Re: [Qemu-devel] [PATCH V2 1/3] colo-compare: introduce colo compare initlization

[Zhang Chen <zhangchen.fnst@cn.fujitsu.com>]

On 03/30/2016 05:25 PM, Dr. David Alan Gilbert wrote:
> * Zhang Chen (zhangchen.fnst@cn.fujitsu.com) wrote:
>> packet come from primary char indev will be send to
>> outdev - packet come from secondary char dev will be drop
> Please put in the description an example of how you invoke
> the filter on the primary and secondary.

OK.
colo-compare get packet from chardev(primary_in,secondary_in),
and output to other chardev(outdev), so, we can use it with the
help of filter-mirror and filter-redirector. like that:

primary:
-netdev 
tap,id=hn0,vhost=off,script=/etc/qemu-ifup,downscript=/etc/qemu-ifdown
-device e1000,id=e0,netdev=hn0,mac=52:a4:00:12:78:66
-chardev socket,id=mirror0,host=3.3.3.3,port=9003,server,nowait
-chardev socket,id=compare1,host=3.3.3.3,port=9004,server,nowait
-chardev socket,id=compare0,host=3.3.3.3,port=9001,server,nowait
-chardev socket,id=compare0-0,host=3.3.3.3,port=9001
-chardev socket,id=compare_out,host=3.3.3.3,port=9005,server,nowait
-chardev socket,id=compare_out0,host=3.3.3.3,port=9005
-object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0
-object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out
-object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0
-object 
colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,outdev=compare_out0 


secondary:
-netdev tap,id=hn0,vhost=off,script=/etc/qemu-ifup,down 
script=/etc/qemu-ifdown
-device e1000,netdev=hn0,mac=52:a4:00:12:78:66
-chardev socket,id=red0,host=3.3.3.3,port=9003
-chardev socket,id=red1,host=3.3.3.3,port=9004
-object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0
-object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1



