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qemu/scsi/qemu-pr-helper.c

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/*
* Privileged helper to handle persistent reservation commands for QEMU
*
* Copyright (C) 2017 Red Hat, Inc. <pbonzini@redhat.com>
*
* Author: Paolo Bonzini <pbonzini@redhat.com>
*
* 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; under version 2 of the License.
*
* This program 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 this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include <getopt.h>
#include <sys/ioctl.h>
#include <linux/dm-ioctl.h>
#include <scsi/sg.h>
#ifdef CONFIG_LIBCAP
#include <cap-ng.h>
#endif
#include <pwd.h>
#include <grp.h>
#ifdef CONFIG_MPATH
#include <libudev.h>
#include <mpath_cmd.h>
#include <mpath_persist.h>
#endif
#include "qapi/error.h"
#include "qemu-common.h"
#include "qemu/cutils.h"
#include "qemu/main-loop.h"
#include "qemu/error-report.h"
#include "qemu/config-file.h"
#include "qemu/bswap.h"
#include "qemu/log.h"
#include "qemu/systemd.h"
#include "qapi/util.h"
#include "qapi/qmp/qstring.h"
#include "io/channel-socket.h"
#include "trace/control.h"
#include "qemu-version.h"
#include "block/aio.h"
#include "block/thread-pool.h"
#include "scsi/constants.h"
#include "scsi/utils.h"
#include "pr-helper.h"
#define PR_OUT_FIXED_PARAM_SIZE 24
static char *socket_path;
static char *pidfile;
static enum { RUNNING, TERMINATE, TERMINATING } state;
static QIOChannelSocket *server_ioc;
static int server_watch;
static int num_active_sockets = 1;
static int noisy;
static int verbose;
#ifdef CONFIG_LIBCAP
static int uid = -1;
static int gid = -1;
#endif
static void usage(const char *name)
{
(printf) (
"Usage: %s [OPTIONS] FILE\n"
"Persistent Reservation helper program for QEMU\n"
"\n"
" -h, --help display this help and exit\n"
" -V, --version output version information and exit\n"
"\n"
" -d, --daemon run in the background\n"
" -f, --pidfile=PATH PID file when running as a daemon\n"
" (default '%s')\n"
" -k, --socket=PATH path to the unix socket\n"
" (default '%s')\n"
" -T, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
" specify tracing options\n"
#ifdef CONFIG_LIBCAP
" -u, --user=USER user to drop privileges to\n"
" -g, --group=GROUP group to drop privileges to\n"
#endif
"\n"
QEMU_HELP_BOTTOM "\n"
, name, pidfile, socket_path);
}
static void version(const char *name)
{
printf(
"%s " QEMU_FULL_VERSION "\n"
"Written by Paolo Bonzini.\n"
"\n"
QEMU_COPYRIGHT "\n"
"This is free software; see the source for copying conditions. There is NO\n"
"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n"
, name);
}
static void write_pidfile(void)
{
int pidfd;
char pidstr[32];
pidfd = qemu_open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
if (pidfd == -1) {
error_report("Cannot open pid file, %s", strerror(errno));
exit(EXIT_FAILURE);
}
if (lockf(pidfd, F_TLOCK, 0)) {
error_report("Cannot lock pid file, %s", strerror(errno));
goto fail;
