From: Oliver Hartkopp <socketcan@hartkopp.net>
To: Erik Flodin <erik@flodin.me>, mkl@pengutronix.de
Cc: davem@davemloft.net, kuba@kernel.org, corbet@lwn.net,
linux-can@vger.kernel.org, netdev@vger.kernel.org,
linux-doc@vger.kernel.org
Subject: Re: [PATCH v2 1/2] can: add support for filtering own messages only
Date: Wed, 5 May 2021 08:58:57 +0200 [thread overview]
Message-ID: <cf5fdb14-47e2-2d08-0d29-c621bff7b312@hartkopp.net> (raw)
In-Reply-To: <20210504203546.115734-2-erik@flodin.me>
Hi Erik,
IMO putting linux-can@vger.kernel.org in CC would be sufficient in this
stage of discussion.
On 04.05.21 22:35, Erik Flodin wrote:
> Add a new flag to can_rx_register/unregister that, when set, requires
> that the received sk_buff's owning socket matches the socket pointer
> given when setting the filter. This makes it possible to set a filter
> that matches all frames sent on a given socket and nothing else.
This is a pretty simple requirement and you are touching almost every
CAN network layer file.
From this description I would suggest a two-liner to be added in raw.c
diff --git a/net/can/raw.c b/net/can/raw.c
index 139d9471ddcf..8c6371a0c8a6 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -123,10 +123,14 @@ static void raw_rcv(struct sk_buff *oskb, void *data)
/* check the received tx sock reference */
if (!ro->recv_own_msgs && oskb->sk == sk)
return;
+ /* check the received tx sock reference */
+ if (ro->recv_only_own_msgs && oskb->sk != sk)
+ return;
+
/* do not pass non-CAN2.0 frames to a legacy socket */
if (!ro->fd_frames && oskb->len != CAN_MTU)
return;
/* eliminate multiple filter matches for the same skb */
And then add CAN_RAW_RECV_ONLY_OWN_MSGS accordingly.
Wouldn't that already match your requirements?
Best regards,
Oliver
ps. please reduce the CC receipient list before answering, thanks.
>
> Signed-off-by: Erik Flodin <erik@flodin.me>
> ---
> include/linux/can/core.h | 4 ++--
> net/can/af_can.c | 50 ++++++++++++++++++++++------------------
> net/can/af_can.h | 1 +
> net/can/bcm.c | 9 +++++---
> net/can/gw.c | 7 +++---
> net/can/isotp.c | 8 +++----
> net/can/j1939/main.c | 4 ++--
> net/can/proc.c | 11 +++++----
> net/can/raw.c | 10 ++++----
> 9 files changed, 58 insertions(+), 46 deletions(-)
>
> diff --git a/include/linux/can/core.h b/include/linux/can/core.h
> index 5fb8d0e3f9c1..7ee68128dc10 100644
> --- a/include/linux/can/core.h
> +++ b/include/linux/can/core.h
> @@ -48,12 +48,12 @@ extern int can_proto_register(const struct can_proto *cp);
> extern void can_proto_unregister(const struct can_proto *cp);
>
> int can_rx_register(struct net *net, struct net_device *dev,
> - canid_t can_id, canid_t mask,
> + canid_t can_id, canid_t mask, bool match_sk,
> void (*func)(struct sk_buff *, void *),
> void *data, char *ident, struct sock *sk);
>
> extern void can_rx_unregister(struct net *net, struct net_device *dev,
> - canid_t can_id, canid_t mask,
> + canid_t can_id, canid_t mask, bool match_sk,
> void (*func)(struct sk_buff *, void *),
> void *data);
>
> diff --git a/net/can/af_can.c b/net/can/af_can.c
> index cce2af10eb3e..7b639c121653 100644
> --- a/net/can/af_can.c
> +++ b/net/can/af_can.c
> @@ -414,6 +414,7 @@ static struct hlist_head *can_rcv_list_find(canid_t *can_id, canid_t *mask,
> * @dev: pointer to netdevice (NULL => subscribe from 'all' CAN devices list)
> * @can_id: CAN identifier (see description)
> * @mask: CAN mask (see description)
> + * @match_sk: match socket pointer on received sk_buff (see description)
> * @func: callback function on filter match
> * @data: returned parameter for callback function
> * @ident: string for calling module identification
> @@ -428,6 +429,9 @@ static struct hlist_head *can_rcv_list_find(canid_t *can_id, canid_t *mask,
> * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can
> * filter for error message frames (CAN_ERR_FLAG bit set in mask).
