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Re: [Qemu-devel] [PATCH V4 1/2] net/filter-mirror: implement filter-redi
From: |
Wen Congyang |
Subject: |
Re: [Qemu-devel] [PATCH V4 1/2] net/filter-mirror: implement filter-redirector |
Date: |
Wed, 16 Mar 2016 17:34:58 +0800 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 |
On 03/16/2016 04:18 PM, Jason Wang wrote:
>
>
> On 03/15/2016 06:03 PM, Zhang Chen wrote:
>> Filter-redirector is a netfilter plugin.
>> It gives qemu the ability to redirect net packet.
>> redirector can redirect filter's net packet to outdev.
>> and redirect indev's packet to filter.
>>
>> filter
>> +
>> |
>> |
>> redirector |
>> +--------------+
>> | | |
>> | | |
>> | | |
>> indev +-----------+ +----------> outdev
>> | | |
>> | | |
>> | | |
>> +--------------+
>> |
>> |
>> v
>> filter
>>
>> usage:
>>
>> -netdev user,id=hn0
>> -chardev socket,id=s0,host=ip_primary,port=X,server,nowait
>> -chardev socket,id=s1,host=ip_primary,port=Y,server,nowait
>> -filter-redirector,id=r0,netdev=hn0,queue=tx/rx/all,indev=s0,outdev=s1
>>
>> Signed-off-by: Zhang Chen <address@hidden>
>> Signed-off-by: Wen Congyang <address@hidden>
>> Signed-off-by: Li Zhijian <address@hidden>
>> ---
>> net/filter-mirror.c | 236
>> ++++++++++++++++++++++++++++++++++++++++++++++++++++
>> qemu-options.hx | 9 ++
>> vl.c | 3 +-
>> 3 files changed, 247 insertions(+), 1 deletion(-)
>>
>> diff --git a/net/filter-mirror.c b/net/filter-mirror.c
>> index 1b1ec16..77ece41 100644
>> --- a/net/filter-mirror.c
>> +++ b/net/filter-mirror.c
>> @@ -26,12 +26,23 @@
>> #define FILTER_MIRROR(obj) \
>> OBJECT_CHECK(MirrorState, (obj), TYPE_FILTER_MIRROR)
>>
>> +#define FILTER_REDIRECTOR(obj) \
>> + OBJECT_CHECK(MirrorState, (obj), TYPE_FILTER_REDIRECTOR)
>> +
>> #define TYPE_FILTER_MIRROR "filter-mirror"
>> +#define TYPE_FILTER_REDIRECTOR "filter-redirector"
>> +#define REDIRECTOR_MAX_LEN NET_BUFSIZE
>>
>> typedef struct MirrorState {
>> NetFilterState parent_obj;
>> + char *indev;
>> 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];
>> } MirrorState;
>>
>> static int filter_mirror_send(CharDriverState *chr_out,
>> @@ -68,6 +79,89 @@ err:
>> return ret < 0 ? ret : -EIO;
>> }
>>
>> +static void
>> +redirector_to_filter(NetFilterState *nf, const uint8_t *buf, int len)
>> +{
>> + struct iovec iov = {
>> + .iov_base = (void *)buf,
>> + .iov_len = len,
>> + };
>> +
>> + if (nf->direction == NET_FILTER_DIRECTION_ALL ||
>> + nf->direction == NET_FILTER_DIRECTION_TX) {
>> + qemu_netfilter_pass_to_next(nf->netdev, 0, &iov, 1, nf);
>> + }
>> +
>> + if (nf->direction == NET_FILTER_DIRECTION_ALL ||
>> + nf->direction == NET_FILTER_DIRECTION_RX) {
>> + qemu_netfilter_pass_to_next(nf->netdev->peer, 0, &iov, 1, nf);
>> + }
>> +}
>> +
>> +static int redirector_chr_can_read(void *opaque)
>> +{
>> + return REDIRECTOR_MAX_LEN;
>> +}
>> +
>> +static void redirector_chr_read(void *opaque, const uint8_t *buf, int size)
>> +{
>> + NetFilterState *nf = opaque;
>> + MirrorState *s = FILTER_REDIRECTOR(nf);
>> + unsigned int l;
>> +
>> + if (size == 0) {
>> + /* the peer is closed ? */
>> + return ;
>> + }
>
> Looks like if you want to handle connection close, you need use event
> handler when calling qemu_chr_add_handlers().
