The -E is used to provide a secret for decrypting IPsec.
The secret may be provided through command line or as the file.
The problem is that tcpdump doesn't support yet opening files in capability mode
and the file may contain a list of the files to open.
As a workaround, for now, let's just disable capsicum if the -E
the option is provided.
PR: 236819
MFC after: 2 weeks
Not all libpcap backends use the BPF compatible set
of IOCTLs. For example the mlx5 backend uses libibverbs
which is currently not capsicum compatible.
Disable sandboxing for such backends.
MFC after: 3 days
Discussed with: emaste@
Approved by: re (kib)
Sponsored by: Mellanox Technologies
Vendor import two upstream commits:
c1bb8784abd3ca978e376b0d10e324db0491237b
9c4af7213cc2543a1f5586d8f2c19f86aa0cbe72
When using tcpdump -I -i wlanN and wlanN is not a monitor mode VAP,
tcpdump will print an error message saying rfmon is not supported.
Give a concise explanation as to how one might solve this problem by
creating a monitor mode VAP.
MFC after: 1 month
Approved by: hselasky (mentor), kib (mentor)
Sponsored by: Mellanox Technologies
Using HAVE_* is a internal tcpdump style standard.
We want to be consistent with the standard to upstream those changes in
the future.
Requested by: glebius@
of Capser and should use openat(2) unconditionally on FreeBSD.
openat(2) is mandatory when sandboxed with Capsicum, but still works
in the absence of Capsicum.
Reviewed by: AllanJude
After calling the cap_init(3) function Casper will fork from it's original
process, using pdfork(2). Forking from a process has a lot of advantages:
1. We have the same cwd as the original process.
2. The same uid, gid and groups.
3. The same MAC labels.
4. The same descriptor table.
5. The same routing table.
6. The same umask.
7. The same cpuset(1).
From now services are also in form of libraries.
We also removed libcapsicum at all and converts existing program using Casper
to new architecture.
Discussed with: pjd, jonathan, ed, drysdale@google.com, emaste
Partially reviewed by: drysdale@google.com, bdrewery
Approved by: pjd (mentor)
Differential Revision: https://reviews.freebsd.org/D4277
Also, the changes made in r272451 and r272653 that were lost in the
merge of 4.6.2 (r276788) have been restored.
PR: 199568
Differential Revision: https://reviews.freebsd.org/D3007
Reviewed by: brooks, hiren
Approved by: jmallett (mentor)
MFC after: 1 month
to casperd, but we cannot access the service we need we exit with an error.
This should not happen and just indicates some configuration error which
should be fixed, so we force the user to do it by failing.
Discussed with: emaste
in the future in a backward compatible (API and ABI) way.
The cap_rights_t represents capability rights. We used to use one bit to
represent one right, but we are running out of spare bits. Currently the new
structure provides place for 114 rights (so 50 more than the previous
cap_rights_t), but it is possible to grow the structure to hold at least 285
rights, although we can make it even larger if 285 rights won't be enough.
The structure definition looks like this:
struct cap_rights {
uint64_t cr_rights[CAP_RIGHTS_VERSION + 2];
};
The initial CAP_RIGHTS_VERSION is 0.
The top two bits in the first element of the cr_rights[] array contain total
number of elements in the array - 2. This means if those two bits are equal to
0, we have 2 array elements.
The top two bits in all remaining array elements should be 0.
The next five bits in all array elements contain array index. Only one bit is
used and bit position in this five-bits range defines array index. This means
there can be at most five array elements in the future.
To define new right the CAPRIGHT() macro must be used. The macro takes two
arguments - an array index and a bit to set, eg.
#define CAP_PDKILL CAPRIGHT(1, 0x0000000000000800ULL)
We still support aliases that combine few rights, but the rights have to belong
to the same array element, eg:
#define CAP_LOOKUP CAPRIGHT(0, 0x0000000000000400ULL)
#define CAP_FCHMOD CAPRIGHT(0, 0x0000000000002000ULL)
#define CAP_FCHMODAT (CAP_FCHMOD | CAP_LOOKUP)
There is new API to manage the new cap_rights_t structure:
cap_rights_t *cap_rights_init(cap_rights_t *rights, ...);
void cap_rights_set(cap_rights_t *rights, ...);
void cap_rights_clear(cap_rights_t *rights, ...);
bool cap_rights_is_set(const cap_rights_t *rights, ...);
bool cap_rights_is_valid(const cap_rights_t *rights);
void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src);
void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src);
bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little);
Capability rights to the cap_rights_init(), cap_rights_set(),
cap_rights_clear() and cap_rights_is_set() functions are provided by
separating them with commas, eg:
cap_rights_t rights;
cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT);
There is no need to terminate the list of rights, as those functions are
actually macros that take care of the termination, eg:
#define cap_rights_set(rights, ...) \
__cap_rights_set((rights), __VA_ARGS__, 0ULL)
void __cap_rights_set(cap_rights_t *rights, ...);
Thanks to using one bit as an array index we can assert in those functions that
there are no two rights belonging to different array elements provided
together. For example this is illegal and will be detected, because CAP_LOOKUP
belongs to element 0 and CAP_PDKILL to element 1:
cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL);
Providing several rights that belongs to the same array's element this way is
correct, but is not advised. It should only be used for aliases definition.
This commit also breaks compatibility with some existing Capsicum system calls,
but I see no other way to do that. This should be fine as Capsicum is still
experimental and this change is not going to 9.x.
Sponsored by: The FreeBSD Foundation
tcpdump will print an error message saying rfmon is not supported.
Give a concise explanation as to how one might solve this problem by
creating a monitor mode VAP.
For now, sandboxing is done only if -n option was specified and neither -z nor
-V options were given. Because it is very common to run tcpdump(8) with the -n
option for speed, I decided to commit sandboxing now. To also support
sandboxing when -n option wasn't specified, we need Casper daemon and its
services that are not available in FreeBSD yet.
- Limit file descriptors of a file specified by -r option or files specified
via -V option to CAP_READ only.
- If neither -r nor -V options were specified, we operate on /dev/bpf.
Limit its descriptor to CAP_READ and CAP_IOCTL plus limit allowed ioctls to
BIOCGSTATS only.
- Limit file descriptor of a file specified by -w option to CAP_SEEK and
CAP_WRITE.
- If either -C or -G options were specified, we open directory containing
destination file and we limit directory descriptor to CAP_CREATE, CAP_FCNTL,
CAP_FTRUNCATE, CAP_LOOKUP, CAP_SEEK and CAP_WRITE. Newly opened/created
files are limited to CAP_SEEK and CAP_WRITE only.
- Enter capability mode if -n option was specified and neither -z nor -V
options were specified.
Approved by: delphij, wxs
Sponsored by: The FreeBSD Foundation
o print-fr.c returned to code on vendor branch
o remove pmap_prot.h include from print-sunrprc.c
o remove gcc/i386-specific ntoh* write-arounds from tcpdump-stdinc.h
Reviewed by: bms
print-atm.c no longer performs special handling for FORE headers; these
can no doubt be re-added at a later date.
print-fr.c is effectively a no-op.
print-llc.c has had the default_print_unaligned() call removed as
tcpdump no longer defines this function, however the prototype is still
present. Suggest we roll in a diff to use print_unknown_data().