> *
> + * If match_sk is true, the received sk_buff's owning socket must also match
> + * the given socket pointer.
> + *
> * The provided pointer to the sk_buff is guaranteed to be valid as long as
> * the callback function is running. The callback function must *not* free
> * the given sk_buff while processing it's task. When the given sk_buff is
> @@ -440,8 +444,9 @@ static struct hlist_head *can_rcv_list_find(canid_t *can_id, canid_t *mask,
> * -ENODEV unknown device
> */
> int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
> - canid_t mask, void (*func)(struct sk_buff *, void *),
> - void *data, char *ident, struct sock *sk)
> + canid_t mask, bool match_sk,
> + void (*func)(struct sk_buff *, void *), void *data,
> + char *ident, struct sock *sk)
> {
> struct receiver *rcv;
> struct hlist_head *rcv_list;
> @@ -468,6 +473,7 @@ int can_rx_register(struct net *net, struct net_device *dev, canid_t can_id,
>
> rcv->can_id = can_id;
> rcv->mask = mask;
> + rcv->match_sk = match_sk;
> rcv->matches = 0;
> rcv->func = func;
> rcv->data = data;
> @@ -503,6 +509,7 @@ static void can_rx_delete_receiver(struct rcu_head *rp)
> * @dev: pointer to netdevice (NULL => unsubscribe from 'all' CAN devices list)
> * @can_id: CAN identifier
> * @mask: CAN mask
> + * @match_sk: match socket pointer on received sk_buff
> * @func: callback function on filter match
> * @data: returned parameter for callback function
> *
> @@ -510,8 +517,8 @@ static void can_rx_delete_receiver(struct rcu_head *rp)
> * Removes subscription entry depending on given (subscription) values.
> */
> void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id,
> - canid_t mask, void (*func)(struct sk_buff *, void *),
> - void *data)
> + canid_t mask, bool match_sk,
> + void (*func)(struct sk_buff *, void *), void *data)
> {
> struct receiver *rcv = NULL;
> struct hlist_head *rcv_list;
> @@ -535,7 +542,8 @@ void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id,
> */
> hlist_for_each_entry_rcu(rcv, rcv_list, list) {
> if (rcv->can_id == can_id && rcv->mask == mask &&
> - rcv->func == func && rcv->data == data)
> + rcv->match_sk == match_sk && rcv->func == func &&
> + rcv->data == data)
> break;
> }
>
> @@ -546,8 +554,8 @@ void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id,
> * a warning here.
