qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Jason Wang <jasowang@redhat.com>
To: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>,
	qemu devel <qemu-devel@nongnu.org>
Cc: "eddie . dong" <eddie.dong@intel.com>,
	Li Zhijian <lizhijian@cn.fujitsu.com>,
	"Dr . David Alan Gilbert" <dgilbert@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] net/net: Add ReadState for reuse codes
Date: Thu, 12 May 2016 09:11:46 +0800	[thread overview]
Message-ID: <5733D852.9080301@redhat.com> (raw)
In-Reply-To: <57331577.2090206@cn.fujitsu.com>



On 2016年05月11日 19:20, Zhang Chen wrote:
>
>
> On 05/11/2016 05:01 PM, Jason Wang wrote:
>>
>>
>> On 2016年05月06日 18:56, Zhang Chen wrote:
>>> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
>>> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
>>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>>
>> Looks good, just few nits.
>>
>> It's better to have a commit log.
>
> OK, I will add this log:
>
> 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.

Looks good. Thanks

>
>>
>>> ---
>>>   include/net/net.h   |  8 ++++++
>>>   net/filter-mirror.c | 60 ++++++++------------------------------------
>>>   net/net.c           | 56 ++++++++++++++++++++++++++++++++++++++++++
>>>   net/socket.c        | 71 
>>> +++++++++++++----------------------------------------
>>>   4 files changed, 91 insertions(+), 104 deletions(-)
>>>
>>> diff --git a/include/net/net.h b/include/net/net.h
>>> index 73e4c46..1439cf9 100644
>>> --- a/include/net/net.h
>>> +++ b/include/net/net.h
>>> @@ -102,6 +102,14 @@ typedef struct NICState {
>>>       bool peer_deleted;
>>>   } NICState;
>>>   +typedef struct ReadState {
>>> +    int state; /* 0 = getting length, 1 = getting data */
>>> +    uint32_t index;
>>> +    uint32_t packet_len;
>>> +    uint8_t buf[NET_BUFSIZE];
>>> +} ReadState;
>>
>> I think SocketReadState is better here.
>>
>
> I will rename it in next version.
>
>>> +
>>> +int net_fill_rstate(ReadState *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,
>>> diff --git a/net/filter-mirror.c b/net/filter-mirror.c
>>> index c0c4dc6..bcec509 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];
>>> +    ReadState rs;
>>>   } MirrorState;
>>>     static int filter_mirror_send(CharDriverState *chr_out,
>>> @@ -108,51 +105,14 @@ 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) {
>>> +        redirector_to_filter(nf, s->rs.buf, s->rs.packet_len);
>>>       }
>>>   }
>>>   @@ -274,7 +234,7 @@ static void 
>>> filter_redirector_setup(NetFilterState *nf, Error **errp)
>>>           }
>>>       }
>>>   -    s->state = s->index = 0;
>>> +    s->rs.state = s->rs.index = 0;
>>>         if (s->indev) {
>>>           s->chr_in = qemu_chr_find(s->indev);
>>> diff --git a/net/net.c b/net/net.c
>>> index 0ad6217..926457e 100644
>>> --- a/net/net.c
>>> +++ b/net/net.c
>>> @@ -1573,3 +1573,59 @@ QemuOptsList qemu_net_opts = {
>>>           { /* end of list */ }
>>>       },
>>>   };
>>> +
>>> +/*
>>> + * Returns
>>> + * 0: readstate is not ready
>>> + * 1: readstate is ready
>>> + * otherwise error occurs
>>> + */
>>> +int net_fill_rstate(ReadState *rs, const uint8_t *buf, int size)
>>> +{
>>> +    unsigned int l;
>>> +    while (size > 0) {
>>> +        /* reassemble a packet from the network */
>>> +        switch (rs->state) { /* 0 = getting length, 1 = getting 
>>> data */
>>> +        case 0:
>>> +            l = 4 - rs->index;
>>> +            if (l > size) {
