diff mbox series

[net-next,v18,07/13] net: ethtool: Introduce a command to list PHYs on an interface

Message ID 20240821151009.1681151-8-maxime.chevallier@bootlin.com (mailing list archive)
State New, archived
Headers show
Series Introduce PHY listing and link_topology tracking | expand

Commit Message

Maxime Chevallier Aug. 21, 2024, 3:10 p.m. UTC
As we have the ability to track the PHYs connected to a net_device
through the link_topology, we can expose this list to userspace. This
allows userspace to use these identifiers for phy-specific commands and
take the decision of which PHY to target by knowing the link topology.

Add PHY_GET and PHY_DUMP, which can be a filtered DUMP operation to list
devices on only one interface.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 Documentation/networking/ethtool-netlink.rst |  41 +++
 include/uapi/linux/ethtool_netlink.h         |  19 ++
 net/ethtool/Makefile                         |   3 +-
 net/ethtool/netlink.c                        |   9 +
 net/ethtool/netlink.h                        |   5 +
 net/ethtool/phy.c                            | 308 +++++++++++++++++++
 6 files changed, 384 insertions(+), 1 deletion(-)
 create mode 100644 net/ethtool/phy.c

Comments

Eric Dumazet Sept. 10, 2024, 4:41 p.m. UTC | #1
On Wed, Aug 21, 2024 at 5:10 PM Maxime Chevallier
<maxime.chevallier@bootlin.com> wrote:
>
> As we have the ability to track the PHYs connected to a net_device
> through the link_topology, we can expose this list to userspace. This
> allows userspace to use these identifiers for phy-specific commands and
> take the decision of which PHY to target by knowing the link topology.
>
> Add PHY_GET and PHY_DUMP, which can be a filtered DUMP operation to list
> devices on only one interface.
>
> Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  Documentation/networking/ethtool-netlink.rst |  41 +++
>  include/uapi/linux/ethtool_netlink.h         |  19 ++
>  net/ethtool/Makefile                         |   3 +-
>  net/ethtool/netlink.c                        |   9 +
>  net/ethtool/netlink.h                        |   5 +
>  net/ethtool/phy.c                            | 308 +++++++++++++++++++
>  6 files changed, 384 insertions(+), 1 deletion(-)
>  create mode 100644 net/ethtool/phy.c
>
> diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
> index 2d14b8551348..8c152871c23c 100644
> --- a/Documentation/networking/ethtool-netlink.rst
> +++ b/Documentation/networking/ethtool-netlink.rst
> @@ -2191,6 +2191,46 @@ string.
>  The ``ETHTOOL_A_MODULE_FW_FLASH_DONE`` and ``ETHTOOL_A_MODULE_FW_FLASH_TOTAL``
>  attributes encode the completed and total amount of work, respectively.
>
> +PHY_GET
> +=======
> +
> +Retrieve information about a given Ethernet PHY sitting on the link. The DO
> +operation returns all available information about dev->phydev. User can also
> +specify a PHY_INDEX, in which case the DO request returns information about that
> +specific PHY.
> +As there can be more than one PHY, the DUMP operation can be used to list the PHYs
> +present on a given interface, by passing an interface index or name in
> +the dump request.
> +
> +Request contents:
> +
> +  ====================================  ======  ==========================
> +  ``ETHTOOL_A_PHY_HEADER``              nested  request header
> +  ====================================  ======  ==========================
> +
> +Kernel response contents:
> +
> +  ===================================== ======  ===============================
> +  ``ETHTOOL_A_PHY_HEADER``              nested  request header
> +  ``ETHTOOL_A_PHY_INDEX``               u32     the phy's unique index, that can
> +                                                be used for phy-specific
> +                                                requests
> +  ``ETHTOOL_A_PHY_DRVNAME``             string  the phy driver name
> +  ``ETHTOOL_A_PHY_NAME``                string  the phy device name
> +  ``ETHTOOL_A_PHY_UPSTREAM_TYPE``       u32     the type of device this phy is
> +                                                connected to
> +  ``ETHTOOL_A_PHY_UPSTREAM_INDEX``      u32     the PHY index of the upstream
> +                                                PHY
> +  ``ETHTOOL_A_PHY_UPSTREAM_SFP_NAME``   string  if this PHY is connected to
> +                                                its parent PHY through an SFP
> +                                                bus, the name of this sfp bus
> +  ``ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME`` string  if the phy controls an sfp bus,
> +                                                the name of the sfp bus
> +  ===================================== ======  ===============================
> +
> +When ``ETHTOOL_A_PHY_UPSTREAM_TYPE`` is PHY_UPSTREAM_PHY, the PHY's parent is
> +another PHY.
> +
>  Request translation
>  ===================
>
> @@ -2298,4 +2338,5 @@ are netlink only.
>    n/a                                 ``ETHTOOL_MSG_MM_GET``
>    n/a                                 ``ETHTOOL_MSG_MM_SET``
>    n/a                                 ``ETHTOOL_MSG_MODULE_FW_FLASH_ACT``
> +  n/a                                 ``ETHTOOL_MSG_PHY_GET``
>    =================================== =====================================
> diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
> index 49d1f9220fde..45d8bcdea056 100644
> --- a/include/uapi/linux/ethtool_netlink.h
> +++ b/include/uapi/linux/ethtool_netlink.h
> @@ -58,6 +58,7 @@ enum {
>         ETHTOOL_MSG_MM_GET,
>         ETHTOOL_MSG_MM_SET,
>         ETHTOOL_MSG_MODULE_FW_FLASH_ACT,
> +       ETHTOOL_MSG_PHY_GET,
>
>         /* add new constants above here */
>         __ETHTOOL_MSG_USER_CNT,
> @@ -111,6 +112,8 @@ enum {
>         ETHTOOL_MSG_MM_GET_REPLY,
>         ETHTOOL_MSG_MM_NTF,
>         ETHTOOL_MSG_MODULE_FW_FLASH_NTF,
> +       ETHTOOL_MSG_PHY_GET_REPLY,
> +       ETHTOOL_MSG_PHY_NTF,
>
>         /* add new constants above here */
>         __ETHTOOL_MSG_KERNEL_CNT,
> @@ -1055,6 +1058,22 @@ enum {
>         ETHTOOL_A_MODULE_FW_FLASH_MAX = (__ETHTOOL_A_MODULE_FW_FLASH_CNT - 1)
>  };
>
> +enum {
> +       ETHTOOL_A_PHY_UNSPEC,
> +       ETHTOOL_A_PHY_HEADER,                   /* nest - _A_HEADER_* */
> +       ETHTOOL_A_PHY_INDEX,                    /* u32 */
> +       ETHTOOL_A_PHY_DRVNAME,                  /* string */
> +       ETHTOOL_A_PHY_NAME,                     /* string */
> +       ETHTOOL_A_PHY_UPSTREAM_TYPE,            /* u32 */
> +       ETHTOOL_A_PHY_UPSTREAM_INDEX,           /* u32 */
> +       ETHTOOL_A_PHY_UPSTREAM_SFP_NAME,        /* string */
> +       ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME,      /* string */
> +
> +       /* add new constants above here */
> +       __ETHTOOL_A_PHY_CNT,
> +       ETHTOOL_A_PHY_MAX = (__ETHTOOL_A_PHY_CNT - 1)
> +};
> +
>  /* generic netlink info */
>  #define ETHTOOL_GENL_NAME "ethtool"
>  #define ETHTOOL_GENL_VERSION 1
> diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
> index 9a190635fe95..9b540644ba31 100644
> --- a/net/ethtool/Makefile
> +++ b/net/ethtool/Makefile
> @@ -8,4 +8,5 @@ ethtool_nl-y    := netlink.o bitset.o strset.o linkinfo.o linkmodes.o rss.o \
>                    linkstate.o debug.o wol.o features.o privflags.o rings.o \
>                    channels.o coalesce.o pause.o eee.o tsinfo.o cabletest.o \
>                    tunnels.o fec.o eeprom.o stats.o phc_vclocks.o mm.o \
> -                  module.o cmis_fw_update.o cmis_cdb.o pse-pd.o plca.o mm.o
> +                  module.o cmis_fw_update.o cmis_cdb.o pse-pd.o plca.o mm.o \
> +                  phy.o
> diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
> index b00061924e80..e3f0ef6b851b 100644
> --- a/net/ethtool/netlink.c
> +++ b/net/ethtool/netlink.c
> @@ -1234,6 +1234,15 @@ static const struct genl_ops ethtool_genl_ops[] = {
>                 .policy = ethnl_module_fw_flash_act_policy,
>                 .maxattr = ARRAY_SIZE(ethnl_module_fw_flash_act_policy) - 1,
>         },
> +       {
> +               .cmd    = ETHTOOL_MSG_PHY_GET,
> +               .doit   = ethnl_phy_doit,
> +               .start  = ethnl_phy_start,
> +               .dumpit = ethnl_phy_dumpit,
> +               .done   = ethnl_phy_done,
> +               .policy = ethnl_phy_get_policy,
> +               .maxattr = ARRAY_SIZE(ethnl_phy_get_policy) - 1,
> +       },
>  };
>
>  static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
> diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
> index e326699405be..203b08eb6c6f 100644
> --- a/net/ethtool/netlink.h
> +++ b/net/ethtool/netlink.h
> @@ -484,6 +484,7 @@ extern const struct nla_policy ethnl_plca_get_status_policy[ETHTOOL_A_PLCA_HEADE
>  extern const struct nla_policy ethnl_mm_get_policy[ETHTOOL_A_MM_HEADER + 1];
>  extern const struct nla_policy ethnl_mm_set_policy[ETHTOOL_A_MM_MAX + 1];
>  extern const struct nla_policy ethnl_module_fw_flash_act_policy[ETHTOOL_A_MODULE_FW_FLASH_PASSWORD + 1];
> +extern const struct nla_policy ethnl_phy_get_policy[ETHTOOL_A_PHY_HEADER + 1];
>
>  int ethnl_set_features(struct sk_buff *skb, struct genl_info *info);
>  int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info);
> @@ -494,6 +495,10 @@ int ethnl_tunnel_info_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
>  int ethnl_act_module_fw_flash(struct sk_buff *skb, struct genl_info *info);
>  int ethnl_rss_dump_start(struct netlink_callback *cb);
>  int ethnl_rss_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
> +int ethnl_phy_start(struct netlink_callback *cb);
> +int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info);
> +int ethnl_phy_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
> +int ethnl_phy_done(struct netlink_callback *cb);
>
>  extern const char stats_std_names[__ETHTOOL_STATS_CNT][ETH_GSTRING_LEN];
>  extern const char stats_eth_phy_names[__ETHTOOL_A_STATS_ETH_PHY_CNT][ETH_GSTRING_LEN];
> diff --git a/net/ethtool/phy.c b/net/ethtool/phy.c
> new file mode 100644
> index 000000000000..560dd039c662
> --- /dev/null
> +++ b/net/ethtool/phy.c
> @@ -0,0 +1,308 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright 2023 Bootlin
> + *
> + */
> +#include "common.h"
> +#include "netlink.h"
> +
> +#include <linux/phy.h>
> +#include <linux/phy_link_topology.h>
> +#include <linux/sfp.h>
> +
> +struct phy_req_info {
> +       struct ethnl_req_info           base;
> +       struct phy_device_node          *pdn;
> +};
> +
> +#define PHY_REQINFO(__req_base) \
> +       container_of(__req_base, struct phy_req_info, base)
