qemu/contrib/rdmacm-mux/main.c
Philippe Mathieu-Daudé 1e1f6ab0eb contrib/rdmacm-mux: Remove superfluous semicolon
Fixes: a5d2f6f877
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200218094402.26625-14-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-02-18 20:20:49 +01:00

832 lines
22 KiB
C

/*
* QEMU paravirtual RDMA - rdmacm-mux implementation
*
* Copyright (C) 2018 Oracle
* Copyright (C) 2018 Red Hat Inc
*
* Authors:
* Yuval Shaia <yuval.shaia@oracle.com>
* Marcel Apfelbaum <marcel@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include <sys/poll.h>
#include <sys/ioctl.h>
#include <pthread.h>
#include <syslog.h>
#include <infiniband/verbs.h>
#include <infiniband/umad.h>
#include <infiniband/umad_types.h>
#include <infiniband/umad_sa.h>
#include <infiniband/umad_cm.h>
#include "rdmacm-mux.h"
#define SCALE_US 1000
#define COMMID_TTL 2 /* How many SCALE_US a context of MAD session is saved */
#define SLEEP_SECS 5 /* This is used both in poll() and thread */
#define SERVER_LISTEN_BACKLOG 10
#define MAX_CLIENTS 4096
#define MAD_RMPP_VERSION 0
#define MAD_METHOD_MASK0 0x8
#define IB_USER_MAD_LONGS_PER_METHOD_MASK (128 / (8 * sizeof(long)))
#define CM_REQ_DGID_POS 80
#define CM_SIDR_REQ_DGID_POS 44
/* The below can be override by command line parameter */
#define UNIX_SOCKET_PATH "/var/run/rdmacm-mux"
/* Has format %s-%s-%d" <path>-<rdma-dev--name>-<port> */
#define SOCKET_PATH_MAX (PATH_MAX - NAME_MAX - sizeof(int) - 2)
#define RDMA_PORT_NUM 1
typedef struct RdmaCmServerArgs {
char unix_socket_path[PATH_MAX];
char rdma_dev_name[NAME_MAX];
int rdma_port_num;
} RdmaCMServerArgs;
typedef struct CommId2FdEntry {
int fd;
int ttl; /* Initialized to 2, decrement each timeout, entry delete when 0 */
__be64 gid_ifid;
} CommId2FdEntry;
typedef struct RdmaCmUMadAgent {
int port_id;
int agent_id;
GHashTable *gid2fd; /* Used to find fd of a given gid */
GHashTable *commid2fd; /* Used to find fd on of a given comm_id */
} RdmaCmUMadAgent;
typedef struct RdmaCmServer {
bool run;
RdmaCMServerArgs args;
struct pollfd fds[MAX_CLIENTS];
int nfds;
RdmaCmUMadAgent umad_agent;
pthread_t umad_recv_thread;
pthread_rwlock_t lock;
} RdmaCMServer;
static RdmaCMServer server = {0};
static void usage(const char *progname)
{
printf("Usage: %s [OPTION]...\n"
"Start a RDMA-CM multiplexer\n"
"\n"
"\t-h Show this help\n"
"\t-d rdma-device-name Name of RDMA device to register with\n"
"\t-s unix-socket-path Path to unix socket to listen on (default %s)\n"
"\t-p rdma-device-port Port number of RDMA device to register with (default %d)\n",
progname, UNIX_SOCKET_PATH, RDMA_PORT_NUM);
}
static void help(const char *progname)
{
fprintf(stderr, "Try '%s -h' for more information.\n", progname);
}
static void parse_args(int argc, char *argv[])
{
int c;
char unix_socket_path[SOCKET_PATH_MAX];
strcpy(server.args.rdma_dev_name, "");
strcpy(unix_socket_path, UNIX_SOCKET_PATH);
server.args.rdma_port_num = RDMA_PORT_NUM;
