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Diffstat (limited to 'examples/sg_simple4.c')
-rw-r--r-- | examples/sg_simple4.c | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/examples/sg_simple4.c b/examples/sg_simple4.c new file mode 100644 index 00000000..95a5023b --- /dev/null +++ b/examples/sg_simple4.c @@ -0,0 +1,238 @@ +#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; +} |