> +
> +const struct nla_policy ethnl_phy_get_policy[ETHTOOL_A_PHY_HEADER + 1] = {
> +       [ETHTOOL_A_PHY_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
> +};
> +
> +/* Caller holds rtnl */
> +static ssize_t
> +ethnl_phy_reply_size(const struct ethnl_req_info *req_base,
> +                    struct netlink_ext_ack *extack)
> +{
> +       struct phy_req_info *req_info = PHY_REQINFO(req_base);
> +       struct phy_device_node *pdn = req_info->pdn;
> +       struct phy_device *phydev = pdn->phy;
> +       size_t size = 0;
> +
> +       ASSERT_RTNL();
> +
> +       /* ETHTOOL_A_PHY_INDEX */
> +       size += nla_total_size(sizeof(u32));
> +
> +       /* ETHTOOL_A_DRVNAME */
> +       if (phydev->drv)
> +               size += nla_total_size(strlen(phydev->drv->name) + 1);
> +
> +       /* ETHTOOL_A_NAME */
> +       size += nla_total_size(strlen(dev_name(&phydev->mdio.dev)) + 1);
> +
> +       /* ETHTOOL_A_PHY_UPSTREAM_TYPE */
> +       size += nla_total_size(sizeof(u32));
> +
> +       if (phy_on_sfp(phydev)) {
> +               const char *upstream_sfp_name = sfp_get_name(pdn->parent_sfp_bus);
> +
> +               /* ETHTOOL_A_PHY_UPSTREAM_SFP_NAME */
> +               if (upstream_sfp_name)
> +                       size += nla_total_size(strlen(upstream_sfp_name) + 1);
> +
> +               /* ETHTOOL_A_PHY_UPSTREAM_INDEX */
> +               size += nla_total_size(sizeof(u32));
> +       }
> +
> +       /* ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME */
> +       if (phydev->sfp_bus) {
> +               const char *sfp_name = sfp_get_name(phydev->sfp_bus);
> +
> +               if (sfp_name)
> +                       size += nla_total_size(strlen(sfp_name) + 1);
> +       }
> +
> +       return size;
> +}
> +
> +static int
> +ethnl_phy_fill_reply(const struct ethnl_req_info *req_base, struct sk_buff *skb)
> +{
> +       struct phy_req_info *req_info = PHY_REQINFO(req_base);
> +       struct phy_device_node *pdn = req_info->pdn;
> +       struct phy_device *phydev = pdn->phy;
> +       enum phy_upstream ptype;
> +
> +       ptype = pdn->upstream_type;
> +
> +       if (nla_put_u32(skb, ETHTOOL_A_PHY_INDEX, phydev->phyindex) ||
> +           nla_put_string(skb, ETHTOOL_A_PHY_NAME, dev_name(&phydev->mdio.dev)) ||
> +           nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_TYPE, ptype))
> +               return -EMSGSIZE;
> +
> +       if (phydev->drv &&
> +           nla_put_string(skb, ETHTOOL_A_PHY_DRVNAME, phydev->drv->name))
> +               return -EMSGSIZE;
> +
> +       if (ptype == PHY_UPSTREAM_PHY) {
> +               struct phy_device *upstream = pdn->upstream.phydev;
> +               const char *sfp_upstream_name;
> +
> +               /* Parent index */
> +               if (nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_INDEX, upstream->phyindex))
> +                       return -EMSGSIZE;
> +
> +               if (pdn->parent_sfp_bus) {
> +                       sfp_upstream_name = sfp_get_name(pdn->parent_sfp_bus);
> +                       if (sfp_upstream_name &&
> +                           nla_put_string(skb, ETHTOOL_A_PHY_UPSTREAM_SFP_NAME,
> +                                          sfp_upstream_name))
> +                               return -EMSGSIZE;
> +               }
> +       }
> +
> +       if (phydev->sfp_bus) {
> +               const char *sfp_name = sfp_get_name(phydev->sfp_bus);
> +
> +               if (sfp_name &&
> +                   nla_put_string(skb, ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME,
> +                                  sfp_name))
> +                       return -EMSGSIZE;
> +       }
> +
> +       return 0;
> +}
> +
> +static int ethnl_phy_parse_request(struct ethnl_req_info *req_base,
> +                                  struct nlattr **tb,
> +                                  struct netlink_ext_ack *extack)
> +{
> +       struct phy_link_topology *topo = req_base->dev->link_topo;
> +       struct phy_req_info *req_info = PHY_REQINFO(req_base);
> +       struct phy_device *phydev;
> +
> +       phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_PHY_HEADER],
> +                                     extack);
> +       if (!phydev)
> +               return 0;
> +
> +       if (IS_ERR(phydev))
> +               return PTR_ERR(phydev);
> +
> +       if (!topo)
> +               return 0;
> +
> +       req_info->pdn = xa_load(&topo->phys, phydev->phyindex);
> +
> +       return 0;
> +}
> +
> +int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info)
> +{
> +       struct phy_req_info req_info = {};
> +       struct nlattr **tb = info->attrs;
> +       struct sk_buff *rskb;
> +       void *reply_payload;
> +       int reply_len;
> +       int ret;
> +
> +       ret = ethnl_parse_header_dev_get(&req_info.base,
> +                                        tb[ETHTOOL_A_PHY_HEADER],
> +                                        genl_info_net(info), info->extack,
> +                                        true);
> +       if (ret < 0)
> +               return ret;
> +
> +       rtnl_lock();
> +
> +       ret = ethnl_phy_parse_request(&req_info.base, tb, info->extack);
> +       if (ret < 0)
> +               goto err_unlock_rtnl;
> +
> +       /* No PHY, return early */