while ((c = getopt(argc, argv, "hs:d:p:")) != -1) {
switch (c) {
case 'h':
usage(argv[0]);
exit(0);
case 'd':
strncpy(server.args.rdma_dev_name, optarg, NAME_MAX - 1);
break;
case 's':
/* This is temporary, final name will build below */
strncpy(unix_socket_path, optarg, SOCKET_PATH_MAX - 1);
break;
case 'p':
server.args.rdma_port_num = atoi(optarg);
break;
default:
help(argv[0]);
exit(1);
}
}
if (!strcmp(server.args.rdma_dev_name, "")) {
fprintf(stderr, "Missing RDMA device name\n");
help(argv[0]);
exit(1);
}
/* Build unique unix-socket file name */
snprintf(server.args.unix_socket_path, PATH_MAX, "%s-%s-%d",
unix_socket_path, server.args.rdma_dev_name,
server.args.rdma_port_num);
syslog(LOG_INFO, "unix_socket_path=%s", server.args.unix_socket_path);
syslog(LOG_INFO, "rdma-device-name=%s", server.args.rdma_dev_name);
syslog(LOG_INFO, "rdma-device-port=%d", server.args.rdma_port_num);
}
static void hash_tbl_alloc(void)
{
server.umad_agent.gid2fd = g_hash_table_new_full(g_int64_hash,
g_int64_equal,
g_free, g_free);
server.umad_agent.commid2fd = g_hash_table_new_full(g_int_hash,
g_int_equal,
g_free, g_free);
}
static void hash_tbl_free(void)
{
if (server.umad_agent.commid2fd) {
g_hash_table_destroy(server.umad_agent.commid2fd);
}
if (server.umad_agent.gid2fd) {
g_hash_table_destroy(server.umad_agent.gid2fd);
}
}
static int _hash_tbl_search_fd_by_ifid(__be64 *gid_ifid)
{
int *fd;
fd = g_hash_table_lookup(server.umad_agent.gid2fd, gid_ifid);
if (!fd) {
/* Let's try IPv4 */
*gid_ifid |= 0x00000000ffff0000;
fd = g_hash_table_lookup(server.umad_agent.gid2fd, gid_ifid);
}
return fd ? *fd : 0;
}
static int hash_tbl_search_fd_by_ifid(int *fd, __be64 *gid_ifid)
{
pthread_rwlock_rdlock(&server.lock);
*fd = _hash_tbl_search_fd_by_ifid(gid_ifid);
pthread_rwlock_unlock(&server.lock);
if (!fd) {
syslog(LOG_WARNING, "Can't find matching for ifid 0x%llx\n", *gid_ifid);
return -ENOENT;
}
return 0;
}
static int hash_tbl_search_fd_by_comm_id(uint32_t comm_id, int *fd,
__be64 *gid_idid)
{
CommId2FdEntry *fde;
pthread_rwlock_rdlock(&server.lock);
fde = g_hash_table_lookup(server.umad_agent.commid2fd, &comm_id);
pthread_rwlock_unlock(&server.lock);
if (!fde) {
syslog(LOG_WARNING, "Can't find matching for comm_id 0x%x\n", comm_id);
return -ENOENT;
}
*fd = fde->fd;
*gid_idid = fde->gid_ifid;
return 0;
}
static RdmaCmMuxErrCode add_fd_ifid_pair(int fd, __be64 gid_ifid)
{
int fd1;
pthread_rwlock_wrlock(&server.lock);
fd1 = _hash_tbl_search_fd_by_ifid(&gid_ifid);
if (fd1) { /* record already exist - an error */
pthread_rwlock_unlock(&server.lock);
return fd == fd1 ? RDMACM_MUX_ERR_CODE_EEXIST :
RDMACM_MUX_ERR_CODE_EACCES;
}
g_hash_table_insert(server.umad_agent.gid2fd, g_memdup(&gid_ifid,
sizeof(gid_ifid)), g_memdup(&fd, sizeof(fd)));
pthread_rwlock_unlock(&server.lock);
syslog(LOG_INFO, "0x%lx registered on socket %d",
be64toh((uint64_t)gid_ifid), fd);
return RDMACM_MUX_ERR_CODE_OK;
}
