From 6a5b2b73635eecbb7c3c67063f0ac78450a4b57b Mon Sep 17 00:00:00 2001 From: Justin Reichardt Date: Wed, 23 Feb 2022 21:22:12 -0600 Subject: [PATCH] Filters out duplicates and comments Creates a list of only the sites that can then be used to remove duplicates and then set the sending address, currently 0.0.0.0 --- src/rhosts.go | 230 ++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 174 insertions(+), 56 deletions(-) diff --git a/src/rhosts.go b/src/rhosts.go index e8f6921..3f99d8c 100644 --- a/src/rhosts.go +++ b/src/rhosts.go @@ -31,6 +31,16 @@ import ( "flag" "time" ) +// siteList holds the location of all the sites along with a list of their location +type siteList struct { + location string + siteEntry []siteEntry +} +// siteEntry holds a single entry and if it is a repeat +type siteEntry struct { + repeat bool + site string +} func main() { tmpdir := "" @@ -38,6 +48,7 @@ func main() { cfgloc := "" var daemon bool=false var interval int=1440 + var siteBuff []siteList // Parsing Flags flag.BoolVar(&daemon, "d", false, "Should this be run in daemon mode") @@ -61,21 +72,28 @@ func main() { continue } defer os.Remove(tmpdir + "rhosts") - err = downloadcontent(downloads, tmpdir, hostsloc) + err, siteBuff = downloadcontent(downloads, tmpdir, hostsloc) if (err != nil){ log.Print("Failed to download entries") continue } - err = writesites(sites, tmpdir) + err = writesites(sites, tmpdir, &siteBuff) if (err != nil){ log.Print("Failed to failed to copy rhosts static entries") continue } + removeduplicates(&siteBuff) + err = write2tmp(tmpdir, &siteBuff) + if (err != nil){ + log.Print("Failed to write sites to tmpfile") + continue + } err = writetmp2hosts(hostsloc, tmpdir) if (err != nil){ log.Print("Failed to copy to hosts file") continue } + log.Print("Finished updating host") if (daemon == true){ time.Sleep(time.Duration(interval) * time.Minute) @@ -216,49 +234,82 @@ func copystatichosts(tmpdir, hostsloc string) error { err = filebuf.Err() return err } - -// downloadcontent attempts to download the provided url to the temp file. If the file fails to download it attempts to find an old copy from the hosts file. -func downloadcontent(downloads []string, tmpdir string, hostsloc string) error{ - var err error=nil - fileloc := tmpdir + "rhosts" - log.Print("Opening: ", fileloc) - file,err := os.OpenFile(fileloc, os.O_APPEND|os.O_WRONLY, 0644) - if (err != nil) { - log.Print(err) - return err - } - defer file.Close() - +// downloadcontent attempts to download the provided url and create a siteList. If the file fails to download it attempts to find an old copy from the hosts file. +func downloadcontent(downloads []string, tmpdir string, hostsloc string) (err error, list []siteList){ for _, d := range downloads { + var site siteList + site.location = d log.Print("Downloading: ",d) - file.WriteString("# rhosts download - " + d + "\n") - if (err != nil) { - } response, err := http.Get(d) if (err !=nil) { log.Print(err) log.Print("Looking for old record in hosts file") - downloadoldlookup(file, hostsloc, d) - continue + downloadoldlookup(hostsloc, d, &site) }else{ - _,err := io.Copy(file,response.Body) - if (err != nil){ - log.Print(err) - return err + defer response.Body.Close() + scanner := bufio.NewScanner(response.Body) + for scanner.Scan() { + resp := checkDownloadLine(scanner.Text()) + if resp.site != "" { + site.siteEntry = append(site.siteEntry, resp) + } } } - defer response.Body.Close() - file.WriteString("\n") - if (err != nil) { - log.Print(err) - return err - } + list = append(list, site) } - return err + return err, list } -// downloadoldlookup attemps to find an entry in the hosts file and write it to the temp file. -func downloadoldlookup(file *os.File, hostsloc, d string) error { +// checkDownloadLine parses the download line into just the address that needs to be blocked +func checkDownloadLine (line string) (address siteEntry){ + var token []string + address.repeat = false + address.site = "" + buff := "" + lineLength := len(line) -1 + for i, c := range(line){ + if c != ' ' && i < lineLength { + buff += string(c) + }else if len(buff) > 0 { + if i == lineLength{ + buff += string(c) + } + token = append(token,buff) + buff = "" + } + } + if len(token) == 0 { + return + } + if token[0][0] == '#' { + return + } + for _, t := range(token) { + var period uint + var failed bool + period = 0 + failed = false + for _, c := range(t) { + switch c{ + case '.': + period ++ + case '#': + return + case ':': + failed = true + break + } + } + if period <=2 && failed == false { + address.site = t + return + } + } + return +} + +// downloadoldlookup attemps to find an entry in the hosts file and add it to the siteList +func downloadoldlookup(hostsloc, d string, site *siteList) error { var err error = nil var state uint8 = 0 @@ -283,10 +334,9 @@ func downloadoldlookup(file *os.File, hostsloc, d string) error { if (len(buff) >=9 && buff[0:8] == "# rhosts"){ state = 2 }else{ - _,err := file.WriteString(buff + "\n") - if (err != nil) { - log.Print(err) - return err + siteBuff := checkDownloadLine(buff) + if siteBuff.site != "" { + site.siteEntry = append(site.siteEntry, siteBuff) } } case 3: @@ -298,32 +348,100 @@ func downloadoldlookup(file *os.File, hostsloc, d string) error { return err } -// writesites writes the list of sites from the config file to the temp file -func writesites(sites []string, tmpdir string) error { - var err error = nil +// writesites writes the list of sites from the config file to the local siteList +func writesites(sites []string, tmpdir string, siteBuff *[]siteList) (err error) { + var localList siteList + localList.location = "local" + err = nil fileloc := tmpdir + "rhosts" log.Print("Opening: " + fileloc) - file,err := os.OpenFile(fileloc, os.O_APPEND|os.O_WRONLY, 0644) - defer file.Close() - if (err != nil) { - log.Print(err) - return err - } - _,err = file.WriteString("# rhosts sites\n") - if (err != nil){ - log.Print(err) - return err + if len(sites) == 0 { + return } for _,s := range sites { - _,err = file.WriteString(s) - if (err != nil){ - log.Print(err) - break + var site siteEntry + site.repeat = false + site.site = s + localList.siteEntry = append(localList.siteEntry,site) + } + *siteBuff = append(*siteBuff,localList) + return +} +// removeduplicates removes any duplicate addresses +func removeduplicates(siteBuff *[]siteList){ + var safewords = []string{"localhost", "localhost.localdomain", "broadcasthost", "ip6-loopback", "ip6-localhost", "ip6-localnet", "ip6-mcastprefix", "ip6-allnodes", "ip6-allrouters", "ip6-allhosts", "local"} + var counter = uint(0) + log.Print("Checking for duplicates") + var entry []struct{ + r *bool + s *string + } + var entryBuff struct{ + r *bool + s *string + } + _ = entry + for i := len((*siteBuff))-1; i > -1; i --{ + for j := len((*siteBuff)[i].siteEntry)-1; j > -1; j -- { + entryBuff.r = &((*siteBuff)[i].siteEntry[j].repeat) + entryBuff.s = &((*siteBuff)[i].siteEntry[j].site) + entry = append(entry,entryBuff) } } - return err -} + lenEntry := len(entry) + for i,e := range(entry) { + for _,w := range(safewords){ + if *e.s == w { + *(entry[i].r) = true + counter ++ + break + } + } + if *(entry[i].r) == true { + continue + } + if i == lenEntry { + break + } + for j,n := range(entry[i+1:]){ + if *e.s == *n.s || *e.s == "localhost" { + *(entry[i+j].r) = true + counter ++ + } + } + } + log.Printf("Removed %d uneeded entries\n", counter) +} +// write2tmp write the siteBuff to the tempfile +func write2tmp(tmpdir string, siteBuff *[]siteList) (err error) { + err = nil + tmploc := tmpdir+ "rhosts" + tmpf, err := os.OpenFile(tmploc, os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0600) + defer tmpf.Close() + if err != nil { + log.Print(err) + return err + } + for _,location := range(*siteBuff){ + if len(location.siteEntry) == 0 { + continue + } + _,err := tmpf.WriteString("# rhosts download - " + location.location + "\n") + if err != nil { + return err + } + for _,site := range(location.siteEntry){ + if site.repeat == false { + _, err = tmpf.WriteString("0.0.0.0 " + site.site + "\n") + if err != nil { + return err + } + } + } + } + return +} // writetmp2hosts overwrites the hostsfile with the tmp file func writetmp2hosts(hostsloc, tmpdir string) error { var err error = nil