In which case, we will see size is 0 if we don't have a event handler?
For redirector filter, I think we don't care about if the char device
is disconnected. If the char device is ready again, we will continue
to read from the char device.
So I think we just add more comments here.
>
>> +
>> + /* most of code is stolen from net_socket_send */
>
> This comment seems redundant.
>
>> + 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");
>
> error_report() looks better.
>
>> + s->state = 0;
>> + /* FIXME: do something ? */
>
> This needs some thought, but at least reset the fd handler and state is
> needed.
Maybe we can read the data from the chardev, and drop it?
Thanks
Wen Congyang
>
>> + 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;
>> + }
>> + }
>> +}
>> +
>> static ssize_t filter_mirror_receive_iov(NetFilterState *nf,
>> NetClientState *sender,
>> unsigned flags,
>> @@ -90,6 +184,27 @@ static ssize_t filter_mirror_receive_iov(NetFilterState
>> *nf,
>> return 0;
>> }
>>
>> +static ssize_t filter_redirector_receive_iov(NetFilterState *nf,
>> + NetClientState *sender,
>> + unsigned flags,
>> + const struct iovec *iov,
>> + int iovcnt,
>> + NetPacketSent *sent_cb)
>> +{
>> + MirrorState *s = FILTER_REDIRECTOR(nf);
>> + int ret;
>> +
>> + if (s->chr_out) {
>> + ret = filter_mirror_send(s->chr_out, iov, iovcnt);
>> + if (ret) {
>> + error_report("filter_mirror_send failed(%s)", strerror(-ret));
>> + }
>> + return iov_size(iov, iovcnt);
>> + } else {
>> + return 0;
>> + }
>> +}
>> +
>> static void filter_mirror_cleanup(NetFilterState *nf)
>> {
>> MirrorState *s = FILTER_MIRROR(nf);
>> @@ -99,6 +214,18 @@ static void filter_mirror_cleanup(NetFilterState *nf)
>> }
>> }
>>
>> +static void filter_redirector_cleanup(NetFilterState *nf)
>> +{
>> + MirrorState *s = FILTER_REDIRECTOR(nf);
>> +
>> + if (s->chr_in) {
>> + qemu_chr_fe_release(s->chr_in);
>> + }
>> + if (s->chr_out) {
>> + qemu_chr_fe_release(s->chr_out);
>> + }
>> +}
>> +
>> static void filter_mirror_setup(NetFilterState *nf, Error **errp)
>> {
>> MirrorState *s = FILTER_MIRROR(nf);
>> @@ -122,6 +249,48 @@ static void filter_mirror_setup(NetFilterState *nf,
>> Error **errp)
>> }
>> }
>>
>> +static void filter_redirector_setup(NetFilterState *nf, Error **errp)
>> +{
>> + MirrorState *s = FILTER_REDIRECTOR(nf);
>> +
>> + if (!s->indev && !s->outdev) {
>> + error_setg(errp, "filter redirector needs 'indev' or "
>> + "'outdev' at least one property set");
>> + return;
>> + } else if (s->indev && s->outdev) {
>> + if (!strcmp(s->indev, s->outdev)) {
>> + error_setg(errp, "filter redirector needs 'indev' and "
>> + "'outdev' are not same");
>> + return;
>> + }
>> + }
>> +
>> + s->state = s->index = 0;
>> +
>> + if (s->indev) {
>> + s->chr_in = qemu_chr_find(s->indev);
>> + if (s->chr_in == NULL) {
>> + error_set(errp, ERROR_CLASS_DEVICE_NOT_FOUND,