}
if (ftruncate(pidfd, 0)) {
error_report("Failed to truncate pid file");
goto fail;
}
snprintf(pidstr, sizeof(pidstr), "%d\n", getpid());
if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
error_report("Failed to write pid file");
goto fail;
}
return;
fail:
unlink(pidfile);
close(pidfd);
exit(EXIT_FAILURE);
}
/* SG_IO support */
typedef struct PRHelperSGIOData {
int fd;
const uint8_t *cdb;
uint8_t *sense;
uint8_t *buf;
int sz; /* input/output */
int dir;
} PRHelperSGIOData;
static int do_sgio_worker(void *opaque)
{
PRHelperSGIOData *data = opaque;
struct sg_io_hdr io_hdr;
int ret;
int status;
SCSISense sense_code;
memset(data->sense, 0, PR_HELPER_SENSE_SIZE);
memset(&io_hdr, 0, sizeof(io_hdr));
io_hdr.interface_id = 'S';
io_hdr.cmd_len = PR_HELPER_CDB_SIZE;
io_hdr.cmdp = (uint8_t *)data->cdb;
io_hdr.sbp = data->sense;
io_hdr.mx_sb_len = PR_HELPER_SENSE_SIZE;
io_hdr.timeout = 1;
io_hdr.dxfer_direction = data->dir;
io_hdr.dxferp = (char *)data->buf;
io_hdr.dxfer_len = data->sz;
ret = ioctl(data->fd, SG_IO, &io_hdr);
status = sg_io_sense_from_errno(ret < 0 ? errno : 0, &io_hdr,
&sense_code);
if (status == GOOD) {
data->sz -= io_hdr.resid;
} else {
data->sz = 0;
}
if (status == CHECK_CONDITION &&
!(io_hdr.driver_status & SG_ERR_DRIVER_SENSE)) {
scsi_build_sense(data->sense, sense_code);
}
return status;
}
static int do_sgio(int fd, const uint8_t *cdb, uint8_t *sense,
uint8_t *buf, int *sz, int dir)
{
ThreadPool *pool = aio_get_thread_pool(qemu_get_aio_context());
int r;
PRHelperSGIOData data = {
.fd = fd,
.cdb = cdb,
.sense = sense,
.buf = buf,
.sz = *sz,
.dir = dir,
};
r = thread_pool_submit_co(pool, do_sgio_worker, &data);
*sz = data.sz;
return r;
}
/* Device mapper interface */
#ifdef CONFIG_MPATH
#define CONTROL_PATH "/dev/mapper/control"
typedef struct DMData {
struct dm_ioctl dm;
uint8_t data[1024];
} DMData;
static int control_fd;
static void *dm_ioctl(int ioc, struct dm_ioctl *dm)
{
static DMData d;
memcpy(&d.dm, dm, sizeof(d.dm));
QEMU_BUILD_BUG_ON(sizeof(d.data) < sizeof(struct dm_target_spec));
d.dm.version[0] = DM_VERSION_MAJOR;
d.dm.version[1] = 0;
d.dm.version[2] = 0;
d.dm.data_size = 1024;
d.dm.data_start = offsetof(DMData, data);
if (ioctl(control_fd, ioc, &d) < 0) {
return NULL;
}
memcpy(dm, &d.dm, sizeof(d.dm));
return &d.data;
}
static void *dm_dev_ioctl(int fd, int ioc, struct dm_ioctl *dm)
{
struct stat st;
int r;
r = fstat(fd, &st);
if (r < 0) {
perror("fstat");
exit(1);
}
dm->dev = st.st_rdev;
return dm_ioctl(ioc, dm);
}
static void dm_init(void)
{
control_fd = open(CONTROL_PATH, O_RDWR);
if (control_fd < 0) {
perror("Cannot open " CONTROL_PATH);
exit(1);
}
struct dm_ioctl dm = { 0 };
if (!dm_ioctl(DM_VERSION, &dm)) {
perror("ioctl");
exit(1);
}
if (dm.version[0] != DM_VERSION_MAJOR) {
fprintf(stderr, "Unsupported device mapper interface");
exit(1);
}
}
/* Variables required by libmultipath and libmpathpersist. */
QEMU_BUILD_BUG_ON(PR_HELPER_DATA_SIZE > MPATH_MAX_PARAM_LEN);
