diff options
Diffstat (limited to 'net/sunrpc/svcsock.c')
-rw-r--r-- | net/sunrpc/svcsock.c | 1644 |
1 files changed, 1644 insertions, 0 deletions
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c new file mode 100644 index 0000000000..e0ce427627 --- /dev/null +++ b/net/sunrpc/svcsock.c @@ -0,0 +1,1644 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/net/sunrpc/svcsock.c + * + * These are the RPC server socket internals. + * + * The server scheduling algorithm does not always distribute the load + * evenly when servicing a single client. May need to modify the + * svc_xprt_enqueue procedure... + * + * TCP support is largely untested and may be a little slow. The problem + * is that we currently do two separate recvfrom's, one for the 4-byte + * record length, and the second for the actual record. This could possibly + * be improved by always reading a minimum size of around 100 bytes and + * tucking any superfluous bytes away in a temporary store. Still, that + * leaves write requests out in the rain. An alternative may be to peek at + * the first skb in the queue, and if it matches the next TCP sequence + * number, to extract the record marker. Yuck. + * + * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> + */ + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/fcntl.h> +#include <linux/net.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/udp.h> +#include <linux/tcp.h> +#include <linux/unistd.h> +#include <linux/slab.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <linux/file.h> +#include <linux/freezer.h> +#include <linux/bvec.h> + +#include <net/sock.h> +#include <net/checksum.h> +#include <net/ip.h> +#include <net/ipv6.h> +#include <net/udp.h> +#include <net/tcp.h> +#include <net/tcp_states.h> +#include <net/tls_prot.h> +#include <net/handshake.h> +#include <linux/uaccess.h> +#include <linux/highmem.h> +#include <asm/ioctls.h> +#include <linux/key.h> + +#include <linux/sunrpc/types.h> +#include <linux/sunrpc/clnt.h> +#include <linux/sunrpc/xdr.h> +#include <linux/sunrpc/msg_prot.h> +#include <linux/sunrpc/svcsock.h> +#include <linux/sunrpc/stats.h> +#include <linux/sunrpc/xprt.h> + +#include <trace/events/sock.h> +#include <trace/events/sunrpc.h> + +#include "socklib.h" +#include "sunrpc.h" + +#define RPCDBG_FACILITY RPCDBG_SVCXPRT + +/* To-do: to avoid tying up an nfsd thread while waiting for a + * handshake request, the request could instead be deferred. + */ +enum { + SVC_HANDSHAKE_TO = 5U * HZ +}; + +static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *, + int flags); +static int svc_udp_recvfrom(struct svc_rqst *); +static int svc_udp_sendto(struct svc_rqst *); +static void svc_sock_detach(struct svc_xprt *); +static void svc_tcp_sock_detach(struct svc_xprt *); +static void svc_sock_free(struct svc_xprt *); + +static struct svc_xprt *svc_create_socket(struct svc_serv *, int, + struct net *, struct sockaddr *, + int, int); +#ifdef CONFIG_DEBUG_LOCK_ALLOC +static struct lock_class_key svc_key[2]; +static struct lock_class_key svc_slock_key[2]; + +static void svc_reclassify_socket(struct socket *sock) +{ + struct sock *sk = sock->sk; + + if (WARN_ON_ONCE(!sock_allow_reclassification(sk))) + return; + + switch (sk->sk_family) { + case AF_INET: + sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD", + &svc_slock_key[0], + "sk_xprt.xpt_lock-AF_INET-NFSD", + &svc_key[0]); + break; + + case AF_INET6: + sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFSD", + &svc_slock_key[1], + "sk_xprt.xpt_lock-AF_INET6-NFSD", + &svc_key[1]); + break; + + default: + BUG(); + } +} +#else +static void svc_reclassify_socket(struct socket *sock) +{ +} +#endif + +/** + * svc_tcp_release_ctxt - Release transport-related resources + * @xprt: the transport which owned the context + * @ctxt: the context from rqstp->rq_xprt_ctxt or dr->xprt_ctxt + * + */ +static void svc_tcp_release_ctxt(struct svc_xprt *xprt, void *ctxt) +{ +} + +/** + * svc_udp_release_ctxt - Release transport-related resources + * @xprt: the transport which owned the context + * @ctxt: the context from rqstp->rq_xprt_ctxt or dr->xprt_ctxt + * + */ +static void svc_udp_release_ctxt(struct svc_xprt *xprt, void *ctxt) +{ + struct sk_buff *skb = ctxt; + + if (skb) + consume_skb(skb); +} + +union svc_pktinfo_u { + struct in_pktinfo pkti; + struct in6_pktinfo pkti6; +}; +#define SVC_PKTINFO_SPACE \ + CMSG_SPACE(sizeof(union svc_pktinfo_u)) + +static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh) +{ + struct svc_sock *svsk = + container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt); + switch (svsk->sk_sk->sk_family) { + case AF_INET: { + struct in_pktinfo *pki = CMSG_DATA(cmh); + + cmh->cmsg_level = SOL_IP; + cmh->cmsg_type = IP_PKTINFO; + pki->ipi_ifindex = 0; + pki->ipi_spec_dst.s_addr = + svc_daddr_in(rqstp)->sin_addr.s_addr; + cmh->cmsg_len = CMSG_LEN(sizeof(*pki)); + } + break; + + case AF_INET6: { + struct in6_pktinfo *pki = CMSG_DATA(cmh); + struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp); + + cmh->cmsg_level = SOL_IPV6; + cmh->cmsg_type = IPV6_PKTINFO; + pki->ipi6_ifindex = daddr->sin6_scope_id; + pki->ipi6_addr = daddr->sin6_addr; + cmh->cmsg_len = CMSG_LEN(sizeof(*pki)); + } + break; + } +} + +static int svc_sock_result_payload(struct svc_rqst *rqstp, unsigned int offset, + unsigned int length) +{ + return 0; +} + +/* + * Report socket names for nfsdfs + */ +static int svc_one_sock_name(struct svc_sock *svsk, char *buf, int remaining) +{ + const struct sock *sk = svsk->sk_sk; + const char *proto_name = sk->sk_protocol == IPPROTO_UDP ? + "udp" : "tcp"; + int len; + + switch (sk->sk_family) { + case PF_INET: + len = snprintf(buf, remaining, "ipv4 %s %pI4 %d\n", + proto_name, + &inet_sk(sk)->inet_rcv_saddr, + inet_sk(sk)->inet_num); + break; +#if IS_ENABLED(CONFIG_IPV6) + case PF_INET6: + len = snprintf(buf, remaining, "ipv6 %s %pI6 %d\n", + proto_name, + &sk->sk_v6_rcv_saddr, + inet_sk(sk)->inet_num); + break; +#endif + default: + len = snprintf(buf, remaining, "*unknown-%d*\n", + sk->sk_family); + } + + if (len >= remaining) { + *buf = '\0'; + return -ENAMETOOLONG; + } + return len; +} + +static int +svc_tcp_sock_process_cmsg(struct socket *sock, struct msghdr *msg, + struct cmsghdr *cmsg, int ret) +{ + u8 content_type = tls_get_record_type(sock->sk, cmsg); + u8 level, description; + + switch (content_type) { + case 0: + break; + case TLS_RECORD_TYPE_DATA: + /* TLS sets EOR at the end of each application data + * record, even though there might be more frames + * waiting to be decrypted. + */ + msg->msg_flags &= ~MSG_EOR; + break; + case TLS_RECORD_TYPE_ALERT: + tls_alert_recv(sock->sk, msg, &level, &description); + ret = (level == TLS_ALERT_LEVEL_FATAL) ? + -ENOTCONN : -EAGAIN; + break; + default: + /* discard this record type */ + ret = -EAGAIN; + } + return ret; +} + +static int +svc_tcp_sock_recv_cmsg(struct svc_sock *svsk, struct msghdr *msg) +{ + union { + struct cmsghdr cmsg; + u8 buf[CMSG_SPACE(sizeof(u8))]; + } u; + struct socket *sock = svsk->sk_sock; + int ret; + + msg->msg_control = &u; + msg->msg_controllen = sizeof(u); + ret = sock_recvmsg(sock, msg, MSG_DONTWAIT); + if (unlikely(msg->msg_controllen != sizeof(u))) + ret = svc_tcp_sock_process_cmsg(sock, msg, &u.cmsg, ret); + return ret; +} + +#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE +static void svc_flush_bvec(const struct bio_vec *bvec, size_t size, size_t seek) +{ + struct bvec_iter bi = { + .bi_size = size + seek, + }; + struct bio_vec bv; + + bvec_iter_advance(bvec, &bi, seek & PAGE_MASK); + for_each_bvec(bv, bvec, bi, bi) + flush_dcache_page(bv.bv_page); +} +#else +static inline void svc_flush_bvec(const struct bio_vec *bvec, size_t size, + size_t seek) +{ +} +#endif + +/* + * Read from @rqstp's transport socket. The incoming message fills whole + * pages in @rqstp's rq_pages array until the last page of the message + * has been received into a partial page. + */ +static ssize_t svc_tcp_read_msg(struct svc_rqst *rqstp, size_t buflen, + size_t seek) +{ + struct svc_sock *svsk = + container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt); + struct bio_vec *bvec = rqstp->rq_bvec; + struct msghdr msg = { NULL }; + unsigned int i; + ssize_t len; + size_t t; + + clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); + + for (i = 0, t = 0; t < buflen; i++, t += PAGE_SIZE) + bvec_set_page(&bvec[i], rqstp->rq_pages[i], PAGE_SIZE, 0); + rqstp->rq_respages = &rqstp->rq_pages[i]; + rqstp->rq_next_page = rqstp->rq_respages + 1; + + iov_iter_bvec(&msg.msg_iter, ITER_DEST, bvec, i, buflen); + if (seek) { + iov_iter_advance(&msg.msg_iter, seek); + buflen -= seek; + } + len = svc_tcp_sock_recv_cmsg(svsk, &msg); + if (len > 0) + svc_flush_bvec(bvec, len, seek); + + /* If we read a full record, then assume there may be more + * data to read (stream based sockets only!) + */ + if (len == buflen) + set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); + + return len; +} + +/* + * Set socket snd and rcv buffer lengths + */ +static void svc_sock_setbufsize(struct svc_sock *svsk, unsigned int nreqs) +{ + unsigned int max_mesg = svsk->sk_xprt.xpt_server->sv_max_mesg; + struct socket *sock = svsk->sk_sock; + + nreqs = min(nreqs, INT_MAX / 2 / max_mesg); + + lock_sock(sock->sk); + sock->sk->sk_sndbuf = nreqs * max_mesg * 2; + sock->sk->sk_rcvbuf = nreqs * max_mesg * 2; + sock->sk->sk_write_space(sock->sk); + release_sock(sock->sk); +} + +static void svc_sock_secure_port(struct svc_rqst *rqstp) +{ + if (svc_port_is_privileged(svc_addr(rqstp))) + set_bit(RQ_SECURE, &rqstp->rq_flags); + else + clear_bit(RQ_SECURE, &rqstp->rq_flags); +} + +/* + * INET callback when data has been received on the socket. + */ +static void svc_data_ready(struct sock *sk) +{ + struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data; + + trace_sk_data_ready(sk); + + if (svsk) { + /* Refer to svc_setup_socket() for details. */ + rmb(); + svsk->sk_odata(sk); + trace_svcsock_data_ready(&svsk->sk_xprt, 0); + if (test_bit(XPT_HANDSHAKE, &svsk->sk_xprt.xpt_flags)) + return; + if (!test_and_set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags)) + svc_xprt_enqueue(&svsk->sk_xprt); + } +} + +/* + * INET callback when space is newly available on the socket. + */ +static void svc_write_space(struct sock *sk) +{ + struct svc_sock *svsk = (struct svc_sock *)(sk->sk_user_data); + + if (svsk) { + /* Refer to svc_setup_socket() for details. */ + rmb(); + trace_svcsock_write_space(&svsk->sk_xprt, 0); + svsk->sk_owspace(sk); + svc_xprt_enqueue(&svsk->sk_xprt); + } +} + +static int svc_tcp_has_wspace(struct svc_xprt *xprt) +{ + struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); + + if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) + return 1; + return !test_bit(SOCK_NOSPACE, &svsk->sk_sock->flags); +} + +static void svc_tcp_kill_temp_xprt(struct svc_xprt *xprt) +{ + struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); + + sock_no_linger(svsk->sk_sock->sk); +} + +/** + * svc_tcp_handshake_done - Handshake completion handler + * @data: address of xprt to wake + * @status: status of handshake + * @peerid: serial number of key containing the remote peer's identity + * + * If a security policy is specified as an