>
>> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
>> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>> ---
>>   net/Makefile.objs  |   1 +
>>   net/colo-compare.c | 344 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   vl.c               |   3 +-
>>   3 files changed, 347 insertions(+), 1 deletion(-)
>>   create mode 100644 net/colo-compare.c
>>
>> diff --git a/net/Makefile.objs b/net/Makefile.objs
>> index b7c22fd..ba92f73 100644
>> --- a/net/Makefile.objs
>> +++ b/net/Makefile.objs
>> @@ -16,3 +16,4 @@ common-obj-$(CONFIG_NETMAP) += netmap.o
>>   common-obj-y += filter.o
>>   common-obj-y += filter-buffer.o
>>   common-obj-y += filter-mirror.o
>> +common-obj-y += colo-compare.o
>> diff --git a/net/colo-compare.c b/net/colo-compare.c
>> new file mode 100644
>> index 0000000..62c66df
>> --- /dev/null
>> +++ b/net/colo-compare.c
>> @@ -0,0 +1,344 @@
>> +/*
>> + * Copyright (c) 2016 FUJITSU LIMITED
>> + * Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
>> + *
>> + * This work is licensed under the terms of the GNU GPL, version 2 or
>> + * later.  See the COPYING file in the top-level directory.
>> + */
>> +
>> +#include "qemu/osdep.h"
>> +#include "qemu-common.h"
>> +#include "qapi/qmp/qerror.h"
>> +#include "qemu/error-report.h"
>> +
>> +#include "net/net.h"
>> +#include "net/vhost_net.h"
>> +#include "qom/object_interfaces.h"
>> +#include "qemu/iov.h"
>> +#include "qom/object.h"
>> +#include "qemu/typedefs.h"
>> +#include "net/queue.h"
>> +#include "sysemu/char.h"
>> +#include "qemu/sockets.h"
>> +
>> +#define TYPE_COLO_COMPARE "colo-compare"
>> +#define COLO_COMPARE(obj) \
>> +    OBJECT_CHECK(CompareState, (obj), TYPE_COLO_COMPARE)
>> +
>> +#define COMPARE_READ_LEN_MAX NET_BUFSIZE
>> +
>> +static QTAILQ_HEAD(, CompareState) net_compares =
>> +       QTAILQ_HEAD_INITIALIZER(net_compares);
>> +
>> +typedef struct ReadState {
>> +    int state; /* 0 = getting length, 1 = getting data */
>> +    unsigned int index;
>> +    unsigned int packet_len;
> Please make packet_len and index  uint32_t, since they're sent over the wire
> as 32bit.
>
>> +    uint8_t buf[COMPARE_READ_LEN_MAX];
>> +} ReadState;
>> +
>> +typedef struct CompareState {
>> +    Object parent;
>> +
>> +    char *pri_indev;
>> +    char *sec_indev;
>> +    char *outdev;
>> +    CharDriverState *chr_pri_in;
>> +    CharDriverState *chr_sec_in;
>> +    CharDriverState *chr_out;
>> +    QTAILQ_ENTRY(CompareState) next;
>> +    ReadState pri_rs;
>> +    ReadState sec_rs;
>> +} CompareState;
>> +
>> +static int compare_chr_send(CharDriverState *out, const uint8_t *buf, int size)
>> +{
>> +    int ret = 0;
>> +    uint32_t len = htonl(size);
>> +
> Similarly, make 'size' uint32_t - everything that gets converted into a uint32_t
> it's probably best to make a uint32_t.
>
>> +    if (!size) {
>> +        return 0;
>> +    }
>> +
>> +    ret = qemu_chr_fe_write_all(out, (uint8_t *)&len, sizeof(len));
>> +    if (ret != sizeof(len)) {
>> +        goto err;
>> +    }
>> +
>> +    ret = qemu_chr_fe_write_all(out, (uint8_t *)buf, size);
>> +    if (ret != size) {
>> +        goto err;
>> +    }
>> +
> You can make this slightly simpler and save the return 0;
>
>> +    return 0;
>> +
>> +err:
>> +    return ret < 0 ? ret : -EIO;
> err:
>         return ret <= 0 ? ret : -EIO;
>
>> +}
>> +
>> +static int compare_chr_can_read(void *opaque)
>> +{
>> +    return COMPARE_READ_LEN_MAX;
>> +}
>> +
>> +/* Returns
>> + * 0: readstate is not ready
>> + * 1: readstate is ready
>> + * otherwise error occurs
>> + */
>> +static int compare_chr_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 {
>> +                error_report("serious error: oversized packet received.");
> Isn't it easier to do this check above in the 'got length' if ?
> Instead of 'serious error' say where it's coming from;
>    'colo-compare: Received oversized packet over socket'
>
> that makes it a lot easier when people see the error for the first time.
> Also, should you check for the error case of receiving a packet where
> packet_len == 0 ?
>
>> +                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;
>> +}
>> +
>> +static void compare_pri_chr_in(void *opaque, const uint8_t *buf, int size)