static struct config *multipath_conf;
unsigned mpath_mx_alloc_len = PR_HELPER_DATA_SIZE;
int logsink;
struct udev *udev;
extern struct config *get_multipath_config(void);
struct config *get_multipath_config(void)
{
return multipath_conf;
}
extern void put_multipath_config(struct config *conf);
void put_multipath_config(struct config *conf)
{
}
static void multipath_pr_init(void)
{
udev = udev_new();
multipath_conf = mpath_lib_init();
}
static int is_mpath(int fd)
{
struct dm_ioctl dm = { .flags = DM_NOFLUSH_FLAG };
struct dm_target_spec *tgt;
tgt = dm_dev_ioctl(fd, DM_TABLE_STATUS, &dm);
if (!tgt) {
if (errno == ENXIO) {
return 0;
}
perror("ioctl");
exit(EXIT_FAILURE);
}
return !strncmp(tgt->target_type, "multipath", DM_MAX_TYPE_NAME);
}
static SCSISense mpath_generic_sense(int r)
{
switch (r) {
case MPATH_PR_SENSE_NOT_READY:
return SENSE_CODE(NOT_READY);
case MPATH_PR_SENSE_MEDIUM_ERROR:
return SENSE_CODE(READ_ERROR);
case MPATH_PR_SENSE_HARDWARE_ERROR:
return SENSE_CODE(TARGET_FAILURE);
case MPATH_PR_SENSE_ABORTED_COMMAND:
return SENSE_CODE(IO_ERROR);
default:
abort();
}
}
static int mpath_reconstruct_sense(int fd, int r, uint8_t *sense)
{
switch (r) {
case MPATH_PR_SUCCESS:
return GOOD;
case MPATH_PR_SENSE_NOT_READY:
case MPATH_PR_SENSE_MEDIUM_ERROR:
case MPATH_PR_SENSE_HARDWARE_ERROR:
case MPATH_PR_SENSE_ABORTED_COMMAND:
{
/* libmpathpersist ate the exact sense. Try to find it by
* issuing TEST UNIT READY.
*/
uint8_t cdb[6] = { TEST_UNIT_READY };
int sz = 0;
int r = do_sgio(fd, cdb, sense, NULL, &sz, SG_DXFER_NONE);
if (r != GOOD) {
return r;
}
scsi_build_sense(sense, mpath_generic_sense(r));
return CHECK_CONDITION;
}
case MPATH_PR_SENSE_UNIT_ATTENTION:
/* Congratulations libmpathpersist, you ruined the Unit Attention...
* Return a heavyweight one.
*/
scsi_build_sense(sense, SENSE_CODE(SCSI_BUS_RESET));
return CHECK_CONDITION;
case MPATH_PR_SENSE_INVALID_OP:
/* Only one valid sense. */
scsi_build_sense(sense, SENSE_CODE(INVALID_OPCODE));
return CHECK_CONDITION;
case MPATH_PR_ILLEGAL_REQ:
/* Guess. */
scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM));
return CHECK_CONDITION;
case MPATH_PR_NO_SENSE:
scsi_build_sense(sense, SENSE_CODE(NO_SENSE));
return CHECK_CONDITION;
case MPATH_PR_RESERV_CONFLICT:
return RESERVATION_CONFLICT;
case MPATH_PR_OTHER:
default:
scsi_build_sense(sense, SENSE_CODE(LUN_COMM_FAILURE));
return CHECK_CONDITION;
}
}
static int multipath_pr_in(int fd, const uint8_t *cdb, uint8_t *sense,
uint8_t *data, int sz)
{
int rq_servact = cdb[1];
struct prin_resp resp;
size_t written;
int r;
switch (rq_servact) {
case MPATH_PRIN_RKEY_SA:
case MPATH_PRIN_RRES_SA:
case MPATH_PRIN_RCAP_SA:
break;
case MPATH_PRIN_RFSTAT_SA:
/* Nobody implements it anyway, so bail out. */
default:
/* Cannot parse any other output. */
scsi_build_sense(sense, SENSE_CODE(INVALID_FIELD));
return CHECK_CONDITION;
}
r = mpath_persistent_reserve_in(fd, rq_servact, &resp, noisy, verbose);
if (r == MPATH_PR_SUCCESS) {
