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/compat.c | 33 ++++++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) (limited to 'net/compat.c') diff --git a/net/compat.c b/net/compat.c index a407c3addba..e13f5256fd2 100644 --- a/net/compat.c +++ b/net/compat.c @@ -727,10 +727,10 @@ EXPORT_SYMBOL(compat_mc_getsockopt); /* Argument list sizes for compat_sys_socketcall */ #define AL(x) ((x) * sizeof(u32)) -static unsigned char nas[19]={AL(0),AL(3),AL(3),AL(3),AL(2),AL(3), +static unsigned char nas[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 asmlinkage long compat_sys_sendmsg(int fd, struct compat_msghdr __user *msg, unsigned flags) @@ -755,13 +755,36 @@ asmlinkage long compat_sys_recvfrom(int fd, void __user *buf, size_t len, return sys_recvfrom(fd, buf, len, flags | MSG_CMSG_COMPAT, addr, addrlen); } +asmlinkage long compat_sys_recvmmsg(int fd, struct compat_mmsghdr __user *mmsg, + unsigned vlen, unsigned int flags, + struct timespec __user *timeout) +{ + int datagrams; + struct timespec ktspec; + struct compat_timespec __user *utspec = + (struct compat_timespec __user *)timeout; + + if (get_user(ktspec.tv_sec, &utspec->tv_sec) || + get_user(ktspec.tv_nsec, &utspec->tv_nsec)) + return -EFAULT; + + datagrams = __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen, + flags | MSG_CMSG_COMPAT, &ktspec); + if (datagrams > 0 && + (put_user(ktspec.tv_sec, &utspec->tv_sec) || + put_user(ktspec.tv_nsec, &utspec->tv_nsec))) + datagrams = -EFAULT; + + return datagrams; +} + asmlinkage long compat_sys_socketcall(int call, u32 __user *args) { int ret; u32 a[6]; u32 a0, a1; - if (call < SYS_SOCKET || call > SYS_ACCEPT4) + if (call < SYS_SOCKET || call > SYS_RECVMMSG) return -EINVAL; if (copy_from_user(a, args, nas[call])) return -EFAULT; @@ -823,6 +846,10 @@ asmlinkage long compat_sys_socketcall(int call, u32 __user *args) case SYS_RECVMSG: ret = compat_sys_recvmsg(a0, compat_ptr(a1), a[2]); break; + case SYS_RECVMMSG: + ret = compat_sys_recvmmsg(a0, compat_ptr(a1), a[2], a[3], + compat_ptr(a[4])); + break; case SYS_ACCEPT4: ret = sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]); break; -- cgit v1.2.3