freebsd-dev/lib/libcam/camlib.c
Edward Tomasz Napierala 3e404b8c53 libcam(3): make cam_getccb(3) zero the whole ccb, not just the header
Leaving zeroing to the clients leads to error-prone pointer
tricks (zeroing needs to preserve the CCB header), and this
code is not performance-critical, so there's really no reason
to not do it.

Reviewed By:	imp, rpokala (manpages)
Sponsored by:	NetApp, Inc.
Sponsored by:	Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D27333
2020-12-29 14:26:06 +00:00

759 lines
20 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 1997, 1998, 1999, 2002 Kenneth D. Merry.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/param.h>
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <ctype.h>
#include <cam/cam.h>
#include <cam/scsi/scsi_all.h>
#include <cam/cam_ccb.h>
#include <cam/scsi/scsi_pass.h>
#include "camlib.h"
static const char *nonrewind_devs[] = {
"sa"
};
char cam_errbuf[CAM_ERRBUF_SIZE];
static struct cam_device *cam_real_open_device(const char *path, int flags,
struct cam_device *device,
const char *given_path,
const char *given_dev_name,
int given_unit_number);
static struct cam_device *cam_lookup_pass(const char *dev_name, int unit,
int flags, const char *given_path,
struct cam_device *device);
/*
* Send a ccb to a passthrough device.
*/
int
cam_send_ccb(struct cam_device *device, union ccb *ccb)
{
return(ioctl(device->fd, CAMIOCOMMAND, ccb));
}
/*
* Malloc a CCB, zero out the header and set its path, target and lun ids.
*/
union ccb *
cam_getccb(struct cam_device *dev)
{
union ccb *ccb;
ccb = calloc(1, sizeof(*ccb));
if (ccb != NULL) {
ccb->ccb_h.path_id = dev->path_id;
ccb->ccb_h.target_id = dev->target_id;
ccb->ccb_h.target_lun = dev->target_lun;
}
return(ccb);
}
/*
* Free a CCB.
*/
void
cam_freeccb(union ccb *ccb)
{
free(ccb);
}
/*
* Take a device name or path passed in by the user, and attempt to figure
* out the device name and unit number. Some possible device name formats are:
* /dev/foo0
* foo0
* nfoo0
*
* Some peripheral drivers create separate device nodes with 'n' prefix for
* non-rewind operations. Currently only sa(4) tape driver has this feature.
* We extract pure peripheral name as device name for this special case.
*
* Input parameters: device name/path, length of devname string
* Output: device name, unit number
* Return values: returns 0 for success, -1 for failure
*/
int
cam_get_device(const char *path, char *dev_name, int devnamelen, int *unit)
{
char *tmpstr, *tmpstr2;
char *newpath;
int unit_offset;
int i;
if (path == NULL) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: device pathname was NULL", __func__);
return(-1);
}
/*
* We can be rather destructive to the path string. Make a copy of
* it so we don't hose the user's string.
*/
newpath = (char *)strdup(path);
if (newpath == NULL)
return (-1);
tmpstr = newpath;
/*
* Check to see whether we have an absolute pathname.
*/
if (*tmpstr == '/') {
tmpstr2 = tmpstr;
tmpstr = strrchr(tmpstr2, '/');
/* We know that tmpstr2 contains a '/', so strrchr can't fail */
assert(tmpstr != NULL && *tmpstr != '\0');
tmpstr++;
}
if (*tmpstr == '\0') {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: no text after slash", __func__);
free(newpath);
return(-1);
}
/*
* Check to see whether the user has given us a nonrewound tape
* device.
*/
if (*tmpstr == 'n' || *tmpstr == 'e') {
for (i = 0; i < sizeof(nonrewind_devs)/sizeof(char *); i++) {
int len = strlen(nonrewind_devs[i]);
if (strncmp(tmpstr + 1, nonrewind_devs[i], len) == 0) {
if (isdigit(tmpstr[len + 1])) {
tmpstr++;
break;
}
}
}
}
/*
* We should now have just a device name and unit number.
* That means that there must be at least 2 characters.
* If we only have 1, we don't have a valid device name.
