% CST8207 Assignment 11 - processes, syslog, crontab, at % Ian! D. Allen - - [www.idallen.com] % Fall 2013 - September to December 2013 - Updated 2017-05-31 12:15 EDT - [Course Home Page] - [Course Outline] - [All Weeks] - [Plain Text] Due Date and Deliverables ========================= > **Do not print this assignment on paper!** > > - On paper, you will miss updates, corrections, and hints added to the > online version. > - On paper, you cannot follow any of the [hyperlink URLs] that lead you > to hints and course notes relevant to answering a question. > - On paper, scrolling text boxes will be cut off and not print properly. - **Due Date**: `08h00 (8am) Monday November 25, 2013 (start of Week 13)` - Your next assignments are due at the end of Week 14. Don't delay. - Late assignments or wrong file names may not be marked. Be accurate. - **Available online**: - Version 1 -- 18:40 Monday November 11, 2013 - Version 2 -- 12:30 Monday November 18, 2013 (New Due Date) - **Prerequisites**: - All [Class Notes] since the beginning of term. - All your previous [Assignments]. - an ability to **READ ALL THE WORDS** to work effectively - **Deliverables**: 1. One text file uploaded to Blackboard according to the steps in the [Checking Program] section below. 2. Directory structure created and left for marking on the [Course Linux Server] (**CLS**).\ **Do not delete any assignment work from the CLS or your CentOS Virtual Machines until after the term is over!** **WARNING:** Some inattentive students upload Assignment #11 into the Assignment #10 upload area. Don't make that mistake! Be exact. Purpose of this Assignment ========================== > Do not print this assignment on paper. On paper, you cannot follow any of > the hyperlink URLs that lead you to hints and course notes relevant to > answering a question. This assignment is based on your weekly [Class Notes][All Weeks]. 1. Practice controlling [Processes and Jobs]. 2. Search [System Log Files]. 3. Schedule jobs using [Crontab and At]. 4. Review minimal permissions from [Worksheet #08] Introduction and Overview ========================= This is an overview of how you are expected to complete this assignment. Read all the words before you start working. 1. Complete the **Tasks** listed below. 2. Verify your own work before running the [Checking Program]. 3. Run the [Checking Program] to help you find errors. 4. Submit the output of the [Checking Program] to Blackboard before the due date. 5. **READ ALL THE WORDS** to work effectively and not waste time. Practice controlling [Processes and Jobs]. Search [System Log Files]. Schedule jobs using [Crontab and At]. Review minimal permissions from [Worksheet #08]. > Since I also do manual marking of student assignments, your final mark may > not be the same as the mark submitted using the current version of the > [Checking Program]. I do not guarantee that any version of the [Checking > Program] will find all the errors in your work. Complete your assignments > according to the specifications, not according to the incomplete set of the > mistakes detected by the [Checking Program]. The Source Directory -------------------- All references to the "Source Directory" below are to the CLS directory `~idallen/cst8207/13f/assignment11/` and that name starts with a *tilde* character `~` followed by a userid with no intervening slash. The leading tilde indicates to the shell that the pathname starts with the HOME directory of the account `idallen` (seven letters). Tasks ===== - Do the following tasks in order, from top to bottom. - These tasks must be done in your account on the [Course Linux Server]. - **READ ALL THE WORDS!** and do not skip steps. - Your instructor will mark on the due date the work you do in your account on the CLS. Leave all your work on the CLS and do not modify it. - **Do not delete any assignment work from the CLS until after the course is over.** Set Up ------ 1. Create the following directory structure in your CLS HOME directory and record (for study purposes) the series of Unix commands you used to create it. Spelling and capitalization must be exactly as shown: CST8207-13F `-- Assignments `-- assignment11 **This directory is the base directory for most pathnames in this assignment. Store your files and answers here.