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

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

On 03/31/2016 09:41 AM, Zhang Chen wrote:
>
>
> 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.

OK~ will fix.

>>
>>> +    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.

OK

>>
>>> +    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;
>>

will fix~~

>>> +    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 ?

Yes , will fix it in next version.

>>
>>> +                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).
>>

OK

>>> +                  "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?

Yes, the way on top of this mail.

>> Would you ever have a pri_indev and sec_indev on the same filter?

Not same one.

>> 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.

will fix


>>
>>> + 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: ?

I will fix code style to this.
we don't need set a handler for out, because we just send packet to out.
so we don't have to clean up out.

Thanks
Zhang Chen

>>
>>> +}
>>> +
>>> +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