> */
> if (!rcv) {
> - pr_warn("can: receive list entry not found for dev %s, id %03X, mask %03X\n",
> - DNAME(dev), can_id, mask);
> + pr_warn("can: receive list entry not found for dev %s, id %03X, mask %03X%s\n",
> + DNAME(dev), can_id, mask, match_sk ? " (match sk)" : "");
> goto out;
> }
>
> @@ -569,10 +577,14 @@ void can_rx_unregister(struct net *net, struct net_device *dev, canid_t can_id,
> }
> EXPORT_SYMBOL(can_rx_unregister);
>
> -static inline void deliver(struct sk_buff *skb, struct receiver *rcv)
> +static inline int deliver(struct sk_buff *skb, struct receiver *rcv)
> {
> - rcv->func(skb, rcv->data);
> - rcv->matches++;
> + if (!rcv->match_sk || skb->sk == rcv->sk) {
> + rcv->func(skb, rcv->data);
> + rcv->matches++;
> + return 1;
> + }
> + return 0;
> }
>
> static int can_rcv_filter(struct can_dev_rcv_lists *dev_rcv_lists, struct sk_buff *skb)
> @@ -589,8 +601,7 @@ static int can_rcv_filter(struct can_dev_rcv_lists *dev_rcv_lists, struct sk_buf
> /* check for error message frame entries only */
> hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ERR], list) {
> if (can_id & rcv->mask) {
> - deliver(skb, rcv);
> - matches++;
> + matches += deliver(skb, rcv);
> }
> }
> return matches;
> @@ -598,23 +609,20 @@ static int can_rcv_filter(struct can_dev_rcv_lists *dev_rcv_lists, struct sk_buf
>
> /* check for unfiltered entries */
> hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_ALL], list) {
> - deliver(skb, rcv);
> - matches++;
> + matches += deliver(skb, rcv);
> }
>
> /* check for can_id/mask entries */
> hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_FIL], list) {
> if ((can_id & rcv->mask) == rcv->can_id) {
> - deliver(skb, rcv);
> - matches++;
> + matches += deliver(skb, rcv);
> }
> }
>
> /* check for inverted can_id/mask entries */
> hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx[RX_INV], list) {
> if ((can_id & rcv->mask) != rcv->can_id) {
> - deliver(skb, rcv);
> - matches++;
> + matches += deliver(skb, rcv);
> }
> }
>
> @@ -625,15 +633,13 @@ static int can_rcv_filter(struct can_dev_rcv_lists *dev_rcv_lists, struct sk_buf
> if (can_id & CAN_EFF_FLAG) {
> hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_eff[effhash(can_id)], list) {
> if (rcv->can_id == can_id) {
> - deliver(skb, rcv);
> - matches++;
> + matches += deliver(skb, rcv);
> }
> }
> } else {
> can_id &= CAN_SFF_MASK;
> hlist_for_each_entry_rcu(rcv, &dev_rcv_lists->rx_sff[can_id], list) {
> - deliver(skb, rcv);
> - matches++;
> + matches += deliver(skb, rcv);
> }
> }
>
> diff --git a/net/can/af_can.h b/net/can/af_can.h
> index 7c2d9161e224..ea98b10d93e7 100644
> --- a/net/can/af_can.h
> +++ b/net/can/af_can.h
> @@ -52,6 +52,7 @@ struct receiver {
> struct hlist_node list;
> canid_t can_id;
> canid_t mask;
> + bool match_sk;
> unsigned long matches;
> void (*func)(struct sk_buff *skb, void *data);
> void *data;
> diff --git a/net/can/bcm.c b/net/can/bcm.c
> index 909b9e684e04..d89dd82c2178 100644
> --- a/net/can/bcm.c
> +++ b/net/can/bcm.c
> @@ -729,7 +729,8 @@ static void bcm_rx_unreg(struct net_device *dev, struct bcm_op *op)
> {
> if (op->rx_reg_dev == dev) {
> can_rx_unregister(dev_net(dev), dev, op->can_id,
> - REGMASK(op->can_id), bcm_rx_handler, op);
> + REGMASK(op->can_id), false, bcm_rx_handler,
> + op);
>
> /* mark as removed subscription */
> op->rx_reg_dev = NULL;
> @@ -775,6 +776,7 @@ static int bcm_delete_rx_op(struct list_head *ops, struct bcm_msg_head *mh,
> can_rx_unregister(sock_net(op->sk), NULL,
> op->can_id,
> REGMASK(op->can_id),
> + false,
> bcm_rx_handler, op);
>
> list_del(&op->list);
> @@ -1193,6 +1195,7 @@ static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
> err = can_rx_register(sock_net(sk), dev,