switch (rq_servact) {
case MPATH_PRIN_RKEY_SA:
case MPATH_PRIN_RRES_SA: {
struct prin_readdescr *out = &resp.prin_descriptor.prin_readkeys;
assert(sz >= 8);
written = MIN(out->additional_length + 8, sz);
stl_be_p(&data[0], out->prgeneration);
stl_be_p(&data[4], out->additional_length);
memcpy(&data[8], out->key_list, written - 8);
break;
}
case MPATH_PRIN_RCAP_SA: {
struct prin_capdescr *out = &resp.prin_descriptor.prin_readcap;
assert(sz >= 6);
written = 6;
stw_be_p(&data[0], out->length);
data[2] = out->flags[0];
data[3] = out->flags[1];
stw_be_p(&data[4], out->pr_type_mask);
break;
}
default:
scsi_build_sense(sense, SENSE_CODE(INVALID_OPCODE));
return CHECK_CONDITION;
}
assert(written <= sz);
memset(data + written, 0, sz - written);
}
return mpath_reconstruct_sense(fd, r, sense);
}
static int multipath_pr_out(int fd, const uint8_t *cdb, uint8_t *sense,
const uint8_t *param, int sz)
{
int rq_servact = cdb[1];
int rq_scope = cdb[2] >> 4;
int rq_type = cdb[2] & 0xf;
struct prout_param_descriptor paramp;
char transportids[PR_HELPER_DATA_SIZE];
int r;
switch (rq_servact) {
case MPATH_PROUT_REG_SA:
case MPATH_PROUT_RES_SA:
case MPATH_PROUT_REL_SA:
case MPATH_PROUT_CLEAR_SA:
case MPATH_PROUT_PREE_SA:
case MPATH_PROUT_PREE_AB_SA:
case MPATH_PROUT_REG_IGN_SA:
break;
case MPATH_PROUT_REG_MOV_SA:
/* Not supported by struct prout_param_descriptor. */
default:
/* Cannot parse any other input. */
scsi_build_sense(sense, SENSE_CODE(INVALID_FIELD));
return CHECK_CONDITION;
}
/* Convert input data, especially transport IDs, to the structs
* used by libmpathpersist (which, of course, will immediately
* do the opposite).
*/
memset(&paramp, 0, sizeof(paramp));
memcpy(&paramp.key, &param[0], 8);
memcpy(&paramp.sa_key, &param[8], 8);
paramp.sa_flags = param[20];
if (sz > PR_OUT_FIXED_PARAM_SIZE) {
size_t transportid_len;
int i, j;
if (sz < PR_OUT_FIXED_PARAM_SIZE + 4) {
scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM_LEN));
return CHECK_CONDITION;
}
transportid_len = ldl_be_p(&param[24]) + PR_OUT_FIXED_PARAM_SIZE + 4;
if (transportid_len > sz) {
scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM));
return CHECK_CONDITION;
}
for (i = PR_OUT_FIXED_PARAM_SIZE + 4, j = 0; i < transportid_len; ) {
struct transportid *id = (struct transportid *) &transportids[j];
int len;
id->format_code = param[i] & 0xc0;
id->protocol_id = param[i] & 0x0f;
switch (param[i] & 0xcf) {
case 0:
/* FC transport. */
if (i + 24 > transportid_len) {
goto illegal_req;
}
memcpy(id->n_port_name, &param[i + 8], 8);
j += offsetof(struct transportid, n_port_name[8]);
i += 24;
break;
case 5:
case 0x45:
/* iSCSI transport. */
len = lduw_be_p(&param[i + 2]);
if (len > 252 || (len & 3) || i + len + 4 > transportid_len) {
/* For format code 00, the standard says the maximum is 223
* plus the NUL terminator. For format code 01 there is no
* maximum length, but libmpathpersist ignores the first
* byte of id->iscsi_name so our maximum is 252.
