-
Notifications
You must be signed in to change notification settings - Fork 24
/
rules.go
535 lines (471 loc) · 12.3 KB
/
rules.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
package sgfw
import (
"encoding/binary"
"fmt"
"io/ioutil"
"net"
"os"
"path"
"regexp"
"strconv"
"strings"
nfqueue "github.com/subgraph/go-nfnetlink/nfqueue"
// "github.com/subgraph/go-nfnetlink"
"github.com/subgraph/go-procsnitch"
)
const matchAny = 0
//const noAddress = uint32(0xffffffff)
var anyAddress net.IP = net.IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
var noAddress net.IP = net.IP{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}
type Rule struct {
id uint
policy *Policy
mode RuleMode
rtype RuleAction
proto string
pid int
hostname string
network *net.IPNet
addr net.IP
saddr net.IP
port uint16
uid int
gid int
uname string
gname string
sandbox string
}
func (r *Rule) String() string {
return r.getString(false)
}
func (r *Rule) getString(redact bool) string {
rtype := RuleActionString[RULE_ACTION_DENY]
if r.rtype == RULE_ACTION_ALLOW {
rtype = RuleActionString[RULE_ACTION_ALLOW]
} else if r.rtype == RULE_ACTION_ALLOW_TLSONLY {
rtype = RuleActionString[RULE_ACTION_ALLOW_TLSONLY]
}
rmode := ""
if r.mode == RULE_MODE_SYSTEM {
rmode = "|" + RuleModeString[RULE_MODE_SYSTEM]
}
if r.mode == RULE_MODE_PERMANENT {
rmode = "|" + RuleModeString[RULE_MODE_PERMANENT]
}
protostr := ""
if r.proto != "tcp" {
protostr = r.proto + ":"
}
rpriv := fmt.Sprintf("|%d:%d", r.uid, r.gid)
sbox := "|"
if r.sandbox != "" {
sbox = "|" + sbox
} else {
log.Notice("sandbox is ", r.sandbox)
}
return fmt.Sprintf("%s|%s%s%s%s%s", rtype, protostr, r.AddrString(redact), rmode, rpriv, sbox)
}
func (r *Rule) AddrString(redact bool) string {
addr := "*"
port := "*"
if r.hostname != "" {
addr = r.hostname
} else if r.network != nil {
addr = r.network.String()
} else if !addrMatchesAny(r.addr) && !addrMatchesNone(r.addr) {
// bs := make([]byte, 4)
// binary.BigEndian.PutUint32(bs, r.addr)
// addr = fmt.Sprintf("%d.%d.%d.%d", bs[0], bs[1], bs[2], bs[3])
addr = r.addr.String()
}
if r.port != matchAny || r.proto == "icmp" {
port = fmt.Sprintf("%d", r.port)
}
if redact && addr != "*" {
addr = STR_REDACTED
}
return fmt.Sprintf("%s:%s", addr, port)
}
type RuleList []*Rule
func (r *Rule) match(src net.IP, dst net.IP, dstPort uint16, hostname string, proto string, uid, gid int, uname, gname string) bool {
if r.proto != proto {
return false
}
if r.uid != -1 && r.uid != uid {
return false
} else if r.gid != -1 && r.gid != gid {
return false
} else if r.uname != "" && r.uname != uname {
return false
} else if r.gname != "" && r.gname != gname {
return false
}
log.Notice("comparison: ", hostname, " / ", dst, " : ", dstPort, " -> ", r.addr, " / ", r.hostname, " : ", r.port)
if r.port != matchAny && r.port != dstPort {
return false
}
if addrMatchesAny(r.addr) {
return true
}
if r.hostname != "" {
log.Notice("comparing hostname")
if strings.ContainsAny(r.hostname, "*") {