I got a syzbot report here.

Should we fix this with :

diff --git a/net/ethtool/phy.c b/net/ethtool/phy.c
index 560dd039c6625ac0925a0f28c14ce77cf768b6a5..4ef7c6e32d1087dc71acb467f9cd2ab8faf4dc39
100644
--- a/net/ethtool/phy.c
+++ b/net/ethtool/phy.c
@@ -164,7 +164,7 @@ int ethnl_phy_doit(struct sk_buff *skb, struct
genl_info *info)
                goto err_unlock_rtnl;

        /* No PHY, return early */
-       if (!req_info.pdn->phy)
+       if (!req_info.pdn)
                goto err_unlock_rtnl;

        ret = ethnl_phy_reply_size(&req_info.base, info->extack);


> +       if (!req_info.pdn->phy)
> +               goto err_unlock_rtnl;
> +
> +       ret = ethnl_phy_reply_size(&req_info.base, info->extack);
> +       if (ret < 0)
> +               goto err_unlock_rtnl;
> +       reply_len = ret + ethnl_reply_header_size();
> +
> +       rskb = ethnl_reply_init(reply_len, req_info.base.dev,
> +                               ETHTOOL_MSG_PHY_GET_REPLY,
> +                               ETHTOOL_A_PHY_HEADER,
> +                               info, &reply_payload);
> +       if (!rskb) {
> +               ret = -ENOMEM;
> +               goto err_unlock_rtnl;
> +       }
> +
> +       ret = ethnl_phy_fill_reply(&req_info.base, rskb);
> +       if (ret)
> +               goto err_free_msg;
> +
> +       rtnl_unlock();
> +       ethnl_parse_header_dev_put(&req_info.base);
> +       genlmsg_end(rskb, reply_payload);
> +
> +       return genlmsg_reply(rskb, info);
> +
> +err_free_msg:
> +       nlmsg_free(rskb);
> +err_unlock_rtnl:
> +       rtnl_unlock();
> +       ethnl_parse_header_dev_put(&req_info.base);
> +       return ret;
> +}
> +
> +struct ethnl_phy_dump_ctx {
> +       struct phy_req_info     *phy_req_info;
> +       unsigned long ifindex;
> +       unsigned long phy_index;
> +};
> +
> +int ethnl_phy_start(struct netlink_callback *cb)
> +{
> +       const struct genl_info *info = genl_info_dump(cb);
> +       struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
> +       int ret;
> +
> +       BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
> +
> +       ctx->phy_req_info = kzalloc(sizeof(*ctx->phy_req_info), GFP_KERNEL);
> +       if (!ctx->phy_req_info)
> +               return -ENOMEM;
> +
> +       ret = ethnl_parse_header_dev_get(&ctx->phy_req_info->base,
> +                                        info->attrs[ETHTOOL_A_PHY_HEADER],
> +                                        sock_net(cb->skb->sk), cb->extack,
> +                                        false);
> +       ctx->ifindex = 0;
> +       ctx->phy_index = 0;
> +
> +       if (ret)
> +               kfree(ctx->phy_req_info);
> +
> +       return ret;
> +}
> +
> +int ethnl_phy_done(struct netlink_callback *cb)
> +{
> +       struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
> +
> +       if (ctx->phy_req_info->base.dev)
> +               ethnl_parse_header_dev_put(&ctx->phy_req_info->base);
> +
> +       kfree(ctx->phy_req_info);
> +
> +       return 0;
> +}
> +
> +static int ethnl_phy_dump_one_dev(struct sk_buff *skb, struct net_device *dev,
> +                                 struct netlink_callback *cb)
> +{
> +       struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
> +       struct phy_req_info *pri = ctx->phy_req_info;
> +       struct phy_device_node *pdn;
> +       int ret = 0;
> +       void *ehdr;
> +
> +       pri->base.dev = dev;
> +
> +       if (!dev->link_topo)
> +               return 0;
> +
> +       xa_for_each_start(&dev->link_topo->phys, ctx->phy_index, pdn, ctx->phy_index) {
> +               ehdr = ethnl_dump_put(skb, cb, ETHTOOL_MSG_PHY_GET_REPLY);
> +               if (!ehdr) {
> +                       ret = -EMSGSIZE;
> +                       break;
> +               }
> +
> +               ret = ethnl_fill_reply_header(skb, dev, ETHTOOL_A_PHY_HEADER);
> +               if (ret < 0) {
> +                       genlmsg_cancel(skb, ehdr);
> +                       break;
> +               }
> +
> +               pri->pdn = pdn;
> +               ret = ethnl_phy_fill_reply(&pri->base, skb);
> +               if (ret < 0) {
> +                       genlmsg_cancel(skb, ehdr);
> +                       break;
> +               }
> +
> +               genlmsg_end(skb, ehdr);
> +       }
> +
> +       return ret;
> +}
> +
> +int ethnl_phy_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
> +{
> +       struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
> +       struct net *net = sock_net(skb->sk);
> +       struct net_device *dev;
> +       int ret = 0;
> +
> +       rtnl_lock();
> +
> +       if (ctx->phy_req_info->base.dev) {
> +               ret = ethnl_phy_dump_one_dev(skb, ctx->phy_req_info->base.dev, cb);
> +       } else {
> +               for_each_netdev_dump(net, dev, ctx->ifindex) {
> +                       ret = ethnl_phy_dump_one_dev(skb, dev, cb);
> +                       if (ret)
> +                               break;
> +
> +                       ctx->phy_index = 0;
> +               }
> +       }
> +       rtnl_unlock();
> +
> +       return ret;
> +}
> --
> 2.45.2
>
Maxime Chevallier Sept. 10, 2024, 5:20 p.m. UTC | #2
Hello Eric,

