ooni-probe-cli/internal/engine/cmd/jafar/iptables/iptables.go
Simone Basso 99b28c1d95
refactor: start building an Android package (#205)
* refactor: start building an Android package

Part of https://github.com/ooni/probe/issues/1335.

This seems also a good moment to move some packages out of the
engine, e.g., oonimkall. This package, for example, is a consumer
of the engine, so it makes sense it's not _inside_ it.

* fix: committed some stuff I didn't need to commit

* fix: oonimkall needs to be public to build

The side effect is that we will probably need to bump the major
version number every time we change one of these APIs.

(We can also of course choose to violate the basic guidelines of Go
software, but I believe this is bad form.)

I have no problem in bumping the major quite frequently and in
any case this monorepo solution is convinving me more than continuing
to keep a split between engine and cli. The need to embed assets to
make the probe more reliable trumps the negative effects of having to
~frequently bump major because we expose a public API.

* fix: let's not forget about libooniffi

Honestly, I don't know what to do with this library. I added it
to provide a drop in replacement for MK but I have no idea whether
it's used and useful. I would not feel comfortable exposing it,
unlike oonimkall, since we're not using it.

It may be that the right thing to do here is just to delete the
package and reduce the amount of code we're maintaining?

* woops, we're still missing the publish android script

* fix(publish-android.bash): add proper API key

* ouch fix another place where the name changed
2021-02-03 10:51:14 +01:00

99 lines
3.4 KiB
Go

// Package iptables contains code for managing firewall rules. This package
// really only works reliably on Linux. In all other systems the functionality
// in here is just a set of stubs returning errors.
package iptables
import (
"github.com/ooni/probe-cli/v3/internal/engine/runtimex"
)
type shell interface {
createChains() error
dropIfDestinationEquals(ip string) error
rstIfDestinationEqualsAndIsTCP(ip string) error
dropIfContainsKeywordHex(keyword string) error
dropIfContainsKeyword(keyword string) error
rstIfContainsKeywordHexAndIsTCP(keyword string) error
rstIfContainsKeywordAndIsTCP(keyword string) error
hijackDNS(address string) error
hijackHTTPS(address string) error
hijackHTTP(address string) error
waive() error
}
// CensoringPolicy implements a censoring policy.
type CensoringPolicy struct {
DropIPs []string // drop IP traffic to these IPs
DropKeywordsHex []string // drop IP packets with these hex keywords
DropKeywords []string // drop IP packets with these keywords
HijackDNSAddress string // where to hijack DNS to
HijackHTTPSAddress string // where to hijack HTTPS to
HijackHTTPAddress string // where to hijack HTTP to
ResetIPs []string // RST TCP/IP traffic to these IPs
ResetKeywordsHex []string // RST TCP/IP flows with these hex keywords
ResetKeywords []string // RST TCP/IP flows with these keywords
sh shell
}
// NewCensoringPolicy returns a new censoring policy.
func NewCensoringPolicy() *CensoringPolicy {
return &CensoringPolicy{
sh: newShell(),
}
}
// Apply applies the censorship policy
func (c *CensoringPolicy) Apply() (err error) {
defer func() {
if recover() != nil {
// JUST KNOW WE'VE BEEN HERE
}
}()
err = c.sh.createChains()
runtimex.PanicOnError(err, "c.sh.createChains failed")
// Implementation note: we want the RST rules to be first such
// that we end up enforcing them before the drop rules.
for _, keyword := range c.ResetKeywordsHex {
err = c.sh.rstIfContainsKeywordHexAndIsTCP(keyword)
runtimex.PanicOnError(err, "c.sh.rstIfContainsKeywordHexAndIsTCP failed")
}
for _, keyword := range c.ResetKeywords {
err = c.sh.rstIfContainsKeywordAndIsTCP(keyword)
runtimex.PanicOnError(err, "c.sh.rstIfContainsKeywordAndIsTCP failed")
}
for _, ip := range c.ResetIPs {
err = c.sh.rstIfDestinationEqualsAndIsTCP(ip)
runtimex.PanicOnError(err, "c.sh.rstIfDestinationEqualsAndIsTCP failed")
}
for _, keyword := range c.DropKeywordsHex {
err = c.sh.dropIfContainsKeywordHex(keyword)
runtimex.PanicOnError(err, "c.sh.dropIfContainsKeywordHex failed")
}
for _, keyword := range c.DropKeywords {
err = c.sh.dropIfContainsKeyword(keyword)
runtimex.PanicOnError(err, "c.sh.dropIfContainsKeyword failed")
}
for _, ip := range c.DropIPs {
err = c.sh.dropIfDestinationEquals(ip)
runtimex.PanicOnError(err, "c.sh.dropIfDestinationEquals failed")
}
if c.HijackDNSAddress != "" {
err = c.sh.hijackDNS(c.HijackDNSAddress)
runtimex.PanicOnError(err, "c.sh.hijackDNS failed")
}
if c.HijackHTTPSAddress != "" {
err = c.sh.hijackHTTPS(c.HijackHTTPSAddress)
runtimex.PanicOnError(err, "c.sh.hijackHTTPS failed")
}
if c.HijackHTTPAddress != "" {
err = c.sh.hijackHTTP(c.HijackHTTPAddress)
runtimex.PanicOnError(err, "c.sh.hijackHTTP failed")
}
return
}
// Waive removes any censorship policy
func (c *CensoringPolicy) Waive() error {
return c.sh.waive()
}