*/
if (strlen(tmpstr) < 2) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: must have both device name and unit number",
__func__);
free(newpath);
return(-1);
}
/*
* If the first character of the string is a digit, then the user
* has probably given us all numbers. Point out the error.
*/
if (isdigit(*tmpstr)) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: device name cannot begin with a number",
__func__);
free(newpath);
return(-1);
}
/*
* At this point, if the last character of the string isn't a
* number, we know the user either didn't give us a device number,
* or he gave us a device name/number format we don't recognize.
*/
if (!isdigit(tmpstr[strlen(tmpstr) - 1])) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: unable to find device unit number", __func__);
free(newpath);
return(-1);
}
/*
* Attempt to figure out where the device name ends and the unit
* number begins. As long as unit_offset is at least 1 less than
* the length of the string, we can still potentially have a device
* name at the front of the string. When we get to something that
* isn't a digit, we've hit the device name. Because of the check
* above, we know that this cannot happen when unit_offset == 1.
* Therefore it is okay to decrement unit_offset -- it won't cause
* us to go past the end of the character array.
*/
for (unit_offset = 1;
(unit_offset < (strlen(tmpstr)))
&& (isdigit(tmpstr[strlen(tmpstr) - unit_offset])); unit_offset++);
unit_offset--;
/*
* Grab the unit number.
*/
*unit = atoi(&tmpstr[strlen(tmpstr) - unit_offset]);
/*
* Put a null in place of the first number of the unit number so
* that all we have left is the device name.
*/
tmpstr[strlen(tmpstr) - unit_offset] = '\0';
strlcpy(dev_name, tmpstr, devnamelen);
/* Clean up allocated memory */
free(newpath);
return(0);
}
/*
* Backwards compatible wrapper for the real open routine. This translates
* a pathname into a device name and unit number for use with the real open
* routine.
*/
struct cam_device *
cam_open_device(const char *path, int flags)
{
int unit;
char dev_name[DEV_IDLEN + 1];
/*
* cam_get_device() has already put an error message in cam_errbuf,
* so we don't need to.
*/
if (cam_get_device(path, dev_name, sizeof(dev_name), &unit) == -1)
return(NULL);
return(cam_lookup_pass(dev_name, unit, flags, path, NULL));
}
/*
* Open the passthrough device for a given bus, target and lun, if the
* passthrough device exists.
*/
struct cam_device *
cam_open_btl(path_id_t path_id, target_id_t target_id, lun_id_t target_lun,
int flags, struct cam_device *device)
{
union ccb ccb;
struct periph_match_pattern *match_pat;
int fd, bufsize;
if ((fd = open(XPT_DEVICE, O_RDWR)) < 0) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: couldn't open %s\n%s: %s", __func__, XPT_DEVICE,
__func__, strerror(errno));
return(NULL);
}
bzero(&ccb, sizeof(union ccb));
ccb.ccb_h.func_code = XPT_DEV_MATCH;
ccb.ccb_h.path_id = CAM_XPT_PATH_ID;
ccb.ccb_h.target_id = CAM_TARGET_WILDCARD;
ccb.ccb_h.target_lun = CAM_LUN_WILDCARD;
/* Setup the result buffer */
bufsize = sizeof(struct dev_match_result);
ccb.cdm.match_buf_len = bufsize;
ccb.cdm.matches = (struct dev_match_result *)malloc(bufsize);
if (ccb.cdm.matches == NULL) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: couldn't malloc match buffer", __func__);
close(fd);
return(NULL);
}
ccb.cdm.num_matches = 0;
/* Setup the pattern buffer */
ccb.cdm.num_patterns = 1;
ccb.cdm.pattern_buf_len = sizeof(struct dev_match_pattern);
ccb.cdm.patterns = (struct dev_match_pattern *)malloc(
sizeof(struct dev_match_pattern));
if (ccb.cdm.patterns == NULL) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: couldn't malloc pattern buffer", __func__);
free(ccb.cdm.matches);
ccb.cdm.matches = NULL;
close(fd);
return(NULL);
}
ccb.cdm.patterns[0].type = DEV_MATCH_PERIPH;
match_pat = &ccb.cdm.patterns[0].pattern.periph_pattern;
/*
* We're looking for the passthrough device associated with this
* particular bus/target/lun.
