
-      /* The protocol tree will be "visible", i.e., printed, only if we're
-         printing packet details, which is true if we're printing stuff
-         ("print_packet_info" is true) and we're in verbose mode
-         ("packet_details" is true). */
-      edt = epan_dissect_new(cf->epan, create_proto_tree, print_packet_info && print_details);
-    }
-
-    while (wtap_read(cf->wth, &err, &err_info, &data_offset)) {
-      framenum++;
-
-      if (process_packet(cf, edt, data_offset, wtap_phdr(cf->wth),
-                         wtap_buf_ptr(cf->wth),
-                         tap_flags)) {
-        /* Either there's no read filtering or this packet passed the
-           filter, so, if we're writing to a capture file, write
-           this packet out. */
-        if (pdh != NULL) {
-          if (!wtap_dump(pdh, wtap_phdr(cf->wth), wtap_buf_ptr(cf->wth), &err)) {
-            /* Error writing to a capture file */
-            switch (err) {
-
-            case WTAP_ERR_UNSUPPORTED_ENCAP:
-              /*
-               * This is a problem with the particular frame we're writing
-               * and the file type and subtype we're writing; note that,
-               * and report the frame number and file type/subtype.
-               */
-              fprintf(stderr,
-                      "Frame %u of \"%s\" has a network type that can't be saved in a \"%s\" file.\n",
-                      framenum, cf->filename,
-                      wtap_file_type_subtype_short_string(out_file_type));
-              break;
-
-            case WTAP_ERR_PACKET_TOO_LARGE:
-              /*
-               * This is a problem with the particular frame we're writing
-               * and the file type and subtype we're writing; note that,
-               * and report the frame number and file type/subtype.
-               */
-              fprintf(stderr,
-                      "Frame %u of \"%s\" is too large for a \"%s\" file.\n",
-                      framenum, cf->filename,
-                      wtap_file_type_subtype_short_string(out_file_type));
-              break;
-
-            default:
-              show_capture_file_io_error(save_file, err, FALSE);
-              break;
-            }
-            wtap_dump_close(pdh, &err);
-            g_free(shb_hdr);
-            exit(2);
-          }
+        /* If we're supposed to stop after max_packet_count packets,
+         * count this packet. 
+         * When the -c option has not been used, max_packet_count
+         * starts at 0.
+         */
+        if (max_packet_count != 0) {
+          max_packet_count--;
+          if (max_packet_count == 0)
+            packet_count_reached = TRUE;
         }
       }
-      /* 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.
-       * (unless we roll over max_packet_count ?)
+
+      /* Stop reading if we have the maximum number of packets or the
+       * maximum file size.
        */
-      if ( (--max_packet_count == 0) || (max_byte_count != 0 && data_offset >= max_byte_count)) {
+      if ( packet_count_reached || (max_byte_count != 0 && data_offset >= max_byte_count)) {
         err = 0; /* This is not an error */
         break;
       }