static RdmaCmMuxErrCode delete_fd_ifid_pair(int fd, __be64 gid_ifid)
{
int fd1;
pthread_rwlock_wrlock(&server.lock);
fd1 = _hash_tbl_search_fd_by_ifid(&gid_ifid);
if (!fd1) { /* record not exist - an error */
pthread_rwlock_unlock(&server.lock);
return RDMACM_MUX_ERR_CODE_ENOTFOUND;
}
g_hash_table_remove(server.umad_agent.gid2fd, g_memdup(&gid_ifid,
sizeof(gid_ifid)));
pthread_rwlock_unlock(&server.lock);
syslog(LOG_INFO, "0x%lx unregistered on socket %d",
be64toh((uint64_t)gid_ifid), fd);
return RDMACM_MUX_ERR_CODE_OK;
}
static void hash_tbl_save_fd_comm_id_pair(int fd, uint32_t comm_id,
uint64_t gid_ifid)
{
CommId2FdEntry fde = {fd, COMMID_TTL, gid_ifid};
pthread_rwlock_wrlock(&server.lock);
g_hash_table_insert(server.umad_agent.commid2fd,
g_memdup(&comm_id, sizeof(comm_id)),
g_memdup(&fde, sizeof(fde)));
pthread_rwlock_unlock(&server.lock);
}
static gboolean remove_old_comm_ids(gpointer key, gpointer value,
gpointer user_data)
{
CommId2FdEntry *fde = (CommId2FdEntry *)value;
return !fde->ttl--;
}
static gboolean remove_entry_from_gid2fd(gpointer key, gpointer value,
gpointer user_data)
{
if (*(int *)value == *(int *)user_data) {
syslog(LOG_INFO, "0x%lx unregistered on socket %d",
be64toh(*(uint64_t *)key), *(int *)value);
return true;
}
return false;
}
static void hash_tbl_remove_fd_ifid_pair(int fd)
{
pthread_rwlock_wrlock(&server.lock);
g_hash_table_foreach_remove(server.umad_agent.gid2fd,
remove_entry_from_gid2fd, (gpointer)&fd);
pthread_rwlock_unlock(&server.lock);
}
static int get_fd(const char *mad, int umad_len, int *fd, __be64 *gid_ifid)
{
struct umad_hdr *hdr = (struct umad_hdr *)mad;
char *data = (char *)hdr + sizeof(*hdr);
int32_t comm_id = 0;
uint16_t attr_id = be16toh(hdr->attr_id);
int rc = 0;
if (umad_len <= sizeof(*hdr)) {
rc = -EINVAL;
syslog(LOG_DEBUG, "Ignoring MAD packets with header only\n");
goto out;
}
switch (attr_id) {
case UMAD_CM_ATTR_REQ:
if (unlikely(umad_len < sizeof(*hdr) + CM_REQ_DGID_POS +
sizeof(*gid_ifid))) {
rc = -EINVAL;
syslog(LOG_WARNING,
"Invalid MAD packet size (%d) for attr_id 0x%x\n", umad_len,
attr_id);
goto out;
}
memcpy(gid_ifid, data + CM_REQ_DGID_POS, sizeof(*gid_ifid));
rc = hash_tbl_search_fd_by_ifid(fd, gid_ifid);
break;
case UMAD_CM_ATTR_SIDR_REQ:
if (unlikely(umad_len < sizeof(*hdr) + CM_SIDR_REQ_DGID_POS +
sizeof(*gid_ifid))) {
rc = -EINVAL;
syslog(LOG_WARNING,
"Invalid MAD packet size (%d) for attr_id 0x%x\n", umad_len,
attr_id);
goto out;
}
memcpy(gid_ifid, data + CM_SIDR_REQ_DGID_POS, sizeof(*gid_ifid));
rc = hash_tbl_search_fd_by_ifid(fd, gid_ifid);
break;
case UMAD_CM_ATTR_REP:
/* Fall through */
case UMAD_CM_ATTR_REJ:
/* Fall through */
case UMAD_CM_ATTR_DREQ:
/* Fall through */
case UMAD_CM_ATTR_DREP:
/* Fall through */
case UMAD_CM_ATTR_RTU:
data += sizeof(comm_id);
/* Fall through */
case UMAD_CM_ATTR_SIDR_REP:
if (unlikely(umad_len < sizeof(*hdr) + sizeof(comm_id))) {
rc = -EINVAL;
syslog(LOG_WARNING,
