| 1 | #define _GNU_SOURCE |
| 2 | #include <sys/socket.h> |
| 3 | #include <limits.h> |
| 4 | #include <errno.h> |
| 5 | #include "syscall.h" |
| 6 | |
| 7 | int sendmmsg(int fd, struct mmsghdr *msgvec, unsigned int vlen, unsigned int flags) |
| 8 | { |
| 9 | #if LONG_MAX > INT_MAX |
| 10 | /* Can't use the syscall directly because the kernel has the wrong |
| 11 | * idea for the types of msg_iovlen, msg_controllen, and cmsg_len, |
| 12 | * and the cmsg blocks cannot be modified in-place. */ |
| 13 | int i; |
| 14 | if (vlen > IOV_MAX) vlen = IOV_MAX; /* This matches the kernel. */ |
| 15 | if (!vlen) return 0; |
| 16 | for (i=0; i<vlen; i++) { |
| 17 | /* As an unfortunate inconsistency, the sendmmsg API uses |
| 18 | * unsigned int for the resulting msg_len, despite sendmsg |
| 19 | * returning ssize_t. However Linux limits the total bytes |
| 20 | * sent by sendmsg to INT_MAX, so the assignment is safe. */ |
| 21 | ssize_t r = sendmsg(fd, &msgvec[i].msg_hdr, flags); |
| 22 | if (r < 0) goto error; |
| 23 | msgvec[i].msg_len = r; |
| 24 | } |
| 25 | error: |
| 26 | return i ? i : -1; |
| 27 | #else |
| 28 | return syscall_cp(SYS_sendmmsg, fd, msgvec, vlen, flags); |
| 29 | #endif |
| 30 | } |