[Qemu-devel] [RFC][PATCH v3 15/21] virtproxy: add read handler for proxied connections

[Michael Roth <mdroth@linux.vnet.ibm.com>]

reads data from client/server connections as they become readable, then
sends the data over the channel

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 virtproxy.c |  114 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 virtproxy.h |    1 +
 2 files changed, 115 insertions(+), 0 deletions(-)

diff --git a/virtproxy.c b/virtproxy.c
index 9e1745f..f1f6859 100644
--- a/virtproxy.c
+++ b/virtproxy.c
@@ -37,6 +37,40 @@
 #define VP_CHAN_DATA_LEN 4096   /* max bytes channel can send at a time */
 #define VP_MAGIC 0x1F374059
 
+QemuOptsList vp_opts = {
+    .name = "vpargs",
+    .head = QTAILQ_HEAD_INITIALIZER(vp_opts.head),
+    .desc = {
+        {
+            .name = "service_id",
+            .type = QEMU_OPT_STRING,
+        },{
+            .name = "channel_method",
+            .type = QEMU_OPT_STRING,
+        },{
+            .name = "index",
+            .type = QEMU_OPT_NUMBER,
+        },{
+            .name = "path",
+            .type = QEMU_OPT_STRING,
+        },{
+            .name = "host",
+            .type = QEMU_OPT_STRING,
+        },{
+            .name = "port",
+            .type = QEMU_OPT_STRING,
+        },{
+            .name = "ipv4",
+            .type = QEMU_OPT_BOOL,
+        },{
+            .name = "ipv6",
+            .type = QEMU_OPT_BOOL,
+        },
+        { /* end of list */ }
+    },
+};
+
+
 /* listening fd, one for each service we're forwarding to remote end */
 typedef struct VPOForward {
     VPDriver *drv;
@@ -233,6 +267,86 @@ static VPIForward *get_iforward(const VPDriver *drv, const char *service_id)
     return NULL;
 }
 
+/* read handler for proxied connections */
+static void vp_conn_read(void *opaque)
+{
+    VPConn *conn = opaque;
+    VPDriver *drv = conn->drv;
+    VPPacket pkt;
+    char buf[VP_CONN_DATA_LEN];
+    int fd, count, ret;
+    bool client;
+
+    TRACE("called with opaque: %p, drv: %p", opaque, drv);
+
+    if (conn->state != VP_STATE_CONNECTED) {
+        LOG("invalid connection state");
+        return;
+    }
+
+    if (conn->type != VP_CONN_CLIENT && conn->type != VP_CONN_SERVER) {
+        LOG("invalid connection type");
+        return;
+    }
+
+    /* TODO: all fields should be explicitly set so we shouldn't
+     * need to memset. this might hurt if we beef up VPPacket size
+     */
+    memset(&pkt, 0, sizeof(VPPacket));
+    pkt.magic = VP_MAGIC;
+
+    if (conn->type == VP_CONN_CLIENT) {
+        client = true;
+        fd = conn->client_fd;
+    } else {
+        client = false;
+        fd = conn->server_fd;
+    }
+
+    count = read(fd, buf, VP_CONN_DATA_LEN);
+    if (count == -1) {
+        LOG("read() failed: %s", strerror(errno));
+        return;
+    } else if (count == 0) {
+        /* connection closed, tell remote end to clean up */
+        TRACE("connection closed");
+        pkt.type = VP_PKT_CONTROL;
+        pkt.payload.msg.type = VP_CONTROL_CLOSE;
+        if (client) {
+            /* we're closing the client, have remote close the server conn */
+            TRACE("closing connection for client fd %d", conn->client_fd);
+            pkt.payload.msg.args.close.client_fd = -1;
+            pkt.payload.msg.args.close.server_fd = conn->server_fd;
+        } else {
+            TRACE("closing connection for server fd %d", conn->server_fd);
+            pkt.payload.msg.args.close.server_fd = -1;
+            pkt.payload.msg.args.close.client_fd = conn->client_fd;;
+        }
+        /* clean up things on our end */
+        closesocket(fd);
+        vp_set_fd_handler(fd, NULL, NULL, NULL);
+        QLIST_REMOVE(conn, next);
+        qemu_free(conn);
+    } else {
+        TRACE("data read");
+        pkt.type = client ? VP_PKT_CLIENT : VP_PKT_SERVER;
+        pkt.payload.proxied.client_fd = conn->client_fd;
+        pkt.payload.proxied.server_fd = conn->server_fd;
+        memcpy(pkt.payload.proxied.data, buf, count);
+        pkt.payload.proxied.bytes = count;
+    }
+
+    ret = vp_channel_send_all(drv, (uint8_t*)&pkt, sizeof(VPPacket));
+    if (ret == -1) {
+        LOG("error sending data over channel: %s", strerror(errno));
+        return;
+    }
+    if (ret != sizeof(VPPacket)) {
+        TRACE("buffer full?");
+        return;
+    }
+}
+
 /* accept handler for communication channel
  *
  * accept()s connection to communication channel (for sockets), and sets
diff --git a/virtproxy.h b/virtproxy.h
index 83cc905..ef168b0 100644
--- a/virtproxy.h
+++ b/virtproxy.h
@@ -23,6 +23,7 @@ enum vp_context {
     VP_CTX_CHARDEV, /* in qemu/host, channel is a virtproxy chardev */
     VP_CTX_FD,      /* in guest, channel is an FD */
 };
+extern QemuOptsList vp_opts;
 
 /* wrappers for s/vp/qemu/ functions we need */
 int vp_send_all(int fd, const void *buf, int len1);
-- 
1.7.0.4