/* Copyright 2021 Alain Knaff. * This file is part of mtools. * * Mtools 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 3 of the License, or * (at your option) any later version. * * Mtools is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with Mtools. If not, see . * * I/O to a SCSI device * * written by: * * Alain L. Knaff * alain@knaff.lu * */ #include "sysincludes.h" #include "stream.h" #include "mtools.h" #include "msdos.h" #include "llong.h" #include "open_image.h" #include "scsi.h" #include "plain_io.h" #include "scsi_io.h" typedef struct ScsiDevice_t { struct Stream_t head; int fd; int privileged; uint32_t scsi_sector_size; mt_off_t device_size; uint32_t tot_sectors; void *extra_data; /* extra system dependent information for scsi. On some platforms, filled in by scsi_open, and to be supplied to scsi_cmd */ } ScsiDevice_t; /* ZIP or other scsi device on Solaris or SunOS system. Since Sun won't accept a non-Sun label on a scsi disk, we must bypass Sun's disk interface and use low-level SCSI commands to read or write the ZIP drive. We thus replace the file_read and file_write routines with our own scsi_read and scsi_write routines, that use the uscsi ioctl interface. By James Dugal, jpd@usl.edu, 11-96. Tested under Solaris 2.5 and SunOS 4.3.1_u1 using GCC. Note: the mtools.conf entry for a ZIP drive would look like this: (solaris) drive C: file="/dev/rdsk/c0t5d0s2" partition=4 FAT=16 nodelay exclusive scsi=1 (sunos) drive C: file="/dev/rsd5c" partition=4 FAT=16 nodelay exclusive scsi=1 Note 2: Sol 2.5 wants mtools to be suid-root, to use the ioctl. SunOS is happy if we just have access to the device, so making mtools sgid to a group called, say, "ziprw" which has rw permission on /dev/rsd5c, is fine. */ static int scsi_init(ScsiDevice_t *This) { int fd = This->fd; unsigned char cdb[10],buf[8]; memset(cdb, 0, sizeof cdb); memset(buf,0, sizeof(buf)); cdb[0]=SCSI_READ_CAPACITY; if (scsi_cmd(fd, (unsigned char *)cdb, sizeof(cdb), SCSI_IO_READ, buf, sizeof(buf), This->extra_data)==0) { This->tot_sectors= ((unsigned)buf[0]<<24)| ((unsigned)buf[1]<<16)| ((unsigned)buf[2]<<8)| (unsigned)buf[3]; if(This->tot_sectors < UINT32_MAX) This->tot_sectors++; This->scsi_sector_size= ((unsigned)buf[5]<<16)| ((unsigned)buf[6]<<8)| (unsigned)buf[7]; if (This->scsi_sector_size != 512) fprintf(stderr," (scsi_sector_size=%d)\n",This->scsi_sector_size); return 0; } else return -1; } /** * Overflow-safe conversion of bytes to sectors */ static uint32_t bytesToSectors(size_t bytes, uint32_t sector_size) { size_t sectors = bytes / sector_size; if(bytes % sector_size) sectors++; if(sectors > UINT32_MAX) return UINT32_MAX; else return (uint32_t) sectors; } static ssize_t scsi_io(Stream_t *Stream, char *buf, mt_off_t where, size_t len, scsi_io_mode_t rwcmd) { unsigned int firstblock, nsect; uint8_t clen; int r; unsigned int max; uint32_t offset; unsigned char cdb[10]; DeclareThis(ScsiDevice_t); firstblock=truncMtOffTo32u(where/(mt_off_t)This->scsi_sector_size); /* 512,1024,2048,... bytes/sector supported */ offset=(smt_off_t) where % This->scsi_sector_size; nsect=bytesToSectors(offset+len, This->scsi_sector_size); #if defined(OS_sun) && defined(OS_i386) if (This->scsi_sector_size>512) firstblock*=This->scsi_sector_size/512; /* work around a uscsi bug */ #endif /* sun && i386 */ if (len>512) { /* avoid buffer overruns. The transfer MUST be smaller or * equal to the requested size! */ while (nsect*This->scsi_sector_size>len) --nsect; if(!nsect) { fprintf(stderr,"Scsi buffer too small\n"); exit(1); } if(rwcmd == SCSI_IO_WRITE && offset) { /* there seems to be no memmove before a write */ fprintf(stderr,"Unaligned write\n"); exit(1); } /* a better implementation should use bounce buffers. * However, in normal operation no buffer overruns or * unaligned writes should happen anyways, as the logical * sector size is (hopefully!) equal to the physical one */ } max = scsi_max_length(); if (nsect > max) nsect=max; /* set up SCSI READ/WRITE command */ memset(cdb, 