[Bug 217490] tcpdump fails on 10-stable complaining: "pcap_loop: BIOCROTZBUF: Capabilities insufficient"

[bugzilla-noreply at freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=217490

            Bug ID: 217490
           Summary: tcpdump fails on 10-stable complaining: "pcap_loop:
                    BIOCROTZBUF: Capabilities insufficient"
           Product: Base System
           Version: 10.3-STABLE
          Hardware: Any
                OS: Any
            Status: New
          Severity: Affects Some People
          Priority: ---
         Component: kern
          Assignee: freebsd-bugs at FreeBSD.org
          Reporter: jau at iki.fi

Here is an example of the problem in action...

# tcpdump host www.funet.fi
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on em0, link-type EN10MB (Ethernet), capture size 65535 bytes
tcpdump: pcap_loop: BIOCROTZBUF: Capabilities insufficient
0 packets captured
1 packet received by filter
0 packets dropped by kernel


When running tcpdump as root I certainly did not expect that.

When I tried "ktrace -dit+ tcpdump host www.funet.fi" the relevant part of
the output from kdump was as shown below. This does not make any sense
to me. It is not all that long ago when tcpdump worked just fine.
I can only imagine that the capabilities check for the ioctl() operation
BIOCROTZBUF ends up somehow totally pearshape.


 63208 tcpdump  GIO   fd 2 wrote 72 bytes
       "listening on em0, link-type EN10MB (Ethernet), capture size 65535 byte\
        s
       "
 63208 tcpdump  RET   write 72/0x48
 63208 tcpdump  CALL  clock_gettime(0x4,0x7fffffffe380)
 63208 tcpdump  RET   clock_gettime 0
 63208 tcpdump  CALL  select(0x4,0x7fffffffe300,0,0,0x7fffffffe390)
 63208 tcpdump  RET   select 0
 63208 tcpdump  CALL  ioctl(0x3,0x40184280,0x7fffffffe3a0)
 63208 tcpdump  RET   ioctl -1 errno 93 Capabilities insufficient
 63208 tcpdump  CALL  stat(0x7fffffffddf0,0x7fffffffdd78)
 63208 tcpdump  NAMI  "/usr/share/nls/C/libc.cat"
 63208 tcpdump  RET   stat -1 errno 2 No such file or directory
 63208 tcpdump  CALL  stat(0x7fffffffddf0,0x7fffffffdd78)
 63208 tcpdump  NAMI  "/usr/share/nls/libc/C"
 63208 tcpdump  RET   stat -1 errno 2 No such file or directory
 63208 tcpdump  CALL  stat(0x7fffffffddf0,0x7fffffffdd78)
 63208 tcpdump  NAMI  "/usr/local/share/nls/C/libc.cat"
 63208 tcpdump  RET   stat -1 errno 2 No such file or directory
 63208 tcpdump  CALL  stat(0x7fffffffddf0,0x7fffffffdd78)
 63208 tcpdump  NAMI  "/usr/local/share/nls/libc/C"
 63208 tcpdump  RET   stat -1 errno 2 No such file or directory
 63208 tcpdump  CALL  write(0x2,0x7fffffffdeb0,0x3b)
 63208 tcpdump  GIO   fd 2 wrote 59 bytes
       "tcpdump: pcap_loop: BIOCROTZBUF: Capabilities insufficient
       "

My assumption is that this will affect anyone using tcpdump on
10-stable.

-- 
You are receiving this mail because:
You are the assignee for the bug.