X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/1c79356b52d46aa6b508fb032f5ae709b1f2897b..c0fea4742e91338fffdcf79f86a7c1d5e2b97eb1:/osfmk/mach/port.h diff --git a/osfmk/mach/port.h b/osfmk/mach/port.h index 42c182000..8803a516c 100644 --- a/osfmk/mach/port.h +++ b/osfmk/mach/port.h @@ -1,5 +1,5 @@ /* - * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * @@ -52,72 +52,123 @@ /* * File: mach/port.h * - * Definition of a port + * Definition of a Mach port + * + * Mach ports are the endpoints to Mach-implemented communications + * channels (usually uni-directional message queues, but other types + * also exist). + * + * Unique collections of these endpoints are maintained for each + * Mach task. Each Mach port in the task's collection is given a + * [task-local] name to identify it - and the the various "rights" + * held by the task for that specific endpoint. + * + * This header defines the types used to identify these Mach ports + * and the various rights associated with them. For more info see: + * + * - manipulation of port rights in a given space + * - message queue [and port right passing] mechanism * - * [The basic port_t type should probably be machine-dependent, - * as it must be represented by a 32-bit integer.] */ #ifndef _MACH_PORT_H_ #define _MACH_PORT_H_ +#include #include #include /* - * A port_name_t is a 32 bit value which represents a name of a - * port right within some ipc space. This is a constant definition - * everywhere. + * mach_port_name_t - the local identity for a Mach port * - * The type port_t represents a reference added or deleted to a - * port right. + * The name is Mach port namespace specific. It is used to + * identify the rights held for that port by the task whose + * namespace is implied [or specifically provided]. * - * At user space, this is represented by returning the name of - * the right(s) that got altered within the user's ipc space. - * So a port_t is the same type as a port_name_t there. + * Use of this type usually implies just a name - no rights. + * See mach_port_t for a type that implies a "named right." * - * Since there is no right space for the kernel proper (all rights - * are naked rights) these rights are represented by passing a - * pointer to the specific ipc_object_t subclass (typically - * ipc_port_t) that got altered/is to be altered. */ -typedef natural_t port_name_t; -typedef port_name_t *port_name_array_t; + +typedef natural_t mach_port_name_t; +typedef mach_port_name_t *mach_port_name_array_t; + +#ifdef KERNEL -#ifdef KERNEL_PRIVATE +/* + * mach_port_t - a named port right + * + * In the kernel, "rights" are represented [named] by pointers to + * the ipc port object in question. There is no port namespace for the + * rights to be collected. + * + * Actually, there is namespace for the kernel task. But most kernel + * code - including, but not limited to, Mach IPC code - lives in the + * limbo between the current user-level task and the "next" task. Very + * little of the kernel code runs in full kernel task context. So very + * little of it gets to use the kernel task's port name space. + * + * Because of this implementation approach, all in-kernel rights for + * a given port coalesce [have the same name/pointer]. The actual + * references are counted in the port itself. It is up to the kernel + * code in question to "just remember" how many [and what type of] + * rights it holds and handle them appropriately. + * + */ -#include -typedef ipc_port_t port_t; +#ifndef MACH_KERNEL_PRIVATE +/* + * For kernel code that resides outside of Mach proper, we opaque the + * port structure definition. + */ +struct ipc_port ; + +#endif /* MACH_KERNEL_PRIVATE */ + +typedef struct ipc_port *ipc_port_t; + +#define IPC_PORT_NULL ((ipc_port_t) 0) +#define IPC_PORT_DEAD ((ipc_port_t)~0) +#define IPC_PORT_VALID(port) \ + ((port) != IPC_PORT_NULL && (port) != IPC_PORT_DEAD) + +typedef ipc_port_t mach_port_t; + +#else /* KERNEL */ + +/* + * mach_port_t - a named port right + * + * In user-space, "rights" are represented by the name of the + * right in the Mach port namespace. Even so, this type is + * presented as a unique one to more clearly denote the presence + * of a right coming along with the name. + * + * Often, various rights for a port held in a single name space + * will coalesce and are, therefore, be identified by a single name + * [this is the case for send and receive rights]. But not + * always [send-once rights currently get a unique name for + * each right]. + * + */ -#else /* ! KERNEL_PRIVATE */ +#ifndef _MACH_PORT_T +#define _MACH_PORT_T +typedef mach_port_name_t mach_port_t; +#endif -typedef port_name_t port_t; +#endif /* KERNEL */ -#endif /* KERNEL_PRIVATE */ +typedef mach_port_t *mach_port_array_t; /* - * PORT_NULL is a legal value that can be carried in messages. + * MACH_PORT_NULL is a legal value that can be carried in messages. * It indicates the absence of any port or port rights. (A port * argument keeps the message from being "simple", even if the - * value is PORT_NULL.) The value PORT_DEAD is also a legal + * value is MACH_PORT_NULL.) The value MACH_PORT_DEAD is also a legal * value that can be carried in messages. It indicates * that a port right was present, but it died. */ -#define PORT_NULL ((port_t) 0) -#define PORT_DEAD ((port_t) ~0) -#define PORT_VALID(name) \ - (((port_t)(name) != PORT_NULL) && \ - ((port_t)(name) != PORT_DEAD)) - -/* - * Mach 3.0 renamed everything to have mach_ in front of it. - * Do that mapping here, so we have the types and macros in - * both formats. - */ -typedef port_t mach_port_t; -typedef port_t *mach_port_array_t; -typedef port_name_t mach_port_name_t; -typedef mach_port_name_t *mach_port_name_array_t; #define MACH_PORT_NULL 0 /* intentional loose typing */ #define MACH_PORT_DEAD ((mach_port_name_t) ~0) @@ -125,35 +176,39 @@ typedef mach_port_name_t *mach_port_name_array_t; (((name) != MACH_PORT_NULL) && \ ((name) != MACH_PORT_DEAD)) + /* - * mach_port_name_t must be an unsigned type. Port values - * have two parts, a generation number and an index. - * These macros encapsulate all knowledge of how - * a mach_port_name_t is laid out. They are made visible - * to user tasks so that packages to map from a mach_port_name_t - * to associated user data can discount the generation - * nuber (if desired) in doing the mapping. + * For kernel-selected [assigned] port names, the name is + * comprised of two parts: a generation number and an index. + * This approach keeps the exact same name from being generated + * and reused too quickly [to catch right/reference counting bugs]. + * The dividing line between the constituent parts is exposed so + * that efficient "mach_port_name_t to data structure pointer" + * conversion implementation can be made. But it is possible + * for user-level code to assign their own names to Mach ports. + * These are not required to participate in this algorithm. So + * care should be taken before "assuming" this model. * - * Within the kernel, ipc/ipc_entry.c implicitly assumes - * when it uses the splay tree functions that the generation - * number is in the low bits, so that names are ordered first - * by index and then by generation. If the size of generation - * numbers changes, be sure to update IE_BITS_GEN_MASK and - * friends in ipc/ipc_entry.h. */ -#ifndef NO_PORT_GEN + +#ifndef NO_PORT_GEN + #define MACH_PORT_INDEX(name) ((name) >> 8) #define MACH_PORT_GEN(name) (((name) & 0xff) << 24) #define MACH_PORT_MAKE(index, gen) \ (((index) << 8) | (gen) >> 24) -#else + +#else /* NO_PORT_GEN */ + #define MACH_PORT_INDEX(name) (name) #define MACH_PORT_GEN(name) (0) #define MACH_PORT_MAKE(index, gen) (index) -#endif /* !NO_PORT_GEN */ + +#endif /* NO_PORT_GEN */ + /* - * These are the different rights a task may have. + * These are the different rights a task may have for a port. * The MACH_PORT_RIGHT_* definitions are used as arguments * to mach_port_allocate, mach_port_get_refs, etc, to specify * a particular right to act upon. The mach_port_names and @@ -214,16 +269,10 @@ typedef natural_t mach_port_msgcount_t; /* number of msgs */ typedef natural_t mach_port_rights_t; /* number of rights */ /* - * A port may have NMS detection enabled, in which case - * it tracks outstanding send rights. Otherwise, there - * is no information available about outstanding srights. - * The return values are deliberately chosen to match - * the old boolean (0=FALSE=no srights, 1=TRUE=srights, - * 2=xxx=no information available). + * Are there outstanding send rights for a given port? */ -#define MACH_PORT_SRIGHTS_NONE 0 /* NMS: no srights */ -#define MACH_PORT_SRIGHTS_PRESENT 1 /* NMS: srights */ -#define MACH_PORT_SRIGHTS_NO_INFO 2 /* no NMS */ +#define MACH_PORT_SRIGHTS_NONE 0 /* no srights */ +#define MACH_PORT_SRIGHTS_PRESENT 1 /* srights */ typedef unsigned int mach_port_srights_t; /* status of send rights */ typedef struct mach_port_status { @@ -236,11 +285,11 @@ typedef struct mach_port_status { boolean_t mps_srights; /* do send rights exist? */ boolean_t mps_pdrequest; /* port-deleted requested? */ boolean_t mps_nsrequest; /* no-senders requested? */ - unsigned int mps_flags; /* port flags */ + natural_t mps_flags; /* port flags */ } mach_port_status_t; #define MACH_PORT_QLIMIT_DEFAULT ((mach_port_msgcount_t) 5) -#define MACH_PORT_QLIMIT_MAX ((mach_port_msgcount_t) 16) +#define MACH_PORT_QLIMIT_MAX ((mach_port_msgcount_t) 16) typedef struct mach_port_limits { mach_port_msgcount_t mpl_qlimit; /* number of msgs */ @@ -254,17 +303,16 @@ typedef int mach_port_flavor_t; #define MACH_PORT_RECEIVE_STATUS 2 /* uses mach_port_limits_t */ #define MACH_PORT_DNREQUESTS_SIZE 3 /* info is int */ -#define MACH_PORT_LIMITS_INFO_COUNT \ - (sizeof(mach_port_limits_t)/sizeof(natural_t)) -#define MACH_PORT_RECEIVE_STATUS_COUNT \ - (sizeof(mach_port_status_t)/sizeof(natural_t)) +#define MACH_PORT_LIMITS_INFO_COUNT ((natural_t) \ + (sizeof(mach_port_limits_t)/sizeof(natural_t))) +#define MACH_PORT_RECEIVE_STATUS_COUNT ((natural_t) \ + (sizeof(mach_port_status_t)/sizeof(natural_t))) #define MACH_PORT_DNREQUESTS_SIZE_COUNT 1 /* * Structure used to pass information about port allocation requests. * Must be padded to 64-bits total length. */ - typedef struct mach_port_qos { boolean_t name:1; /* name given */ boolean_t prealloc:1; /* prealloced message */ @@ -272,4 +320,21 @@ typedef struct mach_port_qos { natural_t len; } mach_port_qos_t; +#if !defined(_POSIX_C_SOURCE) && !defined(_NO_PORT_T_FROM_MACH) +/* + * Mach 3.0 renamed everything to have mach_ in front of it. + * These types and macros are provided for backward compatibility + * but are deprecated. + */ +typedef mach_port_t port_t; +typedef mach_port_name_t port_name_t; +typedef mach_port_name_t *port_name_array_t; + +#define PORT_NULL ((port_t) 0) +#define PORT_DEAD ((port_t) ~0) +#define PORT_VALID(name) \ + ((port_t)(name) != PORT_NULL && (port_t)(name) != PORT_DEAD) + +#endif /* !_POSIX_C_SOURCE && !_NO_PORT_T_FROM_MACH */ + #endif /* _MACH_PORT_H_ */