hexdump(1): First cut capsicumification

[cem]

Summary

For now, only enter the sandbox for the last file processed (including
stdin for zero-argument mode).

Sandboxing all inputs will require a little restructuring of the
program.

Test Plan

• hexdump (tty input)
• hexdump -C foo.txt
• hexdump < foo.txt (stdin)

[emaste]

usr.bin/hexdump/display.c

340

extra blank line?
also cap_rights_t should probably sort first

usr.bin/hexdump/hexdump.c

44–45

style(9) as previously noted

100

up to you but I think we can combine all of the cap_*_limit into one if statement and one error

[cem]

usr.bin/hexdump/display.c

340

I think a blank line separating static variables from the rest makes it more clear that they aren't ordinary stack variables. Same reason to not have rights first.

usr.bin/hexdump/hexdump.c

44–45

Someone should actually add it to style(9) if we're going to keep claiming it's in there.

100

Sure.

[emaste]

usr.bin/hexdump/display.c

340

Ah I guess that makes sense.

usr.bin/hexdump/hexdump.c

44–45

Ok, just "style as previously noted" then :-)

Yes, we need to make this explicit in the man page.

[cem]

• Compress cap_*_limits together
• Put sys/capsicum.h in the right place

[cem]

Update to use helpers.