Handle data coming in over the channel as VPPackets: Process control
messages and forward data from remote client/server connections to the
appropriate server/client FD on our end. We also provide here a helper
function to process a stream of packets from the channel.
Signed-off-by: Michael Roth <mdr...@linux.vnet.ibm.com>
---
virtproxy.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
virtproxy.h | 3 ++
2 files changed, 99 insertions(+), 0 deletions(-)
diff --git a/virtproxy.c b/virtproxy.c
index 770b57b..091a223 100644
--- a/virtproxy.c
+++ b/virtproxy.c
@@ -33,6 +33,7 @@
#define VP_SERVICE_ID_LEN 32 /* max length of service id string */
#define VP_PKT_DATA_LEN 1024 /* max proxied bytes per VPPacket */
#define VP_CONN_DATA_LEN 1024 /* max bytes conns can send at a time */
+#define VP_CHAN_DATA_LEN 4096 /* max bytes channel can send at a time */
#define VP_MAGIC 0x1F374059
/* listening fd, one for each service we're forwarding to remote end */
@@ -152,6 +153,8 @@ static QemuOptsList vp_socket_opts = {
},
};
+static void vp_channel_read(void *opaque);
+
static int vp_channel_send_all(VPDriver *drv, uint8_t *buf, int count)
{
int ret;
@@ -263,3 +266,96 @@ static void vp_channel_accept(void *opaque)
/* dont accept anymore connections until channel_fd is closed */
vp_set_fd_handler(drv->listen_fd, NULL, NULL, NULL);
}
+
+/* process a stream of packets coming in from the channel */
+int vp_handle_packet_buf(VPDriver *drv, const void *buf, int count)
+{
+ VPPacket pkt;
+ int ret, buf_offset;
+ char *pkt_ptr;
+ const char *buf_ptr;
+
+ if (drv->buflen + count >= sizeof(VPPacket)) {
+ TRACE("initial packet, drv->buflen: %d", drv->buflen);
+ pkt_ptr = (char *)&pkt;
+ memcpy(pkt_ptr, drv->buf, drv->buflen);
+ pkt_ptr += drv->buflen;
+ memcpy(pkt_ptr, buf, sizeof(VPPacket) - drv->buflen);
+ /* handle first packet */
+ ret = vp_handle_packet(drv, &pkt);
+ if (ret != 0) {
+ LOG("error handling packet");
+ }
+ /* handle the rest of the buffer */
+ buf_offset = sizeof(VPPacket) - drv->buflen;
+ drv->buflen = 0;
+ buf_ptr = buf + buf_offset;
+ count -= buf_offset;
+ while (count > 0) {
+ if (count >= sizeof(VPPacket)) {
+ /* handle full packet */
+ TRACE("additional packet, drv->buflen: %d", drv->buflen);
+ memcpy((void *)&pkt, buf_ptr, sizeof(VPPacket));
+ ret = vp_handle_packet(drv, &pkt);
+ if (ret != 0) {
+ LOG("error handling packet");
+ }
+ count -= sizeof(VPPacket);
+ buf_ptr += sizeof(VPPacket);
+ } else {
+ /* buffer the remainder */
+ TRACE("buffering packet, drv->buflen: %d", drv->buflen);
+ memcpy(drv->buf, buf_ptr, count);
+ drv->buflen = count;
+ break;
+ }
+ }
+ } else {
+ /* haven't got a full VPPacket yet, buffer for later */
+ TRACE("buffering packet, drv->buflen: %d", drv->buflen);
+ memcpy(drv->buf + drv->buflen, buf, count);
+ drv->buflen += count;
+ }
+ return 0;
+}
+
+/* read handler for communication channel
+ *
+ * de-multiplexes data coming in over the channel. for control messages
+ * we process them here, for data destined for a service or client we
+ * send it to the appropriate FD.
+ */
+static void vp_channel_read(void *opaque)
+{
+ VPDriver *drv = opaque;
+ int count, ret;
+ char buf[VP_CHAN_DATA_LEN];
+
+ TRACE("called with opaque: %p", drv);
+
+ count = read(drv->channel_fd, buf, sizeof(buf));
+
+ if (count == -1) {
+ LOG("read() failed: %s", strerror(errno));
+ return;
+ } else if (count == 0) {
+ /* TODO: channel closed, this probably shouldn't happen for guest-side
+ * serial/virtio-serial connections, but need to confirm and consider
+ * what should happen in this case. as it stands this virtproxy
instance
+ * is basically defunct at this point, same goes for "client" instances
+ * of virtproxy where the remote end has hung-up.
+ */
+ LOG("channel connection closed");
+ vp_set_fd_handler(drv->channel_fd, NULL, NULL, drv);
+ drv->channel_fd = -1;
+ if (drv->listen_fd) {
+ vp_set_fd_handler(drv->listen_fd, vp_channel_accept, NULL, drv);
+ }
+ /* TODO: should close/remove/delete all existing VPConns here */
+ }
+
+ ret = vp_handle_packet_buf(drv, buf, count);
+ if (ret != 0) {
+ LOG("error handling packet stream");
+ }
+}
diff --git a/virtproxy.h b/virtproxy.h
index 1a5e56a..8fa0142 100644
--- a/virtproxy.h
+++ b/virtproxy.h
@@ -32,4 +32,7 @@ int vp_set_fd_handler(int fd,
void *opaque);
void vp_chr_read(CharDriverState *s, uint8_t *buf, int len);
+/* virtproxy interface */
+int vp_handle_packet_buf(VPDriver *drv, const void *buf, int count);
+
#endif /* VIRTPROXY_H */
--
1.7.0.4