>>> +                l = size;
>>> +            }
>>> +            memcpy(rs->buf + rs->index, buf, l);
>>> +            buf += l;
>>> +            size -= l;
>>> +            rs->index += l;
>>> +            if (rs->index == 4) {
>>> +                /* got length */
>>> +                rs->packet_len = ntohl(*(uint32_t *)rs->buf);
>>> +                rs->index = 0;
>>> +                rs->state = 1;
>>> +            }
>>> +            break;
>>> +        case 1:
>>> +            l = rs->packet_len - rs->index;
>>> +            if (l > size) {
>>> +                l = size;
>>> +            }
>>> +            if (rs->index + l <= sizeof(rs->buf)) {
>>> +                memcpy(rs->buf + rs->index, buf, l);
>>> +            } else {
>>> +                fprintf(stderr, "serious error: oversized packet 
>>> received,"
>>> +                    "connection terminated.\n");
>>> +                rs->index = rs->state = 0;
>>> +                return -1;
>>> +            }
>>> +
>>> +            rs->index += l;
>>> +            buf += l;
>>> +            size -= l;
>>> +            if (rs->index >= rs->packet_len) {
>>> +                rs->index = 0;
>>> +                rs->state = 0;
>>> +                return 1;
>>> +            }
>>> +            break;
>>> +        }
>>> +    }
>>> +    return 0;
>>> +}
>>> diff --git a/net/socket.c b/net/socket.c
>>> index 9fa2cd8..9ecdd3b 100644
>>> --- a/net/socket.c
>>> +++ b/net/socket.c
>>> @@ -38,11 +38,8 @@ typedef struct NetSocketState {
>>>       NetClientState nc;
>>>       int listen_fd;
>>>       int fd;
>>> -    int state; /* 0 = getting length, 1 = getting data */
>>> -    unsigned int index;
>>> -    unsigned int packet_len;
>>> +    ReadState rs;
>>>       unsigned int send_index;      /* number of bytes sent (only 
>>> SOCK_STREAM) */
>>> -    uint8_t buf[NET_BUFSIZE];
>>>       struct sockaddr_in dgram_dst; /* contains inet host and port 
>>> destination iff connectionless (SOCK_DGRAM) */
>>>       IOHandler *send_fn;           /* differs between 
>>> SOCK_STREAM/SOCK_DGRAM */
>>>       bool read_poll;               /* waiting to receive data? */
>>> @@ -147,7 +144,7 @@ static void net_socket_send(void *opaque)
>>>   {
>>>       NetSocketState *s = opaque;
>>>       int size;
>>> -    unsigned l;
>>> +    int ret;
>>>       uint8_t buf1[NET_BUFSIZE];
>>>       const uint8_t *buf;
>>>   @@ -166,60 +163,26 @@ static void net_socket_send(void *opaque)
>>>           closesocket(s->fd);
>>>             s->fd = -1;
>>> -        s->state = 0;
>>> -        s->index = 0;
>>> -        s->packet_len = 0;
>>> +        s->rs.state = 0;
>>> +        s->rs.index = 0;
>>> +        s->rs.packet_len = 0;
>>>           s->nc.link_down = true;
>>> -        memset(s->buf, 0, sizeof(s->buf));
>>> +        memset(s->rs.buf, 0, sizeof(s->rs.buf));
>>
>> How about introduce a helper to do the initialization?
>
> Do you mean
>
> remove
> +        s->rs.state = 0;
> +        s->rs.index = 0;
> +        s->rs.packet_len = 0;
> +        memset(s->rs.buf, 0, sizeof(s->rs.buf));
>
> add
>            s->rs->cb = xxx_cb;
>            s->rs->opxx = xxx;
>
> void xxx_cb(void *opaque)
> {
>     NetSocketState *s = opaque;
>
>     s->rs.state = 0;
>     s->rs.index = 0;
>     s->rs.packet_len = 0;
>     memset(s->rs.buf, 0, sizeof(s->rs.buf));
> }
>

Kind of, and looks like there's no need for opaque, you can just pass 
pointer to SocketReadState. And another parameter of callbacks.