"Invalid MAD packet size (%d) for attr_id 0x%x\n", umad_len,
attr_id);
goto out;
}
memcpy(&comm_id, data, sizeof(comm_id));
if (comm_id) {
rc = hash_tbl_search_fd_by_comm_id(comm_id, fd, gid_ifid);
}
break;
default:
rc = -EINVAL;
syslog(LOG_WARNING, "Unsupported attr_id 0x%x\n", attr_id);
}
syslog(LOG_DEBUG, "mad_to_vm: %d 0x%x 0x%x\n", *fd, attr_id, comm_id);
out:
return rc;
}
static void *umad_recv_thread_func(void *args)
{
int rc;
RdmaCmMuxMsg msg = {};
int fd = -2;
msg.hdr.msg_type = RDMACM_MUX_MSG_TYPE_REQ;
msg.hdr.op_code = RDMACM_MUX_OP_CODE_MAD;
while (server.run) {
do {
msg.umad_len = sizeof(msg.umad.mad);
rc = umad_recv(server.umad_agent.port_id, &msg.umad, &msg.umad_len,
SLEEP_SECS * SCALE_US);
if ((rc == -EIO) || (rc == -EINVAL)) {
syslog(LOG_CRIT, "Fatal error while trying to read MAD");
}
if (rc == -ETIMEDOUT) {
g_hash_table_foreach_remove(server.umad_agent.commid2fd,
remove_old_comm_ids, NULL);
}
} while (rc && server.run);
if (server.run) {
rc = get_fd(msg.umad.mad, msg.umad_len, &fd,
&msg.hdr.sgid.global.interface_id);
if (rc) {
continue;
}
send(fd, &msg, sizeof(msg), 0);
}
}
return NULL;
}
static int read_and_process(int fd)
{
int rc;
RdmaCmMuxMsg msg = {};
struct umad_hdr *hdr;
uint32_t *comm_id = 0;
uint16_t attr_id;
rc = recv(fd, &msg, sizeof(msg), 0);
syslog(LOG_DEBUG, "Socket %d, recv %d\n", fd, rc);
if (rc < 0 && errno != EWOULDBLOCK) {
syslog(LOG_ERR, "Fail to read from socket %d\n", fd);
return -EIO;
}
if (!rc) {
syslog(LOG_ERR, "Fail to read from socket %d\n", fd);
return -EPIPE;
}
if (msg.hdr.msg_type != RDMACM_MUX_MSG_TYPE_REQ) {
syslog(LOG_WARNING, "Got non-request message (%d) from socket %d\n",
msg.hdr.msg_type, fd);
return -EPERM;
}
switch (msg.hdr.op_code) {
case RDMACM_MUX_OP_CODE_REG:
rc = add_fd_ifid_pair(fd, msg.hdr.sgid.global.interface_id);
break;
case RDMACM_MUX_OP_CODE_UNREG:
rc = delete_fd_ifid_pair(fd, msg.hdr.sgid.global.interface_id);
break;
case RDMACM_MUX_OP_CODE_MAD:
/* If this is REQ or REP then store the pair comm_id,fd to be later
* used for other messages where gid is unknown */
hdr = (struct umad_hdr *)msg.umad.mad;
attr_id = be16toh(hdr->attr_id);
if ((attr_id == UMAD_CM_ATTR_REQ) || (attr_id == UMAD_CM_ATTR_DREQ) ||
(attr_id == UMAD_CM_ATTR_SIDR_REQ) ||
(attr_id == UMAD_CM_ATTR_REP) || (attr_id == UMAD_CM_ATTR_DREP)) {
comm_id = (uint32_t *)(msg.umad.mad + sizeof(*hdr));
hash_tbl_save_fd_comm_id_pair(fd, *comm_id,
msg.hdr.sgid.global.interface_id);
}
syslog(LOG_DEBUG, "vm_to_mad: %d 0x%x 0x%x\n", fd, attr_id,
comm_id ? *comm_id : 0);
rc = umad_send(server.umad_agent.port_id, server.umad_agent.agent_id,
&msg.umad, msg.umad_len, 1, 0);
if (rc) {
syslog(LOG_ERR,
"Fail to send MAD message (0x%x) from socket %d, err=%d",
attr_id, fd, rc);
}
break;
default:
syslog(LOG_ERR, "Got invalid op_code (%d) from socket %d",
msg.hdr.msg_type, fd);
rc = RDMACM_MUX_ERR_CODE_EINVAL;
}
msg.hdr.msg_type = RDMACM_MUX_MSG_TYPE_RESP;
msg.hdr.err_code = rc;
