Kamil Frankowicz had found that truncated BE_STR and BE_SEQ ASN.1
elements could lead to an overread, from the source code it looked like
other ids could have this problem too. Move the checks introduced in
commit 72e501f out of the switch blocks to cover all ids by default.
This fixes GH#559 and GH#566.
Have asn1_print() print out OIDs regardless of whether we have any
modules loaded or not.
Have smi_decode_oid decode the OID to an array of unsigned ints
regardless of whether we have any modules loaded or not.
Have smi_print_variable() just use asn1_print() to print the OID of a
variable binding if we don't have any modules loaded; in that case,
we're not going to try to look the OID up with libsmi, so we don't need
a decoded version.
Have smi_print_value() not bother decoding the OID or looking the OID up
if we don't have any modules loaded; also, if we *do* have modules
loaded, check whether smi_decode_oid() succeeds.
Have the OID prefixes be arrays of uint8_t, and put the size of the
array into the list, rather than having them be "strings" and et the
length with strlen().
Have a macro to encapsulate X.690 section 8.19.4's rules for the first
octet of an OID value, and use it; that makes the components of the OID
clearer.
Also, if the prefix is longer than the remaining data in the OID - or
the remaining captured data - just skip it, don't treat that as an
error.
Catch INTEGER values with a length of 0, so we don't fetch a byte that
doesn't belong to the value.
Fix what appears to be a long-standing bug in the OID prefix matching
code, wherein the length of the *first* prefix in the table is used as
the length of *all* prefixes, and add some packet-length checking to
that list.
Report packets with an invalid SNMP version number as being SNMP, so
we at least indicate *that*.
Pull the code in asn1_print() to print octet sequences and (presumed)
printable strings into routines of their own, and use them when we're
printing them outside asn1_print().
That fixes some cases where we can run past the end of the packet
buffer.
with the tag '\summary:' for greping.
Remark: Currently some printers have no summary line.
Moreover:
Summarize all printers with a single line in INSTALL.txt
Have the call to smiLoadModule() be in a nd_load_smi_module() routine.
Have it set a *global* flag indicating whether a module has been loaded;
that's not per-netdissect_options. Use that global flag in print-snmp.c
- and don't test it once per loop iteration, it's not going to change
while the loop is running.
Have a routine to return the version of the library if we're built with
it or NULL if we're not.
That removes the last of the code that tests USE_LIBSMI or uses libsmi
from tcpdump.c.
Even if frontend/backend separation is ongoing, keep coherence between
option name and flag name at the moment.
Option name is 'm', thus s/ndo_sflag/ndo_mflag/.
Rename the variable to "error_status", as that's what it represents, and
as that doesn't collide with the error() function. Don't set it and
then not use the resulting value.
The purpose of this macro was to enable the file-by-file switch to NDO,
after which only tcpdump.c had a use of it and the definitions guarded
by it. Update tcpdump.c not to require them any more and dismiss the
unused definitions.
First, check for smi.h. If we don't have it, don't check for anything
else.
If we do have it, check for libsmi containing smiInit. If we don't have
it, don't check for anything else.
If we do have it, check, with our test program, whether we can use it.
If that succeeds, prepend -lsmi to LIBS, and set USE_LIBSMI. Otherwise,
don't do either of those.
Check, in source, *only* for USE_LIBSMI. If it's set, use libsmi,
otherwise don't - don't even include smi.h, even if we happened to have
found it, and don't print the libsmi version string.
If you pass in a value of oidlen and oidsize such that we can't store
*anything* into OID, this would be a problem; that *shouldn't* ever
happen, but this makes the code a bit more obviously correct.
And, as we require at least autoconf 2.61, and as autoconf 2.61 and
later have AC_TYPE_UINTn_T and AC_TYPE_INTn_T macros, we use them to
define the uintN_t and intN_t macros if the system doesn't define them
for us.
This lets us get rid of bitypes.h as well.
