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Re: [Qemu-devel] [PATCH V4 1/2] net/filter-mirror: implement filter-redi
From: |
Jason Wang |
Subject: |
Re: [Qemu-devel] [PATCH V4 1/2] net/filter-mirror: implement filter-redirector |
Date: |
Wed, 16 Mar 2016 16:18:51 +0800 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 |
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().
> +
> + /* 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.
> + 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 <=
- 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, 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, 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