1 #include <sys/socket.h>
2 #include <limits.h>
3 #include <string.h>
4 #include <errno.h>
5 #include "syscall.h"
6
sendmsg(int fd,const struct msghdr * msg,int flags)7 ssize_t sendmsg(int fd, const struct msghdr *msg, int flags)
8 {
9 #if LONG_MAX > INT_MAX
10 struct msghdr h;
11 /* Kernels before 2.6.38 set SCM_MAX_FD to 255, allocate enough
12 * space to support an SCM_RIGHTS ancillary message with 255 fds.
13 * Kernels since 2.6.38 set SCM_MAX_FD to 253. */
14 struct cmsghdr chbuf[CMSG_SPACE(255*sizeof(int))/sizeof(struct cmsghdr)+1], *c;
15 if (msg) {
16 h = *msg;
17 h.__pad1 = h.__pad2 = 0;
18 msg = &h;
19 if (h.msg_controllen) {
20 if (h.msg_controllen > sizeof chbuf) {
21 errno = ENOMEM;
22 return -1;
23 }
24 memcpy(chbuf, h.msg_control, h.msg_controllen);
25 h.msg_control = chbuf;
26 for (c=CMSG_FIRSTHDR(&h); c; c=CMSG_NXTHDR(&h,c))
27 c->__pad1 = 0;
28 }
29 }
30 #endif
31 return socketcall_cp(sendmsg, fd, msg, flags, 0, 0, 0);
32 }
33