From a2e2725541fad72416326798c2d7fa4dafb7d337 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 12 Oct 2009 23:40:10 -0700 Subject: net: Introduce recvmmsg socket syscall MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Meaning receive multiple messages, reducing the number of syscalls and net stack entry/exit operations. Next patches will introduce mechanisms where protocols that want to optimize this operation will provide an unlocked_recvmsg operation. This takes into account comments made by: . Paul Moore: sock_recvmsg is called only for the first datagram, sock_recvmsg_nosec is used for the rest. . Caitlin Bestler: recvmmsg now has a struct timespec timeout, that works in the same fashion as the ppoll one. If the underlying protocol returns a datagram with MSG_OOB set, this will make recvmmsg return right away with as many datagrams (+ the OOB one) it has received so far. . Rémi Denis-Courmont & Steven Whitehouse: If we receive N < vlen datagrams and then recvmsg returns an error, recvmmsg will return the successfully received datagrams, store the error and return it in the next call. This paves the way for a subsequent optimization, sk_prot->unlocked_recvmsg, where we will be able to acquire the lock only at batch start and end, not at every underlying recvmsg call. Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- net/socket.c | 225 ++++++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 183 insertions(+), 42 deletions(-) (limited to 'net/socket.c') diff --git a/net/socket.c b/net/socket.c index 807935693846..9dff31c9b799 100644 --- a/net/socket.c +++ b/net/socket.c @@ -683,10 +683,9 @@ void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, } EXPORT_SYMBOL_GPL(sock_recv_ts_and_drops); -static inline int __sock_recvmsg(struct kiocb *iocb, struct socket *sock, - struct msghdr *msg, size_t size, int flags) +static inline int __sock_recvmsg_nosec(struct kiocb *iocb, struct socket *sock, + struct msghdr *msg, size_t size, int flags) { - int err; struct sock_iocb *si = kiocb_to_siocb(iocb); si->sock = sock; @@ -695,13 +694,17 @@ static inline int __sock_recvmsg(struct kiocb *iocb, struct socket *sock, si->size = size; si->flags = flags; - err = security_socket_recvmsg(sock, msg, size, flags); - if (err) - return err; - return sock->ops->recvmsg(iocb, sock, msg, size, flags); } +static inline int __sock_recvmsg(struct kiocb *iocb, struct socket *sock, + struct msghdr *msg, size_t size, int flags) +{ + int err = security_socket_recvmsg(sock, msg, size, flags); + + return err ?: __sock_recvmsg_nosec(iocb, sock, msg, size, flags); +} + int sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, int flags) { @@ -717,6 +720,21 @@ int sock_recvmsg(struct socket *sock, struct msghdr *msg, return ret; } +static int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg, + size_t size, int flags) +{ + struct kiocb iocb; + struct sock_iocb siocb; + int ret; + + init_sync_kiocb(&iocb, NULL); + iocb.private = &siocb; + ret = __sock_recvmsg_nosec(&iocb, sock, msg, size, flags); + if (-EIOCBQUEUED == ret) + ret = wait_on_sync_kiocb(&iocb); + return ret; +} + int kernel_recvmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec, size_t num, size_t size, int flags) { @@ -1983,22 +2001,15 @@ out: return err; } -/* - * BSD recvmsg interface - */ - -SYSCALL_DEFINE3(recvmsg, int, fd, struct msghdr __user *, msg, - unsigned int, flags) +static int __sys_recvmsg(struct socket *sock, struct msghdr __user *msg, + struct msghdr *msg_sys, unsigned flags, int