Revamp process attribution of network connections
This commit is contained in:
Daniel
168
network/proc/findpid.go
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168
network/proc/findpid.go
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@@ -0,0 +1,168 @@
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// +build linux
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package proc
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import (
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"fmt"
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"os"
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"sort"
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"strconv"
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"sync"
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"syscall"
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"github.com/safing/portbase/log"
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)
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const (
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unidentifiedProcessID = -1
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)
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var (
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pidsByUserLock sync.Mutex
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pidsByUser = make(map[int][]int)
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)
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// FindPID returns the pid of the given uid and socket inode.
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func FindPID(uid, inode int) (pid int, ok bool) { //nolint:gocognit // TODO
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pidsByUserLock.Lock()
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defer pidsByUserLock.Unlock()
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pidsUpdated := false
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// get pids of user, update if missing
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pids, ok := pidsByUser[uid]
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if !ok {
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// log.Trace("process: no processes of user, updating table")
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updatePids()
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pidsUpdated = true
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pids, ok = pidsByUser[uid]
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}
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if ok {
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// if user has pids, start checking them first
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var checkedUserPids []int
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for _, possiblePID := range pids {
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if findSocketFromPid(possiblePID, inode) {
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return possiblePID, true
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}
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checkedUserPids = append(checkedUserPids, possiblePID)
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}
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// if we fail on the first run and have not updated, update and check the ones we haven't tried so far.
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if !pidsUpdated {
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// log.Trace("process: socket not found in any process of user, updating table")
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// update
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updatePids()
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// sort for faster search
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for i, j := 0, len(checkedUserPids)-1; i < j; i, j = i+1, j-1 {
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checkedUserPids[i], checkedUserPids[j] = checkedUserPids[j], checkedUserPids[i]
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}
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len := len(checkedUserPids)
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// check unchecked pids
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for _, possiblePID := range pids {
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// only check if not already checked
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if sort.SearchInts(checkedUserPids, possiblePID) == len {
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if findSocketFromPid(possiblePID, inode) {
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return possiblePID, true
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}
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}
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}
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}
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}
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// check all other pids
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// log.Trace("process: socket not found in any process of user, checking all pids")
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// TODO: find best order for pidsByUser for best performance
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for possibleUID, pids := range pidsByUser {
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if possibleUID != uid {
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for _, possiblePID := range pids {
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if findSocketFromPid(possiblePID, inode) {
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return possiblePID, true
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}
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}
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}
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}
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return unidentifiedProcessID, false
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}
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func findSocketFromPid(pid, inode int) bool {
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socketName := fmt.Sprintf("socket:[%d]", inode)
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entries := readDirNames(fmt.Sprintf("/proc/%d/fd", pid))
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if len(entries) == 0 {
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return false
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}
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for _, entry := range entries {
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link, err := os.Readlink(fmt.Sprintf("/proc/%d/fd/%s", pid, entry))
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if err != nil {
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if !os.IsNotExist(err) {
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log.Warningf("process: failed to read link /proc/%d/fd/%s: %s", pid, entry, err)
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}
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continue
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}
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if link == socketName {
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return true
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}
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}
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return false
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}
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func updatePids() {
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pidsByUser = make(map[int][]int)
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entries := readDirNames("/proc")
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if len(entries) == 0 {
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return
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}
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entryLoop:
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for _, entry := range entries {
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pid, err := strconv.ParseInt(entry, 10, 32)
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if err != nil {
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continue entryLoop
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}
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statData, err := os.Stat(fmt.Sprintf("/proc/%d", pid))
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if err != nil {
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log.Warningf("process: could not stat /proc/%d: %s", pid, err)
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continue entryLoop
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}
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sys, ok := statData.Sys().(*syscall.Stat_t)
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if !ok {
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log.Warningf("process: unable to parse /proc/%d: wrong type", pid)
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continue entryLoop
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}
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pids, ok := pidsByUser[int(sys.Uid)]
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if ok {
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pidsByUser[int(sys.Uid)] = append(pids, int(pid))
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} else {
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pidsByUser[int(sys.Uid)] = []int{int(pid)}
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}
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}
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for _, slice := range pidsByUser {
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for i, j := 0, len(slice)-1; i < j; i, j = i+1, j-1 {
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slice[i], slice[j] = slice[j], slice[i]
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}
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}
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}
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func readDirNames(dir string) (names []string) {
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file, err := os.Open(dir)
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if err != nil {
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if !os.IsNotExist(err) {
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log.Warningf("process: could not open directory %s: %s", dir, err)
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}
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return
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}
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defer file.Close()
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names, err = file.Readdirnames(0)
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if err != nil {
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log.Warningf("process: could not get entries from directory %s: %s", dir, err)
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return []string{}
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}
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return
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}
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218
network/proc/tables.go
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218
network/proc/tables.go
Normal file
@@ -0,0 +1,218 @@
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// +build linux
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package proc
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import (
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"bufio"
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"encoding/hex"
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"net"
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"os"
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"strconv"
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"strings"
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"unicode"
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"github.com/safing/portmaster/network/socket"
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"github.com/safing/portbase/log"
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)
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/*
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1. find socket inode
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- by incoming (listenting sockets) or outgoing (local port + external IP + port) - also local IP?
