mirror of
https://github.com/isc-projects/bind9.git
synced 2026-02-26 03:11:56 -05:00
deal with partial writes correctly
This commit is contained in:
Michael Graff
parent
ad4f276061
commit
3467456ae4
1 changed files with 79 additions and 68 deletions
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@ -188,10 +188,12 @@ static void internal_connect(isc_task_t *, isc_event_t *);
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static void internal_recv(isc_task_t *, isc_event_t *);
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static void internal_send(isc_task_t *, isc_event_t *);
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static void process_cmsg(isc_socket_t *, struct msghdr *, isc_socketevent_t *);
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static int build_msghdr_send(isc_socketevent_t *, struct msghdr *,
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struct iovec *, unsigned int maxiov);
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static int build_msghdr_recv(isc_socketevent_t *, struct msghdr *,
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struct iovec *, unsigned int maxiov);
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static int build_msghdr_send(isc_socket_t *, isc_socketevent_t *,
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struct msghdr *, struct iovec *, unsigned int,
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size_t *);
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static int build_msghdr_recv(isc_socket_t *, isc_socketevent_t *,
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struct msghdr *, struct iovec *, unsigned int,
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unsigned int *);
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#define SELECT_POKE_SHUTDOWN (-1)
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#define SELECT_POKE_NOTHING (-2)
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@ -303,25 +305,50 @@ process_cmsg(isc_socket_t *sock, struct msghdr *msg, isc_socketevent_t *dev)
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* on the buffer linked list for this function to be meaningful.
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*/
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static int
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build_msghdr_send(isc_socketevent_t *dev, struct msghdr *msg,
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struct iovec *iov, unsigned int maxiov)
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build_msghdr_send(isc_socket_t *sock, isc_socketevent_t *dev,
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struct msghdr *msg, struct iovec *iov, unsigned int maxiov,
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size_t *write_countp)
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{
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unsigned int iovcount;
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isc_buffer_t *buffer;
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isc_region_t used;
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size_t write_count;
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size_t skip_count;
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memset(msg, 0, sizeof (struct msghdr));
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if (sock->type == isc_sockettype_udp) {
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msg->msg_name = (void *)&dev->address.type.sa;
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msg->msg_namelen = dev->address.length;
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}
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buffer = ISC_LIST_HEAD(dev->bufferlist);
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write_count = 0;
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skip_count = 0;
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/*
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* Single buffer I/O?
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* Single buffer I/O? Skip what we've done so far in this region.
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*/
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if (buffer == NULL) {
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iov[0].iov_base = (void *)dev->region.base;
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iov[0].iov_len = dev->region.length;
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write_count = dev->region.length - dev->n;
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iov[0].iov_base = (void *)(dev->region.base + dev->n);
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iov[0].iov_len = write_count;
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msg->msg_iov = iov;
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msg->msg_iovlen = 1;
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return (0);
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goto config;
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}
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/*
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* Multibuffer I/O.
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* Skip the data in the buffer list that we have already written.
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*/
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while (buffer != NULL) {
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isc_buffer_used(buffer, &used);
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if (skip_count < used.length)
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break;
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skip_count -= used.length;
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buffer = ISC_LIST_NEXT(buffer, link);
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}
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iovcount = 0;
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@ -330,9 +357,13 @@ build_msghdr_send(isc_socketevent_t *dev, struct msghdr *msg,
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return (-1);
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isc_buffer_used(buffer, &used);
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if (used.length > 0) {
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iov[iovcount].iov_base = (void *)used.base;
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iov[iovcount].iov_len = used.length;
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iov[iovcount].iov_base = (void *)(used.base
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+ skip_count);
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iov[iovcount].iov_len = used.length - skip_count;
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write_count += (used.length - skip_count);
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skip_count = 0;
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iovcount++;
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}
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buffer = ISC_LIST_NEXT(buffer, link);
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@ -341,9 +372,37 @@ build_msghdr_send(isc_socketevent_t *dev, struct msghdr *msg,
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msg->msg_iov = iov;
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msg->msg_iovlen = iovcount;
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config:
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#ifdef ISC_NET_BSD44MSGHDR
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msg->msg_control = NULL;
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msg->msg_controllen = 0;
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msg->msg_flags = 0;
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#else
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msg->msg_accrights = NULL;
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msg->msg_accrightslen = 0;
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#endif
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if (write_countp != NULL)
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*write_countp = write_count;
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return (0);
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}
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static void
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set_dev_address(isc_sockaddr_t *address, isc_socket_t *sock,
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isc_socketevent_t *dev)
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{
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if (sock->type == isc_sockettype_udp) {
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if (address != NULL)
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dev->address = *address;
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else
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dev->address = sock->address;
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} else if (sock->type == isc_sockettype_tcp) {
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INSIST(address == NULL);
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dev->address = sock->address;
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}
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}
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static isc_socketevent_t *
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allocate_socketevent(isc_socket_t *sock, isc_eventtype_t eventtype,
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isc_taskaction_t action, void *arg)
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@ -1199,27 +1258,8 @@ internal_send(isc_task_t *me, isc_event_t *ev)
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* It must be a write request. Try to satisfy it as best
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* we can.
