ICMP extensions for MPLS support for traceroute(8).
[dragonfly.git] / sys / sys / msgport.h
CommitLineData
ece04fd0
MD
1/*
2 * SYS/MSGPORT.H
3 *
4 * Implements LWKT messages and ports.
5 *
c19b9a17 6 * $DragonFly: src/sys/sys/msgport.h,v 1.23 2007/05/23 02:09:41 dillon Exp $
ece04fd0
MD
7 */
8
9#ifndef _SYS_MSGPORT_H_
10#define _SYS_MSGPORT_H_
11
12#ifndef _SYS_QUEUE_H_
13#include <sys/queue.h> /* TAILQ_* macros */
14#endif
05220613
MD
15#ifndef _SYS_STDINT_H_
16#include <sys/stdint.h>
17#endif
ece04fd0 18
6aad077d
MD
19#ifdef _KERNEL
20
21#ifndef _SYS_MALLOC_H_
22#include <sys/malloc.h>
23#endif
24
25#endif
26
ece04fd0
MD
27struct lwkt_msg;
28struct lwkt_port;
335dda38 29struct thread;
ece04fd0
MD
30
31typedef struct lwkt_msg *lwkt_msg_t;
32typedef struct lwkt_port *lwkt_port_t;
33
335dda38
MD
34typedef TAILQ_HEAD(lwkt_msg_queue, lwkt_msg) lwkt_msg_queue;
35
b44419cb
MD
36/*
37 * LWKT command message operator type. This type holds a message's
38 * 'command'. The command format is opaque to the LWKT messaging system,
39 * meaning that it is specific to whatever convention the API chooses.
40 * By convention lwkt_cmd_t is passed by value and is expected to
41 * efficiently fit into a machine register.
42 */
43typedef union lwkt_cmd {
44 int cm_op;
45 int (*cm_func)(lwkt_msg_t msg);
46} lwkt_cmd_t;
47
ece04fd0
MD
48/*
49 * The standard message and port structure for communications between
50 * threads. See kern/lwkt_msgport.c for documentation on how messages and
51 * ports work.
a64ba182 52 *
e7906ee5
MD
53 * For the most part a message may only be manipulated by whomever currently
54 * owns it, which generally means the originating port if the message has
55 * not been sent yet or has been replied, and the target port if the message
56 * has been sent and/or is undergoing processing.
57 *
58 * The one exception to this rule is an abort. Aborts must be initiated
59 * by the originator and may 'chase' the target (especially if a message
60 * is being forwarded), potentially even 'chase' the message all the way
61 * back to the originator if it races against the target replying the
62 * message. The ms_abort_port field is the only field that may be modified
63 * by the originator or intermediate target (when the abort is chasing
64 * a forwarding or reply op). An abort may cause a reply to be delayed
65 * until the abort catches up to it.
66 *
b44419cb
MD
67 * Messages which support an abort will have MSGF_ABORTABLE set, indicating
68 * that the ms_abort field has been initialized. An abort will cause a
69 * message to be requeued to the target port so the target sees the same
70 * message twice: once during initial processing of the message, and a
71 * second time to process the abort request. lwkt_getport() will detect
72 * the requeued abort and will copy ms_abort into ms_cmd before returning
73 * the requeued message the second time. This makes target processing a
74 * whole lot less complex.
e7906ee5 75 *
a64ba182 76 * NOTE! 64-bit-align this structure.
ece04fd0
MD
77 */
78typedef struct lwkt_msg {
ce280ce5 79 TAILQ_ENTRY(lwkt_msg) ms_node; /* link node */
df2244e3 80 lwkt_port_t ms_target_port; /* current target or relay port */
e7906ee5
MD
81 lwkt_port_t ms_reply_port; /* async replies returned here */
82 lwkt_port_t ms_abort_port; /* abort chasing port */
b44419cb
MD
83 lwkt_cmd_t ms_cmd; /* message command operator */
84 lwkt_cmd_t ms_abort; /* message abort operator */
df2244e3 85 int ms_flags; /* message flags */
df2244e3 86 int ms_error; /* positive error code or 0 */
a64ba182 87 union {
df2244e3 88 void *ms_resultp; /* misc pointer data or result */
90b9818c
MD
89 int ms_result; /* standard 'int'eger result */
90 long ms_lresult; /* long result */
91 int ms_fds[2]; /* two int bit results */
05220613
MD
92 __int32_t ms_result32; /* 32 bit result */
93 __int64_t ms_result64; /* 64 bit result */
94 __off_t ms_offset; /* off_t result */
a64ba182
MD
95 } u;
96 int ms_pad[2]; /* future use */
ece04fd0
MD
97} lwkt_msg;
98
99#define MSGF_DONE 0x0001 /* asynch message is complete */
e7906ee5 100#define MSGF_REPLY1 0x0002 /* asynch message has been returned */
ece04fd0
MD
101#define MSGF_QUEUED 0x0004 /* message has been queued sanitychk */
102#define MSGF_ASYNC 0x0008 /* sync/async hint */
b44419cb 103#define MSGF_ABORTED 0x0010 /* indicate pending abort */
e7906ee5
MD
104#define MSGF_PCATCH 0x0020 /* catch proc signal while waiting */
105#define MSGF_REPLY2 0x0040 /* reply processed by rport cpu */
b44419cb
MD
106#define MSGF_ABORTABLE 0x0080 /* message supports abort */
107#define MSGF_RETRIEVED 0x0100 /* message retrieved on target */
ece04fd0 108
335dda38
MD
109#define MSG_CMD_CDEV 0x00010000
110#define MSG_CMD_VFS 0x00020000
111#define MSG_CMD_SYSCALL 0x00030000
112#define MSG_SUBCMD_MASK 0x0000FFFF
113
9eeaa8a9 114#ifdef _KERNEL
9eeaa8a9
JH
115MALLOC_DECLARE(M_LWKTMSG);
116#endif
9eeaa8a9 117
3efe7008
MD
118/*
119 * Notes on port processing requirements:
120 *
121 * mp_putport():
122 * - may return synchronous error code (error != EASYNC) directly and
123 * does not need to check or set MSGF_DONE if so, or set ms_target_port
124 * - for asynch procesing should clear MSGF_DONE and set ms_target_port
125 * to port prior to initiation of the command.