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- /proc/net/{tcp|udp}[6]
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2. get list of processes of uid
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3. find socket inode in process fds
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- if not found, refresh map of uid->pids
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- if not found, check ALL pids: maybe euid != uid
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4. gather process info
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Cache every step!
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*/
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// Network Related Constants
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const (
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TCP4 uint8 = iota
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UDP4
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TCP6
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UDP6
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ICMP4
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ICMP6
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TCP4Data = "/proc/net/tcp"
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UDP4Data = "/proc/net/udp"
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TCP6Data = "/proc/net/tcp6"
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UDP6Data = "/proc/net/udp6"
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ICMP4Data = "/proc/net/icmp"
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ICMP6Data = "/proc/net/icmp6"
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UnfetchedProcessID = -2
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tcpListenStateHex = "0A"
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)
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// GetTCP4Table returns the system table for IPv4 TCP activity.
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func GetTCP4Table() (connections []*socket.ConnectionInfo, listeners []*socket.BindInfo, err error) {
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return getTableFromSource(TCP4, TCP4Data, convertIPv4)
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}
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// GetTCP6Table returns the system table for IPv6 TCP activity.
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func GetTCP6Table() (connections []*socket.ConnectionInfo, listeners []*socket.BindInfo, err error) {
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return getTableFromSource(TCP6, TCP6Data, convertIPv6)
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}
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// GetUDP4Table returns the system table for IPv4 UDP activity.
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func GetUDP4Table() (binds []*socket.BindInfo, err error) {
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_, binds, err = getTableFromSource(UDP4, UDP4Data, convertIPv4)
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return
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}
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// GetUDP6Table returns the system table for IPv6 UDP activity.
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func GetUDP6Table() (binds []*socket.BindInfo, err error) {
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_, binds, err = getTableFromSource(UDP6, UDP6Data, convertIPv6)
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return
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}
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func getTableFromSource(stack uint8, procFile string, ipConverter func(string) net.IP) (connections []*socket.ConnectionInfo, binds []*socket.BindInfo, err error) {
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// open file
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socketData, err := os.Open(procFile)
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if err != nil {
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return nil, nil, err
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}
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defer socketData.Close()
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// file scanner
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scanner := bufio.NewScanner(socketData)
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scanner.Split(bufio.ScanLines)
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// parse
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scanner.Scan() // skip first line
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for scanner.Scan() {
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line := strings.FieldsFunc(scanner.Text(), procDelimiter)
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if len(line) < 14 {
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// log.Tracef("process: too short: %s", line)
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continue
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}
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localIP := ipConverter(line[1])
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if localIP == nil {
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continue
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}
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localPort, err := strconv.ParseUint(line[2], 16, 16)
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if err != nil {
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log.Warningf("process: could not parse port: %s", err)
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continue
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}
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uid, err := strconv.ParseInt(line[11], 10, 32)
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// log.Tracef("uid: %s", line[11])
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if err != nil {
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log.Warningf("process: could not parse uid %s: %s", line[11], err)
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continue
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}
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inode, err := strconv.ParseInt(line[13], 10, 32)
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// log.Tracef("inode: %s", line[13])
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if err != nil {
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log.Warningf("process: could not parse inode %s: %s", line[13], err)
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continue
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}
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switch stack {
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case UDP4, UDP6:
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binds = append(binds, &socket.BindInfo{
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Local: socket.Address{
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IP: localIP,
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Port: uint16(localPort),
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},
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PID: UnfetchedProcessID,
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UID: int(uid),
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Inode: int(inode),
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})
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case TCP4, TCP6:
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if line[5] == tcpListenStateHex {
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// listener
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binds = append(binds, &socket.BindInfo{
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Local: socket.Address{
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IP: localIP,
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Port: uint16(localPort),
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},
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PID: UnfetchedProcessID,
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UID: int(uid),
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Inode: int(inode),
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})
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} else {
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// connection