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*/
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write_count = dev->region.length - dev->n;
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iov[0].iov_base = (void *)(dev->region.base + dev->n);
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iov[0].iov_len = write_count;
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memset(&msghdr, 0, sizeof (msghdr));
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if (sock->type == isc_sockettype_udp) {
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msghdr.msg_name = (void *)&dev->address.type.sa;
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msghdr.msg_namelen = dev->address.length;
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}
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msghdr.msg_iov = iov;
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msghdr.msg_iovlen = 1;
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#ifdef ISC_NET_BSD44MSGHDR
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msghdr.msg_control = NULL;
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msghdr.msg_controllen = 0;
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msghdr.msg_flags = 0;
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#else
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msghdr.msg_accrights = NULL;
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msghdr.msg_accrightslen = 0;
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#endif
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build_msghdr_send(sock, dev, &msghdr, iov,
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ISC_SOCKET_MAXSCATTERGATHER, &write_count);
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cc = sendmsg(sock->fd, &msghdr, 0);
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@ -1917,6 +1957,7 @@ isc_socket_sendto(isc_socket_t *sock, isc_region_t *region,
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isc_boolean_t was_empty;
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struct msghdr msghdr;
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struct iovec iov[ISC_SOCKET_MAXSCATTERGATHER];
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size_t write_count;
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REQUIRE(VALID_SOCKET(sock));
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REQUIRE(region != NULL);
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@ -1935,52 +1976,22 @@ isc_socket_sendto(isc_socket_t *sock, isc_region_t *region,
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UNLOCK(&sock->lock);
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return (ISC_R_NOMEMORY);
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}
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ISC_LINK_INIT(dev, link);
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ISC_LIST_INIT(dev->bufferlist);
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dev->result = ISC_R_SUCCESS;
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dev->minimum = region->length;
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dev->n = 0;
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dev->region = *region;
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was_empty = ISC_LIST_EMPTY(sock->send_list);
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if (sock->type == isc_sockettype_udp) {
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if (address != NULL)
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dev->address = *address;
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else
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dev->address = sock->address;
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} else if (sock->type == isc_sockettype_tcp) {
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INSIST(address == NULL);
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dev->address = sock->address;
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}
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set_dev_address(address, sock, dev);
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/*
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* If the read queue is empty, try to do the I/O right now.
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*/
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was_empty = ISC_LIST_EMPTY(sock->send_list);
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if (!was_empty)
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goto queue;
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iov[0].iov_base = (void *)(dev->region.base);
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iov[0].iov_len = dev->region.length;
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memset(&msghdr, 0, sizeof (msghdr));
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if (sock->type == isc_sockettype_udp) {
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msghdr.msg_name = (void *)&dev->address.type.sa;
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msghdr.msg_namelen = dev->address.length;
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}
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msghdr.msg_iov = iov;
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msghdr.msg_iovlen = 1;
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#ifdef ISC_NET_BSD44MSGHDR
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msghdr.msg_control = NULL;
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msghdr.msg_controllen = 0;
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msghdr.msg_flags = 0;
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#else
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msghdr.msg_accrights = NULL;
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msghdr.msg_accrightslen = 0;
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#endif
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build_msghdr_send(sock, dev, &msghdr,
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iov, ISC_SOCKET_MAXSCATTERGATHER, &write_count);
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cc = sendmsg(sock->fd, &msghdr, 0);
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@ -2029,7 +2040,7 @@ isc_socket_sendto(isc_socket_t *sock, isc_region_t *region,
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/*
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* Partial writes need to be queued
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*/
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if ((size_t)cc != dev->region.length)
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if ((size_t)cc != write_count)
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goto queue;
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/*
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