Re: [Qemu-devel] [RFC PATCH 4/9] colo-proxy: add colo-proxy setup work

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Zhang Chen (zhangchen.fnst@cn.fujitsu.com) wrote:
> From: zhangchen <zhangchen.fnst@cn.fujitsu.com>
> 
> Secondary setup socket server for colo-forward
> primary setup connect to secondary for colo-forward
> add data structure will be uesed

I wodner if it's possible to reuse the '-netdev socket,' stuff rather
than handling the socket connection yourself (I don't know much about it,
but since it's there it might be worth checking, see net/socket)

> Signed-off-by: zhangchen <zhangchen.fnst@cn.fujitsu.com>
> ---
>  net/colo-proxy.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>  net/colo-proxy.h | 61 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 147 insertions(+), 1 deletion(-)
> 
> diff --git a/net/colo-proxy.c b/net/colo-proxy.c
> index 98c2699..89d9616 100644
> --- a/net/colo-proxy.c
> +++ b/net/colo-proxy.c
> @@ -22,6 +22,8 @@
>  #define DEBUG(format, ...)
>  #endif
>  
> +static char *mode;

Do we really need this as a global - you parse it and put it into the
ColoProxyState anyway? If it really does need to be a global you need to
use a better name.

> +static bool colo_do_checkpoint;
>  
>  static ssize_t colo_proxy_receive_iov(NetFilterState *nf,
>                                           NetClientState *sender,
> @@ -46,13 +48,84 @@ static ssize_t colo_proxy_receive_iov(NetFilterState *nf,
>  
>  static void colo_proxy_cleanup(NetFilterState *nf)
>  {
> -     /* cleanup */
> +    ColoProxyState *s = FILTER_COLO_PROXY(nf);
> +    close(s->sockfd);
> +    s->sockfd = -1;
> +    g_free(mode);
> +    g_free(s->addr);
>  }
>  
> +static void colo_accept_incoming(ColoProxyState *s)
> +{
> +    DEBUG("into colo_accept_incoming\n");
> +    struct sockaddr_in addr;
> +    socklen_t addrlen = sizeof(addr);
> +    int acceptsock, err;
> +
> +    do {
> +        acceptsock = qemu_accept(s->sockfd, (struct sockaddr *)&addr, &addrlen);
> +        err = socket_error();
> +    } while (acceptsock < 0 && err == EINTR);
> +    qemu_set_fd_handler(s->sockfd, NULL, NULL, NULL);
> +    closesocket(s->sockfd);
> +
> +    DEBUG("accept colo proxy\n");
> +
> +    if (acceptsock < 0) {
> +        printf("could not accept colo connection (%s)\n",
> +                     strerror(err));

use error_report instead of printf please; also instead of 'colo connection'
make sure to say 'colo proxy connection' to make it easy to know which
failure it is.

> +        return;
> +    }
> +    s->sockfd = acceptsock;
> +    /* TODO: handle the packets that primary forward */
> +    return;
> +}
> +
> +/* Return 1 on success, or return -1 if failed */
> +static ssize_t colo_start_incoming(ColoProxyState *s)
> +{
> +    int serversock;
> +    serversock = inet_listen(s->addr, NULL, 256, SOCK_STREAM, 0, NULL);
> +    if (serversock < 0) {
> +        g_free(s->addr);
> +        return -1;
> +    }
> +    s->sockfd = serversock;
> +    qemu_set_fd_handler(serversock, (IOHandler *)colo_accept_incoming, NULL,
> +                        (void *)s);
> +    g_free(s->addr);
> +    return 1;
> +}
> +
> +/* Return 1 on success, or return -1 if setup failed */
> +static ssize_t colo_proxy_primary_setup(NetFilterState *nf)
> +{
> +    ColoProxyState *s = FILTER_COLO_PROXY(nf);
> +    int sock;
> +    sock = inet_connect(s->addr, NULL);
> +    if (sock < 0) {
> +        printf("colo proxy connect failed\n");
> +        g_free(s->addr);
> +        return -1;
> +    }
> +    DEBUG("colo proxy connect success\n");
> +    s->sockfd = sock;
> +   /* TODO: handle the packets that secondary forward */
> +    g_free(s->addr);
> +    return 1;
> +}
> +
> +/* Return 1 on success, or return -1 if setup failed */
> +static ssize_t colo_proxy_secondary_setup(NetFilterState *nf)
> +{
> +    ColoProxyState *s = FILTER_COLO_PROXY(nf);
> +    return colo_start_incoming(s);
> +}
>  
>  static void colo_proxy_setup(NetFilterState *nf, Error **errp)
>  {
>      ColoProxyState *s = FILTER_COLO_PROXY(nf);
> +    ssize_t ret = 0;
>      if (!s->addr) {
>          error_setg(errp, "filter colo_proxy needs 'addr' \
>                       property set!");
> @@ -68,17 +141,29 @@ static void colo_proxy_setup(NetFilterState *nf, Error **errp)
>      s->sockfd = -1;
>      s->has_failover = false;
>      colo_do_checkpoint = false;
> +    s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf);
> +    s->unprocessed_packets = g_hash_table_new_full(connection_key_hash,
> +                                                       connection_key_equal,
> +                                                       g_free,
> +                                                       connection_destroy);
>      g_queue_init(&s->unprocessed_connections);
>  
>      if (!strcmp(mode, PRIMARY_MODE)) {
>          s->colo_mode = COLO_PRIMARY_MODE;
> +        ret = colo_proxy_primary_setup(nf);
>      } else if (!strcmp(mode, SECONDARY_MODE)) {
>          s->colo_mode = COLO_SECONDARY_MODE;
> +        ret = colo_proxy_secondary_setup(nf);
>      } else {
>          error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "mode",
>                      "primary or secondary");
>          return;
>      }
> +    if (ret) {
> +        DEBUG("colo_proxy_setup success\n");
> +    } else {
> +        DEBUG("colo_proxy_setup failed\n");
> +    }

