1 files changed, 123 insertions, 38 deletions

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 9d504234af4a..23128ee191ae 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -240,42 +240,76 @@ out:
 /*
  * Report socket names for nfsdfs
  */
-static int one_sock_name(char *buf, struct svc_sock *svsk)
+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(svsk->sk_sk->sk_family) {
-        case AF_INET:
-                len = sprintf(buf, "ipv4 %s %pI4 %d\n",
-                              svsk->sk_sk->sk_protocol == IPPROTO_UDP ?
-                              "udp" : "tcp",
-                              &inet_sk(svsk->sk_sk)->rcv_saddr,
-                              inet_sk(svsk->sk_sk)->num);
+        switch (sk->sk_family) {
+        case PF_INET:
+                len = snprintf(buf, remaining, "ipv4 %s %pI4 %d\n",
+                                proto_name,
+                                &inet_sk(sk)->rcv_saddr,
+                                inet_sk(sk)->num);
+                break;
+        case PF_INET6:
+                len = snprintf(buf, remaining, "ipv6 %s %pI6 %d\n",
+                                proto_name,
+                                &inet6_sk(sk)->rcv_saddr,
+                                inet_sk(sk)->num);
                 break;
         default:
-                len = sprintf(buf, "*unknown-%d*\n",
-                               svsk->sk_sk->sk_family);
+                len = snprintf(buf, remaining, "*unknown-%d*\n",
+                                sk->sk_family);
+        }
+
+        if (len >= remaining) {
+                *buf = '\0';
+                return -ENAMETOOLONG;
         }
         return len;
 }
 
-int
-svc_sock_names(char *buf, struct svc_serv *serv, char *toclose)
+/**
+ * svc_sock_names - construct a list of listener names in a string
+ * @serv: pointer to RPC service
+ * @buf: pointer to a buffer to fill in with socket names
+ * @buflen: size of the buffer to be filled
+ * @toclose: pointer to '\0'-terminated C string containing the name
+ *              of a listener to be closed
+ *
+ * Fills in @buf with a '\n'-separated list of names of listener
+ * sockets.  If @toclose is not NULL, the socket named by @toclose
+ * is closed, and is not included in the output list.
+ *
+ * Returns positive length of the socket name string, or a negative
+ * errno value on error.
+ */
+int svc_sock_names(struct svc_serv *serv, char *buf, const size_t buflen,
+                   const char *toclose)
 {
         struct svc_sock *svsk, *closesk = NULL;
         int len = 0;
 
         if (!serv)
                 return 0;
+
         spin_lock_bh(&serv->sv_lock);
         list_for_each_entry(svsk, &serv->sv_permsocks, sk_xprt.xpt_list) {
-                int onelen = one_sock_name(buf+len, svsk);
-                if (toclose && strcmp(toclose, buf+len) == 0)
+                int onelen = svc_one_sock_name(svsk, buf + len, buflen - len);
+                if (onelen < 0) {
+                        len = onelen;
+                        break;
+                }
+                if (toclose && strcmp(toclose, buf + len) == 0)
                         closesk = svsk;
                 else
                         len += onelen;
         }
         spin_unlock_bh(&serv->sv_lock);
+
         if (closesk)
                 /* Should unregister with portmap, but you cannot
                  * unregister just one protocol...
@@ -346,6 +380,7 @@ static void svc_sock_setbufsize(struct socket *sock, unsigned int snd,
         sock->sk->sk_sndbuf = snd * 2;
         sock->sk->sk_rcvbuf = rcv * 2;
         sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK|SOCK_RCVBUF_LOCK;
+        sock->sk->sk_write_space(sock->sk);
         release_sock(sock->sk);
 #endif
 }
@@ -387,6 +422,15 @@ static void svc_write_space(struct sock *sk)
         }
 }
 
+static void svc_tcp_write_space(struct sock *sk)
+{
+        struct socket *sock = sk->sk_socket;
+
+        if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) && sock)
+                clear_bit(SOCK_NOSPACE, &sock->flags);
+        svc_write_space(sk);
+}
+
 /*
  * Copy the UDP datagram's destination address to the rqstp structure.
  * The 'destination' address in this case is the address to which the
@@ -427,13 +471,14 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp)
                 long            all[SVC_PKTINFO_SPACE / sizeof(long)];
         } buffer;
         struct cmsghdr *cmh = &buffer.hdr;
-        int             err, len;
         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
@@ -465,8 +510,8 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp)
                 return -EAGAIN;
         }
         len = svc_addr_len(svc_addr(rqstp));
-        if (len < 0)
-                return len;
+        if (len == 0)
+                return -EAFNOSUPPORT;
         rqstp->rq_addrlen = len;
         if (skb->tstamp.tv64 == 0) {
                 skb->tstamp = ktime_get_real();
@@ -980,25 +1025,16 @@ static void svc_tcp_prep_reply_hdr(struct svc_rqst *rqstp)
 static int svc_tcp_has_wspace(struct svc_xprt *xprt)
 {
         struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
-        struct svc_serv *serv = svsk->sk_xprt.xpt_server;
+        struct svc_serv *serv = svsk->sk_xprt.xpt_server;
         int required;
-        int wspace;
 
