1#define _GNU_SOURCE
 2#include <sys/socket.h>
 3#include <limits.h>
 4#include <errno.h>
 5#include <time.h>
 6#include "syscall.h"
 7
 8#define IS32BIT(x) !((x)+0x80000000ULL>>32)
 9#define CLAMP(x) (int)(IS32BIT(x) ? (x) : 0x7fffffffU+((0ULL+(x))>>63))
10
11hidden void __convert_scm_timestamps(struct msghdr *, socklen_t);
12
13int recvmmsg(int fd, struct mmsghdr *msgvec, unsigned int vlen, unsigned int flags, struct timespec *timeout)
14{
15#if LONG_MAX > INT_MAX
16	struct mmsghdr *mh = msgvec;
17	unsigned int i;
18	for (i = vlen; i; i--, mh++)
19		mh->msg_hdr.__pad1 = mh->msg_hdr.__pad2 = 0;
20#endif
21#ifdef SYS_recvmmsg_time64
22	time_t s = timeout ? timeout->tv_sec : 0;
23	long ns = timeout ? timeout->tv_nsec : 0;
24	int r = __syscall_cp(SYS_recvmmsg_time64, fd, msgvec, vlen, flags,
25			timeout ? ((long long[]){s, ns}) : 0);
26	if (SYS_recvmmsg == SYS_recvmmsg_time64 || r!=-ENOSYS)
27		return __syscall_ret(r);
28	if (vlen > IOV_MAX) vlen = IOV_MAX;
29	socklen_t csize[vlen];
30	for (int i=0; i<vlen; i++) csize[i] = msgvec[i].msg_hdr.msg_controllen;
31	r = __syscall_cp(SYS_recvmmsg, fd, msgvec, vlen, flags,
32		timeout ? ((long[]){CLAMP(s), ns}) : 0);
33	for (int i=0; i<r; i++)
34		__convert_scm_timestamps(&msgvec[i].msg_hdr, csize[i]);
35	return __syscall_ret(r);
36#else
37	return syscall_cp(SYS_recvmmsg, fd, msgvec, vlen, flags, timeout);
38#endif
39}