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[Qemu-devel] [PULL 046/103] Add chardev API qemu_chr_fe_set_msgfds
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PULL 046/103] Add chardev API qemu_chr_fe_set_msgfds |
Date: |
Tue, 17 Jun 2014 20:38:56 +0300 |
From: Nikolay Nikolaev <address@hidden>
This will set an array of file descriptors to the internal structures.
The next time a message is send the array will be send as ancillary
data. This feature works on the UNIX domain socket backend only.
Signed-off-by: Antonios Motakis <address@hidden>
Signed-off-by: Nikolay Nikolaev <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
include/sysemu/char.h | 14 ++++++++
qemu-char.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 101 insertions(+), 1 deletion(-)
diff --git a/include/sysemu/char.h b/include/sysemu/char.h
index 9981a6a..d99dcf6 100644
--- a/include/sysemu/char.h
+++ b/include/sysemu/char.h
@@ -62,6 +62,7 @@ struct CharDriverState {
void (*chr_update_read_handler)(struct CharDriverState *s);
int (*chr_ioctl)(struct CharDriverState *s, int cmd, void *arg);
int (*get_msgfd)(struct CharDriverState *s);
+ int (*set_msgfds)(struct CharDriverState *s, int *fds, int num);
int (*chr_add_client)(struct CharDriverState *chr, int fd);
IOEventHandler *chr_event;
IOCanReadHandler *chr_can_read;
@@ -229,6 +230,19 @@ int qemu_chr_fe_ioctl(CharDriverState *s, int cmd, void
*arg);
int qemu_chr_fe_get_msgfd(CharDriverState *s);
/**
+ * @qemu_chr_fe_set_msgfds:
+ *
+ * For backends capable of fd passing, set an array of fds to be passed with
+ * the next send operation.
+ * A subsequent call to this function before calling a write function will
+ * result in overwriting the fd array with the new value without being send.
+ * Upon writing the message the fd array is freed.
+ *
+ * Returns: -1 if fd passing isn't supported.
+ */
+int qemu_chr_fe_set_msgfds(CharDriverState *s, int *fds, int num);
+
+/**
* @qemu_chr_fe_claim:
*
* Claim a backend before using it, should be called before calling
diff --git a/qemu-char.c b/qemu-char.c
index ba47a8a..ed9f679 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -207,6 +207,11 @@ int qemu_chr_fe_get_msgfd(CharDriverState *s)
return s->get_msgfd ? s->get_msgfd(s) : -1;
}
+int qemu_chr_fe_set_msgfds(CharDriverState *s, int *fds, int num)
+{
+ return s->set_msgfds ? s->set_msgfds(s, fds, num) : -1;
+}
+
int qemu_chr_add_client(CharDriverState *s, int fd)
{
return s->chr_add_client ? s->chr_add_client(s, fd) : -1;
@@ -2333,15 +2338,71 @@ typedef struct {
int do_nodelay;
int is_unix;
int msgfd;
+ int *write_msgfds;
+ int write_msgfds_num;
} TCPCharDriver;
static gboolean tcp_chr_accept(GIOChannel *chan, GIOCondition cond, void
*opaque);
+#ifndef _WIN32
+static int unix_send_msgfds(CharDriverState *chr, const uint8_t *buf, int len)
+{
+ TCPCharDriver *s = chr->opaque;
+ struct msghdr msgh;
+ struct iovec iov;
+ int r;
+
+ size_t fd_size = s->write_msgfds_num * sizeof(int);
+ char control[CMSG_SPACE(fd_size)];
+ struct cmsghdr *cmsg;
+
+ memset(&msgh, 0, sizeof(msgh));
+ memset(control, 0, sizeof(control));
+
+ /* set the payload */
+ iov.iov_base = (uint8_t *) buf;
+ iov.iov_len = len;
+
+ msgh.msg_iov = &iov;
+ msgh.msg_iovlen = 1;
+
+ msgh.msg_control = control;
+ msgh.msg_controllen = sizeof(control);
+
+ cmsg = CMSG_FIRSTHDR(&msgh);
+
+ cmsg->cmsg_len = CMSG_LEN(fd_size);
+ cmsg->cmsg_level = SOL_SOCKET;
+ cmsg->cmsg_type = SCM_RIGHTS;
+ memcpy(CMSG_DATA(cmsg), s->write_msgfds, fd_size);
+
+ do {
+ r = sendmsg(s->fd, &msgh, 0);
+ } while (r < 0 && errno == EINTR);
+
+ /* free the written msgfds, no matter what */
