diff options
| -rw-r--r-- | pkg/abi/linux/msgqueue.go | 2 | ||||
| -rw-r--r-- | pkg/sentry/kernel/msgqueue/msgqueue.go | 109 |
2 files changed, 110 insertions, 1 deletions
diff --git a/pkg/abi/linux/msgqueue.go b/pkg/abi/linux/msgqueue.go index e1e8d0357..0612a8214 100644 --- a/pkg/abi/linux/msgqueue.go +++ b/pkg/abi/linux/msgqueue.go @@ -47,7 +47,7 @@ const ( MSGSSZ = 16 // MSGSEG is simplified due to the inexistance of a ternary operator. - MSGSEG = (MSGPOOL * 1024) / MSGSSZ + MSGSEG = 0xffff ) // MsqidDS is equivelant to struct msqid64_ds. Source: diff --git a/pkg/sentry/kernel/msgqueue/msgqueue.go b/pkg/sentry/kernel/msgqueue/msgqueue.go index c111297d7..950edfd8c 100644 --- a/pkg/sentry/kernel/msgqueue/msgqueue.go +++ b/pkg/sentry/kernel/msgqueue/msgqueue.go @@ -206,6 +206,48 @@ func (r *Registry) FindByID(id ipc.ID) (*Queue, error) { return mech.(*Queue), nil } +// IPCInfo reports global parameters for message queues. See msgctl(IPC_INFO). +func (r *Registry) IPCInfo(ctx context.Context) *linux.MsgInfo { + return &linux.MsgInfo{ + MsgPool: linux.MSGPOOL, + MsgMap: linux.MSGMAP, + MsgMax: linux.MSGMAX, + MsgMnb: linux.MSGMNB, + MsgMni: linux.MSGMNI, + MsgSsz: linux.MSGSSZ, + MsgTql: linux.MSGTQL, + MsgSeg: linux.MSGSEG, + } +} + +// MsgInfo reports global parameters for message queues. See msgctl(MSG_INFO). +func (r *Registry) MsgInfo(ctx context.Context) *linux.MsgInfo { + r.mu.Lock() + defer r.mu.Unlock() + + var messages, bytes uint64 + r.reg.ForAllObjects( + func(o ipc.Mechanism) { + q := o.(*Queue) + q.mu.Lock() + messages += q.messageCount + bytes += q.byteCount + q.mu.Unlock() + }, + ) + + return &linux.MsgInfo{ + MsgPool: int32(r.reg.ObjectCount()), + MsgMap: int32(messages), + MsgTql: int32(bytes), + MsgMax: linux.MSGMAX, + MsgMnb: linux.MSGMNB, + MsgMni: linux.MSGMNI, + MsgSsz: linux.MSGSSZ, + MsgSeg: linux.MSGSEG, + } +} + // Send appends a message to the message queue, and returns an error if sending // fails. See msgsnd(2). func (q *Queue) Send(ctx context.Context, m Message, b Blocker, wait bool, pid int32) (err error) { @@ -452,6 +494,73 @@ func (q *Queue) msgAtIndex(mType int64) *Message { return msg } +// Set modifies some values of the queue. See msgctl(IPC_SET). +func (q *Queue) Set(ctx context.Context, ds *linux.MsqidDS) error { + q.mu.Lock() + defer q.mu.Unlock() + + creds := auth.CredentialsFromContext(ctx) + if ds.MsgQbytes > maxQueueBytes && !creds.HasCapabilityIn(linux.CAP_SYS_RESOURCE, q.obj.UserNS) { + // "An attempt (IPC_SET) was made to increase msg_qbytes beyond the + // system parameter MSGMNB, but the caller is not privileged (Linux: + // does not have the CAP_SYS_RESOURCE capability)." + return linuxerr.EPERM + } + + if err := q.obj.Set(ctx, &ds.MsgPerm); err != nil { + return err + } + + q.maxBytes = ds.MsgQbytes + q.changeTime = ktime.NowFromContext(ctx) + return nil +} + +// Stat returns a MsqidDS object filled with information about the queue. See +// msgctl(IPC_STAT) and msgctl(MSG_STAT). +func (q *Queue) Stat(ctx context.Context) (*linux.MsqidDS, error) { + return q.stat(ctx, fs.PermMask{Read: true}) +} + +// StatAny is similar to Queue.Stat, but doesn't require read permission. See +// msgctl(MSG_STAT_ANY). +func (q *Queue) StatAny(ctx context.Context) (*linux.MsqidDS, error) { + return q.stat(ctx, fs.PermMask{}) +} + +// stat returns a MsqidDS object filled with information about the queue. An +// error is returned if the user doesn't have the specified permissions. +func (q *Queue) stat(ctx context.Context, mask fs.PermMask) (*linux.MsqidDS, error) { + q.mu.Lock() + defer q.mu.Unlock() + + creds := auth.CredentialsFromContext(ctx) + if !q.obj.CheckPermissions(creds, mask) { + // "The caller must have read permission on the message queue." + return nil, linuxerr.EACCES + } + + return &linux.MsqidDS{ + MsgPerm: linux.IPCPerm{ + Key: uint32(q.obj.Key), + UID: uint32(creds.UserNamespace.MapFromKUID(q.obj.Owner.UID)), + GID: uint32(creds.UserNamespace.MapFromKGID(q.obj.Owner.GID)), + CUID: uint32(creds.UserNamespace.MapFromKUID(q.obj.Creator.UID)), + CGID: uint32(creds.UserNamespace.MapFromKGID(q.obj.Creator.GID)), + Mode: uint16(q.obj.Perms.LinuxMode()), + Seq: 0, // IPC sequences not supported. + }, + MsgStime: q.sendTime.TimeT(), + MsgRtime: q.receiveTime.TimeT(), + MsgCtime: q.changeTime.TimeT(), + MsgCbytes: q.byteCount, + MsgQnum: q.messageCount, + MsgQbytes: q.maxBytes, + MsgLspid: q.sendPID, + MsgLrpid: q.receivePID, + }, nil +} + // Lock implements ipc.Mechanism.Lock. func (q *Queue) Lock() { q.mu.Lock() |