> op->can_id,
> REGMASK(op->can_id),
> + false,
> bcm_rx_handler, op,
> "bcm", sk);
>
> @@ -1202,7 +1205,7 @@ static int bcm_rx_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
>
> } else
> err = can_rx_register(sock_net(sk), NULL, op->can_id,
> - REGMASK(op->can_id),
> + REGMASK(op->can_id), false,
> bcm_rx_handler, op, "bcm", sk);
> if (err) {
> /* this bcm rx op is broken -> remove it */
> @@ -1500,7 +1503,7 @@ static int bcm_release(struct socket *sock)
> }
> } else
> can_rx_unregister(net, NULL, op->can_id,
> - REGMASK(op->can_id),
> + REGMASK(op->can_id), false,
> bcm_rx_handler, op);
>
> bcm_remove_op(op);
> diff --git a/net/can/gw.c b/net/can/gw.c
> index ba4124805602..5dbc7b85e0fc 100644
> --- a/net/can/gw.c
> +++ b/net/can/gw.c
> @@ -567,14 +567,15 @@ static void can_can_gw_rcv(struct sk_buff *skb, void *data)
> static inline int cgw_register_filter(struct net *net, struct cgw_job *gwj)
> {
> return can_rx_register(net, gwj->src.dev, gwj->ccgw.filter.can_id,
> - gwj->ccgw.filter.can_mask, can_can_gw_rcv,
> - gwj, "gw", NULL);
> + gwj->ccgw.filter.can_mask, false,
> + can_can_gw_rcv, gwj, "gw", NULL);
> }
>
> static inline void cgw_unregister_filter(struct net *net, struct cgw_job *gwj)
> {
> can_rx_unregister(net, gwj->src.dev, gwj->ccgw.filter.can_id,
> - gwj->ccgw.filter.can_mask, can_can_gw_rcv, gwj);
> + gwj->ccgw.filter.can_mask, false, can_can_gw_rcv,
> + gwj);
> }
>
> static int cgw_notifier(struct notifier_block *nb,
> diff --git a/net/can/isotp.c b/net/can/isotp.c
> index 9f94ad3caee9..44d943bbe0b1 100644
> --- a/net/can/isotp.c
> +++ b/net/can/isotp.c
> @@ -1029,7 +1029,7 @@ static int isotp_release(struct socket *sock)
> if (dev) {
> can_rx_unregister(net, dev, so->rxid,
> SINGLE_MASK(so->rxid),
> - isotp_rcv, sk);
> + false, isotp_rcv, sk);
> dev_put(dev);
> }
> }
> @@ -1111,7 +1111,7 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
> if (do_rx_reg)
> can_rx_register(net, dev, addr->can_addr.tp.rx_id,
> SINGLE_MASK(addr->can_addr.tp.rx_id),
> - isotp_rcv, sk, "isotp", sk);
> + false, isotp_rcv, sk, "isotp", sk);
>
> dev_put(dev);
>
> @@ -1122,7 +1122,7 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
> if (dev) {
> can_rx_unregister(net, dev, so->rxid,
> SINGLE_MASK(so->rxid),
> - isotp_rcv, sk);
> + false, isotp_rcv, sk);
> dev_put(dev);
> }
> }
> @@ -1323,7 +1323,7 @@ static int isotp_notifier(struct notifier_block *nb, unsigned long msg,
> if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST)))
> can_rx_unregister(dev_net(dev), dev, so->rxid,
> SINGLE_MASK(so->rxid),
> - isotp_rcv, sk);
> + false, isotp_rcv, sk);
>
> so->ifindex = 0;
> so->bound = 0;
> diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
> index da3a7a7bcff2..466a20c76fb6 100644
> --- a/net/can/j1939/main.c
> +++ b/net/can/j1939/main.c
> @@ -177,7 +177,7 @@ static int j1939_can_rx_register(struct j1939_priv *priv)
>
> j1939_priv_get(priv);
> ret = can_rx_register(dev_net(ndev), ndev, J1939_CAN_ID, J1939_CAN_MASK,
> - j1939_can_recv, priv, "j1939", NULL);
> + false, j1939_can_recv, priv, "j1939", NULL);
> if (ret < 0) {
> j1939_priv_put(priv);
> return ret;
> @@ -191,7 +191,7 @@ static void j1939_can_rx_unregister(struct j1939_priv *priv)
> struct net_device *ndev = priv->ndev;
>
> can_rx_unregister(dev_net(ndev), ndev, J1939_CAN_ID, J1939_CAN_MASK,
> - j1939_can_recv, priv);
> + false, j1939_can_recv, priv);
>
> j1939_priv_put(priv);
> }
> diff --git a/net/can/proc.c b/net/can/proc.c
> index d1fe49e6f16d..d312077832a6 100644
> --- a/net/can/proc.c
> +++ b/net/can/proc.c
> @@ -191,11 +191,12 @@ static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
>
> hlist_for_each_entry_rcu(r, rx_list, list) {
> char *fmt = (r->can_id & CAN_EFF_FLAG)?
