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author | Guy Harris <guy@alum.mit.edu> | 2017-06-04 18:58:40 -0700 |
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committer | Guy Harris <guy@alum.mit.edu> | 2017-06-05 05:28:26 +0000 |
commit | d0865fd619454a9ac06b1c7d287dc438aff50bb0 (patch) | |
tree | 91efc24ec72d274b1529342041641b36939236f2 /wiretap/pcap-common.c | |
parent | 17965f57f178aa7e4027f2d363658098e2f1abb3 (diff) | |
download | wireshark-d0865fd619454a9ac06b1c7d287dc438aff50bb0.tar.gz |
Allow bigger snapshot lengths for D-Bus captures.
Use WTAP_MAX_PACKET_SIZE_STANDARD, set to 256KB, for everything except
for D-Bus captures. Use WTAP_MAX_PACKET_SIZE_DBUS, set to 128MB, for
them, because that's the largest possible D-Bus message size. See
https://bugs.freedesktop.org/show_bug.cgi?id=100220
for an example of the problems caused by limiting the snapshot length to
256KB for D-Bus.
Have a snapshot length of 0 in a capture_file structure mean "there is
no snapshot length for the file"; we don't need the has_snap field in
that case, a value of 0 mean "no, we don't have a snapshot length".
In dumpcap, start out with a pipe buffer size of 2KB, and grow it as
necessary. When checking for a too-big packet from a pipe, check
against the appropriate maximum - 128MB for DLT_DBUS, 256KB for
everything else.
Change-Id: Ib2ce7a0cf37b971fbc0318024fd011e18add8b20
Reviewed-on: https://code.wireshark.org/review/21952
Petri-Dish: Guy Harris <guy@alum.mit.edu>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Guy Harris <guy@alum.mit.edu>
Diffstat (limited to 'wiretap/pcap-common.c')
-rw-r--r-- | wiretap/pcap-common.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/wiretap/pcap-common.c b/wiretap/pcap-common.c index e67cd3956f..0950e5adad 100644 --- a/wiretap/pcap-common.c +++ b/wiretap/pcap-common.c @@ -702,6 +702,27 @@ wtap_wtap_encap_to_pcap_encap(int encap) return -1; } +/* + * For most encapsulations, we use WTAP_MAX_PACKET_SIZE_STANDARD, as + * that should be enough for most link-layer types, and shouldn't be + * too big. + * + * For D-Bus, we use WTAP_MAX_PACKET_SIZE_DBUS, because the maximum + * D-Bus message size is 128MB, which is bigger than we'd want for + * all link-layer types - files with that snapshot length might cause + * some programs reading them to allocate a huge and wasteful buffer + * and, at least on 32-bit platforms, run the risk of running out of + * memory. + */ +guint +wtap_max_snaplen_for_encap(int wtap_encap) +{ + if (wtap_encap == WTAP_ENCAP_DBUS) + return WTAP_MAX_PACKET_SIZE_DBUS; + else + return WTAP_MAX_PACKET_SIZE_STANDARD; +} + gboolean wtap_encap_requires_phdr(int wtap_encap) { |