*/
goto illegal_req;
}
if (memchr(&param[i + 4], 0, len) == NULL) {
goto illegal_req;
}
memcpy(id->iscsi_name, &param[i + 2], len + 2);
j += offsetof(struct transportid, iscsi_name[len + 2]);
i += len + 4;
break;
case 6:
/* SAS transport. */
if (i + 24 > transportid_len) {
goto illegal_req;
}
memcpy(id->sas_address, &param[i + 4], 8);
j += offsetof(struct transportid, sas_address[8]);
i += 24;
break;
default:
illegal_req:
scsi_build_sense(sense, SENSE_CODE(INVALID_PARAM));
return CHECK_CONDITION;
}
paramp.trnptid_list[paramp.num_transportid++] = id;
}
}
r = mpath_persistent_reserve_out(fd, rq_servact, rq_scope, rq_type,
&paramp, noisy, verbose);
return mpath_reconstruct_sense(fd, r, sense);
}
#endif
static int do_pr_in(int fd, const uint8_t *cdb, uint8_t *sense,
uint8_t *data, int *resp_sz)
{
#ifdef CONFIG_MPATH
if (is_mpath(fd)) {
/* multipath_pr_in fills the whole input buffer. */
return multipath_pr_in(fd, cdb, sense, data, *resp_sz);
}
#endif
return do_sgio(fd, cdb, sense, data, resp_sz,
SG_DXFER_FROM_DEV);
}
static int do_pr_out(int fd, const uint8_t *cdb, uint8_t *sense,
const uint8_t *param, int sz)
{
int resp_sz;
#ifdef CONFIG_MPATH
if (is_mpath(fd)) {
return multipath_pr_out(fd, cdb, sense, param, sz);
}
#endif
resp_sz = sz;
return do_sgio(fd, cdb, sense, (uint8_t *)param, &resp_sz,
SG_DXFER_TO_DEV);
}
/* Client */
typedef struct PRHelperClient {
QIOChannelSocket *ioc;
Coroutine *co;
int fd;
uint8_t data[PR_HELPER_DATA_SIZE];
} PRHelperClient;
typedef struct PRHelperRequest {
int fd;
size_t sz;
uint8_t cdb[PR_HELPER_CDB_SIZE];
} PRHelperRequest;
static int coroutine_fn prh_read(PRHelperClient *client, void *buf, int sz,
Error **errp)
{
int ret = 0;
while (sz > 0) {
int *fds = NULL;
size_t nfds = 0;
int i;
struct iovec iov;
ssize_t n_read;
iov.iov_base = buf;
iov.iov_len = sz;
n_read = qio_channel_readv_full(QIO_CHANNEL(client->ioc), &iov, 1,
&fds, &nfds, errp);
if (n_read == QIO_CHANNEL_ERR_BLOCK) {
qio_channel_yield(QIO_CHANNEL(client->ioc), G_IO_IN);
continue;
}
if (n_read <= 0) {
ret = n_read ? n_read : -1;
goto err;
}
/* Stash one file descriptor per request. */
if (nfds) {
bool too_many = false;
for (i = 0; i < nfds; i++) {
if (client->fd == -1) {
client->fd = fds[i];
} else {
close(fds[i]);
too_many = true;
}
}
g_free(fds);
if (too_many) {
ret = -1;
goto err;
}
}
buf += n_read;
sz -= n_read;
}
return 0;
err:
if (client->fd != -1) {
close(client->fd);
client->fd = -1;
}
return ret;
}
static int coroutine_fn prh_read_request(PRHelperClient *client,
PRHelperRequest *req,
PRHelperResponse *resp, Error **errp)
{
uint32_t sz;
if (prh_read(client, req->cdb, sizeof(req->cdb), NULL) < 0) {
return -1;
}
if (client->fd == -1) {
error_setg(errp, "No file descriptor in request.");
return -1;
}
if (req->cdb[0] != PERSISTENT_RESERVE_OUT &&
req->cdb[0] != PERSISTENT_RESERVE_IN) {
error_setg(errp, "Invalid CDB, closing socket.");
goto out_close;
}
sz = scsi_cdb_xfer(req->cdb);
if (sz > sizeof(client->data)) {
goto out_close;
}
if (req->cdb[0] == PERSISTENT_RESERVE_OUT) {
if (qio_channel_read_all(QIO_CHANNEL(client->ioc),
(char *)client->data, sz,
errp) < 0) {
goto out_close;
}
if ((fcntl(client->fd, F_GETFL) & O_ACCMODE) == O_RDONLY) {
scsi_build_sense(resp->sense, SENSE_CODE(INVALID_OPCODE));
sz = 0;
} else if (sz < PR_OUT_FIXED_PARAM_SIZE) {
/* Illegal request, Parameter list length error. This isn't fatal;
* we have read the data, send an error without closing the socket.