On Tue, 10 Sep 2024 18:41:03 +0200
Eric Dumazet <edumazet@google.com> wrote:

> > +int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info)
> > +{
> > +       struct phy_req_info req_info = {};
> > +       struct nlattr **tb = info->attrs;
> > +       struct sk_buff *rskb;
> > +       void *reply_payload;
> > +       int reply_len;
> > +       int ret;
> > +
> > +       ret = ethnl_parse_header_dev_get(&req_info.base,
> > +                                        tb[ETHTOOL_A_PHY_HEADER],
> > +                                        genl_info_net(info), info->extack,
> > +                                        true);
> > +       if (ret < 0)
> > +               return ret;
> > +
> > +       rtnl_lock();
> > +
> > +       ret = ethnl_phy_parse_request(&req_info.base, tb, info->extack);
> > +       if (ret < 0)
> > +               goto err_unlock_rtnl;
> > +
> > +       /* No PHY, return early */  
> 
> I got a syzbot report here.

I seem to have missed the report, sorry about that.

> 
> Should we fix this with :
> 
> diff --git a/net/ethtool/phy.c b/net/ethtool/phy.c
> index 560dd039c6625ac0925a0f28c14ce77cf768b6a5..4ef7c6e32d1087dc71acb467f9cd2ab8faf4dc39
> 100644
> --- a/net/ethtool/phy.c
> +++ b/net/ethtool/phy.c
> @@ -164,7 +164,7 @@ int ethnl_phy_doit(struct sk_buff *skb, struct
> genl_info *info)
>                 goto err_unlock_rtnl;
> 
>         /* No PHY, return early */
> -       if (!req_info.pdn->phy)
> +       if (!req_info.pdn)
>                 goto err_unlock_rtnl;
> 
>         ret = ethnl_phy_reply_size(&req_info.base, info->extack);
> 
> 

Indeed that's the correct fix. Should I send it ? ( including
suggested-by/reported-by )

Thanks,

Maxime
Eric Dumazet Sept. 10, 2024, 5:23 p.m. UTC | #3
On Tue, Sep 10, 2024 at 7:20 PM Maxime Chevallier
<maxime.chevallier@bootlin.com> wrote:
>
> Hello Eric,
>
> On Tue, 10 Sep 2024 18:41:03 +0200
> Eric Dumazet <edumazet@google.com> wrote:
>
> > > +int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info)
> > > +{
> > > +       struct phy_req_info req_info = {};
> > > +       struct nlattr **tb = info->attrs;
> > > +       struct sk_buff *rskb;
> > > +       void *reply_payload;
> > > +       int reply_len;
> > > +       int ret;
> > > +
> > > +       ret = ethnl_parse_header_dev_get(&req_info.base,
> > > +                                        tb[ETHTOOL_A_PHY_HEADER],
> > > +                                        genl_info_net(info), info->extack,
> > > +                                        true);
> > > +       if (ret < 0)
> > > +               return ret;
> > > +
> > > +       rtnl_lock();
> > > +
> > > +       ret = ethnl_phy_parse_request(&req_info.base, tb, info->extack);
> > > +       if (ret < 0)
> > > +               goto err_unlock_rtnl;
> > > +
> > > +       /* No PHY, return early */
> >
> > I got a syzbot report here.
>
> I seem to have missed the report, sorry about that.
>
> >
> > Should we fix this with :
> >
> > diff --git a/net/ethtool/phy.c b/net/ethtool/phy.c
> > index 560dd039c6625ac0925a0f28c14ce77cf768b6a5..4ef7c6e32d1087dc71acb467f9cd2ab8faf4dc39
> > 100644
> > --- a/net/ethtool/phy.c
> > +++ b/net/ethtool/phy.c
> > @@ -164,7 +164,7 @@ int ethnl_phy_doit(struct sk_buff *skb, struct
> > genl_info *info)
> >                 goto err_unlock_rtnl;
> >
> >         /* No PHY, return early */
> > -       if (!req_info.pdn->phy)
> > +       if (!req_info.pdn)
> >                 goto err_unlock_rtnl;
> >
> >         ret = ethnl_phy_reply_size(&req_info.base, info->extack);
> >
> >
>
> Indeed that's the correct fix. Should I send it ? ( including
> suggested-by/reported-by )

Yes please, go ahead.

>
> Thanks,
>
> Maxime
diff mbox series

Patch

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 2d14b8551348..8c152871c23c 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -2191,6 +2191,46 @@  string.
 The ``ETHTOOL_A_MODULE_FW_FLASH_DONE`` and ``ETHTOOL_A_MODULE_FW_FLASH_TOTAL``
 attributes encode the completed and total amount of work, respectively.
 