export option, we don't + * have a specific export here to check. So we set a "TLS session + * is present" flag on the xprt and let an upper layer enforce local + * security policy. + */ +static void svc_tcp_handshake_done(void *data, int status, key_serial_t peerid) +{ + struct svc_xprt *xprt = data; + struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); + + if (!status) { + if (peerid != TLS_NO_PEERID) + set_bit(XPT_PEER_AUTH, &xprt->xpt_flags); + set_bit(XPT_TLS_SESSION, &xprt->xpt_flags); + } + clear_bit(XPT_HANDSHAKE, &xprt->xpt_flags); + complete_all(&svsk->sk_handshake_done); +} + +/** + * svc_tcp_handshake - Perform a transport-layer security handshake + * @xprt: connected transport endpoint + * + */ +static void svc_tcp_handshake(struct svc_xprt *xprt) +{ + struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); + struct sock *sk = svsk->sk_sock->sk; + struct tls_handshake_args args = { + .ta_sock = svsk->sk_sock, + .ta_done = svc_tcp_handshake_done, + .ta_data = xprt, + }; + int ret; + + trace_svc_tls_upcall(xprt); + + clear_bit(XPT_TLS_SESSION, &xprt->xpt_flags); + init_completion(&svsk->sk_handshake_done); + + ret = tls_server_hello_x509(&args, GFP_KERNEL); + if (ret) { + trace_svc_tls_not_started(xprt); + goto out_failed; + } + + ret = wait_for_completion_interruptible_timeout(&svsk->sk_handshake_done, + SVC_HANDSHAKE_TO); + if (ret <= 0) { + if (tls_handshake_cancel(sk)) { + trace_svc_tls_timed_out(xprt); + goto out_close; + } + } + + if (!test_bit(XPT_TLS_SESSION, &xprt->xpt_flags)) { + trace_svc_tls_unavailable(xprt); + goto out_close; + } + + /* Mark the transport ready in case the remote sent RPC + * traffic before the kernel received the handshake + * completion downcall. + */ + set_bit(XPT_DATA, &xprt->xpt_flags); + svc_xprt_enqueue(xprt); + return; + +out_close: + set_bit(XPT_CLOSE, &xprt->xpt_flags); +out_failed: + clear_bit(XPT_HANDSHAKE, &xprt->xpt_flags); + set_bit(XPT_DATA, &xprt->xpt_flags); + svc_xprt_enqueue(xprt); +} + +/* + * See net/ipv6/ip_sockglue.c : ip_cmsg_recv_pktinfo + */ +static int svc_udp_get_dest_address4(struct svc_rqst *rqstp, + struct cmsghdr *cmh) +{ + struct in_pktinfo *pki = CMSG_DATA(cmh); + struct sockaddr_in *daddr = svc_daddr_in(rqstp); + + if (cmh->cmsg_type != IP_PKTINFO) + return 0; + + daddr->sin_family = AF_INET; + daddr->sin_addr.s_addr = pki->ipi_spec_dst.s_addr; + return 1; +} + +/* + * See net/ipv6/datagram.c : ip6_datagram_recv_ctl + */ +static int svc_udp_get_dest_address6(struct svc_rqst *rqstp, + struct cmsghdr *cmh) +{ + struct in6_pktinfo *pki = CMSG_DATA(cmh); + struct sockaddr_in6 *daddr = svc_daddr_in6(rqstp); + + if (cmh->cmsg_type != IPV6_PKTINFO) + return 0; + + daddr->sin6_family = AF_INET6; + daddr->sin6_addr = pki->ipi6_addr; + daddr->sin6_scope_id = pki->ipi6_ifindex; + return 1; +} + +/* + * Copy the UDP datagram's destination address to the rqstp structure. + * The 'destination' address in this case is the address to which the + * peer sent the datagram, i.e. our local address. For multihomed + * hosts, this can change from msg to msg. Note that only the IP + * address changes, the port number should remain the same. + */ +static int svc_udp_get_dest_address(struct svc_rqst *rqstp, + struct cmsghdr *cmh) +{ + switch (cmh->cmsg_level) { + case SOL_IP: + return svc_udp_get_dest_address4(rqstp, cmh); + case SOL_IPV6: + return svc_udp_get_dest_address6(rqstp, cmh); + } + + return 0; +} + +/** + * svc_udp_recvfrom - Receive a datagram from a UDP socket. + * @rqstp: request structure into which to receive an RPC Call + * + * Called in a loop when XPT_DATA has been set. + * + * Returns: + * On success, the number of bytes in a received RPC Call, or + * %0 if a complete RPC Call message was not ready to return + */ +static int svc_udp_recvfrom(struct svc_rqst *rqstp) +{ + struct svc_sock *svsk = + container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt); + struct svc_serv *serv = svsk->sk_xprt.xpt_server; + struct sk_buff *skb; + union { + struct cmsghdr hdr; + long all[SVC_PKTINFO_SPACE / sizeof(long)]; + } buffer; + struct cmsghdr *cmh = &buffer.hdr; + struct msghdr msg = { + .msg_name = svc_addr(rqstp), + .msg_control = cmh, + .msg_controllen = sizeof(buffer), + .msg_flags = MSG_DONTWAIT, + }; + size_t len; + int err; + + if (test_and_clear_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags)) + /* udp sockets need large rcvbuf as all pending + * requests are still in that buffer. sndbuf must + * also be large enough that there is enough space + * for one reply per thread. We count all threads + * rather than threads in a particular pool, which + * provides an upper bound on the number of threads + * which will access the socket. + */ + svc_sock_setbufsize(svsk, serv->sv_nrthreads + 3); + + clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); + err = kernel_recvmsg(svsk->sk_sock, &msg, NULL, + 0, 0, MSG_PEEK | MSG_DONTWAIT); + if (err < 0) + goto out_recv_err; + skb = skb_recv_udp(svsk->sk_sk, MSG_DONTWAIT, &err); + if (!skb) + goto out_recv_err; + + len = svc_addr_len(svc_addr(rqstp)); + rqstp->rq_addrlen = len; + if (skb->tstamp == 0) { + skb->tstamp = ktime_get_real(); + /* Don't enable netstamp, sunrpc doesn't + need that much accuracy */ + } + sock_write_timestamp(svsk->sk_sk, skb->tstamp); + set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be more data... */ + + len = skb->len; + rqstp->rq_arg.len = len; + trace_svcsock_udp_recv(&svsk->sk_xprt, len); + + rqstp->rq_prot = IPPROTO_UDP; + + if (!svc_udp_get_dest_address(rqstp, cmh)) + goto out_cmsg_err; + rqstp->rq_daddrlen = svc_addr_len(svc_daddr(rqstp)); + + if (skb_is_nonlinear(skb)) { + /* we have to copy */ + local_bh_disable(); + if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb)) + goto out_bh_enable; + local_bh_enable(); + consume_skb(skb); + } else { + /* we can use it in-place */ + rqstp->rq_arg.head[0].iov_base = skb->data; + rqstp->rq_arg.head[0].iov_len = len; + if (skb_checksum_complete(skb)) + goto out_free; + rqstp->rq_xprt_ctxt = skb; + } + + rqstp->rq_arg.page_base = 0; + if (len <= rqstp->rq_arg.head[0].iov_len) { + rqstp->rq_arg.head[0].iov_len = len; + rqstp->rq_arg.page_len = 0; + rqstp->rq_respages = rqstp->rq_pages+1; + } else { + rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len; + rqstp->rq_respages = rqstp->rq_pages + 1 + + DIV_ROUND_UP(rqstp->rq_arg.page_len, PAGE_SIZE); + } + rqstp->rq_next_page = rqstp->rq_respages+1; + + if (serv->sv_stats) + serv->sv_stats->netudpcnt++; + + svc_sock_secure_port(rqstp); + svc_xprt_received(rqstp->rq_xprt); + return len; + +out_recv_err: + if (err != -EAGAIN) { + /* possibly an icmp error */ + set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); + } + trace_svcsock_udp_recv_err(&svsk->sk_xprt, err); + goto out_clear_busy; +out_cmsg_err: + net_warn_ratelimited("svc: received unknown control message %d/%d; dropping RPC reply datagram\n", + cmh->cmsg_level, cmh->cmsg_type); + goto out_free; +out_bh_enable: + local_bh_enable(); +out_free: + kfree_skb(skb); +out_clear_busy: + svc_xprt_received(rqstp->rq_xprt); + return 0; +} + +/** + * svc_udp_sendto - Send out a reply on a UDP socket + * @rqstp: completed svc_rqst + * + * xpt_mutex ensures @rqstp's whole message is written to the socket + * without interruption. + * + * Returns the number of bytes sent, or a negative errno. + */ +static int svc_udp_sendto(struct svc_rqst *rqstp) +{ + struct svc_xprt *xprt = rqstp->rq_xprt; + struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); + struct xdr_buf *xdr = &rqstp->rq_res; + union { + struct cmsghdr hdr; + long all[SVC_PKTINFO_SPACE / sizeof(long)]; + } buffer; + struct cmsghdr *cmh = &buffer.hdr; + struct msghdr msg = { + .msg_name = &rqstp->rq_addr, + .msg_namelen = rqstp->rq_addrlen, + .msg_control = cmh, + .msg_flags = MSG_SPLICE_PAGES, + .msg_controllen = sizeof(buffer), + }; + unsigned int count; + int err; + + svc_udp_release_ctxt(xprt, rqstp->rq_xprt_ctxt); + rqstp->rq_xprt_ctxt = NULL; + + svc_set_cmsg_data(rqstp, cmh); + + mutex_lock(&xprt->xpt_mutex); + + if (svc_xprt_is_dead(xprt)) + goto out_notconn; + + count = xdr_buf_to_bvec(rqstp->rq_bvec, + ARRAY_SIZE(rqstp->rq_bvec), xdr); + + iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec, + count, rqstp->rq_res.len); + err = sock_sendmsg(svsk->sk_sock, &msg); + if (err == -ECONNREFUSED) { + /* ICMP error on earlier request. */ + iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec, + count, rqstp->rq_res.len); + err = sock_sendmsg(svsk->sk_sock, &msg); + } + + trace_svcsock_udp_send(xprt, err); + + mutex_unlock(&xprt->xpt_mutex); + return err; + +out_notconn: + mutex_unlock(&xprt->xpt_mutex); + return -ENOTCONN; +} + +static int svc_udp_has_wspace(struct svc_xprt *xprt) +{ + struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); + struct svc_serv *serv = xprt->xpt_server; + unsigned long required; + + /* + * Set the SOCK_NOSPACE flag before checking the available + * sock space. + */ + set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags); + required = atomic_read(&svsk->sk_xprt.xpt_reserved) + serv->sv_max_mesg; + if (required*2 > sock_wspace(svsk->sk_sk)) + return 0; + clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags); + return 1; +} + +static struct svc_xprt *svc_udp_accept(struct svc_xprt *xprt) +{ + BUG(); + return NULL; +} + +static void svc_udp_kill_temp_xprt(struct svc_xprt *xprt) +{ +} + +static struct svc_xprt *svc_udp_create(struct svc_serv *serv, + struct net *net, + struct sockaddr *sa, int salen, + int flags) +{ + return svc_create_socket(serv, IPPROTO_UDP, net, sa, salen, flags); +} + +static const struct svc_xprt_ops svc_udp_ops = { + .xpo_create = svc_udp_create, + .xpo_recvfrom = svc_udp_recvfrom, + .xpo_sendto = svc_udp_sendto, + .xpo_result_payload = svc_sock_result_payload, + .xpo_release_ctxt = svc_udp_release_ctxt, + .xpo_detach = svc_sock_detach, + .xpo_free = svc_sock_free, + .xpo_has_wspace = svc_udp_has_wspace, + .xpo_accept = svc_udp_accept, + .xpo_kill_temp_xprt = svc_udp_kill_temp_xprt, +}; + +static struct svc_xprt_class svc_udp_class = { + .xcl_name = "udp", + .xcl_owner = THIS_MODULE, + .xcl_ops = &svc_udp_ops, + .xcl_max_payload = RPCSVC_MAXPAYLOAD_UDP, + .xcl_ident = XPRT_TRANSPORT_UDP, +}; + +static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv) +{ + svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_udp_class, + &svsk->sk_xprt, serv); + clear_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags); + svsk->sk_sk->sk_data_ready = svc_data_ready; + svsk->sk_sk->sk_write_space = svc_write_space; + + /* initialise setting must have enough space to + * receive and respond to one request. + * svc_udp_recvfrom will re-adjust if necessary + */ + svc_sock_setbufsize(svsk, 3); + + /* data might have come in before data_ready set up */ + set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); + set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags); + + /* make sure we get destination address info */ + switch (svsk->sk_sk->sk_family) { + case AF_INET: + ip_sock_set_pktinfo(svsk->sk_sock->sk); + break; + case AF_INET6: + ip6_sock_set_recvpktinfo(svsk->sk_sock->sk); + break; + default: + BUG(); + } +} + +/* + * A data_ready