*/
scsi_build_sense(resp->sense, SENSE_CODE(INVALID_PARAM_LEN));
sz = 0;
}
if (sz == 0) {
resp->result = CHECK_CONDITION;
close(client->fd);
client->fd = -1;
}
}
req->fd = client->fd;
req->sz = sz;
client->fd = -1;
return sz;
out_close:
close(client->fd);
client->fd = -1;
return -1;
}
static int coroutine_fn prh_write_response(PRHelperClient *client,
PRHelperRequest *req,
PRHelperResponse *resp, Error **errp)
{
ssize_t r;
size_t sz;
if (req->cdb[0] == PERSISTENT_RESERVE_IN && resp->result == GOOD) {
assert(resp->sz <= req->sz && resp->sz <= sizeof(client->data));
} else {
assert(resp->sz == 0);
}
sz = resp->sz;
resp->result = cpu_to_be32(resp->result);
resp->sz = cpu_to_be32(resp->sz);
r = qio_channel_write_all(QIO_CHANNEL(client->ioc),
(char *) resp, sizeof(*resp), errp);
if (r < 0) {
return r;
}
r = qio_channel_write_all(QIO_CHANNEL(client->ioc),
(char *) client->data,
sz, errp);
return r < 0 ? r : 0;
}
static void coroutine_fn prh_co_entry(void *opaque)
{
PRHelperClient *client = opaque;
Error *local_err = NULL;
uint32_t flags;
int r;
qio_channel_set_blocking(QIO_CHANNEL(client->ioc),
false, NULL);
qio_channel_attach_aio_context(QIO_CHANNEL(client->ioc),
qemu_get_aio_context());
/* A very simple negotiation for future extensibility. No features
* are defined so write 0.
*/
flags = cpu_to_be32(0);
r = qio_channel_write_all(QIO_CHANNEL(client->ioc),
(char *) &flags, sizeof(flags), NULL);
if (r < 0) {
goto out;
}
r = qio_channel_read_all(QIO_CHANNEL(client->ioc),
(char *) &flags, sizeof(flags), NULL);
if (be32_to_cpu(flags) != 0 || r < 0) {
goto out;
}
while (atomic_read(&state) == RUNNING) {
PRHelperRequest req;
PRHelperResponse resp;
int sz;
sz = prh_read_request(client, &req, &resp, &local_err);
if (sz < 0) {
break;
}
if (sz > 0) {
num_active_sockets++;
if (req.cdb[0] == PERSISTENT_RESERVE_OUT) {
r = do_pr_out(req.fd, req.cdb, resp.sense,
client->data, sz);
resp.sz = 0;
} else {
resp.sz = sizeof(client->data);
r = do_pr_in(req.fd, req.cdb, resp.sense,
client->data, &resp.sz);
resp.sz = MIN(resp.sz, sz);
}
num_active_sockets--;
close(req.fd);
if (r == -1) {
break;
}
resp.result = r;
}
if (prh_write_response(client, &req, &resp, &local_err) < 0) {
break;
}
}
if (local_err) {
if (verbose == 0) {
error_free(local_err);
} else {
error_report_err(local_err);
}
}
out:
qio_channel_detach_aio_context(QIO_CHANNEL(client->ioc));
object_unref(OBJECT(client->ioc));
g_free(client);
}
static gboolean accept_client(QIOChannel *ioc, GIOCondition cond, gpointer opaque)
{
QIOChannelSocket *cioc;
PRHelperClient *prh;
cioc = qio_channel_socket_accept(QIO_CHANNEL_SOCKET(ioc),
NULL);
if (!cioc) {
return TRUE;
}
prh = g_new(PRHelperClient, 1);
prh->ioc = cioc;
prh->fd = -1;
prh->co = qemu_coroutine_create(prh_co_entry, prh);
qemu_coroutine_enter(prh->co);
return TRUE;
}
/*
* Check socket parameters compatibility when socket activation is used.
