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#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include "sg_lib.h"
#include "sg_io_linux.h"
/* This is a simple program executing a SCSI INQUIRY command and a
TEST UNIT READY command using the SCSI generic (sg) driver
This variant shows mmap-ed IO being used to read the data returned
by the INQUIRY command.
* Copyright (C) 2001-2016 D. Gilbert
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
Invocation: sg_simple4 [-x] <sg_device>
Version 1.02 (20160528)
6 byte INQUIRY command:
[0x12][ |lu][pg cde][res ][al len][cntrl ]
6 byte TEST UNIT READY command:
[0x00][ |lu][res ][res ][res ][res ]
*/
#ifndef SG_FLAG_MMAP_IO
#define SG_FLAG_MMAP_IO 4
#endif /* since /usr/include/scsi/sg.h doesn't know about this yet */
#define INQ_REPLY_LEN 96
#define INQ_CMD_LEN 6
#define TUR_CMD_LEN 6
#define EBUFF_SZ 256
int main(int argc, char * argv[])
{
int sg_fd, k, ok;
unsigned char inq_cdb[INQ_CMD_LEN] =
{0x12, 0, 0, 0, INQ_REPLY_LEN, 0};
unsigned char tur_cdb[TUR_CMD_LEN] =
{0x00, 0, 0, 0, 0, 0};
unsigned char * inqBuff;
unsigned char * inqBuff2;
sg_io_hdr_t io_hdr;
char * file_name = 0;
char ebuff[EBUFF_SZ];
unsigned char sense_buffer[32];
int do_extra = 0;
for (k = 1; k < argc; ++k) {
if (0 == memcmp("-x", argv[k], 2))
do_extra = 1;
else if (*argv[k] == '-') {
printf("Unrecognized switch: %s\n", argv[k]);
file_name = 0;
break;
}
else if (0 == file_name)
file_name = argv[k];
else {
printf("too many arguments\n");
file_name = 0;
break;
}
}
if (0 == file_name) {
printf("Usage: 'sg_simple4 [-x] <sg_device>'\n");
return 1;
}
/* N.B. An access mode of O_RDWR is required for some SCSI commands */
if ((sg_fd = open(file_name, O_RDWR)) < 0) {
snprintf(ebuff, EBUFF_SZ,
"sg_simple4: error opening file: %s", file_name);
perror(ebuff);
return 1;
}
/* Just to be safe, check we have a new sg device by trying an ioctl */
if ((ioctl(sg_fd, SG_GET_VERSION_NUM, &k) < 0) || (k < 30122)) {
printf("sg_simple4: %s needs sg driver version >= 3.1.22\n",
file_name);
close(sg_fd);
return 1;
}
/* since I know this program will only read from inqBuff then I use
PROT_READ rather than PROT_READ | PROT_WRITE */
inqBuff = (unsigned char *)mmap(NULL, 8000, PROT_READ | PROT_WRITE,
MAP_SHARED, sg_fd, 0);
if (MAP_FAILED == inqBuff) {
snprintf(ebuff, EBUFF_SZ, "sg_simple4: error using mmap() on "
"file: %s", file_name);
perror(ebuff);
return 1;
}
if (inqBuff[0])
printf("non-null char at inqBuff[0]\n");
if (inqBuff[5000])
printf("non-null char at inqBuff[5000]\n");
/* Prepare INQUIRY command */
memset(&io_hdr, 0, sizeof(sg_io_hdr_t));
io_hdr.interface_id = 'S';
io_hdr.cmd_len = sizeof(inq_cdb);
/* io_hdr.iovec_count = 0; */ /* memset takes care of this */
io_hdr.mx_sb_len = sizeof(sense_buffer);
io_hdr.dxfer_direction = SG_DXFER_FROM_DEV;
io_hdr.dxfer_len = INQ_REPLY_LEN;
/* io_hdr.dxferp = inqBuff; // ignored in mmap-ed IO */
io_hdr.cmdp = inq_cdb;
