MFC r336609:

Fix several Coverity warnings in tftp

Some of the changes are in the libexec/tftpd directory, but to functions that
are only used by tftp(1) (they share some code).

* strcpy => strlcpy (1006793, 1006794, 1006796, 1006741)
* Unchecked return value and TOCTTOU (1009314)
* NULL pointer dereference (1018035, 1018036)

Reported by: Coverity
CID: 1006793, 1006794, 1006796, 1006741, 1009314, 1018035
CID: 1018036

MFC r336605:

Fix multiple Coverity warnings in tftpd(8)

* Initialize uninitialized variable (CID 1006502)
* strcpy => strlcpy (CID 1006792, 1006791, 1006790)
* Check function return values (CID 1009442, 1009441, 1009440)
* Delete dead code in receive_packet (not reported by Coverity)
* Remove redundant alarm(3) in receive_packet (not reported by Coverity)

Reported by: Coverity
CID: 1006502, 1006792, 1006791, 1006790, 1009442, 1009441, 1009440
Differential Revision: https://reviews.freebsd.org/D11287

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Mark tftp_log() as __printflike() (which would have caught the bug
fixed in r246106) and deal with the fallout.

MFC after: 2 weeks

Remove extra %s from debug statement that ends up crashing tftpd if
debug is set very high (like -d15 in my case).

Obtained from: Yahoo! Inc
MFC after: 2 weeks

Use correct size in snprintf.
Remove unused buffer.

PR: 174631
Submitted by: Henning Petersen
MFC after: 1 month

Fix warnings found by -Wmising-variable-declarations.

This self-written compiler warning, which is hopefully going to be
committed into LLVM sources soon, warns about potentially missing
`static' keywords, similar to -Wmissing-prototypes.

- bin/pax: Move external declaration of chdname and s_mask into extern.h.
- bin/setfacl: Move setfacl.c-specific stuff out of setfacl.h.
- sbin/mount_fusefs: Remove char *progname; use getprogname().
- others: add `static' where possible.

Avoid error log for transfer stop w/o error code.

A number of tftp clients, including the one in Intel's pxe boot loader,
may intentionally stop a transfer using error code 0 (i.e., EUNDEF).
These are not real errors. Avoid spamming log files with these by
logging them at level LOG_DEBUG instead.

Discussed on -hackers with an initial patch proposal; this change is an
improved approach suggested by kan@.

Fix warning when compiling with gcc46:
error: variable 'bp' set but not use

Approved by: dim
MFC After: 3 days

Spelling fixes for libexec/

Fix tftp_log() usage.

Move the pfrom initialization from before the setjmp to after the
setjmp to avoid warnings on the powerpc build...

Bring in new files from edwin's tftp