+PHY_GET
+=======
+
+Retrieve information about a given Ethernet PHY sitting on the link. The DO
+operation returns all available information about dev->phydev. User can also
+specify a PHY_INDEX, in which case the DO request returns information about that
+specific PHY.
+As there can be more than one PHY, the DUMP operation can be used to list the PHYs
+present on a given interface, by passing an interface index or name in
+the dump request.
+
+Request contents:
+
+  ====================================  ======  ==========================
+  ``ETHTOOL_A_PHY_HEADER``              nested  request header
+  ====================================  ======  ==========================
+
+Kernel response contents:
+
+  ===================================== ======  ===============================
+  ``ETHTOOL_A_PHY_HEADER``              nested  request header
+  ``ETHTOOL_A_PHY_INDEX``               u32     the phy's unique index, that can
+                                                be used for phy-specific
+                                                requests
+  ``ETHTOOL_A_PHY_DRVNAME``             string  the phy driver name
+  ``ETHTOOL_A_PHY_NAME``                string  the phy device name
+  ``ETHTOOL_A_PHY_UPSTREAM_TYPE``       u32     the type of device this phy is
+                                                connected to
+  ``ETHTOOL_A_PHY_UPSTREAM_INDEX``      u32     the PHY index of the upstream
+                                                PHY
+  ``ETHTOOL_A_PHY_UPSTREAM_SFP_NAME``   string  if this PHY is connected to
+                                                its parent PHY through an SFP
+                                                bus, the name of this sfp bus
+  ``ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME`` string  if the phy controls an sfp bus,
+                                                the name of the sfp bus
+  ===================================== ======  ===============================
+
+When ``ETHTOOL_A_PHY_UPSTREAM_TYPE`` is PHY_UPSTREAM_PHY, the PHY's parent is
+another PHY.
+
 Request translation
 ===================
 
@@ -2298,4 +2338,5 @@  are netlink only.
   n/a                                 ``ETHTOOL_MSG_MM_GET``
   n/a                                 ``ETHTOOL_MSG_MM_SET``
   n/a                                 ``ETHTOOL_MSG_MODULE_FW_FLASH_ACT``
+  n/a                                 ``ETHTOOL_MSG_PHY_GET``
   =================================== =====================================
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 49d1f9220fde..45d8bcdea056 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -58,6 +58,7 @@  enum {
 	ETHTOOL_MSG_MM_GET,
 	ETHTOOL_MSG_MM_SET,
 	ETHTOOL_MSG_MODULE_FW_FLASH_ACT,
+	ETHTOOL_MSG_PHY_GET,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_USER_CNT,
@@ -111,6 +112,8 @@  enum {
 	ETHTOOL_MSG_MM_GET_REPLY,
 	ETHTOOL_MSG_MM_NTF,
 	ETHTOOL_MSG_MODULE_FW_FLASH_NTF,
+	ETHTOOL_MSG_PHY_GET_REPLY,
+	ETHTOOL_MSG_PHY_NTF,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_KERNEL_CNT,
@@ -1055,6 +1058,22 @@  enum {
 	ETHTOOL_A_MODULE_FW_FLASH_MAX = (__ETHTOOL_A_MODULE_FW_FLASH_CNT - 1)
 };
 
+enum {
+	ETHTOOL_A_PHY_UNSPEC,
+	ETHTOOL_A_PHY_HEADER,			/* nest - _A_HEADER_* */
+	ETHTOOL_A_PHY_INDEX,			/* u32 */
+	ETHTOOL_A_PHY_DRVNAME,			/* string */
+	ETHTOOL_A_PHY_NAME,			/* string */
+	ETHTOOL_A_PHY_UPSTREAM_TYPE,		/* u32 */
+	ETHTOOL_A_PHY_UPSTREAM_INDEX,		/* u32 */
+	ETHTOOL_A_PHY_UPSTREAM_SFP_NAME,	/* string */
+	ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME,	/* string */
+
+	/* add new constants above here */
+	__ETHTOOL_A_PHY_CNT,
+	ETHTOOL_A_PHY_MAX = (__ETHTOOL_A_PHY_CNT - 1)
+};
+
 /* generic netlink info */
 #define ETHTOOL_GENL_NAME "ethtool"
 #define ETHTOOL_GENL_VERSION 1
diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
index 9a190635fe95..9b540644ba31 100644
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile
@@ -8,4 +8,5 @@  ethtool_nl-y	:= netlink.o bitset.o strset.o linkinfo.o linkmodes.o rss.o \
 		   linkstate.o debug.o wol.o features.o privflags.o rings.o \
 		   channels.o coalesce.o pause.o eee.o tsinfo.o cabletest.o \
 		   tunnels.o fec.o eeprom.o stats.o phc_vclocks.o mm.o \
-		   module.o cmis_fw_update.o cmis_cdb.o pse-pd.o plca.o mm.o
+		   module.o cmis_fw_update.o cmis_cdb.o pse-pd.o plca.o mm.o \
+		   phy.o
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index b00061924e80..e3f0ef6b851b 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -1234,6 +1234,15 @@  static const struct genl_ops ethtool_genl_ops[] = {
 		.policy	= ethnl_module_fw_flash_act_policy,
 		.maxattr = ARRAY_SIZE(ethnl_module_fw_flash_act_policy) - 1,
 	},
+	{
+		.cmd	= ETHTOOL_MSG_PHY_GET,
+		.doit	= ethnl_phy_doit,
+		.start	= ethnl_phy_start,
+		.dumpit	= ethnl_phy_dumpit,
+		.done	= ethnl_phy_done,
+		.policy = ethnl_phy_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_phy_get_policy) - 1,
+	},
 };
 
