forked from criblio/appscope
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
(criblio#1108) IPC mechanism - client part
- Loading branch information
1 parent
3a1059c
commit 5b8d73b
Showing
14 changed files
with
902 additions
and
56 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,168 @@ | ||
| package util | ||
|
|
||
| import ( | ||
| "errors" | ||
| "fmt" | ||
| "os" | ||
| "syscall" | ||
| "time" | ||
| ) | ||
|
|
||
| // ipc structure representes Inter Process Communication object | ||
| type ipcObj struct { | ||
| sender *sendMessageQueue // Message queue used to send messages | ||
| receiver *receiveMessageQueue // Message queue used to receive messages | ||
| ipcSwitch bool // Indicator if IPC switch occured | ||
| } | ||
|
|
||
| var ( | ||
| errMissingProcMsgQueue = errors.New("missing message queue from PID") | ||
| errMissingResponse = errors.New("missing response from PID") | ||
| ) | ||
|
|
||
| // ipcGetScopeStatus dispatches cmd to the process specified by the pid. | ||
| // Returns the byte answer from scoped process endpoint. | ||
| func ipcGetScopeStatus(pid int) ([]byte, error) { | ||
| return ipcDispatcher(cmdGetScopeStatus, pid) | ||
| } | ||
|
|
||
| // ipcDispatcher dispatches cmd to the process specified by the pid. | ||
| // Returns the byte answer from scoped process endpoint. | ||
| func ipcDispatcher(cmd ipcCmd, pid int) ([]byte, error) { | ||
| var answer []byte | ||
| var responseReceived bool | ||
|
|
||
| ipc, err := newIPC(pid) | ||
| if err != nil { | ||
| return answer, err | ||
| } | ||
| defer ipc.destroyIPC() | ||
|
|
||
| if err := ipc.send(cmd.byte()); err != nil { | ||
| return answer, err | ||
| } | ||
|
|
||
| // TODO: Ugly hack but we need to wait for answer from process | ||
| for i := 0; i < 5000; i++ { | ||
| if !ipc.empty() { | ||
| responseReceived = true | ||
| break | ||
| } | ||
| time.Sleep(time.Millisecond) | ||
| } | ||
|
|
||
| // Missing response | ||
| // The message queue on the application side exists but we are unable to receive | ||
| // an answer from it | ||
| if !responseReceived { | ||
| return answer, fmt.Errorf("%v %v", errMissingResponse, pid) | ||
| } | ||
|
|
||
| return ipc.receive() | ||
| } | ||
|
|
||
| // nsnewNonBlockMsgQReader creates an IPC structure with switching effective uid and gid | ||
| func nsnewNonBlockMsgQReader(name string, nsUid int, nsGid int, restoreUid int, restoreGid int) (*receiveMessageQueue, error) { | ||
|
|
||
| if err := syscall.Setegid(nsGid); err != nil { | ||
| return nil, err | ||
| } | ||
| if err := syscall.Seteuid(nsUid); err != nil { | ||
| return nil, err | ||
| } | ||
|
|
||
| receiver, err := newNonBlockMsgQReader(name) | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
|
|
||
| if err := syscall.Seteuid(restoreUid); err != nil { | ||
| return nil, err | ||
| } | ||
|
|
||
| if err := syscall.Setegid(restoreGid); err != nil { | ||
| return nil, err | ||
| } | ||
|
|
||
| return receiver, err | ||
| } | ||
|
|
||
| // newIPC creates an IPC object designated for communication with specific PID | ||
| func newIPC(pid int) (*ipcObj, error) { | ||
| restoreGid := os.Getegid() | ||
| restoreUid := os.Geteuid() | ||
|
|
||
| ipcSame, err := namespaceSameIpc(pid) | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
|
|
||
| // Retrieve information about user nad group id | ||
| nsUid, err := pidNsTranslateUid(restoreUid, pid) | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
| nsGid, err := pidNsTranslateGid(restoreGid, pid) | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
|
|
||
| // Retrieve information about process namespace PID | ||
| _, ipcPid, err := pidLastNsPid(pid) | ||
| if err != nil { | ||
| return nil, err | ||
| } | ||
|
|
||
| // Switch IPC if neeeded | ||
| if !ipcSame { | ||
| if err := namespaceSwitchIPC(pid); err != nil { | ||
| return nil, err | ||
| } | ||
| } | ||
|
|
||
| // Try to open proc message queue | ||
| sender, err := openMsgQWriter(fmt.Sprintf("ScopeIPCIn.%d", ipcPid)) | ||
| if err != nil { | ||
| namespaceRestoreIPC() | ||
| return nil, errMissingProcMsgQueue | ||
| } | ||
|
|
||
| // Try to create own message queue | ||
| receiver, err := nsnewNonBlockMsgQReader(fmt.Sprintf("ScopeIPCOut.%d", ipcPid), nsUid, nsGid, restoreUid, restoreGid) | ||
| if err != nil { | ||
| sender.close() | ||
| namespaceRestoreIPC() | ||
| return nil, err | ||
| } | ||
|
|
||
| return &ipcObj{sender: sender, receiver: receiver, ipcSwitch: ipcSame}, nil | ||
| } | ||
|
|
||
| // destroyIPC destroys an IPC object | ||
| func (ipc *ipcObj) destroyIPC() { | ||
| ipc.sender.close() | ||
| ipc.receiver.close() | ||
| ipc.receiver.unlink() | ||
| if ipc.ipcSwitch { | ||
| namespaceRestoreIPC() | ||
| } | ||
| } | ||
|
|
||
| // receive receive the message from the process endpoint | ||
| func (ipc *ipcObj) receive() ([]byte, error) { | ||
| return ipc.receiver.receive(0) | ||
| } | ||
|
|
||
| // empty checks if receiver message queque is empty | ||
| func (ipc *ipcObj) empty() bool { | ||
| atr, err := ipc.receiver.getAttributes() | ||
| if err != nil { | ||
| return true | ||
| } | ||
| return atr.CurrentMessages == 0 | ||
| } | ||
|
|
||
| // send sends the message to the process endpoint | ||
| func (ipc *ipcObj) send(msg []byte) error { | ||
| return ipc.sender.send(msg, 0) | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,20 @@ | ||
| package util | ||
|
|
||
| // ipcCmd represents the command structure | ||
| type ipcCmd int64 | ||
|
|
||
| const ( | ||
| cmdGetScopeStatus ipcCmd = iota | ||
| ) | ||
|
|
||
| func (cmd ipcCmd) string() string { | ||
| switch cmd { | ||
| case cmdGetScopeStatus: | ||
| return "getScopeStatus" | ||
| } | ||
| return "unknown" | ||
| } | ||
|
|
||
| func (cmd ipcCmd) byte() []byte { | ||
| return []byte(cmd.string()) | ||
| } |
Oops, something went wrong.