This function will attempt to read data from the chardev trying
to fill the buffer up to the given length.
Signed-off-by: Antonios Motakis <a.mota...@virtualopensystems.com>
Signed-off-by: Nikolay Nikolaev <n.nikol...@virtualopensystems.com>
---
include/sysemu/char.h | 14 +++++++++++
qemu-char.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 79 insertions(+)
diff --git a/include/sysemu/char.h b/include/sysemu/char.h
index b81a6ff..9981a6a 100644
--- a/include/sysemu/char.h
+++ b/include/sysemu/char.h
@@ -56,6 +56,8 @@ typedef void IOEventHandler(void *opaque, int event);
struct CharDriverState {
void (*init)(struct CharDriverState *s);
int (*chr_write)(struct CharDriverState *s, const uint8_t *buf, int len);
+ int (*chr_sync_read)(struct CharDriverState *s,
+ const uint8_t *buf, int len);
GSource *(*chr_add_watch)(struct CharDriverState *s, GIOCondition cond);
void (*chr_update_read_handler)(struct CharDriverState *s);
int (*chr_ioctl)(struct CharDriverState *s, int cmd, void *arg);
@@ -189,6 +191,18 @@ int qemu_chr_fe_write(CharDriverState *s, const uint8_t
*buf, int len);
int qemu_chr_fe_write_all(CharDriverState *s, const uint8_t *buf, int len);
/**
+ * @qemu_chr_fe_read_all:
+ *
+ * Read data to a buffer from the back end.
+ *
+ * @buf the data buffer
+ * @len the number of bytes to read
+ *
+ * Returns: the number of bytes read
+ */
+int qemu_chr_fe_read_all(CharDriverState *s, uint8_t *buf, int len);
+
+/**
* @qemu_chr_fe_ioctl:
*
* Issue a device specific ioctl to a backend.
diff --git a/qemu-char.c b/qemu-char.c
index 30c5a6a..54ac03c 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -84,6 +84,7 @@
#include "ui/qemu-spice.h"
#define READ_BUF_LEN 4096
+#define READ_RETRIES 10
/***********************************************************/
/* character device */
@@ -145,6 +146,41 @@ int qemu_chr_fe_write_all(CharDriverState *s, const
uint8_t *buf, int len)
return offset;
}
+int qemu_chr_fe_read_all(CharDriverState *s, uint8_t *buf, int len)
+{
+ int offset = 0, counter = 10;
+ int res;
+
+ if (!s->chr_sync_read) {
+ return 0;
+ }
+
+ while (offset < len) {
+ do {
+ res = s->chr_sync_read(s, buf + offset, len - offset);
+ if (res == -1 && errno == EAGAIN) {
+ g_usleep(100);
+ }
+ } while (res == -1 && errno == EAGAIN);
+
+ if (res == 0) {
+ break;
+ }
+
+ if (res < 0) {
+ return res;
+ }
+
+ offset += res;
+
+ if (!counter--) {
+ break;
+ }
+ }
+
+ return offset;
+}
+
int qemu_chr_fe_ioctl(CharDriverState *s, int cmd, void *arg)
{
if (!s->chr_ioctl)
@@ -2489,6 +2525,34 @@ static gboolean tcp_chr_read(GIOChannel *chan,
GIOCondition cond, void *opaque)
return TRUE;
}
+static int tcp_chr_sync_read(CharDriverState *chr, const uint8_t *buf, int len)
+{
+ TCPCharDriver *s = chr->opaque;
+ int size;
+
+ if (!s->connected) {
+ return 0;
+ }
+
+ size = tcp_chr_recv(chr, (void *) buf, len);
+ if (size == 0) {
+ /* connection closed */
+ s->connected = 0;
+ if (s->listen_chan) {
+ s->listen_tag = g_io_add_watch(s->listen_chan, G_IO_IN,
+ tcp_chr_accept, chr);
+ }
+ remove_fd_in_watch(chr);
+ g_io_channel_unref(s->chan);
+ s->chan = NULL;
+ closesocket(s->fd);
+ s->fd = -1;
+ qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
+ }
+
+ return size;
+}
+
#ifndef _WIN32
CharDriverState *qemu_chr_open_eventfd(int eventfd)
{
@@ -2660,6 +2724,7 @@ static CharDriverState *qemu_chr_open_socket_fd(int fd,
bool do_nodelay,
chr->opaque = s;
chr->chr_write = tcp_chr_write;
+ chr->chr_sync_read = tcp_chr_sync_read;
chr->chr_close = tcp_chr_close;
chr->get_msgfd = tcp_get_msgfd;
chr->chr_add_client = tcp_chr_add_client;
--
1.8.3.2
