Re: [Qemu-devel] [PATCH V2] net/net: Add SocketReadState for reuse codes

[Zhang Chen]

On 05/13/2016 12:02 PM, Jason Wang wrote:

On 2016年05月12日 17:19, Zhang Chen wrote:

This function is from net/socket.c, move it to net.c and net.h.
Add SocketReadState to make others reuse net_fill_rstate().
suggestion from jason.

v2:
  - rename ReadState to SocketReadState
  - add SocketReadState init and finalize callback

v1:
  - init patch

Signed-off-by: Zhang Chen <zhangchen.f...@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhij...@cn.fujitsu.com>
Signed-off-by: Wen Congyang <we...@cn.fujitsu.com>
---
  include/net/net.h   | 14 +++++++++
  net/filter-mirror.c | 72 ++++++++++++++-----------------------------
  net/net.c           | 65 ++++++++++++++++++++++++++++++++++++++

net/socket.c | 89 +++++++++++++++++++++--------------------------------

  4 files changed, 137 insertions(+), 103 deletions(-)

diff --git a/include/net/net.h b/include/net/net.h
index 73e4c46..4f6b6bf 100644
--- a/include/net/net.h
+++ b/include/net/net.h

@@ -57,6 +57,9 @@ typedef void (SetOffload)(NetClientState *, int, int, int, int, int);

  typedef void (SetVnetHdrLen)(NetClientState *, int);
  typedef int (SetVnetLE)(NetClientState *, bool);
  typedef int (SetVnetBE)(NetClientState *, bool);
+typedef struct SocketReadState SocketReadState;
+typedef void (SocketReadStateInit)(SocketReadState *rs);
+typedef void (SocketReadStateFinalize)(SocketReadState *rs);
    typedef struct NetClientInfo {
      NetClientOptionsKind type;
@@ -102,6 +105,16 @@ typedef struct NICState {
      bool peer_deleted;
  } NICState;
  +struct SocketReadState {
+    int state; /* 0 = getting length, 1 = getting data */
+    uint32_t index;
+    uint32_t packet_len;
+    uint8_t buf[NET_BUFSIZE];
+    SocketReadStateInit *init;
+    SocketReadStateFinalize *finalize;
+};
+
+int net_fill_rstate(SocketReadState *rs, const uint8_t *buf, int size);
  char *qemu_mac_strdup_printf(const uint8_t *macaddr);
  NetClientState *qemu_find_netdev(const char *id);
  int qemu_find_net_clients_except(const char *id, NetClientState **ncs,

@@ -160,6 +173,7 @@ ssize_t qemu_deliver_packet_iov(NetClientState *sender,

    void print_net_client(Monitor *mon, NetClientState *nc);
  void hmp_info_network(Monitor *mon, const QDict *qdict);
+void net_socket_rs_init(SocketReadState *rs);
    /* NIC info */
  diff --git a/net/filter-mirror.c b/net/filter-mirror.c
index c0c4dc6..4e55924 100644
--- a/net/filter-mirror.c
+++ b/net/filter-mirror.c
@@ -40,10 +40,7 @@ typedef struct MirrorState {
      char *outdev;
      CharDriverState *chr_in;
      CharDriverState *chr_out;
-    int state; /* 0 = getting length, 1 = getting data */
-    unsigned int index;
-    unsigned int packet_len;
-    uint8_t buf[REDIRECTOR_MAX_LEN];
+    SocketReadState rs;
  } MirrorState;
    static int filter_mirror_send(CharDriverState *chr_out,

@@ -108,50 +105,15 @@ static void redirector_chr_read(void *opaque, const uint8_t *buf, int size)

  {
      NetFilterState *nf = opaque;
      MirrorState *s = FILTER_REDIRECTOR(nf);
-    unsigned int l;
-
-    while (size > 0) {
-        /* reassemble a packet from the network */
-        switch (s->state) { /* 0 = getting length, 1 = getting data */
-        case 0:
-            l = 4 - s->index;
-            if (l > size) {
-                l = size;
-            }
-            memcpy(s->buf + s->index, buf, l);
-            buf += l;
-            size -= l;
-            s->index += l;
-            if (s->index == 4) {
-                /* got length */
-                s->packet_len = ntohl(*(uint32_t *)s->buf);
-                s->index = 0;
-                s->state = 1;
-            }
-            break;
-        case 1:
-            l = s->packet_len - s->index;
-            if (l > size) {
-                l = size;
-            }
-            if (s->index + l <= sizeof(s->buf)) {
-                memcpy(s->buf + s->index, buf, l);
-            } else {

- error_report("serious error: oversized packet received.");

-                s->index = s->state = 0;

- qemu_chr_add_handlers(s->chr_in, NULL, NULL, NULL, NULL);

-                return;
-            }
-
-            s->index += l;
-            buf += l;
-            size -= l;
-            if (s->index >= s->packet_len) {
-                s->index = 0;
-                s->state = 0;
-                redirector_to_filter(nf, s->buf, s->packet_len);
-            }
-            break;
+    int ret;
+
+    ret = net_fill_rstate(&s->rs, buf, size);
+
+    if (ret == -1) {
+        qemu_chr_add_handlers(s->chr_in, NULL, NULL, NULL, NULL);
+    } else if (ret == 1) {
+        if (s->rs.finalize) {
+            s->rs.finalize(&s->rs);

Why not simply call this in net_fill_rstate()?

Good idea.
I will move it in next version.

          }
      }
  }

@@ -258,6 +220,14 @@ static void filter_mirror_setup(NetFilterState *nf, Error **errp)

      }
  }
  +static void redirector_rs_finalize(SocketReadState *rs)
+{
+    MirrorState *s = container_of(rs, MirrorState, rs);
+    NetFilterState *nf = NETFILTER(s);
+
+    redirector_to_filter(nf, rs->buf, rs->packet_len);
+}
+
  static void filter_redirector_setup(NetFilterState *nf, Error **errp)
  {
      MirrorState *s = FILTER_REDIRECTOR(nf);

@@ -274,7 +244,11 @@ static void filter_redirector_setup(NetFilterState *nf, Error **errp)

          }
      }
  -    s->state = s->index = 0;
+    s->rs.init = net_socket_rs_init;
+    s->rs.finalize = redirector_rs_finalize;
+    if (s->rs.init) {
+        s->rs.init(&s->rs);
+    }

This looks odd, you can call net_socket_rs_init() directly here and pass redirector_rs_finalize to it. Then there's no need to do the open code here.

OK

Thanks
Zhang Chen

.

--
Thanks
zhangchen