 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
diff --git a/net/ethtool/netlink.h b/net/ethtool/netlink.h
index e326699405be..203b08eb6c6f 100644
--- a/net/ethtool/netlink.h
+++ b/net/ethtool/netlink.h
@@ -484,6 +484,7 @@  extern const struct nla_policy ethnl_plca_get_status_policy[ETHTOOL_A_PLCA_HEADE
 extern const struct nla_policy ethnl_mm_get_policy[ETHTOOL_A_MM_HEADER + 1];
 extern const struct nla_policy ethnl_mm_set_policy[ETHTOOL_A_MM_MAX + 1];
 extern const struct nla_policy ethnl_module_fw_flash_act_policy[ETHTOOL_A_MODULE_FW_FLASH_PASSWORD + 1];
+extern const struct nla_policy ethnl_phy_get_policy[ETHTOOL_A_PHY_HEADER + 1];
 
 int ethnl_set_features(struct sk_buff *skb, struct genl_info *info);
 int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info);
@@ -494,6 +495,10 @@  int ethnl_tunnel_info_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
 int ethnl_act_module_fw_flash(struct sk_buff *skb, struct genl_info *info);
 int ethnl_rss_dump_start(struct netlink_callback *cb);
 int ethnl_rss_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
+int ethnl_phy_start(struct netlink_callback *cb);
+int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info);
+int ethnl_phy_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
+int ethnl_phy_done(struct netlink_callback *cb);
 