It's easier to use trace_ (especially with the stderr backend, it's very easy).
Do you not want to return the 'ret' value?

>  }
>  
>  static void colo_proxy_class_init(ObjectClass *oc, void *data)
> diff --git a/net/colo-proxy.h b/net/colo-proxy.h
> index 94afbc7..f77db2f 100644
> --- a/net/colo-proxy.h
> +++ b/net/colo-proxy.h
> @@ -60,4 +60,65 @@ typedef struct ColoProxyState {
>      Coroutine *co;
>  } ColoProxyState;
>  
> +struct ip {
> +#ifdef HOST_WORDS_BIGENDIAN
> +    uint8_t  ip_v:4,                 /* version */
> +             ip_hl:4;                /* header length */
> +#else
> +    uint8_t  ip_hl:4,                /* header length */
> +             ip_v:4;                 /* version */
> +#endif
> +    uint8_t  ip_tos;                 /* type of service */
> +    uint16_t ip_len;                 /* total length */
> +    uint16_t ip_id;                  /* identification */
> +    uint16_t ip_off;                 /* fragment offset field */
> +#define    IP_DF 0x4000              /* don't fragment flag */
> +#define    IP_MF 0x2000              /* more fragments flag */
> +#define    IP_OFFMASK 0x1fff
> +/* mask for fragmenting bits */
> +    uint8_t  ip_ttl;                 /* time to live */
> +    uint8_t  ip_p;                   /* protocol */
> +    uint16_t ip_sum;                 /* checksum */
> +    uint32_t ip_src, ip_dst;         /* source and dest address */
> +} QEMU_PACKED;
> +

Why not just #include slirp/ip.h ?

> +typedef struct Packet {
> +    void *data;
> +    union {
> +        uint8_t *network_layer;
> +        struct ip *ip;
> +    };
> +    uint8_t *transport_layer;
> +    int size;
> +    ColoProxyState *s;
> +    bool should_be_sent;
> +    NetClientState *sender;
> +} Packet;
> +
> +typedef struct Connection_key {
> +    /* (src, dst) must be grouped, in the same way than in IP header */
> +    uint32_t src;
> +    uint32_t dst;
> +    union {
> +        uint32_t ports;
> +        uint16_t port16[2];
> +    };

Why the union?

Dave

> +    uint8_t ip_proto;
> +} QEMU_PACKED Connection_key;
> +
> +typedef struct Connection {
> +    /* connection primary send queue */
> +    GQueue primary_list;
> +    /* connection secondary send queue */
> +    GQueue secondary_list;
> +     /* flag to enqueue unprocessed_connections */
> +    bool processing;
> +} Connection;
> +
> +typedef enum {
> +    PRIMARY_OUTPUT,           /* primary output packet queue */
> +    PRIMARY_INPUT,            /* primary input packet queue */
> +    SECONDARY_OUTPUT,         /* secondary output packet queue */
> +} packet_type;
> +
>  #endif /* QEMU_COLO_PROXY_H */
> -- 
> 1.9.1
> 
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK