#include #include #include #include #include #include #include #include #include #include #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] 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] '\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; }