*/
static const char *socket_activation_validate_opts(void)
{
if (socket_path != NULL) {
return "Unix socket can't be set when using socket activation";
}
return NULL;
}
static void compute_default_paths(void)
{
if (!socket_path) {
socket_path = qemu_get_local_state_pathname("run/qemu-pr-helper.sock");
}
}
static void termsig_handler(int signum)
{
atomic_cmpxchg(&state, RUNNING, TERMINATE);
qemu_notify_event();
}
static void close_server_socket(void)
{
assert(server_ioc);
g_source_remove(server_watch);
server_watch = -1;
object_unref(OBJECT(server_ioc));
num_active_sockets--;
}
#ifdef CONFIG_LIBCAP
static int drop_privileges(void)
{
/* clear all capabilities */
capng_clear(CAPNG_SELECT_BOTH);
if (capng_update(CAPNG_ADD, CAPNG_EFFECTIVE | CAPNG_PERMITTED,
CAP_SYS_RAWIO) < 0) {
return -1;
}
#ifdef CONFIG_MPATH
/* For /dev/mapper/control ioctls */
if (capng_update(CAPNG_ADD, CAPNG_EFFECTIVE | CAPNG_PERMITTED,
CAP_SYS_ADMIN) < 0) {
return -1;
}
#endif
/* Change user/group id, retaining the capabilities. Because file descriptors
* are passed via SCM_RIGHTS, we don't need supplementary groups (and in
* fact the helper can run as "nobody").
*/
if (capng_change_id(uid != -1 ? uid : getuid(),
gid != -1 ? gid : getgid(),
CAPNG_DROP_SUPP_GRP | CAPNG_CLEAR_BOUNDING)) {
return -1;
}
return 0;
}
#endif
int main(int argc, char **argv)
{
const char *sopt = "hVk:fdT:u:g:vq";
struct option lopt[] = {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
{ "socket", required_argument, NULL, 'k' },
{ "pidfile", no_argument, NULL, 'f' },
{ "daemon", no_argument, NULL, 'd' },
{ "trace", required_argument, NULL, 'T' },
{ "user", required_argument, NULL, 'u' },
{ "group", required_argument, NULL, 'g' },
{ "verbose", no_argument, NULL, 'v' },
{ "quiet", no_argument, NULL, 'q' },
{ NULL, 0, NULL, 0 }
};
int opt_ind = 0;
int loglevel = 1;
int quiet = 0;
int ch;
Error *local_err = NULL;
char *trace_file = NULL;
bool daemonize = false;
unsigned socket_activation;
struct sigaction sa_sigterm;
memset(&sa_sigterm, 0, sizeof(sa_sigterm));
sa_sigterm.sa_handler = termsig_handler;
sigaction(SIGTERM, &sa_sigterm, NULL);
sigaction(SIGINT, &sa_sigterm, NULL);
sigaction(SIGHUP, &sa_sigterm, NULL);
signal(SIGPIPE, SIG_IGN);
module_call_init(MODULE_INIT_TRACE);
module_call_init(MODULE_INIT_QOM);
qemu_add_opts(&qemu_trace_opts);
qemu_init_exec_dir(argv[0]);
pidfile = qemu_get_local_state_pathname("run/qemu-pr-helper.pid");
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
switch (ch) {
case 'k':
socket_path = optarg;
if (socket_path[0] != '/') {
error_report("socket path must be absolute");
exit(EXIT_FAILURE);
}
break;
case 'f':
pidfile = optarg;
break;
#ifdef CONFIG_LIBCAP
case 'u': {
unsigned long res;
struct passwd *userinfo = getpwnam(optarg);
if (userinfo) {
uid = userinfo->pw_uid;
} else if (qemu_strtoul(optarg, NULL, 10, &res) == 0 &&
(uid_t)res == res) {