regstr := strings.Replace(r.hostname, "*", ".?", -1)
match, err := regexp.MatchString(regstr, hostname)
if err != nil {
log.Errorf("Error comparing hostname against mask %s: %v", regstr, err)
} else {
return match
}
}
return r.hostname == hostname
}
if r.network != nil && r.network.Contains(dst) {
return true
}
if proto == "icmp" {
fmt.Printf("network = %v, src = %v, r.addr = %x, src to4 = %x\n", r.network, src, r.addr, binary.BigEndian.Uint32(src.To4()))
if (r.network != nil && r.network.Contains(src)) || (r.addr.Equal(src)) {
return true
}
}
return r.addr.Equal(dst)
}
func (rl *RuleList) filterPacket(p *nfqueue.NFQPacket, pinfo *procsnitch.Info, srcip net.IP, hostname, optstr string) FilterResult {
_, dstip := getPacketIPAddrs(p)
_, dstp := getPacketPorts(p)
return rl.filter(p, srcip, dstip, dstp, hostname, pinfo, optstr)
}
func (rl *RuleList) filter(pkt *nfqueue.NFQPacket, src, dst net.IP, dstPort uint16, hostname string, pinfo *procsnitch.Info, optstr string) FilterResult {
if rl == nil {
return FILTER_PROMPT
}
result := FILTER_PROMPT
sandboxed := false
if pinfo.Sandbox != "" {
sandboxed = true
}
// sandboxed := strings.HasPrefix(optstr, "SOCKS5|Tor / Sandbox")
for _, r := range *rl {
log.Notice("fuck ",r)
nfqproto := ""
log.Notice("------------ trying match of src ", src, " against: ", r, " | ", r.saddr, " / optstr = ", optstr, "; pid ", pinfo.Pid, " vs rule pid ", r.pid)
log.Notice("r.saddr: ", r.saddr, "src: ", src, "sandboxed ", sandboxed, "optstr: ", optstr)
if r.saddr == nil && src != nil && sandboxed {
log.Notice("! Skipping comparison against incompatible rule types: rule src = ", r.saddr, " / packet src = ", src)
// continue
} else if r.saddr == nil && src == nil && sandboxed {
// continue
// r.match(src, dst, dstPort, hostname, nil, pinfo.UID, pinfo.GID, uidToUser(pinfo.UID), gidToGroup(pinfo.GID))
nfqproto = "tcp"
} else if r.saddr != nil && !r.saddr.Equal(src) && r.proto != "icmp" {
log.Notice("! Skipping comparison of mismatching source ips")
continue
} else {
if pkt != nil {
nfqproto = getNFQProto(pkt)
} else {
log.Notice("Weird state.")
}
}
log.Notice("r.saddr = ", r.saddr, "src = ", src, "\n")
if r.pid >= 0 && r.pid != pinfo.Pid {
//log.Notice("! Skipping comparison of mismatching PIDs")
continue
}
if r.match(src, dst, dstPort, hostname, nfqproto, pinfo.UID, pinfo.GID, uidToUser(pinfo.UID), gidToGroup(pinfo.GID)) {
log.Notice("+ MATCH SUCCEEDED")
dstStr := dst.String()
if FirewallConfig.LogRedact {
dstStr = STR_REDACTED
}
srcStr := STR_UNKNOWN
if pkt != nil {
srcip, _ := getPacketIPAddrs(pkt)
srcp, _ := getPacketPorts(pkt)
srcStr = fmt.Sprintf("%s:%d", srcip, srcp)
}
log.Noticef("%s > %s %s %s -> %s:%d",
r.getString(FirewallConfig.LogRedact),
pinfo.ExePath, r.proto,
srcStr,
dstStr, dstPort)
if r.rtype == RULE_ACTION_DENY {
log.Warningf("DENIED outgoing connection attempt by %s from %s %s -> %s:%d",
pinfo.ExePath, r.proto,
srcStr,
dstStr, dstPort)
return FILTER_DENY
} else if r.rtype == RULE_ACTION_ALLOW {
