-/* Returns the total of the 'iov_len' members of the 'n_iovs' in 'iovs'.
- * The caller must ensure that the total does not exceed SIZE_MAX. */
-size_t
-iovec_len(const struct iovec iovs[], size_t n_iovs)
-{
- size_t len = 0;
- size_t i;
-
- for (i = 0; i < n_iovs; i++) {
- len += iovs[i].iov_len;
- }
- return len;
-}
-
-/* Returns true if all of the 'n_iovs' iovecs in 'iovs' have length zero. */
-bool
-iovec_is_empty(const struct iovec iovs[], size_t n_iovs)
-{
- size_t i;
-
- for (i = 0; i < n_iovs; i++) {
- if (iovs[i].iov_len) {
- return false;
- }
- }
- return true;
-}
-
-/* Sends the 'n_iovs' iovecs of data in 'iovs' and the 'n_fds' file descriptors
- * in 'fds' on Unix domain socket 'sock'. Returns the number of bytes
- * successfully sent or -1 if an error occurred. On error, sets errno
- * appropriately. */
-int
-send_iovec_and_fds(int sock,
- const struct iovec *iovs, size_t n_iovs,
- const int fds[], size_t n_fds)
-{
- ovs_assert(sock >= 0);
- if (n_fds > 0) {
- union {
- struct cmsghdr cm;
- char control[CMSG_SPACE(SOUTIL_MAX_FDS * sizeof *fds)];
- } cmsg;
- struct msghdr msg;
-
- ovs_assert(!iovec_is_empty(iovs, n_iovs));
- ovs_assert(n_fds <= SOUTIL_MAX_FDS);
-
- memset(&cmsg, 0, sizeof cmsg);
- cmsg.cm.cmsg_len = CMSG_LEN(n_fds * sizeof *fds);
- cmsg.cm.cmsg_level = SOL_SOCKET;
- cmsg.cm.cmsg_type = SCM_RIGHTS;
- memcpy(CMSG_DATA(&cmsg.cm), fds, n_fds * sizeof *fds);
-
- msg.msg_name = NULL;
- msg.msg_namelen = 0;
- msg.msg_iov = CONST_CAST(struct iovec *, iovs);
- msg.msg_iovlen = n_iovs;
- msg.msg_control = &cmsg.cm;
- msg.msg_controllen = CMSG_SPACE(n_fds * sizeof *fds);
- msg.msg_flags = 0;
-
- return sendmsg(sock, &msg, 0);
- } else {
- return writev(sock, iovs, n_iovs);
- }
-}
-
-/* Sends the 'n_iovs' iovecs of data in 'iovs' and the 'n_fds' file descriptors
- * in 'fds' on Unix domain socket 'sock'. If 'skip_bytes' is nonzero, then the
- * first 'skip_bytes' of data in the iovecs are not sent, and none of the file
- * descriptors are sent. The function continues to retry sending until an
- * error (other than EINTR) occurs or all the data and fds are sent.
- *
- * Returns 0 if all the data and fds were successfully sent, otherwise a
- * positive errno value. Regardless of success, stores the number of bytes
- * sent (always at least 'skip_bytes') in '*bytes_sent'. (If at least one byte
- * is sent, then all the fds have been sent.)
- *
- * 'skip_bytes' must be less than or equal to iovec_len(iovs, n_iovs). */
-int
-send_iovec_and_fds_fully(int sock,
- const struct iovec iovs[], size_t n_iovs,
- const int fds[], size_t n_fds,
- size_t skip_bytes, size_t *bytes_sent)
-{
- *bytes_sent = 0;
- while (n_iovs > 0) {
- int retval;
-
- if (skip_bytes) {
- retval = skip_bytes;
- skip_bytes = 0;
- } else if (!*bytes_sent) {
- retval = send_iovec_and_fds(sock, iovs, n_iovs, fds, n_fds);
- } else {
- retval = writev(sock, iovs, n_iovs);
- }
-
- if (retval > 0) {
- *bytes_sent += retval;
- while (retval > 0) {
- const uint8_t *base = iovs->iov_base;
- size_t len = iovs->iov_len;
-
- if (retval < len) {
- size_t sent;
- int error;
-
- error = write_fully(sock, base + retval, len - retval,
- &sent);
- *bytes_sent += sent;
- retval += sent;
- if (error) {
- return error;
- }
- }
- retval -= len;
- iovs++;
- n_iovs--;
- }
- } else if (retval == 0) {
- if (iovec_is_empty(iovs, n_iovs)) {
- break;
- }
- VLOG_WARN("send returned 0");
- return EPROTO;
- } else if (errno != EINTR) {
- return errno;
- }
- }
-
- return 0;
-}
-
-/* Sends the 'n_iovs' iovecs of data in 'iovs' and the 'n_fds' file descriptors
- * in 'fds' on Unix domain socket 'sock'. The function continues to retry
- * sending until an error (other than EAGAIN or EINTR) occurs or all the data
- * and fds are sent. Upon EAGAIN, the function blocks until the socket is
- * ready for more data.
