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      1 /*	$NetBSD: msg.h,v 1.3 2020/03/06 14:06:56 kamil Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2016 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Christos Zoulas.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 struct msg_fds {
     33 	int pfd[2];
     34 	int cfd[2];
     35 };
     36 
     37 #define CLOSEFD(fd) do { \
     38 	if (fd != -1) { \
     39 		close(fd); \
     40 		fd = -1; \
     41 	} \
     42 } while (/*CONSTCOND*/ 0)
     43 
     44 static int __used
     45 msg_open(struct msg_fds *fds)
     46 {
     47 	if (pipe(fds->pfd) == -1)
     48 		return -1;
     49 	if (pipe(fds->cfd) == -1) {
     50 		close(fds->pfd[0]);
     51 		close(fds->pfd[1]);
     52 		return -1;
     53 	}
     54 	return 0;
     55 }
     56 
     57 static void __used
     58 msg_close(struct msg_fds *fds)
     59 {
     60 	CLOSEFD(fds->pfd[0]);
     61 	CLOSEFD(fds->pfd[1]);
     62 	CLOSEFD(fds->cfd[0]);
     63 	CLOSEFD(fds->cfd[1]);
     64 }
     65 
     66 static int __used
     67 msg_write_child(const char *info, struct msg_fds *fds, void *msg, size_t len)
     68 {
     69 	ssize_t rv;
     70 	CLOSEFD(fds->cfd[1]);
     71 	CLOSEFD(fds->pfd[0]);
     72 
     73 //	printf("Send %s\n", info);
     74 	rv = write(fds->pfd[1], msg, len);
     75 	if (rv != (ssize_t)len)
     76 		return 1;
     77 //	printf("Wait %s\n", info);
     78 	rv = read(fds->cfd[0], msg, len);
     79 	if (rv != (ssize_t)len)
     80 		return 1;
     81 	return 0;
     82 }
     83 
     84 static int __used
     85 msg_write_parent(const char *info, struct msg_fds *fds, void *msg, size_t len)
     86 {
     87 	ssize_t rv;
     88 	CLOSEFD(fds->pfd[1]);
     89 	CLOSEFD(fds->cfd[0]);
     90 
     91 //	printf("Send %s\n", info);
     92 	rv = write(fds->cfd[1], msg, len);
     93 	if (rv != (ssize_t)len)
     94 		return 1;
     95 //	printf("Wait %s\n", info);
     96 	rv = read(fds->pfd[0], msg, len);
     97 	if (rv != (ssize_t)len)
     98 		return 1;
     99 	return 0;
    100 }
    101 
    102 static int __used
    103 msg_read_parent(const char *info, struct msg_fds *fds, void *msg, size_t len)
    104 {
    105 	ssize_t rv;
    106 	CLOSEFD(fds->pfd[1]);
    107 	CLOSEFD(fds->cfd[0]);
    108 
    109 //	printf("Wait %s\n", info);
    110 	rv = read(fds->pfd[0], msg, len);
    111 	if (rv != (ssize_t)len)
    112 		return 1;
    113 //	printf("Send %s\n", info);
    114 	rv = write(fds->cfd[1], msg, len);
    115 	if (rv != (ssize_t)len)
    116 		return 1;
    117 	return 0;
    118 }
    119 
    120 static int __used
    121 msg_read_child(const char *info, struct msg_fds *fds, void *msg, size_t len)
    122 {
    123 	ssize_t rv;
    124 	CLOSEFD(fds->cfd[1]);
    125 	CLOSEFD(fds->pfd[0]);
    126 
    127 //	printf("Wait %s\n", info);
    128 	rv = read(fds->cfd[0], msg, len);
    129 	if (rv != (ssize_t)len)
    130 		return 1;
    131 //	printf("Send %s\n", info);
    132 	rv = write(fds->pfd[1], msg, len);
    133 	if (rv != (ssize_t)len)
    134 		return 1;
    135 	return 0;
    136 }
    137 
    138 #define PARENT_TO_CHILD(info, fds, msg) \
    139     SYSCALL_REQUIRE(msg_write_child(info " to child " # fds, &fds, &msg, \
    140 	sizeof(msg)) == 0)
    141 
    142 #define CHILD_FROM_PARENT(info, fds, msg) \
    143     FORKEE_ASSERT(msg_read_parent(info " from parent " # fds, &fds, &msg, \
    144 	sizeof(msg)) == 0)
    145 
    146 #define CHILD_TO_PARENT(info, fds, msg) \
    147     FORKEE_ASSERT(msg_write_parent(info " to parent " # fds, &fds, &msg, \
    148 	sizeof(msg)) == 0)
    149 
    150 #define PARENT_FROM_CHILD(info, fds, msg) \
    151     SYSCALL_REQUIRE(msg_read_child(info " from parent " # fds, &fds, &msg, \
    152 	sizeof(msg)) == 0)
    153