linux/include/net/compat.h
Arnaldo Carvalho de Melo a2e2725541 net: Introduce recvmmsg socket syscall
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 <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-12 23:40:10 -07:00

58 lines
1.9 KiB
C

#ifndef NET_COMPAT_H
#define NET_COMPAT_H
struct sock;
#if defined(CONFIG_COMPAT)
#include <linux/compat.h>
struct compat_msghdr {
compat_uptr_t msg_name; /* void * */
compat_int_t msg_namelen;
compat_uptr_t msg_iov; /* struct compat_iovec * */
compat_size_t msg_iovlen;
compat_uptr_t msg_control; /* void * */
compat_size_t msg_controllen;
compat_uint_t msg_flags;
};
struct compat_mmsghdr {
struct compat_msghdr msg_hdr;
compat_uint_t msg_len;
};
struct compat_cmsghdr {
compat_size_t cmsg_len;
compat_int_t cmsg_level;
compat_int_t cmsg_type;
};
extern int compat_sock_get_timestamp(struct sock *, struct timeval __user *);
extern int compat_sock_get_timestampns(struct sock *, struct timespec __user *);
#else /* defined(CONFIG_COMPAT) */
#define compat_msghdr msghdr /* to avoid compiler warnings */
#endif /* defined(CONFIG_COMPAT) */
extern int get_compat_msghdr(struct msghdr *, struct compat_msghdr __user *);
extern int verify_compat_iovec(struct msghdr *, struct iovec *, struct sockaddr *, int);
extern asmlinkage long compat_sys_sendmsg(int,struct compat_msghdr __user *,unsigned);
extern asmlinkage long compat_sys_recvmsg(int,struct compat_msghdr __user *,unsigned);
extern asmlinkage long compat_sys_recvmmsg(int, struct compat_mmsghdr __user *,
unsigned, unsigned,
struct timespec __user *);
extern asmlinkage long compat_sys_getsockopt(int, int, int, char __user *, int __user *);
extern int put_cmsg_compat(struct msghdr*, int, int, int, void *);
extern int cmsghdr_from_user_compat_to_kern(struct msghdr *, struct sock *, unsigned char *, int);
extern int compat_mc_setsockopt(struct sock *, int, int, char __user *, unsigned int,
int (*)(struct sock *, int, int, char __user *, unsigned int));
extern int compat_mc_getsockopt(struct sock *, int, int, char __user *,
int __user *, int (*)(struct sock *, int, int, char __user *,
int __user *));
#endif /* NET_COMPAT_H */