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#define _GNU_SOURCE
#include <sys/socket.h>
#include <limits.h>
#include <errno.h>
#include "syscall.h"
int sendmmsg(int fd, struct mmsghdr *msgvec, unsigned int vlen, unsigned int flags)
{
#if LONG_MAX > INT_MAX
/* Can't use the syscall directly because the kernel has the wrong
* idea for the types of msg_iovlen, msg_controllen, and cmsg_len,
* and the cmsg blocks cannot be modified in-place. */
int i;
if (vlen > IOV_MAX) vlen = IOV_MAX; /* This matches the kernel. */
for (i=0; i<vlen; i++) {
/* As an unfortunate inconsistency, the sendmmsg API uses
* unsigned int for the resulting msg_len, despite sendmsg
* returning ssize_t. However Linux limits the total bytes
* sent by sendmsg to INT_MAX, so the assignment is safe. */
ssize_t r = sendmsg(fd, &msgvec[i].msg_hdr, flags);
if (r < 0) goto error;
msgvec[i].msg_len = r;
}
error:
return i ? i : -1;
#else
return syscall_cp(SYS_sendmmsg, fd, msgvec, vlen, flags);
#endif
}
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