repos / pico

scp.go

  1package scp
  2
  3import (
  4	"fmt"
  5
  6	"github.com/picosh/pico/pkg/pssh"
  7	"github.com/picosh/pico/pkg/send/utils"
  8)
  9
 10func Middleware(writeHandler utils.CopyFromClientHandler) pssh.SSHServerMiddleware {
 11	return func(sshHandler pssh.SSHServerHandler) pssh.SSHServerHandler {
 12		return func(session *pssh.SSHServerConnSession) error {
 13			cmd := session.Command()
 14			if len(cmd) == 0 || cmd[0] != "scp" {
 15				return sshHandler(session)
 16			}
 17
 18			logger := writeHandler.GetLogger(session).With(
 19				"scp", true,
 20				"cmd", cmd,
 21			)
 22
 23			defer func() {
 24				if r := recover(); r != nil {
 25					logger.Error("error running scp middleware", "err", r)
 26					_, _ = session.Stderr().Write([]byte("error running scp middleware, check the flags you are using\r\n"))
 27				}
 28			}()
 29
 30			info := GetInfo(cmd)
 31			if !info.Ok {
 32				return sshHandler(session)
 33			}
 34
 35			var err error
 36
 37			switch info.Op {
 38			case OpCopyToClient:
 39				if writeHandler == nil {
 40					err = fmt.Errorf("no handler provided for scp -t")
 41					break
 42				}
 43				err = copyToClient(session, info, writeHandler)
 44			case OpCopyFromClient:
 45				if writeHandler == nil {
 46					err = fmt.Errorf("no handler provided for scp -t")
 47					break
 48				}
 49				err = copyFromClient(session, info, writeHandler)
 50			}
 51			if err != nil {
 52				utils.ErrorHandler(session, err)
 53			}
 54
 55			return err
 56		}
 57	}
 58}
 59
 60// Op defines which kind of SCP Operation is going on.
 61type Op byte
 62
 63const (
 64	// OpCopyToClient is when a file is being copied from the server to the client.
 65	OpCopyToClient Op = 'f'
 66
 67	// OpCopyFromClient is when a file is being copied from the client into the server.
 68	OpCopyFromClient Op = 't'
 69)
 70
 71// Info provides some information about the current SCP Operation.
 72type Info struct {
 73	// Ok is true if the current session is a SCP.
 74	Ok bool
 75
 76	// Recursice is true if its a recursive SCP.
 77	Recursive bool
 78
 79	// Path is the server path of the scp operation.
 80	Path string
 81
 82	// Op is the SCP operation kind.
 83	Op Op
 84}
 85
 86func GetInfo(cmd []string) Info {
 87	info := Info{}
 88	if len(cmd) == 0 || cmd[0] != "scp" {
 89		return info
 90	}
 91
 92	for i, p := range cmd {
 93		switch p {
 94		case "-r":
 95			info.Recursive = true
 96		case "-f":
 97			info.Op = OpCopyToClient
 98			info.Path = cmd[i+1]
 99		case "-t":
100			info.Op = OpCopyFromClient
101			info.Path = cmd[i+1]
102		}
103	}
104
105	info.Ok = true
106	return info
107}