result = FILTER_ALLOW
return result
/*
if r.saddr != nil {
return result
}
*/
} else if r.rtype == RULE_ACTION_ALLOW_TLSONLY {
result = FILTER_ALLOW_TLSONLY
return result
}
} else {
log.Notice("+ MATCH FAILED")
}
}
log.Notice("--- RESULT = ", result)
return result
}
func parseError(s string) error {
return fmt.Errorf("unable to parse rule string: %s", s)
}
func (r *Rule) parse(s string) bool {
r.addr = noAddress
r.saddr = nil
parts := strings.Split(s, "|")
if len(parts) < 4 || len(parts) > 6 {
log.Notice("invalid number ", len(parts), " of rule parts in line ", s)
return false
}
if parts[2] == "SYSTEM" {
r.mode = RULE_MODE_SYSTEM
} else if parts[2] == "PERMANENT" {
r.mode = RULE_MODE_PERMANENT
} else if parts[2] != "" {
log.Notice("invalid rule mode ", parts[2], " in line ", s)
return false
}
if !r.parsePrivs(parts[3]) {
log.Notice("invalid privs ", parts[3], " in line ", s)
return false
}
if !r.parseSandbox(parts[4]) {
log.Notice("invalid sandbox ", parts[4], "in line ", s)
return false
}
fmt.Printf("uid = %v, gid = %v, user = %v, group = %v, hostname = %v, sandbox = %v\n", r.uid, r.gid, r.uname, r.gname, r.hostname, r.sandbox)
if len(parts) == 6 && len(strings.TrimSpace(parts[5])) > 0 {
r.saddr = net.ParseIP(parts[5])
if r.saddr == nil {
log.Notice("invalid source IP ", parts[5], " in line ", s)
return false
}
}
return r.parseVerb(parts[0]) && r.parseTarget(parts[1])
}
func (r *Rule) parseSandbox(p string) bool {
r.sandbox = p
return true
}
func (r *Rule) parsePrivs(p string) bool {
toks := strings.Split(p, ":")
if len(toks) > 2 {
return false
}
r.uid, r.gid = -1, -1
r.uname, r.gname = "", ""
ustr := toks[0]
uid, err := strconv.Atoi(ustr)
if err != nil {
r.uname = ustr
} else {
r.uid = uid
}
if len(toks) > 1 {
gstr := toks[1]
gid, err := strconv.Atoi(gstr)
if err != nil {
r.gname = gstr
} else {
r.gid = gid
}
}
return true
}
func (r *Rule) parseVerb(v string) bool {
switch v {
case RuleActionString[RULE_ACTION_ALLOW]:
r.rtype = RULE_ACTION_ALLOW
return true
case RuleActionString[RULE_ACTION_ALLOW_TLSONLY]:
r.rtype = RULE_ACTION_ALLOW_TLSONLY
return true
case RuleActionString[RULE_ACTION_DENY]:
r.rtype = RULE_ACTION_DENY
return true
}
return false
}
func (r *Rule) parseTarget(t string) bool {
addrPort := strings.Split(t, ":")
if len(addrPort) < 2 {
return false
}
sind := 0
lind := len(addrPort) - 1
if addrPort[0] == "udp" || addrPort[0] == "icmp" || addrPort[0] == "tcp" {
r.proto = addrPort[0]
sind++
} else {
r.proto = "tcp"
}
newAddr := strings.Join(addrPort[sind:lind], ":")
return r.parseAddr(newAddr) && r.parsePort(addrPort[lind])
// return r.parseAddr(addrPort[sind]) && r.parsePort(addrPort[sind+1])
}
func (r *Rule) parseAddr(a string) bool {
if a == "*" {
r.hostname = ""
r.addr = anyAddress
return true
}
// if strings.IndexFunc(a, unicode.IsLetter) != -1 {
if net.ParseIP(a) == nil {
r.hostname = a
return true
}
// ip := net.ParseIP(a)
ip, ipnet, err := net.ParseCIDR(a)
if err != nil || ip == nil {
ip = net.ParseIP(a)