event on a listening socket means there's a connection + * pending. Do not use state_change as a substitute for it. + */ +static void svc_tcp_listen_data_ready(struct sock *sk) +{ + struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data; + + trace_sk_data_ready(sk); + + /* + * This callback may called twice when a new connection + * is established as a child socket inherits everything + * from a parent LISTEN socket. + * 1) data_ready method of the parent socket will be called + * when one of child sockets become ESTABLISHED. + * 2) data_ready method of the child socket may be called + * when it receives data before the socket is accepted. + * In case of 2, we should ignore it silently and DO NOT + * dereference svsk. + */ + if (sk->sk_state != TCP_LISTEN) + return; + + if (svsk) { + /* Refer to svc_setup_socket() for details. */ + rmb(); + svsk->sk_odata(sk); + set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags); + svc_xprt_enqueue(&svsk->sk_xprt); + } +} + +/* + * A state change on a connected socket means it's dying or dead. + */ +static void svc_tcp_state_change(struct sock *sk) +{ + struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data; + + if (svsk) { + /* Refer to svc_setup_socket() for details. */ + rmb(); + svsk->sk_ostate(sk); + trace_svcsock_tcp_state(&svsk->sk_xprt, svsk->sk_sock); + if (sk->sk_state != TCP_ESTABLISHED) + svc_xprt_deferred_close(&svsk->sk_xprt); + } +} + +/* + * Accept a TCP connection + */ +static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt) +{ + struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); + struct sockaddr_storage addr; + struct sockaddr *sin = (struct sockaddr *) &addr; + struct svc_serv *serv = svsk->sk_xprt.xpt_server; + struct socket *sock = svsk->sk_sock; + struct socket *newsock; + struct svc_sock *newsvsk; + int err, slen; + + if (!sock) + return NULL; + + clear_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags); + err = kernel_accept(sock, &newsock, O_NONBLOCK); + if (err < 0) { + if (err != -EAGAIN) + trace_svcsock_accept_err(xprt, serv->sv_name, err); + return NULL; + } + if (IS_ERR(sock_alloc_file(newsock, O_NONBLOCK, NULL))) + return NULL; + + set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags); + + err = kernel_getpeername(newsock, sin); + if (err < 0) { + trace_svcsock_getpeername_err(xprt, serv->sv_name, err); + goto failed; /* aborted connection or whatever */ + } + slen = err; + + /* Reset the inherited callbacks before calling svc_setup_socket */ + newsock->sk->sk_state_change = svsk->sk_ostate; + newsock->sk->sk_data_ready = svsk->sk_odata; + newsock->sk->sk_write_space = svsk->sk_owspace; + + /* make sure that a write doesn't block forever when + * low on memory + */ + newsock->sk->sk_sndtimeo = HZ*30; + + newsvsk = svc_setup_socket(serv, newsock, + (SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY)); + if (IS_ERR(newsvsk)) + goto failed; + svc_xprt_set_remote(&newsvsk->sk_xprt, sin, slen); + err = kernel_getsockname(newsock, sin); + slen = err; + if (unlikely(err < 0)) + slen = offsetof(struct sockaddr, sa_data); + svc_xprt_set_local(&newsvsk->sk_xprt, sin, slen); + + if (sock_is_loopback(newsock->sk)) + set_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags); + else + clear_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags); + if (serv->sv_stats) + serv->sv_stats->nettcpconn++; + + return &newsvsk->sk_xprt; + +failed: + sockfd_put(newsock); + return NULL; +} + +static size_t svc_tcp_restore_pages(struct svc_sock *svsk, + struct svc_rqst *rqstp) +{ + size_t len = svsk->sk_datalen; + unsigned int i, npages; + + if (!len) + return 0; + npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; + for (i = 0; i < npages; i++) { + if (rqstp->rq_pages[i] != NULL) + put_page(rqstp->rq_pages[i]); + BUG_ON(svsk->sk_pages[i] == NULL); + rqstp->rq_pages[i] = svsk->sk_pages[i]; + svsk->sk_pages[i] = NULL; + } + rqstp->rq_arg.head[0].iov_base = page_address(rqstp->rq_pages[0]); + return len; +} + +static void svc_tcp_save_pages(struct svc_sock *svsk, struct svc_rqst *rqstp) +{ + unsigned int i, len, npages; + + if (svsk->sk_datalen == 0) + return; + len = svsk->sk_datalen; + npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; + for (i = 0; i < npages; i++) { + svsk->sk_pages[i] = rqstp->rq_pages[i]; + rqstp->rq_pages[i] = NULL; + } +} + +static void svc_tcp_clear_pages(struct svc_sock *svsk) +{ + unsigned int i, len, npages; + + if (svsk->sk_datalen == 0) + goto out; + len = svsk->sk_datalen; + npages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT; + for (i = 0; i < npages; i++) { + if (svsk->sk_pages[i] == NULL) { + WARN_ON_ONCE(1); + continue; + } + put_page(svsk->sk_pages[i]); + svsk->sk_pages[i] = NULL; + } +out: + svsk->sk_tcplen = 0; + svsk->sk_datalen = 0; +} + +/* + * Receive fragment record header into sk_marker. + */ +static ssize_t svc_tcp_read_marker(struct svc_sock *svsk, + struct svc_rqst *rqstp) +{ + ssize_t want, len; + + /* If we haven't gotten the record length yet, + * get the next four bytes. + */ + if (svsk->sk_tcplen < sizeof(rpc_fraghdr)) { + struct msghdr msg = { NULL }; + struct kvec iov; + + want = sizeof(rpc_fraghdr) - svsk->sk_tcplen; + iov.iov_base = ((char *)&svsk->sk_marker) + svsk->sk_tcplen; + iov.iov_len = want; + iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, want); + len = svc_tcp_sock_recv_cmsg(svsk, &msg); + if (len < 0) + return len; + svsk->sk_tcplen += len; + if (len < want) { + /* call again to read the remaining bytes */ + goto err_short; + } + trace_svcsock_marker(&svsk->sk_xprt, svsk->sk_marker); + if (svc_sock_reclen(svsk) + svsk->sk_datalen > + svsk->sk_xprt.xpt_server->sv_max_mesg) + goto err_too_large; + } + return svc_sock_reclen(svsk); + +err_too_large: + net_notice_ratelimited("svc: %s %s RPC fragment too large: %d\n", + __func__, svsk->sk_xprt.xpt_server->sv_name, + svc_sock_reclen(svsk)); + svc_xprt_deferred_close(&svsk->sk_xprt); +err_short: + return -EAGAIN; +} + +static int receive_cb_reply(struct svc_sock *svsk, struct svc_rqst *rqstp) +{ + struct rpc_xprt *bc_xprt = svsk->sk_xprt.xpt_bc_xprt; + struct rpc_rqst *req = NULL; + struct kvec *src, *dst; + __be32 *p = (__be32 *)rqstp->rq_arg.head[0].iov_base; + __be32 xid; + __be32 calldir; + + xid = *p++; + calldir = *p; + + if (!bc_xprt) + return -EAGAIN; + spin_lock(&bc_xprt->queue_lock); + req = xprt_lookup_rqst(bc_xprt, xid); + if (!req) + goto unlock_notfound; + + memcpy(&req->rq_private_buf, &req->rq_rcv_buf, sizeof(struct xdr_buf)); + /* + * XXX!: cheating for now! Only copying HEAD. + * But we know this is good enough for now (in fact, for any + * callback reply in the forseeable future). + */ + dst = &req->rq_private_buf.head[0]; + src = &rqstp->rq_arg.head[0]; + if (dst->iov_len < src->iov_len) + goto unlock_eagain; /* whatever; just giving up. */ + memcpy(dst->iov_base, src->iov_base, src->iov_len); + xprt_complete_rqst(req->rq_task, rqstp->rq_arg.len); + rqstp->rq_arg.len = 0; + spin_unlock(&bc_xprt->queue_lock); + return 0; +unlock_notfound: + printk(KERN_NOTICE + "%s: Got unrecognized reply: " + "calldir 0x%x xpt_bc_xprt %p xid %08x\n", + __func__, ntohl(calldir), + bc_xprt, ntohl(xid)); +unlock_eagain: + spin_unlock(&bc_xprt->queue_lock); + return -EAGAIN; +} + +static void svc_tcp_fragment_received(struct svc_sock *svsk) +{ + /* If we have more data, signal svc_xprt_enqueue() to try again */ + svsk->sk_tcplen = 0; + svsk->sk_marker = xdr_zero; + + smp_wmb(); + tcp_set_rcvlowat(svsk->sk_sk, 1); +} + +/** + * svc_tcp_recvfrom - Receive data from a TCP socket + * @rqstp: request structure into which to receive an RPC Call + * + * Called in a loop when XPT_DATA has been set. + * + * Read the 4-byte stream record marker, then use the record length + * in that marker to set up exactly the resources needed to receive + * the next RPC message into @rqstp. + * + * Returns: + * On success, the number of bytes in a received RPC Call, or + * %0 if a complete RPC Call message was not ready to return + * + * The zero return case handles partial receives and callback Replies. + * The state of a partial receive is preserved in the svc_sock for + * the next call to svc_tcp_recvfrom. + */ +static int svc_tcp_recvfrom(struct svc_rqst *rqstp) +{ + struct svc_sock *svsk = + container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt); + struct svc_serv *serv = svsk->sk_xprt.xpt_server; + size_t want, base; + ssize_t len; + __be32 *p; + __be32 calldir; + + clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); + len = svc_tcp_read_marker(svsk, rqstp); + if (len < 0) + goto error; + + base = svc_tcp_restore_pages(svsk, rqstp); + want = len - (svsk->sk_tcplen - sizeof(rpc_fraghdr)); + len = svc_tcp_read_msg(rqstp, base + want, base); + if (len >= 0) { + trace_svcsock_tcp_recv(&svsk->sk_xprt, len); + svsk->sk_tcplen += len; + svsk->sk_datalen += len; + } + if (len != want || !svc_sock_final_rec(svsk)) + goto err_incomplete; + if (svsk->sk_datalen < 8) + goto err_nuts; + + rqstp->rq_arg.len = svsk->sk_datalen; + rqstp->rq_arg.page_base = 0; + if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) { + rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len; + rqstp->rq_arg.page_len = 0; + } else + rqstp->rq_arg.page_len = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; + + rqstp->rq_xprt_ctxt = NULL; + rqstp->rq_prot = IPPROTO_TCP; + if (test_bit(XPT_LOCAL, &svsk->sk_xprt.xpt_flags)) + set_bit(RQ_LOCAL, &rqstp->rq_flags); + else + clear_bit(RQ_LOCAL, &rqstp->rq_flags); + + p = (__be32 *)rqstp->rq_arg.head[0].iov_base; + calldir = p[1]; + if (calldir) + len = receive_cb_reply(svsk, rqstp); + + /* Reset TCP read info */ + svsk->sk_datalen = 0; + svc_tcp_fragment_received(svsk); + + if (len < 0) + goto error; + + svc_xprt_copy_addrs(rqstp, &svsk->sk_xprt); + if (serv->sv_stats) + serv->sv_stats->nettcpcnt++; + + svc_sock_secure_port(rqstp); + svc_xprt_received(rqstp->rq_xprt); + return rqstp->rq_arg.len; + +err_incomplete: + svc_tcp_save_pages(svsk, rqstp); + if (len < 0 && len != -EAGAIN) + goto err_delete; + if (len == want) + svc_tcp_fragment_received(svsk); + else { + /* Avoid more ->sk_data_ready() calls until the rest + * of the message has arrived. This reduces service + * thread wake-ups on large incoming messages. */ + tcp_set_rcvlowat(svsk->sk_sk, + svc_sock_reclen(svsk) - svsk->sk_tcplen); + + trace_svcsock_tcp_recv_short(&svsk->sk_xprt, + svc_sock_reclen(svsk), + svsk->sk_tcplen - sizeof(rpc_fraghdr)); + } + goto err_noclose; +error: + if (len != -EAGAIN) + goto err_delete; + trace_svcsock_tcp_recv_eagain(&svsk->sk_xprt, 0); + goto err_noclose; +err_nuts: + svsk->sk_datalen = 0; +err_delete: + trace_svcsock_tcp_recv_err(&svsk->sk_xprt, len); + svc_xprt_deferred_close(&svsk->sk_xprt); +err_noclose: + svc_xprt_received(rqstp->rq_xprt); + return 0; /* record not complete */ +} + +/* + * MSG_SPLICE_PAGES is used exclusively to reduce the number of + * copy operations in this path. Therefore the caller must ensure + * that the pages backing @xdr are unchanging. + * + * Note that the send is non-blocking. The caller has incremented + * the reference count on each page backing the RPC message, and + * the network layer will "put" these