*/
sprintf(match_pat->periph_name, "pass");
match_pat->path_id = path_id;
match_pat->target_id = target_id;
match_pat->target_lun = target_lun;
/* Now set the flags to indicate what we're looking for. */
match_pat->flags = PERIPH_MATCH_PATH | PERIPH_MATCH_TARGET |
PERIPH_MATCH_LUN | PERIPH_MATCH_NAME;
if (ioctl(fd, CAMIOCOMMAND, &ccb) == -1) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: CAMIOCOMMAND ioctl failed\n"
"%s: %s", __func__, __func__, strerror(errno));
goto btl_bailout;
}
/*
* Check for an outright error.
*/
if ((ccb.ccb_h.status != CAM_REQ_CMP)
|| ((ccb.cdm.status != CAM_DEV_MATCH_LAST)
&& (ccb.cdm.status != CAM_DEV_MATCH_MORE))) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: CAM error %#x, CDM error %d "
"returned from XPT_DEV_MATCH ccb", __func__,
ccb.ccb_h.status, ccb.cdm.status);
goto btl_bailout;
}
if (ccb.cdm.status == CAM_DEV_MATCH_MORE) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: CDM reported more than one"
" passthrough device at %d:%d:%jx!!\n",
__func__, path_id, target_id, (uintmax_t)target_lun);
goto btl_bailout;
}
if (ccb.cdm.num_matches == 0) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: no passthrough device found at"
" %d:%d:%jx", __func__, path_id, target_id,
(uintmax_t)target_lun);
goto btl_bailout;
}
switch(ccb.cdm.matches[0].type) {
case DEV_MATCH_PERIPH: {
int pass_unit;
char dev_path[256];
struct periph_match_result *periph_result;
periph_result = &ccb.cdm.matches[0].result.periph_result;
pass_unit = periph_result->unit_number;
free(ccb.cdm.matches);
ccb.cdm.matches = NULL;
free(ccb.cdm.patterns);
ccb.cdm.patterns = NULL;
close(fd);
sprintf(dev_path, "/dev/pass%d", pass_unit);
return(cam_real_open_device(dev_path, flags, device, NULL,
NULL, 0));
break; /* NOTREACHED */
}
default:
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: asked for a peripheral match, but"
" got a bus or device match", __func__);
goto btl_bailout;
break; /* NOTREACHED */
}
btl_bailout:
free(ccb.cdm.matches);
ccb.cdm.matches = NULL;
free(ccb.cdm.patterns);
ccb.cdm.patterns = NULL;
close(fd);
return(NULL);
}
struct cam_device *
cam_open_spec_device(const char *dev_name, int unit, int flags,
struct cam_device *device)
{
return(cam_lookup_pass(dev_name, unit, flags, NULL, device));
}
struct cam_device *
cam_open_pass(const char *path, int flags, struct cam_device *device)
{
return(cam_real_open_device(path, flags, device, path, NULL, 0));
}
static struct cam_device *
cam_lookup_pass(const char *dev_name, int unit, int flags,
const char *given_path, struct cam_device *device)
{
int fd;
union ccb ccb;
char dev_path[256];
/*
* The flags argument above only applies to the actual passthrough
* device open, not our open of the given device to find the
* passthrough device.
*/
if ((fd = open(XPT_DEVICE, O_RDWR)) < 0) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: couldn't open %s\n%s: %s", __func__, XPT_DEVICE,
__func__, strerror(errno));
return(NULL);
}
/* This isn't strictly necessary for the GETPASSTHRU ioctl. */
ccb.ccb_h.func_code = XPT_GDEVLIST;
/* These two are necessary for the GETPASSTHRU ioctl to work. */
strlcpy(ccb.cgdl.periph_name, dev_name, sizeof(ccb.cgdl.periph_name));
ccb.cgdl.unit_number = unit;
/*
* Attempt to get the passthrough device. This ioctl will fail if
* the device name is null, if the device doesn't exist, or if the
* passthrough driver isn't in the kernel.