>> +{
>> +    CompareState *s = COLO_COMPARE(opaque);
>> +    int ret;
>> +
>> +    ret = compare_chr_fill_rstate(&s->pri_rs, buf, size);
>> +    if (ret == 1) {
>> +        /* FIXME: enqueue to primary packet list */
>> +        compare_chr_send(s->chr_out, buf, size);
>> +    } else if (ret == -1) {
>> +        qemu_chr_add_handlers(s->chr_pri_in, NULL, NULL, NULL, NULL);
>> +    }
>> +}
>> +
>> +static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
>> +{
>> +    CompareState *s = COLO_COMPARE(opaque);
>> +    int ret;
>> +
>> +    ret = compare_chr_fill_rstate(&s->sec_rs, buf, size);
>> +    if (ret == 1) {
>> +        /* TODO: enqueue to secondary packet list*/
>> +    } else if (ret == -1) {
>> +        qemu_chr_add_handlers(s->chr_sec_in, NULL, NULL, NULL, NULL);
>> +    }
>> +}
>> +
>> +static char *compare_get_pri_indev(Object *obj, Error **errp)
>> +{
>> +    CompareState *s = COLO_COMPARE(obj);
>> +
>> +    return g_strdup(s->pri_indev);
>> +}
>> +
>> +static void compare_set_pri_indev(Object *obj, const char *value, Error **errp)
>> +{
>> +    CompareState *s = COLO_COMPARE(obj);
>> +
>> +    g_free(s->pri_indev);
>> +    s->pri_indev = g_strdup(value);
>> +}
>> +
>> +static char *compare_get_sec_indev(Object *obj, Error **errp)
>> +{
>> +    CompareState *s = COLO_COMPARE(obj);
>> +
>> +    return g_strdup(s->sec_indev);
>> +}
>> +
>> +static void compare_set_sec_indev(Object *obj, const char *value, Error **errp)
>> +{
>> +    CompareState *s = COLO_COMPARE(obj);
>> +
>> +    g_free(s->sec_indev);
>> +    s->sec_indev = g_strdup(value);
>> +}
>> +
>> +static char *compare_get_outdev(Object *obj, Error **errp)
>> +{
>> +    CompareState *s = COLO_COMPARE(obj);
>> +
>> +    return g_strdup(s->outdev);
>> +}
>> +
>> +static void compare_set_outdev(Object *obj, const char *value, Error **errp)
>> +{
>> +    CompareState *s = COLO_COMPARE(obj);
>> +
>> +    g_free(s->outdev);
>> +    s->outdev = g_strdup(value);
>> +}
>> +
>> +static void colo_compare_complete(UserCreatable *uc, Error **errp)
>> +{
>> +    CompareState *s = COLO_COMPARE(uc);
>> +
>> +    if (!s->pri_indev || !s->sec_indev || !s->outdev) {
>> +        error_setg(errp, "colo compare needs 'primary_in' ,"
>> +                   "'secondary_in','outdev' property set");
>> +        return;
>> +    } else if (!strcmp(s->pri_indev, s->outdev) ||
>> +               !strcmp(s->sec_indev, s->outdev) ||
>> +               !strcmp(s->pri_indev, s->sec_indev)) {
>> +        error_setg(errp, "'indev' and 'outdev' could not be same "
>> +                   "for compare module");
>> +        return;
>> +    }
>> +
>> +    s->chr_pri_in = qemu_chr_find(s->pri_indev);
>> +    if (s->chr_pri_in == NULL) {
>> +        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
> I think error_set seems to be discouraged these days, just use error_setg
> (see the comment in include/qapi/error.h just above error_set).
>
>> +                  "IN Device '%s' not found", s->pri_indev);
>> +        goto out;
>> +    }
>> +
>> +    qemu_chr_fe_claim_no_fail(s->chr_pri_in);
>> +    qemu_chr_add_handlers(s->chr_pri_in, compare_chr_can_read,
>> +                          compare_pri_chr_in, NULL, s);
>> +
>> +    s->chr_sec_in = qemu_chr_find(s->sec_indev);
>> +    if (s->chr_sec_in == NULL) {
>> +        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
>> +                  "IN Device '%s' not found", s->sec_indev);
>> +        goto out;
>> +    }
> Can you explain/give an example of the way you create one of these
> filters?
> Would you ever have a pri_indev and sec_indev on the same filter?
> If not, then why not just have an 'indev' option rather than the
> two separate configs.
> If you cna have both then you need to change hte error 'IN Device'
> to say either 'Primary IN device' or secondary.
>
>> +    qemu_chr_fe_claim_no_fail(s->chr_sec_in);
>> +    qemu_chr_add_handlers(s->chr_sec_in, compare_chr_can_read,
>> +                          compare_sec_chr_in, NULL, s);
>> +
>> +    s->chr_out = qemu_chr_find(s->outdev);
>> +    if (s->chr_out == NULL) {
>> +        error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
>> +                  "OUT Device '%s' not found", s->outdev);