io_hdr.sbp = sense_buffer;
io_hdr.timeout = 20000; /* 20000 millisecs == 20 seconds */
io_hdr.flags = SG_FLAG_MMAP_IO;
/* io_hdr.pack_id = 0; */
/* io_hdr.usr_ptr = NULL; */
if (ioctl(sg_fd, SG_IO, &io_hdr) < 0) {
perror("sg_simple4: Inquiry SG_IO ioctl error");
close(sg_fd);
return 1;
}
/* now for the error processing */
ok = 0;
switch (sg_err_category3(&io_hdr)) {
case SG_LIB_CAT_CLEAN:
ok = 1;
break;
case SG_LIB_CAT_RECOVERED:
printf("Recovered error on INQUIRY, continuing\n");
ok = 1;
break;
default: /* won't bother decoding other categories */
sg_chk_n_print3("INQUIRY command error", &io_hdr, 1);
break;
}
if (ok) { /* output result if it is available */
char * p = (char *)inqBuff;
int f = (int)*(p + 7);
printf("Some of the INQUIRY command's results:\n");
printf(" %.8s %.16s %.4s ", p + 8, p + 16, p + 32);
printf("[wide=%d sync=%d cmdque=%d sftre=%d]\n",
!!(f & 0x20), !!(f & 0x10), !!(f & 2), !!(f & 1));
/* Extra info, not necessary to look at */
if (do_extra)
printf("INQUIRY duration=%u millisecs, resid=%d, msg_status=%d\n",
io_hdr.duration, io_hdr.resid, (int)io_hdr.msg_status);
}
/* Prepare TEST UNIT READY command */
memset(&io_hdr, 0, sizeof(sg_io_hdr_t));
io_hdr.interface_id = 'S';
io_hdr.cmd_len = sizeof(tur_cdb);
io_hdr.mx_sb_len = sizeof(sense_buffer);
io_hdr.dxfer_direction = SG_DXFER_NONE;
io_hdr.cmdp = tur_cdb;
io_hdr.sbp = sense_buffer;
io_hdr.timeout = 20000; /* 20000 millisecs == 20 seconds */
if (ioctl(sg_fd, SG_IO, &io_hdr) < 0) {
perror("sg_simple4: Test Unit Ready SG_IO ioctl error");
close(sg_fd);
return 1;
}
/* now for the error processing */
ok = 0;
switch (sg_err_category3(&io_hdr)) {
case SG_LIB_CAT_CLEAN:
ok = 1;
break;
case SG_LIB_CAT_RECOVERED:
printf("Recovered error on Test Unit Ready, continuing\n");
ok = 1;
break;
default: /* won't bother decoding other categories */
sg_chk_n_print3("Test Unit Ready command error", &io_hdr, 1);
break;
}
if (ok)
printf("Test Unit Ready successful so unit is ready!\n");
else
printf("Test Unit Ready failed so unit may _not_ be ready!\n");
if (do_extra)
printf("TEST UNIT READY duration=%u millisecs, resid=%d, "
"msg_status=%d\n",
io_hdr.duration, io_hdr.resid, (int)io_hdr.msg_status);
/* munmap(inqBuff, 8000); */
/* could call munmap(inqBuff, INQ_REPLY_LEN) here but following close()
causes this too happen anyway */
#if 1
inqBuff2 = (unsigned char *)mmap(NULL, 8000, PROT_READ | PROT_WRITE,
MAP_SHARED, sg_fd, 0);
if (MAP_FAILED == inqBuff2) {
snprintf(ebuff, EBUFF_SZ, "sg_simple4: error using mmap() 2 on "
"file: %s", file_name);
perror(ebuff);
return 1;
}
if (inqBuff2[0])
printf("non-null char at inqBuff2[0]\n");
if (inqBuff2[5000])
printf("non-null char at inqBuff2[5000]\n");
{
pid_t pid;
pid = fork();
if (pid) {
inqBuff2[5000] = 33;
munmap(inqBuff, 8000);
sleep(3);
}
else {
inqBuff[5000] = 0xaa;
munmap(inqBuff, 8000);
sleep(1);
}
}
#endif
close(sg_fd);
return 0;
}
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