pages when transmission is + * complete. + * + * This is safe for our RPC services because the memory backing + * the head and tail components is never kmalloc'd. These always + * come from pages in the svc_rqst::rq_pages array. + */ +static int svc_tcp_sendmsg(struct svc_sock *svsk, struct svc_rqst *rqstp, + rpc_fraghdr marker, unsigned int *sentp) +{ + struct msghdr msg = { + .msg_flags = MSG_SPLICE_PAGES, + }; + unsigned int count; + void *buf; + int ret; + + *sentp = 0; + + /* The stream record marker is copied into a temporary page + * fragment buffer so that it can be included in rq_bvec. + */ + buf = page_frag_alloc(&svsk->sk_frag_cache, sizeof(marker), + GFP_KERNEL); + if (!buf) + return -ENOMEM; + memcpy(buf, &marker, sizeof(marker)); + bvec_set_virt(rqstp->rq_bvec, buf, sizeof(marker)); + + count = xdr_buf_to_bvec(rqstp->rq_bvec + 1, + ARRAY_SIZE(rqstp->rq_bvec) - 1, &rqstp->rq_res); + + iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, rqstp->rq_bvec, + 1 + count, sizeof(marker) + rqstp->rq_res.len); + ret = sock_sendmsg(svsk->sk_sock, &msg); + if (ret < 0) + return ret; + *sentp += ret; + return 0; +} + +/** + * svc_tcp_sendto - Send out a reply on a TCP socket + * @rqstp: completed svc_rqst + * + * xpt_mutex ensures @rqstp's whole message is written to the socket + * without interruption. + * + * Returns the number of bytes sent, or a negative errno. + */ +static int svc_tcp_sendto(struct svc_rqst *rqstp) +{ + struct svc_xprt *xprt = rqstp->rq_xprt; + struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); + struct xdr_buf *xdr = &rqstp->rq_res; + rpc_fraghdr marker = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | + (u32)xdr->len); + unsigned int sent; + int err; + + svc_tcp_release_ctxt(xprt, rqstp->rq_xprt_ctxt); + rqstp->rq_xprt_ctxt = NULL; + + mutex_lock(&xprt->xpt_mutex); + if (svc_xprt_is_dead(xprt)) + goto out_notconn; + err = svc_tcp_sendmsg(svsk, rqstp, marker, &sent); + trace_svcsock_tcp_send(xprt, err < 0 ? (long)err : sent); + if (err < 0 || sent != (xdr->len + sizeof(marker))) + goto out_close; + mutex_unlock(&xprt->xpt_mutex); + return sent; + +out_notconn: + mutex_unlock(&xprt->xpt_mutex); + return -ENOTCONN; +out_close: + pr_notice("rpc-srv/tcp: %s: %s %d when sending %d bytes - shutting down socket\n", + xprt->xpt_server->sv_name, + (err < 0) ? "got error" : "sent", + (err < 0) ? err : sent, xdr->len); + svc_xprt_deferred_close(xprt); + mutex_unlock(&xprt->xpt_mutex); + return -EAGAIN; +} + +static struct svc_xprt *svc_tcp_create(struct svc_serv *serv, + struct net *net, + struct sockaddr *sa, int salen, + int flags) +{ + return svc_create_socket(serv, IPPROTO_TCP, net, sa, salen, flags); +} + +static const struct svc_xprt_ops svc_tcp_ops = { + .xpo_create = svc_tcp_create, + .xpo_recvfrom = svc_tcp_recvfrom, + .xpo_sendto = svc_tcp_sendto, + .xpo_result_payload = svc_sock_result_payload, + .xpo_release_ctxt = svc_tcp_release_ctxt, + .xpo_detach = svc_tcp_sock_detach, + .xpo_free = svc_sock_free, + .xpo_has_wspace = svc_tcp_has_wspace, + .xpo_accept = svc_tcp_accept, + .xpo_kill_temp_xprt = svc_tcp_kill_temp_xprt, + .xpo_handshake = svc_tcp_handshake, +}; + +static struct svc_xprt_class svc_tcp_class = { + .xcl_name = "tcp", + .xcl_owner = THIS_MODULE, + .xcl_ops = &svc_tcp_ops, + .xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP, + .xcl_ident = XPRT_TRANSPORT_TCP, +}; + +void svc_init_xprt_sock(void) +{ + svc_reg_xprt_class(&svc_tcp_class); + svc_reg_xprt_class(&svc_udp_class); +} + +void svc_cleanup_xprt_sock(void) +{ + svc_unreg_xprt_class(&svc_tcp_class); + svc_unreg_xprt_class(&svc_udp_class); +} + +static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv) +{ + struct sock *sk = svsk->sk_sk; + + svc_xprt_init(sock_net(svsk->sk_sock->sk), &svc_tcp_class, + &svsk->sk_xprt, serv); + set_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags); + set_bit(XPT_CONG_CTRL, &svsk->sk_xprt.xpt_flags); + if (sk->sk_state == TCP_LISTEN) { + strcpy(svsk->sk_xprt.xpt_remotebuf, "listener"); + set_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags); + sk->sk_data_ready = svc_tcp_listen_data_ready; + set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags); + } else { + sk->sk_state_change = svc_tcp_state_change; + sk->sk_data_ready = svc_data_ready; + sk->sk_write_space = svc_write_space; + + svsk->sk_marker = xdr_zero; + svsk->sk_tcplen = 0; + svsk->sk_datalen = 0; + memset(&svsk->sk_pages[0], 0, sizeof(svsk->sk_pages)); + + tcp_sock_set_nodelay(sk); + + set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); + switch (sk->sk_state) { + case TCP_SYN_RECV: + case TCP_ESTABLISHED: + break; + default: + svc_xprt_deferred_close(&svsk->sk_xprt); + } + } +} + +void svc_sock_update_bufs(struct svc_serv *serv) +{ + /* + * The number of server threads has changed. Update + * rcvbuf and sndbuf accordingly on all sockets + */ + struct svc_sock *svsk; + + spin_lock_bh(&serv->sv_lock); + list_for_each_entry(svsk, &serv->sv_permsocks, sk_xprt.xpt_list) + set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags); + spin_unlock_bh(&serv->sv_lock); +} +EXPORT_SYMBOL_GPL(svc_sock_update_bufs); + +/* + * Initialize socket for RPC use and create svc_sock struct + */ +static struct svc_sock *svc_setup_socket(struct svc_serv *serv, + struct socket *sock, + int flags) +{ + struct svc_sock *svsk; + struct sock *inet; + int pmap_register = !