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/* ISC license. */
#include <skalibs/nonposix.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <string.h>
#include <stdint.h>
#include <unistd.h>
#include <errno.h>
#include <skalibs/uint16.h>
#include <skalibs/uint32.h>
#include <skalibs/disize.h>
#include <skalibs/allreadwrite.h>
#include <skalibs/genalloc.h>
#include <skalibs/djbunix.h>
#include <skalibs/unixmessage.h>
#include <skalibs/posixishard.h>
union aligner_u
{
struct cmsghdr cmsghdr ;
int i ;
} ;
/*
XXX: sendmsg/recvmsg is badly, badly specified.
XXX: We assume ancillary data is attached to the first byte.
*/
int unixmessage_sender_flush (unixmessage_sender *b)
{
disize last = { .left = b->data.len, .right = genalloc_len(int, &b->fds) } ;
disize *offsets = genalloc_s(disize, &b->offsets) ;
size_t n = genalloc_len(disize, &b->offsets) ;
ssize_t r ;
if (b->shorty) /* we had a short write, gotta send the remainder first */
{
disize *next = b->head+1 < n ? offsets + b->head+1 : &last ;
size_t len = next->left - offsets[b->head].left ;
if (b->shorty <= len)
r = fd_write(b->fd, b->data.s + offsets[b->head].left + (len - b->shorty), b->shorty) ;
else
{
size_t nfds = next->right - offsets[b->head].right ;
char pack[6] ;
struct iovec v[2] =
{
{ .iov_base = pack + 6 - (b->shorty - len), .iov_len = b->shorty - len },
{ .iov_base = b->data.s + offsets[b->head].left, .iov_len = len }
} ;
uint32_pack_big(pack, (uint32_t)len) ;
uint16_pack_big(pack + 4, (uint16_t)nfds) ;
r = fd_writev(b->fd, v, 2) ;
}
if (r <= 0) return 0 ;
b->shorty -= r ;
if (b->shorty) return (errno = EWOULDBLOCK, 0) ;
}
for (; b->head < n ; b->head++)
{
disize *next = b->head+1 < n ? offsets + b->head+1 : &last ;
size_t len = next->left - offsets[b->head].left ;
size_t nfds = next->right - offsets[b->head].right ;
char pack[6] ;
struct iovec v[2] =
{
{ .iov_base = pack, .iov_len = 6 },
{ .iov_base = b->data.s + offsets[b->head].left, .iov_len = len }
} ;
union aligner_u ancilbuf[1 + CMSG_SPACE(nfds * sizeof(int)) / sizeof(union aligner_u)] ;
struct msghdr hdr =
{
.msg_name = 0,
.msg_namelen = 0,
.msg_iov = v,
.msg_iovlen = 2,
.msg_control = nfds ? ancilbuf : 0,
.msg_controllen = nfds ? CMSG_SPACE(nfds * sizeof(int)) : 0
} ;
uint32_pack_big(pack, (uint32_t)len) ;
uint16_pack_big(pack + 4, (uint16_t)nfds) ;
if (nfds)
{
struct cmsghdr *cp = CMSG_FIRSTHDR(&hdr) ;
size_t i = 0 ;
memset(hdr.msg_control, 0, hdr.msg_controllen) ;
cp->cmsg_level = SOL_SOCKET ;
cp->cmsg_type = SCM_RIGHTS ;
cp->cmsg_len = CMSG_LEN(nfds * sizeof(int)) ;
for (; i < nfds ; i++)
{
int fd = genalloc_s(int, &b->fds)[offsets[b->head].right + i] ;
((int *)CMSG_DATA(cp))[i] = fd < 0 ? -(fd+1) : fd ;
}
}
do r = sendmsg(b->fd, &hdr, MSG_NOSIGNAL) ;
while (r < 0 && errno == EINTR) ;
if (r <= 0) return 0 ;
if (nfds)
{
size_t i = 0 ;
for (; i < nfds ; i++)
{
int fd = genalloc_s(int, &b->fds)[offsets[b->head].right + i] ;
if (fd < 0) (*b->closecb)(-(fd+1), b->closecbdata) ;
}
}
if ((size_t)r < 6 + len)
{
b->shorty = 6 + len - r ;
return (errno = EWOULDBLOCK, 0) ;
}
}
b->data.len = 0 ;
genalloc_setlen(int, &b->fds, 0) ;
genalloc_setlen(disize, &b->offsets, 0) ;
b->head = 0 ;
return 1 ;
}
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