1 /*
2 * Copyright (C) 2003-2018 D. Gilbert
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2, or (at your option)
6 * any later version.
7 *
8 * SPDX-License-Identifier: GPL-2.0-or-later
9 *
10 * This is a simple program that tests the O_EXCL flag in sg while
11 * executing a SCSI INQUIRY command and a
12 * TEST UNIT READY command using the SCSI generic (sg) driver
13 *
14 * Invocation: sg_excl [-x] <sg_device>
15 *
16 * Version 3.62 (20181227)
17 *
18 * 6 byte INQUIRY command:
19 * [0x12][ |lu][pg cde][res ][al len][cntrl ]
20 *
21 * 6 byte TEST UNIT READY command:
22 * [0x00][ |lu][res ][res ][res ][res ]
23 *
24 */
25
26 #include <unistd.h>
27 #include <fcntl.h>
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <stdint.h>
31 #include <string.h>
32 #include <errno.h>
33 #include <sys/ioctl.h>
34 #include <sys/types.h>
35 #include <sys/stat.h>
36 #include "sg_lib.h"
37 #include "sg_io_linux.h"
38
39
40 #define INQ_REPLY_LEN 96
41 #define INQ_CMD_LEN 6
42 #define TUR_CMD_LEN 6
43
44 #define EBUFF_SZ 256
45
46 #define ME "sg_excl: "
47
main(int argc,char * argv[])48 int main(int argc, char * argv[])
49 {
50 int sg_fd, k, ok /*, sg_fd2 */;
51 uint8_t inq_cdb [INQ_CMD_LEN] = {0x12, 0, 0, 0, INQ_REPLY_LEN, 0};
52 uint8_t tur_cdb [TUR_CMD_LEN] = {0x00, 0, 0, 0, 0, 0};
53 uint8_t inqBuff[INQ_REPLY_LEN];
54 sg_io_hdr_t io_hdr;
55 char * file_name = 0;
56 char ebuff[EBUFF_SZ];
57 uint8_t sense_buffer[32];
58 int do_extra = 0;
59
60 for (k = 1; k < argc; ++k) {
61 if (0 == memcmp("-x", argv[k], 2))
62 do_extra = 1;
63 else if (*argv[k] == '-') {
64 printf("Unrecognized switch: %s\n", argv[k]);
65 file_name = 0;
66 break;
67 }
68 else if (0 == file_name)
69 file_name = argv[k];
70 else {
71 printf("too many arguments\n");
72 file_name = 0;
73 break;
74 }
75 }
76 if (0 == file_name) {
77 printf("Usage: 'sg_excl [-x] <sg_device>'\n");
78 return 1;
79 }
80
81 /* N.B. An access mode of O_RDWR is required for some SCSI commands */
82 if ((sg_fd = open(file_name, O_RDWR | O_EXCL | O_NONBLOCK)) < 0) {
83 snprintf(ebuff, EBUFF_SZ, ME "error opening file: %s", file_name);
84 perror(ebuff);
85 return 1;
86 }
87 /* Just to be safe, check we have a new sg device by trying an ioctl */
88 if ((ioctl(sg_fd, SG_GET_VERSION_NUM, &k) < 0) || (k < 30000)) {
89 printf(ME "%s doesn't seem to be an new sg device\n",
90 file_name);
91 close(sg_fd);
92 return 1;
93 }
94 #if 0
95 if ((sg_fd2 = open(file_name, O_RDWR | O_EXCL)) < 0) {
96 snprintf(ebuff, EBUFF_SZ,
97 ME "error opening file: %s a second time", file_name);
98 perror(ebuff);
99 return 1;
100 } else {
101 printf(ME "second open of %s in violation of O_EXCL\n", file_name);
102 close(sg_fd2);
103 }
104 #endif
105
106 /* Prepare INQUIRY command */
107 memset(&io_hdr, 0, sizeof(sg_io_hdr_t));
108 io_hdr.interface_id = 'S';
109 io_hdr.cmd_len = sizeof(inq_cdb);