>
>>
>>>           memset(s->nc.info_str, 0, sizeof(s->nc.info_str));
>>>             return;
>>>       }
>>>       buf = buf1;
>>> -    while (size > 0) {
>>> -        /* reassemble a packet from the network */
>>> -        switch(s->state) {
>>> -        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 {
>>> -                fprintf(stderr, "serious error: oversized packet 
>>> received,"
>>> -                    "connection terminated.\n");
>>> -                s->state = 0;
>>> -                goto eoc;
>>> -            }
>>>   -            s->index += l;
>>> -            buf += l;
>>> -            size -= l;
>>> -            if (s->index >= s->packet_len) {
>>> -                s->index = 0;
>>> -                s->state = 0;
>>> -                if (qemu_send_packet_async(&s->nc, s->buf, 
>>> s->packet_len,
>>> - net_socket_send_completed) == 0) {
>>> -                    net_socket_read_poll(s, false);
>>> -                    break;
>>> -                }
>>> -            }
>>> -            break;
>>> +    ret = net_fill_rstate(&s->rs, buf, size);
>>> +
>>> +    if (ret == -1) {
>>> +        goto eoc;
>>> +    } else if (ret == 1) {
>>> +        if (qemu_send_packet_async(&s->nc, s->rs.buf,
>>> +                                   s->rs.packet_len,
>>> +                                   net_socket_send_completed) == 0) {
>>> +            net_socket_read_poll(s, false);
>>
>> This looks not elegant, maybe we could use callback (which was 
>> initialized by the helper I mention above) to do this. Any thoughts 
>> on this?
>
> Do you mean:
>
> remove
> +        if (qemu_send_packet_async(&s->nc, s->rs.buf,
> +                                   s->rs.packet_len,
> +                                   net_socket_send_completed) == 0) {
> +            net_socket_read_poll(s, false);
>
> add
>
> s->rs->done
>
> void socket_fill_rsstate_done_cb(SocketReadState *srs, void *opaque)
> {
>     NetSocketState *s = opaque;
>
>     if (qemu_send_packet_async(&s->nc, srs->buf,
>                                srs->packet_len,
>                                net_socket_send_completed) == 0) {
>         net_socket_read_poll(s, false);
>     }
> }

Yes, but there's no need for opaque, we can infer the container by 
container_of().

>
>>
>>>           }
>>>       }
>>>   }
>>> @@ -229,7 +192,7 @@ static void net_socket_send_dgram(void *opaque)
>>>       NetSocketState *s = opaque;
>>>       int size;
>>>   -    size = qemu_recv(s->fd, s->buf, sizeof(s->buf), 0);
>>> +    size = qemu_recv(s->fd, s->rs.buf, sizeof(s->rs.buf), 0);
>>>       if (size < 0)
>>>           return;
>>>       if (size == 0) {
>>> @@ -238,7 +201,7 @@ static void net_socket_send_dgram(void *opaque)
>>>           net_socket_write_poll(s, false);
>>>           return;
>>>       }
>>> -    if (qemu_send_packet_async(&s->nc, s->buf, size,
>>> +    if (qemu_send_packet_async(&s->nc, s->rs.buf, size,
>>>                                  net_socket_send_completed) == 0) {
>>>           net_socket_read_poll(s, false);
>>>       }
>>
>>
>>
>> .
>>
>

  reply	other threads:[~2016-05-12  1:11 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-06 10:56 [Qemu-devel] [PATCH] net/net: Add ReadState for reuse codes Zhang Chen
2016-05-10  2:57 ` Li Zhijian
2016-05-10  5:33   ` Zhang Chen
2016-05-11  7:01   ` Zhang Chen
2016-05-11  9:01 ` Jason Wang
2016-05-11 11:20   ` Zhang Chen
2016-05-12  1:11     ` Jason Wang [this message]
2016-05-12  6:33       ` Zhang Chen
2016-05-12  8:07         ` Jason Wang
2016-05-12  8:23           ` Zhang Chen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=5733D852.9080301@redhat.com \
    --to=jasowang@redhat.com \
    --cc=dgilbert@redhat.com \
    --cc=eddie.dong@intel.com \
    --cc=lizhijian@cn.fujitsu.com \
    --cc=qemu-devel@nongnu.org \
    --cc=zhangchen.fnst@cn.fujitsu.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).