diff options
Diffstat (limited to 'resolv')
| -rw-r--r-- | resolv/res_send.c | 100 |
1 files changed, 83 insertions, 17 deletions
diff --git a/resolv/res_send.c b/resolv/res_send.c index a001c1e..0b5bc91 100644 --- a/resolv/res_send.c +++ b/resolv/res_send.c @@ -1013,8 +1013,9 @@ send_dg(res_state statp, seconds /= statp->nscount; if (seconds <= 0) seconds = 1; - bool single_request = (statp->options & RES_SNGLKUP) != 0; bool single_request_reopen = (statp->options & RES_SNGLKUPREOP) != 0; + bool single_request = (((statp->options & RES_SNGLKUP) != 0) + | single_request_reopen); int save_gotsomewhere = *gotsomewhere; int retval; @@ -1100,24 +1101,89 @@ send_dg(res_state statp, } __set_errno (0); if (pfd[0].revents & POLLOUT) { - ssize_t sr; - if (nwritten != 0) - sr = send (pfd[0].fd, buf2, buflen2, MSG_NOSIGNAL); - else - sr = send (pfd[0].fd, buf, buflen, MSG_NOSIGNAL); +#ifndef __ASSUME_SENDMMSG + static int have_sendmmsg; +#else +# define have_sendmmsg 1 +#endif + if (have_sendmmsg >= 0 && nwritten == 0 && buf2 != NULL + && !single_request) + { + struct iovec iov[2]; + struct mmsghdr reqs[2]; + reqs[0].msg_hdr.msg_name = NULL; + reqs[0].msg_hdr.msg_namelen = 0; + reqs[0].msg_hdr.msg_iov = &iov[0]; + reqs[0].msg_hdr.msg_iovlen = 1; + iov[0].iov_base = (void *) buf; + iov[0].iov_len = buflen; + reqs[0].msg_hdr.msg_control = NULL; + reqs[0].msg_hdr.msg_controllen = 0; + + reqs[1].msg_hdr.msg_name = NULL; + reqs[1].msg_hdr.msg_namelen = 0; + reqs[1].msg_hdr.msg_iov = &iov[1]; + reqs[1].msg_hdr.msg_iovlen = 1; + iov[1].iov_base = (void *) buf2; + iov[1].iov_len = buflen2; + reqs[1].msg_hdr.msg_control = NULL; + reqs[1].msg_hdr.msg_controllen = 0; + + int ndg = sendmmsg (pfd[0].fd, reqs, 2, MSG_NOSIGNAL); + if (__builtin_expect (ndg == 2, 1)) + { + assert (reqs[0].msg_len == buflen); + assert (reqs[1].msg_len == buflen2); - if (sr != buflen) { - if (errno == EINTR || errno == EAGAIN) - goto recompute_resend; - Perror(statp, stderr, "send", errno); + pfd[0].events = POLLIN; + nwritten += 2; + } + else if (ndg == 1 && reqs[0].msg_len == buflen) + goto just_one; + else if (errno == EINTR || errno == EAGAIN) + goto recompute_resend; + else + { +#ifndef __ASSUME_SENDMMSG + if (have_sendmmsg == 0) + { + if (errno == ENOSYS) + { + have_sendmmsg = -1; + goto try_send; + } + have_sendmmsg = 1; + } +#endif + + Perror(statp, stderr, "sendmmsg", errno); goto err_out; - } - if (nwritten != 0 || buf2 == NULL - || single_request || single_request_reopen) - pfd[0].events = POLLIN; + } + } else - pfd[0].events = POLLIN | POLLOUT; - ++nwritten; + { + ssize_t sr; +#ifndef __ASSUME_SENDMMSG + try_send: +#endif + if (nwritten != 0) + sr = send (pfd[0].fd, buf2, buflen2, MSG_NOSIGNAL); + else + sr = send (pfd[0].fd, buf, buflen, MSG_NOSIGNAL); + + if (sr != buflen) { + if (errno == EINTR || errno == EAGAIN) + goto recompute_resend; + Perror(statp, stderr, "send", errno); + goto err_out; + } + just_one: + if (nwritten != 0 || buf2 == NULL || single_request) + pfd[0].events = POLLIN; + else + pfd[0].events = POLLIN | POLLOUT; + ++nwritten; + } goto wait; } else if (pfd[0].revents & POLLIN) { int *thisanssizp; @@ -1327,7 +1393,7 @@ send_dg(res_state statp, recvresp2 = 1; /* Repeat waiting if we have a second answer to arrive. */ if ((recvresp1 & recvresp2) == 0) { - if (single_request || single_request_reopen) { + if (single_request) { pfd[0].events = POLLOUT; if (single_request_reopen) { __res_iclose (statp, false); |