nosec) { struct compat_msghdr __user *msg_compat = (struct compat_msghdr __user *)msg; - struct socket *sock; struct iovec iovstack[UIO_FASTIOV]; struct iovec *iov = iovstack; - struct msghdr msg_sys; unsigned long cmsg_ptr; int err, iov_size, total_len, len; - int fput_needed; /* kernel mode address */ struct sockaddr_storage addr; @@ -2008,27 +2019,23 @@ SYSCALL_DEFINE3(recvmsg, int, fd, struct msghdr __user *, msg, int __user *uaddr_len; if (MSG_CMSG_COMPAT & flags) { - if (get_compat_msghdr(&msg_sys, msg_compat)) + if (get_compat_msghdr(msg_sys, msg_compat)) return -EFAULT; } - else if (copy_from_user(&msg_sys, msg, sizeof(struct msghdr))) + else if (copy_from_user(msg_sys, msg, sizeof(struct msghdr))) return -EFAULT; - sock = sockfd_lookup_light(fd, &err, &fput_needed); - if (!sock) - goto out; - err = -EMSGSIZE; - if (msg_sys.msg_iovlen > UIO_MAXIOV) - goto out_put; + if (msg_sys->msg_iovlen > UIO_MAXIOV) + goto out; /* Check whether to allocate the iovec area */ err = -ENOMEM; - iov_size = msg_sys.msg_iovlen * sizeof(struct iovec); - if (msg_sys.msg_iovlen > UIO_FASTIOV) { + iov_size = msg_sys->msg_iovlen * sizeof(struct iovec); + if (msg_sys->msg_iovlen > UIO_FASTIOV) { iov = sock_kmalloc(sock->sk, iov_size, GFP_KERNEL); if (!iov) - goto out_put; + goto out; } /* @@ -2036,46 +2043,47 @@ SYSCALL_DEFINE3(recvmsg, int, fd, struct msghdr __user *, msg, * kernel msghdr to use the kernel address space) */ - uaddr = (__force void __user *)msg_sys.msg_name; + uaddr = (__force void __user *)msg_sys->msg_name; uaddr_len = COMPAT_NAMELEN(msg); if (MSG_CMSG_COMPAT & flags) { - err = verify_compat_iovec(&msg_sys, iov, + err = verify_compat_iovec(msg_sys, iov, (struct sockaddr *)&addr, VERIFY_WRITE); } else - err = verify_iovec(&msg_sys, iov, + err = verify_iovec(msg_sys, iov, (struct sockaddr *)&addr, VERIFY_WRITE); if (err < 0) goto out_freeiov; total_len = err; - cmsg_ptr = (unsigned long)msg_sys.msg_control; - msg_sys.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT); + cmsg_ptr = (unsigned long)msg_sys->msg_control; + msg_sys->msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT); if (sock->file->f_flags & O_NONBLOCK) flags |= MSG_DONTWAIT; - err = sock_recvmsg(sock, &msg_sys, total_len, flags); + err = (nosec ? sock_recvmsg_nosec : sock_recvmsg)(sock, msg_sys, + total_len, flags); if (err < 0) goto out_freeiov; len = err; if (uaddr != NULL) { err = move_addr_to_user((struct sockaddr *)&addr, - msg_sys.msg_namelen, uaddr, + msg_sys->msg_namelen, uaddr, uaddr_len); if (err < 0) goto out_freeiov; } - err = __put_user((msg_sys.msg_flags & ~MSG_CMSG_COMPAT), + err = __put_user((msg_sys->msg_flags & ~MSG_CMSG_COMPAT), COMPAT_FLAGS(msg)); if (err) goto out_freeiov; if (MSG_CMSG_COMPAT & flags) - err = __put_user((unsigned long)msg_sys.msg_control - cmsg_ptr, + err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr, &msg_compat->msg_controllen); else - err = __put_user((unsigned long)msg_sys.msg_control - cmsg_ptr, + err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr, &msg->msg_controllen); if (err) goto out_freeiov; @@ -2084,21 +2092,150 @@ SYSCALL_DEFINE3(recvmsg, int, fd, struct msghdr __user *, msg, out_freeiov: if (iov != iovstack) sock_kfree_s(sock->sk, iov, iov_size); -out_put: +out: + return err; +} + +/* + * BSD recvmsg interface + */ + +SYSCALL_DEFINE3(recvmsg, int, fd, struct msghdr __user *, msg, + unsigned int, flags) +{ + int fput_needed, err; + struct msghdr msg_sys; + struct socket *sock = sockfd_lookup_light(fd, &err, &fput_needed); + + if (!sock) + goto out; + + err = __sys_recvmsg(sock, msg, &msg_sys, flags, 0); + fput_light(sock->file, fput_needed); out: return err; } -#ifdef __ARCH_WANT_SYS_SOCKETCALL +/* + * Linux recvmmsg interface + */ + +int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen, + unsigned int flags, struct timespec *timeout) +{ + int fput_needed, err, datagrams; + struct socket *sock; + struct mmsghdr __user *entry; + struct msghdr msg_sys; + struct timespec end_time; + + if (timeout && + poll_select_set_timeout(&end_time, timeout->tv_sec, + timeout->tv_nsec)) + return -EINVAL; + + datagrams = 0; + + sock = sockfd_lookup_light(fd, &err, &fput_needed); + if (!sock) + return err; + + err = sock_error(sock->sk); + if (err) + goto out_put; + + entry = mmsg; + + while (datagrams < vlen) { + /* + * No need to ask LSM for more than the first datagram. + */ + err = __sys_recvmsg(sock, (struct msghdr __user *)entry, + &msg_sys, flags, datagrams); + if (err < 0) + break; + err = put_user(err, &entry->msg_len); + if (err) + break; + ++entry; + ++datagrams; + + if (timeout) { + ktime_get_ts(timeout); + *timeout = timespec_sub(end_time, *timeout); + if (timeout->tv_sec < 0) { + timeout->tv_sec = timeout->tv_nsec = 0; + break; + } + + /* Timeout, return less than vlen datagrams */ + if (timeout->tv_nsec == 0 && timeout->tv_sec == 0) + break; + } + + /* Out of band data, return right away */ + if (msg_sys.msg_flags & MSG_OOB) + break; + } + +out_put: + fput_light(sock->file, fput_needed); + if (err == 0) + return datagrams; + + if (datagrams != 0) { + /* + * We may return less entries than requested (vlen) if the + * sock is non block and there aren't enough datagrams... + */ + if (err != -EAGAIN) { + /* + * ... or if recvmsg returns an error after we + * received some datagrams, where we record the + * error to return on the next call or if the + * app asks about it using getsockopt(SO_ERROR). + */ + sock->sk->sk_err = -err; + } + + return datagrams; + } + + return err; +} + +SYSCALL_DEFINE5(recvmmsg, int, fd, struct mmsghdr __user *, mmsg, + unsigned int, vlen, unsigned int, flags, + struct timespec __user *, timeout) +{ + int datagrams; + struct timespec timeout_sys; + + if (!timeout) + return __sys_recvmmsg(fd, mmsg, vlen, flags, NULL); + + if (copy_from_user(&timeout_sys, timeout, sizeof(timeout_sys))) + return -EFAULT; + + datagrams = __sys_recvmmsg(fd, mmsg, vlen, flags, &timeout_sys); + + if (datagrams > 0 && + copy_to_user(timeout, &timeout_sys, sizeof(timeout_sys))) + datagrams = -EFAULT; + + return datagrams; +} + +#ifdef __ARCH_WANT_SYS_SOCKETCALL /* Argument list sizes for sys_socketcall */ #define AL(x) ((x) * sizeof(unsigned long)) -static const unsigned char nargs[19]={ +static const unsigned char nargs[20] = { AL(0),AL(3),AL(3),AL(3),AL(2),AL(3), AL(3),AL(3),AL(4),AL(4),AL(4),AL(6), AL(6),AL(2),AL(5),AL(5),AL(3),AL(3), - AL(4) + AL(4),AL(5) }; #undef AL @@ -2118,7 +2255,7 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args) int err; unsigned int len; - if (call < 1 || call > SYS_ACCEPT4) + if (call < 1 || call > SYS_RECVMMSG) return -EINVAL; len = nargs[call]; @@ -2196,6 +2333,10 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args) case SYS_RECVMSG: err = sys_recvmsg(a0, (struct msghdr __user *)a1, a[2]); break; + case SYS_RECVMMSG: + err = sys_recvmmsg(a0, (struct mmsghdr __user *)a1, a[2], a[3], + (struct timespec __user *)a[4]); + break; case SYS_ACCEPT4: err = sys_accept4(a0, (struct sockaddr __user *)a1, (int __user *)a[2], a[3]); -- cgit v1.2.3-59-g8ed1b