We do *not* want the behavior of isprint() and isgraph() to be
locale-dependent - we want both of them to return "true" only for ASCII
characters.
We have to do our own isascii() and toascii() on non-UN*X systems
anyway, so let's just do all of them ourselves.
Remove lots of $Header's and a few $Id's that all belong to the former
CVS repository of tcpdump itself. These keywords have been frozen since
the migration to git in late 2008.
For each decoder that has more than one instance of truncation signaling
and prints the same string in each instance make sure that the string is
declared as "static const char tstr[]" right after the initial includes
block. Where necessary, replace fputs(s, stdout) with equivalent
printf("%s", s).
with a maximum length, where a string shorter than that length is padded
with NULs), as "fn_print()" won't handle the maximum length *and* the
snapshot length and "fn_printn()" won't stop on a null string. Use it
where appropriate.
Always pass "snapend" to "fn_print()" and "fn_printn()" if they're
passed a pointer into the packet data; only pass NULL if they're being
handed a pointer into a buffer that's not part of the packet data.
Always check the return value of "fn_print()", "fn_printn()", and
"fn_printzp()" if they're passed "snapend", and do the appropriate
string termination and "packet truncated" indication if they return 1.
length; explicitly check against the snapshot length, instead.
In "asn1_parse()", always check against the length passed in before
fetching anything from the packet.
appropriately, and that GNUmakefile and the MSVC++ project file define
it apppriately, as we do with libpcap, rather than defining it in
"interface.h".
Undo the rcsid-shuffling and addition of extra #includes, as we no
longer need to arrange that "interface.h" be included before using _U_
in an RCS ID or copyright.
use "_U_" in the definitions of "rcsid[]", to eliminate
complaints about those variables being unused;
move the definitions after the include of "interface.h", or add
an include of "interface.h", so that "_U_" is defined.
Include "config.h" before including "tcpdump-stdinc.h" in
"missing/datalinks.c".
From Neil T. Spring: fixes for many of those warnings:
addrtoname.c, configure.in: Linux needs netinet/ether.h for
ether_ntohost
print-*.c: change char *foo = "bar" to const char *foo = "bar"
to appease -Wwrite-strings; should affect no run-time behavior.
print-*.c: make some variables unsigned.
print-bgp.c: plen ('prefix len') is unsigned, no reason to
validate by comparing to zero.
print-cnfp.c, print-rx.c: use intoa, provided by addrtoname,
instead of inet_ntoa.
print-domain.c: unsigned int l; (l=foo()) < 0 is guaranteed to
be false, so check for (u_int)-1, which represents failure,
explicitly.
print-isakmp.c: complete initialization of attrmap objects.
print-lwres.c: "if(x); print foo;" seemed much more likely to be
intended to be "if(x) { print foo; }".
print-smb.c: complete initialization of some structures.
In addition, add some fixes for the signed vs. unsigned comparison
warnings:
extract.h: cast the result of the byte-extraction-and-combining,
as, at least for the 16-bit version, C's integral promotions
will turn "u_int16_t" into "int" if there are other "int"s
nearby.
print-*.c: make some more variables unsigned, or add casts to an
unsigned type of signed values known not to be negative, or add
casts to "int" of unsigned values known to fit in an "int", and
make other changes needed to handle the aforementioned variables
now being unsigned.
print-isakmp.c: clean up the handling of error/status indicators
in notify messages.
print-ppp.c: get rid of a check that an unsigned quantity is >=
0.
print-radius.c: clean up some of the bounds checking.
print-smb.c: extract the word count into a "u_int" to avoid the
aforementioned problems with C's integral promotions.
print-snmp.c: change a check that an unsigned variable is >= 0
to a check that it's != 0.
Also, fix some formats to use "%u" rather than "%d" for unsigned
quantities.
following problem:
According to the ASN.1 documents, OIDs of the form 2.100.3 are
correctly encoded as 0x0603813403. tcpdump fails to properly
decode them - it displays the value 4.20.3 instead of 2.100.3.