uid = res;
} else {
error_report("invalid user '%s'", optarg);
exit(EXIT_FAILURE);
}
break;
}
case 'g': {
unsigned long res;
struct group *groupinfo = getgrnam(optarg);
if (groupinfo) {
gid = groupinfo->gr_gid;
} else if (qemu_strtoul(optarg, NULL, 10, &res) == 0 &&
(gid_t)res == res) {
gid = res;
} else {
error_report("invalid group '%s'", optarg);
exit(EXIT_FAILURE);
}
break;
}
#else
case 'u':
case 'g':
error_report("-%c not supported by this %s", ch, argv[0]);
exit(1);
#endif
case 'd':
daemonize = true;
break;
case 'q':
quiet = 1;
break;
case 'v':
++loglevel;
break;
case 'T':
g_free(trace_file);
trace_file = trace_opt_parse(optarg);
break;
case 'V':
version(argv[0]);
exit(EXIT_SUCCESS);
break;
case 'h':
usage(argv[0]);
exit(EXIT_SUCCESS);
break;
case '?':
error_report("Try `%s --help' for more information.", argv[0]);
exit(EXIT_FAILURE);
}
}
/* set verbosity */
noisy = !quiet && (loglevel >= 3);
verbose = quiet ? 0 : MIN(loglevel, 3);
if (!trace_init_backends()) {
exit(EXIT_FAILURE);
}
trace_init_file(trace_file);
qemu_set_log(LOG_TRACE);
#ifdef CONFIG_MPATH
dm_init();
multipath_pr_init();
#endif
socket_activation = check_socket_activation();
if (socket_activation == 0) {
SocketAddress saddr;
compute_default_paths();
saddr = (SocketAddress){
.type = SOCKET_ADDRESS_TYPE_UNIX,
.u.q_unix.path = g_strdup(socket_path)
};
server_ioc = qio_channel_socket_new();
if (qio_channel_socket_listen_sync(server_ioc, &saddr, &local_err) < 0) {
object_unref(OBJECT(server_ioc));
error_report_err(local_err);
return 1;
}
g_free(saddr.u.q_unix.path);
} else {
/* Using socket activation - check user didn't use -p etc. */
const char *err_msg = socket_activation_validate_opts();
if (err_msg != NULL) {
error_report("%s", err_msg);
exit(EXIT_FAILURE);
}
/* Can only listen on a single socket. */
if (socket_activation > 1) {
error_report("%s does not support socket activation with LISTEN_FDS > 1",
argv[0]);
exit(EXIT_FAILURE);
}
server_ioc = qio_channel_socket_new_fd(FIRST_SOCKET_ACTIVATION_FD,
&local_err);
if (server_ioc == NULL) {
error_report("Failed to use socket activation: %s",
error_get_pretty(local_err));
exit(EXIT_FAILURE);
}
socket_path = NULL;
}
if (qemu_init_main_loop(&local_err)) {
error_report_err(local_err);
exit(EXIT_FAILURE);
}
server_watch = qio_channel_add_watch(QIO_CHANNEL(server_ioc),
G_IO_IN,
accept_client,
NULL, NULL);
#ifdef CONFIG_LIBCAP
if (drop_privileges() < 0) {
error_report("Failed to drop privileges: %s", strerror(errno));
exit(EXIT_FAILURE);
}
#endif
if (daemonize) {
if (daemon(0, 0) < 0) {
error_report("Failed to daemonize: %s", strerror(errno));
exit(EXIT_FAILURE);
}
write_pidfile();
}
state = RUNNING;
do {
main_loop_wait(false);
if (state == TERMINATE) {
state = TERMINATING;
close_server_socket();
}
} while (num_active_sockets > 0);
exit(EXIT_SUCCESS);
}
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