Add support for parsing UCL config files to newsyslog

[allanjude]

Summary

Missing man page updates
Requires newer version of UCL than is included in base (remove hack in Makefile once base is updated, in meantime use port)
Requires much review, I am a very novice C programmer

[allanjude]

etc/newsyslog.ucl

2

This 'sentinel' lets newsyslog know that this file is in FreeBSD UCL version 0.1. If it does not see this at the top of the file, it treats it as a legacy .conf file in the original format.

This will allow the new format to keep the original filename, newsyslog.conf
It also allows for 'versioning' of the config schema, so we can easily keep backwards compatibility if we change the config syntax again in the future.

4

This is a comment, of the original line from newsyslog.conf

27

A new format for the time specification would likely be very welcome

204

Working with Vsevolod Stakhov (cebka@) to come up with a way to do opaque strip splitting (https://github.com/vstakhov/libucl/issues/36)

so this could be: flags = binary, nosignal
or something similar

usr.sbin/newsyslog/Makefile

10

Dirty hack until contrib/libucl is updated. Not in a rush for this as there are some more features to be added to libucl that would be useful for this project.

usr.sbin/newsyslog/newsyslog.c

1088

taste the first line of the file. If it isn't what we want, rewind() and continue as before

Otherwise, pass it off to the new config parser

1486

This is the map that uses the callbacks. It ended up different than I originally pictures, but I think it is still nicer than a giant strcmp() if ladder

1690

This is mostly just verbatim from the original code. It can likely be improved, but I wanted to try to avoid introducing too many new bugs at once

[cse_cem_gmail_com]

Not a super thorough review, just passed over briefly. I'm not an expert on UCL nor newsyslog.

etc/newsyslog.ucl

6

Note to other reviewers: UCL doesn't implicitly understand 'mode' is octal, we just parse this field specially later in the patch.

usr.sbin/newsyslog/newsyslog.c

1083

Using double for this is odd. Usually we just multiply by a power of 10 (or 0x10).

1087

Check the return value of fgets(3) before using line.

1093

style(9): The body of the if() statement goes on a line by itself.

1094–1097

Floating point equality is somewhat fragile. Use integers for this.

1503

You probably want to lseek(2) the fd back to the beginning — fgets(3) and other stdio functions may buffer large chunks of the file and the fd may be well past the beginning of the UCL stuff.

1509

extra space (style)

1515

extra space

1521–1523

There's lots of this, so I'm not going to mark it every time. But, in style(9) it is suggested that if/while/for braces be omitted when they are not required (with exceptions for complicated bodies). printf is not complicated.

1657

style(9): return (true);

1665–1666

Ah, I see, you force octal here. Ok.

1700–1701

these should be on the same line (style(9))

[allanjude]

Update with feedback from cem

[allanjude]

More style(9)

[allanjude]

usr.sbin/newsyslog/newsyslog.c

1083

So make 'uclver' an int, and multiply the result of strtod(3) by 10?

[cse_cem_gmail_com]

usr.sbin/newsyslog/newsyslog.c

1083

That'd work. You could also just use an integer version (e.g. 1) and strtol or whatever. (This is just versioning the config schema, right?)

[cse_cem_gmail_com]

Changes between 3218 and 3220 LGTM.

usr.sbin/newsyslog/newsyslog.c

1693–1694

These on the same line too

1735

extra space

[cse_cem_gmail_com]

Looks pretty good!

usr.sbin/newsyslog/newsyslog.c

213

Don't need the backslash. typedef isn't part of the preprocessor.

214

It looks like the 3rd parameter here should be struct conf_entry * based on later functions.

1088–1092

You can drop the lineptr variable entirely. You would use strtod like:

uclver = strtod(&line[5], NULL);

1488–1499

I think you can drop the (conf_helper_func) casts if you change the function typedef from void * to struct conf_entry *.

1552

The usual pattern for this is:

if ((working->flags & CE_NOSIGNAL) != 0) {

1607–1608

You can drop result entirely.

target->uid = ucl_object_toint(obj);

1613

Use atol or strtol. uid_t is unsigned and yes, somebody has >2 billion uids (or at least uses the high numbers).

