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From: Jason Wang <jasowang@redhat.com>
To: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>,
	qemu devel <qemu-devel@nongnu.org>
Cc: Li Zhijian <lizhijian@cn.fujitsu.com>,
	Wen Congyang <wency@cn.fujitsu.com>,
	"eddie . dong" <eddie.dong@intel.com>,
	"Dr . David Alan Gilbert" <dgilbert@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] net/net: Add ReadState for reuse codes
Date: Wed, 11 May 2016 17:01:51 +0800	[thread overview]
Message-ID: <5732F4FF.5060206@redhat.com> (raw)
In-Reply-To: <1462532187-22787-1-git-send-email-zhangchen.fnst@cn.fujitsu.com>



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.

> ---
>   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.

> +
> +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?

>           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?

>           }
>       }
>   }
> @@ -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);
>       }

  parent reply	other threads:[~2016-05-11  9:02 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 [this message]
2016-05-11 11:20   ` Zhang Chen
2016-05-12  1:11     ` Jason Wang
2016-05-12  6:33       ` Zhang Chen
2016-05-12  8:07         ` Jason Wang
2016-05-12  8:23           ` Zhang Chen

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