126 *
127 * mp_waitport():
128 * - if the passed msg is NULL we wait for, remove, and return the
129 * next pending message on the port.
130 * - if the passed msg is non-NULL we wait for that particular message,
131 * which typically involves waiting until MSGF_DONE is set then
132 * pulling the message off the port if MSGF_QUEUED is set and
133 * returning it. If MSGF_PCATCH is set in the message we allow
134 * a signal to interrupt and abort the message.
135 *
136 * mp_replyport():
137 * - reply a message (executed on the originating port to return a
138 * message to it). This can be rather involved if abort is to be
139 * supported, see lwkt_default_replyport(). Generally speaking
140 * one sets MSGF_DONE. If MSGF_ASYNC is set the message is queued
141 * to the port, else the port's thread is scheduled.
142 *
143 * mp_abortport():
144 * - abort a message. The mp_abortport function for the message's
145 * ms_target_port is called. ms_target_port is basically where
146 * the message was sent to or last forwarded to. Aborting a message
147 * can be rather involved. Note that the lwkt_getmsg() code ensures
148 * that a message is returned non-abort before it is returned again
149 * with its ms_cmd set to ms_abort, even if the abort occurs before
150 * the initial retrieval of the message. The setting of ms_cmd to
151 * ms_abort is NOT handled by mp_abortport(). mp_abortport() is
152 * basically responsible for requeueing the message to the target
153 * port and setting the MSGF_ABORTED flag.
154 *
155 */
ece04fd0
MD
156typedef struct lwkt_port {
157 lwkt_msg_queue mp_msgq;
158 int mp_flags;
1fa2b4b4 159 int mp_unused01;
335dda38 160 struct thread *mp_td;
df2244e3
MD
161 int (*mp_putport)(lwkt_port_t, lwkt_msg_t);
162 void * (*mp_waitport)(lwkt_port_t, lwkt_msg_t);
163 void (*mp_replyport)(lwkt_port_t, lwkt_msg_t);
164 void (*mp_abortport)(lwkt_port_t, lwkt_msg_t);
ece04fd0
MD
165} lwkt_port;
166
167#define MSGPORTF_WAITING 0x0001
168
df2244e3
MD
169/*
170 * These functions are good for userland as well as the kernel. The
171 * messaging function support for userland is provided by the kernel's
172 * kern/lwkt_msgport.c. The port functions are provided by userland.
173 */
984ccc17 174void lwkt_initport(lwkt_port_t, struct thread *);
be86a874 175void lwkt_initport_null_rport(lwkt_port_t, struct thread *);
984ccc17
MD
176void lwkt_sendmsg(lwkt_port_t, lwkt_msg_t);
177int lwkt_domsg(lwkt_port_t, lwkt_msg_t);
e7906ee5
MD
178int lwkt_forwardmsg(lwkt_port_t, lwkt_msg_t);
179void lwkt_abortmsg(lwkt_msg_t);
984ccc17
MD
180void *lwkt_getport(lwkt_port_t);
181
182int lwkt_default_putport(lwkt_port_t port, lwkt_msg_t msg);
183void *lwkt_default_waitport(lwkt_port_t port, lwkt_msg_t msg);
184void lwkt_default_replyport(lwkt_port_t port, lwkt_msg_t msg);
185void lwkt_default_abortport(lwkt_port_t port, lwkt_msg_t msg);
be86a874 186void lwkt_null_replyport(lwkt_port_t port, lwkt_msg_t msg);
ece04fd0 187
ece04fd0 188#endif