** 2. There is a [Checking Program] named `assignment11check` in the [Source Directory] on the CLS. Follow the instructions in the first two steps at the start of [Checking Program] to create a working symbolic link to this program. Part A -- Process Listing ------------------------- Review [Processes and Jobs]. 1. Place a full list of all processes for all users, **BSD** format, all users, text user name (not numeric UID), full wide listing (not truncated at all), into file `psbsd.txt` in your `assignment11` directory. It should be "at least" 105 lines and 9KB. One of the very long lines will be a `dhclient` line similar to this (use `fgrep` to find it in the output): root 3171 0.0 0.0 7268 436 ? Ss Oct26 0:00 dhclient3 -e IF_METRIC=9999 -pf /var/run/dhclient.eth0.pid -lf /var/lib/dhcp/dhclient.eth0.leases -1 eth0 2. Place a full list of all processes for all users, **UNIX** (System V) format, text user name (not numeric UID), full wide listing (not truncated at all), into file `psunix.txt` in your `assignment11` directory. It should be "at least" 105 lines and 7KB. One of the very long lines will be a `dhclient` line similar to this (use `fgrep` to find it in the output): root 3171 1 0 Oct26 ? 00:00:00 dhclient3 -e IF_METRIC=9999 -pf /var/run/dhclient.eth0.pid -lf /var/lib/dhcp/dhclient.eth0.leases -1 eth0 Part B -- System Log Files -------------------------- Review [System Log Files]. 1. What is the actual name of the **syslog** program on the CLS? Extract the one line from each file `psbsd.txt` and `psunix.txt` that contains this name and redirect the results (two lines, one from each file) into file `syslog.txt`. (The result will be 2 lines, 21 words.) 2. The system authentication log file is named `auth.log` in the system log directory. Generate an `ls` long listing of this file using the full absolute pathname, and put the results into file `authlog.txt`. (The result will be 1 line, 9 words, at least 64 characters.) (Optional: You may find it convenient to set a shell variable to this absolute pathname, so that you can use the short variable name rather than the long absolute pathname in the rest of these exercises. Or, you could make a short symbolic link to this file.) 3. Put a list (one line) of your userid, UID, group, GID, and additional groups into the file `id.txt`. (The result will be 1 line, 3 words.) (See [Permissions] for the command to use to do this. Do not edit the output of the command.) 4. Look at the contents of the `id.txt` and `authlog.txt` files. Note that your account is in a group that matches the group of the system `auth.log` file, giving you **group permissions** on this file. Using a text editor, put the matching group name (three characters), the symbolic group permissions (three characters), and the octal group permissions (one digit), onto three lines in file `myperms.txt`. (The result will be 3 lines, 3 words, 10 characters. Do you remember why a line containing seven alphanumeric characters on three lines is counted as a 10-character file?) 5. The system `auth.log` file contains over 643,480 lines. Use a command to extract just the first line (one line) from the head of this file and redirect that one line into new file `authhead.txt`. (The result will be 1 line 14 words 109 chars.) The time and date at the start of this line is when this copy of the log file was started. 6. If you count the number of lines in the system `auth.log` containing the exact text string `Failed password`, the count is more than 2,170 lines. Of those lines (the lines containing that text string), extract just lines 1000 through 1010 (inclusive) and put those 11 lines into file `failedpass.txt`. The word count for the file will be `11 162 1219`. Every line should contain the text string somewhere. 7. The CLS is running the `denyhosts` package to blacklist attacking machines. It logs its activity in the expected `denyhosts` log file. Look (`fgrep`) in this file for the line for the text `new denied host` that was logged on November 1 2013 and redirect that one line into file `badhost.txt` (word count `1 10 87`). Hint: Use a pipeline with two `fgrep` commands to find the only line that matches **both** the date and the desired text. You will need to search for the date in the format that it appears in the log file. 8. In the `auth.log` file search for all lines containing the IP address of the attacking machine (that IP address is the one IP address in the one line you just put in `badhost.txt`) to