/* not return sent size, but success: 0 or failure: -1 */
static int py_send_nlmsg(int fd, struct nlmsghdr *nlh, int cdata)
{
struct msghdr msg = {0};
struct iovec iov;
size_t cmsglen = CMSG_SPACE(sizeof(int));
char control[CMSG_SPACE(sizeof(int))];
struct cmsghdr *cmsg;
ssize_t nsent;
iov.iov_base = nlh;
iov.iov_len = nlh->nlmsg_len;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
if (cdata) {
msg.msg_control = control;
msg.msg_controllen = cmsglen;
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
put_unaligned_int(CMSG_DATA(cmsg), cdata);
}
nsent = sendmsg(fd, &msg, MSG_NOSIGNAL);
if (nsent == -1)
return -1;
if (nsent != nlh->nlmsg_len) {
errno = EMSGSIZE;
return -1;
}
return 0;
}
/* at least 1 byte must be sent! */
int send_fd(int unix_socket, void* data, int data_len, int fd)
{
struct msghdr msg;
struct iovec iov[1];
int ret;
#ifdef HAVE_MSGHDR_MSG_CONTROL
struct cmsghdr* cmsg;
/* make sure msg_control will point to properly aligned data */
union {
struct cmsghdr cm;
char control[CMSG_SPACE(sizeof(fd))];
}control_un;
msg.msg_control=control_un.control;
/* openbsd doesn't like "more space", msg_controllen must not
* include the end padding */
msg.msg_controllen=CMSG_LEN(sizeof(fd));
cmsg=CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
put_unaligned_int(CMSG_DATA(cmsg), fd);
msg.msg_flags=0;
#else
msg.msg_accrights=(caddr_t) &fd;
msg.msg_accrightslen=sizeof(fd);
#endif
msg.msg_name=0;
msg.msg_namelen=0;
iov[0].iov_base=data;
iov[0].iov_len=data_len;
msg.msg_iov=iov;
msg.msg_iovlen=1;
again:
ret=sendmsg(unix_socket, &msg, 0);
if (ret<0){
if (errno==EINTR) goto again;
if (errno==EAGAIN || errno==EWOULDBLOCK) {
LM_ERR("sendmsg would block on %d: %s\n",
unix_socket, strerror(errno));
} else {
LM_CRIT("sendmsg failed on %d: %s\n",
unix_socket, strerror(errno));
}
}
return ret;
}