0, sizeof cdb); switch(rwcmd) { case SCSI_IO_READ: cdb[0] = SCSI_READ; break; case SCSI_IO_WRITE: cdb[0] = SCSI_WRITE; break; } cdb[1] = 0; if (firstblock > 0x1fffff || nsect > 0xff) { /* I suspect that the ZIP drive also understands Group 1 * commands. If that is indeed true, we may chose Group 1 * more aggressively in the future */ cdb[0] |= SCSI_GROUP1; clen=10; /* SCSI Group 1 cmd */ /* this is one of the rare case where explicit coding is * more portable than macros... The meaning of scsi command * bytes is standardised, whereas the preprocessor macros * handling it might be not... */ cdb[2] = (unsigned char) (firstblock >> 24) & 0xff; cdb[3] = (unsigned char) (firstblock >> 16) & 0xff; cdb[4] = (unsigned char) (firstblock >> 8) & 0xff; cdb[5] = (unsigned char) firstblock & 0xff; cdb[6] = 0; cdb[7] = (unsigned char) (nsect >> 8) & 0xff; cdb[8] = (unsigned char) nsect & 0xff; cdb[9] = 0; } else { clen = 6; /* SCSI Group 0 cmd */ cdb[1] |= (unsigned char) ((firstblock >> 16) & 0x1f); cdb[2] = (unsigned char) ((firstblock >> 8) & 0xff); cdb[3] = (unsigned char) firstblock & 0xff; cdb[4] = (unsigned char) nsect; cdb[5] = 0; } if(This->privileged) reclaim_privs(); r=scsi_cmd(This->fd, (unsigned char *)cdb, clen, rwcmd, buf, nsect*This->scsi_sector_size, This->extra_data); if(This->privileged) drop_privs(); if(r) { perror(rwcmd == SCSI_IO_READ ? "SCMD_READ" : "SCMD_WRITE"); return -1; } #ifdef JPD printf("finished %u for %u\n", firstblock, nsect); #endif #ifdef JPD printf("zip: read or write OK\n"); #endif if (offset>0) memmove(buf,buf+offset, nsect*This->scsi_sector_size-offset); if (len==256) return 256; else if (len==512) return 512; else return (ssize_t)(nsect*This->scsi_sector_size-offset); } static ssize_t scsi_pread(Stream_t *Stream, char *buf, mt_off_t where, size_t len) { #ifdef JPD printf("zip: to read %d bytes at %d\n", len, where); #endif return scsi_io(Stream, buf, where, len, SCSI_IO_READ); } static ssize_t scsi_pwrite(Stream_t *Stream, char *buf, mt_off_t where, size_t len) { #ifdef JPD Printf("zip: to write %d bytes at %d\n", len, where); #endif return scsi_io(Stream, buf, where, len, SCSI_IO_WRITE); } static int scsi_get_data(Stream_t *Stream, time_t *date, mt_off_t *size, int *type, uint32_t *address) { DeclareThis(ScsiDevice_t); if(date || type || address) fprintf(stderr, "Get_data call not supported\n"); if(size) *size = This->device_size; return 0; } static Class_t ScsiDeviceClass = { 0, 0, scsi_pread, scsi_pwrite, 0, 0, set_geom_noop, scsi_get_data, /* get_data */ 0, /* pre-allocate */ 0, /* dos-convert */ 0 /* discard */ }; Stream_t *OpenScsi(struct device *dev, const char *name, int mode, char *errmsg, int mode2, int locked, int lockMode, mt_off_t *maxSize) { int ret; ScsiDevice_t *This; if (!IS_SCSI(dev)) return NULL; This = New(ScsiDevice_t); if (!This){ printOom(); return 0; } memset((void*)This, 0, sizeof(ScsiDevice_t)); init_head(&This->head, &ScsiDeviceClass, NULL); This->scsi_sector_size = 512; if(dev) { if(!(mode2 & NO_PRIV)) This->privileged = IS_PRIVILEGED(dev); mode |= dev->mode; } precmd(dev); if(IS_PRIVILEGED(dev) && !(mode2 & NO_PRIV)) reclaim_privs(); /* End of stuff copied from top of plain_io.c before actual open */ This->fd = scsi_open(name, mode, IS_NOLOCK(dev)?0444:0666, &This->extra_data); if(IS_PRIVILEGED(dev) && !(mode2 & NO_PRIV)) drop_privs(); if (This->fd < 0) { if(errmsg) { #ifdef HAVE_SNPRINTF snprintf(errmsg, 199, "Can't open %s: %s", name, strerror(errno)); #else sprintf(errmsg, "Can't open %s: %s", name, strerror(errno)); #endif } goto exit_1; } if(IS_PRIVILEGED(dev) && !(mode2 & NO_PRIV)) closeExec(This->fd); if(LockDevice(This->fd, dev, locked, lockMode, errmsg) < 0) goto exit_0; if(maxSize) *maxSize = MAX_OFF_T_B(31+log_2(This->scsi_sector_size)); if(This->privileged) reclaim_privs(); ret=scsi_init(This); if(This->privileged) drop_privs(); if(ret < 0) goto exit_0; dev->tot_sectors = This->tot_sectors; return &This->head; exit_0: close(This->fd); exit_1: Free(This); return NULL; }