Make the maximum block size big enough for max-size D-Bus packets.

Change-Id: I352db07084294629160f16f6cf1e07f902a2844f
Reviewed-on: https://code.wireshark.org/review/29711
Reviewed-by: Guy Harris <guy@alum.mit.edu>

1 files changed, 15 insertions, 12 deletions

diff --git a/wiretap/pcapng.c b/wiretap/pcapng.c
index cfe28b91d6..89c623d537 100644
--- a/wiretap/pcapng.c
+++ b/wiretap/pcapng.c
@@ -51,18 +51,6 @@ pcapng_close(wtap *wth);
 #define MIN_BLOCK_SIZE  ((guint32)(sizeof(pcapng_block_header_t) + sizeof(guint32)))
 
 /*
- * In order to keep from trying to allocate large chunks of memory,
- * which could either fail or, even if it succeeds, chew up so much
- * address space or memory+backing store as not to leave room for
- * anything else, we impose an upper limit on the size of blocks
- * we're willing to handle.
- *
- * For now, we pick an arbitrary limit of 16MB (OK, fine, 16MiB, but
- * don't try saying that on Wikipedia :-) :-) :-)).
- */
-#define MAX_BLOCK_SIZE  (16*1024*1024)
-
-/*
  * Minimum SHB size = minimum block size + size of fixed length portion of SHB.
  */
 #define MIN_SHB_SIZE    ((guint32)(MIN_BLOCK_SIZE + sizeof(pcapng_section_header_block_t)))
@@ -163,6 +151,21 @@ struct option {
 /* MSBit of option code means "local type" */
 #define OPT_LOCAL_FLAG       0x8000
 
+/*
+ * In order to keep from trying to allocate large chunks of memory,
+ * which could either fail or, even if it succeeds, chew up so much
+ * address space or memory+backing store as not to leave room for
+ * anything else, we impose upper limits on the size of blocks we're
+ * willing to handle.
+ *
+ * We pick a limit of an EPB with a maximum-sized D-Bus packet and 128 KiB
+ * worth of options; we use the maximum D-Bus packet size as that's larger
+ * than the maximum packet size for other link-layer types, and the maximum
+ * packet size for other link-layer types is currently small enough that
+ * the resulting block size would be less than the previous 16 MiB limit.
+ */
+#define MAX_BLOCK_SIZE (MIN_EPB_SIZE + WTAP_MAX_PACKET_SIZE_DBUS + 131072)
+
 /* Note: many of the defined structures for block data are defined in wtap.h */
 
 /* Packet data - used for both Enhanced Packet Block and the obsolete Packet Block data */