if ip == nil {
return false
}
} else {
r.network = ipnet
}
r.addr = ip
return true
}
func (r *Rule) parsePort(p string) bool {
if p == "*" {
r.port = matchAny
return true
}
var err error
port, err := strconv.ParseUint(p, 10, 16)
if err != nil || (port == 0 && r.proto != "icmp") || port > 0xFFFF {
return false
}
r.port = uint16(port)
return true
}
const ruleFile = "/var/lib/sgfw/sgfw_rules"
func maybeCreateDir(dir string) error {
_, err := os.Stat(dir)
if os.IsNotExist(err) {
return os.MkdirAll(dir, 0755)
}
return err
}
func rulesPath() (string, error) {
if err := maybeCreateDir(path.Dir(ruleFile)); err != nil {
return ruleFile, err
}
return ruleFile, nil
}
func (fw *Firewall) saveRules() {
fw.lock.Lock()
defer fw.lock.Unlock()
p, err := rulesPath()
if err != nil {
log.Warningf("Failed to open %s for writing: %v", p, err)
return
}
f, err := os.Create(p)
if err != nil {
log.Warningf("Failed to open %s for writing: %v", p, err)
return
}
defer f.Close()
for _, p := range fw.policies {
savePolicy(f, p)
}
}
func savePolicy(f *os.File, p *Policy) {
p.lock.Lock()
defer p.lock.Unlock()
if !p.hasPersistentRules() {
return
}
log.Warningf("p.path: ",p.path)
if !writeLine(f, "["+p.sandbox+"|"+p.path+"]") {
return
}
for _, r := range p.rules {
if r.mode != RULE_MODE_SESSION {
if !writeLine(f, r.String()) {
return
}
}
}
}
func writeLine(f *os.File, line string) bool {
_, err := f.WriteString(line + "\n")
if err != nil {
log.Warningf("Error writing to rule file: %v", err)
return false
}
return true
}
func (fw *Firewall) loadRules() {
fw.lock.Lock()
defer fw.lock.Unlock()
fw.clearRules()
p, err := rulesPath()
if err != nil {
log.Warningf("Failed to open %s for reading: %v", p, err)
return
}
bs, err := ioutil.ReadFile(p)
if err != nil {
if !os.IsNotExist(err) {
log.Warningf("Failed to open %s for reading: %v", p, err)
}
return
}
var policy *Policy
for _, line := range strings.Split(string(bs), "\n") {
if strings.HasPrefix(line, "[") && strings.HasSuffix(line, "]") {
policy = fw.processPathLine(line)
} else {
trimmed := strings.TrimSpace(line)
if len(trimmed) > 0 && trimmed[:1] != "#" {
processRuleLine(policy, trimmed)
}
}
}
}
func (fw *Firewall) processPathLine(line string) *Policy {
pathLine := line[1 : len(line)-1]
toks := strings.Split(pathLine, "|")
policy := fw.policyForPathAndSandbox(toks[1],toks[0])
policy.lock.Lock()
defer policy.lock.Unlock()
policy.rules = nil
return policy
}
func processRuleLine(policy *Policy, line string) {
if policy == nil {
log.Warningf("Cannot process rule line without first seeing policy key line: %s", line)
return
}
_, err := policy.parseRule(line, true)
if err != nil {
log.Warningf("Error parsing rule (%s): %v", line, err)
return
}
}
func addrMatchesAny(addr net.IP) bool {
any := anyAddress
if addr.To4() != nil {
any = net.IP{0, 0, 0, 0}
}
return any.Equal(addr)
}
func addrMatchesNone(addr net.IP) bool {
none := noAddress
if addr.To4() != nil {
none = net.IP{0xff, 0xff, 0xff, 0xff}
}
return none.Equal(addr)
}