>> + "IN Device '%s' not found", s->indev);
>> + return;
>> + }
>> +
>> + qemu_chr_fe_claim_no_fail(s->chr_in);
>> + qemu_chr_add_handlers(s->chr_in, redirector_chr_can_read,
>> + redirector_chr_read, NULL, nf);
>> + }
>> +
>> + if (s->outdev) {
>> + 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);
>> + return;
>> + }
>> + qemu_chr_fe_claim_no_fail(s->chr_out);
>> + }
>> +}
>> +
>> static void filter_mirror_class_init(ObjectClass *oc, void *data)
>> {
>> NetFilterClass *nfc = NETFILTER_CLASS(oc);
>> @@ -131,6 +300,31 @@ static void filter_mirror_class_init(ObjectClass *oc,
>> void *data)
>> nfc->receive_iov = filter_mirror_receive_iov;
>> }
>>
>> +static void filter_redirector_class_init(ObjectClass *oc, void *data)
>> +{
>> + NetFilterClass *nfc = NETFILTER_CLASS(oc);
>> +
>> + nfc->setup = filter_redirector_setup;
>> + nfc->cleanup = filter_redirector_cleanup;
>> + nfc->receive_iov = filter_redirector_receive_iov;
>> +}
>> +
>> +static char *filter_redirector_get_indev(Object *obj, Error **errp)
>> +{
>> + MirrorState *s = FILTER_REDIRECTOR(obj);
>> +
>> + return g_strdup(s->indev);
>> +}
>> +
>> +static void
>> +filter_redirector_set_indev(Object *obj, const char *value, Error **errp)
>> +{
>> + MirrorState *s = FILTER_REDIRECTOR(obj);
>> +
>> + g_free(s->indev);
>> + s->indev = g_strdup(value);
>> +}
>> +
>> static char *filter_mirror_get_outdev(Object *obj, Error **errp)
>> {
>> MirrorState *s = FILTER_MIRROR(obj);
>> @@ -152,12 +346,36 @@ filter_mirror_set_outdev(Object *obj, const char
>> *value, Error **errp)
>> }
>> }
>>
>> +static char *filter_redirector_get_outdev(Object *obj, Error **errp)
>> +{
>> + MirrorState *s = FILTER_REDIRECTOR(obj);
>> +
>> + return g_strdup(s->outdev);
>> +}
>> +
>> +static void
>> +filter_redirector_set_outdev(Object *obj, const char *value, Error **errp)
>> +{
>> + MirrorState *s = FILTER_REDIRECTOR(obj);
>> +
>> + g_free(s->outdev);
>> + s->outdev = g_strdup(value);
>> +}
>> +
>> static void filter_mirror_init(Object *obj)
>> {
>> object_property_add_str(obj, "outdev", filter_mirror_get_outdev,
>> filter_mirror_set_outdev, NULL);
>> }
>>
>> +static void filter_redirector_init(Object *obj)
>> +{
>> + object_property_add_str(obj, "indev", filter_redirector_get_indev,
>> + filter_redirector_set_indev, NULL);
>> + object_property_add_str(obj, "outdev", filter_redirector_get_outdev,
>> + filter_redirector_set_outdev, NULL);
>> +}
>> +
>> static void filter_mirror_fini(Object *obj)
>> {
>> MirrorState *s = FILTER_MIRROR(obj);
>> @@ -165,6 +383,23 @@ static void filter_mirror_fini(Object *obj)
>> g_free(s->outdev);
>> }
>>
>> +static void filter_redirector_fini(Object *obj)
>> +{
>> + MirrorState *s = FILTER_REDIRECTOR(obj);
>> +
>> + g_free(s->indev);
>> + g_free(s->outdev);
>
> We probably want to reset chr handlers there, otherwise there may be
> use-after-free.