1614

target->uid = atol(val); or similar

1625–1626

target->uid = pwd->pw_uid;

1642

extra parens, you don't need them around function calls

1650

Probably atol here too.

1662

Probably: if (sscanf(...) != 1) {.

sscanf may return EOF (-1) as well as (0) depending on what went wrong. Anything other than 1 conversion is failure for us.

1676

(same re: sscanf(...) != 1.)

1713

No 'n' needed for xz, I think?

1794–1795

same line

1797–1798

also same line

1801–1802

same

1806–1812

braces can be dropped here.

1826–1827

same

1887

You can drop the comment, the pattern is well understood.

Alternatively, you can include sys/cdefs.h (if it isn't already) and use __unused like:

conf_set_unknown(..., struct conf_entry *target __unused)

3124

extra space

3137

If you want to reduce indentation, you can do:

if (strcasecmp(...) != 0)
  continue;

And then the rest of the loop body can be unindented.

3139–3141

Can drop NULL check entirely. Just don't put a NULL callback in your table :-).

3145

if (!found && ...)

3151

(ret)

[allanjude]

Update with more feedback from cem

[allanjude]

usr.sbin/newsyslog/newsyslog.c

214

I originally had this code in libucl, so it was generalized to work in places other than just newsyslog. I just dumped it into newsyslog for now.

1088–1092

dropped

1488–1499

see response to https://reviews.freebsd.org/D1548#inline-9104

1503

I moved the rewind(cf) that was done only in the case of a non-ucl config earlier, so it should resolve this

1552

Not my code, but since it is inside my function, fixing it

1607–1608

ok

1613

this case doesn't need to be here, it is left over. If the user entered a number, it will by type UCL_INT, unless they put a decimal in it or something silly, in which case they deserve an error anyway.

1642

those were existing, but removed

1713

It is done so it allows the user to do 'xzip' as well. same reason bzip is cut to 4 chars, so bzip or bzip2 both are accepted.

3139–3141

This is there on purpose. We have a NULL callback for the 'file' key, because it is handled elsewhere, and we don't want that key to trip the 'default' callback. See line #1486

This should be documented better, my goal is to make something generic to speed up the process of converting other utilities to UCL.

[cse_cem_gmail_com]

LGTM.

usr.sbin/newsyslog/newsyslog.c

1713

Ah, I got bzip/bzip2 but hadn't seen xzip before. Seems reasonable to me.

3139–3141

Ok.

3145

Typo — I think you want !found?

[allanjude]

usr.sbin/newsyslog/newsyslog.c

1713

This question made me think about it more, and improve it further
use strncasecmp(val, ..., 2) in all cases:

so gzip accepts: gz gzip
bzip2: bz bz2 bzip bzip2
xz: xz xzip yes
none: no none

(added yes to xz since we accept no)

3145

good catch, thank you

[allanjude]

Further expand the accepted input for the compression parameter

[cse_cem_gmail_com]

LGTM.

usr.sbin/newsyslog/newsyslog.c

1705

Maybe just strcasecmp() for "yes"?

[allanjude]

Feedback from cem

[mat]

Mmm, newsyslog.conf has:

<include> /etc/newsyslog.conf.d/*
<include> /usr/local/etc/newsyslog.conf.d/*

This doesn't seem to have been included here.

[allanjude]

In D1548#23, @mat wrote:

Mmm, newsyslog.conf has:

<include> /etc/newsyslog.conf.d/*
<include> /usr/local/etc/newsyslog.conf.d/*

This doesn't seem to have been included here.

Correct, I've not added that yet. I'll get that done shortly.

[eadler]

overall reasonable, just some quick comments.

usr.sbin/newsyslog/newsyslog.c

1083

style(9) prefers not having init inline

1095

theoretical overflow not handled, but is likely fine

1518

TODO comment :)

1541

if (!success) {} ?

1783

if ul == 0, check errno?

[allanjude]

Address Feedback

[allanjude]

Update based on feedback

[emaste]

What's next for this patch?