*/
if (ioctl(fd, CAMGETPASSTHRU, &ccb) == -1) {
char tmpstr[256];
/*
* If we get ENOENT from the transport layer version of
* the CAMGETPASSTHRU ioctl, it means one of two things:
* either the device name/unit number passed in doesn't
* exist, or the passthrough driver isn't in the kernel.
*/
if (errno == ENOENT) {
snprintf(tmpstr, sizeof(tmpstr),
"\n%s: either the pass driver isn't in "
"your kernel\n%s: or %s%d doesn't exist",
__func__, __func__, dev_name, unit);
}
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: CAMGETPASSTHRU ioctl failed\n"
"%s: %s%s", __func__, __func__, strerror(errno),
(errno == ENOENT) ? tmpstr : "");
close(fd);
return(NULL);
}
close(fd);
/*
* If the ioctl returned the right status, but we got an error back
* in the ccb, that means that the kernel found the device the user
* passed in, but was unable to find the passthrough device for
* the device the user gave us.
*/
if (ccb.cgdl.status == CAM_GDEVLIST_ERROR) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: device %s%d does not exist!",
__func__, dev_name, unit);
return(NULL);
}
sprintf(dev_path, "/dev/%s%d", ccb.cgdl.periph_name,
ccb.cgdl.unit_number);
return(cam_real_open_device(dev_path, flags, device, NULL,
dev_name, unit));
}
/*
* Open a given device. The path argument isn't strictly necessary, but it
* is copied into the cam_device structure as a convenience to the user.
*/
static struct cam_device *
cam_real_open_device(const char *path, int flags, struct cam_device *device,
const char *given_path, const char *given_dev_name,
int given_unit_number)
{
union ccb ccb;
int fd = -1, malloced_device = 0;
/*
* See if the user wants us to malloc a device for him.
*/
if (device == NULL) {
if ((device = (struct cam_device *)malloc(
sizeof(struct cam_device))) == NULL) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: device structure malloc"
" failed\n%s: %s", __func__, __func__,
strerror(errno));
return(NULL);
}
device->fd = -1;
malloced_device = 1;
}
/*
* If the user passed in a path, save it for him.
*/
if (given_path != NULL)
strlcpy(device->device_path, given_path,
sizeof(device->device_path));
else
device->device_path[0] = '\0';
/*
* If the user passed in a device name and unit number pair, save
* those as well.
*/
if (given_dev_name != NULL)
strlcpy(device->given_dev_name, given_dev_name,
sizeof(device->given_dev_name));
else
device->given_dev_name[0] = '\0';
device->given_unit_number = given_unit_number;
if ((fd = open(path, flags)) < 0) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: couldn't open passthrough device %s\n"
"%s: %s", __func__, path, __func__,
strerror(errno));
goto crod_bailout;
}
device->fd = fd;
bzero(&ccb, sizeof(union ccb));
/*
* Unlike the transport layer version of the GETPASSTHRU ioctl,
* we don't have to set any fields.
*/
ccb.ccb_h.func_code = XPT_GDEVLIST;
/*
* We're only doing this to get some information on the device in
* question. Otherwise, we'd have to pass in yet another
* parameter: the passthrough driver unit number.
*/
if (ioctl(fd, CAMGETPASSTHRU, &ccb) == -1) {
/*
* At this point we know the passthrough device must exist
* because we just opened it above. The only way this
* ioctl can fail is if the ccb size is wrong.
*/
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: CAMGETPASSTHRU ioctl failed\n"
"%s: %s", __func__, __func__, strerror(errno));
goto crod_bailout;
}
/*
* If the ioctl returned the right status, but we got an error back
* in the ccb, that means that the kernel found the device the user
* passed in, but was unable to find the passthrough device for
* the device the user gave us.