find out why that IP address was blacklisted. Redirect the output into file `badauth.txt`. The result will be at least 7 lines 88 words 807 chars. (It may be more, if they attack again!) Every line of output will contain that attacking IP address somewhere in the line. 9. Warning! Do not run the `whois` command more than absolutely necessary, since too many uses may result in us being cut off from using the `whois` database! Run the `whois` command (once!) and find out who owns this attacking IP address. Put the two output lines from `whois` containing the string `descr:` into file `baddescr.txt`. The result will count as `2 13 130`. Feel free to explore some other attacking IP addresses to learn what it's like having a machine exposed on the Internet. Part C -- Crontab and At Scheduling ----------------------------------- Review [Crontab and At]. 1. Create a personal `crontab` entry that updates the modification time on file `crontab.txt` in your `assignment11` directory (not in your `HOME` directory) every minute of every day. Use the shortest relative pathname to your `crontab.txt` file. Do not use an absolute pathname. Verify that the modification time of the file changes every minute. (If it doesn't work, read your Linux email for email messages from the **Cron** daemon showing possible errors.) 2. List your personal `crontab` (one entry) and redirect the output into file `crontab1.txt`. 3. Delete your personal `crontab`. 4. Create a personal `crontab` entry that updates the modification time on the same file `crontab.txt` at exactly 7:34 PM every evening. (Also use a relative pathname, not an absolute pathname.) 5. List your personal `crontab` (one entry) and redirect the output into file `crontab2.txt`. Do not delete this `crontab` entry; leave it for marking. 6. Create an `at` job that updates the modification time on the file `atjob.txt` (in your `assignment11` directory, not in your `HOME` directory) one or two minutes from now. (Check the current system time and add a minute or two. Look at the queue of `at` jobs and make sure the scheduled job time is correct.) Make sure that the file time changes one or two minutes from now. (If it doesn't work, read your Linux email for email messages from the **At** daemon showing possible errors. Also check the queue of `at` jobs and make sure the job isn't queued later than you think it is.) 7. Make `assignment11` your current directory and then create an `at` job that updates the modification time on the file `atjob.txt` (in your current directory, not in your `HOME` directory) at the start date and time of your CST8207 final exam. Again, check the queue of `at` jobs and make sure the scheduled time is correct. Leave this job queued on the CLS for marking. 8. Display all your queued `at` jobs and redirect the output into file `atjob.txt`. (You will only have one job -- one line.) (If you have more than one line, delete the other jobs.) Part D -- Minimal Permissions ----------------------------- Copy this text into file `minimal.txt` and replace *all* the underscore characters using your answers from [Worksheet #08]. Missing permissions should be given as dashes so that each set of three underscores is replaced with exactly three other characters: *** Table of MINIMUM rwx symbolic permissions *** 1. copy a file: srcdir=___ srcfile=___ targetdir=___ 2. move a file: srcdir=___ srcfile=___ targetdir=___ 3. link to a file: srcdir=___ srcfile=___ targetdir=___ 4. delete a file: srcdir=___ srcfile=___ 5. read a file: srcdir=___ srcfile=___ 6. modify an existing file: dir=___ oldfile=___ 7. create a new file: dir=___ The original file and the edited file must both have 8 lines and 55 words. When you are done ----------------- That is all the tasks you need to do. Check your work a final time using the [Checking Program] and save the output as described below. Submit your mark following the directions below. Checking, Marking, and Submitting your Work =========================================== **Summary:** Do some tasks, then run the checking program to verify your work as you go. You can run the checking program as often as you want. When you have the best mark, upload the marks file to Blackboard. 