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remoteIP := ipConverter(line[3])
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if remoteIP == nil {
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continue
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}
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remotePort, err := strconv.ParseUint(line[4], 16, 16)
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if err != nil {
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log.Warningf("process: could not parse port: %s", err)
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continue
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}
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connections = append(connections, &socket.ConnectionInfo{
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Local: socket.Address{
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IP: localIP,
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Port: uint16(localPort),
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},
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Remote: socket.Address{
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IP: remoteIP,
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Port: uint16(remotePort),
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},
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PID: UnfetchedProcessID,
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UID: int(uid),
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Inode: int(inode),
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})
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}
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}
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}
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return connections, binds, nil
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}
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func procDelimiter(c rune) bool {
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return unicode.IsSpace(c) || c == ':'
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}
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func convertIPv4(data string) net.IP {
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decoded, err := hex.DecodeString(data)
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if err != nil {
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log.Warningf("process: could not parse IPv4 %s: %s", data, err)
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return nil
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}
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if len(decoded) != 4 {
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log.Warningf("process: decoded IPv4 %s has wrong length", decoded)
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return nil
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}
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ip := net.IPv4(decoded[3], decoded[2], decoded[1], decoded[0])
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return ip
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}
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func convertIPv6(data string) net.IP {
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decoded, err := hex.DecodeString(data)
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if err != nil {
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log.Warningf("process: could not parse IPv6 %s: %s", data, err)
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return nil
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}
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if len(decoded) != 16 {
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log.Warningf("process: decoded IPv6 %s has wrong length", decoded)
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return nil
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}
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ip := net.IP(decoded)
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return ip
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}
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60
network/proc/tables_test.go
Normal file
60
network/proc/tables_test.go
Normal file
@@ -0,0 +1,60 @@
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// +build linux
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package proc
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import (
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"fmt"
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"testing"
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)
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func TestSockets(t *testing.T) {
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connections, listeners, err := GetTCP4Table()
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if err != nil {
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t.Fatal(err)
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}
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fmt.Println("\nTCP 4 connections:")
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for _, connection := range connections {
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pid, _ := FindPID(connection.UID, connection.Inode)
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fmt.Printf("%d: %+v\n", pid, connection)
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}
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fmt.Println("\nTCP 4 listeners:")
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for _, listener := range listeners {
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pid, _ := FindPID(listener.UID, listener.Inode)
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fmt.Printf("%d: %+v\n", pid, listener)
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}
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connections, listeners, err = GetTCP6Table()
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if err != nil {
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t.Fatal(err)
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}
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fmt.Println("\nTCP 6 connections:")
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for _, connection := range connections {
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pid, _ := FindPID(connection.UID, connection.Inode)
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fmt.Printf("%d: %+v\n", pid, connection)
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}
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fmt.Println("\nTCP 6 listeners:")
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for _, listener := range listeners {
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pid, _ := FindPID(listener.UID, listener.Inode)
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fmt.Printf("%d: %+v\n", pid, listener)
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}
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binds, err := GetUDP4Table()
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if err != nil {
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t.Fatal(err)
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}
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fmt.Println("\nUDP 4 binds:")
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for _, bind := range binds {
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pid, _ := FindPID(bind.UID, bind.Inode)
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fmt.Printf("%d: %+v\n", pid, bind)
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}
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binds, err = GetUDP6Table()
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if err != nil {
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t.Fatal(err)
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}
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fmt.Println("\nUDP 6 binds:")
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for _, bind := range binds {
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pid, _ := FindPID(bind.UID, bind.Inode)
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fmt.Printf("%d: %+v\n", pid, bind)
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}
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}
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Reference in New Issue
Block a user