pcapng: have per-section interface tables rather than per-file.

This moves us closer to fixing bug 16531; it addresses the second issue
there, as the right snapslen is used for packets in the second section,
so we no longer get errors reading the file.

It still doesn't fix the *names* of the interfaces, and it doesn't - and
*shouldn't* - show the interfaces with different interface numbers, as
the numbers are per-section rather than global.

Change-Id: Ia3aa3309b75a4bcd9f229048ddce6a981b9409b1
Ping-Bug: 16531
Reviewed-on: https://code.wireshark.org/review/36985
Petri-Dish: Guy Harris <gharris@sonic.net>
Tested-by: Petri Dish Buildbot
Reviewed-by: Guy Harris <gharris@sonic.net>

1 files changed, 34 insertions, 21 deletions

diff --git a/wiretap/pcapng.c b/wiretap/pcapng.c
index 244e02bb7c..9ac8b30933 100644
--- a/wiretap/pcapng.c
+++ b/wiretap/pcapng.c
@@ -208,6 +208,7 @@ typedef struct section_info_t {
     gboolean byte_swapped; /**< TRUE if this section is not in our byte order */
     guint16 version_major; /**< Major version number of this section */
     guint16 version_minor; /**< Minor version number of this section */
+    GArray *interfaces;    /**< Interfaces found in this section */
     gint64 shb_off;        /**< File offset of the SHB for this section */
 } section_info_t;
 
@@ -223,7 +224,6 @@ typedef struct interface_info_s {
 typedef struct {
     guint current_section_number; /**< Section number of the current section being read sequentially */
     GArray *sections;             /**< Sections found in the capture file. */
-    GArray *interfaces;           /**< Interfaces found in the capture file. */
     wtap_new_ipv4_callback_t add_new_ipv4;
     wtap_new_ipv6_callback_t add_new_ipv6;
 } pcapng_t;
@@ -1124,7 +1124,7 @@ pcapng_read_decryption_secrets_block(FILE_T fh, pcapng_block_header_t *bh,
 }
 
 static gboolean
-pcapng_read_packet_block(FILE_T fh, pcapng_block_header_t *bh, pcapng_t *pn,
+pcapng_read_packet_block(FILE_T fh, pcapng_block_header_t *bh,
                          const section_info_t *section_info,
                          wtapng_block_t *wblock,
                          int *err, gchar **err_info, gboolean enhanced)
@@ -1272,13 +1272,14 @@ pcapng_read_packet_block(FILE_T fh, pcapng_block_header_t *bh, pcapng_t *pn,
                   packet.cap_len,
                   packet.interface_id);
 
-    if (packet.interface_id >= pn->interfaces->len) {
+    if (packet.interface_id >= section_info->interfaces->len) {
         *err = WTAP_ERR_BAD_FILE;
-        *err_info = g_strdup_printf("pcapng_read_packet_block: interface index %u is not less than interface count %u",
-                                    packet.interface_id, pn->interfaces->len);
+        *err_info = g_strdup_printf("pcapng_read_packet_block: interface index %u is not less than section interface count %u",
+                                    packet.interface_id,
+                                    section_info->interfaces->len);
         return FALSE;
     }
-    iface_info = g_array_index(pn->interfaces, interface_info_t,
+    iface_info = g_array_index(section_info->interfaces, interface_info_t,
                                packet.interface_id);
 
     if (packet.cap_len > wtap_max_snaplen_for_encap(iface_info.wtap_encap)) {
@@ -1480,7 +1481,6 @@ pcapng_read_packet_block(FILE_T fh, pcapng_block_header_t *bh, pcapng_t *pn,
 
 static gboolean
 pcapng_read_simple_packet_block(FILE_T fh, pcapng_block_header_t *bh,
-                                pcapng_t *pn,
                                 const section_info_t *section_info,
                                 wtapng_block_t *wblock,
                                 int *err, gchar **err_info)
@@ -1511,12 +1511,12 @@ pcapng_read_simple_packet_block(FILE_T fh, pcapng_block_header_t *bh,
         return FALSE;
     }
 
-    if (0 >= pn->interfaces->len) {
+    if (0 >= section_info->interfaces->len) {
         *err = WTAP_ERR_BAD_FILE;
-        *err_info = g_strdup("pcapng_read_simple_packet_block: SPB appeared before any IDBs");
+        *err_info = g_strdup("pcapng_read_simple_packet_block: SPB appeared before any IDBs in the section");
         return FALSE;
     }
-    iface_info = g_array_index(pn->interfaces, interface_info_t, 0);
+    iface_info = g_array_index(section_info->interfaces, interface_info_t, 0);
 