- *
- * Returns 0 if all the data and fds were successfully sent, otherwise a
- * positive errno value. */
-int
-send_iovec_and_fds_fully_block(int sock,
- const struct iovec iovs[], size_t n_iovs,
- const int fds[], size_t n_fds)
-{
- size_t sent = 0;
-
- for (;;) {
- int error;
-
- error = send_iovec_and_fds_fully(sock, iovs, n_iovs,
- fds, n_fds, sent, &sent);
- if (error != EAGAIN) {
- return error;
- }
- poll_fd_wait(sock, POLLOUT);
- poll_block();
- }
-}
-
-/* Attempts to receive from Unix domain socket 'sock' up to 'size' bytes of
- * data into 'data' and up to SOUTIL_MAX_FDS file descriptors into 'fds'.
- *
- * - Upon success, returns the number of bytes of data copied into 'data'
- * and stores the number of received file descriptors into '*n_fdsp'.
- *
- * - On failure, returns a negative errno value and stores 0 in
- * '*n_fdsp'.
- *
- * - On EOF, returns 0 and stores 0 in '*n_fdsp'. */
-int
-recv_data_and_fds(int sock,
- void *data, size_t size,
- int fds[SOUTIL_MAX_FDS], size_t *n_fdsp)
-{
- union {
- struct cmsghdr cm;
- char control[CMSG_SPACE(SOUTIL_MAX_FDS * sizeof *fds)];
- } cmsg;
- struct msghdr msg;
- int retval;
- struct cmsghdr *p;
- size_t i;
-
- *n_fdsp = 0;
-
- do {
- struct iovec iov;
-
- iov.iov_base = data;
- iov.iov_len = size;
-
- msg.msg_name = NULL;
- msg.msg_namelen = 0;
- msg.msg_iov = &iov;
- msg.msg_iovlen = 1;
- msg.msg_control = &cmsg.cm;
- msg.msg_controllen = sizeof cmsg.control;
- msg.msg_flags = 0;
-
- retval = recvmsg(sock, &msg, 0);
- } while (retval < 0 && errno == EINTR);
- if (retval <= 0) {
- return retval < 0 ? -errno : 0;
- }
-
- for (p = CMSG_FIRSTHDR(&msg); p; p = CMSG_NXTHDR(&msg, p)) {
- if (p->cmsg_level != SOL_SOCKET || p->cmsg_type != SCM_RIGHTS) {
- VLOG_ERR("unexpected control message %d:%d",
- p->cmsg_level, p->cmsg_type);
- goto error;
- } else if (*n_fdsp) {
- VLOG_ERR("multiple SCM_RIGHTS received");
- goto error;
- } else {
- size_t n_fds = (p->cmsg_len - CMSG_LEN(0)) / sizeof *fds;
- const int *fds_data = ALIGNED_CAST(const int *, CMSG_DATA(p));
-
- ovs_assert(n_fds > 0);
- if (n_fds > SOUTIL_MAX_FDS) {
- VLOG_ERR("%"PRIuSIZE" fds received but only %d supported",
- n_fds, SOUTIL_MAX_FDS);
- for (i = 0; i < n_fds; i++) {
- close(fds_data[i]);
- }
- goto error;
- }
-
- *n_fdsp = n_fds;
- memcpy(fds, fds_data, n_fds * sizeof *fds);
- }
- }
-
- return retval;
-
-error:
- for (i = 0; i < *n_fdsp; i++) {
- close(fds[i]);
- }
- *n_fdsp = 0;
- return EPROTO;
-}
-