mir/ovs
2
0
Fork 0
mirror of https://github.com/openvswitch/ovs synced 2025-09-03 15:55:19 +00:00
Code Issues Releases Wiki Activity

socket-util: Introduce emulation and wrapper for recvmmsg().

Browse Source 
Not every system will have recvmmsg(), so introduce compatibility code
that will allow it to be used blindly from the rest of the tree.

This assumes that recvmmsg() and sendmmsg() are either both present or
both absent in system libraries and headers.

CC: Yi Yang <yangyi01@inspur.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>
This commit is contained in:
Ben Pfaff
2019-12-17 12:38:37 -08:00
parent b926f577aa
commit b90189841f
3 changed files with 74 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

56
lib/socket-util.c
View File

@@ -1283,3 +1283,59 @@ wrap_sendmmsg(int fd, struct mmsghdr *msgs, unsigned int n, unsigned int flags)
}
#endif
#endif
#ifndef _WIN32 /* Avoid using recvmsg on Windows entirely. */
static int
emulate_recvmmsg(int fd, struct mmsghdr *msgs, unsigned int n,
int flags, struct timespec *timeout OVS_UNUSED)
{
ovs_assert(!timeout); /* XXX not emulated */
bool waitforone = flags & MSG_WAITFORONE;
flags &= ~MSG_WAITFORONE;
for (unsigned int i = 0; i < n; i++) {
ssize_t retval = recvmsg(fd, &msgs[i].msg_hdr, flags);
if (retval < 0) {
return i ? i : retval;
}
msgs[i].msg_len = retval;
if (waitforone) {
flags |= MSG_DONTWAIT;
}
}
return n;
}
#ifndef HAVE_SENDMMSG
int
recvmmsg(int fd, struct mmsghdr *msgs, unsigned int n,
int flags, struct timespec *timeout)
{
return emulate_recvmmsg(fd, msgs, n, flags, timeout);
}
#else
/* recvmmsg was redefined in lib/socket-util.c, should undef recvmmsg here
* to avoid recursion */
#undef recvmmsg
int
wrap_recvmmsg(int fd, struct mmsghdr *msgs, unsigned int n,
int flags, struct timespec *timeout)
{
ovs_assert(!timeout); /* XXX not emulated */
static bool recvmmsg_broken = false;
if (!recvmmsg_broken) {
int save_errno = errno;
int retval = recvmmsg(fd, msgs, n, flags, timeout);
if (retval >= 0 || errno != ENOSYS) {
return retval;
}
recvmmsg_broken = true;
errno = save_errno;
}
return emulate_recvmmsg(fd, msgs, n, flags, timeout);
}
#endif
#endif