     if (section_info->byte_swapped) {
         simple_packet.packet_len   = GUINT32_SWAP_LE_BE(spb.packet_len);
@@ -2610,15 +2610,15 @@ pcapng_read_block(wtap *wth, FILE_T fh, pcapng_t *pn,
                     return PCAPNG_BLOCK_ERROR;
                 break;
             case(BLOCK_TYPE_PB):
-                if (!pcapng_read_packet_block(fh, &bh, pn, section_info, wblock, err, err_info, FALSE))
+                if (!pcapng_read_packet_block(fh, &bh, section_info, wblock, err, err_info, FALSE))
                     return PCAPNG_BLOCK_ERROR;
                 break;
             case(BLOCK_TYPE_SPB):
-                if (!pcapng_read_simple_packet_block(fh, &bh, pn, section_info, wblock, err, err_info))
+                if (!pcapng_read_simple_packet_block(fh, &bh, section_info, wblock, err, err_info))
                     return PCAPNG_BLOCK_ERROR;
                 break;
             case(BLOCK_TYPE_EPB):
-                if (!pcapng_read_packet_block(fh, &bh, pn, section_info, wblock, err, err_info, TRUE))
+                if (!pcapng_read_packet_block(fh, &bh, section_info, wblock, err, err_info, TRUE))
                     return PCAPNG_BLOCK_ERROR;
                 break;
             case(BLOCK_TYPE_NRB):
@@ -2671,7 +2671,8 @@ pcapng_read_block(wtap *wth, FILE_T fh, pcapng_t *pn,
 
 /* Process an IDB that we've just read. The contents of wblock are copied as needed. */
 static void
-pcapng_process_idb(wtap *wth, pcapng_t *pcapng, wtapng_block_t *wblock)
+pcapng_process_idb(wtap *wth, section_info_t *section_info,
+                   wtapng_block_t *wblock)
 {
     wtap_block_t int_data = wtap_block_create(WTAP_BLOCK_IF_DESCR);
     interface_info_t iface_info;
@@ -2699,7 +2700,7 @@ pcapng_process_idb(wtap *wth, pcapng_t *pcapng, wtapng_block_t *wblock)
     else
         iface_info.fcslen = -1;
 
-    g_array_append_val(pcapng->interfaces, iface_info);
+    g_array_append_val(section_info->interfaces, iface_info);
 }
 
 /* Process a DSB that we have just read. */
@@ -2723,8 +2724,6 @@ pcapng_open(wtap *wth, int *err, gchar **err_info)
     gint64 saved_offset;
     section_info_t first_section, new_section, *current_section;
 
-    pn.interfaces = NULL;
-
     /* we don't know the byte swapping of the file yet */
     first_section.byte_swapped = FALSE;
     first_section.version_major = -1;
@@ -2795,13 +2794,18 @@ pcapng_open(wtap *wth, int *err, gchar **err_info)
      * in C, that's section 0. :-)
      */
     pcapng->current_section_number = 0;
+
+    /*
+     * Create the array of interfaces for the first section.
+     */
+    first_section.interfaces = g_array_new(FALSE, FALSE, sizeof(interface_info_t));
+
     /*
      * Allocate the sections table with space reserved for the first
      * section, and add that section.
      */
     pcapng->sections = g_array_sized_new(FALSE, FALSE, sizeof(section_info_t), 1);
     g_array_append_val(pcapng->sections, first_section);
-    pcapng->interfaces = g_array_new(FALSE, FALSE, sizeof(interface_info_t));
 
     wth->subtype_read = pcapng_read;
     wth->subtype_seek_read = pcapng_seek_read;
@@ -2858,7 +2862,7 @@ pcapng_open(wtap *wth, int *err, gchar **err_info)
                 return WTAP_OPEN_ERROR;
             }
         }
-        pcapng_process_idb(wth, pcapng, &wblock);
+        pcapng_process_idb(wth, current_section, &wblock);
         wtap_block_free(wblock.block);
         pcapng_debug("pcapng_open: Read IDB number_of_interfaces %u, wtap_encap %i",
                       wth->interface_data->len, wth->file_encap);
@@ -2932,6 +2936,7 @@ pcapng_read(wtap *wth, wtap_rec *rec, Buffer *buf, int *err,
                  * section_info_t's for this file.
                  */
                 pcapng->current_section_number++;
+                new_section.interfaces = g_array_new(FALSE, FALSE, sizeof(interface_info_t));
                 new_section.shb_off = *data_offset;
                 g_array_append_val(pcapng->sections, new_section);
                 break;
@@ -2939,7 +2944,7 @@ pcapng_read(wtap *wth, wtap_rec *rec, Buffer *buf, int *err,
             case(BLOCK_TYPE_IDB):
                 /* A new interface */
                 pcapng_debug("pcapng_read: block type BLOCK_TYPE_IDB");
-                pcapng_process_idb(wth, pcapng, &wblock);
+                pcapng_process_idb(wth, current_section, &wblock);
                 wtap_block_free(wblock.block);
                 break;
 
@@ -3102,8 +3107,16 @@ pcapng_close(wtap *wth)
     pcapng_t *pcapng = (pcapng_t *)wth->priv;
 
     pcapng_debug("pcapng_close: closing file");
+
+    /*
+     * Free up the interfaces tables for all the sections.
+     */
+    for (guint i = 0; i < pcapng->sections->len; i++) {
+        section_info_t *section_info = &g_array_index(pcapng->sections,
+                                                      section_info_t, i);
+        g_array_free(section_info->interfaces, TRUE);
+    }
     g_array_free(pcapng->sections, TRUE);
-    g_array_free(pcapng->interfaces, TRUE);
 }
 
 typedef struct pcapng_block_size_t