1. There is a [Checking Program] named `assignment11check` in the [Source Directory] on the CLS. Create a [Symbolic Link] to this program named `check` under your new `assignment11` directory so that you can easily run the program to check your work and assign your work a mark. Note: You can create a symbolic link to this executable program but you do not have permission to read or copy the program file. 2. Execute the above "check" program using its new symbolic link. (Review the [Search Path] notes if you forget how to run a program by pathname from the command line.) This program will check your work, assign you a mark, and display the output on your screen. (You may want to paginate the long output so you can read all of it.) You may run the "check" program as many times as you wish, to correct mistakes and get the best mark. **Some task sections require you to finish the whole section before running the checking program at the end; you may not always be able to run the checking program successfully after every single task step.** 3. When you are done with checking this assignment, and you like what you see on your screen, redirect the output of the [Checking Program] into the text file `assignment11.txt` under your `assignment11` directory. Use the *exact* name `assignment11.txt` in your `assignment11` directory. Case (upper/lower case letters) matters. Be absolutely accurate, as if your marks depended on it. Do not edit the file. Make sure the file actually contains the output of the checking program! 4. Transfer the above `assignment11.txt` file from the CLS to your local computer and verify that the file still contains all the output from the checking program. Do not edit this file! No empty files, please! Edited or damaged files will not be marked. You may want to refer to your [File Transfer] notes. 5. Submit the `assignment11.txt` file under the correct Assignment area on Blackboard (with the exact name) before the due date. Upload the file via the **assignment11** "Upload Assignment" facility in Blackboard: click on the underlined **assignment11** link in Blackboard. Use "**Attach File**" and "**Submit**" to upload your plain text file. No word-processor documents. Do not send email. Use only "Attach File". Do not enter any text into the **Submission** or **Comments** boxes on Blackboard; I do not read them. Use only the "**Attach File**" section followed by the **Submit** button. (If you want to send me comments about your assignment, use email.) 6. Your instructor may also mark the `assignment11` directory in your CLS account after the due date. Leave everything there on the CLS. **Do not delete any assignment work from the CLS until after the term is over!** Use the *exact* file name given above. Upload only one single file of plain text, not HTML, not MSWord. No fonts, no word-processing. Plain text only. Did I mention that the format is plain text (suitable for VIM/Nano/Pico/Gedit or Notepad)? **NO EMAIL, WORD PROCESSOR, PDF, RTF, or HTML DOCUMENTS ACCEPTED.** No marks are awarded for submitting under the wrong assignment number or for using the wrong file name. Use the exact name given above. WARNING: Some inattentive students don't read all these words. Don't make that mistake! Be exact. **READ ALL THE WORDS. OH PLEASE, PLEASE, PLEASE READ ALL THE WORDS!** -- | Ian! D. Allen - idallen@idallen.ca - Ottawa, Ontario, Canada | Home Page: http://idallen.com/ Contact Improv: http://contactimprov.ca/ | College professor (Free/Libre GNU+Linux) at: http://teaching.idallen.com/ | Defend digital freedom: http://eff.org/ and have fun: http://fools.ca/ [Plain Text] - plain text version of this page in [Pandoc Markdown] format [www.idallen.com]: http://www.idallen.com/ [Course Home Page]: .. [Course Outline]: course_outline.pdf [All Weeks]: indexcgi.cgi [Plain Text]: assignment11.txt [hyperlink URLs]: indexcgi.cgi#Important_Notes__alphabetical_order_ [Class Notes]: indexcgi.cgi#XImportant_Notes__alphabetical_order_ [Assignments]: indexcgi.cgi#XAssignments [Checking Program]: #checking-marking-and-submitting-your-work [Course Linux Server]: 070_course_linux_server.html [Processes and Jobs]: 600_processes_and_jobs.html [System Log Files]: 580_system_log_files.html [Crontab and At]: 630_crontab_at_job_scheduler.html [Worksheet #08]: worksheet08.html [Source Directory]: #the-source-directory [Permissions]: 500_permissions.html [Symbolic Link]: 460_symbolic_links.html [Search Path]: 400_search_path.html [File Transfer]: 015_file_transfer.html [Pandoc Markdown]: http://johnmacfarlane.net/pandoc/