imterah/bismuthd
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

chore: Adds lots of documentation.

Browse source
This commit is contained in:
greysoh 2024-10-19 18:06:49 -04:00
parent 514ccee264
commit 8eb9bb3cee
Signed by: imterah
GPG key ID: 8FA7DD57BA6CEA37
11 changed files with 101 additions and 14 deletions
Download patch file Download diff file Expand all files Collapse all files

35
commons/conn.go
View file

@ -1,3 +1,5 @@
// Shared connection handler after both the client and server handshake successfully
package commons
import (
@ -9,11 +11,18 @@ import (
"time"
)
// Max size for a TCP packet
// Maximum size for a TCP packet
var ConnStandardMaxBufSize = 65535
var CryptHeader = 43
var cryptHeaderSize = 43
// Wild
// Connection used after both the Bismuth client and server negotiate and start
// transmitting data.
//
// Note that using this has the same API as the net.Conn, but it isn't conformant to
// the interface due to using pointers rather than copies to access the struct.
//
// If you need the same interface, wrap this in WrappedBismuthConn.
// Wrapping BismuthConn is done automatically by the client and server.
type BismuthConn struct {
Aead cipher.AEAD
PassedConn net.Conn
@ -26,10 +35,11 @@ type BismuthConn struct {
contentBufPos int
contentBufSize int
MaxBufSize int
// Maximum buffer size to be used to internally buffer packets
MaxBufSize int
// If true, it enables using the content buffer maximum size
// instead of the TCP packet maximum size
AllowNonstandardPacketSizeLimit bool
net.Conn
}
func (bmConn *BismuthConn) DoInitSteps() {
@ -68,6 +78,7 @@ func (bmConn *BismuthConn) decryptMessage(encMsg []byte) ([]byte, error) {
return decryptedData, nil
}
// After you update the property `bmConn.MaxBufSize`, call this function to resize the content buffer
func (bmConn *BismuthConn) ResizeContentBuf() error {
if !bmConn.initDone {
return fmt.Errorf("bmConn not initialized")
@ -95,6 +106,7 @@ func (bmConn *BismuthConn) ResizeContentBuf() error {
return nil
}
// Reads specifically from the buffer only. If nothing is in the buffer, nothing is returned.
func (bmConn *BismuthConn) ReadFromBuffer(b []byte) (n int, err error) {
bmConn.lock.Lock()
defer bmConn.lock.Unlock()
@ -126,6 +138,7 @@ func (bmConn *BismuthConn) ReadFromBuffer(b []byte) (n int, err error) {
return 0, nil
}
// Reads specifically from the network. Be careful as using only this may overflow the buffer.
func (bmConn *BismuthConn) ReadFromNetwork(b []byte) (n int, err error) {
bmConn.lock.Lock()
defer bmConn.lock.Unlock()
@ -146,7 +159,7 @@ func (bmConn *BismuthConn) ReadFromNetwork(b []byte) (n int, err error) {
// - the max buffer size if 'AllowNonstandardPacketSizeLimit' is set
// We check AFTER we read to make sure that we don't corrupt any future packets, because if we don't read the packet,
// it will think that the actual packet will be the start of the packet, and that would cause loads of problems.
if !bmConn.AllowNonstandardPacketSizeLimit && encryptedContentLength > uint32(65535+CryptHeader) {
if !bmConn.AllowNonstandardPacketSizeLimit && encryptedContentLength > uint32(65535+cryptHeaderSize) {
return 0, fmt.Errorf("packet too large")
} else if bmConn.AllowNonstandardPacketSizeLimit && encryptedContentLength > uint32(bmConn.MaxBufSize) {
return 0, fmt.Errorf("packet too large")
@ -187,6 +200,7 @@ func (bmConn *BismuthConn) ReadFromNetwork(b []byte) (n int, err error) {
return calcSize, nil
}
// Reads from the Bismuth connection, using both the buffered and network methods
func (bmConn *BismuthConn) Read(b []byte) (n int, err error) {
if !bmConn.initDone {
return 0, fmt.Errorf("bmConn not initialized")
@ -211,6 +225,7 @@ func (bmConn *BismuthConn) Read(b []byte) (n int, err error) {
return bufferReadSize + networkReadSize, nil
}
// Encrypts and sends off a message
func (bmConn *BismuthConn) Write(b []byte) (n int, err error) {
encryptedMessage, err := bmConn.encryptMessage(b)
@ -251,8 +266,10 @@ func (bmConn *BismuthConn) SetWriteDeadline(time time.Time) error {
return bmConn.PassedConn.SetWriteDeadline(time)
}
// TODO: remove this ugly hack if possible! There's probably a better way around this...
// Wrapped BismuthConn struct. This is conformant to net.Conn, unlike above.
// To get the raw Bismuth struct, just get the Bismuth property:
//
// `bmConn.Bismuth` -> `BismuthConn`
type BismuthConnWrapped struct {
Bismuth *BismuthConn
}