>> +        goto out;
>> +    }
>> +    qemu_chr_fe_claim_no_fail(s->chr_out);
>> +
>> +    QTAILQ_INSERT_TAIL(&net_compares, s, next);
>> +
>> +    return;
>> +
>> +out:
>> +    if (s->chr_pri_in) {
>> +        qemu_chr_add_handlers(s->chr_pri_in, NULL, NULL, NULL, NULL);
>> +        qemu_chr_fe_release(s->chr_pri_in);
>> +        s->chr_pri_in = NULL;
>> +    }
>> +    if (s->chr_sec_in) {
>> +        qemu_chr_add_handlers(s->chr_sec_in, NULL, NULL, NULL, NULL);
>> +        qemu_chr_fe_release(s->chr_sec_in);
>> +        s->chr_pri_in = NULL;
>> +    }
> Can't you avoid this by making the code:
>
>       s->chr_pri_in = qemu_chr_find(...)
>       if (s->chr_pri_in == NULL) {
>          error (...)
>       }
>       s->chr_sec_in = qemu_chr_find(...)
>       if (s->chr_sec_in == NULL) {
>          error (...)
>       }
>       s->chr_out = qemu_chr_find(...)
>       if (s->chr_out == NULL) {
>          error (...)
>       }
>
>       qemu_chr_fe_claim_no_fail(pri)
>       add_handlers(pri...)
>       qemu_chr_fe_claim_no_fail(sec)
>       add_handlers(sec...)
>       qemu_chr_fe_claim_no_fail(out)
>       add_handlers(out...)
>
> so you don't have to clean up the handlers/release in the out: ?
>
>> +}
>> +
>> +static void colo_compare_class_init(ObjectClass *oc, void *data)
>> +{
>> +    UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
>> +
>> +    ucc->complete = colo_compare_complete;
>> +}
>> +
>> +static void colo_compare_class_finalize(ObjectClass *oc, void *data)
>> +{
>> +    UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
>> +    CompareState *s = COLO_COMPARE(ucc);
>> +
>> +    if (s->chr_pri_in) {
>> +        qemu_chr_add_handlers(s->chr_pri_in, NULL, NULL, NULL, NULL);
>> +        qemu_chr_fe_release(s->chr_pri_in);
>> +    }
>> +    if (s->chr_sec_in) {
>> +        qemu_chr_add_handlers(s->chr_sec_in, NULL, NULL, NULL, NULL);
>> +        qemu_chr_fe_release(s->chr_sec_in);
>> +    }
>> +    if (s->chr_out) {
>> +        qemu_chr_fe_release(s->chr_out);
>> +    }
>> +
>> +    if (!QTAILQ_EMPTY(&net_compares)) {
>> +        QTAILQ_REMOVE(&net_compares, s, next);
>> +    }
>> +}
>> +
>> +static void colo_compare_init(Object *obj)
>> +{
>> +    object_property_add_str(obj, "primary_in",
>> +                            compare_get_pri_indev, compare_set_pri_indev,
>> +                            NULL);
>> +    object_property_add_str(obj, "secondary_in",
>> +                            compare_get_sec_indev, compare_set_sec_indev,
>> +                            NULL);
>> +    object_property_add_str(obj, "outdev",
>> +                            compare_get_outdev, compare_set_outdev,
>> +                            NULL);
>> +}
>> +
>> +static void colo_compare_finalize(Object *obj)
>> +{
>> +    CompareState *s = COLO_COMPARE(obj);
>> +
>> +    g_free(s->pri_indev);
>> +    g_free(s->sec_indev);
>> +    g_free(s->outdev);
>> +}
>> +
>> +static const TypeInfo colo_compare_info = {
>> +    .name = TYPE_COLO_COMPARE,
>> +    .parent = TYPE_OBJECT,
>> +    .instance_size = sizeof(CompareState),
>> +    .instance_init = colo_compare_init,
>> +    .instance_finalize = colo_compare_finalize,
>> +    .class_size = sizeof(CompareState),
>> +    .class_init = colo_compare_class_init,
>> +    .class_finalize = colo_compare_class_finalize,
>> +    .interfaces = (InterfaceInfo[]) {
>> +        { TYPE_USER_CREATABLE },
>> +        { }
>> +    }
>> +};
>> +
>> +static void register_types(void)
>> +{
>> +    type_register_static(&colo_compare_info);
>> +}
>> +
>> +type_init(register_types);
>> diff --git a/vl.c b/vl.c
>> index dc6e63a..70064ad 100644
>> --- a/vl.c
>> +++ b/vl.c
>> @@ -2842,7 +2842,8 @@ static bool object_create_initial(const char *type)
>>       if (g_str_equal(type, "filter-buffer") ||
>>           g_str_equal(type, "filter-dump") ||
>>           g_str_equal(type, "filter-mirror") ||
>> -        g_str_equal(type, "filter-redirector")) {
>> +        g_str_equal(type, "filter-redirector") ||
>> +        g_str_equal(type, "colo-compare")) {
>>           return false;
>>       }
>>   
>> -- 
>> 1.9.1
>>
>>
>>
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>
>
> .
>

-- 
Thanks
zhangchen