rc = send(fd, &msg, sizeof(msg), 0);
return rc == sizeof(msg) ? 0 : -EPIPE;
}
static int accept_all(void)
{
int fd, rc = 0;
pthread_rwlock_wrlock(&server.lock);
do {
if ((server.nfds + 1) > MAX_CLIENTS) {
syslog(LOG_WARNING, "Too many clients (%d)", server.nfds);
rc = -EIO;
goto out;
}
fd = accept(server.fds[0].fd, NULL, NULL);
if (fd < 0) {
if (errno != EWOULDBLOCK) {
syslog(LOG_WARNING, "accept() failed");
rc = -EIO;
goto out;
}
break;
}
syslog(LOG_INFO, "Client connected on socket %d\n", fd);
server.fds[server.nfds].fd = fd;
server.fds[server.nfds].events = POLLIN;
server.nfds++;
} while (fd != -1);
out:
pthread_rwlock_unlock(&server.lock);
return rc;
}
static void compress_fds(void)
{
int i, j;
int closed = 0;
pthread_rwlock_wrlock(&server.lock);
for (i = 1; i < server.nfds; i++) {
if (!server.fds[i].fd) {
closed++;
for (j = i; j < server.nfds - 1; j++) {
server.fds[j] = server.fds[j + 1];
}
}
}
server.nfds -= closed;
pthread_rwlock_unlock(&server.lock);
}
static void close_fd(int idx)
{
close(server.fds[idx].fd);
syslog(LOG_INFO, "Socket %d closed\n", server.fds[idx].fd);
hash_tbl_remove_fd_ifid_pair(server.fds[idx].fd);
server.fds[idx].fd = 0;
}
static void run(void)
{
int rc, nfds, i;
bool compress = false;
syslog(LOG_INFO, "Service started");
while (server.run) {
rc = poll(server.fds, server.nfds, SLEEP_SECS * SCALE_US);
if (rc < 0) {
if (errno != EINTR) {
syslog(LOG_WARNING, "poll() failed");
}
continue;
}
if (rc == 0) {
continue;
}
nfds = server.nfds;
for (i = 0; i < nfds; i++) {
syslog(LOG_DEBUG, "pollfd[%d]: revents 0x%x, events 0x%x\n", i,
server.fds[i].revents, server.fds[i].events);
if (server.fds[i].revents == 0) {
continue;
}
if (server.fds[i].revents != POLLIN) {
if (i == 0) {
syslog(LOG_NOTICE, "Unexpected poll() event (0x%x)\n",
server.fds[i].revents);
} else {
close_fd(i);
compress = true;
}
continue;
}
if (i == 0) {
rc = accept_all();
if (rc) {
continue;
}
} else {
rc = read_and_process(server.fds[i].fd);
if (rc) {
close_fd(i);
compress = true;
}
}
}
if (compress) {
compress = false;
compress_fds();
}
}
}
static void fini_listener(void)
{
int i;
if (server.fds[0].fd <= 0) {
return;
}
for (i = server.nfds - 1; i >= 0; i--) {
if (server.fds[i].fd) {
close(server.fds[i].fd);
}
}
unlink(server.args.unix_socket_path);
}
static void fini_umad(void)
{
if (server.umad_agent.agent_id) {
umad_unregister(server.umad_agent.port_id, server.umad_agent.agent_id);
}
if (server.umad_agent.port_id) {
umad_close_port(server.umad_agent.port_id);
}
hash_tbl_free();
}
static void fini(void)
{
if (server.umad_recv_thread) {
pthread_join(server.umad_recv_thread, NULL);
server.umad_recv_thread = 0;
}
fini_umad();
fini_listener();
pthread_rwlock_destroy(&server.lock);
syslog(LOG_INFO, "Service going down");
}
static int init_listener(void)
{
struct sockaddr_un sun;
int rc, on = 1;
server.fds[0].fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (server.fds[0].fd < 0) {