>
>> +}
>> +
>> +static const TypeInfo filter_redirector_info = {
>> + .name = TYPE_FILTER_REDIRECTOR,
>> + .parent = TYPE_NETFILTER,
>> + .class_init = filter_redirector_class_init,
>> + .instance_init = filter_redirector_init,
>> + .instance_finalize = filter_redirector_fini,
>> + .instance_size = sizeof(MirrorState),
>> +};
>> +
>> static const TypeInfo filter_mirror_info = {
>> .name = TYPE_FILTER_MIRROR,
>> .parent = TYPE_NETFILTER,
>> @@ -177,6 +412,7 @@ static const TypeInfo filter_mirror_info = {
>> static void register_types(void)
>> {
>> type_register_static(&filter_mirror_info);
>> + type_register_static(&filter_redirector_info);
>> }
>>
>> type_init(register_types);
>> diff --git a/qemu-options.hx b/qemu-options.hx
>> index 5379cb5..796d053 100644
>> --- a/qemu-options.hx
>> +++ b/qemu-options.hx
>> @@ -3821,6 +3821,15 @@ queue @var{all|rx|tx} is an option that can be
>> applied to any netfilter.
>> filter-mirror on netdev @var{netdevid},mirror net packet to chardev
>> @var{chardevid}
>>
>> address@hidden -object
>> filter-redirector,address@hidden,address@hidden,address@hidden,
>> address@hidden,address@hidden|rx|tx}]
>> +
>> +filter-redirector on netdev @var{netdevid},redirect filter's net packet to
>> chardev
>> address@hidden,and redirect indev's packet to filter.
>> +Create a filter-redirector we need to differ outdev id from indev id, id
>> can not
>> +be the same. we can just use indev or outdev, but at least one of indev or
>> outdev
>> +need to be specified.
>> +
>> @item -object
>> filter-dump,address@hidden,address@hidden,address@hidden,address@hidden
>>
>> Dump the network traffic on netdev @var{dev} to the file specified by
>> diff --git a/vl.c b/vl.c
>> index 79bb11a..dc6e63a 100644
>> --- a/vl.c
>> +++ b/vl.c
>> @@ -2841,7 +2841,8 @@ 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-mirror") ||
>> + g_str_equal(type, "filter-redirector")) {
>> return false;
>> }
>>
>
>
>
>
> .
>
- [Qemu-devel] [PATCH V4 0/2] Introduce filter-redirector, Zhang Chen, 2016/03/15
- [Qemu-devel] [PATCH V4 1/2] net/filter-mirror: implement filter-redirector, Zhang Chen, 2016/03/15
- Re: [Qemu-devel] [PATCH V4 1/2] net/filter-mirror: implement filter-redirector, Jason Wang, 2016/03/16
- Re: [Qemu-devel] [PATCH V4 1/2] net/filter-mirror: implement filter-redirector, Li Zhijian, 2016/03/16
- Re: [Qemu-devel] [PATCH V4 1/2] net/filter-mirror: implement filter-redirector,
Wen Congyang <=
- Re: [Qemu-devel] [PATCH V4 1/2] net/filter-mirror: implement filter-redirector, Li Zhijian, 2016/03/16
- Re: [Qemu-devel] [PATCH V4 1/2] net/filter-mirror: implement filter-redirector, Jason Wang, 2016/03/17
- Re: [Qemu-devel] [PATCH V4 1/2] net/filter-mirror: implement filter-redirector, Wen Congyang, 2016/03/17
- Re: [Qemu-devel] [PATCH V4 1/2] net/filter-mirror: implement filter-redirector, Jason Wang, 2016/03/17
[Qemu-devel] [PATCH V4 2/2] tests/test-filter-redirector: Add unit test for filter-redirector, Zhang Chen, 2016/03/15
Re: [Qemu-devel] [PATCH V4 0/2] Introduce filter-redirector, Jason Wang, 2016/03/16