Re: [RFC PATCH V3 net-next 1/5] ethtool: Allow network drivers to dump arbitrary EEPROM data
From: Andrew Lunn <andrew@lunn.ch>
Date: 2021-03-18 13:03:58
On Mon, Mar 15, 2021 at 07:12:39PM +0200, Moshe Shemesh wrote:
quoted hunk ↗ jump to hunk
From: Vladyslav Tarasiuk <redacted> Define get_module_eeprom_data_by_page() ethtool callback and implement netlink infrastructure. get_module_eeprom_data_by_page() allows network drivers to dump a part of module's EEPROM specified by page and bank numbers along with offset and length. It is effectively a netlink replacement for get_module_info() and get_module_eeprom() pair, which is needed due to emergence of complex non-linear EEPROM layouts. Signed-off-by: Vladyslav Tarasiuk <redacted> --- Documentation/networking/ethtool-netlink.rst | 34 ++++- include/linux/ethtool.h | 8 +- include/uapi/linux/ethtool.h | 25 +++ include/uapi/linux/ethtool_netlink.h | 19 +++ net/ethtool/Makefile | 2 +- net/ethtool/eeprom.c | 153 +++++++++++++++++++ net/ethtool/netlink.c | 10 ++ net/ethtool/netlink.h | 2 + 8 files changed, 249 insertions(+), 4 deletions(-) create mode 100644 net/ethtool/eeprom.cdiff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst index 05073482db05..25846b97632a 100644 --- a/Documentation/networking/ethtool-netlink.rst +++ b/Documentation/networking/ethtool-netlink.rst@@ -1280,6 +1280,36 @@ Kernel response contents: For UDP tunnel table empty ``ETHTOOL_A_TUNNEL_UDP_TABLE_TYPES`` indicates that the table contains static entries, hard-coded by the NIC. +EEPROM_DATA +=========== + +Fetch module EEPROM data dump. + +Request contents: + + ===================================== ====== ========================== + ``ETHTOOL_A_EEPROM_DATA_HEADER`` nested request header + ``ETHTOOL_A_EEPROM_DATA_OFFSET`` u32 offset within a page + ``ETHTOOL_A_EEPROM_DATA_LENGTH`` u32 amount of bytes to read
I wonder if offset and length should be u8. At most, we should only be returning a 1/2 page, so 128 bytes. We don't need a u32.
quoted hunk ↗ jump to hunk
Request translation ===================@@ -1357,8 +1387,8 @@ are netlink only. ``ETHTOOL_GET_DUMP_FLAG`` n/a ``ETHTOOL_GET_DUMP_DATA`` n/a ``ETHTOOL_GET_TS_INFO`` ``ETHTOOL_MSG_TSINFO_GET`` - ``ETHTOOL_GMODULEINFO`` n/a - ``ETHTOOL_GMODULEEEPROM`` n/a + ``ETHTOOL_GMODULEINFO`` ``ETHTOOL_MSG_MODULE_EEPROM_GET`` + ``ETHTOOL_GMODULEEEPROM`` ``ETHTOOL_MSG_MODULE_EEPROM_GET`` ``ETHTOOL_GEEE`` ``ETHTOOL_MSG_EEE_GET`` ``ETHTOOL_SEEE`` ``ETHTOOL_MSG_EEE_SET`` ``ETHTOOL_GRSSH`` n/a
We should check with Michal about this. It is not a direct replacement of the old IOCTL API, it is new API. He may want it documented differently.
+static int eeprom_data_parse_request(struct ethnl_req_info *req_info, struct nlattr **tb,
+ struct netlink_ext_ack *extack)
+{
+ struct eeprom_data_req_info *request = EEPROM_DATA_REQINFO(req_info);
+ struct net_device *dev = req_info->dev;
+
+ if (!tb[ETHTOOL_A_EEPROM_DATA_OFFSET] ||
+ !tb[ETHTOOL_A_EEPROM_DATA_LENGTH] ||
+ !tb[ETHTOOL_A_EEPROM_DATA_I2C_ADDRESS])
+ return -EINVAL;
+
+ request->i2c_address = nla_get_u8(tb[ETHTOOL_A_EEPROM_DATA_I2C_ADDRESS]);
+ if (request->i2c_address > ETH_MODULE_MAX_I2C_ADDRESS)
+ return -EINVAL;+ + request->offset = nla_get_u32(tb[ETHTOOL_A_EEPROM_DATA_OFFSET]); + request->length = nla_get_u32(tb[ETHTOOL_A_EEPROM_DATA_LENGTH]); + if (tb[ETHTOOL_A_EEPROM_DATA_PAGE] && + dev->ethtool_ops->get_module_eeprom_data_by_page && + request->offset + request->length > ETH_MODULE_EEPROM_PAGE_LEN) + return -EINVAL;
You need to watch out for overflows here. 0xfffffff0 + 0x20 is less
than ETH_MODULE_EEPROM_PAGE_LEN when it wraps around, but will cause
bad things to happen.
Andrew