(flags & SVC_SOCK_ANONYMOUS); + + svsk = kzalloc(sizeof(*svsk), GFP_KERNEL); + if (!svsk) + return ERR_PTR(-ENOMEM); + + inet = sock->sk; + + if (pmap_register) { + int err; + + err = svc_register(serv, sock_net(sock->sk), inet->sk_family, + inet->sk_protocol, + ntohs(inet_sk(inet)->inet_sport)); + if (err < 0) { + kfree(svsk); + return ERR_PTR(err); + } + } + + svsk->sk_sock = sock; + svsk->sk_sk = inet; + svsk->sk_ostate = inet->sk_state_change; + svsk->sk_odata = inet->sk_data_ready; + svsk->sk_owspace = inet->sk_write_space; + /* + * This barrier is necessary in order to prevent race condition + * with svc_data_ready(), svc_tcp_listen_data_ready(), and others + * when calling callbacks above. + */ + wmb(); + inet->sk_user_data = svsk; + + /* Initialize the socket */ + if (sock->type == SOCK_DGRAM) + svc_udp_init(svsk, serv); + else + svc_tcp_init(svsk, serv); + + trace_svcsock_new(svsk, sock); + return svsk; +} + +/** + * svc_addsock - add a listener socket to an RPC service + * @serv: pointer to RPC service to which to add a new listener + * @net: caller's network namespace + * @fd: file descriptor of the new listener + * @name_return: pointer to buffer to fill in with name of listener + * @len: size of the buffer + * @cred: credential + * + * Fills in socket name and returns positive length of name if successful. + * Name is terminated with '\n'. On error, returns a negative errno + * value. + */ +int svc_addsock(struct svc_serv *serv, struct net *net, const int fd, + char *name_return, const size_t len, const struct cred *cred) +{ + int err = 0; + struct socket *so = sockfd_lookup(fd, &err); + struct svc_sock *svsk = NULL; + struct sockaddr_storage addr; + struct sockaddr *sin = (struct sockaddr *)&addr; + int salen; + + if (!so) + return err; + err = -EINVAL; + if (sock_net(so->sk) != net) + goto out; + err = -EAFNOSUPPORT; + if ((so->sk->sk_family != PF_INET) && (so->sk->sk_family != PF_INET6)) + goto out; + err = -EPROTONOSUPPORT; + if (so->sk->sk_protocol != IPPROTO_TCP && + so->sk->sk_protocol != IPPROTO_UDP) + goto out; + err = -EISCONN; + if (so->state > SS_UNCONNECTED) + goto out; + err = -ENOENT; + if (!try_module_get(THIS_MODULE)) + goto out; + svsk = svc_setup_socket(serv, so, SVC_SOCK_DEFAULTS); + if (IS_ERR(svsk)) { + module_put(THIS_MODULE); + err = PTR_ERR(svsk); + goto out; + } + salen = kernel_getsockname(svsk->sk_sock, sin); + if (salen >= 0) + svc_xprt_set_local(&svsk->sk_xprt, sin, salen); + svsk->sk_xprt.xpt_cred = get_cred(cred); + svc_add_new_perm_xprt(serv, &svsk->sk_xprt); + return svc_one_sock_name(svsk, name_return, len); +out: + sockfd_put(so); + return err; +} +EXPORT_SYMBOL_GPL(svc_addsock); + +/* + * Create socket for RPC service. + */ +static struct svc_xprt *svc_create_socket(struct svc_serv *serv, + int protocol, + struct net *net, + struct sockaddr *sin, int len, + int flags) +{ + struct svc_sock *svsk; + struct socket *sock; + int error; + int type; + struct sockaddr_storage addr; + struct sockaddr *newsin = (struct sockaddr *)&addr; + int newlen; + int family; + + if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) { + printk(KERN_WARNING "svc: only UDP and TCP " + "sockets supported\n"); + return ERR_PTR(-EINVAL); + } + + type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM; + switch (sin->sa_family) { + case AF_INET6: + family = PF_INET6; + break; + case AF_INET: + family = PF_INET; + break; + default: + return ERR_PTR(-EINVAL); + } + + error = __sock_create(net, family, type, protocol, &sock, 1); + if (error < 0) + return ERR_PTR(error); + + svc_reclassify_socket(sock); + + /* + * If this is an PF_INET6 listener, we want to avoid + * getting requests from IPv4 remotes. Those should + * be shunted to a PF_INET listener via rpcbind. + */ + if (family == PF_INET6) + ip6_sock_set_v6only(sock->sk); + if (type == SOCK_STREAM) + sock->sk->sk_reuse = SK_CAN_REUSE; /* allow address reuse */ + error = kernel_bind(sock, sin, len); + if (error < 0) + goto bummer; + + error = kernel_getsockname(sock, newsin); + if (error < 0) + goto bummer; + newlen = error; + + if (protocol == IPPROTO_TCP) { + if ((error = kernel_listen(sock, 64)) < 0) + goto bummer; + } + + svsk = svc_setup_socket(serv, sock, flags); + if (IS_ERR(svsk)) { + error = PTR_ERR(svsk); + goto bummer; + } + svc_xprt_set_local(&svsk->sk_xprt, newsin, newlen); + return (struct svc_xprt *)svsk; +bummer: + sock_release(sock); + return ERR_PTR(error); +} + +/* + * Detach the svc_sock from the socket so that no + * more callbacks occur. + */ +static void svc_sock_detach(struct svc_xprt *xprt) +{ + struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); + struct sock *sk = svsk->sk_sk; + + /* put back the old socket callbacks */ + lock_sock(sk); + sk->sk_state_change = svsk->sk_ostate; + sk->sk_data_ready = svsk->sk_odata; + sk->sk_write_space = svsk->sk_owspace; + sk->sk_user_data = NULL; + release_sock(sk); +} + +/* + * Disconnect the socket, and reset the callbacks + */ +static void svc_tcp_sock_detach(struct svc_xprt *xprt) +{ + struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); + + tls_handshake_close(svsk->sk_sock); + + svc_sock_detach(xprt); + + if (!test_bit(XPT_LISTENER, &xprt->xpt_flags)) { + svc_tcp_clear_pages(svsk); + kernel_sock_shutdown(svsk->sk_sock, SHUT_RDWR); + } +} + +/* + * Free the svc_sock's socket resources and the svc_sock itself. + */ +static void svc_sock_free(struct svc_xprt *xprt) +{ + struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); + struct page_frag_cache *pfc = &svsk->sk_frag_cache; + struct socket *sock = svsk->sk_sock; + + trace_svcsock_free(svsk, sock); + + tls_handshake_cancel(sock->sk); + if (sock->file) + sockfd_put(sock); + else + sock_release(sock); + if (pfc->va) + __page_frag_cache_drain(virt_to_head_page(pfc->va), + pfc->pagecnt_bias); + kfree(svsk); +} |