110 /* io_hdr.iovec_count = 0; */ /* memset takes care of this */
111 io_hdr.mx_sb_len = sizeof(sense_buffer);
112 io_hdr.dxfer_direction = SG_DXFER_FROM_DEV;
113 io_hdr.dxfer_len = INQ_REPLY_LEN;
114 io_hdr.dxferp = inqBuff;
115 io_hdr.cmdp = inq_cdb;
116 io_hdr.sbp = sense_buffer;
117 io_hdr.timeout = 20000; /* 20000 millisecs == 20 seconds */
118 /* io_hdr.flags = 0; */ /* take defaults: indirect IO, etc */
119 /* io_hdr.pack_id = 0; */
120 /* io_hdr.usr_ptr = NULL; */
121
122 if (ioctl(sg_fd, SG_IO, &io_hdr) < 0) {
123 perror(ME "Inquiry SG_IO ioctl error");
124 close(sg_fd);
125 return 1;
126 }
127
128 /* now for the error processing */
129 ok = 0;
130 switch (sg_err_category3(&io_hdr)) {
131 case SG_LIB_CAT_CLEAN:
132 ok = 1;
133 break;
134 case SG_LIB_CAT_RECOVERED:
135 printf("Recovered error on INQUIRY, continuing\n");
136 ok = 1;
137 break;
138 default: /* won't bother decoding other categories */
139 sg_chk_n_print3("INQUIRY command error", &io_hdr, 1);
140 break;
141 }
142
143 if (ok) { /* output result if it is available */
144 char * p = (char *)inqBuff;
145 int f = (int)*(p + 7);
146 printf("Some of the INQUIRY command's results:\n");
147 printf(" %.8s %.16s %.4s ", p + 8, p + 16, p + 32);
148 printf("[wide=%d sync=%d cmdque=%d sftre=%d]\n",
149 !!(f & 0x20), !!(f & 0x10), !!(f & 2), !!(f & 1));
150 /* Extra info, not necessary to look at */
151 if (do_extra)
152 printf("INQUIRY duration=%u millisecs, resid=%d, msg_status=%d\n",
153 io_hdr.duration, io_hdr.resid, (int)io_hdr.msg_status);
154 }
155
156
157 /* Prepare TEST UNIT READY command */
158 memset(&io_hdr, 0, sizeof(sg_io_hdr_t));
159 io_hdr.interface_id = 'S';
160 io_hdr.cmd_len = sizeof(tur_cdb);
161 io_hdr.mx_sb_len = sizeof(sense_buffer);
162 io_hdr.dxfer_direction = SG_DXFER_NONE;
163 io_hdr.cmdp = tur_cdb;
164 io_hdr.sbp = sense_buffer;
165 io_hdr.timeout = 20000; /* 20000 millisecs == 20 seconds */
166
167 if (ioctl(sg_fd, SG_IO, &io_hdr) < 0) {
168 perror(ME "Test Unit Ready SG_IO ioctl error");
169 close(sg_fd);
170 return 1;
171 }
172
173 /* now for the error processing */
174 ok = 0;
175 switch (sg_err_category3(&io_hdr)) {
176 case SG_LIB_CAT_CLEAN:
177 ok = 1;
178 break;
179 case SG_LIB_CAT_RECOVERED:
180 printf("Recovered error on Test Unit Ready, continuing\n");
181 ok = 1;
182 break;
183 default: /* won't bother decoding other categories */
184 sg_chk_n_print3("Test Unit Ready command error", &io_hdr, 1);
185 break;
186 }
187
188 if (ok)
189 printf("Test Unit Ready successful so unit is ready!\n");
190 else
191 printf("Test Unit Ready failed so unit may _not_ be ready!\n");
192
193 if (do_extra)
194 printf("TEST UNIT READY duration=%u millisecs, resid=%d, "
195 "msg_status=%d\n", io_hdr.duration, io_hdr.resid,
196 (int)io_hdr.msg_status);
197
198 printf("Wait for 60 seconds with O_EXCL help on %s\n", file_name);
199 sleep(60);
200 close(sg_fd);
201 return 0;
202 }
203