 extern const char stats_std_names[__ETHTOOL_STATS_CNT][ETH_GSTRING_LEN];
 extern const char stats_eth_phy_names[__ETHTOOL_A_STATS_ETH_PHY_CNT][ETH_GSTRING_LEN];
diff --git a/net/ethtool/phy.c b/net/ethtool/phy.c
new file mode 100644
index 000000000000..560dd039c662
--- /dev/null
+++ b/net/ethtool/phy.c
@@ -0,0 +1,308 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2023 Bootlin
+ *
+ */
+#include "common.h"
+#include "netlink.h"
+
+#include <linux/phy.h>
+#include <linux/phy_link_topology.h>
+#include <linux/sfp.h>
+
+struct phy_req_info {
+	struct ethnl_req_info		base;
+	struct phy_device_node		*pdn;
+};
+
+#define PHY_REQINFO(__req_base) \
+	container_of(__req_base, struct phy_req_info, base)
+
+const struct nla_policy ethnl_phy_get_policy[ETHTOOL_A_PHY_HEADER + 1] = {
+	[ETHTOOL_A_PHY_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
+};
+
+/* Caller holds rtnl */
+static ssize_t
+ethnl_phy_reply_size(const struct ethnl_req_info *req_base,
+		     struct netlink_ext_ack *extack)
+{
+	struct phy_req_info *req_info = PHY_REQINFO(req_base);
+	struct phy_device_node *pdn = req_info->pdn;
+	struct phy_device *phydev = pdn->phy;
+	size_t size = 0;
+
+	ASSERT_RTNL();
+
+	/* ETHTOOL_A_PHY_INDEX */
+	size += nla_total_size(sizeof(u32));
+
+	/* ETHTOOL_A_DRVNAME */
+	if (phydev->drv)
+		size += nla_total_size(strlen(phydev->drv->name) + 1);
+
+	/* ETHTOOL_A_NAME */
+	size += nla_total_size(strlen(dev_name(&phydev->mdio.dev)) + 1);
+
+	/* ETHTOOL_A_PHY_UPSTREAM_TYPE */
+	size += nla_total_size(sizeof(u32));
+
+	if (phy_on_sfp(phydev)) {
+		const char *upstream_sfp_name = sfp_get_name(pdn->parent_sfp_bus);
+
+		/* ETHTOOL_A_PHY_UPSTREAM_SFP_NAME */
+		if (upstream_sfp_name)
+			size += nla_total_size(strlen(upstream_sfp_name) + 1);
+
+		/* ETHTOOL_A_PHY_UPSTREAM_INDEX */
+		size += nla_total_size(sizeof(u32));
+	}
+
+	/* ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME */
+	if (phydev->sfp_bus) {
+		const char *sfp_name = sfp_get_name(phydev->sfp_bus);
+
+		if (sfp_name)
+			size += nla_total_size(strlen(sfp_name) + 1);
+	}
+
+	return size;
+}
+
+static int
+ethnl_phy_fill_reply(const struct ethnl_req_info *req_base, struct sk_buff *skb)
+{
+	struct phy_req_info *req_info = PHY_REQINFO(req_base);
+	struct phy_device_node *pdn = req_info->pdn;
+	struct phy_device *phydev = pdn->phy;
+	enum phy_upstream ptype;
+
+	ptype = pdn->upstream_type;
+
+	if (nla_put_u32(skb, ETHTOOL_A_PHY_INDEX, phydev->phyindex) ||
+	    nla_put_string(skb, ETHTOOL_A_PHY_NAME, dev_name(&phydev->mdio.dev)) ||
+	    nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_TYPE, ptype))
+		return -EMSGSIZE;
+
+	if (phydev->drv &&
+	    nla_put_string(skb, ETHTOOL_A_PHY_DRVNAME, phydev->drv->name))
+		return -EMSGSIZE;
+
+	if (ptype == PHY_UPSTREAM_PHY) {
+		struct phy_device *upstream = pdn->upstream.phydev;
+		const char *sfp_upstream_name;
+
+		/* Parent index */
+		if (nla_put_u32(skb, ETHTOOL_A_PHY_UPSTREAM_INDEX, upstream->phyindex))
+			return -EMSGSIZE;
+
+		if (pdn->parent_sfp_bus) {
+			sfp_upstream_name = sfp_get_name(pdn->parent_sfp_bus);
+			if (sfp_upstream_name &&
+			    nla_put_string(skb, ETHTOOL_A_PHY_UPSTREAM_SFP_NAME,
+					   sfp_upstream_name))
+				return -EMSGSIZE;
+		}
+	}
+
+	if (phydev->sfp_bus) {
+		const char *sfp_name = sfp_get_name(phydev->sfp_bus);
+
+		if (sfp_name &&
+		    nla_put_string(skb, ETHTOOL_A_PHY_DOWNSTREAM_SFP_NAME,
+				   sfp_name))
+			return -EMSGSIZE;
+	}
+
+	return 0;
+}
+
+static int ethnl_phy_parse_request(struct ethnl_req_info *req_base,
+				   struct nlattr **tb,
+				   struct netlink_ext_ack *extack)
+{
+	struct phy_link_topology *topo = req_base->dev->link_topo;
+	struct phy_req_info *req_info = PHY_REQINFO(req_base);
+	struct phy_device *phydev;
+
+	phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_PHY_HEADER],
+				      extack);
+	if (!phydev)
+		return 0;
+
+	if (IS_ERR(phydev))
+		return PTR_ERR(phydev);
+
+	if (!topo)
+		return 0;
+
+	req_info->pdn = xa_load(&topo->phys, phydev->phyindex);
+
+	return 0;
+}
+
+int ethnl_phy_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct phy_req_info req_info = {};
+	struct nlattr **tb = info->attrs;
+	struct sk_buff *rskb;
+	void *reply_payload;
+	int reply_len;
+	int ret;
+
+	ret = ethnl_parse_header_dev_get(&req_info.base,
+					 tb[ETHTOOL_A_PHY_HEADER],
+					 genl_info_net(info), info->extack,
+					 true);
+	if (ret < 0)
+		return ret;
+
+	rtnl_lock();
+
+	ret = ethnl_phy_parse_request(&req_info.base, tb, info->extack);
+	if (ret < 0)
+		goto err_unlock_rtnl;
+
+	/* No PHY, return early */
+	if (!req_info.pdn->phy)
+		goto err_unlock_rtnl;
+
+	ret = ethnl_phy_reply_size(&req_info.base, info->extack);
+	if (ret < 0)
+		goto err_unlock_rtnl;
+	reply_len = ret + ethnl_reply_header_size();
+
+	rskb = ethnl_reply_init(reply_len, req_info.base.dev,
+				ETHTOOL_MSG_PHY_GET_REPLY,
+				ETHTOOL_A_PHY_HEADER,
+				info, &reply_payload);
+	if (!rskb) {
+		ret = -ENOMEM;
+		goto err_unlock_rtnl;
+	}
+
+	ret = ethnl_phy_fill_reply(&req_info.base, rskb);
+	if (ret)
+		goto err_free_msg;
+
+	rtnl_unlock();
+	ethnl_parse_header_dev_put(&req_info.base);
+	genlmsg_end(rskb, reply_payload);
+
+	return genlmsg_reply(rskb, info);
+
+err_free_msg:
+	nlmsg_free(rskb);
+err_unlock_rtnl:
+	rtnl_unlock();
+	ethnl_parse_header_dev_put(&req_info.base);
+	return ret;
+}
+
+struct ethnl_phy_dump_ctx {
+	struct phy_req_info	*phy_req_info;
+	unsigned long ifindex;
+	unsigned long phy_index;
+};
+
+int ethnl_phy_start(struct netlink_callback *cb)
+{
+	const struct genl_info *info = genl_info_dump(cb);
+	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
+	int ret;
+
+	BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
+
+	ctx->phy_req_info = kzalloc(sizeof(*ctx->phy_req_info), GFP_KERNEL);
+	if (!ctx->phy_req_info)
+		return -ENOMEM;
+
+	ret = ethnl_parse_header_dev_get(&ctx->phy_req_info->base,
+					 info->attrs[ETHTOOL_A_PHY_HEADER],
+					 sock_net(cb->skb->sk), cb->extack,
+					 false);
+	ctx->ifindex = 0;
+	ctx->phy_index = 0;
+
+	if (ret)
+		kfree(ctx->phy_req_info);
+
+	return ret;
+}
+
+int ethnl_phy_done(struct netlink_callback *cb)
+{
+	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
+
+	if (ctx->phy_req_info->base.dev)
+		ethnl_parse_header_dev_put(&ctx->phy_req_info->base);
+
+	kfree(ctx->phy_req_info);
+
+	return 0;
+}
+
+static int ethnl_phy_dump_one_dev(struct sk_buff *skb, struct net_device *dev,
+				  struct netlink_callback *cb)
+{
+	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
+	struct phy_req_info *pri = ctx->phy_req_info;
+	struct phy_device_node *pdn;
+	int ret = 0;
+	void *ehdr;
+
+	pri->base.dev = dev;
+
+	if (!dev->link_topo)
+		return 0;
+
+	xa_for_each_start(&dev->link_topo->phys, ctx->phy_index, pdn, ctx->phy_index) {
+		ehdr = ethnl_dump_put(skb, cb, ETHTOOL_MSG_PHY_GET_REPLY);
+		if (!ehdr) {
+			ret = -EMSGSIZE;
+			break;
+		}
+
+		ret = ethnl_fill_reply_header(skb, dev, ETHTOOL_A_PHY_HEADER);
+		if (ret < 0) {
+			genlmsg_cancel(skb, ehdr);
+			break;
+		}
+
+		pri->pdn = pdn;
+		ret = ethnl_phy_fill_reply(&pri->base, skb);
+		if (ret < 0) {
+			genlmsg_cancel(skb, ehdr);
+			break;
+		}
+
+		genlmsg_end(skb, ehdr);
+	}
+
+	return ret;
+}
+
+int ethnl_phy_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct ethnl_phy_dump_ctx *ctx = (void *)cb->ctx;
+	struct net *net = sock_net(skb->sk);
+	struct net_device *dev;
+	int ret = 0;
+
+	rtnl_lock();
+
+	if (ctx->phy_req_info->base.dev) {
+		ret = ethnl_phy_dump_one_dev(skb, ctx->phy_req_info->base.dev, cb);
+	} else {
+		for_each_netdev_dump(net, dev, ctx->ifindex) {
+			ret = ethnl_phy_dump_one_dev(skb, dev, cb);
+			if (ret)
+				break;
+
+			ctx->phy_index = 0;
+		}
+	}
+	rtnl_unlock();
+
+	return ret;
+}