> - " %-5s %08x %08x %pK %pK %8ld %s\n" :
> - " %-5s %03x %08x %pK %pK %8ld %s\n";
> + " %-5s %08x %08x %c %pK %pK %8ld %s\n" :
> + " %-5s %03x %08x %c %pK %pK %8ld %s\n";
>
> seq_printf(m, fmt, DNAME(dev), r->can_id, r->mask,
> - r->func, r->data, r->matches, r->ident);
> + r->match_sk ? '*' : ' ', r->func, r->data,
> + r->matches, r->ident);
> }
> }
>
> @@ -206,9 +207,9 @@ static void can_print_recv_banner(struct seq_file *m)
> * ....... 0 tp20
> */
> if (IS_ENABLED(CONFIG_64BIT))
> - seq_puts(m, " device can_id can_mask function userdata matches ident\n");
> + seq_puts(m, " device can_id can_mask own function userdata matches ident\n");
> else
> - seq_puts(m, " device can_id can_mask function userdata matches ident\n");
> + seq_puts(m, " device can_id can_mask own function userdata matches ident\n");
> }
>
> static int can_stats_proc_show(struct seq_file *m, void *v)
> diff --git a/net/can/raw.c b/net/can/raw.c
> index 139d9471ddcf..acfbae28d451 100644
> --- a/net/can/raw.c
> +++ b/net/can/raw.c
> @@ -187,13 +187,13 @@ static int raw_enable_filters(struct net *net, struct net_device *dev,
>
> for (i = 0; i < count; i++) {
> err = can_rx_register(net, dev, filter[i].can_id,
> - filter[i].can_mask,
> + filter[i].can_mask, false,
> raw_rcv, sk, "raw", sk);
> if (err) {
> /* clean up successfully registered filters */
> while (--i >= 0)
> can_rx_unregister(net, dev, filter[i].can_id,
> - filter[i].can_mask,
> + filter[i].can_mask, false,
> raw_rcv, sk);
> break;
> }
> @@ -209,7 +209,7 @@ static int raw_enable_errfilter(struct net *net, struct net_device *dev,
>
> if (err_mask)
> err = can_rx_register(net, dev, 0, err_mask | CAN_ERR_FLAG,
> - raw_rcv, sk, "raw", sk);
> + false, raw_rcv, sk, "raw", sk);
>
> return err;
> }
> @@ -222,7 +222,7 @@ static void raw_disable_filters(struct net *net, struct net_device *dev,
>
> for (i = 0; i < count; i++)
> can_rx_unregister(net, dev, filter[i].can_id,
> - filter[i].can_mask, raw_rcv, sk);
> + filter[i].can_mask, false, raw_rcv, sk);
> }
>
> static inline void raw_disable_errfilter(struct net *net,
> @@ -233,7 +233,7 @@ static inline void raw_disable_errfilter(struct net *net,
> {
> if (err_mask)
> can_rx_unregister(net, dev, 0, err_mask | CAN_ERR_FLAG,
> - raw_rcv, sk);
> + false, raw_rcv, sk);
> }
>
> static inline void raw_disable_allfilters(struct net *net,
>
next prev parent reply other threads:[~2021-05-05 7:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-04 20:35 [PATCH v2 0/2] can: Add CAN_RAW_RECV_OWN_MSGS_ALL socket option Erik Flodin
2021-05-04 20:35 ` [PATCH v2 1/2] can: add support for filtering own messages only Erik Flodin
2021-05-05 6:58 ` Oliver Hartkopp [this message]
2021-05-04 20:35 ` [PATCH v2 2/2] can: raw: add CAN_RAW_RECV_OWN_MSGS_ALL socket option Erik Flodin
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