syslog(LOG_ALERT, "socket() failed");
return -EIO;
}
rc = setsockopt(server.fds[0].fd, SOL_SOCKET, SO_REUSEADDR, (char *)&on,
sizeof(on));
if (rc < 0) {
syslog(LOG_ALERT, "setsockopt() failed");
rc = -EIO;
goto err;
}
rc = ioctl(server.fds[0].fd, FIONBIO, (char *)&on);
if (rc < 0) {
syslog(LOG_ALERT, "ioctl() failed");
rc = -EIO;
goto err;
}
if (strlen(server.args.unix_socket_path) >= sizeof(sun.sun_path)) {
syslog(LOG_ALERT,
"Invalid unix_socket_path, size must be less than %ld\n",
sizeof(sun.sun_path));
rc = -EINVAL;
goto err;
}
sun.sun_family = AF_UNIX;
rc = snprintf(sun.sun_path, sizeof(sun.sun_path), "%s",
server.args.unix_socket_path);
if (rc < 0 || rc >= sizeof(sun.sun_path)) {
syslog(LOG_ALERT, "Could not copy unix socket path\n");
rc = -EINVAL;
goto err;
}
rc = bind(server.fds[0].fd, (struct sockaddr *)&sun, sizeof(sun));
if (rc < 0) {
syslog(LOG_ALERT, "bind() failed");
rc = -EIO;
goto err;
}
rc = listen(server.fds[0].fd, SERVER_LISTEN_BACKLOG);
if (rc < 0) {
syslog(LOG_ALERT, "listen() failed");
rc = -EIO;
goto err;
}
server.fds[0].events = POLLIN;
server.nfds = 1;
server.run = true;
return 0;
err:
close(server.fds[0].fd);
return rc;
}
static int init_umad(void)
{
long method_mask[IB_USER_MAD_LONGS_PER_METHOD_MASK];
server.umad_agent.port_id = umad_open_port(server.args.rdma_dev_name,
server.args.rdma_port_num);
if (server.umad_agent.port_id < 0) {
syslog(LOG_WARNING, "umad_open_port() failed");
return -EIO;
}
memset(&method_mask, 0, sizeof(method_mask));
method_mask[0] = MAD_METHOD_MASK0;
server.umad_agent.agent_id = umad_register(server.umad_agent.port_id,
UMAD_CLASS_CM,
UMAD_SA_CLASS_VERSION,
MAD_RMPP_VERSION, method_mask);
if (server.umad_agent.agent_id < 0) {
syslog(LOG_WARNING, "umad_register() failed");
return -EIO;
}
hash_tbl_alloc();
return 0;
}
static void signal_handler(int sig, siginfo_t *siginfo, void *context)
{
static bool warned;
/* Prevent stop if clients are connected */
if (server.nfds != 1) {
if (!warned) {
syslog(LOG_WARNING,
"Can't stop while active client exist, resend SIGINT to overid");
warned = true;
return;
}
}
if (sig == SIGINT) {
server.run = false;
fini();
}
exit(0);
}
static int init(void)
{
int rc;
struct sigaction sig = {};
rc = init_listener();
if (rc) {
return rc;
}
rc = init_umad();
if (rc) {
return rc;
}
pthread_rwlock_init(&server.lock, 0);
rc = pthread_create(&server.umad_recv_thread, NULL, umad_recv_thread_func,
NULL);
if (rc) {
syslog(LOG_ERR, "Fail to create UMAD receiver thread (%d)\n", rc);
return rc;
}
sig.sa_sigaction = &signal_handler;
sig.sa_flags = SA_SIGINFO;
rc = sigaction(SIGINT, &sig, NULL);
if (rc < 0) {
syslog(LOG_ERR, "Fail to install SIGINT handler (%d)\n", errno);
return rc;
}
return 0;
}
int main(int argc, char *argv[])
{
int rc;
memset(&server, 0, sizeof(server));
parse_args(argc, argv);
rc = init();
if (rc) {
syslog(LOG_ERR, "Fail to initialize server (%d)\n", rc);
rc = -EAGAIN;
goto out;
}
run();
out:
fini();
return rc;
}