+ if (s->write_msgfds_num) {
+ g_free(s->write_msgfds);
+ s->write_msgfds = 0;
+ s->write_msgfds_num = 0;
+ }
+
+ return r;
+}
+#endif
+
static int tcp_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
{
TCPCharDriver *s = chr->opaque;
if (s->connected) {
- return io_channel_send(s->chan, buf, len);
+#ifndef _WIN32
+ if (s->is_unix && s->write_msgfds_num) {
+ return unix_send_msgfds(chr, buf, len);
+ } else
+#endif
+ {
+ return io_channel_send(s->chan, buf, len);
+ }
} else {
/* XXX: indicate an error ? */
return len;
@@ -2416,6 +2477,25 @@ static int tcp_get_msgfd(CharDriverState *chr)
return fd;
}
+static int tcp_set_msgfds(CharDriverState *chr, int *fds, int num)
+{
+ TCPCharDriver *s = chr->opaque;
+
+ /* clear old pending fd array */
+ if (s->write_msgfds) {
+ g_free(s->write_msgfds);
+ }
+
+ if (num) {
+ s->write_msgfds = g_malloc(num * sizeof(int));
+ memcpy(s->write_msgfds, fds, num * sizeof(int));
+ }
+
+ s->write_msgfds_num = num;
+
+ return 0;
+}
+
#ifndef _WIN32
static void unix_process_msgfd(CharDriverState *chr, struct msghdr *msg)
{
@@ -2677,6 +2757,9 @@ static void tcp_chr_close(CharDriverState *chr)
}
closesocket(s->listen_fd);
}
+ if (s->write_msgfds_num) {
+ g_free(s->write_msgfds);
+ }
g_free(s);
qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
}
@@ -2706,6 +2789,8 @@ static CharDriverState *qemu_chr_open_socket_fd(int fd,
bool do_nodelay,
s->fd = -1;
s->listen_fd = -1;
s->msgfd = -1;
+ s->write_msgfds = 0;
+ s->write_msgfds_num = 0;
chr->filename = g_malloc(256);
switch (ss.ss_family) {
@@ -2737,6 +2822,7 @@ static CharDriverState *qemu_chr_open_socket_fd(int fd,
bool do_nodelay,
chr->chr_sync_read = tcp_chr_sync_read;
chr->chr_close = tcp_chr_close;
chr->get_msgfd = tcp_get_msgfd;
+ chr->set_msgfds = tcp_set_msgfds;
chr->chr_add_client = tcp_chr_add_client;
chr->chr_add_watch = tcp_chr_add_watch;
chr->chr_update_read_handler = tcp_chr_update_read_handler;
--
MST
- [Qemu-devel] [PULL 097/103] pc: acpi: do not hardcode preprocessor, (continued)
- [Qemu-devel] [PULL 097/103] pc: acpi: do not hardcode preprocessor, Michael S. Tsirkin, 2014/06/17
- [Qemu-devel] [PULL 098/103] numa: handle mmaped memory allocation failure correctly, Michael S. Tsirkin, 2014/06/17
- [Qemu-devel] [PULL 102/103] qmp: add query-acpi-ospm-status command, Michael S. Tsirkin, 2014/06/17
- [Qemu-devel] [PULL 036/103] virtio: Drop superfluous conditionals around g_free(), Michael S. Tsirkin, 2014/06/17
- [Qemu-devel] [PULL 088/103] qmp: add query-memdev, Michael S. Tsirkin, 2014/06/17
- [Qemu-devel] [PULL 034/103] acpi: update generated files, Michael S. Tsirkin, 2014/06/17
- [Qemu-devel] [PULL 060/103] libqemustub: add stubs to be able to use qemu-char.c, Michael S. Tsirkin, 2014/06/17
- [Qemu-devel] [PULL 068/103] qmp: improve error reporting for -object and object-add, Michael S. Tsirkin, 2014/06/17
- [Qemu-devel] [PULL 035/103] acpi-test: update expected tables, Michael S. Tsirkin, 2014/06/17
- [Qemu-devel] [PULL 086/103] hostmem: add property to map memory with MAP_SHARED, Michael S. Tsirkin, 2014/06/17
- [Qemu-devel] [PULL 046/103] Add chardev API qemu_chr_fe_set_msgfds,
Michael S. Tsirkin <=
- [Qemu-devel] [PULL 087/103] hostmem: add properties for NUMA memory policy, Michael S. Tsirkin, 2014/06/17
- [Qemu-devel] [PULL 103/103] qmp: add ACPI_DEVICE_OST event handling, Michael S. Tsirkin, 2014/06/17
- [Qemu-devel] [PULL 101/103] acpi: implement ospm_status() method for PIIX4/ICH9_LPC devices, Michael S. Tsirkin, 2014/06/17
- Re: [Qemu-devel] [PULL 000/103] pc, pci, virtio, hotplug fixes, enhancements for 2.1, Peter Maydell, 2014/06/18