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Diffstat (limited to 'examples/sg_excl.c')
| -rw-r--r-- | examples/sg_excl.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/examples/sg_excl.c b/examples/sg_excl.c new file mode 100644 index 00000000..7e589b23 --- /dev/null +++ b/examples/sg_excl.c @@ -0,0 +1,202 @@ +/* + * Copyright (C) 2003-2018 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. + * + * SPDX-License-Identifier: GPL-2.0-or-later + * + * This is a simple program that tests the O_EXCL flag in sg while + * executing a SCSI INQUIRY command and a + * TEST UNIT READY command using the SCSI generic (sg) driver + * + * Invocation: sg_excl [-x] <sg_device> + * + * Version 3.62 (20181227) + * + * 6 byte INQUIRY command: + * [0x12][ |lu][pg cde][res ][al len][cntrl ] + * + * 6 byte TEST UNIT READY command: + * [0x00][ |lu][res ][res ][res ][res ] + * + */ + +#include <unistd.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <string.h> +#include <errno.h> +#include <sys/ioctl.h> +#include <sys/types.h> +#include <sys/stat.h> +#include "sg_lib.h" +#include "sg_io_linux.h" + + +#define INQ_REPLY_LEN 96 +#define INQ_CMD_LEN 6 +#define TUR_CMD_LEN 6 + +#define EBUFF_SZ 256 + +#define ME "sg_excl: " + +int main(int argc, char * argv[]) +{ + int sg_fd, k, ok /*, sg_fd2 */; + uint8_t inq_cdb [INQ_CMD_LEN] = {0x12, 0, 0, 0, INQ_REPLY_LEN, 0}; + uint8_t tur_cdb [TUR_CMD_LEN] = {0x00, 0, 0, 0, 0, 0}; + uint8_t inqBuff[INQ_REPLY_LEN]; + sg_io_hdr_t io_hdr; + char * file_name = 0; + char ebuff[EBUFF_SZ]; + uint8_t 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_excl [-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 | O_EXCL | O_NONBLOCK)) < 0) { + snprintf(ebuff, EBUFF_SZ, ME "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 < 30000)) { + printf(ME "%s doesn't seem to be an new sg device\n", + file_name); + close(sg_fd); + return 1; + } +#if 0 + if ((sg_fd2 = open(file_name, O_RDWR | O_EXCL)) < 0) { + snprintf(ebuff, EBUFF_SZ, + ME "error opening file: %s a second time", file_name); + perror(ebuff); + return 1; + } else { + printf(ME "second open of %s in violation of O_EXCL\n", file_name); + close(sg_fd2); + } +#endif + + /* 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; + io_hdr.cmdp = inq_cdb; + io_hdr.sbp = sense_buffer; + io_hdr.timeout = 20000; /* 20000 millisecs == 20 seconds */ + /* io_hdr.flags = 0; */ /* take defaults: indirect IO, etc */ + /* io_hdr.pack_id = 0; */ + /* io_hdr.usr_ptr = NULL; */ + + if (ioctl(sg_fd, SG_IO, &io_hdr) < 0) { + perror(ME "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(ME "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); + + printf("Wait for 60 seconds with O_EXCL help on %s\n", file_name); + sleep(60); + close(sg_fd); + return 0; +} |