-        /*
-         * Set the SOCK_NOSPACE flag before checking the available
-         * sock space.
-         */
+        if (test_bit(XPT_LISTENER, &xprt->xpt_flags))
+                return 1;
+        required = atomic_read(&xprt->xpt_reserved) + serv->sv_max_mesg;
+        if (sk_stream_wspace(svsk->sk_sk) >= required)
+                return 1;
         set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
-        required = atomic_read(&svsk->sk_xprt.xpt_reserved) + serv->sv_max_mesg;
-        wspace = sk_stream_wspace(svsk->sk_sk);
-
-        if (wspace < sk_stream_min_wspace(svsk->sk_sk))
-                return 0;
-        if (required * 2 > wspace)
-                return 0;
-
-        clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
-        return 1;
+        return 0;
 }
 
 static struct svc_xprt *svc_tcp_create(struct svc_serv *serv,
@@ -1054,7 +1090,7 @@ static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
                 dprintk("setting up TCP socket for reading\n");
                 sk->sk_state_change = svc_tcp_state_change;
                 sk->sk_data_ready = svc_tcp_data_ready;
-                sk->sk_write_space = svc_write_space;
+                sk->sk_write_space = svc_tcp_write_space;
 
                 svsk->sk_reclen = 0;
                 svsk->sk_tcplen = 0;
@@ -1148,9 +1184,19 @@ static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
         return svsk;
 }
 
-int svc_addsock(struct svc_serv *serv,
-                int fd,
-                char *name_return)
+/**
+ * svc_addsock - add a listener socket to an RPC service
+ * @serv: pointer to RPC service to which to add a new listener
+ * @fd: file descriptor of the new listener
+ * @name_return: pointer to buffer to fill in with name of listener
+ * @len: size of the buffer
+ *
+ * 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, const int fd, char *name_return,
+                const size_t len)
 {
         int err = 0;
         struct socket *so = sockfd_lookup(fd, &err);
@@ -1190,7 +1236,7 @@ int svc_addsock(struct svc_serv *serv,
                 sockfd_put(so);
                 return err;
         }
-        return one_sock_name(name_return, svsk);
+        return svc_one_sock_name(svsk, name_return, len);
 }
 EXPORT_SYMBOL_GPL(svc_addsock);
 
@@ -1327,3 +1373,42 @@ static void svc_sock_free(struct svc_xprt *xprt)
                 sock_release(svsk->sk_sock);
         kfree(svsk);
 }
+
+/*
+ * Create a svc_xprt.
+ *
+ * For internal use only (e.g. nfsv4.1 backchannel).
+ * Callers should typically use the xpo_create() method.
+ */
+struct svc_xprt *svc_sock_create(struct svc_serv *serv, int prot)
+{
+        struct svc_sock *svsk;
+        struct svc_xprt *xprt = NULL;
+
+        dprintk("svc: %s\n", __func__);
+        svsk = kzalloc(sizeof(*svsk), GFP_KERNEL);
+        if (!svsk)
+                goto out;
+
+        xprt = &svsk->sk_xprt;
+        if (prot == IPPROTO_TCP)
+                svc_xprt_init(&svc_tcp_class, xprt, serv);
+        else if (prot == IPPROTO_UDP)
+                svc_xprt_init(&svc_udp_class, xprt, serv);
+        else
+                BUG();
+out:
+        dprintk("svc: %s return %p\n", __func__, xprt);
+        return xprt;
+}
+EXPORT_SYMBOL_GPL(svc_sock_create);
+
+/*
+ * Destroy a svc_sock.
+ */
+void svc_sock_destroy(struct svc_xprt *xprt)
+{
+        if (xprt)
+                kfree(container_of(xprt, struct svc_sock, sk_xprt));
+}
+EXPORT_SYMBOL_GPL(svc_sock_destroy);