*/
if (ccb.cgdl.status == CAM_GDEVLIST_ERROR) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: passthrough device does not exist!", __func__);
goto crod_bailout;
}
device->dev_unit_num = ccb.cgdl.unit_number;
strlcpy(device->device_name, ccb.cgdl.periph_name,
sizeof(device->device_name));
device->path_id = ccb.ccb_h.path_id;
device->target_id = ccb.ccb_h.target_id;
device->target_lun = ccb.ccb_h.target_lun;
ccb.ccb_h.func_code = XPT_PATH_INQ;
if (ioctl(fd, CAMIOCOMMAND, &ccb) == -1) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: Path Inquiry CCB failed\n"
"%s: %s", __func__, __func__, strerror(errno));
goto crod_bailout;
}
strlcpy(device->sim_name, ccb.cpi.dev_name, sizeof(device->sim_name));
device->sim_unit_number = ccb.cpi.unit_number;
device->bus_id = ccb.cpi.bus_id;
/*
* It doesn't really matter what is in the payload for a getdev
* CCB, the kernel doesn't look at it.
*/
ccb.ccb_h.func_code = XPT_GDEV_TYPE;
if (ioctl(fd, CAMIOCOMMAND, &ccb) == -1) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: Get Device Type CCB failed\n"
"%s: %s", __func__, __func__, strerror(errno));
goto crod_bailout;
}
device->pd_type = SID_TYPE(&ccb.cgd.inq_data);
bcopy(&ccb.cgd.inq_data, &device->inq_data,
sizeof(struct scsi_inquiry_data));
device->serial_num_len = ccb.cgd.serial_num_len;
bcopy(&ccb.cgd.serial_num, &device->serial_num, device->serial_num_len);
/*
* Zero the payload, the kernel does look at the flags.
*/
CCB_CLEAR_ALL_EXCEPT_HDR(&ccb.cts);
/*
* Get transfer settings for this device.
*/
ccb.ccb_h.func_code = XPT_GET_TRAN_SETTINGS;
ccb.cts.type = CTS_TYPE_CURRENT_SETTINGS;
if (ioctl(fd, CAMIOCOMMAND, &ccb) == -1) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: Get Transfer Settings CCB failed\n"
"%s: %s", __func__, __func__, strerror(errno));
goto crod_bailout;
}
if (ccb.cts.transport == XPORT_SPI) {
struct ccb_trans_settings_spi *spi =
&ccb.cts.xport_specific.spi;
device->sync_period = spi->sync_period;
device->sync_offset = spi->sync_offset;
device->bus_width = spi->bus_width;
} else {
device->sync_period = 0;
device->sync_offset = 0;
device->bus_width = 0;
}
return(device);
crod_bailout:
if (fd >= 0)
close(fd);
if (malloced_device)
free(device);
return(NULL);
}
void
cam_close_device(struct cam_device *dev)
{
if (dev == NULL)
return;
cam_close_spec_device(dev);
free(dev);
}
void
cam_close_spec_device(struct cam_device *dev)
{
if (dev == NULL)
return;
if (dev->fd >= 0) {
close(dev->fd);
dev->fd = -1;
}
}
char *
cam_path_string(struct cam_device *dev, char *str, int len)
{
if (dev == NULL) {
snprintf(str, len, "No path");
return(str);
}
snprintf(str, len, "(%s%d:%s%d:%d:%d:%jx): ",
(dev->device_name[0] != '\0') ? dev->device_name : "pass",
dev->dev_unit_num,
(dev->sim_name[0] != '\0') ? dev->sim_name : "unknown",
dev->sim_unit_number,
dev->bus_id,
dev->target_id,
(uintmax_t)dev->target_lun);
return(str);
}
/*
* Malloc/duplicate a CAM device structure.
*/
struct cam_device *
cam_device_dup(struct cam_device *device)
{
struct cam_device *newdev;
if (device == NULL) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: device is NULL", __func__);
return (NULL);
}
newdev = malloc(sizeof(struct cam_device));
if (newdev == NULL) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: couldn't malloc CAM device structure", __func__);
return (NULL);
}
bcopy(device, newdev, sizeof(struct cam_device));
return(newdev);
}
/*
* Copy a CAM device structure.
*/
void
cam_device_copy(struct cam_device *src, struct cam_device *dst)
{
if (src == NULL) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: source device struct was NULL", __func__);
return;
}
if (dst == NULL) {
snprintf(cam_errbuf, nitems(cam_errbuf),
"%s: destination device struct was NULL", __func__);
return;
}
bcopy(src, dst, sizeof(struct cam_device));
}