| #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. */ |
| if (!vlen) return 0; |
| 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 |
| } |
