diff options
Diffstat (limited to 'scsi/qemu-pr-helper.c')
| -rw-r--r-- | scsi/qemu-pr-helper.c | 1075 |
1 files changed, 1075 insertions, 0 deletions
diff --git a/scsi/qemu-pr-helper.c b/scsi/qemu-pr-helper.c new file mode 100644 index 0000000000..d58184833f --- /dev/null +++ b/scsi/qemu-pr-helper.c @@ -0,0 +1,1075 @@ +/* + * 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_VERSION QEMU_PKGVERSION "\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); +unsigned mpath_mx_alloc_len = PR_HELPER_DATA_SIZE; +int logsink; + +static void multipath_pr_init(void) +{ + static struct udev *udev; + + udev = udev_new(); + mpath_lib_init(udev); +} + +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 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; + return do_sgio(fd, cdb, sense, NULL, &sz, SG_DXFER_NONE); + } + + 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(¶mp, 0, sizeof(paramp)); + memcpy(¶mp.key, ¶m[0], 8); + memcpy(¶mp.sa_key, ¶m[8], 8); + paramp.sa_flags = param[10]; + 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(¶m[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, ¶m[i + 8], 8); + j += offsetof(struct transportid, n_port_name[8]); + i += 24; + break; + case 3: + case 0x43: + /* iSCSI transport. */ + len = lduw_be_p(¶m[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(¶m[i + 4], 0, len) == NULL) { + goto illegal_req; + } + memcpy(id->iscsi_name, ¶m[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, ¶m[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, + ¶mp, 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); +} |