noel alanguilan

givens:
server is running samba on linux; users are on windows

problem:
a single or group of files need to be “isolated” from the users, i.e. certain executables, malware, spyware, etc. on the server.

it files cannot be deleted yet because the malware in the users’ computer will jusT recreate them. a remedial solution is to set the file permissions of the files to non-readable; non-executable and the file ownership ‘root’. once the workstations are cleaned then the files can be deleted.

commands:

• go to the top of the shared subdirectory
• set the ownership and file permissions using the commands below; ‘research/’ and ‘root.root’ are examples, change to what applies to your setup

$ find research/ -iname *.exe -exec chmod 0000 {} \;
$ find research/ -iname *.exe -exec chown 'root.root' {} \;

links:
samba ownerships and permissions

this has been a long time in coming. finally. i can run photoshop with the help of wine on linux. i would prefer that it run natively — a photoshop version that runs specifically on linux — but adobe so far has been mum about plans to port photoshop to linux.

wine is an open source compatibility layer that helps windows programs run on linux. the wine people (codeweavers) with some google money has improved its support for photoshop — versions 5.0 up to cs2 is supported but not cs3. well, not yet anyway.

interesting times indeed.

january 2008 is ending and i think its been a good month. granted that there has been glitches here and there and i’m late on some of my workload (with good reason) but no one under my care has been hacked and work-related stuff are moving forward although at a slower pace than i want them to.

still, its been a good month because i went riding more often, i got to meet new faces and made new friends. and mostly because i found a dear, dear friend that i lost many years ago.

its a good month.

givens:
desktops are running windows with ms office; file server is running samba on linux

problem:
file ownership of a shared file gets messed up once a user opens, edits and saves the shared file.

what happens in the background is when user1 opens, for example, an excel spreadsheet with a file ownership of nobody.research, excel copies the file into a temporary file and offers the temporary file for the user to edit. this temporary file now has file ownership of user1.user1. once the user saves the file, excel deletes the original file and saves the temporary copy in place of the original. this now makes the ownership of the “original” file user1.user1 and not nobody.research and therefore no one else in the research group other than user1 will be able to edit the file.

limitations:
each group have their own subdirectory and no one else can view or edit them; only the owner and group members can create, edit/modify and delete files located within their respective subdirectories.

one solution:

• go to the top of the shared subdirectory
• set the ownership and file permissions using the commands below; ‘research/’ and ‘nobody.research’ are examples, change to what applies to your setup

$ find research/ -type d -exec chown 'nobody.research' {} \;
$ find research/ -type d -exec chmod 1770 {} \;
$ find research/ -type f -exec chmod 0770 {} \;
$ find research/ -type f -exec chown 'nobody.research' {} \;

• in smb.conf, in the [research] share add the following:

force create mode = 0770
force directory mode = 0770

links:
linux devcenter: find command
samba 3: official how-to

note: this is a copy of samba ownerships and permission from my old blog and was reposted here in its entirety for my convenience.

i had a visit from a friend of mine who works as a web designer. she was half way through her pint of ice cream when she came in. i was working on a website and she took one look at the page i was working on and she gave me that knowing smile.

“obssessive/compulsive.”

“what?!?”, i said.

“everything has to be visually aligned to almost everything else be it vertically or horizontally; consistency and readability are sacrificed for the sake of alignment; this paragraph’s font is smaller than the other paragraph because it has to fit in the confines of the length or width of the image beside, above or below it; even the consistency of the menu is compromised for the sake of aligning the top and bottom of the menu to the top and bottom of the content; there’s very little white space to rest the eyes; everything is filled. obssessive/compulsive.”

“and apparently, they’re not familiar with web politics.”

“huh?!?”, i asked.

“well, if they are familiar with it, they would know that even if you move this image or that paragraph by 4 or 5 or even 2 or 3 tiny pixels up or down it wouldn’t matter because each computer has its own video configuration quirks and will always show things a little differently; each user has her/his own browser preference which in themselves render a page differently; not all the chosen fonts — which are too many by the way — are installed in all of the computers in the world which means this or that may or may not be displayed or rendered properly.”

“if i were you, either i’d tell them about it and compromise or drop them like a hot potato.”

“why?”, i asked, indignantly impressed.

“because they don’t get it.”

she dives into her ice cream again.

