read packets is "p->bufsize" bytes long, not MAXDLBUF bytes long
("p->bufsize" is set to (MAXDLBUF * sizeof sizeof(bpf_u_int32))), so
supply that as the "maxlen" value in the "data" argument to "getmsg()".
1. During termination processing set up by atexit() under a 2.0.x
kernel, if a socket had been previously closed and the handle freed
due to an error, pcap_close_all() and pcap_close_linux() would
nevertheless try to work with these structures and then crash.
pcap_close_linux() is now called directly when necessary during
error processing.
2. atexit() could get called more than once because the did_atexit
flag wasn't being set.
3. If iface_get_arptype() returns an error because the ioctl() call
failed (probably due to "no such device"), live_open_new() now
returns a fatal error to pcap_open_live() and the call to
live_open_old() is short-circuited.
4. Applications using libpcap would appear to listen on an interface
that was down.
a. iface_bind() and iface_bind_old() now check for pending errors
after bind(). In turn, pcap_open_live() now returns an error
status if there was a pending error after bind().
b. After draining the socket, set_kernel_filter() now checks to see
if the error was the expected EAGAIN and returns a fatal error
to pcap_setfilter() if not. In turn, pcap_setfilter() now
returns an error status if there was a network error.
5. pcap_setfilter() was putting an error message into errbuf after a
failed call to install_bpf_program(). This was unnecessary since
install_bpf_program() puts its own error message into errbuf.
ARPHRD_IEEE80211_PRISM, for sniffing on Prism II-based 802.11 interfaces
and getting the special Prism header, so we should map it to
DLT_PRISM_HEADER.
Don't subtract "tp_drops" from "tp_packets" - "ps_recv", on BSD,
at least, includes packets dropped due to lack of buffer space,
so it should do so on Linux as well.
The "len" argument to "getsockopt()" is a value-result
parameter, initially containing the size of the buffer being
supplied; set it before the call.
Catch "getsockopt()" errors and, if it's an error other than
EOPNOTSUPP, return an error.
Add a new "pcap_findalldevs()" routine to get a list of all
interfaces that can be opened with "pcap_open_live()", and a
"pcap_freealldevs()" routine to free the list.
Make "pcap_lookupdev()" use it, which also arranges that it will
not return a device that cannot be opened by "pcap_open_live()".
Allow the "any" device to be opened, on Linux, with "promisc"
non-zero; ignore the request for promiscuity, and return a
warning message indicating that promiscuous mode isn't supported
on the "any" device.
Document "pcap_findalldevs()" and "pcap_lookupdev()", and clean up some
items in the libpcap man page.
packets queued up on the socket when we set a kernel filter on the
socket, so that if there are any queue-up packets that wouldn't have
passed the new filter, we don't see them. (Some other packet capture
mechanisms do this automatically; this prevents tcpdump, for example,
from showing or saving, when run with a filter, some packets that
wouldn't have passed the filter.)
XXX - do we have to do this on any other platforms?
Choose whether to compile in the code to modify filter programs for use
in the kernel, and to flush queued-up packet and set a kernel filter, on
whether SO_ATTACH_FILTER is defined (i.e., on whether we have kernel
filter support in our build environment), rather than on whether
HAVE_PF_PACKET_SOCKETS is defined (i.e., on whether we have PF_PACKET
support in our build environment), as we choose whether to *use* that
code based on whether SO_ATTACH_FILTER is defined.
SOL_PACKET/PACKET_STATISTICS "getsockopt()" call, on Linux kernels that
support it, to get packet statistics, so that we can report the number
of dropped packets, and always use <linux/if_packet.h> to get
definitions for PF_PACKET sockets, so that we don't depend on glibc's
header files having been updated to support all the latest shiniest
kernel features (many systems with 2.4[.x] kernels don't have a
<netpacket/packet.h> that defines "struct tpacket_stats", for example,
so we wouldn't have been able to support that kernel feature on those
systems).
Update the note on libpcap being "not very well suited for interactive
programs" to note that at least some of what it says is necessary is
already supported.
to DLT_C_HDLC.
Arrange that if "map_arphrd_to_dlt()" supplies DLT_LINUX_SLL as the
link-layer DLT_ value, we capture in cooked mode.
Return DLT_LINUX_SLL for ARPHRD_PPP, as some PPP code in the kernel
supplies no link-layer header whatsoever to PF_PACKET sockets, other PPP
code supplies PPP link-layer headers ("syncppp.c"), and PPP-over-ISDN
appears to supply random link-layer headers (there's code in Ethereal,
for example, to cope with PPP-over-ISDN captures with which the Ethereal
developers have had to cope, heuristically trying to determine which of
the oddball link-layer headers particular packets have).
#5228, to correctly check for Appletalk for EtherTalk phase II - they
use 802.3 with LLC SNAP packets, rather than D/I/X Ethernet packets.
His patch made "atalk" check for Appletalk ARP as well as other
Appletalk packets; I've instead added a separate "aarp" packet type,
leaving "atalk" checking only for ETHERTYPE_ATALK, so you can check for
ETHERTYPE_ATALK, ETHERTYPE_AARP, or both.
counting any extra jumps required by a flowgraph node (the conditional
jump instructions have an 8-bit offset; if the target is more than 256
instructions away, we generate a nearby "jump always" to the target, and
jump to that instead).
letting you filter based on the VLAN to which a packet belongs, and an
improvement to the printing of VLAN packets (adding an extra space to
separate the VLAN priority and flags from the next stuff printed).
guy