“at the end of the day, its doesn’t really matter if this picture is higher by 2 millimeters from the top of text column beside it. what matters is that they saw the picture and was able to read what you have to say.”

“you don’t eat the container. you eat the ice cream”, raising her pint.

“its the content.”

note: this post has already been published previously and is re-posted here in its entirely. its always worth revisiting. photo courtesy of Häagen Dazs rum raisin. yum!

the other day i received an e-mail which looked a lot like spam but it didn’t get filtered. i took a closer look and i found out that the address of the sender was my e-mail address and it was sent to the same. i’m absolutely sure i didn’t send anything with a subject “january 74% off” let alone to myself. and with yahoo! doing my mail serving needs i’m sure i didn’t. they would only allow a limited number of e-mails per day.

this is interesting. curiosity gets the best of me and i opened it up. it just contained an image. i set my mail reader not to show me any images when i open an e-mail. i’m not about to start with this one.

the juicier part would be to look at the e-mail headers. its that part of the message that is not normally seen by the reader. in part, it is used as a troubleshooting aid to look for kinks in the mailing system. it has the data from what service provider it came from, which mail server received it, and where it was sent. all e-mail programs would have a way of letting you see the full headers of a particular e-mail. i use yahoo’s web interface and the headers is located on the right side of the open e-mail message.

click on the full header and you’ll get to some of the e-mail internals.

the first line in the screenshot above is suppose to be the sending address — who sent it. the second line with the return path is the e-mail address that will be put in the to: field when you click on reply. the fifth to seventh line (received) is interesting. it shows where the e-mail was supposedly sent from — a dsl subscriber in russia — and which server in yahoo! received it.

i got another spam with the same subject and opening the headers reveals something similar but the fifth line (received) is different. it says intel sent it but when i checked the ip address the sender is from poland. hmmm…

two similar mails from two different countries. this leads me to the conclusion that the spam mail wasn’t sent by me (or yahoo!) but by a botnet that is posing as me.

you may have received something similar so you can likely check it using the steps i took.

disclosure: i do not like spam and i do not and will not knowingly send any. i take great pains to make sure of that. my firewall here only allows sending via one particular yahoo! smtp server. and we don’t even use pop mail. all of us use yahoo!’s webmail interface.

tinymce, the visual editor that came with wordpress 2.3.2 has a little trouble with html tables. i made a couple of tables in my html editor, copy and pasted the code into the wordpress page editor, in code mode of course. when i saved the page only the first row of the tables came out in the final page. apparently, the visual editor was stripping some table tags before the page is saved — part of its function i suppose.

a search in the wp forums gave a few solutions, mostly relating to installing a plugin. what worked for me was to turn off the visual editor while i pasted and saved the page. quick and dirty solution i think.

in the wp dashboard, click on users – your profile and uncheck the “use the visual editor when writing” checkbox (above) and then click on update profile.

it started about a couple of months ago. my electricity bill went down by almost a thousand pesos per month. that is pretty big. you can buy lots of stuff with 1k. and the only thing that i did was stop using my desktop computer. seriously.

for the record, my desktop is an athlon xp 2 ghz (slightly overclocked) with three hard drives (1 is scsi), a cdr/rw, a cdr, six fans plus two for the power supply, three expansion cards and a 17″ crt (read as power hogging) monitor. it seems that this setup can really pull some decent current.

these days, i’m working off a pentium m 1.6ghz laptop with a 15″ screen running on linux. i can still do my work thing (with the exception of my games) at essentially the same pace while drawing less power — 1k pesos less.

this got me thinking. considering the rising prices of fuel and electricity and the growing availability of smaller, less power-hungry (but faster) computers, it would be beneficial to get a smaller, energy-efficient computer. better if one gets a laptop so you can add mobility to the list of pluses. and of course, there’s that “wow” factor of possessing a laptop.

although the prices of reasonable laptops has gone down, they are still up there compared to the currently available desktops but not by much. the cheapest laptop in rising sun is the msi vr320-p2 (intel dual core 1.8ghz, 2 gig ram, 80 gig hd, 13.3″ lcd) at almost 30k pesos and a pc package with the equivalent configuration would run to about 25k pesos.

do the numbers and then add in the cost of running the thing (electricity) and you’ll find that getting an energy-efficient computer or a laptop is actually cheaper in the medium to long term.